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Sample records for air exhaust tunnel

  1. H-CANYON AIR EXHAUST TUNNEL INSPECTION VEHICLE DEVELOPMENT

    SciTech Connect

    Minichan, R.; Fogle, R.; Marzolf, A.

    2011-05-24

    The H-Canyon at Savannah River Site is a large concrete structure designed for chemical separation processes of radioactive material. The facility requires a large ventilation system to maintain negative pressure in process areas for radioactive contamination control and personnel protection. The ventilation exhaust is directed through a concrete tunnel under the facility which is approximately five feet wide and 8 feet tall that leads to a sand filter and stack. Acidic vapors in the exhaust have had a degrading effect on the surface of the concrete tunnels. Some areas have been inspected; however, the condition of other areas is unknown. Experience from historical inspections with remote controlled vehicles will be discussed along with the current challenge of inspecting levels below available access points. The area of interest in the exhaust tunnel must be accessed through a 14 X 14 inch concrete plug in the floor of the hot gang valve corridor. The purpose for the inspection is to determine the condition of the inside of the air tunnel and establish if there are any structural concerns. Various landmarks, pipe hangers and exposed rebar are used as reference points for the structural engineers when evaluating the current integrity of the air tunnel.

  2. The impact of the tunnel exhausts in terms of heavy metals to the surrounding ecosystem.

    PubMed

    Jozic, Marija; Peer, Thomas; Türk, Roman

    2009-03-01

    Samples of soil, plants, and lichens were analysed for heavy metal content (Cd, Cr, Cu, Ni, Pb, and Zn) in relation to different distances from the tunnel ventilation systems in order to evaluate the environmental pollution caused by car exhausts pollution from the Tauerntunnel and the Katschbergtunnel (Austria). Results show that the extent of heavy metal pollution is related to the type of tunnel ventilation system. The vertical ventilation system which ends in an exhaust air tower in the alpine pasture of Mosermandl 1,900 m above sea level contaminates soils and plants up to a distance of 750 m from the exhaust source. The dispersion of metals in front of the horizontal ventilation systems, which are located next to the tunnel portals, exhibits a rapid decrease with distance. Lichen transplants placed in front of the horizontal ventilation systems show very high metal accumulation, which gradually declines with the distance from the emitter source, therefore the lichen species Pseudevernia furfuracea can be used as a very efficient biomonitor for monitoring heavy metal pollution caused by tunnel exhausts over time. Data from former years (1986, 1988, 1990 and 1992) and from this present research suggest that the contamination of heavy metals at Mosermandl has decreased slightly in soil samples, except for Cu, but increased in plant samples, whereas a significant increase of Pb was observed.

  3. Air Pollution in Road Tunnels

    PubMed Central

    Waller, R. E.; Commins, B. T.; Lawther, P. J.

    1961-01-01

    As a part of a study of pollution of the air by motor vehicles, measurements have been made in two London road tunnels during periods of high traffic density. The concentrations of smoke and polycyclic hydrocarbons found there are much higher than the average values in Central London, but they are of the same order of magnitude as those occurring during temperature inversions on winter evenings when smoke from coal fires accumulates at a low level. An attempt has been made to relate the concentration of each pollutant to the type and amount of traffic. Both diesel and petrol vehicles make some contribution to the amounts of smoke and polycyclic hydrocarbons found in the tunnels, but in the case of smoke, fluoranthene, 1: 2-benzpyrene, pyrene, and 3: 4-benzpyrene, the concentrations appear to be more closely related to the density of diesel traffic than to that of petrol traffic. The concentrations of lead and carbon monoxide have also been determined, and these are very closely related to the density of petrol traffic. During the morning and evening rush hours the mean concentration of carbon monoxide was just over 100 p.p.m. and peak values up to 500 p.p.m. were recorded at times. Oxides of nitrogen were determined in some of the experiments and there was always much more nitric oxide than nitrogen dioxide. Eye irritation was experienced but its cause was not investigated. The concentration of pollution in the tunnels does not appear to be high enough to create any special hazards for short-term exposures. The amosphere at peak periods may become very dirty and unpleasant and the concentration of carbon monoxide would be sufficient to produce some effect over a period of several hours' continuous exposure. The total emission of pollution from road vehicles must still be small in comparison with that from coal fires, but the effect of traffic on the concentration of smoke, polycyclic hydrocarbons, carbon monoxide, and lead in the air of city streets deserves

  4. Quantification of vehicle fleet PM10 particulate matter emission factors from exhaust and non-exhaust sources using tunnel measurement techniques.

    PubMed

    Lawrence, Samantha; Sokhi, Ranjeet; Ravindra, Khaiwal

    2016-03-01

    Road tunnels act like large laboratories; they provide an excellent environment to quantify atmospheric particles emission factors from exhaust and non-exhaust sources due to their known boundary conditions. Current work compares the High Volume, Dichotomous Stacked Filter Unit and Partisol Air Sampler for coarse, PM10 and PM2.5 particle concentration measurement and found that they do not differ significantly (p = 95%). PM2.5 fraction contributes 66% of PM10 proportions and significantly influenced by traffic (turbulence) and meteorological conditions. Mass emission factors for PM10 varies from 21.3 ± 1.9 to 28.8 ± 3.4 mg/vkm and composed of Motorcycle (0.0003-0.001 mg/vkm), Cars (26.1-33.4 mg/vkm), LDVs (2.4-3.0 mg/vkm), HDVs (2.2-2.8 mg/vkm) and Buses (0.1 mg/vkm). Based on Lawrence et al. (2013), source apportionment modelling, the PM10 emission of brake wear (3.8-4.4 mg/vkm), petrol exhaust (3.9-4.5 mg/vkm), diesel exhaust (7.2-8.3 mg/vkm), re-suspension (9-10.4 mg/vkm), road surface wear (3.9-4.5 mg/vkm), and unexplained (7.2 mg/vkm) were also calculated. The current study determined that the combined non-exhaust fleet PM10 emission factor (16.7-19.3 mg/vkm) are higher than the combined exhaust emission factor (11.1-12.8 mg/vkm). Thus, highlight the significance of non-exhaust emissions and the need for legislation and abatement strategies to reduce their contributions to ambient PM concentrations.

  5. 2. View of Liquified Propane Air Plant (New), former Exhaust ...

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

    2. View of Liquified Propane Air Plant (New), former Exhaust and Compressor Building and former Purifying Plant in background. - Concord Gas Light Company, South Main Street, Concord, Merrimack County, NH

  6. 6. VIEW OF FIVEFOOT WIND TUNNEL WITH AIR STRAIGHTENER AND ...

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

    6. VIEW OF FIVE-FOOT WIND TUNNEL WITH AIR STRAIGHTENER AND OPERATOR STATION IN FOREGROUND (1991). - Wright-Patterson Air Force Base, Area B, Building No. 19, Five-Foot Wind Tunnel, Dayton, Montgomery County, OH

  7. Analyses of turbulent flow fields and aerosol dynamics of diesel engine exhaust inside two dilution sampling tunnels using the CTAG model.

    PubMed

    Wang, Yan Jason; Yang, Bo; Lipsky, Eric M; Robinson, Allen L; Zhang, K Max

    2013-01-15

    Experimental results from laboratory emission testing have indicated that particulate emission measurements are sensitive to the dilution process of exhaust using fabricated dilution systems. In this paper, we first categorize the dilution parameters into two groups: (1) aerodynamics (e.g., mixing types, mixing enhancers, dilution ratios, residence time); and (2) mixture properties (e.g., temperature, relative humidity, particle size distributions of both raw exhaust and dilution gas). Then we employ the Comprehensive Turbulent Aerosol Dynamics and Gas Chemistry (CTAG) model to investigate the effects of those parameters on a set of particulate emission measurements comparing two dilution tunnels, i.e., a T-mixing lab dilution tunnel and a portable field dilution tunnel with a type of coaxial mixing. The turbulent flow fields and aerosol dynamics of particles are simulated inside two dilution tunnels. Particle size distributions under various dilution conditions predicted by CTAG are evaluated against the experimental data. It is found that in the area adjacent to the injection of exhaust, turbulence plays a crucial role in mixing the exhaust with the dilution air, and the strength of nucleation dominates the level of particle number concentrations. Further downstream, nucleation terminates and the growth of particles by condensation and coagulation continues. Sensitivity studies reveal that a potential unifying parameter for aerodynamics, i.e., the dilution rate of exhaust, plays an important role in new particle formation. The T-mixing lab tunnel tends to favor the nucleation due to a larger dilution rate of the exhaust than the coaxial mixing field tunnel. Our study indicates that numerical simulation tools can be potentially utilized to develop strategies to reduce the uncertainties associated with dilution samplings of emission sources.

  8. Exhaust ventilation in attached garages improves residential indoor air quality.

    PubMed

    Mallach, G; St-Jean, M; MacNeill, M; Aubin, D; Wallace, L; Shin, T; Van Ryswyk, K; Kulka, R; You, H; Fugler, D; Lavigne, E; Wheeler, A J

    2017-03-01

    Previous research has shown that indoor benzene levels in homes with attached garages are higher than homes without attached garages. Exhaust ventilation in attached garages is one possible intervention to reduce these concentrations. To evaluate the effectiveness of this intervention, a randomized crossover study was conducted in 33 Ottawa homes in winter 2014. VOCs including benzene, toluene, ethylbenzene, and xylenes, nitrogen dioxide, carbon monoxide, and air exchange rates were measured over four 48-hour periods when a garage exhaust fan was turned on or off. A blower door test conducted in each garage was used to determine the required exhaust fan flow rate to provide a depressurization of 5 Pa in each garage relative to the home. When corrected for ambient concentrations, the fan decreased geometric mean indoor benzene concentrations from 1.04 to 0.40 μg/m(3) , or by 62% (P<.05). The garage exhaust fan also significantly reduced outdoor-corrected geometric mean indoor concentrations of other pollutants, including toluene (53%), ethylbenzene (47%), m,p-xylene (45%), o-xylene (43%), and carbon monoxide (23%) (P<.05) while having no impact on the home air exchange rate. This study provides evidence that mechanical exhaust ventilation in attached garages can reduce indoor concentrations of pollutants originating from within attached garages.

  9. New Model Exhaust System Supports Testing in NASA Lewis' 10- by 10-Foot Supersonic Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Roeder, James W., Jr.

    1998-01-01

    In early 1996, the ability to run NASA Lewis Research Center's Abe Silverstein 10- by 10- Foot Supersonic Wind Tunnel (10x10) at subsonic test section speeds was reestablished. Taking advantage of this new speed range, a subsonic research test program was scheduled for the 10x10 in the fall of 1996. However, many subsonic aircraft test models require an exhaust source to simulate main engine flow, engine bleed flows, and other phenomena. This was also true of the proposed test model, but at the time the 10x10 did not have a model exhaust capability. So, through an in-house effort over a period of only 5 months, a new model exhaust system was designed, installed, checked out, and made ready in time to support the scheduled test program.

  10. 40 CFR 1065.240 - Dilution air and diluted exhaust flow meters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.240 Dilution air and diluted exhaust flow meters. (a) Application. Use a diluted exhaust flow... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Dilution air and diluted exhaust...

  11. 40 CFR 1065.240 - Dilution air and diluted exhaust flow meters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.240 Dilution air and diluted exhaust flow meters. (a) Application. Use a diluted exhaust flow... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Dilution air and diluted exhaust...

  12. 40 CFR 1065.240 - Dilution air and diluted exhaust flow meters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.240 Dilution air and diluted exhaust flow meters. (a) Application. Use a diluted exhaust flow... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Dilution air and diluted exhaust...

  13. 40 CFR 1065.240 - Dilution air and diluted exhaust flow meters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.240 Dilution air and diluted exhaust flow meters. (a) Application. Use a diluted exhaust flow... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Dilution air and diluted exhaust...

  14. 40 CFR 1065.240 - Dilution air and diluted exhaust flow meters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.240 Dilution air and diluted exhaust flow meters. (a) Application. Use a diluted exhaust flow... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Dilution air and diluted exhaust...

  15. Magnetic analyses of powders from exhausted cabin air filters

    NASA Astrophysics Data System (ADS)

    Winkler, Aldo; Sagnotti, Leonardo

    2013-04-01

    The automotive cabin air filter is a pleated-paper filter placed in the outside-air intake for the car's passenger compartment. Dirty and saturated cabin air filters significantly reduce the airflow from the outside and introduce particulate matter (PM) and allergens (for example, pollen) into the cabin air stream. Magnetic measurements and analyses have been carried out on powders extracted from exhausted cabin air filters to characterize their magnetic properties and to compare them to those already reported for powders collected from disk brakes, gasoline exhaust pipes and Quercus ilex leaves. This study is also aimed at the identification and quantification of the contribution of the ultrafine fraction, superparamagnetic (SP) at room temperature, to the overall magnetic properties of these powders. This contribution was estimated by interpreting and comparing data from FORCs, isothermal remanent magnetization vs time decay curves, frequency and field dependence of the magnetic susceptibility and out-of-phase susceptibility. The magnetic properties and the distribution of the SP particles are generally homogenous and independent of the brand of the car, of the model of the filter and of its level of usage. The relatively high concentration of magnetic PM trapped in these filters poses relevant questions about the air quality inside a car.

  16. Field Study of Exhaust Fans for Mitigating Indoor Air Quality Problems & Indoor Air Quality - Exhaust Fan Mitigation.

    SciTech Connect

    United States. Bonneville Power Administration.

    1987-07-01

    Overall, the findings show that exhaust fans basically provide small amounts of ventilation compensation. By monitoring the common indoor air pollutants (radon, formaldehyde, carbon monoxide, nitrogen dioxide, and water vapor), it was found that the quality of the indoor air was not adversely affected by the use of exhaust fans. Nor did their use provide any measurable or significant benefits since no improvement in air quality was ascertained. While exhaust fans of this small size did not increase radon, which is the contaminant of most concern, the researchers caution that operation of a larger fan or installation in a very tight home could result in higher levels because depressurization is greater. The daily energy consumption for use of these appliances during the heating season was calculated to be 1.5 kilowatt hours or approximately 3% of the energy consumption in the study homes. The information collected in this collaborative field study indicates that the use of these particular ventilation systems has no significant effect on indoor air quality.

  17. Pitot survey of exhaust flow field of a 2-D scramjet nozzle at Mach 6 with air or freon and argon used for exhaust simulation

    NASA Technical Reports Server (NTRS)

    Monta, William J.

    1992-01-01

    A pitot-rake survey of the simulated exhaust of a half-span scramjet nozzle model was conducted in the Langley 20-Inch Mach 6 Tunnel to provide an additional data set for computational fluid dynamics (CFD) code comparisons. A wind-tunnel model was tested with a 26-tube pitot rake that could be manually positioned along the mid-semispan plane of the model. The model configuration had an external expansion surface of 20 degrees and an internal cowl expansion of 12 degrees; tests were also performed with a flow fence. Tests were conducted at a free-stream Reynolds number of approximately 6.5 x 10(exp 6) per foot and a model angle of attack of -0.75 degrees. The two exhaust gas mediums that were tested were air and a Freon 12-argon mixture. Each medium was tested at two jet total pressures at approximately 28 and 14 psia. This document presents the flow-field survey results in graphical as well as tabular form, and several observations concerning the results are discussed. The surveys reveal the major expected flow-field characteristics for each test configuration. For a 50-percent freon 12 and 50-percent argon mixture by volume (Fr-Ar), the exhaust jet pressures were slightly higher than those for air. The addition of a flow fence slightly raised the pitot pressure for the Fr-Ar mixture, but it produced little change for air. For the Fr-Ar exhaust, the plume was larger and the region between the shock wave and plume was smaller.

  18. Effects of diesel exhaust on the microbiota within a tuffaceous tunnel system

    SciTech Connect

    Haldeman, D.L.; Lagadinos, T.; Amy, P.S.; Hersman, L.; Meike, A.

    1996-08-01

    The abundance and distribution of microbiota that may be impacted by diesel and diesel exhaust were investigated from three depths into the walls and invert (floor) of U12n tunnel at Rainier Mesa, Nevada Test Site, a potential geological analog of Yucca Mountain. Enumerations included total cell counts, and numbers of aerobic heterotrophic, sulfate-reducing, nitrate-reducing, and diesel-degrading bacteria. Additionally, the disappearance of total petroleum hydrocarbons was determined in microcosms containing subsurface materials that were amended with diesel fuel. Results revealed that microbes capable of utilizing diesel and diesel combustion products were present in the subsurface in both the walls and the invert of the tunnel. The abundance of specific bacterial types in the tunnel invert, a perturbed environment, was greater than that observed in the tunnel wall. Few trends of microbial distribution either into the tunnel wall or the invert were noted with the exception of aerobic heterotrophic abundance which increased with depth into the wall and decreased with depth into the invert. No correlation between microbiota and a specific introduced chemical species have yet been determined. The potential for microbial contamination of the tunnel wall during sampling was determined to be negligible by the use of fluorescently labeled latex spheres (1{mu}m in dia.) as tracers. Results indicate that additional investigations might be needed to examine the microbiota and their possible impacts on the geology and geochemistry of the subsurface, both indigenous microbiota and those microorganisms that will likely be introduced by anthropogenic activity associated with the construction of a high-level waste repository.

  19. Air pollution and lung cancer: diesel exhaust, coal combustion

    SciTech Connect

    Higgins, I.T.

    1984-03-01

    It is known, that cigarette smoking is by far the most important cause of lung cancer and that about a dozen occupational exposures are also established as causes of this disease. There has been continuing uncertainty about the role of general air pollution. During the past few years, this uncertainty has been compounded with anxiety that the increasing use of diesel-powered vehicles might lead to a deterioration in air quality and, with it, an increase in the incidence of lung cancer. The purpose of this paper is to assess the current role of air pollution as a factor in lung cancer and specifically the contribution of diesel exhaust emissions to the incidence of that disease.

  20. Air quality inside a tunnel tube and in the vicinity of the tunnel portals

    SciTech Connect

    Pucher, K.; Zwiener, K.

    1997-12-31

    Due to the continually growing number of motor vehicles more and more roads are reaching the limits of their capability. This has led to slowly moving traffic and longer persisting traffic blockages. In cities and conurbation centers especially this leads to complete traffic chaos. The pollutant emissions of vehicles that only move very little mostly lead to high pollutant burdens also and in some circumstances to poor air quality. Therefore in more and more cities one is attempting to get traffic moving again through efficient road tunnels and underground lines and thereby also reduce the pollutant emission. Typical examples of such developments are the Central Artery Tunnel Project in Boston, the planned Ringroad tunnel in Stockholm and the Ringtunnel projects in Paris. Tunnel constructions and underground lines in densely built-up areas are also planned in many small cities. For all these tunnel projects the following points concerning the air quality are to be observed. On the one hand, a tunnel construction can accommodate traffic and thereby reduce the traffic blockages in the vicinity of the tunnel, so long as no additional traffic is attracted. This would therefore lead to a reduction of the pollutant burden and also to an improvement in the air quality in large areas of further surroundings of the tunnel construction. On the other hand, at the portals of the tunnel, alongside mobile pollutant sources from vehicles travelling on the already existing road, a stationary pollutant source of the tunnel ventilation flowing out from the tunnel portal also results. It is then to be investigated how high the emerging pollutant concentrations will be at the portal of the planned tunnel and how these pollutants will disseminate. In this report therefore, the air quality in the tunnel as well as in the vicinity of the tunnel portals will be more closely dealt with.

  1. 4. VENTILATION FAN SHOWING RELATIVE POSITION IN THE AIR TUNNEL. ...

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

    4. VENTILATION FAN SHOWING RELATIVE POSITION IN THE AIR TUNNEL. - Hot Springs National Park, Bathhouse Row, Ozark Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

  2. Multiscale turbulence effects in supersonic jets exhausting into still air

    NASA Technical Reports Server (NTRS)

    Abdol-Hamid, Khaled S.; Wilmoth, Richard G.

    1987-01-01

    A modified version of the multiscale turbulence model of Hanjalic has been applied to the problem of supersonic jets exhausting into still air. In particular, the problem of shock-cell decay through turbulent interaction with the mixing layer has been studied for both mildly interacting and strongly resonant jet conditions. The modified Hanjalic model takes into account the nonequilibrium energy transfer between two different turbulent spectral scales. The turbulence model was incorporated into an existing shock-capturing, parabolized Navier-Stokes computational model in order to perform numerical experiments. The results show that the two-scale turbulence model provides significant improvement over one-scale models in the prediction of plume shock structure for underexpanded supersonic (Mach 2) and sonic (Mach 1) jets. For the supersonic jet, excellent agreement with experiment was obtained for the centerline shock-cell pressure decay up to 40 jet radii. For the sonic jet, the agreement with experiment was not so good, but the two-scale model still showed significant improvement over the one-scale model. It is shown that by relating some of the coefficients in the turbulent-transport equations to the relative time scale for transfer of energy between scales the two-scale model can provide predictions that bound the measured shock-cell decay rate for the sonic jet.

  3. 40 CFR 1065.655 - Chemical balances of fuel, intake air, and exhaust.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.655 Chemical balances of fuel, intake air, and exhaust. (a) General. Chemical balances of fuel, intake air, and... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Chemical balances of fuel, intake...

  4. 40 CFR 1065.655 - Chemical balances of fuel, intake air, and exhaust.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.655 Chemical balances of fuel, intake air, and exhaust. (a) General. Chemical balances of fuel, intake air, and... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Chemical balances of fuel, intake...

  5. 40 CFR 1065.655 - Chemical balances of fuel, intake air, and exhaust.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.655 Chemical balances of fuel, intake air, and exhaust. (a) General. Chemical balances of fuel, intake air, and... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Chemical balances of fuel, intake...

  6. 40 CFR 1065.655 - Chemical balances of fuel, intake air, and exhaust.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.655 Chemical balances of fuel, intake air, and exhaust. (a) General. Chemical balances of fuel, intake air, and... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Chemical balances of fuel, intake...

  7. 40 CFR 1065.655 - Chemical balances of fuel, intake air, and exhaust.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.655 Chemical balances of fuel, intake air, and exhaust. (a) General. Chemical balances of fuel, intake air, and... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Chemical balances of fuel, intake...

  8. Improving microbial air quality in air-conditioned mass transport buses by opening the bus exhaust ventilation fans.

    PubMed

    Luksamijarulkul, Pipat; Arunchai, Nongphon; Luksamijarulkul, Soavalug; Kaewboonchoo, Orawan

    2005-07-01

    The air quality in air-conditioned mass transport buses may affect bus drivers' health. In-bus air quality improvement with the voluntary participation of bus drivers by opening the exhaust ventilation fans in the bus was implemented in the Seventh Bus Zone of Bangkok Mass Transit Authority. Four bus numbers, including bus numbers 16, 63, 67 and 166, were randomly selected to investigate microbial air quality and to observe the effect of opening the exhaust ventilation fans in the bus. With each bus number, 9 to 10 air-conditioned buses (total, 39 air-conditioned buses) were included. In-bus air samples were collected at 5 points in each studied bus using the Millipore Air Tester. A total of 195 air samples were cultured for bacterial and fungal counts. The results reveal that the exhaust ventilation fans of 17 air-conditioned buses (43.6%) were opened to ventilate in-bus air during the cycle of the bus route. The means +/- SD of bacterial counts and fungal counts in the studied buses with opened exhaust ventilation fans (83.8 +/- 70.7 and 38.0 +/- 42.8 cfu/m3) were significantly lower than those in the studied buses without opened exhaust ventilation fans (199.6 +/- 138.8 and 294.1 +/- 178.7 cfu/m3), p < 0.0005. All the air samples collected from the studied buses with opened exhaust ventilation fans were at acceptable levels (< 500 cfu/m3) compared with 4.6% of the air samples collected from the studied buses without opened exhaust ventilation fans, which had high levels (> 500 cfu/m3). Of the studied buses with opened exhaust ventilation fans (17 buses), the bacterial and fungal counts after opening the exhaust ventilation fans (68.3 +/- 33.8 and 28.3 +/- 19.3 cfu/m3) were significantly lower than those before opening the exhaust ventilation fans (158.3 +/- 116.9 and 85.3 +/- 71.2 cfu/m3), p < 0.005.

  9. Altitude-Wind-Tunnel Investigation of R-4360-18 Power-Plant Installation for XR60 Airplane. 3; Performance of Induction and Exhaust Systems

    NASA Technical Reports Server (NTRS)

    Dupree, David T.; Hawkins, W. Kent

    1947-01-01

    A study has been made of the performance of the induction and the exhaust systems on the XR60 power-plant installation as part of an investigation conducted in the Cleveland altitude wind tunnel. Altitude flight conditions from 5000 to 30,000 feet were simulated for a range of engine powers from 750 to 3000 brake horsepower. Slipstream rotation prevented normal pressure recoveries in the right side of the main duct in the region of the right intercooler cooling-air duct inlet. Total-pressure losses in the charge-air flow between the turbosupercharger and the intercoolers were as high as 2.1 inches of mercury. The total-pressure distribution of the charge air at the intercooler inlets was irregular and varied as much as 1.0 inch of mercury from the average value at extreme conditions, Total-pressure surveys at the carburetor top deck showed a variation from the average value of 0.3 inch of mercury at take-off power and 0.05 inch of mercury at maximum cruising power, The carburetor preheater system increased the temperature of the engine charge air a maximum of about 82 F at an average cowl-inlet air temperature of 9 F, a pressure altitude of 5000 feet, and a brake horsepower of 1240.

  10. Wind Tunnel Model Design for the Study of Plume Effects on Sonic Boom for Isolated Exhaust Nozzles

    NASA Technical Reports Server (NTRS)

    Castner, Raynold S.

    2010-01-01

    A low cost test capability was developed at the NASA Glenn Research Center 1- by 1-Foot Supersonic Wind Tunnel (SWT), with a goal to reduce the disturbance caused by supersonic aircraft flight over populated areas. This work focused on the shock wave structure caused by the exhaust nozzle plume. Analysis and design was performed on a new rig to test exhaust nozzle plume effects on sonic boom signature. Test capability included a baseline nozzle test article and a wind tunnel model consisting of a strut, a nosecone and an upper plenum. Analysis was performed on the external and internal aerodynamic configuration, including the shock reflections from the wind tunnel walls caused by the presence of the model nosecone. This wind tunnel model was designed to operate from Mach 1.4 to Mach 3.0 with nozzle pressure ratios from 6 to 12 and altitudes from 30,000 ft (4.36 psia) to 50,000 ft (1.68 psia). The model design was based on a 1 in. outer diameter, was 9 in. in overall length, and was mounted in the wind tunnel on a 3/8 in. wide support strut. For test conditions at 50,000 ft the strut was built to supply 90 psia of pressure, and to achieve 20 psia at the nozzle inlet with a maximum nozzle pressure of 52 psia. Instrumentation was developed to measure nozzle pressure ratio, and an external static pressure probe was designed to survey near field static pressure profiles at one nozzle diameter above the rig centerline. Model layout placed test nozzles between two transparent sidewalls in the 1 1 SWT for Schlieren photography and comparison to CFD analysis.

  11. Wind Tunnel Model Design for the Study of Plume Effects on Sonic Boom for Isolated Exhaust Nozzles

    NASA Technical Reports Server (NTRS)

    Castner, Raymond S.

    2009-01-01

    A low cost test capability was developed at the NASA Glenn Research Center 1- by 1-Foot Supersonic Wind Tunnel (SWT), with a goal to reduce the disturbance caused by supersonic aircraft flight over populated areas. This work focused on the shock wave structure caused by the exhaust nozzle plume. Analysis and design was performed on a new rig to test exhaust nozzle plume effects on sonic boom signature. Test capability included a baseline nozzle test article and a wind tunnel model consisting of a strut, a nose cone and an upper plenum. Analysis was performed on the external and internal aerodynamic configuration, including the shock reflections from the wind tunnel walls caused by the presence of the model nosecone. This wind tunnel model was designed to operate from Mach 1.4 to Mach 3.0 with nozzle pressure ratios from 6 to 12 and altitudes from 30,000 ft (4.36 psia) to 50,000 ft (1.68 psia). The model design was based on a 1 in. outer diameter, was 9 in. in overall length, and was mounted in the wind tunnel on a 3/8 in. wide support strut. For test conditions at 50,000 ft the strut was built to supply 90 psia of pressure, and to achieve 20 psia at the nozzle inlet with a maximum nozzle pressure of 52 psia. Instrumentation was developed to measure nozzle pressure ratio, and an external static pressure probe was designed to survey near field static pressure profiles at one nozzle diameter above the rig centerline. Model layout placed test nozzles between two transparent sidewalls in the 1x1 SWT for Schlieren photography and comparison to CFD analysis.

  12. Characteristics of vertical and lateral tunnel turbulence measured in air in the Langley Transonic Dynamics Tunnel

    NASA Technical Reports Server (NTRS)

    Sleeper, Robert K.; Keller, Donald F.; Perry, Boyd, III; Sandford, Maynard C.

    1993-01-01

    Preliminary measurements of the vertical and lateral velocity components of tunnel turbulence were obtained in the Langley Transonic Dynamics Tunnel test section using a constant-temperature anemometer equipped with a hot-film X-probe. For these tests air was the test medium. Test conditions included tunnel velocities ranging from 100 to 500 fps at atmospheric pressure. Standard deviations of turbulence velocities were determined and power spectra were computed. Unconstrained optimization was employed to determine parameter values of a general spectral model of a form similar to that used to describe atmospheric turbulence. These parameters, and others (notably break frequency and integral scale length), were determined at each test condition and compared with those of Dryden and Von Karman atmospheric turbulence spectra. When the data were discovered to be aliased, the spectral model was modified to account for and 'eliminate' the aliasing.

  13. Use of exhaust gas as sweep flow to enhance air separation membrane performance

    DOEpatents

    Dutart, Charles H.; Choi, Cathy Y.

    2003-01-01

    An intake air separation system for an internal combustion engine is provided with purge gas or sweep flow on the permeate side of separation membranes in the air separation device. Exhaust gas from the engine is used as a purge gas flow, to increase oxygen flux in the separation device without increasing the nitrogen flux.

  14. Aeorodynamic characteristics of an air-exchanger system for the 40- by 80-foot wind tunnel at Ames Research Center

    NASA Technical Reports Server (NTRS)

    Rossow, V. J.; Schmidt, G. I.; Meyn, L. A.; Ortner, K. R.; Holmes, R. E.

    1986-01-01

    A 1/50-scale model of the 40- by 80-Foot Wind Tunnel at Ames Research Center was used to study various air-exchange configurations. System components were tested throughout a range of parameters, and approximate analytical relationships were derived to explain the observed characteristics. It is found that the efficiency of the air exchanger could be increased (1) by adding a shaped wall to smoothly turn the incoming air downstream, (2) by changing to a contoured door at the inlet to control the flow rate, and (3) by increasing the size of the exhaust opening. The static pressures inside the circuit then remain within the design limits at the higher tunnel speeds if the air-exchange rate is about 5% or more. Since the model is much smaller than the full-scale facility, it is not possible to completely duplicate the tunnel, and it will be necessary to measure such characteristics as flow rate and tunnel pressures during implementation of the remodeled facility. The aerodynamic loads estimated for the inlet door and for nearby walls are also presented.

  15. Characterization of microbial communities in exhaust air treatment systems of large-scale pig housing facilities.

    PubMed

    Haneke, J; Lee, N M; Gaul, T W; Van den Weghe, H F A

    2010-01-01

    Exhaust air treatment has gained importance as an essential factor in intensive livestock areas due to the rising emissions in the environment. Wet filter walls of multi-stage exhaust air treatment systems precipitate gaseous ammonia and dust particles from exhaust air in washing water. Microbial communities in the biomass developed in the washing water of five large-scale exhaust air treatment units of pig housing facilities, were investigated by fluorescence in situ hybridization (FISH) and 16S rDNA sequence analyses. No "standard" nitrifying bacteria were found in the washing water. Instead mainly α-Proteobacteria, aggregating β- and χ-Proteobacteria, a large number of Actinobacteria, as well as individual Planctomycetales and Crenarchaeota were detected after more than twelve months' operation. The main Proteobacteria species present were affiliated to the families Alcaligenaceae, Comamonadaceae and Xanthomonadaceae. Furthermore, we investigated the consumption of inorganic nitrogen compounds in the washing water of one exhaust air treatment unit during a fattening period with and without pH control. Maintaining the pH at 6.0 resulted in a ca. fivefold higher ammonium concentration and a ca. fourfold lower concentration of oxidized nitrogen compounds after the fattening period was finished.

  16. Occupational Exposure to Respirable Dust, Respirable Crystalline Silica and Diesel Engine Exhaust Emissions in the London Tunnelling Environment.

    PubMed

    Galea, Karen S; Mair, Craig; Alexander, Carla; de Vocht, Frank; van Tongeren, Martie

    2016-03-01

    Personal 8-h shift exposure to respirable dust, diesel engine exhaust emissions (DEEE) (as respirable elemental carbon), and respirable crystalline silica of workers involved in constructing an underground metro railway tunnel was assessed. Black carbon (BC) concentrations were also assessed using a MicroAeth AE51. During sprayed concrete lining (SCL) activities in the tunnel, the geometric mean (GM) respirable dust exposure level was 0.91mg m(-3), with the highest exposure measured on a back-up sprayer (3.20mg m(-3)). The GM respirable crystalline silica concentration for SCL workers was 0.03mg m(-3), with the highest measurement also for the back-up sprayer (0.24mg m(-3)). During tunnel boring machine (TBM) activities, the GM respirable dust concentration was 0.54mg m(-3). The GM respirable elemental carbon concentration for all the TBM operators was 18 µg m(-3); with the highest concentration measured on a segment lifter. The BC concentrations were higher in the SCL environment in comparison to the TBM environment (daily GM 18-54 µg m(-3) versus 3-6 µg m(-3)). This small-scale monitoring campaign provides additional personal data on exposures experienced by underground tunnel construction workers.

  17. A Tunneling Microscope for Operation in Air or Fluids.

    DTIC Science & Technology

    1985-10-01

    between IBM Zurich designs and squeezable tunnel junctions has been operated in air, oil, and liquid nitro - gen. Key design goals were 1) maximum...from 10 Hz to 20kHz. The inner shield (a coffee can) provides electrical screening and shuts out light. Not shown is approximately 150kg of lead that was...image individual atoms in a close-packed, unreconstructed layer is obtainable with submersion in liquid nitro - o gen. This implies lateral resolution

  18. The Resistance of Spheres in Wind Tunnels and In Air

    NASA Technical Reports Server (NTRS)

    Bacon, D L; Reid, E G

    1924-01-01

    To supplement the standardization tests now in progress at several laboratories, a broad investigation of the resistance of spheres in wind tunnels and free air has been carried out by the National Advisory Committee for Aeronautics. The subject has been classed in aerodynamic research, and in consequence there is available a great mass of data from previous investigations. This material was given careful consideration in laying out the research, and explanation of practically all the disagreement between former experiments has resulted. A satisfactory confirmation of Reynolds law has been accomplished, the effect of means of support determined, the range of experiment greatly extended by work in the new variable density wind tunnel, and the effects of turbulence investigated by work in the tunnels and by towing and dropping tests in free air. It is concluded that the erratic nature of most of the previous work is due to support interference and differing turbulence conditions. While the question of support has been investigated thoroughly, a systematic and comprehensive study of the effects of scale and quality of turbulence will be necessary to complete the problem, as this phase was given only general treatment.

  19. Breathless in Los Angeles: The Exhausting Search for Clean Air

    PubMed Central

    Künzli, Nino; McConnell, Rob; Bates, David; Bastain, Tracy; Hricko, Andrea; Lurmann, Fred; Avol, Ed; Gilliland, Frank; Peters, John

    2003-01-01

    Population growth and the proliferation of roadways in Southern California have facilitated a glut of mobile air pollution sources (cars and trucks), resulting in substantial atmospheric pollution. Despite successful efforts over the past 40 years to reduce pollution, an alarming set of health effects attributable to air pollution have been described in Southern California. The Children’s Health Study indicates that reduced lung function growth, increased school absences, asthma exacerbation, and new-onset asthma are occurring at current levels of air pollution, with sizable economic consequences. We describe these findings and urge a more aggressive effort to reduce air pollution exposures to protect our children’s health. Lessons from this “case study” have national implications. PMID:12948969

  20. Breathless in Los Angeles: the exhausting search for clean air.

    PubMed

    Künzli, Nino; McConnell, Rob; Bates, David; Bastain, Tracy; Hricko, Andrea; Lurmann, Fred; Avol, Ed; Gilliland, Frank; Peters, John

    2003-09-01

    Population growth and the proliferation of roadways in Southern California have facilitated a glut of mobile air pollution sources (cars and trucks), resulting in substantial atmospheric pollution. Despite successful efforts over the past 40 years to reduce pollution, an alarming set of health effects attributable to air pollution have been described in Southern California. The Children's Health Study indicates that reduced lung function growth, increased school absences, asthma exacerbation, and new-onset asthma are occurring at current levels of air pollution, with sizable economic consequences. We describe these findings and urge a more aggressive effort to reduce air pollution exposures to protect our children's health. Lessons from this "case study" have national implications.

  1. Effect of wind tunnel air velocity on VOC flux rates from CAFO manure and wastewater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind tunnels and flux chambers are often used to estimate volatile organic compound (VOC) emissions from animal feeding operations (AFOs) without regard to air velocity or sweep air flow rates. Laboratory experiments were conducted to evaluate the effect of wind tunnel air velocity on VOC emission ...

  2. Diesel Exhaust Activates & Primes Microglia: Air Pollution, Neuroinflammation, & Regulation of Dopaminergic Neurotoxicity

    EPA Science Inventory

    Air pollution is linked to central nervous system (CNS) disease, but the mechanisms responsible are poorly understood. Rats exposed to Diesel Exhaust (DE, 2.0,0.5, and 0 mg/m3) by inhalation over 4 weeks demonstrated elevated levels of whole brain IL-6 protein, nitrated proteins,...

  3. Air gap resonant tunneling bandpass filter and polarizer.

    PubMed

    Melnyk, A; Bitarafan, M H; Allen, T W; DeCorby, R G

    2016-04-15

    We describe a bandpass filter based on resonant tunneling through an air layer in the frustrated total internal reflection regime, and show that the concept of induced transmission can be applied to the design of thin film matching stacks. Experimental results are reported for Si/SiO2-based devices exhibiting a polarization-dependent passband, with bandwidth on the order of 10 nm in the 1550 nm wavelength range, peak transmittance on the order of 80%, and optical density greater than 5 over most of the near infrared region.

  4. Urban air quality: the challenge of traffic non-exhaust emissions.

    PubMed

    Amato, Fulvio; Cassee, Flemming R; Denier van der Gon, Hugo A C; Gehrig, Robert; Gustafsson, Mats; Hafner, Wolfgang; Harrison, Roy M; Jozwicka, Magdalena; Kelly, Frank J; Moreno, Teresa; Prevot, Andre S H; Schaap, Martijn; Sunyer, Jordi; Querol, Xavier

    2014-06-30

    About 400,000 premature adult deaths attributable to air pollution occur each year in the European Region. Road transport emissions account for a significant share of this burden. While important technological improvements have been made for reducing particulate matter (PM) emissions from motor exhausts, no actions are currently in place to reduce the non-exhaust part of emissions such as those from brake wear, road wear, tyre wear and road dust resuspension. These "non-exhaust" sources contribute easily as much and often more than the tailpipe exhaust to the ambient air PM concentrations in cities, and their relative contribution to ambient PM is destined to increase in the future, posing obvious research and policy challenges. This review highlights the major and more recent research findings in four complementary fields of research and seeks to identify the current gaps in research and policy with regard to non-exhaust emissions. The objective of this article is to encourage and direct future research towards an improved understanding on the relationship between emissions, concentrations, exposure and health impact and on the effectiveness of potential remediation measures in the urban environment.

  5. Rocket exhaust effluent modeling for tropospheric air quality and environmental assessments

    NASA Technical Reports Server (NTRS)

    Stephens, J. B.; Stewart, R. B.

    1977-01-01

    The various techniques for diffusion predictions to support air quality predictions and environmental assessments for aerospace applications are discussed in terms of limitations imposed by atmospheric data. This affords an introduction to the rationale behind the selection of the National Aeronautics and Space Administration (NASA)/Marshall Space Flight Center (MSFC) Rocket Exhaust Effluent Diffusion (REED) program. The models utilized in the NASA/MSFC REED program are explained. This program is then evaluated in terms of some results from a joint MSFC/Langley Research Center/Kennedy Space Center Titan Exhaust Effluent Prediction and Monitoring Program.

  6. Hydrogen chloride partitioning in a Titan III exhaust cloud diluted with ambient air

    NASA Technical Reports Server (NTRS)

    Sebacher, D. I.; Wornom, D. E.; Bendura, R. J.

    1979-01-01

    Measurements and analysis are presented of the partitioning of HCl between hydrochloric acid aerosol and gaseous HCl in a Titan III exhaust cloud, as the cloud is diluted with humid ambient air. Partitioning was determined by measuring the gaseous HCl concentration with a recently developed airborne Gas Filter Correlation detector and simultaneously with a chemiluminescence detector which measures total HCl. Although equilibrium predictions for HCl aerosol formation indicated that no HCl aerosol should exist in the exhaust cloud for the meteorological conditions of this launch, the measurements indicated significant HCl aerosol formation. These measurements will provide verification for advanced modeling programs now under development.

  7. Local ventilation for powder handling--combination of local supply and exhaust air.

    PubMed

    Heinonen, K; Kulmala, I; Säämänen, A

    1996-04-01

    The performance of a modified local ventilation unit equipped with local supply and exhaust ventilation was evaluated during the manual handling of flour additive powder. The investigation tested five different configurations to study the effects of the exhaust opening location and local supply air on worker exposure. The measurements were done under controlled conditions in a test room. The breathing zone (BZ) dust concentration was measured by gravimetric sampling and real time monitoring. The different local ventilation configurations were also modeled numerically using computational fluid dynamics. Without local ventilation the average BZ dust concentration was 42 mg/m3. With local exhaust only the exposure was reduced below 1 mg/m3. The addition of local supply air further reduced the exposure to below 0.5 mg/m3. The lowest results were achieved by locating two exhaust openings on either side of the contaminant source combined with local supply air. With this configuration the average BZ exposure was only 0.08 mg/m3, a reduction of 99.8%. Numerical simulations also gave useful information about the airflow fields in stationary conditions. However, the worker's exposure was greatly affected by body movements, and this was not possible to simulate numerically. The results of this investigation can be useful when controlling dust exposure in manual powder handling operations.

  8. The Measurement of Fuel-air Ratio by Analysis of the Oxidized Exhaust Gas

    NASA Technical Reports Server (NTRS)

    Memm, J. Lawrence, Jr.

    1943-01-01

    An investigation was made to determine a method of measuring fuel-air ratio that could be used for test purposes in flight and for checking conventional equipment in the laboratory. Two single-cylinder test engines equipped with typical commercial engine cylinders were used. The fuel-air ratio of the mixture delivered to the engines was determined by direct measurement of the quantity of air and of fuel supplied and also by analysis of the oxidized exhaust gas and of the normal exhaust gas. Five fuels were used: gasoline that complied with Army-Navy Fuel Specification, No. AN-VV-F-781 and four mixtures of this gasoline with toluene, benzene, and xylene. The method of determining the fuel-air ratio described in this report involves the measurement of the carbon-dioxide content of the oxidized exhaust gas and the use of graphs or the presented equation. This method is considered useful in aircraft, in the field, or in the laboratory for a range of fuel-air ratios from 0.047 to 0.124

  9. The Measurement of Fuel-Air Ratio by Analysis for the Oxidized Exhaust Gas

    NASA Technical Reports Server (NTRS)

    Gerrish, Harold C.; Meem, J. Lawrence, Jr.

    1943-01-01

    An investigation was made to determine a method of measuring fuel-air ratio that could be used for test purposes in flight and for checking conventional equipment in the laboratory. Two single-cylinder test engines equipped with typical commercial engine cylinders were used. The fuel-air ratio of the mixture delivered to the engines was determined by direct measurement of the quantity of air and of fuel supplied and also by analysis of the oxidized exhaust gas and of the normal exhaust gas. Five fuels were used: gasoline that complied with Army-Navy fuel Specification No. AN-VV-F-781 and four mixtures of this gasoline with toluene, benzene, and xylene. The method of determining the fuel-air ratio described in this report involves the measurement of the carbon-dioxide content of the oxidized exhaust gas and the use of graphs for the presented equation. This method is considered useful in aircraft, in the field, or in the laboratory for a range of fuel-air ratios from 0.047 to 0.124.

  10. Positive Streamers and Glows in Air and Exhaust Gases

    NASA Astrophysics Data System (ADS)

    Morrow, R.

    1998-10-01

    Theoretical and experimental studies have been made of the effects of sub-microsecond voltage pulses on the plasma chemistry of real flue gases in a test cell. Chemical analysis shows that, for real flue gases, the pulsed system can remove up to 90 % of NO, and 30 % of SO_2, if a residence time of ~ 30s is used. We also find that (i) water vapour is essential to the removal of SO_2, but not for the removal of NO or NO_2; and (ii) that small quantities of N_2O are produced. The removal of SO2 is primarily due to reactions with OH radicals from water vapour, producing sulphuric acid, whereas nitrogen oxides are reduced by N atoms. When a positive voltage is abruptly applied to a point in air at atmospheric pressure, positive streamers are produced. A theory is presented for the development of the first such streamer by solving the continuity equations for electrons, positive ions and negative ions, including the effects of ionisation, attachment, recombination, electron diffusion, and photoionisation, simultaneously with Poisson's equation. With an applied voltage of 20 kV across a 50 mm gap, the streamer does not reach the cathode. When the voltage is sustained in the presence of free electrons, the electric field at the anode starts to recover until positive glow pulses develop at the anode. The presence of the positive glow corona precludes any further streamer formation; this limits the number of chemical reactions stimulated by the discharge because the positive glow is confined close to the anode. Thus, a limit is set for the voltage pulse width. A theory is also presented for the current and light pulses of positive glow corona from a point in air; results are obtained by solving the continuity equations, described above, in concentric sphere geometry. A series of ``saw--toothed'' current pulses of period ~ 1 μs are predicted with a dc current level. Accompanying the current peaks are discrete 30 ns wide pulses of light. It is found that if, in the presence

  11. Sustainable intensive livestock production demands manure and exhaust air treatment technologies.

    PubMed

    Melse, Roland W; Timmerman, Maikel

    2009-11-01

    Intensive livestock production is connected with a number of environmental effects, including discharges to soils and surface waters and emissions to the atmosphere. In areas with a high livestock density the low availability of nearby arable land, together with the preferred use of chemical fertilizer by arable farmers, results in high off-farm disposal costs for manure. Furthermore, ammonia abatement technologies, such as treatment of exhaust air, are important as ammonia emissions may account up to a quarter of the total nitrogen flux. Firstly, the paper describes and discusses the development of manure treatment in the Netherlands since the 1970's. Manure treatment processes that result in products that compete with and replace the use of chemical fertilizers can (partly) close the nutrient cycle again. From this point of view aerobic treatment of manure (nitrification/denitrification) can not be considered sustainable as nitrogen is taken out of the cycle at high environmental costs. Secondly, the state-of-the-art of techniques for treatment of exhaust air is presented. Besides ammonia, application of air treatment may also reduce environmental emissions of odour and particulate matter (dust). Both manure treatment and treatment of exhaust air are considered essential for sustainable livestock operations in areas with a high livestock density.

  12. 27. VIEW OF EXHAUST AND DEFLECTOR FOR SUBSONIC AERODYNAMICS RESEARCH ...

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

    27. VIEW OF EXHAUST AND DEFLECTOR FOR SUBSONIC AERODYNAMICS RESEARCH LABORATORY, BUILDING 25C, WHICH REPLACED THE 10-FOOT WIND TUNNEL (1991). - Wright-Patterson Air Force Base, Area B, Buildings 25 & 24,10-foot & 20-foot Wind Tunnel Complex, Northeast side of block bounded by K, G, Third, & Fifth Streets, Dayton, Montgomery County, OH

  13. 28. VIEW OF EXHAUST AND DEFLECTOR FOR SUBSONIC AERODYNAMICS RESEARCH ...

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

    28. VIEW OF EXHAUST AND DEFLECTOR FOR SUBSONIC AERODYNAMICS RESEARCH LABORATORY, BUILDING 25C, WHICH REPLACED THE 10-FOOT WIND TUNNEL (1991). - Wright-Patterson Air Force Base, Area B, Buildings 25 & 24,10-foot & 20-foot Wind Tunnel Complex, Northeast side of block bounded by K, G, Third, & Fifth Streets, Dayton, Montgomery County, OH

  14. 26. VIEW OF EXHAUST AND DEFLECTOR FOR SUBSONIC AERODYNAMICS RESEARCH ...

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

    26. VIEW OF EXHAUST AND DEFLECTOR FOR SUBSONIC AERODYNAMICS RESEARCH LABORATORY, BUILDING 25C, WHICH REPLACED THE 10-FOOT WIND TUNNEL (1991). - Wright-Patterson Air Force Base, Area B, Buildings 25 & 24,10-foot & 20-foot Wind Tunnel Complex, Northeast side of block bounded by K, G, Third, & Fifth Streets, Dayton, Montgomery County, OH

  15. Simulation investigation of the effect of the NASA Ames 80-by 120-foot wind tunnel exhaust flow on light aircraft operating in the Moffett field trafffic pattern

    NASA Technical Reports Server (NTRS)

    Streeter, Barry G.

    1986-01-01

    A preliminary study of the exhaust flow from the Ames Research Center 80 by 120 Foot Wind Tunnel indicated that the flow might pose a hazard to low-flying light aircraft operating in the Moffett Field traffic pattern. A more extensive evaluation of the potential hazard was undertaken using a fixed-base, piloted simulation of a light, twin-engine, general-aviation aircraft. The simulated aircraft was flown through a model of the wind tunnel exhaust by pilots of varying experience levels to develop a data base of aircraft and pilot reactions. It is shown that a light aircraft would be subjected to a severe disturbance which, depending upon entry condition and pilot reaction, could result in a low-altitude stall or cause damage to the aircraft tail structure.

  16. Investigation of the components of the NAL high Reynolds number two-dimensional wind tunnel. Part 4: Design, construction and performance of the exhaust silencer

    NASA Technical Reports Server (NTRS)

    Sakakibara, S.; Miwa, H.; Kayaba, S.; Sato, M.

    1986-01-01

    Presented is a description of the design construction and performance of the exhaust silencer for the NAL high Reynolds number two-dimensional transonic blow down wind tunnel, which was completed in October 1979. The silencer is a two-storied construction made of reinforced concrete, 40 m. long, 10 m. wide and 19 m. high and entirely enclosed by thick concrete walls. The upstream part of the first story, particularly, is covered with double walls, the thickness of the two walls being 0.3 m. (inner wall) and 0.2 m. (outer wall), respectively. A noise reduction system using three kinds of parallel baffles and two kinds of lined bends is adopted for the wind tunnel exhaust noise.

  17. Axisymmetric & non-axisymmetric exhaust jet induced-effects on a V/STOL vehicle design. Part 1: Data presentation. [conducted in Ames 11-foot transonic tunnel

    NASA Technical Reports Server (NTRS)

    Schnell, W. C.; Ordonez, G. W.

    1981-01-01

    A 1/8 scale jet-effects model was tested in the NASA Ames 11 ft transonic tunnel at static conditions and over a range of Mach numbers from 0.4 to 1.4. The data presented show that significant differences in aeropropulsion performance can be expected by varying the exhaust nozzle type and its geometric parameters on a V/STOL underwing nacelle installation.

  18. Aircraft engine exhaust emissions and other airport-related contributions to ambient air pollution: A review

    NASA Astrophysics Data System (ADS)

    Masiol, Mauro; Harrison, Roy M.

    2014-10-01

    Civil aviation is fast-growing (about +5% every year), mainly driven by the developing economies and globalisation. Its impact on the environment is heavily debated, particularly in relation to climate forcing attributed to emissions at cruising altitudes and the noise and the deterioration of air quality at ground-level due to airport operations. This latter environmental issue is of particular interest to the scientific community and policymakers, especially in relation to the breach of limit and target values for many air pollutants, mainly nitrogen oxides and particulate matter, near the busiest airports and the resulting consequences for public health. Despite the increased attention given to aircraft emissions at ground-level and air pollution in the vicinity of airports, many research gaps remain. Sources relevant to air quality include not only engine exhaust and non-exhaust emissions from aircraft, but also emissions from the units providing power to the aircraft on the ground, the traffic due to the airport ground service, maintenance work, heating facilities, fugitive vapours from refuelling operations, kitchens and restaurants for passengers and operators, intermodal transportation systems, and road traffic for transporting people and goods in and out to the airport. Many of these sources have received inadequate attention, despite their high potential for impact on air quality. This review aims to summarise the state-of-the-art research on aircraft and airport emissions and attempts to synthesise the results of studies that have addressed this issue. It also aims to describe the key characteristics of pollution, the impacts upon global and local air quality and to address the future potential of research by highlighting research needs.

  19. Photon emission from gold surfaces in air using scanning tunneling microscopy

    NASA Astrophysics Data System (ADS)

    Gallagher, Mark J.; Howells, Sam; Yi, Leon; Chen, Ting; Sarid, Dror

    1992-11-01

    Photon emission was observed at the tunnel junction of a scanning tunneling microscope while scanning Au structures in air. Emission levels of about 4000 counts per second (cps) were routinely achieved with Au tips, allowing photon maps to be produced. The similarity between these photon maps and the topographic images of the Au samples are discussed.

  20. 10. INTERIOR VIEW OF WIND TUNNEL (1991). WrightPatterson Air ...

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

    10. INTERIOR VIEW OF WIND TUNNEL (1991). - Wright-Patterson Air Force Base, Area B, Buildings 25 & 24,10-foot & 20-foot Wind Tunnel Complex, Northeast side of block bounded by K, G, Third, & Fifth Streets, Dayton, Montgomery County, OH

  1. 9. INTERIOR VIEW OF WIND TUNNEL (1991). WrightPatterson Air ...

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

    9. INTERIOR VIEW OF WIND TUNNEL (1991). - Wright-Patterson Air Force Base, Area B, Buildings 25 & 24,10-foot & 20-foot Wind Tunnel Complex, Northeast side of block bounded by K, G, Third, & Fifth Streets, Dayton, Montgomery County, OH

  2. 11. INTERIOR VIEW OF WIND TUNNEL (1991). WrightPatterson Air ...

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

    11. INTERIOR VIEW OF WIND TUNNEL (1991). - Wright-Patterson Air Force Base, Area B, Buildings 25 & 24,10-foot & 20-foot Wind Tunnel Complex, Northeast side of block bounded by K, G, Third, & Fifth Streets, Dayton, Montgomery County, OH

  3. Calibration of the Langley 16-foot transonic tunnel with test section air removal

    NASA Technical Reports Server (NTRS)

    Corson, B. W., Jr.; Runckel, J. F.; Igoe, W. B.

    1974-01-01

    The Langley 16-foot transonic tunnel with test section air removal (plenum suction) was calibrated to a Mach number of 1.3. The results of the calibration, including the effects of slot shape modifications, test section wall divergence, and water vapor condensation, are presented. A complete description of the wind tunnel and its auxiliary equipment is included.

  4. Assessment of analytical and experimental techniques utilized in conducting plume technology tests 575 and 593. [exhaust flow simulation (wind tunnel tests) of scale model Space Shuttle Orbiter

    NASA Technical Reports Server (NTRS)

    Baker, L. R.; Sulyma, P. R.; Tevepaugh, J. A.; Penny, M. M.

    1976-01-01

    Since exhaust plumes affect vehicle base environment (pressure and heat loads) and the orbiter vehicle aerodynamic control surface effectiveness, an intensive program involving detailed analytical and experimental investigations of the exhaust plume/vehicle interaction was undertaken as a pertinent part of the overall space shuttle development program. The program, called the Plume Technology program, has as its objective the determination of the criteria for simulating rocket engine (in particular, space shuttle propulsion system) plume-induced aerodynamic effects in a wind tunnel environment. The comprehensive experimental program was conducted using test facilities at NASA's Marshall Space Flight Center and Ames Research Center. A post-test examination of some of the experimental results obtained from NASA-MSFC's 14 x 14-inch trisonic wind tunnel is presented. A description is given of the test facility, simulant gas supply system, nozzle hardware, test procedure and test matrix. Analysis of exhaust plume flow fields and comparison of analytical and experimental exhaust plume data are presented.

  5. Field study of exhaust fans for mitigating indoor air quality problems: Final report

    SciTech Connect

    Grimsrud, D.T.; Szydlowski, R.F.; Turk, B.H.

    1986-09-01

    Residential ventilation in the United States housing stock is provided primarily by infiltration, the natural leakage of outdoor air into a building through cracks and holes in the building shell. Since ventilation is the dominant mechanism for control of indoor pollutant concentrations, low infiltration rates caused fluctuation in weather conditions may lead to high indoor pollutant concentrations. Supplemental mechanical ventilation can be used to eliminate these periods of low infiltration. This study examined effects of small continuously-operating exhaust fan on pollutant concentrations and energy use in residences.

  6. Exhaust emission control apparatus

    SciTech Connect

    Eng, J.W.

    1991-09-24

    This patent describes an exhaust control apparatus for muffling noise and treating odors and pollutants, including solid particulate and gases in the exhaust of an internal combustion engine. It comprises an exhaust inlet tube for receiving the exhaust generated by an internal combustion engine; a cyclone barrier concentrically surrounding the exhaust inlet tube, a ring cavity between the cyclone tube and exhaust inlet tube defining a cyclone chamber in which the exhaust is treated; means for directing the exhaust from the exhaust inlet tube into the cyclone chamber; electrode means having small openings through which the exhaust passes to enter the cyclone chamber, the electrode means generating electrostatic forces which charge the solid particulate in the exhaust, ionize air and generate ozone in the cyclone chamber near the electrode; means for injecting air into the cyclone chamber causing centrifugal flow of the air and the exhausted within the cyclone chamber and increasing a dwell time of the exhaust within the cyclone chamber.

  7. Correlation of Exhaust-Valve Temperatures with Engine Operating Conditions and Valve Design in an Air-Cooled Cylinder

    NASA Technical Reports Server (NTRS)

    Zipkin, M A; Sanders, J C

    1945-01-01

    A semiempirical equation correlating exhaust-valve temperatures with engine operating conditions and exhaust-valve design has been developed. The correlation is based on the theory correlating engine and cooling variables developed in a previous NACA report. In addition to the parameters ordinarily used in the correlating equation, a term is included in the equation that is a measure of the resistance of the complex heat-flow paths between the crown of the exhaust valve and a point on the outside surface of the cylinder head. A means for comparing exhaust valves of different designs with respect to cooling is consequently provided. The necessary empirical constants included in the equation were determined from engine investigations of a large air-cooled cylinder. Tests of several valve designs showed that the calculated and experimentally determined exhaust-valve temperatures were in good agreement.

  8. Automation&Characterization of US Air Force Bench Top Wind Tunnels - Summary Report

    SciTech Connect

    Hardy, J.E.

    2006-03-23

    The United States Air Force Precision Measurement Equipment Laboratories (PMEL) calibrate over 1,000 anemometer probes per year. To facilitate a more efficient calibration process for probe-style anemometers, the Air Force Metrology and Calibration Program underwent an effort to modernize the existing PMEL bench top wind tunnels. Through a joint effort with the Department of Energy's Oak Ridge National Laboratory, the performance of PMEL wind tunnels was improved. The improvement consisted of new high accuracy sensors, automatic data acquisition, and a software-driven calibration process. As part of the wind tunnel upgrades, an uncertainty analysis was completed, laser Doppler velocimeter profiling was conducted to characterize the velocities at probe locations in the wind tunnel, and pitot tube calibrations of the wind tunnel were verified. The bench top wind tunnel accuracy and repeatability has been measured for nine prototype wind tunnel systems and valuable field experience has been gained with these wind tunnels at the PMELs. This report describes the requirements for the wind tunnel improvements along with actual implementation strategies and details. Lessons-learned from the automation, the velocity profiling, and the software-driven calibration process will also be discussed.

  9. Numerical Study of a Winged Container Moving in an Air Tunnel

    NASA Astrophysics Data System (ADS)

    Shibani, W. M.; Zulkafli, M. F.; Basuno, B.

    2016-11-01

    This study explores the movement of an object placed in an air tunnel. In expectation this exploration leads to obtaining a suitable shape of the object and the flow parameters, the object moves along the air tunnel has a particular trajectory. This study used the body of the main object is a cube in which a rectangular wing of aspect ratio 2 is set in the middle of body object. The object can be used as a carrier to transport goods from one place to another through an air tunnel. Three types wing-cube configurations, they are namely wing- cube configuration with airfoil sections (1) FX63-137, (2) NACA 4412, and (3) NACA 0012 are evaluated by using Fluent's software. The flow problems are treated as an internal flow problem with the assumption that the pressure ratio between the inlet and outlet of the air tunnel is 700 N/m2. The flow is treated as turbulent flow with k — ɛ as its turbulence modelling. In this respect Fluent uses a SIMPLE scheme for solving their governing equation of fluid motion. Their computational results on the way the object moves along the air tunnel, it had been the carrier which uses airfoil NACA 0012 has better performance than the carrier that uses airfoil FX 63-137 or airfoil NACA 4412. This research work gives contribution in understanding the movement of the carrier in the form wing-cube configuration inside an air tunnel.

  10. Estimation of exhaust and non-exhaust gaseous, particulate matter and air toxics emissions from on-road vehicles in Delhi

    NASA Astrophysics Data System (ADS)

    Nagpure, Ajay Singh; Gurjar, B. R.; Kumar, Vivek; Kumar, Prashant

    2016-02-01

    Analysis of emissions from on-road vehicles in an Indian megacity, Delhi, have been performed by comparing exhaust emissions of gaseous, particulate matter and mobile source air toxics (MSATs), together with volatile organic compound (VOCs) and PM10 (particulate matter ≤10 μm) from non-exhaust vehicular sources, during the past (1991-2011) and future (2011-2020) scenarios. Results indicate that emissions of most of the pollutants from private vehicles (two wheelers and cars) have increased by 2- to 18-times in 2020 over the 1991 levels. Two wheelers found to be dominating the emissions of carbon monoxide (CO, 29-51%), hydrocarbons (HC, 45-73%), acetaldehyde (46-51%) and total poly aromatic hydrocarbons (PAHs, 37-42%). Conversely, private cars were found to be responsible for the majority of the carbon dioxide (CO2, 24-42%), 1,3-butadiene (72-89%), benzene (60-82%), formaldehyde (23-44%) and total aldehyde (27-52%) between 1991 and 2011. The heavy-duty commercial vehicles (HCVs) shows their accountability for most of the nitrogen oxide (NOx, 18-41%) and PM10 (33-43%) emissions during the years 1991-2011. In terms of PM10 emissions, vehicular exhaust contributed by 21-55%, followed by road dust (42-73%) and brake wear (3-5%) between 1991 and 2011. After 2002, non-exhaust emissions (e.g. road dust, brake wear and tyre wear) together indicate higher accountability (66-86%) for PM10 emission than the exhaust emissions (14-34%). The temporal trend of emissions of NOx and CO show reasonable agreement with available ambient air concentrations that were monitored at locations, significantly influenced by vehicular activity. Encouraging results were emerged, showing a good correlation coefficient for CO (0.94) and NOx (0.68).

  11. Recombination of Hydrogen-Air Combustion Products in an Exhaust Nozzle

    NASA Technical Reports Server (NTRS)

    Lezberg, Erwin A.; Lancashire, Richard B.

    1961-01-01

    Thrust losses due to the inability of dissociated combustion gases to recombine in exhaust nozzles are of primary interest for evaluating the performance of hypersonic ramjets. Some results for the expansion of hydrogen-air combustion products are described. Combustion air was preheated up to 33000 R to simulate high-Mach-number flight conditions. Static-temperature measurements using the line reversal method and wall static pressures were used to indicate the state of the gas during expansion. Results indicated substantial departure from the shifting equilibrium curve beginning slightly downstream of the nozzle throat at stagnation pressures of 1.7 and 3.6 atmospheres. The results are compared with an approximate method for determining a freezing point using an overall rate equation for the oxidation of hydrogen.

  12. Subway platform air quality: Assessing the influences of tunnel ventilation, train piston effect and station design

    NASA Astrophysics Data System (ADS)

    Moreno, T.; Pérez, N.; Reche, C.; Martins, V.; de Miguel, E.; Capdevila, M.; Centelles, S.; Minguillón, M. C.; Amato, F.; Alastuey, A.; Querol, X.; Gibbons, W.

    2014-08-01

    A high resolution air quality monitoring campaign (PM, CO2 and CO) was conducted on differently designed station platforms in the Barcelona subway system under: (a) normal forced tunnel ventilation, and (b) with daytime tunnel ventilation systems shut down. PM concentrations are highly variable (6-128 μgPM1 m-3, 16-314 μgPM3 m-3, and 33-332 μgPM10 m-3, 15-min averages) depending on ventilation conditions and station design. Narrow platforms served by single-track tunnels are heavily dependent on forced tunnel ventilation and cannot rely on the train piston effect alone to reduce platform PM concentrations. In contrast PM levels in stations with spacious double-track tunnels are not greatly affected when tunnel ventilation is switched off, offering the possibility of significant energy savings without damaging air quality. Sampling at different positions along the platform reveals considerable lateral variation, with the greatest accumulation of particulates occurring at one end of the platform. Passenger accesses can dilute PM concentrations by introducing cleaner outside air, although lateral down-platform accesses are less effective than those positioned at the train entry point. CO concentrations on the platform are very low (≤1 ppm) and probably controlled by ingress of traffic-contaminated street-level air. CO2 averages range from 371 to 569 ppm, changing during the build-up and exchange of passengers with each passing train.

  13. Calibration of a system for measuring low air flow velocity in a wind tunnel

    NASA Astrophysics Data System (ADS)

    Krach, Andrzej; Kruczkowski, Janusz

    2016-08-01

    This article presents the calibration of a system for measuring air flow velocity in a wind tunnel with a multiple-hole orifice. The comparative method was applied for the calibration. The method consists in equalising the air flow velocity in a test section of the tunnel with that of the hot-wire anemometer probe which should then read zero value. The hot-wire anemometer probe moves reciprocally in the tunnel test section with a constant velocity, aligned and opposite to the air velocity. Air velocity in the tunnel test section is adjusted so that the minimum values of a periodic hot-wire anemometer signal displayed on an oscilloscope screen reach the lowest position (the minimum method). A sinusoidal component can be superimposed to the probe constant velocity. Then, the air flow velocity in the tunnel test section is adjusted so that, when the probe moves in the direction of air flow, only the second harmonic of the periodically variable velocity superimposed on the constant velocity (second harmonic method) remains at the output of the low-pass filter to which the hot-wire anemometer signal, displayed on the oscilloscope screen, is supplied. The velocity of the uniform motion of the hot-wire anemometer probe is measured with a magnetic linear encoder. The calibration of the system for the measurement of low air velocities in the wind tunnel was performed in the following steps: 1. Calibration of the linear encoder for the measurement of the uniform motion velocity of the hot-wire anemometer probe in the test section of the tunnel. 2. Calibration of the system for measurement of low air velocities with a multiple-hole orifice for the velocities of 0.1 and 0.25 m s-1: - (a) measurement of the probe movement velocity setting; - (b) measurement of air velocity in the tunnel test section with comparison according to the second harmonic method; - (c) measurement of air velocity in the tunnel with comparison according to the minimum method. The calibration

  14. 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.

  15. Imaging graphite in air by scanning tunneling microscopy - Role of the tip

    NASA Technical Reports Server (NTRS)

    Colton, R. J.; Baker, S. M.; Driscoll, R. J.; Youngquist, M. G.; Baldeschwieler, J. D.; Kaiser, W. J.

    1988-01-01

    Atomically resolved images of highly oriented pyrolytic graphite (HOPG) in air at point contact have been obtained. Direct contact between tip and sample or contact through a contamination layer provides a conduction mechanism in addition to the exponential tunneling mechanism responsible for scanning tunneling microscopy (STM) imaging. Current-voltage (I-V) spectra were obtained while scanning in the current imaging mode with the feedback circuit interrupted in order to study the graphite imaging mechanism. Multiple tunneling tips are probably responsible for images without the expected hexagonal or trigonal symmetry. The observations indicate that the use of HOPG for testing and calibration of STM instrumentation may be misleading.

  16. Surveillance of a Ventilated Rack System for Corynebacterium bovis by Sampling Exhaust-Air Manifolds.

    PubMed

    Manuel, Christopher A; Pugazhenthi, Umarani; Leszczynski, Jori K

    2016-01-01

    Corynebacterium bovis causes an opportunistic infection of nude (Foxn1, nu/nu) mice, leading to nude mouse hyperkeratotic dermatitis (scaly skin disease). Enzootic in many nude mouse colonies, C. bovis spreads rapidly to naive nude mice, despite modern husbandry practices, and is very difficult to eradicate. To facilitate rapid detection in support of eradication efforts, we investigated a surveillance method based on quantitative real-time PCR (qPCR) evaluation of swabs collected from the horizontal exhaust manifold (HEM) of an IVC rack system. We first evaluated the efficacy of rack sanitation methods for removing C. bovis DNA from the HEM of racks housing endemic colonies of infected nude mice. Pressurized water used to flush the racks' air exhaust system followed by a standard rack-washer cycle was ineffective in eliminating C. bovis DNA. Only after autoclaving did all sanitized racks test negative for C. bovis DNA. We then measured the effects of stage of infection (early or established), cage density, and cage location on the rack on time-to-detection at the HEM. Stage of infection significantly affected time-to-detection, independent of cage location. Early infections required 7.3 ± 1.2 d whereas established infections required 1 ± 0 d for detection of C. bovis at the HEM. Cage density influenced the quantity of C. bovis DNA detected but not time-to-detection. The location of the cage on the rack affected the time-to-detection only during early C. bovis infections. We suggest that qPCR swabs of HEM are useful during the routine surveillance of nude mouse colonies for C. bovis infection.

  17. Surveillance of a Ventilated Rack System for Corynebacterium bovis by Sampling Exhaust-Air Manifolds

    PubMed Central

    Manuel, Christopher A; Pugazhenthi, Umarani; Leszczynski, Jori K

    2016-01-01

    Corynebacterium bovis causes an opportunistic infection of nude (Foxn1, nu/nu) mice, leading to nude mouse hyperkeratotic dermatitis (scaly skin disease). Enzootic in many nude mouse colonies, C. bovis spreads rapidly to naive nude mice, despite modern husbandry practices, and is very difficult to eradicate. To facilitate rapid detection in support of eradication efforts, we investigated a surveillance method based on quantitative real-time PCR (qPCR) evaluation of swabs collected from the horizontal exhaust manifold (HEM) of an IVC rack system. We first evaluated the efficacy of rack sanitation methods for removing C. bovis DNA from the HEM of racks housing endemic colonies of infected nude mice. Pressurized water used to flush the racks’ air exhaust system followed by a standard rack-washer cycle was ineffective in eliminating C. bovis DNA. Only after autoclaving did all sanitized racks test negative for C. bovis DNA. We then measured the effects of stage of infection (early or established), cage density, and cage location on the rack on time-to-detection at the HEM. Stage of infection significantly affected time-to-detection, independent of cage location. Early infections required 7.3 ± 1.2 d whereas established infections required 1 ± 0 d for detection of C. bovis at the HEM. Cage density influenced the quantity of C. bovis DNA detected but not time-to-detection. The location of the cage on the rack affected the time-to-detection only during early C. bovis infections. We suggest that qPCR swabs of HEM are useful during the routine surveillance of nude mouse colonies for C. bovis infection. PMID:26817981

  18. Spectroscopy of Light Emission from a Scanning Tunneling Microscope in Air

    NASA Astrophysics Data System (ADS)

    Péchou, R.; Coratger, R.; Girardin, C.; Ajustron, F.; Beauvillain, J.

    1996-11-01

    Light emission has been detected at the tip-sample junction of a Scanning Tunneling Microscope (S.T.M.) in air on noble metallic surfaces. A spectroscopic study of emitted photons for Au-Au and PtIr-Au tunneling junctions is presented. The general aspect of the spectra depends on the materials used in the junctions; a study of the spectra as a function of tunneling current and surface bias voltage reveals similar and reproducible characteristics. Une émission de lumière a été détectée au niveau de la jonction pointe-surface d'un microscope à effet tunnel dans l'air sur des surfaces de métaux nobles. Une étude spectroscopique des photons émis par des jonctions tunnel Au-Au et PtIr-Au est présentée. L'aspect général des spectres dépend des matériaux utilisés ; une étude en fonction du courant tunnel et de la tension de polarisation de la jonction révéle des caractéristiques similaires et reproductibles.

  19. Biomonitoring of inhaled complex mixtures--ambient air, diesel exhaust and cigarette smoke.

    PubMed

    Scherer, Gerhard

    2005-07-01

    Human biomonitoring comprises the determination of biomarkers in body-fluids, cells and tissues. Biomarkers are generally assigned to one of three classes, namely, biomarkers of exposure, effect or susceptibility. Since biomarkers represent steps in an exposure-disease continuum, their application in epidemiological studies ('molecular epidemiology') shows promise. However, to be a predictor of disease, a biomarker has to be validated. Validation criteria for a biomarker include intrinsic qualities such as specificity, sensitivity, knowledge of background in the population, existence of dose-response relationships, degree of inter- and intra-individual variability, knowledge of the kinetics, confounding and modifying factors. In addition, properties of the sampling and analytical procedures are of relevance, including constraints and non-invasiveness of sampling, stability of sample as well as simplicity, high sensitivity, specificity and speed of the analytical method. It is of particular importance to prove by suitable studies that the biomarker of exposure indicates the actual exposure, the biomarker of effect strongly predicts the actual risk of disease and the biomarker of susceptibility actually modifies the risk. Biomonitoring of the exposure to complex mixtures such as polluted ambient air, diesel exhaust or tobacco smoke is a particular challenge since these exposures have many constituents in common and many people were exposed to more than one of these mixtures. Data on the exposure to polycyclic aromatic hydrocarbons (PAH) and benzene from ambient air, diesel exhaust and tobacco smoke will be presented. In addition, some source-specific biomarkers such as nitro-arenes and nicotine metabolites as well as their application in population groups will be discussed. The second part of the presentation addresses the application of biomarkers for assessing so called 'potentially reduced exposure products' (PREPs). According to a recent report of the Institute

  20. Air/water two-phase flow test tunnel for airfoil studies

    NASA Astrophysics Data System (ADS)

    Ohashi, H.; Matsumoto, Y.; Ichikawa, Y.; Tsukiyama, T.

    1990-02-01

    A test tunnel for the study of airfoil performances under air/water two-phase flow condition has been designed and constructed. This facility will serve for a better understanding of the flow phenomena and characteristics of hydraulic machinery under gas/ liquid two-phase flow operating conditions. At the test section of the tunnel, a two-dimensional isolated airfoil or a cascade of airfoils is installed in a two-phase inlet flow with a uniform velocity (up to 10 m/s) and void fraction (up to 12%) distribution. The details of the tunnel structure and the measuring systems are described and the basic characteristics of the constructed tunnel are also given. As an example of the test results, void fraction distribution around a test airfoil is shown.

  1. Air/water two-phase flow test tunnel for airfoil studies

    NASA Astrophysics Data System (ADS)

    Ohashi, H.; Matsumoto, Y.; Ichikawa, Y.; Tsukiyama, T.

    1994-01-01

    A test tunnel for the study of airfoil performances under air/water two-phase flow condition has been designed and constructed. This facility will serve for a better understanding of the flow phenomena and characteristics of hydraulic machinery under gas/ liquid two-phase flow operating conditions. At the test section of the tunnel, a two-dimensional isolated airfoil or a cascade of airfoils is installed in a two-phase inlet flow with a uniform velocity (up to 10 m/s) and void fraction (up to 12%) distribution. The details of the tunnel structure and the measuring systems are described and the basic characteristics of the constructed tunnel are also given. As an example of the test results, void fraction distribution around a test airfoil is shown.

  2. Modeling the Air Flow in the 3410 Building Filtered Exhaust Stack System

    SciTech Connect

    Recknagle, Kurtis P.; Barnett, J. Matthew; Suffield, Sarah R.

    2013-01-23

    Additional ventilation capacity has been designed for the 3410 Building filtered exhaust stack system. The updated system will increase the number of fans from two to three and will include ductwork to incorporate the new fan into the existing stack. Stack operations will involve running various two-fan combinations at any given time. The air monitoring system of the existing two-fan stack was previously found to be in compliance with the ANSI/HPS N13.1-1999 standard, however it is not known if the modified (three-fan) system will comply. Subsequently, a full-scale three-dimensional (3-D) computational fluid dynamics (CFD) model of the modified stack system has been created to examine the sampling location for compliance with the standard. The CFD modeling results show good agreement with testing data collected from the existing 3410 Building stack and suggest that velocity uniformity and flow angles will remain well within acceptance criteria when the third fan and associated ductwork is installed. This includes two-fan flow rates up to 31,840 cfm for any of the two-fan combinations. For simulation cases in which tracer gas and particles are introduced in the main duct, the model predicts that both particle and tracer gas coefficients of variance (COVs) may be larger than the acceptable 20 percent criterion of the ANSI/HPS N13.1-1999 standard for each of the two-fan, 31,840 cfm combinations. Simulations in which the tracers are introduced near the fans result in improved, though marginally acceptable, COV values for the tracers. Due to the remaining uncertainty that the stack will qualify with the addition of the third fan and high flow rates, a stationary air blender from Blender Products, Inc. is considered for inclusion in the stack system. A model of the air blender has been developed and incorporated into the CFD model. Simulation results from the CFD model that includes the air blender show striking improvements in tracer gas mixing and tracer particle

  3. Study on the traffic air pollution inside and outside a road tunnel in Shanghai, China.

    PubMed

    Zhou, Rui; Wang, Shanshan; Shi, Chanzhen; Wang, Wenxin; Zhao, Heng; Liu, Rui; Chen, Limin; Zhou, Bin

    2014-01-01

    To investigate the vehicle induced air pollution situations both inside and outside the tunnel, the field measurement of the pollutants concentrations and its diurnal variations was performed inside and outside the Xiangyin tunnel in Shanghai from 13:00 on April 24th to 13:00 on April 25th, 2013. The highest hourly average concentrations of pollutants were quantified that CO, NO, NO2 and NOX inside the tunnel were 13.223 mg/m3, 1.829 mg/m3, 0.291 mg/m3 and 3.029 mg/m3, respectively, while the lowest ones were 3.086 mg/m3, 0.344 mg/m3, 0.080 mg/m3 and 0.619 mg/m3. Moreover, the concentrations of pollutants were higher during the daytime, and lower at night, which is relevant to the traffic conditions inside the tunnel. Pollutants concentrations inside the tunnel were much higher than those outside the tunnel. Then in a case of slow wind, the effect of wind is much smaller than the impact of pollution sources. Additionally, the PM2.5 concentrations climbed to the peak sharply (468.45 µg/m3) during the morning rush hours. The concentrations of organic carbon (OC) and elemental carbon (EC) in PM2.5 inside the tunnel were 37.09-99.06 µg/m3 and 22.69-137.99 µg/m3, respectively. Besides, the OC/EC ratio ranged from 0.72 to 2.19 with an average value of 1.34. Compared with the results of other tunnel experiments in Guangzhou and Shenzhen, China, it could be inferred that the proportion of HDVs through the Xiangyin tunnel is relatively lower.

  4. A large volume 2000 MPA air source for the radiatively driven hypersonic wind tunnel

    SciTech Connect

    Constantino, M

    1999-07-14

    An ultra-high pressure air source for a hypersonic wind tunnel for fluid dynamics and combustion physics and chemistry research and development must provide a 10 kg/s pure air flow for more than 1 s at a specific enthalpy of more than 3000 kJ/kg. The nominal operating pressure and temperature condition for the air source is 2000 MPa and 900 K. A radial array of variable radial support intensifiers connected to an axial manifold provides an arbitrarily large total high pressure volume. This configuration also provides solutions to cross bore stress concentrations and the decrease in material strength with temperature. [hypersonic, high pressure, air, wind tunnel, ground testing

  5. Radioactive air emissions notice of construction use of a portable exhauster at 244-AR vault. Revision 2

    SciTech Connect

    Carrell, D.J.

    1997-12-17

    This document serves as a notice of construction (NOC), pursuant to the requirements of Washington Administrative Code (WAC) 246-247-060, and as a request for approval to construct, pursuant to 40 Code of Federal Regulations (CFR) 61.96, a portable exhauster at the 244-AR Vault. The exhauster would be used during air jetting of accumulated liquids from the cell sumps into the tanks and to make transfers among the tanks within the vault when needed. The 244-AR Vault is considered to be a double-contained receiver tank (OCRT) based on its functional characteristics, although it is not listed as one of the five designated DCRTs in the 200 Area Tank Farm systems. Process operations at the vault have been inactive since 1978 and the vault`s two stacks have not operated since 1993. Since cessation of vault operations an extremely large amount of rain water and snow melt have accumulated in the cell sumps. The water level in the sumps is substantially above their respective operating levels and there is concern for leakage to the environment through containment failure due to corrosion from backed-up sump liquid. Active ventilation is required to provide contamination control during air jetting operations within the vault. It has been determined that it would not be cost effective to repair the existing exhaust systems to an operational condition; thus, a portable exhauster will be used to support the intermittent operations.

  6. Program and charts for determining shock tube, and expansion tunnel flow quantities for real air

    NASA Technical Reports Server (NTRS)

    Miller, C. G., III; Wilder, S. E.

    1975-01-01

    A computer program in FORTRAN 4 language was written to determine shock tube, expansion tube, and expansion tunnel flow quantities for real-air test gas. This program permits, as input data, a number of possible combinations of flow quantities generally measured during a test. The versatility of the program is enhanced by the inclusion of such effects as a standing or totally reflected shock at the secondary diaphragm, thermochemical-equilibrium flow expansion and frozen flow expansion for the expansion tube and expansion tunnel, attenuation of the flow in traversing the acceleration section of the expansion tube, real air as the acceleration gas, and the effect of wall boundary layer on the acceleration section air flow. Charts which provide a rapid estimation of expansion tube performance prior to a test are included.

  7. Assessing the impact of the forthcoming decrease in diesel exhaust particulate matter emissions on air quality: implications for black carbon concentrations in ambient air

    NASA Astrophysics Data System (ADS)

    González, Y.; Rodríguez, S.; Cuevas, E.; Ramos, R.; Abreu-Afonso, J.; Baldasano, J. M.

    2009-04-01

    Forthcoming regulations (e.g. EURO 5 and EURO 6) are planned to reduce particulate matter emissions (PM) in the exhaust of forthcoming vehicles. In this study we assess the impact of such reduction in the diesel PM exhaust emissions on the urban ambient air PM concentrations. This has been done by studying the relationship between black carbon (BC) and carbon monoxide (CO) in urban ambient air and in the exhaust of current and forthcoming vehicles. The slope of the BC-vs-CO linear relationship is mainly affected by the percentage (%) of diesel automobiles in the urban vehicles fleet. This slope is a better indicator of the diesel PM emissions than bulk BC concentrations in urban ambient air. BC-vs-CO slopes within the range 1-3 and 7-14 ngBC/µgCO are typically observed in urban areas with low (<25%) and high (≥50%) proportions of diesel-fuel consumption for on road transportation, respectively. The entry into force of forthcoming regulations will decrease the BC-vs-CO slope in urban ambient air from about 10 to 5 ngBC/µgCO in the next decade, according to calculations based on the current data on diesel vehicles in urban fleets in Spanish cities. However, this will not necessary prompt a significant decrease in the urban BC concentrations if road traffic volume follows the increasing trend of the last decade. The results of this study shows that the analysis of the BC-vs-CO slope trend in ambient air is an useful tool for understanding the involvement "of the changes in the vehicle exhaust emissions rates" and "of the changes in the road traffic volume" in the BC and PMx trends in urban ambient air.

  8. Assessment and prediction of urban air pollution caused by motor transport exhaust gases using computer simulation methods

    NASA Astrophysics Data System (ADS)

    Boyarshinov, Michael G.; Vaismana, Yakov I.

    2016-10-01

    The following methods were used in order to identify the pollution fields of urban air caused by the motor transport exhaust gases: the mathematical model, which enables to consider the influence of the main factors that determine pollution fields formation in the complex spatial domain; the authoring software designed for computational modeling of the gas flow, generated by numerous mobile point sources; the results of computing experiments on pollutant spread analysis and evolution of their concentration fields. The computational model of exhaust gas distribution and dispersion in a spatial domain, which includes urban buildings, structures and main traffic arteries, takes into account a stochastic character of cars apparition on the borders of the examined territory and uses a Poisson process. The model also considers the traffic lights switching and permits to define the fields of velocity, pressure and temperature of the discharge gases in urban air. The verification of mathematical model and software used confirmed their satisfactory fit to the in-situ measurements data and the possibility to use the obtained computing results for assessment and prediction of urban air pollution caused by motor transport exhaust gases.

  9. Considerations on the effect of wind-tunnel walls on oscillating air forces for two-dimensional subsonic compressible flow

    NASA Technical Reports Server (NTRS)

    Runyan, Harry L; Watkins, Charles E

    1953-01-01

    This report treats the effect of wind-tunnel walls on the oscillating two-dimensional air forces in a compressible medium. The walls are simulated by the usual method of placing images at appropriate distances above and below the wing. An important result shown is that, for certain conditions of wing frequency, tunnel height, and Mach number, the tunnel and wing may form a resonant system so that the forces on the wing are greatly changed from the condition of no tunnel walls. It is pointed out that similar conditions exist for three-dimensional flow in circular and rectangular tunnels and apparently, within certain Mach number ranges, in tunnels of nonuniform cross section or even in open tunnels or jets.

  10. Development of naval diesel engine duty cycles for air exhaust emission environmental impact analysis. Master's thesis

    SciTech Connect

    Markle, S.P.

    1994-05-01

    A strategy for testing naval diesel engines for exhaust emissions was developed. A survey of existing international and national standard diesel engine duty cycles was conducted. All were found to be inadequate for testing and certification of engine exhaust emissions from naval diesel powered ships. Naval ship data covering 11,500 hours of engine operation of four U.S. Navy LSD 41 Class amphibious ships was analyzed to develop a 27 point class operating profile. A procedure combining ship hull form characteristics, ship propulsion plant parameters, and ship operating profile was detailed to derive an 11-Mode duty cycle representative for testing LSD 41 Class propulsion diesel engines. A similar procedure was followed for ship service diesel engines. Comparisons with industry accepted duty cycles were conducted using exhaust emission contour plots for the Colt-Pielstick PC-4B diesel engines. Results showed the 11-Mode LSD 41 Class Duty Cycle best predicted ship propulsion engine emissions compared to the 27 point operating profile propeller curve. The procedure was applied to T-AO 187 Class with similar results. The application of civilian industry standards to measure naval diesel ship propulsion engine exhaust emissions was found to be inadequate. Engine exhaust flow chemistry post turbocharger was investigated using the SANDIA Lab computer tool CHEMKIN. Results showed oxidation and reduction reactions within exhaust gases are quenched in the exhaust stack. Since the exhaust stream in the stack is unreactive, emission sampling may be performed where most convenient. A proposed emission measurement scheme for LSD 41 Class ships was presented.

  11. Vehicle cabin cooling system for capturing and exhausting heated boundary layer air from inner surfaces of solar heated windows

    DOEpatents

    Farrington, Robert B.; Anderson, Ren

    2001-01-01

    The cabin cooling system includes a cooling duct positioned proximate and above upper edges of one or more windows of a vehicle to exhaust hot air as the air is heated by inner surfaces of the windows and forms thin boundary layers of heated air adjacent the heated windows. The cabin cooling system includes at least one fan to draw the hot air into the cooling duct at a flow rate that captures the hot air in the boundary layer without capturing a significant portion of the cooler cabin interior air and to discharge the hot air at a point outside the vehicle cabin, such as the vehicle trunk. In a preferred embodiment, the cooling duct has a cross-sectional area that gradually increases from a distal point to a proximal point to the fan inlet to develop a substantially uniform pressure drop along the length of the cooling duct. Correspondingly, this cross-sectional configuration develops a uniform suction pressure and uniform flow rate at the upper edge of the window to capture the hot air in the boundary layer adjacent each window.

  12. The mechanism of light emission from a scanning tunnelling microscope operating in air

    NASA Astrophysics Data System (ADS)

    Rogez, B.; Cao, S.; Dujardin, G.; Comtet, G.; Le Moal, E.; Mayne, A.; Boer-Duchemin, E.

    2016-11-01

    The scanning tunnelling microscope (STM) may be used as a low-energy, electrical nanosource of surface plasmon polaritons and light. In this article, we demonstrate that the optimum mode of operation of the STM for maximum photon emission is completely different in air than in vacuum. To this end, we investigate the emission of photons, the variation in the relative tip-sample distance and the measured current as a function of time for an STM operating in air. Contrary to the case of an STM operating in vacuum, the measured current between the tip and sample for an STM in air is very unstable (rapidly fluctuating in time) when the applied voltage between the tip and sample is in the ˜1.5-3 V range (i.e., in the energy range of visible photons). The photon emission occurs in short (50 μs) bursts when the STM tip is closest to the sample. The current instabilities are shown to be a key ingredient for producing intense light emission from an STM operating in air (photon emission rate several orders of magnitude higher than for stable current). These results are explained in terms of the interplay between the tunnel current and the electrochemical current in the ubiquitous thin water layer that exists when working in air.

  13. Tunneled central venous catheter exchange: techniques to improve prevention of air embolism.

    PubMed

    Rossi, Umberto G; Torcia, Pierluca; Rigamonti, Paolo; Colombo, Francesca; Giordano, Antonino; Gallieni, Maurizio; Cariati, Maurizio

    2016-01-01

    Malfunctioning tunneled hemodialysis central venous catheters (CVCs), because of thrombotic or infectious complications, are frequently exchanged. During the CVC exchanging procedure, there are several possible technical complications, as in first insertion, including air embolism. Prevention remains the key to the management of air embolism. Herein, we emphasize the technical tricks capable of reducing the risk of air embolism in long-term CVC exchange. In particular, adoption of a 5 to 10 degrees Trendelenburg position, direct puncture of the previous CVC venous lumen for guide-wire insertion, as opposed to guide-wire introduction after cutting the CVC, a light manual compression of the internal jugular vein venotomy site after catheter removal. The Valsalva maneuvre in collaborating patients, valved introducers, and correction of hypovolemia are also useful precautions. Principles of air embolism diagnosis and treatment are also outlined in the article.

  14. Neural network modeling of air pollution in tunnels according to indirect measurements

    NASA Astrophysics Data System (ADS)

    Kaverzneva, T.; Lazovskaya, T.; Tarkhov, D.; Vasilyev, A.

    2016-11-01

    The article deals with the problem of providing the necessary parameters of air of the working area in dead-end tunnels in the case of ventilation systems powered off. An ill-posed initialboundary problem for the diffusion equation is used as a mathematical model for a description and analysis of mass transfer processes in the tunnel. The neural network approach is applied to construct an approximate solution (regularization) of the identification problem in the case of the approximate measurement data and the set of interval parameters of the modeled system. Two types of model measurements included binary data are considered. The direct problem solution and the inverse problem regularization for the offered neural network approach are constructed uniformly.

  15. Model aerodynamic test results for two variable cycle engine coannular exhaust systems at simulated takeoff and cruise conditions. [Lewis 8 by 6-foot supersonic wind tunnel tests

    NASA Technical Reports Server (NTRS)

    Nelson, D. P.

    1980-01-01

    Wind tunnel tests were conducted to evaluate the aerodynamic performance of a coannular exhaust nozzle for a proposed variable stream control supersonic propulsion system. Tests were conducted with two simulated configurations differing primarily in the fan duct flowpaths: a short flap mechanism for fan stream control with an isentropic contoured flow splitter, and an iris fan nozzle with a conical flow splitter. Both designs feature a translating primary plug and an auxiliary inlet ejector. Tests were conducted at takeoff and simulated cruise conditions. Data were acquired at Mach numbers of 0, 0.36, 0.9, and 2.0 for a wide range of nozzle operating conditions. At simulated supersonic cruise, both configurations demonstrated good performance, comparable to levels assumed in earlier advanced supersonic propulsion studies. However, at subsonic cruise, both configurations exhibited performance that was 6 to 7.5 percent less than the study assumptions. At take off conditions, the iris configuration performance approached the assumed levels, while the short flap design was 4 to 6 percent less.

  16. Power plant including an exhaust gas recirculation system for injecting recirculated exhaust gases in the fuel and compressed air of a gas turbine engine

    DOEpatents

    Anand, Ashok Kumar; Nagarjuna Reddy, Thirumala Reddy; Shaffer, Jason Brian; York, William David

    2014-05-13

    A power plant is provided and includes a gas turbine engine having a combustor in which compressed gas and fuel are mixed and combusted, first and second supply lines respectively coupled to the combustor and respectively configured to supply the compressed gas and the fuel to the combustor and an exhaust gas recirculation (EGR) system to re-circulate exhaust gas produced by the gas turbine engine toward the combustor. The EGR system is coupled to the first and second supply lines and configured to combine first and second portions of the re-circulated exhaust gas with the compressed gas and the fuel at the first and second supply lines, respectively.

  17. Effect of Wind Tunnel Air Velocity on VOC Flux from Standard Solutions and CAFO Manure/Wastewater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Researchers and practitioners have used wind tunnels and flux chambers to quantify the flux of volatile organic compounds (VOCs), ammonia, and hydrogen sulfide and estimate emission factors from animal feeding operations (AFOs) without accounting for effects of air velocity or sweep air flow rate. L...

  18. A 2-Liter, 2000 MPa Air Source for the Radiatively Driven Hypersonic Wind Tunnel

    SciTech Connect

    Costantino, M; Lofftus, D

    2002-05-30

    The A2 LITE is a 2 liter, 2000 MPa, 750 K ultra-high pressure (UHP) vessel used to demonstrate UHP technology and to provide an air flow for wind tunnel nozzle development. It is the largest volume UHP vessel in the world. The design is based on a 100:1 pressure intensification using a hydraulic ram as a low pressure driver and a three-layer compound cylinder UHP section. Active control of the 900 mm piston stroke in the 63.5 mm bore permits pressure-time profiles ranging from static to constant pressure during flow through a 1 mm throat diameter nozzle for 1 second.

  19. PERSONAL EXPOSURE TO JP-8 JET FUEL VAPORS AND EXHAUST AT AIR FORCE BASES

    EPA Science Inventory

    JP-8 jet fuel (similar to commercial/international jet A-1 fuel) is the standard military fuel for all types of vehicles, including the U.S. Air Force aircraft inventory. As such, JP-8 presents the most common chemical exposure in the Air Force, particularly for flight and gro...

  20. Fuel-air mixing apparatus for reducing gas turbine combustor exhaust emissions

    NASA Technical Reports Server (NTRS)

    Zupanc, Frank J. (Inventor); Yankowich, Paul R. (Inventor)

    2006-01-01

    A fuel-air mixer for use in a combustion chamber of a gas turbine engine is provided. The fuel air mixing apparatus comprises an annular fuel injector having a plurality of discrete plain jet orifices, a first swirler wherein the first swirler is located upstream from the fuel injector and a second swirler wherein the second swirler is located downstream from the fuel injector. The plurality of discrete plain jet orifices are situated between the highly swirling airstreams generated by the two radial swirlers. The distributed injection of the fuel between two highly swirling airstreams results in rapid and effective mixing to the desired fuel-air ratio and prevents the formation of local hot spots in the combustor primary zone. A combustor and a gas turbine engine comprising the fuel-air mixer of the present invention are also provided as well as a method using the fuel-air mixer of the present invention.

  1. Air-Loads Prediction of a UH-60A Rotor inside the 40- by 80-Foot Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Chang, I-Chung; Romander, Ethan A.; Potsdam, Mark; Yeo, Hyeonsoo

    2010-01-01

    The presented research extends the capability of a loose coupling computational fluid dynamics (CFD) and computational structure dynamics (CSD) code to calculate the flow-field around a rotor and test stand mounted inside a wind tunnel. Comparison of predicted air-load results for a full-scale UH-60A rotor recently tested inside the National Full-Scale Aerodynamics Complex (NFAC) 40- by 80-Foot Wind Tunnel at Ames Research Center and in free-air flight are made for three challenging flight data points from the earlier conducted UH-60A Air-loads Program. Overall results show that the extension of the coupled CFD/CSD code to the wind-tunnel environment is generally successful.

  2. A parametric experimental investigation of a scramjet nozzle at Mach 6 with Freon and argon or air used for exhaust simulation

    NASA Technical Reports Server (NTRS)

    Cubbage, James M.; Monta, William J.

    1991-01-01

    A parametric experimental investigation of a scramjet nozzle was conducted with a gas mixture used to simulate the scramjet engine exhaust flow at a free-stream Reynolds number of approximately 6.5 x 10(exp 6) per foot. External nozzle surface angles of 16, 20, and 24 deg were tested with a fixed-length ramp and for cowl internal surface angles of 6 and 12 deg. Pressure data on the external nozzle surface were obtained for mixtures of Freon and argon gases with a ratio of specific heats of about 1.23, which matches that of a scramjet exhaust. Forces and moments were determined by integration of the pressure data. Two nozzle configurations were also tested with air used to simulate the exhaust flow. On the external nozzle surface, lift and thrust forces for air exhaust simulation were approximately half of those for Freon-argon exhaust simulation and the pitching moment was approximately a third. These differences were primarily due to the difference in the ratios of specific heats between the two exhaust simulation gases. A 20 deg external surface angle produced the greatest thrust for a 6 deg cowl internal surface angle. A flow fence significantly increased lift and thrust forces over those for the nozzle without a flow fence.

  3. The effects of oxygen-enriched intake air on FFV exhaust emissions using M85

    SciTech Connect

    Poola, R.B.; Sekar, R.; Ng, H.K.; Baudino, J.H.; Colucci, C.P.

    1996-05-01

    This paper presents results of emission tests of a flexible fuel vehicle (FFV) powered by an SI engine, fueled by M85 (methanol), and supplied with oxygen-enriched intake air containing 21, 23, and 25 vol% O2. Engine-out total hydrocarbons (THCs) and unburned methanol were considerably reduced in the entire FTP cycle when the O2 content of the intake air was either 23 or 25%. However, CO emissions did not vary much, and NOx emissions were higher. HCHO emissions were reduced by 53% in bag 1, 84% in bag 2, and 59% in bag 3 of the FTP cycle with 25% oxygen-enriched intake air. During cold-phase FTP,reductions of 42% in THCs, 40% in unburned methanol, 60% in nonmethane hydrocarbons, and 45% in nonmethane organic gases (NMOGs) were observed with 25% enriched air; NO{sub x} emissions increased by 78%. Converter-out emissions were also reduced with enriched air but to a lesser degree. FFVs operating on M85 that use 25% enriched air during only the initial 127 s of cold-phase FTP or that use 23 or 25% enriched air during only cold-phase FTP can meet the reactivity-adjusted NMOG, CO, NO{sub x}, and HCHO emission standards of the transitional low-emission vehicle.

  4. Air intake contamination by building exhausts: tracer gas investigation of atmospheric dispersion models in the urban environment.

    PubMed

    Lazure, Louis; Saathoff, Pat; Stathopoulos, Ted

    2002-02-01

    The establishment of a safe distance between sources of pollution and air intakes is based on a complex exercise that should take into account several wind, physical, and topographical factors. To estimate the maximum concentrations of the pollutants as a function of the distance from the emission source, some heating, ventilation, and air conditioning (HVAC) system designers use the atmospheric dispersion models suggested by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). Two of these models, the Halitsky and Wilson-Chui-Lamb models, have been developed and evaluated mainly with laboratory data. There have been relatively few evaluations with full-scale field data. The objective of this study, carried out on a building in downtown Montreal, Quebec, Canada, was to compare the measured concentrations of a tracer gas emitted by an exhaust stack with those predicted by these models. The results indicate that the Halitsky model gives lower than actual dilution, while the Wilson-Chui-Lamb model generally gives acceptable estimates, with occasional over-estimations of the dilution.

  5. Application of local exhaust ventilation system and integrated collectors for control of air pollutants in mining company.

    PubMed

    Ghorbani Shahna, Farshid; Bahrami, Abdulrahman; Farasati, Farhad

    2012-01-01

    Local exhaust ventilation (LEV) systems and integrated collectors were designed and implemented in a mining company in order to control emitted air pollutant from furnaces. The LEV was designed for capture and transition of air pollutants emitted from furnaces to the integrated collectors. The integrated collectors including four high efficiency Stairmand model cyclones for control of particulate matter, a venturi scrubber for control of the fine particles, SO(2) and a part of H(2)S to follow them, and a packed scrubber for treatment of the residual H(2)S and SO(2) were designed. Pollutants concentration were measured to determine system effectiveness. The results showed that the effectiveness of LEV for reducing workplace pollution is 91.83%, 96.32% and 83.67% for dust, SO(2) and H(2)S, respectively. Average removal efficiency of particles by combination of cyclone and venturi scrubber was 98.72%. Average removal efficiency of SO(2) and H(2)S were 95.85% and 47.13% for the venturi scrubber and 68.45% and 92.7% for the packed bed scrubber. The average removal efficiency of SO(2) and H(2)S were increased to 99.1% and 95.95% by the combination of venturi and packed bed scrubbers. According to the results, integrated collectors are a good air pollution control option for industries with economic constraints and ancient technologies.

  6. Estimation of road vehicle exhaust emissions from 1992 to 2010 and comparison with air quality measurements in Genoa, Italy

    NASA Astrophysics Data System (ADS)

    Zamboni, Giorgio; Capobianco, Massimo; Daminelli, Enrico

    An investigation into road transport exhaust emissions in the Genoa urban area was performed by comparing the quantities of carbon monoxide (CO), nitrogen oxides (NO x), nitrogen dioxide (NO 2) and particulate matter (PM) emitted by different vehicle categories with air quality measurements referred to the same pollutants. Exhaust emissions were evaluated by applying the PROGRESS (computer PROGramme for Road vehicle EmiSSions evaluation) code, developed by the Internal Combustion Engines Group of the University of Genoa, to eight different years (from 1992 to 2010), considering spark ignition and Diesel passenger cars and light duty vehicles, heavy duty vehicles and buses, motorcycles and mopeds. Changes in terms of vehicles number, mileage and total emissions are presented together with relative distributions among the various vehicle categories. By comparing 1992 and 2010 data, calculated trends show a 7% increase in the number of vehicles, with total mileage growing at a faster rate (approx. 22%); total emissions decrease considerably, by approximately 50% for NO x and PM, 70% for HC and 80% for CO, due to improvements in engines and fuels forced by the stricter European legislation and the fleet renewal, while primary NO 2 emission will be very close to 1992 level, after a decrease of about 18% in 2000. Air quality was analysed by selecting traffic and background measuring stations from the monitoring network managed by the Environmental Department of the Province of Genoa: average annual concentrations of considered pollutants from 1994 to 2007 were calculated in order to obtain the relative historical trends and compare them with European public health limits and with road vehicle emissions. Though an important reduction in pollutant concentrations has been achieved as a consequence of cleaner vehicles, some difficulties in complying with present and/or future NO 2 and PM 10 limits are also apparent, thus requiring suitable measures to be taken by the local

  7. Impact of vehicular exhaust on ambient air quality of Rohtak city, India.

    PubMed

    Shukla, Vineeta; Dalal, Poonam; Chaudhry, Dhruva

    2010-11-01

    In the present study, ambient air quality of Rohtak city (Haryana) was monitored by High Volume Sampler. The selected parameters to judge the quality of air were Sulphur dioxide (SO2), Nitrogen dioxide NO), Ozone (O3) and Suspended particulate matters (SPM) which give a fair idea of pollution load carried by the air. The monitoring data were collected from six sites randomly selected in Rohtak city. Sulphur dioxide was found below the permissible limits of National Ambient Avo Quality Standards (NAAQS) at all the sites. Higher concentration of SO2 was observed during winter in comparison to summer and monsoon seasons. Nitrogen dioxide concentration was found to be above the prescribed standards of NAAOS at four sites in winter season. Ozone concentration was found below the prescribed standards (NAAOS), but its concentration was higher in summer season as compared to winter. Suspended particulate matter concentration was observed above the safety limits at all the sites in all three seasons.

  8. Detection of mutagenic activity in automobile exhaust.

    PubMed

    Ohnishi, Y; Kachi, K; Sato, K; Tahara, I; Takeyoshi, H; Tokiwa, H

    1980-03-01

    Using the Ames Salmonella-microsome system, we detected mutagenic activity in the exhaust from two kinds of 4-cycle gasoline engines of unregulated and regulated cars, and from diesel engines, as well as in the particulates from air collected in tunnels. The mutagenicity of particulates from a car equipped with a catalyst (regulated car), as compared with that from an unregulated car, was reduced very much (down to 500 from 4500 revertants/plate/m3 in tester strain TA98). However, the mutagenicity of the ether-soluble acid and neutral fractions from the condensed water of emissions from a regulated car was still high (down to 2880 from 10 900 revertants/plate/m3 in tester strain TA100). The mutagenic activity of emission exhaust from old diesel car engines was very high; the particulates showed 9140 and 19 600 revertants/plate/m3 from strain TA98 incubated with an activating rat-liver S9 fraction. A small diesel engine of the type used for the generation of electric power or in farm machinery also produced exhaust with highly mutagenic particulates. The mutagenic activity of a methanol extract of particulate air pollutants collected in a highway tunnel showed 39 revertants/plate/m3 toward strain TA98 and 87 toward strain TA100. The ether-soluble neutral fraction yielded 86 revertants/plate/m3 from strain TA98 and 100 from strain TA100. This fraction also contained carcinogenic compounds, including benzo[a]pyrene, benzo[e]pyrene, benz[a]anthracene, benzo[ghi]perylene and chrysene. Very high mutagenic activity was detected, especially in the particulate air pollutants collected at night, in another tunnel on a superhighway: 60-88 revertants/plate/m3 from strain TA100 for the sample collected by day, but 121-238, by night. Night traffic includes many more diesel-powered vehicles compared with gasoline-powered automobiles.

  9. Influence of in-tunnel environment to in-bus air quality and thermal condition in Hong Kong.

    PubMed

    Mui, K W; Shek, K W

    2005-07-15

    In this study, the potential exposure of bus commuters to significant air parameters (CO(2), CO and RSP) and thermal environment (air temperature and relative humidity) when buses traveled through tunnels in Hong Kong was investigated. It was found that air-conditioned buses provided a better commuting environment than non-air-conditioned buses. The blate increasing trend was found on air-conditioned buses as the in-bus air parameters concentration levels rose slowly throughout the traveling process. In contrast, the in-bus environment varied rapidly on non-air-conditioned buses as it depended on the out-bus environment. The measured in-bus CO concentration was 2.9 ppm on air-conditioned buses, while it was 4.6 ppm (even reaching the highest level at 12.0 ppm) on non-air-conditioned buses. Considering the in-bus thermal environment, air-conditioned buses provided thermally comfortable cabins (about 24 degrees C and 59% of relative humidity). However, on non-air-conditioned buses, the thermal environment varied with the out-bus environment. The mean in-bus air temperature was about 34 degrees C and 66% of relative humidity, and the in-bus air temperature varied between 29 and 38 degrees C. Also, the lower-deck to upper-deck air parameters concentration ratios indicated that the vertical dispersion of air pollutants in tunnels influenced non-air-conditioned buses as higher air parameters concentration levels were obtained on the lower-deck cabins.

  10. Air pollution from aircraft. [jet exhaust - aircraft fuels/combustion efficiency

    NASA Technical Reports Server (NTRS)

    Heywood, J. B.; Chigier, N. A.

    1975-01-01

    A model which predicts nitric oxide and carbon monoxide emissions from a swirl can modular combustor is discussed. A detailed analysis of the turbulent fuel-air mixing process in the swirl can module wake region is reviewed. Hot wire anemometry was employed, and gas sampling analysis of fuel combustion emissions were performed.

  11. Personal exposure to JP-8 jet fuel vapors and exhaust at air force bases.

    PubMed Central

    Pleil, J D; Smith, L B; Zelnick, S D

    2000-01-01

    JP-8 jet fuel (similar to commercial/international jet A-1 fuel) is the standard military fuel for all types of vehicles, including the U.S. Air Force aircraft inventory. As such, JP-8 presents the most common chemical exposure in the Air Force, particularly for flight and ground crew personnel during preflight operations and for maintenance personnel performing routine tasks. Personal exposure at an Air Force base occurs through occupational exposure for personnel involved with fuel and aircraft handling and/or through incidental exposure, primarily through inhalation of ambient fuel vapors. Because JP-8 is less volatile than its predecessor fuel (JP-4), contact with liquid fuel on skin and clothing may result in prolonged exposure. The slowly evaporating JP-8 fuel tends to linger on exposed personnel during their interaction with their previously unexposed colleagues. To begin to assess the relative exposures, we made ambient air measurements and used recently developed methods for collecting exhaled breath in special containers. We then analyzed for certain volatile marker compounds for JP-8, as well as for some aromatic hydrocarbons (especially benzene) that are related to long-term health risks. Ambient samples were collected by using compact, battery-operated, personal whole-air samplers that have recently been developed as commercial products; breath samples were collected using our single-breath canister method that uses 1-L canisters fitted with valves and small disposable breathing tubes. We collected breath samples from various groups of Air Force personnel and found a demonstrable JP-8 exposure for all subjects, ranging from slight elevations as compared to a control cohort to > 100 [mutilpe] the control values. This work suggests that further studies should be performed on specific issues to obtain pertinent exposure data. The data can be applied to assessments of health outcomes and to recommendations for changes in the use of personal protective

  12. Wind tunnel experiments: cold-air pooling and atmospheric decoupling above a melting snow patch

    NASA Astrophysics Data System (ADS)

    Mott, R.; Paterna, E.; Horender, S.; Crivelli, P.; Lehning, M.

    2015-10-01

    The longevity of perennial snow fields is not fully understood but it is known that strong atmospheric stability and thus boundary layer decoupling limits the amount of (sensible and latent) heat that can be transmitted to the snow surface. The strong stability is typically caused by two factors, (i) the temperature difference between the (melting) snow surface and the near-surface atmosphere and (ii) cold-air pooling in topographic depressions. These factors are almost always a prerequisite for perennial snow fields to exist. For the first time, this contribution investigates the relative importance of the two factors in a controlled wind tunnel environment. Vertical profiles of sensible heat fluxes are measured using two-component hot wire and one-component cold-wire anemometry directly over the melting snow patch. The comparison between a flat snow surface and one that has a depression shows that atmospheric decoupling is strongly increased in the case of topographic sheltering but only for low to moderate wind speeds. For those conditions, the near-surface suppression of turbulent mixing was observed to be strongest and drainage flows were decoupled from the surface enhancing atmospheric stability and promoting the cold-air pooling over the single snow patch. Further work is required to systematically and quantitatively describe the flux distribution for varying terrain geometry, wind speeds and air temperatures.

  13. Wind-Tunnel Investigation of Air Inlet and Outlet Openings on a Streamline Body

    NASA Technical Reports Server (NTRS)

    Becker, John V

    1951-01-01

    In connection with the general problem of providing air flow to an aircraft power plant located within a fuselage, an investigation was conducted in the Langley 8-foot high-speed tunnel to determine the effect on external drag and pressure distribution of air inlet openings located at the nose of a streamline body. Air outlet openings located at the tail and at the 21-percent and 63-percent stations of the body were also investigated. Boundary layer transition measurements were made and correlated with the force and the pressure data. Individual openings were investigated with the aid of a blower and then practicable combinations of inlet and outlet openings were tested. Various modifications to the internal duct shape near the inlet opening and the aerodynamic effects of a simulated gun in the duct were also studied. The results of the tests suggested that outlet openings should be designed so that the static pressure of the internal flow at the outlet would be the same as the static pressure of the external flow in the vicinity of the opening.

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

    SciTech Connect

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

    1994-12-01

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

  15. 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.

  16. 3-Nitrobenzanthrone, a potential human cancer hazard in diesel exhaust and urban air pollution: a review of the evidence.

    PubMed

    Arlt, Volker M

    2005-11-01

    Epidemiological studies have shown that exposure to diesel exhaust and urban air pollution is associated with an increased risk of lung cancer. 3-Nitrobenzanthrone [3-nitro-7H-benz[de]anthracen-7-one (3-NBA)] is an extremely potent mutagen and suspected human carcinogen identified in diesel exhaust and ambient air particulate matter. The main metabolite of 3-NBA, 3-aminobenzanthrone (3-ABA), was found in the urine of salt mine workers occupationally exposed to diesel emissions, indicating that human exposure to 3-NBA due to diesel emissions can be significant and is detectable. There is clear evidence that 3-NBA is a genotoxic mutagen forming DNA adducts after metabolic activation through simple reduction of the nitro group. Several human enzymes have been shown to activate 3-NBA and its metabolites in vitro and in cells to form electrophilic arylnitrenium and rearranged carbenium ions, leading to the formation of purine adducts at the C8 and N2 position of guanine and at the C8 and N6 position of adenine. The predominant DNA adducts in vivo, 2-(2'-deoxyguanosin-N2-yl)-3-aminobenzanthrone and N-(2'-deoxyguanosin-8-yl)-3-aminobenzanthrone are also the most persistent adducts in target tissue in rodents, and are most probably responsible for the induction of GC-->TA transversion mutations observed in vivo. It is concluded that these adducts not only represent premutagenic lesions in DNA but are of primary importance for the initiation of the carcinogenic process and subsequent tumour formation in target tissue. Indeed, 3-NBA is carcinogenic in rats after intratracheal instillation, inducing mainly squamous cell carcinoma in lung. The intention of this article is to provide a critical review on the potential genotoxic effects of 3-NBA on human health. However, in general, there is a need for more mechanistic studies that relate 3-NBA to all processes that are considered to orchestrate tumour development and of studies on the ability of particles to promote 3-NBA

  17. Optimization of operating conditions in tunnel drying of food

    SciTech Connect

    Dong Sun Lee . Dept. of Food Engineering); Yu Ryang Pyun . Dept. of Food Engineering)

    1993-01-01

    A food drying process in a tunnel dryer was modeled from Keey's drying model and experimental drying curve, and optimized in operating conditions consisting of inlet air temperature, air recycle ratio and air flow rate. Radish was chosen as a typical food material to be dried, because it has the typical drying characteristics of food and quality indexes of ascorbic acid destruction and browning during drying. Optimization results of cocurrent and counter current tunnel drying showed higher inlet air temperature, lower recycle ratio and higher air flow rate with shorter total drying time. Compared with cocurrent operation counter current drying used lower air temperature, lower recycle ratio and lower air flow rate, and appeared to be more efficient in energy usage. Most of consumed energy was shown to be used for sir heating and then escaped from the dryer in the form of exhaust air.

  18. Unit for combustion of process exhaust gas and production of hot air

    SciTech Connect

    Andersson, J.O.; Eriksson, T.L.; Nystrom, O.

    1982-12-07

    Unit for thermal incineration of non-explosive gases with minor amounts of organic pollutants and for production of hot air, and which can be adapted to various types of supplementary fuel. There is a combustion chamber which consists of a flame pipe inside an outer jacket. Through the space therebetween, incoming process gas is led as coolant. At its front end, the combustion chamber has a burner for supplementary fuel and a mixing-in zone for process gas. The process gas rapidly mixes with the hot combustion gases in the flame, the gas reaching its reaction temperature directly. Powerful turbulence in the mixing-in zone gas, film-layer cooling, convective cooling and even flow give highly efficient and pure combustion while keeping the flame pipe temperature low enough to prevent corrosion.

  19. Tables of the Thermodynamic Properties of Air and the Exhaust Gas from a Turbine Engine

    DTIC Science & Technology

    1976-03-01

    0 .010 0 .020 0 .030 0 ,040 O.OSO 0 ,060 144.1969 144,4135 145.1259 145,8~45 146.S097 147,1819 147,8413 146.5966 146.8202 147 ,$554 148.7763 14R...g~ PRESSURE • O*S - 6 0 0 ( P S I A ) TEMPERATURE I FUEL/AIR RATIO DEGREES R 0.005 O.OOT 1680,0 ~19.R979 4~0.7917 1690.0 4~Z.~ 147 4 Z 3 . 5 1...1 2 7 . 6 0 7 9 1156.3711 lll~.~90 llJ~.0~ St 11~s.~3rE- 1116.3967 1136.5581 1166.8736 ll~0.591b ll~l.0~ II~9.2~10 1 1 2 6 . 8 1 6 0 I 1 6 5 . 6

  20. Modelling the effect of air exchange on 222Rn and its progeny concentration in a tunnel atmosphere.

    PubMed

    Perrier, Frédéric; Richon, Patrick; Sabroux, Jean-Christophe

    2005-11-01

    The effect of air exchange on the concentration of 222Rn and its progeny in the atmosphere of the Roselend tunnel, in the French Alps, is estimated using a box modelling scheme. In this scheme, the atmosphere is divided into a small number of well mixed zones, separated by flow restricted interfaces, characterized by their exchange rate. A four-box model, representing the three sections of the tunnel present until 2001 and an adjacent inner room, accounts for the spatial variations of the background 222Rn concentration, and for the time structure of transient bursts observed regularly in this tunnel since 1995. A delay of the order of one day, observed during some transient bursts in the inner room with respect to the end of the tunnel, is accounted for if the bursts are assumed to be mainly generated in the end section of the tunnel, and stored temporarily in the inner room via air exchange. The measured radon concentration is reproduced by this model for an air exchange rate of 1.6x10(-6) s-1 between the room and the tunnel, in a context of a global ventilation rate of 10(-5) s-1 in the tunnel. Gradual onset and decay phases, varying from burst to burst, are also suggested. The equilibrium factor of 222Rn with its progeny, measured in 2002 with values varying from 0.60+/-0.05 to 0.78+/-0.06, is interpreted with a five-box model representing the five sections of the tunnel present after 2001. This model indicates that the equilibrium factor does not provide additional constraints on the air exchange rates, but the value of the deposition rate of the unattached short-lived radon progeny can be inferred, with results varying from 0.2 to 6 h-1 in the various sections. This study illustrates the benefits of a simple modelling tool to evaluate the effect of natural ventilation on 222Rn and its progeny concentration in underground cavities, which is important for radioprotection and for a reliable characterization of signatures of hydrogeological or geodynamical

  1. Wind and water tunnel testing of a morphing aquatic micro air vehicle.

    PubMed

    Siddall, Robert; Ortega Ancel, Alejandro; Kovač, Mirko

    2017-02-06

    Aerial robots capable of locomotion in both air and water would enable novel mission profiles in complex environments, such as water sampling after floods or underwater structural inspections. The design of such a vehicle is challenging because it implies significant propulsive and structural design trade-offs for operation in both fluids. In this paper, we present a unique Aquatic Micro Air Vehicle (AquaMAV), which uses a reconfigurable wing to dive into the water from flight, inspired by the plunge diving strategy of water diving birds in the family Sulidae. The vehicle's performance is investigated in wind and water tunnel experiments, from which we develop a planar trajectory model. This model is used to predict the dive behaviour of the AquaMAV, and investigate the efficacy of passive dives initiated by wing folding as a means of water entry. The paper also includes first field tests of the AquaMAV prototype where the folding wings are used to initiate a plunge dive.

  2. Repair of Corrosion in Air Supply Piping at the NASA Glenn Research Center's 1 by 1 Foot Supersonic Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Henry, Michael

    2000-01-01

    During a test at the NASA Glenn Research Center's 1 x 1 Supersonic Wing Tunnel, it was discovered that particles entrained in the air flow were damaging the pressure sensitive paint on a test article. An investigation found the source of the entrained particles to be rust on the internal surfaces of the air supply piping. To remedy the situation, the air supply line components made from carbon steel were either refurbished or replaced with new stainless steel components. The refurbishment process included various combinations of chemical cleaning, bead blasting, painting and plating.

  3. Hanford Site radionuclide national emission standards for hazardous air pollutants unregistered stack (power exhaust) source assessment

    SciTech Connect

    Davis, W.E.

    1994-08-04

    On February 3, 1993, the US Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency, Region 10. The Compliance Order requires the Richland Operations Office to evaluate all radionuclide emission points at the Hanford Site to determine which are subject to continuous emission measurement requirements in 40 Code of Federal Regulations (CFR) 61, Subpart H, and to continuously measure radionuclide emissions in accordance with 40 CFR 61.93. This evaluation provides an assessment of the 39 unregistered stacks, under Westinghouse Hanford Company`s management, and their potential radionuclide emissions, i.e., emissions with no control devices in place. The evaluation also determined if the effective dose equivalent from any of these stack emissions exceeded 0.1 mrem/yr, which will require the stack to have continuous monitoring. The result of this assessment identified three stacks, 107-N, 296-P-26 and 296-P-28, as having potential emissions that would cause an effective dose equivalent greater than 0.1 mrem/yr. These stacks, as noted by 40 CFR 61.93, would require continuous monitoring.

  4. Evaluation of In Vitro Cytoxicity and Genotoxicity of Size-Fractionated Air Particles Sampled during Road Tunnel Construction

    PubMed Central

    Dominici, Luca; Guerrera, Elena; Villarini, Milena; Fatigoni, Cristina; Moretti, Massimo; Blasi, Paolo; Monarca, Silvano

    2013-01-01

    In tunnel construction, workers exposed to dust from blasting, gases, diesel exhausts, and oil mist have shown higher risk for pulmonary diseases. A clear mechanism to explain how these pollutants determine diseases is lacking, and alveolar epithelium's capacity to ingest inhaled fine particles is not well characterized. The objective of this study was to assess the genotoxic effect exerted by fine particles collected in seven tunnels using the cytokinesis-block micronuclei test in an in vitro model on type II lung epithelium A549 cells. For each tunnel, five fractions with different aerodynamic diameters of particulate matter were collected with a multistage cascade sampler. The human epithelial cell line A549 was exposed to 0.2 m3/mL equivalent of particulate for 24 h before testing. The cytotoxic effects of particulate matter on A549 cells were also evaluated in two different viability tests. In order to evaluate the cells' ability to take up fine particles, imaging with transmission electron microscopy of cells after exposure to particulate matter was performed. Particle endocytosis after 24 h exposure was observed as intracellular aggregates of membrane-bound particles. This morphologic evidence did not correspond to an increase in genotoxicity detected by the micronucleus test. PMID:24069598

  5. Air quality and ventilation fan control based on aerosol measurement in the bi-directional undersea Bømlafjord tunnel.

    PubMed

    Indrehus, Oddny; Aralt, Tor Tybring

    2005-04-01

    Aerosol, NO and CO concentration, temperature, air humidity, air flow and number of running ventilation fans were measured by continuous analysers every minute for a whole week for six different one-week periods spread over ten months in 2001 and 2002 at measuring stations in the 7860 m long tunnel. The ventilation control system was mainly based on aerosol measurements taken by optical scatter sensors. The ventilation turned out to be satisfactory according to Norwegian air quality standards for road tunnels; however, there was some uncertainty concerning the NO2 levels. The air humidity and temperature inside the tunnel were highly influenced by the outside metrological conditions. Statistical models for NO concentration were developed and tested; correlations between predicted and measured NO were 0.81 for a partial least squares regression (PLS1) model based on CO and aerosol, and 0.77 for a linear regression model based only on aerosol. Hence, the ventilation control system should not solely be based on aerosol measurements. Since NO2 is the hazardous polluter, modelling NO2 concentration rather than NO should be preferred in any further optimising of the ventilation control.

  6. 40 CFR 1065.130 - Engine exhaust.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... exhaust tubing that has either a wall thickness of less than 2 mm or is air gap-insulated to minimize... balance of fuel, intake air, and exhaust according to § 1065.655 to verify exhaust system integrity....

  7. 40 CFR 1065.130 - Engine exhaust.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... exhaust tubing that has either a wall thickness of less than 2 mm or is air gap-insulated to minimize... balance of fuel, intake air, and exhaust according to § 1065.655 to verify exhaust system integrity....

  8. 40 CFR 1065.130 - Engine exhaust.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... exhaust tubing that has either a wall thickness of less than 2 mm or is air gap-insulated to minimize..., intake air, and exhaust according to § 1065.655 to verify exhaust system integrity. (f)...

  9. 40 CFR 1065.130 - Engine exhaust.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ....130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... exhaust tubing that has either a wall thickness of less than 2 mm or is air gap-insulated to minimize... balance of fuel, intake air, and exhaust according to § 1065.655 to verify exhaust system integrity....

  10. 40 CFR 1065.130 - Engine exhaust.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS... exhaust tubing that has either a wall thickness of less than 2 mm or is air gap-insulated to minimize... balance of fuel, intake air, and exhaust according to § 1065.655 to verify exhaust system integrity....

  11. Comparison of pressurized fluid extraction, Soxhlet extraction and sonication for the determination of polycyclic aromatic hydrocarbons in urban air and diesel exhaust particulate matter.

    PubMed

    Rynö, M; Rantanen, L; Papaioannou, E; Konstandopoulos, A G; Koskentalo, T; Savela, K

    2006-04-01

    In order to characterize and compare the chemical composition of diesel particulate matter and ambient air samples collected on filters, different extraction procedures were tested and their extraction efficiencies and recoveries determined. This study is an evaluation of extraction methods using the standard 16 EPA PAHs with HPLC fluorescence analysis. Including LC analysis also GC and MS methods for the determination of PAHs can be used. Soxhlet extraction was compared with ultrasonic agitation and pressurized fluid extraction (PFE) using three solvents to extract PAHs from diesel exhaust and urban air particulates. The selected PAH compounds of soluble organic fractions were analyzed by HPLC with a multiple wavelength shift fluorescence detector. The EPA standard mixture of 16 PAH compounds was used as a standard to identify and quantify diesel exhaust-derived PAHs. The most effective extraction method of those tested was pressurized fluid extraction using dichloromethane as a solvent.

  12. Overestimation of on-road air quality surveying data measured with a mobile laboratory caused by exhaust plumes of a vehicle ahead in dense traffic areas.

    PubMed

    Woo, Sang-Hee; Kwak, Kyung-Hwan; Bae, Gwi-Nam; Kim, Kyung Hwan; Kim, Chang Hyeok; Yook, Se-Jin; Jeon, Sangzin; Kwon, Sangil; Kim, Jeongsoo; Lee, Seung-Bok

    2016-11-01

    The unintended influence of exhaust plumes emitted from a vehicle ahead to on-road air quality surveying data measured with a mobile laboratory (ML) at 20-40 km h(-1) in dense traffic areas was investigated by experiment and life-sized computational fluidic dynamics (CFD) simulation. The ML equipped with variable sampling inlets of five columns by four rows was used to measure the spatial distribution of CO2 and NOx concentrations when following 5-20 m behind a sport utility vehicle (SUV) as an emitter vehicle equipped with a portable emission monitoring system (PEMS). The PEMS measured exhaust gases at the tailpipe for input data of the CFD simulations. After the CFD method was verified with experimental results of the SUV, dispersion of exhaust plumes emitted from a bus and a sedan was numerically analyzed. More dilution of the exhaust plume was observed at higher vehicle speeds, probably because of eddy diffusion that was proportional to turbulent kinetic energy and vehicle speed. The CO2 and NOx concentrations behind the emitter vehicle showed less overestimation as both the distance between the two vehicles and their background concentrations increased. If the height of the ML inlet is lower than 2 m and the ML travels within 20 m behind a SUV and a sedan ahead at 20 km h(-1), the overestimation should be considered by as much as 200 ppb in NOx and 80 ppm in CO2. Following a bus should be avoided if possible, because effect of exhaust plumes from a bus ahead could not be negligible even when the distance between the bus and the ML with the inlet height of 2 m, was more than 40 m. Recommendations are provided to avoid the unintended influence of exhaust plumes from vehicles ahead of the ML during on-road measurement in urban dense traffic conditions.

  13. Wind tunnel experiments: cold-air pooling and atmospheric decoupling above a melting snow patch

    NASA Astrophysics Data System (ADS)

    Mott, Rebecca; Paterna, Enrico; Horender, Stefan; Crivelli, Philip; Lehning, Michael

    2016-02-01

    The longevity of perennial snowfields is not fully understood, but it is known that strong atmospheric stability and thus boundary-layer decoupling limit the amount of (sensible and latent) heat that can be transmitted from the atmosphere to the snow surface. The strong stability is typically caused by two factors, (i) the temperature difference between the (melting) snow surface and the near-surface atmosphere and (ii) cold-air pooling in topographic depressions. These factors are almost always a prerequisite for perennial snowfields to exist. For the first time, this contribution investigates the relative importance of the two factors in a controlled wind tunnel environment. Vertical profiles of sensible heat and momentum fluxes are measured using two-component hot-wire and one-component cold-wire anemometry directly over the melting snow patch. The comparison between a flat snow surface and one that has a depression shows that atmospheric decoupling is strongly increased in the case of topographic sheltering but only for low to moderate wind speeds. For those conditions, the near-surface suppression of turbulent mixing was observed to be strongest, and the ambient flow was decoupled from the surface, enhancing near-surface atmospheric stability over the single snow patch.

  14. Electrochemical Nanolithography on Amorphous WO3 Thin Films Using Scanning Tunneling Microscope in Air

    NASA Astrophysics Data System (ADS)

    Qiu, Hong; Lu, Yong-Feng; Mai, Zhi-Hong

    2001-11-01

    Tungsten oxide (WO3) thin films have shown interesting properties as lithography resist materials. In this study, the scanning tunneling microscope (STM) was used in air for nanometer etching of α-WO3-x thin films, an n-type semiconductor. The current-voltage (I-V) curve was found to be affected by the water layer absorbed on the surface. For low voltage (< 3 V) with long duration (˜ 10 s) or high voltage pulse (> 3 V) with short pulsewidth (˜ 200 ms), holes were formed on the film surface at high humidity (> 70%) by applying a pulse voltage. A threshold voltage existed for hole formation. Higher pulse voltage and negative polarity corresponded to larger modified size. All the structures formed in STM images were topographical in nature by comparison with the AFM images. The hole formation was reasonably attributed to electrochemistry and high dissolution of WO3 in high pH solutions, which was co-manifested by links between the holes and eroded materials on the surface. Alkaline solutions instead of deionized water were chosen to act in the tip-surface gap. Alkaline ions being expelled from the tip due to electric polarity demonstrated the ion movement and their effect on etching. Lines of nanometer width were fabricated.

  15. Radioactive air emissions notice of construction use of a portable exhauster on single shell tanks (SSTs) during salt well pumping

    SciTech Connect

    GRANDO, C.J.

    1999-11-18

    This document serves as a notice of construction (NOC), pursuant to the requirements of Washington Administrative Code (WAC) 246-247-060, and as a request for approval to construct, pursuant to 40 Code of Federal Regulations (CFR) 61.07, portable exhausters for use on single-shell tanks (SSTs) during salt well pumping. Table 1-1 lists 18 SSTs covered by this NOC. This NOC also addresses other activities that are performed in support of salt well pumping but do not require the application of a portable exhauster. Specifically this NOC analyzes the following three activities that have the potential for emissions. (1) Salt well pumping (i.e., the actual transferring of waste from one tank to another) under nominal tank operating conditions. Nominal tank operating conditions include existing passive breathing rates. (2) Salt well pumping (the actual transferring of waste from one tank to another) with use of a portable exhauster. (3) Use of a water lance on the waste to facilitate salt well screen and salt well jet pump installation into the waste. This activity is to be performed under nominal (existing passive breathing rates) tank operating conditions. The use of portable exhausters represents a cost savings because one portable exhauster can be moved back and forth between SSTs as schedules for salt well pumping dictate. A portable exhauster also could be used to simultaneously exhaust more than one SST during salt well pumping.

  16. Simulation of hypersonic scramjet exhaust. [pressure distribution on afterbody/nozzle sections of vehicle

    NASA Technical Reports Server (NTRS)

    Oman, R. A.; Foreman, K. M.; Leng, J.; Hopkins, H. B.

    1975-01-01

    A plan and some preliminary analysis for the accurate simulation of pressure distributions on the afterbody/nozzle portions of a hypersonic scramjet vehicle are described. The objectives fulfilled were to establish the standards of similitude for a hydrogen/air scramjet exhaust interacting with a vehicle afterbody, determine an experimental technique for validation of the procedures that will be used in conventional wind tunnel facilities, suggest a program of experiments for proof of the concept, and explore any unresolved problems in the proposed simulation procedures. It is shown that true enthalpy, Reynolds number, and nearly exact chemistry can be provided in the exhaust flow for the flight regime from Mach 4 to 10 by a detonation tube simulation. A detailed discussion of the required similarity parameters leads to the conclusion that substitute gases can be used as the simulated exhaust gas in a wind tunnel to achieve the correct interaction forces and moments.

  17. Effect of air temperature and relative humidity at various fuel-air ratios on exhaust emissions on a per-mode basis of an Avco Lycoming 0-320 DIAD light aircraft engine. Volume 2: Individual data points

    NASA Technical Reports Server (NTRS)

    Skorobatckyi, M.; Cosgrove, D. V.; Meng, P. R.; Kempke, E. R.

    1976-01-01

    A carbureted four cylinder air cooled 0-320 DIAD Lycoming aircraft engine was tested to establish the effects of air temperature and humidity at various fuel-air ratios on the exhaust emissions on a per-mode basis. The test conditions included carburetor lean-out at air temperatures of 50, 59, 80, and 100 F at relative humidities of 0, 30, 60, and 80 percent. Temperature-humidity effects at the higher values of air temperature and relative humidity tested indicated that the HC and CO emissions increased significantly, while the NOx emissions decreased. Even at a fixed fuel-air ratio, the HC emissions increase and the NOx emissions decrease at the higher values of air temperature and humidity. Volume II contains the data taken at each of the individual test points.

  18. Scanning Tunneling Microscopy and Spectroscopy of Air Exposure Effects on Molecular Beam Epitaxy Grown WSe2 Monolayers and Bilayers.

    PubMed

    Park, Jun Hong; Vishwanath, Suresh; Liu, Xinyu; Zhou, Huawei; Eichfeld, Sarah M; Fullerton-Shirey, Susan K; Robinson, Joshua A; Feenstra, Randall M; Furdyna, Jacek; Jena, Debdeep; Xing, Huili Grace; Kummel, Andrew C

    2016-04-26

    The effect of air exposure on 2H-WSe2/HOPG is determined via scanning tunneling microscopy (STM). WSe2 was grown by molecular beam epitaxy on highly oriented pyrolytic graphite (HOPG), and afterward, a Se adlayer was deposited in situ on WSe2/HOPG to prevent unintentional oxidation during transferring from the growth chamber to the STM chamber. After annealing at 773 K to remove the Se adlayer, STM images show that WSe2 layers nucleate at both step edges and terraces of the HOPG. Exposure to air for 1 week and 9 weeks caused air-induced adsorbates to be deposited on the WSe2 surface; however, the band gap of the terraces remained unaffected and nearly identical to those on decapped WSe2. The air-induced adsorbates can be removed by annealing at 523 K. In contrast to WSe2 terraces, air exposure caused the edges of the WSe2 to oxidize and form protrusions, resulting in a larger band gap in the scanning tunneling spectra compared to the terraces of air-exposed WSe2 monolayers. The preferential oxidation at the WSe2 edges compared to the terraces is likely the result of dangling edge bonds. In the absence of air exposure, the dangling edge bonds had a smaller band gap compared to the terraces and a shift of about 0.73 eV in the Fermi level toward the valence band. However, after air exposure, the band gap of the oxidized WSe2 edges became about 1.08 eV larger than that of the WSe2 terraces, resulting in the electronic passivation of the WSe2.

  19. Experimental Investigation of Project Orion Crew Exploration Vehicle Aeroheating: LaRC 20-Inch Mach 6 Air Tunnel Test 6931

    NASA Technical Reports Server (NTRS)

    Hollis, Brian R.

    2009-01-01

    An investigation of the aeroheating environment of the Project Orion Crew Entry Vehicle has been performed in the Langley Research Center 20-Inch Mach 6 Air Tunnel. Data were measured on a approx.3.5% scale model (0.1778-m/7-inch diameter) of the vehicle using coaxial thermocouples at free stream Reynolds numbers of 2.0 10(exp 6)/ft to 7.30 10(exp 6)/ft and computational predictions were generated for all test conditions. The primary goals of this test were to obtain convective heating data for use in assessing the accuracy of the computational technique and to validate test methodology and heating data from a test of the same wind tunnel model in the Arnold Engineering Development Center Tunnel 9. Secondary goals were to determine the extent of transitional/turbulent data which could be produced on a CEV model in this facility, either with or without boundary-layer trips, and to demonstrate continuous pitch-sweep operation in this tunnel for heat transfer testing.

  20. Tank exhaust comparison with 40 CFR 61.93, Subpart H, and other referenced guidelines for Tank Farms National Emission Standards for Hazardous Air Pollutant (NESHAP) designated stacks

    SciTech Connect

    Bachand, D.D.; Crummel, G.M.

    1994-07-01

    The US Environmental Protection Agency (EPA) promulgated National Emission Standards other than Radon from US Department of Energy (DOE) Facilities (40 CFR 61, Subpart H) on December 15, 1989. The regulations specify procedures, equipment, and test methods that.are to be used to measure radionuclide emissions from exhaust stacks that are designated as National Emission Standards for Hazardous Air Pollutant (NESHAP) stacks. Designated NESHAP stacks are those that have the potential to cause any member of the public to receive an effective dose equivalent (EDE) greater than or equal to 0.1 mrem/year, assuming all emission controls were removed. Tank Farms currently has 33 exhaust stacks, 15 of which are designated NESHAP stacks. This document assesses the compliance status of the monitoring and sampling systems for the designated NESHAP stacks.

  1. Radioactive air emissions notice of construction for deactivation of the PUREX storage tunnel number 2

    SciTech Connect

    JOHNSON, R.E.

    1999-10-11

    The Plutonium-Uranium Extraction (PUREX) Plant Storage Tunnel Number 2 (hereafter referred to as the PUREX Tunnel) was built in 1964. Since that time, the PUREX Tunnel has been used for storage of radioactive and mixed waste. In 1991, the PUREX Plant ceased operations and was transitioned to deactivation. The PUREX Tunnel continued to receive PUREX Plant waste material for storage during transition activities. Before 1995, a decision was made to store radioactive and mixed waste in the PUREX Tunnel generated from other onsite sources, on a case-by-case basis. This notice of construction (NOC) describes the activities associated with the reactivation of the PUREX Tunnel ventilation system and the transfer of up to 3.5 million curies (MCi) of radioactive waste to the PUREX Tunnel from any location on the Hanford Site. The unabated total effective dose equivalent (TEDE) estimated for the hypothetical offsite maximally exposed individual (MEI) is 5.6 E-2 millirem (mrem). The abated TEDE conservatively is estimated to account for 1.9 E-5 mrem to the MEI. The following text provides information requirements of Appendix A of Washington Administrative Code (WAC) 246-247 (requirements 1 through 18).

  2. A lumped parameter mathematical model for simulation of subsonic wind tunnels

    NASA Technical Reports Server (NTRS)

    Krosel, S. M.; Cole, G. L.; Bruton, W. M.; Szuch, J. R.

    1986-01-01

    Equations for a lumped parameter mathematical model of a subsonic wind tunnel circuit are presented. The equation state variables are internal energy, density, and mass flow rate. The circuit model is structured to allow for integration and analysis of tunnel subsystem models which provide functions such as control of altitude pressure and temperature. Thus the model provides a useful tool for investigating the transient behavior of the tunnel and control requirements. The model was applied to the proposed NASA Lewis Altitude Wind Tunnel (AWT) circuit and included transfer function representations of the tunnel supply/exhaust air and refrigeration subsystems. Both steady state and frequency response data are presented for the circuit model indicating the type of results and accuracy that can be expected from the model. Transient data for closed loop control of the tunnel and its subsystems are also presented, demonstrating the model's use as a control analysis tool.

  3. Recent advances in investigations of toxicity of automotive exhaust.

    PubMed

    Stupfel, M

    1976-10-01

    The influence of auto exhaust on man's health is difficult to gauge considering the intricacy of human environmental urban stresses and particularly of other air polluting (industrial, domestic) emissions. Epidemiological surveys made in road tunnel employees and in traffic officers have not demonstrated specific effects and have often been complicated by cigarette smoking as a factor. Long-term animal experiments run mostly on small rodents give evidence of little effect of the pathological actions of dilutions such as those encountered in high polluted cities. However the acute toxicity of gasoline exhaust emission is well known and mostly due to carbon monoxide. Considering the different types of cycles and operating conditions of vehicles (gasoline and diesel), auto exhaust gases constitute no more a chemical entity than they show, a definite toxicity. A great number of substances that they contain (nitrogen oxides, aldehydes, antiknock additives, heavy metals, possible catalysts are highly toxic as shown by in vivo and in vitro (mutagenic) tests. Interactions of the components are for the moment ignored or poorly understood. Besides, the evolution of the physicochemical properties and natures of the auto exhaust emission in the gaseous biotope of man under determined conditions of ultraviolet irradiation, temperature, and hygrometry provoke the formation of secondary products such as oxidants and ozone. Several experiments show clearly that irradiation increases the toxicity of auto exhaust significantly. For these reasons, geographical, meteorological, and chronological (circadian and seasonal) factors should be taken into consideration, especially with regard to emission standards.

  4. Recent advances in investigations of toxicity of automotive exhaust

    PubMed Central

    Stupfel, Maurice

    1976-01-01

    The influence of auto exhaust on man's health is difficult to gauge considering the intricacy of human environmental urban stresses and particularly of other air polluting (industrial, domestic) emissions. Epidemiological surveys made in road tunnel employees and in traffic officers have not demonstrated specific effects and have often been complicated by cigarette smoking as a factor. Long-term animal experiments run mostly on small rodents give evidence of little effect of the pathological actions of dilutions such as those encountered in high polluted cities. However the acute toxicity of gasoline exhaust emission is well known and mostly due to carbon monoxide. Considering the different types of cycles and operating conditions of vehicles (gasoline and diesel), auto exhaust gases constitute no more a chemical entity than they show, a definite toxicity. A great number of substances that they contain (nitrogen oxides, aldehydes, antiknock additives, heavy metals, possible catalysts are highly toxic as shown by in vivo and in vitro (mutagenic) tests. Interactions of the components are for the moment ignored or poorly understood. Besides, the evolution of the physicochemical properties and natures of the auto exhaust emission in the gaseous biotope of man under determined conditions of ultraviolet irradiation, temperature, and hygrometry provoke the formation of secondary products such as oxidants and ozone. Several experiments show clearly that irradiation increases the toxicity of auto exhaust significantly. For these reasons, geographical, meteorological, and chronological (circadian and seasonal) factors should be taken into consideration, especially with regard to emission standards. PMID:67944

  5. Performance of the 0.3-meter transonic cryogenic tunnel with air, nitrogen, and sulfur hexafluoride media under closed loop automatic control

    NASA Technical Reports Server (NTRS)

    Balakrishna, S.; Kilgore, W. Allen

    1995-01-01

    The NASA Langley 0.3-m Transonic Cryogenic Tunnel was modified in 1994, to operate with any one of the three test gas media viz., air, cryogenic nitrogen gas, or sulfur hexafluoride gas. This document provides the initial test results with respect to the tunnel performance and tunnel control, as a part of the commissioning activities on the microcomputer based controller. The tunnel can provide precise and stable control of temperature to less than or equal to +/- 0.3 K in the range 80-320 K in cyro mode or 300-320 K in air/SF6 mode, pressure to +/- 0.01 psia in the range 15-88 psia and Mach number to +/- O.0015 in the range 0.150 to transonic Mach numbers up to 1.000. A new heat exchanger has been included in the tunnel circuit and is performing adequately. The tunnel airfoil testing benefits considerably by precise control of tunnel states and helps in generating high quality aerodynamic test data from the 0.3-m TCT.

  6. Air conditioned suit

    NASA Technical Reports Server (NTRS)

    Carl, G. R. (Inventor)

    1973-01-01

    An environmentally controlled suit is described consisting of an airtight outergarment attached by an airtight bellows to the wall of a sterile chamber, an undergarment providing for circulation of air near the skin of the wearer, and a circulation system comprised of air supply and distribution to the extremities of the undegarment and central collection and exhaust of air from the midsection of the undergarment. A workman wearing the undergarment and attached circulation system enters the outer garment through a tunnel in the chamber wall and the attached bellows to work in the chamber without any danger of spreading bacteria.

  7. Wind tunnel evaluation of air-foil performance using simulated ice shapes

    NASA Technical Reports Server (NTRS)

    Bragg, M. B.; Zaguli, R. J.; Gregorek, G. M.

    1982-01-01

    A two-phase wind tunnel test was conducted in the 6 by 9 foot Icing Research Tunnel (IRT) at NASA Lewis Research Center to evaluate the effect of ice on the performance of a full scale general aviation wing. In the first IRT tests, rime and glaze shapes were carefully documented as functions of angle of attack and free stream conditions. Next, simulated ice shapes were constructed for two rime and two glaze shapes and used in the second IRT tunnel entry. The ice shapes and the clean airfoil were tapped to obtain surface pressures and a probe used to measure the wake characteristics. These data were recorded and processed, on-line, with a minicomputer/digital data acquisition system. The effect of both rime and glaze ice on the pressure distribution, Cl, Cd, and Cm are presented.

  8. X-33 (Rev-F) Aeroheating Results of Test 6770 in NASA Langley 20-Inch Mach 6 Air Tunnel

    NASA Technical Reports Server (NTRS)

    Berry, Scott A.; Horvath, Thomas J.; Kowalkowski, Matthew K.; Liechty, Derek S.

    1999-01-01

    Aeroheating characteristics of the X-33 Rev-F configuration have been experimentally examined in the Langley 20-Inch Mach 6 Air Tunnel (Test 6770). Global surface heat transfer distributions, surface streamline patterns, and shock shapes were measured on a 0.013-scale model at Mach 6 in air. Parametric variations include angles-of-attack of 20-deg, 30-deg, and 40-deg; Reynolds numbers based on model length of 0.9 to 4.9 million; and body-flap deflections of 10-deg and 20-deg. The effects of discrete roughness elements on boundary layer transition, which included trip height, size, and location, both on and off the windward centerline, were investigated. This document is intended to serve as a quick release of preliminary data to the X-33 program; analysis is limited to observations of the experimental trends in order to expedite dissemination.

  9. Measured performance of the heat exchanger in the NASA icing research tunnel under severe icing and dry-air conditions

    NASA Technical Reports Server (NTRS)

    Olsen, W.; Vanfossen, J.; Nussle, R.

    1987-01-01

    Measurements were made of the pressure drop and thermal perfomance of the unique refrigeration heat exchanger in the NASA Lewis Icing Research Tunnel (IRT) under severe icing and frosting conditions and also with dry air. This data will be useful to those planning to use or extend the capability of the IRT and other icing facilities (e.g., the Altitude Wind Tunnel-AWT). The IRT heat exchanger and refrigeration system is able to cool air passing through the test section down to at least a total temperature of -30 C (well below icing requirements), and usually up to -2 C. The system maintains a uniform temperature across the test section at all airspeeds, which is more difficult and time consuming at low airspeeds, at high temperatures, and on hot, humid days when the cooling towers are less efficient. The very small surfaces of the heat exchanger prevent any icing cloud droplets from passing through it and going through the tests section again. The IRT heat exchanger was originally designed not to be adversely affected by severe icing. During a worst-case icing test the heat exchanger iced up enough so that the temperature uniformaity was no worse than about +/- 1 deg C. The conclusion is that the heat exchanger design performs well.

  10. ANALYSIS OF MOTOR VEHICLE EMISSIONS IN A HOUSTON TUNNEL DURING THE TEXAS AIR QUALITY STUDY 2000

    EPA Science Inventory

    Measurements from a Houston tunnel were used to develop fuel consumption based emission factors for CO, NOx, and Non-Methane Organic Compound (NMOC) for on-road gasoline vehicles. The Houston NOx emission factor was at the low range of emission factors reported in previous (pr...

  11. Pitot pressure measurements in flow fields behind circular-arc nozzles with exhaust jets at subsonic free-stream Mach numbers. [langley 16 foot transonic tunnel

    NASA Technical Reports Server (NTRS)

    Mason, M. L.; Putnam, L. E.

    1979-01-01

    The flow field behind a circular arc nozzle with exhaust jet was studied at subsonic free stream Mach numbers. A conical probe was used to measure the pitot pressure in the jet and free stream regions. Pressure data were recorded for two nozzle configurations at nozzle pressure ratios of 2.0, 2.9, and 5.0. At each set of test conditions, the probe was traversed from the jet center line into the free stream region at seven data acquisition stations. The survey began at the nozzle exit and extended downstream at intervals. The pitot pressure data may be applied to the evaluation of computational flow field models, as illustrated by a comparison of the flow field data with results of inviscid jet plume theory.

  12. Investigation at supersonic and subsonic Mach numbers of auxiliary inlets supplying secondary air flow to ejector exhaust nozzles

    NASA Technical Reports Server (NTRS)

    Hearth, Donald P; Cubbison, Robert W

    1956-01-01

    The results indicated increases in auxiliary-inlet pressure recovery with increases in scoop height relative to the boundary-layer thickness. The pressure recovery increased at about the same rate as theoretically predicted for an inlet in a boundary layer having a one-seventh power profile, but was only about 0.68 to 0.75 of the theoretically obtainable values. Under some operating conditions, flow from the primary jet was exhausted through the auxiliary inlet. This phenomenon could be predicted from the ejector pumping characteristics.

  13. Wind-Tunnel Investigation of Air Inlet and Outlet Openings for Aircraft, Special Report

    NASA Technical Reports Server (NTRS)

    Rogallo, Francis M.; Gauvain, William E.

    1938-01-01

    An investigation was made in the NACA 5-foot vertical wind tunnel of a large variety of duct inlets and outlets to obtain information relative to their design for the cooling or the ventilation systems on aircraft. Most of the tests were of openings in a flat plate but, in order to determine the best locations and the effects of interference, a few tests were made of openings in an airfoil. The best inlet location for a system not including a blower was found to be at the forward stagnation point; for one including a blower, the best location was found to be in the region of lowest total head, probably in the boundary layer near the trailing edge. Design recommendations are given, and it is shown that correct design demands a knowledge of the external flow and of the internal requirements in addition to that obtained from the results of the wind tunnel tests.

  14. Review of the Air Force summer study program on the integration of wind tunnels and computers

    NASA Technical Reports Server (NTRS)

    Marschner, B. W.

    1978-01-01

    The present state of computational fluid dynamics and its impact on the design cycle and computer requirements for future developments in this field were explored. The increase in productivity and efficiency which experimental facilities can achieve by a close integration with computers was investigated together with possible improvements in simulation quality of wind tunnels in conjunction with computer control. Research experiments are outlined to provide a better understanding of the physics of fluid flow and to assist in the modeling of these phenomena for computational methods, with primary emphasis on turbulent flows.

  15. Evaluation of dust-related health hazards associated with air coring at G-Tunnel, Nevada Test Site

    SciTech Connect

    Skaggs, B.J.; Ortiz, L.W.; Burton, D.J.; Isom, B.L.; Vigil, E.A.

    1991-03-01

    The Yucca Mountain Project was established to evaluate the potential for storing high-level radioactive wastes in geologic formations. Hydrologists recommended that drilling or coring in support of characterization tests be performed dry. Dry drilling, or air coring, presents a concern about health protection for the drilling personnel. The rock generally has a high silica content, and natural zeolites are abundant. Some zeolites are fibrous, leading to concerns that inhalation may result in asbestos-like lung diseases. An industrial hygiene study (IH) was conducted as part of an air coring technical feasibility test. The IH study found the potential for exposures to airborne silica and nuisance dusts to be within regulatory requirements and determined the commercial dust control equipment monitored to be effective when used in conjunction with a good area ventilation system and sound IH practices. Fibrous zeolites were not detected. Recommendations for the Yucca Mountain studies are (1) dust collection and control equipment equivalent or superior to that monitored must be used for any dry drilling activity and must be used with good general dilution ventilation and local exhaust ventilation provided on major emission sources; (2) good industrial hygiene work practices must be implemented, including monitoring any area where zeolitic fibers are suspect; and (3) a study should be conducted to determine the biological effects of the fibrous zeolite, mordenite. 25 refs., 17 figs., 14 tabs.

  16. In Vitro Exposures in Diesel Exhaust Atmospheres: Resuspension of PM from Filters Verses Direct Deposition of PM from Air

    PubMed Central

    Lichtveld, Kim M.; Ebersviller, Seth M.; Sexton, Kenneth G.; Vizuete, William; Jaspers, Ilona; Jeffries, Harvey E.

    2012-01-01

    One of the most widely used in vitro particulate matter (PM) exposures methods is the collection of PM on filters, followed by resuspension in a liquid medium, with subsequent addition onto a cell culture. To avoid disruption of equilibria between gases and PM, we have developed a direct in vitro sampling and exposure method (DSEM) capable of PM-only exposures. We hypothesize that the separation of phases and post-treatment of filter-collected PM significantly modifies the toxicity of the PM compared to direct deposition, resulting in a distorted view of the potential PM health effects. Controlled test environments were created in a chamber that combined diesel exhaust with an urban-like mixture. The complex mixture was analyzed using both the DSEM and concurrently-collected filter samples. The DSEM showed that PM from test atmospheres produced significant inflammatory response, while the resuspension exposures at the same exposure concentration did not. Increasing the concentration of resuspended PM sixteen times was required to yield measurable IL-8 expression. Chemical analysis of the resuspended PM indicated a total absence of carbonyl compounds compared to the test atmosphere during the direct-exposures. Therefore, collection and resuspension of PM into liquid modifies its toxicity and likely leads to underestimating toxicity. PMID:22834915

  17. Diesel exhaust particles and airway inflammation

    EPA Science Inventory

    Purpose of review. Epidemiologic investigation has associated traffic-related air pollution with adverse human health outcomes. The capacity ofdiesel exhaust particles (DEP), a major emission source air pollution particle, to initiate an airway inflammation has subsequently been ...

  18. Current wind tunnel capability and planned improvements at Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Bowditch, D. N.

    1986-01-01

    As the propulsion and power generation center of NASA, Lewis has designed its wind tunnels for propulsion research. Therefore, the 8 by 6 Foot Supersonic Wind Tunnel and the 10 by 10 Foot Supersonic Wind Tunnel provide the capability to test operating propulsion systems from Mach 0.4 to 3.5. The 9 by 15 Foot Wind Tunnel can investigate propulsion installation problems at the lower takeoff and landing speeds and provides an excellent anechoic environment to measure propeller and fan noise. The Lewis Central Air System provides steady air supplies to 450 psi, and exhaust to 3 in. of mercury absolute, which are available to the wind tunnels for simulation of jets and engine induced flows. The Lewis Icing Research Tunnel is the largest in the free world that can produce icing conditions throughout the year. Rehabilitation of the Altitude Wind Tunnel at Lewis would allow testing of propulsion systems in the upper left hand corner which would be a unique capability. Also, in a mothballed state at Lewis, the Hypersonic Tunnel Facility could provide the best simulation of nonvitiated Mach 5-7 test conditions available. Studies are currently being made of the Lewis facilities to identify enhancements of their research potential for the 1990's and beyond.

  19. Development and application of a three-dimensional Taylor-Galerkin numerical model for an air quality simulation near roadway tunnel portals

    SciTech Connect

    Okamoto, Shin`ichi; Sakai, Kazuhiro; Matsumoto, Koichi

    1996-12-31

    Since highway traffic has become one of the major emission sources of air pollution, air pollution prediction near roadway tunnel portals is a very important subject. Although many models have been suggested to predict pollutant concentrations near roadways, almost all models have been suggested to predict pollutant concentrations near roadways, almost all models can only be applied to at-grade or cut-off straight highways. Therefore, we have developed a numerical model which can be applied to the site near roadway tunnels in complex terrain. The first stage of our study is to make a database of air quality and the meteorological condition near roadway tunnel portals. The second stage is a screening of the wind field models as described in our cooperative paper presented by Kimura et al. The third stage is an evaluation of the numerical schemes for the advection equation, mainly carried out based on the results of the rotating cone problem. In our limited comparative study, the most accurate and high-speed-computing scheme was a Taylor-Galerkin scheme. The three dimensional model based on this scheme, was developed by an operator splitting of locally one dimensional calculations. The final stage is a validation study of the proposed model. The composite model consists of a wind field model, a model for the jet stream from a tunnel portal, and a model for the diffusion and advection of pollutants. The calculated concentrations near a tunnel portal have been compared with the air tracer experimental data and good conformity could be obtained.

  20. The 1977 emissions inventory for southeastern Virginia. [environment model of air quality based on exhaust emission from urban areas

    NASA Technical Reports Server (NTRS)

    Brewer, D. A.; Remsberg, E. E.; Woodbury, G. E.; Quinn, L. C.

    1979-01-01

    Regional tropospheric air pollution modeling and data compilation to simulate the time variation of species concentrations in and around an urban area is discussed. The methods used to compile an emissions inventory are outlined. Emissions factors for vehicular travel in the urban area are presented along with an analysis of the emission gases. Emission sources other than vehicular including industrial wastes, residential solid waste disposal, aircraft emissions, and emissions from the railroads are investigated.

  1. Long-term oxidation of candidate cast iron and stainless steel exhaust system alloys from 650 to 800 °C in air with water vapor

    SciTech Connect

    Brady, Michael P.; Muralidharan, Govindarajan; Leonard, Donovan .; Haynes, James A.; Weldon, R. G.; England, R. D.

    2014-08-29

    Here, the oxidation behavior of SiMo cast iron, Ni-resist D5S cast iron, cast chromia-forming austenitic stainless steels of varying Cr/Ni content based on CF8C plus, HK, and HP, and a developmental cast alumina-forming austenitic (AFA) stainless steel of interest for diesel exhaust system components were studied for up to 5000 h at 650-800 °C in air with 10% H2O. At 650 °C, the Ni-resist D5S exhibited moderately better oxidation resistance than did the SiMo cast iron. However, the D5S suffered from oxide scale spallation issues at 700 °C and higher, whereas the oxide scales formed on SiMo cast iron remained adherent from 700-800 °C despite oxide scales hundreds of microns thick. The oxidation of the SiMo cast iron exhibited unusual temperature dependence, with periods of slower oxidation kinetics at 750-800 °C compared to 650-700 °C due to continuous silica-rich scale formation at the higher temperatures. The oxidation of the cast chromia-forming austenitics trended with the level of Cr and Ni additions, with small mass losses consistent with Cr oxy-hydroxide volatilization processes for the higher 25Cr/25-35Ni HK and HP type alloys, and transition to rapid Fe-base oxide formation and scale spallation in the lower 19Cr/12Ni CF8C plus type alloy. In contrast, small positive mass changes consistent with protective alumina scale formation were observed for the cast AFA alloy under all conditions studied. Implications of these findings for diesel exhaust system components are discussed.

  2. Long-term oxidation of candidate cast iron and stainless steel exhaust system alloys from 650 to 800 °C in air with water vapor

    DOE PAGES

    Brady, Michael P.; Muralidharan, Govindarajan; Leonard, Donovan .; ...

    2014-08-29

    Here, the oxidation behavior of SiMo cast iron, Ni-resist D5S cast iron, cast chromia-forming austenitic stainless steels of varying Cr/Ni content based on CF8C plus, HK, and HP, and a developmental cast alumina-forming austenitic (AFA) stainless steel of interest for diesel exhaust system components were studied for up to 5000 h at 650-800 °C in air with 10% H2O. At 650 °C, the Ni-resist D5S exhibited moderately better oxidation resistance than did the SiMo cast iron. However, the D5S suffered from oxide scale spallation issues at 700 °C and higher, whereas the oxide scales formed on SiMo cast iron remainedmore » adherent from 700-800 °C despite oxide scales hundreds of microns thick. The oxidation of the SiMo cast iron exhibited unusual temperature dependence, with periods of slower oxidation kinetics at 750-800 °C compared to 650-700 °C due to continuous silica-rich scale formation at the higher temperatures. The oxidation of the cast chromia-forming austenitics trended with the level of Cr and Ni additions, with small mass losses consistent with Cr oxy-hydroxide volatilization processes for the higher 25Cr/25-35Ni HK and HP type alloys, and transition to rapid Fe-base oxide formation and scale spallation in the lower 19Cr/12Ni CF8C plus type alloy. In contrast, small positive mass changes consistent with protective alumina scale formation were observed for the cast AFA alloy under all conditions studied. Implications of these findings for diesel exhaust system components are discussed.« less

  3. Exhaust-nozzle characterisitcs for a twin-jet variable-wing-sweep fighter airplane model at Mach numbers to 2.2

    NASA Technical Reports Server (NTRS)

    Reubush, D. E.; Mercer, C. E.

    1974-01-01

    A wind-tunnel investigation has been conducted to determine the exhaust-nozzle aerodynamic and propulsive characteristics for a twin-jet variable-wing-sweep fighter airplane model. The powered model was tested in the Langley 16-foot transonic tunnel and in the Langley 4-foot supersonic pressure tunnel at Mach numbers to 2.2 and at angles of attack from about minus 2 to 6 deg. Compressed air was used to simulate the nozzle exhaust flow at values of jet total-pressure ratio from approximately 1 (jet off) to about 21. Effects of configuration variables such as speed-brake deflection, store installation, and boundary-layer thickness on the the nozzle characteristics were also investigated.

  4. Exhaust gas recirculation system for an internal combustion engine

    SciTech Connect

    Wu, Ko-Jen

    2013-05-21

    An exhaust gas recirculation system for an internal combustion engine comprises an exhaust driven turbocharger having a low pressure turbine outlet in fluid communication with an exhaust gas conduit. The turbocharger also includes a low pressure compressor intake and a high pressure compressor outlet in communication with an intake air conduit. An exhaust gas recirculation conduit fluidly communicates with the exhaust gas conduit to divert a portion of exhaust gas to a low pressure exhaust gas recirculation branch extending between the exhaust gas recirculation conduit and an engine intake system for delivery of exhaust gas thereto. A high pressure exhaust gas recirculation branch extends between the exhaust gas recirculation conduit and the compressor intake and delivers exhaust gas to the compressor for mixing with a compressed intake charge for delivery to the intake system.

  5. Turbulent Navier-Stokes Flow Analysis of an Advanced Semispan Diamond-Wing Model in Tunnel and Free Air at High-Lift Conditions

    NASA Technical Reports Server (NTRS)

    Ghaffari, Farhad; Biedron, Robert T.; Luckring, James M.

    2002-01-01

    Turbulent Navier-Stokes computational results are presented for an advanced diamond wing semispan model at low-speed, high-lift conditions. The numerical results are obtained in support of a wind-tunnel test that was conducted in the National Transonic Facility at the NASA Langley Research Center. The model incorporated a generic fuselage and was mounted on the tunnel sidewall using a constant-width non-metric standoff. The computations were performed at to a nominal approach and landing flow conditions.The computed high-lift flow characteristics for the model in both the tunnel and in free-air environment are presented. The computed wing pressure distributions agreed well with the measured data and they both indicated a small effect due to the tunnel wall interference effects. However, the wall interference effects were found to be relatively more pronounced in the measured and the computed lift, drag and pitching moment. Although the magnitudes of the computed forces and moment were slightly off compared to the measured data, the increments due the wall interference effects were predicted reasonably well. The numerical results are also presented on the combined effects of the tunnel sidewall boundary layer and the standoff geometry on the fuselage forebody pressure distributions and the resulting impact on the configuration longitudinal aerodynamic characteristics.

  6. An experimental wind-tunnel investigation of a ram-air-spoiler roll-control device on a forward-control missile at supersonic speeds

    NASA Technical Reports Server (NTRS)

    Blair, A. B., Jr.

    1978-01-01

    A parametric experimental wind-tunnel investigation was made at supersonic Mach numbers to provide design data on a ram-air-spoiler roll-control device that is to be used on forward-control cruciform missile configurations. The results indicate that the ram-air-spoiler tail fin is an effective roll-control device and that roll control is generally constant with vehicle attitude and Mach number unless direct canard and/or forebody shock impingement occurs. The addition of the ram-air-spoiler tail fins resulted in only small changes in aerodynamic-center location. For the ram-air-spoiler configuration tested, there are large axial force coefficient effects associated with the increased fin thickness and ram-air momentum loss.

  7. Remote launch operations building, showing diesel exhaust (left) and intake ...

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

    Remote launch operations building, showing diesel exhaust (left) and intake (right) shafts, and tunnel entrance on the far right - Stanley R. Mickelsen Safeguard Complex, Remote Launch Operations Building, Near Service Road exit from Patrol Road, Nekoma, Cavalier County, ND

  8. Planar Rayleigh Scattering Results in Helium/Air Mixing Experiments in a Mach 6 Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Shirinzadeh, B.; Balla, R. Jeffrey; Hillard, M. E.; Anders, J. B.; Exton, R. J.; Waitz, I. A.

    1991-01-01

    Planar Rayleigh scattering measurements using an ArF-excimer laser have been performed to investigate helium mixing into air at supersonic speeds. The capability of the Rayleigh scattering technique for flow visualization of a turbulent environment is demonstrated in a large-scale, Mach 6facility. The detection limit obtained with the present setup indicates that planar, quantitative measurements of density can be made over a large cross sectional area (5 cm by 10 cm) of the flow field in the absence of clusters.

  9. Emission of carcinogenic components with automobile exhausts.

    PubMed Central

    Stenberg, U; Alsberg, T; Westerholm, R

    1983-01-01

    Different sampling methods for mutagenic polynuclear aromatic hydrocarbons (PAH) are described. These methods involve either direct sampling of raw exhausts which prior to filtering are cooled in a condenser, or filter sampling of exhausts diluted in a tunnel. The relevance of gas-phase PAHs of samples from diluted exhausts is discussed; methods used are either adsorbents (XAD-2) or cryogenic condensation. The emission of benzo(a)pyrene and certain other PAHs is reported from vehicles using different fuels (gasoline, diesel, LPG, alcohols) or different emission control systems. The emission of some volatiles, such as benzene, ethylene and alkylnitrites, is also presented from different types of fuels used. PMID:6186483

  10. Ventilation Exhaust Power Recovery Design

    NASA Astrophysics Data System (ADS)

    Yandell, Jeremy

    2012-11-01

    Due to the expense of designing ductwork and exhaust fans to meet the exact desired flow rate for building exhaust, there is wasted energy that is unrecovered when exhausted to the atmosphere. By designing a small diameter wind turbine the kinetic energy in the exhaust stream can be recovered and power provided back into the building. Unlike large scale commercial wind turbines that must be designed to provide power from a large range of wind speeds and directions, this smaller scale turbine can be optimized for a single constant wind speed with no variation in direction. The critical component is to prevent backpressure feeding through the system and increasing the load on the exhaust fan. This design project began with the theoretical airfoil and blade design, followed by modeling the system in fluid dynamics software, a full CAD design was created and modified for the selected manufacturing process, prototype creation and testing will be completed both in a wind tunnel and in a real environment, and the completed data will be compared with theoretical and computational results. Note: There is a patent pending for this design and concept.

  11. Direct measurements of HONO and NO2 by tunable infrared differential absorption spectroscopy; Results from two field campaigns sampling aircraft exhaust and ambient urban air

    NASA Astrophysics Data System (ADS)

    Lee, B. H.; Santoni, G.; Herndon, S. C.; Wood, E. C.; Miake-Lye, R. C.; Munger, J. W.; Wofsy, S. C.; Zahniser, M. S.; McManus, J. B.; Nelson, D. D.

    2009-12-01

    Nitrous acid (HONO) is an important source of hydroxyl radicals (OH), the main oxidizing agent in the atmosphere. However, gaseous HONO has historically proven difficult to measure accurately and to date there is no standard technique. We describe a new instrument capable of high-frequency measurements of HONO and nitrogen dioxide (NO2) mixing ratios by tunable infrared differential absorption spectrometry. Mid-infrared light from two continuous-wave mode quantum cascade lasers traverse a 210 m path through a multi-pass astigmatic cell at reduced pressures for the direct detection of HONO (1660 cm-1) and NO2 (1604 cm-1). We achieve an absorbance precision less than 3×10-6 Hz-1 in one second, which translates to detection limits (S/N=3) of 300 and 30 ppt for HONO and NO2, respectively, in one second. Both lasers and the detector are thermoelectrically cooled, facilitating long-term unattended measurements. We also report preliminary results from two field campaigns; the Alternative Aviation Fuels Experiment (AAFEX) and the Study of Houston Air Radical Precursors (SHARP). At AAFEX, HONO emission ratios relative to CO2 and NOy observed in commercial aircraft exhaust are larger than in most other combustion sources and likely to play a significant role in regional HOx chemistry. Preliminary analysis from the SHARP campaign shows good agreement in HONO and NO2 levels between various measurement techniques.

  12. Volatile hydrocarbon emissions from vehicles and vertical ventilations in the Hsuehshan traffic tunnel, Taiwan.

    PubMed

    Lai, Chia-Hsiang; Peng, Yen-Ping

    2012-07-01

    The concentrations of 56 volatile organic hydrocarbons (VOCs) were measured simultaneously in the southbound bore, the northbound bore and the exhaust air shafts of the Hsuehshan tunnel near Yilan, Taiwan during 2007 and 2008. A total of 60 integrated air samples were collected using stainless steel canisters and analyzed using GC/FID and GC/MS. The highest temperature and lowest relative humidity were observed at the exit of the tunnel owing to the accumulation in the tunnel of waste heat that was exhausted from vehicles. The five most abundant species in all samples were ethylene, acetylene, isopentane, propylene, and toluene. The exit/entrance ratios of total non-methane hydrocarbon (NMHC) concentration were 7.8 and 4.8 for the southbound and northbound bores, respectively. Furthermore, the most abundant species of emission rate (ER) is toluene (21.93-42.89 mg s(-1)), followed by isopentane, ethylene, propylene and 1-butene, with ER ranging from 2.50 to 9.31 mg s(-1) for the three shafts. The ozone formation potential (OFP)/total NMHC ratios in three exhaust air shafts show that the reactivities of these emissions are similar to those of vehicle emissions.

  13. Validation of scramjet exhaust simulation technique

    NASA Technical Reports Server (NTRS)

    Hopkins, H. B.; Konopka, W.; Leng, J.

    1976-01-01

    Scramjet/airframe integration design philosophy for hypersonic aircraft results in configurations having lower aft surfaces that serve as exhaust nozzles. There is a strong coupling between the exhaust plume and the aerodynamics of the vehicle, making accurate simulation of the engine exhaust mandatory. The experimental verification of the simulation procedure is described. The detonation tube simulator was used to produce an exact simulation of the scramjet exhaust for a Mach 8 flight condition. The pressure distributions produced by the exact exhaust flow were then duplicated by a cool mixture Argon and Freon 13B1. Such a substitute gas mixture validated by the detonation tube technique could be used in conventional wind tunnel tests. The results presented show the substitute gas simulation technique to be valid for shockless expansions.

  14. 46 CFR 111.33-9 - Ventilation exhaust.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-9 Ventilation exhaust. The exhaust of each forced-air semiconductor rectifier system must: (a) Terminate in a location other than a hazardous...

  15. Design and Integrate Improved Systems for Nuclear Facility Ventilation and Exhaust Operations

    SciTech Connect

    Moore, Murray E.

    2014-04-15

    Objective: The objective of this R&D project would complete the development of three new systems and integrate them into a single experimental effort. However, each of the three systems has stand-alone applicability across the DOE complex. At US DOE nuclear facilities, indoor air is filtered and ventilated for human occupancy, and exhaust air to the outdoor environment must be regulated and monitored. At least three technical standards address these functions, and the Los Alamos National Laboratory would complete an experimental facility to answer at least three questions: (1) Can the drag coefficient of a new Los Alamos air mixer be reduced for better operation in nuclear facility exhaust stacks? (2) Is it possible to verify the accuracy of a new dilution method for HEPA filter test facilities? (3) Is there a performance-based air flow metric (volumetric flow or mass flow) for operating HEPA filters? In summary, the three new systems are: a mixer, a diluter and a performance-based metric, respectively. The results of this project would be applicable to at least four technical standards: ANSI N13.1 Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities; ASTM F1471 Standard Test Method for Air Cleaning Performance of a High-Efficiency Particulate Air Filter System, ASME N511: In-Service Testing of Nuclear Air Treatment, Heating, Ventilating, and Air-Conditioning Systems, and ASME AG-1: Code On Nuclear Air And Gas Treatment. All of the three proposed new systems must be combined into a single experimental device (i.e. to develop a new function of the Los Alamos aerosol wind tunnel). Technical Approach: The Radiation Protection RP-SVS group at Los Alamos has an aerosol wind tunnel that was originally (2006) designed to evaluate small air samplers (cf. US EPA 40 CFR 53.42). In 2009, the tunnel was modified for exhaust stack verifications per the ANSI N13.1 standard. In 2010, modifications were started on the

  16. NASA Glenn 1-by 1-Foot Supersonic Wind Tunnel User Manual

    NASA Technical Reports Server (NTRS)

    Seablom, Kirk D.; Soeder, Ronald H.; Stark, David E.; Leone, John F. X.; Henry, Michael W.

    1999-01-01

    This manual describes the NASA Glenn Research Center's 1 - by 1 -Foot Supersonic Wind Tunnel and provides information for customers who wish to conduct experiments in this facility. Tunnel performance envelopes of total pressure, total temperature, and dynamic pressure as a function of test section Mach number are presented. For each Mach number, maps are presented of Reynolds number per foot as a function of the total air temperature at the test section inlet for constant total air pressure at the inlet. General support systems-such as the service air, combustion air, altitude exhaust system, auxiliary bleed system, model hydraulic system, schlieren system, model pressure-sensitive paint, and laser sheet system are discussed. In addition, instrumentation and data processing, acquisition systems are described, pretest meeting formats and schedules are outlined, and customer responsibilities and personnel safety are addressed.

  17. PHYSICAL AND NUMERICAL MODELING OF ASD EXHAUST DISPERSION AROUND HOUSES

    EPA Science Inventory

    The report discusses the use of a wind tunnel to physically model the dispersion of exhaust plumes from active soil depressurization (ASD) radon mitigation systems in houses. he testing studied the effects of exhaust location (grade level vs. above the eave), as house height, roo...

  18. Exhaust gas recirculation in a homogeneous charge compression ignition engine

    DOEpatents

    Duffy, Kevin P.; Kieser, Andrew J.; Rodman, Anthony; Liechty, Michael P.; Hergart, Carl-Anders; Hardy, William L.

    2008-05-27

    A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.

  19. Health Impact Assessment of a Predicted Air Quality Change by Moving Traffic from an Urban Ring Road into a Tunnel. The Case of Antwerp, Belgium

    PubMed Central

    Van Brusselen, Daan; Arrazola de Oñate, Wouter; Maiheu, Bino; Vranckx, Stijn; Lefebvre, Wouter; Janssen, Stijn; Nawrot, Tim S; Nemery, Ben; Avonts, Dirk

    2016-01-01

    Background The Antwerp ring road has a traffic density of 300,000 vehicles per day and borders the city center. The ‘Ringland project’ aims to change the current ‘open air ring road’ into a ‘filtered tunneled ring road’, putting the entire urban ring road into a tunnel and thus filtering air pollution. We conducted a health impact assessment (HIA) to quantify the possible benefit of a ‘filtered tunneled ring road’, as compared to the ‘open air ring road’ scenario, on air quality and its long-term health effects. Materials and Methods We modeled the change in annual ambient PM2.5 and NO2 concentrations by covering 15 kilometers of the Antwerp ring road in high resolution grids using the RIO-IFDM street canyon model. The exposure-response coefficients used were derived from a literature review: all-cause mortality, life expectancy, cardiopulmonary diseases and childhood Forced Vital Capacity development (FVC). Results Our model predicts changes between -1.5 and +2 μg/m³ in PM2.5 within a 1,500 meter radius around the ring road, for the ‘filtered tunneled ring road’ scenario as compared to an ‘open air ring road’. These estimated annual changes were plotted against the population exposed to these differences. The calculated change of PM2.5 is associated with an expected annual decrease of 21 deaths (95% CI 7 to 41). This corresponds with 11.5 deaths avoided per 100,000 inhabitants (95% CI 3.9–23) in the first 500 meters around the ring road every year. Of 356 schools in a 1,500 meter perimeter around the ring road changes between -10 NO2 and + 0.17 μg/m³ were found, corresponding to FVC improvement of between 3 and 64ml among school-age children. The predicted decline in lung cancer mortality and incidence of acute myocardial infarction were both only 0.1 per 100,000 inhabitants or less. Conclusion The expected change in PM2,5 and NO2 by covering the entire urban ring road in Antwerp is associated with considerable health gains for

  20. Wind-Tunnel Tests of a 1/6-Scale Model of Republic XF-12 Vertical Tail Incorporating a De-Icing Air Duct

    NASA Technical Reports Server (NTRS)

    MacLachlan, Robert; Miller, Sadie M.

    1945-01-01

    A 1/6-scale model of the Republic XF-12 vertical tail with stub fuselage, stub horizontal tail, and a de-icing air duct was tested in the Langley stability tunnel. The investigation consisted of a study of the effects of the duct, with and without air flow, on the aerodynamic characteristics of the model. The model tested was a revision of a model previously tested in the Langley stability tunnel. The revised model differed from the original model in that it incorporated a de-icing air duct, included a dorsal fin, and had a larger stub fuselage. A comparison of data obtained form tests of the original and revised models was made. The results of the investigation indicated that the air duct had very little effect on the aerodynamic characteristics of the model. A small change occurred in the variation of rudder hinge-moment coefficient with angle of attack but it is believed that this change can be corrected by a properly applied spring tab.

  1. Performance evaluation of Space Shuttle SRB parachutes from air drop and scaled model wind tunnel tests. [Solid Rocket Booster recovery system

    NASA Technical Reports Server (NTRS)

    Moog, R. D.; Bacchus, D. L.; Utreja, L. R.

    1979-01-01

    The aerodynamic performance characteristics have been determined for the Space Shuttle Solid Rocket Booster drogue, main, and pilot parachutes. The performance evaluation on the 20-degree conical ribbon parachutes is based primarily on air drop tests of full scale prototype parachutes. In addition, parametric wind tunnel tests were performed and used in parachute configuration development and preliminary performance assessments. The wind tunnel test data are compared to the drop test results and both sets of data are used to determine the predicted performance of the Solid Rocket Booster flight parachutes. Data from other drop tests of large ribbon parachutes are also compared with the Solid Rocket Booster parachute performance characteristics. Parameters assessed include full open terminal drag coefficients, reefed drag area, opening characteristics, clustering effects, and forebody interference.

  2. Experimental research in the use of electrets in measuring effluents from rocket exhaust and a review of standard air quality measuring devices

    NASA Technical Reports Server (NTRS)

    Susko, M.

    1976-01-01

    Seven standard types of measuring devices used to obtain the chemical composition of rocket exhaust effluents were discussed. The electrets, a new measuring device, are investigated and compared with established measuring techniques. The preliminary results obtained show that electrets have multipollutant measuring capabilities, simplicity of deployment, speed of assessment or analysis, and may be an important and valuable tool in measuring pollutants from space vehicle rocket exhaust.

  3. Diesel Exhaust in New England | US EPA

    EPA Pesticide Factsheets

    2017-04-10

    Pollution from diesel engines is a widespread problem across New England and it significantly contributes to air pollution, especially in urban areas. Diesel exhaust is made up of small particles, known as fine particulate matter.

  4. Modification of NASA Langley 8 Foot High Temperature Tunnel to provide a unique national research facility for hypersonic air-breathing propulsion systems

    NASA Technical Reports Server (NTRS)

    Kelly, H. N.; Wieting, A. R.

    1984-01-01

    A planned modification of the NASA Langley 8-Foot High Temperature Tunnel to make it a unique national research facility for hypersonic air-breathing propulsion systems is described, and some of the ongoing supporting research for that modification is discussed. The modification involves: (1) the addition of an oxygen-enrichment system which will allow the methane-air combustion-heated test stream to simulate air for propulsion testing; and (2) supplemental nozzles to expand the test simulation capability from the current nominal Mach number to 7.0 include Mach numbers 3.0, 4.5, and 5.0. Detailed design of the modifications is currently underway and the modified facility is scheduled to be available for tests of large scale propulsion systems by mid 1988.

  5. Modification of NASA Langley 8 foot high temperature tunnel to provide a unique national research facility for hypersonic air-breathing propulsion systems

    NASA Technical Reports Server (NTRS)

    Kelly, H. N.; Wieting, A. R.

    1984-01-01

    A planned modification of the NASA Langley 8-Foot High Temperature Tunnel to make it a unique national research facility for hypersonic air-breathing propulsion systems is described, and some of the ongoing supporting research for that modification is discussed. The modification involves: (1) the addition of an oxygen-enrichment system which will allow the methane-air combustion-heated test stream to simulate air for propulsion testing; and (2) supplemental nozzles to expand the test simulation capability from the current nominal Mach number to 7.0 include Mach numbers 3.0, 4.5, and 5.0. Detailed design of the modifications is currently underway and the modified facility is scheduled to be available for tests of large scale propulsion systems by mid 1988.

  6. X-33 Rev-F Turbulent Aeroheating Results From Test 6817 in NASA Langley 20-Inch Mach 6 Air Tunnel and Comparisons With Computations

    NASA Technical Reports Server (NTRS)

    Hollis, Brian R.; Horvath, Thomas J.; Berry, Scott A.

    2003-01-01

    Measurements and predictions of the X-33 turbulent aeroheating environment have been performed at Mach 6, perfect-gas air conditions. The purpose of this investigation was to compare measured turbulent aeroheating levels on smooth models, models with discrete trips, and models with arrays of bowed panels (which simulate bowed thermal protections system tiles) with each other and with predictions from two Navier-Stokes codes, LAURA and GASP. The wind tunnel testing was conducted at free stream Reynolds numbers based on length of 1.8 x 10(exp 6) to 6.1 x 10(exp 6) on 0.0132 scale X-33 models at a = 40-deg. Turbulent flow was produced by the discrete trips and by the bowed panels at ill but the lowest Reynolds number, but turbulent flow on the smooth model was produced only at the highest Reynolds number. Turbulent aeroheating levels on each of the three model types were measured using global phosphor thermography and were found to agree to within .he estimated uncertainty (plus or minus 15%) of the experiment. Computations were performed at the wind tunnel free stream conditions using both codes. Turbulent aeroheating levels predicted using the LAURA code were generally 5%-10% lower than those from GASP, although both sets of predictions fell within the experimental accuracy of the wind tunnel data.

  7. Particle number emission factors for an urban highway tunnel

    NASA Astrophysics Data System (ADS)

    Perkins, Jessica L.; Padró-Martínez, Luz T.; Durant, John L.

    2013-08-01

    Exposure to traffic-related air pollution has been linked to increased risks of cardiopulmonary disease, asthma, and reduced lung function. Ultrafine particles (UFP; aerodynamic diameter < 100 nm), one component of traffic exhaust, may contribute to these risks. This paper describes the development of UFP emission factors, an important input parameter for dispersion models used for exposure assessment. Measurements of particle number concentration (PNC), a proxy for UFP, were performed in the Central Artery Tunnel on Interstate-93 in Boston (MA, USA). The tunnel system consists of two, unidirectional bores, which each carry ˜9 × 104 vehicles per day (diesel vehicles comprise 2-5% of the fleet in the southbound tunnel and 1-3% in the northbound tunnel). A tunnel was chosen for study because it provided an enclosed environment where the effects of lateral and vertical dispersion by ambient air and photochemical reactions would be minimized. Data were collected using a mobile platform equipped with rapid-response instruments for measuring PNC (4-3000 nm) as well as NOx. Because Boston is located in a temperate region (latitude 42° N), we were interested in studying seasonal and diurnal differences in emission factors. To characterize seasonal differences, mobile monitoring was performed on 36 days spaced at 7-14 day intervals over one year (Sept. 2010-Sept. 2011); to characterize diurnal differences intensive mobile monitoring (n = 90 total trips through the tunnels) was performed over the course of two consecutive days in January 2012. All data collected during congested traffic conditions (˜7% of total data set) were removed from the analysis. The median PNC inside the two tunnels for all trips during the 12-month campaign was 3-4-fold higher than on I-93 immediately outside the tunnel and 7-10-fold higher than on I-93 4 km from the tunnel. The median particle number emission factors (EFPN) (±median absolute deviation) for the southbound and northbound tunnels

  8. GASOLINE VEHICLE EXHAUST PARTICLE SAMPLING STUDY

    SciTech Connect

    Kittelson, D; Watts, W; Johnson, J; Zarling, D Schauer,J Kasper, K; Baltensperger, U; Burtscher, H

    2003-08-24

    The University of Minnesota collaborated with the Paul Scherrer Institute, the University of Wisconsin (UWI) and Ricardo, Inc to physically and chemically characterize the exhaust plume from recruited gasoline spark ignition (SI) vehicles. The project objectives were: (1) Measure representative particle size distributions from a set of on-road SI vehicles and compare these data to similar data collected on a small subset of light-duty gasoline vehicles tested on a chassis dynamometer with a dilution tunnel using the Unified Drive Cycle, at both room temperature (cold start) and 0 C (cold-cold start). (2) Compare data collected from SI vehicles to similar data collected from Diesel engines during the Coordinating Research Council E-43 project. (3) Characterize on-road aerosol during mixed midweek traffic and Sunday midday periods and determine fleet-specific emission rates. (4) Characterize bulk- and size-segregated chemical composition of the particulate matter (PM) emitted in the exhaust from the gasoline vehicles. Particle number concentrations and size distributions are strongly influenced by dilution and sampling conditions. Laboratory methods were evaluated to dilute SI exhaust in a way that would produce size distributions that were similar to those measured during laboratory experiments. Size fractionated samples were collected for chemical analysis using a nano-microorifice uniform deposit impactor (nano-MOUDI). In addition, bulk samples were collected and analyzed. A mixture of low, mid and high mileage vehicles were recruited for testing during the study. Under steady highway cruise conditions a significant particle signature above background was not measured, but during hard accelerations number size distributions for the test fleet were similar to modern heavy-duty Diesel vehicles. Number emissions were much higher at high speed and during cold-cold starts. Fuel specific number emissions range from 1012 to 3 x 1016 particles/kg fuel. A simple

  9. The Stability Tunnel

    NASA Technical Reports Server (NTRS)

    1943-01-01

    Engineers operate the controls of the Stability Tunnel: Plans for a new tunnel to study stability problems began in the late thirties. The Stability Tunnel was authorized in 1939 and began operations in June 1941. The installation was completed in December that year with the completion of a new 10,000 Horsepower Diesel-electric generating plant. It was a single return, closed jet tunnel with a 6-foot square test section. The tunnel was disassembled and shipped to Virginia Polytechnic Institute and State University in 1958. The tunnel had two separate test sections: one for curved flow, the other for rolling flow. 'The facility...simulates the motion of the aircraft in curved or rolling flight. This is done by actually curving or rolling the airstream as it passes over the model and at the same time providing the proper velocity distribution.' (From AIAA-80-0309) >From Alan Pope, Wind-Tunnel Testing: 'The only tunnel directly designed for dynamic stability work is located at the Langley Field branch of the NACA. Its most vital feature is its ability to subject the models to curving air streams that simulate those actually encountered when an airplane rolls, pitches, or yaws. the rotating airstream for simulating roll is produced by a motor-driven paddle just ahead of the test section. Curved air of properly varying velocity for simulating pitch and yaw is produced by a combination of a curved test section and velocity screens. The proper use of this apparatus makes possible the determination of the stability derivatives.' Published in F.H. Lutze, 'Experimental Determination of Pure Rotary Stability Derivatives using a Curved and Rolling Flow Wind Tunnel,' AIAA-80-0309, AIAA 18th Aerospace Sciences Meeting, Pasadena, CA, January 14-16, 1980; Alan Pope, Wind-Tunnel Testing (New York: John Wiley & Sons, 1947).

  10. Full Scale Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Construction of motor fairing for the fan motors of the Full-Scale Tunnel (FST). The motors and their supporting structures were enclosed in aerodynamically smooth fairings to minimize resistance to the air flow. Close examination of this photograph reveals the complicated nature of constructing a wind tunnel. This motor fairing, like almost every other structure in the FST, represents a one-of-a-kind installation.

  11. Exhaust purification with on-board ammonia production

    DOEpatents

    Robel, Wade J.; Driscoll, James J.; Coleman, Gerald N.; Knox, Kevin J.

    2009-06-30

    A power source is provided for use with selective catalytic reduction systems for exhaust-gas purification. The power source includes a first cylinder group with a first air-intake passage and a first exhaust passage, and a second cylinder group with a second air-intake passage and a second exhaust passage. The second air-intake passage is fluidly isolated from the first air-intake passage. A fuel-supply device may be configured to supply fuel into the first exhaust passage, and a catalyst may be disposed downstream of the fuel-supply device to convert at least a portion of the exhaust stream in the first exhaust passage into ammonia.

  12. Internal performance of Highly Integrated Deployable Exhaust Nozzles

    NASA Technical Reports Server (NTRS)

    Taylor, John G.; Asbury, Scott C.; Mason, Mary L.; Lamb, Milton

    1993-01-01

    The internal performance characteristics of Highly Integrated Deployable Exhaust Nozzles (HIDEN) applicable to advanced short take-off and vertical landing aircraft have been investigated. Four nozzle concepts, designed for fan and core flow installations, were tested with varying contraction ratio and nozzle exit plane shape. In addition, two offtake duct designs, along with several centerbody and blocker geometries were tested to evaluate their effect on the static thrust and flow performance. This investigation was conducted in the static test facility of the NASA Langley 16-Foot Transonic Tunnel. A six-component strain-gage balance collected force and moment data, and static pressure, total pressure, and total temperature measurements were also made internal to the model. Room temperature, dry high-pressure air was used to simulate jet exhaust. The results indicate that the internal performance of these HIDEN concepts is comparable to previously tested nozzle concepts designed for thrust vectoring about a bearing plane. This report presents the configuration design of the HIDEN concepts and the results of the internal performance testing.

  13. Experimental study on burning rates of square/rectangular gasoline and methanol pool fires under longitudinal air flow in a wind tunnel.

    PubMed

    Hu, L H; Liu, S; Peng, W; Huo, R

    2009-09-30

    Square pool fires with length of 5, 7.5, 10, 15, 20, 25 and 30 cm and rectangular pool fires with dimensions of 10 cm x 20 cm and 10 cm x 40 cm were burned in a wind tunnel, under a longitudinal air flow ranged from 0 to 3m/s with incremental change of about 0.5m/s. Methanol and gasoline were burned and compared, with results indicated that their burning rates showed different response to the longitudinal air flow. With the increase of the longitudinal air flow speed, the burning rates of methanol pool fires, except the 5 cm square one, first decreased and then increased, but those of the 5 cm methanol square one and the gasoline pool fires increased monotonously. The burning rate of smaller square pool fires increased more significantly than that of the larger ones, as well as the enlargement of their flame attachment length along the ground. The burning rate of a rectangular pool fire with longer rim parallel to the longitudinal flow increased faster, but the flame attachment length seemed to increase more gradually, with the increase of the longitudinal air flow speed than that perpendicular to.

  14. 54. DETAIL OF AIRCONDITIONING EXHAUST DUCTS ON NORTH FACE OF ...

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

    54. DETAIL OF AIR-CONDITIONING EXHAUST DUCTS ON NORTH FACE OF ERECT UMBILICAL MAST - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  15. A Hydrogen Peroxide Hot-Jet Simulator for Wind-Tunnel Tests of Turbojet-Exit Models

    NASA Technical Reports Server (NTRS)

    Runckel, Jack F.; Swihart, John M.

    1959-01-01

    A turbojet-engine-exhaust simulator which utilizes a hydrogen peroxide gas generator has been developed for powered-model testing in wind tunnels with air exchange. Catalytic decomposition of concentrated hydrogen peroxide provides a convenient and easily controlled method of providing a hot jet with characteristics that correspond closely to the jet of a gas turbine engine. The problems associated with simulation of jet exhausts in a transonic wind tunnel which led to the selection of a liquid monopropellant are discussed. The operation of the jet simulator consisting of a thrust balance, gas generator, exit nozzle, and auxiliary control system is described. Static-test data obtained with convergent nozzles are presented and shown to be in good agreement with ideal calculated values.

  16. Laboratory evaluation of a prototype photochemical chamber designed to investigate the health effects of fresh and aged vehicular exhaust emissions.

    PubMed

    Papapostolou, Vasileios; Lawrence, Joy E; Diaz, Edgar A; Wolfson, Jack M; Ferguson, Stephen T; Long, Mark S; Godleski, John J; Koutrakis, Petros

    2011-07-01

    Laboratory experiments simulating atmospheric aging of motor vehicle exhaust emissions were conducted using a single vehicle and a photochemical chamber. A compact automobile was used as a source of emissions. The vehicle exhaust was diluted with ambient air to achieve carbon monoxide (CO) concentrations similar to those observed in an urban highway tunnel. With the car engine idling, it is expected that the CO concentration is a reasonable surrogate for volatile organic compounds (VOCs) emissions. Varying the amount of dilution of the exhaust gas to produce different CO concentrations, allowed adjustment of the concentrations of VOCs in the chamber to optimize production of secondary organic aerosol (SOA) needed for animal toxicological exposures. Photochemical reactions in the chamber resulted in nitric oxide (NO) depletion, nitrogen dioxide (NO₂) formation, ozone (O₃) accumulation, and SOA formation. A stable SOA concentration of approximately 40 μg m⁻³ at a chamber mean residence time of 30 min was achieved. This relatively short mean residence time provided adequate chamber flow output for both particle characterization and animal exposures. The chamber was operated as a continuous flow reactor for animal toxicological tests. SOA mass generated from the car exhaust diluted with ambient air was almost entirely in the ultrafine mode. Chamber performance was improved by using different types of seed aerosol to provide a surface for condensation of semivolatile reaction products, thus increasing the yield of SOA. Toxicological studies using Sprague-Dawley rats found significant increases of in vivo chemiluminescence in lungs following exposure to SOA.

  17. Laboratory evaluation of a prototype photochemical chamber designed to investigate the health effects of fresh and aged vehicular exhaust emissions

    PubMed Central

    Papapostolou, Vasileios; Lawrence, Joy E.; Diaz, Edgar A.; Wolfson, Jack M.; Ferguson, Stephen T.; Long, Mark S.; Godleski, John J.; Koutrakis, Petros

    2013-01-01

    Laboratory experiments simulating atmospheric aging of motor vehicle exhaust emissions were conducted using a single vehicle and a photochemical chamber. A compact automobile was used as a source of emissions. The vehicle exhaust was diluted with ambient air to achieve carbon monoxide (CO) concentrations similar to those observed in an urban highway tunnel. With the car engine idling, it is expected that the CO concentration is a reasonable surrogate for volatile organic compounds (VOCs) emissions. Varying the amount of dilution of the exhaust gas to produce different CO concentrations, allowed adjustment of the concentrations of VOCs in the chamber to optimize production of secondary organic aerosol (SOA) needed for animal toxicological exposures. Photochemical reactions in the chamber resulted in nitric oxide (NO) depletion, nitrogen dioxide (NO2) formation, ozone (O3) accumulation, and SOA formation. A stable SOA concentration of approximately 40 µg m−3 at a chamber mean residence time of 30 min was achieved. This relatively short mean residence time provided adequate chamber flow output for both particle characterization and animal exposures. The chamber was operated as a continuous flow reactor for animal toxicological tests. SOA mass generated from the car exhaust diluted with ambient air was almost entirely in the ultrafine mode. Chamber performance was improved by using different types of seed aerosol to provide a surface for condensation of semivolatile reaction products, thus increasing the yield of SOA. Toxicological studies using Sprague-Dawley rats found significant increases of in vivo chemiluminescence in lungs following exposure to SOA. PMID:21689011

  18. Effects of jet exhaust gas properties on exhaust simulation and afterbody drag

    NASA Technical Reports Server (NTRS)

    Compton, W. B., III

    1975-01-01

    The effect of varying the jet exhaust's ratio of specific heats, gas constant, and temperature on airplane afterbody drag was investigated. Jet exhaust simulation parameters were evaluated also. Subsonic and transonic tests were made using a single nacelle model with afterbodies having boattail angles of 10 deg and 20 deg. Besides air, three other jet exhaust gases were investigated. The ratios of specific heats, gas constants, and total temperatures of the four exhaust gases ranged from 1.40 to 1.26, 287 to 376 J/kg-K, and 300 to 1013 K, respectively. For steep boattail angles, and transonic speeds and typical turbojet pressure ratios, the current data indicate that the use of air to simulate a dry turbojet exhaust can result in an overprediction of afterbody drag as high as 17 percent of the dry turbojet value.

  19. Instrumentation in wind tunnels

    NASA Technical Reports Server (NTRS)

    Takashima, K.

    1986-01-01

    Requirements in designing instrumentation systems and measurements of various physical quantities in wind tunnels are surveyed. Emphasis is given to sensors used for measuring pressure, temperature, and angle, and the measurements of air turbulence and boundary layers. Instrumentation in wind tunnels require accuracy, fast response, diversity and operational simplicity. Measurements of force, pressure, attitude angle, free flow, pressure distribution, and temperature are illustrated by a table, and a block diagram. The LDV (laser Doppler velocimeter) method for measuring air turbulence and flow velocity and measurement of skin friction and flow fields using laser holograms are discussed. The future potential of these techniques is studied.

  20. Doppler ultrasound surveillance in deep tunneling compressed-air work with Trimix breathing: bounce dive technique compared to saturation-excursion technique.

    PubMed

    Vellinga, T P van Rees; Sterk, W; de Boer, A G E M; van der Beek, A J; Verhoeven, A C; van Dijk, F J H

    2008-01-01

    The Western Scheldt Tunneling Project in The Netherlands provided a unique opportunity to evaluate two deep-diving techniques with Doppler ultrasound surveillance. Divers used the bounce diving techniques for repair and maintenance of the TBM. The tunnel boring machine jammed at its deepest depth. As a result the work time was not sufficient. The saturation diving technique was developed and permitted longer work time at great depth. Thirty-one divers were involved in this project. Twenty-three divers were examined using Doppler ultrasound. Data analysis addressed 52 exposures to Trimix at 4.6-4.8 bar gauge using the bounce technique and 354 exposures to Trimix at 4.0-6.9 bar gauge on saturation excursions. No decompression incidents occurred with either technique during the described phase of the project. Doppler ultrasound revealed that the bubble loads assessed in both techniques were generally low. We find out, that despite longer working hours, shorter decompression times and larger physical workloads, the saturation-excursion technique was associated with significant lower bubble grades than in the bounce technique using Doppler Ultrasound. We conclude that the saturation-excursion technique with Trimix is a good option for deep and long exposures in caisson work. The Doppler technique proved valuable, and it should be incorporated in future compressed-air work.

  1. Horizontal coring using air as the circulating fluid: Some prototype studies conducted in G Tunnel at the Nevada Test Site for the Yucca Mountain Project

    SciTech Connect

    Chornack, M.P.; French, C.A.

    1989-12-31

    Horizontal coring using air as the circulating fluid has been conducted in the G Tunnel Underground Facility (GTUF) at the Nevada Test Site. This work is part of the prototype investigations of hydrogeology for the Yucca Mountain Project. The work is being conducted to develop methods and procedures that will be used at the Department of Energy`s Yucca Mountain Site, a candidate site for the nation`s first high-level nuclear waste repository, during the site characterization phase of the investigations. The United States Geological Survey (USGS) is conducting this prototype testing under the guidance of the Los Alamos National Laboratory (LANL) and in conjunction with Reynolds Electrical & Engineering Company (REECo), the drilling contractor. 7 refs., 8 figs., 5 tabs.

  2. Characteristics of particle number and mass emissions during heavy-duty diesel truck parked active DPF regeneration in an ambient air dilution tunnel

    NASA Astrophysics Data System (ADS)

    Yoon, Seungju; Quiros, David C.; Dwyer, Harry A.; Collins, John F.; Burnitzki, Mark; Chernich, Donald; Herner, Jorn D.

    2015-12-01

    Diesel particle number and mass emissions were measured during parked active regeneration of diesel particulate filters (DPF) in two heavy-duty diesel trucks: one equipped with a DPF and one equipped with a DPF + SCR (selective catalytic reduction), and compliant with the 2007 and 2010 emission standards, respectively. The emission measurements were conducted using an ambient air dilution tunnel. During parked active regeneration, particulate matter (PM) mass emissions measured from a 2007 technology truck were significantly higher than the emissions from a 2010 technology truck. Particle number emissions from both trucks were dominated by nucleation mode particles having a diameter less than 50 nm; nucleation mode particles were orders of magnitude higher than accumulation mode particles having a diameter greater than 50 nm. Accumulation mode particles contributed 77.8 %-95.8 % of the 2007 truck PM mass, but only 7.3 %-28.2 % of the 2010 truck PM mass.

  3. Forced Boundary-Layer Transition on X-43 (Hyper-X) in NASA LaRC 20-Inch Mach 6 Air Tunnel

    NASA Technical Reports Server (NTRS)

    Berry, Scott A.; DiFulvio, Michael; Kowalkowski, Matthew K.

    2000-01-01

    Aeroheating and boundary layer transition characteristics for the X-43 (Hyper-X) configuration have been experimentally examined in the Langley 20-Inch Mach 6 Air Tunnel. Global surface heat transfer distributions, and surface streamline patterns were measured on a 0.333-scale model of the Hyper-X forebody. Parametric variations include angles-of-attack of 0-deg, 2-deg, and 4-deg; Reynolds numbers based on model length of 1.2 to 15.4 million; and inlet cowl door both open and closed. The effects of discrete roughness elements on the forebody boundary layer, which included variations in trip configuration and height, were investigated. This document is intended to serve as a release of preliminary data to the Hyper-X program; analysis is limited to observations of the experimental trends in order to expedite dissemination.

  4. Forced Boundary-Layer Transition on X-43 (Hyper-X) in NASA LaRC 31-Inch Mach 10 Air Tunnel

    NASA Technical Reports Server (NTRS)

    Berry, Scott A.; DiFulvio, Michael; Kowalkowski, Matthew K.

    2000-01-01

    Aeroheating and boundary layer transition characteristics for the X-43 (Hyper-X) configuration have been experimentally examined in the Langley 31-Inch Mach 10 Air Tunnel. Global surface heat transfer distributions, and surface streamline patterns were measured on a 0.333-scale model of the Hyper-X forebody. Parametric variations include angles-of-attack of 0-deg, 2-deg, 3-deg, and 4-deg; Reynolds numbers based on model length of 1.2 to 5.1 million; and inlet cowl door both open and closed. The effects of discrete roughness elements on the forebody boundary layer, which included variations in trip configuration and height, were investigated. This document is intended to serve as a release of preliminary data to the Hyper-X program; analysis is limited to observations of the experimental trends in order to expedite dissemination.

  5. Bronchoalveolar inflammation after exposure to diesel exhaust: comparison between unfiltered and particle trap filtered exhaust

    PubMed Central

    Rudell, B.; Blomberg, A.; Helleday, R.; Ledin, M. C.; Lundback, B.; Stjernberg, N.; Horstedt, P.; Sandstrom, T.

    1999-01-01

    OBJECTIVES: Air pollution particulates have been identified as having adverse effects on respiratory health. The present study was undertaken to further clarify the effects of diesel exhaust on bronchoalveolar cells and soluble components in normal healthy subjects. The study was also designed to evaluate whether a ceramic particle trap at the end of the tail pipe, from an idling engine, would reduce indices of airway inflammation. METHODS: The study comprised three exposures in all 10 healthy never smoking subjects; air, diluted diesel exhaust, and diluted diesel exhaust filtered with a ceramic particle trap. The exposures were given for 1 hour in randomised order about 3 weeks apart. The diesel exhaust exposure apperatus has previously been carefully developed and evaluated. Bronchoalveolar lavage was performed 24 hours after exposures and the lavage fluids from the bronchial and bronchoalveolar region were analysed for cells and soluble components. RESULTS: The particle trap reduced the mean steady state number of particles by 50%, but the concentrations of the other measured compounds were almost unchanged. It was found that diesel exhaust caused an increase in neutrophils in airway lavage, together with an adverse influence on the phagocytosis by alveolar macrophages in vitro. Furthermore, the diesel exhaust was found to be able to induce a migration of alveolar macrophages into the airspaces, together with reduction in CD3+CD25+ cells. (CD = cluster of differentiation) The use of the specific ceramic particle trap at the end of the tail pipe was not sufficient to completely abolish these effects when interacting with the exhaust from an idling vehicle. CONCLUSIONS: The current study showed that exposure to diesel exhaust may induce neutrophil and alveolar macrophage recruitment into the airways and suppress alveolar macrophage function. The particle trap did not cause significant reduction of effects induced by diesel exhaust compared with unfiltered diesel

  6. 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 ...

  7. Tunneling path toward spintronics

    NASA Astrophysics Data System (ADS)

    Miao, Guo-Xing; Münzenberg, Markus; Moodera, Jagadeesh S.

    2011-03-01

    The phenomenon of quantum tunneling, which was discovered almost a century ago, has led to many subsequent discoveries. One such discovery, spin polarized tunneling, was made 40 years ago by Robert Meservey and Paul Tedrow (Tedrow and Meservey 1971 Phys. Rev. Lett. 26 192), and it has resulted in many fundamental observations and opened up an entirely new field of study. Until the mid-1990s, this field developed at a steady, low rate, after which a huge increase in activity suddenly occurred as a result of the unraveling of successful spin tunneling between two ferromagnets. In the past 15 years, several thousands of papers related to spin polarized tunneling and transport have been published, making this topic one of the hottest areas in condensed matter physics from both fundamental science and applications viewpoints. Many review papers and book chapters have been written in the past decade on this subject. This paper is not exhaustive by any means; rather, the emphases are on recent progress, technological developments and informing the reader about the current direction in which this topic is moving.

  8. A Comparative Study of Weights and Sizes of Flat-Plate Exhaust-Gas-to-Air Heat Exchangers with and without Fins

    DTIC Science & Technology

    1947-07-01

    tests of both heat exchangers, air or-d exhauj’t-gaa flow rates wtre mnr.sur’sd with venturi motors located downstream from the heat exchanger. Air...cas— flow ratoa aa di.torrin.jd froo the venturi notor. TEST rBOCEDUPE Flii^it toatJn3 of tho host exchangers wr.3 conduced to evaluate their tho...Static pressures upstrean and downctroTa frca tho hoat- oxchangor core wore raacurod with etat5c tubos , and air flow rates ware raacurcd vith n vonturi

  9. Decomposition of nitric oxide in a hot nitrogen stream to synthesize air for hypersonic wind tunnel combustion testing

    NASA Technical Reports Server (NTRS)

    Zumdieck, J. F.; Zlatarich, S. A.

    1974-01-01

    A clean source of high enthalpy air was obtained from the exothermic decomposition of nitric oxide in the presence of strongly heated nitrogen. A nitric oxide jet was introduced into a confined coaxial nitrogen stream. Measurements were made of the extent of mixing and reaction. Experimental results are compared with one- and two-dimensional chemical kinetics computations. Both analyses predict much lower reactivity than was observed experimentally. Inlet nitrogen temperatures above 2400 K were sufficient to produce experimentally a completely reacted gas stream of synthetic air.

  10. Dilution rates for tailpipe emissions: effects of vehicle shape, tailpipe position, and exhaust velocity.

    PubMed

    Chang, Victor W C; Hildemann, Lynn M; Chang, Cheng-hisn

    2009-06-01

    The rate at which motor vehicle exhaust undergoes dilution with ambient air will greatly affect the size distribution characteristics of the particulate emissions. Wind tunnel experiments were conducted to investigate the impacts of vehicle shape, tailpipe orientation, and exhaust exit velocity on the dilution profiles under steady driving conditions for three model vehicles: a light-duty truck, a passenger car, and a heavy-duty tractor head. A three dimensional array of 60 sensors provided simultaneous measurements of dilution ratios for the emissions in the near- and far-wake regions downstream of the vehicle. The processes underlying the observations were investigated via nondimensionalization. Many of the trends seen substantially downstream can be well generalized using a simple nondimensionalization technique; however, this is not true in the near-wake region (within a downstream distance equivalent to a few vehicle heights). In the near-wake region, using the vehicle width and length to normalize for the vehicle shape is not enough to fully account for the variations seen. Including the exhaust flow rate in the nondimensionalization process is effective further downwind but does not adequately capture the complexity in the near-wake region. Tailpipe orientation and location are also shown to be influential factors affecting the near-wake dilution characteristics.

  11. Turbojet-exhaust-nozzle secondary-airflow pumping as an exit control of an inlet-stability bypass system for a Mach 2.5 axisymmetric mixed-compression inlet. [Lewis 10- by 10-ft. supersonic wind tunnel test

    NASA Technical Reports Server (NTRS)

    Sanders, B. W.

    1980-01-01

    The throat of a Mach 2.5 inlet that was attached to a turbojet engine was fitted with large, porous bleed areas to provide a stability bypass system that would allow a large, stable airflow range. Exhaust-nozzle, secondary-airflow pumping was used as the exit control for the stability bypass airflow. Propulsion system response and stability bypass performance were obtained for several transient airflow disturbances, both internal and external. Internal airflow disturbances included reductions in overboard bypass airflow, power lever angle, and primary-nozzle area, as well as compressor stall. Nozzle secondary pumping as a stability bypass exit control can provide the inlet with a large stability margin with no adverse effects on propulsion system performance.

  12. Duplex tab exhaust nozzle

    NASA Technical Reports Server (NTRS)

    Gutmark, Ephraim Jeff (Inventor); Martens, Steven (nmn) (Inventor)

    2012-01-01

    An exhaust nozzle includes a conical duct terminating in an annular outlet. A row of vortex generating duplex tabs are mounted in the outlet. The tabs have compound radial and circumferential aft inclination inside the outlet for generating streamwise vortices for attenuating exhaust noise while reducing performance loss.

  13. Effect of air deflectors on fan performance in tunnel-ventilated broiler houses with a dropped ceiling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Air velocity is a critical design parameter for modern commercial broiler houses, owing to the beneficial effects of increased cooling on live performance and thermal comfort in broiler chickens. As a result, design velocities have increased over the last 15 years and broiler growers have installed ...

  14. Mixed exhaust flow supersonic jet engine and method

    SciTech Connect

    Klees, G.W.

    1993-06-08

    A method of operating a supersonic jet engine installation is described comprising (a) providing an engine having a variable area air inlet means and an outlet to discharge engine exhaust; (b) providing a secondary air passageway means; (c) receiving ambient air in the air inlet means and providing the ambient air as primary air to the engine inlet and secondary air to the secondary air passageway means; (d) providing a mixing section having an inlet portion and an exit portion, utilizing the mixing section in directing the exhaust from the engine to primary convergent/divergent exit passageway segments, where the exhaust is discharged at supersonic velocity as primary flow components, and directing secondary air flow from the secondary air passageway means to secondary exit passageway segments which are interspersed with the primary segments and from which the secondary air is discharged at subsonic velocity as secondary flow components; and (e) providing an exhaust section to receive the primary and secondary flow components in a mixing region and causing the primary and secondary flow components to mix to create a supersonic mixed flow, the exhaust section having a variable area final nozzle through which the mixed flow is discharged.

  15. An investigation of drag reduction for tractor trailer vehicles with air deflector and boattail. [wind tunnel tests

    NASA Technical Reports Server (NTRS)

    Muirhead, V. U.

    1981-01-01

    A wind tunnel investigation was conducted to determine the influence of several physical variables on the aerodynamic drag of a trailer model. The physical variables included: a cab mounted wind deflector, boattail on trailer, flow vanes on trailer front, forced transition on trailer, and decreased gap between tractor and trailer. Tests were conducted at yaw angles (relative wind angles) of 0, 5, 10, 20, and 30 degrees and Reynolds numbers of 3.58 x 10 to the 5th power 6.12 x 10 to the 5th power based upon the equivalent diameter of the vehicles. The wind deflector on top of the cab produced a calculated reduction in fuel consumption of about 5 percent of the aerodynamic portion of the fuel budget for a wind speed of 15.3 km/hr (9.5 mph) over a wind angle range of 0 deg to 180 deg and for a vehicle speed of 88.5 km/hr (55 mph). The boattail produced a calculated 7 percent to 8 percent reduction in fuel consumption under the same conditions. The decrease in gap reduced the calculated fuel consumption by about 5 percent of the aerodynamic portion of the fuel budget.

  16. Engine with pulse-suppressed dedicated exhaust gas recirculation

    SciTech Connect

    Keating, Edward J.; Baker, Rodney E.

    2016-06-07

    An engine assembly includes an intake assembly, a spark-ignited internal combustion engine, and an exhaust assembly. The intake assembly includes a charge air cooler disposed between an exhaust gas recirculation (EGR) mixer and a backpressure valve. The charge air cooler has both an inlet and an outlet, and the back pressure valve is configured to maintain a minimum pressure difference between the inlet of the charge air cooler and an outlet of the backpressure valve. A dedicated exhaust gas recirculation system is provided in fluid communication with at least one cylinder and with the EGR mixer. The dedicated exhaust gas recirculation system is configured to route all of the exhaust gas from the at least one cylinder to the EGR mixer for recirculation back to the engine.

  17. A Method for Reducing the Temperature of Exhaust Manifolds

    NASA Technical Reports Server (NTRS)

    Schey, Oscar W; Young, Alfred W

    1931-01-01

    This report describes tests conducted at the Langley Memorial Aeronautical Laboratory on an "air-inducting" exhaust manifold for aircraft engines. The exhaust gases from each cylinder port are discharged into the throat of an exhaust pipe which has a frontal bellmouth. Cooling air is drawn into the pipe, where it surrounds and mixes with the exhaust gases. Temperatures of the manifold shell and of the exhaust gases were obtained in flight for both a conventional manifold and the air-inducting manifold. The air-inducting manifold was installed on an engine which was placed on a test stand. Different fuels were sprayed on and into the manifold to determine whether the use of this manifold reduced the fire hazard. The flight tests showed reductions in manifold temperatures of several hundred degrees, to values below the ignition point of aviation gasoline. On the test stand when the engine was run at idling speeds fuels sprayed into the manifold ignited. It is believed that at low engine speeds the fuel remained in the manifold long enough to become thoroughly heated, and was then ignited by the exhaust gas which had not mixed with cooling air. The use of the air-inducting exhaust manifold must reduce the fire hazard by virtue of its lower operating temperature, but it is not a completely satisfactory solution of the problem.

  18. Air-loads Prediction of a UH-60A Rotor Inside the 40- by 80-Foot Wind Tunnel

    DTIC Science & Technology

    2010-01-22

    schemes allow a bigger time step for numerical stability. Viscous flow boundary conditions with the Spalart - Allmaras turbulence model are used in...free-air flight case. One possible reason for the failed convergence could be that the Spalart - Allmaras turbulence model is used, instead of the...Baldwin-Barth turbulence model, in the present calculations. The Baldwin- Barth turbulence model was applied in the previous work and did yield

  19. The Benefits of Mixed Flow Technology: Roof Exhaust Fans.

    ERIC Educational Resources Information Center

    Tetley, Paul A.

    2001-01-01

    Explores the problems associated with laboratory workstation exhaust faced by most colleges and universities and explains how the selection of a proper fume hood exhaust system can prevent or eliminate these problems and provide a clean and safe lab environment. Also highlighted are indoor air quality legal implications. (GR)

  20. 40 CFR 1065.127 - Exhaust gas recirculation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Exhaust gas recirculation. 1065.127 Section 1065.127 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.127 Exhaust gas recirculation. Use...

  1. 40 CFR 1065.127 - Exhaust gas recirculation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Exhaust gas recirculation. 1065.127 Section 1065.127 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.127 Exhaust gas recirculation. Use...

  2. 40 CFR 1065.127 - Exhaust gas recirculation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Exhaust gas recirculation. 1065.127 Section 1065.127 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.127 Exhaust gas recirculation. Use...

  3. 40 CFR 1065.127 - Exhaust gas recirculation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Exhaust gas recirculation. 1065.127 Section 1065.127 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.127 Exhaust gas recirculation. Use...

  4. 40 CFR 1065.127 - Exhaust gas recirculation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Exhaust gas recirculation. 1065.127 Section 1065.127 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.127 Exhaust gas recirculation. Use...

  5. 40 CFR 86.240-94 - Exhaust sample analysis.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Exhaust sample analysis. 86.240-94 Section 86.240-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.240-94 Exhaust sample analysis....

  6. 40 CFR 86.1544 - Calculation; idle exhaust emissions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Calculation; idle exhaust emissions. 86.1544 Section 86.1544 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Test Procedures § 86.1544 Calculation; idle exhaust emissions. (a) The final idle emission test...

  7. Quantitative planar laser-induced fluorescence imaging of multi-component fuel/air mixing in a firing gasoline-direct-injection engine: Effects of residual exhaust gas on quantitative PLIF

    SciTech Connect

    Williams, Ben; Ewart, Paul; Wang, Xiaowei; Stone, Richard; Ma, Hongrui; Walmsley, Harold; Cracknell, Roger; Stevens, Robert; Richardson, David; Fu, Huiyu; Wallace, Stan

    2010-10-15

    A study of in-cylinder fuel-air mixing distributions in a firing gasoline-direct-injection engine is reported using planar laser-induced fluorescence (PLIF) imaging. A multi-component fuel synthesised from three pairs of components chosen to simulate light, medium and heavy fractions was seeded with one of three tracers, each chosen to co-evaporate with and thus follow one of the fractions, in order to account for differential volatility of such components in typical gasoline fuels. In order to make quantitative measurements of fuel-air ratio from PLIF images, initial calibration was by recording PLIF images of homogeneous fuel-air mixtures under similar conditions of in-cylinder temperature and pressure using a re-circulation loop and a motored engine. This calibration method was found to be affected by two significant factors. Firstly, calibration was affected by variation of signal collection efficiency arising from build-up of absorbing deposits on the windows during firing cycles, which are not present under motored conditions. Secondly, the effects of residual exhaust gas present in the firing engine were not accounted for using a calibration loop with a motored engine. In order to account for these factors a novel method of PLIF calibration is presented whereby 'bookend' calibration measurements for each tracer separately are performed under firing conditions, utilising injection into a large upstream heated plenum to promote the formation of homogeneous in-cylinder mixtures. These calibration datasets contain sufficient information to not only characterise the quantum efficiency of each tracer during a typical engine cycle, but also monitor imaging efficiency, and, importantly, account for the impact of exhaust gas residuals (EGR). By use of this method EGR is identified as a significant factor in quantitative PLIF for fuel mixing diagnostics in firing engines. The effects of cyclic variation in fuel concentration on burn rate are analysed for different

  8. Aerothermodynamic Testing of Protuberances and Penetrations on the NASA Crew Exploration Vehicle Heat Shield in the NASA Langley 20-Inch Mach 6 Air Tunnel

    NASA Technical Reports Server (NTRS)

    Liechty, Derek S.

    2008-01-01

    An experimental wind tunnel program is being conducted in support of an Agency wide effort to develop a replacement for the Space Shuttle and to support the NASA s long-term objective of returning to the moon and then on to Mars. This paper documents experimental measurements made on several scaled ceramic heat transfer models of the proposed Crew Exploration Vehicle. Global heat transfer images and heat transfer distributions obtained using phosphor thermography were used to infer interference heating on the Crew Exploration Vehicle Cycle 1 heat shield from local protuberances and penetrations for both laminar and turbulent heating conditions. Test parametrics included free stream Reynolds numbers of 1.0x10(exp 6)/ft to 7.25x10(exp 6)/ft in Mach 6 air at a fixed angle-of-attack. Single arrays of discrete boundary layer trips were used to trip the boundary layer approaching the protuberances/penetrations to a turbulent state. Also, the effects of three compression pad diameters, two radial locations of compression pad/tension tie location, compression pad geometry, and rotational position of compression pad/tension tie were examined. The experimental data highlighted in this paper are to be used to validate CFD tools that will be used to generate the flight aerothermodynamic database. Heat transfer measurements will also assist in the determination of the most appropriate engineering methods that will be used to assess local flight environments associated with protuberances/penetrations of the CEV thermal protection system.

  9. A Mach 6 external nozzle experiment with Argon-Freon exhaust simulation

    NASA Technical Reports Server (NTRS)

    Pittman, James L.

    1989-01-01

    A scramjet exhaust simulation technique for hypersonic wind tunnel testing has been developed. Mixtures of Argon and Freon correctly match the inviscid simulation parameters of Mach number, static-pressure ratio, and the ratio of specific heats at the combustor exit location; this simulation is accomplished at significantly reduced temperatures and without combustion. An investigation of nozzle parametrics in a Mach 6 freestream showed that the external nozzle ramp angle, the cowl trailing-edge angle, an external nozzle flow fence and the nozzle static-pressure ratio significantly affected the external nozzle thrust and pitching moment as measured by the integration of surface-pressure data. A comparison of Argon-Freon and air exhaust simulation showed that the external nozzle thrust and pitching moment were in error by roughly a factor of 2 using air due to the incorrect match of the ratio of specific heats. An assessment of two-dimensional Euler and Navier-Stokes codes for predicting external nozzle aerodynamic characteristics was made by comparing computed and experimental results.

  10. Photochemical Reaction Altered Cardiac Toxicity of Diesel Exhaust Inhalation

    EPA Science Inventory

    Rationale: Epidemiological studies have indicated an association between urban air pollution exposure and cardiovascular morbidity and mortality. The present study was designed to evaluate the cardiac effects of inhaled diesel exhaust and compared with photochemically altered d...

  11. INCREASED SUSCEPTIBILITY TO INFLUENZA INFECTION AFTER DIESEL EXHAUST EXPOSURE.

    EPA Science Inventory

    Inhaled environmental pollutants have a possible role in modulating the susceptibility of humans to respiratory infections. Diesel exhaust (DE) is a major component of urban air pollution and their effects on pulmonary infections is of great concern. Influenza infections cause ...

  12. DIESEL EXHAUST ENHANCES INFLUENZA VIRUS INFECTIONS IN RESPIRATORY EPITHELIAL CELLS

    EPA Science Inventory

    Several factors, such as age and nutritional status can affect the susceptibility to influenza infections. Moreover, exposure to air pollutants, such as diesel exhaust (DE), has been shown to affect respiratory virus infections in rodent models. Influenza virus primarily infects ...

  13. INCREASED SUSCEPTIBILITY TO INFLUENZA INFECTION AFTER DIESEL EXHAUST EXPOSURE

    EPA Science Inventory

    Inhaled environmental pollutants have a possible role in modulating the susceptibility of humans to respiratory infections. Diesel exhaust (DE) is a major component of urban air pollution and their effects on pulmonary infections is of great concern. Influenza infections cause ...

  14. DETAIL VIEW OF STARBOARD SRB EXHAUST OPENING, LOOKING UP FROM ...

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

    DETAIL VIEW OF STARBOARD SRB EXHAUST OPENING, LOOKING UP FROM THE GROUND - Cape Canaveral Air Force Station, Launch Complex 39, Mobile Launcher Platforms, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  15. VIEW OF 0 LEVEL OF MLP, SHOWING SSME EXHAUST OPENING ...

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

    VIEW OF 0 LEVEL OF MLP, SHOWING SSME EXHAUST OPENING - Cape Canaveral Air Force Station, Launch Complex 39, Mobile Launcher Platforms, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  16. DETAIL VIEW OF SSME EXHAUST OPENING, LOOKING UP FROM THE ...

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

    DETAIL VIEW OF SSME EXHAUST OPENING, LOOKING UP FROM THE GROUND - Cape Canaveral Air Force Station, Launch Complex 39, Mobile Launcher Platforms, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  17. DETAIL VIEW OF STARBOARD SRB EXHAUST OPENING FROM 0 LEVEL ...

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

    DETAIL VIEW OF STARBOARD SRB EXHAUST OPENING FROM 0 LEVEL - Cape Canaveral Air Force Station, Launch Complex 39, Mobile Launcher Platforms, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  18. Atmospheric scavenging exhaust

    NASA Technical Reports Server (NTRS)

    Fenton, D. L.; Purcell, R. Y.

    1977-01-01

    Solid propellant rocket exhaust was directly utilized to ascertain raindrop scavenging rates for hydrogen chloride. The airborne HCl concentration varied from 0.2 to 10.0 ppm and the raindrop sizes tested included 0.55 mm, 1.1 mm, and 3.0 mm. Two chambers were used to conduct the experiments. A large, rigid walled, spherical chamber stored the exhaust constituents while the smaller chamber housing all the experiments was charged as required with rocket exhaust HCl. Surface uptake experiments demonstrated an HCl concentration dependence for distilled water. Sea water and brackish water HCl uptake was below the detection limit of the chlorine-ion analysis technique employed. Plant life HCl uptake experiments were limited to corn and soybeans. Plant age effectively correlated the HCl uptake data. Metallic corrosion was not significant for single 20 minute exposures to the exhaust HCl under varying relative humidity.

  19. Wind tunnel experiments on flow separation control of an Unmanned Air Vehicle by nanosecond discharge plasma aerodynamic actuation

    NASA Astrophysics Data System (ADS)

    Kang, Chen; Hua, Liang

    2016-02-01

    Plasma flow control (PFC) is a new kind of active flow control technology, which can improve the aerodynamic performances of aircrafts remarkably. The flow separation control of an unmanned air vehicle (UAV) by nanosecond discharge plasma aerodynamic actuation (NDPAA) is investigated experimentally in this paper. Experimental results show that the applied voltages for both the nanosecond discharge and the millisecond discharge are nearly the same, but the current for nanosecond discharge (30 A) is much bigger than that for millisecond discharge (0.1 A). The flow field induced by the NDPAA is similar to a shock wave upward, and has a maximal velocity of less than 0.5 m/s. Fast heating effect for nanosecond discharge induces shock waves in the quiescent air. The lasting time of the shock waves is about 80 μs and its spread velocity is nearly 380 m/s. By using the NDPAA, the flow separation on the suction side of the UAV can be totally suppressed and the critical stall angle of attack increases from 20° to 27° with a maximal lift coefficient increment of 11.24%. The flow separation can be suppressed when the discharge voltage is larger than the threshold value, and the optimum operation frequency for the NDPAA is the one which makes the Strouhal number equal one. The NDPAA is more effective than the millisecond discharge plasma aerodynamic actuation (MDPAA) in boundary layer flow control. The main mechanism for nanosecond discharge is shock effect. Shock effect is more effective in flow control than momentum effect in high speed flow control. Project supported by the National Natural Science Foundation of China (Grant Nos. 61503302, 51207169, and 51276197), the China Postdoctoral Science Foundation (Grant No. 2014M562446), and the Natural Science Foundation of Shaanxi Province, China (Grant No. 2015JM1001).

  20. On-Road Measurement of Exhaust Emission Factors for Individual Diesel Trucks

    NASA Astrophysics Data System (ADS)

    Dallmann, T. R.; DeMartini, S.; Harley, R. A.; Kirchstetter, T. W.; Wood, E. C.; Onasch, T. B.; Herndon, S. C.

    2011-12-01

    Diesel trucks are an important source of primary fine particulate matter (PM2.5) that includes black carbon (BC) as a major component. More stringent exhaust emission standards for new engines, effective starting in 2007, considerably reduce allowable emissions and have led to use of after-treatment control devices such as diesel particle filters. The state of California is also implementing programs to accelerate replacement or retrofit of older trucks. In light of these changes, measurements of emissions from in-use heavy-duty diesel trucks are timely and needed to understand the impact of new control technologies on emissions. PM2.5, BC mass, particle light absorption, and particle light extinction emission factors for hundreds of individual diesel trucks were measured in this study. Emissions were measured in July 2010 from trucks driving through the Caldecott tunnel in the San Francisco Bay area. Gas-phase emissions including nitric oxide, nitrogen dioxide, carbon monoxide, and carbon dioxide (CO2) were also measured. Pollutants were measured using air sampling inlets located directly above the vertical exhaust stacks of heavy-duty trucks driving by on the roadway below. All of these measurements were made using fast time response (1 Hz) sensors. Particle optical properties were simultaneously characterized with direct measurements of absorption (babs) and extinction (bext) coefficients. Emission factors for individual trucks were calculated using a carbon balance method in which emissions of PM2.5, BC, babs, and bext in each exhaust plume were normalized to emissions of CO2. Emission factor distributions and fleet-average values are quantified. Absorption and extinction emission factors are used to calculate the aerosol single scattering albedo and BC mass absorption efficiency for individual truck exhaust plumes.

  1. Development of a 100 nmol mol(-1) propane-in-air SRM for automobile-exhaust testing for new low-emission requirements.

    PubMed

    Rhoderick, George C

    2007-04-01

    New US federal low-level automobile emission requirements, for example zero-level-emission vehicle (ZLEV), for hydrocarbons and other species, have resulted in the need by manufacturers for new certified reference materials. The new emission requirement for hydrocarbons requires the use, by automobile manufacturing testing facilities, of a 100 nmol mol(-1) propane in air gas standard. Emission-measurement instruments are required, by federal law, to be calibrated with National Institute of Standards and Technology (NIST) traceable reference materials. Because a NIST standard reference material (SRM) containing 100 nmol mol(-1) propane was not available, the US Environmental Protection Agency (EPA) and the Automobile Industry/Government Emissions Research Consortium (AIGER) requested that NIST develop such an SRM. A cylinder lot of 30 gas mixtures containing 100 nmol mol(-1) propane in air was prepared in 6-L aluminium gas cylinders by a specialty gas company and delivered to the Gas Metrology Group at NIST. Another mixture, contained in a 30-L aluminium cylinder and included in the lot, was used as a lot standard (LS). Using gas chromatography with flame-ionization detection all 30 samples were compared to the LS to obtain the average of six peak-area ratios to the LS for each sample with standard deviations of <0.31%. The average sample-to-LS ratio determinations resulted in a range of 0.9828 to 0.9888, a spread of 0.0060, which corresponds to a relative standard deviation of 0.15% of the average for all 30 samples. NIST developed its first set of five propane in air primary gravimetric standards covering a concentration range 91 to 103 nmol mol(-1) with relative uncertainties of 0.15%. This new suite of propane gravimetric standards was used to analyze and assign a concentration value to the SRM LS. On the basis of these data each SRM sample was individually certified, furnishing the desired relative expanded uncertainty of +/-0.5%. Because automobile companies

  2. Boosting devices with integral features for recirculating exhaust gas

    DOEpatents

    Wu, Ko -Jen

    2015-09-15

    According to one embodiment of the invention, a compressor housing includes a compressor inlet in fluid communication with a compressor volute configured to house a compressor wheel, the compressor inlet configured to provide a first air flow to the compressor wheel and a compressor outlet in fluid communication with the compressor volute, the compressor outlet configured to direct a compressed gas to an intake manifold. The compressor housing further includes an exhaust gas recirculation inlet port in fluid communication with the compressor volute, the exhaust gas recirculation inlet port being configured to combine an exhaust gas flow with the air flow to the compressor wheel.

  3. Recognition Tunneling

    PubMed Central

    Lindsay, Stuart; He, Jin; Sankey, Otto; Hapala, Prokop; Jelinek, Pavel; Zhang, Peiming; Chang, Shuai; Huang, Shuo

    2010-01-01

    Single molecules in a tunnel junction can now be interrogated reliably using chemically-functionalized electrodes. Monitoring stochastic bonding fluctuations between a ligand bound to one electrode and its target bound to a second electrode (“tethered molecule-pair” configuration) gives insight into the nature of the intermolecular bonding at a single molecule-pair level, and defines the requirements for reproducible tunneling data. Simulations show that there is an instability in the tunnel gap at large currents, and this results in a multiplicity of contacts with a corresponding spread in the measured currents. At small currents (i.e. large gaps) the gap is stable, and functionalizing a pair of electrodes with recognition reagents (the “free analyte” configuration) can generate a distinct tunneling signal when an analyte molecule is trapped in the gap. This opens up a new interface between chemistry and electronics with immediate implications for rapid sequencing of single DNA molecules. PMID:20522930

  4. Acid droplet generation in SRM exhaust clouds

    NASA Technical Reports Server (NTRS)

    Dingle, A. N.

    1983-01-01

    A free energy analysis is applied to the co-condensation/evaporation of H2O and HCl vapors on wettable particles in open air in order to model droplet nucleation in solid rocket motor (SRM) exhaust clouds. Formulations are defined for the free energy change, the drop radius, the saturation ratio, the total number of molecules, and the mean molecular radius in solution, as well as the molecular volume and the concentration range. The free energy release in the phase transition for the AL2O3 nuclei in the SRM exhaust is examined as a function of the HCl molefraction and nucleating particle radius, based on Titan III launch exhaust cloud conditions 90 sec after ignition. The most efficient droplet growth is determined to occur at an HCl molefraction of 0.082 and a particle radius of 0.0000013 cm, i.e. a molality of 5.355.

  5. Air Quality in Mecca and Surrounding Holy Places in Saudi Arabia during Hajj: Initial Survey

    NASA Astrophysics Data System (ADS)

    Simpson, I. J.; Aburizaiza, O. S.; Siddique, A.; Barletta, B.; Blake, N. J.; Gartner, A.; Khwaja, H. A.; Meinardi, S.; Zeb, J.; Blake, D. R.

    2014-12-01

    The Arabian Peninsula experiences severe air pollution yet is highly understudied in terms of surface measurements of ozone and its precursors. Every year the air pollution in Saudi Arabia is intensified by additional traffic and activities during Hajj, the world's largest religious pilgrimage that draws 3‒4 million pilgrims to Mecca (population of 2 million). Using whole air sampling and high-precision measurements of carbon monoxide (CO) and 97 volatile organic compounds (VOCs), we performed an initial survey of air quality in Mecca, its tunnels, and surrounding holy sites during the 2012 Hajj (October 24-27; n = 77). This is the first time such a campaign has been undertaken. Levels of the combustion tracer CO and numerous VOCs were strongly elevated along the pilgrimage route, especially in the tunnels of Mecca, and are a concern for human health. For example CO reached 57 ppmv in the tunnels, exceeding the 30-min exposure guideline of 50 ppmv. Benzene, a known carcinogen, reached 185 ppbv in the tunnels, exceeding the 1-hr exposure limit of 9 ppbv. The gasoline evaporation tracer i-pentane was the most abundant VOC during Hajj, reaching 1200 ppbv in the tunnels. Even though VOC concentrations were generally lower during a follow-up non-Hajj sampling period (April, 2013), many were still comparable to other large cities suffering from poor air quality. Major VOC sources during Hajj included vehicular exhaust, gasoline evaporation, liquefied petroleum gas, and air conditioners. Of the measured compounds, reactive alkenes (associated with gasoline evaporation) and CO showed the strongest potential to form ground-level ozone. Therefore efforts to curb ozone formation likely require dual targeting of both combustive and evaporative fossil fuel sources. However, modeling and other measurements (e.g., nitrogen oxides) are also needed to fully understand Mecca's oxidative environment. We also present specific recommendations to reduce VOC emissions and exposure in

  6. Error analysis and assessment of unsteady forces acting on a flapping wing micro air vehicle: free flight versus wind-tunnel experimental methods.

    PubMed

    Caetano, J V; Percin, M; van Oudheusden, B W; Remes, B; de Wagter, C; de Croon, G C H E; de Visser, C C

    2015-08-20

    An accurate knowledge of the unsteady aerodynamic forces acting on a bio-inspired, flapping-wing micro air vehicle (FWMAV) is crucial in the design development and optimization cycle. Two different types of experimental approaches are often used: determination of forces from position data obtained from external optical tracking during free flight, or direct measurements of forces by attaching the FWMAV to a force transducer in a wind-tunnel. This study compares the quality of the forces obtained from both methods as applied to a 17.4 gram FWMAV capable of controlled flight. A comprehensive analysis of various error sources is performed. The effects of different factors, e.g., measurement errors, error propagation, numerical differentiation, filtering frequency selection, and structural eigenmode interference, are assessed. For the forces obtained from free flight experiments it is shown that a data acquisition frequency below 200 Hz and an accuracy in the position measurements lower than ± 0.2 mm may considerably hinder determination of the unsteady forces. In general, the force component parallel to the fuselage determined by the two methods compares well for identical flight conditions; however, a significant difference was observed for the forces along the stroke plane of the wings. This was found to originate from the restrictions applied by the clamp to the dynamic oscillations observed in free flight and from the structural resonance of the clamped FWMAV structure, which generates loads that cannot be distinguished from the external forces. Furthermore, the clamping position was found to have a pronounced influence on the eigenmodes of the structure, and this effect should be taken into account for accurate force measurements.

  7. The Sky is Falling: An air deposition/stormwater runoff model simulating the pathways of five heavy metals from their status as mobile and stack exhaust constituents to their delivery to the Elizabeth River

    SciTech Connect

    Barrett-McDaniels, J.; Barrett, M.

    1997-12-31

    Recent studies by the Environmental Protection Agency (EPA) indicate that air emissions contribute a major portion of the total loading of toxic metals to the waters of the Chesapeake Bay and its tributaries. According to the Chesapeake Executive Council of the interstate Chesapeake Bay Program, five of these metals, cadmium, chromium, copper, lead, and zinc, have been observed to have a negative impact on the waters of the Elizabeth River, which is within the Chesapeake Bay watershed. In order to better define the sources and processes which contribute to concentrations of these metals in the Elizabeth River, this analysis simulates the pathway of these metals from their status as mobile and stack exhaust constituents to their delivery to the river. EPA`s ISCST3 model was used to predict deposition loading on the Elizabeth River water and watershed surfaces, using regional annual meteorological data. Air emissions input to the ISCST3 model were derived from stationary and mobile sources: stationary source emissions were estimated using Virginia Department of Environmental Quality inventories and EPA-approved emissions factors for major sources with the potential to impact the watershed, while mobile source emissions were estimated using traffic volumes provided by the Department of Transportation and EPA-approved emissions factors. EPA`s SWMM model was then used to predict maximum short term and average annual build up and wash off rates for these metals using recorded rainfall data and existing land use and impervious cover for the watershed. The results are compared to water quality monitoring data from the municipal NPDES stormwater wet weather monitoring permit program.

  8. Multispectral imaging of aircraft exhaust

    NASA Astrophysics Data System (ADS)

    Berkson, Emily E.; Messinger, David W.

    2016-05-01

    Aircraft pollutants emitted during the landing-takeoff (LTO) cycle have significant effects on the local air quality surrounding airports. There are currently no inexpensive, portable, and unobtrusive sensors to quantify the amount of pollutants emitted from aircraft engines throughout the LTO cycle or to monitor the spatial-temporal extent of the exhaust plume. We seek to thoroughly characterize the unburned hydrocarbon (UHC) emissions from jet engine plumes and to design a portable imaging system to remotely quantify the emitted UHCs and temporally track the distribution of the plume. This paper shows results from the radiometric modeling of a jet engine exhaust plume and describes a prototype long-wave infrared imaging system capable of meeting the above requirements. The plume was modeled with vegetation and sky backgrounds, and filters were selected to maximize the detectivity of the plume. Initial calculations yield a look-up chart, which relates the minimum amount of emitted UHCs required to detect the presence of a plume to the noise-equivalent radiance of a system. Future work will aim to deploy the prototype imaging system at the Greater Rochester International Airport to assess the applicability of the system on a national scale. This project will help monitor the local pollution surrounding airports and allow better-informed decision-making regarding emission caps and pollution bylaws.

  9. System for the incineraton of refuse and the treatment of the incineration exhaust gasses

    SciTech Connect

    Wilson, P.

    1991-09-24

    This patent describes a method for the incineration of refuse and the treatment of incineration exhaust gases, it comprises: incinerating the refuse in a fire box having air intake means, oil decomposition product removal means, and exhaust gas off take means, directing the gases from the off take means to cooling means, treating the exhaust gases in the cooling means by heat exchange with a cooling liquid, passing the exhaust gases through filtration means whereby particulates are removed from the exhaust gases, subjecting the exhaust gases to after-burning in a closed after-burner chamber, passing the exhaust gases through a wash assembly whereby the exhaust gases are passed through a water bath and subjected to a water spray, and discharging the cleaned exhaust gases to the atmosphere.

  10. Hyperventilation and exhaustion syndrome.

    PubMed

    Ristiniemi, Heli; Perski, Aleksander; Lyskov, Eugene; Emtner, Margareta

    2014-12-01

    Chronic stress is among the most common diagnoses in Sweden, most commonly in the form of exhaustion syndrome (ICD-10 classification - F43.8). The majority of patients with this syndrome also have disturbed breathing (hyperventilation). The aim of this study was to investigate the association between hyperventilation and exhaustion syndrome. Thirty patients with exhaustion syndrome and 14 healthy subjects were evaluated with the Nijmegen Symptom Questionnaire (NQ). The participants completed questionnaires about exhaustion, mental state, sleep disturbance, pain and quality of life. The evaluation was repeated 4 weeks later, after half of the patients and healthy subjects had engaged in a therapy method called 'Grounding', a physical exercise inspired by African dance. The patients reported significantly higher levels of hyperventilation as compared to the healthy subjects. All patients' average score on NQ was 26.57 ± 10.98, while that of the healthy subjects was 15.14 ± 7.89 (t = -3.48, df = 42, p < 0.001). The NQ scores correlated strongly with two measures of exhaustion (Karolinska Exhaustion Scale KES r = 0.772, p < 0.01; Shirom Melamed Burnout Measure SMBM r = 0.565, p < 0.01), mental status [Hospital Anxiety and Depression Score (HADS) depression r = 0.414, p < 0.01; HADS anxiety r = 0.627, p < 0.01], sleep disturbances (r = -0.514, p < 0.01), pain (r = -.370, p < 0.05) and poor well-being (Medical Outcomes Survey Short Form 36 questionnaire- SR Health r = -0.529, p < 0.05). In the logistic regression analysis, the variance in the scores from NQ were explained to a high degree (R(2) = 0.752) by scores in KES and HADS. The brief Grounding training contributed to a near significant reduction in hyperventilation (F = 2.521, p < 0.124) and to significant reductions in exhaustion scores and scores of depression and anxiety. The conclusion is that hyperventilation is common in exhaustion syndrome patients and that it can be reduced by systematic physical therapy

  11. Full Scale Tunnel model

    NASA Technical Reports Server (NTRS)

    1929-01-01

    Interior view of Full-Scale Tunnel (FST) model. (Small human figures have been added for scale.) On June 26, 1929, Elton W. Miller wrote to George W. Lewis proposing the construction of a model of the full-scale tunnel . 'The excellent energy ratio obtained in the new wind tunnel of the California Institute of Technology suggests that before proceeding with our full scale tunnel design, we ought to investigate the effect on energy ratio of such factors as: 1. small included angle for the exit cone; 2. carefully designed return passages of circular section as far as possible, without sudden changes in cross sections; 3. tightness of walls. It is believed that much useful information can be obtained by building a model of about 1/16 scale, that is, having a closed throat of 2 ft. by 4 ft. The outside dimensions would be about 12 ft. by 25 ft. in plan and the height 4 ft. Two propellers will be required about 28 in. in diameter, each to be driven by direct current motor at a maximum speed of 4500 R.P.M. Provision can be made for altering the length of certain portions, particularly the exit cone, and possibly for the application of boundary layer control in order to effect satisfactory air flow.

  12. Exhaust bypass flow control for exhaust heat recovery

    DOEpatents

    Reynolds, Michael G.

    2015-09-22

    An exhaust system for an engine comprises an exhaust heat recovery apparatus configured to receive exhaust gas from the engine and comprises a first flow passage in fluid communication with the exhaust gas and a second flow passage in fluid communication with the exhaust gas. A heat exchanger/energy recovery unit is disposed in the second flow passage and has a working fluid circulating therethrough for exchange of heat from the exhaust gas to the working fluid. A control valve is disposed downstream of the first and the second flow passages in a low temperature region of the exhaust heat recovery apparatus to direct exhaust gas through the first flow passage or the second flow passage.

  13. Hybrid Exhaust Component

    NASA Technical Reports Server (NTRS)

    Pelletier, Gerard D. (Inventor); Logan, Charles P. (Inventor); McEnerney, Bryan William (Inventor); Haynes, Jeffrey D. (Inventor)

    2015-01-01

    An exhaust includes a wall that has a first composite material having a first coefficient of thermal expansion and a second composite material having a second coefficient of the thermal expansion that is less than the first coefficient of thermal expansion.

  14. Diesel engine exhaust

    Integrated Risk Information System (IRIS)

    Diesel engine exhaust ; CASRN N.A . Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  15. A Preliminary Study of the Prevention of Ice on Aircraft by the Use of Engine-exhaust Heat

    NASA Technical Reports Server (NTRS)

    Rodert, Lewis A

    1939-01-01

    An investigation was made in the N.A.C.A. ice tunnel at air temperatures from 20 degrees to 28 degrees Fahrenheit and at a velocity of 80 miles per hour to determine whether ice formations on a model wing could be prevented by the use of the heat from the engine-exhaust gas. Various spanwise duct systems were tested in a 6-foot-chord N.A.C.A. 23012 wing model. The formation of ice over the entire wing chord was prevented by the direct heating of the forward 10 percent of the wing by hot air, which was passed through leading-edge ducts. Under dry conditions, enough heat to maintain the temperature of the forward 10 percent of the wing at about 200 degrees Fahrenheit above that of the ambient air was required for the prevention of ice formation. The air temperature in the ducts that was necessary to produce these skin temperatures varied from 360 degrees to 834 degrees Fahrenheit; the corresponding air velocities in the duct were 152 and 45 feet per second. Ice formations at the leading edge were locally prevented by air that passed over the interior of the wing surface at a velocity of 30 feet per second and a temperature of 122 degrees Fahrenheit.

  16. De-icing of the altitude wind tunnel turning vanes by electro-magnetic impulse

    NASA Technical Reports Server (NTRS)

    Zumwalt, G. W.; Ross, R.

    1986-01-01

    The Altitude Wind Tunnel at the NASA-Lewis facility is being proposed for a refurbishment and moderization. Two major changes are: (1) the increasing of the test section Mach number to 0.90, and (2) the addition of spray nozzles to provide simulation of flight in icing clouds. Features to be retained are the simulation of atmospheric temperature and pressure to 50,000 foot altitude and provision for full-scale aircraft engine operation by the exhausting of the aircraft combustion gases and ingestion of air to replace that used in combustion. The first change required a re-design of the turning vanes in the two corners downstream of the test section due to the higher Mach number at the corners. The second change threatens the operation of the turning vanes by the expected ice build-up, particulary on the first-corner vanes. De-icing by heat has two drawbacks: (1) an extremely large amount of heat is required, and (2) the melted ice would tend to collect as ice on some other surfaces in the tunnel, namely, the tunnel propellers and the cooling coils. An alternate de-icing method had been under development for three years under NASA-Lewis grants to the Wichita State University. This report describes the electro-impulse de-icing (EIDI) method and the testing work done to assess its applicability to wind tunnel turning vane de-icing. Tests were conducted in the structural dynamics laboratory and in the NASA Icing Research Tunnel. Good ice protection was achieved at lower power consumption and at a wide range of tunnel operations conditions. Recommendations for design and construction of the system for this application of the EIDI method are given.

  17. Exhaustion, a guide to transportation emissions

    SciTech Connect

    1998-10-01

    This publication contains a series of fact sheets on the environmental impact of the automobile, addressing the issues of vehicle exhaust and its impact, alternative and cleaner fuels, and alternative forms of transportation. The sheets are intended to serve as background information and reference material. Specific topics of the sheets include: Components of car exhaust and other automobile-related emissions; air quality in Canada; smog; climate change and the greenhouse effect; acid rain; stratospheric ozone depletion; hazardous air pollutants and the automobile; health impacts; modifications and improvements to diesel fuels; reformulated gasoline; alternative fuels such as propane, ethanol, natural gas, hydrogen, and methanol; emissions standards and controls; inspection and maintenance programs; transportation demand management; driving behavior and the environment; and indirect costs of the automobile.

  18. Comparison of immunotoxic effects induced by the extracts from methanol and gasoline engine exhausts in vitro.

    PubMed

    Che, Wangjun; Liu, Guiming; Qiu, Hong; Zhang, Hao; Ran, Yun; Zeng, Xianggui; Wen, Weihua; Shu, Ya

    2010-06-01

    Gasoline engine exhaust has been considered as a major source of air pollution in China. Due to lower cyto- and geno-toxicity effects of methanol engine exhaust, methanol is regarded as a potential substitute for gasoline. We have previously compared cyto- and geno-toxicities of gasoline engine exhaust with that of methanol engine exhaust in A549 cells (Zhang et al., 2007).To characterize the immunotoxic effects for gasoline and methanol engine exhausts in immune cell, in this study, we further compared effects of gasoline and methanol engine exhausts on immune function in RAW264.7 cell and rabbit alveolar macrophages. Results showed that both gasoline and methanol engine exhaust could evidently inhibit RAW264.7 cell proliferation, promote RAW264.7 cell apoptosis, decrease E-rosette formation rate and inhibit anti-tumor effects of alveolar macrophages, at the same time, these effects of gasoline engine exhaust were far stronger than those of methanol engine exhaust. In addition, gasoline engine exhaust could significantly inhibit activities of ADCC of alveolar macrophages, but methanol engine exhaust could not. These results suggested that both gasoline and methanol engine exhausts might be immunotoxic atmospheric pollutants, but some effects of gasoline engine exhaust on immunotoxicities may be far stronger than that of methanol engine exhaust.

  19. 40 CFR 87.21 - Exhaust emission standards for Tier 4 and earlier engines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Exhaust Emissions (New Aircraft Gas Turbine Engines) § 87.21 Exhaust emission standards for Tier 4 and earlier... apply for aircraft engines manufactured before July 18, 2012 and certain engines exempted under §...

  20. 40 CFR 87.21 - Exhaust emission standards for Tier 4 and earlier engines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Exhaust Emissions (New Aircraft Gas Turbine Engines) § 87.21 Exhaust emission standards for Tier 4 and earlier... apply for aircraft engines manufactured before July 18, 2012 and certain engines exempted under §...

  1. 40 CFR 89.416 - Raw exhaust gas flow.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Measurement of the air flow and the fuel flow by suitable metering systems (for details see SAE J244. This... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Raw exhaust gas flow. 89.416 Section 89.416 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

  2. 40 CFR 89.416 - Raw exhaust gas flow.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Measurement of the air flow and the fuel flow by suitable metering systems (for details see SAE J244. This... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Raw exhaust gas flow. 89.416 Section 89.416 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

  3. 40 CFR 89.416 - Raw exhaust gas flow.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Measurement of the air flow and the fuel flow by suitable metering systems (for details see SAE J244. This... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Raw exhaust gas flow. 89.416 Section 89.416 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

  4. 40 CFR 89.416 - Raw exhaust gas flow.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) Measurement of the air flow and the fuel flow by suitable metering systems (for details see SAE J244. This... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Raw exhaust gas flow. 89.416 Section 89.416 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

  5. 40 CFR 86.1342-90 - Calculations; exhaust emissions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous and Particulate Exhaust Test... mass: HCmass = Vmix × DensityHC × (HCconc/106) (2) Oxides of nitrogen mass: NOxmass = Vmix × DensityNO2... air as determined from dilution air methanol sample in ppm carbon. (2)(i) NOxmass = Oxides of...

  6. The National Environmental Respiratory Center (NERC) experiment in multi-pollutant air quality health research: III. Components of diesel and gasoline engine exhausts, hardwood smoke and simulated downwind coal emissions driving non-cancer biological responses in rodents.

    PubMed

    Mauderly, Joe L; Seilkop, Steven K

    2014-09-01

    An approach to identify causal components of complex air pollution mixtures was explored. Rats and mice were exposed by inhalation 6 h daily for 1 week or 6 months to dilutions of simulated downwind coal emissions, diesel and gasoline exhausts and wood smoke. Organ weights, hematology, serum chemistry, bronchoalveolar lavage, central vascular and respiratory allergic responses were measured. Multiple additive regression tree (MART) analysis of the combined database ranked 45 exposure (predictor) variables for importance to models best fitting 47 significant responses. Single-predictor concentration-response data were examined for evidence of single response functions across all exposure groups. Replication of the responses by the combined influences of the two most important predictors was tested. Statistical power was limited by inclusion of only four mixtures, albeit in multiple concentrations each and with particles removed for some groups. Results gave suggestive or strong evidence of causation of 19 of the 47 responses. The top two predictors of the 19 responses included only 12 organic and 6 inorganic species or classes. An increase in red blood cell count of rats by ammonia and pro-atherosclerotic vascular responses of mice by inorganic gases yielded the strongest evidence for causation and the best opportunity for confirmation. The former was a novel finding; the latter was consistent with other results. The results demonstrated the plausibility of identifying putative causal components of highly complex mixtures, given a database in which the ratios of the components are varied sufficiently and exposures and response measurements are conducted using a consistent protocol.

  7. Partially integrated exhaust manifold

    SciTech Connect

    Hayman, Alan W; Baker, Rodney E

    2015-01-20

    A partially integrated manifold assembly is disclosed which improves performance, reduces cost and provides efficient packaging of engine components. The partially integrated manifold assembly includes a first leg extending from a first port and terminating at a mounting flange for an exhaust gas control valve. Multiple additional legs (depending on the total number of cylinders) are integrally formed with the cylinder head assembly and extend from the ports of the associated cylinder and terminate at an exit port flange. These additional legs are longer than the first leg such that the exit port flange is spaced apart from the mounting flange. This configuration provides increased packaging space adjacent the first leg for any valving that may be required to control the direction and destination of exhaust flow in recirculation to an EGR valve or downstream to a catalytic converter.

  8. Exhaust emissions reduction for intermittent combustion aircraft engines

    NASA Technical Reports Server (NTRS)

    Rezy, B. J.; Stuckas, K. J.; Tucker, J. R.; Meyers, J. E.

    1982-01-01

    Three concepts which, to an aircraft piston engine, provide reductions in exhaust emissions of hydrocarbons and carbon monoxide while simultaneously improving fuel economy. The three chosen concepts, (1) an improved fuel injection system, (2) an improved cooling cylinder head, and (3) exhaust air injection, when combined, show a synergistic relationship in achieving these goals. In addition, the benefits of variable ignition timing were explored and both dynamometer and flight testing of the final engine configuration were accomplished.

  9. Tunneling of heat between metals

    NASA Astrophysics Data System (ADS)

    Mahan, G. D.

    2017-03-01

    We provide a theory of how heat tunnels between two parallel metal surfaces separated by an air gap. Two contributions are calculated: (1) electron-electron interactions and (2) photon fields from surface plasmons. Both contributions can transfer energy through low energy electron pairs. Our concern is with heat flow for small air gaps, on the order of nanometers. In that case the contribution from electron-electron interactions is most important. The contribution from photons is more important at larger separations.

  10. Inspection and rehabilitation of tunnels across faults

    SciTech Connect

    Abramson, L.W.; Schmidt, B.

    1995-12-31

    The inspection and rehabilitation of tunnels that cross faults is unique because they usually are in use and have a large variety of alternative lining types including bare rock, concrete, or steel often coated with accumulations of dirt, grime, algae and other minerals. Inspection methods are important including what to look for, how to clean the inner tunnel lining surfaces, non-destructive testing, coring, soundings, air quality detection and protection, ventilation, lightning, etc. Rehabilitation of tunnels crossing faults requires a practiced knowledge of underground design and construction practices. The most common methods of rehabilitation include grouting and concreting. The Variety of water, wastewater, transit, and highway tunnels in California provide ample examples of tunnels, new and old, that cross active faults. This paper will address specific methods of tunnel inspection and maintenance at fault crossings and give examples of relevant highway, transit, water, and wastewater projects and studies in California to demonstrate the discussions presented.

  11. Environment effects from SRB exhaust effluents: Technique development and preliminary assessment

    NASA Technical Reports Server (NTRS)

    Goldford, A. I.; Adelfang, S. I.; Hickey, J. S.; Smith, S. R.; Welty, R. P.; White, G. L.

    1977-01-01

    Techniques to determine the environmental effects from the space shuttle SRB (Solid Rocket Booster) exhaust effluents are used to perform a preliminary climatological assessment. The exhaust effluent chemistry study was performed and the exhaust effluent species were determined. A reasonable exhaust particle size distribution is constructed for use in nozzle analyses and for the deposition model. The preliminary assessment is used to identify problems that are associated with the full-scale assessment; therefore, these preliminary air quality results are used with caution in drawing conclusion regarding the environmental effects of the space shuttle exhaust effluents.

  12. 105. VIEW NORTH FROM SLC3W CABLE TUNNEL INTO CABLE VAULT ...

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

    105. VIEW NORTH FROM SLC-3W CABLE TUNNEL INTO CABLE VAULT AND SLC-3E CABLE TUNNEL. NOTE WOODEN PLANKING ON FLOOR OF TUNNEL AND CABLE TRAYS LINING TUNNEL WALLS. STAIRS ON EAST WALL OF CABLE VAULT LEAD INTO LANDLINE INSTRUMENTATION ROOM. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  13. Diesel injector additives for a clean exhaust

    SciTech Connect

    Herbstman, S.; Virk, K.S.

    1988-08-01

    Increased public awareness of clean air is causing closer examination of potential health problems associated with diesel exhaust particulates. Recently, the EPA published standards mandating a sixfold reduction in diesel exhaust particulates for heavy duty engines from 0.60 gm/bhp-hr in 1988-1990 to 0.10 gm/bhp-hr in 1994. NOx exhaust concentrations were also reduced. For some time now, we have been interested in ways to reduce black smoke from diesel engines since it is one of the prime contributors to exhaust particulates. One of its causes is dirty or clogged fuel injectors due to deposit buildup. During operation with dirty injectors, the spray pattern of fuel into the combustion chamber is distorted, usually resulting in a fuel-rich environment. Incomplete burning of the rich fuel mixture results in an excess of carbonaceous material which is discharged in the exhaust as black smoke. We are engaged in evaluating additives with detergency and antioxidant properties to reduce deposit buildup in the injectors. Long chain alkylamines, and other types of surfactant molecules have been reported as active in preventing deposit buildup. However, little practical information was available concerning structure-activity relationships for use in developing a commercially acceptable additive package. We decided to investigate additives which are active either as gasoline carburetor detergents or as lubricant dispersants; both categories appear to have the necessary surfactant behavior and oil solubility to satisfy our needs for a diesel injector keep clean agent. Our approach to the problem was to develop an additive package for future use in Texaco fuels to reduce black smoke.

  14. Interrelation of exhaust-gas constituents

    NASA Technical Reports Server (NTRS)

    Gerrish, Harold C; Voss, Fred

    1938-01-01

    This report presents the results of an investigation conducted to determine the interrelation of the constituents of the exhaust gases of internal-combustion engines and the effect of engine performance on these relations. Six single-cylinder, liquid-cooled tests engines and one 9-cylinder radial air-cooled engine were tested. Various types of combustion chambers were used and the engines were operated at compression ratios from 5.1 to 7.0 using spark ignition and from 13.5 to 15.6 using compression ignition. The investigation covered a range of engine speeds from 1,500 to 2,100 r.p.m. The fuels used were two grades of aviation gasoline, auto diesel fuel, and laboratory diesel fuel. Power, friction, and fuel-consumption data were obtained from the single-cylinder engines at the same time that the exhaust-gas samples were collected.

  15. Tunnel-to-tunnel correlation

    NASA Technical Reports Server (NTRS)

    Steinle, F. W., Jr.

    1982-01-01

    Flow quality is discussed. Incremental comparisons of: (1) the angle of attack, (2) the axial force coefficient, and (3) the base cavity axial force coefficient against the normal force coefficient are presented. Relative blockage determination, relative buoyancy corrections, and boundary layer transition length are discussed. Blockage buoyancy caused by tunnel model wall dynamic interaction is discussed in terms of adaptive walls. The effect of 'transonic turbulence factor' is considered.

  16. Chemical laser exhaust pipe design research

    NASA Astrophysics Data System (ADS)

    Sun, Yunqiang; Huang, Zhilong; Chen, Zhiqiang; Ren, Zebin; Guo, Longde

    2016-10-01

    In order to weaken the chemical laser exhaust gas influence of the optical transmission, a vent pipe is advised to emissions gas to the outside of the optical transmission area. Based on a variety of exhaust pipe design, a flow field characteristic of the pipe is carried out by numerical simulation and analysis in detail. The research results show that for uniform deflating exhaust pipe, although the pipeline structure is cyclical and convenient for engineering implementation, but there is a phenomenon of air reflows at the pipeline entrance slit which can be deduced from the numerical simulation results. So, this type of pipeline structure does not guarantee seal. For the design scheme of putting the pipeline contract part at the end of the exhaust pipe, or using the method of local area or tail contraction, numerical simulation results show that backflow phenomenon still exists at the pipeline entrance slit. Preliminary analysis indicates that the contraction of pipe would result in higher static pressure near the wall for the low speed flow field, so as to produce counter pressure gradient at the entrance slit. In order to eliminate backflow phenomenon at the pipe entrance slit, concerned with the pipeline type of radial size increase gradually along the flow, flow field property in the pipe is analyzed in detail by numerical simulation methods. Numerical simulation results indicate that there is not reflow phenomenon at entrance slit of the dilated duct. However the cold air inhaled in the slit which makes the temperature of the channel wall is lower than the center temperature. Therefore, this kind of pipeline structure can not only prevent the leak of the gas, but also reduce the wall temperature. In addition, compared with the straight pipe connection way, dilated pipe structure also has periodic structure, which can facilitate system integration installation.

  17. Exhaust gas ignition

    SciTech Connect

    1996-04-01

    This article describes a system developed for rapid light-off of underbody catalysts that has shown potential to meet Euro Stage III emissions targets and to be more cost-effective than some alternatives. Future emissions legislation will require SI engine aftertreatment systems to approach full operating efficiency within the first few seconds after starting to reduce the high total-emissions fraction currently contributed by the cold phase of driving. A reduction of cold-start emissions during Phase 1 (Euro) or Bag 1 (FTP), which in many cases can be as much as 80% of the total for the cycle, has been achieved by electrical heating of the catalytic converter. But electrically heated catalyst (EHC) systems require high currents (100--200 A) to heat the metallic substrate to light-off temperatures over the first 15--20 seconds. Other viable approaches to reducing cold-start emissions include use of a fuel-powered burner upstream of the catalyst. However, as with EHC, the complexity of parts and the introduction of raw fuel into the exhaust system make this device unsatisfactory. Still another approach, an exhaust gas ignition (EGI) system, was first demonstrated in 1991. The operation of a system developed by engineers at Ford Motor Co., Ltd., Cambustion Ltd., and Tickford Ltd. is described here.

  18. Low-speed wind tunnel investigation of a semispan STOL jet transport wing body with an upper surface blown jet flap

    NASA Technical Reports Server (NTRS)

    Phelps, A. E., III; Letko, W.; Henderson, R. L.

    1973-01-01

    An investigation of the static longitudinal aerodynamic characteristics of a semispan STOL jet transport wing-body with an upper-surface blown jet flap for lift augmentation was conducted in a low-speed wind tunnel having a 12-ft octagonal test section. The semispan swept wing had an aspect ratio of 3.92 (7.84 for the full span) and had two simulated turbofan engines mounted ahead of and above the wing in a siamese pod equipped with an exhaust deflector. The purpose of the deflector was to spread the engine exhaust into a jet sheet attached to the upper surface of the wing so that it would turn downward over the flap and provide lift augmentation. The wing also had optional boundary-layer control provided by air blowing through a thin slot over a full-span plain trailing-edge flap.

  19. 5-foot Vertical Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1932-01-01

    The researcher is sitting above the exit cone of the 5-foot Vertical Wind Tunnel and is examining the new 6-component spinning balance. This balance was developed between 1930 and 1933. It was an important advance in the technology of rotating or rolling balances. As M.J. Bamber and C.H. Zimmerman wrote in NACA TR 456: 'Data upon the aerodynamic characteristics of a spinning airplane may be obtained in several ways; namely, flight tests with full-scale airplanes, flight tests with balanced models, strip-method analysis of wind-tunnel force and moment tests, and wind-tunnel tests of rotating models.' Further, they note: 'Rolling-balance data have been of limited value because it has not been possible to measure all six force and moment components or to reproduce a true spinning condition. The spinning balance used in this investigation is a 6-component rotating balance from which it is possible to obtain wind-tunnel data for any of a wide range of possible spinning conditions.' Bamber and Zimmerman described the balance as follows: 'The spinning balance consists of a balance head that supports the model and contains the force-measuring units, a horizontal turntable supported by streamline struts in the center of the jet and, outside the tunnel, a direct-current driving motor, a liquid tachometer, an air compressor, a mercury manometer, a pair of indicating lamps, and the necessary controls. The balance head is mounted on the turntable and it may be set to give any radius of spin between 0 and 8 inches.' In an earlier report, NACA TR 387, Carl Wenzinger and Thomas Harris supply this description of the tunnel: 'The vertical open-throat wind tunnel of the National Advisory Committee for Aeronautics ... was built mainly for studying the spinning characteristics of airplane models, but may be used as well for the usual types of wind-tunnel tests. A special spinning balance is being developed to measure the desired forces and moments with the model simulating the actual

  20. Results of Aero/Acoustic Tests and Analytical Studies of a Two-Dimensional Eight-Lobe Mixer-Ejector Exhaust Nozzle at Takeoff Conditions

    NASA Technical Reports Server (NTRS)

    Harrington, Douglas (Technical Monitor); Schweiger, P.; Stern, A.; Gamble, E.; Barber, T.; Chiappetta, L.; LaBarre, R.; Salikuddin, M.; Shin, H.; Majjigi, R.

    2005-01-01

    Hot flow aero-acoustic tests were conducted with Pratt & Whitney's High-Speed Civil Transport (HSCT) Mixer-Ejector Exhaust Nozzles by General Electric Aircraft Engines (GEAE) in the GEAE Anechoic Freejet Noise Facility (Cell 41) located in Evendale, Ohio. The tests evaluated the impact of various geometric and design parameters on the noise generated by a two-dimensional (2-D) shrouded, 8-lobed, mixer-ejector exhaust nozzle. The shrouded mixer-ejector provides noise suppression by mixing relatively low energy ambient air with the hot, high-speed primary exhaust jet. Additional attenuation was obtained by lining the shroud internal walls with acoustic panels, which absorb acoustic energy generated during the mixing process. Two mixer designs were investigated, the high mixing "vortical" and aligned flow "axial", along with variations in the shroud internal mixing area ratios and shroud length. The shrouds were tested as hardwall or lined with acoustic panels packed with a bulk absorber. A total of 21 model configurations at 1:11.47 scale were tested. The models were tested over a range of primary nozzle pressure ratios and primary exhaust temperatures representative of typical HSCT aero thermodynamic cycles. Static as well as flight simulated data were acquired during testing. A round convergent unshrouded nozzle was tested to provide an acoustic baseline for comparison to the test configurations. Comparisons were made to previous test results obtained with this hardware at NASA Glenn's 9- by 15-foot low-speed wind tunnel (LSWT). Laser velocimetry was used to investigate external as well as ejector internal velocity profiles for comparison to computational predictions. Ejector interior wall static pressure data were also obtained. A significant reduction in exhaust system noise was demonstrated with the 2-D shrouded nozzle designs.

  1. Carpal Tunnel Syndrome

    MedlinePlus

    ... Just a passing cramp? It could be carpal tunnel syndrome. The carpal tunnel is a narrow passageway of ligament and bones ... from irritated tendons or other swelling narrows the tunnel and causes the nerve to be compressed. Symptoms ...

  2. Looking into Tunnel Books.

    ERIC Educational Resources Information Center

    Hinshaw, Craig

    1999-01-01

    Describes how to make tunnel books, which are viewed by looking into a "tunnel" created by accordion-folded expanding sides. Suggests possible themes. Describes how to create a walk-through tunnel book for first grade students. (CMK)

  3. Data Reduction Functions for the Langley 14- by 22-Foot Subsonic Tunnel

    NASA Technical Reports Server (NTRS)

    Boney, Andy D.

    2014-01-01

    The Langley 14- by 22-Foot Subsonic Tunnel's data reduction software utilizes six major functions to compute the acquired data. These functions calculate engineering units, tunnel parameters, flowmeters, jet exhaust measurements, balance loads/model attitudes, and model /wall pressures. The input (required) variables, the output (computed) variables, and the equations and/or subfunction(s) associated with each major function are discussed.

  4. Exhaust gas sensors

    SciTech Connect

    Hiller, J.; Miree, T.J.

    1997-02-09

    The automotive industry needed a fast, reliable, under-the-hood method of determining nitrogen oxides in automobile exhaust. Several technologies were pursued concurrently. These sensing technologies were based on light absorption, electrochemical methods, and surface mass loading. The Y-12 plant was selected to study the methods based on light absorption. The first phase was defining the detailed technical objectives of the sensors--this was the role of the automobile companies. The second phase was to develop prototype sensors in the laboratories--the national laboratories. The final phase was testing of the prototype sensors by the automobile industries. This program was canceled a few months into what was to be a three-year effort.

  5. Tunnel ventilation system design and management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Properly designed and functioning tunnel ventilation systems in broiler houses are essential for maintaining productivity of broilers in warm weather. Convective heat loss from high air velocity provides cooling which improves performance; however, high air velocities require larger fans and increa...

  6. Numerical Investigation of Engine Inlet Vane Hot-Air Anti-Icing System with Surface Air Film

    NASA Astrophysics Data System (ADS)

    Ma, Hui; Chen, Weijian; Zhang, Dalin

    The inlet vane of aircraft engine needs to be equipped with anti-icing system to prevent ice accretion on the leading edge due to flight safety requirements, and the engine bleed hot-air is mostly used to heat the vane surface in anti-icing system. In order to save the energy consumption, a new anti-icing structure was developed and investigated with numerical simulation. Besides the use of small tunnels to enhance the heat transfer characteristics, a narrow gap was opened and assigned on the vane surface at the end of the anti-icing tunnels, and the exhaust hot-air was released from the gap to form an air film on the outside surface, which was supposed to prevent the droplets from impinging to the surface and sweep the droplets away. The droplets impingement on the vane surface was investigated by solving the 3D Eulerian air/droplets twophase model, and the impingement results were compared with the original system. Meanwhile, the thermodynamic analysis of the anti-icing system was presented in this paper. The results indicate that the air film is effective to decrease the droplets impingement area, and the new structure could provide more heat flux for anti-icing than the regular anti-icing structure.

  7. Automotive Fuel and Exhaust Systems.

    ERIC Educational Resources Information Center

    Irby, James F.; And Others

    Materials are provided for a 14-hour course designed to introduce the automotive mechanic to the basic operations of automotive fuel and exhaust systems incorporated on military vehicles. The four study units cover characteristics of fuels, gasoline fuel system, diesel fuel systems, and exhaust system. Each study unit begins with a general…

  8. Turbocharged engine with exhaust purifier

    SciTech Connect

    Tadokoro, T.; Matsuda, I.; Okimoto, H.

    1986-09-23

    The patent described a control system for an automobile engine having intake and exhaust systems for respectively conducting intake gases to and exhaust gases from the engine, which comprises, in combination: a turbocharger including a turbine disposed in the exhaust system and adapted to be driven by the flow of the exhaust gases therethrough and a blower disposed in the intake system and drivingly connected with the turbine for supercharging the intake gases; and exhaust purifying device disposed in the exhaust system downstream of the turbine with respect to the direction of flow of the exhaust gases; a regulating means for varying the effective cross-section of a portion of the exhaust system leading to the turbine; a control means for controlling the regulating means in dependence on an operating condition of the engine, the control means causing the regulating means to decrease the effective cross-section during a low speed operating condition, but to increase the effective cross-section during a high speed operating condition of the engine.

  9. Air injection system diagnostic

    SciTech Connect

    Kotzan, J.M.; Labus, G.E.

    1992-05-19

    This patent describes a method for diagnosing failures in an air control system that controls a quantity of air admitted into an exhaust path of an internal combustion engine. It comprises sensing the oxygen content of the exhaust gas of the engine at predetermined time intervals at a first predetermined point in the exhaust path of the engine, the oxygen content normally oscillating between a rich oxygen condition and a lean oxygen condition in the absence of air injected into the exhaust path above the first predetermined point; injecting a quantity of air into the exhaust path of the engine at a second predetermined point in the exhaust port, the second predetermined point being above the first predetermined point; counting the number of intervals at which the sensed oxygen content indicates a rich oxygen condition over a predetermined period of time; comparing the counted number of rich oxygen intervals to a predetermined threshold value, the threshold value being greater than a counted number of rich oxygen intervals over the predetermined period of time resulting from the normal oscillations between rich and lean oxygen conditions in the absence of air injected into the exhaust path; indicating the existence of a fault in the air control system when the number of rich oxygen intervals does not exceed the predetermined threshold value.

  10. Diesel exhaust-gas purification system

    SciTech Connect

    Doherty, B.J.

    1982-07-01

    The design of a diesel exhaust gas purification system is presented. It will provide 2000 scfm of dry, anerobic gas (essentially nitrogen) for use in air drilling operations where drill pipe corrosion is a problem, such as geothermal applications. The system is operable in the field and may be transported via highways. It will operate at ambient temperatures up to 110/sup 0/F and requires no water - diesel fuel is used to combust excess oxygen and to generate electricity for the system. Gas production costs, including capital amortization, operations, fuel and maintenance (for reasonable utilization) are about $1.50/1000 scf.

  11. Laboratories for the 21st Century: Best Practices; Modeling Exhaust Dispersion for Specifying Acceptable Exhaust/Intake Design (Brochure)

    SciTech Connect

    Not Available

    2011-09-01

    This guide provides general information on specifying acceptable exhaust and intake designs. It also provides various quantitative approaches that can be used to determine expected concentration levels resulting from exhaust system emissions. In addition, the guide describes methodologies that can be employed to operate laboratory exhaust systems in a safe and energy efficient manner by using variable air volume (VAV) technology. The guide, one in a series on best practices for laboratories, was produced by Laboratories for the 21st Century (Labs21), a joint program of the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE). Geared toward architects, engineers, and facility managers, the guides contain information about technologies and practices to use in designing, constructing, and operating safe, sustainable, high-performance laboratories. Studies show a direct relationship between indoor air quality and the health and productivity of building occupants. Historically, the study and protection of indoor air quality focused on emission sources emanating from within the building. For example, to ensure that the worker is not exposed to toxic chemicals, 'as manufactured' and 'as installed' containment specifications are required for fume hoods. However, emissions from external sources, which may be re-ingested into the building through closed circuiting between the building's exhaust stacks and air intakes, are an often overlooked aspect of indoor air quality.

  12. 40 CFR 86.110-90 - Exhaust gas sampling system; diesel vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... be sufficient to prevent water condensation. However, the sample zone dilute exhaust temperature... 125 °F (52 °C) or less and shall prevent the condensation of water vapor in the dilution tunnel. (2... taken, at a temperature of 125 °F (52 °C) or less and shall prevent the condensation of water vapor...

  13. The theory of wind-tunnel wall interference

    NASA Technical Reports Server (NTRS)

    Theodorsen, Theodore

    1933-01-01

    This report outlines the development of a general theory for the calculation of the effect of the boundaries of the air stream on the flow past an airfoil. Analytical treatments are given for tunnels with horizontal boundaries only, with vertical boundaries only, and with a bottom boundary only. Formulas are developed for the tunnel wall interference in each case for an airfoil located at the center of the tunnel. The correction is given as a function of the width to height ratio of the tunnel. The formulas are exact for infinitely small airfoils only, but give good approximation for spans up to about three-quarters of the tunnel width.

  14. Flight Tests of Exhaust Gas Jet Propulsion, Special Report

    NASA Technical Reports Server (NTRS)

    Pnkel, Benjamin; Turner, L. Richard

    1940-01-01

    Flight test s were conducted on the XP-41 airplane, equipped with a Pratt & Whitney R1830-19, 14-cylinder, air-cooled engine, to determine the increase in flight speed obtainable by the use of individual exhaust stacks directed rearwardly to obtain exhaust-gas thrust. Speed increases up to 18 miles per hour at 20,000 feet altitude were obtained using stacks having an exit area of 3.42 square inches for each cylinder. A slight increase in engine power and decrease in cylinder temperature at a given manifold pressure were obtained with the individual stacks as compared with a collector-ring installation. Exhaust-flame visibility was quite low, particularly in the rich range of fuel-air ratios.

  15. Results of the space shuttle vehicle ascent air data system probe calibration test using a 0.07-scale external tank forebody model (68T) in the AEDC 16-foot transonic wind tunnel (IA-310), volume 1

    NASA Technical Reports Server (NTRS)

    Collette, J. G. R.

    1991-01-01

    A recalibration of the Space Shuttle Vehicle Ascent Air Data System probe was conducted in the Arnold Engineering Development Center (AEDC) transonic wind tunnel. The purpose was to improve on the accuracy of the previous calibration in order to reduce the existing uncertainties in the system. A probe tip attached to a 0.07-scale External Tank Forebody model was tested at angles of attack of -8 to +4 degrees and sideslip angles of -4 to +4 degrees. High precision instrumentation was used to acquire pressure data at discrete Mach numbers ranging from 0.6 to 1.55. Pressure coefficient uncertainties were estimated at less than 0.0020. Data is given in graphical and tabular form.

  16. Results of the space shuttle vehicle ascent air data system probe calibration test using a 0.07-scale external tank forebody model (68T) in the AEDC 16-foot transonic wind tunnel (IA-310), volume 2

    NASA Technical Reports Server (NTRS)

    Collette, J. G. R.

    1991-01-01

    A recalibration of the Space Shuttle Vehicle Ascent Air Data System probe was conducted in the Arnold Engineering and Development Center (AEDC) transonic wind tunnel. The purpose was to improve on the accuracy of the previous calibration in order to reduce the existing uncertainties in the system. A probe tip attached to a 0.07-scale External Tank Forebody model was tested at angles of attack of -8 to +4 degrees and sideslip angles of -4 to +4 degrees. High precision instrumentation was used to acquire pressure data at discrete Mach numbers ranging from 0.6 to 1.55. Pressure coefficient uncertainties were estimated at less than 0.0020. Additional information is given in tabular form.

  17. Static investigation of a two-dimensional convergent-divergent exhaust nozzle with multiaxis thrust-vectoring capability

    NASA Technical Reports Server (NTRS)

    Taylor, John G.

    1990-01-01

    An investigation was conducted in the Static Test Facility of the NASA Langley 16-Foot Transonic Tunnel to determine the internal performance of two-dimensional convergent-divergent nozzles designed to have simultaneous pitch and yaw thrust vectoring capability. This concept utilized divergent flap rotation of thrust vectoring in the pitch plane and deflection of flat yaw flaps hinged at the end of the sidewalls for yaw thrust vectoring. The hinge location of the yaw flaps was varied at four positions from the nozzle exit plane to the throat plane. The yaw flaps were designed to contain the flow laterally independent of power setting. In order to eliminate any physical interference between the yaw flap deflected into the exhaust stream and the divergent flaps, the downstream corners of both upper and lower divergent flaps were cut off to allow for up to 30 deg of yaw flap deflection. The impact of varying the nozzle pitch vector angle, throat area, yaw flap hinge location, yaw flap length, and yaw flap deflection angle on nozzle internal performance characteristics, was studied. High-pressure air was used to simulate jet exhaust at nozzle pressure ratios up to 7.0. Static results indicate that configurations with the yaw flap hinge located upstream of the exit plane provide relatively high levels of thrust vectoring efficiency without causing large losses in resultant thrust ratio. Therefore, these configurations represent a viable concept for providing simultaneous pitch and yaw thrust vectoring.

  18. Automatic control study of the icing research tunnel refrigeration system

    NASA Technical Reports Server (NTRS)

    Kieffer, Arthur W.; Soeder, Ronald H.

    1991-01-01

    The Icing Research Tunnel (IRT) at the NASA Lewis Research Center is a subsonic, closed-return atmospheric tunnel. The tunnel includes a heat exchanger and a refrigeration plant to achieve the desired air temperature and a spray system to generate the type of icing conditions that would be encountered by aircraft. At the present time, the tunnel air temperature is controlled by manual adjustment of freon refrigerant flow control valves. An upgrade of this facility calls for these control valves to be adjusted by an automatic controller. The digital computer simulation of the IRT refrigeration plant and the automatic controller that was used in the simulation are discussed.

  19. Diesel Exhaust Inhalation Increases Cardiac Output, Bradyarrhythmias, and Parasympathetic Tone in Aged Heart Failure-Prone Rats

    EPA Science Inventory

    Acute air pollutant inhalation is linked to adverse cardiac events and death, and hospitalizations for heart failure. Diesel exhaust (DE) is a major air pollutant suspected to exacerbate preexisting cardiac conditions, in part, through autonomic and electrophysiologic disturbance...

  20. Examination of cytokines and metals in exhaled breath condensate and lung lavage fluids after diesel exhaust exposure

    EPA Science Inventory

    Epidemiology studies link human exposure to ambient air pollution with the development and exacerbation of cardiopulmonary disease. Diesel exhaust (DE) is a significant source of ambient air pollution, and thus may contribute to adverse pulmonary health effects. Previous human re...

  1. 14 CFR 23.1123 - Exhaust system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Exhaust System § 23.1123 Exhaust system. (a) Each exhaust system must be fireproof and corrosion-resistant, and must have means...

  2. 14 CFR 23.1123 - Exhaust system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Exhaust System § 23.1123 Exhaust system. (a) Each exhaust system must be fireproof and corrosion-resistant, and must have means...

  3. 14 CFR 23.1123 - Exhaust system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Exhaust System § 23.1123 Exhaust system. (a) Each exhaust system must be fireproof and corrosion-resistant, and must have means...

  4. 14 CFR 23.1123 - Exhaust system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Exhaust System § 23.1123 Exhaust system. (a) Each exhaust system must be fireproof and corrosion-resistant, and must have means...

  5. 14 CFR 23.1123 - Exhaust system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Exhaust System § 23.1123 Exhaust system. (a) Each exhaust system must be fireproof and corrosion-resistant, and must have means...

  6. Rudolf Hermann, wind tunnels and aerodynamics

    NASA Astrophysics Data System (ADS)

    Lundquist, Charles A.; Coleman, Anne M.

    2008-04-01

    Rudolf Hermann was born on December 15, 1904 in Leipzig, Germany. He studied at the University of Leipzig and at the Aachen Institute of Technology. His involvement with wind tunnels began in 1934 when Professor Carl Wieselsberger engaged him to work at Aachen on the development of a supersonic wind tunnel. On January 6, 1936, Dr. Wernher von Braun visited Dr. Hermann to arrange for use of the Aachen supersonic wind tunnel for Army problems. On April 1, 1937, Dr. Hermann became Director of the Supersonic Wind Tunnel at the Army installation at Peenemunde. Results from the Aachen and Peenemunde wind tunnels were crucial in achieving aerodynamic stability for the A-4 rocket, later designated as the V-2. Plans to build a Mach 10 'hypersonic' wind tunnel facility at Kochel were accelerated after the Allied air raid on Peenemunde on August 17, 1943. Dr. Hermann was director of the new facility. Ignoring destruction orders from Hitler as WWII approached an end in Europe, Dr. Hermann and his associates hid documents and preserved wind tunnel components that were acquired by the advancing American forces. Dr. Hermann became a consultant to the Air Force at its Wright Field in November 1945. In 1951, he was named professor of Aeronautical Engineering at the University of Minnesota. In 1962, Dr. Hermann became the first Director of the Research Institute at the University of Alabama in Huntsville (UAH), a position he held until he retired in 1970.

  7. 40 CFR 1066.610 - Mass-based and molar-based exhaust emission calculations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Mass-based and molar-based exhaust... (CONTINUED) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Calculations § 1066.610 Mass-based and molar-based exhaust emission calculations. (a) Calculate your total mass of emissions over a test cycle...

  8. 40 CFR 1066.610 - Mass-based and molar-based exhaust emission calculations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Mass-based and molar-based exhaust... (CONTINUED) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Calculations § 1066.610 Mass-based and molar-based exhaust emission calculations. (a) Calculate your total mass of emissions over a test cycle...

  9. 40 CFR 85.2224 - Exhaust analysis system-EPA 81.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Exhaust analysis system-EPA 81. 85.2224 Section 85.2224 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Tests § 85.2224 Exhaust analysis system—EPA 81. (a) Applicability. The requirements of this...

  10. 40 CFR 85.2224 - Exhaust analysis system-EPA 81.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Exhaust analysis system-EPA 81. 85.2224 Section 85.2224 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Tests § 85.2224 Exhaust analysis system—EPA 81. (a) Applicability. The requirements of this...

  11. Wind tunnel pressurization and recovery system

    NASA Technical Reports Server (NTRS)

    Pejack, Edwin R.; Meick, Joseph; Ahmad, Adnan; Lateh, Nordin; Sadeq, Omar

    1988-01-01

    The high density, low toxicity characteristics of refrigerant-12 (dichlorofluoromethane) make it an ideal gas for wind tunnel testing. Present limitations on R-12 emissions, set to slow the rate of ozone deterioration, pose a difficult problem in recovery and handling of large quantities of R-12. This preliminary design is a possible solution to the problem of R-12 handling in wind tunnel testing. The design incorporates cold temperature condensation with secondary purification of the R-12/air mixture by adsorption. Also discussed is the use of Freon-22 as a suitable refrigerant for the 12 foot wind tunnel.

  12. DIESEL EXHAUST EXPOSURE INCREASES SEVERITY OF AN ONGOING INFLUENZA INFECTION

    EPA Science Inventory

    Numerous studies have shown that air pollutants including diesel exhaust (DE) alter host defense responses, resulting in decreased resistance to respiratory infection. The purpose of this study was to evaluate the effects of DE exposure on the severity of an ongoing influenza in...

  13. EFFECTS OF DIESEL EXHAUST ON TLR3 EXPRESSION IN MICE

    EPA Science Inventory

    There are a variety of intrinsic as well as extrinsic factors, such as exposure to air pollution that can affect the pathogenesis of respiratory infections. Exposure to diesel exhaust (DE) emissions can alter host defense and immune responses and we have previously demonstrated t...

  14. A Technique for the Analysis of Auto Exhaust.

    ERIC Educational Resources Information Center

    Sothern, Ray D.; And Others

    Developed for presentation at the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971, this outline explains a technique for separating the complex mixture of hydrocarbons contained in automotive exhausts. A Golay column and subambient temperature programming technique are…

  15. Exposure to Diesel Exhaust Enhances the Generation of Vascular Microparticles

    EPA Science Inventory

    Introduction: In the study of the health impacts of traffic-related air pollution, diesel exhaust is a pollutant of particular interest, since it is a major source of particulate matter (PM). Epidemiological studies associate exposure to ambient levels of PM with cardiovascular m...

  16. 40 CFR 1065.230 - Raw exhaust flow meter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Raw exhaust flow meter. 1065.230 Section 1065.230 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.230 Raw...

  17. 40 CFR 1065.230 - Raw exhaust flow meter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Raw exhaust flow meter. 1065.230 Section 1065.230 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.230 Raw...

  18. 40 CFR 1065.230 - Raw exhaust flow meter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Raw exhaust flow meter. 1065.230 Section 1065.230 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.230 Raw...

  19. 40 CFR 1066.140 - Diluted exhaust flow calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...: (i) The mean flow rate of the reference flow meter, Q ref. This may include several measurements of... v, at measured values of pressure, temperature and air flow. Calibrate the CFV at the lowest... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Diluted exhaust flow calibration....

  20. 40 CFR 1065.230 - Raw exhaust flow meter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Raw exhaust flow meter. 1065.230 Section 1065.230 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.230 Raw...

  1. 40 CFR 1065.230 - Raw exhaust flow meter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Raw exhaust flow meter. 1065.230 Section 1065.230 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.230 Raw...

  2. 40 CFR 86.244-94 - Calculations; exhaust emissions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Calculations; exhaust emissions. 86.244-94 Section 86.244-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.244-94 Calculations;...

  3. Propulsion simulation for magnetically suspended wind tunnel models

    NASA Technical Reports Server (NTRS)

    Joshi, Prakash B.; Beerman, Henry P.; Chen, James; Krech, Robert H.; Lintz, Andrew L.; Rosen, David I.

    1990-01-01

    The feasibility of simulating propulsion-induced aerodynamic effects on scaled aircraft models in wind tunnels employing Magnetic Suspension and Balance Systems. The investigation concerned itself with techniques of generating exhaust jets of appropriate characteristics. The objectives were to: (1) define thrust and mass flow requirements of jets; (2) evaluate techniques for generating propulsive gas within volume limitations imposed by magnetically-suspended models; (3) conduct simple diagnostic experiments for techniques involving new concepts; and (4) recommend experiments for demonstration of propulsion simulation techniques. Various techniques of generating exhaust jets of appropriate characteristics were evaluated on scaled aircraft models in wind tunnels with MSBS. Four concepts of remotely-operated propulsion simulators were examined. Three conceptual designs involving innovative adaptation of convenient technologies (compressed gas cylinders, liquid, and solid propellants) were developed. The fourth innovative concept, namely, the laser-assisted thruster, which can potentially simulate both inlet and exhaust flows, was found to require very high power levels for small thrust levels.

  4. Full-Scale Tunnel (FST)

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Full-Scale Tunnel (FST). Construction of balance housing. Smith DeFrance noted the need for this housing in his NACA TR No. 459: 'The entire floating frame and scale assembly is enclosed in a room for protection from air currents and the supporting struts are shielded by streamlined fairings which are secured to the roof of the balance room and free from the balance.'

  5. Capture of Heat Energy from Diesel Engine Exhaust

    SciTech Connect

    Chuen-Sen Lin

    2008-12-31

    Diesel generators produce waste heat as well as electrical power. About one-third of the fuel energy is released from the exhaust manifolds of the diesel engines and normally is not captured for useful applications. This project studied different waste heat applications that may effectively use the heat released from exhaust of Alaskan village diesel generators, selected the most desirable application, designed and fabricated a prototype for performance measurements, and evaluated the feasibility and economic impact of the selected application. Exhaust flow rate, composition, and temperature may affect the heat recovery system design and the amount of heat that is recoverable. In comparison with the other two parameters, the effect of exhaust composition may be less important due to the large air/fuel ratio for diesel engines. This project also compared heat content and qualities (i.e., temperatures) of exhaust for three types of fuel: conventional diesel, a synthetic diesel, and conventional diesel with a small amount of hydrogen. Another task of this project was the development of a computer-aided design tool for the economic analysis of selected exhaust heat recovery applications to any Alaskan village diesel generator set. The exhaust heat recovery application selected from this study was for heating. An exhaust heat recovery system was fabricated, and 350 hours of testing was conducted. Based on testing data, the exhaust heat recovery heating system showed insignificant effects on engine performance and maintenance requirements. From measurements, it was determined that the amount of heat recovered from the system was about 50% of the heat energy contained in the exhaust (heat contained in exhaust was evaluated based on environment temperature). The estimated payback time for 100% use of recovered heat would be less than 3 years at a fuel price of $3.50 per gallon, an interest rate of 10%, and an engine operation of 8 hours per day. Based on experimental data

  6. Graphene tunnel junctions with aluminum oxide barrier

    NASA Astrophysics Data System (ADS)

    Feng, Ying; Trainer, Daniel J.; Chen, Ke

    2016-10-01

    We report a development of graphene tunnel junctions made by chemical vapor deposition grown graphene and sputtered aluminum insulating by an in-situ grown aluminum oxide. The thin oxide layer formed in between the metal layer and the two-dimensional material is a crucial part of a tunnel junction. We characterized surface morphology of oxide layers and studied tunneling spectra of lead and silver tunnel junctions to estimate the quality of the aluminum oxide. The Brinkman-Rowell-Dynes model was applied to fit the conductance-voltage plots to calculate the thickness of oxide layers. Junctions with graphene both on bottom and on top were fabricated and their tunneling properties were characterized after exposure to air for weeks to test time stability. Furthermore, the resistances of graphene tunnel junctions with aluminum oxide formed naturally and in an oxygen atmosphere were studied. Our results demonstrate that in-situ aluminum oxide is an effective barrier for graphene tunnel junctions. The methods of barrier formation enable the realization of more tunnel devices and circuits based on graphene.

  7. An inventory of aeronautical ground research facilities. Volume 2: Air breathing engine test facilities

    NASA Technical Reports Server (NTRS)

    Pirrello, C. J.; Hardin, R. D.; Heckart, M. V.; Brown, K. R.

    1971-01-01

    The inventory covers free jet and direct connect altitude cells, sea level static thrust stands, sea level test cells with ram air, and propulsion wind tunnels. Free jet altitude cells and propulsion wind tunnels are used for evaluation of complete inlet-engine-exhaust nozzle propulsion systems under simulated flight conditions. These facilities are similar in principal of operation and differ primarily in test section concept. The propulsion wind tunnel provides a closed test section and restrains the flow around the test specimen while the free jet is allowed to expand freely. A chamber of large diameter about the free jet is provided in which desired operating pressure levels may be maintained. Sea level test cells with ram air provide controlled, conditioned air directly to the engine face for performance evaluation at low altitude flight conditions. Direct connect altitude cells provide a means of performance evaluation at simulated conditions of Mach number and altitude with air supplied to the flight altitude conditions. Sea level static thrust stands simply provide an instrumented engine mounting for measuring thrust at zero airspeed. While all of these facilities are used for integrated engine testing, a few provide engine component test capability.

  8. 15-Foot Spin Tunnel

    NASA Technical Reports Server (NTRS)

    1935-01-01

    A researcher is launching a model into the tunnel airstream of the 15-Foot Spin Tunnel. Charles Zimmerman wrote in NASA TR No. 557: 'After the observations have been made, the model is lowered into a net held in the air stream by one of the operators or into a large bowl-shaped net at the bottom of the test section. When lowered into the large net, the model is retrieved with a long- handled clamp.' (p. 267) 'The models used are generally 1/10 to 1/16 scale. The size of the models is limited by the wing span and the wing loading. The maximum allowable span is about 36 inches; the maximum wing loading is about 1.3 pounds per square foot.' (p. 266) 'Balsa wood is the usual structural material because of its low density. It is necessary to hollow out the after portion of the fuselage and to cut out a large portion of the wood in the wings to permit proper mass distribution. The wing cut-outs are covered with silk tissue paper. The leading and trailing edges and tips of the wings are fitted with strips of spruce, pattern pine, or bamboo inset into the edge of the balsa to prevent disfigurement from accidental blows or from striking the safety netting. Lead is used for ballast.' (p. 266)

  9. Embryotoxicity of irradiated and nonirradiated catalytic convertertreated automotive exhaust.

    PubMed

    Hoffman, D J; Campbell, K I

    1977-11-01

    This study was undertaken to examine the relative embryotoxicity in chick embryos of photochemically reacted and unreacted diluted automotive exhaust emissions from a system equipped with a catalytic converter. Clean air controls and H2SO4 aerosol controls equivalent in concentration to those found in the catalytic exhaust atmosphere were also studied. From day 1 through day 14 of development, continuous exposure to nonirradiated exhause resulted in decreased survival, lowered embryonic weight, a small increase in heart/body weight ratio, and altered hematocrit and serum enzyme activities (LDH and GOT). Irradiated exhaust had little effect on survival or on embryonic weight but resulted in a higher liver/body weight ratio as well as altered hematocrit and serum enzyme activities. Interactions or cumulative effects of different compositions of exhaust atmospheres may play a role in differing biological responses between unreacted and irradiated exhaust. Sulfuric acid aerosol had a minimal effect on survival and resulted in only a slight decrease in embryonic weight and serum LDH activity, with no other apparent effects. In previous studies where the catalytic converter was not used, more pronounced effects on survival, increased heart/body weigh ratio, elevated serum GPT activity, and liver discoloration were observed. Thus, the introduction of an oxidizing catalytic converter appeared to alleviate some but not all of the embryotoxic effects of automotive exhaust.

  10. Measurement of Gas-phase Acids in Diesel Exhaust

    NASA Astrophysics Data System (ADS)

    Wentzell, J. J.; Liggio, J.; Li, S.; Vlasenko, A. L.; Staebler, R. M.; Brook, J.; Lu, G.; Poitras, M.; Chan, T.

    2012-12-01

    Gas-phase acids were measured using chemical ionization mass spectrometry (CIMS) as part of the Diesel Engine Emission Research Experiment (DEERE). The CIMS technique, utilizing acetate ion (CH3COO-) as a reagent ion, proved to be a rapid (measurements on the order of seconds) and sensitive (several counts/pptv) method of quantifying the acid emissions. Diluted diesel exhaust measurements were made from a Constant Volume Sampling dilution tunnel using a light duty (1.9L turbocharged Volkswagen Jetta TDI) diesel engine equipped with an OEM diesel oxidation catalyst and exhaust gas recirculation, mounted on an engine dynamometer. Acids measured included isocyanic, nitrous, nitric, propionic and sum of lactic and oxalic, as well as other unidentified compounds. Complimentary measurements of CO, CO2, Total Hydrocarbon (THC), and NOx, were also performed. Several engine modes (different engine rpm and torque outputs) at steady state were examined to determine their effect on acid emissions. Emission rates with respect to NOx and fuel based emission factors were determined. Measurements of HONO fuel emission factors agree well with real-world measurements within a traffic tunnel.1 The first estimate of isocyanic acid emission factors from a diesel engine is reported, and suggests that the emission of this highly toxic compound in diesel exhaust should not be ignored. 1. Kurtenbach, R., Becker, K. H., Gomes, J. A. G., Kleffmann, J.,Lorzer, J. C., Spittler, M., Wiesen, P., Ackermann, R., Geyer, A.,and Platt, U.: Investigations of emissions and heterogeneous formation of HONO in a road traffic tunnel, Atmos. Environ., 35, 3385-3394, doi:10.1016/S1352-2310(01)00138-8, 2001.

  11. Investigation of NOx Removal from Small Engine Exhaust

    NASA Technical Reports Server (NTRS)

    Akyurtlu, Ates; Akyurtlu, Jale F.

    1999-01-01

    Contribution of emissions from small engines to the air pollution is significant. Due to differences in operating conditions and economics, the pollution control systems designed for automobiles will be neither suitable nor economically feasible for use on small engines. The objective of this project was to find a catalyst for the removal of NOx from the exhaust of small engines which use a rich air to fuel ratio. The desired catalyst should be inexpensive so that the cost of the pollution control unit will be only a small fraction of the total equipment cost. The high cost of noble metals makes them too expensive for use as NOx catalyst for small engines. Catalytic reduction of Nitrogen Oxide (NO) can also be accomplished by base-metal oxide catalysts. The main disadvantage of base-metal catalysts is their deactivation by poisons and high temperatures. Requirements for the length of the life of the small engine exhaust catalysts are much less than those for automobile exhaust catalysts. Since there is no oxygen in the exhaust gases, reduction selectivity is not a problem. Also, the reducing exhaust gases might help prevent the harmful interactions of the catalyst with the support. For these reasons only the supported metal oxide catalysts were investigated in this project.

  12. Investigation of NO(x) Removal from Small Engine Exhaust

    NASA Technical Reports Server (NTRS)

    Akyurtlu, Ates; Akyurtlu, Jale F.

    1999-01-01

    Contribution of emissions from small engines to the air pollution is significant. Due to differences in operating conditions and economics, the pollution control systems designed for automobiles will be neither suitable nor economically feasible for use on small engines. The objective of this project was to find a catalyst for the removal of NOx from the exhaust of small engines which use a rich air to fuel ratio. The desired catalyst should be inexpensive so that the cost of the pollution control unit will be only a small fraction of the total equipment cost. The high cost of noble metals makes them too expensive for use as NOx catalyst for small engines. Catalytic reduction of NO can also be accomplished by base-metal oxide catalysts. The main disadvantage of base-metal catalysts is their deactivation by poisons and high temperatures. Requirements for the length of the life of the small engine exhaust catalysts are much less than those for automobile exhaust catalysts. Since there is no oxygen in the exhaust gases, reduction selectivity is not a problem. Also, the reducing exhaust gases might help prevent the harmful interactions of the catalyst with the support. For these reasons only the supported metal oxide catalysts were investigated in this project.

  13. Tunnelling microscopy of DNA

    NASA Astrophysics Data System (ADS)

    Selci, Stefano; Cricenti, Antonio

    1991-01-01

    Uncoated DNA molecules marked with an activated tris (1-aziridinyl) phosphine oxide (TAPO) solution were deposited on gold substrates and imaged in air with a high resolution Scanning Tunnelling Microscope (STM). The STM operated simultaneously in the constant-current and gap-modulated mode. Highly reproducible STM images have been obtained and interpreted in terms of expected DNA structure. The main periodicity, regularly presented in molecules several hundred Ångstrom long, ranges from 25 Å to 35 Å with an average diameter of 22 Å. Higher resolution images of the minor groove have revealed the phosphate groups along the DNA backbones. Constant-current images of TAPO deposited on gold show a crystalline structure of rows of molecules with a side-by-side spacing of 3 Å.

  14. Analysis, Verification, and Application of Equations and Procedures for Design of Exhaust-pipe Shrouds

    NASA Technical Reports Server (NTRS)

    Ellerbrock, Herman H.; Wcislo, Chester R.; Dexter, Howard E.

    1947-01-01

    Investigations were made to develop a simplified method for designing exhaust-pipe shrouds to provide desired or maximum cooling of exhaust installations. Analysis of heat exchange and pressure drop of an adequate exhaust-pipe shroud system requires equations for predicting design temperatures and pressure drop on cooling air side of system. Present experiments derive such equations for usual straight annular exhaust-pipe shroud systems for both parallel flow and counter flow. Equations and methods presented are believed to be applicable under certain conditions to the design of shrouds for tail pipes of jet engines.

  15. Wind tunnel tests of a zero length, slotted-lip engine air inlet for a fixed nacelle V/STOL aircraft

    NASA Technical Reports Server (NTRS)

    Woollett, R. R.; Beck, W. E., Jr.; Glasgow, E. R.

    1982-01-01

    Zero length, slotted lip inlet performance and associated fan blade stresses were determined during model tests using a 20 inch diameter fan simulator in the NASA-LeRC 9 by 15 foot low speed wind tunnel. The model configuration variables consisted of inlet contraction ratio, slot width, circumferential extent of slot fillers, and length of a constant area section between the inlet throat and fan face. The inlet performance was dependent on slot gap width and relatively independent of inlet throat/fan face spacer length and slot flow blockage created by 90 degree slot fillers. Optimum performance was obtained at a slot gap width of 0.36 inch. The zero length, slotted lip inlet satisfied all critical low speed inlet operating requirements for fixed horizontal nacelles subsonic V/STOL aircraft.

  16. Vascular and Cardiac Impairments in Rats Inhaling Ozone and Diesel Exhaust Particles

    EPA Science Inventory

    Background -Mechanisms of cardiovascular injuries from exposure to gas and particulate air pollutants are unknown. Objective -We hypothesized that episodic exposure of rats to ozone or diesel exhaust particles (DEP) will cause differential cardiovascular impairments, which will b...

  17. DIESEL EXHAUST PARTICLES INDUCE ABERRANT ALVEOLAR EPITHELIAL DIRECTED CELL MOVEMENT BY DISRUPTION OF POLARITY MECHANISMS

    EPA Science Inventory

    Disruption of the respiratory epithelium contributes to the progression of a variety of respiratory diseases that are aggravated by exposure to air pollutants, specifically traffic-based pollutants such as diesel exhaust particles (DEP). Recognizing that lung repair following inj...

  18. Exacerbation of allergic inflammation in mice exposed to diesel exhaust particles prior to viral infection.

    EPA Science Inventory

    Background: Viral infections and exposure to oxidant air pollutants are two ofthe most important inducers ofasthma exacerbation. Our previous studies have demonstrated that exposure to diesel exhaust increases the susceptibility to influenza virus infections both in epithelial ce...

  19. Results of an investigation to determine local flow characteristics at the air data probe locations using an 0.030-scale model (45-0) of the space shuttle vehicle orbiter configuration 140A/B (modified) in the NASA Ames Research Center unitary plan wind tunnel (OA161, A, B, C), volume 1

    NASA Technical Reports Server (NTRS)

    Nichols, M. E.

    1976-01-01

    Results are presented of wind tunnel test 0A161 of a 0.030-scale model 45-0 of the configuration 140A/B (modified) space shuttle vehicle orbiter in the NASA Ames Research Center Unitary Plan Wind Tunnel facilities. The purpose of this test was to determine local total and static pressure environments for the air data probe locations and relative effectiveness of alternate flight-test probe configurations. Testing was done in the Mach number range from 0.30 to 3.5. Angle of attack was varied from -8 to 25 degrees while sideslip varied between -8 and 8 degrees.

  20. Cryogenic wind tunnels. II

    NASA Technical Reports Server (NTRS)

    Kilgore, Robert A.

    1987-01-01

    The application of the cryogenic concept to various types of tunnels including Ludwieg tube tunnel, Evans clean tunnel, blowdown, induced-flow, and continuous-flow fan-driven tunnels is discussed. Benefits related to construction and operating costs are covered, along with benefits related to new testing capabilities. It is noted that cooling the test gas to very low temperatures increases Reynolds number by more than a factor of seven. From the energy standpoint, ambient-temperature fan-driven closed-return tunnels are considered to be the most efficient type of tunnel, while a large reduction in the required tunnel stagnation pressure can be achieved through cryogenic operation. Operating envelopes for three modes of operation for a cryogenic transonic pressure tunnel with a 2.5 by 2.5 test section are outlined. A computer program for calculating flow parameters and power requirements for wind tunnels with operating temperatures from saturation to above ambient is highlighted.

  1. A Passive Cavity Concept for Improving the Off-Design Performance of Fixed-Geometry Exhaust Nozzles

    NASA Technical Reports Server (NTRS)

    Asbury, Scott C.; Gunther, Christopher L.; Hunter, Craig A.

    1996-01-01

    An investigation was conducted in the model preparation area of the Langley 16-Foot Transonic Tunnel to study a passive cavity concept for improving the off-design performance of fixed-geometry exhaust nozzles. Passive cavity ventilation (through a porous surface) was applied to divergent flap surfaces and tested at static conditions in a sub-scale, nonaxisymmetric, convergent-divergent nozzle. As part of a comprehensive investigation, force, moment and pressure measurements were taken and focusing schlieren flow visualization was obtained for a baseline configuration and D passive cavity configurations. All tests were conducted with no external flow and high-pressure air was used to simulate jet-exhaust flow at nozzle pressure ratios from 1.25 to approximately 9.50. Results indicate that baseline nozzle performance was dominated by unstable shock-induced boundary-layer separation at off-design conditions, which came about through the natural tendency of overexpanded exhaust flow to satisfy conservation requirements by detaching from the nozzle divergent flaps. Passive cavity ventilation added the ability to control off-design separation in the nozzle by either alleviating separation or encouraging stable separation of the exhaust flow. Separation alleviation offers potential for installed nozzle performance benefits by reducing drag at forward flight speeds, even though it may reduce off-design static thrust efficiency as much as 3.2 percent. Encouraging stable separation of the exhaust flow offers significant performance improvements at static, low NPR and low Mach number flight conditions by improving off-design static thrust efficiency as much as 2.8 percent. By designing a fixed-geometry nozzle with fully porous divergent flaps, where both cavity location and percent open porosity of the flaps could be varied, passive flow control would make it possible to improve off-design nozzle performance across a wide operating range. In addition, the ability to

  2. Environmental assessment for the depleted uranium testing program at the Nevada Test Site by the United States Army Ballistics Research Laboratory. [Open-Air Tests and X-Tunnel Tests

    SciTech Connect

    Not Available

    1992-11-24

    This proposed action provides the Department of Energy (DOE) authorization to the US Army to conduct a testing program using Depleted Uranium (DU) in Area 25 at the Nevada Test Site (NTS). The US Army Ballistic Research Laboratory (BRL) would be the managing agency for the program. The proposed action site would utilize existing facilities, and human activity would be confined to areas identified as having no tortoise activity. Two classifications of tests would be conducted under the testing program: (1) open-air tests, and (2) X-Tunnel tests. A series of investigative tests would be conducted to obtain information on DU use under the conditions of each classification. The open-air tests would include DU ammunition hazard classification and combat systems activity tests. Upon completion of each test or series of tests, the area would be decontaminated to meet requirements of DOE Order 5400.5, Radiation Protection of the Public and Environment. All contaminated materials would be decontaminated or disposed of as radioactive waste in an approved low-level Radioactive Waste Management Site (RWMS) by personnel trained specifically for this purpose.

  3. Effects of diesel exhaust on lung inflammation related to bacterial endotoxin in mice.

    PubMed

    Inoue, Ken-Ichiro; Takano, Hirohisa; Yanagisawa, Rie; Sakurai, Miho; Ueki, Naoko; Yoshikawa, Toshikazu

    2006-11-01

    We have previously shown that intratracheal instillation of diesel exhaust particles enhances lung inflammation and lung expression of proinflammatory cytokines and chemokines related to bacterial endotoxin (lipopolysaccharide) in mice. The present study was designed to elucidate the effects of inhalation of diesel exhaust on lung inflammation related to lipopolysaccharide. ICR mice were exposed for 12 hr to clean air or diesel exhaust at a soot concentration of 0.3, 1.0, or 3.0 mg/m(3) after intratracheal challenge with 125 microg/kg of lipopolysaccharide. Lung inflammation and lung expression of proinflammatory chemokines such as macrophage chemoattractant protein-1 and keratinocyte chemoattractant were evaluated 24 hr after intratracheal administration. Diesel exhaust inhalation decreased lipopolysaccharide-elicited inflammatory cell recruitment into the bronchoalveolar lavage fluid as compared with clean air inhalation. Histological study demonstrated that exposure to diesel exhaust did not affect lipopolysaccharide-enhanced neutrophil recruitment into the lung parenchyma. Lipopolysaccharide instillation elevated lung expression of macrophage chemoattractant protein-1 and keratinocyte chemoattractant under clean air or diesel exhaust inhalation. However, diesel exhaust exposure did not influence but rather did suppress these levels in the presence of lipopolysaccharide. These results suggest that short-term exposure to diesel exhaust did not exacerbate lung inflammation related to bacterial endotoxin.

  4. Increased risk of obstructive pulmonary disease in tunnel workers

    PubMed Central

    Ulvestad, B.; Bakke, B.; Melbostad, E.; Fuglerud, P.; Kongerud, J.; Lund, M. B.

    2000-01-01

    BACKGROUND—Tunnel workers are exposed to gases and particles from blasting and diesel exhausts. The aim of this study was to assess the occurrence of respiratory symptoms and airflow limitation in tunnel workers and to relate these findings to years of exposure.
METHODS—Two hundred and twelve tunnel workers and a reference group of 205 other heavy construction workers participated in a cross sectional investigation. Exposure measurements were carried out to demonstrate the difference in exposure between the two occupational groups. Spirometric tests and a questionnaire on respiratory symptoms and smoking habits were applied. Atopy was determined by a multiple radioallergosorbent test (RAST). Radiological signs of silicosis were evaluated. Respiratory symptoms and lung function were studied in relation to years of exposure and adjusted for smoking habits and atopy.
RESULTS—Compared with the reference subjects the tunnel workers had a significant decrease in forced vital capacity (FVC) % predicted and forced expiratory volume in one second (FEV1) % predicted when related to years of exposure. Adjusted FEV1 decreased by 17 ml for each year of tunnel work exposure compared with 0.5 ml in outdoor heavy construction workers. The tunnel workers also reported significantly higher occurrence of respiratory symptoms. The prevalence of chronic obstructive pulmonary disease (COPD) was 14% in the tunnel workers compared with 8% in the reference subjects.
CONCLUSION—Exposure to dust and gases from diesel exhaust, blasting, drilling and rock transport in tunnel work enhances the risk for accelerated decline in FEV1, respiratory symptoms, and COPD in tunnel workers compared with other heavy construction workers.

 PMID:10722766

  5. Comparison of cytotoxicity and genotoxicity induced by the extracts of methanol and gasoline engine exhausts.

    PubMed

    Zhang, Zunzhen; Che, Wangjun; Liang, Ying; Wu, Mei; Li, Na; Shu, Ya; Liu, Fang; Wu, Desheng

    2007-09-01

    Gasoline engine exhaust has been considered a major source of air pollution in China, and methanol is considered as a potential substitute for gasoline fuel. In this study, the genotoxicity and cytotoxicity of organic extracts of condensate, particulate matters (PM) and semivolatile organic compounds (SVOC) of gasoline and absolute methanol engine exhaust were examined by using MTT assay, micronucleus assay, comet assay and Ames test. The results have showed that gasoline engine exhaust exhibited stronger cytotoxicity to human lung carcinoma cell lines (A549 cell) than methanol engine exhaust. Furthermore, gasoline engine exhaust increased micronucleus formation, induced DNA damage in A549 cells and increased TA98 revertants in the presence of metabolic activating enzymes in a concentration-dependent manner. In contrast, methanol engine exhaust failed to exhibit these adverse effects. The results suggest methanol may be used as a cleaner fuel for automobile.

  6. Development of a multicopter-carried whole air sampling apparatus and its applications in environmental studies.

    PubMed

    Chang, Chih-Chung; Wang, Jia-Lin; Chang, Chih-Yuan; Liang, Mao-Chang; Lin, Ming-Ren

    2016-02-01

    To advance the capabilities of probing chemical composition aloft, we designed a lightweight remote-controlled whole air sampling component (WASC) and integrated it into a multicopter drone with agile maneuverability to perform aerial whole air sampling. A field mission hovering over an exhaust shaft of a roadway tunnel to collect air samples was performed to demonstrate the applicability of the multicopter-carried WASC apparatus. Ten aerial air samples surrounding the shaft vent were collected by the multicopter-carried WASC. Additional five samples were collected manually inside the shaft for comparison. These samples were then analyzed in the laboratory for the chemical composition of 109 volatile organic compounds (VOCs), CH4, CO, CO2, or CO2 isotopologues. Most of the VOCs in the upwind samples (the least affected by shaft exhaust) were low in concentrations (5.9 ppbv for total 109 VOCs), posting a strong contrast to those in the shaft exhaust (235.8 ppbv for total 109 VOCs). By comparing the aerial samples with the in-shaft samples for chemical compositions, the influence of the shaft exhaust on the surrounding natural air was estimated. Through the aerial measurements, three major advantages of the multicopter-carried WASC were demonstrated: 1. The highly maneuverable multicopter-carried WASC can be readily deployed for three-dimensional environmental studies at a local scale (0-1.5 km); 2. Aerial sampling with superior sample integrity and preservation conditions can now be performed with ease; and 3. Data with spatial resolution for a large array of gaseous species with high precision can be easily obtained.

  7. 4. 'Ring Stones & Tunnel Sections, Tunnel #33,' Southern Pacific ...

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

    4. 'Ring Stones & Tunnel Sections, Tunnel #33,' Southern Pacific Standard Double-Track Tunnel, ca. 1913. Compare to photos in documentation sets for Tunnel 18 (HAER No. CA-197), Tunnel 34 (HAER No. CA-206), and Tunnel 1 (HAER No. CA-207). - Central Pacific Transcontinental Railroad, Sacramento to Nevada state line, Sacramento, Sacramento County, CA

  8. 14. EXTERIOR VIEW OF OLD TENFOOT WIND TUNNEL (1991). ...

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

    14. EXTERIOR VIEW OF OLD TEN-FOOT WIND TUNNEL (1991). - Wright-Patterson Air Force Base, Area B, Buildings 25 & 24,10-foot & 20-foot Wind Tunnel Complex, Northeast side of block bounded by K, G, Third, & Fifth Streets, Dayton, Montgomery County, OH

  9. 13. EXTERIOR VIEW OF OLD TENFOOT WIND TUNNEL (1991). ...

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

    13. EXTERIOR VIEW OF OLD TEN-FOOT WIND TUNNEL (1991). - Wright-Patterson Air Force Base, Area B, Buildings 25 & 24,10-foot & 20-foot Wind Tunnel Complex, Northeast side of block bounded by K, G, Third, & Fifth Streets, Dayton, Montgomery County, OH

  10. Experimental Aeroheating Study of Mid-L/D Entry Vehicle Geometries: NASA LaRC 20-Inch Mach 6 Air Tunnel Test 6966

    NASA Technical Reports Server (NTRS)

    Hollis, Brian R.; Hollingsworth, Kevin E.

    2014-01-01

    Aeroheating data on mid lift-to-drag ratio entry vehicle configurations has been obtained through hypersonic wind tunnel testing. Vehicles of this class have been proposed for high-mass Mars missions, such as sample return and crewed exploration, for which the conventional sphere-cone entry vehicle geometries of previous Mars missions are insufficient. Several configurations were investigated, including elliptically-blunted cylinders with both circular and elliptical cross sections, biconic geometries based on launch vehicle dual-use shrouds, and parametrically-optimized analytic geometries. Testing was conducted at Mach 6 over a range of Reynolds numbers sufficient to generate laminar, transitional, and turbulent flow. Global aeroheating data were obtained using phosphor thermography. Both stream-wise and cross-flow transition occured on different configurations. Comparisons were made with laminar and turbulent computational predictions generated with an algebraic turbulence model. Predictions were generally in good agreement in regions of laminar or fully-turbulent flow; however for transitional cases, the lack of a transition onset prediction capability produced less accurate comparisons. The data obtained in this study are intended to be used for prelimary mission design studies and the development and validation of computational methods.

  11. Carpal tunnel repair - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100078.htm Carpal tunnel repair - series—Normal anatomy To use the sharing ... in the wrist and the wrist bones (carpal tunnel). Review Date 5/9/2015 Updated by: C. ...

  12. Integrated exhaust gas recirculation and charge cooling system

    SciTech Connect

    Wu, Ko-Jen

    2013-12-10

    An intake system for an internal combustion engine comprises an exhaust driven turbocharger configured to deliver compressed intake charge, comprising exhaust gas from the exhaust system and ambient air, through an intake charge conduit and to cylinders of the internal combustion engine. An intake charge cooler is in fluid communication with the intake charge conduit. A cooling system, independent of the cooling system for the internal combustion engine, is in fluid communication with the intake charge cooler through a cooling system conduit. A coolant pump delivers a low temperature cooling medium from the cooling system to and through the intake charge cooler for the transfer of heat from the compressed intake charge thereto. A low temperature cooler receives the heated cooling medium through the cooling system conduit for the transfer or heat therefrom.

  13. Outdoor smog-chamber experiments: reactivity of methanol exhaust

    SciTech Connect

    Jeffries, H.E.; Sexton, K.G.; Holleman, M.S.

    1985-09-01

    The purpose of the report was to provide an experimental smog-chamber database especially designed to test photochemical kinetics mechanisms that would be used to assess the effects of methanol fuel use in automobiles. The mechanisms would be used in urban air-quality control models to investigate the advantages of large-scale use of methanol fuel in automobiles. The smog-chamber experiments were performed during three summer months. They have been added to the existing UNC database for photochemical mechanism validation and testing, bringing the total number of dual experiments in the database to over 400. Three different hydrocarbon mixtures were used: a 13-component mixture representing synthetic automobile exhaust; an 18-component mixture representing synthetic urban ambient hydrocarbons; and a 14-component mixture derived from the synthetic automobile exhaust by the addition of n-butane. Three different synthetic methanol-exhaust mixtures were used: 80% methanol/10% formaldehyde; and 100% methanol.

  14. Scale Model Icing Research Tunnel

    NASA Technical Reports Server (NTRS)

    Canacci, Victor A.

    1997-01-01

    NASA Lewis Research Center's Icing Research Tunnel (IRT) is the world's largest refrigerated wind tunnel and one of only three icing wind tunnel facilities in the United States. The IRT was constructed in the 1940's and has been operated continually since it was built. In this facility, natural icing conditions are duplicated to test the effects of inflight icing on actual aircraft components as well as on models of airplanes and helicopters. IRT tests have been used successfully to reduce flight test hours for the certification of ice-detection instrumentation and ice protection systems. To ensure that the IRT will remain the world's premier icing facility well into the next century, Lewis is making some renovations and is planning others. These improvements include modernizing the control room, replacing the fan blades with new ones to increase the test section maximum velocity to 430 mph, installing new spray bars to increase the size and uniformity of the artificial icing cloud, and replacing the facility heat exchanger. Most of the improvements will have a first-order effect on the IRT's airflow quality. To help us understand these effects and evaluate potential improvements to the flow characteristics of the IRT, we built a modular 1/10th-scale aerodynamic model of the facility. This closed-loop scale-model pilot tunnel was fabricated onsite in the various shops of Lewis' Fabrication Support Division. The tunnel's rectangular sections are composed of acrylic walls supported by an aluminum angle framework. Its turning vanes are made of tubing machined to the contour of the IRT turning vanes. The fan leg of the tunnel, which transitions from rectangular to circular and back to rectangular cross sections, is fabricated of fiberglass sections. The contraction section of the tunnel is constructed from sheet aluminum. A 12-bladed aluminum fan is coupled to a turbine powered by high-pressure air capable of driving the maximum test section velocity to 550 ft

  15. Variable Density Tunnel

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Variable Density Tunnel in operation. Man at far right is probably Harold J. 'Cannonball' Tuner, longtime safety officer, who started with Curtiss in the teens. This view of the Variable Density Tunnel clearly shows the layout of the Tunnel's surroundings, as well as the plumbing and power needs of the this innovative research tool.

  16. Boost pulverizer performance with new exhauster rotor

    SciTech Connect

    Lauber, J.A.

    1994-10-01

    Georgia Power Co.'s Jack McDonough station, near Atlanta, Ga, consists of two tangentially fired boilers rated 1.734-million lb/hr, each paired with a 265-MW turbine/generator. The plant's primary fuel is Eastern Bituminous coal, which is ground by five pulverizers. In April 1993, it first began evaluating a new high-efficiency rotor for the pulverizer exhausters, supplied by ABB C-E Services Inc. Windsor, Conn. McDonough was designed to burn coal with a Hardgrove Grindability Index (HGI) of 55 and is typically supplied fuel with an HGI of 45. Thus, the units must operate with all five pulverizers to obtain full load, although each was intended to generate full load using four pulverizers. Now that the plant is burning low-sulfur coal to comply with the clean Air Act Amendments of 1990, the increased hardness limits McDonough's full-load capabilities and will dramatically increase pulverizer maintenance. Management was left with two options: a complete pulverizer replacement or further modifications. (The mills had already been upgraded several years ago.) The introduction of high-efficiency rotors for the exhauster fans made the second option more attractive. Unfortunately, the vendor had no significant operating experience with the rotor design, still in the developmental stage. Therefore, the plant decided to install a test rotor at McDonough Unit 2. This article is a review of the rotor's basic theory of operation, test results, and wear characteristics experienced at the unit.

  17. Photocatalytic destruction of automobile exhaust emissions

    SciTech Connect

    Kaviranta, P.D.; Peden, C.H.F.

    1996-10-01

    Hydrocarbons, carbon monoxide, and nitrogen oxides contained in automobile exhaust emissions are among the major atmospheric air pollutants. During the first few minutes of a cold start of the engine, the emission levels of unburned hydrocarbon and CO pollutants are very high due to the inefficiency of the cold engine and the poor activity of the catalysts lower temperatures. Therefore, it is necessary to provide an alternative approach to deal with this specific problem in order to meet near-term regulatory requirements. Our approach has been to use known photocatalytic reactions obtainable on semiconducting powders such as titanium dioxide. In this presentation we describe our recent studies aimed at the photocatalytic reduction of unburned hydrocarbons and carbon monoxide in automobile exhaust emissions. Our results demonstrate the effective destruction of propylene into water and carbon dioxide. The conversion was found to be dependent on the propylene flow rate. The reaction rate was studied as a function of time, humidity and temperature. The effect of the power of the UV source on conversion will also be presented.

  18. Non-exhaust PM emissions from electric vehicles

    NASA Astrophysics Data System (ADS)

    Timmers, Victor R. J. H.; Achten, Peter A. J.

    2016-06-01

    Particulate matter (PM) exposure has been linked to adverse health effects by numerous studies. Therefore, governments have been heavily incentivising the market to switch to electric passenger cars in order to reduce air pollution. However, this literature review suggests that electric vehicles may not reduce levels of PM as much as expected, because of their relatively high weight. By analysing the existing literature on non-exhaust emissions of different vehicle categories, this review found that there is a positive relationship between weight and non-exhaust PM emission factors. In addition, electric vehicles (EVs) were found to be 24% heavier than equivalent internal combustion engine vehicles (ICEVs). As a result, total PM10 emissions from EVs were found to be equal to those of modern ICEVs. PM2.5 emissions were only 1-3% lower for EVs compared to modern ICEVs. Therefore, it could be concluded that the increased popularity of electric vehicles will likely not have a great effect on PM levels. Non-exhaust emissions already account for over 90% of PM10 and 85% of PM2.5 emissions from traffic. These proportions will continue to increase as exhaust standards improve and average vehicle weight increases. Future policy should consequently focus on setting standards for non-exhaust emissions and encouraging weight reduction of all vehicles to significantly reduce PM emissions from traffic.

  19. Pollutant Removal Efficiency of Residential Cooking Exhaust Hoods

    SciTech Connect

    Singer, Brett C.; Sherman, Alexander D.; Hotchi, Toshifumi; Sullivan, Douglas P.

    2011-07-01

    Capture efficiency (CE) of exhaust from a natural gas cooking range was quantified for three common designs of residential range hoods in laboratory experiments: (A) microwave exhaust combination; (B) short hood with grease-screen-covered air inlet at bottom; and (C) deep, open hood exhausting at top. Devices were evaluated at varying installation heights, at highest and lowest fan settings, and with the hood installed 15 cm away from back wall with intent to improve CE for front burners. Each configuration was evaluated for the oven and for three cooktop burner combinations (two back, two front, one front and one back). At highest fan settings and standard installation against the wall, Hoods A and C captured back cooktop burner exhaust at > 90 percent and Hood B at > 80 percent. In this configuration, CE for front burner exhaust was 73-78 percent for Hoods A and C but only 46-63 percent for Hood B. CEs followed similar patterns but were substantially lower on the lowest fan speed. Installing the hood away from the wall improved CE for oven and front burners on Hood A at low speed, but substantially reduced CE for back burners for all hoods at low and high speed.

  20. Further exhaust emission control for two-stroke engines

    SciTech Connect

    Sato, Kazuo; Nakano, Masamitsu; Ukawa, Haruo; Inaga, Hisashi

    1994-09-01

    Two-stroke engines are being utilized in large numbers as small utility, lawn and garden equipment engines. The following two subjects were examined with regards to exhaust emission control. The first subject was to compare the theoretical values of a combustion model simulation with the experimentally measured values of the base line emission of two-stroke volume. The second subject was to examine the emission conformability to the 1995 and 1999 California Air Resources Board (CARB) exhaust emission regulations California Regulations for 1995 and Later Utility and Lawn and Garden Equipment Engine, adopted at March 20, 1992, amended, at November 3, 1993. in two-stroke engines with various combinations between various fuels, fuel supply systems and scavenging systems. For this subject it was determine;that the emission control systems based on the lean combustion can be used to meet the 1995 CARB exhaust emission regulations. However, it was also concluded that to meet the 1999 CARB exhaust emission regulations, various emission control systems with various combinations regarding such parameters as fuels, scavenging systems and exhaust systems must be used. 27 refs., 20 figs., 4 tabs.

  1. Vehicle engines produce exhaust nanoparticles even when not fueled.

    PubMed

    Rönkkö, Topi; Pirjola, Liisa; Ntziachristos, Leonidas; Heikkilä, Juha; Karjalainen, Panu; Hillamo, Risto; Keskinen, Jorma

    2014-01-01

    Vehicle engines produce submicrometer exhaust particles affecting air quality, especially in urban environments. In on-road exhaust studies with a heavy duty diesel vehicle and in laboratory studies with two gasoline-fueled passenger cars, we found that as much as 20-30% of the number of exhaust particles larger than 3 nm may be formed during engine braking conditions-that is, during decelerations and downhill driving while the engine is not fueled. Particles appeared at size ranges extending even below 7 nm and at high number concentrations. Their small size and nonvolatility, coupled with the observation that these particles contain lube-oil-derived metals zinc, phosphorus, and calcium, are suggestive of health risks at least similar to those of exhaust particles observed before. The particles' characteristics indicate that their emissions can be reduced using exhaust after-treatment devices, although these devices have not been mandated for all relevant vehicle types. Altogether, our findings enhance the understanding of the formation vehicle emissions and allow for improved protection of human health in proximity to traffic.

  2. 23. Tunnel junction, view from the lower elevator room. Lyon ...

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

    23. Tunnel junction, view from the lower elevator room. Lyon - Whiteman Air Force Base, Oscar O-1 Minuteman Missile Alert Facility, Southeast corner of Twelfth & Vendenberg Avenues, Knob Noster, Johnson County, MO

  3. 39. Launch Control Equipment Room, seen from tunnel junction. Lyon ...

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

    39. Launch Control Equipment Room, seen from tunnel junction. Lyon - Whiteman Air Force Base, Oscar O-1 Minuteman Missile Alert Facility, Southeast corner of Twelfth & Vendenberg Avenues, Knob Noster, Johnson County, MO

  4. Preliminary Performance Data on Westinghouse Electronic Power Regulator Operating on J34-WE-32 Turbojet Engine in Altitude Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Ketchum, James R.; Blivas, Darnold; Pack, George J.

    1950-01-01

    The behavior of the Westinghouse electronic power regulator operating on a J34-WE-32 turbojet engine was investigated in the NACA Lewis altitude wind tunnel at the request of the Bureau of Aeronautics, Department of the Navy. The object of the program was to determine the, steady-state stability and transient characteristics of the engine under control at various altitudes and ram pressure ratios, without afterburning. Recordings of the response of the following parameters to step changes in power lever position throughout the available operating range of the engine were obtained; ram pressure ratio, compressor-discharge pressure, exhaust-nozzle area, engine speed, turbine-outlet temperature, fuel-valve position, jet thrust, air flow, turbine-discharge pressure, fuel flow, throttle position, and boost-pump pressure. Representative preliminary data showing the actual time response of these variables are presented. These data are presented in the form of reproductions of oscillographic traces.

  5. Rocket Plume Scaling for Orion Wind Tunnel Testing

    NASA Technical Reports Server (NTRS)

    Brauckmann, Gregory J.; Greathouse, James S.; White, Molly E.

    2011-01-01

    A wind tunnel test program was undertaken to assess the jet interaction effects caused by the various solid rocket motors used on the Orion Launch Abort Vehicle (LAV). These interactions of the external flowfield and the various rocket plumes can cause localized aerodynamic disturbances yielding significant and highly non-linear control amplifications and attenuations. This paper discusses the scaling methodologies used to model the flight plumes in the wind tunnel using cold air as the simulant gas. Comparisons of predicted flight, predicted wind tunnel, and measured wind tunnel forces-and-moments and plume flowfields are made to assess the effectiveness of the selected scaling methodologies.

  6. Wind tunnel measurements of the dilution of tailpipe emissions downstream of a car, a light-duty truck, and a heavy-duty truck tractor head.

    PubMed

    Chang, Victor W C; Hildemann, Lynn M; Chang, Cheng-hisn

    2009-06-01

    The particle and gaseous pollutants in vehicle exhaust emissions undergo rapid dilution with ambient air after exiting the tailpipe. The rate and extent of this dilution can greatly affect both the size evolution of primary exhaust particles and the potential for formation of ultrafine particles. Dilution ratios were measured inside of a wind tunnel in the region immediately downstream of the tailpipe using model vehicles (approximately one-fifth to one-seventh scale models) representing a light-duty truck, a passenger car, and a heavy-duty tractor head (without the trailer). A tracer gas (ethene) was released at a measured flow rate from the tailpipe, and 60 sampling probes placed downstream of the vehicle simultaneously sampled gas tracer concentrations in the near-wake (first few vehicle heights) and far-wake regions (beyond 10 vehicle heights). Tests using different tunnel wind speeds show the range of dilution ratios that can be expected as a function of vehicle type and downstream distance (i.e., time). The vehicle shape quite strongly influences dilution profiles in the near-wake region but is much less important in the far-wake region. The tractor generally produces higher dilution rates than the automobile and light-duty truck under comparable conditions.

  7. Rocket exhaust ground cloud/atmospheric interactions

    NASA Technical Reports Server (NTRS)

    Hwang, B.; Gould, R. K.

    1978-01-01

    An attempt to identify and minimize the uncertainties and potential inaccuracies of the NASA Multilayer Diffusion Model (MDM) is performed using data from selected Titan 3 launches. The study is based on detailed parametric calculations using the MDM code and a comparative study of several other diffusion models, the NASA measurements, and the MDM. The results are discussed and evaluated. In addition, the physical/chemical processes taking place during the rocket cloud rise are analyzed. The exhaust properties and the deluge water effects are evaluated. A time-dependent model for two aerosol coagulations is developed and documented. Calculations using this model for dry deposition during cloud rise are made. A simple model for calculating physical properties such as temperature and air mass entrainment during cloud rise is also developed and incorporated with the aerosol model.

  8. Effect of Base Bleed and Terminal Fairings on the Performance of Exhaust-Nozzle-Afterbody Combinations at Mach Numbers of 1.93, 2.55, and 3.05

    NASA Technical Reports Server (NTRS)

    Norton, Harry T., Jr.; Keith, Arvid L., Jr.

    1960-01-01

    An investigation of four exhaust-nozzle-afterbody combinations has been conducted in the Langley 9- by 12-inch blowdown tunnel at Mach numbers of 1.93, 2.55, and 3.05. The models were tested on a pylon-mounted nacelle and the jet exhaust was simulated with cold air. Base bleed w a s varied from 0 to about 12 percent of the primary jet weight flow and was discharged in to the base region through either a sonic or supersonic bleed nozzle. The models were tested at zero degree angle of attack and the Reynolds number range was from 8 x 10(exp 6) to 9 x 10(exp 6) per foot. The results indicate that the base pressure and the performance of the exhaust-nozzle-afterbody combinations were little affected gy the high-velocity base bleed. The efficiency of the terminal-fairing model was only slightly less than that of the convergent-divergent nozzle-afterbody combinations; this difference indicates the loss associated with improved transonic efficiency at higher Mach numbers.

  9. Supersonic Jet Exhaust Noise at High Subsonic Flight Speed

    NASA Technical Reports Server (NTRS)

    Norum, Thomas D.; Garber, Donald P.; Golub, Robert A.; Santa Maria, Odilyn L.; Orme, John S.

    2004-01-01

    An empirical model to predict the effects of flight on the noise from a supersonic transport is developed. This model is based on an analysis of the exhaust jet noise from high subsonic flights of the F-15 ACTIVE Aircraft. Acoustic comparisons previously attainable only in a wind tunnel were accomplished through the control of both flight operations and exhaust nozzle exit diameter. Independent parametric variations of both flight and exhaust jet Mach numbers at given supersonic nozzle pressure ratios enabled excellent correlations to be made for both jet broadband shock noise and jet mixing noise at flight speeds up to Mach 0.8. Shock noise correlated with flight speed and emission angle through a Doppler factor exponent of about 2.6. Mixing noise at all downstream angles was found to correlate well with a jet relative velocity exponent of about 7.3, with deviations from this behavior only at supersonic eddy convection speeds and at very high flight Mach numbers. The acoustic database from the flight test is also provided.

  10. Gas separation process using membranes with permeate sweep to remove CO.sub.2 from gaseous fuel combustion exhaust

    DOEpatents

    Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

    2012-05-15

    A gas separation process for treating exhaust gases from the combustion of gaseous fuels, and gaseous fuel combustion processes including such gas separation. The invention involves routing a first portion of the exhaust stream to a carbon dioxide capture step, while simultaneously flowing a second portion of the exhaust gas stream across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas back to the combustor.

  11. Automotive Fuel and Exhaust Systems.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, originally developed for the Marine Corps, is designed to provide mechanics with an understanding of the construction, operation, malfunction, diagnosis, maintenance, and repair of the fuel and exhaust systems used in automobiles. The course contains five study units covering fundamentals of gasoline engine fuel…

  12. Cost effective use of liquid nitrogen in cryogenic wind tunnels

    NASA Technical Reports Server (NTRS)

    Mcintosh, Glen E.; Lombard, David S.; Martindale, David L.; Dunn, Robert P.

    1987-01-01

    A method of reliquefying from 12 to 19% of the nitrogen exhaust gas from a cryogenic wind tunnel has been developed. Technical feasibility and cost effectiveness of the system depends on performance of an innovative positive displacement expander which requires scale model testing to confirm design studies. The existing cryogenic system at the 0.3-m transonic cryogenic tunnel has been surveyed and extensive upgrades proposed. Upgrades are generally cost effective and may be implemented immediately since they are based on established technology.

  13. An experimental investigation of end treatments for nonreturn wind tunnels

    NASA Technical Reports Server (NTRS)

    Eckert, W. T.; Mort, K. W.; Piazza, J. E.

    1976-01-01

    The results of a series of flow quality and performance tests on several inlet and exit configurations for nonreturn wind tunnels are presented. Test section flow angularities, local dynamic pressure variations, and total-pressure-loss variations are presented as functions of wind-to-test-section dynamic pressure ratio. The results show that a nonreturn wind tunnel should have end treatments with three characteristics: (1) a vertical exit system, (2) a horizontal inlet system, and (3) an area of protected enclosure at the inlet. Inlet and exhaust treatments were developed that produced good aerodynamic flow qualities with low power penalties.

  14. RE-ENTRAINMENT AND DISPERSION OF EXHAUSTS FROM INDOOR RADON REDUCTION SYSTEMS: ANALYSIS OF TRACER GAS DATA

    EPA Science Inventory

    Tracer gas studies were conducted around four model houses in a wind tunnel, and around one house in the field, to quantify re-entrainment and dispersion of exhaust gases released from residential indoor radon reduction systems. Re-entrainment tests in the field suggest that acti...

  15. Exhaust emissions of polycyclic aromatic hydrocarbons, n-alkanes and phenols from vehicles coming within different European classes

    NASA Astrophysics Data System (ADS)

    Perrone, Maria Grazia; Carbone, Claudio; Faedo, Davide; Ferrero, Luca; Maggioni, Angela; Sangiorgi, Giorgia; Bolzacchini, Ezio

    2014-01-01

    EU emission standards for vehicles do not include many particulate (PM) and gaseous species, despite their considerable impact on air pollution and health. Emission factors (EFs) were measured for unregulated species, i.e. polycyclic aromatic hydrocarbons (PAHs) and n-alkanes (ALKs) in the particle phase, and, for the first time, EFs for phenols in both particle and gas phases. Exhaust samples were collected under controlled operating conditions (chassis dynamometer tests) for in-service vehicles (private cars, PCs and light duty vehicles, LDVs) from different EURO classes. EFs of trace organics were highest for the old EURO 1 vehicles (the tested EURO 1 vehicles were without emission-control devices), and lowest for the more recent EURO 3 and 4 vehicles. ALKs (C20-C32) were the most abundant trace organic compounds found in PM vehicle exhaust, and their EF ranged between 2034 and 101 μg km-1 (Euro 1-4 LDVs). PM-phased phenols EFs were in the range 0.42-2.50 μg km-1, and 4-nitrophenol was the most abundant one. The highest EFs were measured for phenols in the gas phase (dominated by the presence of phenol) for gasoline EURO 1 (43.16 ± 9.99 μg km-1). Emissions of PAHs changed depending on the fuel used. The PAH EFs of diesel-driven PCs were 4-5 times higher than those of gasoline vehicles, with PAHs diesel exhaust being mainly enriched in low 4-ring PAHs (85%), while 5-6 ring PAHs were prevalent (55%) in gasoline vehicles. Results of source profiles from chassis dynamometer tests were compared with ambient data, and the traffic PAH source profile derived from a tunnel study (Milan) agreed with the estimated emissions from a mix of diesel and gasoline vehicles circulating in the same area. Moreover, the impact of EURO regulatory changes on exhaust emissions was calculated, and this made it possible to estimate the downward trend of PAH emissions in the Province of Milan in the period 2005-2020.

  16. Cheyenne Mountain Air Force Station NPDES Permit

    EPA Pesticide Factsheets

    Under NPDES permit CO-0034762, the Cheyenne Mountain Air Force Station is authorized to discharge from the interior storm drainage system and air exhaust stacks at the Cheyenne Mountain Complex, in El Paso County, Colorado, to tributaries Fountain Creek.

  17. Full-Scale Tunnel (FST)

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Modification of entrance cone Full-Scale Tunnel (FST). Smith DeFrance describes the entrance cone in NACA TR 459 as follows: 'The entrance cone is 75 feet in length and in this distance the cross section changes from a rectangle 72 by 110 feet to a 30 by 60 foot elliptic section. The area reduction in the entrance cone is slightly less than 5:1. The shape of the entrance cone was chosen to give as fas as possible a constant acceleration to the air stream and to retain a 9-foot length of nozzle for directing the flow.' (p. 293)

  18. Automobile exhaust level of CO: study in Chidambaram town.

    PubMed

    Ramamurthy, N; Thirumarran, M

    2002-01-01

    The exhaust gases from automobiles constitute about 75% of air pollution. Among the various pollutants emitted from vehicles, CO is the primary pollutant and very toxic one. The CO monitor method was used to predict the CO level in Chidambaram town. From the study it is evident that the pollution level is closely related to the density of motor vehicles on the roads. With increase in number of motor vehicles pollution level also increases which pollutes the roadside environment severely in future.

  19. Partitioning of initial energy release in a tunnel environment

    NASA Astrophysics Data System (ADS)

    Felts, Joshua E.; Lee, Richard J.; Mychajlonka, Kyle; Davis, Andy

    2017-01-01

    After the detonation of an explosive charge in the closed end of a tunnel, product gases and metal fuels can continue to react with one another as well as combust with the available air while expanding down the tunnel. It is that total reaction that drives the blast wave at long distances from the charge. The initial energy release was calculated from pressure wave time of arrival at distances of 5 to 30 tunnel diameters away for several explosives in a 127-mm diameter tunnel using point blast theory. For similarly sized explosives, the anaerobic energy was measured using a detonation calorimeter. Comparisons were made for four explosives: one nearly ideal, two with aluminum, and one with aluminum and an oxidizer. The measured tunnel and calorimeter energies were equal, within error, for the near-ideal explosive. The other three explosives had tunnel and calorimeter energies higher than that which can be accounted for from the detonable ingredients alone, especially in the tunnel. The differences between the tunnel and calorimeter for the three aluminized explosives were taken to be from aerobic combustion of aluminum. The presence of higher concentrations of aluminum or an oxidizer enhanced the amount of aerobic combustion of aluminum. The aluminized explosive with additional oxidizer consumed more than twice the aluminum of the other two in the tunnel. More experiments are needed to better define the early partitioning of anaerobic and aerobic combustion of aluminum in the small-scale tunnel.

  20. Recirculating electric air filter

    DOEpatents

    Bergman, Werner

    1986-01-01

    An electric air filter cartridge has a cylindrical inner high voltage eleode, a layer of filter material, and an outer ground electrode formed of a plurality of segments moveably connected together. The outer electrode can be easily opened to remove or insert filter material. Air flows through the two electrodes and the filter material and is exhausted from the center of the inner electrode.

  1. Recirculating electric air filter

    DOEpatents

    Bergman, W.

    1985-01-09

    An electric air filter cartridge has a cylindrical inner high voltage electrode, a layer of filter material, and an outer ground electrode formed of a plurality of segments moveably connected together. The outer electrode can be easily opened to remove or insert filter material. Air flows through the two electrodes and the filter material and is exhausted from the center of the inner electrode.

  2. Wind tunnel interference factors for high-lift wings in closed wind tunnels. Ph.D. Thesis - Princeton Univ.

    NASA Technical Reports Server (NTRS)

    Joppa, R. G.

    1973-01-01

    A problem associated with the wind tunnel testing of very slow flying aircraft is the correction of observed pitching moments to free air conditions. The most significant effects of such corrections are to be found at moderate downwash angles typical of the landing approach. The wind tunnel walls induce interference velocities at the tail different from those induced at the wing, and these induced velocities also alter the trajectory of the trailing vortex system. The relocated vortex system induces different velocities at the tail from those experienced in free air. The effect of the relocated vortex and the walls is to cause important changes in the measured pitching moments in the wind tunnel.

  3. 46 CFR 169.609 - Exhaust systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Electrical Internal Combustion Engine Installations § 169.609 Exhaust systems. Engine exhaust installations... separate from the engine cooling system, a suitable warning device must be provided to indicate a...

  4. 46 CFR 169.609 - Exhaust systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Electrical Internal Combustion Engine Installations § 169.609 Exhaust systems. Engine exhaust installations... separate from the engine cooling system, a suitable warning device must be provided to indicate a...

  5. 46 CFR 169.609 - Exhaust systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Electrical Internal Combustion Engine Installations § 169.609 Exhaust systems. Engine exhaust installations... separate from the engine cooling system, a suitable warning device must be provided to indicate a...

  6. 46 CFR 169.609 - Exhaust systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Electrical Internal Combustion Engine Installations § 169.609 Exhaust systems. Engine exhaust installations... separate from the engine cooling system, a suitable warning device must be provided to indicate a...

  7. 46 CFR 169.609 - Exhaust systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Electrical Internal Combustion Engine Installations § 169.609 Exhaust systems. Engine exhaust installations... separate from the engine cooling system, a suitable warning device must be provided to indicate a...

  8. 14 CFR 25.1123 - Exhaust piping.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Exhaust System § 25.1123 Exhaust piping. For powerplant... corrosion resistant, and must have provisions to prevent failure due to expansion by operating...

  9. 14 CFR 25.1123 - Exhaust piping.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Exhaust System § 25.1123 Exhaust piping. For powerplant... corrosion resistant, and must have provisions to prevent failure due to expansion by operating...

  10. 14 CFR 25.1123 - Exhaust piping.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Exhaust System § 25.1123 Exhaust piping. For powerplant... corrosion resistant, and must have provisions to prevent failure due to expansion by operating...

  11. 14 CFR 25.1123 - Exhaust piping.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Exhaust System § 25.1123 Exhaust piping. For powerplant... corrosion resistant, and must have provisions to prevent failure due to expansion by operating...

  12. 14 CFR 25.1123 - Exhaust piping.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Exhaust System § 25.1123 Exhaust piping. For powerplant... corrosion resistant, and must have provisions to prevent failure due to expansion by operating...

  13. Engine Would Recover Exhaust Energy More Efficiently

    NASA Technical Reports Server (NTRS)

    Dimpelfeld, Philip M.

    1993-01-01

    Exhaust energy used for supercharging and extra shaft power. Flow of exhaust apportioned by waste gate to meet demand of turbocharger, and portion not fed to turbocharger sent to power-recovery turbine. Expected to increase fuel efficiency.

  14. 49 CFR 325.91 - Exhaust systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... sound reduction, such as exhaust gas leaks or alteration or deterioration of muffler elements, (small traces of soot on flexible exhaust pipe sections shall not constitute a violation of this subpart);...

  15. Heat exhaustion in a deep underground metalliferous mine

    PubMed Central

    Donoghue, A; Sinclair, M.; Bates, G.

    2000-01-01

    OBJECTIVES—To examine the incidence, clinical state, personal risk factors, haematology, and biochemistry of heat exhaustion occurring at a deep underground metalliferous mine. To describe the underground thermal conditions associated with the occurrence of heat exhaustion.
METHODS—A 1 year prospective case series of acute heat exhaustion was undertaken. A history was obtained with a structured questionnaire. Pulse rate, blood pressure, tympanic temperature, and specific gravity of urine were measured before treatment. Venous blood was analysed for haematological and biochemical variables, during the acute presentation and after recovery. Body mass index (BMI) and maximum O2 consumption (V̇O2 max) were measured after recovery. Psychrometric wet bulb temperature, dry bulb temperature, and air velocity were measured at the underground sites where heat exhaustion had occurred. Air cooling power and psychrometric wet bulb globe temperature were derived from these data.
RESULTS—106 Cases were studied. The incidence of heat exhaustion during the year was 43.0 cases / million man-hours. In February it was 147 cases / million man-hours. The incidence rate ratio for mines operating below 1200 m compared with those operating above 1200 m was 3.17. Mean estimated fluid intake was 0.64 l/h (SD 0.29, range 0.08-1.50). The following data were increased in acute presentation compared with recovery (p value, % of acute cases above the normal clinical range): neutrophils (p<0.001, 36%), anion gap (p<0.001, 63%), urea (p<0.001, 21%), creatinine (p<0.001, 30%), glucose (p<0.001, 15%), serum osmolality (p=0.030, 71%), creatine kinase (p=0.002, 45%), aspartate transaminase (p<0.001, 14%), lactate dehydrogenase (p<0.001, 9.5%), and ferritin (p<0.001, 26%). The following data were depressed in acute presentation compared with recovery (p value, % of acute cases below the normal clinical range): eosinophils (p=0.003, 38%) and bicarbonate (p=0.011, 32%). Urea and

  16. A comparison of genotoxicity of automotive exhaust particles from laboratory and environmental sources.

    PubMed

    Brooks, A L; Li, A P; Dutcher, J S; Clark, C R; Rothenberg, S J; Kiyoura, R; Bechtold, W E; McClellan, R O

    1984-01-01

    This research (1) ranked the genotoxicity of methylene chloride extracts of laboratory and environmentally collected particles and (2) evaluated the role of collection location and sample composition on genotoxic potency. Samples of exhaust from a spark-ignition automobile, light-duty diesel automobile, and a heavy-duty diesel engine operated in a laboratory on a dynamometer were studied, as well as samples taken in a highway tunnel and outside the same tunnel. The tunnel samples were collected 30 m inside or 56 m outside the exit portal at times when between 70%-95% of the traffic consisted of diesel trucks. In the Ames Salmonella mutagenicity assay, each extract produced a dose-dependent increase in mutagenicity in strain TA-98 without addition of liver S-9 fraction. Extracts from two tunnel samples collected 1 yr apart, and extracts of particles collected outside the tunnel had similar mutagenic activity. The order of mutagenic activity per microgram of extract in TA-98 without S-9 from the lowest to the highest was environmental sample less than or equal to tunnel less than heavy-duty diesel less than light-duty diesel less than spark ignition. Addition of S-9 or testing in Salmonella strains resistant to the mutagenicity of nitroaromatic compounds (TA-98 NR and TA-98 1,8-DNP6) decreased the mutagenic response. With cell killing, sister chromatid exchanges, and mutations as endpoints in Chinese hamster ovary cells (CHO), the order of potency was tunnel less than light-duty less than spark-ignition samples. All three extracts induced a similar amount of mitotic delay per microgram with or without S-9. Enhanced chromosome aberration frequency was detected only in cells exposed to extracts from spark-ignition exhaust. The data indicated that genotoxic activity was detected in each particle extract, that the potency ranking was similar using different genetic endpoints, and that the magnitude of the genotoxic potency was similar.

  17. 40 CFR 1045.103 - What exhaust emission standards must my outboard and personal watercraft engines meet?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS Emission Standards and Related Requirements § 1045.103 What exhaust.... (3) Other engines: THC emissions. (e) Useful life. Your engines must meet the exhaust...

  18. 40 CFR 1045.103 - What exhaust emission standards must my outboard and personal watercraft engines meet?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS Emission Standards and Related Requirements § 1045.103 What exhaust.... (3) Other engines: THC emissions. (e) Useful life. Your engines must meet the exhaust...

  19. 40 CFR 1045.103 - What exhaust emission standards must my outboard and personal watercraft engines meet?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS Emission Standards and Related Requirements § 1045.103 What exhaust.... (3) Other engines: THC emissions. (e) Useful life. Your engines must meet the exhaust...

  20. 40 CFR 1045.103 - What exhaust emission standards must my outboard and personal watercraft engines meet?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS Emission Standards and Related Requirements § 1045.103 What exhaust.... (3) Other engines: THC emissions. (e) Useful life. Your engines must meet the exhaust...

  1. Remote passive detection of aircraft exhausts at airports

    NASA Astrophysics Data System (ADS)

    Schaefer, Klaus P.; Jahn, Carsten; Harig, Roland; Aleyt, Christian; Rusch, Peter

    Emissions from vented sources are often important inputs for the development of emission inventories and contribute to local air pollution and global enhancement of greenhouse gases. Aircraft engines are part of these emission sources. A passive measurement technique such as FTIR emission spectrometry is more cost effective and faster in operation for the determination of the composition of hot exhausts of this kind than other measurement systems as e.g. in situ techniques. Within the scope of aircraft emission investigations the measurements were performed from a measurement van which is equipped with an FTIR spectrometer of high spectral resolution coupled with a telescope and a two-axis movable mirror for rapid orientation towards the emission sources. At airports the emission indices of CO2, CO and NO of main engines and auxiliary power units of standing aircraft were determined. The measurement time is about one minute. The accuracy is better than 30 % as found from burner experiments with calibration gases (CO and NO). The method is also applied to detect exhausts of flares and smoke stacks. Currently, a new scanning FTIR-system is developed. The system allows imaging of the exhaust gas and rapid automated alignment of the field of view. The goal of the new development is to measure aircraft exhausts during normal operations at the airport. The spectrometer is coupled with a camera giving an image of the scenery so that a rapid selection of the hottest exhaust area is possible. It is planned to equip the system with an infrared camera for automatic tracking of this area with the scanning mirror so that measurements of the exhausts of a moving aircraft are possible.

  2. A Transonic and Surpersonic Investigation of Jet Exhaust Plume Effects on the Afterbody and Base Pressures of a Body of Revolution

    NASA Technical Reports Server (NTRS)

    Andrews, C. D.; Cooper, C. E., Jr.

    1974-01-01

    An experimental aerodynamic investigation was conducted to provide data for studies to determine the criteria for simulating rocket engine plume induced aerodynamic effects in the wind tunnel using a simulated gaseous plume. Model surface and base pressure data were obtained in the presence of both a simulated and a prototype gaseous plume for a matrix of plume properties to enable investigators to determine the parameters that correlate the simulated and prototype plume-induced data. The test program was conducted in the Marshall Space Flight Center's 14 x 14-inch trisonic wind tunnel using two models, the first being a strut mounted cone-ogive-cylinder model with a fineness ratio of 9. Model exterior pressures, model plenum chamber and nozzle performance data were obtained at Mach numbers of 0.9, 1.2, 1.46, and 3.48. The exhaust plume was generated by using air as the simulant gas, or Freon-14 (CF4) as the prototype gas, over a chamber pressure range from 0 to 2,000 psia and a total temperature range from 50 to 600 F.

  3. Data reduction formulas for the 16-foot transonic tunnel: NASA Langley Research Center, revision 2

    NASA Technical Reports Server (NTRS)

    Mercer, Charles E.; Berrier, Bobby L.; Capone, Francis J.; Grayston, Alan M.

    1992-01-01

    The equations used by the 16-Foot Transonic Wind Tunnel in the data reduction programs are presented in nine modules. Each module consists of equations necessary to achieve a specific purpose. These modules are categorized in the following groups: (1) tunnel parameters; (2) jet exhaust measurements; (3) skin friction drag; (4) balance loads and model attitudes calculations; (5) internal drag (or exit-flow distribution); (6) pressure coefficients and integrated forces; (7) thrust removal options; (8) turboprop options; and (9) inlet distortion.

  4. EFFECTS OF DIESEL EXHAUST ON TLR3 SIGNALING IN RESPIRATORY EPITHELIAL CELLS

    EPA Science Inventory

    There are a variety of intrinsic as well as extrinsic factors, such as exposure to air pollution that can affect the pathogenesis of respiratory infections. Diesel exhaust (DE) emissions can significantly contribute to air pollution levels and exposure to DE can alter host defens...

  5. 40 CFR 86.160-00 - Exhaust emission test procedure for SC03 emissions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.160-00 Exhaust emission test... official test cycle, is either conducted in an environmental test facility or under test conditions that... ambient test conditions of: 95 °F air temperature, 100 grains of water/pound of dry air (approximately...

  6. The cryogenic wind tunnel

    NASA Technical Reports Server (NTRS)

    Kilgore, R. A.

    1976-01-01

    Based on theoretical studies and experience with a low speed cryogenic tunnel and with a 1/3-meter transonic cryogenic tunnel, the cryogenic wind tunnel concept was shown to offer many advantages with respect to the attainment of full scale Reynolds number at reasonable levels of dynamic pressure in a ground based facility. The unique modes of operation available in a pressurized cryogenic tunnel make possible for the first time the separation of Mach number, Reynolds number, and aeroelastic effects. By reducing the drive-power requirements to a level where a conventional fan drive system may be used, the cryogenic concept makes possible a tunnel with high productivity and run times sufficiently long to allow for all types of tests at reduced capital costs and, for equal amounts of testing, reduced total energy consumption in comparison with other tunnel concepts.

  7. Simulator of Road Tunnel

    NASA Astrophysics Data System (ADS)

    Danišovič, Peter; Schlosser, František; Šrámek, Juraj; Rázga, Martin

    2015-05-01

    A Tunnel Traffic & Operation Simulator is a device of the Centre of Transport Research at the University of Žilina. The Simulator allows managing technological equipment of virtual two-tube highway tunnel, which is interconnected with simulation of vehicle traffic in tunnel. Changes of the traffic-operation states and other equipment are reflecting at the simulated traffic, as well as simulations of various emergency events in traffic initiate changes in tunnel detecting and measuring devices. It is thus possible to simulate emergency states, which can be affected by various faults of technology as well as by climatic conditions. The solutions can be found in irreplaceable experiences of Slovak road tunnel operators, changes of trafficoperation states, visualizations of operator technological display screens, technological devices labelling in order to increase operational safety of road tunnels.

  8. 15-Foot Spin Tunnel

    NASA Technical Reports Server (NTRS)

    1935-01-01

    Interior view of model in 15-Foot Spin Tunnel. Charles Zimmerman wrote in NASA TR No. 557: 'After the observations have been made, the model is lowered into a net held in the air stream by one of the operators or into a large bowl-shaped net at the bottom of the test section. When lowered into the large net, the model is retrieved with a long-handled clamp.' (p. 267) 'The models mused are generally 1/10 to 1/16 scale. The size of the models is limited by the wing span and the wing loading. The maximum allowable span is about 36 inches; the maximum wing loading is about 1.3 pounds per square foot.' (p. 266) 'Balsa wood is the usual structural material because of its low density. It is necessary to hollow out the after portion of the fuselage and to cut out a large portion of the wood in the wings to permit proper mass distribution. The wing cut-outs are covered with silk tissue paper. The leading and trailing edges and tips of the wings are fitted with strips of spruce, pattern pine, or bamboo inset into the edge of the balsa to prevent disfigurement from accidental blows or from striking the safety netting. Lead is used for ballast.' (p. 266)

  9. Full Scale Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Installation of propeller and motor fairing for east exit cone. Smith DeFrance described the propellers and motors in NACA TR No. 459. ' The propellers are located side by side and 48 feet aft of the throat of the exit-cone bell. The propellers are 35 feet 5 inches in diameter and each consists of four cast aluminum alloy blades screwed into a cast steel hub.' 'The most commonly used power plant for operating a wind tunnel is a direct-current motor and motor-generator set with Ward Leonard control system. For the FST it was found that alternating current slip-ring induction motors, together with satisfactory control equipment, could be purchased for approximately 30 percent less than the direct-current equipment. Two 4,000-horsepower slip-ring induction motors with 24 steps of speed between 75 and 300 r.p.m. were therefore installed. In order to obtain the range of speed one pole change was provided and the other variations are obtained by the introduction of resistance in the rotor circuit. This control permits a variation in air speed from 25 to 118 miles per hour. The two motors are connected through an automatic switchboard to one drum-type controller located in the test chamber. All the control equipment is interlocked and connected through time-limit relays, so that regardless of how fast the controller handle is moved the motors will increase in speed at regular intervals.' (p. 294-295)

  10. 46 CFR 128.320 - Exhaust systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Exhaust systems. 128.320 Section 128.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Main and Auxiliary Machinery § 128.320 Exhaust systems. No diesel-engine exhaust...

  11. 46 CFR 128.320 - Exhaust systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Exhaust systems. 128.320 Section 128.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Main and Auxiliary Machinery § 128.320 Exhaust systems. No diesel-engine exhaust...

  12. 46 CFR 128.320 - Exhaust systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Exhaust systems. 128.320 Section 128.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Main and Auxiliary Machinery § 128.320 Exhaust systems. No diesel-engine exhaust...

  13. 46 CFR 128.320 - Exhaust systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Exhaust systems. 128.320 Section 128.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Main and Auxiliary Machinery § 128.320 Exhaust systems. No diesel-engine exhaust...

  14. 46 CFR 128.320 - Exhaust systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Exhaust systems. 128.320 Section 128.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS MARINE ENGINEERING: EQUIPMENT AND SYSTEMS Main and Auxiliary Machinery § 128.320 Exhaust systems. No diesel-engine exhaust...

  15. Pipetron Tunnel Construction Issues

    SciTech Connect

    Friant, James E.; Bauer, Robert A.; Gross, David L.; May, Michael; Lach, Joseph

    1997-01-01

    This report examines issues involved in the civil construction aspects of the tunneling that could be done in the region of Fermilab to support the Pipetron along, moderately deep, tunnel loop. Cost, technical and political aspects of tunneling are addressed in this preliminary guide for further study. At Snowmass 96, in a series of informal, but comprehensive discussions, several guidelines were developed to frame this report.

  16. Charge Islands Through Tunneling

    NASA Technical Reports Server (NTRS)

    Robinson, Daryl C.

    2002-01-01

    It has been recently reported that the electrical charge in a semiconductive carbon nanotube is not evenly distributed, but rather it is divided into charge "islands." This paper links the aforementioned phenomenon to tunneling and provides further insight into the higher rate of tunneling processes, which makes tunneling devices attractive. This paper also provides a basis for calculating the charge profile over the length of the tube so that nanoscale devices' conductive properties may be fully exploited.

  17. Development of the 5-cm Agent Fate Wind Tunnel

    DTIC Science & Technology

    2006-12-01

    fixture commenced in June 2002. 22 Hot Wire Vernier Anemometer Height Gage Straightener / Test Section \\: Inlet Exhaust Plexi-Glass Blower Figure 4. Plexi...Glass Test Fixture Velocity measurements in the test section were achieved using a TSI Model IFA 300 hot wire anemometer , a research grade instrument...Prototype) Type a 3 4Poucin Evluin f -m in une APPENDDý- A 15, Tunnel Designation: Plexi-Glass Test Fixture Hot Wire Vernier Anemometer Height

  18. Effect of Exhaust Pressure on the Cooling Characteristics of a Liquid-Cooled Engine

    NASA Technical Reports Server (NTRS)

    Doyle, Ronald B.; Desmon, Leland G.

    1947-01-01

    Data for a liquid-cooled engine with a displacement volume of 1710 cubic inches were analyzed to determine the effect of exhaust pressure on the engine cooling characteristics. The data covered a range of exhaust pressures from 7 to 62 inches of mercury absolute, inlet-manifold pressures from 30 to 50 inches of mercury absolute, engine speeds from 1600 to 3000 rpm, and fuel-air ratios from 0.063 to 0.100. The effect of exhaust pressure on engine cooling was satisfactorily incorporated in the NACA cooling-correlation method as a variation in effective gas temperature with exhaust pressure. Large variations of cylinder-head temperature with exhaust pressure were obtained for operation at constant charge flow. At a constant charge flow of 2 pounds per second (approximately 1000 bhp) and a fuel-air ratio of 0.085, an increase in exhaust pressure from 10 to 60 inches of mercury absolute resulted in an increase of 40 F in average cylinder-head temperature. For operation at constant engine speed and inlet-manifold pressure and variable exhaust pressure (variable charge flow), however, the effect of exhaust pressure on cylinder-head temperature is small. For example, at an inlet-manifold pressure of 40 inches of mercury absolute, an engine speed of 2400 rpm.- and a fuel-air ratio of 0.085, the average cylinder-head temperature was about the same at exhaust pressures of 10 and 60 inches of,mercury absolute; a rise and a subsequent decrease of about 70 occurred between these extremes.

  19. An analysis of combustion studies in shock expansion tunnels and reflected shock tunnels

    NASA Technical Reports Server (NTRS)

    Jachimowski, Casimir J.

    1992-01-01

    The effect of initial nonequilibrium dissociated air constituents on the combustion of hydrogen in high-speed flows for a simulated Mach 17 flight condition was investigated by analyzing the results of comparative combustion experiments performed in a reflected shock tunnel test gas and in a shock expansion tunnel test gas. The results were analyzed and interpreted with a one-dimensional quasi-three-stream combustor code that includes finite rate combustion chemistry. The results of this study indicate that the combustion process is kinetically controlled in the experiments in both tunnels and the presence of the nonequilibrium partially dissociated oxygen in the reflected shock tunnel enhances the combustion. Methods of compensating for the effect of dissociated oxygen are discussed.

  20. EXHAUST STACK RISES. STEEL FRAMEWORK FOR FAN HOUSE IN PLACE. ...

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

    EXHAUST STACK RISES. STEEL FRAMEWORK FOR FAN HOUSE IN PLACE. TRENCH IN FOREGROUND IS FOR DUCT THAT WILL CARRY COOLANT AIR FROM MTR'S THERMAL SHIELD. DUCT LINES UP WITH NORTH SIDE OF FAN HOUSE. AT RIGHT OF VIEW, NOTE TRENCH LEADING TO SOUTH SIDE OF FAN HOUSE; IT WILL BRING CONTAMINATED AIR FROM LABORATORY HOODS AND VENTS. CAMERA FACING EAST. INL NEGATIVE NO. 2764. Unknown Photographer, 6/29/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  1. Tunnel closure calculations

    SciTech Connect

    Moran, B.; Attia, A.

    1995-07-01

    When a deeply penetrating munition explodes above the roof of a tunnel, the amount of rubble that falls inside the tunnel is primarily a function of three parameters: first the cube-root scaled distance from the center of the explosive to the roof of the tunnel. Second the material properties of the rock around the tunnel, and in particular the shear strength of that rock, its RQD (Rock Quality Designator), and the extent and orientation of joints. And third the ratio of the tunnel diameter to the standoff distance (distance between the center of explosive and the tunnel roof). The authors have used CALE, a well-established 2-D hydrodynamic computer code, to calculate the amount of rubble that falls inside a tunnel as a function of standoff distance for two different tunnel diameters. In particular they calculated three of the tunnel collapse experiments conducted in an iron ore mine near Kirkeness, Norway in the summer of 1994. The failure model that they used in their calculations combines an equivalent plastic strain criterion with a maximum tensile strength criterion and can be calibrated for different rocks using cratering data as well as laboratory experiments. These calculations are intended to test and improve the understanding of both the Norway Experiments and the ACE (Array of conventional Explosive) phenomenology.

  2. Exhaust emission control and diagnostics

    DOEpatents

    Mazur, Christopher John; Upadhyay, Devesh

    2006-11-14

    A diesel engine emission control system uses an upstream oxidation catalyst and a downstream SCR catalyst to reduce NOx in a lean exhaust gas environment. The engine and upstream oxidation catalyst are configured to provide approximately a 1:1 ratio of NO to NO2 entering the downstream catalyst. In this way, the downstream catalyst is insensitive to sulfur contamination, and also has improved overall catalyst NOx conversion efficiency. Degradation of the system is determined when the ratio provided is no longer near the desired 1:1 ratio. This condition is detected using measurements of engine operating conditions such as from a NOx sensor located downstream of the catalysts. Finally, control action to adjust an injected amount of reductant in the exhaust gas based on the actual NO to NO2 ratio upstream of the SCR catalyst and downstream of the oxidation catalyst.

  3. Investigations of detail design issues for the high speed acoustic wind tunnel using a 60th scale model tunnel. Part 1: Tests with open circuits

    NASA Technical Reports Server (NTRS)

    Barna, P. Stephen

    1991-01-01

    This report summarizes the tests on the 1:60 scale model of the High Speed Acoustic Wind Tunnel (HSAWT) performed during the period of November 1989 to December 1990. Throughout the testing the tunnel was operated in the 'open circuit mode', that is when the airflow was induced by a powerful exhaust fan located outside the tunnel circuit. The tests were first performed with the closed test section and were subsequently repeated with the open test section. While operating with the open test section, a novel device, called the 'nozzle-diffuser,' was also tested in order to establish its usefulness of increasing pressure recovery in the first diffuser. The tests established the viability of the tunnel design. The flow distribution in each tunnel component was found acceptable and pressure recovery in the diffusers were found satisfactory. The diffusers appeared to operate without flow separation. All tests were performed at NASA LaRC.

  4. Something in the Air: Air Pollution in Schools.

    ERIC Educational Resources Information Center

    Villaire, Ted

    2002-01-01

    Discusses the danger of unhealthy air in the school environment, describing common problems and how parents and schools can respond. The article focuses on the dangers of mold, pesticides, diesel exhaust, and radon. The three sidebars describe how to promote indoor air quality at school, note how to determine whether the school's air is making…

  5. The National Environmental Respiratory Center (NERC) experiment in multi-pollutant air quality health research: II. Comparison of responses to diesel and gasoline engine exhausts, hardwood smoke and simulated downwind coal emissions.

    PubMed

    Mauderly, J L; Barrett, E G; Day, K C; Gigliotti, A P; McDonald, J D; Harrod, K S; Lund, A K; Reed, M D; Seagrave, J C; Campen, M J; Seilkop, S K

    2014-09-01

    The NERC Program conducted identically designed exposure-response studies of the respiratory and cardiovascular responses of rodents exposed by inhalation for up to 6 months to diesel and gasoline exhausts (DE, GE), wood smoke (WS) and simulated downwind coal emissions (CE). Concentrations of the four combustion-derived mixtures ranged from near upper bound plausible to common occupational and environmental hotspot levels. An "exposure effect" statistic was created to compare the strengths of exposure-response relationships and adjustments were made to minimize false positives among the large number of comparisons. All four exposures caused statistically significant effects. No exposure caused overt illness, neutrophilic lung inflammation, increased circulating micronuclei or histopathology of major organs visible by light microscopy. DE and GE caused the greatest lung cytotoxicity. WS elicited the most responses in lung lavage fluid. All exposures reduced oxidant production by unstimulated alveolar macrophages, but only GE suppressed stimulated macrophages. Only DE retarded clearance of bacteria from the lung. DE before antigen challenge suppressed responses of allergic mice. CE tended to amplify allergic responses regardless of exposure order. GE and DE induced oxidant stress and pro-atherosclerotic responses in aorta; WS and CE had no such effects. No overall ranking of toxicity was plausible. The ranking of exposures by number of significant responses varied among the response models, with each of the four causing the most responses for at least one model. Each exposure could also be deemed most or least toxic depending on the exposure metric used for comparison. The database is available for additional analyses.

  6. Influence of preexisting pulmonary emphysema on susceptibility of rats to inhaled diesel exhaust

    SciTech Connect

    Mauderly, J.L.; Bice, D.E.; Cheng, Y.S.; Gillett, N.A.; Griffith, W.C.; Henderson, R.F.; Pickrell, J.A.; Wolff, R.K. )

    1990-05-01

    The susceptibilities of normal rats and rats with preexisting pulmonary emphysema to chronically inhaled diesel exhaust were compared. Rats were exposed 7 h/day, 5 days/wk for 24 months to diesel exhaust at 3.5 mg soot/m3, or to clean air as controls. Emphysema was induced in one-half of the rats by intratracheal instillation of elastase 6 wk before exhaust exposure. Measurements included lung burdens of diesel soot, respiratory function, bronchoalveolar lavage, clearance of radiolabeled particles, pulmonary immune responses, lung collagen, excised lung weight and volume, histopathology, and mean linear intercept of terminal air spaces. Parameters indicated by analysis of variance to exhibit significant interactions between the influences of emphysema and exhaust were examined to determine if the effects were more than additive (indicating increased susceptibility). Although 14 of 63 parameters demonstrated emphysema-exhaust interactions, none indicated increased susceptibility. Less soot accumulated in lungs of emphysematous rats than in those of nonemphysematous rats, and the reduced accumulation had a sparing effect in the emphysematous rats. The results did not support the hypothesis that emphysematous lungs are more susceptible than are normal lungs to chronic exposure to high levels of diesel exhaust. The superimposition of effects of emphysema and exhaust, however, might still warrant special concern for heavy exposures of emphysematous subjects.

  7. Effects of motor vehicle exhaust on male reproductive function and associated proteins.

    PubMed

    Rengaraj, Deivendran; Kwon, Woo-Sung; Pang, Myung-Geol

    2015-01-02

    Air pollution is consistently associated with various diseases and subsequent death among children, adult, and elderly people worldwide. Motor vehicle exhaust contributes to a large proportion of the air pollution present. The motor vehicle exhaust systems emit a variety of toxic components, including carbon monoxide, nitrogen oxides, volatile organic compounds, ozone, particulate matter, and polycyclic aromatic hydrocarbons. Several epidemiological studies and laboratory studies have demonstrated that these components are potentially mutagenic, carcinogenic, and endocrine disrupting agents. However, their impact on male reproductive function and associated proteins is not very clear. Therefore, a comprehensive review on the effects of motor vehicle exhaust on male reproductive function and associated proteins is needed to better understand the risks of exhaust exposure for men. We found that motor vehicle exhaust can cause harmful effects on male reproductive functions by altering organ weights, reducing the spermatozoa qualities, and inducing oxidative stress. Remarkably, motor vehicle exhaust exposure causes significant changes in the expression patterns of proteins that are key components involved in spermatogenesis and testosterone synthesis. In conclusion, this review helps to describe the risks of vehicle exhaust exposure and its relationship to potential adverse effects on the male reproduction system.

  8. Space shuttle exhaust cloud properties

    NASA Technical Reports Server (NTRS)

    Anderson, B. J.; Keller, V. W.

    1983-01-01

    A data base describing the properties of the exhaust cloud produced by the launch of the Space Transportation System and the acidic fallout observed after each of the first four launches was assembled from a series of ground and aircraft based measurements made during the launches of STS 2, 3, and 4. Additional data were obtained from ground-based measurements during firings of the 6.4 percent model of the Solid Rocket Booster at the Marshall Center. Analysis indicates that the acidic fallout is produced by atomization of the deluge water spray by the rocket exhaust on the pad followed by rapid scavening of hydrogen chloride gas aluminum oxide particles from the Solid Rocket Boosters. The atomized spray is carried aloft by updrafts created by the hot exhaust and deposited down wind. Aircraft measurements in the STS-3 ground cloud showed an insignificant number of ice nuclei. Although no measurements were made in the column cloud, the possibility of inadvertent weather modification caused by the interaction of ice nuclei with natural clouds appears remote.

  9. Combustion-derived nanoparticulate induces the adverse vascular effects of diesel exhaust inhalation

    PubMed Central

    Mills, Nicholas L.; Miller, Mark R.; Lucking, Andrew J.; Beveridge, Jon; Flint, Laura; Boere, A. John F.; Fokkens, Paul H.; Boon, Nicholas A.; Sandstrom, Thomas; Blomberg, Anders; Duffin, Rodger; Donaldson, Ken; Hadoke, Patrick W.F.; Cassee, Flemming R.; Newby, David E.

    2011-01-01

    Aim Exposure to road traffic and air pollution may be a trigger of acute myocardial infarction, but the individual pollutants responsible for this effect have not been established. We assess the role of combustion-derived-nanoparticles in mediating the adverse cardiovascular effects of air pollution. Methods and results To determine the in vivo effects of inhalation of diesel exhaust components, 16 healthy volunteers were exposed to (i) dilute diesel exhaust, (ii) pure carbon nanoparticulate, (iii) filtered diesel exhaust, or (iv) filtered air, in a randomized double blind cross-over study. Following each exposure, forearm blood flow was measured during intra-brachial bradykinin, acetylcholine, sodium nitroprusside, and verapamil infusions. Compared with filtered air, inhalation of diesel exhaust increased systolic blood pressure (145 ± 4 vs. 133 ± 3 mmHg, P< 0.05) and attenuated vasodilatation to bradykinin (P= 0.005), acetylcholine (P= 0.008), and sodium nitroprusside (P< 0.001). Exposure to pure carbon nanoparticulate or filtered exhaust had no effect on endothelium-dependent or -independent vasodilatation. To determine the direct vascular effects of nanoparticulate, isolated rat aortic rings (n= 6–9 per group) were assessed in vitro by wire myography and exposed to diesel exhaust particulate, pure carbon nanoparticulate and vehicle. Compared with vehicle, diesel exhaust particulate (but not pure carbon nanoparticulate) attenuated both acetylcholine (P< 0.001) and sodium-nitroprusside (P= 0.019)-induced vasorelaxation. These effects were partially attributable to both soluble and insoluble components of the particulate. Conclusion Combustion-derived nanoparticulate appears to predominately mediate the adverse vascular effects of diesel exhaust inhalation. This provides a rationale for testing environmental health interventions targeted at reducing traffic-derived particulate emissions. PMID:21753226

  10. Relation of Hydrogen and Methane to Carbon Monoxide in Exhaust Gases from Internal-Combustion Engines

    NASA Technical Reports Server (NTRS)

    Gerrish, Harold C; Tessmann, Arthur M

    1935-01-01

    The relation of hydrogen and methane to carbon monoxide in the exhaust gases from internal-combustion engines operating on standard-grade aviation gasoline, fighting-grade aviation gasoline, hydrogenated safety fuel, laboratory diesel fuel, and auto diesel fuel was determined by analysis of the exhaust gases. Two liquid-cooled single-cylinder spark-ignition, one 9-cylinder radial air-cooled spark-ignition, and two liquid-cooled single-cylinder compression-ignition engines were used.

  11. The simulation of a propulsive jet and force measurement using a magnetically suspended wind tunnel model

    NASA Technical Reports Server (NTRS)

    Garbutt, K. S.; Goodyer, M. J.

    1994-01-01

    Models featuring the simulation of exhaust jets were developed for magnetic levitation in a wind tunnel. The exhaust gas was stored internally producing a discharge of sufficient duration to allow nominal steady state to be reached. The gas was stored in the form of compressed gas or a solid rocket propellant. Testing was performed with the levitated models although deficiencies prevented the detection of jet-induced aerodynamic effects. Difficulties with data reduction led to the development of a new force calibration technique, used in conjunction with an exhaust simulator and also in separate high incidence aerodynamic tests.

  12. Reducing drag of a commuter train, using engine exhaust momentum

    NASA Astrophysics Data System (ADS)

    Ha, Dong Keun

    The objective of this thesis was to perform numerical investigations of two different methods of injecting fluid momentum into the air flow above a commuter train to reduce its drag. Based on previous aerodynamic modifications of heavy duty trucks in improving fuel efficiency, two structural modifications were designed and applied to a Metrolink Services commuter train in the Los Angeles (LA) County area to reduce its drag and subsequently improve fuel efficiency. The first modification was an L-shaped channel, added to the exhaust cooling fan above the locomotive roof to divert and align the exhaust gases in the axial direction. The second modification was adding an airfoil shaped lid over the L-shape channel, to minimize the drag of the perturbed structure, and thus reduce the overall drag. The computational fluid dynamic (CFD) software CCM+ from CD-Adapco with the ?-? turbulence model was used for the simulations. A single train set which consists of three vehicles: one locomotive, one trailer car and one cab car were used. All the vehicles were modeled based on the standard Metrolink fleet train size. The wind speed was at 90 miles per hour (mph), which is the maximum speed for the Orange County Metrolink line. Air was used as the exhaust gas in the simulation. The temperature of the exhausting air emitting out of the cooling fan on the roof was 150 F and the average fan speed was 120 mph. Results showed that with the addition of the lid, momentum injection results in reduced flow separation and pressure recovery behind the locomotive, which reduces the overall drag by at least 30%.

  13. HUBBLE SEES SUPERSONIC EXHAUST FROM NEBULA

    NASA Technical Reports Server (NTRS)

    2002-01-01

    2-9 is a striking example of a 'butterfly' or a bipolar planetary nebula. Another more revealing name might be the 'Twin Jet Nebula.' If the nebula is sliced across the star, each side of it appears much like a pair of exhausts from jet engines. Indeed, because of the nebula's shape and the measured velocity of the gas, in excess of 200 miles per second, astronomers believe that the description as a super-super-sonic jet exhaust is quite apt. Ground-based studies have shown that the nebula's size increases with time, suggesting that the stellar outburst that formed the lobes occurred just 1,200 years ago. The central star in M2-9 is known to be one of a very close pair which orbit one another at perilously close distances. It is even possible that one star is being engulfed by the other. Astronomers suspect the gravity of one star pulls weakly bound gas from the surface of the other and flings it into a thin, dense disk which surrounds both stars and extends well into space. The disk can actually be seen in shorter exposure images obtained with the Hubble telescope. It measures approximately 10 times the diameter of Pluto's orbit. Models of the type that are used to design jet engines ('hydrodynamics') show that such a disk can successfully account for the jet-exhaust-like appearance of M2-9. The high-speed wind from one of the stars rams into the surrounding disk, which serves as a nozzle. The wind is deflected in a perpendicular direction and forms the pair of jets that we see in the nebula's image. This is much the same process that takes place in a jet engine: The burning and expanding gases are deflected by the engine walls through a nozzle to form long, collimated jets of hot air at high speeds. M2-9 is 2,100 light-years away in the constellation Ophiucus. The observation was taken Aug. 2, 1997 by the Hubble telescope's Wide Field and Planetary Camera 2. In this image, neutral oxygen is shown in red, once-ionized nitrogen in green, and twice-ionized oxygen in

  14. Hot streak characterization in serpentine exhaust nozzles

    NASA Astrophysics Data System (ADS)

    Crowe, Darrell S.

    Modern aircraft of the United States Air Force face increasingly demanding cost, weight, and survivability requirements. Serpentine exhaust nozzles within an embedded engine allow a weapon system to fulfill mission survivability requirements by providing denial of direct line-of-sight into the high-temperature components of the engine. Recently, aircraft have experienced material degradation and failure along the aft deck due to extreme thermal loading. Failure has occurred in specific regions along the aft deck where concentrations of hot gas have come in contact with the surface causing hot streaks. The prevention of these failures will be aided by the accurate prediction of hot streaks. Additionally, hot streak prediction will improve future designs by identifying areas of the nozzle and aft deck surfaces that require thermal management. To this end, the goal of this research is to observe and characterize the underlying flow physics of hot streak phenomena. The goal is accomplished by applying computational fluid dynamics to determine how hot streak phenomena is affected by changes in nozzle geometry. The present research first validates the computational methods using serpentine inlet experimental and computational studies. A design methodology is then established for creating six serpentine exhaust nozzles investigated in this research. A grid independent solution is obtained on a nozzle using several figures of merit and the grid-convergence index method. An investigation into the application of a second-order closure turbulence model is accomplished. Simulations are performed for all serpentine nozzles at two flow conditions. The research introduces a set of characterization and performance parameters based on the temperature distribution and flow conditions at the nozzle throat and exit. Examination of the temperature distribution on the upper and lower nozzle surfaces reveals critical information concerning changes in hot streak phenomena due to changes

  15. RESPONSES OF CULTURED HUMAN AIRWAY EPITHELIAL CELLS TREATED WITH DIESEL EXHAUST EXTRACTS WILL VARY WITH THE ENGINE

    EPA Science Inventory

    Epidemiologic evidence suggests that increased morbidity and mortality are associated with the concentrations of ambient air particulate matter (PM). Many sources contribute to the particulate fraction of ambient pollution, including diesel exhaust particulates (DEP). Diesel ex...

  16. Stratospheric aircraft exhaust plume and wake chemistry studies

    NASA Technical Reports Server (NTRS)

    Miake-Lye, R. C.; Martinez-Sanchez, M.; Brown, R. C.; Kolb, C. E.; Worsnop, D. R.; Zahniser, M. S.; Robinson, G. N.; Rodriguez, J. M.; Ko, M. K. W.; Shia, R-L.

    1992-01-01

    This report documents progress to date in an ongoing study to analyze and model emissions leaving a proposed High Speed Civil Transport (HSCT) from when the exhaust gases leave the engine until they are deposited at atmospheric scales in the stratosphere. Estimates are given for the emissions, summarizing relevant earlier work (CIAP) and reviewing current propulsion research efforts. The chemical evolution and the mixing and vortical motion of the exhaust are analyzed to track the exhaust and its speciation as the emissions are mixed to atmospheric scales. The species tracked include those that could be heterogeneously reactive on the surfaces of the condensed solid water (ice) particles and on exhaust soot particle surfaces. Dispersion and reaction of chemical constituents in the far wake are studied with a Lagrangian air parcel model, in conjunction with a radiation code to calculate the net heating/cooling. Laboratory measurements of heterogeneous chemistry of aqueous sulfuric acid and nitric acid hydrates are also described. Results include the solubility of HCl in sulfuric acid which is a key parameter for modeling stratospheric processing. We also report initial results for condensation of nitric acid trihydrate from gas phase H2O and HNO3.

  17. A numerical study of the controlled flow tunnel for a high lift model

    NASA Technical Reports Server (NTRS)

    Parikh, P. C.

    1984-01-01

    A controlled flow tunnel employs active control of flow through the walls of the wind tunnel so that the model is in approximately free air conditions during the test. This improves the wind tunnel test environment, enhancing the validity of the experimentally obtained test data. This concept is applied to a three dimensional jet flapped wing with full span jet flap. It is shown that a special treatment is required for the high energy wake associated with this and other V/STOL models. An iterative numerical scheme is developed to describe the working of an actual controlled flow tunnel and comparisons are shown with other available results. It is shown that control need be exerted over only part of the tunnel walls to closely approximate free air flow conditions. It is concluded that such a tunnel is able to produce a nearly interference free test environment even with a high lift model in the tunnel.

  18. The carpal tunnel.

    PubMed

    Ellis, Harold

    2009-12-01

    The carpal bones are deeply convex anteriorly. This bony gutter is converted by the flexor retinaculum into a tube - the carpal tunnel, which conveys the median nerve, together with the long flexor tendons of the fingers and thumb, into the hand. It is of special interest to the surgeon because it is the site of a common nerve entrapment, the carpal tunnel syndrome.

  19. Shotcrete in tunnel design

    SciTech Connect

    Golser, J.; Galler, R.; Schubert, P.; Rabensteiner, K.

    1995-12-31

    Shotcrete is an important structural element for tunnel support. Green shotcrete is exposed to compression strain rates and tunnel design requires a realistic material law for shotcrete. A modified rate of flow method simulates shotcrete behavior very well and can be incorporated in Finite Element calculations.

  20. 29 CFR 1926.306 - Air receivers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... compressed air to convey materials nor the problems created when men work in compressed air as in tunnels and... transportation vehicles such as steam railroad cars, electric railway cars, and automotive equipment. (2) New...

  1. 29 CFR 1926.306 - Air receivers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... compressed air to convey materials nor the problems created when men work in compressed air as in tunnels and... transportation vehicles such as steam railroad cars, electric railway cars, and automotive equipment. (2) New...

  2. 29 CFR 1926.306 - Air receivers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... compressed air to convey materials nor the problems created when men work in compressed air as in tunnels and... transportation vehicles such as steam railroad cars, electric railway cars, and automotive equipment. (2) New...

  3. Diesel Exhaust Exposure Increases Susceptibility to Influenza ...

    EPA Pesticide Factsheets

    Mice were necropsied at day 1, 4, 8 and 14 post-infection and lung tissue was assessed for virus titers by TCID50, lung injury and inflammation. Lung and lymph node DC populations (CD11c+, MHCII, CD45+, CD80+ and CD86+) were identified by flow cytometry. Prior exposure to DE significantly increased viral titers in the lung at 4 and 8 days post infection in association with increased neutrophil influx and lung injury. Pro-inflammatory cytokines including IP-10, MCP-1, GM-CSF, and IL-1β, and the antiviral cytokine IFN-β were also increased at days 1, 4 and 8 post infection compared to air/flu controls. The number of DCs in the lung was not affected with previous exposure to DE, however the lymph nodes had increased number of mature DCs at 1, 4, and 8 days post infection compared to the air/flu controls. We conclude that exposure to DE prior to an influenza infection increases pulmonary inflammation, viral titers, and stimulates more DCs to migrate to the lymph nodes and mature as a consequence of the DE-enhanced influenza infection. Numerous studies have shown that diesel exhaust (DE) decreases resistance to respiratory infection and can alter the maturation and migration of dendritic cells (DCs). The purpose of this study was to evaluate the effects of DE exposure on susceptibilty to influenza infection in mice and to determine if this correlated with changes in the pulmonary DC populations. BALB/c mice were exposed to air or 0.5 mg/m3 DE from a diesel-power

  4. Computations for the 16-foot transonic tunnel, NASA, Langley Research Center, revision 1

    NASA Technical Reports Server (NTRS)

    Mercer, Charles E.; Berrier, Bobby L.; Capone, Francis J.; Grayston, Alan M.; Sherman, C. D.

    1987-01-01

    The equations used by the 16 foot transonic tunnel in the data reduction programs are presented in eight modules. Each module consists of equations necessary to achieve a specific purpose. These modules are categorized in the following groups: tunnel parameters; jet exhaust measurements; skin friction drag; balance loads and model attitudes calculations; internal drag (or exit-flow distributions); pressure coefficients and integrated forces; thrust removal options; and turboprop options. This document is a companion document to NASA TM-83186, A User's Guide to the Langley 16 Foot Transonic Tunnel, August 1981.

  5. Airborne asbestos fibres monitoring in tunnel excavation.

    PubMed

    Gaggero, Laura; Sanguineti, Elisa; Yus González, Adrián; Militello, Gaia Maria; Scuderi, Alberto; Parisi, Giovanni

    2017-04-03

    Tunnelling across ophiolitic formation with Naturally Occurring Asbestos (NOA) can release fibres into the environment, exposing workers, and the population, if fibres spread outside the tunnel, leading to increased risk of developing asbestos-related disease. Therefore, a careful plan of environmental monitoring is carried out during Terzo Valico tunnel excavation. In the present study, data of 1571 samples of airborne dust, collected between 2014 and 2016 inside the tunnels, and analyzed by SEM-EDS for quantification of workers exposure, are discussed. In particular, the engineering and monitoring management of 100 m tunnelling excavation across a serpentinite lens (Cravasco adit), intercalated within calcschists, is reported. At this chrysotile occurrence, 84% of 128 analyzed samples (from the zone closer to the front rock) were above 2 ff/l. However, thanks to safety measures implemented and tunnel compartmentation in zones, the asbestos fibre concentration did not exceed the Italian standard of occupational exposure (100 ff/l) and 100% of samples collected in the outdoor square were below 1 ff/l. During excavation under normal working conditions, asbestos concentrations were below 2 ff/l in 97.4% of the 668 analyzed samples. Our results showed that air monitoring can objectively confirm the presence of asbestos minerals at a rock front in relative short time and provide information about the nature of the lithology at the front. The present dataset, the engineering measures described and the operative conclusions are liable to support the improvement of legislation on workers exposure to asbestos referred to the tunnelling sector, lacking at present.

  6. Exhaust gas clean up process

    DOEpatents

    Walker, R.J.

    1988-06-16

    A method of cleaning an exhaust gas containing particulates, SO/sub 2/ and NO/sub x/ is described. The method involves prescrubbing with water to remove HCl and most of the particulates, scrubbing with an aqueous absorbent containing a metal chelate and dissolved sulfite salt to remove NO/sub x/ and SO/sub 2/, and regenerating the absorbent solution by controlled heating, electrodialysis and carbonate salt addition. The NO/sub x/ is removed as N/sub 2/ gas or nitrogen sulfonate ions and the oxides of sulfur are removed as a valuable sulfate salt. 4 figs.

  7. Exhaust gas clean up process

    DOEpatents

    Walker, Richard J.

    1989-01-01

    A method of cleaning an exhaust gas containing particulates, SO.sub.2 and NO.sub.x includes prescrubbing with water to remove HCl and most of the particulates, scrubbing with an aqueous absorbent containing a metal chelate and dissolved sulfite salt to remove NO.sub.x and SO.sub.2, and regenerating the absorbent solution by controlled heating, electrodialysis and carbonate salt addition. The NO.sub.x is removed as N.sub.2 or nitrogen-sulfonate ions and the oxides of sulfur are removed as a vaulable sulfate salt.

  8. Peribronchiolar fibrosis in lungs of cats chronically exposed to diesel exhaust

    SciTech Connect

    Hyde, D.M.; Plopper, C.G.; Weir, A.J.; Murnane, R.D.; Warren, D.L.; Last, J.A.; Pepelko, W.E.

    1985-02-01

    This study reports the quantitative changes in the pulmonary proximal acinar region following chronic exposure to diesel exhaust and following an additional 6 months in clean air. Cats (13 months of age) from a minimum disease colony were exposed to clean air (eight cats for 27 months and nine cats for 33 months), diesel exhaust for 8 hours/day, 7 days/week (nine cats for 27 months), or diesel exhaust for 27 months followed by 6 months in clean air (10 cats). Morphologic and morphometric evaluation using light microscopy and scanning and transmission electron microscopy revealed two major exposure-related lesions in proximal acinar regions of lungs of cats: peribronchiolar fibrosis associated with significant increases in lymphocytes, fibroblasts, and interstitial macrophages containing diesel particulate-like inclusions and bronchiolar epithelial metaplasia associated with the presence of ciliated and basal cells and alveolar macrophages containing diesel particulate-like inclusions. Peribronchiolar fibrosis was greater at the end of the 6 months in clean air following exposure, whereas the bronchiolar epithelial metaplasia was most severe at the end of exposure. Following an additional 6 months in clean air the epithelium more closely resembled the control epithelial cell population. The labeling index of terminal bronchiolar epithelium was significantly increased at the end of exposure but was not significantly different from controls or exposed cats following an additional 6 months in clean air. The ultrastructural appearance of epithelial cells remained relatively unchanged following diesel exhaust exposure with the exception of diesel particulate-like inclusions.

  9. Ultrafast scanning tunneling microscopy

    SciTech Connect

    Botkin, D.A. |

    1995-09-01

    I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.

  10. Source apportionment of traffic emissions of particulate matter using tunnel measurements

    NASA Astrophysics Data System (ADS)

    Lawrence, Samantha; Sokhi, Ranjeet; Ravindra, Khaiwal; Mao, Hongjun; Prain, Hunter Douglas; Bull, Ian D.

    2013-10-01

    This study aims to quantify exhaust/non-exhaust emissions and the uncertainties associated with them by combining innovative motorway tunnel sampling and source apportionment modelling. Analytical techniques ICP-AES and GC-MS were used to identify the metallic and organic composition of PM10, respectively. Good correlation was observed between Fe, Cu, Mn, Ni, Pb and Sb and change in traffic volume. The concentration of polycyclic aromatic hydrocarbons and other organics varies significantly at the entrance and exit site of the tunnel, with fluoranthene, pyrene, benzo[a]pyrene, chrysene and benzothiazole having the highest incremented concentrations. The application of Principal Component Analysis and Multiple Linear Regression Analysis helped to identify the emission sources for 82% of the total PM10 mass inside the tunnel. Identified sources include resuspension (27%), diesel exhaust emissions (21%), petrol exhaust emissions (12%), brake wear emissions (11%) and road surface wear (11%). This study shows that major health related chemical species of PM10 originate from non-exhaust sources, further signifying the need for legislation to reduce these emissions.

  11. [Anterior tarsal tunnel syndrome].

    PubMed

    Miliam, Palle B; Basse, Peter N

    2009-03-30

    Anterior tarsal tunnel syndrome is a rare entrapment neuropathy of the deep peroneal nerve beneath the extensor retinaculum of the ankle. It may be rare because it is underrecognized clinically.We present a case regarding a 29-year-old man, drummer, who for one and a half year experienced clinical symptoms of anterior tarsal tunnel syndrome. A surgical decompression of the anterior tarsal tunnel was performed, and at the check three months later the symptoms where gone. One year after, there were still no symptoms.

  12. The effects of operating conditions on particulate matter exhaust from diesel locomotive engines.

    PubMed

    Park, Duckshin; Yoon, Younghun; Kwon, Soon-Bark; Jeong, Wootae; Cho, Youngmin; Lee, Kiyoung

    2012-03-01

    Numerous reports have shown that fine particulates threaten human health. Since their health impact is associated with both mass and number concentrations, it is necessary to evaluate the emission standards for particulate mass accordingly. This study examined the particulate matter characteristics of diesel locomotive engine exhaust at various engine ratings. Diesel engine exhaust was collected via a dilution tunnel and the concentration and size distribution of fine particles were measured by a scanning mobility particle sizer. Exhaust gasses were measured simultaneously by a stack sampler. The maximum carbon monoxide emission was reached at 59% of the maximum rating, after which emissions decreased. The particle count median diameter increased with the engine rating, until a maximum was reached at 40% of the maximum rating. Most exhaust particles were nanoparticles with the nuclei mode range, a particle diameter (D(P))<50 nm. The increase in particles with the accumulation mode range, 50exhaust particle mass and size distribution should be considered in emission regulations.

  13. Exhaust emissions from light- and heavy-duty vehicles: chemical composition, impact of exhaust after treatment, and fuel parameters.

    PubMed Central

    Westerholm, R; Egebäck, K E

    1994-01-01

    This paper presents results from the characterization of vehicle exhaust that were obtained primarily within the Swedish Urban Air Project, "Tätortsprojektet." Exhaust emissions from both gasoline- and diesel-fueled vehicles have been investigated with respect to regulated pollutants (carbon monoxide [CO], hydrocarbon [HC], nitrogen oxides [NOx], and particulate), unregulated pollutants, and in bioassay tests (Ames test, TCDD receptor affinity tests). Unregulated pollutants present in both the particle- and the semi-volatile phases were characterized. Special interest was focused on the impact of fuel composition on heavy-duty diesel vehicle emissions. It was confirmed that there exists a quantifiable relationship between diesel-fuel variables of the fuel blends, the chemical composition of the emissions, and their biological effects. According to the results from the multivariate analysis, the most important fuel parameters are: polycyclic aromatic hydrocarbons (PAH) content, 90% distillation point, final boiling point, specific heat, aromatic content, density, and sulfur content. PMID:7529699

  14. Oxidation of tunnel barrier metals in magnetic tunnel junctions

    NASA Astrophysics Data System (ADS)

    Yang, J. Joshua; Ladwig, Peter F.; Yang, Ying; Ji, Chengxiang; Chang, Y. Austin; Liu, Feng X.; Pant, Bharat B.; Schultz, Allan E.

    2005-05-01

    The oxidation of an ultrathin metal layer (<1nm) to form an oxide tunnel barrier is of critical importance for the fabrication of magnetic tunnel junctions (MTJs) with low product of resistance and area (R×A). Nonuniform and excessive or insufficient oxidation will occur by using conventional plasma, air, or O2 and noble gas mixtures as oxidation methods. An oxidation method was investigated to oxidize only an ultrathin layer of metal (such as Y) without oxidizing adjacent ferromagnetic thin film layers. We have now demonstrated that a gas mixture of H2O/H2 with a fixed chemical potential of oxygen determined by the relative amounts of the two gases can oxidize Y and Ta thin layers while simultaneously keeping a Co ferromagnetic layer completely unoxidized. This universal method can be used to preferentially oxidize a host of other metals with high tendency to form oxides, such as Zr, Hf, Nb, rare earth metals, etc. and may allow us to access the feasible lower limit of barrier thickness in MTJs.

  15. Steam atmosphere drying exhaust steam recompression system

    DOEpatents

    Becker, Frederick E.; Smolensky, Leo A.; Doyle, Edward F.; DiBella, Francis A.

    1994-01-01

    This invention relates to a heated steam atmosphere drying system comprising dryer in combination with an exhaust recompression system which is extremely energy efficient and eliminates dangers known to air dryers. The system uses superheated steam as the drying medium, which recirculated through the system where its heat of evaporation and heat of compression is recovered, thereby providing a constant source of heat to the drying chamber. The dryer has inlets whereby feedstock and superheated steam are fed therein. High heat transfer and drying rates are achieved by intimate contact of the superheated steam with the particles being dried The dryer comprises a vessel which enables the feedstock and steam to enter recirculate together. When the feedstock becomes dry it will exit the dryer with the steam and become separated from the steam through the use of a curvilinear louver separator (CLS). The CLS enables removal of fine and ultrafine particles from the dryer. Water vapor separated from the particles in the CLS as superheated steam, may then be recovered and recirculated as steam through the use of a compressor to either directly or indirectly heat the dryer, and a heat exchanger or a heater to directly provide heat to the dryer. This system not only provides a very efficient heat transfer system but results in a minimum carry-over of ultrafine particles thereby eliminating any explosive hazard.

  16. Steam atmosphere drying exhaust steam recompression system

    DOEpatents

    Becker, F.E.; Smolensky, L.A.; Doyle, E.F.; DiBella, F.A.

    1994-03-08

    This invention relates to a heated steam atmosphere drying system comprising dryer in combination with an exhaust recompression system which is extremely energy efficient and eliminates dangers known to air dryers. The system uses superheated steam as the drying medium, which recirculates through the system where its heat of evaporation and heat of compression is recovered, thereby providing a constant source of heat to the drying chamber. The dryer has inlets whereby feedstock and superheated steam are fed therein. High heat transfer and drying rates are achieved by intimate contact of the superheated steam with the particles being dried. The dryer comprises a vessel which enables the feedstock and steam to enter and recirculate together. When the feedstock becomes dry it will exit the dryer with the steam and become separated from the steam through the use of a curvilinear louver separator (CLS). The CLS enables removal of fine and ultrafine particles from the dryer. Water vapor separated from the particles in the CLS as superheated steam, may then be recovered and recirculated as steam through the use of a compressor to either directly or indirectly heat the dryer, and a heat exchanger or a heater to directly provide heat to the dryer. This system not only provides a very efficient heat transfer system but results in a minimum carry-over of ultrafine particles thereby eliminating any explosive hazard. 17 figures.

  17. Exhaust gas bypass valve control for thermoelectric generator

    SciTech Connect

    Reynolds, Michael G; Yang, Jihui; Meisner, Greogry P.; Stabler, Francis R.; De Bock, Hendrik Pieter Jacobus; Anderson, Todd Alan

    2012-09-04

    A method of controlling engine exhaust flow through at least one of an exhaust bypass and a thermoelectric device via a bypass valve is provided. The method includes: determining a mass flow of exhaust exiting an engine; determining a desired exhaust pressure based on the mass flow of exhaust; comparing the desired exhaust pressure to a determined exhaust pressure; and determining a bypass valve control value based on the comparing, wherein the bypass valve control value is used to control the bypass valve.

  18. Carpal tunnel release

    MedlinePlus

    ... you are taking. This includes medicines, supplements, or herbs you bought without a prescription. You may be ... gov/pubmed/23026458 . Zhao M, Burke DT. Median neuropathy (carpal tunnel syndrome). In: Frontera WR, Silver JK, ...

  19. Endoscopic cubital tunnel release.

    PubMed

    Cobb, Tyson K

    2010-10-01

    A minimally invasive endoscopic approach has been successfully applied to surgical treatment of cubital tunnel syndrome. This procedure allows for smaller incisions with faster recovery time. This article details relevant surgical anatomy, indications, contraindications, surgical technique, complications, and postoperative management.

  20. Inelastic electron tunneling spectroscopy

    NASA Technical Reports Server (NTRS)

    Khanna, S. K.; Lambe, J.

    1983-01-01

    Inelastic electron tunneling spectroscopy is a useful technique for the study of vibrational modes of molecules adsorbed on the surface of oxide layers in a metal-insulator-metal tunnel junction. The technique involves studying the effects of adsorbed molecules on the tunneling spectrum of such junctions. The data give useful information about the structure, bonding, and orientation of adsorbed molecules. One of the major advantages of inelastic electron tunneling spectroscopy is its sensitivity. It is capable of detecting on the order of 10 to the 10th molecules (a fraction of a monolayer) on a 1 sq mm junction. It has been successfully used in studies of catalysis, biology, trace impurity detection, and electronic excitations. Because of its high sensitivity, this technique shows great promise in the area of solid-state electronic chemical sensing.

  1. Hydrogen chloride measurements in the Space Shuttle exhaust cloud - First launch, April 12, 1981

    NASA Technical Reports Server (NTRS)

    Sebacher, D. I.; Bendura, R. J.; Gregory, G. L.

    1982-01-01

    Partitioning of hydrogen chloride between the aerosol and gaseous phases in the first Space Shuttle exhaust cloud was experimentally investigated as the exhaust cloud was diluted with ambient air. Airborne measurements were obtained of gaseous hydrogen chloride (HCl), total HCl, relative humidity, and temperature to determine the conditions controlling HCl aerosol formation in the Shuttle exhaust cloud. Two segments of the cloud, each at a significantly different relative humidity, were monitored. Equilibrium predictions of HCl aerosol formation agreed with the measured HCl partitioning at the higher and lower relative humidity conditions, but do not agree at the aerosol formation threshold region. Measurements were taken in the Shuttle exhaust cloud from 8.6 min until 2 h and 8 min after launch. HCl concentrations ranged from 17.5 to 0.9 ppm and relative humidity from 86% to less than 10%.

  2. World's Largest Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1987-01-01

    NASA's National Full Scale Aerodynamics Complex, which houses two of the world's largest wind tunnels and has been used for testing experimental aircraft since 1944, is presented. This video highlights the structure and instrumentation of the 40 x 80 foot and 80 x 120 foot wind tunnels and documents their use in testing full scale aircraft, NASA's Space Shuttle and the XV-15 Tiltrotor aircraft.

  3. Electron tunnel sensor technology

    NASA Technical Reports Server (NTRS)

    Kenny, T. W.; Waltman, S. B.; Reynolds, J. K.; Kaiser, W. J.

    1991-01-01

    Researchers designed and constructed a novel electron tunnel sensor which takes advantage of the mechanical properties of micro-machined silicon. For the first time, electrostatic forces are used to control the tunnel electrode separation, thereby avoiding the thermal drift and noise problems associated with piezoelectric actuators. The entire structure is composed of micro-machined silicon single crystals, including a folded cantilever spring and a tip. The application of this sensor to the development of a sensitive accelerometer is described.

  4. Full-Scale Tunnel (FST)

    NASA Technical Reports Server (NTRS)

    1931-01-01

    Modification of entrance cone of the Full-Scale Tunnel (FST). To the left are the FST guide vanes which Smith DeFrance described in NACA TR No. 459: 'The air is turned at the four corners of each return passage by guide vanes. The vanes are of the curved-airfoil type formed by two intersecting arcs with a rounded nose. The arcs were so chosen as to give a practically constant area through the vanes.' (p. 295) These vanes 'have chords of 3 feet 6 inches and are spaced at 0.41 of a chord length. By a proper adjustment of the angular setting of the vanes, a satisfactory velocity distribution has been obtained and no honeycomb has been found necessary.' (p. 295). Close inspection of the photograph will reveal a number of workers on the scaffolding. The heights were great and the work was quite dangerous. In October 1930, one construction worker working on the roof of the tunnel would die when he stepped off the planking to fetch a tool and fell through an unsupported piece of Careystone to the floor some 70 feet below.

  5. Novel tunnelling barriers for spin tunnelling junctions

    NASA Astrophysics Data System (ADS)

    Sharma, Manish

    A tunnel junction consists of two metal electrodes separated by an insulating barrier thin enough for electrons to tunnel across. With ferromagnetic electrodes, a spin-dependent tunnelling (SDT) effect, electrons of one spin tunnelling preferentially over those of the other, is observed. When the electrodes are switched from a parallel to an anti-parallel alignment, the tunnelling current changes and gives rise to tunnelling magnetoresistance (TMR). Since 1995, interest in SDT junctions has increased as TMR in excess of 15% has been achieved, making viable their use in non-volatile memory and magnetic sensors applications. In this work, two key issues of SDT junctions are addressed: spin polarization of the electrode and the tunnel barrier. Spin polarization, a measure of electron states of up and down spins, is widely believed to be an intrinsic property of the electrode. In junctions with barriers formed by plasma oxidation of composite Ta/Al films, the surprising effect of the resistance being lower with the electrodes aligned antiparallel was observed. Junctions with Ta/Al barriers and those with Al/Ta barriers behave opposite to each other and exhibit an inversion only when the Ta side of the barrier is biased positive. This demonstrates the spin polarization is also influenced by the barrier material. Half-metallic materials such as magnetite (Fe3O4) have a gap in one of the spins' states at the fermi level, thus having a theoretical spin polarization of 100%. In this work, an ultrathin Fe3O 4 layer was added between the Al2O3 barrier and the NiFe electrode. The TMR increased sharply from 4% to 16% for thicknesses less than 0.5nm. As the tunnel barrier must be thinner than 2nm, choice of the barrier material becomes critical. Presently, Al2O3 is the best known barrier. In looking for alternative materials, AlN and AlON were formed by plasma nitridation and oxy-nitridation of deposited Al films. TMR results of up to 18% and resistance-area products down to 3

  6. The Beginner's Guide to Wind Tunnels with TunnelSim and TunnelSys

    NASA Technical Reports Server (NTRS)

    Benson, Thomas J.; Galica, Carol A.; Vila, Anthony J.

    2010-01-01

    The Beginner's Guide to Wind Tunnels is a Web-based, on-line textbook that explains and demonstrates the history, physics, and mathematics involved with wind tunnels and wind tunnel testing. The Web site contains several interactive computer programs to demonstrate scientific principles. TunnelSim is an interactive, educational computer program that demonstrates basic wind tunnel design and operation. TunnelSim is a Java (Sun Microsystems Inc.) applet that solves the continuity and Bernoulli equations to determine the velocity and pressure throughout a tunnel design. TunnelSys is a group of Java applications that mimic wind tunnel testing techniques. Using TunnelSys, a team of students designs, tests, and post-processes the data for a virtual, low speed, and aircraft wing.

  7. Effects on symptoms and lung function in humans experimentally exposed to diesel exhaust.

    PubMed Central

    Rudell, B; Ledin, M C; Hammarström, U; Stjernberg, N; Lundbäck, B; Sandström, T

    1996-01-01

    OBJECTIVES: Diesel exhaust is a common air pollutant made up of several gases, hydrocarbons, and particles. An experimental study was carried out which was designed to evaluate if a particle trap on the tail pipe of an idling diesel engine would reduce effects on symptoms and lung function caused by the diesel exhaust, compared with exposure to unfiltered exhaust. METHODS: Twelve healthy non-smoking volunteers (aged 20-37) were investigated in an exposure chamber for one hour during light work on a bicycle ergometer at 75 W. Each subject underwent three separate double blind exposures in a randomised sequence: to air and to diesel exhaust with the particle trap at the tail pipe and to unfiltered diesel exhaust. Symptoms were recorded according to the Borg scale before, every 10 minutes during, and 30 minutes after the exposure. Lung function was measured with a computerised whole body plethysmograph. RESULTS: The ceramic wall flow particle trap reduced the number of particles by 46%, whereas other compounds were relatively constant. It was shown that the most prominent symptoms during exposure to diesel exhaust were irritation of the eyes and nose and an unpleasant smell increasing during exposure. Both airway resistance (R(aw)) and specific airway resistance (SR(aw)) increased significantly during the exposures to diesel exhaust. Despite the 46% reduction in particle numbers by the trap effects on symptoms and lung function were not significantly attenuated. CONCLUSION: Exposure to diesel exhaust caused symptoms and bronchoconstriction which were not significantly reduced by a particle trap. PMID:8943829

  8. Langley Field wind tunnel apparatus

    NASA Technical Reports Server (NTRS)

    Bacon, D L

    1921-01-01

    The difficulties experienced in properly holding thin tipped or tapered airfoils while testing on an N.P.L. type aerodynamic balance even at low air speeds, and the impossibility of holding even solid metal models at the high speeds attainable at the National Advisory Committee's wind tunnel, necessitated the design of a balance which would hold model airfoils of any thickness and at speeds up to 150 m.p.h. In addition to mechanical strength and rigidity, it was highly desirable that the balance readings should require a minimum amount of correction and mathematical manipulation in order to obtain the lift and drag coefficients and the center of pressure. The balance described herein is similar to one in use at the University of Gottingen, the main difference lying in the addition of a device for reading the center of pressure directly, without the necessity of any correction whatsoever. Details of the design and operation of the device are given.

  9. Dust and gas exposure in tunnel construction work.

    PubMed

    Bakke, B; Stewart, P; Ulvestad, B; Eduard, W

    2001-01-01

    Personal exposures to dust and gases were measured among 189 underground construction workers who were divided into seven occupational groups performing similar tasks in similar working conditions: drill and blast crew; shaft-drilling crew; tunnel-boring machine crew; shotcreting operators; support workers; concrete workers; and electricians. Outdoor tunnel workers were included as a low-exposed reference group. The highest geometric mean (GM) exposures to total dust (6-7 mg/m3) and respirable dust (2-3 mg/m3) were found for the shotcreters, shaft drillers, and tunnel-boring machine workers. Shaft drillers and tunnel-boring machine workers also had the highest GM exposures to respirable alpha-quartz (0.3-0.4 mg/m3), which exceeded the Norwegian occupational exposure limit (OEL) of 0.1 mg/m3. Shaft drillers had the highest exposure to oil mists (GM=1.4 mg/m3), which was generated mainly from pneumatic drilling. For other groups, exposure to oil mist from diesel exhaust and spraying of oil onto concrete forms resulted in exposures of 0.1-0.5 mg/m3. Exposure to nitrogen dioxide was similar across all groups (GM=0.4-0.9 ppm), except for shaft drillers and tunnel-boring machine workers, who had lower exposures. High short-term exposures (>10 ppm), however, occurred when workers were passing through the blasting cloud.

  10. Full-Scale Tunnel (FST)

    NASA Technical Reports Server (NTRS)

    1929-01-01

    Modified propeller and spinner in Full-Scale Tunnel (FST) model. On June 26, 1929, Elton W. Miller wrote to George W. Lewis proposing the construction of a model of the full-scale tunnel. 'The excellent energy ratio obtained in the new wind tunnel of the California Institute of Technology suggests that before proceeding with our full scale tunnel design, we ought to investigate the effect on energy ratio of such factors as: 1. small included angle for the exit cone; 2. carefully designed return passages of circular section as far as possible, without sudden changes in cross sections; 3. tightness of walls. It is believed that much useful information can be obtained by building a model of about 1/16 scale, that is, having a closed throat of 2 ft. by 4 ft. The outside dimensions would be about 12 ft. by 25 ft. in plan and the height 4 ft. Two propellers will be required about 28 in. in diameter, each to be driven by direct current motor at a maximum speed of 4500 R.P.M. Provision can be made for altering the length of certain portions, particularly the exit cone, and possibly for the application of boundary layer control in order to effect satisfactory air flow. This model can be constructed in a comparatively short time, using 2 by 4 framing with matched sheathing inside, and where circular sections are desired they can be obtained by nailing sheet metal to wooden ribs, which can be cut on the band saw. It is estimated that three months will be required for the construction and testing of such a model and that the cost will be approximately three thousand dollars, one thousand dollars of which will be for the motors. No suitable location appears to exist in any of our present buildings, and it may be necessary to build it outside and cover it with a roof.' George Lewis responded immediately (June 27) granting the authority to proceed. He urged Langley to expedite construction and to employ extra carpenters if necessary. Funds for the model came from the FST project

  11. 49 CFR 393.83 - Exhaust systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... combustible part of the motor vehicle. (b) No exhaust system shall discharge to the atmosphere at a location... gasoline engine shall discharge to the atmosphere at or within 6 inches forward of the rearmost part of the bus. (d) The exhaust system of a bus using fuels other than gasoline shall discharge to the...

  12. 49 CFR 393.83 - Exhaust systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... combustible part of the motor vehicle. (b) No exhaust system shall discharge to the atmosphere at a location... gasoline engine shall discharge to the atmosphere at or within 6 inches forward of the rearmost part of the bus. (d) The exhaust system of a bus using fuels other than gasoline shall discharge to the...

  13. Controlled human exposures to diesel exhaust

    EPA Science Inventory

    Diesel exhaust (DE) is a complex mixture of gaseous and particulate compounds resulting from an incomplete combustion of diesel fuel. Controlled human exposures to DE and diesel exhaust particles (DEP) have contributed to understanding health effects. Such exposure studies of h...

  14. Correlates of Work Exhaustion for Medical Technologists.

    ERIC Educational Resources Information Center

    Blau, Gary; Tatum, Donna Surges; Ward-Cook, Kory

    2003-01-01

    Medical technologists (n=196) were followed over 4 years. Higher levels of work exhaustion were related to perceived work interference with family, task load, and lower organizational support. Distributive justice partly mediated the effects of work interference and support on exhaustion. Distributive justice mediated the impact of procedural…

  15. Exhaust emissions of a double annular combustor: Parametric study

    NASA Technical Reports Server (NTRS)

    Schultz, D. F.

    1974-01-01

    A full scale double-annular ram-induction combustor designed for Mach 3.0 cruise operation was tested. Emissions of oxides of nitrogen, carbon monoxide, unburned hydrocarbons, and smoke were measured over a range of combustor operating variables including reference velocity, inlet air temperature and pressure, and exit average temperature. ASTM Jet-A fuel was used for these tests. An equation is provided relating oxides of nitrogen emissions as a function of the combustor, operating variables. A small effect of radial fuel staging on reducing exhaust emissions (which were originally quite low) is demonstrated.

  16. Fast exhaust channel optical absorption method and apparatus to study the gas exchange in large diesel engines

    NASA Astrophysics Data System (ADS)

    Vattulainen, J.; Hernberg, R.; Hattar, C.; Gros, S.

    1998-01-01

    An optical absorption spectroscopic method and apparatus with shorter than 1 ms response time have been used to study the gas exchange processes in realistic conditions for a single cylinder of a large diesel engine. The method is based on measuring the differential line-of-sight optical uv absorption of the exhaust-gas-contained SO2 as a function of time in the exhaust port area just after the exhaust valves. The optical absorption by SO2 is determined from light transmission measurements at 280 and 340 nm performed through optical probes installed into the exhaust channel wall. The method has been applied to a continuously fired, large, medium speed production-line-type diesel engine with 990 kW rated power. The test engine was operated with standard light fuel oil (MDO Termoshell) and with light fuel oil treated with a sulfur additive {Di-Tert-Butyldisulfid [(CH3)3C]2S2}. The latter was to improve the optical absorption signals without increasing the fouling of the exhaust channel optical probes as in the case of heavier fuel oil qualities. In the reported case of a four-stroke diesel engine measurement results show that the method can provide time-resolved information of the SO2 density in the exhaust channel and thus give information on the single-cylinder gas exchange. During the inlet and exhaust valve overlap period the moment of fresh air entering into the measurement volume can be detected. If independent exhaust gas temperature and pressure data are available, the absorption measurements can readily be used for determining the burnt gas fraction in the exhaust channel. In this work the possibility of using the optical absorption measurement to determine the instaneous exhaust gas temperature was studied. Based on known fuel properties and conventional averaged SO2 measurements from the exhaust channel a known concentration of SO2 was assumed in the exhaust gas after the exhaust valves opening and before the inlet and exhaust valves overlap period

  17. Utilization of LPG and gasoline engine exhaust emissions by microalgae.

    PubMed

    Taştan, Burcu Ertit; Duygu, Ergin; Ilbaş, Mustafa; Dönmez, Gönül

    2013-02-15

    The effect of engine exhaust emissions on air pollution is one of the greatest problems that the world is facing today. The study focused on the effects of realistic levels of engine exhaust emissions of liquid petroleum gas (LPG) and gasoline (GSN) on Phormidium sp. and Chlorella sp. Multi parameters including pH, different medial compositions, fuel types, flow rates and biomass concentrations were described in detail. Effects of some growth factors such as triacontanol (TRIA) and salicylic acid (SA) have also been tested. The maximum biomass concentration of Phormidium sp. reached after 15 days at 0.36 and 0.15 g/L initial biomass concentrations were found as 1.160 g/L for LPG emission treated cultures and 1.331 g/L for GSN emission treated cultures, respectively. The corresponding figures were 1.478 g/L for LPG emission treated cultures and 1.636 g/L for GSN emission treated cultures at 0.65 and 0.36 g/L initial Chlorella sp. biomass concentrations. This study highlights the significance of using Phormidium sp. and Chlorella sp. for utilization of LPG and GSN engine exhaust emissions by the help of growth factors.

  18. 40 CFR 86.110-94 - Exhaust gas sampling system; diesel-cycle vehicles, and Otto-cycle vehicles requiring particulate...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... heated flame ionization detector (HFID) (375 °±20 °F (191 °±11 °C)) sample for total hydrocarbon (THC... the exhaust enters the dilution tunnel). (ii) Sufficiently distant (radially) from the THC probe so as to be free from the influence of any wakes or eddies produced by the THC probe. (iii) 0.5 inch...

  19. Tunneling mode in a frustrated total internal reflection structure with hyperbolic metamaterial

    NASA Astrophysics Data System (ADS)

    Luo, Li; Li, Chaoyang; Tang, Tingting

    2016-10-01

    We study the tunneling modes in a frustrated total internal reflection (FTIR) structure with hyperbolic metamaterial (HMM). The physical mechanism of tunneling mode is analyzed by the condition of general zero average permittivity. The influence of anisotropy, loss and dispersion of HMM on tunneling modes is discussed based on simulation results. Tunneling mode merging or splitting can be realized by adjusting the thickness of air or HMM. We can also find the absorption of HMM significantly reduces the transmittance peak of tunneling mode. When a recently reported HMM of ZnAlO/ZnO multilayer is introduced in the FTIR structure, the combined action of HMM loss and dispersion brings many small tunneling modes in the angular spectrum. The tunneling mode in the proposed structure can be used to design filters and wavelength selectors which may also have applications in wavelength de-multiplexing in optical communications.

  20. Fibrin clot structure remains unaffected in young, healthy individuals after transient exposure to diesel exhaust

    PubMed Central

    2010-01-01

    Exposure to urban particulate matter has been associated with an increased risk of cardiovascular disease and thrombosis. We studied the effects of transient exposure to diesel particles on fibrin clot structure of 16 healthy individuals (age 21- 44). The subjects were randomly exposed to diesel exhaust and filtered air on two separate occasions. Blood samples were collected before exposure, and 2 and 6 hours after exposure. There were no significant changes on clot permeability, maximum turbidity, lag time, fibre diameter, fibre density and fibrinogen level between samples taken after diesel exhaust exposure and samples taken after filtered air exposure. These data show that there are no prothrombotic changes in fibrin clot structure in young, healthy individuals exposed to diesel exhaust. PMID:20565709

  1. Single Electron Tunneling

    SciTech Connect

    Ruggiero, Steven T.

    2005-07-25

    Financial support for this project has led to advances in the science of single-electron phenomena. Our group reported the first observation of the so-called ''Coulomb Staircase'', which was produced by tunneling into ultra-small metal particles. This work showed well-defined tunneling voltage steps of width e/C and height e/RC, demonstrating tunneling quantized on the single-electron level. This work was published in a now well-cited Physical Review Letter. Single-electron physics is now a major sub-field of condensed-matter physics, and fundamental work in the area continues to be conducted by tunneling in ultra-small metal particles. In addition, there are now single-electron transistors that add a controlling gate to modulate the charge on ultra-small photolithographically defined capacitive elements. Single-electron transistors are now at the heart of at least one experimental quantum-computer element, and single-electron transistor pumps may soon be used to define fundamental quantities such as the farad (capacitance) and the ampere (current). Novel computer technology based on single-electron quantum dots is also being developed. In related work, our group played the leading role in the explanation of experimental results observed during the initial phases of tunneling experiments with the high-temperature superconductors. When so-called ''multiple-gap'' tunneling was reported, the phenomenon was correctly identified by our group as single-electron tunneling in small grains in the material. The main focus throughout this project has been to explore single electron phenomena both in traditional tunneling formats of the type metal/insulator/particles/insulator/metal and using scanning tunneling microscopy to probe few-particle systems. This has been done under varying conditions of temperature, applied magnetic field, and with different materials systems. These have included metals, semi-metals, and superconductors. Amongst a number of results, we have

  2. Suppression of tunneling rate fluctuations in tunnel field-effect transistors by enhancing tunneling probability

    NASA Astrophysics Data System (ADS)

    Mori, Takahiro; Migita, Shinji; Fukuda, Koichi; Asai, Hidehiro; Morita, Yukinori; Mizubayashi, Wataru; Liu, Yongxun; O’uchi, Shin-ichi; Fuketa, Hiroshi; Otsuka, Shintaro; Yasuda, Tetsuji; Masahara, Meishoku; Ota, Hiroyuki; Matsukawa, Takashi

    2017-04-01

    This paper discusses the impact of the tunneling probability on the variability of tunnel field-effect transistors (TFETs). Isoelectronic trap (IET) technology, which enhances the tunneling current in TFETs, is used to suppress the variability of the ON current and threshold voltage. The simulation results show that suppressing the tunneling rate fluctuations results in suppression of the variability. In addition, a formula describing the relationship between the tunneling rate fluctuations and the electric field strength is derived based on Kane’s band-to-band tunneling model. This formula indicates that the magnitude of the tunneling rate fluctuations is proportional to the magnitude of the fluctuations in the electric field strength and a higher tunneling probability results in a lower variability. The derived relationship is universally valid for any technologies that exploit enhancement of the tunneling probability, including IET technology, channel material engineering, heterojunctions, strain engineering, etc.

  3. Pollutant monitoring of aircraft exhaust with multispectral imaging

    NASA Astrophysics Data System (ADS)

    Berkson, Emily E.; Messinger, David W.

    2016-10-01

    Communities surrounding local airports are becoming increasingly concerned about the aircraft pollutants emitted during the landing-takeoff (LTO) cycle, and their potential for negative health effects. Chicago, Los Angeles, Boston and London have all recently been featured in the news regarding concerns over the amount of airport pollution being emitted on a daily basis, and several studies have been published on the increased risks of cancer for those living near airports. There are currently no inexpensive, portable, and unobtrusive sensors that can monitor the spatial and temporal nature of jet engine exhaust plumes. In this work we seek to design a multispectral imaging system that is capable of tracking exhaust plumes during the engine idle phase, with a specific focus on unburned hydrocarbon (UHC) emissions. UHCs are especially potent to local air quality, and their strong absorption features allow them to act as a spatial and temporal plume tracer. Using a Gaussian plume to radiometrically model jet engine exhaust, we have begun designing an inexpensive, portable, and unobtrusive imaging system to monitor the relative amount of pollutants emitted by aircraft in the idle phase. The LWIR system will use two broadband filters to detect emitted UHCs. This paper presents the spatial and temporal radiometric models of the exhaust plume from a typical jet engine used on 737s. We also select filters for plume tracking, and propose an imaging system layout for optimal detectibility. In terms of feasibility, a multispectral imaging system will be two orders of magnitude cheaper than current unobtrusive methods (PTR-MS) used to monitor jet engine emissions. Large-scale impacts of this work will include increased capabilities to monitor local airport pollution, and the potential for better-informed decision-making regarding future developments to airports.

  4. Health effects of subchronic inhalation exposure to gasoline engine exhaust.

    PubMed

    Reed, M D; Barrett, E G; Campen, M J; Divine, K K; Gigliotti, A P; McDonald, J D; Seagrave, J C; Mauderly, J L; Seilkop, S K; Swenberg, J A

    2008-10-01

    Gasoline engine emissions are a ubiquitous source of exposure to complex mixtures of particulate matter (PM) and non-PM pollutants; yet their health hazards have received little study in comparison with those of diesel emissions. As a component of the National Environmental Respiratory Center (NERC) multipollutant research program, F344 and SHR rats and A/J, C57BL/6, and BALBc mice were exposed 6 h/day, 7 days/week for 1 week to 6 months to exhaust from 1996 General Motors 4.3-L engines burning national average fuel on a simulated urban operating cycle. Exposure groups included whole exhaust diluted 1:10, 1:15, or 1:90, filtered exhaust at the 1:10 dilution, or clean air controls. Evaluations included organ weight, histopathology, hematology, serum chemistry, bronchoalveolar lavage, cardiac electrophysiology, micronuclei in circulating cells, DNA methylation and oxidative injury, clearance of Pseudomonas aeruginosa from the lung, and development of respiratory allergic responses to ovalbumin. Among the 120 outcome variables, only 20 demonstrated significant exposure effects. Several statistically significant effects appeared isolated and were not supported by related variables. The most coherent and consistent effects were those related to increased red blood cells, interpreted as likely to have resulted from exposure to 13-107 ppm carbon monoxide. Other effects supported by multiple variables included mild lung irritation and depression of oxidant production by alveolar macrophages. The lowest exposure level caused no significant effects. Because only 6 of the 20 significant effects appeared to be substantially reversed by PM filtration, the majority of effects were apparently caused by non-PM components of exhaust.

  5. Carpal Tunnel Syndrome

    PubMed Central

    Zimmerman, Gregory R.

    1994-01-01

    Carpal tunnel syndrome is a neuropathy resulting from compression of the median nerve as it passes through a narrow tunnel in the wrist on its way to the hand. The lack of precise objective and clinical tests, along with symptoms that are synonymous with other syndromes in the upper extremity, cause carpal tunnel syndrome to appear to be a rare entity in athletics. However, it should not be ruled out as a possible etiology of upper extremity paralysis in the athlete. More typically, carpal tunnel syndrome is the most common peripheral entrapment neuropathy encountered in industry. Treatment may include rest and/or splinting of the involved wrist, ice application, galvanic stimulation, or iontophoresis to reduce inflammation, and then transition to heat modalities and therapeutic exercises for developing flexibility, strength, and endurance. In addition, an ergonomic assessment should be conducted, resulting in modifications to accommodate the carpal tunnel syndrome patient. ImagesFig 3.Fig 4.Fig 5.Fig 6.Fig 7. PMID:16558255

  6. Condensate Mixtures and Tunneling

    SciTech Connect

    Timmermans, E.

    1998-09-14

    The experimental study of condensate mixtures is a particularly exciting application of the recently developed atomic-trap Bose-Einstein condensate (BEC) technology: such multiple condensates represent the first laboratory systems of distinguishable boson superfluid mixtures. In addition, as the authors point out in this paper, the possibility of inter-condensate tunneling greatly enhances the richness of the condensate mixture physics. Not only does tunneling give rise to the oscillating particle currents between condensates of different chemical potentials, such as those studied extensively in the condensed matter Josephson junction experiments, it also affects the near-equilibrium dynamics and stability of the condensate mixtures. In particular, the stabilizing influence of tunneling with respect to spatial separation (phase separation) could be of considerable practical importance to the atomic trap systems. Furthermore, the creation of mixtures of atomic and molecular condensates could introduce a novel type of tunneling process, involving the conversion of a pair of atomic condensate bosons into a single molecular condensate boson. The static description of condensate mixtures with such type of pair tunneling suggests the possibility of observing dilute condensates with the liquid-like property of a self-determined density.

  7. Operating Temperatures of a Sodium-Cooled Exhaust Valve as Measured by a Thermocouple

    NASA Technical Reports Server (NTRS)

    Sanders, J C; Wilsted, H D; Mulcahy, B A

    1943-01-01

    Report presents the results of a thermocouple installed in the crown of a sodium-cooled exhaust valve. The valve was tested in an air-cooled engine cylinder and valve temperatures under various engine operating conditions were determined. A temperature of 1337 degrees F. was observed at a fuel-air ratio of 0.064, a brake mean effective pressure of 179 pounds per square inch, and an engine speed of 2000 r.p.m. Fuel-air ratio was found to have a large influence on valve temperature, but cooling-air pressure and variation in spark advance had little effect. An increase in engine power by change of speed or mean effective pressure increased the valve temperature. It was found that the temperature of the rear-spark-plug bushing was not a satisfactory indication of the temperature of the exhaust valve.

  8. Operating Temperatures of a Sodium-Cooled Exhaust Valve as Measured by a Thermocouple

    NASA Technical Reports Server (NTRS)

    Sanders, J. C.; Wilsted, H. D.; Mulcahy, B. A.

    1943-01-01

    A thermocouple was installed in the crown of a sodium-cooled exhaust valve. The valve was then tested in an air-cooled engine cylinder and valve temperatures under various engine operating conditions were determined. A temperature of 1337 F was observed at a fuel-air ratio of 0.064, a brake mean effective pressure of 179 pounds per square inch, and an engine speed of 2000 rpm. Fuel-air ratio was found to have a large influence on valve temperature, but cooling-air pressure and variation in spark advance had little effect. An increase in engine power by change of speed or mean effective pressure increased the valve temperature. It was found that the temperature of the rear spark-plug bushing was not a satisfactory indication of the temperature of the exhaust valve.

  9. 40 CFR 86.160-00 - Exhaust emission test procedure for SC03 emissions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....161-00. (ii) Turn on the solar heating system. (iii) All vehicle test phases of preconditioning, soak... percent relative humidity), a solar heat load intensity of 850 W/m2, and vehicle cooling air flow... all vehicle windows. (4) Connect the emission test sampling system to the vehicle's exhaust tail...

  10. 40 CFR 86.160-00 - Exhaust emission test procedure for SC03 emissions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....161-00. (ii) Turn on the solar heating system. (iii) All vehicle test phases of preconditioning, soak... percent relative humidity), a solar heat load intensity of 850 W/m2, and vehicle cooling air flow... all vehicle windows. (4) Connect the emission test sampling system to the vehicle's exhaust tail...

  11. 40 CFR 86.160-00 - Exhaust emission test procedure for SC03 emissions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....161-00. (ii) Turn on the solar heating system. (iii) All vehicle test phases of preconditioning, soak... percent relative humidity), a solar heat load intensity of 850 W/m2, and vehicle cooling air flow... all vehicle windows. (4) Connect the emission test sampling system to the vehicle's exhaust tail...

  12. 40 CFR 86.160-00 - Exhaust emission test procedure for SC03 emissions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ....161-00. (ii) Turn on the solar heating system. (iii) All vehicle test phases of preconditioning, soak... percent relative humidity), a solar heat load intensity of 850 W/m2, and vehicle cooling air flow... all vehicle windows. (4) Connect the emission test sampling system to the vehicle's exhaust tail...

  13. 40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION... subject to not-to-exceed standards. (d) Useful life. Your engines must meet the exhaust emission standards of this section over their full useful life, expressed as a period in years or hours of...

  14. 40 CFR 1042.240 - Demonstrating compliance with exhaust emission standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION... the deterioration expected in emissions over your engines' full useful life. See paragraph (e) of this... additive deterioration factor is the difference between exhaust emissions at the end of the useful life...

  15. 40 CFR 1054.105 - What exhaust emission standards must my nonhandheld engines meet?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK... for marine generator engines Class I 10.0 610 5.0 Class II 8.0 610 5.0 (b) Averaging, banking, and...) Other engines: THC emissions. (d) Useful life. Your engines must meet the exhaust emission standards...

  16. 40 CFR 1054.105 - What exhaust emission standards must my nonhandheld engines meet?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK... for marine generator engines Class I 10.0 610 5.0 Class II 8.0 610 5.0 (b) Averaging, banking, and...) Other engines: THC emissions. (d) Useful life. Your engines must meet the exhaust emission standards...

  17. 40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION... engines are not subject to not-to-exceed standards. (d) Useful life. Your engines must meet the exhaust emission standards of this section over their full useful life, expressed as a period in years or hours...

  18. 40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION... subject to not-to-exceed standards. (d) Useful life. Your engines must meet the exhaust emission standards of this section over their full useful life, expressed as a period in years or hours of...

  19. 40 CFR 1042.240 - Demonstrating compliance with exhaust emission standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION... the deterioration expected in emissions over your engines' full useful life. See paragraph (e) of this... additive deterioration factor is the difference between exhaust emissions at the end of the useful life...

  20. 40 CFR 1054.105 - What exhaust emission standards must my nonhandheld engines meet?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK... for marine generator engines Class I 10.0 610 5.0 Class II 8.0 610 5.0 (b) Averaging, banking, and...) Other engines: THC emissions. (d) Useful life. Your engines must meet the exhaust emission standards...