Science.gov

Sample records for air water noise

  1. Noise Emission from Laboratory Air Blowers

    ERIC Educational Resources Information Center

    Rossing, Thomas D.; Windham, Betty

    1978-01-01

    Product noise ratings for a number of laboratory air blowers are reported and several recommendations for reducing laboratory noise from air blowers are given. Relevant noise ratings and methods for measuring noise emission of appliances are discussed. (BB)

  2. Air transportation noise technology overview

    NASA Technical Reports Server (NTRS)

    Maggin, B.; Chestnutt, D.

    1973-01-01

    The NASA and DOT technology program planning for quieter air transportation systems is reviewed. To put this planning in context, the nature of the noise problem and the projected nature of the air transportation fleet are identified. The technology program planning reviewed here is discussed in relation to the following areas of activity: systems analysis, community acceptance, basic research and technology, and the various classes of civil aircraft, i.e. existing and advanced transports, powered-lift transports, and general aviation.

  3. Technologies for Maintaining Animals in Space: Lighting, Air Quality, Noise, Food and Water

    NASA Technical Reports Server (NTRS)

    Winget, C. M.; Skidmore, M. G.; Holley, D. C.; Dalton, Bonnie P. (Technical Monitor)

    1995-01-01

    In the terrestrial environment multiple time cues exist. Zeitgebers have been identified and studied for their ability to convey temporal information to various physiological systems, In the microgravity experiment it is necessary to define time cues within the flight hardware prior to flight. During flight if changes in the Circadian System (e.g., mean, phase angle, period) occur this would indicate that the gravity vector is important relative to biological timing. This presentation is concerned with the environmental parameters to support rodent experiments in microgravity. The Animal Enclosure Module (AEM) provides solid food bars and water via lixits ad libitum. Flight animals (Sprague-Dawley rats, 60 - 300g) when compared to ground controls show similar growth (mean growth per day, g +/- SD; flight 5.4 +/- 2.0, ground 5.9 +/- 2.1). Current AEMs use incandescent lighting (approx. 5 Lux). Light emitting diode (LED) arrays are being developed that provide a similar light environment as cool-white fluorescent sources (40 Lux). In ground based tests (12L:12D), these arrays show normal circadian entrainment (Tau = 24.0) with respect to the behavioral responses. measured (drinking, eating, gross locomotor activity). A newly developed ultra high efficiency filter system can entrap all feces, urine and odors from 6 rats for 24 days. Maximum sound level exposure limits (per octave band 22 Hz - 179 kHz) have been established. The AEM will effectively support animal experiments in microgravity.

  4. Technologies For Maintaining Animals In Space: Lighting, Air Quality, Noise, Food And Water

    NASA Technical Reports Server (NTRS)

    Winget, C. M.; Skidmore, M. G.; Holley, D. C.; Dalton, Bonnie P. (Technical Monitor)

    1995-01-01

    In the terrestrial environment multiple time cues exist. Zeitgebers have been identified and studied for their ability to convey temporal information to various physiological systems. In the microgravity experiment it is necessary to define time cues within the flight hardware prior to flight. During flight if changes in the Circadian System (e.g., mean, phase angle, period) occur this would indicate that the gravity vector is important relative to biological timing. This presentation is concerned with the environmental parameter: to support rodent experiments in microgravity. The Animal Enclosure Module (AEM) provides solid food bars and water via lixits and ad libitum. Flight animals (Sprague-Dawley rats, 60 - 300g) when compared to ground controls show similar growth (mean growth per day g, plus or minus SD; flight 5.4 plus or minus 2.0, ground 5.9 plus or minus 2.1). Current AEMs use incandescent lighting (approx. 5 Lux). Light emitting diode (LED) arrays are being developed that provide a similar light environment as cool-white fluorescent sources (40 Lux). In ground based tests (12L:12D), these arrays show normal circadian entrainment (Tau = 24.0) with respect to the behavioral responses, measured (drinking, eating, gross locomotor activity). A newly developed ultra high efficiency filter system can entrap all feces, urine and odors from 6 rats for 24 days. Maximum sound level exposure limits (per octave band 22 Hz - 179 kHz) have been established. The AEM will effectively support animal experiments in microgravity.

  5. Air-moving device noise: An overview

    NASA Astrophysics Data System (ADS)

    Maling, George C., Jr.

    This paper presents a review of published information on the noise emission of small blowers and fans. The design is given for a noise meter for air-movement devices. The summary of research on noise sources and noise reduction includes information on axial-flow fans and centrifugal blowers. Sound reduction methods discussed include the introduction of obstructions and dampening plates and grilles. References are given for information on environmetal effects of fan noise. Design criteria and scaling laws are presented for minimal noise production. The paper identifies issues where further research is needed.

  6. Air/Water Purification

    NASA Technical Reports Server (NTRS)

    1992-01-01

    After 18 years of research into air/water pollution at Stennis Space Center, Dr. B. C. Wolverton formed his own company, Wolverton Environmental Services, Inc., to provide technology and consultation in air and water treatment. Common houseplants are used to absorb potentially harmful materials from bathrooms and kitchens. The plants are fertilized, air is purified, and wastewater is converted to clean water. More than 100 U.S. communities have adopted Wolverton's earlier water hyacinth and artificial marsh applications. Catfish farmers are currently evaluating the artificial marsh technology as a purification system.

  7. Impact of air gun noise on the behaviour of marine fish and squid.

    PubMed

    Fewtrell, J L; McCauley, R D

    2012-05-01

    In this study various species of captive marine fish and one species of squid were exposed to the noise from a single air gun. Six trials were conducted off the coast of Western Australia with each trial using a different noise exposure regime. Noise levels received by the animals ranged between 120 and 184 dB re 1 μPa(2).s (SEL). Behavioural observations of the fish and squid were made before, during and after air gun noise exposure. Results indicate that as air gun noise levels increase, fish respond by moving to the bottom of the water column and swimming faster in more tightly cohesive groups. Significant increases in alarm responses were observed in fish and squid to air gun noise exceeding 147-151 dB re 1 μPa SEL. An increase in the occurrence of alarm responses was also observed as noise level increased. PMID:22385754

  8. Predicting Anthropogenic Noise Contributions to US Waters.

    PubMed

    Gedamke, Jason; Ferguson, Megan; Harrison, Jolie; Hatch, Leila; Henderson, Laurel; Porter, Michael B; Southall, Brandon L; Van Parijs, Sofie

    2016-01-01

    To increase understanding of the potential effects of chronic underwater noise in US waters, the National Oceanic and Atmospheric Administration (NOAA) organized two working groups in 2011, collectively called "CetSound," to develop tools to map the density and distribution of cetaceans (CetMap) and predict the contribution of human activities to underwater noise (SoundMap). The SoundMap effort utilized data on density, distribution, acoustic signatures of dominant noise sources, and environmental descriptors to map estimated temporal, spatial, and spectral contributions to background noise. These predicted soundscapes are an initial step toward assessing chronic anthropogenic noise impacts on the ocean's varied acoustic habitats and the animals utilizing them. PMID:26610977

  9. Factor of safety method, application to air and noise pollution

    SciTech Connect

    Green, A.E.S.; Buckley, T.J.; Rio, D.E.; Makarewicz, R.; MacEachern, A.

    1980-01-01

    Technical report:Air quality indexes were used to calculate air and noise pollution factors of safety for 82 U.S. cities. Pollutants considered in the safety study are: total suspended particulates, sulfur dioxide, carbon monoxide, nitrogen dioxide, and ozone. Mathematical models that were used to calculate the factors of safety are presented. The utilization of air quality indexes for regional planning and decision-making is discussed. (5 graphs, 3 photos, 25 references, 6 tables)

  10. Study of noise transmission from an air compressor

    NASA Astrophysics Data System (ADS)

    Nathak, Subhro; Puranik, Anand; Schut, Jeffrey; Wells, Lee; Rao, M. D.

    2005-09-01

    The paper discusses the reduction of noise from a Porter Cable 4-gal, 135-psi air compressor. The objectives were to identify the major sources of noise, implement possible noise control measures, and evaluate their effectiveness. Sound measurements were taken according to a procedure that was developed and based on the standards for power tools. Broadband analysis (1/12 octave band) was done to determine the main sources of noise. Ranking of noise sources was done accordingly. The major source of noise was determined to be the piston cylinder assembly and efforts were taken to reduce this main source of noise. The noise control treatments included manufacturing of new parts, use of gasket made of cork between the housing and the cylinder sleeve to isolate the vibrations, implementing a silencer at the exhaust side of the piston and finally, an enclosure encircling the piston/cylinder assembly. The sound-pressure level measurements of the prototype were compared to the baseline measurements to test the effectiveness of the treatments. The overall sound pressure level was reduced from 101.5 to 94.3 dB with the implementation of enclosure around the piston/cylinder assembly and the silencer at the exhaust side of the piston.

  11. Attenuating noise generated by variable-air-volume systems

    SciTech Connect

    Stokes, R.

    1985-03-01

    Sound generated by HVAC systems is receiving much attention because they are generally the principal contributors to room background sound levels that may become irritating and distracting noise if not controlled. This article discusses the creation of a quiet working environment through an analysis of the three traditional sound paths associated with air handling systems: radiated sound, inlet or return air sound and discharge sound. Recommended standards are given as well as a brief overview of materials used to fabricate HVAC system components.

  12. Noise reduction by the application of an air-bubble curtain in offshore pile driving

    NASA Astrophysics Data System (ADS)

    Tsouvalas, A.; Metrikine, A. V.

    2016-06-01

    Underwater noise pollution is a by-product of marine industrial operations. In particular, the noise generated when a foundation pile is driven into the soil with an impact hammer is considered to be harmful for the aquatic species. In an attempt to reduce the ecological footprint, several noise mitigation techniques have been investigated. Among the various solutions proposed, the air-bubble curtain is often applied due to its efficacy in noise reduction. In this paper, a model is proposed for the investigation of the sound reduction during marine piling when an air-bubble curtain is placed around the pile. The model consists of the pile, the surrounding water and soil media, and the air-bubble curtain which is positioned at a certain distance from the pile surface. The solution approach is semi-analytical and is based on the dynamic sub-structuring technique and the modal decomposition method. Two main results of the paper can be distinguished. First, a new model is proposed that can be used for predictions of the noise levels in a computationally efficient manner. Second, an analysis is presented of the principal mechanisms that are responsible for the noise reduction due to the application of the air-bubble curtain in marine piling. The understanding of these mechanisms turns to be crucial for the exploitation of the maximum efficiency of the system. It is shown that the principal mechanism of noise reduction depends strongly on the frequency content of the radiated sound and the characteristics of the bubbly medium. For piles of large diameter which radiate most of the acoustic energy at relatively low frequencies, the noise reduction is mainly attributed to the mismatch of the acoustic impedances between the seawater and the bubbly layer. On the contrary, for smaller piles and when the radiated acoustic energy is concentrated at frequencies close to, or higher than, the resonance frequency of the air bubbles, the sound absorption within the bubbly layer

  13. Low-noise flow valve for air ducts

    NASA Technical Reports Server (NTRS)

    Gallo, E. A.

    1970-01-01

    Valve assembly controls air flow from feeder into main duct, with minimum of turbulence, friction, pressure differential, and noise. Valve consists of damper, deflector, and spring. Streamlining of damper and deflector merges flow smoothly, while spring keeps damper and deflector in contact and eliminates valve chatter and damping vibrations.

  14. Noise Reduction Of Air Blower Casing Using Composites

    NASA Astrophysics Data System (ADS)

    Kolla*, S.; Kumar, Y. Anil; Rajesh, S.

    Sound subjectively, what is heard by the ear; objectively, is a mecha nical disturbance from equilibrium in an elastic medium. The noise produced by a rotating component has two main components, the broadband noise and the discrete frequency noise. The broadband noise from a rotor is due to random loading forces on the blades, which are induced by the absorption of atmospheric turbulence. The discrete frequency noise is due to periodic interaction of incoming air with the blades of the rotor. At present the centrifugal blowers, in Naval defense application which is made of steel is generating a noise of 86dB, which causes mental imbalance to the people working near the blower on ship. Therefore in Naval defense applications the reduction of sound level from a source is very important and critical task. Hence the objective of this paper is to reduce the noise level produced by the metal air blower. The noise radiated by the casing of a centrifugal blower can be effectively reduced by the use of (1) Composite Materials, (2) Visco-Elastic material treatment and (3) Stiffness addition. In this paper it is proposed to carry out a study to evaluate the effectiveness of composites in reducing noise levels of the casing. Composite materials are those containing more than one bonded material, each with different struc tural properties. The advantage of composite materials is the potential for a high ratio of stiffness to weight. In order to evaluate the effectiveness of composites over metals, modal analysis (Eigen value analysis) and Static analysis was performed on both composite and metal blowers using FEA package (ANSYS). Modal analysis is performed on both metals (Alluminium and Composite) blower casing to find out the first ten natural frequencies and static analysis is performed for a pressure of 1570 Pa. This paper also describes the experimental setup of the centrifugal blower, the values of the sound levels for both metal and FRP blowers are taken at a distance of

  15. Acoustic background noise variation in Air Force platforms and its effect on noise removal algorithms

    NASA Astrophysics Data System (ADS)

    Lafollette, Philip A.

    1991-06-01

    In this study of short-term noise variation in Air Force platforms, we followed two avenues of investigation. First, we applied quantitative measures of variation to individual noise recordings, and compared the results across various aircraft. Some measures used were simple descriptive statistics, but we also measured attenuation obtained by spectral restoration (spectral subtraction), applied to the noise signal alone. The noise attenuation obtained for real aircraft environments was in most cases about the same as predicted theoretically for white Gaussian noise, but in some instances was considerably higher, especially in the presence of propeller noise. Second, we applied the nonparametric Mann-Whitney statistic to test the stationarity of power spectrum estimates on time scales of 200 to 800 ms. There was little or no evidence of nonstationarity in large jet or turboprop aircraft. In fighter aircraft and helicopters, there was some evidence of nonstationarity confined to more or less narrow frequency ranges. The nonstationarity found did not appear to limit the performance of special restoration algorithms. The noise recordings used were taken from the RADC/EEV database of field recordings made in the E-3A, E-4B, EC-135, E-130, P-3C, F-15, F-16, F-4, A-10, HH-53 and Tornado aircraft.

  16. Far Noise Field of Air Jets and Jet Engines

    NASA Technical Reports Server (NTRS)

    Callaghan, Edmund E; Coles, Willard D

    1957-01-01

    An experimental investigation was conducted to study and compare the acoustic radiation of air jets and jet engines. A number of different nozzle-exit shapes were studied with air jets to determine the effect of exit shape on noise generation. Circular, square, rectangular, and elliptical convergent nozzles and convergent-divergent and plug nozzles were investigated. The spectral distributions of the sound power for the engine and the air jet were in good agreement for the case where the engine data were not greatly affected by reflection or jet interference effects. Such power spectra for a subsonic or slightly choked engine or air jet show that the peaks of the spectra occur at a Strouhal number of 0.3.

  17. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  18. 40 CFR 204.52 - Portable air compressor noise emission standard.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Portable air compressor noise emission standard. 204.52 Section 204.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Portable Air Compressors § 204.52 Portable air compressor...

  19. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  20. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  1. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  2. Air-water centrifugal convection

    NASA Astrophysics Data System (ADS)

    Herrada, Miguel; Shtern, Vladimir

    2014-07-01

    A sealed cylindrical container is filled with air and water. The container rotation and the axial gradient of temperature induce the steady axisymmetric meridional circulation of both fluids due to the thermal buoyancy and surface-tension (Marangoni) effects. If the temperature gradient is small, the water circulation is one-cellular while the air circulation can be one- or two-cellular depending on water fraction Wf. The numerical simulations are performed for the cylinder length-to-radius ratio l = 1 and l = 4. The l = 4 results and the analytical solution for l → ∞ agree in the cylinder's middle part. As the temperature gradient increases, the water circulation becomes one-, two-, or three-cellular depending on Wf. The results are of fundamental interest and can be applied for bioreactors.

  3. Reductions in Multi-Component Jet Noise by Water Injection

    NASA Technical Reports Server (NTRS)

    Norum, Thomas D.

    2004-01-01

    An experimental investigation was performed in the NASA Langley Low Speed Aeroacoustics Wind Tunnel to determine the extent of jet exhaust noise reduction that can be obtained using water injection in a hot jet environment. The effects of water parameters such as mass flow rate, injection location, and spray patterns on suppression of dominant noise sources in both subsonic and supersonic jets were determined, and extrapolations to full-scale engine noise reduction were made. Water jets and sprays were injected in to the shear layers of cold and hot circular jets operating at both subsonic and supersonic exhaust conditions. Use of convergent-divergent and convergent nozzles (2.7in. D) allowed for simulations of all major jet noise sources. The experimental results show that water injection clearly disrupts shock noise sources within the jet plume, with large reductions in radiated shock noise. There are smaller reductions in jet mixing noise, resulting in only a small decrease in effective perceived noise level when projections are made to full scale. The fact that the measured noise reduction in the direction upstream of the nozzle was consistently larger than in the noisier downstream direction contributed to keeping effective perceived noise reductions small. Variations in the operation of the water injection system clearly show that injection at the nozzle exit rather than further downstream is required for the largest noise reduction. Noise reduction increased with water pressure as well as with its mass flow, although the type of injector had little effect.

  4. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  5. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  6. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  7. 40 CFR 204.52 - Portable air compressor noise emission standard.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Portable air compressor noise emission standard. 204.52 Section 204.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Portable Air Compressors §...

  8. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  12. 40 CFR 204.52 - Portable air compressor noise emission standard.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Portable air compressor noise emission standard. 204.52 Section 204.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Portable Air Compressors §...

  13. 40 CFR 204.52 - Portable air compressor noise emission standard.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Portable air compressor noise emission standard. 204.52 Section 204.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Portable Air Compressors §...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  15. 40 CFR 204.52 - Portable air compressor noise emission standard.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Portable air compressor noise emission standard. 204.52 Section 204.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Portable Air Compressors §...

  16. Meeting 2006, outdoor noise directive (OND) noise levels for a diesel engine driven air compressor: A case study in noise reduction

    NASA Astrophysics Data System (ADS)

    Rowe, David F.

    2005-09-01

    In January 2006, the noise limits for many products in the European Union will drop by 2-3 dBA, as directed by 2000/14/EC ``Noise Emission in the Environment by Equipment Used Outdoors,'' commonly called the ``Outdoor Noise Directive,'' or ``OND.'' Air compressors are among the products addressed by this directive. At Ingersoll-Rand, significant effort has been directed at meeting the challenge of reducing noise on a variety of diesel engine driven air compressor platforms, ranging from 15 to 350 kW diesel engine power ratings. This paper presents a case study of the noise reduction on a 750 cfm (21 m3/min) air compressor operating at 300 psig (21 bar), to meet the 2006 OND noise limit of 100 LwA.

  17. Broadband Shock Noise Reduction in Turbulent Jets by Water Injection

    NASA Technical Reports Server (NTRS)

    Kandula, Max

    2008-01-01

    The concept of effective jet properties introduced by the author (AIAA-2007-3 645) has been extended to the estimation of broadband shock noise reduction by water injection in supersonic jets. Comparison of the predictions with the test data for cold underexpanded supersonic nozzles shows a satisfactory agreement. The results also reveal the range of water mass flow rates over which saturation of mixing noise reduction and existence of parasitic noise are manifest.

  18. On the impact noise of a drop falling on water

    NASA Astrophysics Data System (ADS)

    Howe, M. S.; Hagen, N. A. A.

    2011-02-01

    An analysis is made of the impact sound generated when a water droplet impinges on a nominally smooth air-water interface. Guo and Ffowcs Williams [ Journal of Fluid Mechanics 227 (1991) 345-355] derived a mathematical representation of the sound produced in the initial period of impact of duration ≪1 μs. The theory of this paper is a simple extension of their method that covers all of the effective life time ( ˜100 μs) of the impact sound pulse. At the acoustic wavefront the predicted pressure signature in the water consists of a large impulsive peak with the directivity of an acoustic monopole source. Behind this peak lower frequency components of the sound are strongly influenced by the effective pressure-release condition on the free surface of the water, and the radiation acquires the characteristics of a much weaker dipole field (with dipole axis normal to the water interface) accompanied by a rapid decrease in wave amplitude. The dipole pressure exhibits a single cycle oscillation before decaying to evanescence about 0.1 ms after the initial impact. Predictions of the acoustic pressure spectral level are shown to be consistent with measurements available in the literature. Applications of the theory are envisaged to situations where the entrainment of air bubbles by droplets is not important, so that the impact is the dominant source of sound—for example, in estimating the contribution to the self-noise of a supercavitating vehicle from ventilating gas containing a 'spray' of small droplets impinging on the cavity gas-water interface.

  19. Noise impacts from professional dog grooming forced-air dryers

    PubMed Central

    Scheifele, Peter M.; Johnson, Michael T.; Byrne, David C.; Clark, John G.; Vandlik, Ashley; Kretschmer, Laura W.; Sonstrom, Kristine E.

    2015-01-01

    This study was designed to measure the sound output of four commonly used brands of forced-air dryers used by dog groomers in the United States. Many dog groomers have questions about the effect of this exposure on their hearing, as well as on the hearing of the dogs that are being groomed. Readings taken from each dryer at 1 meter (the likely distance of the dryer from the groomer and the dog) showed average levels ranging from 105.5 to 108.3 dB SPL or 94.8 to 108.0 dBA. Using the 90 dBA criterion required by the US Occupational Safety and Health Administration, dog groomers/bathers are at risk if exposure to the lowest intensity dryer (94.8 dBA) exceeds 4 hours per day. If the more stringent 85 dBA criterion and 3 dB tradeoff is applied, less than one hour of exposure is permissible in an 8 hour day. Cautions are recommended for any persons exposed to noise from forced-air dryers. PMID:23117536

  20. High pressure air jet in the endoscopic preparation room: risk of noise exposure on occupational health.

    PubMed

    Chiu, King-Wah; Lu, Lung-Sheng; Wu, Cheng-Kun

    2015-01-01

    After high-level disinfection of gastrointestinal endoscopes, they are hung to dry in order to prevent residual water droplets impact on patient health. To allow for quick drying and clinical reuse, some endoscopic units use a high pressure air jet (HPAJ) to remove the water droplets on the endoscopes. The purpose of this study was to evaluate the excessive noise exposure with the use of HPAJ in endoscopic preparation room and to investigate the risk to occupational health. Noise assessment was taken during 7 automatic endoscopic reprocessors (AERs) and combined with/without HPAJ use over an 8-hour time-weighted average (TWA). Analytical procedures of the NIOSH and the ISO for noise-induced hearing loss were estimated to develop analytic models. The peak of the noise spectrum of combined HPAJ and 7 AERs was significantly higher than that of the 7 AERs alone (108.3 ± 1.36 versus 69.3 ± 3.93 dBA, P < 0.0001). The risk of hearing loss (HL > 2.5 dB) was 2.15% at 90 dBA, 11.6% at 95 dBA, and 51.3% at 100 dBA. The odds ratio was 49.1 (95% CI: 11.9 to 203.6). The noise generated by the HPAJ to work over TWA seriously affected the occupational health and safety of those working in an endoscopic preparation room. PMID:25710009

  1. Nocturnal air, road, and rail traffic noise and daytime cognitive performance and annoyance.

    PubMed

    Elmenhorst, Eva-Maria; Quehl, Julia; Müller, Uwe; Basner, Mathias

    2014-01-01

    Various studies indicate that at the same noise level and during the daytime, annoyance increases in the order of rail, road, and aircraft noise. The present study investigates if the same ranking can be found for annoyance to nocturnal exposure and next day cognitive performance. Annoyance ratings and performance change during combined noise exposure were also tested. In the laboratory 72 participants were exposed to air, road, or rail traffic noise and all combinations. The number of noise events and LAS,eq were kept constant. Each morning noise annoyance questionnaires and performance tasks were administered. Aircraft noise annoyance ranked first followed by railway and road noise. A possible explanation is the longer duration of aircraft noise events used in this study compared to road and railway noise events. In contrast to road and rail traffic, aircraft noise annoyance was higher after nights with combined exposure. Pooled noise exposure data showed small but significant impairments in reaction times (6 ms) compared to nights without noise. The noise sources did not have a differential impact on performance. Combined exposure to multiple traffic noise sources did not induce stronger impairments than a single noise source. This was reflected also in low workload ratings. PMID:24437761

  2. AIR CONVECTION NOISE OF PENCIL-BEAM INTERFERMETER FOR LONG TRACE PROFILER.

    SciTech Connect

    YASHCHUK, V.V.; IRICK, S.C.; MACDOWELL, A.A.; MCKINNEY, W.R.; TAKACS, P.Z.

    2006-08-14

    In this work, we investigate the effect of air convection on laser-beam pointing noise essential for the long trace profiler (LTP). We describe this pointing error with noise power density (NPD) frequency distributions. It is shown that the NPD spectra due to air convection have a very characteristic form. In the range of frequencies from {approx}0.05 Hz to {approx}0.5 Hz, the spectra can be modeled with an inverse-power-law function. Depending on the intensity of air convection that is controlled with a resistive heater of 100 to 150 mW along a one-meter-long optical path, the power index lies between 2 and 3 at an overall rms noise of {approx}0.5 to 1 microradian. The efficiency of suppression of the convection noise by blowing air across the beam optical path is also discussed. Air-blowing leads to a white-noise-like spectrum. Air blowing was applied to the reference channel of an LTP allowing demonstration of the contribution of air convection noise to the LTP reference beam. The ability to change (with the blowing technique presented) the spectral characteristics of the beam pointing noise due to air convection allows one to investigate the contribution of the convection effect, and thus make corrections to the power spectral density spectra measured with the LTP.

  3. Air convection noise of pencil-beam interferometer for long traceprofiler

    SciTech Connect

    Yashchuk, Valeriy V.; Irick, Steve C.; MacDowell, Alastair A.; McKinney, Wayne R.; Takacs, Peter Z.

    2006-07-12

    In this work, we investigate the effect of air convection onlaser-beam pointing noise essential for the long trace profiler (LTP). Wedescribe this pointing error with noise power density (NPD) frequencydistributions. It is shown that the NPD spectra due to air convectionhave a very characteristic form. In the range of frequencies from ~;0.05Hz to ~;0.5 Hz, the spectra can be modeled with an inverse-power-lawfunction. Depending on the intensity of air convection that is controlledwith a resistive heater of 100 to 150 mW along a one-meter-long opticalpath, the power index lies between 2 and 3 at an overall rms noise of~;0.5 to 1 microradian. The efficiency of suppression of the convectionnoise by blowing air across the beam optical path is also discussed.Air-blowing leads to a white-noise-like spectrum. Air blowing was appliedto the reference channel of an LTP allowing demonstration of thecontribution of air convection noise to the LTP reference beam. Theability to change (with the blowing technique presented) the spectralcharacteristics of the beam pointing noise due to air convection allowsone to investigate the contribution of the convection effect, and thusmake corrections to the power spectral density spectra measured with theLTP.

  4. Environmental Chemistry: Air and Water Pollution.

    ERIC Educational Resources Information Center

    Stoker, H. Stephen; Seager, Spencer L.

    This is a book about air and water pollution whose chapters cover the topics of air pollution--general considerations, carbon monoxide, oxides of nitrogen, hydrocarbons and photochemical oxidants, sulfur oxides, particulates, temperature inversions and the greenhouse effect; and water pollution--general considerations, mercury, lead, detergents,…

  5. Water gun vs air gun: A comparison

    USGS Publications Warehouse

    Hutchinson, D.R.; Detrick, R. S.

    1984-01-01

    The water gun is a relatively new marine seismic sound source that produces an acoustic signal by an implosive rather than explosive mechanism. A comparison of the source characteristics of two different-sized water guns with those of conventional air guns shows the the water gun signature is cleaner and much shorter than that of a comparable-sized air gun: about 60-100 milliseconds (ms) for an 80-in3. (1.31-liter (I)) water gun compared with several hundred ms for an 80-in3. (1.31-1) air gun. The source spectra of water guns are richer in high frequencies (>200 Hz) than are those of air guns, but they also have less energy than those of air guns at low frequencies. A comparison between water gun and air gun reflection profiles in both shallow (Long Island Sound)-and deep (western Bermuda Rise)-water settings suggests that the water gun offers a good compromise between very high resolution, limited penetration systems (e.g. 3.5-kHz profilers and sparkers) and the large volume air guns and tuned air gun arrays generally used where significant penetration is required. ?? 1984 D. Reidel Publishing Company.

  6. Assessment of Impulsive and Continuous Low-Frequency Noise in Irish Waters.

    PubMed

    Beck, Suzanne; O'Brien, Joanne; Berrow, Simon; O'Connor, Ian; Wall, Dave

    2016-01-01

    As part of the European Union Marine Strategy Framework Directive (MSFD), member states are required to address noise pollution in the marine environment under Descriptor 11. This study aimed to provide a practical desk-based application of Descriptor 11 assessment, focusing on the main contributors of ocean noise pollution in Irish waters, seismic surveying and shipping. To highlight specific geographical areas subject to elevated levels of noise pollution, the proportion of days over a calendar year that seismic air guns were operational was calculated and the vessel density per 50-km(2) grids was determined across Ireland's exclusive economic zone (EEZ). Additionally, cetacean sighting data were used to determine the degree of spatial overlap between areas of elevated noise pollution and areas of cetacean abundance. PMID:26610946

  7. Physiological noise compensation in gradient-echo myelin water imaging.

    PubMed

    Nam, Yoonho; Kim, Dong-Hyun; Lee, Jongho

    2015-10-15

    In MRI, physiological noise which originates from cardiac and respiratory functions can induce substantial errors in detecting small signals in the brain. In this work, we explored the effects of the physiological noise and their compensation methods in gradient-echo myelin water imaging (GRE-MWI). To reduce the cardiac function induced inflow noise, flow saturation RF pulses were applied to the inferior portion of the head, saturating inflow blood signals. For the respiratory function induced B0 fluctuation compensation, a navigator echo was acquired, and respiration induced phase errors were corrected during reconstruction. After the compensations, the resulting myelin water images show substantially improved image quality and reproducibility. These improvements confirm the importance and usefulness of the physiological noise compensations in GRE-MWI. PMID:26172308

  8. Single and Combined Effects of Air, Road, and Rail Traffic Noise on Sleep and Recuperation

    PubMed Central

    Basner, Mathias; Müller, Uwe; Elmenhorst, Eva-Maria

    2011-01-01

    Study Objective: Traffic noise disturbs sleep and may impair recuperation. There is limited information on single and combined effects of air, road, and rail traffic noise on sleep and recuperation. Design: Repeated measures. Setting: Polysomnographic laboratory study. Participants: 72 healthy subjects, mean ± standard deviation 40 ± 13 years, range 18-71 years, 32 male. Interventions: Exposure to 40, 80, or 120 rail, road, and/or air traffic noise events. Measurement and Results: Subjects were investigated for 11 consecutive nights, which included 8 noise exposure nights and one noise-free control night. Noise effects on sleep structure and continuity were subtle, even in nights with combined exposure, most likely because of habituation and an increase in arousal thresholds both within and across nights. However, cardiac arousals did not habituate across nights. Noise exposure significantly affected subjective assessments of sleep quality and recuperation, whereas objective performance was unaffected, except for a small increase in mean PVT reaction time (+4 ms, adjusted P < 0.05). Road traffic noise led to the strongest changes in sleep structure and continuity, whereas subjective assessments of sleep were worse after nights with air and rail traffic noise exposure. In contrast to daytime annoyance, cortical arousal probabilities and cardiac responses were significantly lower for air than for road and rail traffic noise (all P < 0.0001). These differences were explained by sound pressure level rise time and high frequency (> 3 kHz) noise event components. Conclusions: Road, rail, and air traffic noise differentially affect objective and subjective assessments of sleep. Differences in the degree of noise-induced sleep fragmentation between traffic modes were explained by the specific spectral and temporal composition of noise events, indicating potential targets for active and passive noise control. Field studies are needed to validate our findings in a setting

  9. [The problems of assessment of the high noise impact on the experts of the Air Force].

    PubMed

    Zinkin, V N; Sheshegov, P M

    2012-01-01

    Air Force specialists are exposed to high intensity noise levels exceeded the maximum permissible levels. Infrasound as a productive factor in accordance with the general technical requirements (OTT) Air Force-86 is not included in the list of standardized factors. The adverse acoustic environment makes the risk of occupational (sensorineural deafness) and professionally-related diseases of the nervous and cardiovascular systems. The system of physical fitness for military service in the Air Force and serving in the Air Force with high-intensity sources of noise, the system of treatment and preventive measures for adverse effects of noise and the procedure for examination of persons with diseases caused by the influence of noise are needed to be reviewed in accordance with the existing state legislative frameworks. PMID:22545451

  10. Reduction of Altitude Diffuser Jet Noise Using Water Injection

    NASA Technical Reports Server (NTRS)

    Allgood, Daniel C.; Saunders, Grady P.; Langford, Lester A.

    2011-01-01

    A feasibility study on the effects of injecting water into the exhaust plume of an altitude rocket diffuser for the purpose of reducing the far-field acoustic noise has been performed. Water injection design parameters such as axial placement, angle of injection, diameter of injectors, and mass flow rate of water have been systematically varied during the operation of a subscale altitude test facility. The changes in acoustic far-field noise were measured with an array of free-field microphones in order to quantify the effects of the water injection on overall sound pressure level spectra and directivity. The results showed significant reductions in noise levels were possible with optimum conditions corresponding to water injection at or just upstream of the exit plane of the diffuser. Increasing the angle and mass flow rate of water injection also showed improvements in noise reduction. However, a limit on the maximum water flow rate existed as too large of flow rate could result in un-starting the supersonic diffuser.

  11. Reduction of Altitude Diffuser Jet Noise Using Water Injection

    NASA Technical Reports Server (NTRS)

    Allgood, Daniel C.; Saunders, Grady P.; Langford, Lester A.

    2014-01-01

    A feasibility study on the effects of injecting water into the exhaust plume of an altitude rocket diffuser for the purpose of reducing the far-field acoustic noise has been performed. Water injection design parameters such as axial placement, angle of injection, diameter of injectors, and mass flow rate of water have been systematically varied during the operation of a subscale altitude test facility. The changes in acoustic far-field noise were measured with an array of free-field microphones in order to quantify the effects of the water injection on overall sound pressure level spectra and directivity. The results showed significant reductions in noise levels were possible with optimum conditions corresponding to water injection at or just upstream of the exit plane of the diffuser. Increasing the angle and mass flow rate of water injection also showed improvements in noise reduction. However, a limit on the maximum water flow rate existed as too large of flow rate could result in un-starting the supersonic diffuser.

  12. Noise Effects on Health in the Context of Air Pollution Exposure.

    PubMed

    Stansfeld, Stephen A

    2015-10-01

    For public health policy and planning it is important to understand the relative contribution of environmental noise on health compared to other environmental stressors. Air pollution is the primary environmental stressor in relation to cardiovascular morbidity and mortality. This paper reports a narrative review of studies in which the associations of both environmental noise and air pollution with health have been examined. Studies of hypertension, myocardial infarction, stroke, mortality and cognitive outcomes were included. Results suggest independent effects of environmental noise from road traffic, aircraft and, with fewer studies, railway noise on cardiovascular outcomes after adjustment for air pollution. Comparative burden of disease studies demonstrate that air pollution is the primary environmental cause of disability adjusted life years lost (DALYs). Environmental noise is ranked second in terms of DALYs in Europe and the DALYs attributed to noise were more than those attributed to lead, ozone and dioxins. In conclusion, in planning and health impact assessment environmental noise should be considered an independent contributor to health risk which has a separate and substantial role in ill-health separate to that of air pollution. PMID:26473905

  13. Noise Effects on Health in the Context of Air Pollution Exposure

    PubMed Central

    Stansfeld, Stephen A.

    2015-01-01

    For public health policy and planning it is important to understand the relative contribution of environmental noise on health compared to other environmental stressors. Air pollution is the primary environmental stressor in relation to cardiovascular morbidity and mortality. This paper reports a narrative review of studies in which the associations of both environmental noise and air pollution with health have been examined. Studies of hypertension, myocardial infarction, stroke, mortality and cognitive outcomes were included. Results suggest independent effects of environmental noise from road traffic, aircraft and, with fewer studies, railway noise on cardiovascular outcomes after adjustment for air pollution. Comparative burden of disease studies demonstrate that air pollution is the primary environmental cause of disability adjusted life years lost (DALYs). Environmental noise is ranked second in terms of DALYs in Europe and the DALYs attributed to noise were more than those attributed to lead, ozone and dioxins. In conclusion, in planning and health impact assessment environmental noise should be considered an independent contributor to health risk which has a separate and substantial role in ill-health separate to that of air pollution. PMID:26473905

  14. Annoyance due to noise and air pollution to the residents of heavily frequented streets

    NASA Technical Reports Server (NTRS)

    Wanner, H. U.; Wehrli, B.; Nemecek, J.; Turrian, V.

    1980-01-01

    The residents of different streets with varying traffic density and building density were questioned about annoyance due to traffic noise and air pollution. Results show that annoyance felt is dependent not only on the measured noise levels and/or air pollution concentrations, but that there do exist interactions between the residential quarters and annoyance. These interactions should be considered when fixing the limits and standards.

  15. Noise emission and propagation in an air flow

    NASA Astrophysics Data System (ADS)

    Legendre, R.

    1983-01-01

    Sound propagation from a jet engine on an aircraft moving at a constant airspeed is examined in terms of the turbulent field, the near field, and the far field. The near and far fields are irrotational disturbances of a permanently adiabatic flow for which the entropy and enthalpy are the critical parameters. The propagation velocity of the noise is formulated, together with the extent of the acoustic field. The acoustic excitation is shown to dominate the extent of the acoustic field, while the pseudo-noise and the sound density are equal to the sound pressure and are not noise sources. The unsteady part of the turbulence noise is controlled by the pressure gradient, particularly that around the axes of the eddies.

  16. Geoacoustic inversion of noise coherence in shallow water

    NASA Astrophysics Data System (ADS)

    Thomson, David J.; Desharnais, Francine; Drover, Matthew L.; Gillard, Chris A.

    2002-11-01

    It is known that the geoacoustic properties of a shallow-water sea-bed can be inferred from relatively simple measurements of the ambient noise coherence between a pair of vertically separated hydrophones [D. M. F. Chapman, ''Surface-generated noise in shallow water: A model,'' Proc. Inst. Acoust. 9, 1-11 (1987)]. The design of an autonomous buoy package for acquiring geoacoustic information by this method is currently being considered by DRDC-Atlantic in support of matched-field localization efforts that are being developed for use with rapidly deployable arrays. Initially, vertical coherence estimates from a simple shallow water noise model were fit to measured coherences by adjusting geoacoustic parameters by a trial and error procedure. A more systematic approach involves combining noise coherence models with nonlinear global optimization methods based on matched-coherence processing concepts to search the space of possible sea-bed parameters more efficiently. In this paper, we report on recent efforts to use a hybrid simplex simulated annealing scheme [M. R. Fallat and S. E. Dosso, ''Geoacoustic inversion via local, global, and hybrid algorithms,'' J. Acoust. Soc. Am. 105, 3219-3230 (1999)] to match an increasingly realistic suite of candidate geoacoustic parametrizations to some acoustic noise coherent data measured with modified sonobuoys deployed at several shallow water locations on the Scotian Shelf.

  17. Spatial variation in environmental noise and air pollution in New York City.

    PubMed

    Kheirbek, Iyad; Ito, Kazuhiko; Neitzel, Richard; Kim, Jung; Johnson, Sarah; Ross, Zev; Eisl, Holger; Matte, Thomas

    2014-06-01

    Exposure to environmental noise from traffic is common in urban areas and has been linked to increased risks of adverse health effects including cardiovascular disease. Because traffic sources also produce air pollutants that increase the risk of cardiovascular morbidity, associations between traffic exposures and health outcomes may involve confounding and/or synergisms between air pollution and noise. While prior studies have characterized intraurban spatial variation in air pollution in New York City (NYC), limited data exists on the levels and spatial variation in noise levels. We measured 1-week equivalent continuous sound pressure levels (Leq) at 56 sites during the fall of 2012 across NYC locations with varying traffic intensity and building density that are routinely monitored for combustion-related air pollutants. We evaluated correlations among several noise metrics used to characterize noise exposures, including Leq during different time periods (night, day, weekday, weekend), Ldn (day-night noise), and measures of intermittent noise defined as the ratio of peak levels to median and background levels. We also examined correlations between sound pressure levels and co-located simultaneous measures of nitric oxide (NO), nitrogen dioxide (NO2), fine particulate matter (PM2.5), and black carbon (BC) as well as estimates of traffic and building density around the monitoring sites. Noise levels varied widely across the 56 monitoring sites; 1-week Leq varied by 21.6 dBA (range 59.1-80.7 dBA) with the highest levels observed during the weekday, daytime hours. Indices of average noise were well correlated with each other (r > 0.83), while indices of intermittent noise were not well correlated with average noise levels (r < 0.41). One-week Leq correlated well with NO, NO2, and EC levels (r = 0.61 to 0.68) and less so with PM2.5 levels (r = 0.45). We observed associations between 1-week noise levels and traffic intensity within 100 m of the monitoring sites (r = 0

  18. Evaluation studies of noise and air pollution during festival seasons in India.

    PubMed

    Battalwar, D G; Meshram, S U; Yenkie, M K N; Puri, P J

    2012-07-01

    The present research work is based on assessment of noise levels and ambient air quality at selected locations during festival seasons in Nagpur city. The noise levels were exceeding the permissible limits almost at every location during the festival period. The huge emissions of smoke arising out bursting of firecrackers have significantly resulted into air pollution; particularly in terms of Sulphur Dioxide (SO2) and Respirable Suspended Particulate Matter (Fine Dust). The immediate effect of increasing noise levels is impairing of hearing that may cause auditory fatigue and finally lead to deafness. PMID:24749201

  19. Cleaning verification by air/water impingement

    NASA Technical Reports Server (NTRS)

    Jones, Lisa L.; Littlefield, Maria D.; Melton, Gregory S.; Caimi, Raoul E. B.; Thaxton, Eric A.

    1995-01-01

    This paper will discuss how the Kennedy Space Center intends to perform precision cleaning verification by Air/Water Impingement in lieu of chlorofluorocarbon-113 gravimetric nonvolatile residue analysis (NVR). Test results will be given that demonstrate the effectiveness of the Air/Water system. A brief discussion of the Total Carbon method via the use of a high temperature combustion analyzer will also be given. The necessary equipment for impingement will be shown along with other possible applications of this technology.

  20. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.140 Section 84.140 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air...

  1. Noise Pollution

    MedlinePlus

    ... here: EPA Home Air and Radiation Noise Pollution Noise Pollution This page has moved. You should be ... epa.gov/clean-air-act-overview/title-iv-noise-pollution Local Navigation Air & Radiation Home Basic Information ...

  2. Air and water cooled modulator

    DOEpatents

    Birx, Daniel L.; Arnold, Phillip A.; Ball, Don G.; Cook, Edward G.

    1995-01-01

    A compact high power magnetic compression apparatus and method for delivering high voltage pulses of short duration at a high repetition rate and high peak power output which does not require the use of environmentally unacceptable fluids such as chlorofluorocarbons either as a dielectric or as a coolant, and which discharges very little waste heat into the surrounding air. A first magnetic switch has cooling channels formed therethrough to facilitate the removal of excess heat. The first magnetic switch is mounted on a printed circuit board. A pulse transformer comprised of a plurality of discrete electrically insulated and magnetically coupled units is also mounted on said printed board and is electrically coupled to the first magnetic switch. The pulse transformer also has cooling means attached thereto for removing heat from the pulse transformer. A second magnetic switch also having cooling means for removing excess heat is electrically coupled to the pulse transformer. Thus, the present invention is able to provide high voltage pulses of short duration at a high repetition rate and high peak power output without the use of environmentally unacceptable fluids and without discharging significant waste heat into the surrounding air.

  3. Air and water cooled modulator

    DOEpatents

    Birx, D.L.; Arnold, P.A.; Ball, D.G.; Cook, E.G.

    1995-09-05

    A compact high power magnetic compression apparatus and method are disclosed for delivering high voltage pulses of short duration at a high repetition rate and high peak power output which does not require the use of environmentally unacceptable fluids such as chlorofluorocarbons either as a dielectric or as a coolant, and which discharges very little waste heat into the surrounding air. A first magnetic switch has cooling channels formed therethrough to facilitate the removal of excess heat. The first magnetic switch is mounted on a printed circuit board. A pulse transformer comprised of a plurality of discrete electrically insulated and magnetically coupled units is also mounted on said printed board and is electrically coupled to the first magnetic switch. The pulse transformer also has cooling means attached thereto for removing heat from the pulse transformer. A second magnetic switch also having cooling means for removing excess heat is electrically coupled to the pulse transformer. Thus, the present invention is able to provide high voltage pulses of short duration at a high repetition rate and high peak power output without the use of environmentally unacceptable fluids and without discharging significant waste heat into the surrounding air. 9 figs.

  4. Road, rail, and air transportation noise in residential and workplace neighborhoods and blood pressure (RECORD Study).

    PubMed

    Méline, Julie; Van Hulst, Andraea; Thomas, Frederique; Chaix, Basile

    2015-01-01

    Associations between road traffic noise and hypertension have been repeatedly documented, whereas associations with rail or total road, rail, and air (RRA) traffic noise have rarely been investigated. Moreover, most studies of noise in the environment have only taken into account the residential neighborhood. Finally, few studies have taken into account individual/neighborhood confounders in the relationship between noise and hypertension. We performed adjusted multilevel regression analyses using data from the 7,290 participants of the RECORD Study to investigate the associations of outdoor road, rail, air, and RRA traffic noise estimated at the place of residence, at the workplace, and in the neighborhoods around the residence and workplace with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension. Associations were documented between higher outdoor RRA and road traffic noise estimated at the workplace and a higher SBP [+1.36 mm of mercury, 95% confidence interval (CI): +0.12, +2.60 for 65-80 dB(A) vs 30-45 dB(A)] and DBP [+1.07 (95% CI: +0.28, +1.86)], after adjustment for individual/neighborhood confounders. These associations remained after adjustment for risk factors of hypertension. Associations were documented neither with rail traffic noise nor for hypertension. Associations between transportation noise at the workplace and blood pressure (BP) may be attributable to the higher levels of road traffic noise at the workplace than at the residence. To better understand why only noise estimated at the workplace was associated with BP, our future work will combine Global Positioning System (GPS) tracking, assessment of noise levels with sensors, and ambulatory monitoring of BP. PMID:26356373

  5. Road, rail, and air transportation noise in residential and workplace neighborhoods and blood pressure (RECORD Study)

    PubMed Central

    Méline, Julie; Van Hulst, Andraea; Thomas, Frederique; Chaix, Basile

    2015-01-01

    Associations between road traffic noise and hypertension have been repeatedly documented, whereas associations with rail or total road, rail, and air (RRA) traffic noise have rarely been investigated. Moreover, most studies of noise in the environment have only taken into account the residential neighborhood. Finally, few studies have taken into account individual/neighborhood confounders in the relationship between noise and hypertension. We performed adjusted multilevel regression analyses using data from the 7,290 participants of the RECORD Study to investigate the associations of outdoor road, rail, air, and RRA traffic noise estimated at the place of residence, at the workplace, and in the neighborhoods around the residence and workplace with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension. Associations were documented between higher outdoor RRA and road traffic noise estimated at the workplace and a higher SBP [+1.36 mm of mercury, 95% confidence interval (CI): +0.12, +2.60 for 65-80 dB(A) vs 30-45 dB(A)] and DBP [+1.07 (95% CI: +0.28, +1.86)], after adjustment for individual/neighborhood confounders. These associations remained after adjustment for risk factors of hypertension. Associations were documented neither with rail traffic noise nor for hypertension. Associations between transportation noise at the workplace and blood pressure (BP) may be attributable to the higher levels of road traffic noise at the workplace than at the residence. To better understand why only noise estimated at the workplace was associated with BP, our future work will combine Global Positioning System (GPS) tracking, assessment of noise levels with sensors, and ambulatory monitoring of BP. PMID:26356373

  6. Passive Underwater Noise Attenuation Using Large Encapsulated Air Bubbles.

    PubMed

    Lee, Kevin M; Wochner, Mark S; Wilson, Preston S

    2016-01-01

    Measurements demonstrating low-frequency underwater sound attenuation using arrays of large, tethered, stationary encapsulated bubbles to surround a sound source were compared with various effective medium models for the acoustic dispersion relationship in bubbly liquids. Good agreement was observed between measurements for the large bubbles (on the order of 10 cm) at frequencies below 1 kHz and a model originally intended to describe the acoustic behavior of ultrasound contrast agents. The primary goal is to use the model for designing encapsulated-bubble-based underwater noise abatement systems and to reduce uncertainty in system performance. PMID:26611010

  7. Prediction of Turbulent Jet Mixing Noise Reduction by Water Injection

    NASA Technical Reports Server (NTRS)

    Kandula, Max

    2008-01-01

    A one-dimensional control volume formulation is developed for the determination of jet mixing noise reduction due to water injection. The analysis starts from the conservation of mass, momentum and energy for the confrol volume, and introduces the concept of effective jet parameters (jet temperature, jet velocity and jet Mach number). It is shown that the water to jet mass flow rate ratio is an important parameter characterizing the jet noise reduction on account of gas-to-droplet momentum and heat transfer. Two independent dimensionless invariant groups are postulated, and provide the necessary relations for the droplet size and droplet Reynolds number. Results are presented illustrating the effect of mass flow rate ratio on the jet mixing noise reduction for a range of jet Mach number and jet Reynolds number. Predictions from the model show satisfactory comparison with available test data on perfectly expanded hot supersonic jets. The results suggest that significant noise reductions can be achieved at increased flow rate ratios.

  8. Impacts of Noise Barriers on Near-Road Air Quality

    EPA Science Inventory

    Numerous health studies show an increase in adverse health effects for populations near large roadways. A study was designed to assess traffic emission impacts on air quality near a heavily traveled highway. The portion of highway studied included a section of open field and a se...

  9. Influence of traffic-related noise and air pollution on self-reported fatigue.

    PubMed

    Jazani, Reza Khani; Saremi, Mahnaz; Rezapour, Tara; Kavousi, Amir; Shirzad, Hadi

    2015-01-01

    A growing body of evidence suggests that exposure to environmental pollutions is related to health problems. It is, however, questionable whether this condition affects working performance in occupational settings. The aim of this study is to determine the predictive value of age as well as traffic related air and noise pollutions for fatigue. 246 traffic officers participated in this study. Air pollution data were obtained from the local Air Quality Control Company. A sound level meter was used for measuring ambient noise. Fatigue was evaluated by the MFI-20 questionnaire. The general and physical scales showed the highest, while the reduced activity scale showed the lowest level of fatigue. Age had an independent direct effect on reduced activity and physical fatigue. The average of daytime equivalent noise level was between 71.63 and 88.51 dB(A). In the case of high noise exposure, older officers feel more fatigue than younger ones. Exposure to PM10 and O3 resulted in general and physical fatigue. Complex Interactions between SO2, CO and NO2 were found. Exposure to noise and some components of air pollution, especially O3 and PM10, increases fatigue. The authorities should adopt and rigorously implement environmental protection policies in order to protect people. PMID:26323778

  10. Penguin vision in air and water.

    PubMed

    Howland, H C; Sivak, J G

    1984-01-01

    Refractive states measured by retinoscopy and photorefraction indicate that rockhopper (Eudyptes crestatus), Magellanic (Spheniscus magellanicus) and gentoo (Pygoscelis papua) penguins are approximately emmetropic in air and water. Extensive myopia in air, as predicted by early authors, is nonexistent. Photorefractive measurements of refractive state in water indicate that rockhopper, gentoo, Magellanic and king (Aptenodytes patagonica) penguins can accommodate sufficiently to make up for the loss of refractive power of the cornea. Corneas of rockhopper and Megellanic penguins are flattened relative to the overall size of the eye. This feature minimizes the optical effect of submergence. PMID:6534014

  11. Combined air and water pollution control system

    NASA Technical Reports Server (NTRS)

    Wolverton, Billy C. (Inventor); Jarrell, Lamont (Inventor)

    1990-01-01

    A bioaquatic air pollution control system for controlling both water and atmospheric pollution is disclosed. The pollution control system includes an exhaust for directing polluted gases out of a furnace and a fluid circulating system which circulates fluid, such as waste water, from a source, past the furnace where the fluid flow entrains the pollutants from the furnace. The combined fluid and pollutants are then directed through a rock/plant/microbial filtering system. A suction pump pumps the treated waste water from the filter system past the exhaust to again entrain more pollutants from the furnace where they are combined with the fluid (waste water) and directed to the filter system.

  12. Air blast circuit breaker noise and hearing loss: a multifactorial model for risk assessment.

    PubMed

    McBride, D I; Williams, S

    2000-04-01

    The assessment of the risk to hearing from impulse noise exposure may be a problem for the occupational physician because existing legislative and international noise exposure standards deal primarily with continuous noise, and are not valid in excess of the peak exposure limit of 200 pa (140 dB). Noise exposure in excess of this level, for example that due to firearms, is frequently perceived as harmful, but this is not necessarily the case, as impulse noise standards do, in fact, allow exposure with a maximum in the order of 6.3 kPa (170 dB). To illustrate this, a cross-sectional group of electrical transmission workers have been studied who were exposed to significant levels of impulse noise from air blast circuit breakers and firearms. Important hearing loss factors have been identified by means of a specially designed questionnaire. Using the Health & Safety Executive definition, the risk of hearing loss was determined by calculating prevalence odds ratios (ORs) for exposure to these factors. The OR for those with fewer than eight unprotected air blast circuit breaker exposures was 2.27 (95% confidence interval (CI), 1.01-5.08), whilst for those with more than eight exposures the OR was 2.10 (95% CI, 0.97-4.54). For firearm exposure, ORs of 1.61 (95% CI, 0.95-2.74) were noted in the medium exposure group and 2.05 (95% CI, 1.08-3.86) in the high exposure group. When all the factors were included in the model, the most significant factor was age. The study gives support to the impulse noise exposure criteria, confirming the borderline risk from air blast circuit breaker noise exposure and the relative safety of moderate gunfire exposure. PMID:10912360

  13. Quenching using air-water mixtures

    SciTech Connect

    Wallis, R.A.; Garwood, R.; Ward, J.; Xia, Q.

    1996-12-31

    With the current trend toward reduced manufacturing cycle time there is considerable interest in minimizing heat treatment related distortion and the residual stresses that are present in components. There is therefore a need to optimize the quenching process for a particular part such that the desired cooling rate, and hence mechanical properties, are obtained while minimizing distortion. This paper describes work aimed at developing a system to provide heat transfer rates between those obtained for oil quenching and fan cooling. Tests are described in which quenching was carried out by spraying water into the stream of air exiting a fan cooling system. Data are also presented for air mist quenching using atomizing nozzles. Comparison of computer predicted cooling rates and residual stress levels in components are presented for oil quenching, fan cooling, fan plus water injection cooling and air-mist cooling.

  14. Integration of air and water quality issues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The environmental sustainability of dairy farms is dependent upon a number of air and water quality issues. Atmospheric emissions include hazardous compounds such as ammonia and hydrogen sulfide along with greenhouse gases and their implications with global climate change. Runoff of sediment, phosph...

  15. Noise

    MedlinePlus

    Noise is all around you, from televisions and radios to lawn mowers and washing machines. Normally, you ... sensitive structures of the inner ear and cause noise-induced hearing loss. More than 30 million Americans ...

  16. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.1139 Section 84.1139 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and...

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

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.202 Section 84.202 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Chemical...

  18. Ethylene-air detonation in water spray

    NASA Astrophysics Data System (ADS)

    Jarsalé, G.; Virot, F.; Chinnayya, A.

    2016-07-01

    Detonation experiments are conducted in a 52 mm square channel with an ethylene-air gaseous mixture with dispersed liquid water droplets. The tests were conducted with a fuel-air equivalence ratio ranging from 0.9 to 1.1 at atmospheric pressure. An ultrasonic atomizer generates a polydisperse liquid water spray with droplet diameters of 8.5-12 μm, yielding an effective density of 100-120 g/m3 . Pressure signals from seven transducers and cellular structure are recorded for each test. The detonation structure in the two-phase mixture exhibits a gaseous-like behaviour. The pressure profile in the expansion fan is not affected by the addition of water. A small detonation velocity deficit of up to 5 % was measured. However, the investigation highlights a dramatic increase in the cell size (λ ) associated with the increase in the liquid water mass fraction in the two-phase mixture. The detonation structure evolves from a multi-cell to a half-cell mode. The analysis of the decay of the post-shock pressure fluctuations reveals that the ratio of the hydrodynamic thickness over the cell size (x_{{HT}}/{λ } ) remains quite constant, between 5 and 7. A slight decrease of this ratio is observed as the liquid water mass fraction is increased, or the ethylene-air mixture is made leaner.

  19. Measurements of Operational Wind Turbine Noise in UK Waters.

    PubMed

    Cheesman, Samuel

    2016-01-01

    The effects of wind farm operational noise have not been addressed to the same extent as their construction methods such as piling and drilling of the foundations despite their long operational lifetimes compared with weeks of construction. The results of five postconstruction underwater sound-monitoring surveys on wind farms located throughout the waters of the British Isles are discussed. These wind farms consist of differing turbine power outputs, from 3 to 3.6 MW, and differing numbers of turbines. This work presents an overview of the results obtained and discusses both the levels and frequency components of the sound in several metrics. PMID:26610955

  20. The Covariance between Air Pollution Annoyance and Noise Annoyance, and Its Relationship with Health-Related Quality of Life

    PubMed Central

    Shepherd, Daniel; Dirks, Kim; Welch, David; McBride, David; Landon, Jason

    2016-01-01

    Air pollution originating from road traffic is a known risk factor of respiratory and cardiovascular disease (both in terms of chronic and acute effects). While adverse effects on cardiovascular health have also been linked with noise (after controlling for air pollution), noise exposure has been commonly linked to sleep impairment and negative emotional reactions. Health is multi-faceted, both conceptually and operationally; Health-Related Quality of Life (HRQOL) is one of many measures capable of probing health. In this study, we examine pre-collected data from postal surveys probing HRQOL obtained from a variety of urban, suburban, and rural contexts across the North Island of New Zealand. Analyses focus on the covariance between air pollution annoyance and noise annoyances, and their independent and combined effects on HRQOL. Results indicate that the highest ratings of air pollution annoyance and noise annoyances were for residents living close to the motorway, while the lowest were for rural residents. Most of the city samples indicated no significant difference between air pollution- and noise-annoyance ratings, and of all of the correlations between air pollution- and noise-annoyance, the highest were found in the city samples. These findings suggest that annoyance is driven by exposure to environmental factors and not personality characteristics. Analysis of HRQOL indicated that air pollution annoyance predicts greater variability in the physical HRQOL domain while noise annoyance predicts greater variability in the psychological, social and environmental domains. The lack of an interaction effect between air pollution annoyance and noise annoyance suggests that air pollution and noise impact on health independently. These results echo those obtained from objective measures of health and suggest that mitigation of traffic effects should address both air and noise pollution. PMID:27509512

  1. The Covariance between Air Pollution Annoyance and Noise Annoyance, and Its Relationship with Health-Related Quality of Life.

    PubMed

    Shepherd, Daniel; Dirks, Kim; Welch, David; McBride, David; Landon, Jason

    2016-01-01

    Air pollution originating from road traffic is a known risk factor of respiratory and cardiovascular disease (both in terms of chronic and acute effects). While adverse effects on cardiovascular health have also been linked with noise (after controlling for air pollution), noise exposure has been commonly linked to sleep impairment and negative emotional reactions. Health is multi-faceted, both conceptually and operationally; Health-Related Quality of Life (HRQOL) is one of many measures capable of probing health. In this study, we examine pre-collected data from postal surveys probing HRQOL obtained from a variety of urban, suburban, and rural contexts across the North Island of New Zealand. Analyses focus on the covariance between air pollution annoyance and noise annoyances, and their independent and combined effects on HRQOL. Results indicate that the highest ratings of air pollution annoyance and noise annoyances were for residents living close to the motorway, while the lowest were for rural residents. Most of the city samples indicated no significant difference between air pollution- and noise-annoyance ratings, and of all of the correlations between air pollution- and noise-annoyance, the highest were found in the city samples. These findings suggest that annoyance is driven by exposure to environmental factors and not personality characteristics. Analysis of HRQOL indicated that air pollution annoyance predicts greater variability in the physical HRQOL domain while noise annoyance predicts greater variability in the psychological, social and environmental domains. The lack of an interaction effect between air pollution annoyance and noise annoyance suggests that air pollution and noise impact on health independently. These results echo those obtained from objective measures of health and suggest that mitigation of traffic effects should address both air and noise pollution. PMID:27509512

  2. Air backed mandrel type fiber optic hydrophone with low noise floor

    NASA Astrophysics Data System (ADS)

    Rajesh, R.; V, Sreehari C.; N, Praveen Kumar; Awasthi, R. L.; K, Vivek; B, Vishnu M.; Santhanakrishnan, T.; Moosad, K. P. B.; Mathew, Basil

    2014-10-01

    Low noise fiber optic hydrophone based on optical fiber coil wound on air-backed mandrel was developed. The sensor can be effectively used for underwater acoustic sensing. The design and characterization of the hydrophone is illustrated in this paper. A fiber Mach-Zehnder Interferometer (MZI) was developed and coupled with a Distributed Feedback (DFB) fiber laser source and an optical phase demodulation system, with an active modulation in one of the arms. The sensor head design was optimized to achieve noise spectral density <10 μrad/√Hz, for yielding sufficient sensitivity to sense acoustic pressure close to Deep Sea Sate Zero (DSS0).

  3. 14 CFR 1260.34 - Clean air and water.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Clean air and water. 1260.34 Section 1260... AGREEMENTS General Provisions § 1260.34 Clean air and water. Clean Air and Water October 2000 (Applicable... the Clean Air Act (42 U.S.C. 1857c-8(c)(1) or the Federal Water Pollution Control Act (33 U.S.C....

  4. 14 CFR 1260.34 - Clean air and water.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Clean air and water. 1260.34 Section 1260... AGREEMENTS General Provisions § 1260.34 Clean air and water. Clean Air and Water October 2000 (Applicable... the Clean Air Act (42 U.S.C. 1857c-8(c)(1) or the Federal Water Pollution Control Act (33 U.S.C....

  5. 14 CFR 1260.34 - Clean air and water.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Clean air and water. 1260.34 Section 1260... AGREEMENTS General Provisions § 1260.34 Clean air and water. Clean Air and Water October 2000 (Applicable... the Clean Air Act (42 U.S.C. 1857c-8(c)(1) or the Federal Water Pollution Control Act (33 U.S.C....

  6. 14 CFR § 1260.34 - Clean air and water.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Clean air and water. § 1260.34 Section Â... AGREEMENTS General Provisions § 1260.34 Clean air and water. Clean Air and Water October 2000 (Applicable... the Clean Air Act (42 U.S.C. 1857c-8(c)(1) or the Federal Water Pollution Control Act (33 U.S.C....

  7. Airport noise complaint patterns and interviews of frequent complainers at two major air carrier airports

    NASA Astrophysics Data System (ADS)

    Jaggers, Nicholas; Eiff, Gary

    2005-09-01

    The complex and highly sensitive topic of aircraft noise and population annoyance continues to be a major inhibitor to airport development plans. The projected growth of air travel necessitates expanded capacity at many existing airports and the development and construction of new airports in order to accommodate burgeoning traveler needs. Concerns by citizens near major airports about their economic, health, and social welfare continue to generate community and individual declarations of annoyance and concern which threaten timely solutions to airport expansion plans. A deeper understanding of the nature of these concerns is important to more effectively cope with airport expansion concerns among adjacent communities and surrounding neighbors. This study analyzed existing noise complaints registered at Denver International Airport (DEN) and Fort Lauderdale/Hollywood International Airport (FLL) in an attempt to gain greater understanding of noise complaint drivers and public annoyance. Interviews of frequent complainers were utilized in order to gain richer data concerning individual annoyance issues.

  8. Air Force procedure for predicting aircraft noise around airbases: Airbase operations program (BASEOPS) description

    NASA Astrophysics Data System (ADS)

    Lee, Robert A.; Mohlman, Henry T.

    1990-01-01

    A user manual is presented for the BASEOPS 3.00 program developed by AAMRL/BBE. The installation, use and limitations of this program is described. BASEOPS is the menu driven computerized airbase operations input program used in doing airbase noise assessments under the USAF Air Installation Compatible Use Zone (AICUZ) program. BASEOPS will create a file that can be directly interfaced to the NOISEMAP 6.0 program, used to calculate the total noise exposure from these input operations. BASEOPS contains default performance profiles (takeoff and landing) for Military Transient and Civil aircraft. The program also allows the user to create a NOISEMAP input file for any subset of the input data through a Global Editing Menu. This can be used for quickly creating multiple noise analyses for different operational input scenarios.

  9. Noise reduction evaluation of grids in a supersonic air stream with application to Space Shuttle

    NASA Technical Reports Server (NTRS)

    Seiner, J. M.; Manning, J. C.; Nystrom, P.; Pao, S. P.

    1977-01-01

    Near field acoustic measurements were obtained for a model supersonic air jet perturbed by a screen. Noise reduction potential in the vicinity of the space shuttle vehicle during ground launch when the rocket exhaust flow is perturbed by a grid was determined. Both 10 and 12 mesh screens were utilized for this experiment, and each exhibited a noise reduction only at very low frequencies in the near field forward arc. A power spectrum analysis revealed that a modest reduction of from 3 to 5 decibels exists below a Strouhal number S sub t = 0.11. Above S sub t = 0.11 screen harmonics increased the observed sound pressure level. The favorable noise reductions obtained with screens for S sub t 0.11 may be of substantial interest for the space shuttle at ground launch.

  10. USAF Bioenvironmental Noise Data Handbook. Volume 167: MA-3M air conditioner

    NASA Astrophysics Data System (ADS)

    Rau, T. H.

    1982-06-01

    The MA-3M is an electric motor-driven air conditioner designed to cool electronic equipment on aircraft during ground maintenance. This report provides measured and extrapolated data defining the bioacoustic environments produced by this unit operating at a normal rated condition. Near-field data are reported for 37 locations in a wide variety of physical and psychoacoustic measures: overall and band sound pressure levels, C-weighted and A-weighted sound levels, preferred speech interference levels, perceived noise levels, and limiting times for total daily exposure of personnel with and without standard Air Force ear protectors.

  11. Impact of Diwali celebrations on urban air and noise quality in Delhi City, India.

    PubMed

    Mandal, Papiya; Prakash, Mamta; Bassin, J K

    2012-01-01

    A study was conducted in the residential areas of Delhi, India, to assess the variation in ambient air quality and ambient noise levels during pre-Diwali month (DM), Diwali day (DD) and post-Diwali month during the period 2006 to 2008. The use of fireworks during DD showed 1.3 to 4.0 times increase in concentration of respirable particulate matter (PM(10)) and 1.6 to 2.5 times increase in concentration of total suspended particulate matter (TSP) than the concentration during DM. There was a significant increase in sulfur dioxide (SO(2)) concentration but the concentration of nitrogen dioxide (NO(2)) did not show any considerable variation. Ambient noise level were 1.2 to 1.3 times higher than normal day. The study also showed a strong correlation between PM(10) and TSP (R (2) ≥ 0.9) and SO(2) and NO(2) (R (2) ≥ 0.9) on DD. The correlation between noise level and gaseous pollutant were moderate (R (2) ≥ 0.5). The average concentration of the pollutants during DD was found higher in 2007 which could be due to adverse meteorological conditions. The statistical interpretation of data indicated that the celebration of Diwali festival affects the ambient air and noise quality. The study would provide public awareness about the health risks associated with the celebrations of Diwali festival so as to take proper precautions. PMID:21424668

  12. Photodetoxification and purification of water and air

    SciTech Connect

    Anderson, M.; Blake, D.M.

    1996-09-01

    The scope of interest in this section is basic research in photochemistry that can remove barriers to the development of photochemical technologies for the removal of hazardous chemicals from contaminated air or water (photodetoxification). Photochemistry is be broadly interpreted to include direct photochemistry, indirect photochemistry (sensitized and photocatalytic), photochemistry of species adsorbed on inert surfaces, and complementary effects of high energy radiation photons and particles. These may occur in either homogeneous or heterogeneous media. The photon source may span the range from ionizing radiation to the near infrared.

  13. Stable Encapsulated Air Nanobubbles in Water.

    PubMed

    Wang, Yu; Liu, Guojun; Hu, Heng; Li, Terry Yantian; Johri, Amer M; Li, Xiaoyu; Wang, Jian

    2015-11-23

    The dispersion into water of nanocapsules bearing a highly hydrophobic fluorinated internal lining yielded encapsulated air nanobubbles. These bubbles, like their micrometer-sized counterparts (microbubbles), effectively reflected ultrasound. More importantly, the nanobubbles survived under ultrasonication 100-times longer than a commercial microbubble sample that is currently in clinical use. We justify this unprecedented stability theoretically. These nanobubbles, owing to their small size and potential ability to permeate the capillary networks of tissues, may expand the applications of microbubbles in diagnostic ultrasonography and find new applications in ultrasound-regulated drug delivery. PMID:26439669

  14. NBC detection in air and water

    NASA Technical Reports Server (NTRS)

    Hartley, Frank T.; Smith, Steven J.; McMurtry, Gary M.

    2003-01-01

    Participating in a Navy STTR project to develop a system capable of the 'real-time' detection and quanitification of nuclear, biological and chemical (NBC) warfare agents, and of related industrial chemicals including NBC agent synthesis by-products in water and in air immediately above the water's surface. This project uses JPL's Soft Ionization Membrane (SIM) technology which totally ionizes molecules without fragmentation (a process that can markedly improve the sensitivity and specificity of molecule compostition identification), and JPL's Rotating Field Mass Spectrometer (RFMS) technology which has large enough dynamic mass range to enable detection of nuclear materials as well as biological and chemical agents. This Navy project integrates these JPL Environmental Monitoring UnitS (REMUS) an autonomous underwater vehicle (AUV). It is anticipated that the REMUS AUV will be capable of 'real-time' detection and quantification of NBC warefare agents.

  15. Influence of solid noise barriers on near-road and on-road air quality

    NASA Astrophysics Data System (ADS)

    Baldauf, Richard W.; Isakov, Vlad; Deshmukh, Parikshit; Venkatram, Akula; Yang, Bo; Zhang, K. Max

    2016-03-01

    Public health concerns regarding adverse health effects for populations spending significant amounts of time near high traffic roadways has increased substantially in recent years. Roadside features, including solid noise barriers, have been investigated as potential methods that can be implemented in a relatively short time period to reduce air pollution exposures from nearby traffic. A field study was conducted to determine the influence of noise barriers on both on-road and downwind pollutant concentrations near a large highway in Phoenix, Arizona, USA. Concentrations of nitrogen dioxide, carbon monoxide, ultrafine particles, and black carbon were measured using a mobile platform and fixed sites along two limited-access stretches of highway that contained a section of noise barrier and a section with no noise barrier at-grade with the surrounding terrain. Results of the study showed that pollutant concentrations behind the roadside barriers were significantly lower relative to those measured in the absence of barriers. The reductions ranged from 50% within 50 m from the barrier to about 30% as far as 300 m from the barrier. Reductions in pollutant concentrations generally began within the first 50 m of the barrier edge; however, concentrations were highly variable due to vehicle activity behind the barrier and along nearby urban arterial roadways. The concentrations on the highway, upwind of the barrier, varied depending on wind direction. Overall, the on-road concentrations in front of the noise barrier were similar to those measured in the absence of the barrier, contradicting previous modeling results that suggested roadside barriers increase pollutant levels on the road. Thus, this study suggests that noise barriers do reduce potential pollutant exposures for populations downwind of the road, and do not likely increase exposures to traffic-related pollutants for vehicle passengers on the highway.

  16. Wavelet based de-noising of breath air absorption spectra profiles for improved classification by principal component analysis

    NASA Astrophysics Data System (ADS)

    Kistenev, Yu. V.; Shapovalov, A. V.; Borisov, A. V.; Vrazhnov, D. A.; Nikolaev, V. V.; Nikiforova, O. Yu.

    2015-11-01

    The comparison results of different mother wavelets used for de-noising of model and experimental data which were presented by profiles of absorption spectra of exhaled air are presented. The impact of wavelets de-noising on classification quality made by principal component analysis are also discussed.

  17. Proximity to Traffic, Ambient Air Pollution, and Community Noise in Relation to Incident Rheumatoid Arthritis

    PubMed Central

    Koehoorn, Mieke; Tamburic, Lillian; Davies, Hugh W.; Brauer, Michael

    2014-01-01

    Background: The risk of rheumatoid arthritis (RA) has been associated with living near traffic; however, there is evidence suggesting that air pollution may not be responsible for this association. Noise, another traffic-generated exposure, has not been studied as a risk factor for RA. Objectives: We investigated proximity to traffic, ambient air pollution, and community noise in relation to RA in the Vancouver and Victoria regions of British Columbia, Canada. Methods: Cases and controls were identified in a cohort of adults that was assembled using health insurance registration records. Incident RA cases from 1999 through 2002 were identified by diagnostic codes in combination with prescriptions and type of physician (e.g., rheumatologist). Controls were matched to RA cases by age and sex. Environmental exposures were assigned to each member of the study population by their residential postal code(s). We estimated relative risks using conditional logistic regression, with additional adjustment for median income at the postal code. Results: RA incidence was increased with proximity to traffic, with an odds ratio (OR) of 1.37 (95% CI: 1.11, 1.68) for residence ≤ 50 m from a highway compared with residence > 150 m away. We found no association with traffic-related exposures such as PM2.5, nitrogen oxides, or noise. Ground-level ozone, which was highest in suburban areas, was associated with an increased risk of RA (OR = 1.26; 95% CI: 1.18, 1.36 per interquartile range increase). Conclusions: Our study confirms a previously observed association of RA risk with proximity to traffic and suggests that neither noise levels nor traffic-related air pollutants are responsible for this relationship. Additional investigation of neighborhood and individual correlates of residence near roadways may provide new insight into risk factors for RA. Citation: De Roos AJ, Koehoorn M, Tamburic L, Davies HW, Brauer M. 2014. Proximity to traffic, ambient air pollution, and community

  18. Modeling the impact of solid noise barriers on near road air quality

    NASA Astrophysics Data System (ADS)

    Venkatram, Akula; Isakov, Vlad; Deshmukh, Parikshit; Baldauf, Richard

    2016-09-01

    Studies based on field measurements, wind tunnel experiments, and controlled tracer gas releases indicate that solid, roadside noise barriers can lead to reductions in downwind near-road air pollutant concentrations. A tracer gas study showed that a solid barrier reduced pollutant concentrations as much as 80% next to the barrier relative to an open area under unstable meteorological conditions, which corresponds to typical daytime conditions when residents living or children going to school near roadways are most likely to be exposed to traffic emissions. The data from this tracer gas study and a wind tunnel simulation were used to develop a model to describe dispersion of traffic emissions near a highway in the presence of a solid noise barrier. The model is used to interpret real-world data collected during a field study conducted in a complex urban environment next to a large highway in Phoenix, Arizona, USA. We show that the analysis of the data with the model yields useful information on the emission factors and the mitigation impact of the barrier on near-road air quality. The estimated emission factors for the four species, ultrafine particles, CO, NO2, and black carbon, are consistent with data cited in the literature. The results suggest that the model accounted for reductions in pollutant concentrations from a 4.5 m high noise barrier, ranging from 40% next to the barrier to 10% at 300 m from the barrier.

  19. [Utility of noise addition image made by using water phantom and image addition and subtraction software].

    PubMed

    Watanabe, Ryo; Ogawa, Masato; Mituzono, Hiroki; Aoki, Takahiro; Hayano, Mizuho; Watanabe, Yuka

    2010-08-20

    In optimizing exposures, it is very important to evaluate the impact of image noise on image quality. To realize this, there is a need to evaluate how much image noise will make the subject disease invisible. But generally it is very difficult to shoot images of different quality in a clinical examination. Thus, a method to create a noise addition image by adding the image noise to raw data has been reported. However, this approach requires a special system, so it is difficult to implement in many facilities. We have invented a method to easily create a noise addition image by using the water phantom and image add-subtract software that accompanies the device. To create a noise addition image, first we made a noise image by subtracting the water phantom with different SD. A noise addition image was then created by adding the noise image to the original image. By using this method, a simulation image with intergraded SD can be created from the original. Moreover, the noise frequency component of the created noise addition image is as same as the real image. Thus, the relationship of image quality to SD in the clinical image can be evaluated. Although this method is an easy method of LDSI creation on image data, a noise addition image can be easily created by using image addition and subtraction software and water phantom, and this can be implemented in many facilities. PMID:20953102

  20. 21 CFR 874.1800 - Air or water caloric stimulator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Air or water caloric stimulator. 874.1800 Section 874.1800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1800 Air or water caloric stimulator. (a) Identification. An air or...

  1. 14 CFR 1260.34 - Clean air and water.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Clean air and water. 1260.34 Section 1260.34... Provisions § 1260.34 Clean air and water. Clean Air and Water October 2000 (Applicable only if the award... (42 U.S.C. 1857c-8(c)(1) or the Federal Water Pollution Control Act (33 U.S.C. 1319(c)), and is...

  2. A PIV Study of Slotted Air Injection for Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda S.; Wernet, Mark P.

    2012-01-01

    Results from acoustic and Particle Image Velocimetry (PIV) measurements are presented for single and dual-stream jets with fluidic injection on the core stream. The fluidic injection nozzles delivered air to the jet through slots on the interior of the nozzle at the nozzle trailing edge. The investigations include subsonic and supersonic jet conditions. Reductions in broadband shock noise and low frequency mixing noise were obtained with the introduction of fluidic injection on single stream jets. Fluidic injection was found to eliminate shock cells, increase jet mixing, and reduce turbulent kinetic energy levels near the end of the potential core. For dual-stream subsonic jets, the introduction of fluidic injection reduced low frequency noise in the peak jet noise direction and enhanced jet mixing. For dual-stream jets with supersonic fan streams and subsonic core streams, the introduction of fluidic injection in the core stream impacted the jet shock cell structure but had little effect on mixing between the core and fan streams.

  3. Effect of long-term outdoor air pollution and noise on cognitive and psychological functions in adults.

    PubMed

    Tzivian, Lilian; Winkler, Angela; Dlugaj, Martha; Schikowski, Tamara; Vossoughi, Mohammad; Fuks, Kateryna; Weinmayr, Gudrun; Hoffmann, Barbara

    2015-01-01

    It has been hypothesized that air pollution and ambient noise might impact neurocognitive function. Early studies mostly investigated the associations of air pollution and ambient noise exposure with cognitive development in children. More recently, several studies investigating associations with neurocognitive function, mood disorders, and neurodegenerative disease in adult populations were published, yielding inconsistent results. The purpose of this review is to summarize the current evidence on air pollution and noise effects on mental health in adults. We included studies in adult populations (≥18 years old) published in English language in peer-reviewed journals. Fifteen articles related to long-term effects of air pollution and eight articles on long-term effects of ambient noise were extracted. Both exposures were separately shown to be associated with one or several measures of global cognitive function, verbal and nonverbal learning and memory, activities of daily living, depressive symptoms, elevated anxiety, and nuisance. No study considered both exposures simultaneously and few studies investigated progression of neurocognitive decline or psychological factors. The existing evidence generally supports associations of environmental factors with mental health, but does not suffice for an overall conclusion about the independent effect of air pollution and noise. There is a need for studies investigating simultaneously air pollution and noise exposures in association mental health, for longitudinal studies to corroborate findings from cross-sectional analyses, and for parallel toxicological and epidemiological studies to elucidate mechanisms and pathways of action. PMID:25242804

  4. Estimation of Broadband Shock Noise Reduction in Turbulent Jets by Water Injection

    NASA Technical Reports Server (NTRS)

    Kandula, Max; Lonerjan, Michael J.

    2008-01-01

    The concept of effective jet properties introduced by the authors (AIAA-2007-3645) has been extended to the estimation of broadband shock noise reduction by water injection in supersonic jets. Comparison of the predictions with the test data for cold underexpanded supersonic nozzles shows a satisfactory agreement. The results also reveal the range of water mass flow rates over which saturation of mixing noise reduction and existence of parasitic noise are manifest.

  5. Spatial and temporal associations of road traffic noise and air pollution in London: Implications for epidemiological studies.

    PubMed

    Fecht, Daniela; Hansell, Anna L; Morley, David; Dajnak, David; Vienneau, Danielle; Beevers, Sean; Toledano, Mireille B; Kelly, Frank J; Anderson, H Ross; Gulliver, John

    2016-03-01

    Road traffic gives rise to noise and air pollution exposures, both of which are associated with adverse health effects especially for cardiovascular disease, but mechanisms may differ. Understanding the variability in correlations between these pollutants is essential to understand better their separate and joint effects on human health. We explored associations between modelled noise and air pollutants using different spatial units and area characteristics in London in 2003-2010. We modelled annual average exposures to road traffic noise (LAeq,24h, Lden, LAeq,16h, Lnight) for ~190,000 postcode centroids in London using the UK Calculation of Road Traffic Noise (CRTN) method. We used a dispersion model (KCLurban) to model nitrogen dioxide, nitrogen oxide, ozone, total and the traffic-only component of particulate matter ≤2.5μm and ≤10μm. We analysed noise and air pollution correlations at the postcode level (~50 people), postcodes stratified by London Boroughs (~240,000 people), neighbourhoods (Lower layer Super Output Areas) (~1600 people), 1km grid squares, air pollution tertiles, 50m, 100m and 200m in distance from major roads and by deprivation tertiles. Across all London postcodes, we observed overall moderate correlations between modelled noise and air pollution that were stable over time (Spearman's rho range: |0.34-0.55|). Correlations, however, varied considerably depending on the spatial unit: largest ranges were seen in neighbourhoods and 1km grid squares (both Spearman's rho range: |0.01-0.87|) and was less for Boroughs (Spearman's rho range: |0.21-0.78|). There was little difference in correlations between exposure tertiles, distance from road or deprivation tertiles. Associations between noise and air pollution at the relevant geographical unit of analysis need to be carefully considered in any epidemiological analysis, in particular in complex urban areas. Low correlations near roads, however, suggest that independent effects of road noise and

  6. The spatial relationship between traffic-generated air pollution and noise in 2 US cities☆

    PubMed Central

    Allen, Ryan W.; Davies, Hugh; Cohen, Martin A.; Mallach, Gary; Kaufman, Joel D.; Adar, Sara D.

    2011-01-01

    Traffic-generated air pollution and noise have both been linked to cardiovascular morbidity. Since traffic is a shared source, there is potential for correlated exposures that may lead to confounding in epidemiologic studies. As part of the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air), 2-week NO and NO2 concentrations were measured at up to 105 locations, selected primarily to characterize gradients near major roads, in each of 9 US communities. We measured 5-min A-weighted equivalent continuous sound pressure levels (Leq) and ultrafine particle (UFP) counts at a subset of these NO/NO2 monitoring locations in Chicago, IL (N = 69 in December 2006; N = 36 in April 2007) and Riverside County, CA (N = 46 in April 2007). Leq and UFP were measured during non-“rush hour” periods (10:00–16:00) to maximize comparability between measurements. We evaluated roadway proximity exposure surrogates in relation to the measured levels, estimated noise–air pollution correlation coefficients, and evaluated the impact of regional-scale pollution gradients, wind direction, and roadway proximity on the correlations. Five-minute Leq measurements in December 2006 and April 2007 were highly correlated (r = 0.84), and measurements made at different times of day were similar (coefficients of variation: 0.5–13%), indicating that 5-min measurements are representative of long-term Leq. Binary and continuous roadway proximity metrics characterized Leq as well or better than NO or NO2. We found strong regional-scale gradients in NO and NO2, particularly in Chicago, but only weak regional-scale gradients in Leq and UFP. Leq was most consistently correlated with NO, but the correlations were moderate (0.20–0.60). After removing the influence of regional-scale gradients the correlations generally increased (Leq–NO: r = 0.49–0.62), and correlations downwind of major roads (Leq–NO: r = 0.53–0.74) were consistently higher than those upwind (0.35–0.65). There

  7. Food-Growing, Air- And Water-Cleaning Module

    NASA Technical Reports Server (NTRS)

    Sauer, R. L.; Scheld, H. W.; Mafnuson, J. W.

    1988-01-01

    Apparatus produces fresh vegetables and removes pollutants from air. Hydroponic apparatus performs dual function of growing fresh vegetables and purifying air and water. Leafy vegetables rooted in granular growth medium grow in light of fluorescent lamps. Air flowing over leaves supplies carbon dioxide and receives fresh oxygen from them. Adaptable to production of food and cleaning of air and water in closed environments as in underwater research stations and submarines.

  8. Perceptual assessment of quality of urban soundscapes with combined noise sources and water sounds.

    PubMed

    Jeon, Jin Yong; Lee, Pyoung Jik; You, Jin; Kang, Jian

    2010-03-01

    In this study, urban soundscapes containing combined noise sources were evaluated through field surveys and laboratory experiments. The effect of water sounds on masking urban noises was then examined in order to enhance the soundscape perception. Field surveys in 16 urban spaces were conducted through soundwalking to evaluate the annoyance of combined noise sources. Synthesis curves were derived for the relationships between noise levels and the percentage of highly annoyed (%HA) and the percentage of annoyed (%A) for the combined noise sources. Qualitative analysis was also made using semantic scales for evaluating the quality of the soundscape, and it was shown that the perception of acoustic comfort and loudness was strongly related to the annoyance. A laboratory auditory experiment was then conducted in order to quantify the total annoyance caused by road traffic noise and four types of construction noise. It was shown that the annoyance ratings were related to the types of construction noise in combination with road traffic noise and the level of the road traffic noise. Finally, water sounds were determined to be the best sounds to use for enhancing the urban soundscape. The level of the water sounds should be similar to or not less than 3 dB below the level of the urban noises. PMID:20329835

  9. 77 FR 18297 - Air Traffic Noise, Fuel Burn, and Emissions Modeling Using the Aviation Environmental Design Tool...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-27

    ... Federal Aviation Administration Air Traffic Noise, Fuel Burn, and Emissions Modeling Using the Aviation... methodology for performing air quality analysis modeling for aviation sources.'' Section 2.4d states that... using the most recent EDMS model available at the start of the environmental analysis process.'' ]...

  10. Methylglyoxal at the Air-Water Interface

    NASA Astrophysics Data System (ADS)

    Wren, S. N.; Gordon, B. P.; McWilliams, L.; Valley, N. A.; Richmond, G.

    2014-12-01

    Recently, it has been suggested that aqueous-phase processing of atmospheric α-dicarbonyl compounds such as methylglyoxal (MG) could constitute an important source of secondary organic aerosol (SOA). The uptake of MG to aqueous particles is higher than expected due to the fact that its carbonyl moieties can hydrate to form diols, as well as the fact that MG can undergo aldol condensation reactions to form larger oligomers in solution. MG is known to be surface active but an improved description of its surface behaviour is crucial to understanding MG-SOA formation, in addition to understanding its gas-to-particle partitioning and cloud forming potential. Here, we employ a combined experimental and theoretical approach involving vibrational sum frequency generation spectroscopy (VSFS), surface tensiometry, molecular dynamics simulations, and density functional theory calculations to study MG's surface adsorption, in both the presence and absence of salts. We are particularly interested in determining MG's hydration state at the surface. Our experimental results indicate that MG slowly adsorbs to the air-water interface and strongly perturbs the water structure there. This perturbation is enhanced in the presence of NaCl. Together our experimental and theoretical results suggest that singly-hydrated MG is the dominant form of MG at the surface.

  11. Air flow measurement techniques applied to noise reduction of a centrifugal blower

    NASA Astrophysics Data System (ADS)

    Laage, John W.; Armstrong, Ashli J.; Eilers, Daniel J.; Olsen, Michael G.; Mann, J. Adin

    2005-09-01

    The air flow in a centrifugal blower was studied using a variety of flow and sound measurement techniques. The flow measurement techniques employed included Particle Image Velocimetry (PIV), pitot tubes, and a five hole spherical probe. PIV was used to measure instantaneous and ensemble-averaged velocity fields over large area of the outlet duct as a function of fan position, allowing for the visualization of the flow as it leave the fan blades and progressed downstream. The results from the flow measurements were reviewed along side the results of the sound measurements with the goal of identifying sources of noise and inefficiencies in flow performance. The radiated sound power was divided into broadband and tone noise and measures of the flow. The changes in the tone and broadband sound were compared to changes in flow quantities such as the turbulent kinetic energy and Reynolds stress. Results for each method will be presented to demonstrate the strengths of each flow measurement technique as well as their limitations. Finally, the role that each played in identifying noise sources is described.

  12. 21 CFR 874.1800 - Air or water caloric stimulator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1800 Air or water caloric... or water to the ear canal at controlled rates of flow and temperature and that is intended...

  13. 21 CFR 874.1800 - Air or water caloric stimulator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1800 Air or water caloric... or water to the ear canal at controlled rates of flow and temperature and that is intended...

  14. 21 CFR 874.1800 - Air or water caloric stimulator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1800 Air or water caloric... or water to the ear canal at controlled rates of flow and temperature and that is intended...

  15. 21 CFR 874.1800 - Air or water caloric stimulator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1800 Air or water caloric... or water to the ear canal at controlled rates of flow and temperature and that is intended...

  16. Annoyance Caused by Noise and Air Pollution during Pregnancy: Associated Factors and Correlation with Outdoor NO2 and Benzene Estimations

    PubMed Central

    Fernández-Somoano, Ana; Llop, Sabrina; Aguilera, Inmaculada; Tamayo-Uria, Ibon; Martínez, María Dolores; Foraster, Maria; Ballester, Ferran; Tardón, Adonina

    2015-01-01

    This study aimed to describe the degree of annoyance among pregnant women in a Spanish cohort and to examine associations with proximity to traffic, NO2 and benzene exposure. We included 2457 participants from the Spanish Childhood and Environment study. Individual exposures to outdoor NO2 and benzene were estimated, temporally adjusted for pregnancy. Interviews about sociodemographic variables, noise and air pollution were carried out. Levels of annoyance were assessed using a scale from 0 (none) to 10 (strong and unbearable); a level of 8 to 10 was considered high. The reported prevalence of high annoyance levels from air pollution was 11.2% and 15.0% from noise; the two variables were moderately correlated (0.606). Significant correlations between NO2 and annoyance from air pollution (0.154) and that from noise (0.181) were observed. Annoyance owing to noise and air pollution had a low prevalence in our Spanish population compared with other European populations. Both factors were associated with proximity to traffic. In multivariate models, annoyance from air pollution was related to NO2, building age, and country of birth; annoyance from noise was only related to the first two. The health burden of these exposures can be increased by stress caused by the perception of pollution sources. PMID:26095869

  17. Annoyance Caused by Noise and Air Pollution during Pregnancy: Associated Factors and Correlation with Outdoor NO2 and Benzene Estimations.

    PubMed

    Fernández-Somoano, Ana; Llop, Sabrina; Aguilera, Inmaculada; Tamayo-Uria, Ibon; Martínez, María Dolores; Foraster, Maria; Ballester, Ferran; Tardón, Adonina

    2015-06-01

    This study aimed to describe the degree of annoyance among pregnant women in a Spanish cohort and to examine associations with proximity to traffic, NO2 and benzene exposure. We included 2457 participants from the Spanish Childhood and Environment study. Individual exposures to outdoor NO2 and benzene were estimated, temporally adjusted for pregnancy. Interviews about sociodemographic variables, noise and air pollution were carried out. Levels of annoyance were assessed using a scale from 0 (none) to 10 (strong and unbearable); a level of 8 to 10 was considered high. The reported prevalence of high annoyance levels from air pollution was 11.2% and 15.0% from noise; the two variables were moderately correlated (0.606). Significant correlations between NO2 and annoyance from air pollution (0.154) and that from noise (0.181) were observed. Annoyance owing to noise and air pollution had a low prevalence in our Spanish population compared with other European populations. Both factors were associated with proximity to traffic. In multivariate models, annoyance from air pollution was related to NO2, building age, and country of birth; annoyance from noise was only related to the first two. The health burden of these exposures can be increased by stress caused by the perception of pollution sources. PMID:26095869

  18. Method and apparatus for extracting water from air

    DOEpatents

    Spletzer, Barry L.; Callow, Diane Schafer; Marron, Lisa C.; Salton, Jonathan R.

    2002-01-01

    The present invention provides a method and apparatus for extracting liquid water from moist air using minimal energy input. The method comprises compressing moist air under conditions that foster the condensation of liquid water. The air can be decompressed under conditions that do not foster the vaporization of the condensate. The decompressed, dried air can be exchanged for a fresh charge of moist air and the process repeated. The liquid condensate can be removed for use. The apparatus can comprise a compression chamber having a variable internal volume. An intake port allows moist air into the compression chamber. An exhaust port allows dried air out of the compression chamber. A condensation device fosters condensation at the desired conditions. A condensate removal port allows liquid water to be removed.

  19. Method and apparatus for extracting water from air

    DOEpatents

    Spletzer, Barry L.

    2001-01-01

    The present invention provides a method and apparatus for extracting liquid water from moist air using minimal energy input. The method comprises compressing moist air under conditions that foster the condensation of liquid water (ideally isothermal to a humidity of 1.0, then adiabatic thereafter). The air can be decompressed under conditions that do not foster the vaporization of the condensate. The decompressed, dried air can be exchanged for a fresh charge of moist air and the process repeated. The liquid condensate can be removed for use. The apparatus can comprise a compression chamber having a variable internal volume. An intake port allows moist air into the compression chamber. An exhaust port allows dried air out of the compression chamber. A condensation device fosters condensation at the desired conditions. A condensate removal port allows liquid water to be removed.

  20. Linking Air, Land, and Water Pollution for Effective Environmental Management

    EPA Science Inventory

    Since the passage of the National Environmental Policy Act in 1970, the U.S. Environmental Protection Agency, other federal agencies, and the states have made substantial progress in improving the Nation’s air and water quality. Traditionally, the air, land, and water pollution ...

  1. Large Field of View PIV Measurements of Air Entrainment by SLS SMAT Water Sound Suppression System

    NASA Astrophysics Data System (ADS)

    Stegmeir, Matthew; Pothos, Stamatios; Bissell, Dan

    2015-11-01

    Water-based sound suppressions systems have been used to reduce the acoustic impact of space vehicle launches. Water flows at a high rate during launch in order to suppress Engine Generated Acoustics and other potentially damaging sources of noise. For the Space Shuttle, peak flow rates exceeded 900,000 gallons per minute. Such large water flow rates have the potential to induce substantial entrainment of the surrounding air, affecting the launch conditions and generating airflow around the launch vehicle. Validation testing is necessary to quantify this impact for future space launch systems. In this study, PIV measurements were performed to map the flow field above the SMAT sub-scale launch vehicle scaled launch stand. Air entrainment effects generated by a water-based sound suppression system were studied. Mean and fluctuating fluid velocities were mapped up to 1m above the test stand deck and compared to simulation results. Measurements performed with NASA MSFC.

  2. Airport noise

    NASA Technical Reports Server (NTRS)

    Pendley, R. E.

    1982-01-01

    The problem of airport noise at several airports and air bases is detailed. Community reactions to the noise, steps taken to reduce jet engine noise, and the effect of airport use restrictions and curfews on air transportation are discussed. The adverse effect of changes in allowable operational noise on airport safety and altenative means for reducing noise pollution are considered. Community-airport relations and public relations are discussed.

  3. Thermodynamic and transport properties of air/water mixtures

    NASA Technical Reports Server (NTRS)

    Fessler, T. E.

    1981-01-01

    Subroutine WETAIR calculates properties at nearly 1,500 K and 4,500 atmospheres. Necessary inputs are assigned values of combinations of density, pressure, temperature, and entropy. Interpolation of property tables obtains dry air and water (steam) properties, and simple mixing laws calculate properties of air/water mixture. WETAIR is used to test gas turbine engines and components operating in relatively humid air. Program is written in SFTRAN and FORTRAN.

  4. A study of the prediction of cruise noise and laminar flow control noise criteria for subsonic air transports

    NASA Technical Reports Server (NTRS)

    Swift, G.; Mungur, P.

    1979-01-01

    General procedures for the prediction of component noise levels incident upon airframe surfaces during cruise are developed. Contributing noise sources are those associated with the propulsion system, the airframe and the laminar flow control (LFC) system. Transformation procedures from the best prediction base of each noise source to the transonic cruise condition are established. Two approaches to LFC/acoustic criteria are developed. The first is a semi-empirical extension of the X-21 LFC/acoustic criteria to include sensitivity to the spectrum and directionality of the sound field. In the second, the more fundamental problem of how sound excites boundary layer disturbances is analyzed by deriving and solving an inhomogeneous Orr-Sommerfeld equation in which the source terms are proportional to the production and dissipation of sound induced fluctuating vorticity. Numerical solutions are obtained and compared with corresponding measurements. Recommendations are made to improve and validate both the cruise noise prediction methods and the LFC/acoustic criteria.

  5. AFFECT OF NEW BLADES ON NOISE REDUCTION OF SMALL WIND TURBINE WATER PUMPING SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acoustical noise data were collected on small wind turbines used for water pumping -- different blade designs were tested on each wind turbine. Three different blade designs were tested on 1 kW wind turbines and each successive blade design was shown to produce less noise with respect to rotor spee...

  6. Gas and liquid measurements in air-water bubbly flows

    SciTech Connect

    Zhou, X.; Doup, B.; Sun, X.

    2012-07-01

    Local measurements of gas- and liquid-phase flow parameters are conducted in an air-water two-phase flow loop. The test section is a vertical pipe with an inner diameter of 50 mm and a height of 3.2 m. The measurements are performed at z/D = 10. The gas-phase measurements are performed using a four-sensor conductivity probe. The data taken from this probe are processed using a signal processing program to yield radial profiles of the void fraction, bubble velocity, and interfacial area concentration. The velocity measurements of the liquid-phase are performed using a state-of-the-art Particle Image Velocimetry (PIV) system. The raw PIV images are acquired using fluorescent particles and an optical filtration device. Image processing is used to remove noise in the raw PIV images. The statistical cross correlation is introduced to determine the axial velocity field and turbulence intensity of the liquid-phase. Measurements are currently being performed at z/D = 32 to provide a more complete data set. These data can be used for computational fluid dynamic model development and validation. (authors)

  7. Regional Variations and Trends in Ambient Noise: Examples from Australian Waters.

    PubMed

    McCauley, Robert D; Cato, Douglas H; Duncan, Alec J

    2016-01-01

    Studies of ambient noise south of Australia show higher levels at low frequencies in the deep water off the continental shelf compared with locations on the shelf. The difference arises because of differences in transmission loss. Marine animals would experience significantly different noise levels and directionality in the two regions and while crossing the boundary, provide positional information. Opportunities for long-range, low-frequency communication by animals would be significantly limited by the higher background noise in the open ocean. Measures of long-term sea noise trends highlight the influence of biological sources and the importance of local sound transmission regimens. PMID:26611020

  8. 9. Water Purification System and Instrument Air Receiver Tank, view ...

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

    9. Water Purification System and Instrument Air Receiver Tank, view to the south. The water purification system is visible in the right foreground of the photograph and the instrument air receiver tank is visible in the right background of the photograph. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  9. Acoustical and perceptual assessment of water sounds and their use over road traffic noise.

    PubMed

    Galbrun, Laurent; Ali, Tahrir T

    2013-01-01

    This paper examines physical and perceptual properties of water sounds generated by small to medium sized water features that have applications for road traffic noise masking. A large variety of water sounds were produced in the laboratory by varying design parameters. Analysis showed that estimations can be made on how these parameters affect sound pressure levels, frequency content, and psychoacoustic properties. Comparisons with road traffic noise showed that there is a mismatch between the frequency responses of traffic noise and water sounds, with the exception of waterfalls with high flow rates, which can generate large low frequency levels comparable to traffic noise. Perceptual assessments were carried out in the context of peacefulness and relaxation, where both water sounds and noise from dense road traffic were audible. Results showed that water sounds should be similar or not less than 3 dB below the road traffic noise level (confirming previous research), and that stream sounds tend to be preferred to fountain sounds, which are in turn preferred to waterfall sounds. Analysis made on groups of sounds also indicated that low sharpness and large temporal variations were preferred on average, although no acoustical or psychoacoustical parameter correlated well with the individual sound preferences. PMID:23297897

  10. Associations between Traffic Noise, Particulate Air Pollution, Hypertension, and Isolated Systolic Hypertension in Adults: The KORA Study

    PubMed Central

    Wolf, Kathrin; Petz, Markus; Heinrich, Joachim; Cyrys, Josef; Peters, Annette

    2014-01-01

    Background: Studies on the association between traffic noise and cardiovascular diseases have rarely considered air pollution as a covariate in the analyses. Isolated systolic hypertension has not yet been in the focus of epidemiological noise research. Methods: The association between traffic noise (road and rail) and the prevalence of hypertension was assessed in two study populations with a total of 4,166 participants 25–74 years of age. Traffic noise (weighted day–night average noise level; LDN) at the facade of the dwellings was derived from noise maps. Annual average PM2.5 mass concentrations at residential addresses were estimated by land-use regression. Hypertension was assessed by blood pressure readings, self-reported doctor-diagnosed hypertension, and antihypertensive drug intake. Results: In the Greater Augsburg, Germany, study population, traffic noise and air pollution were not associated with hypertension. In the City of Augsburg population (n = 1,893), where the exposure assessment was more detailed, the adjusted odds ratio (OR) for a 10-dB(A) increase in noise was 1.16 (95% CI: 1.00, 1.35), and 1.11 (95% CI: 0.94, 1.30) after additional adjustment for PM2.5. The adjusted OR for a 1-μg/m3 increase in PM2.5 was 1.15 (95% CI: 1.02, 1.30), and 1.11 (95% CI: 0.98, 1.27) after additional adjustment for noise. For isolated systolic hypertension, the fully adjusted OR for noise was 1.43 (95% CI: 1.10, 1.86) and for PM2.5 was 1.08 (95% CI: 0.87, 1.34). Conclusions: Traffic noise and PM2.5 were both associated with a higher prevalence of hypertension. Mutually adjusted associations with hypertension were positive but no longer statistically significant. Citation: Babisch W, Wolf K, Petz M, Heinrich J, Cyrys J, Peters A. 2014. Associations between traffic noise, particulate air pollution, hypertension, and isolated systolic hypertension in adults: the KORA Study. Environ Health Perspect 122:492–498; http://dx.doi.org/10.1289/ehp.1306981 PMID:24602804

  11. Environmental Resources of Selected Areas of Hawaii: Climate, Ambient Air Quality, and Noise (DRAFT)

    SciTech Connect

    Lombardi, D.A.; Blasing, T.J.; Easterly, C.E.; Hamilton, C.B.

    1994-06-01

    This report has been prepared to make available and archive background scientific data and related information on climate, ambient air quality, and ambient noise levels collected during the preparation of the environmental impact statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of hawaii in its April 1989 proposal to Congress. The US Department of Energy (DOE) published a notice in the Federal Register on May 17, 1994 withdrawing its Notice of Intent of February 14, 1992, to prepare the HGP-EIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. The report presents a general description of the climate and air quality for the islands of Hawaii (henceforth referred to as Hawaii), Maui, and Oahu. It also presents a literature review as baseline information on the health effects of hydrogen sulfide. the scientific background data and related information is being made available for use by others in conducting future scientific research in these areas. This report describes the environmental resources present in the areas studied (i.e., the affected environment) and does not represent an assessment of environmental impacts.

  12. Environmental resources of selected areas of Hawaii: Climate, ambient air quality, and noise

    SciTech Connect

    Lombardi, D.A.; Blasing, T.J.; Easterly, C.E.; Reed, R.M.; Hamilton, C.B.

    1995-03-01

    This report has been prepared to make available and archive background scientific data and related information on climate, ambient air quality, and ambient noise levels collected during the preparation of the environmental impact statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of Hawaii in its April 1989 proposal to Congress. The US Department of Energy (DOE) published a notice withdrawing its Notice of Intent to prepare the HGP-EIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. The report presents a general description of the climate add air quality for the islands of Hawaii (henceforth referred to as Hawaii), Maui and Oahu. It also presents a literature review as baseline information on the health effects of sulfide. The scientific background data and related information is being made available for use by others in conducting future scientific research in these areas. This report describes the environmental resources present in the areas studied (i.e., the affected environment) and does not represent an assessment of environmental impacts.

  13. 32 CFR 256.10 - Air installations compatible use zone noise descriptors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... noise contours and these noise contours shall be plotted on maps accompanying AICUZ studies. (c) Where... used, data shall be collected sufficient to permit computation of Ldn 75 noise contours and these noise contours shall be plotted on maps accompanying AICUZ studies. (d) Where previous studies have used CNR...

  14. Energy and Environment 1990: Transportation-induced noise and air pollution

    SciTech Connect

    Not Available

    1990-01-01

    Contents: public reaction to low levels of aircraft noise; airport noise insulation of homes surrounding stapleton international airport; sound insulation and thermal performance modifications: case study for three dwellings near bwi airport; single-number ratings for outdoor-indoor sound insulation; control of wheel squeal noise in rail transit cars; knowledge-based preprocessor for traffic noise prediction; barrier overlap analysis procedure; atmospheric effects on traffic noise propagation; predicting stop-and-go traffic noise with stamina 2.0; feasibility of transparent noise barriers; field testing of the effectiveness of open-graded asphalt pavement in reducing tire noise from highway vehicles; cost of noise barrier construction in the united states; comparisons of emissions of transit buses using methanol and diesel fuel; high-speed rail system noise assessment; energy-related, environmental, and economic benefits of florida's high-speed rail and maglev systems proposals.

  15. 18 CFR 1316.5 - Clean Air and Water Acts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Conditions and Certifications § 1316.5 Clean Air and Water Acts. When so indicated in TVA contract documents... Acts. 1316.5 Section 1316.5 Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY... Water Acts (a) If performance of this contract would involve the use of facilities which have given...

  16. 18 CFR 1316.5 - Clean Air and Water Acts.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Conditions and Certifications § 1316.5 Clean Air and Water Acts. When so indicated in TVA contract documents... Acts. 1316.5 Section 1316.5 Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY... Water Acts (a) If performance of this contract would involve the use of facilities which have given...

  17. Forced convection heat transfer to air/water vapor mixtures

    NASA Technical Reports Server (NTRS)

    Richards, D. R.; Florschuetz, L. W.

    1986-01-01

    Heat transfer coefficients were measured using both dry air and air/water vapor mixtures in the same forced convection cooling test rig (jet array impingement configurations) with mass ratios of water vapor to air up to 0.23. The primary objective was to verify by direct experiment that selected existing methods for evaluation of viscosity and thermal conductivity of air/water vapor mixtures could be used with confidence to predict heat transfer coefficients for such mixtures using as a basis heat transfer data for dry air only. The property evaluation methods deemed most appropriate require as a basis a measured property value at one mixture composition in addition to the property values for the pure components.

  18. Evaluation of the effects of exposure to organic solvents and hazardous noise among US Air Force Reserve personnel.

    PubMed

    Hughes, Hayley; Hunting, Katherine L

    2013-01-01

    Hearing loss affects many workers including those in the military and may be caused by noise, medications, and chemicals. Exposures to some chemicals may lead to an increase in the incidence of hearing loss when combined with hazardous noise. This retrospective study evaluated the risk for hearing loss among Air Force Reserve personnel exposed to occupational noise with and without exposures to toluene, styrene, xylene, benzene, and JP-8 (jet fuel). Risk factors associated with hearing loss were determined using logistic and linear regression. Stratified analysis was used to evaluate potential interaction between solvent and noise exposure. The majority of the subjects were male (94.6%) and 35 years or older on the date of their first study audiogram (66%). Followed for an average of 3.2 years, 9.2% of the study subjects had hearing loss in at least one ear. Increasing age (odds ratio [OR] = 1.03 per year of age) and each year of follow-up time (OR = 1.23) were significantly associated with hearing loss. Low and moderate solvent exposures were not associated with hearing loss. Linear regression demonstrated that hearing loss was significantly associated with age at first study audiogram, length of follow-up time, and exposure to noise. Hearing decreased by 0.04 decibels for every decibel increase in noise level or by almost half a decibel (0.4 dB) for every 10 decibel increase in noise level. PMID:24231416

  19. Overweight, air and noise pollution: Universal risk factors for pediatric pre-hypertension

    PubMed Central

    Kelishadi, Roya; Poursafa, Parinaz; Keramatian, Kasra

    2011-01-01

    Pediatric pre-hypertension (pre-HTN) has a complex multifactorial etiology. Although most cases are secondary to other disorders, a substantial number of children and adolescents have primary or essential HTN and pre-HTN. The gene-gene and gene-environment interactions should be considered in this context. The strong relationship of pre-HTN with environmental factors such as air pollution, noise pollution and passive smoking and obesity suggest that its prevalence will be escalating. Exposure to ambient particulate matters may increase blood pressure (BP) within hours to days. The underlying biologic pathways include autonomic nervous system imbalance and arterial vascular dysfunction or vasoconstriction because of systemic oxidative stress and inflammation. Likewise, tobacco smoke exposure of pregnant mothers increases systolic BP of their offspring in early infancy. Parental smoking also independently affects systolic BP among healthy preschool children. Noise exposure, notably in night, is associated with catecholamine secretion, increased BP and a pre-HTN state even in pre-school age children. Excess weight is associated with dysfunction of the adipose tissue, consisting of enlarged hypertrophied adipocytes, increased infiltration by macrophages and variations in secretion of adipokines and free fatty acids. These changes would result in chronic vascular inflammation, oxidative stress, activation of the renin-angiotensin-aldosterone system and sympathetic response, and ultimately to pre-HTN from childhood. Prevention and control of the modifiable risk factors of pre-HTN from prenatal period can have long-term health impact on primordial and primary prevention of chronic non-communicable diseases. This review presents a general view on the diagnosis, prevalence and etiology of pre-HTN along with practical measures for its prevention and control. PMID:22973395

  20. Specific features of aluminum nanoparticle water and wet air oxidation

    SciTech Connect

    Lozhkomoev, Aleksandr S. Glazkova, Elena A. Svarovskaya, Natalia V. Bakina, Olga V. Kazantsev, Sergey O. Lerner, Marat I.

    2015-10-27

    The oxidation processes of the electrically exploded aluminum nanopowders in water and in wet air are examined in the paper. The morphology of the intermediate reaction products of aluminum oxidation has been studied using the transmission electron microscopy. It was shown that the aluminum nanopowder water oxidation causes the formation of the hollow spheres with mesoporous boehmite nanosheets coating. The wedge-like bayerite particles are formed during aluminum nanopowder wet air oxidation.

  1. Specific features of aluminum nanoparticle water and wet air oxidation

    NASA Astrophysics Data System (ADS)

    Lozhkomoev, Aleksandr S.; Glazkova, Elena A.; Svarovskaya, Natalia V.; Bakina, Olga V.; Kazantsev, Sergey O.; Lerner, Marat I.

    2015-10-01

    The oxidation processes of the electrically exploded aluminum nanopowders in water and in wet air are examined in the paper. The morphology of the intermediate reaction products of aluminum oxidation has been studied using the transmission electron microscopy. It was shown that the aluminum nanopowder water oxidation causes the formation of the hollow spheres with mesoporous boehmite nanosheets coating. The wedge-like bayerite particles are formed during aluminum nanopowder wet air oxidation.

  2. The European Marine Strategy: Noise Monitoring in European Marine Waters from 2014.

    PubMed

    Dekeling, René; Tasker, Mark; Ainslie, Michael; Andersson, Mathias; André, Michel; Borsani, Fabrizio; Brensing, Karsten; Castellote, Manuel; Dalen, John; Folegot, Thomas; van der Graaf, Sandra; Leaper, Russell; Liebschner, Alexander; Pajala, Jukka; Robinson, Stephen; Sigray, Peter; Sutton, Gerry; Thomsen, Frank; Werner, Stefanie; Wittekind, Dietrich; Young, John V

    2016-01-01

    The European Marine Strategy Framework Directive requires European member states to develop strategies for their marine waters leading to programs of measures that achieve or maintain good environmental status (GES) in all European seas by 2020. An essential step toward reaching GES is the establishment of monitoring programs, enabling the state of marine waters to be assessed on a regular basis. A register for impulsive noise-generating activities would enable assessment of their cumulative impacts on wide temporal and spatial scales; monitoring of ambient noise would provide essential insight into current levels and any trend in European waters. PMID:26610961

  3. Effective Jet Properties for the Prediction of Turbulent Mixing Noise Reduction by Water Injection

    NASA Technical Reports Server (NTRS)

    Kandula, Max; Lonergan, Michael J.

    2007-01-01

    A one-dimensional control volume formulation is developed for the determination of jet mixing noise reduction due to water injection. The analysis starts from the conservation of mass, momentum and energy for the control volume, and introduces the concept of effective jet parameters (jet temperature, jet velocity and jet Mach number). It is shown that the water to jet mass flow rate ratio is an important parameter characterizing the jet noise reduction on account of gas-to-droplet momentum and heat transfer. Two independent dimensionless invariant groups are postulated, and provide the necessary relations for the droplet size and droplet Reynolds number. Results are presented illustrating the effect of mass flow rate ratio on the jet mixing noise reduction for a range of jet Mach number and jet Reynolds number. Predictions from the model show satisfactory comparison with available test data on supersonic jets. The results suggest that significant noise reductions can be achieved at increased flow rate ratios.

  4. Seasonal presence of cetaceans and ambient noise levels in polar waters of the North Atlantic.

    PubMed

    Klinck, Holger; Nieukirk, Sharon L; Mellinger, David K; Klinck, Karolin; Matsumoto, Haruyoshi; Dziak, Robert P

    2012-09-01

    In 2009 two calibrated acoustic recorders were deployed in polar waters of the North Atlantic to study the seasonal occurrence of blue, fin, and sperm whales and to assess current ambient noise levels. Sounds from these cetaceans were recorded at both locations in most months of the year. During the summer months, seismic airguns associated with oil and gas exploration were audible for weeks at a time and dominated low frequency noise levels. Noise levels might further increase in the future as the receding sea ice enables extended human use of the area. PMID:22979829

  5. Cold water aquifer storage. [air conditioning

    NASA Technical Reports Server (NTRS)

    Reddell, D. L.; Davison, R. R.; Harris, W. B.

    1980-01-01

    A working prototype system is described in which water is pumped from an aquifer at 70 F in the winter time, chilled to a temperature of less than 50 F, injected into a ground-water aquifer, stored for a period of several months, pumped back to the surface in the summer time. A total of 8.1 million gallons of chilled water at an average temperature of 48 F were injected. This was followed by a storage period of 100 days. The recovery cycle was completed a year later with a total of 8.1 million gallons recovered. Approximately 20 percent of the chill energy was recovered.

  6. Rotationally resolved water dimer spectra in atmospheric air and pure water vapour in the 188-258 GHz range.

    PubMed

    Serov, E A; Koshelev, M A; Odintsova, T A; Parshin, V V; Tretyakov, M Yu

    2014-12-21

    New experimental results regarding "warm" water dimer spectra under equilibrium conditions are presented. An almost equidistant series of six peaks corresponding to the merged individual lines of the bound dimer with consecutive rotational quantum numbers is studied in the 188-258 GHz frequency range in water vapour over a broad range of pressures and temperatures relevant to the Earth's atmosphere. The series is a continuation of the sequence detected earlier at lower frequencies at room temperature. The signal-to-noise ratio of the observed spectra allowed investigating their evolution, when water vapour was diluted by atmospheric air with partial pressure from 0 up to 540 Torr. Analysis of the obtained spectra permitted determining the dimerization constant as well as the hydrogen bond dissociation energy and the dimer spectral parameters, including the average coefficient of collisional broadening of individual lines by water vapour and air. The manifestation of metastable states of the dimer in the observed spectra is assessed. The contribution of three possible pair states of water molecules to the second virial coefficient is evaluated over the broad range of temperatures. The work supports the significant role of the water dimer in atmospheric absorption and related processes. PMID:25363156

  7. Minimizing the water and air impacts of unconventional energy extraction

    NASA Astrophysics Data System (ADS)

    Jackson, R. B.

    2014-12-01

    Unconventional energy generates income and, done well, can reduce air pollution compared to other fossil fuels and even water use compared to fossil fuels and nuclear energy. Alternatively, it could slow the adoption of renewables and, done poorly, release toxic chemicals into water and air. Based on research to date, some primary threats to water resources come from surface spills, wastewater disposal, and drinking-water contamination through poor well integrity. For air resources, an increase in volatile organic compounds and air toxics locally is a potential health threat, but the switch from coal to natural gas for electricity generation will reduce sulfur, nitrogen, mercury, and particulate pollution regionally. Critical needs for future research include data for 1) estimated ultimate recovery (EUR) of unconventional hydrocarbons; 2) the potential for further reductions of water requirements and chemical toxicity; 3) whether unconventional resource development alters the frequency of well-integrity failures; 4) potential contamination of surface and ground waters from drilling and spills; and 5) the consequences of greenhouse gases and air pollution on ecosystems and human health.

  8. Forced convection heat transfer to air/water vapor mixtures

    NASA Technical Reports Server (NTRS)

    Richards, D. R.; Florschuetz, L. W.

    1984-01-01

    Heat transfer coefficients were measured using both dry and humid air in the same forced convection cooling scheme and were compared using appropriate nondimensional parameters (Nusselt, Prandtl and Reynolds numbers). A forced convection scheme with a complex flow field, two dimensional arrays of circular jets with crossflow, was utilized with humidity ratios (mass ratio of water vapor to air) up to 0.23. The dynamic viscosity, thermal conductivity and specific heat of air, steam and air/steam mixtures are examined. Methods for determining gaseous mixture properties from the properties of their pure components are reviewed as well as methods for determining these properties with good confidence. The need for more experimentally determined property data for humid air is discussed. It is concluded that dimensionless forms of forced convection heat transfer data and empirical correlations based on measurements with dry air may be applied to conditions involving humid air with the same confidence as for the dry air case itself, provided that the thermophysical properties of the humid air mixtures are known with the same confidence as their dry air counterparts.

  9. Interrelationships of petiole air canal architecture, water depth and convective air flow in Nymphaea odorata (Nymphaeaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Premise of the study--Nymphaea odorata grows in water up to 2 m deep, producing fewer, larger leaves in deeper water. This species has a convective flow system that moves gases from younger leaves through submerged parts to older leaves, aerating submerged parts. Petiole air canals are in the conv...

  10. Utilizing air purge to reduce water contamination of lube systems

    SciTech Connect

    Sirois, H.J.

    1994-12-31

    Lubrication systems are exposed to contaminants including dirt, process dilutants and water. Water contamination of lubricating oil is commonly experienced by users of machinery such as steam and gas turbines, compressors, pumps, motors, generators and others. Poorly designed or maintained turbomachinery features such as bearing housing seals and shaft packing do not prevent moisture laden air, the primary source of water, from entering the lube system. This paper presents a case history where a mechanical drive steam turbine and boiler feed pump was experiencing severe water contamination of the lube system. Bearing and control system component failures resulted from water induced corrosion. Various systems and approaches for dealing with this contamination are reviewed. Installation of a very simple and cost effective system using low pressure air applied directly to the bearing housing oil seals proved a most effective method for eliminating measurable water contamination of the lubrication system and can be applied to machinery of all types.

  11. Plants Clean Air and Water for Indoor Environments

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Wolverton Environmental Services Inc., founded by longtime government environmental scientist B.C. "Bill" Wolverton, is an environmental consulting firm that gives customers access to the results of his decades of cutting-edge bioremediation research. Findings about how to use plants to improve indoor air quality have been published in dozens of NASA technical papers and in the book, "How to Grow Fresh Air: 50 Houseplants That Purify Your Home or Office." The book has now been translated into 12 languages and has been on the shelves of bookstores for nearly 10 years. A companion book, "Growing Clean Water: Nature's Solution to Water Pollution," explains how plants can clean waste water. Other discoveries include that the more air that is allowed to circulate through the roots of the plants, the more effective they are at cleaning polluted air; and that plants play a psychological role in welfare in that people recover from illness faster in the presence of plants. Wolverton Environmental is also working in partnership with Syracuse University, to engineer systems consisting of modular wicking filters tied into duct work and water supplies, essentially tying plant-based filters into heating, ventilation, and air conditioning (HVAC) systems. Also, the company has recently begun to assess the ability of the EcoPlanter to remove formaldehyde from interior environments. Wolverton Environmental is also in talks with designers of the new Stennis Visitor's Center, who are interested in using its designs for indoor air-quality filters

  12. Methane flux across the air-water interface - Air velocity effects

    NASA Technical Reports Server (NTRS)

    Sebacher, D. I.; Harriss, R. C.; Bartlett, K. B.

    1983-01-01

    Methane loss to the atmosphere from flooded wetlands is influenced by the degree of supersaturation and wind stress at the water surface. Measurements in freshwater ponds in the St. Marks Wildlife Refuge, Florida, demonstrated that for the combined variability of CH4 concentrations in surface water and air velocity over the water surface, CH4 flux varied from 0.01 to 1.22 g/sq m/day. The liquid exchange coefficient for a two-layer model of the gas-liquid interface was calculated as 1.7 cm/h for CH4 at air velocity of zero and as 1.1 + 1.2 v to the 1.96th power cm/h for air velocities from 1.4 to 3.5 m/s and water temperatures of 20 C.

  13. Noise emitted from road, rail and air traffic and their effects on sleep

    NASA Astrophysics Data System (ADS)

    Griefahn, Barbara; Marks, Anke; Robens, Sibylle

    2006-08-01

    This study compared the effects of road, rail, and aircraft noise and tested the applicability of the equivalent noise level for the evaluation of sleep disturbances. Sixteen women and 16 men (19-28 years) slept during 3 consecutive weeks in the laboratory. Eight persons slept in quiet throughout. Twenty-four persons were exposed to road, rail, or aircraft noise with weekly permuted changes. Each week consisted of a random sequence of a quiet night (32 dBA) and 3 nights with equivalent noise levels of 39, 44, and 50 dBA and maximum levels of 50-62, 56-68, and 62-74 dBA, respectively. The polysomnogram was recorded during all nights, sleep quality was assessed and performance tests were completed in the morning. Subjectively evaluated sleep quality decreased and reaction time increased gradually with noise levels, whereas most physiological variables revealed the same reactions to both the lower and considerably stronger reactions to the highest noise load. Aircraft noise, rail and road traffic noise caused similar after-effects but physiological sleep parameters were most severely affected by rail noise. The equivalent noise level seems to be a suitable predictor for subjectively evaluated sleep quality but not for physiological sleep disturbances.

  14. 33 CFR 334.490 - Atlantic Ocean off Georgia Coast; air-to-air and air-to-water gunnery and bombing ranges for...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Atlantic Ocean off Georgia Coast; air-to-air and air-to-water gunnery and bombing ranges for fighter and bombardment aircraft, U.S. Air... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.490 Atlantic Ocean...

  15. 33 CFR 334.490 - Atlantic Ocean off Georgia Coast; air-to-air and air-to-water gunnery and bombing ranges for...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Atlantic Ocean off Georgia Coast; air-to-air and air-to-water gunnery and bombing ranges for fighter and bombardment aircraft, U.S. Air... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.490 Atlantic Ocean...

  16. 33 CFR 334.490 - Atlantic Ocean off Georgia Coast; air-to-air and air-to-water gunnery and bombing ranges for...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Atlantic Ocean off Georgia Coast; air-to-air and air-to-water gunnery and bombing ranges for fighter and bombardment aircraft, U.S. Air... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.490 Atlantic Ocean...

  17. Behavior of Water Jet Accompanied with Air Suction

    NASA Astrophysics Data System (ADS)

    Kawakami, Hironobu; Ishido, Tsutomu; Ihara, Akio

    In order to atomize a liquid, the authors have investigated the behavior of air-water jets. In a series of experiments, we have discovered a strange phenomenon that the water jet accompanied with air suction from the free surface has made a periodic radial splash of water drop. The purpose of the present paper is to clear out the origin of this phenomenon and the behavior of water jet accompanied with air suction. The behavior of water jet has been photographed by a digital camera aided with a flashlight and high-speed video camera. Those experiments enable us to find the origin of a periodic radial splash due to a formation of single air bubble at the flow separation region inside the nozzle and due to explosive expansion of the bubble after injected in the free space. In order to analyze the radial splash of water, we have conducted the equation of spherical liquid membrane. The numerical results obtained have been compared with the experimental results and good agreement has been obtained in radial expansion velocity.

  18. Water Tank with Capillary Air/Liquid Separation

    NASA Technical Reports Server (NTRS)

    Ungar, Eugene K.; Smith, Frederick; Edeen, Gregg; Almlie, Jay C.

    2010-01-01

    A bladderless water tank (see figure) has been developed that contains capillary devices that allow it to be filled and emptied, as needed, in microgravity. When filled with water, the tank shields human occupants of a spacecraft against cosmic radiation. A membrane that is permeable by air but is hydrophobic (neither wettable nor permeable by liquid water) covers one inside surface of the tank. Grooves between the surface and the membrane allow air to flow through vent holes in the surface as the tank is filled or drained. A margin of wettable surface surrounds the edges of the membrane, and all the other inside tank surfaces are also wettable. A fill/drain port is located in one corner of the tank and is covered with a hydrophilic membrane. As filling begins, water runs from the hydrophilic membrane into the corner fillets of the tank walls. Continued filling in the absence of gravity will result in a single contiguous air bubble that will be vented through the hydrophobic membrane. The bubble will be reduced in size until it becomes spherical and smaller than the tank thickness. Draining the tank reverses the process. Air is introduced through the hydrophobic membrane, and liquid continuity is maintained with the fill/drain port through the corner fillets. Even after the tank is emptied, as long as the suction pressure on the hydrophilic membrane does not exceed its bubble point, no air will be drawn into the liquid line.

  19. A novel membrane device for the removal of water vapor and water droplets from air

    NASA Technical Reports Server (NTRS)

    Ray, Rod; Newbold, David D.; Mccray, Scott B.; Friesen, Dwayne T.; Kliss, Mark

    1992-01-01

    One of the key challenges facing NASA engineers is the development of systems for separating liquids and gases in microgravity environments. In this paper, a novel membrane-based phase separator is described. This device, known as a water recovery heat exchanger (WRHEX), overcomes the inherent deficiencies of current phase-separation technology. Specifically, the WRHEX cools and removes water vapor or water droplets from feed-air streams without the use of a vacuum or centrifugal force. As is shown in this paper, only a low-power air blower and a small stream of recirculated cool water is required for WRHEX operation. This paper presents the results of tests using this novel membrane device over a wide range of operating conditions. The data show that the WRHEX produces a dry air stream containing no entrained or liquid water - even when the feed air contains water droplets or mist. An analysis of the operation of the WRHEX is presented.

  20. Economics of water injected air screw compressor systems

    NASA Astrophysics Data System (ADS)

    Venu Madhav, K.; Kovačević, A.

    2015-08-01

    There is a growing need for compressed air free of entrained oil to be used in industry. In many cases it can be supplied by oil flooded screw compressors with multi stage filtration systems, or by oil free screw compressors. However, if water injected screw compressors can be made to operate reliably, they could be more efficient and therefore cheaper to operate. Unfortunately, to date, such machines have proved to be insufficiently reliable and not cost effective. This paper describes an investigation carried out to determine the current limitations of water injected screw compressor systems and how these could be overcome in the 15-315 kW power range and delivery pressures of 6-10 bar. Modern rotor profiles and approach to sealing and cooling allow reasonably inexpensive air end design. The prototype of the water injected screw compressor air system was built and tested for performance and reliability. The water injected compressor system was compared with the oil injected and oil free compressor systems of the equivalent size including the economic analysis based on the lifecycle costs. Based on the obtained results, it was concluded that water injected screw compressor systems could be designed to deliver clean air free of oil contamination with a better user value proposition than the oil injected or oil free screw compressor systems over the considered range of operations.

  1. Water, Air, Earth and Cosmic Radiation

    NASA Astrophysics Data System (ADS)

    Bassez, Marie-Paule

    2015-06-01

    In the context of the origin of life, rocks are considered mainly for catalysis and adsorption-desorption processes. Here it is shown how some rocks evolve in energy and might induce synthesis of molecules of biological interest. Radioactive rocks are a source of thermal energy and water radiolysis producing molecular hydrogen, H2. Mafic and ultramafic rocks evolve in water and dissolved carbon dioxide releasing thermal energy and H2. Peridotites and basalts contain ferromagnesian minerals which transform through exothermic reactions with the generation of heat. These reactions might be triggered by any heating process such as radioactive decay, hydrothermal and subduction zones or post-shock of meteorite impacts. H2 might then be generated from endothermic hydrolyses of the ferromagnesian minerals olivine and pyroxene. In both cases of mafic and radioactive rocks, production of CO might occur through high temperature hydrogenation of CO2. CO, instead of CO2, was proven to be necessary in experiments synthesizing biological-type macromolecules with a gaseous mixture of CO, N2 and H2O. In the geological context, N2 is present in the environment, and the activation source might arise from cosmic radiation and/or radionuclides. Ferromagnesian and radioactive rocks might consequently be a starting point of an hydrothermal chemical evolution towards the abiotic formation of biological molecules. The two usually separate worlds of rocks and life are shown to be connected through molecular and thermodynamic chemical evolution. This concept has been proposed earlier by the author (Bassez J Phys: Condens Matter 15:L353-L361, 2003, 2008a, 2008b; Bassez Orig Life Evol Biosph 39(3-4):223-225, 2009; Bassez et al. 2011; Bassez et al. Orig Life Evol Biosph 42(4):307-316, 2012, Bassez 2013) without thermodynamic details. This concept leads to signatures of prebiotic chemistry such as radionuclides and also iron and magnesium carbonates associated with serpentine and/or talc, which

  2. Water, air, Earth and cosmic radiation.

    PubMed

    Bassez, Marie-Paule

    2015-06-01

    In the context of the origin of life, rocks are considered mainly for catalysis and adsorption-desorption processes. Here it is shown how some rocks evolve in energy and might induce synthesis of molecules of biological interest. Radioactive rocks are a source of thermal energy and water radiolysis producing molecular hydrogen, H2. Mafic and ultramafic rocks evolve in water and dissolved carbon dioxide releasing thermal energy and H2. Peridotites and basalts contain ferromagnesian minerals which transform through exothermic reactions with the generation of heat. These reactions might be triggered by any heating process such as radioactive decay, hydrothermal and subduction zones or post-shock of meteorite impacts. H2 might then be generated from endothermic hydrolyses of the ferromagnesian minerals olivine and pyroxene. In both cases of mafic and radioactive rocks, production of CO might occur through high temperature hydrogenation of CO2. CO, instead of CO2, was proven to be necessary in experiments synthesizing biological-type macromolecules with a gaseous mixture of CO, N2 and H2O. In the geological context, N2 is present in the environment, and the activation source might arise from cosmic radiation and/or radionuclides. Ferromagnesian and radioactive rocks might consequently be a starting point of an hydrothermal chemical evolution towards the abiotic formation of biological molecules. The two usually separate worlds of rocks and life are shown to be connected through molecular and thermodynamic chemical evolution. This concept has been proposed earlier by the author (Bassez J Phys: Condens Matter 15:L353-L361, 2003, 2008a, 2008b; Bassez Orig Life Evol Biosph 39(3-4):223-225, 2009; Bassez et al. 2011; Bassez et al. Orig Life Evol Biosph 42(4):307-316, 2012, Bassez 2013) without thermodynamic details. This concept leads to signatures of prebiotic chemistry such as radionuclides and also iron and magnesium carbonates associated with serpentine and/or talc

  3. 33 CFR 334.490 - Atlantic Ocean off Georgia Coast; air-to-air and air-to-water gunnery and bombing ranges for...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Atlantic Ocean off Georgia Coast; air-to-air and air-to-water gunnery and bombing ranges for fighter and bombardment aircraft, U.S. Air Force. 334.490 Section 334.490 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE...

  4. Propagation of density disturbances in air-water flow

    NASA Technical Reports Server (NTRS)

    Nassos, G. P.

    1969-01-01

    Study investigated the behavior of density waves propagating vertically in an atmospheric pressure air-water system using a technique based on the correlation between density change and electric resistivity. This information is of interest to industries working with heat transfer systems and fluid power and control systems.

  5. Earth, Air, Fire and Water in Our Elements

    ERIC Educational Resources Information Center

    Lievesley, Tara

    2007-01-01

    The idea that everything is made of the four "elements", earth, air, fire and water, goes back to the ancient Greeks. In this article, the author talks about the origins of ideas about the elements. The author provides an account that attempts to summarise thousands of years of theoretical development of the elements in a thousand words or so.

  6. MONITORING CYCLICAL AIR-WATER ELEMENTAL MERCURY EXCHANGE

    EPA Science Inventory

    Previous experimental work has demonstrated that elemental mercury evasion from natural water displays a diel cycle; evasion rates during the day can be two to three times evasion rates observed at night. A study with polychlorinated biphenyls (PCBS) found that diurnal PCB air/wa...

  7. VOLATILIZATION RATES FROM WATER TO INDOOR AIR PHASE II

    EPA Science Inventory

    Contaminated water can lead to volatilization of chemicals to residential indoor air. Previous research has focused on only one source (shower stalls) and has been limited to chemicals in which gas-phase resistance to mass transfer is of marginal significance. As a result, attemp...

  8. External exposure to radionuclides in air, water, and soil

    SciTech Connect

    Eckerman, K.F.; Ryman, J.C.

    1996-05-01

    Federal Guidance Report No. 12 tabulates dose coefficients for external exposure to photons and electrons emitted by radionuclides distributed in air, water, and soil. The dose coefficients are intended for use by Federal Agencies in calculating the dose equivalent to organs and tissues of the body.

  9. Water and Air Measures That Make 'PureSense'

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Each day, we read about mounting global concerns regarding the ability to sustain supplies of clean water and to reduce air contamination. With water and air serving as life s most vital elements, it is important to know when these environmental necessities may be contaminated, in order to eliminate exposure immediately. The ability to respond requires an understanding of the conditions impacting safety and quality, from source to tap for water, and from outdoor to indoor environments for air. Unfortunately, the "time-to-know" is not immediate with many current technologies, which is a major problem, given the greater likelihood of risky situations in today s world. Accelerating alert and response times requires new tools, methods, and technologies. New solutions are needed to engage in more rapid detection, analysis, and response. This is the focus of a company called PureSense Environmental, Inc., which evolved out of a unique relationship with NASA. The need for real-time management and operations over the quality of water and air, and the urgency to provide new solutions, were reinforced by the events of September 11, 2001. This, and subsequent events, exposed many of the vulnerabilities facing the multiple agencies tasked with working in tandem to protect communities from harmful disaster. Much has been done since September 11 to accelerate responses to environmental contamination. Partnerships were forged across the public and private sectors to explore, test, and use new tools. Methods and technologies were adopted to move more astutely from proof-of-concept to working solutions.

  10. Traffic-Related Air Pollution, Noise at School, and Behavioral Problems in Barcelona Schoolchildren: A Cross-Sectional Study

    PubMed Central

    Forns, Joan; Dadvand, Payam; Foraster, Maria; Alvarez-Pedrerol, Mar; Rivas, Ioar; López-Vicente, Mònica; Suades-Gonzalez, Elisabet; Garcia-Esteban, Raquel; Esnaola, Mikel; Cirach, Marta; Grellier, James; Basagaña, Xavier; Querol, Xavier; Guxens, Mònica; Nieuwenhuijsen, Mark J.; Sunyer, Jordi

    2015-01-01

    Background: The available evidence of the effects of air pollution and noise on behavioral development is limited, and it overlooks exposure at schools, where children spend a considerable amount of time. Objective: We aimed to investigate the associations of exposure to traffic-related air pollutants (TRAPs) and noise at school on behavioral development of schoolchildren. Methods: We evaluated children 7–11 years of age in Barcelona (Catalonia, Spain) during 2012–2013 within the BREATHE project. Indoor and outdoor concentrations of elemental carbon (EC), black carbon (BC), and nitrogen dioxide (NO2) were measured at schools in two separate 1-week campaigns. In one campaign we also measured noise levels inside classrooms. Parents filled out the strengths and difficulties questionnaire (SDQ) to assess child behavioral development, while teachers completed the attention deficit/hyperactivity disorder criteria of the DSM-IV (ADHD-DSM-IV) list to assess specific ADHD symptomatology. Negative binomial mixed-effects models were used to estimate associations between the exposures and behavioral development scores. Results: Interquartile range (IQR) increases in indoor and outdoor EC, BC, and NO2 concentrations were positively associated with SDQ total difficulties scores (suggesting more frequent behavioral problems) in adjusted multivariate models, whereas noise was significantly associated with ADHD-DSM-IV scores. Conclusion: In our study population of 7- to 11-year-old children residing in Barcelona, exposure to TRAPs at school was associated with increased behavioral problems in schoolchildren. Noise exposure at school was associated with more ADHD symptoms. Citation: Forns J, Dadvand P, Foraster M, Alvarez-Pedrerol M, Rivas I, López-Vicente M, Suades-Gonzalez E, Garcia-Esteban R, Esnaola M, Cirach M, Grellier J, Basagaña X, Querol X, Guxens M, Nieuwenhuijsen MJ, Sunyer J. 2016. Traffic-related air pollution, noise at school, and behavioral problems in Barcelona

  11. Locating air leaks in manned spacecraft using structure-borne noise.

    PubMed

    Holland, Stephen D; Chimenti, D E; Roberts, Ron; Strei, Michael

    2007-06-01

    All manned spacecraft are vulnerable to leaks generated by micrometeorite or debris impacts. Methods for locating such leaks using leak-generated, structure-borne ultrasonic noise are discussed and demonstrated. Cross-correlations of ultrasonic noise waveforms from a leak into vacuum are used to find the location of the leak. Four methods for sensing and processing leak noise have been developed and tested and each of these can be used to reveal the leak location. The methods, based on phased-array, distributed sensor, and dual sensor approaches, utilize the propagation patterns of guided ultrasonic Lamb waves in the spacecraft skin structure to find the source or direction of the leak noise. It is shown that each method can be used to successfully locate the leak to within a few millimeters on a 0.6-m2 aluminum plate. The relative merits of the four methods are discussed. PMID:17552700

  12. Influence of Solid Noise Barriers on Near-Road and On-Road Air Quality

    EPA Science Inventory

    Public health concerns regarding adverse health effects for populations spending significant amounts of time near high traffic roadways has increased substantially in recent years. Roadside features, including solid noise barriers, have been investigated as potential methods to ...

  13. Low-noise humidity controller for imaging water mediated processes in atomic force microscopy.

    PubMed

    Gaponenko, I; Gamperle, L; Herberg, K; Muller, S C; Paruch, P

    2016-06-01

    We demonstrate the construction of a novel low-noise continuous flow humidity controller and its integration with a commercial variable-temperature atomic force microscope fluid cell, allowing precise control of humidity and temperature at the sample during nanoscale measurements. Based on wet and dry gas mixing, the design allows a high mechanical stability to be achieved by means of an ultrasonic atomiser for the generation of water-saturated gas, improving upon previous bubbler-based architectures. Water content in the flow is measured both at the inflow and outflow of the fluid cell, enabling the monitoring of water condensation and icing, and allowing controlled variation of the sample temperature independently of the humidity. To benchmark the performance of the controller, the results of detailed noise studies and time-based imaging of the formation of ice layers on highly oriented pyrolytic graphite are shown. PMID:27370461

  14. Low-noise humidity controller for imaging water mediated processes in atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Gaponenko, I.; Gamperle, L.; Herberg, K.; Muller, S. C.; Paruch, P.

    2016-06-01

    We demonstrate the construction of a novel low-noise continuous flow humidity controller and its integration with a commercial variable-temperature atomic force microscope fluid cell, allowing precise control of humidity and temperature at the sample during nanoscale measurements. Based on wet and dry gas mixing, the design allows a high mechanical stability to be achieved by means of an ultrasonic atomiser for the generation of water-saturated gas, improving upon previous bubbler-based architectures. Water content in the flow is measured both at the inflow and outflow of the fluid cell, enabling the monitoring of water condensation and icing, and allowing controlled variation of the sample temperature independently of the humidity. To benchmark the performance of the controller, the results of detailed noise studies and time-based imaging of the formation of ice layers on highly oriented pyrolytic graphite are shown.

  15. Air and water quality monitor assessment of life support subsystems

    NASA Technical Reports Server (NTRS)

    Whitley, Ken; Carrasquillo, Robyn L.; Holder, D.; Humphries, R.

    1988-01-01

    Preprotype air revitalization and water reclamation subsystems (Mole Sieve, Sabatier, Static Feed Electrolyzer, Trace Contaminant Control, and Thermoelectric Integrated Membrane Evaporative Subsystem) were operated and tested independently and in an integrated arrangement. During each test, water and/or gas samples were taken from each subsystem so that overall subsystem performance could be determined. The overall test design and objectives for both subsystem and integrated subsystem tests were limited, and no effort was made to meet water or gas specifications. The results of chemical analyses for each of the participating subsystems are presented along with other selected samples which were analyzed for physical properties and microbiologicals.

  16. Aircraft noise problems

    NASA Astrophysics Data System (ADS)

    1981-01-01

    The problems related to aircraft noise were studied. Physical origin (sound), human reaction (noise), quantization of noise and sound sources of aircraft noise are discussed. Noise abatement at the source, technical, fleet-political and air traffic measures are explained. The measurements and future developments are also discussed. The position of Lufthansa as regards aircraft noise problems is depicted.

  17. In-core coolant flow monitoring of pressurized water reactors using temperature and neutron noise

    SciTech Connect

    Sweeney, F.J.; Upadhyaya, B.R.; Shieh, D.J.

    1984-01-01

    Noise measurements were performed at the Loss-of-Fluid-Test (LOFT) and Sequoyah-1 pressurized water reactors (PWRs) in order to investigate the possibility of inferring in-core coolant velocities from cross-power spectral density (CPSD) phases of core-exit thermocouple and in-core neutron detector signals. These noise measurements were used to investigate the effects of inlet coolant temperature, core flow, reactor power, and random heat transfer fluctuations on the noise-inferred coolant velocities. The effect on the inferred velocities of varying in-core neutron detector and core-exit thermocouple locations was also investigated. Theoretical models of temperature noise were developed, and the results were used to interpret the experimental measurements. Results of these studies indicate that the neutron detector/thermocouple phase is useful for monitoring core flow in PWRs. Results show that the interpretation of the phase between these signals depends on the source of temperature noise, the response times and locations of the sensors, and the neutron dynamics of the reactor. At Sequoyah-1 we found that the in-core neutron detector/core-exit thermocouple phase can be used to infer in-core coolant velocities, provided that the measurements are corrected for the thermocouple response time.

  18. Definitional Noise in Estimates of Water Use for Electrical Generation (Invited)

    NASA Astrophysics Data System (ADS)

    Diehl, T. H.

    2013-12-01

    A key challenge in water-resources planning and policy is determining how much water is withdrawn and consumed to meet various needs. In the case of electrical power generation, quantifying water use is beset by differences and confusion in defining the basic terms relating water used in generating electricity to its hydrologic context, leading to wide disagreement on the amounts of withdrawal and consumption. Water withdrawals by plants with artificial cooling ponds, water consumption by plants with once-through cooling systems, and water diversion and consumption associated with hydroelectric power generation provide three examples of this 'definitional noise'. Plants that use cooling ponds withdraw water from other water bodies to make up for water lost from the pond, primarily as evaporation. Some of these plants report as withdrawal all flow from the pond to the condenser; others report only the much smaller flows needed to make up for water lost from the pond. Inconsistent assignment of plants to these two categories produces differences of several billion gallons per day in withdrawal estimates. Estimates of water consumption at plants with once-through cooling systems directly connected to natural surface water bodies vary substantially depending on whether 'consumption' is defined as being restricted to water loss within the plant or includes forced evaporation outside the plant caused by heat from the warmed cooling water returned to the source water body. Blurring of this distinction has produced wildly divergent consumption estimates. Differences in defining the processes that constitute water use for electrical generation produce dramatic differences in estimated water use. Historically, hydroelectric plants have been defined as having no water withdrawals or consumption. However, if flow through hydroelectric turbines were treated as withdrawal it would dwarf all other types of withdrawal, and if evaporation from reservoirs used for hydroelectric

  19. Connecting Water Quality With Air Quality Through Microbial Aerosols

    NASA Astrophysics Data System (ADS)

    Dueker, M. Elias

    Aerosol production from surface waters results in the transfer of aquatic materials (including nutrients and bacteria) to air. These materials can then be transported by onshore winds to land, representing a biogeochemical connection between aquatic and terrestrial systems not normally considered. In urban waterfront environments, this transfer could result in emissions of pathogenic bacteria from contaminated waters. Despite the potential importance of this link, sources, near-shore deposition, identity and viability of microbial aerosols are largely uncharacterized. This dissertation focuses on the environmental and biological mechanisms that define this water-air connection, as a means to build our understanding of the biogeochemical, biogeographical, and public health implications of the transfer of surface water materials to the near-shore environment in both urban and non-urban environments. The effects of tidal height, wind speed and fog on coastal aerosols and microbial content were first quantified on a non-urban coast of Maine, USA. Culture-based, culture-independent, and molecular methods were used to simultaneously sample microbial aerosols while monitoring meteorological parameters. Aerosols at this site displayed clear marine influence and high concentrations of ecologically-relevant nutrients. Coarse aerosol concentrations significantly increased with tidal height, onshore wind speed, and fog presence. Tidal height and fog presence did not significantly influence total microbial aerosol concentrations, but did have a significant effect on culturable microbial aerosol fallout. Molecular analyses of the microbes settling out of near-shore aerosols provided further evidence of local ocean to terrestrial transport of microbes. Aerosol and surface ocean bacterial communities shared species and in general were dominated by organisms previously sampled in marine environments. Fog presence strengthened the microbial connection between water and land through

  20. [Investigation of the distribution of water clusters in vegetables, fruits, and natural waters by flicker noise spectroscopy].

    PubMed

    Zubov, A V; Zubov, K V; Zubov, V A

    2007-01-01

    The distribution of water clusters in fresh rain water and in rain water that was aged for 30 days (North Germany, 53 degrees 33' N, 12 degrees 47' E, 293 K, rain on 25.06.06) as well as in fresh vegetables and fruits was studied by flicker noise spectroscopy. In addition, the development of water clusters in apples and potatoes during ripening in 2006 was investigated. A different distribution of water clusters in irrigation water (river and rain) and in the biomatrix of vegetables (potatoes, onions, tomatoes, red beets) and fruits (apples, bananas) was observed. It was concluded that the cluster structure of irrigation water differs from that of water of the biomatrix of vegetables and fruits and depends on drought and the biomatrix nature. Water clusters in plants are more stable and reproducible than water clusters in natural water. The main characteristics of cluster formation in materials studied were given. The oscillation frequencies of water clusters in plants (biofield) are given at which they interact with water clusters of the Earth hydrosphere. A model of series of clusters 16(H2O)100 <--> 4(H2O)402 <--> 2(H2O)903 <--> (H2O)1889 in the biomatrix of vegetables and fruits was discussed. PMID:17907398

  1. Measurements of acoustic ambient noise in shallow water due to breaking surf

    NASA Astrophysics Data System (ADS)

    Wilson, O. B., Jr.; Wolf, S. N.; Ingenito, F.

    1982-12-01

    Horizontal directionality of ambient noise was measured at ranges up to 15 km from the south-eastern shore of Monterey Bay, California. Water depths at the sites ranged from 8 to 175 m. A steerable cardioid receiving pattern was formed using signals telemetered from dipole and omnidirectional hydrophones suspended from tethered buoys. With no nearby shipping, whenever the maximum of the cardioid pattern was directed toward the beach, noise levels in the frequency range from 20 Hz to 70 Hz were greater than those obtained when the maximum was directed seaward. This difference or anisotropy (seaward vs. shoreward), which depends on range from the beach, on frequency and on surf intensity, was 10 dB at 300 Hz at the 9 km site during very heavy surf. Surf beat was clearly audible when the cardioid maximum was steered shoreward at ranges as great as 2 km. During heavy surf, the omnidirectional ambient noise levels also increased significantly in the same frequency range at which the anisotropy is evident. The anisotropy effects diminish both in magnitude and in frequency range with lower wave height but are still observable during light surf. We have concluded that intense breaking surf can contribute significantly to ambient noise in fairly deep continental shelf waters.

  2. High Blood Pressure and Long-Term Exposure to Indoor Noise and Air Pollution from Road Traffic

    PubMed Central

    Künzli, Nino; Aguilera, Inmaculada; Rivera, Marcela; Agis, David; Vila, Joan; Bouso, Laura; Deltell, Alexandre; Marrugat, Jaume; Ramos, Rafel; Sunyer, Jordi; Elosua, Roberto; Basagaña, Xavier

    2014-01-01

    Background: Traffic noise has been associated with prevalence of hypertension, but reports are inconsistent for blood pressure (BP). To ascertain noise effects and to disentangle them from those suspected to be from traffic-related air pollution, it may be essential to estimate people’s noise exposure indoors in bedrooms. Objectives: We analyzed associations between long-term exposure to indoor traffic noise in bedrooms and prevalent hypertension and systolic (SBP) and diastolic (DBP) BP, considering long-term exposure to outdoor nitrogen dioxide (NO2). Methods: We evaluated 1,926 cohort participants at baseline (years 2003–2006; Girona, Spain). Outdoor annual average levels of nighttime traffic noise (Lnight) and NO2 were estimated at postal addresses with a detailed traffic noise model and a land-use regression model, respectively. Individual indoor traffic Lnight levels were derived from outdoor Lnight with application of insulations provided by reported noise-reducing factors. We assessed associations for hypertension and BP with multi-exposure logistic and linear regression models, respectively. Results: Median levels were 27.1 dB(A) (indoor Lnight), 56.7 dB(A) (outdoor Lnight), and 26.8 μg/m3 (NO2). Spearman correlations between outdoor and indoor Lnight with NO2 were 0.75 and 0.23, respectively. Indoor Lnight was associated both with hypertension (OR = 1.06; 95% CI: 0.99, 1.13) and SBP (β = 0.72; 95% CI: 0.29, 1.15) per 5 dB(A); and NO2 was associated with hypertension (OR = 1.16; 95% CI: 0.99, 1.36), SBP (β = 1.23; 95% CI: 0.21, 2.25), and DBP (β⊇= 0.56; 95% CI: –0.03, 1.14) per 10 μg/m3. In the outdoor noise model, Lnight was associated only with hypertension and NO2 with BP only. The indoor noise–SBP association was stronger and statistically significant with a threshold at 30 dB(A). Conclusion: Long-term exposure to indoor traffic noise was associated with prevalent hypertension and SBP, independently of NO2. Associations were less

  3. Estuary Turbulence and Air-Water Carbon Dioxide Exchange

    NASA Astrophysics Data System (ADS)

    Orton, Philip Mark

    The mixing of constituents between estuarine bottom and surface waters or between estuarine surface waters and the atmosphere are two topics of growing interest, in part due to the potentially important role of estuaries in global carbon budgets. These two types of mixing are typically driven by turbulence, and a research project was developed to improve the scientific understanding of atmospheric and tidal controls on estuary turbulence and airwater exchange processes. Highlights of method development and field research on the Hudson River estuary include several deployments of bottom mounted current profilers to quantify the turbulent kinetic energy (TKE) budget, and construction and deployment of an instrumented catamaran that makes autonomous measurements of air-water CO2 exchange (FCO2), water TKE dissipation at 50 cm depth (epsilon50), and other physical properties just above and below the air-water interface. On the Hudson, wind correlates strongly with epsilon50, but surface water speed and airwater heat flux also have moderate correlations with epsilon50. In partially mixed estuaries such as the Hudson, as well as salt wedge estuaries, baroclinic pressure forcing typically causes spring ebb tides to have much stronger upper water column shear than flood tides. The Hudson data are used to show that this shear leads to local shear instability and stronger near-surface turbulence on spring ebbs. Also, buoyancy budget terms are compared to demonstrate how water-to-air heat fluxes can influence stratification and indirectly influence epsilon50. Looking more closely at the role of wind forcing, it is demonstrated that inland propagation of the sea breeze on warm sunny days leads to arrival in phase with peak solar forcing at seaward stations, but several hours later at up-estuary stations. Passage of the sea breeze front raises the air-water CO2 flux by 1-2 orders of magnitude, and drives epsilon50 comparable to spring tide levels in the upper meter of the water

  4. Biphilic Surfaces for Enhanced Water Collection from Humid Air

    NASA Astrophysics Data System (ADS)

    Benkoski, Jason; Gerasopoulos, Konstantinos; Luedeman, William

    Surface wettability plays an important role in water recovery, distillation, dehumidification, and heat transfer. The efficiency of each process depends on the rate of droplet nucleation, droplet growth, and mass transfer. Unfortunately, hydrophilic surfaces are good at nucleation but poor at shedding. Hydrophobic surfaces are the reverse. Many plants and animals overcome this tradeoff through biphilic surfaces with patterned wettability. For example, the Stenocara beetle uses hydrophilic patches on a superhydrophobic background to collect fog from air. Cribellate spiders similarly collect fog on their webs through periodic spindle-knot structures. In this study, we investigate the effects of wettability patterns on the rate of water collection from humid air. The steady state rate of water collection per unit area is measured as a function of undercooling, angle of inclination, water contact angle, hydrophilic patch size, patch spacing, area fraction, and patch height relative to the hydrophobic background. We then model each pattern by comparing the potential and kinetic energy of a droplet as it rolls downwards at a fixed angle. The results indicate that the design rules for collecting fog differ from those for condensation from humid air. The authors gratefully acknowledge the Office of Naval Research for financial support through Grant Number N00014-15-1-2107.

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

    SciTech Connect

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

    1994-12-31

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

  6. Numerical simulation of tonal fan noise of computers and air conditioning systems

    NASA Astrophysics Data System (ADS)

    Aksenov, A. A.; Gavrilyuk, V. N.; Timushev, S. F.

    2016-07-01

    Current approaches to fan noise simulation are mainly based on the Lighthill equation and socalled aeroacoustic analogy, which are also based on the transformed Lighthill equation, such as the wellknown FW-H equation or the Kirchhoff theorem. A disadvantage of such methods leading to significant modeling errors is associated with incorrect solution of the decomposition problem, i.e., separation of acoustic and vortex (pseudosound) modes in the area of the oscillation source. In this paper, we propose a method for tonal noise simulation based on the mesh solution of the Helmholtz equation for the Fourier transform of pressure perturbation with boundary conditions in the form of the complex impedance. A noise source is placed on the surface surrounding each fan rotor. The acoustic fan power is determined by the acoustic-vortex method, which ensures more accurate decomposition and determination of the pressure pulsation amplitudes in the near field of the fan.

  7. Proton Transfers at the Air-Water Interface

    NASA Astrophysics Data System (ADS)

    Mishra, Himanshu

    Proton transfer reactions at the interface of water with hydrophobic media, such as air or lipids, are ubiquitous on our planet. These reactions orchestrate a host of vital phenomena in the environment including, for example, acidification of clouds, enzymatic catalysis, chemistries of aerosol and atmospheric gases, and bioenergetic transduction. Despite their importance, however, quantitative details underlying these interactions have remained unclear. Deeper insight into these interfacial reactions is also required in addressing challenges in green chemistry, improved water quality, self-assembly of materials, the next generation of micro-nanofluidics, adhesives, coatings, catalysts, and electrodes. This thesis describes experimental and theoretical investigation of proton transfer reactions at the air-water interface as a function of hydration gradients, electrochemical potential, and electrostatics. Since emerging insights hold at the lipid-water interface as well, this work is also expected to aid understanding of complex biological phenomena associated with proton migration across membranes. Based on our current understanding, it is known that the physicochemical properties of the gas-phase water are drastically different from those of bulk water. For example, the gas-phase hydronium ion, H3O +(g), can protonate most (non-alkane) organic species, whereas H 3O+(aq) can neutralize only relatively strong bases. Thus, to be able to understand and engineer water-hydrophobe interfaces, it is imperative to investigate this fluctuating region of molecular thickness wherein the 'function' of chemical species transitions from one phase to another via steep gradients in hydration, dielectric constant, and density. Aqueous interfaces are difficult to approach by current experimental techniques because designing experiments to specifically sample interfacial layers (< 1 nm thick) is an arduous task. While recent advances in surface-specific spectroscopies have provided

  8. Modeling of membrane processes for air revitalization and water recovery

    NASA Technical Reports Server (NTRS)

    Lange, Kevin E.; Foerg, Sandra L.; Dall-Bauman, Liese A.

    1992-01-01

    Gas-separation and reverse-osmosis membrane models are being developed in conjunction with membrane testing at NASA JSC. The completed gas-separation membrane model extracts effective component permeabilities from multicomponent test data, and predicts the effects of flow configuration, operating conditions, and membrane dimensions on module performance. Variable feed- and permeate-side pressures are considered. The model has been applied to test data for hollow-fiber membrane modules with simulated cabin-air feeds. Results are presented for a membrane designed for air drying applications. Extracted permeabilities are used to predict the effect of operating conditions on water enrichment in the permeate. A first-order reverse-osmosis model has been applied to test data for spiral wound membrane modules with a simulated hygiene water feed. The model estimates an effective local component rejection coefficient under pseudosteady-state conditions. Results are used to define requirements for a detailed reverse-osmosis model.

  9. Modelling of Air Bubble Rising in Water and Polymeric Solution

    NASA Astrophysics Data System (ADS)

    Hassan, N. M. S.; Khan, M. M. K.; Rasul, M. G.; Subaschandar, N.

    2010-06-01

    This study investigates a Computational Fluid Dynamics (CFD) model for a single air bubble rising in water and xanthan gum solution. The bubble rise characteristics through the stagnant water and 0.05% xanthan gum solution in a vertical cylindrical column is modelled using the CFD code Fluent. Single air bubble rise dispersed into the continuous liquid phase has been considered and modelled for two different bubble sizes. Bubble velocity and vorticity magnitudes were captured through a surface-tracking technique i.e. Volume of Fluid (VOF) method by solving a single set of momentum equations and tracking the volume fraction of each fluid throughout the domain. The simulated results of the bubble flow contours at two different heights of the cylindrical column were validated by the experimental results and literature data. The model developed is capable of predicting the entire flow characteristics of different sizes of bubble inside the liquid column.

  10. Use of Surfactants to Decrease Air-Water Interfacial Tension During Sparging (OKC, OK)

    EPA Science Inventory

    Air sparging is a remediation procedure of injecting air into polluted ground water. The primary intention of air sparging is to promote biodegradation of volatile organic compounds (VOCs) in the groundwater passing through the treatment sector. Sparging treatment efficiency dep...

  11. Use of Surfactants to Decrease Air-Water Interfacial Tension During Sparging

    EPA Science Inventory

    Air sparging is a remediation procedure of injecting air into polluted ground water. The primary intention of air sparging is to promote biodegradation of volatile organic compounds (VOCs) in the groundwater passing through the treatment sector. Sparging treatment efficiency dep...

  12. Air-water analogy and the study of hydraulic models

    NASA Technical Reports Server (NTRS)

    Supino, Giulio

    1953-01-01

    The author first sets forth some observations about the theory of models. Then he established certain general criteria for the construction of dynamically similar models in water and in air, through reference to the perfect fluid equations and to the ones pertaining to viscous flow. It is, in addition, pointed out that there are more cases in which the analogy is possible than is commonly supposed.

  13. The influence of tree stands and a noise barrier on near-roadway air quality

    EPA Science Inventory

    Prediction of air pollution exposure levels of people living near or commuting on roadways is still very problematic due to the highly localized nature of traffic intensity, fleet composition, and extremely complex air flow patterns in urban areas. Both modelling and field studie...

  14. Air and water pollution control: a benefit-cost assessment

    SciTech Connect

    Freeman, A.M. III

    1982-01-01

    Freeman attempts to assess the net benefits associated with environmental programs dealing with air and water quality. He concludes that stationary controls have been justified, but that mobile sources and water controls, as presently designed and implemented, have had costs greater than benefits to society. The reviewer notes that the book is more than just a compendium of mechanistic, technical detail; there is rather, far more general information on how economists view environmental problems than suggested by the title. An example is the discussions of the various approaches to valuing environmental benefits.

  15. Bacterial Swimming at Air/Water and Oil/Water Interfaces

    NASA Astrophysics Data System (ADS)

    Morse, Michael; Huang, Athena; Li, Guanglai; Tang, Jay

    2012-02-01

    The microbes inhabiting the planet over billions of years have adapted to diverse physical environments of water, soil, and interfaces between water and either solid or air. Following recent studies on bacterial swimming and accumulation near solid surfaces, we turn our attention to the behavior of Caulobacter crescentus, a singly flagellated bacterium, at water/air and water/oil interfaces. The latter is motivated by relevance to microbial degradation of crude oil in light of the recent oil spill in the Gulf of Mexico. Our ongoing study suggests that Caulobacter swarmer cells tend to get physically trapped at both water/air and water/oil interfaces, accumulating at the surface to a greater degree than boundary confinement properties like that of solid surfaces would predict. At the water/air interface, swimmers move in tight circles at half the speed of swimmers in the bulk fluid. At the water/oil interface, swimming circles are even tighter with further reduced swimming speed. We report experimental data and present preliminary analysis of the findings based on low Reynolds number hydrodynamics, the known surface tension, and surface viscosity at the interface. The analysis will help determine properties of the bacterium such as their surface charge and hydrophobicity.

  16. Tangential stress beneath wind-driven air water interfaces

    NASA Astrophysics Data System (ADS)

    Banner, Michael L.; Peirson, William L.

    1998-06-01

    The detailed structure of the aqueous surface sublayer flow immediately adjacent to the wind-driven air water interface is investigated in a laboratory wind-wave flume using particle image velocimetry (PIV) techniques. The goal is to investigate quantitatively the character of the flow in this crucial, very thin region which is often disrupted by microscale breaking events. In this study, we also examine critically the conclusions of Okuda, Kawai & Toba (1977), who argued that for very short, strongly forced wind-wave conditions, shear stress is the dominant mechanism for transmitting the atmospheric wind stress into the water motion waves and surface drift currents. In strong contrast, other authors have more recently observed very substantial normal stress contributions on the air side. The availability of PIV and associated image technology now permits a timely re-examination of the results of Okuda et al., which have been influential in shaping present perceptions of the physics of this dynamically important region. The PIV technique used in the present study overcomes many of the inherent shortcomings of the hydrogen bubble measurements, and allows reliable determination of the fluid velocity and shear within 200 [mu]m of the instantaneous wind-driven air water interface.

  17. Coaxial injector spray characterization using water/air as simulants

    NASA Technical Reports Server (NTRS)

    Zaller, Michelle M.; Klem, Mark D.

    1991-01-01

    Quantitative information about the atomization of injector sprays is required to improve the accuracy of computational models that predict the performance and stability of liquid propellant rocket engines. An experimental program is being conducted at NASA-Lewis to measure the drop size and velocity distributions in shear coaxial injector sprays. A phase/Doppler interferometer is used to obtain drop size data in water air shear coaxial injector sprays. Droplet sizes and axial component of droplet velocities are measured at different radii for various combinations of water flow rate, air flow rate, injector liquid jet diameter, injector annular gap, and liquid post recess. Sauter mean diameters measured in the spray center 51 mm downstream of the liquid post tip range from 28 to 68 microns, and mean axial drop velocities at the same location range from 37 to 120 m/s. The shear coaxial injector sprays show a high degree of symmetry; the mean drop size and velocity profiles vary with liquid flow rate, post recess, and distance from the injector face. The drop size data can be used to estimate liquid oxygen/hydrogen spray drop sizes by correcting property differences between water-air and liquid oxygen/hydrogen.

  18. New research on bioregenerative air/water purification systems

    NASA Technical Reports Server (NTRS)

    Johnson, Anne H.; Ellender, R. D.; Watkins, Paul J.

    1991-01-01

    For the past several years, air and water purification systems have been developed and used. This technology is based on the combined activities of plants and microorganisms as they function in a natural environment. More recently, researchers have begun to address the problems associated with indoor air pollution. Various common houseplants are currently being evaluated for their abilities to reduce concentrations of volatile organic compounds (VOCS) such as formaldehyde and benzene. With development of the Space Exploration Initiative, missions will increase in duration, and problems with resupply necessitates implementation of regenerative technology. Aspects of bioregenerative technology have been included in a habitat known as the BioHome. The ultimate goal is to use this technology in conjunction with physicochemical systems for air and water purification within closed systems. This study continued the risk assessment of bioregenerative technology with emphasis on biological hazards. In an effort to evaluate the risk for human infection, analyses were directed at enumeration of fecal streptococci and enteric viruses with the BioHome waste water treatment system.

  19. Energy and air emission effects of water supply.

    PubMed

    Stokes, Jennifer R; Horvath, Arpad

    2009-04-15

    Life-cycle air emission effects of supplying water are explored using a hybrid life-cycle assessment For the typically sized U.S. utility analyzed, recycled water is preferable to desalination and comparable to importation. Seawater desalination has an energy and air emission footprint that is 1.5-2.4 times larger than that of imported water. However, some desalination modes fare better; brackish groundwater is 53-66% as environmentally intensive as seawater desalination. The annual water needs (326 m3) of a typical Californian that is met with imported water requires 5.8 GJ of energy and creates 360 kg of CO2 equivalent emissions. With seawater desalination, energy use would increase to 14 GJ and 800 kg of CO2 equivalent emissions. Meeting the water demand of California with desalination would consume 52% of the state's electricity. Supply options were reassessed using alternative electricity mixes, including the average mix of the United States and several renewable sources. Desalination using solar thermal energy has lower greenhouse gas emissions than that of imported and recycled water (using California's electricity mix), but using the U.S. mix increases the environmental footprint by 1.5 times. A comparison with a more energy-intensive international scenario shows that CO2 equivalent emissions for desalination in Dubai are 1.6 times larger than in California. The methods, decision support tool (WEST), and results of this study should persuade decision makers to make informed water policy choices by including energy consumption and material use effects in the decision-making process. PMID:19475934

  20. AirSWOT: An Airborne Platform for Surface Water Monitoring

    NASA Astrophysics Data System (ADS)

    Rodriguez, E.; Moller, D.; Smith, L. C.; Pavelsky, T. M.; Alsdorf, D. E.

    2010-12-01

    The SWOT mission, expected to launch in 2020, will provide global measurements of surface water extent and elevation from which storage change and discharge can be derived. SWOT-like measurements are not routinely used by the hydrology community, and their optimal use and associated errors are areas of active research. The purpose of AirSWOT, a system that has been proposed to NASA’s Instrument Incubator Program, is to provide SWOT-like measurements to the hydrology and ocean community to be used to advance the understanding and use of SWOT data in the pre-launch phase. In the post-launch phase, AirSWOT will be used as the SWOT calibration/validation platform. The AirSWOT payload will consist of Kaspar, a multi-beam Ka-band radar interferometer able to produce elevations over a 5 km swath with centimetric precision. The absolute elevation accuracy of the AirSWOT system will be achieved with a combination of high precision Inertial Motion Units (IMUs), ground calibration points, and advanced calibration techniques utilizing a priori knowledge. It is expected that the accuracy of AirSWOT will exceed or match SWOT’s accuracy requirements. In addition to elevation measurements, the AirSWOT payload will include a near-infrared camera able to provide coincident high-resolution optical imagery of the water bodies imaged by the radar. In its initial hydrology deployments, AirSWOT will investigate four field sites: the Ohio-Mississippi confluence, the lower Atchafalaya River on the Mississippi River Delta, the Yukon River basin near Fairbanks, and the Sacramento River, California. The Ohio-Mississippi confluence is targeted for its large discharge, modest slope, and control structures that modulate Ohio but not Mississippi River slopes and elevations. The lower Atchafalaya River includes low slopes, wetlands with differing vegetation types, and some open lakes. Vegetation includes Cyprus forests, floating macrophytes, and grass marshes, all of which impact radar returns

  1. Environmental issues: Energy, water, noise, waste, and natural resources. Transportation research record

    SciTech Connect

    1995-11-01

    Car scrappage rates and their effects on fleet fuel efficiency in the United States between 1966 and 1992 are described. Transportation energy consumption and energy intensity from 1972 to 1992 are reviewed. Pavement damage caused by buses fueled by compressed natural gas is assessed, and the market for electric vehicles is reexamined. Another paper reports on studies to evaluate the costs and benefits associated with technologies for reducing vehicle emissions. Among the papers on environmental concerns, one suggests techniques for accelerating the remediation of a hazardous waste site, and another explores the integration of the environmental review process and the new planning process known as major metropolitan transportation investment studies. Four papers tracked vehicles, airport noise generated by transportation: issues include noise generated by highspeed tracked vehicles, airport noise contours, the perceptions of helicopter noise in rural communities, and vibration-attenuating rail fasteners. The papers that address waste management discuss Superfund site cleanup efforts, control of groundwater contamination plumes during highway construction, large-scale groundwater remediation of a contaminated storm water runoff construction pond, and gas sampling and analysis of petroleum-contaminated soils. The final two papers describe wetland function and value assessment using computer-aided drafting and design and geographic information system techniques, and the mitigation of adverse impacts on natural resources and fragmentation of vertebrate habitats.

  2. Exposures to road traffic, noise, and air pollution as risk factors for type 2 diabetes: A feasibility study in Bulgaria.

    PubMed

    Dzhambov, Angel M; Dimitrova, Donka D

    2016-01-01

    Type 2 diabetes mellitus (T2DM) is a growing public health problem in Bulgaria. While individual and lifestyle determinants have been researched; till date there has been no study on environmental risks such as road traffic, noise, and air pollution. As a first step toward designing a large-scale population-based survey, we aimed at exploring the overall associations of prevalent T2DM with exposures to road traffic, noise, and air pollution. A total of 513 residents of Plovdiv city, Bulgaria were recruited. Individual data on self-reported doctor-diagnosed T2DM and confounding factors were linked to objective and self-rated exposure indicators. Logistic and log-link Poisson regressions were conducted. In the fully adjusted logistic models, T2DM was positively associated with exposures to L(den) 71-80 dB (odds ratio (OR) = 4.49, 95% confidence interval (CI): 1.38, 14.68), fine particulate matter (PM) 2.5 25.0-66.8 μg/m 3 (OR = 1.32, 95% CI: 0.28, 6.24), benzo alpha pyrene 6.0-14.02 ng/m 3 (OR = 1.76, 95% CI: 0.52, 5.98) and high road traffic (OR = 1.40, 95% CI: 0.48, 4.07). L(den) remained a significant risk factor in the: Poisson regression model. Other covariates with consistently high multivariate effects were age, gender, body mass index, family history of T2DM, subjective sleep disturbance, and especially bedroom location. We concluded that residential noise exposure might be associated with elevated risk of prevalent T2DM. The inferences made by this research and the lessons learned from its limitations could guide the designing of a longitudinal epidemiological survey in Bulgaria. PMID:27157686

  3. Exposures to road traffic, noise, and air pollution as risk factors for type 2 diabetes: A feasibility study in Bulgaria

    PubMed Central

    Dzhambov, Angel M; Dimitrova, Donka D

    2016-01-01

    Type 2 diabetes mellitus (T2DM) is a growing public health problem in Bulgaria. While individual and lifestyle determinants have been researched; till date there has been no study on environmental risks such as road traffic, noise, and air pollution. As a first step toward designing a large-scale population-based survey, we aimed at exploring the overall associations of prevalent T2DM with exposures to road traffic, noise, and air pollution. A total of 513 residents of Plovdiv city, Bulgaria were recruited. Individual data on self-reported doctor-diagnosed T2DM and confounding factors were linked to objective and self-rated exposure indicators. Logistic and log-link Poisson regressions were conducted. In the fully adjusted logistic models, T2DM was positively associated with exposures to Lden 71-80 dB (odds ratio (OR) = 4.49, 95% confidence interval (CI): 1.38, 14.68), fine particulate matter (PM)2.5 25.0-66.8 μg/m3 (OR = 1.32, 95% CI: 0.28, 6.24), benzo alpha pyrene 6.0-14.02 ng/m3 (OR = 1.76, 95% CI: 0.52, 5.98) and high road traffic (OR = 1.40, 95% CI: 0.48, 4.07). Lden remained a significant risk factor in the: Poisson regression model. Other covariates with consistently high multivariate effects were age, gender, body mass index, family history of T2DM, subjective sleep disturbance, and especially bedroom location. We concluded that residential noise exposure might be associated with elevated risk of prevalent T2DM. The inferences made by this research and the lessons learned from its limitations could guide the designing of a longitudinal epidemiological survey in Bulgaria. PMID:27157686

  4. 32 CFR 256.10 - Air installations compatible use zone noise descriptors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Forecast (NEF) values as previously required by Sections III., IV., and V. of DoD Instruction 4165.57, “Air... available in the Office of the Assistant Secretary of Defense (Installations and Logistics)—IO,...

  5. THE INFLUENCE OF A NOISE BARRIER AND VEGETATION ON AIR QUALITY NEAR A ROADWAY

    EPA Science Inventory

    A growing number of epidemiological studies conducted throughout the world have identified an increase in occurrence of adverse health effects for populations residing, working or attending school near major roadways. In addition, several air quality studies have identified incr...

  6. 78 FR 37713 - Safety Zone; Chicago Air and Water Show; Lake Michigan; Chicago, IL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-24

    ... SECURITY Coast Guard 33 CFR Part 165 Safety Zone; Chicago Air and Water Show; Lake Michigan; Chicago, IL... enforce the safety zone on Lake Michigan near Chicago, Illinois for the Chicago Air and Water Show. This... Chicago Air and Water Show. During the aforementioned periods, the Coast Guard will enforce...

  7. 78 FR 37710 - Safety Zone; Milwaukee Air and Water Show; Lake Michigan; Milwaukee, WI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-24

    ... SECURITY Coast Guard 33 CFR Part 165 Safety Zone; Milwaukee Air and Water Show; Lake Michigan; Milwaukee... will enforce the safety zone on Lake Michigan in Milwaukee, Wisconsin for the Milwaukee Air and Water... 2013 Milwaukee Air and Water Show. During the aforementioned periods, the Coast Guard will...

  8. 14 CFR 1274.926 - Clean Air-Water Pollution Control Acts.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Clean Air-Water Pollution Control Acts. 1274... AGREEMENTS WITH COMMERCIAL FIRMS Other Provisions and Special Conditions § 1274.926 Clean Air-Water Pollution Control Acts. Clean Air-Water Pollution Control Acts July 2002 If this cooperative agreement or...

  9. Air/water oxydesulfurization of coal: laboratory investigation

    SciTech Connect

    Warzinski, R. P.; Friedman, S.; Ruether, J. A.; LaCount, R. B.

    1980-08-01

    Air/water oxidative desulfurization has been demonstrated in autoclave experiments at the Pittsburgh Energy Technology Center for various coals representative of the major US coal basins. This experimentation has shown that the reaction proceeds effectively for pulverized coals at temperatures of 150 to 200/sup 0/C with air at a total system pressure of 500 to 1500 psig. Above 200/sup 0/C, the loss of coal and product heating value increases due to oxidative consumption of carbon and hydrogen. The pyritic sulfur solubilization reactions are typically complete (95 percent removal) within 15 to 40 minutes at temperature; however, significant apparent organic sulfur removal requires residence times of up to 60 minutes at the higher temperatures. The principal products of the reaction are sulfuric acid, which can be neutralized with limestone, and iron oxide. Under certain conditions, especially for high pyritic sulfur coals, the precipitation of sulfur-containing compounds from the products of the pyrite reaction may cause anomalous variations in the sulfur form data. The influence of various parameters on the efficiency of sulfur removal from coal by air/water oxydesulfurization has been studied.

  10. Aircraft Noise

    NASA Astrophysics Data System (ADS)

    Michel, Ulf; Dobrzynski, Werner; Splettstoesser, Wolf; Delfs, Jan; Isermann, Ullrich; Obermeier, Frank

    Aircraft industry is exposed to increasing public pressure aiming at a continuing reduction of aircraft noise levels. This is necessary to both compensate for the detrimental effect on noise of the expected increase in air traffic and improve the quality of living in residential areas around airports.

  11. Environmental Noise

    NASA Astrophysics Data System (ADS)

    Rumberg, Martin

    Environmental noise may be defined as unwanted sound that is caused by emissions from traffic (roads, air traffic corridors, and railways), industrial sites and recreational infrastructures, which may cause both annoyance and damage to health. Noise in the environment or community seriously affects people, interfering with daily activities at school, work and home and during leisure time.

  12. Determining the depth of a sound source in shallow water against intense background noise

    NASA Astrophysics Data System (ADS)

    Besedina, T. N.; Kuznetsov, G. N.; Kuz'kin, V. M.; Pereselkov, S. A.

    2015-11-01

    We consider a method for estimating the depth of a sound source in a shallow water acoustic waveguide for a weak signal, based on information on the ratio of the amplitude of neighboring modes of the wave field. Results of a numerical experiment using a single receiver and a horizontal linear array in the lowfrequency region are given. We demonstrate the stability of the method to errors in measuring the amplitudes of filtered modes and variations of the waveguide model, as well as high noise immunity. It is established that the error in reconstructing the depth of a source with increasing noise tends to the established value. We give a qualitative and quantitative explanation of the simulation results.

  13. Impact of climatic noise on global estimates of terrestrial water balance components

    NASA Astrophysics Data System (ADS)

    Nasonova, Olga; Gusev, Yeugeniy; Semenov, Vladimir; Kovalev, Evgeny

    2016-04-01

    Estimates of water balance components performed by different authors in climate impact studies are characterized by a large scatter or uncertainty associated, in particular, with application of different meteorological forcing data (simulated by climate models), different estimates of model parameters, and different hydrological models. In the present work, the objective uncertainty, which cannot be reduced by means of better physical description of the processes under study or by means of improvement of the quality of input data for model simulations, and which is an internal feature of the atmosphere - hydrosphere - land surface system, is considered. This uncertainty is caused by a chaotic character of atmospheric processes (i.e. by so-called climatic noise), their instability with respect to small errors in determination of initial conditions for modeling the evolution of meteorological variables. Our study is devoted to investigating the impact of climatic noise on the estimates of terrestrial water balance components (precipitation, runoff and evapotranspiration) on a global scale. To achieve the effect of climatic noise 45 simulations were performed by the atmospheric general circulation model ECHAM5 under identical lower boundary conditions (including sea surface temperatures and sea ice concentrations) and constant external forcing parameters. The only differences between the simulations were initial conditions of the atmosphere. Meteorological fields simulated by ECHAM5 for the period of 1979-2012 were used as forcing data (with 6-hour temporal resolution and one-degree spatial one) by the land surface model Soil Water - Atmosphere - Plants (SWAP) for hydrological simulations on a global scale. As a result, 45-member ensemble of the water balance components for the land surface of the Earth excluding Antarctica was obtained. Analysis of the obtained results allowed us to estimate the lowest level of uncertainty which can be achieved in climate impact

  14. New Mechanistic Pathways for Criegee-Water Chemistry at the Air/Water Interface.

    PubMed

    Zhu, Chongqin; Kumar, Manoj; Zhong, Jie; Li, Lei; Francisco, Joseph S; Zeng, Xiao Cheng

    2016-09-01

    Understanding Criegee chemistry has become one of central topics in atmospheric research recently. The reaction of Criegee intermediates with gas-phase water clusters has been widely viewed as a key Criegee reaction in the troposphere. However, the effect of aerosols or clouds on Criegee chemistry has received little attention. In this work, we have investigated the reaction between the smallest Criegee intermediate, CH2OO, and water clusters in the gas phase, as well as at the air/water surface using ab initio quantum chemical calculations and adaptive buffered force quantum mechanics/molecular mechanics (QM/MM) dynamics simulations. Our simulation results show that the typical time scale for the reaction of CH2OO with water at the air/water interface is on the order of a few picoseconds, 2-3 orders of magnitude shorter than that in the gas phase. Importantly, the adbf-QM/MM dynamics simulations suggest several reaction pathways for the CH2OO + water reaction at the air/water interface, including the loop-structure-mediated mechanism and the stepwise mechanism. Contrary to the conventional gas-phase CH2OO reaction, the loop-structure is not a prerequisite for the stepwise mechanism. For the latter, a water molecule and the CH2OO at the air/water interface, upon their interaction, can result in the formation of (H3O)(+) and (OH)CH2(OO)(-). Thereafter, a hydrogen bond can be formed between (H3O)(+) and the terminal oxygen atom of (OH)CH2(OO)(-), leading to direct proton transfer and the formation of α-hydroxy methylperoxide, HOCH2OOH. The mechanistic insights obtained from this simulation study should motivate future experimental studies of the effect of water clouds on Criegee chemistry. PMID:27509207

  15. Ice berg cracking events as identified from underwater ambient noise measurements in the shallow waters of Ny-Alesund, Arctic

    NASA Astrophysics Data System (ADS)

    Ashokan, M.; Latha, G.; Thirunavukkarasu, A.; Raguraman, G.; Venkatesan, R.

    2016-06-01

    This paper presents the work carried out on the analysis of preliminary underwater ambient noise measurements in the shallow waters of Kongsfjorden fjord, Arctic in the summer season, in which the ice berg cracking noise is identified. In the summer period, the melting of ice cover is fast and hence the ice bergs are free to move and float in the ocean. Underwater ambient noise has been acquired in the Kongsfjorden fjord, Arctic sea on 19th July 2015 at 5 m water depth, where the ocean depth is 50 m. Due to the tensile cracks at the surface of the sea ice by thermal expansion, ice berg calving and bobbing occurred near the experiment site. Analysis of power spectra shows that ice berg calving noise falls in the frequency band 100 Hz-500 Hz and the ice berg bobbing noise falls in the frequency band 200 Hz-400 Hz.

  16. Impacts of Western Area Power Administration`s power marketing alternatives on air quality and noise

    SciTech Connect

    Chun, K.C.; Chang, Y.S.; Rabchuk, J.A.

    1995-05-01

    The Western Area Power Administration, which is responsible for marketing electricity produced at the hydroelectric power-generating facilities operated by the Bureau of Reclamation on the Upper Colorado River, has proposed changes in the levels of its commitment (sales) of long-term firm capacity and energy to its customers. This report describes (1) the existing conditions of air resources (climate and meteorology, ambient air quality, and acoustic environment) of the region potentially affected by the proposed action and (2) the methodology used and the results of analyses conducted to assess the potential impacts on air resources of the proposed action and the commitment-level alternatives. Analyses were performed for the potential impacts of both commitment-level alternatives and supply options, which include combinations of electric power purchases and different operational scenarios of the hydroelectric power-generating facilities.

  17. Nuclear Magnetic Spin-Noise and Unusual Relaxation of Oxygen-17 in Water

    NASA Astrophysics Data System (ADS)

    Bendet-Taicher, Eli

    Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) have evolved into widely used techniques, providing diagnostic power in medicine and material sciences due to their high precision and non-invasive nature. Due to the small population differences between spin energy states, a significant sensitivity problem for NMR arises. The low sensitivity of NMR is probably its greatest limitation for applications to biological systems. An alternative probe tuning strategy based on the spin-noise response for application in standard one-dimensional and common high-resolution multidimensional standard biomolecular NMR experiments has shown an increase of up to 50% signal-to-noise (SNR) in one-dimensional NMR experiments and an increase of up to 22% in multi-dimensional ones. The method requires the adjustment of the optimal tuning condition, which may be offset by several hundreds kHz from the conventional tuning settings using the noise response of the water protons as an indicator. This work is described in the first part of the thesis (chapters 2--3). The second part (Chapter 4) of the thesis deals with anomalous oxygen-17 NMR relaxation behavior in water. Oxygen-17 (17O), which has spin of 5/2 and a natural abundance of 0.0373% possesses an electric quadrupole moment. Spin-lattice and spin-spin relaxation occur by the quadrupole interaction, while the J-coupling to 1H spins and exchange are deciding factors. T1 and T2 of 17O in water have been previously measured over a large range of temperatures. The spin-spin relaxation times of 17O as a function of temperature show an anomalous behaviour, expressed by a local maximum at the temperature of maximum density (TMD) of water. It is shown that the same anomalous behaviour shifts to the respective temperatures of maximum density for H2O/D2O solutions with different compositions and salt concentrations. This phenomenon can be correlated to the pH dependency of T2 of 17O in water, and water proton exchange rates

  18. Willingness to pay to avoid health risks from road-traffic-related air pollution and noise across five countries.

    PubMed

    Istamto, Tifanny; Houthuijs, Danny; Lebret, Erik

    2014-11-01

    We conducted a multi-country study to estimate the perceived economic values of traffic-related air pollution and noise health risks within the framework of a large European project. We used contingent valuation as a method to assess the willingness-to-pay (WTP) for both types of pollutants simultaneously. We asked respondents how much they would be willing to pay annually to avoid certain health risks from specific pollutants. Three sets of vignettes with different levels of information were provided prior to the WTP questions. These vignettes described qualitative general health risks, a quantitative single health risk related to a pollutant, and a quantitative scenario of combined health risks related to a pollutant. The mean WTP estimates to avoid road-traffic air pollution effects for the three vignettes were: €130 per person per year (pp/y) for general health risks, €80 pp/y for a half year shorter in life expectancy, and €330 pp/y to a 50% decrease in road-traffic air pollution. Their medians were €40 pp/y, €10 pp/y and €50 pp/y, respectively. The mean WTP estimates to avoid road-traffic noise effects for the three vignettes were: €90 pp/y for general health risks, €100 pp/y for a 13% increase in severe annoyance, and €320 pp/y for a combined-risk scenario related to an increase of a noise level from 50 dB to 65 dB. Their medians were €20 pp/y, €20 pp/y and €50 pp/y, respectively. Risk perceptions and attitudes as well as environmental and pollutant concerns significantly affected WTP estimates. The observed differences in crude WTP estimates between countries changed considerably when perception-related variables were included in the WTP regression models. For this reason, great care should be taken when performing benefit transfer from studies in one country to another. PMID:25146911

  19. Hurricane Isabel, Amount of Atmospheric Water Vapor Observed By AIRS

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site] Figure 1

    These false-color images show the amount of atmospheric water vapor observed by AIRS two weeks prior to the passage of Hurricane Isabel, and then when it was a Category 5 storm. The region shown includes parts of South America and the West Indies. Puerto Rico is the large island below the upper left corner.

    Total water vapor represents the depth of a layer if all the water vapor in the atmosphere were to condense and fall to the surface. The color bar on the right sides of the plots give the thickness of this layer in millimeters (mm). The first image, from August 28, shows typical tropical water vapor amounts over the ocean: between roughly 25 and 50 mm, or 1 to 2 inches. The highest values of roughly 80 mm, seen as a red blob over South America, corresponds to intense thunderstorms. Thunderstorms pull in water vapor from surrounding regions and concentrate it, with much of it then falling as rain.

    Figure 1 shows total water during the passage of Hurricane Isabel on September 13. The storm is apparent: the ring of moderate values surrounding a very strong maximum of 100 mm. Total water of more than 80 mm is unusual, and these values correspond to the intense thunderstorms contained within Isabel. The thunderstorms--and the large values of total water--are fed by evaporation from the ocean in the hurricane's high winds. The water vapor near the center of the storm does not remain there long, since hurricane rain rates as high 50 mm (2 inches) per hour imply rapid cycling of the water we observe. Away from the storm the amount of total water vapor is rather low, associated with fair weather where air that ascended near the storm's eye returns to earth, having dropped its moisture as rain. Also seen in the second images are two small regions of about 70 mm of total water over south America. These are yet more thunderstorms, though likely much more benign than those in Isabel.

    The

  20. Air-water partitioning of 222Rn and its dependence on water temperature and salinity.

    PubMed

    Schubert, Michael; Paschke, Albrecht; Lieberman, Eric; Burnett, William C

    2012-04-01

    Radon is useful as a tracer of certain geophysical processes in marine and aquatic environments. Recent applications include detection of groundwater discharges into surface waters and assessment of air/sea gas piston velocities. Much of the research performed in the past decade has relied on continuous measurements made in the field using a radon stripping unit connected to a radon-in-air detection system. This approach assumes that chemical equilibrium is attained between the water and gas phases and that the resulting air activity can be multiplied by a partition coefficient to obtain the corresponding radon-in-water activity. We report here the results of a series of laboratory experiments that describes the dependence of the partition coefficient upon both water temperature and salinity. Our results show that the temperature dependence for freshwater closely matches results that were previously available. The salinity effect, however, has largely been ignored and our results show that this can result in an overestimation of radon concentrations, especially in cooler, more saline waters. Related overestimates in typical situations range between 10 (warmer less saline waters) and 20% (cooler, more saline waters). PMID:22385122

  1. Inactivation of the biofilm by the air plasma containing water

    NASA Astrophysics Data System (ADS)

    Suganuma, Ryota; Yasuoka, Koichi; Yasuoka Takeuchi lab Team

    2014-10-01

    Biofilms are caused by environmental degradation in food factory and medical facilities. Inactivation of biofilm has the method of making it react to chemicals including chlorine, hydrogen peroxide, and ozone. Although inactivation by chemicals has the problem that hazardous property of a residual substance and hydrogen peroxide have slow reaction velocity. We achieved advanced oxidation process (AOP) with air plasma. Hydrogen peroxide and ozone, which were used for the formation of OH radicals in our experiment, were able to be generated selectively by adjusting the amount of water supplied to the plasma. We inactivated Pseudomonas aeruginosa biofilm in five minutes with OH radicals generated by using hydrogen peroxide and ozone.

  2. Nano- and microstructure of air/oil/water interfaces.

    PubMed

    McGillivray, Duncan J; Mata, Jitendra P; White, John W; Zank, Johann

    2009-04-01

    We report the creation of air/oil/water interfaces with variable-thickness oil films using polyisobutylene-based (PIB) surfactants cospread with long-chain paraffinic alkanes on clean water surfaces. The resultant stable oil layers are readily measurable with simple surface techniques, exhibit physical densities the same as expected for bulk oils, and are up to approximately 100 A thick above the water surface as determined using X-ray reflectometry. This provides a ready system for studying the competition of surfactants at the oil/water interface. Results from the competition of a nonionic polyamide surfactant or an anionic sodium dodecyl sulfate with the PIB surfactant are reported. However, this smooth oil layer does not account for the total volume of spread oil nor is the increase in thickness proportional to the film compression. Brewster angle microscopy (BAM) reveals surfactant and oil structures on the scale of 1 to 10 microm at the interface. At low surface pressure (pi < 24 mN m(-1)) large, approximately 10 microm inhomogeneities are observed. Beyond a phase transition observed at pi approximately = 24 mN m(-1), a structure with a spongy appearance and a microscale texture develops. These structures have implications for understanding the microstructure at the oil/water interface in emulsions. PMID:19714829

  3. Rigid-plug elastic-water model for transient pipe flow with entrapped air pocket

    SciTech Connect

    Zhou, Ling; Liu, Prof. Deyou; Karney, Professor Byran W.; Zhang, Qin Fen; OU, CHANGQI

    2011-01-01

    Pressure transients in a rapidly filling pipe with an entrapped air pocket are investigated analytically. A rigid-plug elastic water model is developed by applying elastic water hammer to the majority of the water column while applying rigid water analysis to a small portion near the air-water interface, which avoids effectively the interpolation error of previous approaches. Moreover, another two simplified models are introduced respectively based on constant water length and by neglecting water elasticity. Verification of the three models is confirmed by experimental results. Calculations show that the simplification of constant water length is feasible for small air pockets. The complete rigid water model is appropriate for cases with large initial air volume. The rigid-plug elastic model can predict all the essential features for the entire range of initial air fraction considered in this study, and it is the effective model for analysis of pressure transients of entrapped air.

  4. Deformation of a water shell during free fall in air

    NASA Astrophysics Data System (ADS)

    Nakoryakov, V. E.; Kuznetsov, G. V.; Strizhak, P. A.

    2016-04-01

    The basic regularities of the change in the shape and sizes (the initial volume is 0.05-0.5 L) of a water shell are singled out in its deformation during free fall in air from a height of 3 m. The 3D recording of the basic stages of deformation (flattening of the shell, nucleation, growth, and destruction of bubbles, formation of the droplet cloud) is carried out using high-speed (up to 105 frames per second) Phantom V411 and Phantom Miro M310 video cameras and the program complex Tema Automotive (with the function of continuous tracking). The physical model of destruction of large water bodies is formulated at free fall with the formation of the droplet cloud.

  5. Microrheology Using Optical Tweezers at the Air-Water Interface

    NASA Astrophysics Data System (ADS)

    Boatwright, Thomas; Levine, Alex; Dennin, Michael

    2010-11-01

    Microrheological techniques have been used successfully to determine mechanical properties of materials important in cellular structure. Also critical to cellular mechanical functions are biological membranes. Many aspects of biological membranes can be modeled using Langmuir monolayers, which are single layers surfactants at the air-water interface. The macroscopic mechanical properties of Langmuir monolayers have been extensively characterized. In contrast to macroscopic measurements, we report on experimental methods for studying the rheological properties of Langmuir monolayers on the micron scale. A water immersion optical tweezers system is used to trap ˜1 micron diameter beads in a monolayer. The passive motion of the trapped beads is recorded at high frequency and the complex shear modulus is calculated. Preliminary microrheological data of a fatty acid monolayer showing dependence on surface pressure will be presented. Experimental obstacles will also be discussed.

  6. Proton Transfers at the Air-Water Interface

    NASA Astrophysics Data System (ADS)

    Mishra, Himanshu

    Proton transfer reactions at the interface of water with hydrophobic media, such as air or lipids, are ubiquitous on our planet. These reactions orchestrate a host of vital phenomena in the environment including, for example, acidification of clouds, enzymatic catalysis, chemistries of aerosol and atmospheric gases, and bioenergetic transduction. Despite their importance, however, quantitative details underlying these interactions have remained unclear. Deeper insight into these interfacial reactions is also required in addressing challenges in green chemistry, improved water quality, self-assembly of materials, the next generation of micro-nanofluidics, adhesives, coatings, catalysts, and electrodes. This thesis describes experimental and theoretical investigation of proton transfer reactions at the air-water interface as a function of hydration gradients, electrochemical potential, and electrostatics. Since emerging insights hold at the lipid-water interface as well, this work is also expected to aid understanding of complex biological phenomena associated with proton migration across membranes. Based on our current understanding, it is known that the physicochemical properties of the gas-phase water are drastically different from those of bulk water. For example, the gas-phase hydronium ion, H3O +(g), can protonate most (non-alkane) organic species, whereas H 3O+(aq) can neutralize only relatively strong bases. Thus, to be able to understand and engineer water-hydrophobe interfaces, it is imperative to investigate this fluctuating region of molecular thickness wherein the 'function' of chemical species transitions from one phase to another via steep gradients in hydration, dielectric constant, and density. Aqueous interfaces are difficult to approach by current experimental techniques because designing experiments to specifically sample interfacial layers (< 1 nm thick) is an arduous task. While recent advances in surface-specific spectroscopies have provided

  7. Simulation model finned water-air-coil withoutcondensation

    SciTech Connect

    Wetter, Michael

    1999-01-01

    A simple simulation model of a finned water-to- air coil without condensation is presented. The model belongs to a collection of simulation models that allows eficient computer simulation of heating, ventilation, and air-conditioning (HVAC) systems. The main emphasis of the models is short computation time and use of input data that are known in the design process of an HVAC system. The target of the models is to describe the behavior of HVAC components in the part load operation mode, which is becoming increasingly important for energy efficient HVAC systems. The models are intended to be used for yearly energy calculation or load calculation with time steps of about 10 minutes or larger. Short-time dynamic effects, which are of interest for different aspects of control performance, are neglected. The part load behavior of the coil is expressed in terms of the nominal condition and the dimensionless variation of the heat transfer with change of mass flow and temperature on the water side and the air side. The effectiveness- NTU relations are used to parametrize the convective heat transfer at nominal conditions and to compute the part load conditions. Geometrical data for the coil are not required, The calculation of the convective heat transfer coefficients at nominal conditions is based on the ratio of the air side heat transfer coefficients multiplied by the fin eficiency and divided by the water side heat transfer coefficient. In this approach, the only geometrical information required are the cross section areas, which are needed to calculate the~uid velocities. The formulas for estimating this ratio are presented. For simplicity the model ignores condensation. The model is static and uses only explicit equations. The explicit formulation ensures short computation time and numerical stability. This allows using the model with sophisticated engineering methods such as automatic system optimization. The paper fully outlines the algorithm description and its

  8. Surfactin at the Water/Air Interface and in Solution.

    PubMed

    Iglesias-Fernández, Javier; Darré, Leonardo; Kohlmeyer, Axel; Thomas, Robert K; Shen, Hsin-Hui; Domene, Carmen

    2015-10-13

    The lipopeptide surfactin produced by certain strains of Bacillus subtillis is a potent biosurfactant with high amphiphilicity and a strong tendency for self-aggregation. Surfactin possesses a number of valuable biological properties such as antiviral, antibacterial, antifungal, and hemolytic activities. Owing to these properties, in addition to the general advantages of biosurfactants over synthetic surfactants, surfactin has potential biotechnological and biomedical applications. Here, the aggregation properties of surfactin in solution together with its behavior at the water/air interface were studied using classical molecular dynamics simulations (MD) at three different pH values. Validation of the MD structural data was performed by comparing neutron reflectivity and volume fraction profiles computed from the simulations with their experimental counterparts. Analysis of the MD trajectories supported conclusions about the distribution, conformations, and interactions of surfactin in solution and at the water-air interface. Considering altogether, the work presented provides atomistic models for the rationalization of some of the structural and dynamic characteristics as well as the modes of action of surfactin at different pH values. PMID:26393968

  9. Patterns and properties of polarized light in air and water

    PubMed Central

    Cronin, Thomas W.; Marshall, Justin

    2011-01-01

    Natural sources of light are at best weakly polarized, but polarization of light is common in natural scenes in the atmosphere, on the surface of the Earth, and underwater. We review the current state of knowledge concerning how polarization and polarization patterns are formed in nature, emphasizing linearly polarized light. Scattering of sunlight or moonlight in the sky often forms a strongly polarized, stable and predictable pattern used by many animals for orientation and navigation throughout the day, at twilight, and on moonlit nights. By contrast, polarization of light in water, while visible in most directions of view, is generally much weaker. In air, the surfaces of natural objects often reflect partially polarized light, but such reflections are rarer underwater, and multiple-path scattering degrades such polarization within metres. Because polarization in both air and water is produced by scattering, visibility through such media can be enhanced using straightforward polarization-based methods of image recovery, and some living visual systems may use similar methods to improve vision in haze or underwater. Although circularly polarized light is rare in nature, it is produced by the surfaces of some animals, where it may be used in specialized systems of communication. PMID:21282165

  10. Environmental application of nanotechnology: air, soil, and water.

    PubMed

    Ibrahim, Rusul Khaleel; Hayyan, Maan; AlSaadi, Mohammed Abdulhakim; Hayyan, Adeeb; Ibrahim, Shaliza

    2016-07-01

    Global deterioration of water, soil, and atmosphere by the release of toxic chemicals from the ongoing anthropogenic activities is becoming a serious problem throughout the world. This poses numerous issues relevant to ecosystem and human health that intensify the application challenges of conventional treatment technologies. Therefore, this review sheds the light on the recent progresses in nanotechnology and its vital role to encompass the imperative demand to monitor and treat the emerging hazardous wastes with lower cost, less energy, as well as higher efficiency. Essentially, the key aspects of this account are to briefly outline the advantages of nanotechnology over conventional treatment technologies and to relevantly highlight the treatment applications of some nanomaterials (e.g., carbon-based nanoparticles, antibacterial nanoparticles, and metal oxide nanoparticles) in the following environments: (1) air (treatment of greenhouse gases, volatile organic compounds, and bioaerosols via adsorption, photocatalytic degradation, thermal decomposition, and air filtration processes), (2) soil (application of nanomaterials as amendment agents for phytoremediation processes and utilization of stabilizers to enhance their performance), and (3) water (removal of organic pollutants, heavy metals, pathogens through adsorption, membrane processes, photocatalysis, and disinfection processes). PMID:27074929

  11. Use of Air2Air Technology to Recover Fresh-Water from the Normal Evaporative Cooling Loss at Coal-Based Thermoelectric Power Plants

    SciTech Connect

    Ken Mortensen

    2009-06-30

    This program was undertaken to build and operate the first Air2Air{trademark} Water Conservation Cooling Tower at a power plant, giving a validated basis and capability for water conservation by this method. Air2Air{trademark} water conservation technology recovers a portion of the traditional cooling tower evaporate. The Condensing Module provides an air-to-air heat exchanger above the wet fill media, extracting the heat from the hot saturated moist air leaving in the cooling tower and condensing water. The rate of evaporate water recovery is typically 10%-25% annually, depending on the cooling tower location (climate).

  12. Airframe noise

    NASA Astrophysics Data System (ADS)

    Crighton, David G.

    1991-08-01

    Current understanding of airframe noise was reviewed as represented by experiment at model and full scale, by theoretical modeling, and by empirical correlation models. The principal component sources are associated with the trailing edges of wing and tail, deflected trailing edge flaps, flap side edges, leading edge flaps or slats, undercarriage gear elements, gear wheel wells, fuselage and wing boundary layers, and panel vibration, together with many minor protrusions like radio antennas and air conditioning intakes which may contribute significantly to perceived noise. There are also possibilities for interactions between the various mechanisms. With current engine technology, the principal airframe noise mechanisms dominate only at low frequencies, typically less than 1 kHz and often much lower, but further reduction of turbomachinery noise in particular may make airframe noise the principal element of approach noise at frequencies in the sensitive range.

  13. On the notion of ``1/f noise'' and data analysis for glassy water

    NASA Astrophysics Data System (ADS)

    Johari, G. P.

    2005-07-01

    It is argued that the measured dielectric loss is the sum of a background loss and a dipolar relaxation loss, and both should be considered in a dielectric spectrum analysis. The background loss can be determined by fitting a relaxation function to the spectral peak region. It is also shown that the dielectric loss tangent tanδ of glassy water, which has been rejected as "1/f noise" [A. Minoguchi, R. Richert, and C. A. Angell, Phys. Rev. Lett.93, 215703 (2004)], contains a large contribution from dipole relaxation loss, and its tanδ neither remains constant with change in f nor varies as 1/f. The incorrect attribution of water's tanδ of Minoguchi et al. puts into question the basis of their analysis.

  14. Aircraft noise: accounting for changes in air traffic with time of day.

    PubMed

    Schäffer, Beat; Bütikofer, Rudolf; Plüss, Stefan; Thomann, Georg

    2011-01-01

    Aircraft noise contours are estimated using model calculations and, due to their impact on land use planning, they need to be highly accurate. During night time, not only the number and dominant types of aircraft may differ from daytime but also the flight paths flown may differ. To determine to which detail these variations in flight paths need to be considered, calculations were performed exemplarily for two airports using all available radar data over 1 year, taking into account their changes over the day. The results of this approach were compared with results of a simpler approach which does not consider such changes. While both calculations yielded similar results for the day and close to the airport, differences increased with distance as well as with the period of day (day

  15. 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 ...

  16. [Virus adsorption from batch experiments as influenced by air-water interface].

    PubMed

    Zhang, Hui; Zhao, Bing-zi; Zhang, Jia-bao; Zhang, Cong-zhi; Wang, Qiu-ying; Chen, Ji

    2007-12-01

    The presence of air-water interface in batch sorption experiments may result in inaccurate estimation of virus adsorption onto various soils. A batch sorption experiment was conducted to compare the adsorption results of MS2 in different soils under presence/absence of air-water interface. Soils with sterilization/nonterilization treatment were used. Virus recovery efficiency in a blank experiment (no soil) was also evaluated as affected by different amount of air-water interface. The presence of air-water interface altered the results of virus adsorption in different soils with different extent, with Sandy fluvo-aquic soil being the most considerably affected, followed by Red loam soil, and the least being Red clay soil, probably because of different soil properties associated with virus adsorption/inactivation. Soil sterilization resulted in more significant difference of virus adsorption onto the Sandy fluvo-aquic soil between the presence and absence of air-water interface, while a reduced difference was observed in the Red loam soil. The presence of air-water interface significantly decreased virus recovery efficiency, with the values being decreased with increase in the amount of air-water interface. Soil particles likely prohibit viruses from reaching the air-water interface or alter the forces at the solid-water-air interface so that the results from the blank experiment did not truly represent results from control blank, which probably resulted in adsorption difference between presence and absence of the air-water interface. PMID:18290440

  17. Some Measurements of Noise Transmission and Stress Response of a 0.020-Inch Duralumin Panel in the Presence of Air Flow

    NASA Technical Reports Server (NTRS)

    Kantarges, George T.

    1960-01-01

    Noise transmission measurements were made for a 0.020-inch panel with and without air flow on its surface. Tests were conducted with both an absorbent and reverberant chamber behind the panel. Panel stresses for some of these tests were also determined. Noise spectra obtained inside the absorbent chamber with flow attached and flow not attached to the panel appeared to contain several peaks corresponding in frequency to panel vibration modes. These peaks were notably absent when the chamber was reverberant. The noise reduction through the test panel measured with the aid of an absorbent chamber for the flow-not-attached case is in general agreement with values predicted by the theoretical weight law, which assumes negligible panel stiffness. Corresponding data for the flow-attached case do not follow the weight law but rather indicate less noise reduction at the high frequencies. The main stress responses of the panel without air flow occurred at its fundamental vibration mode. In the presence of air flow the main response occurs in a vibration mode having a node line perpendicular to the direction of air flow.

  18. Microscopic dynamics of nanoparticle monolayers at air-water interface.

    PubMed

    Bhattacharya, R; Basu, J K

    2013-04-15

    We present results of surface mechanical and particle tracking measurements of nanoparticles trapped at the air-water interface as a function of their areal density. We monitor both the surface pressure (Π) and isothermal compression modulus (ϵ) as well as the dynamics of nanoparticle clusters, using fluorescence confocal microscopy while they are compressed to very high density near the two dimensional close packing density Φ∼0.82. We observe non-monotonic variation in both ϵ and the dynamic heterogeneity, characterized by the dynamical susceptibility χ4 with Φ, in such high density monolayers. We provide insight into the underlying nature of such transitions in close packed high density nanoparticle monolayers in terms of the morphology and flexibility of these soft colloidal particles. We discuss the significance our results in the context of related studies on two dimensional granular or colloidal systems. PMID:23411354

  19. Entrapment of ciliates at the water-air interface.

    PubMed

    Ferracci, Jonathan; Ueno, Hironori; Numayama-Tsuruta, Keiko; Imai, Yohsuke; Yamaguchi, Takami; Ishikawa, Takuji

    2013-01-01

    The importance of water-air interfaces (WAI) on microorganism activities has been recognized by many researchers. In this paper, we report a novel phenomenon: the entrapment of ciliates Tetrahymena at the WAI. We first characterized the behavior of cells at the interface and showed that the cells' swimming velocity was considerably reduced at the WAI. To verify the possible causes of the entrapment, we investigated the effects of positive chemotaxis for oxygen, negative geotaxis and surface properties. Even though the taxes were still effective, the entrapment phenomenon was not dependent on the physiological conditions, but was instead affected by the physical properties at the interface. This knowledge is useful for a better understanding of the physiology of microorganisms at interfaces in nature and in industry. PMID:24130692

  20. 15 CFR 923.45 - Air and water pollution control requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

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

  1. 15 CFR 923.45 - Air and water pollution control requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

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

  2. 45 CFR 2543.86 - Clean Air Act and the Federal Water Pollution Control Act.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 4 2014-10-01 2014-10-01 false Clean Air Act and the Federal Water Pollution... Water Pollution Control Act. Contracts and subgrants of amounts in excess of $100,000 shall contain a... regulations issued pursuant to the Clean Air Act (42 U.S.C. 7401 et seq.) and the Federal Water...

  3. 45 CFR 2543.86 - Clean Air Act and the Federal Water Pollution Control Act.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 4 2012-10-01 2012-10-01 false Clean Air Act and the Federal Water Pollution... Water Pollution Control Act. Contracts and subgrants of amounts in excess of $100,000 shall contain a... regulations issued pursuant to the Clean Air Act (42 U.S.C. 7401 et seq.) and the Federal Water...

  4. 15 CFR 923.45 - Air and water pollution control requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  5. 15 CFR 923.45 - Air and water pollution control requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

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

  6. 14 CFR 1274.926 - Clean Air-Water Pollution Control Acts.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Clean Air-Water Pollution Control Acts...-Water Pollution Control Acts. Clean Air-Water Pollution Control Acts July 2002 If this cooperative... Violating Facilities” published pursuant to 40 CFR 15.20. By acceptance of a cooperative agreement in...

  7. 45 CFR 2543.86 - Clean Air Act and the Federal Water Pollution Control Act.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 4 2013-10-01 2013-10-01 false Clean Air Act and the Federal Water Pollution... Water Pollution Control Act. Contracts and subgrants of amounts in excess of $100,000 shall contain a... regulations issued pursuant to the Clean Air Act (42 U.S.C. 7401 et seq.) and the Federal Water...

  8. 14 CFR § 1274.926 - Clean Air-Water Pollution Control Acts.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Clean Air-Water Pollution Control Acts. Â...-Water Pollution Control Acts. Clean Air-Water Pollution Control Acts July 2002 If this cooperative... Violating Facilities” published pursuant to 40 CFR 15.20. By acceptance of a cooperative agreement in...

  9. 14 CFR 1274.926 - Clean Air-Water Pollution Control Acts.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Clean Air-Water Pollution Control Acts...-Water Pollution Control Acts. Clean Air-Water Pollution Control Acts July 2002 If this cooperative... Violating Facilities” published pursuant to 40 CFR 15.20. By acceptance of a cooperative agreement in...

  10. 15 CFR 923.45 - Air and water pollution control requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

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

  11. 45 CFR 2543.86 - Clean Air Act and the Federal Water Pollution Control Act.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Clean Air Act and the Federal Water Pollution... Water Pollution Control Act. Contracts and subgrants of amounts in excess of $100,000 shall contain a... regulations issued pursuant to the Clean Air Act (42 U.S.C. 7401 et seq.) and the Federal Water...

  12. Relay cropping for improved air and water quality.

    PubMed

    Schepers, James S; Francis, Dennis D; Shanahan, John F

    2005-01-01

    Using plants to extract excess nitrate from soil is important in protecting against eutrophication of standing water, hypoxic conditions in lakes and oceans, or elevated nitrate concentrations in domestic water supplies Global climate change issues have raised new concerns about nitrogen (N) management as it relates to crop production even though there may not be an immediate threat to water quality. Carbon dioxide (CO2) emissions are frequently considered the primary cause of global climate change, but under anaerobic conditions, animals can contribute by expelling methane (CH4) as do soil microbes. In terms of the potential for global climate change, CH4 is approximately 25 times more harmful than CO2. This differential effect is minuscule compared to when nitrous oxide (N2O) is released into the atmosphere because it is approximately 300 times more harmful than CO2. N2O losses from soil have been positively correlated with residual N (nitrate, NO3-) concentrations in soil. It stands to reason that phytoremediation via nitrate scavenger crops is one approach to help protect air quality, as well as soil and water quality. Winter wheat was inserted into a seed corn/soybean rotation to utilize soil nitrate and thereby reduce the potential for nitrate leaching and N2O emissions. The net effect of the 2001-2003 relay cropping sequence was to produce three crops in two years, scavenge 130 kg N/ha from the root zone, produce an extra 2 Mg residue/ha, and increase producer profitability by approximately 250 dollars/ha. PMID:15948582

  13. The Effect of Rain on Air-Water Gas Exchange

    NASA Technical Reports Server (NTRS)

    Ho, David T.; Bliven, Larry F.; Wanninkhof, Rik; Schlosser, Peter

    1997-01-01

    The relationship between gas transfer velocity and rain rate was investigated at NASA's Rain-Sea Interaction Facility (RSIF) using several SF, evasion experiments. During each experiment, a water tank below the rain simulator was supersaturated with SF6, a synthetic gas, and the gas transfer velocities were calculated from the measured decrease in SF6 concentration with time. The results from experiments with IS different rain rates (7 to 10 mm/h) and 1 of 2 drop sizes (2.8 or 4.2 mm diameter) confirm a significant and systematic enhancement of air-water gas exchange by rainfall. The gas transfer velocities derived from our experiment were related to the kinetic energy flux calculated from the rain rate and drop size. The relationship obtained for mono-dropsize rain at the RSIF was extrapolated to natural rain using the kinetic energy flux of natural rain calculated from the Marshall-Palmer raindrop size distribution. Results of laboratory experiments at RSIF were compared to field observations made during a tropical rainstorm in Miami, Florida and show good agreement between laboratory and field data.

  14. Non-thermal plasma for air and water remediation.

    PubMed

    Hashim, Siti Aiasah; Samsudin, Farah Nadia Dayana Binti; Wong, Chiow San; Abu Bakar, Khomsaton; Yap, Seong Ling; Mohd Zin, Mohd Faiz

    2016-09-01

    A modular typed dielectric barrier discharge (DBD) device is designed and tested for air and water remediation. The module is made of a number of DBD tubes that can be arranged in series or parallel. Each of the DBD tubes comprises inner electrode enclosed with dielectric barrier and arranged as such to provide a gap for the passage of gases. Non-thermal plasma generated in the gap effectively creates gaseous chemical reactions. Its efficacy in the remediation of gas stream containing high NOx, similar to diesel emission and wastewater containing latex, are presented. A six tubes DBD module has successfully removed more than 80% of nitric oxide from the gas stream. In another arrangement, oxygen was fed into a two tubes DBD to generate ozone for treatment of wastewater. Samples of wastewater were collected from a treatment pond of a rubber vulcanization pilot plant. The water pollution load was evaluated by the chemical oxygen demand (COD) and biological oxygen demand (BOD5) values. Preliminary results showed some improvement (about 13%) on the COD after treatment and at the same time had increased the BOD5 by 42%. This results in higher BOD5/COD ratio after ozonation which indicate better biodegradability of the wastewater. PMID:27056469

  15. Passive range estimation using ship-radiated noise in range-dependent shallow water environments

    NASA Astrophysics Data System (ADS)

    Sell, Alexander W.

    The motivation for this work is a desire to exploit ship-radiated noise in shallow water environments for the purpose of passive range estimation. The method presented utilizes range-frequency intensity striations, arising from multi-path interference in shallow water waveguides and measured across a horizontal line array, to estimate range between a source and a receiver array. This method is based upon the premise that the effects of waveguide geometry on multi-path interference may be represented by a single parameter, beta, called the waveguide invariant, which relates striation slope to source range. Much of the literature on striation-based passive range estimation is focused on range-independent environments or relies on the assumption that beta ≈ 1 in shallow water waveguides in order to eliminate the requirement of knowing the specific values of propagation parameters a priori. However, prior work has shown that range-dependent effects from bathymetry or sound speed profiles can cause the value of beta to vary from its canonical shallow water value and introduce significant bias to range estimates. This work specifically focuses on the effects of range-dependent bathymetry in shallow water waveguides and discusses issues surrounding normal mode propagation and mode coupling. Beyond discussing range-dependent modal propagation, several signal, array, and image processing techniques are presented, which enable estimation of range-frequency intensity images from acoustic data and permit the images to be characterized in terms of striation angle and slope distributions. Using these techniques, a method for estimating range from striation patterns is developed and applied to simulated striation patterns and acoustic data from a 2007 experiment performed off the coast of Port Everglades, Florida. To improve range estimates obtained from the application of this method, an analytical formulation of a waveguide invariant distribution is derived, which takes into

  16. ISSUES IN SIMULATING ELEMENTAL MERCURY AIR/WATER EXCHANGE AND AQUEOUS MONOMETHYLMERCURY SPECIATION

    EPA Science Inventory

    This presentation focuses on two areas relevant to assessing the global fate and bioavailability of mercury: elemental mercury air/water exchange and aqueous environmental monomethylmercury speciation.

  17. Air-Water Gas Exchange in Wetland Water Columns Due To Wind and Thermal Convection

    NASA Astrophysics Data System (ADS)

    Poindexter, C.; Variano, E. A.

    2011-12-01

    The goal of this work is to provide a parameterization of the air-water gas transfer rate in wetlands, and do so in terms of easily measured environmental variables. This parameterization is intended to support biogeochemical modeling in wetlands by providing an interfacial flux of key importance. Our approach uses laboratory experiments describe the oxygen transfer across an air-water interface in a model wetland. The oxygen transfer is sensitive to the externally imposed wind, vegetation characteristics, and vertical thermal convection. We vary these systematically, determining the gas transfer (or "piston") velocity that describes interfacial gas flux. We measure velocity vector fields near the air-water interface using particle image velocimetry, and use these measurements to help explain the mechanisms behind the measured trends in oxygen transfer. The explanatory power of these measurements includes the relationship between plant geometry and surface divergence. We explore the potential impact of our results on wetland modeling and management, for issues such as carbon sequestration and methane emission.

  18. Noise Pollution

    MedlinePlus

    ... menu Learn the Issues Air Chemicals and Toxics Climate Change Emergencies Greener Living Health and Safety Land and Cleanup Pesticides Waste Water Science & Technology Air Climate Change Ecosystems Health Land, Waste and Cleanup Pesticides Substances ...

  19. Long term estimations of low frequency noise levels over water from an off-shore wind farm.

    PubMed

    Bolin, Karl; Almgren, Martin; Ohlsson, Esbjörn; Karasalo, Ilkka

    2014-03-01

    This article focuses on computations of low frequency sound propagation from an off-shore wind farm. Two different methods for sound propagation calculations are combined with meteorological data for every 3 hours in the year 2010 to examine the varying noise levels at a reception point at 13 km distance. It is shown that sound propagation conditions play a vital role in the noise impact from the off-shore wind farm and ordinary assessment methods can become inaccurate at longer propagation distances over water. Therefore, this paper suggests that methodologies to calculate noise immission with realistic sound speed profiles need to be combined with meteorological data over extended time periods to evaluate the impact of low frequency noise from modern off-shore wind farms. PMID:24606254

  20. Computer programs for producing single-event aircraft noise data for specific engine power and meteorological conditions for use with USAF (United States Air Force) community noise model (NOISEMAP)

    NASA Astrophysics Data System (ADS)

    Mohlman, H. T.

    1983-04-01

    The Air Force community noise prediction model (NOISEMAP) is used to describe the aircraft noise exposure around airbases and thereby aid airbase planners to minimize exposure and prevent community encroachment which could limit mission effectiveness of the installation. This report documents two computer programs (OMEGA 10 and OMEGA 11) which were developed to prepare aircraft flight and ground runup noise data for input to NOISEMAP. OMEGA 10 is for flight operations and OMEGA 11 is for aircraft ground runups. All routines in each program are documented at a level useful to a programmer working with the code or a reader interested in a general overview of what happens within a specific subroutine. Both programs input normalized, reference aircraft noise data; i.e., data at a standard reference distance from the aircraft, for several fixed engine power settings, a reference airspeed and standard day meteorological conditions. Both programs operate on these normalized, reference data in accordance with user-defined, non-reference conditions to derive single-event noise data for 22 distances (200 to 25,000 feet) in a variety of physical and psycho-acoustic metrics. These outputs are in formats ready for input to NOISEMAP.

  1. Surface, Water, and Air Biocharacterization (SWAB) Flight Experiment

    NASA Technical Reports Server (NTRS)

    Castro, V. A.; Ott, C. M.; Pierson, D. L.

    2012-01-01

    The determination of risk from infectious disease during spaceflight missions is composed of several factors including both the concentration and characteristics of the microorganisms to which the crew are exposed. Thus, having a good understanding of the microbial ecology aboard spacecraft provides the necessary information to mitigate health risks to the crew. While preventive measures are taken to minimize the presence of pathogens on spacecraft, medically significant organisms have been isolated from both the Mir and International Space Station (ISS). Historically, the method for isolation and identification of microorganisms from spacecraft environmental samples depended upon their growth on culture media. Unfortunately, only a fraction of the organisms may grow on a specific culture medium, potentially omitting those microorganisms whose nutritional and physical requirements for growth are not met. To address this bias in our understanding of the ISS environment, the Surface, Water, and Air Biocharacterization (SWAB) Flight Experiment was designed to investigate and develop monitoring technology to provide better microbial characterization. For the SWAB flight experiment, we hypothesized that environmental analysis using non-culture-based technologies would reveal microorganisms, allergens, and microbial toxins not previously reported in spacecraft, allowing for a more complete health assessment. Key findings during this experiment included: a) Generally, advanced molecular techniques were able to reveal a few organisms not recovered using culture-based methods; however, there is no indication that current monitoring is "missing" any medically significant bacteria or fungi. b) Molecular techniques have tremendous potential for microbial monitoring, however, sample preparation and data analysis present challenges for spaceflight hardware. c) Analytical results indicate that some molecular techniques, such as denaturing gradient gel electrophoresis (DGGE), can

  2. Wind driven vertical transport in a vegetated, wetland water column with air-water gas exchange

    NASA Astrophysics Data System (ADS)

    Poindexter, C.; Variano, E. A.

    2010-12-01

    Flow around arrays of cylinders at low and intermediate Reynolds numbers has been studied numerically, analytically and experimentally. Early results demonstrated that at flow around randomly oriented cylinders exhibits reduced turbulent length scales and reduced diffusivity when compared to similarly forced, unimpeded flows (Nepf 1999). While horizontal dispersion in flows through cylinder arrays has received considerable research attention, the case of vertical dispersion of reactive constituents has not. This case is relevant to the vertical transfer of dissolved gases in wetlands with emergent vegetation. We present results showing that the presence of vegetation can significantly enhance vertical transport, including gas transfer across the air-water interface. Specifically, we study a wind-sheared air-water interface in which randomly arrayed cylinders represent emergent vegetation. Wind is one of several processes that may govern physical dispersion of dissolved gases in wetlands. Wind represents the dominant force for gas transfer across the air-water interface in the ocean. Empirical relationships between wind and the gas transfer coefficient, k, have been used to estimate spatial variability of CO2 exchange across the worlds’ oceans. Because wetlands with emergent vegetation are different from oceans, different model of wind effects is needed. We investigated the vertical transport of dissolved oxygen in a scaled wetland model built inside a laboratory tank equipped with an open-ended wind tunnel. Plastic tubing immersed in water to a depth of approximately 40 cm represented emergent vegetation of cylindrical form such as hard-stem bulrush (Schoenoplectus acutus). After partially removing the oxygen from the tank water via reaction with sodium sulfite, we used an optical probe to measure dissolved oxygen at mid-depth as the tank water re-equilibrated with the air above. We used dissolved oxygen time-series for a range of mean wind speeds to estimate the

  3. The associations between traffic-related air pollution and noise with blood pressure in children: results from the GINIplus and LISAplus studies.

    PubMed

    Liu, Chuang; Fuertes, Elaine; Tiesler, Carla M T; Birk, Matthias; Babisch, Wolfgang; Bauer, Carl-Peter; Koletzko, Sibylle; von Berg, Andrea; Hoffmann, Barbara; Heinrich, Joachim

    2014-01-01

    Although traffic emits both air pollution and noise, studies jointly examining the effects of both of these exposures on blood pressure (BP) in children are scarce. We investigated associations between land-use regression modeled long-term traffic-related air pollution and BP in 2368 children aged 10 years from Germany (1454 from Munich and 914 from Wesel). We also studied this association with adjustment of long-term noise exposure (defined as day-evening-night noise indicator "Lden" and night noise indicator "Lnight") in a subgroup of 605 children from Munich inner city. In the overall analysis including 2368 children, NO2, PM2.5 mass (particles with aerodynamic diameters below 2.5μm), PM10 mass (particles with aerodynamic diameters below 10μm) and PM2.5 absorbance were not associated with BP. When restricting the analysis to the subgroup of children with noise information (N=605), a significant association between NO2 and diastolic BP was observed (-0.88 (95% confidence interval: -1.67, -0.08)). However, upon adjusting the models for noise exposure, only noise remained independently and significantly positively associated with diastolic BP. Diastolic BP increased by 0.50 (-0.03, 1.02), 0.59 (0.05, 1.13), 0.55 (0.03, 1.07), and 0.58 (0.05, 1.11)mmHg for every five decibel increase in Lden and by 0.59 (-0.05, 1.22), 0.69 (0.04, 1.33), 0.64 (0.02, 1.27), and 0.68 (0.05, 1.32)mmHg for every five decibel increase in Lnight, in different models of NO2, PM2.5 mass, PM10 mass and PM2.5 absorbance as the main exposure, respectively. In conclusion, air pollution was not consistently associated with BP with adjustment for noise, noise was independently and positively associated with BP in children. PMID:24183515

  4. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    SciTech Connect

    Not Available

    1992-03-01

    This report contains information related to the sampling and chemical analysis of ground water at the Wright-Patterson Air Force Base. It is part of a field investigation of ground water contamination.

  5. Bromine and heavy halide chemistry at the air/water and air/ice interfaces: a computational approach

    NASA Astrophysics Data System (ADS)

    Gladich, I.; Shepson, P. B.; Szleifer, I.; Carignano, M.

    2010-12-01

    The air-water and air-ice interfaces are critically important surfaces, with respect to the physical and chemical properties of the Earth's atmosphere. In particular chloride, bromide and iodide ions are strongly involved in the reactions occurring at aerosol surfaces that are hydrated and at the air-ice interface in the polar boundary layer. Unfortunately, experimental access to these interfaces are quite problematic and the computational approach, based on molecular dynamic simulations and quantum mechanic calculations, is an interesting alternative approach. In this work, molecular dynamic (MD) simulations are used to study the halide enhancements at the air-water interface in the case of a dilute mixture of iodide, bromide and chloride ions. The MD results show how the air- water halide enhancement is different in the case of mixtures from the case of binary solutions (i.e. anions plus counter-positive ions) and how the presence of these halides at the interfaces depends from their relative concentrations in solution. In detail, heavy halides are strongly enhanced at the interfaces even if they are minor constituents in the bulk. Furthermore the enhancement of the larger halide ions, like bromide, at the surface is greater if lighter halides, like chloride, are in greater excess in the bulk. The applications of this last result on some real system, like sea-water, and the importance of bromide ions in the polar chemistry of ozone depletion events suggest a combined approach, MD and quantum mechanism (QM) calculation, to investigate the ozonation reaction of bromide (Br-+O3 → BrO-+O2 ) in the ice-QLL and in bulk water. The study of the reaction constants suggests how the different environments can affect the kinetics of such reaction. These results can help to understand the complex chemistry occurring at the air-water interface of hydrated aerosol and at the air-ice interface in the polar boundary layer.

  6. Improvement to Air2Air Technology to Reduce Fresh-Water Evaporative Cooling Loss at Coal-Based Thermoelectric Power Plants

    SciTech Connect

    Ken Mortensen

    2011-12-31

    This program was undertaken to enhance the manufacturability, constructability, and cost of the Air2Air{TM} Water Conservation and Plume Abatement Cooling Tower, giving a validated cost basis and capability. Air2Air{TM} water conservation technology recovers a portion of the traditional cooling tower evaporate. The Condensing Module provides an air-to-air heat exchanger above the wet fill media, extracting the heat from the hot saturated moist air leaving in the cooling tower and condensing water. The rate of evaporate water recovery is typically 10% - 25% annually, depending on the cooling tower location (climate). This program improved the efficiency and cost of the Air2Air{TM} Water Conservation Cooling Tower capability, and led to the first commercial sale of the product, as described.

  7. Air-water oxygen exchange in a large whitewater river

    USGS Publications Warehouse

    Hall, Robert O.; Kennedy, Theodore A.; Rosi-Marshall, Emma J.

    2012-01-01

    Air-water gas exchange governs fluxes of gas into and out of aquatic ecosystems. Knowing this flux is necessary to calculate gas budgets (i.e., O2) to estimate whole-ecosystem metabolism and basin-scale carbon budgets. Empirical data on rates of gas exchange for streams, estuaries, and oceans are readily available. However, there are few data from large rivers and no data from whitewater rapids. We measured gas transfer velocity in the Colorado River, Grand Canyon, as decline in O2 saturation deficit, 7 times in a 28-km segment spanning 7 rapids. The O2 saturation deficit exists because of hypolimnetic discharge from Glen Canyon Dam, located 25 km upriver from Lees Ferry. Gas transfer velocity (k600) increased with slope of the immediate reach. k600 was -1 in flat reaches, while k600 for the steepest rapid ranged 3600-7700 cm h-1, an extremely high value of k600. Using the rate of gas exchange per unit length of water surface elevation (Kdrop, m-1), segment-integrated k600 varied between 74 and 101 cm h-1. Using Kdrop we scaled k600 to the remainder of the Colorado River in Grand Canyon. At the scale corresponding to the segment length where 80% of the O2 exchanged with the atmosphere (mean length = 26.1 km), k600 varied 4.5-fold between 56 and 272 cm h-1 with a mean of 113 cm h-1. Gas transfer velocity for the Colorado River was higher than those from other aquatic ecosystems because of large rapids. Our approach of scaling k600 based on Kdrop allows comparing gas transfer velocity across rivers with spatially heterogeneous morphology.

  8. The effect of the partial pressure of water vapor on the surface tension of the liquid water-air interface.

    PubMed

    Pérez-Díaz, José L; Álvarez-Valenzuela, Marco A; García-Prada, Juan C

    2012-09-01

    Precise measurements of the surface tension of water in air vs. humidity at 5, 10, 15, and 20 °C are shown. For constant temperature, surface tension decreases linearly for increasing humidity in air. These experimental data are in good agreement with a simple model based on Newton's laws here proposed. It is assumed that evaporating molecules of water are ejected from liquid to gas with a mean normal component of the speed of "ejection" greater than zero. A high humidity in the air reduces the net flow of evaporating water molecules lowering the effective surface tension on the drop. Therefore, just steam in air acts as an effective surfactant for the water-air interface. It can partially substitute chemical surfactants helping to reduce their environmental impact. PMID:22717083

  9. Environmental monitoring of chromium in air, soil, and water.

    PubMed

    Vitale, R J; Mussoline, G R; Rinehimer, K A

    1997-08-01

    Historical uses of chromium have resulted in its widespread release into the environment. In recent years, a significant amount of research has evaluated the impact of chromium on human health and the environment. Additionally, numerous analytical methods have been developed to identify and quantitate chromium in environmental media in response to various state and federal mandates such as CERCLA, RCRA, CWA, CAA, and SWDA. Due to the significant toxicity differences between trivalent [Cr(III)] and hexavalent [Cr(VI)] chromium, it is essential that chromium be quantified in these two distinct valence states to assess the potential risks to exposure to each in environmental media. Speciation is equally important because of their marked differences in environmental behavior. As the knowledge of risks associated with each valence state has grown and regulatory requirements have evolved, methods to accurately quantitate these species at ever-decreasing concentrations within environmental media have also evolved. This paper addresses the challenges of chromium species quantitation and some of the most relevant current methods used for environmental monitoring, including ASTM Method D5281 for air, SW-846 Methods 3060A, 7196A and 7199 for soils, sediments, and waste, and U.S. EPA Method 218.6 for water. PMID:9380841

  10. Motion of Air Bubbles in Water Subjected to Microgravity Accelerations

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard; Kelly, Eric M.; Hrovat, Kenneth; Nelson, Emily S.; Pettit, Donald R.

    2006-01-01

    The International Space Station (ISS) serves as a platform for microgravity research for the foreseeable future. A microgravity environment is one in which the effects of gravity are drastically reduced which then allows physical experiments to be conducted without the over powering effects of gravity. During his 6-month stay on the ISS, astronaut Donald R. Pettit performed many informal/impromptu science experiments with available equipment. One such experiment focused on the motion of air bubbles in a rectangular container nearly filled with de-ionized water. Bubbles were introduced by shaking and then the container was secured in place for several hours while motion of the bubbles was recorded using time-lapse photography. This paper shows correlation between bubble motion and quasi-steady acceleration levels during one such experiment operation. The quasi-steady acceleration vectors were measured by the Microgravity Acceleration Measurement System (MAMS). Essentially linear motion was observed in the condition considered here. Dr. Pettit also created other conditions which produced linear and circulating motion, which are the subjects of further study. Initial observations of this bubble motion agree with calculations from many microgravity physical science experiments conducted on shuttle microgravity science missions. Many crystal-growth furnaces involve heavy metals and high temperatures in which undesired acceleration-driven convection during solidification can adversely affect the crystal. Presented in this paper will be results showing correlation between bubble motion and the quasi-steady acceleration vector.

  11. Motion of Air Bubbles in Water Subjected to Microgravity Accelerations

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard; Kelly, Eric M.; Hrovar, Kenneth; Nelson, Emily S.; Pettit, Donald R.

    2004-01-01

    The International Space Station (ISS) serves as a platform for microgravity research for the foreseeable future. A microgravity environment is one in which the effects of gravity are drastically reduced which then allows physical experiments to be conducted without the overpowering effects of gravity. During his six month stay on the ISS, astronaut Donald R Pettit performed many informal/impromptu science experiments with available equipment. One such experiment focused on the motion of air bubbles in a rectangular container nearly filled with de-ionized water. Bubbles were introduced by shaking and the container was secured in place for several hours while motion of the bubbles were recorded using time-lapse photography. This paper shows correlation between bubble motion and quasi-steady acceleration levels during one such experiment operation. The quasi-steady acceleration vectors were measured by the Microgravity Acceleration Measurement System. Essentially linear motion was observed in the condition considered here. Dr. Pettit also created other conditions which produced linear and circulating motion, which are the subjects of further study. Initial observations of this bubble motion agree with calculations from many microgravity physical science experiments conducted on Shuttle microgravity science missions. Many crystal-growth furnaces involve heavy metals and high temperatures in which undesired acceleration-driven convection during solidification can adversely affect the crystal. Presented in this paper will be results showing correlation between bubble motion and the quasi-steady acceleration vector.

  12. Audio-visual interaction and perceptual assessment of water features used over road traffic noise.

    PubMed

    Galbrun, Laurent; Calarco, Francesca M A

    2014-11-01

    This paper examines the audio-visual interaction and perception of water features used over road traffic noise, including their semantic aural properties, as well as their categorization and evocation properties. The research focused on a wide range of small to medium sized water features that can be used in gardens and parks to promote peacefulness and relaxation. Paired comparisons highlighted the inter-dependence between uni-modal (audio-only or visual-only) and bi-modal (audio-visual) perception, indicating that equal attention should be given to the design of both stimuli. In general, natural looking features tended to increase preference scores (compared to audio-only paired comparison scores), while manmade looking features decreased them. Semantic descriptors showed significant correlations with preferences and were found to be more reliable design criteria than physical parameters. A principal component analysis identified three components within the nine semantic attributes tested: "emotional assessment," "sound quality," and "envelopment and temporal variation." The first two showed significant correlations with audio-only preferences, "emotional assessment" being the most important predictor of preferences, and its attributes naturalness, relaxation, and freshness also being significantly correlated with preferences. Categorization results indicated that natural stream sounds are easily identifiable (unlike waterfalls and fountains), while evocation results showed no unique relationship with preferences. PMID:25373962

  13. Three-dimensional freezing of flowing water in a tube cooled by air flow

    NASA Astrophysics Data System (ADS)

    Sugawara, M.; Komatsu, Y.; Beer, H.

    2015-05-01

    The 3-D freezing of flowing water in a copper tube cooled by air flow is investigated by means of a numerical analysis. The air flows normal to the tube axis. Several parameters as inlet water mean velocity w m , inlet water temperature T iℓ t , air flow temperature T a and air flow velocity u a are selected in the calculations to adapt it to a winter season actually encountered. The numerical results present the development of the ice layer mean thickness and its 3-D morphologies as well as the critical ice layer thickness in the tube choked by the ice layer.

  14. Acoustic wave propagation in air-bubble curtains in water. Part 1. History and theory

    SciTech Connect

    Domenico, S.N.

    1982-03-01

    Air bubbles in water increase the compressibility several orders of magnitude above that in bubble-free water, thereby greatly reducing the velocity and increasing attenuation of acoustic waves. Currently, air bubble curtains are used to prevent damage of submerged structures (e.g., dams) by shock waves from submarine explosives. Also, air-bubble curtains are used to reduce damage to water-filler tanks in which metals are formed by explosives. Published results of laboratory experiments confirm theoretic velocity and attenuation functions and demonstrate that these quantities are dependent principally upon frequency, bubble size, and fractional volume of air. 31 references.

  15. 77 FR 49349 - Safety Zone; Chicago Air and Water Show, Lake Michigan, Chicago, IL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-16

    ... DHS Department of Homeland Security FR Federal Register NPRM Notice of Proposed Rulemaking A... CFR Part 165 RIN 1625-AA00 Safety Zone; Chicago Air and Water Show, Lake Michigan, Chicago, IL AGENCY... deviation to the Chicago Air and Water Show safety zone on Lake Michigan near Lincoln Park. This action...

  16. 75 FR 32664 - Safety Zone; Milwaukee Air and Water Show, Lake Michigan, Milwaukee, WI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-09

    ..., Milwaukee, Wisconsin in the Federal Register (75 FR 19307). The Coast Guard received 0 comments on this... determined that the Milwaukee Air and Water show does pose significant risks to public safety and property... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Milwaukee Air and Water Show, Lake...

  17. 14 CFR 1274.926 - Clean Air-Water Pollution Control Acts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Clean Air-Water Pollution Control Acts. 1274.926 Section 1274.926 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION COOPERATIVE AGREEMENTS WITH COMMERCIAL FIRMS Other Provisions and Special Conditions § 1274.926 Clean Air-Water Pollution Control Acts. Clean...

  18. Effects of water-contaminated air on blowoff limits of opposed jet hydrogen-air diffusion flames

    NASA Technical Reports Server (NTRS)

    Pellett, Gerald L.; Jentzen, Marilyn E.; Wilson, Lloyd G.; Northam, G. Burton

    1988-01-01

    The effects of water-contaminated air on the extinction and flame restoration of the central portion of N2-diluted H2 versus air counterflow diffusion flames are investigated using a coaxial tubular opposed jet burner. The results show that the replacement of N2 contaminant in air by water on a mole for mole basis decreases the maximum sustainable H2 mass flow, just prior to extinction, of the flame. This result contrasts strongly with the analogous substitution of water for N2 in a relatively hot premixed H2-O2-N2 flame, which was shown by Koroll and Mulpuru (1986) to lead to a significant, kinetically controlled increase in laminar burning velocity.

  19. Managing the Drivers of Air Flow and Water Vapor Transport in Existing Single Family Homes (Revised)

    SciTech Connect

    Cummings, J.; Withers, C.; Martin, E.; Moyer, N.

    2012-10-01

    This document focuses on managing the driving forces which move air and moisture across the building envelope. While other previously published Measure Guidelines focus on elimination of air pathways, the ultimate goal of this Measure Guideline is to manage drivers which cause air flow and water vapor transport across the building envelope (and also within the home), control air infiltration, keep relative humidity (RH) within acceptable limits, avoid combustion safety problems, improve occupant comfort, and reduce house energy use.

  20. Advances in simulating radiance signatures for dynamic air/water interfaces

    NASA Astrophysics Data System (ADS)

    Goodenough, Adam A.; Brown, Scott D.; Gerace, Aaron

    2015-05-01

    The air-water interface poses a number of problems for both collecting and simulating imagery. At the surface, the magnitude of observed radiance can change by multiple orders of magnitude at high spatiotemporal frequency due to glinting effects. In the volume, similarly high frequency focusing of photons by a dynamic wave surface significantly changes the reflected radiance of in-water objects and the scattered return of the volume itself. These phenomena are often manifest as saturated pixels and artifacts in collected imagery (often enhanced by time delays between neighboring pixels or interpolation between adjacent filters) and as noise and greater required computation times in simulated imagery. This paper describes recent advances made to the Digital Image and Remote Sensing Image Generation (DIRSIG) model to address the simulation issues to better facilitate an understanding of a multi/hyper-spectral collection. Glint effects are simulated using a dynamic height field that can be driven by wave frequency models and generates a sea state at arbitrary time scales. The volume scattering problem is handled by coupling the geometry representing the surface (facetization by the height field) with the single scattering contribution at any point in the water. The problem is constrained somewhat by assuming that contributions come from a Snell's window above the scattering point and by assuming a direct source (sun). Diffuse single scattered and multiple scattered energy contributions are handled by Monte Carlo techniques employed previously. The model is compared to existing radiative transfer codes where possible, with the objective of providing a robust movel of time-dependent absolute radiance at many wavelengths.

  1. Long-Term Air Pollution and Traffic Noise Exposures and Mild Cognitive Impairment in Older Adults: A Cross-Sectional Analysis of the Heinz Nixdorf Recall Study

    PubMed Central

    Tzivian, Lilian; Dlugaj, Martha; Winkler, Angela; Weinmayr, Gudrun; Hennig, Frauke; Fuks, Kateryna B.; Vossoughi, Mohammad; Schikowski, Tamara; Weimar, Christian; Erbel, Raimund; Jöckel, Karl-Heinz; Moebus, Susanne; Hoffmann, Barbara

    2016-01-01

    Background: Mild cognitive impairment (MCI) describes the intermediate state between normal cognitive aging and dementia. Adverse effects of air pollution (AP) on cognitive functions have been proposed, but investigations of simultaneous exposure to noise are scarce. Objectives: We analyzed the cross-sectional associations of long-term exposure to AP and traffic noise with overall MCI and amnestic (aMCI) and nonamnestic (naMCI) MCI. Methods: At the second examination of the population-based Heinz Nixdorf Recall study, cognitive assessment was completed in 4,086 participants who were 50–80 years old. Of these, 592 participants were diagnosed as having MCI (aMCI, n = 309; naMCI, n = 283) according to previously published criteria using five neuropsychological subtests. We assessed long-term residential concentrations for size-fractioned particulate matter (PM) and nitrogen oxides with land use regression, and for traffic noise [weighted 24-hr (LDEN) and night-time (LNIGHT) means]. Logistic regression models adjusted for individual risk factors were calculated to estimate the association of environmental exposures with MCI in single- and two-exposure models. Results: Most air pollutants and traffic noise were associated with overall MCI and aMCI. For example, an interquartile range increase in PM2.5 and a 10 A-weighted decibel [dB(A)] increase in LDEN were associated with overall MCI as follows [odds ratio (95% confidence interval)]: 1.16 (1.05, 1.27) and 1.40 (1.03, 1.91), respectively, and with aMCI as follows: 1.22 (1.08, 1.38) and 1.53 (1.05, 2.24), respectively. In two-exposure models, AP and noise associations were attenuated [e.g., for aMCI, PM2.5 1.13 (0.98, 1.30) and LDEN 1.46 (1.11, 1.92)]. Conclusions: Long-term exposures to air pollution and traffic noise were positively associated with MCI, mainly with the amnestic subtype. Citation: Tzivian L, Dlugaj M, Winkler A, Weinmayr G, Hennig F, Fuks KB, Vossoughi M, Schikowski T, Weimar C, Erbel R, Jöckel KH

  2. Does Traffic-related Air Pollution Explain Associations of Aircraft and Road Traffic Noise Exposure on Children's Health and Cognition? A Secondary Analysis of the United Kingdom Sample From the RANCH Project

    PubMed Central

    Clark, Charlotte; Crombie, Rosanna; Head, Jenny; van Kamp, Irene; van Kempen, Elise; Stansfeld, Stephen A.

    2012-01-01

    The authors examined whether air pollution at school (nitrogen dioxide) is associated with poorer child cognition and health and whether adjustment for air pollution explains or moderates previously observed associations between aircraft and road traffic noise at school and children's cognition in the 2001–2003 Road Traffic and Aircraft Noise Exposure and Children's Cognition and Health (RANCH) project. This secondary analysis of a subsample of the United Kingdom RANCH sample examined 719 children who were 9–10 years of age from 22 schools around London's Heathrow airport for whom air pollution data were available. Data were analyzed using multilevel modeling. Air pollution exposure levels at school were moderate, were not associated with a range of cognitive and health outcomes, and did not account for or moderate associations between noise exposure and cognition. Aircraft noise exposure at school was significantly associated with poorer recognition memory and conceptual recall memory after adjustment for nitrogen dioxide levels. Aircraft noise exposure was also associated with poorer reading comprehension and information recall memory after adjustment for nitrogen dioxide levels. Road traffic noise was not associated with cognition or health before or after adjustment for air pollution. Moderate levels of air pollution do not appear to confound associations of noise on cognition and health, but further studies of higher air pollution levels are needed. PMID:22842719

  3. Does traffic-related air pollution explain associations of aircraft and road traffic noise exposure on children's health and cognition? A secondary analysis of the United Kingdom sample from the RANCH project.

    PubMed

    Clark, Charlotte; Crombie, Rosanna; Head, Jenny; van Kamp, Irene; van Kempen, Elise; Stansfeld, Stephen A

    2012-08-15

    The authors examined whether air pollution at school (nitrogen dioxide) is associated with poorer child cognition and health and whether adjustment for air pollution explains or moderates previously observed associations between aircraft and road traffic noise at school and children's cognition in the 2001-2003 Road Traffic and Aircraft Noise Exposure and Children's Cognition and Health (RANCH) project. This secondary analysis of a subsample of the United Kingdom RANCH sample examined 719 children who were 9-10 years of age from 22 schools around London's Heathrow airport for whom air pollution data were available. Data were analyzed using multilevel modeling. Air pollution exposure levels at school were moderate, were not associated with a range of cognitive and health outcomes, and did not account for or moderate associations between noise exposure and cognition. Aircraft noise exposure at school was significantly associated with poorer recognition memory and conceptual recall memory after adjustment for nitrogen dioxide levels. Aircraft noise exposure was also associated with poorer reading comprehension and information recall memory after adjustment for nitrogen dioxide levels. Road traffic noise was not associated with cognition or health before or after adjustment for air pollution. Moderate levels of air pollution do not appear to confound associations of noise on cognition and health, but further studies of higher air pollution levels are needed. PMID:22842719

  4. [Experimental research on combined water and air backwashing reactor technology for biological activated carbon].

    PubMed

    Xie, Zhi-Gang; Qiu, Xue-Min; Zhao, Yan-Ling

    2012-01-01

    To proper control the backwashing process of biological activated carbon (BAC) reactor and improve the overall operation performance, the evaluative indexes such as backwashing wastewater turbidity, organic pollutants removal rate of pre and post-backwashing, and the variation of biomass and biological activity in carbon column are used to compare and analyze the effect of three different combined water and air backwashing methods on the operation of BAC reactor. The result shows that intermittent combined water and air backwashing method is most suitable to BAC reactor. The biological activaty obviously increases by 62.5% after intermittent combined water and air backwashing process. While, the biological activaty using the backwashing method of air plus water and the backwashing method of water and air compounded plus water washing increases by 55.6%, 38.5%, respectively. After backwashing 308h, the reactor recovered to its normal function after intermittent combined water and air backwashing process with the removal rate of UV254 reaching to 60.0%. The fulvic-like fluorescence peak of backwashing water are very weak, and are characterized by low-excitation wavelength tryptophan like (peak S) and high excitation wavelength of tryptophan (peak T), which are caused by the microbial debris washed down. The three-dimensional fluorescence spectra also show that microbial fragments are easy to be washed clean with intermittent combined water and air backwashing. PMID:22452199

  5. Influence of water depth on the sound generated by air-bubble vibration in the water musical instrument

    NASA Astrophysics Data System (ADS)

    Ohuchi, Yoshito; Nakazono, Yoichi

    2014-06-01

    We have developed a water musical instrument that generates sound by the falling of water drops within resonance tubes. The instrument can give people who hear it the healing effect inherent in the sound of water. The sound produced by falling water drops arises from air- bubble vibrations. To investigate the impact of water depth on the air-bubble vibrations, we conducted experiments at varying values of water pressure and nozzle shape. We found that air-bubble vibration frequency does not change at a water depth of 50 mm or greater. Between 35 and 40 mm, however, the frequency decreases. At water depths of 30 mm or below, the air-bubble vibration frequency increases. In our tests, we varied the nozzle diameter from 2 to 4 mm. In addition, we discovered that the time taken for air-bubble vibration to start after the water drops start falling is constant at water depths of 40 mm or greater, but slower at depths below 40 mm.

  6. Signal and noise in vegetation patterns in drylands: distinguishing the baby from the bath water

    NASA Astrophysics Data System (ADS)

    Parsons, Anthony; Wainwright, John; Stewart, Jill; Okin, Gregory

    2014-05-01

    Patterns, and particularly banded patterns, are widely reported in dryland vegetation, and have been the subject of considerable modelling effort. However, much of this modelling effort is predicated on a mathematical approach that is designed to produce patterns and relies on physical processes that are unreasonable. In consequence, whereas in nature dryland vegetation patterns are irregular, disjointed and discontinuous, those produced by such models tend to be regular, continuous and even. The question, therefore, arises "Is it the irregularity, disjointed and discontinuous character of these patterns that holds the key to their formation rather than any apparent, human-imposed semblance of regularity and continuity?" By focusing on this apparent patterning have such models rejected as noise the key to understanding the signal? Models that produce regular vegetation patterns, typically do so by imposing global rules (largely for the distribution of water). Is it not more likely that vegetation responds to the local supply of water, nutrients and propagules? Here, we present a model for the growth of vegetation in deserts that is predicated on the local conditions of input of water, nutrients and propagules and output, such as loss of biomass by herbivory. The approach represents our best quantitative understanding of how desert ecosystems work. Patterns emerge that show the irregularity and discontinuity seen in nature. By focusing on the process rather than the patterns per se our model has the ability to address specific questions of the role of such patterns in land degradation. Further, it has the potential to provide quantitative estimates of the response of the landscape to specific management strategies, as well as the identification of the key thresholds and tipping points that are so important to the management of drylands. In providing a way to understand and predict the vegetation patterns that may develop during desertification, the approach also

  7. Reduction of noise generated by air conditioning and ventilation plants and transmitted to inhabited areas. [application of silencers

    NASA Technical Reports Server (NTRS)

    Harastaseanu, E.; Cristescu, G.; Mercea, F.

    1974-01-01

    The fans with which the conditioning and ventilation plants of weaving and spinning mills are equipped and the conditioning devices used in certain confection and knit wear departments of the textile industry generate loud noise. Solutions are presented for reducing the noise generated by the fans of ventilation and conditioning plants and transmitted to inhabited regions down to the admissible level, as well as the results obtained by experimental application of some noise reduction solutions in the conditioning plants of a spinning mill.

  8. Pulse laser ablation at water-air interface

    NASA Astrophysics Data System (ADS)

    Utsunomiya, Yuji; Kajiwara, Takashi; Nishiyama, Takashi; Nagayama, Kunihito; Kubota, Shiro

    2010-06-01

    We studied a new pulse laser ablation phenomenon on a liquid surface layer, which is caused by the difference between the refractive indices of the two materials involved. The present study was motivated by our previous study, which showed that laser ablation can occur at the interface between a transparent material and a gas or liquid medium when the laser pulse is focused through the transparent material. In this case, the ablation threshold fluence is reduced remarkably. In the present study, experiments were conducted in water and air in order to confirm this phenomenon for a combination of two fluid media with different refractive indices. This phenomenon was observed in detail by pulse laser shadowgraphy. A high-resolution film was used to record the phenomenon with a Nd:YAG pulse laser with 10-ns duration as a light source. The laser ablation phenomenon on the liquid surface layer caused by a focused Nd:YAG laser pulse with 1064-nm wavelength was found to be followed by the splashing of the liquid surface, inducing a liquid jet with many ligaments. The liquid jet extension velocity was around 1000 m/s in a typical case. The liquid jet decelerated drastically due to rapid atomization at the tips of the ligaments. The liquid jet phenomenon was found to depend on the pulse laser parameters such as the laser fluence on the liquid surface, laser energy, and laser beam pattern. The threshold laser fluence for the generation of a liquid jet was 20 J/cm2. By increasing the incident laser energy with a fixed laser fluence, the laser focused area increased, which eventually led to an increase in the size of the plasma column. The larger the laser energy, the larger the jet size and the longer the temporal behavior. The laser beam pattern was found to have significant effects on the liquid jet’s velocity, shape, and history.

  9. Investigation of ferroelectric phase transitions of water in nanoporous silicates in simultaneous electrical noise and calorimetric measurements

    NASA Astrophysics Data System (ADS)

    Bordonskiy, G. S.; Orlov, A. O.

    2014-08-01

    The phase transitions of water in the nanoporous silicate materials SBA-15 and MCM-41 with an ordered system of cylindrical pores have been investigated. Measurements of low-frequency electrical noises (Barkhausen noises) in the frequency range of 1-100 Hz have been performed simultaneously with relative calorimetric measurements. It has been found that the voltage of electrical fluctuations increases approximately 100 times in the temperature range from -30 to -50°C, which is associated with the first-order and second-order ferroelectric phase transitions. It has been assumed that the ferroelectric ice XI can be formed in capillary pores of the materials under investigations.

  10. Characterization of predominantly hydrophobic poly(styrene)-poly(ethylene oxide) copolymers at air/water and cyclohexane/water interfaces

    SciTech Connect

    Gragson, D.E.; Jensen, J.M.; Baker, S.M.

    1999-09-14

    Interfacial tension measurements are employed to explore the spreading behavior of predominantly hydrophobic poly(styrene)--poly(ethylene oxide), PS-PEO, diblock copolymers at air/water and cyclohexane/water interfaces. Two copolymers with 7%- and 15.5%-PEO are examined in this study. The former is expected to have a PS block limiting area in air roughly equal to the limiting PEO pancake area, whereas the latter is expected to have a limiting PS block area in air approximately 3 times smaller than the limiting PEO pancake area. At the air/water interface, the 7%-PEO copolymer does not spread well, which is attributed to interference from the hydrophobic PS block. In contrast, the 7%-PEO copolymer spreads well at the cyclohexane/water interface, producing an isotherm with a terminating mean molecular area 3 times smaller than that obtained at the air/water interface. The 15.5%-PEO copolymer spreads well at both the air/water ad cyclohexane/water interfaces due to less interference from the smaller hydrophobic PS block. These observations are compared to compression isotherms, and the results are discussed in terms of the solvating nature of the adjacent cyclohexane phase for the PS block.

  11. Flow-Noise Calculation Using the Mutual Coupling Between Vulcanized Rubber and the Flow Around in Water

    NASA Astrophysics Data System (ADS)

    Li, Xue-Gang; Yang, Kun-De; Ma, Yuan-Liang

    2012-06-01

    A vulcanized rubber layer is usually used on the head of an axisymmetric body to keep it streamlined and watertight. The elastic boundary condition is considered when the flow noise of an axisymmetric body is calculated, and we employ the mutual coupling method between the vulcanized rubber layer and the flow around to solve the flow-noise field for an axisymmetric body in water. The results show that the deformation of the vulcanized rubber layer is reduced with the increase in Young's modulus. The Young's modulus of the rubber material should be large enough to keep it streamlined, and the noise power levels in the peak of the axisymmetric body are smaller than the other positions, which provides us with important theoretical support for laying acoustic arrays on the head of the body.

  12. Effects of air and water temperatures on resting metabolism of auklets and other diving birds.

    PubMed

    Richman, Samantha E; Lovvorn, James R

    2011-01-01

    For small aquatic endotherms, heat loss while floating on water can be a dominant energy cost, and requires accurate estimation in energetics models for different species. We measured resting metabolic rate (RMR) in air and on water for a small diving bird, the Cassin's auklet (Ptychoramphus aleuticus), and compared these results to published data for other diving birds of diverse taxa and sizes. For 8 Cassin's auklets (~165 g), the lower critical temperature was higher on water (21 °C) than in air (16 °C). Lowest values of RMR (W kg⁻¹) averaged 19% higher on water (12.14 ± 3.14 SD) than in air (10.22 ± 1.43). At lower temperatures, RMR averaged 25% higher on water than in air, increasing with similar slope. RMR was higher on water than in air for alcids, cormorants, and small penguins but not for diving ducks, which appear exceptionally resistant to heat loss in water. Changes in RMR (W) with body mass either in air or on water were mostly linear over the 5- to 20-fold body mass ranges of alcids, diving ducks, and penguins, while cormorants showed no relationship of RMR with mass. The often large energetic effects of time spent floating on water can differ substantially among major taxa of diving birds, so that relevant estimates are critical to understanding their patterns of daily energy use. PMID:21527823

  13. Monolayers at air-water interfaces: from origins-of-life to nanotechnology.

    PubMed

    Ariga, Katsuhiko; Hill, Jonathan P

    2011-08-01

    The air-water interface presents several interesting features, namely a) a molecularly flat environment, b) a boundary region between two phases with different dielectric constants, c) permits or promotes dynamic interactions within the interface region, and d) a point of interaction between hydrophobic compounds and aqueous molecules. Accordingly, Langmuir monolayers at the air-water interface have several unique characteristics and properties, which require investigation. In this review-type personal account, typical examples of molecular recognition and molecular patterning at air-water interfaces are first introduced, followed by descriptions of specific and unusual properties of monolayers on water. In addition, two examples of our own results concerning Langmuir monolayers are explained. We have selected examples from two apparently unrelated research areas, these being the origin of life and future nanotechnology, in order to emphasize the diverse scientific contribution of research on monolayers at the air-water interface. PMID:21739568

  14. WETAIR: A computer code for calculating thermodynamic and transport properties of air-water mixtures

    NASA Technical Reports Server (NTRS)

    Fessler, T. E.

    1979-01-01

    A computer program subroutine, WETAIR, was developed to calculate the thermodynamic and transport properties of air water mixtures. It determines the thermodynamic state from assigned values of temperature and density, pressure and density, temperature and pressure, pressure and entropy, or pressure and enthalpy. The WETAIR calculates the properties of dry air and water (steam) by interpolating to obtain values from property tables. Then it uses simple mixing laws to calculate the properties of air water mixtures. Properties of mixtures with water contents below 40 percent (by mass) can be calculated at temperatures from 273.2 to 1497 K and pressures to 450 MN/sq m. Dry air properties can be calculated at temperatures as low as 150 K. Water properties can be calculated at temperatures to 1747 K and pressures to 100 MN/sq m. The WETAIR is available in both SFTRAN and FORTRAN.

  15. Predicting Air-Water Geysers and Their Implications on Reducing Combined Sewer Overflows

    NASA Astrophysics Data System (ADS)

    Choi, Y.; Leon, A.; Apte, S.

    2014-12-01

    An air-water geyser in a closed conduit system is characterized by an explosive jetting of a mixture of air and water through drop-shafts. In this study, three scenarios of geysers are numerically simulated using a 3D computational fluid dynamics (CFD) model. The three tested scenarios are comprised of a drop shaft that is closed at its bottom and partially or fully open at the top. Initially, the lower section of the drop shaft is filled with pressurized air, the middle section with stagnant water and the upper section with air at atmospheric pressure. The pressure and volume of the pressurized air, and hence the stored energy, is different for all three test cases. The volume of the stagnant water and the air at atmospheric pressure are kept constant in the tests. The numerical simulations aim to identify the correlation between dimensionless energy stored in the pressurized air pocket and dimensionless maximum pressure reached at the outlet. This dimensionless correlation could be used to determine the energy threshold that does not produce air-water geyser, which in turn could be used in the design of combined sewer systems for minimizing geysers.

  16. PILOT STUDY FOR REMOVAL OF ARSENIC FROM DRINKING WATER AT THE FALLON, NEVADA NAVAL AIR STATION

    EPA Science Inventory

    The report presents the results of pilot plant testing of two treatment methods capable of removing arsenic from drinking water; activated alumina and ion exchange. Using the Naval Air Station (NAS) drinking water (raw water arsenic concentration = 0.080 - 0.116 mg/l) for evaluat...

  17. Computer modeling of the sensitivity of a laser water vapor sensor to variations in temperature and air speed

    NASA Technical Reports Server (NTRS)

    Tucker, George F.

    1994-01-01

    Currently, there is disagreement among existing methods of determining atmospheric water vapor concentration at dew-points below -40 C. A major source of error is wall effects which result from the necessity of bringing samples into the instruments. All of these instruments also have response times on the order of seconds. NASA Langley is developing a water vapor sensor which utilizes the absorption of the infrared radiation produced by a diode laser to estimate water vapor concentration. The laser beam is directed through an aircraft window to a retroreflector located on an engine. The reflected beam is detected by an infrared detector located near the laser. To maximize signal to noise, derivative signals are analyzed. By measuring the 2f/DC signal and correcting for ambient temperature, atmospheric pressure and air speed (which results in a Doppler shifting of the laser beam), the water vapor concentration can be retrieved. Since this is an in situ measurement there are no wall effects and measurements can be made at a rate of more than 20 per second. This allows small spatial variations of water vapor to be studied. In order to study the sensitivity of the instrument to variations in temperature and air speed, a computer program which generated the 2f, 3f, 4f, DC and 2f/DC signals of the instrument as a function of temperature, pressure and air speed was written. This model was used to determine the effect of errors in measurement of the temperature and air speed on the measured water vapor concentration. Future studies will quantify the effect of pressure measurement errors, which are expected to be very small. As a result of these studied, a retrieval algorithm has been formulated, and will be applied to data taken during the PEM-West atmospheric science field mission. Spectroscopic studies of the water vapor line used by the instrument will be used to refine this algorithm. To prepare for these studies, several lasers have been studied to determine their

  18. Use Of The Operational Air Quality Monitor (AQM) For In-Flight Water Testing Project

    NASA Technical Reports Server (NTRS)

    Macatangay, Ariel

    2014-01-01

    A primary requirement for manned spaceflight is Environmental Health which ensures air and water contaminants, acoustic profiles, microbial flora, and radiation exposures within the cabin are maintained to levels needed for crew health and for vehicle system functionality. The reliance on ground analyses of returned samples is a limitation in the current environmental monitoring strategy that will prevent future Exploration missions beyond low-Earth orbit. This proposal attempts to address this shortcoming by advancing in-flight analyses of water and air. Ground analysis of in-flight, air and water samples typically employ vapor-phase analysis by gas chromatography-mass spectrometry (GC-MS) to identify and quantify organic compounds present in the samples. We envision the use of newly-developed direct ionization approaches as the most viable avenue leading towards an integrated analytical platform for the monitoring of water, air, and, potentially bio-samples in the cabin environment. Development of an in-flight instrument capable of analyzing air and water samples would be the logical next step to meeting the environmental monitoring needs of Exploration missions. Currently, the Air Quality Monitor (AQM) on-board ISS provides this specific information for a number of target compounds in the air. However, there is a significant subset of common target compounds between air and water. Naturally, the following question arises, "Can the AQM be used for both air and water quality monitoring?" Previous directorate-level IR&D funding led to the development of a water sample introduction method for mass spectrometry using electrothermal vaporization (ETV). This project will focus on the integration of the ETV with a ground-based AQM. The capabilities of this integrated platform will be evaluated using a subset of toxicologically important compounds.

  19. Studies of ambient noise in shallow water environments off Mexico and Alaska: characteristics, metrics and time-synchronization applications

    NASA Astrophysics Data System (ADS)

    Guerra, Melania

    Sound in the ocean originates from multiple mechanisms, both natural and anthropogenic. Collectively, underwater ambient noise accumulates valuable information about both its sources and the oceanic environment that propagates this noise. Characterizing the features of ambient noise source mechanisms is challenging, but essential, for properly describing an acoustic environment. Disturbances to a local acoustic environment may affect many aquatic species that have adapted to be heavily dependent on this particular sense for survival functions. In the case of marine mammals, which are federally protected, demand exists for understanding such potential impacts, which drives important scientific efforts that utilize passive acoustic monitoring (PAM) tools to inform regulatory decisions. This dissertation presents two independent studies that use PAM data to investigate the characteristics of source mechanisms that dominate ambient noise in two diverse shallow water environments. The study in Chapter 2 directly addresses the concern of how anthropogenic activities can degrade the effectiveness of PAM. In the Alaskan Beaufort Sea, an environment where ambient noise is normally dominated by natural causes, seismic surveys create impulsive sounds to map the composition of the bottom. By inspecting single-sensor PAM data, the spectral characteristics of seismic survey airgun reverberation are measured, and their contribution to the overall ambient noise is quantified. This work is relevant to multiple ongoing mitigation protocols that rely on PAM to acoustically detect marine mammal presence during industrial operations. Meanwhile, Chapter 3 demonstrates that by analyzing data from multiple PAM sensors, features embedded in both directional and omnidirectional ambient noise can be used to develop new time-synchronization processing techniques for aligning autonomous elements of an acoustic array, a tool commonly used in PAM for detecting and tracking marine mammals. Using

  20. Influence of tap water quality and household water use activities on indoor air and internal dose levels of trihalomethanes.

    PubMed

    Nuckols, John R; Ashley, David L; Lyu, Christopher; Gordon, Sydney M; Hinckley, Alison F; Singer, Philip

    2005-07-01

    Individual exposure to trihalomethanes (THMs) in tap water can occur through ingestion, inhalation, or dermal exposure. Studies indicate that activities associated with inhaled or dermal exposure routes result in a greater increase in blood THM concentration than does ingestion. We measured blood and exhaled air concentrations of THM as biomarkers of exposure to participants conducting 14 common household water use activities, including ingestion of hot and cold tap water beverages, showering, clothes washing, hand washing, bathing, dish washing, and indirect shower exposure. We conducted our study at a single residence in each of two water utility service areas, one with relatively high and the other low total THM in the residence tap water. To maintain a consistent exposure environment for seven participants, we controlled water use activities, exposure time, air exchange, water flow and temperature, and nonstudy THM sources to the indoor air. We collected reference samples for water supply and air (pre-water use activity), as well as tap water and ambient air samples. We collected blood samples before and after each activity and exhaled breath samples at baseline and post-activity. All hot water use activities yielded a 2-fold increase in blood or breath THM concentrations for at least one individual. The greatest observed increase in blood and exhaled breath THM concentration in any participant was due to showering (direct and indirect), bathing, and hand dishwashing. Average increase in blood THM concentration ranged from 57 to 358 pg/mL due to these activities. More research is needed to determine whether acute and frequent exposures to THM at these concentrations have public health implications. Further research is also needed in designing epidemiologic studies that minimize data collection burden yet maximize accuracy in classification of dermal and inhalation THM exposure during hot water use activities. PMID:16002374

  1. Characterization of AIRS temperature and water vapor measurement capability using correlative observations

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Eldering, Annmarie; Lee, Sung-Yung

    2005-01-01

    In this presentation we address several fundamental issues in the measurement of temperature and water vapor by AIRS: accuracy, precision, vertical resolution and biases as a function of cloud amount. We use two correlative data sources. First we compare AIRS total water vapor with that from the Advanced microwave Sounding Radiometer for EOS (AMSR-E) instrument, also onboard the Aqua spacecraft. AMSRE uses a mature methodology with a heritage including the operational Special Sensor Microwave Imager (SSM/I) instruments. AIRS and AMSR-E observations are collocated and simultaneous, providing a very large data set for comparison: about 200,000 over-ocean matches daily. We show small cloud-dependent biases between AIRS and AMSR-E total water vapor for several oceanic regions. Our second correlative data source is several hundred dedicated radiosondes launched during AIRS overpasses.

  2. Reduction of aircraft noise in civil air transport by optimization of flight tracks and takeoff and approach procedures

    NASA Astrophysics Data System (ADS)

    Rottmann, Uwe

    1988-08-01

    Noise optimized design of operational flight procedures for effective noise pollution reduction is analyzed. Power cutback during certain stages of approach and takeoff, extension of distance between sound source and sound receiver, as well as diminution of sound impact time are optimized for specific flight procedures and routings. Five takeoff and three landing procedures are analyzed in acoustic effects. Sound immission is computed by NOISIMSIS (NOISe IMpact SImulation System), a simulation system especially created for this task, under consideration of aircraft type specified sound emission characteristics and performance data as well as different meteorological conditions. The investigations for the example of Frankfurt airport result in formulating a planning guideline with notes and impulses for activities in operational noise abatement.

  3. 75 FR 11560 - Notice of Lodging of Consent Decree Under the Clean Water Act and Clean Air Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-11

    ... of Lodging of Consent Decree Under the Clean Water Act and Clean Air Act Notice is hereby given that... violations of the Clean Water Act, 33 U.S.C. 1251 et seq., and the Clean Air Act, 42 U.S.C. 7401 et seq. at... of water effluent controls, the rerouting of air emissions through control devices, and...

  4. A Comprehensive Analysis of AIRS Near Surface Air Temperature and Water Vapor Over Land and Tropical Ocean

    NASA Astrophysics Data System (ADS)

    Dang, H. V. T.; Lambrigtsen, B.; Manning, E. M.; Fetzer, E. J.; Wong, S.; Teixeira, J.

    2015-12-01

    Version 6 (V6) of the Atmospheric Infrared Sounder's (AIRS) combined infrared and microwave (IR+MW) retrieval of near surface air temperature (NSAT) and water vapor (NSWV) is validated over the United States with the densely populated MESONET data. MESONET data is a collection of surface/near surface meteorological data from many federal and state agencies. The ones used for this analysis are measured from instruments maintained by the National Weather Service (NWS), the Federal Aviation Administration (FAA), and the Interagency Remote Automatic Weather Stations (RAWS), resulting in a little more than four thousand locations throughout the US. Over the Tropical oceans, NSAT and NSWV are compared to a network of moored buoys from the Tropical Atmosphere Ocean/Triangle Trans-Ocean Buoy Network (TAO/TRITON), and the Pilot Research Moored Array in the Tropical Atlantic (PIRATA). With the analysis of AIRS surface and near surface products over ocean, we glean information on how retrieval of NSAT and NSWV over land can be improved and why it needs some adjustments. We also compare AIRS initial guess of near surface products that are trained on fifty days of ECMWF along with AIRS calibrated radiances, to ECMWF analysis data. The comparison is done to show the differing characteristics of AIRS initial guesses from ECMWF.

  5. Climatic and anthropogenic stress on water levels: basin-scale observations with seismic noise

    NASA Astrophysics Data System (ADS)

    Lecocq, Thomas; Pedersen, Helle; Brenguier, Florent; Stammler, Klaus

    2016-04-01

    Monitoring changes in shear wave velocities within the crust have become possible through recently developed techniques based on seismic noise analysis. In the present work we address the challenge of using these techniques for environmental monitoring at upper crustal level. Our work is based on data from the broadband Gräfenberg array (Germany) which was installed in 1976 and for which the continuous data acquired has been preserved until today. Using state of the art pre-processing and cross-correlation techniques (MSNoise), we computed daily cross-correlation functions (CCF) between 4 stations (6 pairs) of the Gräfenberg array over the period 1977-2007. The daily CCFs are then stacked to form an average CCF per month. Instead of doing classic "one versus reference" comparisons, the monthly CCFs are compared pairwise using Moving Window Cross-Spectral analysis (MWCS). In total, 387 720 MWCS have been computed between 20 s and 80 s lapse time to obtain relative velocity changes (dv/v). All dv/v are then inverted using a Bayesian weighted least square procedure. Depending on the smoothing weight used during the inversion, seasonal to long term trends can be evidenced. The results show clear and stable trends in the data. We present possible causes explaining these trends and abrupt changes of dv/v by showing modelled (GLDAS) and observed climatic data together with anthropogenic observables. A combination of climatic (warmer surface temperatures, less rainfall) and anthropogenic (more population, more irrigated land) factors are the most probable causes of the progressive relative increase of seismic velocities under the Gräfenberg array. We interpret these results as a progressive depletion of the water resources in the large karstified Malm reservoir (Late Jurassic) below the array.

  6. Air Stripping Designs and Reactive Water Purification Processes for the Lunar Surface

    NASA Technical Reports Server (NTRS)

    Boul, Peter J.; Lange, Kevin; Conger, Bruce; Anderson, Molly

    2010-01-01

    Air stripping designs are considered to reduce the presence of volatile organic compounds in the purified water. Components of the wastewater streams are ranked by Henry's Law Constant and the suitability of air stripping in the purification of wastewater in terms of component removal is evaluated. Distillation processes are modeled in tandem with air stripping to demonstrate the potential effectiveness and utility of these methods in recycling wastewater on the Moon. Scaling factors for distillation and air stripping columns are presented to account for the difference in the lunar gravitation environment. Commercially available distillation and air stripping units which are considered suitable for Exploration Life Support are presented. The advantages to the various designs are summarized with respect to water purity levels, power consumption, and processing rates. An evaluation of reactive distillation and air stripping is presented with regards to the reduction of volatile organic compounds in the contaminated water and air. Among the methods presented, an architecture is presented for the evaluation of the simultaneous oxidation of organics in air and water. These and other designs are presented in light of potential improvements in power consumptions and air and water purities for architectures which include catalytic activity integrated into the water processor. In particular, catalytic oxidation of organics may be useful as a tool to remove contaminants that more traditional distillation and/or air stripping columns may not remove. A review of the current leading edge at the commercial level and at the research frontier in catalytically active materials is presented. Themes and directions from the engineering developments in catalyst design are presented conceptually in light of developments in the nanoscale chemistry of a variety of catalyst materials.

  7. Method and apparatus for extracting water from air using a desiccant

    DOEpatents

    Spletzer, Barry L.; Callow, Diane Schafer

    2003-01-01

    The present invention provides a method and apparatus for extracting liquid water from moist air using minimal energy input. The method can be considered as four phases: (1) adsorbing water from air into a desiccant, (2) isolating the water-laden desiccant from the air source, (3) desorbing water as vapor from the desiccant into a chamber, and (4) isolating the desiccant from the chamber, and compressing the vapor in the chamber to form liquid condensate. The liquid condensate can be removed for use. Careful design of the dead volumes and pressure balances can minimize the energy required. The dried air can be exchanged for fresh moist air and the process repeated. An apparatus comprises a first chamber in fluid communication with a desiccant, and having ports to intake moist air and exhaust dried air. The apparatus also comprises a second chamber in fluid communication with the desiccant. The second chamber allows variable internal pressure, and has a port for removal of liquid condensate. Each chamber can be configured to be isolated or in communication with the desiccant. The first chamber can be configured to be isolated or in communication with a course of moist air. Various arrangements of valves, pistons, and chambers are described.

  8. It's Alive!: Students Observe Air-Water Interface Samples Rich with Organisms

    ERIC Educational Resources Information Center

    Avant, Thomas

    2002-01-01

    This article describes an experiment, designed by Cindy Henk, manager of the Socolofsky Microscopy Center at Louisiana State University (LSU), that involved collecting and viewing microorganisms in the air-water interface. The experiment was participated by Leesville High School microbiology students. The students found that the air-water…

  9. Driving Students and Parents to Cleaner Air: An Interview with Michelle Waters

    ERIC Educational Resources Information Center

    Curriculum Review, 2006

    2006-01-01

    After spending three years as a kindergarten teacher and one as a reading specialist, Michelle Waters recently became the education outreach coordinator for the Georgia-based Clean Air Campaign. In that role, she has helped roll out a comprehensive Better Air Schools initiative to 20 Atlanta-area elementary schools. The program includes a…

  10. The transfer of carbon fibers through a commercial aircraft water separator and air cleaner

    NASA Technical Reports Server (NTRS)

    Meyers, J. A.

    1979-01-01

    The fraction of carbon fibers passing through a water separator and an air filter was determined in order to estimate the proportion of fibers outside a closed aircraft that are transmitted to the electronics through the air conditioning system. When both devices were used together and only fibers 3 mm or larger were considered, a transfer function of .001 was obtained.

  11. 75 FR 19307 - Safety Zone; Milwaukee Air and Water Show, Milwaukee, Lake Michigan, Milwaukee, WI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-14

    ... public dockets in the January 17, 2008, issue of the Federal Register (73 FR 3316). Public Meeting We do... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Milwaukee Air and Water Show, Milwaukee... ensure the safety of the public and vessels from the hazards associated with the Milwaukee Air and...

  12. Sensory descriptive Profiles of Air and Water Chilled Broiler Breast Fillets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Air chilled chicken products are gaining popularity in the USA. It has been claimed that air chilling (AC) results in improved tenderness and flavor of broiler meat compared with water chilling (WC). However, there was lack of published sensory study results to support the claims. The objective of...

  13. The Clean Air and Clean Water Acts: The "Fifth" and "Eighth" Most Significant Events.

    ERIC Educational Resources Information Center

    Knight, Laurel A.

    1991-01-01

    The history and impact of this federal legislation are discussed. An assessment of the progress of federal legislation in these areas is presented. Key issues for federal legislation regarding water and air quality are identified. (CW)

  14. SURVIVAL OF 'DAPHNIA', CRAYFISH, AND STONEFLIES IN AIR-SUPERSATURATED WATER

    EPA Science Inventory

    Daphnia magna, the crayfish Pacifastacus leniusculus, and nymphs of the stoneflies, Acroneuria californica, A. pacifica, and Pteronarcys californica were tested in the laboratory to determine their survival in different concentrations of air-supersaturated water. The mean 96-h LC...

  15. A CRITICAL ASSESSMENT OF ELEMENTAL MERCURY AIR/WATER EXCHANGE PARTNERS

    EPA Science Inventory

    Although evasion of elemental mercury from aquatic systems can significantly deplete net mercury accumulation resulting from atmospheric deposition, the current ability to model elemental mercury air/water exchange is limited by uncertainties in our understanding of all gaseous a...

  16. Boundary layer flow of air over water on a flat plate

    NASA Technical Reports Server (NTRS)

    Nelson, John; Alving, Amy E.; Joseph, Daniel D.

    1993-01-01

    A non-similar boundary layer theory for air blowing over a water layer on a flat plate is formulated and studied as a two-fluid problem in which the position of the interface is unknown. The problem is considered at large Reynolds number (based on x), away from the leading edge. A simple non-similar analytic solution of the problem is derived for which the interface height is proportional to x(sub 1/4) and the water and air flow satisfy the Blasius boundary layer equations, with a linear profile in the water and a Blasius profile in the air. Numerical studies of the initial value problem suggests that this asymptotic, non-similar air-water boundary layer solution is a global attractor for all initial conditions.

  17. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    SciTech Connect

    Not Available

    1991-10-01

    This report presents information concerning field procedures employed during the monitoring, well construction, well purging, sampling, and well logging at the Wright-Patterson Air Force Base. Activities were conducted in an effort to evaluate ground water contamination.

  18. Fluidized bed heat exchanger with water cooled air distributor and dust hopper

    DOEpatents

    Jukkola, Walfred W.; Leon, Albert M.; Van Dyk, Jr., Garritt C.; McCoy, Daniel E.; Fisher, Barry L.; Saiers, Timothy L.; Karstetter, Marlin E.

    1981-11-24

    A fluidized bed heat exchanger is provided in which air is passed through a bed of particulate material containing fuel. A steam-water natural circulation system is provided for heat exchange and the housing of the heat exchanger has a water-wall type construction. Vertical in-bed heat exchange tubes are provided and the air distributor is water-cooled. A water-cooled dust hopper is provided in the housing to collect particulates from the combustion gases and separate the combustion zone from a volume within said housing in which convection heat exchange tubes are provided to extract heat from the exiting combustion gases.

  19. A theoretical remark about waves on a static water surface beneath a layer of moving air

    NASA Astrophysics Data System (ADS)

    Kida, T.; Hayashi, R.; Yasutomi, Z.

    1990-12-01

    Grundy and Tuck (1987) treat the problem of large-amplitude waves on an air-water interface where the air is a steady nonuniform flow and the water is stationary. Both periodic nonlinear Stokes-like waves far downstream and a configuration of the water surface from the edge region of a hovercraft were computed. However, there is no work that treats the existence of such Stokes-like waves theoretically. The present work aims to prove the existence of such solutions in the case where the cushion pressure is low, that is, the depression at the upstream stagnation point from the mean water level is small.

  20. Water permeability of primary mouse keratinocyte cultures grown at the air-liquid interface

    SciTech Connect

    Cumpstone, M.B.; Kennedy, A.H.; Harmon, C.S.; Potts, R.O.

    1989-04-01

    In order to study the development of the epidermal permeability barrier in vitro, tritiated water (HTO) flux was measured across murine keratinocytes cultured at the air-liquid interface. Using a micro-diffusion technique, it was shown that air-liquid cultures form areas where the water diffusion is comparable to that of intact neonatal mouse skin. When water permeability is measured over a large area of the culture surface, however, significantly higher flux is obtained. These results show that under the culture conditions used, areas of water barrier comparable to intact neonatal mouse skin coexist with regions of less complete barrier formation.

  1. The behavior of NaOH at the air-water interface, a computational study

    SciTech Connect

    Wick, Collin D.; Dang, Liem X.

    2010-07-14

    Molecular dynamics simulations with a polarizable multi-state empirical valence bond model were carried out to investigate NaOH dissociation and pairing in water bulk and at the air-water interface. It was found that NaOH readily dissociates in the bulk, and the effect of the air-water interface on NaOH dissociation is fairly minor. Also, NaOH complexes were found to be strongly repelled from the air-water interface, which is consistent with surface tension measurements. At the same time, a very strong preference for the hydroxide anion to be oriented towards the air was found that persisted a few angstroms towards the liquid from the Gibbs dividing surface of the air-water interface. This was due to a preference for the hydroxide anion to have its hydrogen pointing towards the air, and the fact that the sodium ion was more likely to be found near the hydroxide oxygen than hydrogen. As a consequence, the simulation results show that surfaces of NaOH solutions should be negatively charged, in agreement with experimental observations, but also that the hydroxide has little surface affinity. This provides the possibility that the surface of water can be devoid of hydroxide anions, but still have a strong negative charge. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  2. Sedation and anesthesia of hatchling leatherback sea turtles (Dermochelys coriacea) for auditory evoked potential measurement in air and in water.

    PubMed

    Harms, Craig A; Piniak, Wendy E D; Eckert, Scott A; Stringer, Elizabeth M

    2014-03-01

    Sedation or anesthesia of hatchling leatherback sea turtles was employed to acquire auditory evoked potential (AEP) measurements in air and in water to assess their hearing sensitivity in relation to potential consequences from anthropogenic noise. To reduce artifacts in AEP collection caused by muscle movement, hatchlings were sedated with midazolam 2 or 3 mg/kg i.v. for in-air (n = 7) or in-water (n = 11) AEP measurements; hatchlings (n = 5) were anesthetized with ketamine 6 mg/kg and dexmedetomidine 30 microg/kg i.v. reversed with atipamezole 300 microg/kg, half i.m. and half i.v. for in-air AEP measurements. Midazolam-sedated turtles were also physically restrained with a light elastic wrap. For in-water AEP measurements, sedated turtles were brought to the surface every 45-60 sec, or whenever they showed intention signs for breathing, and not submerged again until they took a breath. Postprocedure temperature-corrected venous blood pH, pCO2, pO2, and HCO3- did not differ among groups, although for the midazolam-sedated in-water group, pCO2 trended lower, and in the ketamine-dexmedetomidine anesthetized group there was one turtle considered clinically acidotic (temperature-corrected pH = 7.117). Venous blood lactate was greater for hatchlings recently emerged from the nest than for turtles sedated with midazolam in air, with the other two groups falling intermediate between, but not differing significantly from the high and low lactate groups. Disruptive movements were less frequent with anesthesia than with sedation in the in-air group. Both sedation with midazolam and anesthesia with ketamine-dexmedetomidine were successful for allowing AEP measurements in hatchling leatherback sea turtles. Sedation allowed the turtle to protect its airway voluntarily while limiting flipper movement. Midazolam or ketamine-dexmedetomidine (and reversal with atipamezole) would be useful for other procedures requiring minor or major restraint in leatherback sea turtle hatchlings

  3. Development of a Model to Assess Masking Potential for Marine Mammals by the Use of Air Guns in Antarctic Waters.

    PubMed

    Wittekind, Dietrich; Tougaard, Jakob; Stilz, Peter; Dähne, Michael; Clark, Christopher W; Lucke, Klaus; von Benda-Beckmann, Sander; Ainslie, Michael A; Siebert, Ursula

    2016-01-01

    We estimated the long-range effects of air gun array noise on marine mammal communication ranges in the Southern Ocean. Air gun impulses are subject to significant distortion during propagation, potentially resulting in a quasi-continuous sound. Propagation modeling to estimate the received waveform was conducted. A leaky integrator was used as a hearing model to assess communication masking in three species due to intermittent/continuous air gun sounds. Air gun noise is most probably changing from impulse to continuous noise between 1,000 and 2,000 km from the source, leading to a reduced communication range for, e.g., blue and fin whales up to 2,000 km from the source. PMID:26611093

  4. Surface tension of ab initio liquid water at the water-air interface

    NASA Astrophysics Data System (ADS)

    Nagata, Yuki; Ohto, Tatsuhiko; Bonn, Mischa; Kühne, Thomas D.

    2016-05-01

    We report calculations on the surface tension of the water-air interface using ab initio molecular dynamics (AIMD) simulations. We investigate the influence of the cell size on surface tension of water from force field molecular dynamics simulations. We find that the calculated surface tension increases with increasing simulation cell size, thereby illustrating that a correction for finite size effects is essential for small systems that are customary in AIMD simulations. Moreover, AIMD simulations reveal that the use of a double-ζ basis set overestimates the experimentally measured surface tension due to the Pulay stress while more accurate triple and quadruple-ζ basis sets give converged results. We further demonstrate that van der Waals corrections critically affect the surface tension. AIMD simulations without the van der Waals correction substantially underestimate the surface tension while the van der Waals correction with the Grimme's D2 technique results in a value for the surface tension that is too high. The Grimme's D3 van der Waals correction provides a surface tension close to the experimental value. Whereas the specific choices for the van der Waals correction and basis sets critically affect the calculated surface tension, the surface tension is remarkably insensitive to the details of the exchange and correlation functionals, which highlights the impact of long-range interactions on the surface tension. Our simulated values provide important benchmarks, both for improving van der Waals corrections and AIMD simulations of aqueous interfaces.

  5. International Space Station Common Cabin Air Assembly Water Separator On-Orbit Operation, Failure, and Redesign

    NASA Technical Reports Server (NTRS)

    Balistreri, Steven F., Jr.; Shaw, Laura A.; Laliberte, Yvon

    2010-01-01

    The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The Water Separator (WS) pulls in air and water from the CHX, and centrifugally separates the mixture, sending the water to the condensate bus and the air back into the CHX outlet airstream. Two distinct early failures of the CCAA Water Separator in the Quest Airlock forced operational changes and brought about the re-design of the Water Separator to improve the useful life via modification kits. The on-orbit operational environment of the Airlock presented challenges that were not foreseen with the original design of the Water Separator. Operational changes were instituted to prolong the life of the third installed WS, while waiting for newly designed Water Separators to be delivered on-orbit. The modification kit design involved several different components of the Water Separator, including the innovative use of a fabrication technique to build the impellers used in Water Separators out of titanium instead of aluminum. The technique allowed for the cost effective production of the low quantity build. This paper will describe the failures of the Water Separators in the Quest Airlock, the operational constraints that were implemented to prolong the life of the installed Water Separators throughout the USOS, and the innovative re-design of the CCAA Water Separator.

  6. Monte Carlo simulation of a quantum noise limited Čerenkov detector based on air-spaced light guiding taper for megavoltage x-ray imaging

    SciTech Connect

    Teymurazyan, A.; Rowlands, J. A.; Pang, G.

    2014-04-15

    Purpose: Electronic Portal Imaging Devices (EPIDs) have been widely used in radiation therapy and are still needed on linear accelerators (Linacs) equipped with kilovoltage cone beam CT (kV-CBCT) or MRI systems. Our aim is to develop a new high quantum efficiency (QE) Čerenkov Portal Imaging Device (CPID) that is quantum noise limited at dose levels corresponding to a single Linac pulse. Methods: Recently a new concept of CPID for MV x-ray imaging in radiation therapy was introduced. It relies on Čerenkov effect for x-ray detection. The proposed design consisted of a matrix of optical fibers aligned with the incident x-rays and coupled to an active matrix flat panel imager (AMFPI) for image readout. A weakness of such design is that too few Čerenkov light photons reach the AMFPI for each incident x-ray and an AMFPI with an avalanche gain is required in order to overcome the readout noise for portal imaging application. In this work the authors propose to replace the optical fibers in the CPID with light guides without a cladding layer that are suspended in air. The air between the light guides takes on the role of the cladding layer found in a regular optical fiber. Since air has a significantly lower refractive index (∼1 versus 1.38 in a typical cladding layer), a much superior light collection efficiency is achieved. Results: A Monte Carlo simulation of the new design has been conducted to investigate its feasibility. Detector quantities such as quantum efficiency (QE), spatial resolution (MTF), and frequency dependent detective quantum efficiency (DQE) have been evaluated. The detector signal and the quantum noise have been compared to the readout noise. Conclusions: Our studies show that the modified new CPID has a QE and DQE more than an order of magnitude greater than that of current clinical systems and yet a spatial resolution similar to that of current low-QE flat-panel based EPIDs. Furthermore it was demonstrated that the new CPID does not require an

  7. Two-phase air-water stratified flow measurement using ultrasonic techniques

    SciTech Connect

    Fan, Shiwei; Yan, Tinghu; Yeung, Hoi

    2014-04-11

    In this paper, a time resolved ultrasound system was developed for investigating two-phase air-water stratified flow. The hardware of the system includes a pulsed wave transducer, a pulser/receiver, and a digital oscilloscope. The time domain cross correlation method is used to calculate the velocity profile along ultrasonic beam. The system is able to provide velocities with spatial resolution of around 1mm and the temporal resolution of 200μs. Experiments were carried out on single phase water flow and two-phase air-water stratified flow. For single phase water flow, the flow rates from ultrasound system were compared with those from electromagnetic flow (EM) meter, which showed good agreement. Then, the experiments were conducted on two-phase air-water stratified flow and the results were given. Compared with liquid height measurement from conductance probe, it indicated that the measured velocities were explainable.

  8. Theoretical study of vibrational energy transfer of free OH groups at the water-air interface

    NASA Astrophysics Data System (ADS)

    Zheng, Renhui; Wei, Wenmei; Sun, Yuanyuan; Song, Kai; Shi, Qiang

    2016-04-01

    Recent experimental studies have shown that the vibrational dynamics of free OH groups at the water-air interface is significantly different from that in bulk water. In this work, by performing molecular dynamics simulations and mixed quantum/classical calculations, we investigate different vibrational energy transfer pathways of free OH groups at the water-air interface. The calculated intramolecular vibrational energy transfer rate constant and the free OH bond reorientation time scale agree well with the experiment. It is also found that, due to the small intermolecular vibrational couplings, the intermolecular vibrational energy transfer pathway that is very important in bulk water plays a much less significant role in the vibrational energy relaxation of the free OH groups at the water-air interface.

  9. Fracture toughness of Alloy 600 and EN82H weld in air and water

    SciTech Connect

    Mills, W.J.; Brown, C.M.

    1999-06-01

    The fracture toughness of Alloy 600 and its weld, EN82H, was characterized in 54 C to 338 C air and hydrogenated water. Elastic-plastic J{sub IC} testing was performed due to the inherent high toughness of these materials. Alloy 600 exhibited excellent fracture toughness under all test conditions. While EN82H welds displayed excellent toughness in air and high temperature water, a dramatic toughness degradation occurred in water at temperatures below 149 C. Comparison of the cracking response in low temperature water with that for hydrogen-precharged specimens tested in air demonstrated that the loss in toughness is due to a hydrogen-induced intergranular cracking mechanism. At loading rates about approx. 1000 MPa {radical}m/h, the toughness in low temperature water is improved because there is insufficient time for hydrogen to embrittle grain boundaries. Electron fractographic examinations were performed to correlate macroscopic properties with key microstructural features and operative fracture mechanisms.

  10. Theoretical study of vibrational energy transfer of free OH groups at the water-air interface.

    PubMed

    Zheng, Renhui; Wei, Wenmei; Sun, Yuanyuan; Song, Kai; Shi, Qiang

    2016-04-14

    Recent experimental studies have shown that the vibrational dynamics of free OH groups at the water-air interface is significantly different from that in bulk water. In this work, by performing molecular dynamics simulations and mixed quantum/classical calculations, we investigate different vibrational energy transfer pathways of free OH groups at the water-air interface. The calculated intramolecular vibrational energy transfer rate constant and the free OH bond reorientation time scale agree well with the experiment. It is also found that, due to the small intermolecular vibrational couplings, the intermolecular vibrational energy transfer pathway that is very important in bulk water plays a much less significant role in the vibrational energy relaxation of the free OH groups at the water-air interface. PMID:27083739

  11. Major Upgrades to the AIRS Version-6 Water Vapor Profile Methodology

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Blaisdell, John; Iredell, Lena

    2015-01-01

    This research is a continuation of part of what was shown at the last AIRS Science Team Meeting and the AIRS 2015 NetMeeting. AIRS Version 6 was finalized in late 2012 and is now operational. Version 6 contained many significant improvements in retrieval methodology compared to Version 5. Version 6 retrieval methodology used for the water vapor profile q(p) and ozone profile O3(p) retrievals is basically unchanged from Version 5, or even from Version 4. Subsequent research has made significant improvements in both water vapor and O3 profiles compared to Version 6.

  12. Potable water recovery for spacecraft application by electrolytic pretreatment/air evaporation

    NASA Technical Reports Server (NTRS)

    Wells, G. W.

    1975-01-01

    A process for the recovery of potable water from urine using electrolytic pretreatment followed by distillation in a closed-cycle air evaporator has been developed and tested. Both the electrolytic pretreatment unit and the air evaporation unit are six-person, flight-concept prototype, automated units. Significantly extended wick lifetimes have been achieved in the air evaporation unit using electrolytically pretreated, as opposed to chemically pretreated, urine feed. Parametric test data are presented on product water quality, wick life, process power, maintenance requirements, and expendable requirements.

  13. X-ray microtomography determination of air-water interfacial area-water saturation relationships in sandy porous media.

    PubMed

    Costanza-Robinson, Molly S; Harrold, Katherine H; Lieb-Lappen, Ross M

    2008-04-15

    In this work, total smooth air-water interfacial areas were measured for a series of nine natural and model sandy porous media as a function of water saturation using synchrotron X-ray microtomography. Interfacial areas decreased linearly with water satuation, while the estimated maximum interfacial area compared favorably to the media geometric surface areas. Importantly, relative interfacial area (i.e., normalized by geometric surface area) versus water saturation plots for all media collapsed into a single linear cluster (r2 = 0.93), suggesting that geometric surface area is an important, and perhaps sufficient, descriptor of sandy media that governs total smooth interfacial area-water saturation relationships. Measured relationships were used to develop an empirical model for estimating interfacial area-water saturation relationships for sandy porous media. Model-based interfacial area estimates for independent media were generally slightly higher than interfacial areas measured using aqueous-phase interfacial tracer methods, which may indicate that microtomography captures regions of the air-water interface that are not accessible to aqueous-phase interfacial tracers. The empirical model presented here requires only average particle diameter and porosity as input parameters and can be used to readily estimate air-water interfacial area-water saturation relationships for sandy porous media. PMID:18497149

  14. Design and preliminary tests of a blade tip air mass injection system for vortex modification and possible noise reduction on a full-scale helicopter rotor

    NASA Technical Reports Server (NTRS)

    Pegg, R. J.; Hosier, R. N.; Balcerak, J. C.; Johnson, H. K.

    1975-01-01

    Full-scale tests were conducted on the Langley helicopter rotor test facility as part of a study to evaluate the effectiveness of a turbulent blade tip air mass injection system in alleviating the impulsive noise (blade slap) caused by blade-vortex interaction. Although blade-slap conditions could not be induced during these tests, qualitative results from flow visualization studies using smoke showed that the differential velocity between the jet velocity and the rotor tip speed was a primary parameter controlling the vortex modification.

  15. Reducing Water/Hull Drag By Injecting Air Into Grooves

    NASA Technical Reports Server (NTRS)

    Reed, Jason C.; Bushnell, Dennis M.; Weinstein, Leonard M.

    1991-01-01

    Proposed technique for reduction of friction drag on hydrodynamic body involves use of grooves and combinations of surfactants to control motion of layer on surface of such body. Surface contains many rows of side-by-side, evenly spaced, longitudinal grooves. Dimensions of grooves and sharpnesses of tips in specific case depends on conditions of flow about vessel. Requires much less air than does microbubble-injection method.

  16. Effects of background noise on total noise annoyance

    NASA Technical Reports Server (NTRS)

    Willshire, K. F.

    1987-01-01

    Two experiments were conducted to assess the effects of combined community noise sources on annoyance. The first experiment baseline relationships between annoyance and noise level for three community noise sources (jet aircraft flyovers, traffic and air conditioners) presented individually. Forty eight subjects evaluated the annoyance of each noise source presented at four different noise levels. Results indicated the slope of the linear relationship between annoyance and noise level for the traffic noise was significantly different from that of aircraft and of air conditioner noise, which had equal slopes. The second experiment investigated annoyance response to combined noise sources, with aircraft noise defined as the major noise source and traffic and air conditioner noise as background noise sources. Effects on annoyance of noise level differences between aircraft and background noise for three total noise levels and for both background noise sources were determined. A total of 216 subjects were required to make either total or source specific annoyance judgements, or a combination of the two, for a wide range of combined noise conditions.

  17. Oxygen and Air Nanobubble Water Solution Promote the Growth of Plants, Fishes, and Mice

    PubMed Central

    Ebina, Kosuke; Shi, Kenrin; Hirao, Makoto; Hashimoto, Jun; Kawato, Yoshitaka; Kaneshiro, Shoichi; Morimoto, Tokimitsu; Koizumi, Kota; Yoshikawa, Hideki

    2013-01-01

    Nanobubbles (<200 nm in diameter) have several unique properties such as long lifetime in liquid owing to its negatively charged surface, and its high gas solubility into the liquid owing to its high internal pressure. They are used in variety of fields including diagnostic aids and drug delivery, while there are no reports assessing their effects on the growth of lives. Nanobubbles of air or oxygen gas were generated using a nanobubble aerator (BUVITAS; Ligaric Company Limited, Osaka, Japan). Brassica campestris were cultured hydroponically for 4 weeks within air-nanobubble water or within normal water. Sweetfish (for 3 weeks) and rainbow trout (for 6 weeks) were kept either within air-nanobubble water or within normal water. Finally, 5 week-old male DBA1/J mice were bred with normal free-chaw and free-drinking either of oxygen-nanobubble water or of normal water for 12 weeks. Oxygen-nanobubble significantly increased the dissolved oxygen concentration of water as well as concentration/size of nanobubbles which were relatively stable for 70 days. Air-nanobubble water significantly promoted the height (19.1 vs. 16.7 cm; P<0.05), length of leaves (24.4 vs. 22.4 cm; P<0.01), and aerial fresh weight (27.3 vs. 20.3 g; P<0.01) of Brassica campestris compared to normal water. Total weight of sweetfish increased from 3.0 to 6.4 kg in normal water, whereas it increased from 3.0 to 10.2 kg in air-nanobubble water. In addition, total weight of rainbow trout increased from 50.0 to 129.5 kg in normal water, whereas it increased from 50.0 to 148.0 kg in air-nanobubble water. Free oral intake of oxygen-nanobubble water significantly promoted the weight (23.5 vs. 21.8 g; P<0.01) and the length (17.0 vs. 16.1 cm; P<0.001) of mice compared to that of normal water. We have demonstrated for the first time that oxygen and air-nanobubble water may be potentially effective tools for the growth of lives. PMID:23755221

  18. Oxygen and air nanobubble water solution promote the growth of plants, fishes, and mice.

    PubMed

    Ebina, Kosuke; Shi, Kenrin; Hirao, Makoto; Hashimoto, Jun; Kawato, Yoshitaka; Kaneshiro, Shoichi; Morimoto, Tokimitsu; Koizumi, Kota; Yoshikawa, Hideki

    2013-01-01

    Nanobubbles (<200 nm in diameter) have several unique properties such as long lifetime in liquid owing to its negatively charged surface, and its high gas solubility into the liquid owing to its high internal pressure. They are used in variety of fields including diagnostic aids and drug delivery, while there are no reports assessing their effects on the growth of lives. Nanobubbles of air or oxygen gas were generated using a nanobubble aerator (BUVITAS; Ligaric Company Limited, Osaka, Japan). Brassica campestris were cultured hydroponically for 4 weeks within air-nanobubble water or within normal water. Sweetfish (for 3 weeks) and rainbow trout (for 6 weeks) were kept either within air-nanobubble water or within normal water. Finally, 5 week-old male DBA1/J mice were bred with normal free-chaw and free-drinking either of oxygen-nanobubble water or of normal water for 12 weeks. Oxygen-nanobubble significantly increased the dissolved oxygen concentration of water as well as concentration/size of nanobubbles which were relatively stable for 70 days. Air-nanobubble water significantly promoted the height (19.1 vs. 16.7 cm; P<0.05), length of leaves (24.4 vs. 22.4 cm; P<0.01), and aerial fresh weight (27.3 vs. 20.3 g; P<0.01) of Brassica campestris compared to normal water. Total weight of sweetfish increased from 3.0 to 6.4 kg in normal water, whereas it increased from 3.0 to 10.2 kg in air-nanobubble water. In addition, total weight of rainbow trout increased from 50.0 to 129.5 kg in normal water, whereas it increased from 50.0 to 148.0 kg in air-nanobubble water. Free oral intake of oxygen-nanobubble water significantly promoted the weight (23.5 vs. 21.8 g; P<0.01) and the length (17.0 vs. 16.1 cm; P<0.001) of mice compared to that of normal water. We have demonstrated for the first time that oxygen and air-nanobubble water may be potentially effective tools for the growth of lives. PMID:23755221

  19. Critical air/water blow-down in safety valves at low qualities.

    PubMed

    Moncalvo, D; Friedel, L

    2011-02-28

    Critical air/water blow-downs in safety valves for qualities from 0.01 to 0.113 and mass flow rates from 1.5 up to 4.3 kg/s have been observed in our test facility. These critical blow-downs are characterized by a large void fraction and by an intense mixing of the phases both in the valve body and in the outlet pipe. A qualitative estimation of the flow pattern in the outlet pipe using the map of Taitel and Dukler suggests that these air/water flows are intermittent flows--presumably slug flows--evolving to annular flows for qualities above 0.1. Intermittent flows are also predicted for critical air/water and air/glycerine flows taken from the literature for the same safety valve at slightly larger relieving pressures. PMID:21227579

  20. Experimental study on bi-phase flow Air-Oil in Water Emulsion

    NASA Astrophysics Data System (ADS)

    Arnone, Davide; Poesio, Pietro

    2015-11-01

    Bi-phase slug flow oil-in-water emulsion [5%-20%] and air through a horizontal pipe (inner diameter 22mm) is experimentally studied. A test with water and air has been performed as comparison. First we create and analyze the flow pattern map to identify slug flow liquid and air inlet conditions. Flow maps are similar for all the used liquid. A video analysis procedure using an high speed camera has been created to obtain all the characteristics of unit slugs: slug velocity, slug length, bubble velocity, bubbles length and slug frequency. We compare translational velocity and frequency with models finding a good agreement. We calculate the pdfs of the lengths to find the correlations between mean values and STD on different air and liquid superficial velocities. We also perform pressure measurements along the pipe. We conclude that the percentage of oil-in- water has no influence on results in terms of velocity, lengths, frequency and pressure drop.

  1. Validating AIRS upper atmosphere water vapor retrievals using aircraft and balloon in situ measurements

    NASA Astrophysics Data System (ADS)

    Hagan, D. E.; Webster, C. R.; Farmer, C. B.; May, R. D.; Herman, R. L.; Weinstock, E. M.; Christensen, L. E.; Lait, L. R.; Newman, P. A.

    2004-11-01

    This paper provides an initial assessment of the accuracy of the Atmospheric Infrared Sounder (AIRS) water vapor retrievals from 500 to 100 mbar. AIRS satellite measurements are compared with accurate aircraft (NASA WB57) and balloon in situ water vapor measurements obtained during the NASA Pre-Aura Validation Experiment (Pre-AVE) in Costa Rica during Jan. 2004. AIRS retrieval (each pressure level of a single footprint) of water vapor amount agrees with the in situ measurements to ~25% or better if matched closely in time (1 hr) and space (50-100 km). Both AIRS and in situ measurements observe similar significant variation in moisture amount over a two-day period, associated with large-scale changes in weather patterns.

  2. Using advanced oxidation treatment for biofilm inactivation by varying water vapor content in air plasma

    NASA Astrophysics Data System (ADS)

    Ryota, Suganuma; Koichi, Yasuoka

    2015-09-01

    Biofilms are caused by environmental degradation in food factories and medical facilities. The inactivation of biofilms involves making them react with chemicals including chlorine, hydrogen peroxide, and ozone, although inactivation using chemicals has a potential problem because of the hazardous properties of the residual substance and hydrogen peroxide, which have slow reaction velocity. We successfully performed an advanced oxidation process (AOP) using air plasma. Hydrogen peroxide and ozone, which were used for the formation of OH radicals in our experiment, were generated by varying the amount of water vapor supplied to the plasma. By varying the content of the water included in the air, the main product was changed from air plasma. When we increased the water content in the air, hydrogen peroxide was produced, while ozone peroxide was produced when we decreased the water content in the air. By varying the amount of water vapor, we realized a 99.9% reduction in the amount of bacteria in the biofilm when we discharged humidified air only. This work was supported by JSPS KAKENHI Grant Number 25630104.

  3. Air-cooled condensers eliminate plant water use

    SciTech Connect

    Wurtz, W.; Peltier, R.

    2008-09-15

    River or ocean water has been the mainstay for condensing turbine exhaust steam since the first steam turbine began generating electricity. A primary challenge facing today's plant developers, especially in drought-prone regions, is incorporating processes that reduce plant water use and consumption. One solution is to shed the conventional mindset that once-through cooling is the only option and adopt dry cooling technologies that reduce plant water use from a flood to a few sips. A case study at the Astoria Energy plant, New York City is described. 14 figs.

  4. 78 FR 17229 - Notice of Lodging of Proposed Consent Decree Amendment Under the Clean Air Act; the Clean Water...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ... of Lodging of Proposed Consent Decree Amendment Under the Clean Air Act; the Clean Water Act; the Resource Conservation and Recovery Act; the Missouri Air Conservation Law; the Missouri Clean Water Law and..., the Clean Water Act, the Missouri Clean Water Law, the Resource Conservation and Recovery......

  5. Dry under water: comparative morphology and functional aspects of air-retaining insect surfaces.

    PubMed

    Balmert, Alexander; Florian Bohn, Holger; Ditsche-Kuru, Petra; Barthlott, Wilhelm

    2011-04-01

    Superhydrophobic surfaces prevent certain body parts of semiaquatic and aquatic insects from getting wet while submerged in water. The air layer on these surfaces can serve the insects as a physical gill. Using scanning electron microscopy, we investigated the morphology of air-retaining surfaces in five insect species with different levels of adaptation to aquatic habitats. We found surfaces with either large and sparse hairs (setae), small and dense hairs (microtrichia), or hierarchically structured surfaces with both types of hairs. The structural parameters and air-film persistence of these surfaces were compared. Air-film persistence varied between 2 days in the beetle Galerucella nymphaea possessing only sparse setae and more than 120 days in the bugs Notonecta glauca and Ilyocoris cimicoides possessing dense microtrichia (up to 6.6 × 10(6) microtrichia per millimeter square). From our results, we conclude that the density of the surface structures is the most important factor that affects the persistence of air films. Combinations of setae and microtrichia are not decisive for the overall persistence of the air film but might provide a thick air store for a short time and a thin but mechanically more stable air film for a long time. Thus, we assume that a dense cover of microtrichia acts as a "backup system" preventing wetting of the body surface in case the air-water interface is pressed toward the surface. Our findings might be beneficial for the development of biomimetic surfaces for long-term air retention and drag reduction under water. In addition, the biological functions of the different air retention capabilities are discussed. PMID:21290417

  6. Air-Liquid Interfaces: II. Water Structure and Salts

    NASA Astrophysics Data System (ADS)

    Allen, Heather; Gopalakrishnan, Sandhya; Ma, Gang; Liu, Dingfang; Levering, Lori

    2004-03-01

    Aqueous salt solutions were investigated using scanning sum frequency generation (SFG), a highly surface-selective spectroscopy, and ATR-IR and Raman spectroscopies. Water surface structure was investigated for NaF, NaCl, NaBr and NaI aqueous solutions and surface data indicate a significantly disturbed hydrogen bonding environment from that of neat water. The spectra strongly suggest the presence of bromide and iodide anions in the interfacial region in addition to an increase in interfacial depth; yet the surfaces of the sodium fluoride and chloride salt solutions do not show evidence of surface water perturbation. Ammonium chloride and sulfate, and sodium sulfate aqueous solutions were also investigated. Surface water structure varied considerably between the three salt solutions. Electric double layer effects are indicated.

  7. 20 Years of Air-Water Gas Exchange Observations for Pesticides in the Western Arctic Ocean.

    PubMed

    Jantunen, Liisa M; Wong, Fiona; Gawor, Anya; Kylin, Henrik; Helm, Paul A; Stern, Gary A; Strachan, William M J; Burniston, Deborah A; Bidleman, Terry F

    2015-12-01

    The Arctic has been contaminated by legacy organochlorine pesticides (OCPs) and currently used pesticides (CUPs) through atmospheric transport and oceanic currents. Here we report the time trends and air-water exchange of OCPs and CUPs from research expeditions conducted between 1993 and 2013. Compounds determined in both air and water were trans- and cis-chlordanes (TC, CC), trans- and cis-nonachlors (TN, CN), heptachlor exo-epoxide (HEPX), dieldrin (DIEL), chlorobornanes (ΣCHBs and toxaphene), dacthal (DAC), endosulfans and metabolite endosulfan sulfate (ENDO-I, ENDO-II, and ENDO SUL), chlorothalonil (CHT), chlorpyrifos (CPF), and trifluralin (TFN). Pentachloronitrobenzene (PCNB and quintozene) and its soil metabolite pentachlorothianisole (PCTA) were also found in air. Concentrations of most OCPs declined in surface water, whereas some CUPs increased (ENDO-I, CHT, and TFN) or showed no significant change (CPF and DAC), and most compounds declined in air. Chlordane compound fractions TC/(TC + CC) and TC/(TC + CC + TN) decreased in water and air, while CC/(TC + CC + TN) increased. TN/(TC + CC + TN) also increased in air and slightly, but not significantly, in water. These changes suggest selective removal of more labile TC and/or a shift in chlordane sources. Water-air fugacity ratios indicated net volatilization (FR > 1.0) or near equilibrium (FR not significantly different from 1.0) for most OCPs but net deposition (FR < 1.0) for ΣCHBs. Net deposition was shown for ENDO-I on all expeditions, while the net exchange direction of other CUPs varied. Understanding the processes and current state of air-surface exchange helps to interpret environmental exposure and evaluate the effectiveness of international protocols and provides insights for the environmental fate of new and emerging chemicals. PMID:26196214

  8. DIRECT TRACE ANALYSIS OF VOLATILE ORGANIC COMPOUNDS IN AIR USING ION TRAP MASS SPECTROMETERS WITH FILTERED NOISE FIELDS

    EPA Science Inventory

    Two ion trap mass spectrometers and direct air sampling interfaces are being evaluated in the laboratory for monitoring toxic air pollutants in real time. he mass spectrometers are the large, laboratory-based Finnigan MAT ion trap (ITMS) and the compact, field-deployable Teledyne...

  9. Comparative intelligibility of speech materials processed by standard Air Force voice communication systems in the presence of simulated cockpit noise

    NASA Astrophysics Data System (ADS)

    Moore, T. J.; Nixon, C. W.; McKinley, R. L.

    1981-06-01

    Among the systems evaluated was the ARC-164 radio which will serve as the reference system against which the performance of jam-resistant, secure systems developed in the immediate future will be compared. Relative differences found between male and female talkers under various levels of simulated cockpit noise are reported.

  10. EFFECTS OF AIR-SUPERSATURATED WATER ON ADULT SOCKEYE SALMON (ONCORHYNCHUS NERKA)

    EPA Science Inventory

    Adult sockeye salmon (Oncorhynchus nerka) were exposed to air supersaturated water in the laboratory from July 8 to August 13, 1974, approximately the same time period that they are exposed to supersaturated water during their movement through the lower and middle sections of the...

  11. AIR LAND WATER ANALYSIS SYSTEM (ALEAS): A MULTI-MEDIA MODEL FOR TOXIC SUBSTANCES

    EPA Science Inventory

    The Air Land Water Analysis System (ALWAS) is a multi-media environmental model for describing the atmospheric dispersion of toxicants, the surface runoff of deposited toxicants, and the subsequent fate of these materials in surface water bodies. ALWAS dipicts the spatial and tem...

  12. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    SciTech Connect

    Not Available

    1992-03-01

    This report presents information related to the sampling of ground water at the Wright-Patterson Air Force Base. It is part of an investigation into possible ground water contamination. Information concerns well drilling/construction; x-ray diffraction and sampling; soil boring logs; and chain-of-custody records.

  13. Calibration of Dissolved Noble Gas Mass Spectrometric Measurements by an Air-Water Equilibration System

    NASA Astrophysics Data System (ADS)

    Hillegonds, Darren; Matsumoto, Takuya; Jaklitsch, Manfred; Han, Liang-Feng; Klaus, Philipp; Wassenaar, Leonard; Aggarwal, Pradeep

    2013-04-01

    Precise measurements by mass spectrometry of dissolved noble gases (He, Ar, Ne, Kr, Xe) in water samples require careful calibration against laboratory standards with known concentrations. Currently, air pipettes are used for day-to-day calibrations, making estimation of overall analytical uncertainties for dissolved noble gas measurements in water difficult. Air equilibrated water (AEW) is often used as a matrix-equivalent laboratory standard for dissolved gases in groundwater, because of the well-known and constant fractions of noble gases in the atmosphere. AEW standards, however, are only useful if the temperature and pressure of the gas-water equilibrium can be controlled and measured precisely (i.e., to better than 0.5%); contamination and partial sample degassing must also be prevented during sampling. Here we present the details of a new custom air-water equilibration system which consists of an insulated 600 liter tank filled with deionized water, held isothermally at a precise target temperature (<0.05 °C) through the use of a heat exchanger. The temperature and total dissolved gas of the water in the tank are monitored continually, as are atmospheric pressure and air temperature in the laboratory. Different noble gas concentration standards can be reliably produced by accurately controlling the water temperature of the equilibration system. Equilibration characteristics and reproducibility of this system for production of copper tubes containing known amounts of noble gases will be presented.

  14. Evaluation of Vertically Resolved Water Winds from AIRS using Hurricane Katrina

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Dobkowski, Edwin C.; Gregorich, David T.

    2005-01-01

    The knowledge of wind velocity as a function of altitude is key to weather forecast improvements. The ability of hyperspectral sounders in principle to measure vertically resolved water winds, which has long been recognized, has been tested with Atmospheric Infrared Sounder (AIRS) data. AIRS retrievals of total column water above 300 mb have been correlated with the radiosonde upper-tropospheric wind velocity and moisture data. The excellent correlation is illustrated with results obtained from hurricane Katrina and from the western United States. AIRS is a hyperspectral infrared sounder in low Earth orbit. It was launched in May 2002. We illustrate the use of AIRS data for the measurement of upper tropospheric water by using the 2387/cm CO2 R-branch channel and the 1551/cm water vapor channel. The 2387/cm channel measures the temperature at 300 mb totally independent of water vapor. The weighting function of the 1551/cm channel peaks at 300 mb only under moist conditions; the peak shifts downward (higher temperature) for less water and upward (lower temperature) for more water. The difference between the brightness temperatures bt2387 and bt1551 cancels the local several degree weather related variability of the temperature and measures the component due to the water vapor at 300 mb.

  15. RELATIONSHIP BETWEEN WATER TEMPERATURES AND AIR TEMPERATURES FOR CENTRAL US STREAMS

    EPA Science Inventory

    An analysis of the relationship between air and stream water temperature records for 11 rivers located in the central United States was conducted. he reliability of commonly available water temperature records was shown to be of unequal quality. imple linear relationships between...

  16. The patterns and implications of diurnal variations in d-excess of plant water, shallow soil water and air moisture

    NASA Astrophysics Data System (ADS)

    Zhao, L.; Wang, L.; Xiao, H.; Cheng, G.; Ruan, Y.; Zhou, M.; Wang, F.

    2014-04-01

    Deuterium excess (d-excess) of air moisture is traditionally considered as a conservative tracer of oceanic evaporation conditions. Recent studies challenge this view and emphasize the importance of vegetation activity in controlling the dynamics of air moisture d-excess. However direct field observations supporting the role of vegetation in d-excess variations is not well documented. In this study, we quantified d-excess of air moisture, leaf and xylem water of multiple dominant species as well as shallow soil water (5 and 10 cm) at hourly interval during three extensive field campaigns at two climatically different locations within the Heihe River Basin. The results showed that with the increase of temperature (T) and decrease of relative humidity (RH), the δD-δ18O plots of leaf water, xylem water and shallow soil water deviated gradually from their corresponding local meteoric water line. There were significant differences in d-excess values among different water pools at all the study sites. The most positive d-excess values were found in air moisture (9.3‰) and the most negative d-excess values (-85.6‰) were found in leaf water. The d-excess values of air moisture (dmoisture) and leaf water (dleaf) during the sunny days, and shallow soil water (dsoil) during the first sunny day after rain event showed strong diurnal patterns. There were significantly positive relationships between dleaf and RH and negative relationships between dmoisture and RH. The correlations of dleaf and dmoisture with T were opposite to their relationships with RH. In addition, we found the opposite diurnal variations for dleaf and dmoisture during the sunny day, and for dleaf during the sunny days, and shallow soil water dsoil and dmoisture during the first sunny day after rain event. Significant negative relationships were found between dleaf and dmoisture in all the sites during the sunny day. Our results provide direct evidence that dmoisture of the surface air at continental

  17. Hearing and underwater noise exposure

    NASA Astrophysics Data System (ADS)

    Smith, P. F.

    1985-08-01

    Exposure of divers to intense noise in water is increasing, yet there is no general hearing conservation standard for such exposures. This paper reviews three theories of underwater hearing as well as empirical data in order to identify some requirements that an underwater conservation standard must meet. Among the problems considered are hearing sensitivity in water, the frequency and dynamic ranges of the water-immersed ear, and nonauditory effects of underwater sound. It is concluded that: first, no well developed theoretical basis exists for extrapolating hearing conservation standards for airborne noise to the underwater situation; second, the empirical data on underwater hearing suggest that the frequency range covered by an underwater hearing conservation standard must be broader than is the case in air; third, in order to establish a general hearing conservation standard for underwater noise exposure further research is required on the dynamic range of the ear in water; fourth, underwater noise exposure may involve hazards to other body systems than the ear; and fifth, some exposure conditions may interfere with job performance of divers.

  18. Comparison of Upper Tropospheric Water Vapor from AIRS and Cryogenic Frostpoint Hygrometers

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Vomel, Holger

    2004-01-01

    Upper tropospheric water vapor (UTWV) from the Atmospheric Infrared Sounder (AIRS) experiment on NASA's Aqua spacecraft has the potential of addressing several important climate questions. The specified AIRS system measurement uncertainty for water vapor is 20 percent absolute averaged over 2 km layers. Cryogenic frostpoint hygrometers (CFH) are balloon-borne water vapor sensors responsive from the surface into the lower stratosphere. Several dozen coincident, collocated CFH profiles have been obtained for AlRS validation. The combination of CFH sensitivity and sample size offers a statistically compelling picture of AIRS UTWV measurement capability. We present a comparison between CFH observations and AlRS retrievals. We focus on the altitude range from the middle troposphere up to heights at the limits of AlRS sensitivity to water vapor, believed to be around 100-1 50 hPa.

  19. Making noise comfortable for people

    SciTech Connect

    Leventhall, H.G.; Wise, S.S.

    1998-10-01

    Typical HVAC noise may produce an uncomfortable environment, leading to the associated problems of general dissatisfaction and reduced productivity. It is not sufficient to have good thermal, lighting, and air cleanliness conditions if the noise is disturbing. In this paper, noise comfort is considered, with special emphasis on the developing criteria for low-frequency noise.

  20. Enforcement under the 1990 CAAA: Hot air or hot water?

    SciTech Connect

    Hanisch, J.

    1998-06-01

    The 1990 Clean Air Act Amendments (CAAA) have caused varying degrees of anxiety in facility and environmental managers. How worried should they be? One area of special concern is Title VII, Provisions Relating to Enforcement, which has led to field citations, new civil penalties, provisions for citizen suits and, of most concern, the new criminal provision. The CAAA include strong new enforcement authority, which allows the US Environmental Protection Agency (EPA) to take swift and strong action against violators. The Agency can issue tickets up to $5,000 per violation, penalties up to $25,000 per day for administrative penalties and $250,000 and up to five years in prison for criminal violations. Sources that maintain compliance with air pollution regulations and maintain accurate records and documentation have nothing to fear from these new regulations. However, sources that violate federal requirements, falsify records or knowingly create risks to the environment or human health can look forward to aggressive enforcement by EPA. This article briefly discusses the new provisions, whom they affect, how one may be able to minimize the potential liabilities and what to do if the EPA begins an enforcement action.

  1. The temperature of inspired air influences respiratory water loss in young lambs.

    PubMed

    Riesenfeld, T; Hammarlund, K; Norsted, T; Sedin, G

    1994-01-01

    The temperature of inspired air influences respiratory water loss (RWL) in young lambs. Water loss from the airways, oxygen consumption and carbon dioxide production were measured using an open flow-through system with a mass spectrometer, specially equipped with a water channel, for gas analysis. Measurements were made in 9 newborn lambs at 3 different inspired air temperatures keeping all other environmental factors stable, including the ambient air temperature. The water content of the inspired air was also kept constant. RWL was found to be 9.9 +/- 3.9 (SD) mg/kg/min when the temperature of the inspired air was 30 degrees C and its humidity 30%. At 40 degrees C this loss increased to 11.5 +/- 3.6 mg/kg/min, and at about 60 degrees C it increased further to 26.0 +/- 8.2 mg/kg/min. The oxygen consumption was 10.0 +/- 0.8 (SD) ml/kg/min at 30 degrees C and 10.4 +/- 2.0 ml/kg/min at 60 degrees C, a change which is not significant. Thus RWL is influenced by the temperature of the inspired air, with greater loss at higher temperatures. PMID:8054401

  2. Performance Evaluation of the Operational Air Quality Monitor for Water Testing Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Wallace, William T.; Limero, Thomas F.; Gazda, Daniel B.; Macatangay, Ariel V.; Dwivedi, Prabha; Fernandez, Facundo M.

    2014-01-01

    In the history of manned spaceflight, environmental monitoring has relied heavily on archival sampling. For short missions, this type of sample collection was sufficient; returned samples provided a snapshot of the presence of chemical and biological contaminants in the spacecraft air and water. However, with the construction of the International Space Station (ISS) and the subsequent extension of mission durations, soon to be up to one year, the need for enhanced, real-time environmental monitoring became more pressing. The past several years have seen the implementation of several real-time monitors aboard the ISS, complemented with reduced archival sampling. The station air is currently monitored for volatile organic compounds (VOCs) using gas chromatography-differential mobility spectrometry (Air Quality Monitor [AQM]). The water on ISS is analyzed to measure total organic carbon and biocide concentrations using the Total Organic Carbon Analyzer (TOCA) and the Colorimetric Water Quality Monitoring Kit (CWQMK), respectively. The current air and water monitors provide important data, but the number and size of the different instruments makes them impractical for future exploration missions. It is apparent that there is still a need for improvements in environmental monitoring capabilities. One such improvement could be realized by modifying a single instrument to analyze both air and water. As the AQM currently provides quantitative, compound-specific information for target compounds present in air samples, and many of the compounds are also targets for water quality monitoring, this instrument provides a logical starting point to evaluate the feasibility of this approach. In this presentation, we will discuss our recent studies aimed at determining an appropriate method for introducing VOCs from water samples into the gas phase and our current work, in which an electro-thermal vaporization unit has been interfaced with the AQM to analyze target analytes at the

  3. Water from air: an overlooked source of moisture in arid and semiarid regions.

    PubMed

    McHugh, Theresa A; Morrissey, Ember M; Reed, Sasha C; Hungate, Bruce A; Schwartz, Egbert

    2015-01-01

    Water drives the functioning of Earth's arid and semiarid lands. Drylands can obtain water from sources other than precipitation, yet little is known about how non-rainfall water inputs influence dryland communities and their activity. In particular, water vapor adsorption--movement of atmospheric water vapor into soil when soil air is drier than the overlying air--likely occurs often in drylands, yet its effects on ecosystem processes are not known. By adding (18)O-enriched water vapor to the atmosphere of a closed system, we documented the conversion of water vapor to soil liquid water across a temperature range typical of arid ecosystems. This phenomenon rapidly increased soil moisture and stimulated microbial carbon (C) cycling, and the flux of water vapor to soil had a stronger impact than temperature on microbial activity. In a semiarid grassland, we also observed that non-rainfall water inputs stimulated microbial activity and C cycling. Together these data suggest that, during rain-free periods, atmospheric moisture in drylands may significantly contribute to variation in soil water content, thereby influencing ecosystem processes. The simple physical process of adsorption of water vapor to soil particles, forming liquid water, represents an overlooked but potentially important contributor to C cycling in drylands. PMID:26345615

  4. Water from air: an overlooked source of moisture in arid and semiarid regions

    PubMed Central

    McHugh, Theresa A.; Morrissey, Ember M.; Reed, Sasha C.; Hungate, Bruce A.; Schwartz, Egbert

    2015-01-01

    Water drives the functioning of Earth’s arid and semiarid lands. Drylands can obtain water from sources other than precipitation, yet little is known about how non-rainfall water inputs influence dryland communities and their activity. In particular, water vapor adsorption – movement of atmospheric water vapor into soil when soil air is drier than the overlying air – likely occurs often in drylands, yet its effects on ecosystem processes are not known. By adding 18O-enriched water vapor to the atmosphere of a closed system, we documented the conversion of water vapor to soil liquid water across a temperature range typical of arid ecosystems. This phenomenon rapidly increased soil moisture and stimulated microbial carbon (C) cycling, and the flux of water vapor to soil had a stronger impact than temperature on microbial activity. In a semiarid grassland, we also observed that non-rainfall water inputs stimulated microbial activity and C cycling. Together these data suggest that, during rain-free periods, atmospheric moisture in drylands may significantly contribute to variation in soil water content, thereby influencing ecosystem processes. The simple physical process of adsorption of water vapor to soil particles, forming liquid water, represents an overlooked but potentially important contributor to C cycling in drylands. PMID:26345615

  5. Water from air: An overlooked source of moisture in arid and semiarid regions

    USGS Publications Warehouse

    McHugh, Theresa; Morrissey, Ember M; Reed, Sasha C.; Hungate, Bruce A.; Schwartz, Egbert

    2015-01-01

    Water drives the functioning of Earth’s arid and semiarid lands. Drylands can obtain water from sources other than precipitation, yet little is known about how non-rainfall water inputs influence dryland communities and their activity. In particular, water vapor adsorption – movement of atmospheric water vapor into soil when soil air is drier than the overlying air – likely occurs often in drylands, yet its effects on ecosystem processes are not known. By adding 18O-enriched water vapor to the atmosphere of a closed system, we documented the conversion of water vapor to soil liquid water across a temperature range typical of arid ecosystems. This phenomenon rapidly increased soil moisture and stimulated microbial carbon (C) cycling, and the flux of water vapor to soil had a stronger impact than temperature on microbial activity. In a semiarid grassland, we also observed that non-rainfall water inputs stimulated microbial activity and C cycling. Together these data suggest that, during rain-free periods, atmospheric moisture in drylands may significantly contribute to variation in soil water content, thereby influencing ecosystem processes. The simple physical process of adsorption of water vapor to soil particles, forming liquid water, represents an overlooked but potentially important contributor to C cycling in drylands.

  6. 18 CFR 1316.5 - Clean Air and Water Acts.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... meaning set forth in 40 CFR 15.4. (b) TVA will not award a contract to any offeror whose performance would... is exempt at the time of contract award from the provisions of 40 CFR part 15 as set forth therein... Water Acts (a) If performance of this contract would involve the use of facilities which have given...

  7. 18 CFR 1316.5 - Clean Air and Water Acts.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... meaning set forth in 40 CFR 15.4. (b) TVA will not award a contract to any offeror whose performance would... is exempt at the time of contract award from the provisions of 40 CFR part 15 as set forth therein... Water Acts (a) If performance of this contract would involve the use of facilities which have given...

  8. ANALYSIS OF SUPERSATUATED AIR IN NATURAL WATERS AND RESERVOIRS

    EPA Science Inventory

    This report provides a state of the art summary and evaluation of the methods for the determination of total gas in water samples. The hollow fiber, the hollow tube, and the flat membrane probes were evaluated. A flat surface probe was developed that has a low dead space, high pe...

  9. Finch, Pruyn cleans air and water while increasing steam production

    SciTech Connect

    Reason, J.; Bauer, P.; Makansi, J.

    1981-11-01

    It is shown how a paper manufacturing company in Glens Falls, NY, employs primary and secondary water-treatment plants, chemical recovery from SO/sub 2/ -laden flue gas, a bark boiler, and waste-liquor boilers to balance the conflicting demands of a changing market, increasing power needs, stringent, pollution regulations, higher fuel costs, and limited production space.

  10. Micro-machining of silicon wafer in air and under water

    NASA Astrophysics Data System (ADS)

    Wee, L. M.; Ng, E. Y. K.; Prathama, A. H.; Zheng, H.

    2011-02-01

    Laser ablation micro-machining tests are conducted on silicon wafer, both in air and under flowing water stream, with the use of 355 nm-X AVIA laser. Effects of laser pulse frequency, power level, scan velocity and focal plane position on the associated laser spatter deposition (in air), irradiated areas (under flowing water film) and taper are investigated. It shows that low frequency, i.e. 30-40 kHz, and high peak power result in smaller spatter and irradiated areas, and the hole taper decreases with increase in pulse frequency. Increase in the laser fluence broadens both the areas and increases the hole taper. Both areas enlarge with the increase of scanning velocity of more than 3 mm s -1. The scan velocity has no effect on hole taper in air environment but inconsistent hole taper is obtained under flowing water stream. Furthermore, moving the focal plane position below the workpiece surface contributes relatively smaller areas of spatter deposition, irradiation and taper in comparison to zero focal plane position. Finally, the differences between laser ablation in air and under water are identified. The reduction in the spatter deposition and irradiated areas around the perimeter of the ablated hole and a smaller taper with the use of laser trepan drilling method in air and under water machining are investigated in this paper.

  11. Reactive Distillation and Air Stripping Processes for Water Recycling and Trace Contaminant Control

    NASA Technical Reports Server (NTRS)

    Boul, Peter J.; Lange, Kevin E.; Conger, Bruce; Anderson, Molly

    2009-01-01

    Reactive distillation designs are considered to reduce the presence of volatile organic compounds in the purified water. Reactive distillation integrates a reactor with a distillation column. A review of the literature in this field has revealed a variety of functional reactive columns in industry. Wastewater may be purified by a combination of a reactor and a distiller (e.g., the EWRS or VPCAR concepts) or, in principle, through a design which integrates the reactor with the distiller. A review of the literature in reactive distillation has identified some different designs in such combinations of reactor and distiller. An evaluation of reactive distillation and reactive air stripping is presented with regards to the reduction of volatile organic compounds in the contaminated water and air. Among the methods presented, an architecture is presented for the evaluation of the simultaneous oxidation of organics in air and water. These and other designs are presented in light of potential improvements in power consumptions and air and water purities for architectures which include catalytic activity integrated into the water processor. In particular, catalytic oxidation of organics may be useful as a tool to remove contaminants that more traditional distillation and/or air stripping columns may not remove. A review of the current leading edge at the commercial level and at the research frontier in catalytically active materials is presented. Themes and directions from the engineering developments in catalyst design are presented conceptually in light of developments in the nanoscale chemistry of a variety of catalyst materials.

  12. Bifurcations of a creeping air-water flow in a conical container

    NASA Astrophysics Data System (ADS)

    Balci, Adnan; Brøns, Morten; Herrada, Miguel A.; Shtern, Vladimir N.

    2016-04-01

    This numerical study describes the eddy emergence and transformations in a slow steady axisymmetric air-water flow, driven by a rotating top disk in a vertical conical container. As water height Hw and cone half-angle β vary, numerous flow metamorphoses occur. They are investigated for β =30°, 45°, and 60°. For small Hw , the air flow is multi-cellular with clockwise meridional circulation near the disk. The air flow becomes one cellular as Hw exceeds a threshold depending on β . For all β , the water flow has an unbounded number of eddies whose size and strength diminish as the cone apex is approached. As the water level becomes close to the disk, the outmost water eddy with clockwise meridional circulation expands, reaches the interface, and induces a thin layer with anticlockwise circulation in the air. Then this layer expands and occupies the entire air domain. The physical reasons for the flow transformations are provided. The results are of fundamental interest and can be relevant for aerial bioreactors.

  13. Fine resolution soil water fluxes measured with a small Smart Field Lysimeter: The noise removal and further interpretation

    NASA Astrophysics Data System (ADS)

    Dolezal, Frantisek; Bekere Mekonnen, Getu; Matula, Svatopluk; Mihalikova, Marketa; Fisak, Jaroslav; Teressa Chala, Ayele; Hrkalova, Marketa; Moreira Barradas, Joao Manuel

    2014-05-01

    A weighable Smart Field Lysimeter (30 cm diameter, 30 cm depth) with an adaptively regulated suction at its bottom was used to measure soil water fluxes at the surface and at the 30 cm depth of a short grass stand. No overland flow or accumulation of water at the surface were observed and there was no groundwater table within the soil profile. Appropriate distinction between the fluxes of different directions made it possible to separately estimate actual evapotranspiration (upward surface flux), precipitation and condensation (downward surface flux and dew on grass leaves), percolation (downward flux at 30 cm) and capillary rise (upward flux at 30 cm). The primary data were collected at 1 minute intervals but required digital filtering to remove the information noise. Various methods of filtering were tested, with a special regard to intensive rain events. The resulting data have a 10-minute resolution. The lysimeter is capable of self-recovery after a period of drought but the noise of percolation and capillary rise estimates is enhanced for some time during, before and after this period. In these situations, it is important that a porous matrix sensor measures the suction in parallel to the reference tensiometer. Both the precipitation and the actual evapotranspiration derived from the lysimeter data alone are in absolute values higher than the analogous quantities obtained with the help of the directly measured tipping bucket precipitation. These discrepancies are probably due to the rain gauge underestimating true precipitation, but partly also due to numerical noise, however smoothed. If the rain gauge data are used only to distinguish the periods of rain from the rainless periods, than the condensation of water in the soil and on the grass leaves can be estimated. The actual evapotranspiration measured by the lysimeter has a diurnal patterns depending on actual weather. The maximum occurs, on average, shortly after the noon. The percolation curves after rain

  14. Air-Water Exchange of Legacy and Emerging Organic Pollutants across the Great Lakes

    NASA Astrophysics Data System (ADS)

    Lohmann, R.; Ruge, Z.; Khairy, M.; Muir, D.; Helm, P.

    2014-12-01

    Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) are transported to great water bodies via long-range atmospheric transport and released from the surface water as air concentrations continue to diminish. As the largest fresh water bodies in North America, the Great Lakes have both the potential to accumulate and serve as a secondary source of persistent bioaccumulative toxins. OCP and PCB concentrations were sampled at 30+ sites across Lake Superior, Ontario and Erie in the summer of 2011. Polyethylene passive samplers (PEs) were simultaneously deployed in surface water and near surface atmosphere to determine air-water gaseous exchange of OCPs and PCBs. In Lake Superior, surface water and atmospheric concentrations were dominated by α-HCH (average 250 pg/L and 4.2 pg/m3, respectively), followed by HCB (average 17 pg/L and 89 pg/m3, respectively). Air-water exchange varied greatly between sites and individual OCPs, however α-endosulfan was consistently deposited into the surface water (average 19 pg/m2/day). PCBs in the air and water were characterized by penta- and hexachlorobiphenyls with distribution along the coast correlated with proximity to developed areas. Air-water exchange gradients generally yielded net volatilization of PCBs out of Lake Superior. Gaseous concentrations of hexachlorobenzene, dieldrin and chlordanes were significantly higher (p < 0.05) at Lake Erie than Lake Ontario. A multiple linear regression that incorporated meteorological, landuse and population data was used to explain variability in the atmospheric concentrations. Results indicated that landuse (urban and/or cropland) greatly explained the variability in the data. Freely dissolved concentrations of OCPs (water quality guidelines for the protection of human health from the consumption of fish. Spatial distributions of

  15. Laboratory study of air sparging of TCE-contaminated saturated soils and ground water

    SciTech Connect

    Adams, J.A.; Reddy, K.R.

    1999-06-30

    Air sparging has proven to be an effective remediation technique for treating saturated soils and ground water contaminated by volatile organic compounds (VOCs). Since little is known about the system variables and mass transfer mechanisms important to air sparging, several researchers have recently performed laboratory investigations to study such issues. This paper presents the results of column experiments performed to investigate the behavior of dense nonaqueous phase liquids (DNAPLs), specifically trichloroethylene (TCE), during air sparging. The specific objectives of the study were (1) to compare the removal of dissolved TCE with the removal of dissolved light nonaqueous phase liquids (LNAPLs), such as benzene or toluene; (2) to determine the effect of injected air-flow rate on dissolved TCE removal; (3) to determine the effect of initial dissolved TCE concentration on removal efficiency; and (4) to determine the differences in removal between dissolved and pure-chase TCE. The test results showed that (1) the removal of dissolved TCE was similar to that of dissolved LNAPL; (2) increased air-injection rates led to increased TCE removal at lower ranges of air injection, but further increases at higher ranges of air injection did not increase the rate of removal, indicating a threshold removal rate had been reached; (3) increased initial concentration of dissolved TCE resulted in similar rates of removal; and (4) the removal pf pure-phase TCE was difficult using a low air-injection rate, but higher air-injection rates led to easier removal.

  16. Superhydrophobic surfaces of the water bug Notonecta glauca: a model for friction reduction and air retention.

    PubMed

    Ditsche-Kuru, Petra; Schneider, Erik S; Melskotte, Jan-Erik; Brede, Martin; Leder, Alfred; Barthlott, Wilhelm

    2011-01-01

    Superhydrophobic surfaces of plants and animals are of great interest for biomimetic applications. Whereas the self-cleaning properties of superhydrophobic surfaces have been extensively investigated, their ability to retain an air film while submerged under water has not, in the past, received much attention. Nevertheless, air retaining surfaces are of great economic and ecological interest because an air film can reduce friction of solid bodies sliding through the water. This opens perspectives for biomimetic applications such as low friction fluid transport or friction reduction on ship hulls. For such applications the durability of the air film is most important. While the air film on most superhydrophobic surfaces usually lasts no longer than a few days, a few semi-aquatic plants and insects are able to hold an air film over a longer time period. Currently, we found high air film persistence under hydrostatic conditions for the elytra of the backswimmer Notonecta glauca which we therefore have chosen for further investigations. In this study, we compare the micro- and nanostructure of selected body parts (sternites, upper side of elytra, underside of elytra) in reference to their air retaining properties. Our investigations demonstrate outstanding air film persistence of the upper side of the elytra of Notonecta glauca under hydrostatic and hydrodynamic conditions. This hierarchically structured surface was able to hold a complete air film under hydrostatic conditions for longer than 130 days while on other body parts with simple structures the air film showed gaps (underside of elytra) or even vanished completely after a few days (sternites). Moreover, the upper side of the elytra was able to keep an air film up to flow velocities of 5 m/s. Obviously the complex surface structure with tiny dense microtrichia and two types of larger specially shaped setae is relevant for this outstanding ability. Besides high air film persistence, the observation of a

  17. Air Evaporation closed cycle water recovery technology - Advanced energy saving designs

    NASA Technical Reports Server (NTRS)

    Morasko, Gwyndolyn; Putnam, David F.; Bagdigian, Robert

    1986-01-01

    The Air Evaporation water recovery system is a visible candidate for Space Station application. A four-man Air Evaporation open cycle system has been successfully demonstrated for waste water recovery in manned chamber tests. The design improvements described in this paper greatly enhance the system operation and energy efficiency of the air evaporation process. A state-of-the-art wick feed design which results in reduced logistics requirements is presented. In addition, several design concepts that incorporate regenerative features to minimize the energy input to the system are discussed. These include a recuperative heat exchanger, a heat pump for energy transfer to the air heater, and solar collectors for evaporative heat. The addition of the energy recovery devices will result in an energy reduction of more than 80 percent over the systems used in earlier manned chamber tests.

  18. Portable RF-Sensor System for the Monitoring of Air Pollution and Water Contamination

    PubMed Central

    Kang, Joonhee; Kim, Jin Young

    2012-01-01

    Monitoring air pollution including the contents of VOC, O3, NO2, and dusts has attracted a lot of interest in addition to the monitoring of water contamination because it affects directly to the quality of living conditions. Most of the current air pollution monitoring stations use the expensive and bulky instruments and are only installed in the very limited area. To bring the information of the air and water quality to the public in real time, it is important to construct portable monitoring systems and distribute them close to our everyday living places. In this work, we have constructed a low-cost portable RF sensor system by using 400 MHz transceiver to achieve this goal. Accuracy of the measurement was comparable to the ones used in the expensive and bulky commercial air pollution forecast systems. PMID:22928151

  19. Noise source detection and measurement in a supersonic air jet using Ultra-high Speed Rainbow Schlieren Deflectometry

    NASA Astrophysics Data System (ADS)

    Rajora, Manik; Agrawal, Ajay; Mitchell, William; Kolhe, Pankaj

    2012-11-01

    Supersonic jets emit noise from various regions including the shear layer containing vortical structures, various shock cell structures in the near field and the downstream jet core breakdown region. Sound waves emitted from these various regions interact with each other and produce distinct noise spectra away from the jet, which depends upon the measurement location. Typically sound is detected by intrusive probes that provide measurements at a specific location, which makes it difficult to identify the origination point of such noise in a supersonic jet. In this study, an ultra-high speed Rainbow Schlieren Deflectometry (RSD) technique has been developed to optically visualize not only the supersonic jet flow but also the sound waves emanating from it in real time. Color schlieren images are acquired at up to 250,000 frames per second to capture the sound wave propagation with adequate spatial resolution. Optical components of the system were optimized to improve the spatial and temporal resolutions and hence, the schlieren video quality. To the best of our knowledge, this is the first time sound wave propagation from supersonic jets has been recorded in real time on a schlieren video. Acquired color schlieren images are amenable to quantitative analysis, and can provide data on sound power and sound wave frequency across the whole field. This project was funded by NSF REU 1062611 and Department of Energy for Institue for Sustainable Energy EE003134.

  20. Simulation of in-core neutron noise measurements for axial void profile reconstruction in boiling water reactors

    SciTech Connect

    Dykin, V.; Pazsit, I.

    2012-07-01

    A possibility to reconstruct the axial void profile from the simulated in-core neutron noise which is caused by density fluctuations in a Boiling Water Reactor (BWR) heated channel is considered. For this purpose, a self-contained model of the two-phase flow regime is constructed which has quantitatively and qualitatively similar properties to those observed in real BWRs. The model is subsequently used to simulate the signals of neutron detectors induced by the corresponding perturbations in the flow density. The bubbles are generated randomly in both space and time using Monte-Carlo techniques. The axial distribution of the bubble production is chosen such that the mean axial void fraction and void velocity follow the actual values of BWRs. The induced neutron noise signals are calculated and then processed by the standard signal analysis methods such as Auto-Power Spectral Density (APSD) and Cross-Power Spectral Density (CPSD). Two methods for axial void and velocity profiles reconstruction are discussed: the first one is based on the change of the break frequency of the neutron auto-power spectrum with axial core elevation, while the second refers to the estimation of transit times of propagating steam fluctuations between different axial detector positions. This paper summarizes the principles of the model and presents a numerical testing of the qualitative applicability to estimate the required parameters for the reconstruction of the void fraction profile from the neutron noise measurements. (authors)

  1. Hydrogeology, simulated ground-water flow, and ground-water quality, Wright-Patterson Air Force Base, Ohio

    USGS Publications Warehouse

    Dumouchelle, D.H.; Schalk, C.W.; Rowe, G.L.; De Roche, J.T.

    1993-01-01

    Ground water is the primary source of water in the Wright-Patterson Air Force Base area. The aquifer consists of glacial sands and gravels that fill a buried bedrock-valley system. Consolidated rocks in the area consist of poorly permeable Ordovician shale of the Richmondian stage, in the upland areas, the Brassfield Limestone of Silurian age. The valleys are filled with glacial sediments of Wisconsinan age consisting of clay-rich tills and coarse-grained outwash deposits. Estimates of hydraulic conductivity of the shales based on results of displacement/recovery tests range from 0.0016 to 12 feet per day; estimates for the glacial sediments range from less than 1 foot per day to more than 1,000 feet per day. Ground water flow from the uplands towards the valleys and the major rivers in the region, the Great Miami and the Mad Rivers. Hydraulic-head data indicate that ground water flows between the bedrock and unconsolidated deposits. Data from a gain/loss study of the Mad River System and hydrographs from nearby wells reveal that the reach of the river next to Wright-Patterson Air Force Base is a ground-water discharge area. A steady-state, three-dimensional ground-water-flow model was developed to simulate ground-water flow in the region. The model contains three layers and encompasses about 100 square miles centered on Wright-Patterson Air Force Base. Ground water enters the modeled area primarily by river leakage and underflow at the model boundary. Ground water exits the modeled area primarily by flow through the valleys at the model boundaries and through production wells. A model sensitivity analysis involving systematic changes in values of hydrologic parameters in the model indicates that the model is most sensitive to decreases in riverbed conductance and vertical conductance between the upper two layers. The analysis also indicates that the contribution of water to the buried-valley aquifer from the bedrock that forms the valley walls is about 2 to 4

  2. Assessment of internal contamination problems associated with bioregenerative air/water purification systems

    NASA Technical Reports Server (NTRS)

    Johnson, Anne H.; Bounds, B. Keith; Gardner, Warren

    1990-01-01

    The emphasis is to characterize the mechanisms of bioregenerative revitalization of air and water as well as to assess the possible risks associated with such a system in a closed environment. Marsh and aquatic plants are utilized for purposes of wastewater treatment as well as possible desalinization and demineralization. Foliage plants are also being screened for their ability to remove toxic organics from ambient air. Preliminary test results indicate that treated wastewater is typically of potable quality with numbers of pathogens such as Salmonella and Shigella significantly reduced by the artificial marsh system. Microbiological analyses of ambient air indicate the presence of bacilli as well as thermophilic actinomycetes.

  3. The adsorption onto fibrous activated carbon applications to water and air treatments

    SciTech Connect

    Le Cloirec, P.; Brasquet, C.; Subrenat, E.

    1996-12-31

    The adsorption of polluted fluids is performed by fiber activated carbon (FAC). The adsorption is carried out in a batch or dynamic reactor. Classic models are applied and kinetic constants are calculated. Results showed that the performances of FAC are significantly higher than that of granular activated carbon (GAC) in terms of adsorption velocity and selectivity. The breakthrough curves obtained with FAC adsorbers are particularly steep, suggesting a smaller mass transfer resistance than GAC. The adsorption zone in the FAC bed is about 3.4 mm and is not really dependent on the water flow rate within the studied range. Applications are developed in water and air treatments. Examples are given in the micropollutants removal of an aqueous solution. Air loaded with VOC or/and odorous molecules is treated by fibers. Regeneration of this material is performed by heating by joule effects or electromagnetic induction. Theses original approaches to water or air treatment processes are successfully put to use.

  4. The adsorption onto fibrous activated carbon - applications to water and air treatments

    SciTech Connect

    Le Cloirec, P.; Subrenat, E.

    1996-10-01

    The adsorption of polluted fluids is performed by fiber activated carbon (FAC). The adsorption is carried out in a batch or dynamic reactor. Classic model`s are applied and kinetic constants are calculated. Results showed that the performances of FAC are significantly higher than that of granular activated carbon (GAC) in terms of adsorption velocity. and selectivity. The breakthrough curves obtained with FAC adsorbers are particularly steep, suggesting a smaller mass transfer resistance than GAC. The adsorption zone in the FAC bed is about 3.4 mm and is not really dependent on the water flow rare within the studied range. Applications are developed in water and air treatments. Examples are given in the micropollutants removal of an aqueous solution. Air loaded with VOC or/and odorous molecules is treated by fibers. Regeneration of this material is performed by heating by joule effects or electromagnetic induction. These original approaches to water or air treatment processes are successfully put to use.

  5. Leaf photosynthetic and water-relations responses for 'Valencia' orange trees exposed to oxidant air pollution

    SciTech Connect

    Olszyk, D.M.; Takemoto, B.K.; Poe, M.

    1991-01-01

    Leaf responses were measured to test a hypothesis that reduced photosynthetic capacity and/or altered water relations were associated with reductions in yield for 'Valencia' orange trees (Citrus sinensis (L.), Osbeck) exposed to ambient oxidant air pollution. Exposures were continuous for 4 years to three levels of oxidants (in charcoal-filtered, half-filtered, and non-filtered air). Oxidants had no effect on net leaf photosynthetic rates or on photosynthetic pigment concentrations. A single set of measurements indicated that oxidants increased leaf starch concentrations (24%) prior to flowering, suggesting a change in photosynthate allocation. Leaves exposed to oxidants had small, but consistent, changes in water relations over the summer growing season, compared to trees growing in filtered air. Other changes included decreased stomatal conductance (12%) and transpiration (9%) rates, and increased water pressure potentials (5%). While all responses were subtle, their cumulative impact over 4 years indicated that 'Valencia' orange trees were subject to increased ambient oxidant stress.

  6. Vision of the Humboldt penguin (Spheniscus humboldti) in air and water.

    PubMed

    Sivak, J; Howland, H C; McGill-Harelstad, P

    1987-01-22

    Refractive states measured by retinoscopy and photorefraction indicate that the eyes of the Humboldt penguin, Spheniscus humboldti, are approximately emmetropic in air and water. Extensive myopia in air, as predicted by earlier authors and by a recent anatomical study, is non-existent. Photorefractive measurements of the refractive state, in water, of the Humboldt penguin indicate that it can accommodate sufficiently to make up the loss of the refractive power of the cornea. The cornea of the Humboldt penguin is flattened relative to the overall size of the eye. In all these respects (corneal flattening, and accommodation in air and water) the eyes of Humboldt penguins are like those of gentoo, (Pygoscelis papua), rockhopper (Eudyptes crestatus), Magellanic (Spheniscus magellanicus), and king penguins (Aptenodytes patagonica). PMID:2881308

  7. Microorganism levels in air near spray irrigation of municipal waste water: The Lubbock Infection Surveillance Study

    SciTech Connect

    Camann, D.E.; Moore, B.E.; Harding, H.J.; Sorber, C.A.

    1988-01-01

    The Lubbock Infection Surveillance Study (LISS) investigated possible adverse effects on human health from slow-rate land application of municipal wastewater. Extensive air sampling was conducted to characterize the irrigation site as a source of infectious microbial aerosols. Spray irrigation of poor-quality waste water received directly from the treatment plant significantly elevated air densities of fecal coliforms, fecal streptococci, mycobacteria, and coliphage above ambient background levels for at least 200 m downwind. Enteroviruses were repeatedly recovered at 44 to 60 m downwind at a higher level (geometric mean = 0.05 pfu/m3) than observed at other waste water aerosol sites in the U.S. and in Israel. Waste water storage in reservoirs reduced downwind air densities of indicator organisms by two orders of magnitude.

  8. Ground-water conditions at Beale Air Force Base and vicinity, California

    USGS Publications Warehouse

    Page, R.W.

    1980-01-01

    Ground-water conditions were studied in a 168-square-mile area between the Sierra Nevada and the Feather River in Yuba County, Calif. The area is in the eastern part of the Sacramento Valley and includes most of Beale Air Force Base. Source, occurrence, movement, and chemical quality of the ground water were evaluated. Ground water occurs in sedimentary and volcanic rocks of Tertiary and Quaternary age. The base of the freshwater is in the undifferentiated sedimentary rocks of Oligocene and Eocene age, that contain water of high dissolved-solids concentration. The ground water occurs under unconfined and partly confined conditions. At Beale Air Force Base it is at times partly confined. Recharge is principally from the rivers. Pumpage in the study area was estimated to be 129,000 acre-feet in 1975. In the 1960's, water levels in most parts of the study area declined less rapidly than in earlier years or became fairly stable. In the 1970's, water levels at Beale Air Force Base declined only slightly. Spacing of wells on the base and rates of pumping are such that excessive pumping interference is avoided. Water quality at the base and throughout the study area is generally good. Dissolved-solids concentrations are 700 to 900 milligrams per liter in the undifferentiated sedimentary rocks beneath the base well field. (USGS)

  9. Demonstration of adaptive optics for mitigating laser propagation through a random air-water interface

    NASA Astrophysics Data System (ADS)

    Land, Phillip; Majumdar, Arun K.

    2016-05-01

    This paper describes a new concept of mitigating signal distortions caused by random air-water interface using an adaptive optics (AO) system. This is the first time the concept of using an AO for mitigating the effects of distortions caused mainly by a random air-water interface is presented. We have demonstrated the feasibility of correcting the distortions using AO in a laboratory water tank for investigating the propagation effects of a laser beam through an airwater interface. The AO system consisting of a fast steering mirror, deformable mirror, and a Shack-Hartmann Wavefront Sensor for mitigating surface water distortions has a unique way of stabilizing and aiming a laser onto an object underneath the water. Essentially the AO system mathematically takes the complex conjugate of the random phase caused by air-water interface allowing the laser beam to penetrate through the water by cancelling with the complex conjugates. The results show the improvement of a number of metrics including Strehl ratio, a measure of the quality of optical image formation for diffraction limited optical system. These are the first results demonstrating the feasibility of developing a new sensor system such as Laser Doppler Vibrometer (LDV) utilizing AO for mitigating surface water distortions.

  10. The interaction of water mists and premixed propane-air flames under low-gravity conditions

    NASA Astrophysics Data System (ADS)

    Abbud-Madrid, Angel; Riedel, Edward P.; McKinnon, J. Thomas

    1999-01-01

    A preliminary investigation of the effect of water mists on premixed flame propagation in a cylindrical tube under low-gravity conditions has been conducted to define the scientific and technical objectives of the experiments to be performed on the Space Shuttle and International Space Station microgravity environments. The inhibiting characteristics of water mists in propagating flames of propane-air mixtures at various equivalence ratios are studied. The effects of droplet size and concentration on the laminar flame speed are used as the measure of fire suppression efficacy. Flame speed and propagation behavior are monitored by a video camera. Reduced gravity is obtained with an aircraft flying parabolic trajectories. Measurements and qualitative observations from the low-gravity experiments clearly show the effect of water mist on flame speed abatement, flame shape, and radiant emission. For lean propane-air mixtures, the flame speed increases at first with low water-mist concentrations and then decreases below its dry value when higher water-mist volumes are introduced in the tube. This phenomenon may be due in part to the heating of the unburned mixture ahead of the flame as a result of radiation absorption by the water droplets. For rich propane-air mixtures, similar behavior of flame speed vs. water concentration is encountered but in this case is mostly due to the formation of cellular flames. At high water loads both lean and rich flames exhibit extinction before reaching the end of the tube.

  11. Using aliphatic alcohols as gaseous tracers in determination of water contents and air-water interfacial areas in unsaturated sands

    NASA Astrophysics Data System (ADS)

    Sung, Menghau; Chen, Bi-Hsiang

    2011-11-01

    A new type of gaseous tracer utilizing nontoxic aliphatic alcohols for the determination of water content and air-water interfacial area is tested on unsaturated sands of low water content. Alcohol vapors are generated at room temperature and passed through the experimental sand column. Breakthrough curves (BTCs) of these vapors are obtained by monitoring their effluent concentrations using GC-FID. The retardation factor with respect to each vapor transport process is obtained by optimizing BTCs data using the CXTFIT program in the reverse problem mode. The water content and the interfacial area are subsequently calculated from their retardation factors by both equilibrium and nonequilibrium transport models. Experimental results indicate that the pentanol tracer is feasible in the determination of water content at conditions when the degree of water saturation is low. In the determination of air-water interfacial area, decanol is selected due to its interfacial adsorption characteristics. By comparing to interfacial areas from theoretical predictions as well as other conventional tarcer methods, the ones determined from the decanol tracer tests are found to be close to the true interfacial areas when the water content is low.

  12. 33 CFR 334.330 - Atlantic Ocean and connecting waters in vicinity of Myrtle Island, Va.; Air Force practice...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Atlantic Ocean and connecting waters in vicinity of Myrtle Island, Va.; Air Force practice bombing, rocket firing, and gunnery range... waters in vicinity of Myrtle Island, Va.; Air Force practice bombing, rocket firing, and gunnery...

  13. 33 CFR 334.330 - Atlantic Ocean and connecting waters in vicinity of Myrtle Island, Va.; Air Force practice...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Atlantic Ocean and connecting waters in vicinity of Myrtle Island, Va.; Air Force practice bombing, rocket firing, and gunnery range... waters in vicinity of Myrtle Island, Va.; Air Force practice bombing, rocket firing, and gunnery...

  14. Optimizing the air flotation water treatment process. Final report, May 1997

    SciTech Connect

    Barnett, B.

    1998-09-01

    The injection water for the Nelson Project is a combination of produced and make-up water, typical of many Eastern Kansas operations. The make-up water is a low-salinity salt water from the Arbuckle Formation and contains dissolved minerals and sulfides. The produced water contains suspended oil, suspended clay and silt particles, along with a combination of other dissolved minerals. The combination of the two waters causes several undesirable reactions. The suspended solids load contained in the combined waters would plug a 75-micron plant bag filter within one day. Wellhead filters of 75-micron size were also being used on the injection wells. The poor water quality resulted in severe loss of injectivity and frequent wellbore cleaning of the injection wells. Various mechanical and graded-bed filtration methods were considered for cleaning the water. These methods were rejected due to the lack of field equipment and service availability. A number of vendors did not even respond to the author`s request. The air flotation process was selected as offering the best hope for a long-term solution. The objective of this work is to: increase the cost effectiveness of the process through optimizing process design factors and operational parameters. A vastly modified air flotation system is the principal tool for accomplishing the project objective. The air flotation unit, as received from manufacturer Separation Specialist, was primarily designed to remove oil from produced water. The additional requirement for solids removal necessitated major physical changes in the unit. Problems encountered with the air flotation unit and specific modifications are detailed in the body of the report.

  15. Laboratory scale studies on mitigation of high 222Rn concentrations in air and water

    NASA Astrophysics Data System (ADS)

    Mamoon, A.; Gomma, M. A.; Sohsah, M.

    2004-01-01

    In view of the occasional occurrence of high 222Rn concentrations in air and water under certain circumstances, and in view of the potential health hazards of increased levels of 222Rn in respirable air and in potable water, mitigation of such high 222Rn concentration has become of primary concern. To facilitate the study of the efficiency of the various 222Rn mitigating factors simple laboratory systems were used. Altered alkali granite was used as radon source to enrich air and a piece of pitchblende was used as radon source to enrich water samples. Both enriched media will then be subjected to the mitigation treatments. Charcoal canister technique along with gamma spectrometry were used to measure 222Rn concentrations in air before and after the different mitigating treatments. These were: use of ventilation, radon barriers such as geo-membranes and aluminum sheet, and sealant such as epoxy and vinyl tape. Regarding high levels of 222Rn in air ventilation was the most efficient mitigating factor. Standard liquid scintillation counting was used to measure 222Rn concentrations in water before and after the different mitigation treatments. These were: use of aeration, activated charcoal and heating. Regarding high levels of 222Rn in water, aeration using bubblers and large volume of air was most effective in removing radon from water in a short time. However all the mitigating factors proved effective, in different degrees in decreasing 222Rn concentrations in the respective media. The result from these studies are in general agreement with reports in the literature. It can be concluded then that the different 222Rn mitigating factors can be tested and compared effectively under controlled conditions using simple laboratory scale systems.

  16. Interaction of Charged Colloidal Particles at the Air-Water Interface.

    PubMed

    Girotto, Matheus; Dos Santos, Alexandre P; Levin, Yan

    2016-07-01

    We study, using Monte Carlo simulations, the interaction between charged colloidal particles confined to the air-water interface. The dependence of force on ionic strength and counterion valence is explored. For 1:1 electrolyte, we find that the electrostatic interaction at the interface is very close to the one observed in the bulk. On the other hand, for salts with multivalent counterions, an interface produces an enhanced attraction between like charged colloids. Finally, we explore the effect of induced surface charge at the air-water interface on the interaction between colloidal particles. PMID:26551757

  17. Pulmonary epithelial permeability after inhaling saline, distilled water ''fog'' and cold air

    SciTech Connect

    Borland, C.; Chamberlain, A.; Barber, B.; Higenbottam, T.

    1985-03-01

    It is recognized that hyperventilation of cold air and the inhalation of fine mists of distilled water provoke significant bronchoconstriction in the asthmatic individual, yet little is known as to how these provocations affect the structural integrity of the alveolar epithelial membrane. In 11 normal subjects, the following effects have been studied: cold air hyperventilation for three minutes, inhalation of 80 L of ultrasonically nebulized distilled water ''fog,'' and 80 L of isotonic saline ''fog'' on the half time clearance (T1/2) from the alveoli of technetium 99m diethylene triamine pentaacetate (DTPA), inhaled as an aerosol. The DTPA T1/2 provided a measurement of pulmonary epithelial permeability.

  18. The effects of aquaculture noise on hearing, growth and disease resistance of rainbow trout Oncorhynchus mykiss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intensive aquaculture production often utilizes equipment (e.g., aerators, air and water pumps, harvesters, blowers, filtration systems, and maintenance machinery) that increases noise levels in fish culture tanks. Consequently, chronic exposure to elevated noise levels in tanks could negatively imp...

  19. Effects of aquaculture noise on hearing, growth, and disease resistance of rainbow trout Oncorhynchus mykiss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intensive aquaculture production often utilizes equipment (e.g., aerators, air and water pumps, harvesters, blowers, filtration systems, and maintenance machinery) that increases noise levels in fish culture tanks. Consequently, chronic exposure to elevated noise levels in tanks could negatively imp...

  20. Experimentally probing the libration of interfacial water: the rotational potential of water is stiffer at the air/water interface than in bulk liquid.

    PubMed

    Tong, Yujin; Kampfrath, Tobias; Campen, R Kramer

    2016-07-21

    Most properties of liquid water are determined by its hydrogen-bond network. Because forming an aqueous interface requires termination of this network, one might expect the molecular level properties of interfacial water to markedly differ from water in bulk. Intriguingly, much prior experimental and theoretical work has found that, from the perspective of their time-averaged structure and picosecond structural dynamics, hydrogen-bonded OH groups at an air/water interface behave the same as hydrogen-bonded OH groups in bulk liquid water. Here we report the first experimental observation of interfacial water's libration (i.e. frustrated rotation) using the laser-based technique vibrational sum frequency spectroscopy. We find this mode has a frequency of 834 cm(-1), ≈165 cm(-1) higher than in bulk liquid water at the same temperature and similar to bulk ice. Because libration frequency is proportional to the stiffness of water's rotational potential, this increase suggests that one effect of terminating bulk water's hydrogen bonding network at the air/water interface is retarding rotation of water around intact hydrogen bonds. Because in bulk liquid water the libration plays a key role in stabilizing reaction intermediates and dissipating excess vibrational energy, we expect the ability to probe this mode in interfacial water to open new perspectives on the kinetics of heterogeneous reactions at aqueous interfaces. PMID:27339861

  1. Understanding the structure of hydrophobic surfactants at the air/water interface from molecular level.

    PubMed

    Zhang, Li; Liu, Zhipei; Ren, Tao; Wu, Pan; Shen, Jia-Wei; Zhang, Wei; Wang, Xinping

    2014-11-25

    Understanding the behavior of fluorocarbon surfactants at the air/water interface is crucial for many applications, such as lubricants, paints, cosmetics, and fire-fighting foams. In this study, molecular dynamics (MD) simulations were employed to investigate the microscopic properties of non-ionic fluorocarbon surfactants at the air/water interface. Several properties, including the distribution of head groups, the distribution probability of the tilt angle between hydrophobic tails with respect to the xy plane, and the order parameter of surfactants, were computed to probe the structure of hydrophobic surfactants at the air/water interface. The effects of the monomer structure on interfacial phenomena of non-ionic surfactants were investigated as well. It is observed that the structure of fluorocarbon surfactants at the air/water interface is more ordered than that of hydrocarbons, which is dominated by the van der Waals interaction between surfactants and water molecules. However, replacing one or two CF2 with one or two CH2 group does not significantly influence the interfacial structure, suggesting that hydrocarbons may be promising alternatives to perfluorinated surfactants. PMID:25358083

  2. Hydrodynamics of a self-propelled camphor boat at the air-water interface

    NASA Astrophysics Data System (ADS)

    Akella, Sathish; Singh, Dhiraj; Singh, Ravi; Bandi, Mahesh

    2015-11-01

    A camphor tablet, when placed at the air-water interface undergoes sublimation and camphor vapour spreads radially outwards across the surface due to Marangoni forces. This steady camphor influx from tablet onto the air-water interface is balanced by the camphor outflux due to evaporation. When spontaneous fluctuations in evaporation break the axial symmetry of Marangoni force acting radially outwards, the camphor tablet is propelled like a boat along the water surface. We report experiments on the hydrodynamics of a self-propelled camphor boat at air-water interfaces. We observe three different modes of motion, namely continuous, harmonic and periodic, due to the volatile nature of camphor. We explain these modes in terms of ratio of two time-scales: the time-scale over which viscous forces are dominant over the Marangoni forces (τη) and the time-scale over which Marangoni forces are dominant over the viscous forces (τσ). The continuous, harmonic and periodic motions are observed when τη /τσ ~ 1 , τη /τσ >= 1 and τη /τσ >> 1 respectively. Experimentally, the ratio of the time scales is varied by changing the interfacial tension of the air-water interface using Sodium Dodecyl Sulfate. This work was supported by the Collective Interactions Unit, OIST Graduate University.

  3. Coupling of phytoplankton uptake and air-water exchange of persistent organic pollutants

    SciTech Connect

    Dachs, J.; Eisenreich, S.J.; Baker, J.E.; Ko, F.C.; Jeremiason, J.D.

    1999-10-15

    A dynamic model that couples air-water exchange and phytoplankton uptake of persistent organic pollutants has been developed and then applied to PCB data from a small experimental lake. A sensitivity analysis of the model, taking into account the influence of physical environmental conditions such as temperature, wind speed, and mixing depth as well as plankton-related parameters such as biomass and growth rate was carried out for a number of PCBs with different physical-chemical properties. The results indicate that air-water exchange dynamics are influenced not only by physical parameters but also by phytoplankton biomass and growth rate. New phytoplankton production results in substantially longer times to reach equilibrium. Phytoplankton uptake-induced depletion of the dissolved phase concentration maintains air and water phases out of equilibrium. Furthermore, PCBs in phytoplankton also take longer times to reach equilibrium with the dissolved water phase when the latter is supported by diffusive air-water exchange. However, both model analysis and model application to the Experimental Lakes Area of northwestern Ontario (Canada) suggest that the gas phase supports the concentrations of persistent organic pollutants, such as PCBs, in atmospherically driven aquatic environments.

  4. Air - water temperature relationships in the trout streams of southeastern Minnesota’s carbonate - sandstone landscape

    USGS Publications Warehouse

    Krider, Lori A.; Magner, Joseph A.; Perry, Jim; Vondracek, Bruce C.; Ferrington, Leonard C., Jr.

    2013-01-01

    Carbonate-sandstone geology in southeastern Minnesota creates a heterogeneous landscape of springs, seeps, and sinkholes that supply groundwater into streams. Air temperatures are effective predictors of water temperature in surface-water dominated streams. However, no published work investigates the relationship between air and water temperatures in groundwater-fed streams (GWFS) across watersheds. We used simple linear regressions to examine weekly air-water temperature relationships for 40 GWFS in southeastern Minnesota. A 40-stream, composite linear regression model has a slope of 0.38, an intercept of 6.63, and R2 of 0.83. The regression models for GWFS have lower slopes and higher intercepts in comparison to surface-water dominated streams. Regression models for streams with high R2 values offer promise for use as predictive tools for future climate conditions. Climate change is expected to alter the thermal regime of groundwater-fed systems, but will do so at a slower rate than surface-water dominated systems. A regression model of intercept vs. slope can be used to identify streams for which water temperatures are more meteorologically than groundwater controlled, and thus more vulnerable to climate change. Such relationships can be used to guide restoration vs. management strategies to protect trout streams.

  5. Performance Evaluation of the Operational Air Quality Monitor for Water Testing Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Wallace, William T.; Limero, Thomas F.; Gazda, Daniel B.; Minton, John M.; Macatangay, Ariel V.; Dwivedi, Prabha; Fernandez, Facundo M.

    2014-01-01

    Real-time environmental monitoring on ISS is necessary to provide data in a timely fashion and to help ensure astronaut health. Current real-time water TOC monitoring provides high-quality trending information, but compound-specific data is needed. The combination of ETV with the AQM showed that compounds of interest could be liberated from water and analyzed in the same manner as air sampling. Calibration of the AQM using water samples allowed for the quantitative analysis of ISS archival samples. Some calibration issues remain, but the excellent accuracy of DMSD indicates that ETV holds promise for as a sample introduction method for water analysis in spaceflight.

  6. Investigation of ground-water pollution at Air Force Plant Number 4, Fort Worth Texas

    SciTech Connect

    Not Available

    1986-10-01

    Beginning in December 1982, an extensive investigation was conducted to determine the presence and extent of industrial chemical pollution at Air Force Plant No. 4. A major portion of this work was devoted to the testing of ground water flowing within the overburden. In addition, 16 wells were drilled to monitor for polluted ground water in the upper and middle zones of the Paluxy Formation. Paluxy ground water was monitored; trichloroethylene, 1,2-trans-dichloroethylene, and lesser amounts of other chlorinated hydrocarbons, and the existence of abnormally high water levels in the upper zone of the Paluxy Formation in well P-8(U) were discovered.

  7. Research on the water hammer protection of the long distance water supply project with the combined action of the air vessel and over-pressure relief valve

    NASA Astrophysics Data System (ADS)

    Li, D. D.; Jiang, J.; Zhao, Z.; Yi, W. S.; Lan, G.

    2013-12-01

    We take a concrete pumping station as an example in this paper. Through the calculation of water hammer protection with a specific pumping station water supply project, and the analysis of the principle, mathematical models and boundary conditions of air vessel and over-pressure relief valve we show that the air vessel can protect the water conveyance system and reduce the transient pressure damage due to various causes. Over-pressure relief valve can effectively reduce the water hammer because the water column re-bridge suddenly stops the pump and prevents pipeline burst. The paper indicates that the combination set of air vessel and over-pressure relief valve can greatly reduce the quantity of the air valve and can eliminate the water hammer phenomenon in the pipeline system due to the vaporization and water column separation and re-bridge. The conclusion could provide a reference for the water hammer protection of long-distance water supply system.

  8. Core Noise Reduction

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduce-Perceived-Noise Technical Challenge; and the current research activities in the core noise area. Recent work1 on the turbine-transmission loss of combustor noise is briefly described, two2,3 new NRA efforts in the core-noise area are outlined, and an effort to develop CMC-based acoustic liners for broadband noise reduction suitable for turbofan-core application is delineated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. The Subsonic Fixed Wing Project's Reduce-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries.

  9. The effects of aquaculture production noise on the growth, condition factor, feed conversion, and survival of rainbow trout, Oncorhynchus mykiss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intensive aquaculture systems, particularly recirculating systems, utilize equipment such as aerators, air and water pumps, blowers, and filtration systems that inadvertently increase noise levels in fish culture tanks. Sound levels and frequencies measured within intensive aquaculture systems are w...

  10. Fluorescence light microscopy of pulmonary surfactant at the air-water interface of an air bubble of adjustable size.

    PubMed

    Knebel, D; Sieber, M; Reichelt, R; Galla, H-J; Amrein, M

    2002-07-01

    The structural dynamics of pulmonary surfactant was studied by epifluorescence light microscopy at the air-water interface of a bubble as a model close to nature for an alveolus. Small unilamellar vesicles of dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylglycerol, a small amount of a fluorescent dipalmitoylphosphatidylcholine-analog, and surfactant-associated protein C were injected into the buffer solution. They aggregated to large clusters in the presence of Ca(2+) and adsorbed from these units to the interface. This gave rise to an interfacial film that eventually became fully condensed with dark, polygonal domains in a fluorescent matrix. When now the bubble size was increased or decreased, respectively, the film expanded or contracted. Upon expansion of the bubble, the dark areas became larger to the debit of the bright matrix and reversed upon contraction. We were able to observe single domains during the whole process. The film remained condensed, even when the interface was increased to twice its original size. From comparison with scanning force microscopy directly at the air-water interface, the fluorescent areas proved to be lipid bilayers associated with the (dark) monolayer. In the lung, such multilayer phase acts as a reservoir that guarantees a full molecular coverage of the alveolar interface during the breathing cycle and provides mechanical stability to the film. PMID:12080141

  11. Measuring Air-Water Interfacial Area via the Interfacial Partitioning Tracer Test Method

    NASA Astrophysics Data System (ADS)

    El Ouni, A.; Zhong, H.; Mainhagu, J.; Araujo, J. B.; Brusseau, M. L.

    2012-12-01

    Interfacial partitioning tracer tests (IPTT) are one method available for measuring air-water interfacial area (Aa-w). Two variations of the aqueous IPTT method are compared. One involves the standard approach comprising tracer injection under steady unsaturated-flow conditions with a uniform water-saturation distribution within the column. The other involves tracer injection under steady saturated-flowconditions in the presence of trapped residual air. Sodium dodecylbezenesulfonate (SDBS) and pentafluorobenzoic acid (PFBA) were used as the partitioning andnonreactive tracers, respectively. A sandy soil with a median grain diameter of 0.234 mm was used as the porous medium. Initial water saturation, Sw,was approximately 80%. Water saturation was monitored gravimetrically during the experiments. The results of the experiments will be assessed and compared to those of prior studies.

  12. Radon removal from flowing air by a water scrubber

    SciTech Connect

    Blue, T.E.; Jarzemba, M.S.; Fentiman, A.W.; Denison, J.E.

    1994-12-31

    As part of a process that is being developed to vitrify tailings from Belgian Congo ore that is stored in large silos at a former U.S. Department of Energy uranium-processing facility in southwestern Ohio, process off-gas is produced that contains large concentrations of radon gas (on the order of hundreds of thousands of picocuries per litre). To meet U.S. Environmental Protection Agency restrictions, the process off-gas must be stripped of its radon content before it is vented to the atmosphere. It is appropriate to consider a charcoal bed as part of an off-gas treatment system for the removal of radon at the vitrification facility. However, a difficulty arises in incorporating a charcoal bed into an off-gas treatment system at a vitrification facility. That difficulty is that the capability of the charcoal bed to capture and retain radon gas decreases with increasing bed temperature. Thus, it may be necessary to include a water scrubber in the off-gas treatment system to cool the process off-gas before it is passed through the charcoal bed.

  13. Basic environmental technology: Water supply, waste disposal, pollution control

    SciTech Connect

    Nathanson, J.A.

    1986-01-01

    This book emphasizes hydrology, hydraulics, water management and water quality. It also discusses solid and hazardous waste, and air and noise pollution. Fundamental scientific concepts are introduced as needed - the text does not assume extensive knowledge of chemistry or biology.

  14. LASER ABSORPTION SPECTROSCOPY METHODS FOR SUBSURFACE MONITORING OF CO2 IN WATER AND AIR PHASES AT SEQUESTRATION SITES

    NASA Astrophysics Data System (ADS)

    Wu, S.; Romanak, K.; Yang, C.

    2009-12-01

    We report the development of two methods for subsurface monitoring of CO2 in both air and water phases at sequestration sites. The first method is based on line-of-sight (LOS) tunable laser spectroscopy. Funded by DOE, we demonstrated the Phase Insensitive Two Tone Frquency Modulation spectroscopy (PITTFM). FM reduces low frequency noise in the beam path due to scintillations; while the PI design gives the ease of installation. We demonstrated measurement over 1 mile distance with an accuracy of 3ppm of CO2 in normal air. Built-in switches shoot the laser beam into multi-directions, thus forming a cellular monitoring network covering 10 km^2. The system cost is under $100K, and COTS telecom components guarantee the reliability in the field over decades. Software will log the data and translate the 2D CO2 profile. When coupled with other parameters, it will be able to locate the point and rate of leakages. Field tests at SECARB sequestration site are proposed. The system also monitors other green house gases (GHG), e.g. CH4, which is also needed where EOR is pursued along with CO2 sequestration. Figures 1 through 2 give the results of this method. The second method is based on the latest technology advances in quantum cascade lasers (QCLs). The current state of the art technology to measure Total/Dissolved Inorganic Carbon (TIC/DIC) in water is menometer. Menometer is both time consuming and costly, and could not be used underground, i.e. high pressure and temperature. We propose to use high brightness QC lasers to extend the current Mid-IR optical path from 30 microns to over 500microns, thus providing the possibility to measure CO2 dissoveled (Aqueous phase) with an accuracy of 0.2mg/Liter. Preliminary results will be presented.

  15. The uncertainty of assessments of the water balance components of river basins due to the climate noise

    NASA Astrophysics Data System (ADS)

    Gusev, Yeugeniy; Semenov, Vladimir; Nasonova, Olga; Kovalev, Evgeny

    2016-04-01

    Assessments of hydrological consequences resulted from climate change impact performed by different authors are characterized by a large scatter or uncertainty caused by a number of reasons. Some reasons are subjective, while others are objective. In the present work, the objective uncertainty, which cannot be reduced by means of better physical description of the processes under study or by means of improvement of the quality of input data for atmospheric and hydrological models, and which is an internal feature of the atmosphere - hydrosphere - land surface system, is considered. This uncertainty is caused by a chaotic character of atmospheric processes (i.e. by so-called climatic noise), their instability with respect to small errors in determination of initial conditions for modeling the evolution of meteorological variables. Here, the impact of climatic noise on the uncertainty of hydrological variables (river runoff and evapotranspiration) is studied for two northern river basins located in the Russian Federation: the Lena and Indigirka basins. Such a selection was motivated by the fact, that northern high-latitude land areas are the major source of fresh water resources of our planet, at the same time these areas will be subjected to the earliest and most significant changes, caused by anthropogenic greenhouse gas emissions. The methodology of solving the problem is based on application of the global climate model (GCM) ECHAM5 and the land surface model (LSM) SWAP that allows an estimation of monthly and annual uncertainties in the simulated water balance components (precipitation, river runoff and evapotranspiration) of the selected river basins, resulted from the climatic noise. The ensemble simulations (45 versions) of meteorological fields were performed by ECHAM5. Since meteorological fields modelled by any GCM differ from observations, the post-processing bias-correction was carried out. Then for each river basin and computational experiment

  16. Influence of entrapped air pockets on hydraulic transients in water pipelines

    SciTech Connect

    Zhou, Ling; Liu, Prof. Deyou; Karney, Professor Byran W.; Zhang, Qin Fen

    2011-01-01

    The pressure variations associated with a filling undulating pipeline containing an entrapped air pocket are investigated both experimentally and numerically. The influence of entrapped air on abnormal transient pressures is often ambiguous since the compressibility of the air pocket permits the liquid flow to accelerate but also partly cushions the system, with the balance of these tendencies being associated with the initial void fraction of the air pocket. Earlier experimental research involved systems with an initial void fraction greater than 5.8%; this paper focuses on initial void fractions ranging from 0% to 10%, in order to more completely characterize the transient response. Experimental results show that the maximum pressure increases and then decreases as the initial void fraction decreases. A simplified model is developed by neglecting the liquid inertia and energy loss of a short water column near the air-water interface. Comparisons of the calculated and observed results show the model is able to accurately predict peak pressures as a function of void fraction and filling conditions. Rigid water column models, however, perform poorly with small void fractions.

  17. Estimation Accuracy of air Temperature and Water Vapor Amount Above Vegetation Canopy Using MODIS Satellite Data

    NASA Astrophysics Data System (ADS)

    Tomosada, M.

    2005-12-01

    Estimation accuracy of the air temperature and water vapor amount above vegetation canopy using MODIS satellite data is indicated at AGU fall meeting. The air temperature and water vapor amount which are satisfied the multilayer energy budget model from the ground surface to the atmosphere are estimated. Energy budget models are described the fluxes of sensible heat and latent heat exchange for the ground surface and the vegetated surface. Used MODIS satellite data is the vegetated surface albedo which is calculated from visible and near infrared band data, the vegetated surface temperature, NDVI (Normalized Difference Vegetation Index), LAI (Leaf Area Index). Estimation accuracy of air temperature and water vapor amount above vegetation canopy is evaluated comparing with the value which is measured on a flux research tower in Tomakomai northern forest of Japan. Meteorological parameters such as temperature, wind speed, water vapor amount, global solar radiation are measured on a flux tower from the ground to atmosphere. Well, MODIS satellite observes at day and night, and it snows in Tomakomai in winter. Therefore, estimation accuracy is evaluated dividing on at daytime, night, snowfall day, and not snowfall day. There is the investigation of the undeveloped region such as dense forest and sea in one of feature of satellite observation. Since there is almost no meteorological observatory at the undeveloped region so far, it is hard to get the meteorological parameters. Besides, it is the one of the subject of satellite observation to get the amount of physical parameter. Although the amount of physical parameter such as surface temperature and concentration of chlorophyll-a are estimated by satellite, air temperature and amount of water vapor above vegetation canopy have not been estimated by satellite. Therefore, the estimation of air temperature and water vapor amount above vegetation canopy using satellite data is significant. Further, a highly accurate

  18. Core-Noise

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2010-01-01

    This presentation is a technical progress report and near-term outlook for NASA-internal and NASA-sponsored external work on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system level noise metrics for the 2015, 2020, and 2025 timeframes; the emerging importance of core noise and its relevance to the SFW Reduced-Noise-Aircraft Technical Challenge; the current research activities in the core-noise area, with some additional details given about the development of a high-fidelity combustion-noise prediction capability; the need for a core-noise diagnostic capability to generate benchmark data for validation of both high-fidelity work and improved models, as well as testing of future noise-reduction technologies; relevant existing core-noise tests using real engines and auxiliary power units; and examples of possible scenarios for a future diagnostic facility. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Noise-Aircraft Technical Challenge aims to enable concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical for enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor designs could increase

  19. Advanced computer technology - An aspect of the Terminal Configured Vehicle program. [air transportation capacity, productivity, all-weather reliability and noise reduction improvements

    NASA Technical Reports Server (NTRS)

    Berkstresser, B. K.

    1975-01-01

    NASA is conducting a Terminal Configured Vehicle program to provide improvements in the air transportation system such as increased system capacity and productivity, increased all-weather reliability, and reduced noise. A typical jet transport has been equipped with highly flexible digital display and automatic control equipment to study operational techniques for conventional takeoff and landing aircraft. The present airborne computer capability of this aircraft employs a multiple computer simple redundancy concept. The next step is to proceed from this concept to a reconfigurable computer system which can degrade gracefully in the event of a failure, adjust critical computations to remaining capacity, and reorder itself, in the case of transients, to the highest order of redundancy and reliability.

  20. Water soluble graphene as electrolyte additive in magnesium-air battery system

    NASA Astrophysics Data System (ADS)

    Mayilvel Dinesh, M.; Saminathan, K.; Selvam, M.; Srither, S. R.; Rajendran, V.; Kaler, Karan V. I. S.

    2015-02-01

    Magnesium-air (Mg-air) batteries are an important energy source used to power electronic equipment and automobiles. Metal-air batteries give more energy density due to surplus air involved in reduction reaction at air cathode. In this study, the scope of improvements in the efficiency of Metal-air batteries is investigated through addition of water soluble graphene (WSG) as inhibitor in NaCl electrolyte. The discharge performance, corrosion behaviour and electrochemical impedance are studied for (i) the conventional Mg-air battery using 3.5% NaCl and (ii) Mg-air battery with WSG-based 3.5% NaCl electrolyte. X-ray diffraction analysis for WSG is carried out and it shows the crystalline nature of WSG by an intense sharp peak at 26.3°. Scanning electron microscope study is also performed and shows the flake-like structure of WSG denoted by thin layers of carbon. The immersion of WSG in 3.5% NaCl electrolyte increased the current density from 13.24 to 19.33 mA cm-2. Meanwhile, the WSG-based Mg-air battery was found to hold specific discharge capacity of 1030.71 mAh g-1, which was higher than that obtained in 3.5% NaCl electrolyte (i.e., 822.85 mAh g-1). The WSG-based Mg-air battery shows good self-discharge capacity and higher electrochemical activity during discharge.

  1. Water soluble graphene as electrolyte additive in magnesium-air battery system

    NASA Astrophysics Data System (ADS)

    Saminathan, K.; Mayilvel Dinesh, M.; Selvam, M.; Srither, S. R.; Rajendran, V.; Kaler, Karan V. I. S.

    2015-02-01

    Magnesium-air (Mg-air) batteries are an important energy source used to power electronic equipment and automobiles. Metal-air batteries give more energy density due to surplus air involved in reduction reaction at air cathode. In this study, the scope of improvements in the efficiency of Metal-air batteries is investigated through addition of water soluble graphene (WSG) as inhibitor in NaCl electrolyte. The discharge performance, corrosion behaviour and electrochemical impedance are studied for (i) the conventional Mg-air battery using 3.5% NaCl and (ii) Mg-air battery with WSG-based 3.5% NaCl electrolyte. X-ray diffraction analysis for WSG is carried out and it shows the crystalline nature of WSG by an intense sharp peak at 26.3°. Scanning electron microscope study is also performed and shows the flake-like structure of WSG denoted by thin layers of carbon. The immersion of WSG in 3.5% NaCl electrolyte increased the current density from 13.24 to 19.33 mA cm-2. Meanwhile, the WSG-based Mg-air battery was found to hold specific discharge capacity of 1030.71 mAh g-1, which was higher than that obtained in 3.5% NaCl electrolyte (i.e., 822.85 mAh g-1). The WSG-based Mg-air battery shows good self-discharge capacity and higher electrochemical activity during discharge.

  2. Noise generated by a flight weight, air flow control valve in a vertical takeoff and landing aircraft thrust vectoring system

    NASA Technical Reports Server (NTRS)

    Huff, Ronald G.

    1989-01-01

    Tests were conducted in the NASA Lewis Research Center's Powered Lift Facility to experimentally evaluate the noise generated by a flight weight, 12 in. butterfly valve installed in a proposed vertical takeoff and landing thrust vectoring system. Fluctuating pressure measurements were made in the circular duct upstream and downstream of the valve. This data report presents the results of these tests. The maximum overall sound pressure level is generated in the duct downstream of the valve and reached a value of 180 dB at a valve pressure ratio of 2.8. At the higher valve pressure ratios the spectra downstream of the valve is broad banded with its maximum at 1000 Hz.

  3. EFFECTS OF AIR-SUPERSATURATED WATER ON SURVIVAL OF PACIFIC SALMON AND STEELHEAD SMOLTS

    EPA Science Inventory

    Coho (Oncorhynchus kisutch) and sockeye (O. nerka) salmon smolts and steelhead trout (Salmo gairdneri) smolts were exposed to several concentrations of air-supersaturated water in the laboratory from March through June, 1974, the normal fish migration period in the Columbia River...

  4. Lead in umbilical blood, indoor air, tap water, and gasoline in Boston.

    PubMed

    Rabinowitz, M; Needleman, H; Burley, M; Finch, H; Rees, J

    1984-01-01

    A strong statistical correlation was found among the monthly averages of lead concentrations in umbilical cord blood (about 500 births/month), indoor air (12 sites/month), and gasoline lead sales between March, 1980 and April, 1981 in Boston. Tap water lead (24/month) variations did not correlate with blood lead in this population. PMID:6497447

  5. Action for Environmental Quality. Standards and Enforcement for Air and Water Pollution Control.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC.

    The U.S. Environmental Protection Agency (EPA) is responsible for setting and enforcing environmental quality standards for the nation. With the Clean Air Act of 1970 (P.L. 91-604) and the Water Pollution Control Act of 1972 (P.L. 92-500), the first truly nationwide control programs were established. This booklet is designed to inform the public…

  6. Air-water Gas Exchange Rates on a Large Impounded River Measured Using Floating Domes (Poster)

    EPA Science Inventory

    Mass balance models of dissolved gases in rivers typically serve as the basis for whole-system estimates of greenhouse gas emission rates. An important component of these models is the exchange of dissolved gases between air and water. Controls on gas exchange rates (K) have be...

  7. Air and Water Transportation Occupations. Reprinted from the Occupational Outlook Handbook, 1978-79 Edition.

    ERIC Educational Resources Information Center

    Bureau of Labor Statistics (DOL), Washington, DC.

    Focusing on air and water transportation occupations, this document is one in a series of forty-one reprints from the Occupational Outlook Handbook providing current information and employment projections for individual occupations and industries through 1985. The specific occupations covered in this document include civil aviation workers, air…

  8. Young Scientists Explore Air, Land, and Water Life. Book 3 Primary Level.

    ERIC Educational Resources Information Center

    Penn, Linda

    Designed to present interesting facts about science and to heighten the curiosity of primary age students, this book contains activities about the natural world and numerous black and white illustrations. The activities focus on familiar animals that are found in the air, on land, and in the water. A duckling named Little Mac Mallard introduces…

  9. Effect of the Entrapped air on Water Flow in Heterogeneous Soil: Experimental Set- up

    NASA Astrophysics Data System (ADS)

    Snehota, M.; Sobotkova, M.; Cislerova, M.

    2008-12-01

    Temporal variations of steady state water flow rates were observed in laboratory infiltration experiments done on a sample of compacted sand and on an undisturbed soil sample (Eutric Cambisol). These variations are found to be in relation with entrapped air content. Infiltration-outflow experiments consisted of a series of ponded infiltration runs with seepage face boundary condition at the lower end of columns. The amount of the entrapped was derived from continuous weighing of the sample. The initial water contents were different for each run, which led to different amount of the air trapped in the soil during the first stages of infiltrations. The results of the experiments done on undisturbed soil showed that the flux rates and water contents varied during quasi-steady state. This finding contradicts the standard theory. The fluctuations of the water content during the steady state flow can be ascribed to the variations in volume of the entrapped air. Similarly, shape of the bromide breakthrough curve, which were performed simultaneously during the quasi-steady state varied for undisturbed soil. The same behaviour was not observed in the sample of homogeneous sand. Computer tomography was used to characterize the structure of the undisturbed soil sample with focus on potential preferential flow pathways, which are likely to host the entrapped air. To formulate more general conclusions, an extended series of infiltration outflow and bromide breakthrough experiments is in progress. This research has been supported by research project GACR 103/08/1552 and MSMT CEZ MSM 6840770002.

  10. Why Do Objects Cool More Rapidly in Water than in Still Air?

    ERIC Educational Resources Information Center

    Bohren, Craig F.

    2011-01-01

    An Internet search for why objects, especially humans, cool more rapidly in water than in air, both at the same temperature, and by how much, yields off-the-cuff answers unsupported by experiment or analysis. To answer these questions in depth requires a smattering of engineering heat transfer, including radiative transfer, and the different…

  11. Water and entrapped air redistribution in heterogeneous sand sample: Quantitative neutron imaging of the process

    NASA Astrophysics Data System (ADS)

    Snehota, Michal; Jelinkova, Vladimira; Sobotkova, Martina; Sacha, Jan; Vontobel, Peter; Hovind, Jan

    2015-02-01

    Saturated flow in soil with the occurrence of preferential flow often exhibits temporal changes of saturated hydraulic conductivity even during the time scale of a single infiltration event. These effects, observed in a number of experiments done mainly on heterogeneous soils, are often attributed to the changing distribution of water and air in the sample. We have measured the variation of the flow rates during the steady state stage of the constant head ponded infiltration experiment conducted on a packed sample composed of three different grades of sand. The experiment was monitored by quantitative neutron imaging, which provided information about the spatial distribution of water in the sample. Measurements were taken during (i) the initial stages of infiltration by neutron radiography and (ii) during the steady state flow by neutron tomography. A gradual decrease of the hydraulic conductivity has been observed during the first 4 h of the infiltration event. A series of neutron tomography images taken during the quasi-steady state stage showed the trapping of air bubbles in coarser sand. Furthermore, the water content in the coarse sand decreased even more while the water content in the embedded fine sand blocks gradually increased. The experimental results support the hypothesis that the effect of the gradual hydraulic conductivity decrease is caused by entrapped air redistribution and the build up of bubbles in preferential pathways. The trapped air thus restricts the preferential flow pathways and causes lower hydraulic conductivity.

  12. THE EFFECT OF SALINITY ON RATES OF ELEMENTAL MERCURY AIR/WATER EXCHANGE

    EPA Science Inventory

    The U.S. EPA laboratory in Athens, Georgia i spursuing the goal of developing a model for describing toxicant vapor phase air/water exchange under all relevant environmental conditions. To date, the two-layer exchange model (suitable for low wind speed conditions) has been modif...

  13. SURVIVAL AND ADULT EMERGENCE OF AQUATIC INSECTS IN AIR-SUPERSATURATED WATER

    EPA Science Inventory

    Mayflies Timpanoga hecuba, caddisflies Dicosmoecus gilvipes, mosquitoes Culex peus and midges Cricotopus sp. were tested in the laboratory to determine the effects of air-supersaturated water on survival and adult emergence. The acute 96-hour LC50 value (lethal concentration whic...

  14. Surface Coordination of Black Phosphorus for Robust Air and Water Stability.

    PubMed

    Zhao, Yuetao; Wang, Huaiyu; Huang, Hao; Xiao, Quanlan; Xu, Yanhua; Guo, Zhinan; Xie, Hanhan; Shao, Jundong; Sun, Zhengbo; Han, Weijia; Yu, Xue-Feng; Li, Penghui; Chu, Paul K

    2016-04-11

    A titanium sulfonate ligand is synthesized for surface coordination of black phosphorus (BP). In contrast to serious degradation observed from the bare BP, the BP after surface coordination exhibits excellent stability during dispersion in water and exposure to air for a long period of time, thereby significantly extending the lifetime and spurring broader application of BP. PMID:26968443

  15. Spatial Distribution and Air-Water Exchange of Organic Flame Retardants in the Lower Great Lakes.

    PubMed

    McDonough, Carrie A; Puggioni, Gavino; Helm, Paul A; Muir, Derek; Lohmann, Rainer

    2016-09-01

    Organic flame retardants (OFRs) such as polybrominated diphenyl ethers (PBDEs) and novel halogenated flame retardants (NHFRs) are ubiquitous, persistent, and bioaccumulative contaminants that have been used in consumer goods to slow combustion. In this study, polyethylene passive samplers (PEs) were deployed throughout the lower Great Lakes (Lake Erie and Lake Ontario) to measure OFRs in air and water, calculate air-water exchange fluxes, and investigate spatial trends. Dissolved Σ12BDE was greatest in Lake Ontario near Toronto (18 pg/L), whereas gaseous Σ12BDE was greatest on the southern shoreline of Lake Erie (11 pg/m(3)). NHFRs were generally below detection limits. Air-water exchange was dominated by absorption of BDEs 47 and 99, ranging from -964 pg/m(2)/day to -30 pg/m(2)/day. Σ12BDE in air and water was significantly correlated with surrounding population density, suggesting that phased-out PBDEs continued to be emitted from population centers along the Great Lakes shoreline in 2012. Correlation with dissolved Σ12BDE was strongest when considering population within 25 km while correlation with gaseous Σ12BDE was strongest when using population within 3 km to the south of each site. Bayesian kriging was used to predict dissolved Σ12BDE over the lakes, illustrating the utility of relatively highly spatially resolved measurements in identifying potential hot spots for future study. PMID:27458653

  16. LEAF PHOTOSYNTHETIC AND WATER RELATIONS RESPONSES FOR "VALENCIA" ORANGE TREES EXPOSED TO OXIDANT AIR POLLUTION

    EPA Science Inventory

    Leaf responses were measured to test a hypothesis that reduced photosynthetic capacity and/or altered water relations were associated with reductions in yield for "Valencia" orange trees exposed to ambient oxidant air pollution. xposures were continuous for four years to three le...

  17. 45 CFR 2543.86 - Clean Air Act and the Federal Water Pollution Control Act.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Clean Air Act and the Federal Water Pollution Control Act. 2543.86 Section 2543.86 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER...

  18. HVAC equipment and noise

    SciTech Connect

    Cerami, V.J.

    1996-03-01

    The purpose of this article is to define how the selection of HVAC equipment and layout impact the achievable noise criteria (NC) levels in occupied spaces. It will focus on the design of HVAC systems that employ floor-by-floor air handling/air conditioning units and their acoustical ramifications. This is of increasing importance since tenants require incorporation of noise limits in lease agreements.

  19. Presence and absence of a water film between moving air bubbles and a plate

    NASA Astrophysics Data System (ADS)

    Remenyik, Carl J.

    1990-01-01

    The thickness of water films between an inclined Lucite plate submerged in water and air bubbles moving beneath it was measured with a small impedance probe. The instrument was calibrated with a laser interferometer built for this purpose. The bubbles released beneath the plate varied in size from 10 cc to 100 cc. At a plate inclination angle of 0.98°, and in tap water, an uninterrupted water film covered most of the bubbles. Some bubbles, however, dewetted the plate, and the water film covered only a forward part of the bubble. When the film was uninterrupted, its thickness was very uniform from front to rear. When the bubble dewetted the plate, a large forward section of the film had the same uniform thickness, but this was followed by a hump on the film the rear slope of which ended at the plate surface. For some of the experiments, the surface tension of the water was reduced by admixing a detergent. In these experiments, dewetting was not observed. In a second set of experiments, a hand held transparent container filled with water and a 1.3 cm3 air bubble was used to observe visually the behavior of the moving bubble and its associated water film.

  20. Dust Control with Use of Air-Water Spraying System / Redukcja Zapylenia Powietrza Z Wykorzystaniem Zraszania Powietrzno-Wodnego

    NASA Astrophysics Data System (ADS)

    Prostański, Dariusz

    2012-12-01

    Results from testing the dust control efficiency, when using air-water spraying system in comparison to the typical water spraying system are presented in the paper. The tests were carried out in conditions of longwall mining and at the places of run-of-mine transportation. Also the results of stand tests of different types of nozzles both for air-water and for water spaying systems carried out at KOMAG's laboratory and in real conditions are presented. The benefits resulting from air-water spraying system have been determined.

  1. Core Noise - Increasing Importance

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduced-Perceived-Noise Technical Challenge; and the current research activities in the core-noise area, with additional details given about the development of a high-fidelity combustor-noise prediction capability as well as activities supporting the development of improved reduced-order, physics-based models for combustor-noise prediction. The need for benchmark data for validation of high-fidelity and modeling work and the value of a potential future diagnostic facility for testing of core-noise-reduction concepts are indicated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor

  2. 27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  3. 27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  4. 27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  5. 27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

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

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  7. Water and Air Redistribution within a Dual Permeability Porous System Investigated Using Neutron Imaging

    NASA Astrophysics Data System (ADS)

    Sacha, Jan; Jelinkova, Vladimira; Snehota, Michal; Vontobel, Peter; Hovind, Jan; Cislerova, Milena

    A ponded infiltration experiment was conducted under simultaneous imaging to investigate variations in quasi-saturated hydraulic conductivity a process frequently observed in infiltration experiments in soils with wide grain -size distribution. An artificially prepared heterogeneous sample composed of coarse quartz sand (representing pathways of preferential flow) and fine porous ceramic (representing soil matrix) was investigated. The sample was 34.5 mm high and 29.0 mm in diameter. Sequences of neutron radiography images (RI) of pixel size 0.045 × 0.045 mm were taken at one angle during particular transient phases of the flow process. During quasi-steady state flow stages of the experiment radiography images were acquired in range of angles 0-180° in 0.9° step and. 3D neutron tomograms (TI) were then developed. Using the data a quantitative evaluation of the spatial and temporal distribution of water content within the sample was conducted. For every RI and TI the amount of water in particular pixels and voxels, respectively, was calculated by subtracting the image of dry sample. The accuracy of the water content estimates derived from the images was checked by comparing them to the corresponding gravimetrically determined water content data. Heavy water with equilibrium air saturation was introduced into the sample during two recurrent infiltrations. Thirty five hours later, during second infiltration, the inflow was switched to degassed heavy water in order to remove residual air present in the sample. During the first twelve hours of first infiltration run flow rate through the sample decreased from 3.7 cm/hour to 1.0 cm/hour at the end of the "steady state flow" stage. The flow rate in second run decreased from 3.6 cm/hour to 1.6 cm/hour. Comparison of the tomogram of the sample at the beginning and one taken at the end of the steady state flow stage in each run shows an increase of water content in the porous ceramic, while the water content in the coarse

  8. Pollutant transfer through air and water pathways in an urban environment

    SciTech Connect

    Brown, M.; Burian, S.; McPherson, T.; Streit, G.; Costigan, K.; Greene, B.

    1998-12-31

    The authors are attempting to simulate the transport and fate of pollutants through air and water pathways in an urban environment. This cross-disciplinary study involves linking together models of mesoscale meteorology, air pollution chemistry and deposition, urban runoff and stormwater transport, water quality, and wetland chemistry and biology. The authors are focusing on the transport and fate of nitrogen species because (1) they track through both air and water pathways, (2) the physics, chemistry, and biology of the complete cycle is not well understood, and (3) they have important health, local ecosystem, and global climate implications. The authors will apply their linked modeling system to the Los Angeles basin, following the fate of nitrates from their beginning as nitrate-precursors produced by auto emissions and industrial processes, tracking their dispersion and chemistry as they are transported by regional winds and eventually wet or dry deposit on the ground, tracing their path as they are entrained into surface water runoff during rain events and carried into the stormwater system, and then evaluating their impact on receiving water bodies such as wetlands where biologically-mediated chemical reactions take place. In this paper, the authors wish to give an overview of the project and at the conference show preliminary results.

  9. Passive cathodic water/air management device for micro-direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Peng, Hsien-Chih; Chen, Po-Hon; Chen, Hung-Wen; Chieng, Ching-Chang; Yeh, Tsung-Kuang; Pan, Chin; Tseng, Fan-Gang

    A high efficient passive water/air management device (WAMD) is proposed and successfully demonstrated in this paper. The apparatus consists of cornered micro-channels and air-breathing windows with hydrophobicity arrangement to regulate liquids and gases to flow on their predetermined pathways. A high performance water/air separation with water removal rate of about 5.1 μl s -1 cm -2 is demonstrated. The performance of the proposed WAMD is sufficient to manage a cathode-generated water flux of 0.26 μl s -1 cm -2 in the micro-direct methanol fuel cells (μDMFCs) which are operated at 100 mW cm -2 or 400 mA cm -2. Furthermore, the condensed vapors can also be collected and recirculated with the existing micro-channels which act as a passive water recycling system for μDMFCs. The durability testing shows that the fuel cells equipped with WAMD exhibit improved stability and higher current density.

  10. Role of water and discharge mode on modulating properties in an atmospheric air MHCD jet

    NASA Astrophysics Data System (ADS)

    Liu, Kun; Wang, Chenying; Lei, Juzhang; Hu, Huimin; Zheng, Peichao; He, Wei

    2016-04-01

    A portable micro hollow cathode discharge (MHCD) device was designed in this paper to generate water-air plasma jet. The results showed that MHCD jet pattern was changed from self-pulsing discharge mode to DC mode with the increasing of voltage, and the critical voltage value of discharge mode increased with the rise of gas flow. In order to study the influences of discharge mode and water content on MHCD jet, the electrical characteristics and radicals were all measured in different conditions. We found that the length of jet decreased and temperature increased with raising water-air ratio, and during self-pulsing discharge mode, •OH content was extremely low because of the low energy of electron, but level of NO was raised with gradually increasing applied voltage. In DC mode, the results showed there was least NO content, on the other hand •OH content increased with rise of voltage and water-air ratio. O existed in both discharge modes and the effect of water content on the O production was complex. Contribution to the Topical Issue "Recent Breakthroughs in Microplasma Science and Technology", edited by Kurt Becker, Jose Lopez, David Staack, Klaus-Dieter Weltmann and Wei Dong Zhu.

  11. Current-use pesticides in inland lake waters, precipitation, and air from Ontario, Canada.

    PubMed

    Kurt-Karakus, Perihan Binnur; Teixeira, Camilla; Small, Jeff; Muir, Derek; Bidleman, Terry F

    2011-07-01

    Concentrations of current-use pesticides (CUPs) in water, zooplankton, precipitation, and air samples as well as stereoisomer fractions (SF; herbicidally active/total stereoisomers) of metolachlor were determined in water samples collected from 10 remote inland lakes in Ontario, Canada, between 2003 and 2005. The most frequently detected chemicals in lake water, precipitation, and air were α-endosulfan, atrazine, metolachlor, chlorpyrifos, chlorothalonil, and trifluralin, and α-endosulfan and chlorpyrifos were the chemicals detected frequently in zooplankton. Air concentrations of these CUPs were within the range of previously reported values for background sites in the Great Lakes basin. High detection frequency of CUPs in lake water and precipitation was attributed to high usage amounts, but some CUPs such as ametryn and disulfoton that were not used in Ontario were also detected. Mean bioaccumulation factors (wet wt) in zooplankton for endosulfan ranged from 160 to 590 and from 20 to 60 for chlorpyrifos. The overall median SF of metolachlor in precipitation samples (0.846) was similar to that of the commercial S-metolachlor (0.882). However, the median SF of metolachlor in water from all sampled inland lakes (0.806) was significantly lower compared with Ontario rivers (0.873) but higher compared with previous measurements in the Great Lakes (0.710). Lakes with smaller watershed areas showed higher SFs, supporting the hypothesis of stereoselective processing of deposited metolachlor within the watersheds, followed by transport to the lakes. PMID:21472774

  12. Experimental Studies of the Acoustic Properties of a Finite Elastic Pipe Filled with Water/air

    NASA Astrophysics Data System (ADS)

    Feng, L.

    1996-02-01

    Vibration of, and sound power radiated from, a water/air-filled steel pipe are measured and analyzed. Two types of pipe terminal are employed in the experiments: embedded in sand boxes or without any absorption treatment. Comparisons are made between experiments and theoretical analysis. The measured wavenumbers agree well with those predicted as do modal responses are sound power of the air-filled pipe. For the water-filled steel pipe used in the test (inner diameter 150 mm), measured modal responses and sound power at high frequencies (higher than 4·5 kHz) are much lower than expected for the lossless model. Influences of pipe terminals on the coupling between the water and pipe are also examined.

  13. Sea breeze forcing of estuary turbulence and air-water CO2 exchange

    NASA Astrophysics Data System (ADS)

    Orton, Philip M.; McGillis, Wade R.; Zappa, Christopher J.

    2010-07-01

    The sea breeze is often a dominant meteorological feature at the coastline, but little is known about its estuarine impacts. Measurements at an anchored catamaran and meteorological stations along the Hudson River and New York Bay estuarine system are used to illustrate some basic characteristics and impacts of the feature. The sea breeze propagates inland, arriving in phase with peak solar forcing at seaward stations, but several hours later at up-estuary stations. Passage of the sea breeze front raises the water-to-air CO2 flux by 1-2 orders of magnitude, and drives turbulence comparable to spring tide levels in the upper meter of the water column, where most primary productivity occurs in this highly turbid system. Modeling and observational studies often use remotely-measured winds to compute air-water fluxes (e.g., momentum, CO2), and this leads to a factor of two flux error on sea breeze days during the study.

  14. The measurement of water vapour transfer rate through clothing system with air gap between layers

    NASA Astrophysics Data System (ADS)

    Oh, Ae-Gyeong

    2008-02-01

    The experiments described in this paper are designed to test the water vapour transfer rates through outdoor clothing system with air gap between layers under conditions more closely actual wear. It was adopted distance of 5 mm to ensure no disturbance of the air gap thickness between layers throughout the measurement period with all fabrics. The results have indicated that the water vapour transfer rates of clothing system decrease very slightly with time, it is shown that they approached nearly equilibrium state throughout the experiment. It is revealed that the water vapour transfer rates of the clothing system were ordered into groups determined by the type of waterproof breathable fabric as a shell layer being ordered.

  15. Effects of saline-water flow rate and air speed on leakage current in RTV coatings

    SciTech Connect

    Kim, S.H.; Hackam, R.

    1995-10-01

    Room temperature vulcanizing (RTV) silicone rubber is increasingly being used to coat porcelain and glass insulators in order to improve their electrical performance in the presence of pollution and moisture. A study of the dependence of leakage current, pulse current count and total charge flowing across the surface of RTV on the flow rate of the saline water and on the compressed air pressure used to create the salt-fog is reported. The fog was directed at the insulating rods either from one or two sides. The RTV was fabricated from polydimethylsiloxane polymer, a filler of alumina trihydrate (ATH), a polymerization catalyst and fumed silica reinforcer, all dispersed in 1,1,1-trichloroethane solvent. The saline water flow rate was varied in the range 0.4 to 2.0 l/min. The compressed air pressure at the input of the fog nozzles was varied from 0.20 to 0.63 MPa. The air speed at the surface of the insulating rods was found to depend linearly on the air pressure measured at the inlet to the nozzles and varied in the range 3 to 14 km/hr. The leakage current increased with increasing flow rate and increasing air speed. This is attributed to the increased loss of hydrophobicity with a larger quantity of saline fog and a larger impact velocities of fog droplets interacting with the surface of the RTV coating.

  16. Evaluation of ground-water flow by particle tracking, Wright-Patterson Air Force Base, Ohio

    USGS Publications Warehouse

    Cunningham, W.L.; Sheets, R.A.; Schalk, C.W.

    1994-01-01

    The U.S. Geological Survey (USGS) and Wright-Patterson Air Force Base (WPAFB) began a Basewide Monitoring Program (BMP) in 1992. The purpose of the BMP was to establish a long-term ground-water and surface- water sampling network in order to (1) characterize current ground-water and surface-water quality; (2) describe water-quality changes as water enters, flows across, and exits Base boundaries; (3) conduct statistical analyses of water quality; and (4) estimate the effect of WPAFB on regional water quality. As part of the BMP, the USGS conducted ground-water particle-tracking analyses based on a ground-water-flow model produced during a previous USGS study. This report briefly describes the previous USGS study, the inherent assumptions of particle-tracking analyses, and information on the regional ground-water-flow field as inferred from particle pathlines. Pathlines for particles placed at the Base boundary and particles placed within identified Installation Restoration Program sites are described.

  17. 78 FR 70960 - Notice of Lodging of Consent Decree Under the Clean Air Act, Clean Water Act, and the Resource...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-27

    ... of Lodging of Consent Decree Under the Clean Air Act, Clean Water Act, and the Resource Conservation and Recovery Act On November 20, 2013, the Department of Justice lodged a proposed consent decree with... the United States and the State of Illinois under the Clean Air Act, the Clean Water Act, the...

  18. Waste water/storm water characterization survey, Willow Grove Air Reserve Facility, Pennsylvania. Final report, 15-26 Jul 91

    SciTech Connect

    McCoy, R.P.

    1992-03-01

    A wastewater characterization survey was conducted at Willow Grove Air Reserve Facility from 15-26 July 1991 by personnel from the Water Quality Function of Armstrong Laboratory. Quantitative data were also collected after a rain event to assess the quality of the water in the storm water holding pond. Sampling of the oil/water separators was also performed and recommendations were made concerning good management practices to implement to maintain the separators. Slight contamination of the wastewater discharged from the Facility was found, indicating the base is using good shop practices to minimize the disposal of industrial wastes through the sanitary sewer system. Results of the storm water sampling showed that the quality of the water in the holding pond was not greatly impacted by storm water runoff from the industrial areas on the Facility. A recommendation was made to install a pollution control device on the drain at the Bulk Fuels Storage Area. One oil/water separator was found to contain oil that had hazardous waste characteristics. All others had oil that was suitable for energy recovery.

  19. Photosensitized Formation of Secondary Organic Aerosols above the Air/Water Interface.

    PubMed

    Bernard, F; Ciuraru, R; Boréave, A; George, C

    2016-08-16

    In this study, we evaluated photosensitized chemistry at the air-sea interface as a source of secondary organic aerosols (SOA). Our results show that, in addition to biogenic emissions, abiotic processes could also be important in the marine boundary layer. Photosensitized production of marine secondary organic aerosol was studied in a custom-built multiphase atmospheric simulation chamber. The experimental chamber contained water, humic acid (1-10 mg L(-1)) as a proxy for dissolved organic matter, and nonanoic acid (0.1-10 mM), a fatty acid proxy which formed an organic film at the air-water interface. Dark secondary reaction with ozone after illumination resulted in SOA particle concentrations in excess of 1000 cm(-3), illustrating the production of unsaturated compounds by chemical reactions at the air-water interface. SOA numbers via photosensitization alone and in the absence of ozone did not exceed background levels. From these results, we derived a dependence of SOA numbers on nonanoic acid surface coverage and dissolved organic matter concentration. We present a discussion on the potential role of the air-sea interface in the production of atmospheric organic aerosol from photosensitized origins. PMID:27434860

  20. Treatability test of a stacked-tray air stripper for VOC in water

    SciTech Connect

    Pico, T., LLNL

    1998-04-01

    A common strategy for hydraulic containment and mass removal at VOC contaminated sites is `pump and treat (P&T)`. In P&T operations, contaminated ground water is pumped from wells, treated above ground, and discharged. Many P&T remediation systems at VOC sites rely on air stripping technology because VOCs are easily transferred to the vapor phase. In stacked-tray air strippers, contaminated water is aerated while it flows down through a series of trays. System operations at LLNL are strictly regulated by the California and federal Environmental Protection Agencies (Cal/EPA and EPA), the Bay Area Air Quality Management District (BAAQMD), the California Regional Water Quality Control Board (RWQCB) and the Department of Toxic Substances Control (DTSC). These agencies set discharge limits, require performance monitoring, and assess penalties for non-compliance. National laboratories are also subject to scrutiny by the public and other government agencies. This extensive oversight makes it necessary to accurately predict field treatment performance at new extraction locations to ensure compliance with all requirements prior to facility activation. This paper presents treatability test results for a stacked- tray air stripper conducted at LLNL and compares them to the vendor`s modeling software results.

  1. Impact of subjacent rocks at the water and air regime of the depleted peat deposits

    NASA Astrophysics Data System (ADS)

    Rakovich, V. A.

    2009-04-01

    At the depleted peat deposits (after peat extraction), where the residual layer of peat with the thickness of about 0,5 meters is laid at the well water permeable rocks, vegetation typical for dry conditions is developed in case of good drainage conditions; birch trees, willow, alder-trees and buckthorn prevail in this vegetation. Water and air regime is characterized here by good aeration with prevailing of oxidative processes. If water regime is regulated, these depleted peat areas are suitable for agricultural and forest lands; however, necessity of transformation of these depleted lands into forest and agricultural lands must be ecologically and economically justified. If the residual layer of peat with the thickness of 0,05-0,3 m is based at the sapropel or peat sapropel, contrast amphibiotic water and air regime with strong fluctuation of oxidative and restoration process depending on the weather conditions is formed; this regime is formed without artificial increase of the ground waters level. This does not allow bog vegetation or vegetation typical for dry conditions to develop. Thus, within 20 and more years after completion of peat extraction, such areas are not covered by vegetation in spite of favorable agro-chemical qualities of peat layer and favorable for vegetation chemical composition of soil and ground waters. Depleted peat deposits, that are based at the sapropel, are not suitable for agricultural use, because agricultural vegetation requires stable water and air regime with good aeration and oxidative and restoration potential within 400-750 mV. Contrast amphibiotic water and air regime of the depleted peat deposits that are based at sapropel excludes possibility to use them as agricultural lands. Because of this reason, areas with residual peat layer that are based at sapropel are not suitable for forest planting. Due to periodic increase of ground waters level, rot systems of the plants can not penetrate into the required depth, and mechanical

  2. Definition of water droplets "strain cycles" in air times dependences on their sizes and movement velocities

    NASA Astrophysics Data System (ADS)

    Volkov, Roman; Zhdanova, Alena; Zabelin, Maxim; Kuznetsov, Geniy; Strizhak, Pavel

    2014-08-01

    Experimental investigation of water droplets deformation regularities during their motion in the air by the action of gravitational forces was executed. Characteristic sizes of droplets were varied in the range from 3 mm to 6 mm. Velocities of droplets movement attained to 5 m/s. The cross-correlation system of video registration was used. More than ten characteristic "strain cycles" of droplets during the 1 m distance motion by them thought the air were established. Characteristic of droplets forms, periods, dimensions and ranges were determined for all "strain cycles". "Strain cycle" times dependences on velocity and sizes of droplets were established.

  3. Steady-state response of a charcoal bed to radon in flowing air with water vapor

    SciTech Connect

    Blue, T.E.; Jarzemba, M.S.; Fentiman, A.W.

    1995-06-01

    Previously we have developed a mathematical model of radon adsorption in active air with water vapor on small U.S. Environmental Protection Agency charcoal canisters that are used for environmental measurements of radon. The purpose of this paper is to extend this mathematical model to describe the adsorption of radon by large charcoal beds with radon-laden air flowing through them. The resulting model equations are solved analytically to predict the steady-state adsorption of radon by such beds. 14 refs., 3 figs.

  4. (Environmental investigation of ground water contamination at Wright- Patterson Air Force Base, Ohio)

    SciTech Connect

    Not Available

    1991-10-01

    This Health and Safety Plan (HSP) was developed for the Environmental Investigation of Ground-water Contamination Investigation at Wright-Patterson Air Force Base near Dayton, Ohio, based on the projected scope of work for the Phase 1, Task 4 Field Investigation. The HSP describes hazards that may be encountered during the investigation, assesses the hazards, and indicates what type of personal protective equipment is to be used for each task performed. The HSP also addresses the medical monitoring program, decontamination procedures, air monitoring, training, site control, accident prevention, and emergency response.

  5. Aircraft noise - Different ways to monitor the noise load

    NASA Astrophysics Data System (ADS)

    Bekebrede, G.

    Measures taken by the Dutch government to reduce aircraft-noise disturbances including the establishment of noise zones in which subsequent building is forbidden, while already existing homes are provided with noise insulation are discussed. To ensure accurate noise monitoring, the following recommendations were made by the NLR: (1) regular noise load calculations, utilizing aircraft noise and performance data, the air traffic mix, and flight route information; (2) flight track monitoring, performed by a computerized Flight Track and Aircraft Noise Monitoring System which identifies all aircraft deviating from the prescribed track (i.e., flying over congested regions); and (3) actual noise monitoring, to guard the noise level at a specific noise-sensitive area in close proximity to the airfield, such as a hospital.

  6. Fisk-based criteria to support validation of detection methods for drinking water and air.

    SciTech Connect

    MacDonell, M.; Bhattacharyya, M.; Finster, M.; Williams, M.; Picel, K.; Chang, Y.-S.; Peterson, J.; Adeshina, F.; Sonich-Mullin, C.; Environmental Science Division; EPA

    2009-02-18

    This report was prepared to support the validation of analytical methods for threat contaminants under the U.S. Environmental Protection Agency (EPA) National Homeland Security Research Center (NHSRC) program. It is designed to serve as a resource for certain applications of benchmark and fate information for homeland security threat contaminants. The report identifies risk-based criteria from existing health benchmarks for drinking water and air for potential use as validation targets. The focus is on benchmarks for chronic public exposures. The priority sources are standard EPA concentration limits for drinking water and air, along with oral and inhalation toxicity values. Many contaminants identified as homeland security threats to drinking water or air would convert to other chemicals within minutes to hours of being released. For this reason, a fate analysis has been performed to identify potential transformation products and removal half-lives in air and water so appropriate forms can be targeted for detection over time. The risk-based criteria presented in this report to frame method validation are expected to be lower than actual operational targets based on realistic exposures following a release. Note that many target criteria provided in this report are taken from available benchmarks without assessing the underlying toxicological details. That is, although the relevance of the chemical form and analogues are evaluated, the toxicological interpretations and extrapolations conducted by the authoring organizations are not. It is also important to emphasize that such targets in the current analysis are not health-based advisory levels to guide homeland security responses. This integrated evaluation of chronic public benchmarks and contaminant fate has identified more than 200 risk-based criteria as method validation targets across numerous contaminants and fate products in drinking water and air combined. The gap in directly applicable values is

  7. Hydrodynamics of a fixed camphor boat at the air-water interface

    NASA Astrophysics Data System (ADS)

    Singh, Dhiraj; Akella, Sathish; Singh, Ravi; Mandre, Shreyas; Bandi, Mahesh

    2015-11-01

    A camphor tablet, when introduced at the air-water interface undergoes sublimation and the camphor vapour spreads radially outwards across the surface. This radial spreading of camphor is due to Marangoni forces setup by the camphor concentration gradient. We report experiments on the hydrodynamics of this process for a camphor tablet held fixed at the air-water interface. During the initial transient, the time-dependent spread radius R (t) of camphor scales algebraically with time t (R (t) ~t 1 / 2) in agreement with empirical scalings reported for spreading of volatile oils on water surface. But unlike surfactants, the camphor stops spreading when the influx of camphor from the tablet onto the air-water interface is balanced by the outflux of camphor due to evaporation, and a steady-state condition is reached. The spreading camphor however, shears the underlying fluid and sets up bulk convective flow. We explain the coupled steady-state dynamics between the interfacial camphor spreading and bulk convective flow with a boundary layer approximation, supported by experimental evidence. This work was supported by the Collective Interactions Unit, OIST Graduate University.

  8. A self-consistent field study of a hydrocarbon droplet at the air-water interface.

    PubMed

    Hilz, Emilia; Leermakers, Frans A M; Vermeer, Arnoldus W P

    2012-04-14

    A molecularly detailed self-consistent field (SCF) approach is applied to describe a sessile hydrocarbon droplet placed at the air-water interface. Predictions of the contact angle for macroscopic droplets follow from using Neumann's equation, wherein the macroscopic interfacial tensions are computed from one-gradient calculations for flat interfaces. A two-gradient cylindrical coordinate system with mirror-like boundary conditions is used to analyse the three dimensional shape of the nano-scale oil droplet at the air-water interface. These small droplets have a finite value of the Laplace pressure and concomitant line tension. It has been calculated that the oil-water and oil-vapour interfacial tensions are curvature dependent and increase slightly with increasing interfacial curvature. In contrast, the line tension tends to decrease with curvature. In all cases there is only a weak influence of the line tension on the droplet shape. We therefore argue that the nano-scale droplets, which are described in the SCF approach, are representative for macroscopic droplets and that the method can be used to efficiently generate accurate information on the spreading of oil droplets at the air-water interface in molecularly more complex situations. As an example, non-ionic surfactants have been included in the system to illustrate how a molecularly more complex situation will change the wetting properties of the sessile drop. This short forecast is aimed to outline and to stress the potential of the method. PMID:22395192

  9. Sources of Atmospheric Pollutants Impacting Air and Water Quality in the Lake Tahoe Basin

    NASA Astrophysics Data System (ADS)

    Gertler, A. W.; Cahill, T. A.; Gillies, J.; Kuhns, H.

    2008-12-01

    Starting in the second half of the 20th century, decline in Lake Tahoe's water clarity and degradation in the basin's air quality have become major concerns due to its unique scenic features. Gaseous and particulate nitrogen (N) and particulate phosphorus (P) loading via direct atmospheric deposition and sediment transport to the lake have also been implicated as responsible for its eutrophication and decline in water clarity. Estimates suggest that atmospheric N deposition contributes 55% of the total N loading to the lake, while atmospheric P deposition contributes 15% of the total P loading. In order to improve both air quality and, as a consequence, water quality, it is necessary to develop an understanding of the sources of the atmospheric pollutants. Once this is accomplished, it is possible to implement cost-effective strategies to reduce this impact. This paper summarizes the findings of a series of studies performed to determine the levels and sources of ambient air pollutants in the basin. Projects have included the development of a Tahoe-specific emissions inventory, long-term measurements of road dust resuspension, modeling to determine the fraction of pollutants coming from in-basin vs. out-of-basin sources, particulate source apportionment, and estimates of nitric acid deposition. These studies found that the pollutants most closely connected to the decline in water quality come largely from within basin sources, as opposed to those coming from the Central Valley and upwind urban areas of California. These results indicate regulators need to control pollutant emissions within the Tahoe basin in order to reduce the impact of atmospheric pollutants on both air and water quality.

  10. Air and Water System (AWS) Design and Technology Selection for the Vision for Space Exploration

    NASA Technical Reports Server (NTRS)

    Jones, Harry; Kliss, Mark

    2005-01-01

    This paper considers technology selection for the crew air and water recycling systems to be used in long duration human space exploration. The specific objectives are to identify the most probable air and water technologies for the vision for space exploration and to identify the alternate technologies that might be developed. The approach is to conduct a preliminary first cut systems engineering analysis, beginning with the Air and Water System (AWS) requirements and the system mass balance, and then define the functional architecture, review the International Space Station (ISS) technologies, and discuss alternate technologies. The life support requirements for air and water are well known. The results of the mass flow and mass balance analysis help define the system architectural concept. The AWS includes five subsystems: Oxygen Supply, Condensate Purification, Urine Purification, Hygiene Water Purification, and Clothes Wash Purification. AWS technologies have been evaluated in the life support design for ISS node 3, and in earlier space station design studies, in proposals for the upgrade or evolution of the space station, and in studies of potential lunar or Mars missions. The leading candidate technologies for the vision for space exploration are those planned for Node 3 of the ISS. The ISS life support was designed to utilize Space Station Freedom (SSF) hardware to the maximum extent possible. The SSF final technology selection process, criteria, and results are discussed. Would it be cost-effective for the vision for space exploration to develop alternate technology? This paper will examine this and other questions associated with AWS design and technology selection.

  11. Hydrogeologic framework and ground-water resources at Seymour Johnson Air Force Base, North Carolina

    USGS Publications Warehouse

    Cardinell, A.P.; Howe, S.S.

    1997-01-01

    A preliminary hydrogeologic framework of the Seymour Johnson Air Force Base was constructed from published data, available well data, and reports from Air Base files, City of Goldsboro and Wayne County records, and North Carolina Geological Survey files. Borehole geophysical logs were run in selected wells; and the surficial, Black Creek, and upper Cape Fear aquifers were mapped. Results indicate that the surficial aquifer appears to have the greatest lateral variability of clay units and aquifer material of the three aquifers. A surficial aquifer water-level surface map, constructed from selected monitoring wells screened exclusively in the surficial aquifer, indicates the general direction of ground-water movement in this mostly unconfined aquifer is toward the Neuse River and Stoney Creek. However, water-level gradient data from a few sites in the surficial aquifer did not reflect this trend, and there are insufficient hydrologic and hydrogeologic data to determine the cause of these few anamalous measurements. The Black Creek aquifer underlies the surficial aquifer and is believed to underlie most of Wayne County, including the Air Base where the aquifer and overlying confining unit are estimated from well log data to be as much as 100 feet thick. The Black Creek confining unit ranges in thickness from less than 8 feet to more than 20 feet. There are currently no accessible wells screened exclusively in the Black Creek aquifer from which to measure water levels. The upper Cape Fear aquifer and confining unit are generally found at depths greater than 80 feet below land surface at the Air Base, and are estimated to be as much as 70 feet thick. Hydrologic and hydrogeologic data are insufficient to determine localized surficial aquifer hydrogeology, ground-water movement at several sites, or hydraulic head differences between the three aquifers.

  12. Propensity of Hydrated Excess Protons and Hydroxide Anions for the Air-Water Interface.

    PubMed

    Tse, Ying-Lung Steve; Chen, Chen; Lindberg, Gerrick E; Kumar, Revati; Voth, Gregory A

    2015-10-01

    Significant effort has been undertaken to better understand the molecular details governing the propensity of ions for the air-water interface. Facilitated by computationally efficient reactive molecular dynamics simulations, new and statistically conclusive molecular-scale results on the affinity of the hydrated excess proton and hydroxide anion for the air-water interface are presented. These simulations capture the dynamic bond breaking and formation processes (charge defect delocalization) that are important for correctly describing the solvation and transport of these complex species. The excess proton is found to be attracted to the interface, which is correlated with a favorable enthalpic contribution and consistent with reducing the disruption in the hydrogen bond network caused by the ion complex. However, a recent refinement of the underlying reactive potential energy function for the hydrated excess proton shows the interfacial attraction to be weaker, albeit nonzero, a result that is consistent with the experimental surface tension measurements. The influence of a weak hydrogen bond donated from water to the protonated oxygen, recently found to play an important role in excess hydrated proton transport in bulk water, is seen to also be important for this study. In contrast, the hydroxide ion is found to be repelled from the air-water interface. This repulsion is characterized by a reduction of the energetically favorable ion-water interactions, which creates an enthalpic penalty as the ion approaches the interface. Finally, we find that the fluctuation in the coordination number around water sheds new light on the observed entropic trends for both ions. PMID:26366480

  13. Free Energies of Cavity and Noncavity Hydrated Electrons Near the Instantaneous Air/Water Interface.

    PubMed

    Casey, Jennifer R; Schwartz, Benjamin J; Glover, William J

    2016-08-18

    The properties of the hydrated electron at the air/water interface are computed for both a cavity and a noncavity model using mixed quantum/classical molecular dynamics simulation. We take advantage of our recently developed formalism for umbrella sampling with a restrained quantum expectation value to calculate free-energy profiles of the hydrated electron's position relative to the water surface. We show that it is critical to use an instantaneous description of the air/water interface rather than the Gibbs' dividing surface to obtain accurate potentials of mean force. We find that noncavity electrons, which prefer to encompass several water molecules, avoid the interface where water molecules are scarce. In contrast, cavity models of the hydrated electron, which prefer to expel water, have a local free-energy minimum near the interface. When the cavity electron occupies this minimum, its absorption spectrum is quite red-shifted, its binding energy is significantly lowered, and its dynamics speed up quite a bit compared with the bulk, features that have not been found by experiment. The surface activity of the electron therefore serves as a useful test of cavity versus noncavity electron solvation. PMID:27479028

  14. Drinking water, diet, indoor air: Comparison of the contribution to environmental micropollutants exposure.

    PubMed

    Enault, Jérôme; Robert, Samuel; Schlosser, Olivier; de Thé, Catherine; Loret, Jean-François

    2015-11-01

    This study collated 254,441 analytical results from drinking water quality monitoring in order to compare levels of exposure of the French adult population from drinking water with that from total diet for 37 pesticides, 11 mineral elements, 11 polycyclic aromatic hydrocarbons (PAH), 6 non dioxin-like polychlorobiphenyls (NDL PCB), 5 ether polybromodiphenyl ethers (BDE), 2 perfluorinated compounds. It also compares levels of exposure from drinking water with that from inhalation of indoor air for 9 volatile organic compounds (VOC) and 3 phthalates. The vast majority of the water analysis results showed values below the limits of quantification and this comparison was primarily made on the basis of a highly pessimistic scenario consisting in considering the data below the limits of quantification as being equal to the limits of quantification. With this conservative scenario, it can be seen that tap water makes a minor but potentially non-negligible contribution for a few micropollutants, by comparison with diet and air. It also shows that exposure through drinking water remains below the toxicity reference values for these substances. Apart from a few extreme values reflecting exceptional local situations, the concentrations measured for the minority of positive samples (below the 95th percentile value) suggest a very low risk for human health. Lower limits of quantification would however be of use in better estimating the safety margin with regard to the toxicity reference values, in particular for BDE, PAH and NDL PCB. PMID:26094108

  15. Core-Noise Research

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2012-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015 (N+1), 2020 (N+2), and 2025 (N+3) timeframes; SFW strategic thrusts and technical challenges; SFW advanced subsystems that are broadly applicable to N+3 vehicle concepts, with an indication where further noise research is needed; the components of core noise (compressor, combustor and turbine noise) and a rationale for NASA's current emphasis on the combustor-noise component; the increase in the relative importance of core noise due to turbofan design trends; the need to understand and mitigate core-noise sources for high-efficiency small gas generators; and the current research activities in the core-noise area, with additional details given about forthcoming updates to NASA's Aircraft Noise Prediction Program (ANOPP) core-noise prediction capabilities, two NRA efforts (Honeywell International, Phoenix, AZ and University of Illinois at Urbana-Champaign, respectively) to improve the understanding of core-noise sources and noise propagation through the engine core, and an effort to develop oxide/oxide ceramic-matrix-composite (CMC) liners for broadband noise attenuation suitable for turbofan-core application. Core noise must be addressed to ensure that the N+3 noise goals are met. Focused, but long-term, core-noise research is carried out to enable the advanced high-efficiency small gas-generator subsystem, common to several N+3 conceptual designs, needed to meet NASA's technical challenges. Intermediate updates to prediction tools are implemented as the understanding of the source structure and engine-internal propagation effects is improved. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The

  16. Air, water, and surface bacterial contamination in a university-hospital autopsy room.

    PubMed

    Maujean, Géraldine; Malicier, Daniel; Fanton, Laurent

    2012-03-01

    Today, little is known about the bacteriological environment of the autopsy room and its potential interest for medico-legal practices. Seven hundred fifty microbiological samples were taken from surface (n = 660), air (n = 48), and water (n = 42) to evaluate it in a French University Forensic Department. Median bacterial counts were compared before and during autopsy for air samples, and before and after autopsy for surface samples, using Wilcoxon matched pairs signed ranks test. Bacterial identification relied on traditional phenotypic methods. Bacterial counts in the air were low before autopsy, increased significantly during procedure, and seemed more linked to the number of people in the room than to an important production of aerosol-containing bacteria. Despite cleaning, human fecal flora was omnipresent on surfaces, which revealed insufficient disinfection. Bacteriological sampling is an easy way to monitor cleaning practices in postmortem rooms, but chiefly a way to improve the reliability of medico-legal proofs of infectious deaths. PMID:22309163

  17. Contact resonance atomic force microscopy imaging in air and water using photothermal excitation

    NASA Astrophysics Data System (ADS)

    Kocun, Marta; Labuda, Aleksander; Gannepalli, Anil; Proksch, Roger

    2015-08-01

    Contact Resonance Force Microscopy (CR-FM) is a leading atomic force microscopy technique for measuring viscoelastic nano-mechanical properties. Conventional piezo-excited CR-FM measurements have been limited to imaging in air, since the "forest of peaks" frequency response associated with acoustic excitation methods effectively masks the true cantilever resonance. Using photothermal excitation results in clean contact, resonance spectra that closely match the ideal frequency response of the cantilever, allowing unambiguous and simple resonance frequency and quality factor measurements in air and liquids alike. This extends the capabilities of CR-FM to biologically relevant and other soft samples in liquid environments. We demonstrate CR-FM in air and water on both stiff silicon/titanium samples and softer polystyrene-polyethylene-polypropylene polymer samples with the quantitative moduli having very good agreement between expected and measured values.

  18. Contact resonance atomic force microscopy imaging in air and water using photothermal excitation

    SciTech Connect

    Kocun, Marta; Labuda, Aleksander; Gannepalli, Anil; Proksch, Roger

    2015-08-15

    Contact Resonance Force Microscopy (CR-FM) is a leading atomic force microscopy technique for measuring viscoelastic nano-mechanical properties. Conventional piezo-excited CR-FM measurements have been limited to imaging in air, since the “forest of peaks” frequency response associated with acoustic excitation methods effectively masks the true cantilever resonance. Using photothermal excitation results in clean contact, resonance spectra that closely match the ideal frequency response of the cantilever, allowing unambiguous and simple resonance frequency and quality factor measurements in air and liquids alike. This extends the capabilities of CR-FM to biologically relevant and other soft samples in liquid environments. We demonstrate CR-FM in air and water on both stiff silicon/titanium samples and softer polystyrene-polyethylene-polypropylene polymer samples with the quantitative moduli having very good agreement between expected and measured values.

  19. Application of a laser Doppler vibrometer for air-water to subsurface signature detection

    NASA Astrophysics Data System (ADS)

    Land, Phillip; Roeder, James; Robinson, Dennis; Majumdar, Arun

    2015-05-01

    There is much interest in detecting a target and optical communications from an airborne platform to a platform submerged under water. Accurate detection and communications between underwater and aerial platforms would increase the capabilities of surface, subsurface, and air, manned and unmanned vehicles engaged in oversea and undersea activities. The technique introduced in this paper involves a Laser Doppler Vibrometer (LDV) for acousto-optic sensing for detecting acoustic information propagated towards the water surface from a submerged platform inside a 12 gallon water tank. The LDV probes and penetrates the water surface from an aerial platform to detect air-water surface interface vibrations caused by an amplifier to a speaker generating a signal generated from underneath the water surface (varied water depth from 1" to 8"), ranging between 50Hz to 5kHz. As a comparison tool, a hydrophone was used simultaneously inside the water tank for recording the acoustic signature of the signal generated between 50Hz to 5kHz. For a signal generated by a submerged platform, the LDV can detect the signal. The LDV detects the signal via surface perturbations caused by the impinging acoustic pressure field; proving a technique of transmitting/sending information/messages from a submerged platform acoustically to the surface of the water and optically receiving the information/message using the LDV, via the Doppler Effect, allowing the LDV to become a high sensitivity optical-acoustic device. The technique developed has much potential usage in commercial oceanography applications. The present work is focused on the reception of acoustic information from an object located underwater.

  20. Gas exchange rates across the sediment-water and air-water interfaces in south San Francisco Bay

    USGS Publications Warehouse

    Hartman, Blayne; Hammond, Douglas E.

    1984-01-01

    Radon 222 concentrations in the water and sedimentary columns and radon exchange rates across the sediment-water and air-water interfaces have been measured in a section of south San Francisco Bay. Two independent methods have been used to determine sediment-water exchange rates, and the annual averages of these methods agree within the uncertainty of the determinations, about 20%. The annual average of benthic fluxes from shoal areas is nearly a factor of 2 greater than fluxes from the channel areas. Fluxes from the shoal and channel areas exceed those expected from simple molecular diffusion by factors of 4 and 2, respectively, apparently due to macrofaunal irrigation. Values of the gas transfer coefficient for radon exchange across the air-water interface were determined by constructing a radon mass balance for the water column and by direct measurement using floating chambers. The chamber method appears to yield results which are too high. Transfer coefficients computed using the mass balance method range from 0.4 m/day to 1.8 m/day, with a 6-year average of 1.0 m/day. Gas exchange is linearly dependent upon wind speed over a wind speed range of 3.2–6.4 m/s, but shows no dependence upon current velocity. Gas transfer coefficients predicted from an empirical relationship between gas exchange rates and wind speed observed in lakes and the oceans are within 30% of the coefficients determined from the radon mass balance and are considerably more accurate than coefficients predicted from theoretical gas exchange models.

  1. Rapid monitoring of soil, water, and air dusts by direct large-area alpha spectrometry.

    PubMed

    Sill, C W

    1995-07-01

    During retrieval and disposition of wastes containing transuranium elements, continuous monitoring of the air, water, and soil for alpha emitters was required to ensure that safety limits were not exceeded and that the waste itself was not disturbed unknowingly. Direct measurements by alpha spectrometry were particularly promising because of their potential speed, sensitivity, and their ability to identify transuranium radionuclides under field conditions. Soil samples or settled dusts were finely ground, suspended in 80% ethanol, sprayed onto circular stainless steel pans, and dried on a hotplate. Water samples were mounted directly by spraying. Air dusts were collected with a high-volume air sampler on 20- by 25-cm membrane filters. The samples were then analyzed directly in a large pressurized gridded ionization chamber without further sample preparation. The lower limits of detection for 10-min counting times were 1.5 Bq g-1 (40 pCi g-1) for 100-mg soil samples, and 4 x 10(-2) Bq m-3 (10(-12) microCi mL-1) for a 10-min air sample taken at 0.4 m3 min-1 (14 cubic feet per minute) and counted without waiting for decay of radon progeny. PMID:7790211

  2. Air- and Dustborne Mycoflora in Houses Free of Water Damage and Fungal Growth

    PubMed Central

    Horner, W. Elliott; Worthan, Anthony G.; Morey, Philip R.

    2004-01-01

    Typically, studies on indoor fungal growth in buildings focus on structures with known or suspected water damage, moisture, and/or indoor fungal growth problems. Reference information on types of culturable fungi and total fungal levels are generally not available for buildings without these problems. This study assessed 50 detached single-family homes in metropolitan Atlanta, Ga., to establish a baseline of “normal and typical” types and concentrations of airborne and dustborne fungi in urban homes which were predetermined not to have noteworthy moisture problems or indoor fungal growth. Each home was visually examined, and samples of indoor and outdoor air and of indoor settled dust were taken in winter and summer. The results showed that rankings by prevalence and abundance of the types of airborne and dustborne fungi did not differ from winter to summer, nor did these rankings differ when air samples taken indoors were compared with those taken outdoors. Water indicator fungi were essentially absent from both air and dust samples. The air and dust data sets were also examined specifically for the proportions of colonies from ecological groupings such as leaf surface fungi and soil fungi. In the analysis of dust for culturable fungal colonies, leaf surface fungi constituted a considerable portion (>20%) of the total colonies in at least 85% of the samples. Thus, replicate dust samples with less than 20% of colonies from leaf surface fungi are unlikely to be from buildings free of moisture or mold growth problems. PMID:15528497

  3. Thermometric measurements of the molecular sublayer at the air-water interface

    NASA Astrophysics Data System (ADS)

    Ward, B.; Donelan, M. A.

    2006-04-01

    A series of measurements was conducted in the Air-Sea Interaction Saltwater Tank (ASIST) to study the response of the air-water interfacial molecular sublayer under various heat flux and wind speed conditions. In-situ gradients were measured with a platinum-plated tungsten wire microthermometer, which resolved the temperature of the thermally conductive sublayer. Air-sea heat flux was controlled by changing the air-water temperature difference (ΔTAW) and the wind speed, and measurements were made for three ΔTAW regimes over a range of wind speeds. A function was fitted to the measured temperature profiles as a way of extracting the boundary layer thickness in a consistent fashion, from which the λ coefficient after Saunders (1967) was computed. This dataset returned a mean λ coefficient of 2.4 +/- 0.5, which was generally lower than previous studies, and was found to be independent of wind speed in the range of 1 to 9 ms-1.

  4. Detailed simulations of air-water interaction phenomena in ocean waves

    NASA Astrophysics Data System (ADS)

    Iafrati, A.; Durante, D.

    2012-04-01

    In the present contribution the flow induced in air by ocean waves is investigated. The air-water interaction problem is of obvious interest in the context of wind generated waves. However, the flow induced in the lower atmosphere layer by ocean waves has also important effects on the exchange processes between atmosphere and ocean and in some circumstances it influences weather conditions on large scales. The problem is studied numerically by a two-dimensional Navier-Stokes solver which models the flow in air and water as that of a single incompressible fluid with density and viscosity expressed as a smooth function of the distance from the interface. The free surface is captured as the zero level set of the distance function. The distance from the interface is reinitialized every time step, so that the thickness of the transition region remains constant in time. The method is applied to two problems characterized by quite different length scales and steepnesses. In both cases the limits associated to the numerical approach and possible effects on the results are discussed. The first application is an attempt of investigating the role played by the flow in air on the dissipation rate of swells. The interest for such problem stems from some studies according to which the flow in air has an important effect on the dissipation of the steepest swells (Ardhuin et al, 2009). Motivated by the above findings, numerical simulations are performed in order to investigate the characteristics of the flow induced in air by swell with wavelengths in a range 50 to 300 m. Results are presented in terms of vorticity field in air with quantitative analyses of the vertical flux of horizontal momentum and of the viscous dissipation in the air phase. The thickness of the air layer which is influenced by the passage of the swell is also given. The second study analyzes the flow induced in air by the evolution of modulated wave trains. In this case the fundamental wavelength is 0.6 m

  5. Smart nanogels at the air/water interface: structural studies by neutron reflectivity.

    PubMed

    Zielińska, Katarzyna; Sun, Huihui; Campbell, Richard A; Zarbakhsh, Ali; Resmini, Marina

    2016-03-01

    The development of effective transdermal drug delivery systems based on nanosized polymers requires a better understanding of the behaviour of such nanomaterials at interfaces. N-Isopropylacrylamide-based nanogels synthesized with different percentages of N,N'-methylenebisacrylamide as cross-linker, ranging from 10 to 30%, were characterized at physiological temperature at the air/water interface, using neutron reflectivity (NR), with isotopic contrast variation, and surface tension measurements; this allowed us to resolve the adsorbed amount and the volume fraction of nanogels at the interface. A large conformational change for the nanogels results in strong deformations at the interface. As the percentage of cross-linker incorporated in the nanogels becomes higher, more rigid matrices are obtained, although less deformed, and the amount of adsorbed nanogels is increased. The data provide the first experimental evidence of structural changes of nanogels as a function of the degree of cross-linking at the air/water interface. PMID:26697736

  6. Structure of phospholipid monolayers containing poly(ethylene glycol) lipids at the air-water interface

    SciTech Connect

    Majewski, J.; Smith, G.S.; Kuhl, T.L.; Israelachvili, J.N.; Gerstenberg, M.C.

    1997-04-17

    The density distribution of a lipid monolayer at the air-water interface mixed with varying amounts of lipid with poly(ethylene glycol)polymer headgroups (polymer-lipid or PEG-lipid) was measured using neutron reflectometry. The structure of the monolayer at the interface was greatly perturbed by the presence of the bulky polymer-lipid headgroups resulting in a large increase in the thickness of the headgroup region normal to the interface and a systematic roughening of the interface with increasing polymer-lipid content. These results show how bulky hydrophilic moieties cause significant deformations and out-of-place protrusions of phospholipid monolayers and presumably bilayers, vesicles and biological membranes. In terms of polymer physics, very short polymer chains tethered to the air-water interface follow scaling behavior with a mushroom to brush transition with increasing polymer grafting density. 34 refs., 9 figs., 1 tab.

  7. Evaluating the relative air permeability of porous media from their water retention curves

    NASA Astrophysics Data System (ADS)

    Assouline, S.; Tuli, A.; Hopmans, J. W.

    2016-05-01

    Accurate modeling of water and air flow in porous media requires the definition of the relevant hydraulic properties, namely, the water retention curve (WRC) and the relative hydraulic conductivity function (RHC), as well as the definition of the relative air permeability function (RAP). Capitalizing on the approach developed previously to represent the RHC, a new model allowing the prediction of RAP based on information resulting from the WRC is proposed. The power value ηa in the model is a decreasing exponential function of the coefficient of variation, ɛ, characterizing the pore size distribution of the porous medium, and derived from its WRC. The model was calibrated using data from 22 disturbed and undisturbed soil samples and was validated using data from eight soil types ranging from quartz sand to silty clay loam. The proposed model provided accurate prediction of the soil RAP and performed in some cases (sandy loam and silty clay loam soils) better than available alternative models.

  8. A criterion for the onset of slugging in horizontal stratified air-water countercurrent flow

    SciTech Connect

    Chun, Moon-Hyun; Lee, Byung-Ryung; Kim, Yang-Seok

    1995-09-01

    This paper presents an experimental and theoretical investigation of wave height and transition criterion from wavy to slug flow in horizontal air-water countercurrent stratified flow conditions. A theoretical formula for the wave height in a stratified wavy flow regime has been developed using the concept of total energy balance over a wave crest to consider the shear stress acting on the interface of two fluids. From the limiting condition of the formula for the wave height, a necessary criterion for transition from a stratified wavy flow to a slug flow has been derived. A series of experiments have been conducted changing the non-dimensional water depth and the flow rates of air in a horizontal pipe and a duct. Comparisons between the measured data and the predictions of the present theory show that the agreement is within {plus_minus}8%.

  9. Shinkansen noise: Research and achievements in countermeasures for Shinkansen noise

    NASA Astrophysics Data System (ADS)

    Kikuchi, I.

    1988-01-01

    In 1982, the Tohoku and Joetsu Shinkansen lines were opened. The result is the present Shinkansen network that runs through Japan from north to south, leading to a remarkable improvement in railway services, together with the provision of new, efficient connections with conventional lines. Since the opening of the Tokaido Shinkansen, the high utility of the Shinkansen as a high speed, large volume, and safe mode of transport has been gaining a high reputation. On the other hand, social demands for environmental preservation increased in strength with the advent of the period of Japan's high economic growth. Such demands were posed in the form of complaints about air and water pollution and noise from transportation. The problems of noise and vibration from Shinkansen train operation were posed mainly in relation to railway viaducts in urban areas. The Japanese National Railways (JNR) has made all-out efforts in technical development for noise reduction, obtained many achievements, and put them into practical use one by one on the Shinkansen lines. In the early stage of studies, there were many virgin areas for JNR staff, such as measurement technology, estimation methods, and noise alleviation technology. With the start of full-scale testing at a general test center in 1975, various studies and the development of effective measures made a great step forward. In March 1985, the maximum speed on the Tohoku Shinkansen was increased to 240 km/h, enhancing the Shinkansen reputation and resulting in a considerable growth of traffic. As a matter of course, new measures for noise reduction were taken for this line. In view of the history and results of voluminous studies over many years on the Shinkansen noise problem, and also of the roles and surrounding conditions of the Shinkansen as a mode of transport, however, new tasks are being posed concerning such aspects as how to accomplish environmental preservation in the future.

  10. LASE Measurements of Water Vapor, Aerosol, and Cloud Distributions in Saharan Air Layers and Tropical Disturbances

    NASA Technical Reports Server (NTRS)

    Ismail, Syed; Ferrare, Richard A.; Browell, Edward V.; Kooi, Susan A.; Dunion, Jason P.; Heymsfield, Gerry; Notari, Anthony; Butler, Carolyn F.; Burton, Sharon; Fenn, Marta; Krishnamurti, T. N.; Chen, Gao; Anderson, Bruce

    2010-01-01

    LASE (Lidar Atmospheric Sensing Experiment) on-board the NASA DC-8 measured high resolution profiles of water vapor and aerosols, and cloud distributions in 14 flights over the eastern North Atlantic during the NAMMA (NASA African Monsoon Multidisciplinary Analyses) field experiment. These measurements were used to study African easterly waves (AEWs), tropical cyclones (TCs), and the Saharan Air Layer(s) (SAL). Interactions between the SAL and tropical air were observed during the early stages of the TC development. These LASE measurements represent the first simultaneous water vapor and aerosol lidar measurements to study the SAL and its impact on AEWs and TCs. Examples of profile measurements of aerosol scattering ratios, aerosol extinction coefficients, aerosol optical thickness, water vapor mixing ratios, RH, and temperature are presented to illustrate their characteristics in SAL, convection, and clear air regions. LASE data suggest that the SAL suppresses low-altitude convection at the convection-SAL interface region. Mid-level convection associated with the AEW and transport are likely responsible for high water vapor content observed in the southern regions of the SAL on August 20, 2008. This interaction is responsible for the transfer of about 7 x 10(exp 15) J latent heat energy within a day to the SAL. Measurements of lidar extinction-to-backscatter ratios in the range 36+/-5 to 45+/-5 are within the range of measurements from other lidar measurements of dust. LASE aerosol extinction and water vapor profiles are validated by comparison with onboard in situ aerosol measurements and GPS dropsonde water vapor soundings, respectively.

  11. Bibliography of work on the photocatalytic removal of hazardous compounds from water and air

    SciTech Connect

    Blake, D.M.

    1994-05-01

    This is a bibliography of information in the open literature on work that has been done to date on the photocatalytic oxidation of compounds, principally organic compounds. The goal of the listing is removing hazardous oompounds from water or air. It contains lists of substances and literature citations. The bibliography includes information obtained through the middle of 1993 and some selected references for the balance of that year.

  12. Managing the Drivers of Air Flow and Water Vapor Transport in Existing Single-Family Homes

    SciTech Connect

    Cummings, James; Withers, Charles; Martin, Eric; Moyer, Neil

    2012-10-01

    This report is a revision of an earlier report titled: Measure Guideline: Managing the Drivers of Air Flow and Water Vapor Transport in Existing Single-Family Homes. Revisions include: Information in the text box on page 1 was revised to reflect the most accurate information regarding classifications as referenced in the 2012 International Residential Code. “Measure Guideline” was dropped from the title of the report. An addition was made to the reference list.

  13. Smart nanogels at the air/water interface: structural studies by neutron reflectivity

    NASA Astrophysics Data System (ADS)

    Zielińska, Katarzyna; Sun, Huihui; Campbell, Richard A.; Zarbakhsh, Ali; Resmini, Marina

    2016-02-01

    The development of effective transdermal drug delivery systems based on nanosized polymers requires a better understanding of the behaviour of such nanomaterials at interfaces. N-Isopropylacrylamide-based nanogels synthesized with different percentages of N,N'-methylenebisacrylamide as cross-linker, ranging from 10 to 30%, were characterized at physiological temperature at the air/water interface, using neutron reflectivity (NR), with isotopic contrast variation, and surface tension measurements; this allowed us to resolve the adsorbed amount and the volume fraction of nanogels at the interface. A large conformational change for the nanogels results in strong deformations at the interface. As the percentage of cross-linker incorporated in the nanogels becomes higher, more rigid matrices are obtained, although less deformed, and the amount of adsorbed nanogels is increased. The data provide the first experimental evidence of structural changes of nanogels as a function of the degree of cross-linking at the air/water interface.The development of effective transdermal drug delivery systems based on nanosized polymers requires a better understanding of the behaviour of such nanomaterials at interfaces. N-Isopropylacrylamide-based nanogels synthesized with different percentages of N,N'-methylenebisacrylamide as cross-linker, ranging from 10 to 30%, were characterized at physiological temperature at the air/water interface, using neutron reflectivity (NR), with isotopic contrast variation, and surface tension measurements; this allowed us to resolve the adsorbed amount and the volume fraction of nanogels at the interface. A large conformational change for the nanogels results in strong deformations at the interface. As the percentage of cross-linker incorporated in the nanogels becomes higher, more rigid matrices are obtained, although less deformed, and the amount of adsorbed nanogels is increased. The data provide the first experimental evidence of structural changes

  14. Physicochemical Study of Viral Nanoparticles at the Air/Water Interface.

    PubMed

    Torres-Salgado, Jose F; Comas-Garcia, Mauricio; Villagrana-Escareño, Maria V; Durán-Meza, Ana L; Ruiz-García, Jaime; Cadena-Nava, Ruben D

    2016-07-01

    The assembly of most single-stranded RNA (ssRNA) viruses into icosahedral nucleocapsids is a spontaneous process driven by protein-protein and RNA-protein interactions. The precise nature of these interactions results in the assembly of extremely monodisperse and structurally indistinguishable nucleocapsids. In this work, by using a ssRNA plant virus (cowpea chlorotic mottle virus [CCMV]) as a charged nanoparticle we show that the diffusion of these nanoparticles from the bulk solution to the air/water interface is an irreversible adsorption process. By using the Langmuir technique, we measured the diffusion and adsorption of viral nucleocapsids at the air/water interface at different pH conditions. The pH changes, and therefore in the net surface charge of the virions, have a great influence in the diffusion rate from the bulk solution to the air/water interface. Moreover, assembly of mesoscopic and microscopic viral aggregates at this interface depends on the net surface charge of the virions and the surface pressure. By using Brewster's angle microscopy we characterized these structures at the interface. Most common structures observed were clusters of virions and soap-frothlike micron-size structures. Furthermore, the CCMV films were compressed to form monolayers and multilayers from moderate to high surface pressures, respectively. After transferring the films from the air/water interface onto mica by using the Langmuir-Blodgett technique, their morphology was characterized by atomic force microscopy. These viral monolayers showed closed-packing nano- and microscopic arrangements. PMID:26999022

  15. Rheology and microrheology of materials at the air-water interface

    NASA Astrophysics Data System (ADS)

    Walder, Robert Benjamin

    2008-10-01

    The study of materials at the air-water interface is an important area of research in soft condensed matter physics. Films at the air-water interface have been a system of interest to physics, chemistry and biology for the last 20 years. The unique properties of these surface films provide ideal models for 2-d films, surface chemistry and provide a platform for creating 2 dimensional analogue materials to cellular membranes. Measurements of the surface rheology of cross-linked F-actin networks associated with a lipid monolayer at the air-water interface of a Langmuir monolayer have been performed. The rheological measurements are made using a Couette cell. These data demonstrate that the network has a finite elastic modulus that grows as a function of the cross-linking concentration. We also note that under steady-state flow the system behaves as a power law fluid in which the effective viscosity decreases with imposed shear. A Langmuir monolayer trough that is equipped for simultaneous microrheology and standard rheology measurements has been constructed. The central elements are the trough itself with a full range of optical tools accessing the air-water interface from below the trough and a portable knife-edge torsion pendulum that can access the interface from above. The ability to simultaneously measure the mechanical response of Langmuir monolayers on very different length scales is an important step for our understanding of the mechanical response of two-dimensional viscoelastic networks. The optical tweezer microrheometer is used to study the micromechanical properties of Langmuir monolayers. Microrheology measurements are made a variety of surface pressures that correspond to different ordered phases of the monolayer. The complex shear modulus shows an order of magnitude increase for the liquid condensed phase of DPPC compared to the liquid expanded phase.

  16. Sensitivity of Hollow Fiber Spacesuit Water Membrane Evaporator Systems to Potable Water Constituents, Contaminants and Air Bubbles

    NASA Technical Reports Server (NTRS)

    Bue, Grant C.; Trevino, Luis A.; Fritts, Sharon; Tsioulos, Gus

    2008-01-01

    The Spacesuit Water Membrane Evaporator (SWME) is the baseline heat rejection technology selected for development for the Constellation lunar suit. The first SWME prototype, designed, built, and tested at Johnson Space Center in 1999 used a Teflon hydrophobic porous membrane sheet shaped into an annulus to provide cooling to the coolant loop through water evaporation to the vacuum of space. This present study describes the test methodology and planning and compares the test performance of three commercially available hollow fiber materials as alternatives to the sheet membrane prototype for SWME, in particular, a porous hydrophobic polypropylene, and two variants that employ ion exchange through non-porous hydrophilic modified Nafion. Contamination tests will be performed to probe for sensitivities of the candidate SWME elements to ordinary constituents that are expected to be found in the potable water provided by the vehicle, the target feedwater source. Some of the impurities in potable water are volatile, such as the organics, while others, such as the metals and inorganic ions are nonvolatile. The non-volatile constituents will concentrate in the SWME as evaporated water from the loop is replaced by the feedwater. At some point in the SWME mission lifecycle as the concentrations of the non-volatiles increase, the solubility limits of one or more of the constituents may be reached. The resulting presence of precipitate in the coolant water may begin to plug pores and tube channels and affect the SWME performance. Sensitivity to macroparticles, lunar dust simulant, and air bubbles will also be investigated.

  17. Why Do Objects Cool More Rapidly in Water Than in Still Air?

    NASA Astrophysics Data System (ADS)

    Bohren, Craig F.

    2011-12-01

    An Internet search for why objects, especially humans, cool more rapidly in water than in air, both at the same temperature, and by how much, yields off-the-cuff answers unsupported by experiment or analysis. To answer these questions in depth requires a smattering of engineering heat transfer, including radiative transfer, and the different thermophysical properties of the two fluids. The correct ratio for humans is closer to 2 than to 10, and if this were not so, swimming in cool water could be fatal.

  18. Tracer study of oxygen and hydrogen uptake by Mg alloys in air with water vapor

    DOE PAGESBeta

    Brady, M. P.; Fayek, M.; Meyer, H. M.; Leonard, D. N.; Elsentriecy, H. H.; Unocic, K. A.; Anovitz, L. M.; Cakmak, E.; Keiser, J. R.; Song, G. L.; et al

    2015-05-15

    We studied the pure oxidation of Mg, Mg–3Al–1Zn (AZ31B), and Mg–1Zn–0.25Zr–<0.5Nd (ZE10A) at 85 °C in humid air using sequential exposures with H218O and D216O for water vapor. Incorporation of 18O in the hydroxide/oxide films indicated that oxygen from water vapor participated in the reaction. Moreover, penetration of hydrogen into the underlying metal was observed, particularly for the Zr- and Nd-containing ZE10A. Isotopic tracer profiles suggested a complex mixed inward/outward film growth mechanism.

  19. Design of a Shuttle air and water prefilter for reduced gravity operation

    NASA Technical Reports Server (NTRS)

    Ungar, Eugene K.; Ouellette, Fred A.

    1992-01-01

    The first design concept of the Space Shuttle humidity separator prefilter, developed to remove debris from the air/water stream which flows from the cabin condensing heat exchanger to the humidity separator, was flown on STS-40 in June 1991. This paper discusses the design of the first prefilter (which was found not to pass water at a constant rate, resulting in a tendency to slug the humidity separator) and explains the on-orbit performance of the prefilter. The redesigned prefilter (made using the results of the flight test of the first prefilter) is described, with particular attention given to the features which would allow successful reduced gravity operation.

  20. Bio-Decontamination of Water and Surfaces by DC Discharges in Atmospheric Air

    NASA Astrophysics Data System (ADS)

    Machala, Zdenko; Tarabová, Barbora; Pelach, Michal; Šipoldová, Zuzana; Hensel, Karol; Janda, Mário; Šikurová, Libuša

    Two types of DC-driven atmospheric air discharges, including a streamer corona and a transient spark with short high current pulses of limited energy, were employed for bio-decontamination of water and various surfaces (agar plates, plastic foils, human teeth) contaminated by bacteria or spores (Salmonella typhimurium, Bacillus cereus). Both discharges generate cold non-equilibrium plasma. The discharges combined with the electro-spraying of the treated water through the needle electrode lead to fast and efficient bio-decontamination. Experiments comparing direct and indirect plasma effects, oxidation stress measurements in the cell membranes, and chemical changes induced in the treated water enable assessment of the plasma agents being responsible for microbial inactivation. Radicals and reactive oxygen species seem to be dominant biocidal agents, although deeper understanding of the plasma-induced water chemistry and of the temporal evolution of the bio-inactivation processes is needed.