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Sample records for aerosol spray target

  1. Design, Characterization, and Aerosol Dispersion Performance Modeling of Advanced Spray-Dried Microparticulate/Nanoparticulate Mannitol Powders for Targeted Pulmonary Delivery as Dry Powder Inhalers

    PubMed Central

    Li, Xiaojian; Vogt, Frederick G.; Hayes, Don

    2014-01-01

    Abstract Background: The purpose was to design and characterize inhalable microparticulate/nanoparticulate dry powders of mannitol with essential particle properties for targeted dry powder delivery for cystic fibrosis mucolytic treatment by dilute organic solution spray drying, and, in addition, to tailor and correlate aerosol dispersion performance delivered as dry powder inhalers based on spray-drying conditions and solid-state physicochemical properties. Methods: Organic solution advanced spray drying from dilute solution followed by comprehensive solid-state physicochemical characterization and in vitro dry powder aerosolization were used. Results: The particle size distribution of the spray-dried (SD) powders was narrow, unimodal, and in the range of ∼500 nm to 2.0 μm. The particles possessed spherical particle morphology, relatively smooth surface morphology, low water content and vapor sorption (crystallization occurred at exposure above 65% relative humidity), and retention of crystallinity by polymorphic interconversion. The emitted dose, fine particle fraction (FPF), and respirable fraction (RF) were all relatively high. The mass median aerodynamic diameters were below 4 μm for all SD mannitol aerosols. Conclusion: The in vitro aerosol deposition stage patterns could be tailored based on spray-drying pump rate. Positive linear correlation was observed between both FPF and RF values with spray-drying pump rates. The interplay between various spray-drying conditions, particle physicochemical properties, and aerosol dispersion performance was observed and examined, which enabled tailoring and modeling of high aerosol deposition patterns. PMID:24502451

  2. Advanced spray-dried design, physicochemical characterization, and aerosol dispersion performance of vancomycin and clarithromycin multifunctional controlled release particles for targeted respiratory delivery as dry powder inhalation aerosols.

    PubMed

    Park, Chun-Woong; Li, Xiaojian; Vogt, Frederick G; Hayes, Don; Zwischenberger, Joseph B; Park, Eun-Seok; Mansour, Heidi M

    2013-10-15

    Respirable microparticles/nanoparticles of the antibiotics vancomycin (VCM) and clarithromycin (CLM) were successfully designed and developed by novel organic solution advanced spray drying from methanol solution. Formulation optimization was achieved through statistical experimental design of pump feeding rates of 25% (Low P), 50% (Medium P) and 75% (High P). Systematic and comprehensive physicochemical characterization and imaging were carried out using scanning electron microscopy (SEM), hot-stage microscopy (HSM), differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), Karl Fischer titration (KFT), laser size diffraction (LSD), gravimetric vapor sorption (GVS), confocal Raman microscopy (CRM) and spectroscopy for chemical imaging mapping. These novel spray-dried (SD) microparticulate/nanoparticulate dry powders displayed excellent aerosol dispersion performance as dry powder inhalers (DPIs) with high values in emitted dose (ED), respirable fraction (RF), and fine particle fraction (FPF). VCM DPIs displayed better aerosol dispersion performance compared to CLM DPIs which was related to differences in the physicochemical and particle properties of VCM and CLM. In addition, organic solution advanced co-spray drying particle engineering design was employed to successfully produce co-spray-dried (co-SD) multifunctional microparticulate/nanoparticulate aerosol powder formulations of VCM and CLM with the essential lung surfactant phospholipid, dipalmitoylphosphatidylcholine (DPPC), for controlled release pulmonary nanomedicine delivery as inhalable dry powder aerosols. Formulation optimization was achieved through statistical experimental design of molar ratios of co-SD VCM:DPPC and co-SD CLM:DPPC. XRPD and DSC confirmed that the phospholipid bilayer structure in the solid-state was preserved following spray drying. Co-SD VCM:DPPC and co-SD CLM:DPPC dry powder aerosols demonstrated controlled release of antibiotic drug that was fitted to various

  3. [The spectra of a laser-produced plasma source with CO2, O2 and CF4 liquid aerosol spray target].

    PubMed

    Ni, Qi-Liang; Chen, Bo

    2008-11-01

    A laser-produced plasma (LPP) source with liquid aerosol spray target and nanosecond laser was developed, based on both soft X-ray radiation metrology and extreme ultraviolet projection lithography (EUVL). The LPP source is composed of a stainless steel solenoid valve whose temperature can be continuously controlled, a Nd : YAG laser with pulse width, working wavelength and pulse energy being 7 ns, 1.064 microm and 1J respectively, and a pulse generator which can synchronously control the valve and the laser. A standard General Valve Corporation series 99 stainless steel solenoid valve with copper gasket seals and a Kel-F poppet are used in order to minimize leakage and poppet deformation during high-pressure cryogenic operation. A close fitting copper cooling jacket surrounds the valve body. The jacket clamps a copper coolant carrying tube 3 mm in diameter, which is fed by an automatically pressurized liquid nitrogen-filled dewar. The valve temperature can be controlled between 77 and 473 K. For sufficiently high backing pressure and low temperature, the valve reservoir gas can undergo a gas-to-liquid phase transition. Upon valve pulsing, the liquid is ejected into a vacuum and breaks up into droplets, which is called liquid aerosol spray target. For the above-mentioned LPP source, firstly, by the use of Cowan program on the basis of non-relativistic quantum mechanics, the authors computed the radiative transition wavelengths and probabilities in soft X-ray region for O4+, O5+, O6+, O7+, F5+, F6+ and F7+ ions which were correspondingly produced from the interaction of the 10(11)-10(12) W x cm(-2) power laser with liquid O2, CO2 and CF4 aerosol spray targets. Secondly, the authors measured the spectra of liquid O2, CO2 and CF4 aerosol spray target LPP sources in the 6-20 nm band for the 8 x 10(11) W x cm(-2) laser irradiance. The measured results were compared with the Cowan calculated results ones, and the radiative transition wavelength and probability for the

  4. Program Models A Laser Beam Focused In An Aerosol Spray

    NASA Technical Reports Server (NTRS)

    Barton, J. P.

    1996-01-01

    Monte Carlo analysis performed on packets of light. Program for Analysis of Laser Beam Focused Within Aerosol Spray (FLSPRY) developed for theoretical analysis of propagation of laser pulse optically focused within aerosol spray. Applied for example, to analyze laser ignition arrangement in which focused laser pulse used to ignite liquid aerosol fuel spray. Scattering and absorption of laser light by individual aerosol droplets evaluated by use of electromagnetic Lorenz-Mie theory. Written in FORTRAN 77 for both UNIX-based computers and DEC VAX-series computers. VAX version of program (LEW-16051). UNIX version (LEW-16065).

  5. Production Flux of Sea-Spray Aerosol

    NASA Astrophysics Data System (ADS)

    de Leeuw, G.; Andreas, E. L.; Anguelova, M. D.; Fairall, C. W.; Lewis, E. R.; O'Dowd, C.; Schulz, M.; Schwartz, S. E.

    2010-12-01

    Knowledge of the size- and composition-dependent production flux of primary sea-spray aerosol (SSA) particles and its dependence on environmental variables is required for modeling cloud microphysical properties and aerosol radiative influences, interpreting measurements of particulate matter in coastal areas and its relation to air quality, and evaluating rates of uptake and reactions of gases in sea-spray drops. This review examines recent research pertinent to SSA production flux with emphasis on particles with r80 (equilibrium radius at 80% relative humidity) less than 1 µm and as small as 0.01 µm. Production of sea-spray particles and its dependence on controlling factors has been investigated in laboratory studies that have examined the dependences on water temperature, salinity, and the presence of organics, and in field measurements with micrometeorological techniques that use newly developed fast optical particle sizers. Extensive measurements show that water-insoluble organic matter contributes substantially to the composition of SSA particles with r80 < 0.25 µm and in locations with high biological activity can be the dominant constituent. Order-of-magnitude variation remains in estimates of the size-dependent production flux per white area, the quantity central to formulations of the production flux based on the whitecap method. This variation indicates that the production flux may depend on quantities, such as the volume flux of air bubbles to the surface, that are not accounted for in current models. Variation in estimates of the whitecap fraction as a function of wind speed contributes additional, comparable uncertainty to production flux estimates.

  6. Production flux of sea spray aerosol

    NASA Astrophysics Data System (ADS)

    de Leeuw, Gerrit; Andreas, Edgar L.; Anguelova, Magdalena D.; Fairall, C. W.; Lewis, Ernie R.; O'Dowd, Colin; Schulz, Michael; Schwartz, Stephen E.

    2011-05-01

    Knowledge of the size- and composition-dependent production flux of primary sea spray aerosol (SSA) particles and its dependence on environmental variables is required for modeling cloud microphysical properties and aerosol radiative influences, interpreting measurements of particulate matter in coastal areas and its relation to air quality, and evaluating rates of uptake and reactions of gases in sea spray drops. This review examines recent research pertinent to SSA production flux, which deals mainly with production of particles with r80 (equilibrium radius at 80% relative humidity) less than 1 μm and as small as 0.01 μm. Production of sea spray particles and its dependence on controlling factors has been investigated in laboratory studies that have examined the dependences on water temperature, salinity, and the presence of organics and in field measurements with micrometeorological techniques that use newly developed fast optical particle sizers. Extensive measurements show that water-insoluble organic matter contributes substantially to the composition of SSA particles with r80 < 0.25 μm and, in locations with high biological activity, can be the dominant constituent. Order-of-magnitude variation remains in estimates of the size-dependent production flux per white area, the quantity central to formulations of the production flux based on the whitecap method. This variation indicates that the production flux may depend on quantities such as the volume flux of air bubbles to the surface that are not accounted for in current models. Variation in estimates of the whitecap fraction as a function of wind speed contributes additional, comparable uncertainty to production flux estimates.

  7. A simplified model of aerosol removal by containment sprays

    SciTech Connect

    Powers, D.A. ); Burson, S.B. . Div. of Safety Issue Resolution)

    1993-06-01

    Spray systems in nuclear reactor containments are described. The scrubbing of aerosols from containment atmospheres by spray droplets is discussed. Uncertainties are identified in the prediction of spray performance when the sprays are used as a means for decontaminating containment atmospheres. A mechanistic model based on current knowledge of the physical phenomena involved in spray performance is developed. With this model, a quantitative uncertainty analysis of spray performance is conducted using a Monte Carlo method to sample 20 uncertain quantities related to phenomena of spray droplet behavior as well as the initial and boundary conditions expected to be associated with severe reactor accidents. Results of the uncertainty analysis are used to construct simplified expressions for spray decontamination coefficients. Two variables that affect aerosol capture by water droplets are not treated as uncertain; they are (1) [open quote]Q[close quote], spray water flux into the containment, and (2) [open quote]H[close quote], the total fall distance of spray droplets. The choice of values of these variables is left to the user since they are plant and accident specific. Also, they can usually be ascertained with some degree of certainty. The spray decontamination coefficients are found to be sufficiently dependent on the extent of decontamination that the fraction of the initial aerosol remaining in the atmosphere, m[sub f], is explicitly treated in the simplified expressions. The simplified expressions for the spray decontamination coefficient are given. Parametric values for these expressions are found for median, 10 percentile, and 90 percentile values in the uncertainty distribution for the spray decontamination coefficient. Examples are given to illustrate the utility of the simplified expressions to predict spray decontamination of an aerosol-laden atmosphere.

  8. Design, physicochemical characterization, and optimization of organic solution advanced spray-dried inhalable dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine poly(ethylene glycol) (DPPE-PEG) microparticles and nanoparticles for targeted respiratory nanomedicine delivery as dry powder inhalation aerosols.

    PubMed

    Meenach, Samantha A; Vogt, Frederick G; Anderson, Kimberly W; Hilt, J Zach; McGarry, Ronald C; Mansour, Heidi M

    2013-01-01

    Novel advanced spray-dried and co-spray-dried inhalable lung surfactant-mimic phospholipid and poly(ethylene glycol) (PEG)ylated lipopolymers as microparticulate/nanoparticulate dry powders of biodegradable biocompatible lipopolymers were rationally formulated via an organic solution advanced spray-drying process in closed mode using various phospholipid formulations and rationally chosen spray-drying pump rates. Ratios of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine PEG (DPPE-PEG) with varying PEG lengths were mixed in a dilute methanol solution. Scanning electron microscopy images showed the smooth, spherical particle morphology of the inhalable particles. The size of the particles was statistically analyzed using the scanning electron micrographs and SigmaScan® software and were determined to be 600 nm to 1.2 μm in diameter, which is optimal for deep-lung alveolar penetration. Differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) were performed to analyze solid-state transitions and long-range molecular order, respectively, and allowed for the confirmation of the presence of phospholipid bilayers in the solid state of the particles. The residual water content of the particles was very low, as quantified analytically via Karl Fischer titration. The composition of the particles was confirmed using attenuated total-reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy and confocal Raman microscopy (CRM), and chemical imaging confirmed the chemical homogeneity of the particles. The dry powder aerosol dispersion properties were evaluated using the Next Generation Impactor™ (NGI™) coupled with the HandiHaler® dry powder inhaler device, where the mass median aerodynamic diameter from 2.6 to 4.3 μm with excellent aerosol dispersion performance, as exemplified by high values of emitted dose, fine particle fraction, and respirable fraction. Overall, it was determined that the pump rates defined in the

  9. Measurements of Hygroscopicity- and Size-Resolved Sea Spray Aerosol

    NASA Astrophysics Data System (ADS)

    Phillips, B.; Dawson, K. W.; Royalty, T. M.; Reed, R. E.; Petters, M.; Meskhidze, N.

    2015-12-01

    Atmospheric aerosols play a central role in many environmental processes by influencing the Earth's radiative balance, tropospheric chemistry, clouds, biogeochemical cycles, and visibility as well as adversely impacting human health. Based on their origin, atmospheric aerosols can be defined as anthropogenic or natural. Recent studies have shown that a large fraction of uncertainty in the radiative effects of anthropogenic aerosols is related to uncertainty in natural—background—aerosols. Marine aerosols are of particular interest due to the abundance of oceans covering the Earth's surface. Despite their importance, limited information is currently available for size- and composition-resolved marine aerosol emission fluxes. Our group has designed and built an instrument for measuring the size- and hygroscopicity-resolved sea spray aerosol fluxes. The instrument was first deployed during spring 2015 at the end of the 560 m pier of the US Army Corps of Engineers' Field Research Facility in Duck, NC. Measurements include 200 nm-sized diameter growth factor (hygroscopicity) distributions, sea spray particle flux measurements, and total sub-micron sized aerosol concentration. Ancillary ocean data includes salinity, pH, sea surface temperature, dissolved oxygen content, and relative fluorescence (proxy for [Chl-a]). Hygroscopicity distribution measurements show two broad peaks, one indicative of organics and sulfates and another suggestive of sea salt. The fraction of 200 nm-sized salt particles having hygroscopicity similar to that of sea-spray aerosol contributes up to ~24% of the distribution on days with high-speed onshore winds and up to ~3% on calm days with winds blowing from the continent. However, the total concentration of sea-spray-like particles originating from offshore versus onshore winds was relatively similar. Changes in the relative contribution of sea-salt to number concentration were caused by a concomitant changes in total aerosol concentration

  10. The Impact of Aerosol Particle Mixing State on the Hygroscopicity of Sea Spray Aerosol.

    PubMed

    Schill, Steven R; Collins, Douglas B; Lee, Christopher; Morris, Holly S; Novak, Gordon A; Prather, Kimberly A; Quinn, Patricia K; Sultana, Camille M; Tivanski, Alexei V; Zimmermann, Kathryn; Cappa, Christopher D; Bertram, Timothy H

    2015-06-24

    Aerosol particles influence global climate by determining cloud droplet number concentrations, brightness, and lifetime. Primary aerosol particles, such as those produced from breaking waves in the ocean, display large particle-particle variability in chemical composition, morphology, and physical phase state, all of which affect the ability of individual particles to accommodate water and grow into cloud droplets. Despite such diversity in molecular composition, there is a paucity of methods available to assess how particle-particle variability in chemistry translates to corresponding differences in aerosol hygroscopicity. Here, an approach has been developed that allows for characterization of the distribution of aerosol hygroscopicity within a chemically complex population of atmospheric particles. This methodology, when applied to the interpretation of nascent sea spray aerosol, provides a quantitative framework for connecting results obtained using molecular mimics generated in the laboratory with chemically complex ambient aerosol. We show that nascent sea spray aerosol, generated in situ in the Atlantic Ocean, displays a broad distribution of particle hygroscopicities, indicative of a correspondingly broad distribution of particle chemical compositions. Molecular mimics of sea spray aerosol organic material were used in the laboratory to assess the volume fractions and molecular functionality required to suppress sea spray aerosol hygroscopicity to the extent indicated by field observations. We show that proper accounting for the distribution and diversity in particle hygroscopicity and composition are important to the assessment of particle impacts on clouds and global climate.

  11. Size distribution and speciation of chromium in paint spray aerosol at an aerospace facility.

    PubMed

    Sabty-Daily, Rania A; Harris, Patricia A; Hinds, William C; Froines, John R

    2005-01-01

    Spray painters are potentially exposed to aerosol containing Cr(VI) via inhalation of chromate-based paint spray. Two field studies were conducted at an aerospace facility to determine the size distribution and speciation of Cr(VI) in paint spray aerosol. Sampled paint products consisted of sparingly soluble strontium chromate in an epoxy resin matrix, a matrix generally known for its durability and toughness. Personal aerosol samples were collected using Sierra Marple personal cascade impactors and analyzed for Cr(VI) and total Cr. The size distribution of total Cr particles in the paint aerosol had a Mass Median Aerodynamic Diameter (MMAD) of 7.5 mum [Geometric Standard Deviation (GSD = 2.7 mum)] in both field studies. The MMAD of Cr(VI) particles was 8.5 mum (GSD = 2.2 mum). Particles >2 mum constituted 90% or more of the total Cr and the Cr(VI) mass, in all sampled paint aerosols and were lognormally distributed. The target site for respiratory deposition of Cr in the aerosol was estimated based on the mass distribution of Cr according to particle size. On an average, 62% of the Cr and Cr(VI) mass in the paint aerosol consisted of particles >10 mum. This study showed that 71.8% of Cr(VI) mass in paint spray aerosol potentially inhaled by a spray painter may deposit in the head airways region. Only 2.0 and 1.4% of Cr(VI) mass in the paint aerosol may potentially deposit in the alveolar and tracheobronchial region, respectively. The ratio of Cr(VI) mass to total Cr mass was determined in bulk paint and the data indicate that Cr was predominantly in the Cr(VI) valence state, before spraying. The ratio of Cr(VI) mass to total Cr mass was also determined in paint aerosol samples. The data indicated that there was a reduction of Cr(VI) regardless of Cr aerosol particle size. Cr(VI) reduction occurred most likely during the 8 h sample collection time period. These findings are in agreement with the findings that observed Cr(VI) reduction during collection of airborne

  12. Design, characterization, and aerosolization of organic solution advanced spray-dried moxifloxacin and ofloxacin dipalmitoylphosphatidylcholine (DPPC) microparticulate/nanoparticulate powders for pulmonary inhalation aerosol delivery

    PubMed Central

    Duan, Jinghua; Vogt, Frederick G; Li, Xiaojian; Hayes, Don; Mansour, Heidi M

    2013-01-01

    The aim of this study was to design and develop respirable antibiotics moxifloxacin (MOXI) hydrochloride and ofloxacin (OFLX) microparticles and nanoparticles, and multifunctional antibiotics particles with or without lung surfactant 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) for targeted dry powder inhalation delivery as a pulmonary nanomedicine. Particles were rationally designed and produced by advanced spray-drying particle engineering from an organic solution in closed mode (no water) from dilute solution. Scanning electron microscopy indicated that these particles had both optimal particle morphology and surface morphology, and the particle size distributions were suitable for pulmonary delivery. Comprehensive and systematic physicochemical characterization and in vitro aerosol dispersion performance revealed significant differences between these two fluoroquinolone antibiotics following spray drying as drug aerosols and as cospray-dried antibiotic drug: DPPC aerosols. Fourier transform infrared spectroscopy and confocal Raman microspectroscopy were employed to probe composition and interactions in the solid state. Spray-dried MOXI was rendered noncrystalline (amorphous) following organic solution advanced spray drying. This was in contrast to spray-dried OFLX, which retained partial crystallinity, as did OFLX:DPPC powders at certain compositions. Aerosol dispersion performance was conducted using inertial impaction with a dry powder inhaler device approved for human use. The present study demonstrates that the use of DPPC offers improved aerosol delivery of MOXI as cospray-dried microparticulate/nanoparticulate powders, whereas residual partial crystallinity influenced aerosol dispersion of OFLX and most of the compositions of OFLX:DPPC inhalation powders. PMID:24092972

  13. Design, characterization, and aerosol dispersion performance modeling of advanced co-spray dried antibiotics with mannitol as respirable microparticles/nanoparticles for targeted pulmonary delivery as dry powder inhalers.

    PubMed

    Li, Xiaojian; Vogt, Frederick G; Hayes, Don; Mansour, Heidi M

    2014-09-01

    Dry powder inhalation aerosols of antibiotic drugs (a first-line aminoglycoside, tobramycin, and a first-line macrolide, azithromycin) and a sugar alcohol mucolytic agent (mannitol) as co-spray dried (co-SD) particles at various molar ratios of drug:mannitol were successfully produced by organic solution advanced co-spray drying from dilute solute concentration. These microparticulate/nanoparticulate aerosols consisting of various antibiotic drug:mannitol molar ratios were rationally designed with a narrow and unimodal primary particle size distribution, spherical particle shape, relatively smooth particle surface, and very low residual water content to minimize the interparticulate interactions and enhance in vitro aerosolization. These microparticulate/nanoparticulate inhalation powders were high-performing aerosols as reflected in the aerosol dispersion performance parameters of emitted dose, fine particle fraction (FPF), respirable fraction (RF), and mass median aerodynamic diameter (MMAD). The glass transition temperature (Tg) values were significantly above room temperature, which indicated that the co-SD powders were all in the amorphous glassy state. The Tg values for co-SD tobramycin:mannitol powders were significantly lower than those for co-SD azithromycin:mannitol powders. The interplay between aerosol dispersion performance parameters and Tg was modeled where higher Tg values (i.e., more ordered glass) were correlated with higher values in FPF and RF and lower values in MMAD.

  14. Small-Scale Spray Releases: Additional Aerosol Test Results

    SciTech Connect

    Schonewill, Philip P.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, G. N.; Mahoney, Lenna A.; Tran, Diana N.; Burns, Carolyn A.; Kurath, Dean E.

    2013-08-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. To expand the data set upon which the WTP accident and safety analyses were based, an aerosol spray leak testing program was conducted by Pacific Northwest National Laboratory (PNNL). PNNL’s test program addressed two key technical areas to improve the WTP methodology (Larson and Allen 2010). The first technical area was to quantify the role of slurry particles in small breaches where slurry particles may plug the hole and prevent high-pressure sprays. The results from an effort to address this first technical area can be found in Mahoney et al. (2012a). The second technical area was to determine aerosol droplet size distribution and total droplet volume from prototypic breaches and fluids, including sprays from larger breaches and sprays of slurries for which literature data are largely absent. To address the second technical area, the testing program collected aerosol generation data at two scales, commonly referred to as small-scale and large-scale. The small-scale testing and resultant data are described in Mahoney et al. (2012b) and the large-scale testing and resultant data are presented in Schonewill et al. (2012). In tests at both scales, simulants were used to mimic the

  15. Large-Scale Spray Releases: Additional Aerosol Test Results

    SciTech Connect

    Daniel, Richard C.; Gauglitz, Phillip A.; Burns, Carolyn A.; Fountain, Matthew S.; Shimskey, Rick W.; Billing, Justin M.; Bontha, Jagannadha R.; Kurath, Dean E.; Jenks, Jeromy WJ; MacFarlan, Paul J.; Mahoney, Lenna A.

    2013-08-01

    One of the events postulated in the hazard analysis for the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak event involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids that behave as a Newtonian fluid. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and in processing facilities across the DOE complex. To expand the data set upon which the WTP accident and safety analyses were based, an aerosol spray leak testing program was conducted by Pacific Northwest National Laboratory (PNNL). PNNL’s test program addressed two key technical areas to improve the WTP methodology (Larson and Allen 2010). The first technical area was to quantify the role of slurry particles in small breaches where slurry particles may plug the hole and prevent high-pressure sprays. The results from an effort to address this first technical area can be found in Mahoney et al. (2012a). The second technical area was to determine aerosol droplet size distribution and total droplet volume from prototypic breaches and fluids, including sprays from larger breaches and sprays of slurries for which literature data are mostly absent. To address the second technical area, the testing program collected aerosol generation data at two scales, commonly referred to as small-scale and large-scale testing. The small-scale testing and resultant data are described in Mahoney et al. (2012b), and the large-scale testing and resultant data are presented in Schonewill et al. (2012). In tests at both scales, simulants were used

  16. Nanosized aerosols from consumer sprays: experimental analysis and exposure modeling for four commercial products

    NASA Astrophysics Data System (ADS)

    Lorenz, Christiane; Hagendorfer, Harald; von Goetz, Natalie; Kaegi, Ralf; Gehrig, Robert; Ulrich, Andrea; Scheringer, Martin; Hungerbühler, Konrad

    2011-08-01

    Consumer spray products are already on the market in the cosmetics and household sector, which suggest by their label that they contain engineered nanoparticles (ENP). Sprays are considered critical for human health, because the lungs represent a major route for the uptake of ENP into the human body. To contribute to the exposure assessment of ENP in consumer spray products, we analyzed ENP in four commercially available sprays: one antiperspirant, two shoe impregnation sprays, and one plant-strengthening agent. The spray dispersions were analyzed by inductively coupled plasma mass spectrometry (ICPMS) and (scanning-) transmission electron microscopy ((S)TEM). Aerosols were generated by using the original vessels, and analyzed by scanning mobility particle sizer (SMPS) and (S)TEM. On the basis of SMPS results, the nanosized aerosol depositing in the respiratory tract was modeled for female and male consumers. The derived exposure levels reflect a single spray application. We identified ENP in the dispersions of two products (shoe impregnation and plant spray). Nanosized aerosols were observed in three products that contained propellant gas. The aerosol number concentration increased linearly with the sprayed amount, with the highest concentration resulting from the antiperspirant. Modeled aerosol exposure levels were in the range of 1010 nanosized aerosol components per person and application event for the antiperspirant and the impregnation sprays, with the largest fraction of nanosized aerosol depositing in the alveolar region. Negligible exposure from the application of the plant spray (pump spray) was observed.

  17. Removal of Sarin Aerosol and Vapor by Water Sprays

    SciTech Connect

    Brockmann, John E.

    1998-09-01

    Falling water drops can collect particles and soluble or reactive vapor from the gas through which they fall. Rain is known to remove particles and vapors by the process of rainout. Water sprays can be used to remove radioactive aerosol from the atmosphere of a nuclear reactor containment building. There is a potential for water sprays to be used as a mitigation technique to remove chemical or bio- logical agents from the air. This paper is a quick-look at water spray removal. It is not definitive but rather provides a reasonable basic model for particle and gas removal and presents an example calcu- lation of sarin removal from a BART station. This work ~ a starting point and the results indicate that further modeling and exploration of additional mechanisms for particle and vapor removal may prove beneficial.

  18. Eddy Covariance Measurements of the Sea-Spray Aerosol Flu

    NASA Astrophysics Data System (ADS)

    Brooks, I. M.; Norris, S. J.; Yelland, M. J.; Pascal, R. W.; Prytherch, J.

    2015-12-01

    Historically, almost all estimates of the sea-spray aerosol source flux have been inferred through various indirect methods. Direct estimates via eddy covariance have been attempted by only a handful of studies, most of which measured only the total number flux, or achieved rather coarse size segregation. Applying eddy covariance to the measurement of sea-spray fluxes is challenging: most instrumentation must be located in a laboratory space requiring long sample lines to an inlet collocated with a sonic anemometer; however, larger particles are easily lost to the walls of the sample line. Marine particle concentrations are generally low, requiring a high sample volume to achieve adequate statistics. The highly hygroscopic nature of sea salt means particles change size rapidly with fluctuations in relative humidity; this introduces an apparent bias in flux measurements if particles are sized at ambient humidity. The Compact Lightweight Aerosol Spectrometer Probe (CLASP) was developed specifically to make high rate measurements of aerosol size distributions for use in eddy covariance measurements, and the instrument and data processing and analysis techniques have been refined over the course of several projects. Here we will review some of the issues and limitations related to making eddy covariance measurements of the sea spray source flux over the open ocean, summarise some key results from the last decade, and present new results from a 3-year long ship-based measurement campaign as part of the WAGES project. Finally we will consider requirements for future progress.

  19. Particle size distribution of aerosols sprayed from household hand-pump sprays containing fluorine-based and silicone-based compounds.

    PubMed

    Kawakami, Tsuyoshi; Isama, Kazuo; Ikarashi, Yoshiaki

    2015-01-01

    Japan has published safety guideline on waterproof aerosol sprays. Furthermore, the Aerosol Industry Association of Japan has adopted voluntary regulations on waterproof aerosol sprays. Aerosol particles of diameter less than 10 µm are considered as "fine particles". In order to avoid acute lung injury, this size fraction should account for less than 0.6% of the sprayed aerosol particles. In contrast, the particle size distribution of aerosols released by hand-pump sprays containing fluorine-based or silicone-based compounds have not been investigated in Japan. Thus, the present study investigated the aerosol particle size distribution of 16 household hand-pump sprays. In 4 samples, the ratio of fine particles in aerosols exceeded 0.6%. This study confirmed that several hand-pump sprays available in the Japanese market can spray fine particles. Since the hand-pump sprays use water as a solvent and their ingredients may be more hydrophilic than those of aerosol sprays, the concepts related to the safety of aerosol-sprays do not apply to the hand pump sprays. Therefore, it may be required for the hand-pump spray to develop a suitable method for evaluating the toxicity and to establish the safety guideline.

  20. Large-Scale Spray Releases: Initial Aerosol Test Results

    SciTech Connect

    Schonewill, Philip P.; Gauglitz, Phillip A.; Bontha, Jagannadha R.; Daniel, Richard C.; Kurath, Dean E.; Adkins, Harold E.; Billing, Justin M.; Burns, Carolyn A.; Davis, James M.; Enderlin, Carl W.; Fischer, Christopher M.; Jenks, Jeromy WJ; Lukins, Craig D.; MacFarlan, Paul J.; Shutthanandan, Janani I.; Smith, Dennese M.

    2012-12-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents was assessed with most of the simulants. Orifices included round holes and

  1. Small-Scale Spray Releases: Initial Aerosol Test Results

    SciTech Connect

    Mahoney, Lenna A.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, Garrett N.; Kurath, Dean E.; Buchmiller, William C.; Smith, Dennese M.; Blanchard, Jeremy; Song, Chen; Daniel, Richard C.; Wells, Beric E.; Tran, Diana N.; Burns, Carolyn A.

    2012-11-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents was assessed with most of the simulants. Orifices included round holes and

  2. Small-Scale Spray Releases: Initial Aerosol Test Results

    SciTech Connect

    Mahoney, Lenna A.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, Garrett N.; Kurath, Dean E.; Buchmiller, William C.; Smith, Dennese M.; Blanchard, Jeremy; Song, Chen; Daniel, Richard C.; Wells, Beric E.; Tran, Diana N.; Burns, Carolyn A.

    2013-05-29

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and net generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of antifoam agents was assessed with most of the simulants. Orifices included round holes and

  3. Aerosol spray pyrolysis & solution phase synthesis of nanostructures

    NASA Astrophysics Data System (ADS)

    Zhang, Hongwang

    This dissertation focuses on the synthesis of nanomaterials by both solution phase and gas phase methods. By the solution phase method, we demonstrate the synthesis of Au/CdS binary hybrid nanoparticles and the Au-induced growth of CdS nanorods. At higher reaction temperature, extremely uniform CdS nanorods were obtained. The size of the Au seed nanoparticles has an important influence on the length and diameter of the nanorods. In addition, preparation of peanut-like FePt-CdS hybrid nanoparticles by spontaneous epitaxial nucleation and growth of CdS onto FePt-seed nanoparticles in high-temperature organic solution is reported. The FePt-CdS hybrid nanoparticles reported here are an example of a bifunctional nanomaterial that combines size-dependent magnetic and optical properties. In the gas phase method, a spray pyrolysis aerosol synthesis method was used to produce tellurium dioxide nanoparticles and zinc sulfide nanoparticles. Tellurite glasses (amorphous TeO2 based materials) have two useful optical properties, high refractive index and high optical nonlinearity, that make them attractive for a range of applications. In the work presented here, TeO2 nanoparticles were prepared by spray pyrolysis of an aqueous solution of telluric acid, Te(OH)6. This laboratory-scale process is capable of producing up to 80 mg/hr of amorphous TeO2-nanoparticles with primary particle diameters from 10 to 40 nm, and allows their synthesis in significant quantities from an inexpensive and environmentally friendly precursor. Furthermore, both Er3+ doped and Er3+ and Yb3+ co-doped tellurium dioxide nanoparticles were synthesized by spray pyrolysis of an aqueous mixture of telluric acid with erbium/ytterbium salts, which exhibit the infrared to green visible upconversion phenomena. ZnS nanoparticles (NPs) were prepared by spray pyrolysis using zinc diethyldithiocarbamate as a single-source precursor. The home-built scanning mobility particle spectrometer (SMPS) is a useful tool for

  4. Aerosol-spray diverse mesoporous metal oxides from metal nitrates

    PubMed Central

    Kuai, Long; Wang, Junxin; Ming, Tian; Fang, Caihong; Sun, Zhenhua; Geng, Baoyou; Wang, Jianfang

    2015-01-01

    Transition metal oxides are widely used in solar cells, batteries, transistors, memories, transparent conductive electrodes, photocatalysts, gas sensors, supercapacitors, and smart windows. In many of these applications, large surface areas and pore volumes can enhance molecular adsorption, facilitate ion transfer, and increase interfacial areas; the formation of complex oxides (mixed, doped, multimetallic oxides and oxide-based hybrids) can alter electronic band structures, modify/enhance charge carrier concentrations/separation, and introduce desired functionalities. A general synthetic approach to diverse mesoporous metal oxides is therefore very attractive. Here we describe a powerful aerosol-spray method for synthesizing various mesoporous metal oxides from low-cost nitrate salts. During spray, thermal heating of precursor droplets drives solvent evaporation and induces surfactant-directed formation of mesostructures, nitrate decomposition and oxide cross-linking. Thirteen types of monometallic oxides and four groups of complex ones are successfully produced, with mesoporous iron oxide microspheres demonstrated for photocatalytic oxygen evolution and gas sensing with superior performances. PMID:25897988

  5. Aerosol-spray diverse mesoporous metal oxides from metal nitrates.

    PubMed

    Kuai, Long; Wang, Junxin; Ming, Tian; Fang, Caihong; Sun, Zhenhua; Geng, Baoyou; Wang, Jianfang

    2015-04-21

    Transition metal oxides are widely used in solar cells, batteries, transistors, memories, transparent conductive electrodes, photocatalysts, gas sensors, supercapacitors, and smart windows. In many of these applications, large surface areas and pore volumes can enhance molecular adsorption, facilitate ion transfer, and increase interfacial areas; the formation of complex oxides (mixed, doped, multimetallic oxides and oxide-based hybrids) can alter electronic band structures, modify/enhance charge carrier concentrations/separation, and introduce desired functionalities. A general synthetic approach to diverse mesoporous metal oxides is therefore very attractive. Here we describe a powerful aerosol-spray method for synthesizing various mesoporous metal oxides from low-cost nitrate salts. During spray, thermal heating of precursor droplets drives solvent evaporation and induces surfactant-directed formation of mesostructures, nitrate decomposition and oxide cross-linking. Thirteen types of monometallic oxides and four groups of complex ones are successfully produced, with mesoporous iron oxide microspheres demonstrated for photocatalytic oxygen evolution and gas sensing with superior performances.

  6. Closed loop spray cooling apparatus. [for particle accelerator targets

    NASA Technical Reports Server (NTRS)

    Alger, D. L.; Schwab, W. B.; Furman, E. R. (Inventor)

    1978-01-01

    A closed loop apparatus for spraying coolant against the back of a radiation target is described. The coolant was circulated through a closed loop with a bubble of inert gas being maintained around the spray. Mesh material was disposed between the bubble and the surface of the liquid coolant which was below the bubble at a predetermined level. In a second embodiment, no inert gas was used, the bubble consisting of a vapor produced when the coolant was sprayed against the target.

  7. Size distribution of chromate paint aerosol generated in a bench-scale spray booth.

    PubMed

    Sabty-Daily, Rania A; Hinds, William C; Froines, John R

    2005-01-01

    Spray painters are potentially exposed to aerosols containing hexavalent chromium [Cr(VI)] via inhalation of chromate-based paint sprays. Evaluating the particle size distribution of a paint spray aerosol, and the variables that may affect this distribution, is necessary to determine the site and degree of respiratory deposition and the damage that may result from inhaled Cr(VI)-containing paint particles. This study examined the effect of spray gun atomization pressure, aerosol generation source and aerosol aging on the size distribution of chromate-based paint overspray aerosols generated in a bench-scale paint spray booth. The study also determined the effect of particle bounce inside a Marple personal cascade impactor on measured size distributions of paint spray aerosols. Marple personal cascade impactors with a modified inlet were used for sample collection. The data indicated that paint particle bounce did not occur inside the cascade impactors sufficiently to affect size distribution when using uncoated stainless steel or PVC substrate sampling media. A decrease in paint aerosol mass median aerodynamic diameter (MMAD) from 8.2 to 7.0 mum was observed as gun atomization pressure increased from 6 to 10 psi. Overspray aerosols were sampled at two locations in the spray booth. A downstream sampling position simulated the exposure of a worker standing between the painted surface and exhaust, a situation encountered in booths with multiple workers. The measured mean MMAD was 7.2 mum. The distance between the painted surface and sampler was varied to sample oversprays of varying ages between 2.8 and 7.7 s. Age was not a significant factor for determining MMAD. Overspray was sampled at a 90 degrees position to simulate a worker standing in front of the surface being painted with air flowing to the worker's side, a common situation in field applications. The resulting overspray MMAD averaged 5.9 mum. Direct-spray aerosols were sampled at ages from 5.3 to 11.7 s

  8. Dissolved organic matter in sea spray: a transfer study from marine surface water to aerosols

    NASA Astrophysics Data System (ADS)

    Schmitt-Kopplin, P.; Liger-Belair, G.; Koch, B. P.; Flerus, R.; Kattner, G.; Harir, M.; Kanawati, B.; Lucio, M.; Tziotis, D.; Hertkorn, N.; Gebefügi, I.

    2012-04-01

    Atmospheric aerosols impose direct and indirect effects on the climate system, for example, by absorption of radiation in relation to cloud droplets size, on chemical and organic composition and cloud dynamics. The first step in the formation of Organic primary aerosols, i.e. the transfer of dissolved organic matter from the marine surface into the atmosphere, was studied. We present a molecular level description of this phenomenon using the high resolution analytical tools of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and nuclear magnetic resonance spectroscopy (NMR). Our experiments confirm the chemoselective transfer of natural organic molecules, especially of aliphatic compounds from the surface water into the atmosphere via bubble bursting processes. Transfer from marine surface water to the atmosphere involves a chemical gradient governed by the physicochemical properties of the involved molecules when comparing elemental compositions and differentiating CHO, CHNO, CHOS and CHNOS bearing compounds. Typical chemical fingerprints of compounds enriched in the aerosol phase were CHO and CHOS molecular series, smaller molecules of higher aliphaticity and lower oxygen content, and typical surfactants. A non-targeted metabolomics analysis demonstrated that many of these molecules corresponded to homologous series of oxo-, hydroxy-, methoxy-, branched fatty acids and mono-, di- and tricarboxylic acids as well as monoterpenes and sugars. These surface active biomolecules were preferentially transferred from surface water into the atmosphere via bubble bursting processes to form a significant fraction of primary organic aerosols. This way of sea spray production leaves a selective biological signature of the surface water in the corresponding aerosol that may be transported into higher altitudes up to the lower atmosphere, thus contributing to the formation of secondary organic aerosol on a global scale or transported laterally with

  9. Physicochemical characterization and aerosol dispersion performance of organic solution advanced spray-dried microparticulate/nanoparticulate antibiotic dry powders of tobramycin and azithromycin for pulmonary inhalation aerosol delivery.

    PubMed

    Li, Xiaojian; Vogt, Frederick G; Hayes, Don; Mansour, Heidi M

    2014-02-14

    The purpose of this study was to systematically design pure antibiotic drug dry powder inhalers (DPIs) for targeted antibiotic pulmonary delivery in the treatment of pulmonary infections and comprehensively correlate the physicochemical properties in the solid-state and spray-drying conditions effects on aerosol dispersion performance as dry powder inhalers (DPIs). The two rationally chosen model antibiotic drugs, tobramycin (TOB) and azithromycin (AZI), represent two different antibiotic drug classes of aminoglycosides and macrolides, respectively. The particle size distributions were narrow, unimodal, and in the microparticulate/nanoparticulate size range. The SD particles possessed relatively spherical particle morphology, smooth surface morphology, low residual water content, and the absence of long-range molecular order. The emitted dose (ED%), fine particle fraction (FPF%) and respirable fraction (RF%) were all excellent. The MMAD values were in the inhalable range (<10 μm) with smaller MMAD values for SD AZI powders in contrast to SD TOB powders. Positive linear correlations were observed between the aerosol dispersion performance parameter of FPF with increasing spray-drying pump rates and also with the difference between thermal parameters expressed as Tg-To (i.e. the difference between the glass transition temperature and outlet temperature) for SD AZI powders. The aerosol dispersion performance for SD TOB appeared to be influenced by its high water vapor sorption behavior (hygroscopicity) and pump rates or To. Aerosol dispersion performance of SD powders were distinct for both antibiotic drug aerosol systems and also between different pump rates for each system.

  10. What Can We Learn From Laboratory Studies of Inorganic Sea Spray Aerosol?

    NASA Astrophysics Data System (ADS)

    Salter, M. E.; Zieger, P.; Acosta Navarro, J. C.; Grythe, H.; Kirkevag, A.; Rosati, B.; Riipinen, I.; Nilsson, E. D.

    2015-12-01

    Since 2013 we have been operating a temperature-controlled plunging-jet sea spray aerosol chamber at Stockholm University using inorganic artificial seawater. Using size-resolved measurements of the foam bubbles responsible for the aerosol production we were able to show that it is changes to these foam bubbles which drive the observed changes in aerosol production and size distribution as water temperature changes (Salter et al., 2014). Further, by combining size-resolved measurements of aerosol production as a function of water temperature with measurements of air entrainment by the plunging-jet we have developed a temperature-dependent sea spray source function for deployment in large-scale models (Salter et al., 2015). We have also studied the hygroscopicity, morphology, and chemical composition of the inorganic sea spray aerosol produced in the chamber. The sea spray aerosol generated from artificial seawater exhibited lower hygroscopic growth than both pure NaCl and output from the E-AIM aerosol thermodynamics model when all relevant inorganic ions in the sea salt were included. Results from sensitivity tests using a large-scale earth system model suggest that the lower hygroscopicity observed in our laboratory measurements has important implications for calculations of the radiative balance of the Earth. In addition, size-dependent chemical fractionation of several inorganic ions was observed relative to the artificial seawater with potentially important implications for the chemistry of the marine boundary layer. Each of these studies suggest that there is still much to be learned from rigorous experiments using inorganic seawater proxies. Salter et al., (2014), On the seawater temperature dependence of the sea spray aerosol generated by a continuous plunging jet. J. Geophys. Res. Atmos., 119, 9052-9072, doi: 10.1002/2013JD021376 Salter et al., (2015), An empirically derived inorganic sea spray source function incorporating sea surface temperature. Atmos

  11. Production Mechanism, Number Concentration, Size Distribution, Chemical Composition, and Optical Properties of Sea Spray Aerosols Workshop, Summer 2012

    SciTech Connect

    Meskhidze, Nicholas

    2013-10-21

    The objective of this workshop was to address the most urgent open science questions for improved quantification of sea spray aerosol-radiation-climate interactions. Sea spray emission and its influence on global climate remains one of the most uncertain components of the aerosol-radiation-climate problem, but has received less attention than other aerosol processes (e.g. production of terrestrial secondary organic aerosols). Thus, the special emphasis was placed on the production flux of sea spray aerosol particles, their number concentration and chemical composition and properties.

  12. Automatic targeting of plasma spray gun

    DOEpatents

    Abbatiello, Leonard A.; Neal, Richard E.

    1978-01-01

    A means for monitoring the material portion in the flame of a plasma spray gun during spraying operations is provided. A collimated detector, sensitive to certain wavelengths of light emission, is used to locate the centroid of the material with each pass of the gun. The response from the detector is then relayed to the gun controller to be used to automatically realign the gun.

  13. Combined X-Ray and Raman Spectroscopic Techniques for the Characterization of Sea Spray Aerosol

    NASA Astrophysics Data System (ADS)

    Aller, J. Y.; Alpert, P. A.; Knopf, D. A.; Kilthau, W.; Bothe, D.; Charnawskas, J. C.; Gilles, M. K.; OBrien, R. E.; Moffet, R.; Radway, J.

    2014-12-01

    Sea spray aerosol along with mineral dust dominates the global mass flux of particles to the atmosphere. Marine aerosol particles are of particular interest because of their continual impact on cloud formation, precipitation, atmospheric chemical processes, and thus global climate. Here we report on the physical/chemical characteristics of sub-surface waters, aerosolized sea spray particles, and particles/organic species present in surface microlayer (SML) samples collected during oceanic field campaigns and generated during laboratory experiments, revealing a biogenic primary source of the organic fraction of airborne particles. We also report on ice nucleation experiments with aerosolized particles collected during the May 2014 WACS II North Atlantic cruise and with laboratory generated exudate material from diatom cultures with the potential to impact cirrus and mixed phase clouds. Physicochemical analyses using a multi-modal approach which includes Scanning Transmission X-ray Microscopy coupled with Near-Edge Absorption Fine Structure Spectroscopy (STXM/NEXAFS) and Raman spectroscopy confirm the presence and chemical similarity of polysaccharide-rich transparent exopolymer (TEP) material and proteins in both SML sea spray aerosol and ice forming aerosol particles, regardless of the extent of biological activity in surface waters. Our results demonstrate a direct relationship between the marine environment and composition of marine aerosol through primary particle emission.

  14. Updating sea spray aerosol emissions in the Community Multiscale Air Quality (CMAQ) model

    EPA Science Inventory

    Sea spray aerosols (SSA) impact the particle mass concentration and gas-particle partitioning in coastal environments, with implications for human and ecosystem health. In this study, the Community Multiscale Air Quality (CMAQ) model is updated to enhance fine mode SSA emissions,...

  15. 7 CFR 305.9 - Aerosol spray for aircraft treatment schedule.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Aerosol spray for aircraft treatment schedule. 305.9 Section 305.9 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE PHYTOSANITARY TREATMENTS Chemical Treatments § 305.9...

  16. Influence of crustal dust and sea spray supermicron particle concentrations and acidity on inorganic NO3− aerosol during the 2013 Southern Oxidant and Aerosol Study

    DOE PAGES

    Allen, H. M.; Draper, D. C.; Ayres, B. R.; ...

    2015-09-25

    Inorganic aerosol composition was measured in the southeastern United States, a region that exhibits high aerosol mass loading during the summer, as part of the 2013 Southern Oxidant and Aerosol Study (SOAS) campaign. Measurements using a Monitor for AeRosols and GAses (MARGA) revealed two periods of high aerosol nitrate (NO3−) concentrations during the campaign. These periods of high nitrate were correlated with increased concentrations of supermicron crustal and sea spray aerosol species, particularly Na+ and Ca2+, and with a shift towards aerosol with larger (1 to 2.5 μm) diameters. We suggest this nitrate aerosol forms by multiphase reactions of HNO3more » and particles, reactions that are facilitated by transport of crustal dust and sea spray aerosol from a source within the United States. The observed high aerosol acidity prevents the formation of NH4NO3, the inorganic nitrogen species often dominant in fine-mode aerosol at higher pH. In addition, calculation of the rate of the heterogeneous uptake of HNO3 on mineral aerosol supports the conclusion that aerosol NO3− is produced primarily by this process, and is likely limited by the availability of mineral cation-containing aerosol surface area. Modeling of NO3− and HNO3 by thermodynamic equilibrium models (ISORROPIA II and E-AIM) reveals the importance of including mineral cations in the southeastern United States to accurately balance ion species and predict gas–aerosol phase partitioning.« less

  17. A Model for the Transport of Sea-Spray Aerosols in the Coastal Zone

    NASA Astrophysics Data System (ADS)

    Piazzola, J.; Tedeschi, G.; Demoisson, A.

    2015-05-01

    We study the dynamics of sea-spray particles in the coastal region of La Reunion Island on the basis of numerical simulations using the transport aerosol model MACMod (Marine Aerosol Concentration Model) and a survey of the aerosol size distributions measured at four locations at two different heights in the north-west part of the island. This allows evaluation of the performance of our model in case of pure marine air masses with implementation of accurate boundary conditions. First of all, an estimate of the aerosol concentration at 10-m height at the upwind boundary of the calculation domain is obtained using a revisited version of the MEDEX (Mediterranean Extinction) model. Estimates of the vertical profile of aerosol concentrations are then provided using aerosol data obtained at two different heights at the upwind boundary of the calculation domain. A parametrization of the vertical profiles of aerosol concentrations for maritime environment is proposed. The results are then compared to the vertical profiles of 0.532 m aerosol particle extinction coefficient obtained from lidar data provided by the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) and also to the data provided by the Aerosol Robotic Network (AERONET). This allows validation of the complete vertical profiles in the mixed layer and shows the validity of satellite data for determination of the vertical profiles. Two kinds of simulation were made: one without a particle advection flux at the upwind boundary of the numerical domain, whereas the second simulation was made with a particle advection flux. In the first case, the influence of the distance to the shoreline on the local sea-spray dynamics is investigated. In the second set of simulation, the particles issued from the local production in the surf zone near the shoreline are mixed with aerosols advected from the remote ocean. A good agreement between the model calculations using our boundary conditions and the data was found. The

  18. Characterizing the Hygroscopicity of Nascent Sea Spray Aerosol from Synthetic Blooms

    NASA Astrophysics Data System (ADS)

    Forestieri, S.; Cappa, C. D.; Sultana, C. M.; Lee, C.; Wang, X.; Helgestad, T.; Moore, K.; Prather, K. A.; Cornwell, G.; Novak, G.; Bertram, T. H.

    2015-12-01

    Marine sea spray aerosol (SSA) particles make up a significant portion of natural aerosols and are therefore important in establishing the baseline for anthropogenic aerosol climate impacts. Scattering of solar radiation by aerosols affects Earth's radiative budget and the degree of scattering is size-dependent. Thus, aerosols scatter more light at elevated relative humidities when they grow larger via water uptake. This growth depends critically on chemical composition. SSA can become enriched in organics during phytoplankton blooms, becoming less salty and therefore less hygroscopic. Subsaturated hygroscopic growth factors at 85% relative humidity (GF(85%)) of SSA particles were quantified during two mesocosm experiments in enclosed marine aerosol reference tanks (MARTs). The two experiments were conducted with filtered seawater collected at separate times from the Scripps Institute of Oceanography Pier in La Jolla, CA. Phytoplankton blooms in each tank were induced via the addition of nutrients and photosynthetically active radiation. The "indoor" MART was illuminated with fluorescent light and the other "outdoor" MART was illuminated with sunlight. The peak chlorophyll-a concentrations were 59 micrograms/L and 341 micrograms /L for the indoor and outdoor MARTs, respectively. GF(85%) values for SSA particles were quantified using a humidified cavity ringdown spectrometer and particle size distributions. Particle composition was monitored with a single particle aerosol mass spectrometer (ATOFMS) and an Aerodyne aerosol mass spectrometer (AMS). Relationships between the observed particle GFs and the particle composition markers will be discussed.

  19. Comparing Organic Aerosol Composition from Marine Biogenic Sources to Seawater and to Physical Sea Spray Models

    NASA Astrophysics Data System (ADS)

    Russell, L. M.; Frossard, A. A.; Sanchez, K.; Massoli, P.; Elliott, S.; Burrows, S. M.; Bates, T. S.; Quinn, P.

    2015-12-01

    In much of the marine atmosphere, organic components in aerosol particles have many sources other than sea spray that contribute organic constituents. For this reason, physical sea spray models provide an important technique for studying the organic composition of particles from marine biogenic sources. The organic composition of particles produced by two different physical sea spray models were measured in three open ocean seawater types: (i) Coastal California in the northeastern Pacific, which is influenced by wind-driven, large-scale upwelling leading to productive or eutrophic (nutrient-rich) seawater and high chl-a concentrations, (ii) George's Bank in the northwestern Atlantic, which is also influenced by nutrient upwelling and eutrophic seawater with phytoplankton productivity and high chl-a concentrations, and (iii) the Sargasso Sea in the subtropical western Atlantic, which is oligotrophic and nutrient-limited, reflected in low phytoplankton productivity and low chl-a concentrations. Fourier transform infrared spectroscopy provides information about the functional group composition that represents the marine organic fraction more completely than is possible with techniques that measure non-refractory mass (vaporizable at 650°C). After separating biogenic marine particles from those from other sources, the measured compositions of atmospheric marine aerosol particles from three ocean regions is 65±12% hydroxyl, 21±9% alkane, 6±6% amine, and 7±8% carboxylic acid functional groups. The organic composition of atmospheric primary marine (ocean-derived) aerosol particles is nearly identical to model generated primary marine aerosol particles from bubbled seawater. Variability in productive and non-productive seawater may be caused by the presence of surfactants that can stabilize the bubble film and lead to preferential drainage of the more soluble (lower alkane group fraction) organic components without substantial changes in overall group composition

  20. How much does sea spray aerosol organic matter impact clouds and radiation? Sensitivity studies in the Community Atmosphere Model

    NASA Astrophysics Data System (ADS)

    Burrows, S. M.; Liu, X.; Elliott, S.; Easter, R. C.; Singh, B.; Rasch, P. J.

    2015-12-01

    Submicron marine aerosol particles are frequently observed to contain substantial fractions of organic material, hypothesized to enter the atmosphere as part of the primary sea spray aerosol formed through bubble bursting. This organic matter in sea spray aerosol may affect cloud condensation nuclei and ice nuclei concentrations in the atmosphere, particularly in remote marine regions. Members of our team have developed a new, mechanistic representation of the enrichment of sea spray aerosol with organic matter, the OCEANFILMS parameterization (Burrows et al., 2014). This new representation uses fields from an ocean biogeochemistry model to predict properties of the emitted aerosol. We have recently implemented the OCEANFILMS representation of sea spray aerosol composition into the Community Atmosphere Model (CAM), and performed sensitivity experiments and comparisons with alternate formulations. Early results from these sensitivity simulations will be shown, including impacts on aerosols, clouds, and radiation. References: Burrows, S. M., Ogunro, O., Frossard, A. A., Russell, L. M., Rasch, P. J., and Elliott, S. M.: A physically based framework for modeling the organic fractionation of sea spray aerosol from bubble film Langmuir equilibria, Atmos. Chem. Phys., 14, 13601-13629, doi:10.5194/acp-14-13601-2014, 2014.

  1. Programmable ultrasonic sensing system for targeted spraying in orchards.

    PubMed

    Stajnko, Denis; Berk, Peter; Lešnik, Mario; Jejčič, Viktor; Lakota, Miran; Strancar, Andrej; Hočevar, Marko; Rakun, Jurij

    2012-11-09

    This research demonstrates the basic elements of a prototype automated orchard sprayer which delivers pesticide spray selectively with respect to the characteristics of the targets. The density of an apple tree canopy was detected by PROWAVE 400EP250 ultrasound sensors controlled by a Cypress PSOC CY8C29466 microcontroller. The ultrasound signal was processed with an embedded computer built around a LPC1343 microcontroller and fed in real time to electro-magnetic valves which open/close spraying nozzles in relation to the canopy structure. The analysis focuses on the detection of appropriate thresholds on 15 cm ultrasound bands, which correspond to maximal response to tree density, and this was selected for accurate spraying guidance. Evaluation of the system was performed in an apple orchard by detecting deposits of tartrazine dye (TD) on apple leaves. The employment of programmable microcontrollers and electro-magnetic valves decreased the amount of spray delivered by up to 48.15%. In contrast, the reduction of TD was only up to 37.7% at some positions within the tree crown and 65.1% in the gaps between trees. For all these reasons, this concept of precise orchard spraying can contribute to a reduction of costs and environmental pollution, while obtaining similar or even better leaf deposits.

  2. Programmable Ultrasonic Sensing System for Targeted Spraying in Orchards

    PubMed Central

    Stajnko, Denis; Berk, Peter; Lešnik, Mario; Jejčič, Viktor; Lakota, Miran; Štrancar, Andrej; Hočevar, Marko; Rakun, Jurij

    2012-01-01

    This research demonstrates the basic elements of a prototype automated orchard sprayer which delivers pesticide spray selectively with respect to the characteristics of the targets. The density of an apple tree canopy was detected by PROWAVE 400EP250 ultrasound sensors controlled by a Cypress PSOC CY8C29466 microcontroller. The ultrasound signal was processed with an embedded computer built around a LPC1343 microcontroller and fed in real time to electro-magnetic valves which open/close spraying nozzles in relation to the canopy structure. The analysis focuses on the detection of appropriate thresholds on 15 cm ultrasound bands, which correspond to maximal response to tree density, and this was selected for accurate spraying guidance. Evaluation of the system was performed in an apple orchard by detecting deposits of tartrazine dye (TD) on apple leaves. The employment of programmable microcontrollers and electro-magnetic valves decreased the amount of spray delivered by up to 48.15%. In contrast, the reduction of TD was only up to 37.7% at some positions within the tree crown and 65.1% in the gaps between trees. For all these reasons, this concept of precise orchard spraying can contribute to a reduction of costs and environmental pollution, while obtaining similar or even better leaf deposits. PMID:23202220

  3. Role of Organic Coatings in Regulating N2O5 Reactive Uptake to Sea Spray Aerosol.

    PubMed

    Ryder, Olivia S; Campbell, Nicole R; Morris, Holly; Forestieri, Sara; Ruppel, Matthew J; Cappa, Christopher; Tivanski, Alexei; Prather, Kimberly; Bertram, Timothy H

    2015-12-03

    Previous laboratory measurements and field observations have suggested that the reactive uptake of N2O5 to sea spray aerosol particles is a complex function of particle chemical composition and phase, where surface active organics can suppress the reactive uptake by up to a factor of 60. To date, there are no direct studies of the reactive uptake of N2O5 to nascent sea spray aerosol that permit assessment of the role that organic molecules present in sea spray aerosol (SSA) may play in suppressing or enhancing N2O5 uptake kinetics. In this study, SSA was generated from ambient seawater and artificial seawater matrices using a Marine Aerosol Reference Tank (MART), capable of producing nascent SSA representative of ambient conditions. The reactive uptake coefficient of N2O5 (γ(N2O5)) on nascent SSA was determined using an entrained aerosol flow reactor coupled to a chemical ionization mass spectrometer for measurement of surface area dependent heterogeneous loss rates. Population averaged measurements of γ(N2O5) for SSA generated from salt water sequentially doped with representative organic molecular mimics, or from ambient seawater, do not deviate statistically from that observed for sodium chloride (γ(N2O5)NaCl = 0.01-0.03) for relative humidity (RH) ranging between 50 and 65%. The results are consistent with measurements made under clean marine conditions at the Scripps Institution of Oceanography Pier and those conducted on nascent SSA generated in the marine aerosol reference tank. The results presented here suggest that organic films present on nascent SSA (at RH greater than 50%) likely do not significantly limit N2O5 reactive uptake.

  4. Satellite assessment of sea spray aerosol productivity: Southern Ocean case study

    NASA Astrophysics Data System (ADS)

    Witek, Marcin L.; Diner, David J.; Garay, Michael J.

    2016-01-01

    Despite many years of observations by multiple sensors, there is still substantial ambiguity regarding aerosol optical depths (AOD) over remote oceans, in particular, over the pristine Southern Ocean. Passive satellite retrievals (e.g., Multiangle Imaging Spectroradiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS)) and global aerosol transport models show a distinct AOD maximum around the 60°S latitude band. Sun photometer measurements performed by the Maritime Aerosol Network (MAN), on the other hand, indicate no increased AODs over the Southern Ocean. In this study elevated Southern Ocean AODs are examined from the modeling perspective. The primary aerosol component over the Southern Ocean is sea spray aerosol (SSA). Multiple simulations of SSA concentrations and optical depths are carried out using a single modeling framework, the Navy Aerosol Analysis and Prediction System (NAAPS) model. Several SSA emission functions are examined, including recently proposed formulations with sea surface temperature corrections. The differences between NAAPS simulations are primarily due to different SSA emission formulations. The results are compared against satellite-derived AODs from the MISR and MODIS instruments. MISR and MODIS AOD retrievals are further filtered to eliminate retrievals potentially affected by cloud contamination and cloud adjacency effects. The results indicate a very large impact of SSA emission parameterization on the simulated AODs. For some scenarios, the Southern Ocean AOD maximum almost completely disappears. Further MISR and MODIS AOD quality screening substantially improves model/satellite agreement. Based on these comparisons, an optimal SSA emission function for global aerosol transport models is recommended.

  5. Targeted delivery of magnetic aerosol droplets to the lung.

    PubMed

    Dames, Petra; Gleich, Bernhard; Flemmer, Andreas; Hajek, Kerstin; Seidl, Nicole; Wiekhorst, Frank; Eberbeck, Dietmar; Bittmann, Iris; Bergemann, Christian; Weyh, Thomas; Trahms, Lutz; Rosenecker, Joseph; Rudolph, Carsten

    2007-08-01

    The inhalation of medical aerosols is widely used for the treatment of lung disorders such as asthma, chronic obstructive pulmonary disease, cystic fibrosis, respiratory infection and, more recently, lung cancer. Targeted aerosol delivery to the affected lung tissue may improve therapeutic efficiency and minimize unwanted side effects. Despite enormous progress in optimizing aerosol delivery to the lung, targeted aerosol delivery to specific lung regions other than the airways or the lung periphery has not been adequately achieved to date. Here, we show theoretically by computer-aided simulation, and for the first time experimentally in mice, that targeted aerosol delivery to the lung can be achieved with aerosol droplets comprising superparamagnetic iron oxide nanoparticles--so-called nanomagnetosols--in combination with a target-directed magnetic gradient field. We suggest that nanomagnetosols may be useful for treating localized lung disease, by targeting foci of bacterial infection or tumour nodules.

  6. Production Mechanisms, Number Concentration, Size Distribution. Chemical Composition, and Optical Properties of Sea Spray Aerosols

    NASA Technical Reports Server (NTRS)

    Meskhidze, Nicholas; Petters, Markus; Tsigaridis, Kostas; Bates. Tim; O'Dowd, Colin; Reid, Jeff; Lewis, Ernie R.; Gantt, Brett; Anguelova, Magdalena D.; Bhave, Prakash V.; Bird, James; Callaghan, Adrian H.; Ceburnis, Darius; Chang, Rachel; Clark, Antony; deLeeuw, Gerrit; Deane, Grant; DeMott, Paul J.; Elliot, Scott; Facchini, Maria Cristina; Fairall, Chris W.; Hawkins, Lelia; Hu, Yongxiang; Smirnov, Alexander

    2013-01-01

    Over forty scientists from six countries convened in Raleigh, NC on June 4-6 2012 to review the status and prospects of sea spray aerosol research. Participants were researchers from the oceanography and atmospheric science communities, including academia, private industry, and government agencies. The recommendations from the working groups are summarized in a science prioritization matrix that is meant to prioritize the research agenda and identify areas of investigation by the magnitude of their impact on proposed science questions. Str

  7. Sea spray aerosol in central Antarctica. Present atmospheric behaviour and implications for paleoclimatic reconstructions

    NASA Astrophysics Data System (ADS)

    Udisti, R.; Dayan, U.; Becagli, S.; Busetto, M.; Frosini, D.; Legrand, M.; Lucarelli, F.; Preunkert, S.; Severi, M.; Traversi, R.; Vitale, V.

    2012-06-01

    From November 2004 to December 2007, size-segregated aerosol samples were collected all-year-round at Dome C (East Antarctica) by using PM10 and PM2.5 samplers, and multi-stage impactors. The data set obtained from the chemical analysis provided the longest and the most time-resolved record of sea spray aerosol (sea salt Na+) in inner Antarctica. Sea spray showed a sharp seasonal pattern. The highest values measured in winter (Apr-Nov) were about ten times larger than in summer (Dec-Mar). For the first time, a size-distribution seasonal pattern was also shown: in winter, sea spray particles are mainly sub-micrometric, while their summer size-mode is around 1-2 μm. Meteorological analysis on a synoptic scale allowed the definition of atmospheric conditions leading sea spray to Dome C. An extreme-value approach along with specific environmental based criteria was taken to yield stronger fingerprints linking atmospheric circulation (means and anomalies) to extreme sea spray events. Air mass back-trajectory analyses for some high sea spray events allowed the identification of two major air mass pathways, reflecting different size distributions: micrometric fractions for transport from the closer Indian-Pacific sector, and sub-micrometric particles for longer trajectories over the Antarctic Plateau. The seasonal pattern of the SO42-/Na+ ratio enabled the identification of few events depleted in sulphate, with respect to the seawater composition. By using methanesulphonic acid (MSA) profile to evaluate the biogenic SO42- contribution, a more reliable sea salt sulphate was calculated. In this way, few events (mainly in April and in September) were identified originating probably from the "frost flower" source. A comparison with daily-collected superficial snow samples revealed that there is a temporal shift between aerosol and snow sea spray trends. This feature could imply a more complex deposition processes of sea spray, involving significant contribution of wet and

  8. A Numerical Study of Sea-Spray Aerosol Motion in a Coastal Thermal Internal Boundary Layer

    NASA Astrophysics Data System (ADS)

    Liang, Tinghao; Yu, Xiping

    2016-08-01

    A three-dimensional large-eddy simulation model is applied to the study of sea-spray aerosol transport, dispersion and settling in the coastal thermal internal boundary layer (IBL) formed by cool airflow from the open sea to the warm land. An idealized situation with constant inflow from the ocean and constant heat flux over the coastal land is considered. The numerical results confirm that the thickness of the coastal thermal IBL increases with the distance from the coastline until the outer edge of the IBL penetrates into the capping inversion layer. The thickness increases also with time until a fully-developed thermal boundary layer is formed. In addition, the thickness of the coastal thermal IBL increases more rapidly when the heat flux over the land is greater. Existence of large-scale eddies within the thermal IBL is identified and the turbulence intensity within the thermal IBL is also found to be significantly higher than that above. It is also indicated that the vertical position of the maximum concentration does not occur at the surface but increases as sea-spray aerosols are transported inland. The vertical position of the maximum flux of sea-spray aerosols within the coastal thermal IBL is shown to coincide with that of the maximum vertical velocity fluctuations when the coastal thermal IBL is fully developed with increased distance in the airflow direction.

  9. Study of application rates of aerosol and pump hair sprays. Final report, July 1986-November 1987

    SciTech Connect

    Boggs, R.R.; Belmont, B.

    1988-03-11

    Application rates of three hair spray dispensing systems, aerosol, pump, and Exxel packaging were determined through a six-week user panel of approximately 300 people. In addition, photochemically reactive organic compounds (PROC) application rates were determined through chemical analysis of the products. The user panel was stratified on the basis of sex, dispenser (pump/aerosol), and age (adult/teen). Weighted-application rates and weighted PROC application rates are included. A Mann-Whitney evaluation was made to evaluate differences between data sets. Product-usage data for both male and female adult groups support the conclusion that increased use of either pumps or Exxel packaging for hair spray would reduce PROC emissions in California. Data from adult groups also indicate that use of Exxel packaging in place of pumps would not reduce PROC. Consumer preference was also sampled. Adult pump users were not very willing to switch to aerosols, but on the order of half of aerosol users were willing to switch to pumps.

  10. Physicochemical Characterization of Lake Spray Aerosol Generated from Great Lakes Water Samples

    NASA Astrophysics Data System (ADS)

    Ault, A. P.; Axson, J. L.; May, N.; Pratt, K.

    2014-12-01

    Wave breaking across bodies of water releases particles into the air which can impact climate and human health. Similar to sea spray aerosols formed through marine wave breaking, freshwater lakes generate lake spray aerosol (LSA). LSA can impact climate directly through scattering/absorption and indirectly through cloud nucleation. In addition, these LSA are suggested to impact human health through inhalation of these particles during algal bloom periods characterized by toxic cyanobacteria. Few studies have been conducted to assess the physical and chemical properties of freshwater LSA. Herein, we discuss constructing a LSA generation system and preliminary physical and chemical characterization of aerosol generated from water samples collected at various sites across Lake Erie, Lake Huron, Lake Superior, and Lake Michigan. Information on aerosol size distributions, number concentrations, and chemical composition will be discussed as a function of lake water blue-green algae concentration, dissolved organic carbon concentration, temperature, conductivity, and dissolved oxygen concentration. These studies represent a first step towards evaluating the potential for LSA to impact climate and health in the Great Lakes region.

  11. Efficacy of Selected Insecticide Sprays and Aerosols against the Common Bed Bug, Cimex lectularius (Hemiptera: Cimicidae)

    PubMed Central

    Wang, Changlu; Singh, Narinderpal; Zha, Chen; Cooper, Richard

    2016-01-01

    We evaluated the residual efficacy of four liquid sprays and four ready-to-use aerosols that are commonly used in the U.S. against a field-collected bed bug, Cimex lectularius L., strain with moderate resistance level to pyrethroids. The four liquid sprays were: Tandem (0.1% thiamethoxam, 0.03% lambda-cyhalothrin), Temprid SC (0.05% imidacloprid, 0.025% cyfluthrin), Transport GHP (0.05% acetamiprid, 0.06% bifenthrin), and Demand CS (0.03% lambda-cyhalothrin). The four aerosols were: Alpine (0.5% dinotefuran), Bedlam (0.4% sumithrin, 1.6% MGK 264), Bedlam Plus (0.4% sumithrin, 1% MGK 264, 0.05% imidacloprid), and Phantom (0.5% chlorfenapyr). Bed bugs were confined for 4 h to treated substrates (aged 24 h). Four substrates were tested: fabric, unpainted wood, painted wood, and vinyl. Bedlam, Demand CS, and Temprid SC resulted in ≤70% mortality on all tested substrates. Among the other five products, substrate type significantly affected their residual efficacy, except for Transport GHP, which caused ≥89.7% mortality regardless of the substrate. The effect of exposure time (5 min, 4 h, and 24 h) on the efficacy of Transport GHP and Phantom aerosol also was evaluated. A 4 h continuous exposure to Phantom aerosol or Transport GHP residue caused similar mortality to 24 h exposure and higher mortality than 5 min exposure. PMID:26840334

  12. Efficacy of Selected Insecticide Sprays and Aerosols against the Common Bed Bug, Cimex lectularius (Hemiptera: Cimicidae).

    PubMed

    Wang, Changlu; Singh, Narinderpal; Zha, Chen; Cooper, Richard

    2016-01-29

    We evaluated the residual efficacy of four liquid sprays and four ready-to-use aerosols that are commonly used in the U.S. against a field-collected bed bug, Cimex lectularius L., strain with moderate resistance level to pyrethroids. The four liquid sprays were: Tandem (0.1% thiamethoxam, 0.03% lambda-cyhalothrin), Temprid SC (0.05% imidacloprid, 0.025% cyfluthrin), Transport GHP (0.05% acetamiprid, 0.06% bifenthrin), and Demand CS (0.03% lambda-cyhalothrin). The four aerosols were: Alpine (0.5% dinotefuran), Bedlam (0.4% sumithrin, 1.6% MGK 264), Bedlam Plus (0.4% sumithrin, 1% MGK 264, 0.05% imidacloprid), and Phantom (0.5% chlorfenapyr). Bed bugs were confined for 4 h to treated substrates (aged 24 h). Four substrates were tested: fabric, unpainted wood, painted wood, and vinyl. Bedlam, Demand CS, and Temprid SC resulted in ≤70% mortality on all tested substrates. Among the other five products, substrate type significantly affected their residual efficacy, except for Transport GHP, which caused ≥89.7% mortality regardless of the substrate. The effect of exposure time (5 min, 4 h, and 24 h) on the efficacy of Transport GHP and Phantom aerosol also was evaluated. A 4 h continuous exposure to Phantom aerosol or Transport GHP residue caused similar mortality to 24 h exposure and higher mortality than 5 min exposure.

  13. Analysis of Organic Anionic Surfactants in Fine and Coarse Fractions of Freshly Emitted Sea Spray Aerosol

    SciTech Connect

    Cochran, Richard E.; Laskina, Olga; Jayarathne, Thilina; Laskin, Alexander; Laskin, Julia; Lin, Peng; Sultana, Camile M.; Lee, Christopher; Moore, Kathryn A.; Cappa, Christopher; Bertram, Timothy; Prather, Kimberly; Grassian, Vicki H.; Stone, Elizabeth

    2016-02-01

    The inclusion of organic compounds in freshly emitted sea spray aerosol (SSA) has been shown to be size-dependent, with an increasing organic fraction in smaller particles. Defining the molecular composition of sea spray aerosol has proven challenging, due to the mix of continental and background particles even in remote marine environments. Here we have used electrospray ionization-high resolution mass spectrometry in negative ion mode to identify organic compounds in nascent sea spray collected throughout a 25-day mesocosm experiment. Over 280 organic compounds from ten major homologous series were identified. These compounds were operationally defined as molecules containing a hydrophobic alkyl chain with a hydrophilic head group making them surface active. The most abundant class of molecules detected were saturated (C8–C24) and unsaturated (C12–C22) fatty acids. Fatty acid derivatives (including saturated oxo-fatty acids (C5–C18) and saturated hydroxy-fatty acids (C5–C18) were also identified. Interestingly, anthropogenic influences on SSA from the seawater were observed in the form of sulfate (C2–C7, C12–C17) and sulfonate (C16–C22) species. During the mesocosm, the distributions of molecules within each homologous series were observed to respond to variations among the levels of phytoplankton and bacteria in the seawater, indicating an important role of biological processes in determining the composition of SSA.

  14. Effects of Relative Humidity and Spraying Medium on UV Decontamination of Filters Loaded with Viral Aerosols

    PubMed Central

    Woo, Myung-Heui; Grippin, Adam; Anwar, Diandra; Smith, Tamara; Wander, Joseph D.

    2012-01-01

    Although respirators and filters are designed to prevent the spread of pathogenic aerosols, a stockpile shortage is anticipated during the next flu pandemic. Contact transfer and reaerosolization of collected microbes from used respirators are also a concern. An option to address these potential problems is UV irradiation, which inactivates microbes by dimerizing thymine/uracil in nucleic acids. The objective of this study was to determine the effects of transmission mode and environmental conditions on decontamination efficiency by UV. In this study, filters were contaminated by different transmission pathways (droplet and aerosol) using three spraying media (deionized water [DI], beef extract [BE], and artificial saliva [AS]) under different humidity levels (30% [low relative humidity {LRH}], 60% [MRH], and 90% [HRH]). UV irradiation at constant intensity was applied for two time intervals at each relative humidity condition. The highest inactivation efficiency (IE), around 5.8 logs, was seen for DI aerosols containing MS2 on filters at LRH after applying a UV intensity of 1.0 mW/cm2 for 30 min. The IE of droplets containing MS2 was lower than that of aerosols containing MS2. Absorption of UV by high water content and shielding of viruses near the center of the aggregate are considered responsible for this trend. Across the different media, IEs in AS and in BE were much lower than in DI for both aerosol and droplet transmission, indicating that solids present in AS and BE exhibited a protective effect. For particles sprayed in a protective medium, RH is not a significant parameter. PMID:22685135

  15. Eddy covariance measurements of the sea spray aerosol flux over the open ocean

    NASA Astrophysics Data System (ADS)

    Norris, Sarah J.; Brooks, Ian M.; Hill, Martin K.; Brooks, Barbara J.; Smith, Michael H.; Sproson, David A. J.

    2012-04-01

    Direct eddy covariance measurements of size-segregated sea spray aerosol fluxes over the open Atlantic Ocean are presented, along with a source function derived from them for a wind speed range of 4 to 18 m s-1 and a size range of 0.176 < R80 < 6.61 μm. This is in broad agreement with other recent estimates of the source function over this size range but shows a more rapid decrease with size above R80 = 2 μm than most other functions. The measurements were made during a 3 week cruise in the North Atlantic as part of the UK contribution to the international Surface Ocean-Lower Atmosphere Study (SOLAS) program. They utilized the new high-rate Compact Lightweight Aerosol Spectrometer Probe (CLASP), providing a 16-channel size spectrum (0.17 spray aerosol flux compared with other air-sea fluxes, both between individual estimates and in the scales contributing to the flux.

  16. Lake spray aerosol generation: a method for producing representative particles from freshwater wave breaking

    NASA Astrophysics Data System (ADS)

    May, Nathaniel W.; Axson, Jessica L.; Watson, Alexa; Pratt, Kerri A.; Ault, Andrew P.

    2016-09-01

    Wave-breaking action in bodies of freshwater produces atmospheric aerosols via a similar mechanism to sea spray aerosol (SSA) from seawater. The term lake spray aerosol (LSA) is proposed to describe particles formed by this mechanism, which have been observed over the Laurentian Great Lakes. Though LSA has been identified from size distribution measurements during a single measurement campaign, no measurements of LSA composition or relationship to bubble-bursting dynamics have been conducted. An LSA generator utilizing a plunging jet, similar to many SSA generators, was constructed for the generation of aerosol from freshwater samples and model salt solutions. To evaluate this new generator, bubble and aerosol number size distributions were measured for salt solutions representative of freshwater (CaCO3) and seawater (NaCl) at concentrations ranging from that of freshwater to seawater (0.05-35 g kg-1), synthetic seawater (inorganic), synthetic freshwater (inorganic), and a freshwater sample from Lake Michigan. Following validation of the bubble and aerosol size distributions using synthetic seawater, a range of salt concentrations were investigated. The systematic studies of the model salts, synthetic freshwater, and Lake Michigan sample indicate that LSA is characterized by a larger number size distribution mode diameter of 300 nm (lognormal), compared to seawater at 110 nm. Decreasing salt concentrations from seawater to freshwater led to greater bubble coalescence and formation of larger bubbles, which generated larger particles and lower aerosol number concentrations. This resulted in a bimodal number size distribution with a primary mode (180 ± 20 nm) larger than that of SSA, as well as a secondary mode (46 ± 6 nm) smaller than that of SSA. This new method for studying LSA under isolated conditions is needed as models, at present, utilize SSA parameterizations for freshwater systems, which do not accurately predict the different size distributions observed

  17. Aerosolization properties, surface composition and physical state of spray-dried protein powders.

    PubMed

    Bosquillon, Cynthia; Rouxhet, Paul G; Ahimou, François; Simon, Denis; Culot, Christine; Préat, Véronique; Vanbever, Rita

    2004-10-19

    Powder aerosols made of albumin, dipalmitoylphosphatidylcholine (DPPC) and a protein stabilizer (lactose, trehalose or mannitol) were prepared by spray-drying and analyzed for aerodynamic behavior, surface composition and physical state. The powders exited a Spinhaler inhaler as particle aggregates, the size of which depending on composition, spray-drying parameters and airflow rate. However, due to low bulk powder tap density (<0.15 g/cm3), the aerodynamic size of a large fraction of aggregates remained respirable (<5 microm). Fine particle fractions ranged between 21% and 41% in an Andersen cascade impactor operated at 28.3 l/min, with mannitol and lactose providing the most cohesive and free-flowing powders, respectively. Particle surface analysis by X-ray photoelectron spectroscopy (XPS) revealed a surface enrichment with DPPC relative to albumin for powders prepared under certain spray-drying conditions. DPPC self-organized in a gel phase in the particle and no sugar or mannitol crystals were detected by X-ray diffraction. Water sorption isotherms showed that albumin protected lactose from moisture-induced crystallization. In conclusion, a proper combination of composition and spray-drying parameters allowed to obtain dry powders with elevated fine particle fractions (FPFs) and a physical environment favorable to protein stability.

  18. Preliminary results for salt aerosol production intended for marine cloud brightening, using effervescent spray atomization

    PubMed Central

    Cooper, Gary; Foster, Jack; Galbraith, Lee; Jain, Sudhanshu; Neukermans, Armand; Ormond, Bob

    2014-01-01

    The large-scale production of vast numbers of suitable salt nuclei and their upward launch is one of the main technological barriers to the experimental testing of marine cloud brightening (MCB). Very promising, though not definitive, results have been obtained using an adapted version of effervescent spray atomization. The process is simple, robust and inexpensive. This form of effervescent spraying uses only pressurized water and air sprayed from small nozzles to obtain very fine distributions. While it is far from optimized, and may not be the best method if full deployment is ever desired, we believe that even in its present form the process would lend itself well to preliminary field test investigations of MCB. Measurements obtained using standard aerosol instrumentation show approximately lognormal distributions of salt nuclei with median diameters of approximately 65 nm and geometric standard deviations slightly less than 2. However, these measurements are not in agreement with those based on scanning electron microscopy imaging of collected particles, an observation that has not yet been explained. Assuming the above distribution, 1015 particles per second could be made with 21 kW of spray power, using approximately 200 nozzles. It is envisioned that existing snow making equipment can be adapted to launch the nuclei 60–100 m into the air, requiring approximately 20 kW of additional power. PMID:25404673

  19. Preliminary results for salt aerosol production intended for marine cloud brightening, using effervescent spray atomization.

    PubMed

    Cooper, Gary; Foster, Jack; Galbraith, Lee; Jain, Sudhanshu; Neukermans, Armand; Ormond, Bob

    2014-12-28

    The large-scale production of vast numbers of suitable salt nuclei and their upward launch is one of the main technological barriers to the experimental testing of marine cloud brightening (MCB). Very promising, though not definitive, results have been obtained using an adapted version of effervescent spray atomization. The process is simple, robust and inexpensive. This form of effervescent spraying uses only pressurized water and air sprayed from small nozzles to obtain very fine distributions. While it is far from optimized, and may not be the best method if full deployment is ever desired, we believe that even in its present form the process would lend itself well to preliminary field test investigations of MCB. Measurements obtained using standard aerosol instrumentation show approximately lognormal distributions of salt nuclei with median diameters of approximately 65 nm and geometric standard deviations slightly less than 2. However, these measurements are not in agreement with those based on scanning electron microscopy imaging of collected particles, an observation that has not yet been explained. Assuming the above distribution, 10(15) particles per second could be made with 21 kW of spray power, using approximately 200 nozzles. It is envisioned that existing snow making equipment can be adapted to launch the nuclei 60-100 m into the air, requiring approximately 20 kW of additional power.

  20. Phytoplankton blooms weakly influence the cloud forming ability of sea spray aerosol

    NASA Astrophysics Data System (ADS)

    Collins, Douglas B.; Bertram, Timothy H.; Sultana, Camille M.; Lee, Christopher; Axson, Jessica L.; Prather, Kimberly A.

    2016-09-01

    After many field studies, the establishment of connections between marine microbiological processes, sea spray aerosol (SSA) composition, and cloud condensation nuclei (CCN) has remained an elusive challenge. In this study, we induced algae blooms to probe how complex changes in seawater composition impact the ability of nascent SSA to act as CCN, quantified by using the apparent hygroscopicity parameter (κapp). Throughout all blooms, κapp ranged between 0.7 and 1.4 (average 0.95 ± 0.15), consistent with laboratory investigations using algae-produced organic matter, but differing from climate model parameterizations and in situ SSA generation studies. The size distribution of nascent SSA dictates that changes in κapp associated with biological processing induce less than 3% change in expected CCN concentrations for typical marine cloud supersaturations. The insignificant effect of hygroscopicity on CCN concentrations suggests that the SSA production flux and/or secondary aerosol chemistry may be more important factors linking ocean biogeochemistry and marine clouds.

  1. A Campaign Study of Sea Spray Aerosol Properties in the Bay of Aarhus

    NASA Astrophysics Data System (ADS)

    Nguyen, Quynh; Rasmussen, Berit; Kristensen, Kasper; Sloth Nielsen, Lærke; Bilde, Merete

    2016-04-01

    The oceans of the world are a dominant source of atmospheric aerosol. Together with mineral dust, sea spray aerosols (SSA) constitute the largest mass flux of particulate matter in the atmosphere (Andreae and Rosenfeld, 2008). Due to their effects on the global radiative budget - both directly as scatterers and absorbers of solar and terrestrial radiation, and indirectly as cloud condensation nuclei (CCN), SSA are considered an important component of the climate system. The sea-surface microlayer (SML) is an ultra-thin boundary layer between the ocean and the atmosphere. The high concentration of surface-active organic compounds in the SML, compared to that of the underlying water column, creates rigid film-like layer over the surface of the ocean. The SML is believed to play an important role in the formation and composition of SSA. However, current knowledge on the SML and its impacts on SSA remain limited. To characterize the SML of natural seawater and examine its impacts on aerosol properties, a field campaign was conducted in the bay of Aarhus, Denmark, during spring 2015. Bulk seawater was collected 1-2 times every week along with selective sampling of the SML. Characterization of the sea water and SML included a wide range of measurements, including surface tension, water activity, dissolved organic matter, and chemical composition analysis by liquid chromatography/electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-Q-TOFMS). SSA was generated from sampled sea water by diffusion of air bubbles through a 10L seawater sample situated in a sea spray tank. Particle number concentration and CCN measurements were conducted along with measurements of the organic share in the aerosol phase as indicated by volatility measurements. To investigate the effect of the SML, spiking of the seawater samples with additional SML was performed and measurements repeated for comparison. Preliminary results show that the SML samples

  2. Size-resolved characterization of the polysaccharidic and proteinaceous components of sea spray aerosol

    NASA Astrophysics Data System (ADS)

    Aller, Josephine Y.; Radway, JoAnn C.; Kilthau, Wendy P.; Bothe, Dylan W.; Wilson, Theodore W.; Vaillancourt, Robert D.; Quinn, Patricia K.; Coffman, Derek J.; Murray, Benjamin J.; Knopf, Daniel A.

    2017-04-01

    Dissolved organic polymers released by phytoplankton and bacteria abiologically self-assemble in surface ocean waters into nano-to micro-sized gels containing polysaccharides, proteins, lipids and other components. These gels concentrate in the sea surface microlayer (SML), where they can potentially contribute to sea spray aerosol (SSA). Sea spray is a major source of atmospheric aerosol mass over much of the earth's surface, and knowledge of its properties (including the amount and nature of the organic content), size distributions and fluxes are fundamental for determining its role in atmospheric chemistry and climate. Using a cascade impactor, we collected size-fractionated aerosol particles from ambient air and from freshly generated Sea Sweep SSA in the western North Atlantic Ocean together with biological and chemical characterization of subsurface and SML waters. Spectrophotometric methods were applied to quantify the polysaccharide-containing transparent exopolymer (TEP) and protein-containing Coomassie stainable material (CSM) in these particles and waters. This study demonstrates that both TEP and CSM in surface ocean waters are aerosolized with sea spray with the greatest total TEP associated with particles <180 nm in diameter and >5 000 nm. The higher concentrations of TEP and CSM in particles >5 000 nm most likely reflects collection of microorganism cells and/or fragments. The greater concentration of CSM in larger size particles may also reflect greater stability of proteinaceous gels compared to polysaccharide-rich gels in surface waters and the SML. Both TEP and CSM were measured in the ambient marine air sample with concentrations of 2.1 ± 0.16 μg xanthan gum equivalents (XG eq.) m-3 and 14 ± 1.0 μg bovine serum albumin equivalents (BSA eq.) m-3. TEP in Sea Sweep SSA averaged 4.7 ± 3.1 μg XG eq. m-3 and CSM 8.6 ± 7.3 μg BSA eq. m-3. This work shows the transport of marine biogenic material across the air-sea interface through primary

  3. Sea Spray Aerosol Structure and Composition Using Cryogenic Transmission Electron Microscopy

    PubMed Central

    2016-01-01

    The composition and surface properties of atmospheric aerosol particles largely control their impact on climate by affecting their ability to uptake water, react heterogeneously, and nucleate ice in clouds. However, in the vacuum of a conventional electron microscope, the native surface and internal structure often undergo physicochemical rearrangement resulting in surfaces that are quite different from their atmospheric configurations. Herein, we report the development of cryogenic transmission electron microscopy where laboratory generated sea spray aerosol particles are flash frozen in their native state with iterative and controlled thermal and/or pressure exposures and then probed by electron microscopy. This unique approach allows for the detection of not only mixed salts, but also soft materials including whole hydrated bacteria, diatoms, virus particles, marine vesicles, as well as gel networks within hydrated salt droplets—all of which will have distinct biological, chemical, and physical processes. We anticipate this method will open up a new avenue of analysis for aerosol particles, not only for ocean-derived aerosols, but for those produced from other sources where there is interest in the transfer of organic or biological species from the biosphere to the atmosphere. PMID:26878061

  4. Direct aerosol chemical composition measurements to evaluate the physicochemical differences between controlled sea spray aerosol generation schemes

    NASA Astrophysics Data System (ADS)

    Collins, D. B.; Zhao, D. F.; Ruppel, M. J.; Laskina, O.; Grandquist, J. R.; Modini, R. L.; Stokes, M. D.; Russell, L. M.; Bertram, T. H.; Grassian, V. H.; Deane, G. B.; Prather, K. A.

    2014-11-01

    Controlled laboratory studies of the physical and chemical properties of sea spray aerosol (SSA) must be under-pinned by a physically and chemically accurate representation of the bubble-mediated production of nascent SSA particles. Bubble bursting is sensitive to the physico-chemical properties of seawater. For a sample of seawater, any important differences in the SSA production mechanism are projected into the composition of the aerosol particles produced. Using direct chemical measurements of SSA at the single-particle level, this study presents an intercomparison of three laboratory-based, bubble-mediated SSA production schemes: gas forced through submerged sintered glass filters ("frits"), a pulsed plunging-waterfall apparatus, and breaking waves in a wave channel filled with natural seawater. The size-resolved chemical composition of SSA particles produced by breaking waves is more similar to particles produced by the plunging waterfall than those produced by sintered glass filters. Aerosol generated by disintegrating foam produced by sintered glass filters contained a larger fraction of organic-enriched particles and a different size-resolved elemental composition, especially in the 0.8-2 μm dry diameter range. Interestingly, chemical differences between the methods only emerged when the particles were chemically analyzed at the single-particle level as a function of size; averaging the elemental composition of all particles across all sizes masked the differences between the SSA samples. When dried, SSA generated by the sintered glass filters had the highest fraction of particles with spherical morphology compared to the more cubic structure expected for pure NaCl particles produced when the particle contains relatively little organic carbon. In addition to an intercomparison of three SSA production methods, the role of the episodic or "pulsed" nature of the waterfall method on SSA composition was under-taken. In organic-enriched seawater, the continuous

  5. Inhalable spray-dried formulation of D-LAK antimicrobial peptides targeting tuberculosis.

    PubMed

    Kwok, Philip Chi Lip; Grabarek, Adam; Chow, Michael Y T; Lan, Yun; Li, Johnny C W; Casettari, Luca; Mason, A James; Lam, Jenny K W

    2015-08-01

    Tuberculosis (TB) is a global disease that is becoming more difficult to treat due to the emergence of multidrug resistant (MDR) Mycobacterium tuberculosis. Inhalable antimicrobial peptides (AMPs) are potentially useful alternative anti-TB agents because they can overcome resistance against classical antibiotics, reduce systemic adverse effects, and achieve local targeting. The aims of the current study were to produce inhalable dry powders containing d-enantiomeric AMPs (D-LAK120-HP13 and D-LAK120-A) and evaluate their solid state properties, aerosol performance, and structural conformation. These two peptides were spray dried with mannitol as a bulking agent at three mass ratios (peptide:mannitol 1:99, 1:49, and 1:24) from aqueous solutions. The resultant particles were spherical, with those containing D-LAK120-HP13 being more corrugated than those with D-LAK120-A. The median volumetric diameter of the particles was approximately 3μm. The residual water content of all powders were <3% w/w and crystalline, due to the low hygroscopicity and crystallinity of mannitol, respectively. The mannitol changed from a mixture of alpha- and beta-forms to delta form with an increasing proportion of AMP in the formulation. The emitted fraction and fine particle fraction of the powders when dispersed from an Osmohaler(®) at 90L/min were about 80% and 50-60% of the loaded dose, respectively, indicating good aerosol performance. Circular dichroism data showed that D-LAK120-HP13 dissolved in Tris buffer at pH 7.15 was of a disordered conformation. In contrast, D-LAK120-A showed greater α-helical conformation. Since the conformations of the AMPs were comparable to the controls (unprocessed peptides), the spray drying process did not substantially affect their secondary structures. In conclusion, spray dried powders containing d-enantiomeric AMPs with preserved secondary molecular structures and good aerosol performance could be successfully produced. They may potentially be used

  6. Animal viruses, coliphages, and bacteria in aerosols and wastewater at a spray irrigation site.

    PubMed Central

    Brenner, K P; Scarpino, P V; Clark, C S

    1988-01-01

    Aerosol samples collected at the Muskegon County Wastewater Management System Number 1 spray irrigation site in Michigan by using the Army prototype XM2 Biological Sampler/Collector were examined for the presence of animal viruses, coliphages, and bacteria. Air samples, collected in Earle lactalbumen hydrolysate, and wastewater samples were filtered through a 0.45- and 1.2-micron membrane filter sandwich, pretreated with 10% beef extract (pH 7.0), and assayed for animal viruses by the plaque method on Buffalo green monkey kidney cells. Untreated air and wastewater samples were assayed for coliphages by the soft agar overlay method with three Escherichia coli hosts (ATCC 13706, 15597, and 11303) and for bacteria by the heterotrophic plate count method. Filtered air samples were assayed for coliphages by the most-probable-number method with the same three hosts. Although no animal viruses were detected in the aerosol samples, coliphages and bacteria were recovered. E. coli ATCC 13706 coliphage were recovered more often and in greater numbers than either of the other two types of coliphages. Concentrations of animal viruses, coliphages, and bacteria detected in the raw influent decreased as the wastewater was aerated and stored in the lagoons. No animal viruses were detected in the wastewater at the pump station just before distribution to the spray irrigation rigs. The most-probable-number method was more sensitive and consistent than the overlay procedure in detecting low levels of coliphages in air samples. PMID:3128164

  7. Animal viruses, coliphages, and bacteria in aerosols and wastewater at a spray irrigation site.

    PubMed

    Brenner, K P; Scarpino, P V; Clark, C S

    1988-02-01

    Aerosol samples collected at the Muskegon County Wastewater Management System Number 1 spray irrigation site in Michigan by using the Army prototype XM2 Biological Sampler/Collector were examined for the presence of animal viruses, coliphages, and bacteria. Air samples, collected in Earle lactalbumen hydrolysate, and wastewater samples were filtered through a 0.45- and 1.2-micron membrane filter sandwich, pretreated with 10% beef extract (pH 7.0), and assayed for animal viruses by the plaque method on Buffalo green monkey kidney cells. Untreated air and wastewater samples were assayed for coliphages by the soft agar overlay method with three Escherichia coli hosts (ATCC 13706, 15597, and 11303) and for bacteria by the heterotrophic plate count method. Filtered air samples were assayed for coliphages by the most-probable-number method with the same three hosts. Although no animal viruses were detected in the aerosol samples, coliphages and bacteria were recovered. E. coli ATCC 13706 coliphage were recovered more often and in greater numbers than either of the other two types of coliphages. Concentrations of animal viruses, coliphages, and bacteria detected in the raw influent decreased as the wastewater was aerated and stored in the lagoons. No animal viruses were detected in the wastewater at the pump station just before distribution to the spray irrigation rigs. The most-probable-number method was more sensitive and consistent than the overlay procedure in detecting low levels of coliphages in air samples.

  8. Physicochemical Characterization of Coarse Lake Spray Aerosol Particle from Lake Michigan

    NASA Astrophysics Data System (ADS)

    Ault, A. P.; Axson, J. L.; May, N.; Pratt, K.; Colon-Bernal, I. D.

    2015-12-01

    Wave breaking across bodies of water releases coarse particles into the air which can impact climate and human health. Freshwater lakes, such as the Great Lakes, can generate lake spray aerosols (LSA), similarly to how sea spray is generated, during periods of high winds and wave action. This LSA has the potential to impact climate through direct and indirect effects (ie. scattering/absorption and cloud nucleation) and are suggested to impact human health via inhalation of these particles during algal bloom periods characterized by toxic cyanobacteria. Very few studies have been conducted to assess the physicochemical properties of freshwater LSA. Prior work in our lab included the construction and characterization of a laboratory based LSA generator. In this work, we examine laboratory generated aerosol particles from laboratory based freshwater standards, freshwater samples collected from Lake Michigan, and ambient particles collected during a wave event on the shores of Lake Michigan in the summer of 2015. Particle size distributions, number concentrations, and chemical composition are presented and discussed as a function of laboratory generated and ambient collected LSA. Results indicate that there are characteristic particles that represent LSA. This study represents the next step towards evaluating and understanding the potential for coarse LSA to impact climate and health in the Great Lakes region.

  9. Experimental study of elementary collection efficiency of aerosols by spray: Design of the experimental device

    SciTech Connect

    Ducret, D.; Vendel, J.; Garrec. S.L.

    1995-02-01

    The safety of a nuclear power plant containment building, in which pressure and temperature could increase because of a overheating reactor accident, can be achieved by spraying water drops. The spray reduces the pressure and the temperature levels by condensation of steam on cold water drops. The more stringent thermodynamic conditions are a pressure of 5.10{sup 5} Pa (due to steam emission) and a temperature of 413 K. Moreover its energy dissipation function, the spray leads to the washout of fission product particles emitted in the reactor building atmosphere. The present study includes a large program devoted to the evaluation of realistic washout rates. The aim of this work is to develop experiments in order to determine the collection efficiency of aerosols by a single drop. To do this, the experimental device has to be designed with fundamental criteria:-Thermodynamic conditions have to be representative of post-accident atmosphere. Thermodynamic equilibrium has to be attained between the water drops and the gaseous phase. Thermophoretic, diffusiophoretic and mechanical effects have to be studied independently. Operating conditions have to be homogenous and constant during each experiment. This paper presents the design of the experimental device. In practice, the consequences on the design of each of the criteria given previously and the necessity of being representative of the real conditions will be described.

  10. Transition metal associations with primary biological particles in sea spray aerosol generated in a wave channel.

    PubMed

    Guasco, Timothy L; Cuadra-Rodriguez, Luis A; Pedler, Byron E; Ault, Andrew P; Collins, Douglas B; Zhao, Defeng; Kim, Michelle J; Ruppel, Matthew J; Wilson, Scott C; Pomeroy, Robert S; Grassian, Vicki H; Azam, Farooq; Bertram, Timothy H; Prather, Kimberly A

    2014-01-21

    In the ocean, breaking waves generate air bubbles which burst at the surface and eject sea spray aerosol (SSA), consisting of sea salt, biogenic organic species, and primary biological aerosol particles (PBAP). Our overall understanding of atmospheric biological particles of marine origin remains poor. Here, we perform a control experiment, using an aerosol time-of-flight mass spectrometer to measure the mass spectral signatures of individual particles generated by bubbling a salt solution before and after addition of heterotrophic marine bacteria. Upon addition of bacteria, an immediate increase occurs in the fraction of individual particle mass spectra containing magnesium, organic nitrogen, and phosphate marker ions. These biological signatures are consistent with 21% of the supermicrometer SSA particles generated in a previous study using breaking waves in an ocean-atmosphere wave channel. Interestingly, the wave flume mass spectral signatures also contain metal ions including silver, iron, and chromium. The nascent SSA bioparticles produced in the wave channel are hypothesized to be as follows: (1) whole or fragmented bacterial cells which bioaccumulated metals and/or (2) bacteria-derived colloids or biofilms which adhered to the metals. This study highlights the potential for transition metals, in combination with specific biomarkers, to serve as unique indicators for the presence of marine PBAP, especially in metal-impacted coastal regions.

  11. Bringing the ocean into the laboratory to probe the chemical complexity of sea spray aerosol

    PubMed Central

    Prather, Kimberly A.; Bertram, Timothy H.; Grassian, Vicki H.; Deane, Grant B.; Stokes, M. Dale; DeMott, Paul J.; Aluwihare, Lihini I.; Palenik, Brian P.; Azam, Farooq; Seinfeld, John H.; Moffet, Ryan C.; Molina, Mario J.; Cappa, Christopher D.; Geiger, Franz M.; Roberts, Gregory C.; Russell, Lynn M.; Ault, Andrew P.; Baltrusaitis, Jonas; Collins, Douglas B.; Corrigan, Craig E.; Cuadra-Rodriguez, Luis A.; Ebben, Carlena J.; Forestieri, Sara D.; Guasco, Timothy L.; Hersey, Scott P.; Kim, Michelle J.; Lambert, William F.; Modini, Robin L.; Mui, Wilton; Pedler, Byron E.; Ruppel, Matthew J.; Ryder, Olivia S.; Schoepp, Nathan G.; Sullivan, Ryan C.; Zhao, Defeng

    2013-01-01

    The production, size, and chemical composition of sea spray aerosol (SSA) particles strongly depend on seawater chemistry, which is controlled by physical, chemical, and biological processes. Despite decades of studies in marine environments, a direct relationship has yet to be established between ocean biology and the physicochemical properties of SSA. The ability to establish such relationships is hindered by the fact that SSA measurements are typically dominated by overwhelming background aerosol concentrations even in remote marine environments. Herein, we describe a newly developed approach for reproducing the chemical complexity of SSA in a laboratory setting, comprising a unique ocean-atmosphere facility equipped with actual breaking waves. A mesocosm experiment was performed in natural seawater, using controlled phytoplankton and heterotrophic bacteria concentrations, which showed SSA size and chemical mixing state are acutely sensitive to the aerosol production mechanism, as well as to the type of biological species present. The largest reduction in the hygroscopicity of SSA occurred as heterotrophic bacteria concentrations increased, whereas phytoplankton and chlorophyll-a concentrations decreased, directly corresponding to a change in mixing state in the smallest (60–180 nm) size range. Using this newly developed approach to generate realistic SSA, systematic studies can now be performed to advance our fundamental understanding of the impact of ocean biology on SSA chemical mixing state, heterogeneous reactivity, and the resulting climate-relevant properties. PMID:23620519

  12. Updating sea spray aerosol emissions in the Community Multiscale Air Quality (CMAQ) model version 5.0.2

    EPA Science Inventory

    Sea spray aerosols (SSAs) impact the particle mass concentration and gas-particle partitioning in coastal environments, with implications for human and ecosystem health. Model evaluations of SSA emissions have mainly focused on the global scale, but regional-scale evaluations are...

  13. Dark Targets, Aerosols, Clouds and Toys

    NASA Astrophysics Data System (ADS)

    Remer, L. A.

    2015-12-01

    Today if you use the Thomson-Reuters Science Citations Index to search for "aerosol*", across all scientific disciplines and years, with no constraints, and you sort by number of citations, you will find a 2005 paper published in the Journal of the Atmospheric Sciences in the top 20. This is the "The MODIS Aerosol Algorithm, Products and Validation". Although I am the first author, there are in total 12 co-authors who each made a significant intellectual contribution to the paper or to the algorithm, products and validation described. This paper, that algorithm, those people lie at the heart of a lineage of scientists whose collaborations and linked individual pursuits have made a significant contribution to our understanding of radiative transfer and climate, of aerosol properties and the global aerosol system, of cloud physics and aerosol-cloud interaction, and how to measure these parameters and maximize the science that can be obtained from those measurements. The 'lineage' had its origins across the globe, from Soviet Russia to France, from the U.S. to Israel, from the Himalayas, the Sahel, the metropolises of Sao Paulo, Taipei, and the cities of east and south Asia. It came together in the 1990s and 2000s at the NASA Goddard Space Flight Center, using cultural diversity as a strength to form a common culture of scientific creativity that continues to this day. The original algorithm has spawned daughter algorithms that are being applied to new satellite and airborne sensors. The original MODIS products have been fundamental to analyses as diverse as air quality monitoring and aerosol-cloud forcing. AERONET, designed originally for the need of validation, is now its own thriving institution, and the lineage continues to push forward to provide new technology for the coming generations.

  14. Physicochemical characterization and aerosol dispersion performance of organic solution advanced spray-dried cyclosporine A multifunctional particles for dry powder inhalation aerosol delivery.

    PubMed

    Wu, Xiao; Zhang, Weifen; Hayes, Don; Mansour, Heidi M

    2013-01-01

    In this systematic and comprehensive study, inhalation powders of the polypeptide immunosuppressant drug - cyclosporine A - for lung delivery as dry powder inhalers (DPIs) were successfully designed, developed, and optimized. Several spray drying pump rates were rationally chosen. Comprehensive physicochemical characterization and imaging was carried out using scanning electron microscopy, hot-stage microscopy, differential scanning calorimetry, powder X-ray diffraction, Karl Fischer titration, laser size diffraction, and gravimetric vapor sorption. Aerosol dispersion performance was conducted using a next generation impactor with a Food and Drug Administration-approved DPI device. These DPIs displayed excellent aerosol dispersion performance with high values in emitted dose, respirable fraction, and fine particle fraction. In addition, novel multifunctional inhalation aerosol powder formulations of cyclosporine A with lung surfactant-mimic phospholipids were also successfully designed and developed by advanced organic solution cospray drying in closed mode. The lung surfactantmimic phospholipids were 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and 1,2-dipalmitoyl-snglycero- 3-(phosphor-rac-1-glycerol). These cyclosporine A lung surfactant-mimic aerosol powder formulations were comprehensively characterized. Powder X-ray diffraction and differential scanning calorimetry confirmed that the phospholipid bilayer structure in the solid state was preserved following advanced organic solution spray drying in closed mode. These novel multifunctional inhalation powders were optimized for DPI delivery with excellent aerosol dispersion performance and high aerosol performance parameters.

  15. Physicochemical characterization and aerosol dispersion performance of organic solution advanced spray-dried cyclosporine A multifunctional particles for dry powder inhalation aerosol delivery

    PubMed Central

    Wu, Xiao; Zhang, Weifen; Hayes, Don; Mansour, Heidi M

    2013-01-01

    In this systematic and comprehensive study, inhalation powders of the polypeptide immunosuppressant drug – cyclosporine A – for lung delivery as dry powder inhalers (DPIs) were successfully designed, developed, and optimized. Several spray drying pump rates were rationally chosen. Comprehensive physicochemical characterization and imaging was carried out using scanning electron microscopy, hot-stage microscopy, differential scanning calorimetry, powder X-ray diffraction, Karl Fischer titration, laser size diffraction, and gravimetric vapor sorption. Aerosol dispersion performance was conducted using a next generation impactor with a Food and Drug Administration-approved DPI device. These DPIs displayed excellent aerosol dispersion performance with high values in emitted dose, respirable fraction, and fine particle fraction. In addition, novel multifunctional inhalation aerosol powder formulations of cyclosporine A with lung surfactant-mimic phospholipids were also successfully designed and developed by advanced organic solution cospray drying in closed mode. The lung surfactantmimic phospholipids were 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and 1,2-dipalmitoyl-snglycero- 3-(phosphor-rac-1-glycerol). These cyclosporine A lung surfactant-mimic aerosol powder formulations were comprehensively characterized. Powder X-ray diffraction and differential scanning calorimetry confirmed that the phospholipid bilayer structure in the solid state was preserved following advanced organic solution spray drying in closed mode. These novel multifunctional inhalation powders were optimized for DPI delivery with excellent aerosol dispersion performance and high aerosol performance parameters. PMID:23569375

  16. Direct aerosol chemical composition measurements to evaluate the physicochemical differences between controlled sea spray aerosol generation schemes

    NASA Astrophysics Data System (ADS)

    Collins, D. B.; Zhao, D. F.; Ruppel, M. J.; Laskina, O.; Grandquist, J. R.; Modini, R. L.; Stokes, M. D.; Russell, L. M.; Bertram, T. H.; Grassian, V. H.; Deane, G. B.; Prather, K. A.

    2014-07-01

    Controlled laboratory studies of the physical and chemical properties of sea spray aerosol (SSA) must be underpinned by a physically and chemically accurate representation of the bubble mediated production of nascent SSA particles. Since bubble bursting is sensitive to the physicochemical properties of seawater, any important differences in the SSA production mechanism are projected into SSA composition. Using direct chemical measurements of SSA at the single-particle level, this study presents an inter-comparison of three laboratory-based, bubble-mediated SSA production schemes: gas forced through submerged sintered glass filters ("frits"), a pulsed plunging waterfall apparatus, and breaking waves in a wave channel filled with natural seawater. The size-resolved chemical composition of SSA particles produced by breaking waves is more similar to particles produced by the plunging waterfall than sintered glass filters. Aerosol generated by disintegrating foam produced by sintered glass filters contained a larger fraction of organic enriched particles and a different size-resolved elemental composition, especially in the 0.8-2 μm size range. These particles, when dried, had more spherical morphologies compared to the more cubic structure expected for pure NaCl particles, which can be attributed to the presence of additional organic carbon. In addition to an inter-comparison of three SSA production methods, the role of the episodic or "pulsed" nature of the waterfall method utilized in this study on SSA composition was undertaken. In organic-enriched seawater, the continuous operation of the plunging waterfall mechanism resulted in the accumulation of surface foam and an over-expression of organic matter in SSA particles compared to pulsed plunging waterfall. Throughout this set of experiments, comparative differences in the SSA number size distribution were coincident with differences in aerosol composition, indicating that the production mechanism of SSA exerts

  17. High-solids paint overspray aerosols in a spray painting booth: particle size analysis and scrubber efficiency

    SciTech Connect

    Chan, T.L.; D'arcy, J.B.; Schreck, R.M.

    1986-07-01

    Particle size distributions of high-solids acrylic-enamel paint overspray aerosols were determined isokinetically in a typical downdraft spray painting booth in which a 7-stage cascade impactor was used. Three different industrial paint atomizers were used, and the paint aerosols were characterized before and after a paint both scrubber. The mass median aerodynamic diameter (MMAD) of a metallic basecoat and an acrylic clearcoat paint aerosol from air-atomized spray guns ranged from 4-12 ..mu..m and was dependent on atomization pressure. When the paint booth was operated under controlled conditions simulating those in a plant, the collection efficiency of paint overspray aerosols by a paint scrubber was found to be size dependent and decreased sharply for particles smaller than 2 ..mu..m to as low as 64% for clearcoat paint particles of 0.6 ..mu..m. Improvement in the overall particulate removal efficiency can be achieved by optimizing the spray painting operations so as to produce the least amount of fine overspray paint aerosols less than 2 ..mu..m. Maintaining a higher static pressure drop across the paint both scrubber also will improve scrubber performance.

  18. Comparison of the aerosol velocity and spray duration of Respimat Soft Mist inhaler and pressurized metered dose inhalers.

    PubMed

    Hochrainer, Dieter; Hölz, Hubert; Kreher, Christoph; Scaffidi, Luigi; Spallek, Michael; Wachtel, Herbert

    2005-01-01

    Apart from particle size distribution, spray velocity is one of the most important aerosol characteristics that influence lung deposition of inhaled drugs. The time period over which the aerosol is released (spray duration) is also important for coordination of inhalation. Respimat Soft Mist Inhaler (SMI) is a new generation, propellant-free inhaler that delivers drug to the lung much more efficiently than pressurised metered dose inhalers (pMDIs). The objective of this study was to compare the velocity and spray duration of aerosol clouds produced by Respimat SMI with those from a variety of chlorofluorocarbon (CFC) and hydrofluoroalkane (HFA) pMDIs. All inhalers contained solutions or suspensions of bronchodilators. A videorecording method was used to determine the aerosol velocity. For spray duration, the time for generation of the Soft Mist by Respimat SMI was initially determined using three different methods (videorecording [techniques A and B], laser light diffraction and rotating disc). Videorecording was then used to compare the spray duration of Respimat SMI with those from the other inhalers. The Soft Mist produced by Respimat SMI moved much more slowly and had a more prolonged duration than aerosol clouds from pMDIs (mean velocity at a 10-cm distance from the nozzle: Respimat SMI, 0.8 m/sec; pMDIs, 2.0-8.4 m/sec; mean duration: Respimat SMI, 1.5 sec; pMDIs, 0.15-0.36 sec). These characteristics should result in improved lung and reduced oropharyngeal deposition, and are likely to simplify coordination of inhaler actuation and inhalation compared with pMDIs.

  19. Emissions and Characteristics of Ice Nucleating Particles Associated with Laboratory Generated Nascent Sea Spray Aerosol

    NASA Astrophysics Data System (ADS)

    McCluskey, C. S.; Hill, T. C. J.; Beall, C.; Sultana, C. M.; Moore, K.; Cornwell, G.; Lee, C.; Al-Mashat, H.; Laskina, O.; Trueblood, J.; Grassian, V. H.; Prather, K. A.; Kreidenweis, S. M.; DeMott, P. J.

    2015-12-01

    Accurate emission rates and activity spectra of atmospheric ice nucleating particles (INPs) are required for proper representation of aerosol-cloud interactions in atmospheric modeling studies. However, few investigations have quantified or characterized oceanic INP emissions. In conjunction with the Center for Aerosol Impacts on the Climate and the Environment, we have directly measured changes in INP emissions and properties of INPs from nascent sea spray aerosol (SSA) through the evolution of phytoplankton blooms. Multiple offline and online instruments were used to monitor aerosol chemistry and size, and bulk water characteristics during two phytoplankton bloom experiments. Two methods were utilized to monitor the number concentrations of INPs from 0 to -34 °C: The online CSU continuous flow diffusion chamber (CFDC) and collections processed offline using the CSU ice spectrometer. Single particle analyses were performed on ice crystal residuals downstream of the CFDC, presumed to be INPs, via scanning transmission electron microscopy (STEM) and Raman microspectroscopy. Preliminary results indicate that laboratory-generated nascent SSA corresponds to number concentrations of INPs that are generally consistent with open ocean regions, based on current knowledge. STEM analyses revealed that the sizes of ice crystal residuals that were associated with nascent SSA ranged from 0.3 to 2.5 μm. Raman microspectroscopy analysis of 1 μm sized residuals found a variety of INP identities, including long chain organics, diatom fragments and polysaccharides. Our data suggest that biological processes play a significant role in ocean INP emissions by generating the species and compounds that were identified during these studies.

  20. Magnetic targeting of aerosol particles for cancer therapy

    NASA Astrophysics Data System (ADS)

    Ally, Javed; Martin, Benjamin; Behrad Khamesee, Mir; Roa, Wilson; Amirfazli, Alidad

    2005-05-01

    An in vitro model was developed to study and demonstrate the potential and feasibility of magnetically targeted deposition of aerosols for potential applications in lung cancer treatment. Also, a numerical particle tracing model was developed to predict the targeting behavior of the in vitro system; the results from the numerical and experimental studies were in agreement.

  1. Spray-freeze-dried liposomal ciprofloxacin powder for inhaled aerosol drug delivery.

    PubMed

    Sweeney, Lyle G; Wang, Zhaolin; Loebenberg, Raimar; Wong, Jonathan P; Lange, Carlos F; Finlay, Warren H

    2005-11-23

    Spray-freeze drying was utilized to manufacture a liposomal powder formulation containing ciprofloxacin as a model active component. The powder forms liposomally encapsulated ciprofloxacin when wetted. Aerosol properties of this formulation were assessed using a new passive inhaler, in which the powder was entrained at a flow rate of 60l/min. A mass median aerodynamic diameter (MMAD) of 2.8 microm was achieved for this formulation. Using the experimental dispersion testing data, ciprofloxacin concentration in the airway surface liquid (ASL) was calculated using a Lagrangian deposition model. The reconstitution of the powder in various aqueous media gave drug encapsulation efficiencies as follows: 50% in water, 93.5% in isotonic saline, 80% in bovine mucin, 75% in porcine mucus and 73% in five-fold-diluted ex vivo human cystic fibrosis patient sputum.

  2. Microparticulate/Nanoparticulate Powders of a Novel Nrf2 Activator and an Aerosol Performance Enhancer for Pulmonary Delivery Targeting the Lung Nrf2/Keap-1 Pathway.

    PubMed

    Muralidharan, Priya; Hayes, Don; Black, Stephen M; Mansour, Heidi M

    2016-01-01

    This systematic and comprehensive study reports for the first time on the successful rational design of advanced inhalable therapeutic dry powders containing dimethyl fumarate, a first-in-class Nrf2 activator drug to treat pulmonary inflammation, using particle engineering design technology for targeted delivery to the lungs as advanced spray dried (SD) one-component DPIs. In addition, two-component co-spray dried (co-SD) DMF:D-Man DPIs with high drug loading were successfully designed for targeted lung delivery as advanced DPIs using organic solution advanced spray drying in closed mode. Regional targeted deposition using design of experiments (DoE) for in vitro predictive lung modeling based on aerodynamic properties was tailored based on composition and spray drying parameters. These findings indicate the significant potential of using D-Man in spray drying to improve particle formation and aerosol performance of small molecule with a relatively low melting point. These respirable microparticles/nanoparticles in the solid-state exhibited excellent aerosol dispersion performance with an FDA-approved human DPI device. Using in vitro predictive lung deposition modeling, the aerosol deposition patterns of these particles show the capability to reach lower airways to treat inflammation in this region in pulmonary diseases such as acute lung injury (ALI), chronic obstructive pulmonary disease (COPD), pulmonary hypertension (PH), and pulmonary endothelial disease.

  3. Constant size, variable density aerosol particles by ultrasonic spray freeze drying.

    PubMed

    D'Addio, Suzanne M; Chan, John Gar Yan; Kwok, Philip Chi Lip; Prud'homme, Robert K; Chan, Hak-Kim

    2012-05-10

    This work provides a new understanding of critical process parameters involved in the production of inhalation aerosol particles by ultrasonic spray freeze drying to enable precise control over particle size and aerodynamic properties. A series of highly porous mannitol, lysozyme, and bovine serum albumin (BSA) particles were produced, varying only the solute concentration in the liquid feed, c(s), from 1 to 5 wt%. The particle sizes of mannitol, BSA, and lysozyme powders were independent of solute concentration, and depend only on the drop size produced by atomization. Both mannitol and lysozyme formulations showed a linear relationship between the computed Fine Particle Fraction (FPF) and the square root of c(s), which is proportional to the particle density, ρ, given a constant particle size d(g). The FPF decreased with increasing c(s) from 57.0% to 16.6% for mannitol and 44.5% to 17.2% for lysozyme. Due to cohesion, the BSA powder FPF measured by cascade impaction was less than 10% and independent of c(s). Ultrasonic spray freeze drying enables separate control over particle size, d(g), and aerodynamic size, d(a) which has allowed us to make the first experimental demonstration of the widely accepted rule d(a)=d(g)(ρ/ρ(o))(1/2) with particles of constant d(g), but variable density, ρ (ρ(o) is unit density).

  4. The effect of water to ethanol feed ratio on physical properties and aerosolization behavior of spray dried cromolyn sodium particles.

    PubMed

    Gilani, Kambiz; Najafabadi, Abdolhossien Rouholamini; Barghi, Mohammadali; Rafiee-Tehrani, Morteza

    2005-05-01

    Cromolyn sodium (CS) was spray dried under constant operation conditions from different water to ethanol feed ratios (50:50-0:100). The spray dried CS samples were characterized for their physicochemical properties including crystallinity, particle size distribution, morphology, density, and water/ethanol content. To determine quantitatively the crystallinity of the powders, an X-ray diffraction (XRD) method was developed using samples with different crystallinity prepared by physical mixing of 100% amorphous and 100% crystalline CS materials. The aerodynamic behavior of the CS samples was determined using an Andersen Cascade Impactor (ACI) with a Spinhaler at an air flow of 60 L/min. Binary mixtures of each spray dried CS powder and Pharmatose 325, a commercial alpha-lactose monohydrate available for DPI formulations, were prepared and in vitro aerosol deposition of the drug from the mixtures was analyzed using ACI to evaluate the effect of carrier on deposition profiles of the spray dried samples. CS spray dried from absolute ethanol exhibited XRD pattern characteristic for crystalline materials and different from patterns of the other samples. The crystallinity of spray dried CS obtained in the presence of water varied from 0% to 28.37%, depending on the ratio of water to ethanol in the feed suspensions. All samples presented different particle size, water/ethanol content, and bulk density values. CS particles spray dried from absolute ethanol presented uniform elongated shape whereas the other samples consisted mainly of particles with irregular shape. Overall, fine particle fraction increased significantly (p < 0.01) with decreasing d50% and water and ethanol content of spray dried CS samples. Significant difference (p < 0.01) in deposition profiles of the drug were observed between corresponding carrier free and carrier blended formulations. The difference in deposition profiles of CS aerosolized from various spray dried samples were described according to

  5. Sea spray aerosol as a unique source of ice nucleating particles

    NASA Astrophysics Data System (ADS)

    DeMott, Paul J.; Hill, Thomas C. J.; McCluskey, Christina S.; Prather, Kimberly A.; Collins, Douglas B.; Sullivan, Ryan C.; Ruppel, Matthew J.; Mason, Ryan H.; Irish, Victoria E.; Lee, Taehyoung; Hwang, Chung Yeon; Siek Rhee, Tae; Snider, Jefferson R.; McMeeking, Gavin R.; Dhaniyala, Suresh; Lewis, Ernie R.; Wentzell, Jeremy J. B.; Abbatt, Jonathan; Lee, Christopher; Sultana, Camille M.; Ault, Andrew P.; Axson, Jessica L.; Diaz Martinez, Myrelis; Venero, Ingrid; Santos-Figueroa, Gilmarie; Stokes, M. Dale; Deane, Grant B.; Mayol-Bracero, Olga L.; Grassian, Vicki H.; Bertram, Timothy H.; Bertram, Allan K.; Moffett, Bruce F.; Franc, Gary D.

    2016-05-01

    Ice nucleating particles (INPs) are vital for ice initiation in, and precipitation from, mixed-phase clouds. A source of INPs from oceans within sea spray aerosol (SSA) emissions has been suggested in previous studies but remained unconfirmed. Here, we show that INPs are emitted using real wave breaking in a laboratory flume to produce SSA. The number concentrations of INPs from laboratory-generated SSA, when normalized to typical total aerosol number concentrations in the marine boundary layer, agree well with measurements from diverse regions over the oceans. Data in the present study are also in accord with previously published INP measurements made over remote ocean regions. INP number concentrations active within liquid water droplets increase exponentially in number with a decrease in temperature below 0 °C, averaging an order of magnitude increase per 5 °C interval. The plausibility of a strong increase in SSA INP emissions in association with phytoplankton blooms is also shown in laboratory simulations. Nevertheless, INP number concentrations, or active site densities approximated using “dry” geometric SSA surface areas, are a few orders of magnitude lower than corresponding concentrations or site densities in the surface boundary layer over continental regions. These findings have important implications for cloud radiative forcing and precipitation within low-level and midlevel marine clouds unaffected by continental INP sources, such as may occur over the Southern Ocean.

  6. Sea spray aerosol as a unique source of ice nucleating particles

    PubMed Central

    DeMott, Paul J.; Hill, Thomas C. J.; McCluskey, Christina S.; Prather, Kimberly A.; Ruppel, Matthew J.; Mason, Ryan H.; Irish, Victoria E.; Lee, Taehyoung; Hwang, Chung Yeon; Snider, Jefferson R.; McMeeking, Gavin R.; Dhaniyala, Suresh; Lewis, Ernie R.; Wentzell, Jeremy J. B.; Abbatt, Jonathan; Lee, Christopher; Sultana, Camille M.; Ault, Andrew P.; Axson, Jessica L.; Diaz Martinez, Myrelis; Venero, Ingrid; Santos-Figueroa, Gilmarie; Stokes, M. Dale; Deane, Grant B.; Mayol-Bracero, Olga L.; Grassian, Vicki H.; Bertram, Timothy H.; Bertram, Allan K.; Moffett, Bruce F.; Franc, Gary D.

    2016-01-01

    Ice nucleating particles (INPs) are vital for ice initiation in, and precipitation from, mixed-phase clouds. A source of INPs from oceans within sea spray aerosol (SSA) emissions has been suggested in previous studies but remained unconfirmed. Here, we show that INPs are emitted using real wave breaking in a laboratory flume to produce SSA. The number concentrations of INPs from laboratory-generated SSA, when normalized to typical total aerosol number concentrations in the marine boundary layer, agree well with measurements from diverse regions over the oceans. Data in the present study are also in accord with previously published INP measurements made over remote ocean regions. INP number concentrations active within liquid water droplets increase exponentially in number with a decrease in temperature below 0 °C, averaging an order of magnitude increase per 5 °C interval. The plausibility of a strong increase in SSA INP emissions in association with phytoplankton blooms is also shown in laboratory simulations. Nevertheless, INP number concentrations, or active site densities approximated using “dry” geometric SSA surface areas, are a few orders of magnitude lower than corresponding concentrations or site densities in the surface boundary layer over continental regions. These findings have important implications for cloud radiative forcing and precipitation within low-level and midlevel marine clouds unaffected by continental INP sources, such as may occur over the Southern Ocean. PMID:26699469

  7. Sea spray aerosol as a unique source of ice nucleating particles.

    PubMed

    DeMott, Paul J; Hill, Thomas C J; McCluskey, Christina S; Prather, Kimberly A; Collins, Douglas B; Sullivan, Ryan C; Ruppel, Matthew J; Mason, Ryan H; Irish, Victoria E; Lee, Taehyoung; Hwang, Chung Yeon; Rhee, Tae Siek; Snider, Jefferson R; McMeeking, Gavin R; Dhaniyala, Suresh; Lewis, Ernie R; Wentzell, Jeremy J B; Abbatt, Jonathan; Lee, Christopher; Sultana, Camille M; Ault, Andrew P; Axson, Jessica L; Diaz Martinez, Myrelis; Venero, Ingrid; Santos-Figueroa, Gilmarie; Stokes, M Dale; Deane, Grant B; Mayol-Bracero, Olga L; Grassian, Vicki H; Bertram, Timothy H; Bertram, Allan K; Moffett, Bruce F; Franc, Gary D

    2016-05-24

    Ice nucleating particles (INPs) are vital for ice initiation in, and precipitation from, mixed-phase clouds. A source of INPs from oceans within sea spray aerosol (SSA) emissions has been suggested in previous studies but remained unconfirmed. Here, we show that INPs are emitted using real wave breaking in a laboratory flume to produce SSA. The number concentrations of INPs from laboratory-generated SSA, when normalized to typical total aerosol number concentrations in the marine boundary layer, agree well with measurements from diverse regions over the oceans. Data in the present study are also in accord with previously published INP measurements made over remote ocean regions. INP number concentrations active within liquid water droplets increase exponentially in number with a decrease in temperature below 0 °C, averaging an order of magnitude increase per 5 °C interval. The plausibility of a strong increase in SSA INP emissions in association with phytoplankton blooms is also shown in laboratory simulations. Nevertheless, INP number concentrations, or active site densities approximated using "dry" geometric SSA surface areas, are a few orders of magnitude lower than corresponding concentrations or site densities in the surface boundary layer over continental regions. These findings have important implications for cloud radiative forcing and precipitation within low-level and midlevel marine clouds unaffected by continental INP sources, such as may occur over the Southern Ocean.

  8. Off-Target Loss in Ornamental Nurseries with Different Spray Techniques

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information is lacking on spray techniques to reduce off-target loss on the ground and via spray drift from the treated area in nursery applications. Airborne deposits at three elevations on sampling towers and on the ground at several distances from the sprayer were investigated with the three spra...

  9. Updating Sea Spray Aerosol Emissions in the Community Multiscale Air Quality Model

    NASA Astrophysics Data System (ADS)

    Gantt, B.; Bash, J. O.; Kelly, J.

    2014-12-01

    Sea spray aerosols (SSA) impact the particle mass concentration and gas-particle partitioning in coastal environments, with implications for human and ecosystem health. In this study, the Community Multiscale Air Quality (CMAQ) model is updated to enhance fine mode SSA emissions, include sea surface temperature (SST) dependency, and revise surf zone emissions. Based on evaluation with several regional and national observational datasets in the continental U.S., the updated emissions generally improve surface concentrations predictions of primary aerosols composed of sea-salt and secondary aerosols affected by sea-salt chemistry in coastal and near-coastal sites. Specifically, the updated emissions lead to better predictions of the magnitude and coastal-to-inland gradient of sodium, chloride, and nitrate concentrations at Bay Regional Atmospheric Chemistry Experiment (BRACE) sites near Tampa, FL. Including SST-dependency to the SSA emission parameterization leads to increased sodium concentrations in the southeast U.S. and decreased concentrations along the Pacific coast and northeastern U.S., bringing predictions into closer agreement with observations at most Interagency Monitoring of Protected Visual Environments (IMPROVE) and Chemical Speciation Network (CSN) sites. Model comparison with California Research at the Nexus of Air Quality and Climate Change (CalNex) observations will also be discussed, with particular focus on the South Coast Air Basin where clean marine air mixes with anthropogenic pollution in a complex environment. These SSA emission updates enable more realistic simulation of chemical processes in coastal environments, both in clean marine air masses and mixtures of clean marine and polluted conditions.

  10. Sea spray aerosol in the Great Barrier Reef and the presence of nonvolatile organics

    NASA Astrophysics Data System (ADS)

    Mallet, Marc; Cravigan, Luke; Miljevic, Branka; Vaattovaara, Petri; Deschaseaux, Elisabeth; Swan, Hilton; Jones, Graham; Ristovski, Zoran

    2016-06-01

    Sea spray aerosol (SSA) particles produced from the ocean surface in regions of biological activity can vary greatly in size, number and composition, and in their influence on cloud formation. Algal species such as phytoplankton can alter the SSA composition. Numerous studies have investigated nascent SSA properties, but all of these have focused on aerosol particles produced by seawater from noncoral related phytoplankton and in coastal regions. Bubble chamber experiments were performed with seawater samples taken from the reef flat around Heron Island in the Great Barrier Reef during winter 2011. Here we show that the SSA from these samples was composed of an internal mixture of varying fractions of sea salt, semivolatile organics, as well as nonvolatile (below 550°C) organics. A relatively constant volume fraction of semivolatile organics of 10%-13% was observed, while nonvolatile organic volume fractions varied from 29% to 49% for 60 nm SSA. SSA organic fractions were estimated to reduce the activation ratios of SSA to cloud condensation nuclei by up to 14% when compared with artificial sea salt. Additionally, a sea-salt calibration was applied so that a compact time-of-flight aerosol mass spectrometer could be used to quantify the contribution of sea salt to submicron SSA, which yielded organic volume fractions of 3%-6%. Overall, these results indicate a high fraction of organics associated with wintertime Aitken mode SSA generated from Great Barrier Reef seawater. Further work is required to fully distinguish any differences coral reefs have on SSA composition when compared to open oceans.

  11. Global modelling of direct and indirect effects of sea spray aerosol using a source function encapsulating wave state

    NASA Astrophysics Data System (ADS)

    Partanen, A.-I.; Dunne, E. M.; Bergman, T.; Laakso, A.; Kokkola, H.; Ovadnevaite, J.; Sogacheva, L.; Baisnée, D.; Sciare, J.; Manders, A.; O'Dowd, C.; de Leeuw, G.; Korhonen, H.

    2014-11-01

    Recently developed parameterizations for the sea spray aerosol source flux, encapsulating wave state, and its organic fraction were incorporated into the aerosol-climate model ECHAM-HAMMOZ to investigate the direct and indirect radiative effects of sea spray aerosol particles. Our simulated global sea salt emission of 805 Tg yr-1 (uncertainty range 378-1233 Tg yr-1) was much lower than typically found in previous studies. Modelled sea salt and sodium ion concentrations agreed relatively well with measurements in the smaller size ranges at Mace Head (annual normalized mean model bias -13% for particles with vacuum aerodynamic diameter Dva < 1 μm), Point Reyes (-29% for particles with aerodynamic diameter Da < 2.5 μm) and Amsterdam Island (-52% for particles with Da < 1 μm) but the larger sizes were overestimated (899% for particles with 2.5 μm < Da < 10 μm) at Amsterdam Island. This suggests that at least the high end of the previous estimates of sea spray mass emissions is unrealistic. On the other hand, the model clearly underestimated the observed concentrations of organic or total carbonaceous aerosol at Mace Head (-82%) and Amsterdam Island (-68%). The large overestimation (212%) of organic matter at Point Reyes was due to the contribution of continental sources. At the remote Amsterdam Island site, the organic concentration was underestimated especially in the biologically active months, suggesting a need to improve the parameterization of the organic sea spray fraction. Globally, the satellite-retrieved AOD over the oceans, using PARASOL data, was underestimated by the model (means over ocean 0.16 and 0.10, respectively); however, in the pristine region around Amsterdam Island the measured AOD fell well within the simulated uncertainty range. The simulated sea spray aerosol contribution to the indirect radiative effect was positive (0.3 W m-2), in contrast to previous studies. This positive effect was ascribed to the tendency of sea salt aerosol to

  12. Variations in hygroscopic growth of sub- and super-micron sea spray aerosols during a phytoplankton bloom

    NASA Astrophysics Data System (ADS)

    Forestieri, S.; Jayarathne, T. S.; Stone, E. A.; Laskina, O.; Grassian, V. H.; Lee, C.; Sultana, C. M.; Moore, K.; Cornwell, G.; Novak, G.; Bertram, T. H.; Prather, K. A.; Cappa, C. D.

    2014-12-01

    Marine sea spray aerosols (SSA) make up an important portion of natural aerosols (prior to anthropogenic influence) and are therefore important in establishing the baseline for anthropogenic aerosol climate impacts. One way aerosols impact climate is by scattering solar radiation, and how much light is scattered depends upon the size of aerosols. Aerosols grow larger via water uptake and thus scatter more light at elevated relative humidities. This growth depends on composition. SSA can become enriched in organics during phytoplankton blooms, becoming less salty and therefore less hygroscopic. Aerosol hygroscopicity of SSA sampled during an in-lab phytoplankton bloom were measured during the CAICE-IMPACTS 2014 study. SSA were generated via breaking waves in an enclosed 33 m wave channel filled with natural seawater. Aerosol hygroscopicity was characterized by measuring light extinction at 532 nm of dry aerosols and of aerosols humidified to 85% relative humidity using a Cavity Ringdown Spectrometer. These optical growth factors (humidified extinction/dry extinction) were converted to physical growth factors using Mie Theory calculations and aerosol size distributions measured with a scanning electrical mobility spectrometer (SEMS) and an aerodynamic particle sizer (APS). Growth factors for super- and sub-micron SSA were quantified separately through the use of a PM2.5 cyclone or PM1 impactor. The observed SSA growth factors will be linked to SSA and source water chemical composition determined by both offline and online analysis of samples. The SSA bulk growth factors will also be compared with concurrent measurements of the efficiency with which SSA act as cloud condensation nuclei. Observed SSA growth factors will also be compared to offline hygroscopic growth measurements.

  13. Marine biogeochemical influence on primary sea spray aerosol composition in the Southern Ocean: predictions from a mechanistic model

    NASA Astrophysics Data System (ADS)

    McCoy, D.; Burrows, S. M.; Elliott, S.; Frossard, A. A.; Russell, L. M.; Liu, X.; Ogunro, O. O.; Easter, R. C.; Rasch, P. J.

    2014-12-01

    Remote marine clouds, such as those over the Southern Ocean, are particularly sensitive to variations in the concentration and chemical composition of aerosols that serve as cloud condensation nuclei (CCN). Observational evidence indicates that the organic content of fine marine aerosol is greatly increased during the biologically active season near strong phytoplankton blooms in certain locations, while being nearly constant in other locations. We have recently developed a novel modeling framework that mechanistically links the organic fraction of submicron sea spray to ocean biogeochemistry (Burrows et al., in discussion, ACPD, 2014; Elliott et al., ERL, 2014). Because of its combination of large phytoplankton blooms and high wind speeds, the Southern Ocean is an ideal location for testing our understanding of the processes driving the enrichment of organics in sea spray aerosol. Comparison of the simulated OM fraction with satellite observations shows that OM fraction is a statistically significant predictor of cloud droplet number concentration over the Southern Ocean. This presentation will focus on predictions from our modeling framework for the Southern Ocean, specifically, the predicted geographic gradients and seasonal cycles in the aerosol organic matter and its functional group composition. The timing and location of a Southern Ocean field campaign will determine its utility in observing the effects of highly localized and seasonal phytoplankton blooms on aerosol composition and clouds. Reference cited: Burrows, S. M., Ogunro, O., Frossard, A. A., Russell, L. M., Rasch, P. J., and Elliott, S.: A physically-based framework for modelling the organic fractionation of sea spray aerosol from bubble film Langmuir equilibria, Atmos. Chem. Phys. Discuss., 14, 5375-5443, doi:10.5194/acpd-14-5375-2014, 2014. Elliott, S., Burrows, S. M., Deal, C., Liu, X., Long, M., Ogunro, O., Russell, L. M., and Wingenter O.. "Prospects for simulating macromolecular surfactant

  14. Linking variations in sea spray aerosol particle hygroscopicity to composition during two microcosm experiments

    NASA Astrophysics Data System (ADS)

    Forestieri, Sara D.; Cornwell, Gavin C.; Helgestad, Taylor M.; Moore, Kathryn A.; Lee, Christopher; Novak, Gordon A.; Sultana, Camille M.; Wang, Xiaofei; Bertram, Timothy H.; Prather, Kimberly A.; Cappa, Christopher D.

    2016-07-01

    The extent to which water uptake influences the light scattering ability of marine sea spray aerosol (SSA) particles depends critically on SSA chemical composition. The organic fraction of SSA can increase during phytoplankton blooms, decreasing the salt content and therefore the hygroscopicity of the particles. In this study, subsaturated hygroscopic growth factors at 85 % relative humidity (GF(85 %)) of predominately submicron SSA particles were quantified during two induced phytoplankton blooms in marine aerosol reference tanks (MARTs). One MART was illuminated with fluorescent lights and the other was illuminated with sunlight, referred to as the "indoor" and "outdoor" MARTs, respectively. Optically weighted GF(85 %) values for SSA particles were derived from measurements of light scattering and particle size distributions. The mean optically weighted SSA diameters were 530 and 570 nm for the indoor and outdoor MARTs, respectively. The GF(85 %) measurements were made concurrently with online particle composition measurements, including bulk composition (using an Aerodyne high-resolution aerosol mass spectrometer) and single particle (using an aerosol time-of-flight mass spectrometer) measurement, and a variety of water-composition measurements. During both microcosm experiments, the observed optically weighted GF(85 %) values were depressed substantially relative to pure inorganic sea salt by 5 to 15 %. There was also a time lag between GF(85 %) depression and the peak chlorophyll a (Chl a) concentrations by either 1 (indoor MART) or 3-to-6 (outdoor MART) days. The fraction of organic matter in the SSA particles generally increased after the Chl a peaked, also with a time lag, and ranged from about 0.25 to 0.5 by volume. The observed depression in the GF(85 %) values (relative to pure sea salt) is consistent with the large observed volume fractions of non-refractory organic matter (NR-OM) comprising the SSA. The GF(85 %) values exhibited a reasonable negative

  15. An improved whitecap timescale for sea spray aerosol production flux modeling using the discrete whitecap method

    NASA Astrophysics Data System (ADS)

    Callaghan, Adrian H.

    2013-09-01

    The discrete whitecap method (DWM) to model the sea spray aerosol (SSA) production flux explicitly requires a whitecap timescale, which up to now has only considered a whitecap decay timescale, τdecay. A reevaluation of the DWM suggests that the whitecap timescale should account for the total whitecap lifetime (τwcap), which consists of both the formation timescale (τform) and the decay timescale (timescale definitions are given in the text). Here values of τform for 552 oceanic whitecaps measured at the Martha's Vineyard Coastal Observatory on the east coast of the USA are presented, and added to the corresponding values of τdecay to form 552 whitecap timescales. For the majority of whitecaps, τform makes up about 20-25% of τwcap, but this can be as large as 70% depending on the value of τdecay. Furthermore, an area-weighted mean whitecap timescale for use in the DWM (τDWM) is defined that encompasses the variable nature of individual whitecap lifetimes within a given time period, and is calculated to be 5.3 s for this entire data set. This value is combined with previously published whitecap coverage parameterizations and estimates of SSA particle production per whitecap area to form a size-resolved SSA production flux parameterization (dF(r80)/dlog10r80). This parameterization yields integrated sea-salt mass fluxes that are largely within the range of uncertainty of recent measurements over the size range 0.029 µm < r80 < 0.580 µm. Physical factors controlling whitecap lifetime such as bubble plume lifetime and surfactant stabilization are discussed in the context of SSA production from whitecaps.

  16. Microbial Control of Sea Spray Aerosol Composition: A Tale of Two Blooms

    PubMed Central

    2015-01-01

    With the oceans covering 71% of the Earth, sea spray aerosol (SSA) particles profoundly impact climate through their ability to scatter solar radiation and serve as seeds for cloud formation. The climate properties can change when sea salt particles become mixed with insoluble organic material formed in ocean regions with phytoplankton blooms. Currently, the extent to which SSA chemical composition and climate properties are altered by biological processes in the ocean is uncertain. To better understand the factors controlling SSA composition, we carried out a mesocosm study in an isolated ocean-atmosphere facility containing 3,400 gallons of natural seawater. Over the course of the study, two successive phytoplankton blooms resulted in SSA with vastly different composition and properties. During the first bloom, aliphatic-rich organics were enhanced in submicron SSA and tracked the abundance of phytoplankton as indicated by chlorophyll-a concentrations. In contrast, the second bloom showed no enhancement of organic species in submicron particles. A concurrent increase in ice nucleating SSA particles was also observed only during the first bloom. Analysis of the temporal variability in the concentration of aliphatic-rich organic species, using a kinetic model, suggests that the observed enhancement in SSA organic content is set by a delicate balance between the rate of phytoplankton primary production of labile lipids and enzymatic induced degradation. This study establishes a mechanistic framework indicating that biological processes in the ocean and SSA chemical composition are coupled not simply by ocean chlorophyll-a concentrations, but are modulated by microbial degradation processes. This work provides unique insight into the biological, chemical, and physical processes that control SSA chemical composition, that when properly accounted for may explain the observed differences in SSA composition between field studies. PMID:27162962

  17. Spray Dried Aerosol Particles of Pyrazinoic Acid Salts for Tuberculosis Therapy. [Corrected].

    PubMed

    Durham, P G; Zhang, Y; German, N; Mortensen, N; Dhillon, J; Mitchison, D A; Fourie, P B; Hickey, A J

    2015-08-03

    Tuberculosis is the most serious infectious disease caused by a single organism, Mycobacterium tuberculosis (Mtb). The standard of care is a protracted and complex drug treatment regimen made more complicated and of longer duration by the incidence of multiple and extensively drug resistant disease. Pulmonary delivery of aerosols as a supplement to the existing regimen offers the advantage of delivering high local drug doses to the initial site of infection and most prominent organ system involved in disease. Pyrazinamide is used in combination with other drugs to treat tuberculosis. It is postulated that the action of pyrazinoic acid (POA), the active moiety of pyrazinamide, may be enhanced by local pH adjustment, when presented as a salt form. POA was prepared as leucine (POA-leu) and ammonium salts (POA-NH4), spray dried, and characterized in terms of physicochemical properties (melting point, crystallinity, moisture content), aerodynamic performance (aerodynamic particle size distribution, emitted dose), and in vitro inhibitory effect on two mycobacteria (Mtb and Mycobacterium bovis). Particles were prepared in sizes suitable for inhalation (3.3 and 5.4 μm mass median aerodynamic diameter and 61 and 40% of the aerodynamic particle size distribution less than 4.46 μm, as measured by inertial impaction, for POA-leu and POA-NH4, respectively) and with properties (stoichiometric 1:1 ratio of salt to drug, melting points at ∼180 °C, with water content of <1%) that would support further development as an inhaled dosage form. In addition, POA salts demonstrated greater potency in inhibiting mycobacterial growth compared with POA alone, which is promising for therapy.

  18. Influence of crustal dust and sea spray supermicron particle concentrations and acidity on inorganic NO3 aerosol during the 2013 Southern Oxidant and Aerosol Study

    SciTech Connect

    Allen, H. M.; Draper, D. C.; Ayres, B. R.; Ault, A.; Bondy, A.; Takahama, S.; Modini, R. L.; Baumann, K.; Edgerton, E.; Knote, C.; Laskin, A.; Wang, B.; Fry, J. L.

    2015-09-25

    Inorganic aerosol composition was measured in the southeastern United States, a region that exhibits high aerosol mass loading during the summer, as part of the 2013 Southern Oxidant and Aerosol Study (SOAS) campaign. Measurements using a Monitor for AeRosols and GAses (MARGA) revealed two periods of high aerosol nitrate (NO3) concentrations during the campaign. These periods of high nitrate were correlated with increased concentrations of supermicron crustal and sea spray aerosol species, particularly Na+ and Ca2+, and with a shift towards aerosol with larger (1 to 2.5 μm) diameters. We suggest this nitrate aerosol forms by multiphase reactions of HNO3 and particles, reactions that are facilitated by transport of crustal dust and sea spray aerosol from a source within the United States. The observed high aerosol acidity prevents the formation of NH4NO3, the inorganic nitrogen species often dominant in fine-mode aerosol at higher pH. In addition, calculation of the rate of the heterogeneous uptake of HNO3 on mineral aerosol supports the conclusion that aerosol NO3 is produced primarily by this process, and is likely limited by the availability of mineral cation-containing aerosol surface area. Modeling of NO3 and HNO3 by thermodynamic equilibrium models (ISORROPIA II and E-AIM) reveals the importance of including mineral cations in the southeastern United States to accurately balance ion species and predict gas–aerosol phase partitioning.

  19. Investigation of the Changes in Aerosolization Behavior Between the Jet-Milled and Spray-Dried Colistin Powders Through Surface Energy Characterization.

    PubMed

    Jong, Teresa; Li, Jian; Morton, David A V; Zhou, Qi Tony; Larson, Ian

    2016-03-01

    This study aimed to investigate the surface energy factors behind improved aerosolization performance of spray-dried colistin powder formulations compared with those produced by jet milling. Inhalable colistin powder formulations were produced by jet milling or spray drying (with or without l-leucine). Scanning electron micrographs showed the jet-milled particles had irregularly angular shapes, whereas the spray-dried particles were more spherical. Significantly higher fine particle fractions were measured for the spray-dried (43.8%-49.6%) versus the jet-milled formulation (28.4%) from a Rotahaler at 60 L/min; albeit the size distribution of the jet-milled powder was smaller. Surprisingly, addition of l-leucine in the spray drying feed solution gave no significant improvement in fine particle fraction. As measured by inverse gas chromatography, spray-dried formulations had significantly (p < 0.001) lower dispersive, specific, and total surface energy values and more uniform surface energy distributions than the jet-milled powder. Interestingly, no significant difference was measured in the specific and total surface energy values between the spray-dried formulation with or without l-leucine. Based on our previous findings in the self-assembling behavior of colistin in aqueous solution and the surface energy data obtained here, we propose the self-assembly of colistin molecules during spray drying contributed significantly to the reduction of surface free energy and the superior aerosolization performance.

  20. Investigation of the changes in aerosolization behavior between the jet-milled and spray-dried colistin powders through surface energy characterization

    PubMed Central

    Jong, Teresa; Li, Jian; Mortonx, David A.V.; Zhou, Qi (Tony); Larson, Ian

    2016-01-01

    This study aimed to investigate the surface energy factors behind improved aerosolization performance of spray-dried colistin powder formulations compared to those produced by jet-milling. Inhalable colistin powder formulations were produced by jet-milling or spray-drying (with or without L-leucine). Scanning electron micrographs showed the jet-milled particles had irregularly angular shapes, while the spray-dried particles were more spherical. Significantly higher fine particle fractions (FPFs) were measured for the spray-dried (43.8-49.6%) vs. the jet-milled formulation (28.4 %) from a Rotahaler at 60L/min; albeit the size distribution of the jet-milled powder was smaller. Surprisingly, addition of L-leucine in the spray drying feed-solution gave no significant improvement in FPF. As measured by inverse gas chromatography, spray-dried formulations had significantly (p<0.001) lower dispersive, specific and total surface energy values and more uniform surface energy distributions than the jet-milled powder. Interestingly, no significant difference was measured in the specific and total surface energy values between the spray-dried formulation with or without L-leucine. Based upon our previous findings in the self-assembling behavior of colistin in aqueous solution and the surface energy data obtained here, we propose the self-assembly of colistin molecules during spray-drying, contributed significantly to the reduction of surface free energy and the superior aerosolization performance. PMID:26886330

  1. Effect of In-Plume Aerosol Processing on the Efficacy of Marine Cloud Albedo Enhancement from Controlled Sea-Spray Injections

    NASA Astrophysics Data System (ADS)

    Stevens, R. G.; Spracklen, D.; Korhonen, H.; Pierce, J. R.

    2010-12-01

    The intentional enhancement of cloud albedo via controlled sea-spray injection from ships has been suggested as a possible means to control anthropogenic global warming (1); however, there remains significant uncertainty in the efficacy of this method due to uncertainties in aerosol and cloud microphysics. Recent analysis showed that more sea-spray may be necessary than previously assumed to reach a desired cooling due to nonlinearities in the aerosol/cloud microphysics (2). A major assumption used in (2) is that all sea-spray was emitted uniformly into some oceanic grid boxes, and thus did not account for sub-grid aerosol microphysics within the sea-spray plumes. However, as a consequnce of the fast sea-spray injection rates which are proposed, in the order of 1x10^17 1/s (1), particle concentrations in these plumes may be quite high and particle coagulation may significantly reduce the number of emitted particles and increase their average size. Therefore, it is possible that the emissions necessary to reach a desired cooling may be even larger than currently assumed. We explore the processing of the freshly emitted sea-spray plumes in the Large-Eddy Simulation (LES)/Cloud Resolving Model (CRM) the System for Atmospheric Modelling (SAM, 3) with the online aerosol microphysics module TOMAS (4). We determine how the final number and size of particles (once well mixed with background air) depends on the emission rate and size distribution of the sea-spray plume and on the pre-existing aerosol concentrations and local atmospheric conditions. Finally, we make suggestions for effective size-resolved emissions for use in climate models. (1) Salter, S. et al., Phil. Trans. R. Soc. A., 2008. (2) Korhonen, H. et al., Atmos. Chem. Phys., 10, 4133-4143, 2010. (3) Khairoutdinov, M., and Randall, D.,. J. Atmos. Sci., 60, 607-625, 2003. (4) Pierce, J. and Adams, P., Atmos. Chem. Phys., 9, 1339-1356, 2009.

  2. A Physically Based Framework for Modelling the Organic Fractionation of Sea Spray Aerosol from Bubble Film Langmuir Equilibria

    SciTech Connect

    Burrows, Susannah M.; Ogunro, O.; Frossard, Amanda; Russell, Lynn M.; Rasch, Philip J.; Elliott, S.

    2014-12-19

    The presence of a large fraction of organic matter in primary sea spray aerosol (SSA) can strongly affect its cloud condensation nuclei activity and interactions with marine clouds. Global climate models require new parameterizations of the SSA composition in order to improve the representation of these processes. Existing proposals for such a parameterization use remotely-sensed chlorophyll-a concentrations as a proxy for the biogenic contribution to the aerosol. However, both observations and theoretical considerations suggest that existing relationships with chlorophyll-a, derived from observations at only a few locations, may not be representative for all ocean regions. We introduce a novel framework for parameterizing the fractionation of marine organic matter into SSA based on a competitive Langmuir adsorption equilibrium at bubble surfaces. Marine organic matter is partitioned into classes with differing molecular weights, surface excesses, and Langmuir adsorption parameters. The classes include a lipid-like mixture associated with labile dissolved organic carbon (DOC), a polysaccharide-like mixture associated primarily with semi-labile DOC, a protein-like mixture with concentrations intermediate between lipids and polysaccharides, a processed mixture associated with recalcitrant surface DOC, and a deep abyssal humic-like mixture. Box model calculations have been performed for several cases of organic adsorption to illustrate the underlying concepts. We then apply the framework to output from a global marine biogeochemistry model, by partitioning total dissolved organic carbon into several classes of macromolecule. Each class is represented by model compounds with physical and chemical properties based on existing laboratory data. This allows us to globally map the predicted organic mass fraction of the nascent submicron sea spray aerosol. Predicted relationships between chlorophyll-\\textit{a} and organic fraction are similar to existing empirical

  3. L-Leucine as an excipient against moisture on in vitro aerosolization performances of highly hygroscopic spray-dried powders.

    PubMed

    Li, Liang; Sun, Siping; Parumasivam, Thaigarajan; Denman, John A; Gengenbach, Thomas; Tang, Patricia; Mao, Shirui; Chan, Hak-Kim

    2016-05-01

    L-Leucine (LL) has been widely used to enhance the dispersion performance of powders for inhalation. LL can also protect powders against moisture, but this effect is much less studied. The aim of this study was to investigate whether LL could prevent moisture-induced deterioration in in vitro aerosolization performances of highly hygroscopic spray-dried powders. Disodium cromoglycate (DSCG) was chosen as a model drug and different amounts of LL (2-40% w/w) were added to the formulation, with the aim to explore the relationship between powder dispersion, moisture protection and physicochemical properties of the powders. The powder formulations were prepared by spray drying of aqueous solutions containing known concentrations of DSCG and LL. The particle sizes were measured by laser diffraction. The physicochemical properties of fine particles were characterized by X-ray powder diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic vapor sorption (DVS). The surface morphology and chemistry of fine particles were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). In vitro aerosolization performances were evaluated by a next generation impactor (NGI) after the powders were stored at 60% or 75% relative humidity (RH), and 25°C for 24h. Spray-dried (SD) DSCG powders were amorphous and absorbed 30-45% (w/w) water at 70-80% RH, resulting in deterioration in the aerosolization performance of the powders. LL did not decrease the water uptake of DSCG powders, but it could significantly reduce the effect of moisture on aerosolization performances. This is due to enrichment of crystalline LL on the surface of the composite particles. The effect was directly related to the percentage of LL coverage on the surface of particles. Formulations having 61-73% (molar percent) of LL on the particle surface (which correspond to 10-20% (w

  4. Alveolar targeting of aerosol pentamidine. Toward a rational delivery system

    SciTech Connect

    Simonds, A.K.; Newman, S.P.; Johnson, M.A.; Talaee, N.; Lee, C.A.; Clarke, S.W. )

    1990-04-01

    Nebulizer systems that deposit a high proportion of aerosolized pentamidine on large airways are likely to be associated with marked adverse side effects, which may lead to premature cessation of treatment. We have measured alveolar deposition and large airway-related side effects (e.g., cough, breathlessness, and effect on pulmonary function) after aerosolization of 150 mg pentamidine isethionate labeled with {sup 99m}Tc-Sn-colloid. Nine patients with AIDS were studied using three nebulizer systems producing different droplet size profiles: the Acorn System 22, Respirgard II, and Respirgard II with the inspiratory baffle removed. Alveolar deposition was greatest and side effects least with the nebulizer producing the smallest droplet size profile (Respirgard II), whereas large airway-related side effects were prominent and alveolar deposition lowest with the nebulizer producing the largest droplet size (Acorn System 22). Values for alveolar deposition and adverse airway effects were intermediate using the Respirgard with inspiratory baffle removed, thus indicating the importance of the baffle valve in determining droplet size. Addition of a similar baffle valve to the Acorn System 22 produced a marked improvement in droplet size profile. Selection of a nebulizer that produces an optimal droplet size range offers the advantage of enhancing alveolar targeting of aerosolized pentamidine while reducing large airway-related side effects.

  5. The Collection 6 'dark-target' MODIS Aerosol Products

    NASA Technical Reports Server (NTRS)

    Levy, Robert C.; Mattoo, Shana; Munchak, Leigh A.; Kleidman, Richard G.; Patadia, Falguni; Gupta, Pawan; Remer, Lorraine

    2013-01-01

    Aerosol retrieval algorithms are applied to Moderate resolution Imaging Spectroradiometer (MODIS) sensors on both Terra and Aqua, creating two streams of decade-plus aerosol information. Products of aerosol optical depth (AOD) and aerosol size are used for many applications, but the primary concern is that these global products are comprehensive and consistent enough for use in climate studies. One of our major customers is the international modeling comparison study known as AEROCOM, which relies on the MODIS data as a benchmark. In order to keep up with the needs of AEROCOM and other MODIS data users, while utilizing new science and tools, we have improved the algorithms and products. The code, and the associated products, will be known as Collection 6 (C6). While not a major overhaul from the previous Collection 5 (C5) version, there are enough changes that there are significant impacts to the products and their interpretation. In its entirety, the C6 algorithm is comprised of three sub-algorithms for retrieving aerosol properties over different surfaces: These include the dark-target DT algorithms to retrieve over (1) ocean and (2) vegetated-dark-soiled land, plus the (3) Deep Blue (DB) algorithm, originally developed to retrieve over desert-arid land. Focusing on the two DT algorithms, we have updated assumptions for central wavelengths, Rayleigh optical depths and gas (H2O, O3, CO2, etc.) absorption corrections, while relaxing the solar zenith angle limit (up to 84) to increase pole-ward coverage. For DT-land, we have updated the cloud mask to allow heavy smoke retrievals, fine-tuned the assignments for aerosol type as function of season location, corrected bugs in the Quality Assurance (QA) logic, and added diagnostic parameters such as topographic altitude. For DT-ocean, improvements include a revised cloud mask for thin-cirrus detection, inclusion of wind speed dependence in the retrieval, updates to logic of QA Confidence flag (QAC) assignment, and

  6. Cells (MC3T3-E1)-laden alginate scaffolds fabricated by a modified solid-freeform fabrication process supplemented with an aerosol spraying.

    PubMed

    Ahn, SeungHyun; Lee, HyeongJin; Bonassar, Lawrence J; Kim, GeunHyung

    2012-09-10

    In this study, we propose a new cell encapsulation method consisting of a dispensing method and an aerosol-spraying method. The aerosol spray using a cross-linking agent, calcium chloride (CaCl(2)), was used to control the surface gelation of dispensed alginate struts during dispensing. To show the feasibility of the method, we used preosteoblast (MC3T3-E1) cells. By changing the relationship between the various dispensing/aerosol-spraying conditions and cell viability, we could determine the optimal cell-dispensing process: a nozzle size (240 μm) and an aerosol spray flow rate (0.93 ± 0.12 mL min(-1)), 10 mm s(-1) nozzle moving speed, a 10 wt % concentration of CaCl(2) in the aerosol solution, and 2 wt % concentration of CaCl(2) in the second cross-linking process. Based on these optimized process conditions, we successfully fabricated a three-dimensional, pore-structured, cell-laden alginate scaffold of 20 × 20 × 4.6 mm(3) and 84% cell viability. During long cell culture periods (16, 25, 33, and 45 days), the preosteoblasts in the alginate scaffold survived and proliferated well.

  7. Agrochemical spray drift; assessment and mitigation--a review.

    PubMed

    Felsot, Allan S; Unsworth, John B; Linders, Jan B H J; Roberts, Graham; Rautman, Dirk; Harris, Caroline; Carazo, Elizabeth

    2011-01-01

    During application of agrochemicals spray droplets can drift beyond the intended target to non-target receptors, including water, plants and animals. Factors affecting this spray drift include mode of application, droplet size, which can be modified by the nozzle types, formulation adjuvants, wind direction, wind speed, air stability, relative humidity, temperature and height of released spray relative to the crop canopy. The rate of fall of spray droplets depends upon the size of the droplets but is modified by entrainment in a mobile air mass and is also influenced by the rate of evaporation of the liquid constituting the aerosol. The longer the aerosol remains in the air before falling to the ground (or alternatively striking an object above ground) the greater the opportunity for it to be carried away from its intended target. In general, all size classes of droplets are capable of movement off target, but the smallest are likely to move the farthest before depositing on the ground or a non-target receptor. It is not possible to avoid spray drift completely but it can be minimized by using best-management practices. These include using appropriate nozzle types, shields, spray pressure, volumes per area sprayed, tractor speed and only spraying when climatic conditions are suitable. Field layout can also influence spray drift, whilst crop-free and spray-free buffer zones and windbreak crops can also have a mitigating effect. Various models are available to estimate the environmental exposure from spray drift at the time of application.

  8. The organic fraction of bubble-generated, accumulation mode Sea Spray Aerosol (SSA)

    NASA Astrophysics Data System (ADS)

    Modini, R. L.; Harris, B.; Ristovski, Z. D.

    2010-03-01

    Recent studies have detected a dominant accumulation mode (~100 nm) in the Sea Spray Aerosol (SSA) number distribution. There is evidence to suggest that particles in this mode are composed primarily of organics. To investigate this hypothesis we conducted experiments on NaCl, artificial SSA and natural SSA particles with a Volatility-Hygroscopicity-Tandem-Differential-Mobility-Analyser (VH-TDMA). NaCl particles were atomiser generated and a bubble generator was constructed to produce artificial and natural SSA particles. Natural seawater samples for use in the bubble generator were collected from biologically active, terrestrially-affected coastal water in Moreton Bay, Australia. Differences in the VH-TDMA-measured volatility curves of artificial and natural SSA particles were used to investigate and quantify the organic fraction of natural SSA particles. Hygroscopic Growth Factor (HGF) data, also obtained by the VH-TDMA, were used to confirm the conclusions drawn from the volatility data. Both datasets indicated that the organic fraction of our natural SSA particles evaporated in the VH-TDMA over the temperature range 170-200 °C. The organic volume fraction for 71-77 nm natural SSA particles was 8±6%. Organic volume fraction did not vary significantly with varying water residence time (40 s to 24 h) in the bubble generator or SSA particle diameter in the range 38-173 nm. At room temperature we measured shape- and Kelvin-corrected HGF at 90% RH of 2.46±0.02 for NaCl, 2.35±0.02 for artifical SSA and 2.26±0.02 for natural SSA particles. Overall, these results suggest that the natural accumulation mode SSA particles produced in these experiments contained only a minor organic fraction, which had little effect on hygroscopic growth. Our measurement of 8±6% is an order of magnitude below two previous measurements of the organic fraction in SSA particles of comparable sizes. We stress that our results were obtained using coastal seawater and they can't necessarily

  9. The organic fraction of bubble-generated, accumulation mode Sea Spray Aerosol (SSA)

    NASA Astrophysics Data System (ADS)

    Modini, R. L.; Harris, B.; Ristovski, Z. D.

    2009-10-01

    Recent studies have detected a dominant accumulation mode (~100 nm) in the Sea Spray Aerosol (SSA) number distribution. There is evidence to suggest that particles in this mode are composed primarily of organics. To investigate this hypothesis we conducted experiments on NaCl, artificial SSA and natural SSA particles with a Volatility-Hygroscopicity-Tandem-Differential-Mobility-Analyser (VH-TDMA). NaCl particles were atomiser generated and a bubble generator was constructed to produce artificial and natural SSA particles. Natural seawater samples for use in the bubble generator were collected from biologically active, terrestrially-affected coastal water in Moreton Bay, Australia. Differences in the VH-TDMA-measured volatility curves of artificial and natural SSA particles were used to investigate and quantify the organic fraction of natural SSA particles. Hygroscopic Growth Factor (HGF) data, also obtained by the VH-TDMA, were used to confirm the conclusions drawn from the volatility data. Both datasets indicated that the organic fraction of our natural SSA particles evaporated in the VH-TDMA over the temperature range 170-200°C. The organic volume fraction for 71-77 nm natural SSA particles was 8±6%. Organic volume fraction did not vary significantly with varying water residence time (40 s0 to 24 h) in the bubble generator or SSA particle diameter in the range 38-173 nm. At room temperature we measured shape- and Kelvin-corrected HGF at 90% RH of 2.46±0.02 for NaCl, 2.35±0.02 for artifical SSA and 2.26±0.02 for natural SSA particles. Overall, these results suggest that the natural accumulation mode SSA particles produced in these experiments contained only a minor organic fraction, which had little effect on hygroscopic growth. Our measurement of 8±6% is an order of magnitude below two previous measurements of the organic fraction in SSA particles of comparable sizes. Further studies with a variety of different seawaters are required to better quantify how

  10. Spray drift and off-target loss reduction with a precision air-assisted sprayer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spray drift and off-target losses are inherent problems of conventional air-assisted sprayers. Their low efficiencies cause environmental pollutions resulting in public anxieties. A new drift reduction technology incorporating laser scanning capabilities with a variable-rate air-assisted sprayer w...

  11. New Monte Carlo model of laser radiation propagation in sprays, aerosols, and other complex polydisperse turbid media

    NASA Astrophysics Data System (ADS)

    Berrocal, E.; Jermy, M.; Meglinski, I. V.

    2006-08-01

    Modern optical diagnostics for quantitative characterization of polydisperse sprays and other aerosols which contain a wide range of droplet size encounter difficulties in the dense regions due to the multiple scattering of laser radiation with the surrounding droplets. The accuracy and efficiency of optical measurements can only be improved if the radiative transfer within such polydisperse turbid media is understood. A novel Monte Carlo code has been developed for modeling of optical radiation propagation in inhomogeneous polydisperse scattering media with typical drop size ranging from 2 μm to 200 μm in diameter. We show how strong variations of both particle size distribution and particle concentration within a 3D scattering medium can be taken into account via the Monte Carlo approach. A new approximation which reduces ~20 times the computational memory space required to determine the phase function is described. The approximation is verified by considering four log-normal drop size distributions. It is found valid for particle sizes in the range of 10-200 μm with increasing errors, due to additional photons scattered at large angles, as the number of particles below than 10 μm increases. The technique is applied to the simulation of typical planar Mie imaging of a hollow cone spray. Simulated and experimental images are compared and shown to agree well. The code has application in developing and testing new optical diagnostics for complex scattering media such as dense sprays.

  12. Laser-driven quasimonoenergetic proton burst from water spray target

    SciTech Connect

    Ramakrishna, B.; Murakami, M.; Borghesi, M.; Ter-Avetisyan, S.; Ehrentraut, L.; Schnuerer, M.; Steinke, S.; Nickles, P. V.; Psikal, J.; Tikhonchuk, V.

    2010-08-15

    A narrow band proton bursts at energies of 1.6{+-}0.08 MeV were observed when a water spray consisting of (150 nm)-diameter droplets was irradiated by an ultrashort laser pulse of about 45 fs duration and at an intensity of 5x10{sup 19} W/cm{sup 2}. The results are explained by a Coulomb explosion of sub-laser-wavelength droplets composed of two ion species. The laser prepulse plays an important role. By pre-evaporation of the droplets, its diameter is reduced so that the main pulse can interact with a smaller droplet, and this remaining bulk can be ionized to high states. In the case of water, the mixture of quite differently charged ions establishes an 'iso-Coulomb-potential' during the droplet explosion such that protons are accelerated to a peak energy with a narrow energy spread. The model explains this crucial point, which differs critically from usual Coulomb explosion or ion sheath acceleration mechanisms.

  13. Effects of wind speed on aerosol spray penetration in adult mosquito bioassay cages.

    PubMed

    Hoffmann, W Clint; Fritz, Bradley K; Farooq, Muhammad; Cooperband, Miriam F

    2008-09-01

    Bioassay cages are commonly used to assess efficacy of insecticides against adult mosquitoes in the field. To correlate adult mortality readings to insecticidal efficacy and/or spray application parameters properly, it is important to know how the cage used in the bioassay interacts with the spray cloud containing the applied insecticide. This study compared the size of droplets, wind speed, and amount of spray material penetrating cages and outside of cages in a wind tunnel at different wind speeds. Two bioassay cages, Center for Medical, Agricultural and Veterinary Entomology (CMAVE) and Circle, were evaluated. The screen materials used on these cages reduced the size of droplets, wind speed, and amount of spray material inside the cages as compared to the spray cloud and wind velocity outside of the cages. When the wind speed in the dispersion tunnel was set at 0.6 m/sec (1.3 mph), the mean wind speed inside of the CMAVE Bioassay Cage and Circle Cage was 0.045 m/sec (0.10 mph) and 0.075 m/sec (0.17 mph), respectively. At air velocities of 2.2 m/sec (4.9 mph) in the dispersion tunnel, the mean wind speed inside of the CMAVE Bioassay Cage and Circle Cage was 0.83 m/sec (1.86 mph) and 0.71 m/sec (1.59 mph), respectively. Consequently, there was a consistent 50-70% reduction of spray material penetrating the cages compared to the spray cloud that approached the cages. These results provide a better understanding of the impact of wind speed, cage design, and construction on ultra-low-volume spray droplets.

  14. Size distribution of heavy metal aerosols in cooling and spray dryer system

    SciTech Connect

    Wey, M.Y.; Yang, J.T.; Peng, C.Y.; Chiang, B.C.

    1999-11-01

    The cooling process prior to treating flue gas and the spray dryer process that removes acid components in flue gas are believed to influence the mass and elemental size distributions of heavy metal in fly ash. The main objective of this study was to investigate the effects of operating parameters on the mass and elemental size distributions of heavy metals in fly ash produced from a fluidized bed incineration and a water cooling or spray dryer flue gas treatment system. The operating parameters investigated included (1) the controlling temperature in the gas cooling system; (2) the controlling temperature in the spray dryer system; (3) the addition of organic chlorides; and (4) the addition of inorganic chloride. The experimental results indicated that the water cooling process and spray dryer process increase the amount of coarse fly ash and increase the total concentration of metal in fly ash. The amounts of fine fly ash and the total concentration of metal in fine fly ash increase with decreasing temperature during the water cooling process. However, the amounts of fine fly ash and the total concentration of metal in fine fly ash decrease with decreasing temperature during the spray dryer process.

  15. Organic Composition and Morphology of Sea Spray Aerosols as a Function of Biological Life during IMPACTS

    NASA Astrophysics Data System (ADS)

    Pham, D.; Moffet, R.; Fraund, M. W.; O'Brien, R.; Laskina, O.; Prather, K. A.; Grassian, V. H.; Beall, C.; Wang, X.; Forestieri, S.; Cappa, C. D.

    2015-12-01

    Aerosols influence climate by directly reflecting or absorbing sunlight, or indirectly by affecting clouds. A major source of aerosols is from oceanic wave breaking. Due to their complexity, the effects of marine aerosol on climate are uncertain. To provide more detailed measurements of the chemical composition of marine aerosols, Scanning Transmission X-Ray Microscopy coupled with Near Edge X-Ray Absorption Fine Structure (SXTM-NEXAFS) was used to give spatially resolved molecular information for carbon and oxygen. Application of STXM/NEXAFS to particles collected during a mesocosm study using a unique wave channel facility to generate aerosols shows that the organic volume fraction of aerosols at the aerodynamic diameter size range of 0.18-0.32 μm are a direct function of the biological activity in the sea water. Aerosol organic volume fraction increased from 0.32 for particles generated from seawater containing low biolife to 0.49 and 0.40 for particles produced during phytoplankton blooms. However, the organic volume fraction of aerosols at the aerodynamic diameter size range of 0.56-1 μm did not change with biological activity. Measurements also show that different types of organics can concentrate into aerosols depending on the enzyme activity expressed at the time. Enhanced spectral signatures for aliphatic hydrocarbons were observed during the first phytoplankton bloom compared to a second phytoplankton bloom occurring directly thereafter. The decreased signature of aliphatic organics in the second phytoplankton bloom was correlated with increased lipase activity from heterobacteria. Organic aggregates having similar morphology also differ in composition from their carbon spectra from the two blooms. For July 17, organic aggregates were much richer in hydrocarbons, which showed a remarkably intense C-H absorbance and a broad C-C absorbance. Organic aggregates observed for July 26-27, did not have the C-H and C-C signatures, but contained more polar

  16. Heat, Mass and Aerosol Transfers in Spray Conditions for Containment Application

    NASA Astrophysics Data System (ADS)

    Porcheron, Emmanuel; Lemaitre, Pascal; Nuboer, Amandine; Vendel, Jacques

    TOSQAN is an experimental program undertaken by the Institut de Radioprotection et de Surété Nucleaire (IRSN) in order to perform thermal hydraulic containment studies. The TOSQAN facility is a large enclosure devoted to simulating typical accidental thermal hydraulic flow conditions in nuclear Pressurized Water Reactor (PWR) containment. The TOSQAN facility, which is highly instrumented with non-intrusive optical diagnostics, is particularly adapted to nuclear safety CFD code validation. The present work is devoted to studying the interaction of a water spray injection used as a mitigation means in order to reduce the gas pressure and temperature in the containment, to produce gases mixing and washout of fission products. In order to have a better understanding of heat and mass transfers between spray droplets and the gas mixture, and to analyze mixing effects due to spray activation, we performed detailed characterization of the two-phase flow.

  17. DEVELOPMENT OF AN INNOVATIVE SPRAY DISPENSER TO REDUCE INDOOR AIR EMISSIONS FROM AEROSOL CONSUMER PRODUCTS

    EPA Science Inventory

    The report presents the operating principles and performance of a new type of spray nozzle. This nozzle, termed a "ligament-controlled effervescent atomizer," was developed to allow consumer product manufacturers to replace volatile organic compound (VOC) solvents with water, and...

  18. Effect of In-Plume Aerosol Processing on the Efficacy of Marine Cloud Albedo Enhancement from Controlled Sea-Spray Injections

    NASA Astrophysics Data System (ADS)

    Stuart, G. S.; Stevens, R. G.; Spracklen, D. V.; Korhonen, H.; Pierce, J. R.

    2012-12-01

    The intentional enhancement of cloud albedo via controlled sea-spray injection from ships has been proposed as a possible method to control anthropogenic global warming (1); however, there remains significant uncertainty in the efficacy of this method due to uncertainties in aerosol and cloud microphysics. A major assumption used in multiple recent studies (2,3) is that all sea-spray was emitted uniformly into some oceanic grid boxes, and thus did not account for sub-grid aerosol microphysics within the sea-spray plumes. However, as a consequence of the fast sea-spray injection rates which are proposed, in the order of 10^17 1/s (1), particle concentrations in these plumes may be quite high and particle coagulation may significantly reduce the number of emitted particles and increase their average size. Therefore, it is possible that the emissions necessary to reach a desired cooling may be even larger than currently assumed. We explore the evolution of these sea-salt plumes using a multi-shelled Gaussian plume model with size-resolved aerosol coagulation. We determine how the final number and size of particles depends on the emission rate and size distribution of the emitted sea-spray plume and local atmospheric conditions, including wind speed and boundary-layer stability. Under the injection rates reported in (1) and typical marine conditions, we find that the number of aerosol particles is reduced by about 40%. This fraction decreases for decreasing emission rates or increasing wind speeds due to lower particle concentrations in the plume. Finally, we make suggestions for effective size-resolved emissions for use in climate models. (1) Salter, S. et al., Phil. Trans. R. Soc. A., 2008. (2) Korhonen, H. et al., Atmos. Chem. Phys., 10, 4133-4143, 2010. (3) Partanen, A.-I. et al., J. Geophys. Res., 117, D02203, 2012.

  19. Simulation of a spray scrubber performance with Eulerian/Lagrangian approach in the aerosol removing process.

    PubMed

    Bozorgi, Y; Keshavarz, P; Taheri, M; Fathikaljahi, J

    2006-09-01

    In this study, a mathematical model has been developed to simulate the performance of a spray scrubber in an industrial ammonium nitrate plant. The model is based on the Lagrangian approach for the droplets movement and particle source in cell (PSI-CELL) model for calculating the droplet concentration distribution. Consequently, unlike former research, the emphasis is on the droplet dynamic behavior. In the current study, for approaching a realistic model, a droplet size distribution rather than average diameter, and also liquid film formation rather than uniform and constant droplet flow rate has been applied. Also, the Eulerian method has been used for the calculation of the particles removal efficiency and energy balance has been applied on the gas to estimate the droplet size distribution. In the experimental section, the concentration of particles and their size distribution in both inlet and outlet gas of the studied scrubber has been measured for the validation of the predicted particles collection efficiency. In addition, the temperature of the gas at inlet, outlet and in the middle of the tower has been measured for the confirmation of the predicted droplet size distribution in the tower. A good consistency between the model and data has been observed. After the model is validated, it is used to investigate the various variable profiles such as liquid film, total projected surface area of the droplets, velocity profile of the droplets and some of the other parameters in the spray scrubbers.

  20. A Process-Modeling Study of Aerosol-Cloud-Precipitation Interactions in Response to Controlled Seawater Spray in Marine Boundary Layer (Invited)

    NASA Astrophysics Data System (ADS)

    Wang, H.; Rasch, P. J.; Feingold, G.

    2010-12-01

    Vast areas of the oceanic surface are covered by stratocumulus (Sc) clouds. They significantly enhance the reflection of incoming solar radiation back to space, leading to a considerable cooling of the Earth-atmosphere system. It has been argued that a 4% increase in the areal coverage or a 0.06 increase in cloud albedo of Sc clouds can offset the warming by atmospheric CO2 doubling (Randall et al. 1984; Latham et al. 2008). Acting as cloud condensation nuclei (CCN), aerosol particles can modify cloud albedo, cloud longevity and precipitation efficiency. Recent observational and modeling studies have suggested that aerosol, through its effect on precipitation, can alter cloud cellular structures in marine Sc region, representing a powerful modification of clouds by aerosol. The possibility of mitigating global warming by spraying sea-salt particles into marine boundary layer to brighten Sc clouds was raised by Latham (1990). The idea has been evaluated by several global climate model studies but their inability to represent cloud-scale dynamics and microphysics raises questions about the validity of the results. Using a high-resolution version of the Weather Research and Forecasting (WRF) model, we investigate the impact of seawater spray on the formation and evolution of marine Sc through aerosol-cloud-precipitation interactions and dynamical feedback. We will demonstrate how injected aerosol particles are transported from the ocean surface into clouds and affect cloud microphysics and macrophysics under various meteorological conditions. We will also use simulation results to explore whether the influx of sea-salt aerosols always enhances cloud albedo and how the performance depends on the distribution of sprayers.

  1. Combining contact tracing with targeted indoor residual spraying significantly reduces dengue transmission.

    PubMed

    Vazquez-Prokopec, Gonzalo M; Montgomery, Brian L; Horne, Peter; Clennon, Julie A; Ritchie, Scott A

    2017-02-01

    The widespread transmission of dengue viruses (DENV), coupled with the alarming increase of birth defects and neurological disorders associated with Zika virus, has put the world in dire need of more efficacious tools for Aedes aegypti-borne disease mitigation. We quantitatively investigated the epidemiological value of location-based contact tracing (identifying potential out-of-home exposure locations by phone interviews) to infer transmission foci where high-quality insecticide applications can be targeted. Space-time statistical modeling of data from a large epidemic affecting Cairns, Australia, in 2008-2009 revealed a complex pattern of transmission driven primarily by human mobility (Cairns accounted for ~60% of virus transmission to and from residents of satellite towns, and 57% of all potential exposure locations were nonresidential). Targeted indoor residual spraying with insecticides in potential exposure locations reduced the probability of future DENV transmission by 86 to 96%, compared to unsprayed premises. Our findings provide strong evidence for the effectiveness of combining contact tracing with residual spraying within a developed urban center, and should be directly applicable to areas with similar characteristics (for example, southern USA, Europe, or Caribbean countries) that need to control localized Aedes-borne virus transmission or to protect pregnant women's homes in areas with active Zika transmission. Future theoretical and empirical research should focus on evaluation of the applicability and scalability of this approach to endemic areas with variable population size and force of DENV infection.

  2. Combining contact tracing with targeted indoor residual spraying significantly reduces dengue transmission

    PubMed Central

    Vazquez-Prokopec, Gonzalo M.; Montgomery, Brian L.; Horne, Peter; Clennon, Julie A.; Ritchie, Scott A.

    2017-01-01

    The widespread transmission of dengue viruses (DENV), coupled with the alarming increase of birth defects and neurological disorders associated with Zika virus, has put the world in dire need of more efficacious tools for Aedes aegypti–borne disease mitigation. We quantitatively investigated the epidemiological value of location-based contact tracing (identifying potential out-of-home exposure locations by phone interviews) to infer transmission foci where high-quality insecticide applications can be targeted. Space-time statistical modeling of data from a large epidemic affecting Cairns, Australia, in 2008–2009 revealed a complex pattern of transmission driven primarily by human mobility (Cairns accounted for ~60% of virus transmission to and from residents of satellite towns, and 57% of all potential exposure locations were nonresidential). Targeted indoor residual spraying with insecticides in potential exposure locations reduced the probability of future DENV transmission by 86 to 96%, compared to unsprayed premises. Our findings provide strong evidence for the effectiveness of combining contact tracing with residual spraying within a developed urban center, and should be directly applicable to areas with similar characteristics (for example, southern USA, Europe, or Caribbean countries) that need to control localized Aedes-borne virus transmission or to protect pregnant women’s homes in areas with active Zika transmission. Future theoretical and empirical research should focus on evaluation of the applicability and scalability of this approach to endemic areas with variable population size and force of DENV infection. PMID:28232955

  3. Aerosols

    Atmospheric Science Data Center

    2013-04-17

    ... article title:  Aerosols over Central and Eastern Europe     View Larger Image ... last weeks of March 2003, widespread aerosol pollution over Europe was detected by several satellite-borne instruments. The Multi-angle ...

  4. Preparation and physicochemical characterization of spray-dried and jet-milled microparticles containing bosentan hydrate for dry powder inhalation aerosols.

    PubMed

    Lee, Hyo-Jung; Kang, Ji-Hyun; Lee, Hong-Goo; Kim, Dong-Wook; Rhee, Yun-Seok; Kim, Ju-Young; Park, Eun-Seok; Park, Chun-Woong

    2016-01-01

    The objectives of this study were to prepare bosentan hydrate (BST) microparticles as dry powder inhalations (DPIs) via spray drying and jet milling under various parameters, to comprehensively characterize the physicochemical properties of the BST hydrate microparticles, and to evaluate the aerosol dispersion performance and dissolution behavior as DPIs. The BST microparticles were successfully prepared for DPIs by spray drying from feeding solution concentrations of 1%, 3%, and 5% (w/v) and by jet milling at grinding pressures of 2, 3, and 4 MPa. The physicochemical properties of the spray-dried (SD) and jet-milled (JM) microparticles were determined via scanning electron microscopy, atomic force microscopy, dynamic light scattering particle size analysis, Karl Fischer titration, surface analysis, pycnometry, differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The in vitro aerosol dispersion performance and drug dissolution behavior were evaluated using an Anderson cascade impactor and a Franz diffusion cell, respectively. The JM microparticles exhibited an irregular corrugated surface and a crystalline solid state, while the SD microparticles were spherical with a smooth surface and an amorphous solid state. Thus, the in vitro aerosol dispersion performance and dissolution behavior as DPIs were considerably different due to the differences in the physicochemical properties of the SD and JM microparticles. In particular, the highest grinding pressures under jet milling exhibited excellent aerosol dispersion performance with statistically higher values of 56.8%±2.0% of respirable fraction and 33.8%±2.3% of fine particle fraction and lower mass median aerodynamic diameter of 5.0±0.3 μm than the others (P<0.05, analysis of variance/Tukey). The drug dissolution mechanism was also affected by the physicochemical properties that determine the dissolution kinetics of the SD and JM microparticles, which were well

  5. Preparation and physicochemical characterization of spray-dried and jet-milled microparticles containing bosentan hydrate for dry powder inhalation aerosols

    PubMed Central

    Lee, Hyo-Jung; Kang, Ji-Hyun; Lee, Hong-Goo; Kim, Dong-Wook; Rhee, Yun-Seok; Kim, Ju-Young; Park, Eun-Seok; Park, Chun-Woong

    2016-01-01

    The objectives of this study were to prepare bosentan hydrate (BST) microparticles as dry powder inhalations (DPIs) via spray drying and jet milling under various parameters, to comprehensively characterize the physicochemical properties of the BST hydrate microparticles, and to evaluate the aerosol dispersion performance and dissolution behavior as DPIs. The BST microparticles were successfully prepared for DPIs by spray drying from feeding solution concentrations of 1%, 3%, and 5% (w/v) and by jet milling at grinding pressures of 2, 3, and 4 MPa. The physicochemical properties of the spray-dried (SD) and jet-milled (JM) microparticles were determined via scanning electron microscopy, atomic force microscopy, dynamic light scattering particle size analysis, Karl Fischer titration, surface analysis, pycnometry, differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The in vitro aerosol dispersion performance and drug dissolution behavior were evaluated using an Anderson cascade impactor and a Franz diffusion cell, respectively. The JM microparticles exhibited an irregular corrugated surface and a crystalline solid state, while the SD microparticles were spherical with a smooth surface and an amorphous solid state. Thus, the in vitro aerosol dispersion performance and dissolution behavior as DPIs were considerably different due to the differences in the physicochemical properties of the SD and JM microparticles. In particular, the highest grinding pressures under jet milling exhibited excellent aerosol dispersion performance with statistically higher values of 56.8%±2.0% of respirable fraction and 33.8%±2.3% of fine particle fraction and lower mass median aerodynamic diameter of 5.0±0.3 μm than the others (P<0.05, analysis of variance/Tukey). The drug dissolution mechanism was also affected by the physicochemical properties that determine the dissolution kinetics of the SD and JM microparticles, which were well

  6. Characterization and aerosol dispersion performance of advanced spray-dried chemotherapeutic PEGylated phospholipid particles for dry powder inhalation delivery in lung cancer.

    PubMed

    Meenach, Samantha A; Anderson, Kimberly W; Zach Hilt, J; McGarry, Ronald C; Mansour, Heidi M

    2013-07-16

    Pulmonary inhalation chemotherapeutic drug delivery offers many advantages for lung cancer patients in comparison to conventional systemic chemotherapy. Inhalable particles are advantageous in their ability to deliver drug deep in the lung by utilizing optimally sized particles and higher local drug dose delivery. In this work, spray-dried and co-spray dried inhalable lung surfactant-mimic PEGylated lipopolymers as microparticulate/nanoparticulate dry powders containing paclitaxel were rationally designed via organic solution advanced spray drying (no water) in closed-mode from dilute concentration feed solution. Dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine poly(ethylene glycol) (DPPE-PEG) with varying PEG chain length were mixed with varying amounts of paclitaxel in methanol to produce co-spray dried microparticles and nanoparticles. Scanning electron microscopy showed the spherical particle morphology of the inhalable particles. Thermal analysis and X-ray powder diffraction confirmed the retention of the phospholipid bilayer structure in the solid-state following spray drying, the degree of solid-state molecular order, and solid-state phase transition behavior. The residual water content of the particles was very low as quantified analytically Karl Fisher titration. The amount of paclitaxel loaded into the particles was quantified which indicated high encapsulation efficiencies (43-99%). Dry powder aerosol dispersion performance was measured in vitro using the Next Generation Impactor (NGI) coupled with the Handihaler dry powder inhaler device and showed mass median aerodynamic diameters in the range of 3.4-7 μm. These results demonstrate that this novel microparticulate/nanoparticulate chemotherapeutic PEGylated phospholipid dry powder inhalation aerosol platform has great potential in lung cancer drug delivery.

  7. Nanomagnetosols: magnetism opens up new perspectives for targeted aerosol delivery to the lung.

    PubMed

    Plank, Christian

    2008-02-01

    A recent article in Nature Nanotechnology reports the guiding of aerosols to specific regions of the lung using an external magnetic field. This novel approach of nanomagnetic drug targeting is made feasible with aerosols that comprise magnetically responsive nanoparticles along with a drug of choice. This promising method could be used in the future to specifically accumulate effective drug doses in diseased lung regions and thus reduce undesired side effects.

  8. Droplet Characterization and Penetration of an Ultra-Low Volume Mosquito Adulticide Spray Targeting the Asian Tiger Mosquito, Aedes albopictus, within Urban and Suburban Environments of Northeastern USA

    PubMed Central

    Faraji, Ary; Unlu, Isik; Crepeau, Taryn; Healy, Sean; Crans, Scott; Lizarraga, Griffith; Fonseca, Dina; Gaugler, Randy

    2016-01-01

    Adult control of Aedes albopictus via ultra-low volume is difficult because this species occurs primarily in peridomestic habitats where obstacles such as buildings and vegetation can disrupt spray plumes and droplet dispersion. We determined droplet penetration and characterization of a pyrethroid adulticide applied from the ground at mid (46.77 ml/ha) and maximum (93.53 ml/ha) label rates within cryptic habitats of urban and suburban environments. Droplets were collected from all habitats, with no significant differences detected between locations within the same application rate or collection method. No differences were detected in droplet densities (drops per mm2) between rates within urban environments, but more droplets were collected in urban (149.93 ± 11.07 SE) than suburban sites (114.37 ± 11.32) at the maximum label rate (P = 0.003). The excellent penetration of aerosols into cryptic habitats of an urban site was likely due to the shorter spray paths afforded by our network of roads and alleys. Mid label rates displayed similar droplet density values as maximum label rates in urban areas, indicating that lower rates may be used effectively to reduce costs, lessen non-target effects, and increase environmental stewardship. Advances in formulations and technology are driving changes in adulticide applications, leading to use of the minimum effective dose for maximum efficacy, precision, and accountability. PMID:27116103

  9. Size distributions and source function of sea spray aerosol over the South China Sea

    NASA Astrophysics Data System (ADS)

    Chu, Yingjia; Sheng, Lifang; Liu, Qian; Zhao, Dongliang; Jia, Nan; Kong, Yawen

    2016-08-01

    The number concentrations in the radius range of 0.06-5 μm of aerosol particles and meteorological parameters were measured on board during a cruise in the South China Sea from August 25 to October 12, 2012. Effective fluxes in the reference height of 10 m were estimated by steady state dry deposition method based on the observed data, and the influences of different air masses on flux were discussed in this paper. The number size distribution was characterized by a bimodal mode, with the average total number concentration of (1.50 ± 0.76)×103 cm-3. The two mode radii were 0.099 µm and 0.886 µm, both of which were within the scope of accumulation mode. A typical daily average size distribution was compared with that measured in the Bay of Bengal. In the whole radius range, the number concentrations were in agreement with each other; the modes were more distinct in this study than that abtained in the Bay of Bengal. The size distribution of the fluxes was fitted with the sum of log-normal and power-law distribution. The impact of different air masses was mainly on flux magnitude, rather than the shape of spectral distribution. A semiempirical source function that is applicable in the radius range of 0.06 µm< r 80<0.3 µm with the wind speed varying from 1.00 m s-1 to 10.00 m s-1 was derived.

  10. Comparison between the ASSET EZ4 NCO and Impinger Sampling Devices for Aerosol Sampling of 4,4'-Methylene Diphenyl Diisocyanate in Spray Foam Application.

    PubMed

    Puscasu, Silvia; Aubin, Simon; Cloutier, Yves; Sarazin, Philippe; Van Tra, Huu; Gagné, Sébastien

    2015-08-01

    4,4'-methylene diphenyl diisocyanate (MDI) aerosol exposure evaluation in spray foam insulation application is known to be a challenge. Current available techniques are either not user-friendly or are inaccurate or are not validated for this application. A new sampler has recently been developed to address the user-friendliness issues with other samplers: the ASSET EZ4-NCO, but the use of this sampler in spray foam insulation applications has not been demonstrated or validated. Because of this, the current work was undertaken to provide a comparison of the ASSET sampler with an impinger method, considered to be the best available method in the context of spray foam insulation, and hence the pertinence of comparing this sampler to an impinger method, considered to be the best available method for measuring MDI monomer and oligomers for this particular application. Liquid chromatography coupled with tandem mass spectrometry method for MDI monomer and oligomer analysis was implemented based on the Supelco literature. It allows the analysis of MDI-dibutylamine (DBA) and MDI 3-ring-DBA with a minimum reported value of 5ng ml(-1), a dynamic range of 5-140ng ml(-1), precision <15% and accuracy >80%. This method was used to quantify MDI aerosols collected with the ASSET sampler in an MDI spray foam environment in parallel with the toluene/MOPIP impinger reference method. The ASSET sampler significantly underestimated the levels of MDI monomer and oligomers when compared to the reference method. The estimated bias was 72% (95% confidence interval [CI] 54-89%) for the monomer and 96% (95% CI 76-115%) for the oligomers. These results demonstrate the importance of evaluating each new sampler for each isocyanate application prior to a formal worker exposure evaluation.

  11. Granule size control and targeting in pulsed spray fluid bed granulation.

    PubMed

    Ehlers, Henrik; Liu, Anchang; Räikkönen, Heikki; Hatara, Juha; Antikainen, Osmo; Airaksinen, Sari; Heinämäki, Jyrki; Lou, Honxiang; Yliruusi, Jouko

    2009-07-30

    The primary aim of the study was to investigate the effects of pulsed liquid feed on granule size. The secondary aim was to increase knowledge of this technique in granule size targeting. Pulsed liquid feed refers to the pump changing between on- and off-positions in sequences, called duty cycles. One duty cycle consists of one on- and off-period. The study was performed with a laboratory-scale top-spray fluid bed granulator with duty cycle length and atomization pressure as studied variables. The liquid feed rate, amount and inlet air temperature were constant. The granules were small, indicating that the powder has only undergone ordered mixing, nucleation and early growth. The effect of atomizing pressure on granule size depends on inlet air relative humidity, with premature binder evaporation as a reason. The duty cycle length was of critical importance to the end product attributes, by defining the extent of intermittent drying and rewetting. By varying only the duty cycle length, it was possible to control granule nucleation and growth, with a wider granule size target range in increased relative humidity. The present study confirms that pulsed liquid feed in fluid bed granulation is a useful tool in end product particle size targeting.

  12. The effect of excipients on the stability and aerosol performance of salmon calcitonin dry powder inhalers prepared via the spray freeze drying process.

    PubMed

    Poursina, Narges; Vatanara, Alireza; Rouini, Mohammad Reza; Gilani, Kambiz; Najafabadi, Abdolhossein Rouholamini

    2016-06-01

    Spray freeze drying was developed to produce dry powders suitable for applications such as inhalation delivery. In the current study, the spray freeze drying technique was employed to produce inhalable salmon calcitonin microparticles. Effects of the carrier type, concentration of hydroxyl propyl-β-cyclodextrin and the presence of Tween 80 on the chemical and structural stability, as well as on the aerosol performance of the particles were investigated. The results indicated that hydroxyl propyl-β-cyclodextrin had the most important effect on the chemical stability of the powder and strongly increased its stability by increasing its concentration in the formulation. Chemically stable formulations (over 90 % recovery) were selected for further examinations. Fluorescence spectroscopy and circular dichroism suggested that the formulations were structurally stable. Aerosol performance showed that the Tween-free powders produced higher fine particle fraction values than the formulations containing Tween (53.7 vs. 41.92 % for trehalose content and 52.85 vs. 43.06 % for maltose content).

  13. Characterization and Cytotoxic Assessment of Ballistic Aerosol Particulates for Tungsten Alloy Penetrators into Steel Target Plates

    PubMed Central

    Machado, Brenda I.; Murr, Lawrence E.; Suro, Raquel M.; Gaytan, Sara M.; Ramirez, Diana A.; Garza, Kristine M.; Schuster, Brian E.

    2010-01-01

    The nature and constituents of ballistic aerosol created by kinetic energy penetrator rods of tungsten heavy alloys (W-Fe-Ni and W-Fe-Co) perforating steel target plates was characterized by scanning and transmission electron microscopy. These aerosol regimes, which can occur in closed, armored military vehicle penetration, are of concern for potential health effects, especially as a consequence of being inhaled. In a controlled volume containing 10 equispaced steel target plates, particulates were systematically collected onto special filters. Filter collections were examined by scanning and transmission electron microscopy (SEM and TEM) which included energy-dispersive (X-ray) spectrometry (EDS). Dark-field TEM identified a significant nanoparticle concentration while EDS in the SEM identified the propensity of mass fraction particulates to consist of Fe and FeO, representing target erosion and formation of an accumulating debris field. Direct exposure of human epithelial cells (A549), a model for lung tissue, to particulates (especially nanoparticulates) collected on individual filters demonstrated induction of rapid and global cell death to the extent that production of inflammatory cytokines was entirely inhibited. These observations along with comparisons of a wide range of other nanoparticulate species exhibiting cell death in A549 culture may suggest severe human toxicity potential for inhaled ballistic aerosol, but the complexity of the aerosol (particulate) mix has not yet allowed any particular chemical composition to be identified. PMID:20948926

  14. Characterization and cytotoxic assessment of ballistic aerosol particulates for tungsten alloy penetrators into steel target plates.

    PubMed

    Machado, Brenda I; Murr, Lawrence E; Suro, Raquel M; Gaytan, Sara M; Ramirez, Diana A; Garza, Kristine M; Schuster, Brian E

    2010-09-01

    The nature and constituents of ballistic aerosol created by kinetic energy penetrator rods of tungsten heavy alloys (W-Fe-Ni and W-Fe-Co) perforating steel target plates was characterized by scanning and transmission electron microscopy. These aerosol regimes, which can occur in closed, armored military vehicle penetration, are of concern for potential health effects, especially as a consequence of being inhaled. In a controlled volume containing 10 equispaced steel target plates, particulates were systematically collected onto special filters. Filter collections were examined by scanning and transmission electron microscopy (SEM and TEM) which included energy-dispersive (X-ray) spectrometry (EDS). Dark-field TEM identified a significant nanoparticle concentration while EDS in the SEM identified the propensity of mass fraction particulates to consist of Fe and FeO, representing target erosion and formation of an accumulating debris field. Direct exposure of human epithelial cells (A549), a model for lung tissue, to particulates (especially nanoparticulates) collected on individual filters demonstrated induction of rapid and global cell death to the extent that production of inflammatory cytokines was entirely inhibited. These observations along with comparisons of a wide range of other nanoparticulate species exhibiting cell death in A549 culture may suggest severe human toxicity potential for inhaled ballistic aerosol, but the complexity of the aerosol (particulate) mix has not yet allowed any particular chemical composition to be identified.

  15. Comparing MODIS C6 'Deep Blue' and 'Dark Target' Aerosol Data

    NASA Technical Reports Server (NTRS)

    Hsu, N. C.; Sayer, A. M.; Bettenhausen, C.; Lee, J.; Levy, R. C.; Mattoo, S.; Munchak, L. A.; Kleidman, R.

    2014-01-01

    The MODIS Collection 6 Atmospheres product suite includes refined versions of both 'Deep Blue' (DB) and 'Dark Target' (DT) aerosol algorithms, with the DB dataset now expanded to include coverage over vegetated land surfaces. This means that, over much of the global land surface, users will have both DB and DT data to choose from. A 'merged' dataset is also provided, primarily for visualization purposes, which takes retrievals from either or both algorithms based on regional and seasonal climatologies of normalized difference vegetation index (NDVI). This poster present some comparisons of these two C6 aerosol algorithms, focusing on AOD at 550 nm derived from MODIS Aqua measurements, with each other and with Aerosol Robotic Network (AERONET) data, with the intent to facilitate user decisions about the suitability of the two datasets for their desired applications.

  16. Aerosol Retrieval over Urban Area in MODIS Dark Target Land Algorithm

    NASA Astrophysics Data System (ADS)

    Gupta, P.; Levy, R. C.; Mattoo, S.

    2013-12-01

    Urban air quality in many parts of the globe has reached at dangerous level (5 to 10 times higher than WHO guidelines) as urbanization and industrialization have amplified many folds during the last few decades. More than half of the world's population now lives in urban areas and their number will increase 60% by 2030. Therefore it is very critical to monitor air quality (aerosol or PM) on a daily basis; especially in populated regions (urban areas) around the world. The new version (C6) of MODIS Dark Target Land Aerosol Algorithm (MDT) provides aerosol optical depth (AOD) retrievals at 10km2 and 3km2 spatial resolutions over dark vegetated regions. Initial validation efforts during DISCOVER-AQ field campaign over Baltimore-DC area shows that MDT overestimates AOD over urban areas, mainly because the bright and complex urban surface is not characterized properly. Accurate estimation of the surface signal within satellite-measured radiance is essential for aerosol retrieval. Surface characterization can be challenging and small error (~0.01) can produce large errors in retrieved AOD (~0.1). In this new approach, we have modified the surface characterization for urban areas, using the urban percentage information from the MODIS Land Product. We used the MODIS land surface spectral reflectance product to redefine the relationship between shortwave-IR and visible wavelengths over urban areas. We derived new surface characterization for urban area and used the DRAGON network measurements, during DISCOVER-AQ field campaigns, to validate the new AOD retrievals both in 10km and 3km spatial resolution. Initial inter-comparison with AERONET data over US shows significant improvement in AOD retrieval over urban areas. This improved AOD retrieval will be an important step toward utilization of satellite based particulate matter estimation for surface air quality monitoring. We also evaluate whether the new 3km product can enable studies of small-scale gradients in aerosol

  17. Single-particle investigation of summertime and wintertime Antarctic sea spray aerosols using low-Z particle EPMA, Raman microspectrometry, and ATR-FTIR imaging techniques

    NASA Astrophysics Data System (ADS)

    Eom, Hyo-Jin; Gupta, Dhrubajyoti; Cho, Hye-Rin; Hwang, Hee Jin; Do Hur, Soon; Gim, Yeontae; Ro, Chul-Un

    2016-11-01

    Two aerosol samples collected at King Sejong Korean scientific research station, Antarctica, on 9 December 2011 in the austral summer (sample S1) and 23 July 2012 in the austral winter (sample S2), when the oceanic chlorophyll a levels on the collection days of the samples were quite different, by ˜ 19 times (2.46 vs. 0.13 µg L-1, respectively), were investigated on a single-particle basis using quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA), called low-Z particle EPMA, Raman microspectrometry (RMS), and attenuated total reflection Fourier transform infrared (ATR-FTIR) imaging techniques to obtain their characteristics based on the elemental chemical compositions, molecular species, and mixing state. X-ray analysis showed that the supermicron summertime and wintertime Antarctic aerosol samples have different elemental chemical compositions, even though all the individual particles analyzed were sea spray aerosols (SSAs); i.e., the contents of C, O, Ca, S, and Si were more elevated, whereas Cl was more depleted, for sample S1 than for sample S2. Based on qualitative analysis of the chemical species present in individual SSAs by the combined application of RMS and ATR-FTIR imaging, different organic species were observed in samples S1 and S2; i.e., Mg hydrate salts of alanine were predominant in samples S1 and S2, whereas Mg salts of fatty acids internally mixed with Mg hydrate salts of alanine were significant in sample S2. Although CaSO4 was observed significantly in both samples S1 and S2, other inorganic species, such as Na2SO4, NaNO3, Mg(NO3)2, SiO2, and CH3SO3Mg, were observed more significantly in sample S1, suggesting that those compounds may be related to the higher phytoplankton activity in summer.

  18. Temporal indications of atmospheric stability affecting off-target spray drift in the midsouth U S

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to determine atmospheric conditions favorable for long-distance spray drift deleterious to susceptible crops. A tall meteorological monitoring tower equipped with six precision (and periodically calibrated) thermistors at six heights to 27.4 m and wind speed anemometers at fo...

  19. Atmospheric stability intervals influencing the potential for off-target movement of spray in aerial application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to determine atmospheric conditions favorable for long-distance movement of spray from aerial application that can have deleterious consequences to susceptible crops. A tall meteorological monitoring tower was equipped with six precision thermistors at six heights to 27.4 m a...

  20. Generation of aerosolized drugs.

    PubMed

    Wolff, R K; Niven, R W

    1994-01-01

    The expanding use of inhalation therapy has placed demands on current aerosol generation systems that are difficult to meet with current inhalers. The desire to deliver novel drug entities such as proteins and peptides, as well as complex formulations including liposomes and microspheres, requires delivery systems of improved efficiency that will target the lung in a reproducible manner. These efforts have also been spurred by the phase out of chlorofluorocarbons (CFCs) and this has included a directed search for alternative propellants. Consequently, a variety of new aerosol devices and methods of generating aerosols are being studied. This includes the use of freon replacement propellants, dry powder generation systems, aqueous unit spray systems and microprocessor controlled technologies. Each approach has advantages and disadvantages depending upon each principle of action and set of design variables. In addition, specific drugs may be better suited for one type of inhaler device vs. another. The extent to which aerosol generation systems achieve their goals is discussed together with a summary of selected papers presented at the recent International Congress of Aerosols in Medicine.

  1. Efficacy of Dinotefuran (Alpine® spray and dust) on six species of stored product insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dinotefuran, an agonist of insect nicotinic acetylcholine receptors, was evaluated both as a 0.5% active ingredient aerosol spray and a dust combined with diatomaceous earth (DE), 5 g/m2 and 10g/m2), at 45% r.h. and 75% r.h. Target species were six adult stored product insect species: Tribolium cast...

  2. Review: The Status of Magnetic Aerosol Drug Targeting in the Lung

    NASA Astrophysics Data System (ADS)

    Ally, Javed; Amirfazli, A.

    2010-12-01

    From a fundamental perspective, to develop a targeting system for aerosolized magnetic particles in the lung, the issues of particle deposition and retention need special attention. Unlike delivery of magnetic particles in the circulatory system, particles must be captured from a gaseous phase flowing in relatively large ducts rather than from a liquid flow in narrow veins. This means that collection efficiencies will be significantly different between the two systems. Furthermore, the airway clearance mechanism is designed to remove foreign particles, but there is no such defense mechanism present in the circulatory system. This presents a challenge which requires understanding of particle aggregation at the target site and drag force operating on them before a robust clinical solution can be developed. This review summarizes recent findings in the literature and presents outlook for further research.

  3. Skin exposure to deodorants/antiperspirants in aerosol form.

    PubMed

    Steiling, W; Buttgereit, P; Hall, B; O'Keeffe, L; Safford, B; Tozer, S; Coroama, M

    2012-06-01

    Many cosmetic products are available in spray form. Even though the principal targets of these products are the skin and hair, spraying leads to the partitioning of the product between the target and the surrounding air. In the previous COLIPA study (Hall et al., 2007) the daily use of deodorant/antiperspirant (Deo/AP) in spray form was quantified in terms of the amount of product dispensed from the spray can, without specifically quantifying the product fraction reaching the skin during use. Results of the present study provide this additional information, necessary for a reliable safety assessment of sprayed Deo/AP products. In a novel experimental approach the information obtained from real-life movement analysis (automated motion imaging) of volunteers using their own products was integrated with the aerosol cloud sampling data obtained from the same products, leading to the computation of the product deposited on the skin. The 90th percentile values, expressed as percent deposition relative to the can weight loss after spraying, are 23.5% and 11.4% for ethanol-based and non-ethanol-based products, respectively. Additionally, the study has generated data on the skin area covered by the products, spray duration time, spray angle and spray distance from the skin.

  4. A modified MODIS dark-target aerosol retrieval over urban areas: Evaluation and applications

    NASA Astrophysics Data System (ADS)

    Levy, R. C.; Gupta, P.; Mattoo, S.

    2015-12-01

    With amplified urbanization and industrialization during the last few decades, now more than half of the world's population lives in urban areas. With surface particle matter (PM) concentration five or ten times higher than World Health Organization guidelines in some cities, it is very critical to accurately monitor PM air quality for global cities on a daily basis. The new version (C6) of MODIS Dark Target Land Aerosol Algorithm (MDT) provides near-daily aerosol optical depth (AOD) retrievals at 10km2 and 3km2 spatial resolutions, which can be used to estimate surface PM. However, initial validation efforts showed that MDT overestimates AOD over urban areas, primarily because the bright and complex urban surface does not meet MDT assumptions. We combined the MODIS Land Classification Product (MCD12Q1) with MODIS land surface spectral reflectance product (MOD09A1) to develop new surface characterization scheme to be used within the MDT algorithm framework. We applied the new surface characterization to the MDT algorithm, and compared the retrieved AOD with AOD observed from the ground-based AERONET's DRAGON network operated during four DISCOVER-AQ field campaigns. AOD retrievals both in 10km and 3km spatial resolution show significant improvement over urban areas over the U.S. The bias in AOD reduced to -0.01 from 0.07, percentage of retrievals within uncertainty window increased to 85% from 62%. We will also present air quality assessment and implication of air quality monitoring in cities using revised MODIS aerosol retrievals.

  5. Agricultural Spraying

    NASA Technical Reports Server (NTRS)

    1986-01-01

    AGDISP, a computer code written for Langley by Continuum Dynamics, Inc., aids crop dusting airplanes in targeting pesticides. The code is commercially available and can be run on a personal computer by an inexperienced operator. Called SWA+H, it is used by the Forest Service, FAA, DuPont, etc. DuPont uses the code to "test" equipment on the computer using a laser system to measure particle characteristics of various spray compounds.

  6. DEVELOPMENT OF AN RH -DENUDED MIE ACTIVE SAMPLING SYSTEM AND TARGETED AEROSOL CALIBRATION

    EPA Science Inventory

    The MIE pDR 1200 nephelometer provides time resolved aerosol concentrations during personal and fixed-site sampling. Active (pumped) operation allows defining an upper PM2.5 particle size, however, this dramatically increases the aerosol mass passing through the phot...

  7. A surface reflectance scheme for retrieving aerosol optical depth over urban surfaces in MODIS Dark Target retrieval algorithm

    NASA Astrophysics Data System (ADS)

    Gupta, Pawan; Levy, Robert C.; Mattoo, Shana; Remer, Lorraine A.; Munchak, Leigh A.

    2016-07-01

    The MODerate resolution Imaging Spectroradiometer (MODIS) instruments, aboard the two Earth Observing System (EOS) satellites Terra and Aqua, provide aerosol information with nearly daily global coverage at moderate spatial resolution (10 and 3 km). Almost 15 years of aerosol data records are now available from MODIS that can be used for various climate and air-quality applications. However, the application of MODIS aerosol products for air-quality concerns is limited by a reduction in retrieval accuracy over urban surfaces. This is largely because the urban surface reflectance behaves differently than that assumed for natural surfaces. In this study, we address the inaccuracies produced by the MODIS Dark Target (MDT) algorithm aerosol optical depth (AOD) retrievals over urban areas and suggest improvements by modifying the surface reflectance scheme in the algorithm. By integrating MODIS Land Surface Reflectance and Land Cover Type information into the aerosol surface parameterization scheme for urban areas, much of the issues associated with the standard algorithm have been mitigated for our test region, the continental United States (CONUS). The new surface scheme takes into account the change in underlying surface type and is only applied for MODIS pixels with urban percentage (UP) larger than 20 %. Over the urban areas where the new scheme has been applied (UP > 20 %), the number of AOD retrievals falling within expected error (EE %) has increased by 20 %, and the strong positive bias against ground-based sun photometry has been eliminated. However, we note that the new retrieval introduces a small negative bias for AOD values less than 0.1 due to the ultra-sensitivity of the AOD retrieval to the surface parameterization under low atmospheric aerosol loadings. Global application of the new urban surface parameterization appears promising, but further research and analysis are required before global implementation.

  8. From MODIS to VIIRS: Steps toward continuing the dark-target aerosol climate data record

    NASA Astrophysics Data System (ADS)

    Levy, R. C.; Mattoo, S.; Liu, H.; Munchak, L. A.; Laszlo, I.; Cronk, H.

    2012-12-01

    By this fall-2012 AGU meeting, the Moderate Resolution Imaging Spectrometer (MODIS) has been flying on NASA's Terra and Aqua satellites for 13 years and 10.5 years, respectively. During this time, the MODIS Aerosol Science Team has fine-tuned the aerosol retrieval algorithms and data processing protocols, resulting in a highly robust, stable and usable aerosol product. The aerosol optical depth (AOD) product has been validated extensively, and the MODIS-retrieved environmental data record (EDR) is becoming a strong foundation for creating an aerosol climate data record (CDR). With last year's launch of the Visible and Infrared Imaging Radiometer Suite (VIIRS) aboard Suomi-NPP, the VIIRS-derived aerosol product has been designed to continue that provided by MODIS. VIIRS and MODIS have similar orbital mechanics and provide similar spectral resolution with similar spatial resolution. At the same time, the VIIRS and MODIS aerosol algorithms have similar physical assumptions. In fact, the initial validation exercises suggest that, in general, the VIIRS aerosol product is performing well, and that the expected error for the VIIRS-derived AOD is similar to that reported by MODIS. Although VIIRS should be able to derive an aerosol product similar in quality to MODIS, can the VIIRS aerosol record be "stitched" together with the MODIS record? To answer this question, instead of qualifying how similar they are, we need to quantify how their differences can and do impact the resulting aerosol products. There are instrumental differences, such as orbit altitude (805km versus 705km), spatial resolution (375m/750m versus 250m/500m/1000m), spectral differences, and sampling differences). There are pre-processing differences (cloud masking, gas correction assumptions, pixel selection protocols). There are retrieval algorithm differences, and of course final processing and quality control differences. Although we expect that most of differences have little or no impact, some may be

  9. Micro-physical properties of carbonaceous aerosol particles generated by laser ablation of a graphite target

    NASA Astrophysics Data System (ADS)

    Ajtai, T.; Utry, N.; Pintér, M.; Tápai, Cs.; Kecskeméti, G.; Smausz, T.; Hopp, B.; Bozóki, Z.; Szabó, G.

    2014-09-01

    In this work the authors propose laser ablation as a highly versatile tool for carbonaceous aerosol generation. The generated carbonaceous particles can be used as a model aerosol for atmospheric black carbon. Various microphysical properties including mass concentration, size distribution and morphology of aerosol particles generated by laser ablation of a high purity graphite sample were investigated in detail. These measurements proved that the proposed method can be used to generate both primary particles and fractal aggregates with a high yield. As a further advantage of the method the size distribution of the generated aerosol can cover a wide range, and can be tuned accurately with laser fluence, the ambient composition or with the volumetric flow rate of the carrier gas.

  10. Comparison of C5 and C6 Aqua-MODIS Dark Target Aerosol Validation

    NASA Technical Reports Server (NTRS)

    Munchak, Leigh A.; Levy, Robert C.; Mattoo, Shana

    2014-01-01

    We compare C5 and C6 validation to compare the C6 10 km aerosol product against the well validated and trusted aerosol product on global and regional scales. Only the 10 km aerosol product is evaluated in this study, validation of the new C6 3 km aerosol product still needs to be performed. Not all of the time series has processed yet for C5 or C6, and the years processed for the 2 products is not exactly the same (this work is preliminary!). To reduce the impact of outlier observations, MODIS is spatially averaged within 27.5 km of the AERONET site, and AERONET is temporatally averaged within 30 minutes of the MODIS overpass time. Only high quality (QA = 3 over land, QA greater than 0 over ocean) pixels are included in the mean.

  11. IN SILLICO LOBAR MODELS OF HUMAN LUNGS FOR TARGETED DELIVERY OF AEROSOLIZED PHARMACEUTICALS

    EPA Science Inventory

    The identification of factors affecting the deposition patterns of aerosolized pharmaceuticals has important implications to medicine (e.g., inhalation therapy regimens) and toxicology (e.g., drug testing protocols). Airway morphology is a critical element of the process, influen...

  12. Ventilation Guidance for Spray Polyurethane Foam Application

    EPA Pesticide Factsheets

    Properly designed ventilation can reduce airborne levels of aerosols, mists, and vapors generated during spray application and can help protect SPF applicators, helpers, and others who may be working in adjacent areas.

  13. Nicotine Delivery to Rats via Lung Alveolar Region-Targeted Aerosol Technology Produces Blood Pharmacokinetics Resembling Human Smoking

    PubMed Central

    2013-01-01

    Introduction: Nicotine is a heavily used addictive drug acquired through smoking tobacco. Nicotine in cigarette smoke is deposited and absorbed in the lungs, which results in a rapidly peaked slowly declining arterial concentration. This pattern plays an important role in initiation of nicotine addiction. Methods: A method and device were developed for delivering nicotine to rodents with lung alveolar region-targeted aerosol technology. The dose of delivery can be controlled by the nicotine aerosol concentration and duration of exposure. Results: Our data showed that, in the breathing zone of the nose-only exposure chamber, the aerosol droplet size distribution was within the respirable diameter range. Rats were exposed to nicotine aerosol for 2min. The arterial blood nicotine concentration reached 43.2±15.7ng/ml (mean ± SD) within 1–4min and declined over the next 20min, closely resembling the magnitude and early pharmacokinetics of a human smoking a cigarette. The acute inhalation toxicity of nicotine: LC50 = 2.3mg/L was determined; it was affected by pH, suggesting that acidification decreases nicotine absorption and/or bioavailability. Conclusions: A noninvasive method and toolkit were developed for delivering nicotine to rodents that enable rapid delivery of a controllable amount of nicotine into the systemic circulation and brain-inducing dose-dependent pharmacological effects, even a lethal dose. Aerosol inhalation can produce nicotine kinetics in both arterial and venous blood resembling human smoking. This method can be applied to studies of the effects of chronic intermittent nicotine exposure, nicotine addiction, toxicology, tobacco-related diseases, teratogenicity, and for discovery of pharmacological therapeutics. PMID:23239844

  14. Closed loop spray cooling apparatus

    NASA Technical Reports Server (NTRS)

    Alger, D. L.; Schwab, W. B.; Furman, E. R. (Inventor)

    1979-01-01

    A closed loop apparatus for jet spraying coolant against the back of a radiation target is described. The coolant is circulated through a closed loop with a bubble of inert gas being maintained around the spray. Mesh material is disposed between the bubble and the surface of the liquid coolant which is below the bubble at a predetermined level. In a second arrangement no inert gas is used, the bubble consists of vapor produced when the coolant is sprayed against the target.

  15. An Unmanned Aerial Vehicle-Mounted Cold Mist Spray of Permethrin and Tetramethylfluthrin Targeting Aedes albopictus in China.

    PubMed

    Li, Chun-Xiao; Zhang, Ying-Mei; Dong, Yan-De; Zhou, Ming-Hao; Zhang, Heng-Duan; Chen, Hong-Na; Tian, Ye; Yang, Wei-Fang; Wu, Xiao-Qun; Chu, Hong-Liang; Zhao, Tong-Yan

    2016-03-01

    Aedes albopictus is the primary vector of dengue fever and dengue hemorrhagic fever in China. Although there are previous studies on the application of adulticides to control this species, the application methods have either been back-pack or vehicle-mounted systems. However, many sites are too large to be effectively treated with back-pack sprayers, and the lack of roads restricts the use of vehicle-mounted sprayers. This paper provides the first study of using unmanned aerial vehicles to conduct cold mist sprays on Ae. albopictus habitats. A spray containing 4% permethrin and 1% tetramethylfluthrin was applied at an effective application rate of 9.0 mg/m(2). This method reduced Ae. albopictus populations by more than 90%. The results indicate this novel spray system is a powerful method to achieve a rapid decline of mosquito population in Ae. albopictus habitats in China.

  16. Improved MODIS Dark Target aerosol optical depth algorithm over land: angular effect correction

    NASA Astrophysics Data System (ADS)

    Wu, Yerong; de Graaf, Martin; Menenti, Massimo

    2016-11-01

    Aerosol optical depth (AOD) product retrieved from MODerate Resolution Imaging Spectroradiometer (MODIS) measurements has greatly benefited scientific research in climate change and air quality due to its high quality and large coverage over the globe. However, the current product (e.g., Collection 6) over land needs to be further improved. The is because AOD retrieval still suffers large uncertainty from the surface reflectance (e.g., anisotropic reflection) although the impacts of the surface reflectance have been largely reduced using the Dark Target (DT) algorithm. It has been shown that the AOD retrieval over dark surface can be improved by considering surface bidirectional distribution reflectance function (BRDF) effects in previous study. However, the relationship of the surface reflectance between visible and shortwave infrared band that applied in the previous study can lead to an angular dependence of the AOD retrieval. This has at least two reasons. The relationship based on the assumption of isotropic reflection or Lambertian surface is not suitable for the surface bidirectional reflectance factor (BRF). However, although the relationship varies with the surface cover type by considering the vegetation index NDVISWIR, this index itself has a directional effect and affects the estimation of the surface reflection, and it can lead to some errors in the AOD retrieval. To improve this situation, we derived a new relationship for the spectral surface BRF in this study, using 3 years of data from AERONET-based Surface Reflectance Validation Network (ASRVN). To test the performance of the new algorithm, two case studies were used: 2 years of data from North America and 4 months of data from the global land. The results show that the angular effects of the AOD retrieval are largely reduced in most cases, including fewer occurrences of negative retrievals. Particularly, for the global land case, the AOD retrieval was improved by the new algorithm compared to the

  17. Plasma-sprayed coatings

    SciTech Connect

    Herman, H.

    1988-09-01

    Plasma spraying is one way to apply protective coatings. The hot, high-speed flame of a plasma gun can melt a powder of almost any ceramic or metal and spray it to form a coating for protection against corrosion, wear or high temperature. The technique carries much less risk of degrading the coating and substrate than many other high-temperature processes do, because the gas in the plasma flame is chemically inert and the target can be kept fairly cool. And yet a plasma gun can be only a little more cumbersome than a paint sprayer. Investigators are applying this technique to new materials. The General Electric Company is using vacuum plasma spraying to make freestanding components: intricate aircraft engine parts formed by plasma-spraying a superalloy on a removable substrate. Other workers spray ceramic particles or fibers and metal powder simulatious wrong, stiff composite materials: the ceramic particles dispersed in a matrix of metal. The author and colleagues at the U.S. Naval Research Laboratory have fabricated a thick film of high-temperature superconductor by plasma-spraying the compound in the form of a powder. 7 figs.

  18. Rapid and Sensitive Detection of Pseudomonas aeruginosa in Chlorinated Water and Aerosols targeting gyrB gene using Real-time PCR

    PubMed Central

    Lee, Chang Soo; Wetzel, Kaedra; Buckley, Timothy; Wozniak, Daniel; Lee, Jiyoung

    2011-01-01

    Aims For the rapid detection of P. aeruginosa from chlorinated water and aerosols, gyrB gene-based real-time PCR assay was developed and investigated. Methods and Results Two novel primer sets (pa722F/746MGB/899R and pa722F/746MGB/788R) were designed using the most updated 611 Pseudomonas and 748 other bacterial gyrB genes for achieving high specificity. Their specificity showed 100% accuracy when tested with various strains including clinical isolates from cystic fibrosis patients. The assay was tested with P. aeruginosa-containing chlorinated water and aerosols to simulate the waterborne and airborne transmission routes (detection limit 3.3 × 102 CFU·PCR−1 − 2.3 × 103 CFU·PCR−1). No chlorine interference in real-time PCR was observed at drinking water level (~ 1 mg·L−1), but high level of chorine (12 mg·L−1) interfered the assay, thus neutralization was needed. P. aeruginosa in aerosol was successfully detected after capturing with gelatin filters with minimum 2 min of sampling time when the initial concentration of 104 CFU·mL−1 bacteria existed in the nebulizer. Conclusions A highly specific and rapid assay (2–3 hrs) was developed by targeting gyrB gene for the detection of P. aeruginosa in chlorinated water and aerosols, combined with optimized sample collection methods and sample processing, so the direct DNA extraction from either water or aerosol was possible while achieving the desired sensitivity of the method. Significance and Impact The new assay can provide timely and accurate risk assessment to prevent P. aeruginosa exposure from water and aerosol, resulting in reduced disease burden, especially among immune-compromised and susceptible individuals. This approach can be easily utilized as a platform technology for the detection of other types of microorganisms, especially for those that are transmitted via water and aerosol routes, such as Legionella pneumophila. PMID:21794031

  19. Tropospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Buseck, P. R.; Schwartz, S. E.

    2003-12-01

    It is widely believed that "On a clear day you can see forever," as proclaimed in the 1965 Broadway musical of the same name. While an admittedly beautiful thought, we all know that this concept is only figurative. Aside from Earth's curvature and Rayleigh scattering by air molecules, aerosols - colloidal suspensions of solid or liquid particles in a gas - limit our vision. Even on the clearest day, there are billions of aerosol particles per cubic meter of air.Atmospheric aerosols are commonly referred to as smoke, dust, haze, and smog, terms that are loosely reflective of their origin and composition. Aerosol particles have arisen naturally for eons from sea spray, volcanic emissions, wind entrainment of mineral dust, wildfires, and gas-to-particle conversion of hydrocarbons from plants and dimethylsulfide from the oceans. However, over the industrial period, the natural background aerosol has been greatly augmented by anthropogenic contributions, i.e., those produced by human activities. One manifestation of this impact is reduced visibility (Figure 1). Thus, perhaps more than in other realms of geochemistry, when considering the composition of the troposphere one must consider the effects of these activities. The atmosphere has become a reservoir for vast quantities of anthropogenic emissions that exert important perturbations on it and on the planetary ecosystem in general. Consequently, much recent research focuses on the effects of human activities on the atmosphere and, through them, on the environment and Earth's climate. For these reasons consideration of the geochemistry of the atmosphere, and of atmospheric aerosols in particular, must include the effects of human activities. (201K)Figure 1. Impairment of visibility by aerosols. Photographs at Yosemite National Park, California, USA. (a) Low aerosol concentration (particulate matter of aerodynamic diameter less than 2.5 μm, PM2.5=0.3 μg m-3; particulate matter of aerodynamic diameter less than 10

  20. Studies and correlation among the structural, electrical and gas response properties of aerosol spray deposited self assembled nanocrystalline CuO

    NASA Astrophysics Data System (ADS)

    Singh, Iqbal; Bedi, R. K.

    2011-06-01

    Nanostructured CuO films have been grown on to the glass substrate by varying the deposition time from 10 to 30 min and substrate temperature from 300 to 400 °C by a simple ultrasonic spray pyrolysis technique, using aqueous a cupric nitrate solution as precursor. The effect of the substrate temperature on the textural, structural, electrical, and gas sensing properties of CuO films was studied and correlated. Thermal analysis of the dried precursor shows the elimination of physisorbed and chemisorbed water. It suggests the formation of CuO phase on substrate at temperature of 300 °C. X-ray diffractograms of the films indicate the formation of polycrystalline monoclinic CuO having monoclinic with crystallite size around 18 nm. The texture coefficient finds the (0 0 2) plane as the preferred orientation in films. The microstrain and dislocation densities have been calculated and found to decreases with increase in substrate temperature. The scanning electron micrographs indicate the formation of trapezium like facet structures on the film surface. AFM analysis shows uniform deposition of the CuO film over the entire substrate surface. Observations reveal that the film deposited at 300 °C show comparatively higher activation energy and appreciable response to ammonia at room temperature. The use of aqueous cupric nitrate as precursor results in the deposition of single phase copper oxide films.

  1. Quantitative Assessment of Spray Deposition with Water-Sensitive Paper

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spray droplets, discharged from the lower six nozzles of an airblast sprayer, were sampled on pairs of absorbent filter and water-sensitive papers at nine distances from sprayer. Spray deposition on filter targets were measured by fluorometry and spray distribution on WSP targets were assessed by t...

  2. Sugars in Antarctic aerosol

    NASA Astrophysics Data System (ADS)

    Barbaro, Elena; Kirchgeorg, Torben; Zangrando, Roberta; Vecchiato, Marco; Piazza, Rossano; Barbante, Carlo; Gambaro, Andrea

    2015-10-01

    The processes and transformations occurring in the Antarctic aerosol during atmospheric transport were described using selected sugars as source tracers. Monosaccharides (arabinose, fructose, galactose, glucose, mannose, ribose, xylose), disaccharides (sucrose, lactose, maltose, lactulose), alcohol-sugars (erythritol, mannitol, ribitol, sorbitol, xylitol, maltitol, galactitol) and anhydrosugars (levoglucosan, mannosan and galactosan) were measured in the Antarctic aerosol collected during four different sampling campaigns. For quantification, a sensitive high-pressure anion exchange chromatography was coupled with a single quadrupole mass spectrometer. The method was validated, showing good accuracy and low method quantification limits. This study describes the first determination of sugars in the Antarctic aerosol. The total mean concentration of sugars in the aerosol collected at the "Mario Zucchelli" coastal station was 140 pg m-3; as for the aerosol collected over the Antarctic plateau during two consecutive sampling campaigns, the concentration amounted to 440 and 438 pg m-3. The study of particle-size distribution allowed us to identify the natural emission from spores or from sea-spray as the main sources of sugars in the coastal area. The enrichment of sugars in the fine fraction of the aerosol collected on the Antarctic plateau is due to the degradation of particles during long-range atmospheric transport. The composition of sugars in the coarse fraction was also investigated in the aerosol collected during the oceanographic cruise.

  3. Physicochemical characterization and water vapor sorption of organic solution advanced spray-dried inhalable trehalose microparticles and nanoparticles for targeted dry powder pulmonary inhalation delivery.

    PubMed

    Li, Xiaojian; Mansour, Heidi M

    2011-12-01

    Novel advanced spray-dried inhalable trehalose microparticulate/nanoparticulate powders with low water content were successfully produced by organic solution advanced spray drying from dilute solution under various spray-drying conditions. Laser diffraction was used to determine the volumetric particle size and size distribution. Particle morphology and surface morphology was imaged and examined by scanning electron microscopy. Hot-stage microscopy was used to visualize the presence/absence of birefringency before and following particle engineering design pharmaceutical processing, as well as phase transition behavior upon heating. Water content in the solid state was quantified by Karl Fisher (KF) coulometric titration. Solid-state phase transitions and degree of molecular order were examined by differential scanning calorimetry (DSC) and powder X-ray diffraction, respectively. Scanning electron microscopy showed a correlation between particle morphology, surface morphology, and spray drying pump rate. All advanced spray-dried microparticulate/nanoparticulate trehalose powders were in the respirable size range and exhibited a unimodal distribution. All spray-dried powders had very low water content, as quantified by KF. The absence of crystallinity in spray-dried particles was reflected in the powder X-ray diffractograms and confirmed by thermal analysis. DSC thermal analysis indicated that the novel advanced spray-dried inhalable trehalose microparticles and nanoparticles exhibited a clear glass transition (T(g)). This is consistent with the formation of the amorphous glassy state. Spray-dried amorphous glassy trehalose inhalable microparticles and nanoparticles exhibited vapor-induced (lyotropic) phase transitions with varying levels of relative humidity as measured by gravimetric vapor sorption at 25°C and 37°C.

  4. Mechanism of Action of Lung Damage Caused by a Nanofilm Spray Product

    PubMed Central

    Larsen, Søren T.; Dallot, Constantin; Larsen, Susan W.; Rose, Fabrice; Poulsen, Steen S.; Nørgaard, Asger W.; Hansen, Jitka S.; Sørli, Jorid B.; Nielsen, Gunnar D.; Foged, Camilla

    2014-01-01

    Inhalation of waterproofing spray products has on several occasions caused lung damage, which in some cases was fatal. The present study aims to elucidate the mechanism of action of a nanofilm spray product, which has been shown to possess unusual toxic effects, including an extremely steep concentration-effect curve. The nanofilm product is intended for application on non-absorbing flooring materials and contains perfluorosiloxane as the active film-forming component. The toxicological effects and their underlying mechanisms of this product were studied using a mouse inhalation model, by in vitro techniques and by identification of the binding interaction. Inhalation of the aerosolized product gave rise to increased airway resistance in the mice, as evident from the decreased expiratory flow rate. The toxic effect of the waterproofing spray product included interaction with the pulmonary surfactants. More specifically, the active film-forming components in the spray product, perfluorinated siloxanes, inhibited the function of the lung surfactant due to non-covalent interaction with surfactant protein B, a component which is crucial for the stability and persistence of the lung surfactant film during respiration. The active film-forming component used in the present spray product is also found in several other products on the market. Hence, it may be expected that these products may have a toxicity similar to the waterproofing product studied here. Elucidation of the toxicological mechanism and identification of toxicological targets are important to perform rational and cost-effective toxicological studies. Thus, because the pulmonary surfactant system appears to be an important toxicological target for waterproofing spray products, study of surfactant inhibition could be included in toxicological assessment of this group of consumer products. PMID:24863969

  5. Development of the aerosol generation system for simulating the dry deposition behavior of radioaerosol emitted by the accident of FDNPP

    NASA Astrophysics Data System (ADS)

    Zhang, Z.

    2015-12-01

    A large amount of radioactivity was discharged by the accident of FDNPP. The long half-life radionuclide, 137Cs was transported through the atmosphere mainly as the aerosol form and deposited to the forests in Fukushima prefecture. After the dry deposition of the 137Cs, the foliar uptake process would occur. To evaluate environmental transfer of radionuclides, the dry deposition and following foliar uptake is very important. There are some pioneering studies for radionuclide foliar uptake with attaching the solution containing stable target element on the leaf, however, cesium oxide aerosols were used for these deposition study [1]. In the FDNPP case, 137Cs was transported in sulfate aerosol form [2], so the oxide aerosol behaviors could not represent the actual deposition behavior in this accident. For evaluation of whole behavior of 137Cs in vegetation system, fundamental data for deposition and uptake process of sulfate aerosol was desired. In this study, we developed aerosol generation system for simulating the dry deposition and the foliar uptake behaviors of aerosol in the different chemical constitutions. In this system, the method of aerosol generation based on the spray drying. Solution contained 137Cs was send to a nozzle by a syringe pump and spraying with a high speed air flow. The sprayed mist was generated in a chamber in the relatively high temperature. The solution in the mist was dried quickly, and micro size solid aerosols consisting 137Cs were generated. The aerosols were suctioned by an ejector and transported inside a tube by the dry air flow, then were directly blown onto the leaves. The experimental condition, such as the size of chamber, chamber temperature, solution flow rate, air flow rate and so on, were optimized. In the deposition experiment, the aerosols on leaves were observed by a SEM/EDX system and the deposition amount was evaluated by measuring the stable Cs remaining on leaf. In the presentation, we will discuss the detail

  6. Spray bottle apparatus with force multiply pistons

    DOEpatents

    Eschbach, Eugene A.

    1992-01-01

    The present invention comprises a spray bottle in which the pressure resulting from the gripping force applied by the user is amplified and this increased pressure used in generating a spray such as an aerosol or fluid stream. In its preferred embodiment, the invention includes a high pressure chamber and a corresponding piston which is operative for driving fluid out of this chamber at high pressure through a spray nozzle and a low pressure chamber and corresponding piston which is acted upon by the hydraulic pressure within the bottle resulting from the gripping force. The low pressure chamber and piston are of larger size than the high pressure chamber and piston. The pistons are rigidly connected so that the force created by the pressure acting on the piston in the low pressure chamber is transmitted to the piston in the high pressure chamber where it is applied over a more limited area thereby generating greater hydraulic pressure for use in forming the spray.

  7. Spray bottle apparatus with pressure multiplying pistons

    DOEpatents

    Moss, Owen R.; Gordon, Norman R.; DeFord, Henry S.

    1990-01-01

    The present invention comprises a spray bottle in which the pressure resulting from the gripping force applied by the user is amplified and this increased pressure used in generating a spray such as an aerosol or fluid stream. In its preferred embodiment, the invention includes a high pressure chamber and a corresponding piston which is operative for driving fluid out of this chamber at high pressure through a spray nozzle and a low pressure chamber and a corresponding piston which is acted upon the hydraulic pressure within the bottle resulting from the gripping force. The low pressure chamber and piston are of larger size than the high pressure chamber and piston. The pistons are rigidly connected so that the force created by the pressure acting on the piston in the low pressure chamber is transmitted to the piston in the high pressure chamber where it is applied over a more limited area thereby generating greater hydraulic pressure for use in forming the spray.

  8. Uniform spray coating for large tanks

    NASA Technical Reports Server (NTRS)

    Carter, J. M.

    1977-01-01

    System employs spray facility located within ventilated plastic booth to uniformly coat exterior of large cylindrical tanks with polyurethane foam insulation. Coating target is rotated on turntable while movable spray guns apply overlapping spirals of foam. Entire operation may be controlled by single operator from remote station.

  9. Spray Drift Issues and Technologies for Mitigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbicide-induced plant damage due to off-target spray drift has become a major problem in some regions prompting States to take regulatory action regarding drift mitigation. For example, the Arkansas Plant Board has proposed new regulations regarding spray of Glyphosate and 2, 4-D. These regulation...

  10. Assimilation of MODIS Dark Target and Deep Blue Observations in the Dust Aerosol Component of NMMB-MONARCH version 1.0

    NASA Technical Reports Server (NTRS)

    Di Tomaso, Enza; Schutgens, Nick A. J.; Jorba, Oriol; Perez Garcia-Pando, Carlos

    2017-01-01

    A data assimilation capability has been built for the NMMB-MONARCH chemical weather prediction system, with a focus on mineral dust, a prominent type of aerosol. An ensemble-based Kalman filter technique (namely the local ensemble transform Kalman filter - LETKF) has been utilized to optimally combine model background and satellite retrievals. Our implementation of the ensemble is based on known uncertainties in the physical parametrizations of the dust emission scheme. Experiments showed that MODIS AOD retrievals using the Dark Target algorithm can help NMMB-MONARCH to better characterize atmospheric dust. This is particularly true for the analysis of the dust outflow in the Sahel region and over the African Atlantic coast. The assimilation of MODIS AOD retrievals based on the Deep Blue algorithm has a further positive impact in the analysis downwind from the strongest dust sources of the Sahara and in the Arabian Peninsula. An analysis-initialized forecast performs better (lower forecast error and higher correlation with observations) than a standard forecast, with the exception of underestimating dust in the long-range Atlantic transport and degradation of the temporal evolution of dust in some regions after day 1. Particularly relevant is the improved forecast over the Sahara throughout the forecast range thanks to the assimilation of Deep Blue retrievals over areas not easily covered by other observational datasets.The present study on mineral dust is a first step towards data assimilation with a complete aerosol prediction system that includes multiple aerosol species.

  11. MODIS Collection 6 aerosol products: Comparison between Aqua's e-Deep Blue, Dark Target, and "merged" data sets, and usage recommendations

    NASA Astrophysics Data System (ADS)

    Sayer, A. M.; Munchak, L. A.; Hsu, N. C.; Levy, R. C.; Bettenhausen, C.; Jeong, M.-J.

    2014-12-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) Atmospheres data product suite includes three algorithms applied to retrieve midvisible aerosol optical depth (AOD): the Enhanced Deep Blue (DB) and Dark Target (DT) algorithms over land, and a DT over-water algorithm. All three have been refined in the recent "Collection 6" (C6) MODIS reprocessing. In particular, DB has been expanded to cover vegetated land surfaces as well as brighter desert/urban areas. Additionally, a new "merged" data set which draws from all three algorithms is included in the C6 products. This study is intended to act as a point of reference for new and experienced MODIS data users with which to understand the global and regional characteristics of the C6 DB, DT, and merged data sets, based on MODIS Aqua data. This includes validation against Aerosol Robotic Network (AERONET) observations at 111 sites, focused toward regional and categorical (surface/aerosol type) analysis. Neither algorithm consistently outperforms the other, although in many cases the retrieved AOD and the level of its agreement with AERONET are very similar. In many regions the DB, DT, and merged data sets are all suitable for quantitative applications, bearing in mind that they cannot be considered independent, while in other cases one algorithm does consistently outperform the other. Usage recommendations and caveats are thus somewhat complicated and regionally dependent.

  12. Assimilation of MODIS Dark Target and Deep Blue observations in the dust aerosol component of NMMB-MONARCH version 1.0

    NASA Astrophysics Data System (ADS)

    Di Tomaso, Enza; Schutgens, Nick A. J.; Jorba, Oriol; Pérez García-Pando, Carlos

    2017-03-01

    A data assimilation capability has been built for the NMMB-MONARCH chemical weather prediction system, with a focus on mineral dust, a prominent type of aerosol. An ensemble-based Kalman filter technique (namely the local ensemble transform Kalman filter - LETKF) has been utilized to optimally combine model background and satellite retrievals. Our implementation of the ensemble is based on known uncertainties in the physical parametrizations of the dust emission scheme. Experiments showed that MODIS AOD retrievals using the Dark Target algorithm can help NMMB-MONARCH to better characterize atmospheric dust. This is particularly true for the analysis of the dust outflow in the Sahel region and over the African Atlantic coast. The assimilation of MODIS AOD retrievals based on the Deep Blue algorithm has a further positive impact in the analysis downwind from the strongest dust sources of the Sahara and in the Arabian Peninsula. An analysis-initialized forecast performs better (lower forecast error and higher correlation with observations) than a standard forecast, with the exception of underestimating dust in the long-range Atlantic transport and degradation of the temporal evolution of dust in some regions after day 1. Particularly relevant is the improved forecast over the Sahara throughout the forecast range thanks to the assimilation of Deep Blue retrievals over areas not easily covered by other observational datasets. The present study on mineral dust is a first step towards data assimilation with a complete aerosol prediction system that includes multiple aerosol species.

  13. Spatial distribution visualization of PWM continuous variable-rate spray

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical application is a dynamic spatial distribution process, during which spray liquid covers the targets with certain thickness and uniformity. Therefore, it is important to study the 2-D and 3-D (dimensional) spray distribution to evaluate spraying quality. The curve-surface generation methods ...

  14. Release of VOCs and particles during use of nanofilm spray products.

    PubMed

    Nørgaard, Asger W; Jensen, Keld A; Janfelt, Christian; Lauritsen, Frants R; Clausen, Per A; Wolkoff, Peder

    2009-10-15

    Here, we present emission data on VOCs and particles emitted during simulated use of four commercial nanofilm spray products (NFPs) used for making easy-to-clean or self-cleaning surfaces on floors, ceramic tiles, and windows. The aim was to characterize the emitted VOCs and to provide specific source strength data for VOCs and particles released to the airduring use of the products. Containers with NFP were mounted on a spray-stand inside a closed stainless steel chamber with no air exchange. NFPs were sprayed in amounts corresponding to 1 m2 surface toward a target plate at a distance of 35 cm. Released VOCs were measured by a combination of air sampling on Tenax TA adsorbent followed by thermal desorption GC/MS and GC/FID analysis and real time measurements using a miniature membrane inlet mass spectrometer. Particles were measured using a fast mobility particle sizer and an aerosol particle sizer. A number of VOCs were identified, including small alcohols, ketones and ethers, chlorinated acetones, a perfluorinated silane, limonene, and cyclic siloxanes. The number of generated particles was on the order of 3 x 10(8) to 2 x 10(10) particles/m3 per g sprayed NFP and were dominated by nanosize particles.

  15. Microgravity Spray Cooling Research for High Powered Laser Applications

    NASA Technical Reports Server (NTRS)

    Zivich, Chad P.

    2004-01-01

    An extremely powerful laser is being developed at Goddard Space Flight Center for use on a satellite. This laser has several potential applications. One application is to use it for upper atmosphere weather research. In this case, the laser would reflect off aerosols in the upper atmosphere and bounce back to the satellite, where the aerosol velocities could be calculated and thus the upper atmosphere weather patterns could be monitored. A second application would be for the US. Air Force, which wants to use the laser strategically as a weapon for satellite defense. The Air Force fears that in the coming years as more and more nations gain limited space capabilities that American satellites may become targets, and the laser could protect the satellites. Regardless of the ultimate application, however, a critical step along the way to putting the laser in space is finding a way to efficiently cool it. While operating the laser becomes very hot and must be cooled to prevent overheating. On earth, this is accomplished by simply running cool tap water over the laser to keep it cool. But on a satellite, this is too inefficient. This would require too much water mass to be practical. Instead, we are investigating spray cooling as a means to cool the laser in microgravity. Spray cooling requires much less volume of fluid, and thus could be suitable for use on a satellite. We have inherited a 2.2 second Drop Tower rig to conduct our research with. In our experiments, water is pressurized with a compressed air tank and sprayed through a nozzle onto our test plate. We can vary the pressure applied to the water and the temperature of the plate before an experiment trial. The whole process takes place in simulated microgravity in the 2.2 second Drop Tower, and a high speed video camera records the spray as it hits the plate. We have made much progress in the past few weeks on these experiments. The rig originally did not have the capability to heat the test plate, but I did

  16. Virus -induced plankton dynamic and sea spray oragnics

    NASA Astrophysics Data System (ADS)

    Facchini, Maria Cristina; O'Dowd, Colin; Danovaro, Roberto

    2015-04-01

    The processes that link phytoplankton biomass and productivity to the organic matter enrichment in sea spray aerosol are far from being understood and modelling predictions remain highly uncertain at the moment. While some studies have asserted that the enrichment of OM in sea spray aerosol is independent on marine productivity, others, on the contrary, have shown significant correlation with phytoplankton biomass and productivity (Chl-a retrieved by satellites). Here we show that viral infection of prokaryotes and phytoplankton, by inducing the release of large quantities of surfaceactive organic matter (cell debris, exudates and other colloidal gel-forming material), in part due to cell lysis and plankton defence reactions, and in part from rapid virus multiplication, triggers the organic matter (OM) enrichment in the sea-spray particles during blooms. We show that virus-induced bloom dynamics may explain the contrasting results present in literature on the link between primary productivity and OM sea spray enrichment.

  17. In Silico Models of Aerosol Delivery to the Respiratory Tract – Development and Applications

    PubMed Central

    Longest, P. Worth; Holbrook, Landon T.

    2011-01-01

    This review discusses the application of computational models to simulate the transport and deposition of inhaled pharmaceutical aerosols from the site of particle or droplet formation to deposition within the respiratory tract. Traditional one-dimensional (1-D) whole-lung models are discussed briefly followed by a more in-depth review of three-dimensional (3-D) computational fluid dynamics (CFD) simulations. The review of CFD models is organized into sections covering transport and deposition within the inhaler device, the extrathoracic (oral and nasal) region, conducting airways, and alveolar space. For each section, a general review of significant contributions and advancements in the area of simulating pharmaceutical aerosols is provided followed by a more in-depth application or case study that highlights the challenges, utility, and benefits of in silico models. Specific applications presented include the optimization of an existing spray inhaler, development of charge-targeted delivery, specification of conditions for optimal nasal delivery, analysis of a new condensational delivery approach, and an evaluation of targeted delivery using magnetic aerosols. The review concludes with recommendations on the need for more refined model validations, use of a concurrent experimental and CFD approach for developing aerosol delivery systems, and development of a stochastic individual path (SIP) model of aerosol transport and deposition throughout the respiratory tract. PMID:21640772

  18. Liquid-Spray Formulation Of Scopolamine

    NASA Technical Reports Server (NTRS)

    Putcha, Lakshmi; Cintron, Nitza M.

    1992-01-01

    Scopolamine, fast-acting anticholinergic drug, formulated into drops administered intranasally. Formulation very useful for people who need immediate relief from motion sickness, and they can administer it to themselves. Also used in other clinical situations in which fast-acting anticholinergic medication required. Modified into such other forms as gel preparation, aqueous-base ointment, or aerosol spray or mist; also dispensed in metered-dose delivery system.

  19. Generation of a monodispersed aerosol

    NASA Technical Reports Server (NTRS)

    Schenck, H.; Mikasa, M.; Devicariis, R.

    1974-01-01

    The identity and laboratory test methods for the generation of a monodispersed aerosol are reported on, and are subjected to the following constraints and parameters; (1) size distribution; (2) specific gravity; (3) scattering properties; (4) costs; (5) production. The procedure called for the collection of information from the literature, commercial available products, and experts working in the field. The following topics were investigated: (1) aerosols; (2) air pollution -- analysis; (3) atomizers; (4) dispersion; (5) particles -- optics, size analysis; (6) smoke -- generators, density measurements; (7) sprays; (8) wind tunnels -- visualization.

  20. Aerosol fabrication methods for monodisperse nanoparticles

    DOEpatents

    Jiang, Xingmao; Brinker, C Jeffrey

    2014-10-21

    Exemplary embodiments provide materials and methods for forming monodisperse particles. In one embodiment, the monodisperse particles can be formed by first spraying a nanoparticle-containing dispersion into aerosol droplets and then heating the aerosol droplets in the presence of a shell precursor to form core-shell particles. By removing either the shell layer or the nanoparticle core of the core-shell particles, monodisperse nanoparticles can be formed.

  1. Two intelligent spraying systems developed for tree crop production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Precision pesticide application technologies are needed to achieve efficient and effective spray deposition on target areas and minimize off-target losses. Two variable-rate intelligent sprayers were developed as an introduction of new generation sprayers for tree crop applications. The first spraye...

  2. Hair spray poisoning

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002705.htm Hair spray poisoning To use the sharing features on this page, please enable JavaScript. Hair spray poisoning occurs when someone breathes in (inhales) ...

  3. Triamcinolone Nasal Spray

    MedlinePlus

    ... itchy nose and itchy, watery eyes caused by hay fever or other allergies. Triamcinolone nasal spray should not ... germs.Triamcinolone nasal spray controls the symptoms of hay fever and allergies but does not cure these conditions. ...

  4. Mometasone Nasal Spray

    MedlinePlus

    ... sneezing, runny, stuffy, or itchy nose caused by hay fever or other allergies. It is also used to ... using mometasone nasal spray to prevent or relieve hay fever or allergy symptoms, it is usually sprayed in ...

  5. Flunisolide Nasal Spray

    MedlinePlus

    ... sneezing, runny, stuffy, or itchy nose caused by hay fever or other allergies. Flunisolide nasal spray should not ... germs.Flunisolide nasal spray controls the symptoms of hay fever or allergies but does not cure these conditions. ...

  6. Nasal corticosteroid sprays

    MedlinePlus

    ... or concerns about your symptoms Trouble using the medicine Alternative Names Steroid nasal sprays; Allergies - nasal corticosteroid sprays References American Academy of ... of Medicine, Division of Allergy, Immunology, and Rheumatology, Georgetown University ...

  7. Remotely controlled spray gun

    NASA Technical Reports Server (NTRS)

    Cunningham, William C. (Inventor)

    1987-01-01

    A remotely controlled spray gun is described in which a nozzle and orifice plate are held in precise axial alignment by an alignment member, which in turn is held in alignment with the general outlet of the spray gun by insert. By this arrangement, the precise repeatability of spray patterns is insured.

  8. Organic aerosols

    SciTech Connect

    Penner, J.E.

    1994-01-01

    Organic aerosols scatter solar radiation. They may also either enhance or decrease concentrations of cloud condensation nuclei. This paper summarizes observed concentrations of aerosols in remote continental and marine locations and provides estimates for the sources of organic aerosol matter. The anthropogenic sources of organic aerosols may be as large as the anthropogenic sources of sulfate aerosols, implying a similar magnitude of direct forcing of climate. The source estimates are highly uncertain and subject to revision in the future. A slow secondary source of organic aerosols of unknown origin may contribute to the observed oceanic concentrations. The role of organic aerosols acting as cloud condensation nuclei (CCN) is described and it is concluded that they may either enhance or decrease the ability of anthropogenic sulfate aerosols to act as CCN.

  9. Measuring Sodium Chloride Contents of Aerosols

    NASA Technical Reports Server (NTRS)

    Sinha, M. P.; Friedlander, S. K.

    1986-01-01

    Amount of sodium chloride in individual aerosol particles measured in real time by analyzer that includes mass spectrometer. Analyzer used to determine mass distributions of active agents in therapeutic or diagnostic aerosols derived from saline solutions and in analyzing ocean spray. Aerosol particles composed of sodium chloride introduced into oven, where individually vaporized on hot wall. Vapor molecules thermally dissociated, and some of resulting sodium atoms ionized on wall. Ions leave oven in burst and analyzed by spectrometer, which is set to monitor sodium-ion intensity.

  10. ICLASS-85; Proceedings of the Third International Conference on Liquid Atomisation and Spray Systems, Imperial College of Science and Technology, London, England, July 8-10, 1985. Volumes 1 & 2

    NASA Astrophysics Data System (ADS)

    Eisenklam, P.; Yule, A.

    The theory, experimental investigation, and applications of liquid atomization and spraying are discussed in reviews and reports. Topics examined include atomizer design and performance, diesel and transient sprays, medical and pressure-pack aerosols, agricultural sprays, and the atomization of specialized fluids. Consideration is given to measurement and data-analysis techniques; spray structure, transfer processes, and combustion; the fundamentals of atomization and drop dynamics; and monosize sprays.

  11. Characterization of sprays

    NASA Technical Reports Server (NTRS)

    Chigier, N.; Mao, C.-P.

    1984-01-01

    It is pointed out that most practical power generation and propulsion systems involve the burning of different types of fuel sprays, taking into account aircraft propulsion, industrial furnaces, boilers, gas turbines, and diesel engines. There has been a lack of data which can serve as a basis for spray model development and validation. A major aim of the present investigation is to fill this gap. Experimental apparatus and techniques for studying the characteristics of fuel sprays are discussed, taking into account two-dimensional still photography, cinematography, holography, a laser diffraction particle sizer, and a laser anemometer. The considered instruments were used in a number of experiments, taking into account three different types of fuel spray. Attention is given to liquid fuel sprays, high pressure pulsed diesel sprays, and coal-water slurry sprays.

  12. A Comparison of Fuel Sprays from Several Types of Injection Nozzles

    NASA Technical Reports Server (NTRS)

    Lee, Dana W

    1936-01-01

    This report presents the tests results of a series of tests made of the sprays from 14 fuel injection nozzles of 9 different types, the sprays being injected into air at atmospheric density and at 6 and 14 times atmospheric density. High-speed spark photographs of the sprays from each nozzle at each air density were taken at the rate of 2,000 per second, and from them were obtained the dimensions of the sprays and the rates of spray-tip penetration. The sprays were also injected against plasticine targets placed at different distances from the nozzles, and the impressions made in the plasticine were used as an indication of the distribution of the fuel within the spray. Cross-sectional sketches of the different types of sprays are given showing the relative sizes of the spray cores and envelopes. The characteristics of the sprays are compared and discussed with respect to their application to various types of engines.

  13. A New Study of Sea Spray Optical Properties from Multi-Sensor Spaceborne Observations

    NASA Technical Reports Server (NTRS)

    Dawson, K. W.; Meskhidze, N.; Josset, D.; Gasso, S.

    2014-01-01

    Retrievals of aerosol optical depth (AOD) from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) satellite sensor require the assumption of an extinction-to-backscatter ratio, also known as the lidar ratio. This paper evaluates a new method to calculate lidar ratio of sea spray aerosol using two independent sources: the AOD from Synergized Optical Depth of Aerosols (SODA) and the integrated attenuated backscatter from CALIOP. The method applied in this study allows particulate lidar ratio to be calculated for individual CALIOP retrievals of single aerosol layer columns over the ocean. Analyses are carried out using CALIOP level 2, 5km sea spray aerosol layer products and collocated SODA nighttime data from December 2007 to December 2009. The global mean lidar ratio for sea spray aerosols was found to be 26 sr, roughly 30 higher than the one prescribed by CALIOP. Data analysis also showed considerable spatiotemporal variability in calculated lidar ratio over different parts of the remote oceans. The calculated aerosol lidar ratios are shown to be inversely related to the mean ocean surface wind speed: increase in ocean surface wind speed (U10) from 0 to 15 ms-1 reduces the mean lidar ratios for sea spray particles from 32 sr (for 0 U10 4 ms-1) to 22 sr (for U10 15 ms-1). Such changes in the lidar ratio are expected to have a corresponding effect on sea spray AOD. The outcomes of this study are relevant for future improvements of the SODA and CALIOP operational product and could lead to more accurate retrievals of sea spray AOD.

  14. Spray Freeze-Drying as an Alternative to the Ionic Gelation Method to Produce Chitosan and Alginate Nano-Particles Targeted to the Colon.

    PubMed

    Gamboa, Alexander; Araujo, Valeria; Caro, Nelson; Gotteland, Martin; Abugoch, Lilian; Tapia, Cristian

    2015-12-01

    Chitosan and alginate nano-composite (NP) carriers intended for colonic delivery containing prednisolone and inulin were obtained by two processes. Spray freeze-drying using chitosan (SFDC) or alginate (SFDA) was proposed as an alternative to the traditional chitosan-tripolyphosphate platform (CTPP). NPs were fully characterised and assessed for their yield of particles; level of prednisolone and inulin release in phosphate and Krebs buffers; and sensitivity to degradation by lysozyme, bacteria and faecal slurry. NPs based on chitosan showed similar properties (size, structure, viscoelastic behaviour), but those based on SFDC showed a higher mean release of both active ingredients, with similar efficiency of encapsulation and loading capacity for prednisolone but lower for inulin. SFDC was less degraded in the presence of lysozyme and E. coli and was degraded by B. thetaiotaomicron but not by faecal slurry. The results obtained with SFDA were promising because this NP showed good encapsulation parameters for both active ingredients and biological degradability by E. coli and faecal slurry. However, it will be necessary to use alginate derivatives to reduce its solubility and improve its mechanical behaviour.

  15. Target animal safety study of meloxicam administered via transmucosal oral spray (Promist(®) technology) for 6 months in dogs.

    PubMed

    Hare, J E; Niemuller, C A; Petrick, D M

    2013-08-01

    This study evaluated the safety of meloxicam administered via transmucosal oral spray (TMOS) at 1, 2, 3 and 5 times the maximum proposed dose for 6 months in dogs. After baseline assessments, 40 Beagles (20 M, 20 F) were randomized to gender-balanced groups administered either water or meloxicam TMOS at 1, 2, 3 and 5 times the maximum proposed dose once daily for 26 weeks. Dogs were subjected to daily food consumption measurements and clinical and dose site observations. Periodic evaluations were made of body weight, physical examination, clinical pathology, urinalysis, buccal mucosal bleeding time (BMBT) and gastroduodenal endoscopy. At study completion, all dogs were subjected to gross necropsy. Histopathology was performed on tissues from dogs in groups 0X and 5X and from selected tissues in other dose groups. Clinical signs of previously reported NSAID-associated gastrointestinal upset were noted with higher frequency in meloxicam-dosed animals than in controls. Despite the presence of statistically significant effects on some clinicopathological variables, no toxicologically relevant dose-associated effects were determined on these or on food consumption, dose site observations, body weight, physical examination, urinalysis, BMBT, endoscopic examination or gross and histopathological examination of necropsy tissues.

  16. Bear Spray Safety Program

    USGS Publications Warehouse

    Blome, C.D.; Kuzniar, R.L.

    2009-01-01

    A bear spray safety program for the U.S. Geological Survey (USGS) was officially initiated by the Firearms Safety Committee to address accident prevention and to promote personnel training in bear spray and its transportation, storage, and use for defense against wild animals. Used as part of a system including firearms, or used alone for those who choose not to carry a firearm, bear spray is recognized as an effective tool that can prevent injury in a wild animal attack.

  17. Assessment of spray deposition with water-sensitive paper cards

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spatial distributions of spray droplets discharged from an airblast sprayer, were sampled on pairs of absorbent paper (AP) and water-sensitive paper (WSP) targets at several distances from the sprayer. Spray solutions, containing a fluorescent tracer, were discharged from two size nozzles to achiev...

  18. Spray Cooling And The Next Generation Of NASA Space Flight

    NASA Technical Reports Server (NTRS)

    Silk, Eric

    2005-01-01

    This viewgraph presentation discusses spray cooling as it applies to thermal management of the new ESMD (Exploration Systems Mission Directorate) programs. It is concluded that given the targeted heat flux and temperature operating regimes, spray cooling is a viable option, although further technology development will be required.

  19. Climatic Effects of Marine Organic Aerosols

    NASA Astrophysics Data System (ADS)

    Xu, J.; Meskhidze, N.; Zhang, Y.; Gantt, B.; Ghan, S. J.; Nenes, A.; Liu, X.; Easter, R. C.; Zaveri, R. A.

    2009-12-01

    Recent studies suggest that the emissions of primary organic matter (POM) of marine biogenic origin and secondary organic aerosol (SOA) from phytoplankton-produced volatile organic compounds can lead to changes of chemical composition and size distribution of marine aerosol, thus modifying the cloud droplet activation potential and affecting climate. In this study, the effects of marine organic aerosol emissions and the dissolved marine organic aerosol components as surfactant are explored using the National Center of Atmospheric Research’s Community Atmosphere Model, coupled with the Pacific Northwest National Laboratory’s Modal Aerosol Model (CAM-MAM). Primary marine organic aerosol emissions are separated into sub- and super-micron modes, and calculated based on wind speed-dependent sea-spray mass flux and remotely-sensed surface chlorophyll-a concentration. Two distinct sea spray emission functions used in this study yield different amounts and spatial distributions of sub-micron marine POM mass flux. The super-micron sea-spray flux is determined based on simulated sea-spray number flux. Both sub and super-micron marine POM are assumed to be mostly water-insoluble and added in the accumulation mode and coarse sea-salt mode, respectively. A prescribed soluble mass fraction of 50% is assumed for marine SOA, formed from phytoplankton-emitted isoprene and allowed to be condensed on existing aerosols in different modes. Surfactant effects from the soluble part of sub-micron marine POM are included in the cloud droplet activation parameterization by some modifications based on the mass fraction of dissolved marine POM. 10 year model simulations are conducted to examine the effects of marine organic aerosols on cloud microphysical and optical properties. Analyses of model results show that different marine aerosol emissions and cloud droplet activation mechanisms can yield 9% to 16% increase in global maritime mean cloud droplet number concentration. Changes

  20. Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction

    PubMed Central

    Fritz, Bradley K.; Hoffmann, W. Clint

    2016-01-01

    When making an application of any crop protection material such as an herbicide or pesticide, the applicator uses a variety of skills and information to make an application so that the material reaches the target site (i.e., plant). Information critical in this process is the droplet size that a particular spray nozzle, spray pressure, and spray solution combination generates, as droplet size greatly influences product efficacy and how the spray moves through the environment. Researchers and product manufacturers commonly use laser diffraction equipment to measure the spray droplet size in laboratory wind tunnels. The work presented here describes methods used in making spray droplet size measurements with laser diffraction equipment for both ground and aerial application scenarios that can be used to ensure inter- and intra-laboratory precision while minimizing sampling bias associated with laser diffraction systems. Maintaining critical measurement distances and concurrent airflow throughout the testing process is key to this precision. Real time data quality analysis is also critical to preventing excess variation in the data or extraneous inclusion of erroneous data. Some limitations of this method include atypical spray nozzles, spray solutions or application conditions that result in spray streams that do not fully atomize within the measurement distances discussed. Successful adaption of this method can provide a highly efficient method for evaluation of the performance of agrochemical spray application nozzles under a variety of operational settings. Also discussed are potential experimental design considerations that can be included to enhance functionality of the data collected. PMID:27684589

  1. Mobile robot based electrostatic spray system for controlling pests on cotton plants in Iraq

    NASA Astrophysics Data System (ADS)

    Al-Mamury, M.; Manivannan, N.; Al-Raweshidy, H.; Balachandran, W.

    2015-10-01

    A mobile robot based electrostatic spray system was developed to combat pest infestation on cotton plants in Iraq. The system consists of a charged spray nozzle, a CCD camera, a mobile robot (vehicle and arm) and Arduino microcontroller. Arduino microcontroller is used to control the spray nozzle and the robot. Matlab is used to process the image from the CCD camera and to generate the appropriate control signals to the robot and the spray nozzle. COMSOL multi-physics FEM software was used to design the induction electrodes to achieve maximum charge transfer onto the fan spray liquid film resulting in achieving the desired charge/mass ratio of the spray. The charged spray nozzle was operated on short duration pulsed spray mode. Image analysis was employed to investigate the spray deposition on improvised insect targets on an artificial plant.

  2. The "Deep Blue" Aerosol Project at NASA GSFC

    NASA Technical Reports Server (NTRS)

    Sayer, Andrew; Hsu, N. C.; Lee, J.; Bettenhausen, C.; Carletta, N.; Chen, S.; Esmaili, R.

    2016-01-01

    Atmospheric aerosols such as mineral dust, wildfire smoke, sea spray, and volcanic ash are of interest for a variety of reasons including public health, climate change, hazard avoidance, and more. Deep Blue is a project which uses satellite observations of the Earth from sensors such as SeaWiFS, MODIS, and VIIRS to monitor the global aerosol burden. This talk will cover some basics about aerosols and the principles of aerosol remote sensing, as well as discussing specific results and future directions for the Deep Blue project.

  3. Effect of aerosolization on subsequent bacterial survival.

    PubMed Central

    Walter, M V; Marthi, B; Fieland, V P; Ganio, L M

    1990-01-01

    To determine whether aerosolization could impair bacterial survival, Pseudomonas syringae and Erwinia herbicola were aerosolized in a greenhouse, the aerosol was sampled at various distances from the site of release by using all-glass impingers, and bacterial survival was followed in the impingers for 6 h. Bacterial survival subsequent to aerosolization of P. syringae and E. herbicola was not impaired 1 m from the site of release. P. syringae aerosolized at 3 to 15 m from the site of release at a temperature of 12 degrees C and a relative humidity of 80% survived 35- to 65-fold better than P. syringae released at 27 degrees C and a relative humidity of 40%. No difference was observed in the survival of P. syringae and E. herbicola following aerosolization at the same temperature and relative humidity. Bacteria sprayed directly onto bean and oat plants established stable populations at comparable numbers on both plants over an 8-day period following inoculation. Bacteria that inoculated adjacent plants by drifting downwind up to 5 m were detectable at an initial population of 10(2) CFU/g on oats and 10(5) CFU/g on beans 2 h after the spray. However, bacterial populations on both plants were undetectable within 48 h. PMID:2268157

  4. Evaluation of droplet velocity and size from nasal spray devices using phase Doppler anemometry (PDA).

    PubMed

    Liu, Xiaofei; Doub, William H; Guo, Changning

    2010-03-30

    To determine aerosol deposition during the inhalation drug delivery, it is important to understand the combination of velocity and droplet size together. In this study, phase Doppler anemometry (PDA) was used to simultaneously characterize the aerosol velocity and droplet size distribution (DSD) of three nasal spray pumps filled with water. Thirteen sampling positions were located in the horizontal cross-sectional area of the nasal spray plumes at a distance of 3cm from the pump orifice. The results showed droplet velocities near the center of the spray plume were higher and more consistent than those near the edge. The pumps examined showed significant differences in their aerosol velocity at the center of the spray plume, which suggest that this metric might be used as a discriminating parameter for in vitro testing of nasal sprays. Droplet size measurements performed using PDA were compared with results from laser light scattering measurements. The ability of PDA to provide simultaneous measurements of aerosol velocity and size makes it a powerful tool for the detailed investigation of nasal spray plume characteristics.

  5. The use of a reliable, ubiquitous, inexpensive, and user-friendly tablet-based system to track target lesion improvements in subjects with plaque psoriasis treated with clobetasol propionate 0.05% spray.

    PubMed

    Wiser, Thomas H; Meckfessel, Matthew H; Winkelman, Warren

    2015-03-01

    Ubiquitous electronic devices, such as smartphones and tablets, have the potential to enable a fundamental shift in the paradigm of healthcare as these devices may allow patients and health care providers (HCPs) to rapidly and remotely communicate with each other. Once fully realized, these devices may facilitate interactions between patients and HCPs. While these devices hold much promise, much work remains in assessing their viability in various diseases. A pilot study was conducted to investigate the use of a tablet-based numeric rating scale to assess improvements in a plaque psoriasis target lesion treated with clobetasol propionate 0.05% spray (CPS). Twenty-eight subjects with plaque psoriasis enrolled and were treated with CPS twice daily for 15 days. Target lesion severity (scale of 0 [no psoriasis] to 10 [very severe psoriasis]) and effectiveness scores (scale of 0 [none] to 3 [severe]) were recorded using a tablet-based system by the investigator and subjects. The tablet was also used to take photos of the target lesion to capture photographic evidence of improvement. Investigator and subject assessed target lesion severity and effectiveness scores improved during the study from baseline to day 15; in addition subjects indicated a high level of satisfaction with CPS treatment. Very few technological failures were reported and captured photographs were consistent visit to visit and of high quality. Taken together, this study supports the use of a tablet-based system to measure and track plaque psoriasis disease progression and also confirmed that CPS is an effective and safe treatment for plaque psoriasis.

  6. Ciclesonide Nasal Spray

    MedlinePlus

    ... Wash the dust cap and applicator with warm water. Dry and replace the applicator and press down and release the pump one time or until you see a fine spray. Replace the dust cap. Do not use pins or other sharp objects in the tiny spray hole on the nasal applicator to remove the blockage. ...

  7. Cold spray nozzle design

    DOEpatents

    Haynes, Jeffrey D.; Sanders, Stuart A.

    2009-06-09

    A nozzle for use in a cold spray technique is described. The nozzle has a passageway for spraying a powder material, the passageway having a converging section and a diverging section, and at least the diverging section being formed from polybenzimidazole. In one embodiment of the nozzle, the converging section is also formed from polybenzimidazole.

  8. Observed aerosol effects on marine cloud nucleation and supersaturation

    NASA Astrophysics Data System (ADS)

    Russell, Lynn M.; Sorooshian, Armin; Seinfeld, John H.; Albrecht, Bruce A.; Nenes, Athanasios; Leaitch, W. Richard; Macdonald, Anne Marie; Ahlm, Lars; Chen, Yi-Chun; Coggon, Matthew; Corrigan, Ashley; Craven, Jill S.; Flagan, Richard C.; Frossard, Amanda A.; Hawkins, Lelia N.; Jonsson, Haflidi; Jung, Eunsil; Lin, Jack J.; Metcalf, Andrew R.; Modini, Robin; Mülmenstädt, Johannes; Roberts, Greg C.; Shingler, Taylor; Song, Siwon; Wang, Zhen; Wonaschütz, Anna

    2013-05-01

    Aerosol particles in the marine boundary layer include primary organic and salt particles from sea spray and combustion-derived particles from ships and coastal cities. These particle types serve as nuclei for marine cloud droplet activation, although the particles that activate depend on the particle size and composition as well as the supersaturation that results from cloud updraft velocities. The Eastern Pacific Emitted Aerosol Cloud Experiment (EPEACE) 2011 was a targeted aircraft campaign to assess how different particle types nucleate cloud droplets. As part of E-PEACE 2011, we studied the role of marine particles as cloud droplet nuclei and used emitted particle sources to separate particle-induced feedbacks from dynamical variability. The emitted particle sources included shipboard smoke-generated particles with 0.05-1 μm diameters (which produced tracks measured by satellite and had drop composition characteristic of organic smoke) and combustion particles from container ships with 0.05-0.2 μm diameters (which were measured in a variety of conditions with droplets containing both organic and sulfate components) [1]. Three central aspects of the collaborative E-PEACE results are: (1) the size and chemical composition of the emitted smoke particles compared to ship-track-forming cargo ship emissions as well as background marine particles, with particular attention to the role of organic particles, (2) the characteristics of cloud track formation for smoke and cargo ships, as well as the role of multi-layered low clouds, and (3) the implications of these findings for quantifying aerosol indirect effects. For comparison with the E-PEACE results, the preliminary results of the Stratocumulus Observations of Los-Angeles Emissions Derived Aerosol-Droplets (SOLEDAD) 2012 provided evidence of the cloud-nucleating roles of both marine organic particles and coastal urban pollution, with simultaneous measurements of the effective supersaturations of the clouds in the

  9. Environmentally compatible spray cement

    SciTech Connect

    Loeschnig, P.

    1995-12-31

    Within the framework of a European research project, Heidelberger Zement developed a quickly setting and hardening binder for shotcrete, called Chronolith S, which avoids the application of setting accelerators. Density and strength of the shotcrete produced with this spray cement correspond to those of an unaccelerated shotcrete. An increased hazard for the heading team and for the environment, which may occur when applying setting accelerators, can be excluded here. Owing to the special setting properties of a spray cement, the process engineering for its manufacturing is of great importance. The treatment of a spray cement as a dry concrete with kiln-dried aggregates is possible without any problems. The use of a naturally damp pre-batched mixture is possible with Chronolith S but requires special process engineering; spray cement and damp aggregate are mixed with one another immediately before entering the spraying machinery.

  10. Spray Rolling Aluminum Strip

    SciTech Connect

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  11. Aerosol processing of materials: Aerosol dynamics and microstructure evolution

    NASA Astrophysics Data System (ADS)

    Gurav, Abhijit Shankar

    Spray pyrolysis is an aerosol process commonly used to synthesize a wide variety of materials in powder or film forms including metals, metal oxides and non-oxide ceramics. It is capable of producing high purity, unagglomerated, and micrometer to submicron-size powders, and scale-up has been demonstrated. This dissertation deals with the study of aerosol dynamics during spray pyrolysis of multicomponent systems involving volatile phases/components, and aspects involved with using fuel additives during spray processes to break apart droplets and particles in order to produce powders with smaller sizes. The gas-phase aerosol dynamics and composition size distributions were measured during spray pyrolysis of (Bi, Pb)-Sr-Ca-Cu-O, and Sr-Ru-O and Bi-Ru-O at different temperatures. A differential mobility analyzer (DMA) was used in conjunction with a condensation particle counter (CPC) to monitor the gas-phase particle size distributions, and a Berner-type low-pressure impactor was used to obtain mass size distributions and size-classified samples for chemical analysis. (Bi, Pb)-Sr-Ca-Cu-O powders made at temperatures up to 700sp°C maintained their initial stoichiometry over the whole range of particle sizes monitored, however, those made at 800sp°C and above were heavily depleted in lead in the size range 0.5-5.0 mum. When the reactor temperature was raised from 700 and 800sp°C to 900sp°C, a large number ({˜}10sp7\\ #/cmsp3) of new ultrafine particles were formed from PbO vapor released from the particles and the reactor walls at the beginning of high temperature runs (at 900sp°C). The metal ruthenate systems showed generation of ultrafine particles (<40-50 nm) at the beginning of runs at 800-900sp°C and also as a steady state process at a reactor temperature of 1000sp°C. The methods of aerosol dynamics measurements were also used to monitor the gas-phase particle size distributions during the generation of fullerene (Csb{60}) nano-particles (30 to 50 nm size

  12. Airborne enteric bacteria and viruses from spray irrigation with wastewater.

    PubMed

    Teltsch, B; Katzenelson, E

    1978-02-01

    The relationship between bacterial concentrations in wastewater used for spray irrigation and in the air was examined. Aerosolized coliforms were detected when their concentration was 10(3)/ml or more in the wastewater. Relative humidity and solar irradiation appeared to affect viable bacteria in the air; a positive correlation was found between relative humidity and the number of aerosolized bacteria. The correlation between solar irradiation and bacterial level, on the other hand, was negative. During night irrigation, up to 10 times more aerosolized bacteria were detected than with day irrigation. Wind velocity did not play an important role in the survival of aerosolized bacteria. Echovirus 7 was isolated in 4 out of 12 air samples collected 40 m downwind from the sprinkler.

  13. An overview of spray drift reduction testing of spray nozzles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The importance of the development and testing of drift reduction technologies (DRTs) is increasing. Common spray drift reduction technologies include spray nozzles and spray adjuvants. Following draft procedures developed for a DRT program, three spray nozzles were tested under high air speed cond...

  14. Spray drift reduction test method correlation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ASTM Standard E609 Terminology Relating to Pesticides defines drift as “The physical movement of an agrochemical through the air at the time of application or soon thereafter to any non or off target site.” Since there are many commercial tank mix adjuvants designed to reduce spray drift, ASTM esta...

  15. Thermal Arc Spray Overview

    NASA Astrophysics Data System (ADS)

    Hafiz Abd Malek, Muhamad; Hayati Saad, Nor; Kiyai Abas, Sunhaji; Mohd Shah, Noriyati

    2013-06-01

    Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

  16. Aerosol Size Distribution in the marine regions

    NASA Astrophysics Data System (ADS)

    Markuszewski, Piotr; Petelski, Tomasz; Zielinski, Tymon; Pakszys, Paulina; Strzalkowska, Agata; Makuch, Przemyslaw; Kowalczyk, Jakub

    2014-05-01

    We would like to present the data obtained during the regular research cruises of the S/Y Oceania over a period of time between 2009 - 2012. The Baltic Sea is a very interesting polygon for aerosol measurements, however, also difficult due to the fact that mostly cases of a mixture of continental and marine aerosols are observed. It is possible to measure clear marine aerosol, but also advections of dust from southern Europe or even Africa. This variability of data allows to compare different conditions. The data is also compared with our measurements from the Arctic Seas, which have been made during the ARctic EXperiment (AREX). The Arctic Seas are very suitable for marine aerosol investigations since continental advections of aerosols are far less frequent than in other European sea regions. The aerosol size distribution was measured using the TSI Laser Aerosol Spectrometer model 3340 (99 channels, measurement range 0.09 μm to 7 μm), condensation particle counter (range 0.01 μm to 3 μm) and laser particle counter PMS CSASP-100-HV-SP (range 0.5 μm to 47 μm in 45 channels). Studies of marine aerosol production and transport are important for many Earth sciences such as cloud physics, atmospheric optics, environmental pollution studies and interaction between ocean and atmosphere. All equipment was placed on one of the masts of S/Y Oceania. Measurements using the laser aerosol spectrometer and condensation particle counter were made on one level (8 meters above sea level). Measurements with the laser particle counter were performed at five different levels above the sea level (8, 11, 14, 17 and 20 m). Based on aerosol size distribution the parameterizations with a Log-Normal and a Power-Law distributions were made. The aerosol source functions, characteristic for the region were also determined. Additionally, poor precision of the sea spray emission determination was confirmed while using only the aerosol concentration data. The emission of sea spray depends

  17. Granulometric characterization of airborne particulate release during spray application of nanoparticle-doped coatings

    NASA Astrophysics Data System (ADS)

    Göhler, Daniel; Stintz, Michael

    2014-08-01

    Airborne particle release during the spray application of coatings was analyzed in the nanometre and micrometre size range. In order to represent realistic conditions of domestic and handcraft use, the spray application was performed using two types of commercial propellant spray cans and a manual gravity spray gun. Four different types of coatings doped with three kinds of metal-oxide tracer nanoparticle additives (TNPA) were analyzed. Depending on the used coating and the kind of spray unit, particulate release numbers between 5 × 108 and 3 × 1010 particles per gram ejection mass were determined in the dried spray aerosols. The nanoparticulate fraction amounted values between 10 and 60 no%. The comparison between nanoparticle-doped coatings with non-doped ones showed no TNPA-attributed differences in both the macroscopic spray process characteristics and the particle release numbers. SEM, TEM and EDX-analyzes showed that the spray aerosols were composed of particles made up solely from matrix material and sheathed pigments, fillers and TNPAs. Isolated ZnO- or Fe2O3-TNPAs could not be observed.

  18. Satellite measurements of tropospheric aerosols

    NASA Technical Reports Server (NTRS)

    Griggs, M.

    1981-01-01

    This investigation uses LANDSAT 2 radiance data and ground-truth measurements of the aerosol optical thickness, obtained previously from five inland sites, to study the usefulness and limitations of the near infrared radiance over inland bodies of water. The linear relationship between LANDSAT 2 MSS7 and aerosol content found in this study can be used to estimate the aerosol content with a standard deviation of 0.42N. Analysis of the data for MSS6 and MSS7 suggest that the larger uncertainty is mostly due to water turbidity, with little contribution from the adjacency effect. The relationship found is best applied to determine an average aerosol content over a period of time at a given target, or an area average at a given time over several targets close together.

  19. Release mitigation spray safety systems for chemical demilitarization applications.

    SciTech Connect

    Leonard, Jonathan; Tezak, Matthew Stephen; Brockmann, John E.; Servantes, Brandon; Sanchez, Andres L.; Tucker, Mark David; Allen, Ashley N.; Wilson, Mollye C.; Lucero, Daniel A.; Betty, Rita G.

    2010-06-01

    Sandia National Laboratories has conducted proof-of-concept experiments demonstrating effective knockdown and neutralization of aerosolized CBW simulants using charged DF-200 decontaminant sprays. DF-200 is an aqueous decontaminant, developed by Sandia National Laboratories, and procured and fielded by the US Military. Of significance is the potential application of this fundamental technology to numerous applications including mitigation and neutralization of releases arising during chemical demilitarization operations. A release mitigation spray safety system will remove airborne contaminants from an accidental release during operations, to protect personnel and limit contamination. Sandia National Laboratories recently (November, 2008) secured funding from the US Army's Program Manager for Non-Stockpile Chemical Materials Agency (PMNSCMA) to investigate use of mitigation spray systems for chemical demilitarization applications. For non-stockpile processes, mitigation spray systems co-located with the current Explosive Destruction System (EDS) will provide security both as an operational protective measure and in the event of an accidental release. Additionally, 'tented' mitigation spray systems for native or foreign remediation and recovery operations will contain accidental releases arising from removal of underground, unstable CBW munitions. A mitigation spray system for highly controlled stockpile operations will provide defense from accidental spills or leaks during routine procedures.

  20. Budesonide Nasal Spray

    MedlinePlus

    ... sneezing, runny, stuffy, or itchy nose caused by hay fever or other allergies (caused by an allergy to ... germs.Budesonide nasal spray controls the symptoms of hay fever or allergies but does not cure these conditions. ...

  1. Fluticasone Nasal Spray

    MedlinePlus

    ... itchy nose and itchy, watery eyes caused by hay fever or other allergies (caused by an allergy to ... germs.Fluticasone nasal spray controls the symptoms of hay fever or allergies but does not cure these conditions. ...

  2. Beclomethasone Nasal Spray

    MedlinePlus

    ... runny, stuffy, or itchy nose (rhinitis) caused by hay fever, other allergies, or vasomotor (nonallergic) rhinitis. It is ... germs.Beclomethasone nasal spray controls the symptoms of hay fever or allergies but does not cure these conditions. ...

  3. Supersonic-Spray Cleaner

    NASA Technical Reports Server (NTRS)

    Caimi, Raoul E. B.; Lin, Feng-Nan; Thaxton, Eric A.

    1995-01-01

    Spraying system for cleaning mechanical components uses less liquid and operates at pressures significantly lower. Liquid currently used is water. Designed to replace chlorofluorocarbon (CFC) solvent-based cleaning and cleanliness verification methods. Consists of spray head containing supersonic converging/diverging nozzles, source of gas at regulated pressure, pressurized liquid tank, and various hoses, fittings, valves, and gauges. Parameters of nozzles set so any of large variety of liquids and gases combined in desired ratio and rate of flow. Size and number of nozzles varied so system built in configurations ranging from small hand-held spray heads to large multinozzle cleaners. Also used to verify part adequately cleaned. Runoff liquid from spray directed at part collected. Liquid analyzed for presence of contaminants, and part recleaned if necessary.

  4. Butorphanol Nasal Spray

    MedlinePlus

    ... spray is used to relieve moderate to severe pain. Butorphanol is in a class of medications called ... works by changing the way the body senses pain. ... This branded product is no longer on the market. Generic alternatives may be available.

  5. Bug spray poisoning

    MedlinePlus

    ... effective bug sprays contain pyrethrins. Pyrethrins are a pesticide made from the chrysanthemum flower. It is generally ... death. References Borron SW. Pyrethrins, repellants, and other pesticides. In: Shannon MW, Borron SW, Burns MJ, eds. ...

  6. Sumatriptan Nasal Spray

    MedlinePlus

    ... spray is used to treat the symptoms of migraine headaches (severe, throbbing headaches that sometimes are accompanied ... that cause pain, nausea, and other symptoms of migraine. Sumatriptan does not prevent migraine attacks or reduce ...

  7. Zolmitriptan Nasal Spray

    MedlinePlus

    ... spray is used to treat the symptoms of migraine headaches (severe, throbbing headaches that sometimes are accompanied ... that cause pain, nausea, and other symptoms of migraine. Zolmitriptan does not prevent migraine attacks or reduce ...

  8. ENCAPSULATED AEROSOLS

    DTIC Science & Technology

    acetate, polymerized rapidly and produced some polymer film encapsulation of the aerosol droplets. A two-stage microcapsule generator was designed...encapsulating material, the generator also produced microcapsules of dibutyl phosphite in polyethylene, nitrocellulose, and natural rubber.

  9. Sensors in Spray Processes

    NASA Astrophysics Data System (ADS)

    Fauchais, P.; Vardelle, M.

    2010-06-01

    This paper presents what is our actual knowledge about sensors, used in the harsh environment of spray booths, to improve the reproducibility and reliability of coatings sprayed with hot or cold gases. First are described, with their limitations and precisions, the different sensors following the in-flight hot particle parameters (trajectories, temperatures, velocities, sizes, and shapes). A few comments are also made about techniques, still under developments in laboratories, to improve our understanding of coating formation such as plasma jet temperature measurements in non-symmetrical conditions, hot gases heat flux, particles flattening and splats formation, particles evaporation. Then are described the illumination techniques by laser flash of either cold particles (those injected in hot gases, or in cold spray gun) or liquid injected into hot gases (suspensions or solutions). The possibilities they open to determine the flux and velocities of cold particles or visualize liquid penetration in the core of hot gases are discussed. Afterwards are presented sensors to follow, when spraying hot particles, substrate and coating temperature evolution, and the stress development within coatings during the spray process as well as the coating thickness. The different uses of these sensors are then described with successively: (i) Measurements limited to particle trajectories, velocities, temperatures, and sizes in different spray conditions: plasma (including transient conditions due to arc root fluctuations in d.c. plasma jets), HVOF, wire arc, cold spray. Afterwards are discussed how such sensor data can be used to achieve a better understanding of the different spray processes, compare experiments to calculations and improve the reproducibility and reliability of the spray conditions. (ii) Coatings monitoring through in-flight measurements coupled with those devoted to coatings formation. This is achieved by either maintaining at their set point both in-flight and

  10. Ventilation Guidance To Promote the Safe Use of Spray Polyurethane Foam (SPF) Insulation, Incluyendo la Versión de Español

    EPA Pesticide Factsheets

    This guidance describes basic ventilation principles and strategies to help protect workers and building occupants and promote the safe use of spray polyurethane foam (SPF) insulation. Guia para la ventilacion sobre la application del aerosol de espuma.

  11. Portable Spray Booth

    NASA Technical Reports Server (NTRS)

    Hansen, Timothy D.; Bardwell, Micheal J.

    1996-01-01

    Portable spray booth provides for controlled application of coating materials with high solvent contents. Includes contoured shroud and carbon filter bed limiting concentration of fumes in vicinity. Designed to substitute spraying for brush application of solvent-based adhesive prior to installing rubber waterproof seals over joints between segments of solid-fuel rocket motor. With minor adjustments and modifications, used to apply other solvent-based adhesives, paints, and like.

  12. Metal atomization spray nozzle

    DOEpatents

    Huxford, T.J.

    1993-11-16

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal. 6 figures.

  13. Metal atomization spray nozzle

    DOEpatents

    Huxford, Theodore J.

    1993-01-01

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal.

  14. Directed spray mast

    DOEpatents

    Nance, Thomas A.; Siddall, Alvin A.; Cheng, William Y.; Counts, Kevin T.

    2005-05-10

    Disclosed is an elongated, tubular, compact high pressure sprayer apparatus for insertion into an access port of vessels having contaminated interior areas that require cleaning by high pressure water spray. The invention includes a spray nozzle and a camera adjacent thereto with means for rotating and raising and lowering the nozzle so that areas identified through the camera may be cleaned with a minimum production of waste water to be removed.

  15. Spray applicator for spraying coatings and other fluids in space

    NASA Technical Reports Server (NTRS)

    Kuminecz, J. F.; Lausten, M. F. (Inventor)

    1985-01-01

    A self contained spray application is developed for one handed operation in a zero gravity vacuum environment by a free flying astronaut not attached to any spacecraft. This spray applicator eliminates contamination of the operator by back spray. This applicator includes a rigid accumulator containment of a fluid within a flexible bladder the fluid being urged out of the accumulator under pressure through a spray gun. The spray gun includes a spring loaded lockable trigger which controls a valve. When in an open position, the fluid passes through the valve into the ambient environment in the form of a spray. A spray shield is provided which directs the flow of the spray from the applicator by trapping errant particles of spray yet allowing the passage of escaping gases through its material.

  16. 77 FR 14279 - National Volatile Organic Compound Emission Standards for Aerosol Coatings-Addition of Dimethyl...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-09

    ... aerosol coatings category (aerosol spray paints) under the Clean Air Act, published elsewhere in the... Primers, Surfacers or Undercoaters........ PCS 1.05 Pleasure Craft Topcoats PCT 0.60 Polyolefin Adhesion....35 Benzene 71-43-2 0.81 1,1,1-Trichloroethane 71-55-6 0.00 Propane 74-98-6 0.56 Vinyl Chloride...

  17. Evaluation of aerosolized medications during parabolic flight maneuvers

    NASA Technical Reports Server (NTRS)

    Lloyd, Charles W.; Martin, William J.; Gosbee, John

    1991-01-01

    The goal was to visually evaluate the effect gravity has on delivery of medications by the use of various aerosol devices. During parabolic flight the same four aerosols were retested as performed in studio ground tests. It appears that the Cetacaine spray and the Ventolin inhaler function without failure during all test. The pump spray (Nostril) appeared to function normally when the container was full, however it appeared to begin to fail to deliver a full mist with larger droplet size when the container was nearly empty. The simple hand spray bottle appeared to work when the container was full and performed progressively worse as the container was emptied. During Apollo flights, it was reported that standard spray bottles did not work well, however, they did not indicate why. It appears that we would also conclude that standard spray bottles do not function as well in zero gravity by failing to produce a normal mist spray. The standard spray bottle allowed the fluid to come out in a narrow fluid stream when held with the nozzle either level or slightly tilted upward.

  18. Principle considerations for the risk assessment of sprayed consumer products.

    PubMed

    Steiling, W; Bascompta, M; Carthew, P; Catalano, G; Corea, N; D'Haese, A; Jackson, P; Kromidas, L; Meurice, P; Rothe, H; Singal, M

    2014-05-16

    In recent years, the official regulation of chemicals and chemical products has been intensified. Explicitly for spray products enhanced requirements to assess the consumers'/professionals' exposure to such product type have been introduced. In this regard the Aerosol-Dispensers-Directive (75/324/EEC) with obligation for marketing aerosol dispensers, and the Cosmetic-Products-Regulation (1223/2009/EC) which obliges the insurance of a safety assessment, have to be mentioned. Both enactments, similar to the REACH regulation (1907/2006/EC), require a robust chemical safety assessment. From such assessment, appropriate risk management measures may be identified to adequately control the risk of these chemicals/products to human health and the environment when used. Currently, the above-mentioned regulations lack the guidance on which data are needed for preparing a proper hazard analysis and safety assessment of spray products. Mandatory in the process of inhalation risk and safety assessment is the determination and quantification of the actual exposure to the spray product and more specifically, its ingredients. In this respect the current article, prepared by the European Aerosol Federation (FEA, Brussels) task force "Inhalation Toxicology", intends to introduce toxicological principles and the state of the art in currently available exposure models adapted for typical application scenarios. This review on current methodologies is intended to guide safety assessors to better estimate inhalation exposure by using the most relevant data.

  19. OCEANFILMS-2: Representing coadsorption of saccharides in marine films and potential impacts on modeled marine aerosol chemistry

    NASA Astrophysics Data System (ADS)

    Burrows, Susannah M.; Gobrogge, Eric; Fu, Li; Link, Katie; Elliott, Scott M.; Wang, Hongfei; Walker, Rob

    2016-08-01

    Here we show that the addition of chemical interactions between soluble monosaccharides and an insoluble lipid surfactant monolayer improves agreement of modeled sea spray chemistry with observed marine aerosol chemistry. In particular, the alkane:hydroxyl mass ratio in modeled sea spray organic matter is reduced from a median of 2.73 to a range of 0.41-0.69, reducing the discrepancy with previous Fourier transform infrared spectroscopy (FTIR) observations of clean marine aerosol (ratio: 0.24-0.38). The overall organic fraction of submicron sea spray also increases, allowing organic mass fractions in the range 0.5-0.7 for submicron sea spray particles over highly active phytoplankton blooms. Sum frequency generation experiments support the modeling approach by demonstrating that soluble monosaccharides can strongly adsorb to a lipid monolayer likely via Coulomb interactions under appropriate conditions. These laboratory findings motivate further research to determine the relevance of coadsorption mechanisms for real-world, sea spray aerosol production.

  20. The MODIS Aerosol Algorithm, Products, Validation and Applications

    NASA Technical Reports Server (NTRS)

    Remer, L. A.; Kaufman, Y. J.; Tanre, D.

    2003-01-01

    The MODerate resolution Imaging Spectroradiometer (MODIS) currently aboard both the Terra and Aqua satellites produces a suite of products designed to characterize global aerosol distribution, optical thickness and particle size. Never before has a space-borne instrument been able to provide such detailed information, complementing field and modeling efforts to produce a comprehensive picture of aerosol characteristics. The three years of Terra-MODIS data have been validated by comparing with co-located AERONET observations of aerosol optical thickness and derivations of aerosol size parameters. Some 8000 comparison points located at 133 AERONET sites around the globe show that the MODIS aerosol optical thickness retrievals are accurate to within the pre-launch expectations. MODIS-derived size parameters are also compared with AERONET retrievals and found to agree well for fine-mode dominated aerosol regimes. Aerosol regimes dominated by dust aerosol are less accurate, attributed to what is thought to be nonsphericity. Errors due to nonsphericity will be reduced by introducing a new set of empirical phase functions, derived without any assumptions of particle shape. The major innovation that MODIS bring to the field of remote sensing of aerosol is the measure of particle size and the separation of finemode and coarsemode dominated aerosol regimes. Particle size can separate finemode man-made aerosols created during combustion, from larger natural aerosols originating from salt spray or wind erosion. This separation allows for the calculation of aerosol radiative effect and the estimation of the man-made aerosol radiative forcing. MODIS can also be used in regional studies of aerosol-cloud interaction that affect the global radiative and hydrological cycles.

  1. Measurements in liquid fuel sprays

    NASA Technical Reports Server (NTRS)

    Chigier, N.

    1984-01-01

    Techniques for studying the events directly preceding combustion in the liquid fuel sprays are being used to provide information as a function of space and time on droplet size, shape, number density, position, angle of flight and velocity. Spray chambers were designed and constructed for: (1) air-assist liquid fuel research sprays; (2) high pressure and temperature chamber for pulsed diesel fuel sprays; and (3) coal-water slurry sprays. Recent results utilizing photography, cinematography, and calibration of the Malvern particle sizer are reported. Systems for simultaneous measurement of velocity and particle size distributions using laser Doppler anemometry interferometry and the application of holography in liquid fuel sprays are being calibrated.

  2. Remote Sensing of Aerosol Backscatter and Earth Surface Targets By Use of An Airborne Focused Continuous Wave CO2 Doppler Lidar Over Western North America

    NASA Technical Reports Server (NTRS)

    Jarzembski, Maurice A.; Srivastava, Vandana; Goodman, H. Michael (Technical Monitor)

    2000-01-01

    Airborne lidar systems are used to determine wind velocity and to measure aerosol or cloud backscatter variability. Atmospheric aerosols, being affected by local and regional sources, show tremendous variability. Continuous wave (cw) lidar can obtain detailed aerosol loading with unprecedented high resolution (3 sec) and sensitivity (1 mg/cubic meter) as was done during the 1995 NASA Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS) mission over western North America and the Pacific Ocean. Backscatter variability was measured at a 9.1 micron wavelength cw focused CO2 Doppler lidar for approximately 52 flight hours, covering an equivalent horizontal distance of approximately 30,000 km in the troposphere. Some quasi-vertical backscatter profiles were also obtained during various ascents and descents at altitudes that ranged from approximately 0.1 to 12 km. Similarities and differences for aerosol loading over land and ocean were observed. Mid-tropospheric aerosol backscatter background mode was approximately 6 x 10(exp -11)/ms/r, consistent with previous lidar datasets. While these atmospheric measurements were made, the lidar also retrieved a distinct backscatter signal from the Earth's surface from the unfocused part of the focused cw lidar beam during aircraft rolls. Atmospheric backscatter can be highly variable both spatially and temporally, whereas, Earth-surface backscatter is relatively much less variant and can be quite predictable. Therefore, routine atmospheric backscatter measurements by an airborne lidar also give Earth surface backscatter which can allow for investigating the Earth terrain. In the case where the Earth's surface backscatter is coming from a well-known and fairly uniform region, then it can potentially offer lidar calibration opportunities during flight. These Earth surface measurements over varying Californian terrain during the mission were compared with laboratory backscatter measurements using the same lidar of various

  3. Marine submicron aerosol gradients, sources and sinks

    NASA Astrophysics Data System (ADS)

    Ceburnis, Darius; Rinaldi, Matteo; Ovadnevaite, Jurgita; Martucci, Giovanni; Giulianelli, Lara; O'Dowd, Colin D.

    2016-10-01

    Aerosol principal sources and sinks over eastern North Atlantic waters were studied through the deployment of an aerosol chemistry gradient sampling system. The chemical gradients of primary and secondary aerosol components - specifically, sea salt (SS), water-insoluble organic matter (WIOM), water-soluble organic matter (WSOM), nitrate, ammonium, oxalate, amines, methanesulfonic acid (MSA) and water-soluble organic nitrogen (WSON) - were examined in great detail. Sea salt fluxes were estimated by the boundary layer box model and ranged from 0.3 to 3.5 ng m-2 s-1 over the wind speed range of 5-12 m s-1 and compared well with the derived fluxes from existing sea salt source parameterisations. The observed seasonal pattern of sea salt gradients was mainly driven by wind stress in addition to the yet unquantified effect of marine OM modifying fractional contributions of SS and OM in sea spray. WIOM gradients were a complex combination of rising and waning biological activity, especially in the flux footprint area, and wind-driven primary sea spray production supporting the coupling of recently developed sea spray and marine OM parameterisations.

  4. The hygroscopicity of indoor aerosol particles

    SciTech Connect

    Wei, L.

    1993-07-01

    A system to study the hygroscopic growth of particle was developed by combining a Tandem Differential Mobility Analyzer (TDMA) with a wetted wall reactor. This system is capable of mimicking the conditions in human respiratory tract, and measuring the particle size change due to the hygroscopic growth. The performance of the system was tested with three kinds of particles of known composition, NaCl, (NH{sub 4}){sub 2}SO{sub 4}, and (NH{sub 4})HS0{sub 4} particles. The hygroscopicity of a variety of common indoor aerosol particles was studied including combustion aerosols (cigarette smoking, cooking, incenses and candles) and consumer spray products such as glass cleaner, general purpose cleaner, hair spray, furniture polish spray, disinfectant, and insect killer. Experiments indicate that most of the indoor aerosols show some hygroscopic growth and only a few materials do not. The magnitude of hygroscopic growth ranges from 20% to 300% depending on the particle size and fraction of water soluble components.

  5. Miniature spray-painting booth

    NASA Technical Reports Server (NTRS)

    Fee, K. W.

    1970-01-01

    Transparent spray booth provides method for quality painting and repair of surfaces in clean room or other specialized environments. Overspray and virtually all contaminating vapor and odor can be eliminated. Touch-up painting is achieved with spray gun.

  6. Nasal spray flu vaccine (image)

    MedlinePlus

    The flu vaccine can also be administered as a nasal spray instead of the usual injection method. It can be ... the recombinant influenza vaccine (RIV). The nasal spray flu vaccine (live attenuated influenza vaccine or LAIV) should not ...

  7. Controlled overspray spray nozzle

    NASA Technical Reports Server (NTRS)

    Prasthofer, W. P. (Inventor)

    1981-01-01

    A spray system for a multi-ingredient ablative material wherein a nozzle A is utilized for suppressing overspray is described. The nozzle includes a cyclindrical inlet which converges to a restricted throat. A curved juncture between the cylindrical inlet and the convergent portion affords unrestricted and uninterrupted flow of the ablative material. A divergent bell-shaped chamber and adjustable nozzle exit B is utilized which provides a highly effective spray pattern in suppressing overspray to an acceptable level and producing a homogeneous jet of material that adheres well to the substrate.

  8. Sprayed Coating Renews Butyl Rubber

    NASA Technical Reports Server (NTRS)

    Martin, R. B.

    1982-01-01

    Damaged butyl rubber products are renewed by spray technique originally developed for protective suits worn by NASA workers. A commercial two-part adhesive is mixed with Freon-113 (or equivalent) trichlorotrifluoroethane to obtain optimum viscosity for spraying. Mix is applied with an external-air-mix spray gun.

  9. Spray combustion stability project

    NASA Technical Reports Server (NTRS)

    Jeng, San-Mou; Litchford, Ron J.

    1992-01-01

    This report summarizes research activity on the Spray Combustion Stability Project, characterizes accomplishments and current status, and discusses projected future work. The purpose is to provide a concise conceptual overview of the research effort to date so the reader can quickly assimilate the gist of the research results and place them within the context of their potential impact on liquid rocket engine design technology.

  10. Picosecond imaging of sprays

    NASA Technical Reports Server (NTRS)

    Breisacher, Kevin; Liou, Larry; Wang, L.; Liang, X.; Galland, P.; Ho, P. P.; Alfano, R. R.

    1994-01-01

    Preliminary results from applying a Kerr-Fourier imaging system to a water/air spray produced by a shear coaxial element are presented. The physics behind ultrafast time-gated optical techniques is discussed briefly. A typical setup of a Kerr-Fourier time gating system is presented.

  11. Ocean Spray Lubricates Winds

    ERIC Educational Resources Information Center

    Journal of College Science Teaching, 2005

    2005-01-01

    According to a new study by two University of California, Berkeley, mathematicians and their Russian colleague, the water droplets kicked up by rough seas serve to lubricate the swirling winds of hurricanes and cyclones, letting them build to speeds approaching 200 miles per hour. Without the lubricating effect of the spray, the mathematicians…

  12. Oxymetazoline Nasal Spray

    MedlinePlus

    ... Rinse the tip of the dispenser with hot water or wipe it clean after you use it.Follow the directions for using the nasal spray that appear on the package label. If you are using a product that comes in a pump dispenser, press down on the rim several times ...

  13. Ultrafine particles emitted by flame and electric arc guns for thermal spraying of metals.

    PubMed

    Bémer, Denis; Régnier, Roland; Subra, Isabelle; Sutter, Benjamin; Lecler, Marie T; Morele, Yves

    2010-08-01

    The ultrafine aerosol emitted by thermal spraying of metals using flame and electric arc processes has been characterized in terms of particle size distribution and emission rates based on both particle number and mass. Thermal spraying of Zn, Zn/Al, and Al was studied. Measurements taken using an electrical low pressure impactor and a condensation nucleus counter reveal an aerosol made up of very fine particles (80-95% of number distribution <100 nm). Ultrafine particle emission rates produced by the electric arc process are very high, the largest values being recorded during spraying of pure aluminium. This process generates high particle emissions and therefore requires careful consideration and possible rethinking of currently implemented protection measures: ventilated cabins, dust collectors, and personal protective equipment.

  14. Optimisation of a vertical spray boom for greenhouse spraying applications.

    PubMed

    Nuyttens, D; Windey, S; Braekman, P; De Moor, A; Sonck, B

    2003-01-01

    The European Crop Protection Association (ECPA) and CLO-DVL joined forces in a project to stimulate a safe use of pesticides in Southern European countries. CLO-DVL optimised a method with mineral chelates to evaluate deposition tests. This quantitative method to evaluate spray deposits and to check spray distributions is used to assess two novel spraying techniques. Deposition tests with water-sensitive paper and mainly with the manganese and molybdenum chelates as tracer elements were performed with a manually pulled trolley and a motorised vehicle both equipped with vertical spray booms. Filter papers were attached to the tomato and pepper plants at several heights to obtain an indication of the spray distribution in the crop. Particular attention was paid to the effect on the spray distribution of the vertical nozzle distance (35 cm vs. 50 cm) and the spray distance to the crop. The tests proved that a nozzle spacing of 35 cm delivers a much better spray distribution than one of 50 cm. The optimal spray distance for flat fan nozzles with a spray angle of 80 degrees and a nozzle spacing of 35 cm is about 30 cm.

  15. Improved Orifice Plate for Spray Gun

    NASA Technical Reports Server (NTRS)

    Cunningham, W.

    1986-01-01

    Erratic spray pattern of commercial spray gun changed to repeatable one by simple redesign of two parts. In modified spray gun orifice plate and polytetrafluoroethylene bushing redesigned to assure centering and alignment with nozzle. Such improvement useful in many industrial applications requiring repeatable spray patterns. Might include spraying of foam insulation, paint, other protective coatings, detergents, abrasives, adhesives, process chemicals, or fuels. Unmodified spray gun produces erratic spray because lateral misalignment between orifice plate and nozzle.

  16. ENCAPSULATED AEROSOLS

    DTIC Science & Technology

    materials determine the range of applicability of each method. A useful microencapsulation method, based on coagulation by inertial force was developed...The generation apparatus, consisting of two aerosol generators in series, was utilized to produce many kinds of microcapsules . A fluid energy mill...was found useful for the production of some microcapsules . The permeability of microcapsule films and the effect of exposure time and humidity were

  17. Isolating factors that determine the organic enrichment of sea spray

    NASA Astrophysics Data System (ADS)

    Gantt, B.; Morris, E.; Petters, M. D.; Meskhidze, N.

    2010-12-01

    Particles formed by the bursting of bubbles entrained in ocean waters may become significantly enriched in organic matter relative to sea water particularly for submicron sea spray aerosols formed from ocean waters characterized by high levels of biological activity. However, the factors controlling enrichment are not yet fully understood. The knowledge of marine aerosol chemical composition, as a function of particle size, is necessary for quantifying and predicting aerosol properties such as their ability to act as cloud condensation nuclei (CCN). The factors that determine the organic enrichment of sea spray were quantified by conducting laboratory experiments measuring the size, number, and CCN distributions of aerosols generated from a bubble-bursting generator using artificial seawater. The generator consists of a cleaned transparent rectangular prism with dimensions of 10 ×10 × 55 cm constructed from Plexiglas filled with 3.5 L of ultrapure water (18.2 MΩ). Zero air was forced through a stainless steel pipe connected to a sealed lid into an aerator located below the water surface to form the bubbles. Particles formed from the bursting bubbles were ejected into the headspace above the solution (~1.5 L) and sampled continuously at a flow rate of 1.5 Lpm by a differential mobility analyzer (DMA) - condensation particle counter (CPC) - CCN counter (CCNc) system. Air removed from the headspace was replaced with filtered room air. Bubble size was controlled by varying the pore size of the aerator and the bubble size distribution was measured using optical imaging. A typical experiment involved creating artificial sea water by mixing ultrapure water, sea salt (35‰ typical of natural sea water), and a known amount of a model organic compound chosen to simulate dissolved organic carbon and slicks in the ocean. For each measurement, the hyroscopicity parameter κ was determined through comparison of CPC and CCNc data and used to infer the chemical composition of

  18. Ambient Air Sampling During Quantum-dot Spray Deposition

    SciTech Connect

    Jankovic, John Timothy; Hollenbeck, Scott M

    2010-01-01

    Ambient air sampling for nano-size particle emissions was performed during spot spray coating operations with a Sono-Tek Exactacoat Benchtop system (ECB). The ECB consisted of the application equipment contained within an exhaust enclosure. The enclosure contained numerous small access openings, including an exhaust hook-up. Door access comprised most of the width and height of the front. The door itself was of the swing-out type. Two types of nanomaterials, Cadmium selenide (Cd-Se) quantum-dots (QDs) and Gold (Au) QDs, nominally 3.3 and 5 nm in diameter respectively, were applied during the evaluation. Median spray drop size was in the 20 to 60 micrometer size range.1 Surface coating tests were of short duration, on the order of one-half second per spray and ten spray applications between door openings. The enclosure was ventilated by connection to a high efficiency particulate aerosol (HEPA) filtered house exhaust system. The exhaust rate was nominally 80 ft3 per minute producing about 5 air changes per minute. Real time air monitoring with a scanning mobility particle size analyzer (SMPS ) with a size detection limit of 7 nm indicated a significant increase in the ambient air concentration upon early door opening. A handheld condensation particle counter (CPC) with a lower size limit of 10 nm did not record changes in the ambient background. This increase in the ambient was not observed when door opening was delayed for 2 minutes (~10 air changes). The ventilated enclosure controlled emissions except for cases of rapid door opening before the overspray could be removed by the exhaust. A time delay sufficient to provide 10 enclosure air changes (a concentration reduction of more than 99.99 %) before door opening prevented the release of aerosol particles in any size.2 Scanning-transmission electron microscopy (STEM) and atomic force microscopy (AFM) demonstrated the presence of agglomerates in the surfaces of the spray applied deposition. A filtered air sample of

  19. Size-fractionated characterization and quantification of nanoparticle release rates from a consumer spray product containing engineered nanoparticles

    NASA Astrophysics Data System (ADS)

    Hagendorfer, Harald; Lorenz, Christiane; Kaegi, Ralf; Sinnet, Brian; Gehrig, Robert; Goetz, Natalie V.; Scheringer, Martin; Ludwig, Christian; Ulrich, Andrea

    2010-09-01

    This study describes methods developed for reliable quantification of size- and element-specific release of engineered nanoparticles (ENP) from consumer spray products. A modified glove box setup was designed to allow controlled spray experiments in a particle-minimized environment. Time dependence of the particle size distribution in a size range of 10-500 nm and ENP release rates were studied using a scanning mobility particle sizer (SMPS). In parallel, the aerosol was transferred to a size-calibrated electrostatic TEM sampler. The deposited particles were investigated using electron microscopy techniques in combination with image processing software. This approach enables the chemical and morphological characterization as well as quantification of released nanoparticles from a spray product. The differentiation of solid ENP from the released nano-sized droplets was achieved by applying a thermo-desorbing unit. After optimization, the setup was applied to investigate different spray situations using both pump and gas propellant spray dispensers for a commercially available water-based nano-silver spray. The pump spray situation showed no measurable nanoparticle release, whereas in the case of the gas spray, a significant release was observed. From the results it can be assumed that the homogeneously distributed ENP from the original dispersion grow in size and change morphology during and after the spray process but still exist as nanometer particles of size <100 nm. Furthermore, it seems that the release of ENP correlates with the generated aerosol droplet size distribution produced by the spray vessel type used. This is the first study presenting results concerning the release of ENP from spray products.

  20. Spray combustion stability project

    NASA Technical Reports Server (NTRS)

    Jeng, San-Mou; Litchford, Ron J.

    1990-01-01

    This report summarizes research activity on the Spray Combustion Stability Project, characterizes accomplishments and current status, and discusses projected future work. The purpose is to provide a concise conceptual overview of the research effort so the reader can quickly assimilate the gist of the research results and place them within the context of their potential impact on liquid rocket engine design technology. Therefore, this report does not elaborate on many of the detailed technical aspects of the research program.

  1. Spray Nozzle Calibrations

    DTIC Science & Technology

    1986-01-01

    1984. The manuscript was submitted for publication on October 2, 1985. AEOC-TR-85-eO CONTENTS Page J.O INTRODUCTION 1.1 General 5 1.2...1.1 GENERAL The formation of ice on aircraft surfaces occurs during flight through clouds of supercooled water droplets. Ice accretion on these... wind tunnel. Both the LWC and mean effective droplet size are set and maintained through variations in the water and air supply pressures of the spray

  2. Combustion Characteristics of Sprays

    DTIC Science & Technology

    1989-08-01

    regarded by implication or otherwise, or in any way licensing the holder or any other person or corporation, or conveying any rights or permission to...00 _’N 1. TI TLE inctuat Security CZaaafication5 Combustion Characteristics of Sprays 12. PERSONAL AUTHOR(S) Sohrab, Siavash H. 13& TYPE OF REPORT...to ?!HF of rich butane/air 3unsen flames. .lso, the rotacion speed and :he oerodic temDeracure fluc:uations of rotacfng ?HF are examined. :’!naily

  3. Simulation of surface roughness during the formation of thermal spray coatings

    SciTech Connect

    Kanouff, M.P.

    1996-07-01

    The formation of a thermal spray coating was analyzed to identify methods to reduce the surface roughness of the coating. A new methodology was developed which uses a string of equally spaced node points to define the shape of the coating surface and to track the shape change as the thermal spray mass is deposited. This allows the calculation of arbitrary shapes for the coating surface which may be very complex. The model simulates the stochastic deposition of a large number of thermal spray droplets, where experimental data is used for the mass flux distribution on the target surface. This data shows that when the thermal spray mass impinges on the target surface, a large fraction of it (over-spray) splashes off the target and is re-deposited with a small spray angle, resulting in a large coating roughness. This analysis was used in a parameter study to identify methods for reducing the coating roughness. Effect of the shape of the profile for the pre-roughened substrate was found to be small. Decreasing the droplet size by a factor of 2 decreased the roughness by 13%. Increasing the spray angle for the over-spray by a factor of 2 decreased the roughness by 50%, and decreasing the amount of over- spray by a factor of 2 decreased the roughness by 51%.

  4. Fundamental studies of spray combustion

    SciTech Connect

    Li, S.C.; Libby, P.A.; Williams, F.A.

    1997-12-31

    Our research on spray combustion involves both experiment and theory and addresses the characteristics of individual droplets and of sprays in a variety of flows: laminar and turbulent, opposed and impinging. Currently our focus concerns water and fuel sprays in two stage laminar flames, i.e., flames arising, for example from a stream of fuel and oxidizer flowing opposite to an air stream carrying a water spray. Our interest in these flames is motivated by the goals of reducing pollutant emissions and extending the range of stable spray combustion. There remains considerable research to be carried out in order to achieve these goals. Thus far our research on the characteristics of sprays in turbulent flows has been limited to nonreacting jets impinging on a plate but this work will be extended to opposed flows with and without a flame. In the following we discuss details of these studies and our plans for future work.

  5. The Sequential Aerosol Technique: A Major Component in an Integrated Strategy of Intervention against Riverine Tsetse in Ghana

    PubMed Central

    Adam, Yahaya; Cecchi, Giuliano; Kgori, Patrick M.; Marcotty, Tanguy; Mahama, Charles I.; Abavana, Martin; Anderson, Benita; Paone, Massimo; Mattioli, Raffaele; Bouyer, Jérémy

    2013-01-01

    Background An integrated strategy of intervention against tsetse flies was implemented in the Upper West Region of Ghana (9.62°–11.00° N, 1.40°–2.76° W), covering an area of ≈18,000 km2 within the framework of the Pan-African Tsetse and Trypanosomosis Eradication Campaign. Two species were targeted: Glossina tachinoides and Glossina palpalis gambiensis. Methodology/Principal Findings The objectives were to test the potentiality of the sequential aerosol technique (SAT) to eliminate riverine tsetse species in a challenging subsection (dense tree canopy and high tsetse densities) of the total sprayed area (6,745 km2) and the subsequent efficacy of an integrated strategy including ground spraying (≈100 km2), insecticide treated targets (20,000) and insecticide treated cattle (45,000) in sustaining the results of tsetse suppression in the whole intervention area. The aerial application of low-dosage deltamethrin aerosols (0.33–0.35 g a.i/ha) was conducted along the three main rivers using five custom designed fixed-wings Turbo thrush aircraft. The impact of SAT on tsetse densities was monitored using 30 biconical traps deployed from two weeks before until two weeks after the operations. Results of the SAT monitoring indicated an overall reduction rate of 98% (from a pre-intervention mean apparent density per trap per day (ADT) of 16.7 to 0.3 at the end of the fourth and last cycle). One year after the SAT operations, a second survey using 200 biconical traps set in 20 sites during 3 weeks was conducted throughout the intervention area to measure the impact of the integrated control strategy. Both target species were still detected, albeit at very low densities (ADT of 0.27 inside sprayed blocks and 0.10 outside sprayed blocks). Conclusions/Significance The SAT operations failed to achieve elimination in the monitored section, but the subsequent integrated strategy maintained high levels of suppression throughout the intervention area, which will

  6. Photomicrographic Studies of Fuel Sprays

    NASA Technical Reports Server (NTRS)

    Lee, Dana W; Spencer, Robert C

    1934-01-01

    A large number of photomicrographs of fuel sprays were taken for the purpose of studying the spray structure and the process of spray formation. They were taken at magnifying powers of 2.5, 3.25, and 10, using a spark discharge of very short duration for illumination. Several types and sizes of nozzles were investigated, different liquids were used, and a wide range of injection pressures was employed. The sprays were photographed as they were injected into a glass-walled chamber in which the air density was varied from 14 atmospheres to 0.0013 atmosphere.

  7. Vacuum Plasma Spraying Replaces Electrodeposition

    NASA Technical Reports Server (NTRS)

    Holmes, Richard R.; Power, Chris; Burns, David H.; Daniel, Ron; Mckechnie, Timothy N.

    1992-01-01

    Vacuum plasma spraying used to fabricate large parts with complicated contours and inner structures, without uninspectable welds. Reduces time, and expense of fabrication. Wall of combustion chamber built up inside of outer nickel-alloy jacket by plasma spraying. Particles of metal sprayed partially melted in plasma gun and thrown at supersonic speed toward deposition surface. Vacuum plasma-spray produces stronger bond between the grooves and covering layer completing channels and wall of combustion chamber. In tests, bond withstood pressure of 20 kpsi, three times allowable limit by old method.

  8. Study on collection efficiency of fission products by spray: Experimental device and modelling

    SciTech Connect

    Ducret, D.; Roblot, D.; Vendel, J.; Billarand, Y.

    1997-08-01

    Consequences of an hypothetical overheating reactor accident in nuclear power plants can be limited by spraying cold water drops into containment building. The spray reduces the pressure and the temperature levels by condensation of steam and leads to the washout of fission products (aerosols and gaseous iodine). The present study includes a large program devoted to the evaluation of realistic washout rates. An experimental device (named CARAIDAS) was designed and built in order to determine the collection efficiency of aerosols and iodine absorption by drops with representative conditions of post-accident atmosphere. This experimental device is presented in the paper and more particularly: (1) the experimental enclosure in which representative thermodynamic conditions can be achieved, (2) the monosized drops generator, the drops diameter measurement and the drops collector, (3) the cesium iodide aerosols generator and the aerosols measurements. Modelling of steam condensation on drops aerosols collection and iodine absorption are described. First experimental and code results on drops and aerosols behaviour are compared. 8 refs., 18 figs.

  9. Aerosolized Surfactants, Anti-Inflammatory Drugs, and Analgesics.

    PubMed

    Willson, Douglas F

    2015-06-01

    Drug delivery by aerosol may have several advantages over other modes, particularly if the lung is the target organ. Aerosol delivery may allow achievement of higher concentrations while minimizing systemic effects and offers convenience, rapid onset of action, and avoidance of the needles and sterile technique necessary with intravenous drug administration. Aerosol delivery may change the pharmacokinetics of many drugs, however, and an awareness of the caveats of aerosolized drug delivery is mandatory to ensure both safety and adequate drug delivery. This paper discusses the administration of surfactants, anti-inflammatory agents, and analgesics by the aerosol route.

  10. Impact of occupational health hazards on serum markers of bone formation in spray painters of Chennai region in Tamil Nadu

    PubMed Central

    Muthaiah, Vijaya Prakash Krishnan; Nathan, Abel Arul; Balakrishnan, Anandan; Rose, Rajiv; Gopalsamy, Jayaraman

    2012-01-01

    Context: The association between spray paint exposure and bone remodeling received little attention despite the high usage of spray paints in automobile industries, steel furniture workshops etc. Aim: The present study was aimed at investigating the level of serum markers of bone formation in spray painters. The spray painting subjects were selected from automobile body repair workshops in Chennai region of TamilNadu which constitutes 30% of India's automobile industry. Setting and Design: All the study subjects, exposed to spray paint were working in a workshop without standard spraying room and did not wore any aerosol removing respirator. The controls were selected from random population irrespective of occupation. Data relevant to the socioeconomic features and personal history was collected using a questionnaire. The current study included 50 spray painters and 25 control subjects of same age group. Materials and Methods: We examined the level of serum calcium, serum phosphorus, serum differentiation markers of bone such as alkaline phosphatase (bone specific) and serum osteocalcin in which these levels were found to be high in serum of spray painters. Conclusion: The current study concludes dysregulation in bone remodeling of spray painters exposed to chronic solvents and paint pigments. PMID:23580840

  11. Small-Scale Spray Releases: Orifice Plugging Test Results

    SciTech Connect

    Mahoney, Lenna A.; Gauglitz, Phillip A.; Blanchard, Jeremy; Kimura, Marcia L.; Kurath, Dean E.

    2012-09-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities, is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations published in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials present in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty introduced by extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches in which the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are largely absent. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine the aerosol release fractions and aerosol generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents (AFA) was assessed with most of the simulants. Orifices

  12. Thermal and flow measurements of continuous cryogenic spray cooling.

    PubMed

    Hsieh, Shou-Shing; Tsai, Huang-Hsiu

    2006-07-01

    The performance of single sprays for high heat flux cooling using R-134a was studied. The heat flux and heat transfer coefficient at the surface of a sprayed jet based on measurements of steady-state temperature gradients on a thin copper plate during continuous spraying. Meanwhile, the spray droplets flow characteristics was also quantified through laser doppler velocimetry (LDV) measurements to obtain the local velocity distributions. The effects of mass flow rate and average droplet velocity, and spray exit-to-target distance on the surface heat flux including the corresponding critical heat flux (CHF) were explored through three different nozzle diameters of 0.2, 0.3, and 0.4 mm. Finally, the effective use of the fluid being delivered based on the cooling efficiency and cooling effectiveness was also examined. The relationship between CHF and nozzle performance in terms of cooling efficiency and cooling effectiveness was found. The heat transfer removal rate can reach up to 140 W/cm(2) for the present nozzle size of d (j)=0.2 and 0.3 mm, which may enhance the current cryogen spray cooling (CSC) technique that assists laser therapy of dermatoses.

  13. Global Atmospheric Aerosol Modeling

    NASA Technical Reports Server (NTRS)

    Hendricks, Johannes; Aquila, Valentina; Righi, Mattia

    2012-01-01

    Global aerosol models are used to study the distribution and properties of atmospheric aerosol particles as well as their effects on clouds, atmospheric chemistry, radiation, and climate. The present article provides an overview of the basic concepts of global atmospheric aerosol modeling and shows some examples from a global aerosol simulation. Particular emphasis is placed on the simulation of aerosol particles and their effects within global climate models.

  14. Spray algorithm without interface construction

    NASA Astrophysics Data System (ADS)

    Al-Kadhem Majhool, Ahmed Abed; Watkins, A. P.

    2012-05-01

    This research is aimed to create a new and robust family of convective schemes to capture the interface between the dispersed and the carrier phases in a spray without the need to build up the interface boundary. The selection of the Weighted Average Flux (WAF) scheme is due to this scheme being designed to deal with random flux scheme which is second-order accurate in space and time. The convective flux in each cell face utilizes the WAF scheme blended with Switching Technique for Advection and Capturing of Surfaces (STACS) scheme for high resolution flux limiters. In the next step, the high resolution scheme is blended with the WAF scheme to provide the sharpness and boundedness of the interface by using switching strategy. In this work, the Eulerian-Eulerian framework of non-reactive turbulent spray is set in terms of theoretical proposed methodology namely spray moments of drop size distribution, presented by Beck and Watkins [1]. The computational spray model avoids the need to segregate the local droplet number distribution into parcels of identical droplets. The proposed scheme is tested on capturing the spray edges in modelling hollow cone sprays without need to reconstruct two-phase interface. A test is made on simple comparison between TVD scheme and WAF scheme using the same flux limiter on convective flow hollow cone spray. Results show the WAF scheme gives a better prediction than TVD scheme. The only way to check the accuracy of the presented models is by evaluating the spray sheet thickness.

  15. Connecting marine productivity to sea-spray via microscale biological processes: phytoplancton demise and viral infection

    NASA Astrophysics Data System (ADS)

    Facchini, C.; O'Dowd, C. D. D.; Danovaro, R.

    2015-12-01

    The processes that link phytoplankton biomass and productivity to the organic matter enrichment in sea spray aerosol are far from being elucidated and modelling predictions remain highly uncertain at the moment. While some studies have asserted that the enrichment of OM in sea spray aerosol is independent on marine productivity, others, have shown significant correlation with phytoplankton biomass and productivity (Chl-a retrieved by satellites). We present here new results illustrating a clear link between OM mass-fraction enrichment in sea spray (OMss) and both phytoplankton-biomass and Net Primary Productivity (NPP). We suggest that the OM enrichment of sea spray through the demise of the bloom, driven by nanoscale biological processes (such as viral infections), which determine the release of celldebris, exudates and other colloidal material. This OM, through processes, leads to enrichment in sea-spray, thus demonstrating an important coupling between biologically-drive plankton bloom termination, marine productivity and sea-spraymodification with potentially significant climate impacts.

  16. Spray printing of organic semiconducting single crystals

    PubMed Central

    Rigas, Grigorios-Panagiotis; Payne, Marcia M.; Anthony, John E.; Horton, Peter N.; Castro, Fernando A.; Shkunov, Maxim

    2016-01-01

    Single-crystal semiconductors have been at the forefront of scientific interest for more than 70 years, serving as the backbone of electronic devices. Inorganic single crystals are typically grown from a melt using time-consuming and energy-intensive processes. Organic semiconductor single crystals, however, can be grown using solution-based methods at room temperature in air, opening up the possibility of large-scale production of inexpensive electronics targeting applications ranging from field-effect transistors and light-emitting diodes to medical X-ray detectors. Here we demonstrate a low-cost, scalable spray-printing process to fabricate high-quality organic single crystals, based on various semiconducting small molecules on virtually any substrate by combining the advantages of antisolvent crystallization and solution shearing. The crystals' size, shape and orientation are controlled by the sheer force generated by the spray droplets' impact onto the antisolvent's surface. This method demonstrates the feasibility of a spray-on single-crystal organic electronics. PMID:27874001

  17. Spray printing of organic semiconducting single crystals

    NASA Astrophysics Data System (ADS)

    Rigas, Grigorios-Panagiotis; Payne, Marcia M.; Anthony, John E.; Horton, Peter N.; Castro, Fernando A.; Shkunov, Maxim

    2016-11-01

    Single-crystal semiconductors have been at the forefront of scientific interest for more than 70 years, serving as the backbone of electronic devices. Inorganic single crystals are typically grown from a melt using time-consuming and energy-intensive processes. Organic semiconductor single crystals, however, can be grown using solution-based methods at room temperature in air, opening up the possibility of large-scale production of inexpensive electronics targeting applications ranging from field-effect transistors and light-emitting diodes to medical X-ray detectors. Here we demonstrate a low-cost, scalable spray-printing process to fabricate high-quality organic single crystals, based on various semiconducting small molecules on virtually any substrate by combining the advantages of antisolvent crystallization and solution shearing. The crystals' size, shape and orientation are controlled by the sheer force generated by the spray droplets' impact onto the antisolvent's surface. This method demonstrates the feasibility of a spray-on single-crystal organic electronics.

  18. Substrate system for spray forming

    DOEpatents

    Chu, Men G.; Chernicoff, William P.

    2002-01-01

    A substrate system for receiving a deposit of sprayed metal droplets including a movable outer substrate on which the sprayed metal droplets are deposited. The substrate system also includes an inner substrate disposed adjacent the outer substrate where the sprayed metal droplets are deposited on the outer substrate. The inner substrate includes zones of differing thermal conductivity to resist substrate layer porosity and to resist formation of large grains and coarse constituent particles in a bulk layer of the metal droplets which have accumulated on the outer substrate. A spray forming apparatus and associated method of spray forming a molten metal to form a metal product using the substrate system of the invention is also provided.

  19. Substrate system for spray forming

    DOEpatents

    Chu, Men G.; Chernicoff, William P.

    2000-01-01

    A substrate system for receiving a deposit of sprayed metal droplets including a movable outer substrate on which the sprayed metal droplets are deposited. The substrate system also includes an inner substrate disposed adjacent the outer substrate where the sprayed metal droplets are deposited on the outer substrate. The inner substrate includes zones of differing thermal conductivity to resist substrate layer porosity and to resist formation of large grains and coarse constituent particles in a bulk layer of the metal droplets which have accumulated on the outer substrate. A spray forming apparatus and associated method of spray forming a molten metal to form a metal product using the substrate system of the invention is also provided.

  20. Incorporation of advanced aerosol activation treatments into CESM/CAM5: model evaluation and impacts on aerosol indirect effects

    NASA Astrophysics Data System (ADS)

    Gantt, B.; He, J.; Zhang, X.; Zhang, Y.; Nenes, A.

    2014-07-01

    One of the greatest sources of uncertainty in the science of anthropogenic climate change is from aerosol-cloud interactions. The activation of aerosols into cloud droplets is a direct microphysical linkage between aerosols and clouds; parameterizations of this process link aerosol with cloud condensation nuclei (CCN) and the resulting indirect effects. Small differences between parameterizations can have a large impact on the spatiotemporal distributions of activated aerosols and the resulting cloud properties. In this work, we incorporate a series of aerosol activation schemes into the Community Atmosphere Model version 5.1.1 within the Community Earth System Model version 1.0.5 (CESM/CAM5) which include factors such as insoluble aerosol adsorption and giant cloud condensation nuclei (CCN) activation kinetics to understand their individual impacts on global-scale cloud droplet number concentration (CDNC). Compared to the existing activation scheme in CESM/CAM5, this series of activation schemes increase the computation time by ~10% but leads to predicted CDNC in better agreement with satellite-derived/in situ values in many regions with high CDNC but in worse agreement for some regions with low CDNC. Large percentage changes in predicted CDNC occur over desert and oceanic regions, owing to the enhanced activation of dust from insoluble aerosol adsorption and reduced activation of sea spray aerosol after accounting for giant CCN activation kinetics. Comparison of CESM/CAM5 predictions against satellite-derived cloud optical thickness and liquid water path shows that the updated activation schemes generally improve the low biases. Globally, the incorporation of all updated schemes leads to an average increase in column CDNC of 150% and an increase (more negative) in shortwave cloud forcing of 12%. With the improvement of model-predicted CDNCs and better agreement with most satellite-derived cloud properties in many regions, the inclusion of these aerosol activation

  1. Aerosol gels

    NASA Technical Reports Server (NTRS)

    Sorensen, Christopher M. (Inventor); Chakrabarti, Amitabha (Inventor); Dhaubhadel, Rajan (Inventor); Gerving, Corey (Inventor)

    2010-01-01

    An improved process for the production of ultralow density, high specific surface area gel products is provided which comprises providing, in an enclosed chamber, a mixture made up of small particles of material suspended in gas; the particles are then caused to aggregate in the chamber to form ramified fractal aggregate gels. The particles should have a radius (a) of up to about 50 nm and the aerosol should have a volume fraction (f.sub.v) of at least 10.sup.-4. In preferred practice, the mixture is created by a spark-induced explosion of a precursor material (e.g., a hydrocarbon) and oxygen within the chamber. New compositions of matter are disclosed having densities below 3.0 mg/cc.

  2. Effect of aerosol propellants and surfactants on airway resistance

    PubMed Central

    Sterling, G. M.; Batten, J. C.

    1969-01-01

    The effects on the airways of inhalation of the vehicles used in two commercial pressurized bronchodilator aerosols were studied in 20 normal and seven asthmatic subjects. Changes in bronchial calibre due to bronchoconstriction were measured as changes in airway resistance using a constant volume whole body plethysmograph, and results were expressed as changes in the ratio Airway conductance/Thoracic gas volume (=specific airway conductance). The aerosols caused very slight bronchoconstriction in the normal subjects, with a mean decrease of 5·3% in specific airway conductance after inhalation of a spray containing sorbitol trioleate as a surface tension lowering agent, and of 9·7% after inhalation of a spray containing lecithin. This effect was prevented by prior inhalation of atropine methonitrate, and its mechanism was therefore probably a vagally mediated reflex. The bronchoconstriction was also reversed by the addition of isoprenaline to the aerosol. The asthmatic subjects showed larger mean reductions in specific airway conductance of 13% and 21% after sorbitol and lecithin respectively: the response was again prevented by atropine. We conclude that, although the aerosol vehicles cause slight bronchoconstriction, this is unlikely to be a clinical danger since it is insufficient to cause symptoms of wheezing, and is less than that caused by inhalation of a single cigarette. Moreover, the constriction is regularly converted to dilatation in both normal and asthmatic subjects by the addition of atropine or isoprenaline to the aerosol. PMID:5821624

  3. Baseline Maritime Aerosol: Methodology to Derive the Optical Thickness and Scattering Properties

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram J.; Smirnov, Alexander; Holben, Brent N.; Dubovik, Oleg; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Satellite Measurements of the global distribution of aerosol and their effect on climate should be viewed in respect to a baseline aerosol. In this concept, concentration of fine mode aerosol particles is elevated above the baseline by man-made activities (smoke or urban pollution), while coarse mode by natural processes (e.g. dust or sea-spray). Using 1-3 years of measurements in 10 stations of the Aerosol Robotic network (ACRONET we develop a methodology and derive the optical thickness and properties of this baseline aerosol for the Pacific and Atlantic Oceans. Defined as the median for periods of stable optical thickness (standard deviation < 0.02) during 2-6 days, the median baseline aerosol optical thickness over the Pacific Ocean is 0.052 at 500 am with Angstrom exponent of 0.77, and 0.071 and 1.1 respectively, over the Atlantic Ocean.

  4. Aerosol typing - key information from aerosol studies

    NASA Astrophysics Data System (ADS)

    Mona, Lucia; Kahn, Ralph; Papagiannopoulos, Nikolaos; Holzer-Popp, Thomas; Pappalardo, Gelsomina

    2016-04-01

    Aerosol typing is a key source of aerosol information from ground-based and satellite-borne instruments. Depending on the specific measurement technique, aerosol typing can be used as input for retrievals or represents an output for other applications. Typically aerosol retrievals require some a priori or external aerosol type information. The accuracy of the derived aerosol products strongly depends on the reliability of these assumptions. Different sensors can make use of different aerosol type inputs. A critical review and harmonization of these procedures could significantly reduce related uncertainties. On the other hand, satellite measurements in recent years are providing valuable information about the global distribution of aerosol types, showing for example the main source regions and typical transport paths. Climatological studies of aerosol load at global and regional scales often rely on inferred aerosol type. There is still a high degree of inhomogeneity among satellite aerosol typing schemes, which makes the use different sensor datasets in a consistent way difficult. Knowledge of the 4d aerosol type distribution at these scales is essential for understanding the impact of different aerosol sources on climate, precipitation and air quality. All this information is needed for planning upcoming aerosol emissions policies. The exchange of expertise and the communication among satellite and ground-based measurement communities is fundamental for improving long-term dataset consistency, and for reducing aerosol type distribution uncertainties. Aerosol typing has been recognized as one of its high-priority activities of the AEROSAT (International Satellite Aerosol Science Network, http://aero-sat.org/) initiative. In the AEROSAT framework, a first critical review of aerosol typing procedures has been carried out. The review underlines the high heterogeneity in many aspects: approach, nomenclature, assumed number of components and parameters used for the

  5. Aerially released spray penetration of a tall coniferous canopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An aerial spray deposition project was designed to evaluate aerial application to an Eastern Hemlock (Tsuga canadensis) canopy to combat Hemlock Woolly Adelgid (Adelges tsugae). This adelgid offers a difficult target residing in the forest canopy at the nodes of branchlets. The study collected 1680 ...

  6. Fluidic spray control

    NASA Astrophysics Data System (ADS)

    Tseng, Kuo-Tung

    An original fluidic control method in an axisymmetric spray orifice is investigated using both experiments and existing CFD. Cavitation images, droplet size measurements, discharge coefficient, unsteadiness measurements and CFD are incorporated to find out the causes resulting in small droplets. A flow rig delivering pressurized water flow to an orifice is constructed. A secondary flow is introduced through an annular slot in the orifice wall to control the cavitation, and thus the spray, at pressures up to 550 kPa driving pressure difference. The orifice used is nominally axisymmetric with a diameter 0.81 mm and length 5.08 mm. Two types of orifices are made. Orifice 1 has the slot located 0.81 mm below the orifice inlet, and the slot orientation is angled at 67.5° to the hole axis. Orifice 2 has the slot situated at 0.41 mm below the orifice inlet, and the slot orientation is angled at 15° to the hole axis. Devices, including a CCD camera, a particle-sizer and a He-Ne laser system, were utilized for flow visualization and relevant measurements. The cavitation and spray were photographed with a high resolution CCD digital camera. Droplet size measurements were made with a laser diffraction particle-sizer. Moreover, the cavitation frequencies were explored using a He-Ne laser along with a photodiode and an oscilloscope. CFD codes developed by Chen and Heister were used to model the internal flow. 54 cases were run, including 5 slot locations, 5 slot orientations, and 4 secondary flow rates. Compared with the experimental results, the agreement between CFD and experimental results is good except for hydraulic flip. Generally the high pressure region upstream of the slot, the large high pressure variation over time, and the long cavitation length are the favorable conditions for creating small droplets. The CFD together with experimental measurements correlate the flow structures with droplet sizes. Understanding the relationship between flow structures and droplet

  7. Atomistic Simulation of Sea Spray Particles

    NASA Astrophysics Data System (ADS)

    Gokturk, H.

    2012-12-01

    . Interaction of carbon dioxide with the ion is examined for two cases: (a) When the CO2 molecule interacts directly with the ion, energy of interaction is 0.6 eV for Na+ and 0.3 eV for Cl-. (b) When the CO2 molecule is located behind water molecules which are nearest neighbors of the ion, interaction energy is about 0.2 eV for both ions. In both cases the interaction energy is significantly greater than typical thermal energies encountered in the atmosphere. Hence one can surmise that ions located close to the surface of sea spray particles might enhance the absorption of atmospheric CO2 into the particles. Similar calculations are in progress for doubly charged ions found in seawater and results will be reported during the presentation. [1] Lewis, R., and Schwartz, E. (2004), Sea Salt Aerosol Production: Mechanisms, Methods, Measurements and Models—A Critical Review, Geophys. Monogr. Ser., vol. 152, AGU, Washington, D. C., doi:10.1029/GM152 [2] Saltzman, E. S. (2009), Marine aerosols, in Surface Ocean—Lower Atmosphere Processes, Geophys. Monogr. Ser., vol. 187, edited by C. Le Quere and E. S. Saltzman, pp. 17-35, AGU, Washington, D. C., doi:10.1029/2008GM000769 [3] Salter, S., Sortino, G., and Latham, J. (2008), Sea Going Hardware for the Cloud Albedo Method of Reversing Global Warming, Phil. Trans. R. Soc. A, vol. 366, pp. 3989-4006, doi: 10.1098/rsta.2008.0136

  8. Ionic surface active compounds in atmospheric aerosols.

    PubMed

    Sukhapan, Jariya; Brimblecombe, Peter

    2002-04-27

    Surfactants in the atmosphere have several potential roles in atmospheric chemistry. They can form films on aqueous surfaces, which lowers the surface tension and possibly delays water evaporation and gaseous transportation across the aqueous interface. They can also increase the solubility of organic compounds in the aqueous phase. Recently, the decrease of surface tension in cloud growing droplets has been suggested as relevant to increases in the number of droplets of smaller size, potentially enhancing cloud albedo. Natural surfactants in the lung aid gas transfer and influence the dissolution rate of aerosol particles, so surfactants in atmospheric aerosols, once inhaled, may interact with pulmonary surfactants. Ambient aerosols were collected from the edge of Norwich, a small city in a largely agricultural region of England, and analysed for surfactants. Methylene blue, a conventional dye for detecting anionic surfactants, has been used as a colorimetric agent. The concentration of surfactants expressed as methylene blue active substances (MBAS) is in the range of 6-170 pmol m(-3)(air). A negative correlation with chloride aerosol indicates that these surfactants are probably not the well-known surfactants derived from marine spray. A more positive correlation with aerosol nitrate and gaseous NOx supports an association with more polluted inland air masses. The surfactants found in aerosols seem to be relatively strong acids, compared with weaker acids such as the long-chain carboxylic acids previously proposed as atmospheric surfactants. Surfactants from the oxidation of organic materials (perhaps vegetation- or soil-derived) seem a likely source of these substances in the atmosphere.

  9. INEL Spray-forming Research

    NASA Technical Reports Server (NTRS)

    Mchugh, Kevin M.; Key, James F.

    1993-01-01

    Spray forming is a near-net-shape fabrication technology in which a spray of finely atomized liquid droplets is deposited onto a suitably shaped substrate or mold to produce a coherent solid. The technology offers unique opportunities for simplifying materials processing without sacrificing, and oftentimes substantially improving, product quality. Spray forming can be performed with a wide range of metals and nonmetals, and offers property improvements resulting from rapid solidification (e.g., refined microstructures, extended solid solubilities and reduced segregation). Economic benefits result from process simplification and the elimination of unit operations. Researchers at the Idaho National Engineering Laboratory (INEL) are developing spray-forming technology for producing near-net-shape solids and coatings of a variety of metals, polymers, and composite materials. Results from several spray forming programs are presented to illustrate the range of capabilities of the technique as well as the accompanying technical and economic benefits. Low-carbon steel strip greater than 0.75 mm thick and polymer membranes for gas/gas and liquid/liquid separations that were spray formed are discussed; recent advances in spray forming molds, dies, and other tooling using low-melting-point metals are described.

  10. Influence of herbicide active ingredient, nozzle type, orifice size, spray pressure, and carrier volume rate on spray droplet size characteristics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent concerns on herbicide spray drift and its subsequent impact on the surrounding environment and herbicide efficacy have prompted applicators to focus on methods to reduce off-target movement of herbicides. Herbicide applications are complex processes and as such few studies have been conducted...

  11. Surfactants in the sea-surface microlayer and atmospheric aerosol around the southern region of Peninsular Malaysia.

    PubMed

    Jaafar, Shoffian Amin; Latif, Mohd Talib; Chian, Chong Woan; Han, Wong Sook; Wahid, Nurul Bahiyah Abd; Razak, Intan Suraya; Khan, Md Firoz; Tahir, Norhayati Mohd

    2014-07-15

    This study was conducted to determine the composition of surfactants in the sea-surface microlayer (SML) and atmospheric aerosol around the southern region of the Peninsular Malaysia. Surfactants in samples taken from the SML and atmospheric aerosol were determined using a colorimetric method, as either methylene blue active substances (MBAS) or disulphine blue active substances (DBAS). Principal component analysis with multiple linear regressions (PCA-MLR), using the anion and major element composition of the aerosol samples, was used to determine possible sources of surfactants in atmospheric aerosol. The results showed that the concentrations of surfactants in the SML and atmospheric aerosol were dominated by anionic surfactants and that surfactants in aerosol were not directly correlated (p>0.05) with surfactants in the SML. Further PCA-MLR from anion and major element concentrations showed that combustion of fossil fuel and sea spray were the major contributors to surfactants in aerosol in the study area.

  12. Plasma spraying with wire feedstock

    SciTech Connect

    Scholl, M.

    1994-12-31

    Plasma spraying has been limited to using powder feedstocks for a number of reasons. One limitation has been the low energy output of conventional plasma guns. The advent of high energy plasma spraying (HEPS) devices and the associated technology has effectively removed this functional limitation. With HEPS, the combination of high gas velocities and high thermal plasma temperatures coupled with a large exit gas volume enables wire and rod feedstocks to be effectively utilized. Rather than a bulk melting mechanism, a model based on ablation phenomena is considered. The paper examines an analysis of melting phenomena and presents a simple model for molten droplet formation for plasma spraying using wire feedstocks.

  13. Gas Dynamic Spray Technology Demonstration

    NASA Technical Reports Server (NTRS)

    Burford, Pattie Lewis

    2011-01-01

    Zinc primer systems are currently used across NASA and AFSPC for corrosion protection of steel. AFSPC and NASA have approved the use of Thermal Spray Coatings (TSCs) as an environmentally preferable alternative. TSCs are approved in NASA-STD-5008 and AFSPC and KSC is currently looking for additional applications in which TSC can be used. Gas Dynamic Spray (GDS, also known as Cold Spray) is being evaluated as a means of repairing TSCs and for areas such as corners and edges where TSCs do not work as well. Other applications could include spot repair/maintenance of steel on structures, facilities, and ground support equipment.

  14. Quantitative assessment of inhalation exposure and deposited dose of aerosol from nanotechnology-based consumer sprays†

    PubMed Central

    Nazarenko, Yevgen; Lioy, Paul J.; Mainelis, Gediminas

    2015-01-01

    This study provides a quantitative assessment of inhalation exposure and deposited aerosol dose in the 14 nm to 20 μm particle size range based on the aerosol measurements conducted during realistic usage simulation of five nanotechnology-based and five regular spray products matching the nano-products by purpose of application. The products were also examined using transmission electron microscopy. In seven out of ten sprays, the highest inhalation exposure was observed for the coarse (2.5–10 μm) particles while being minimal or below the detection limit for the remaining three sprays. Nanosized aerosol particles (14–100 nm) were released, which resulted in low but measurable inhalation exposures from all of the investigated consumer sprays. Eight out of ten products produced high total deposited aerosol doses on the order of 101–103 ng kg−1 bw per application, ~85–88% of which were in the head airways, only <10% in the alveolar region and <8% in the tracheobronchial region. One nano and one regular spray produced substantially lower total deposited doses (by 2–4 orders of magnitude less), only ~52–64% of which were in the head while ~29–40% in the alveolar region. The electron microscopy data showed nanosized objects in some products not labeled as nanotechnology-based and conversely did not find nano-objects in some nano-sprays. We found no correlation between nano-object presence and abundance as per the electron microscopy data and the determined inhalation exposures and deposited doses. The findings of this study and the reported quantitative exposure data will be valuable for the manufacturers of nanotechnology-based consumer sprays to minimize inhalation exposure from their products, as well as for the regulators focusing on protecting the public health. PMID:25621175

  15. Spray-freeze-dried dry powder inhalation of insulin-loaded liposomes for enhanced pulmonary delivery.

    PubMed

    Bi, Ru; Shao, Wei; Wang, Qun; Zhang, Na

    2008-11-01

    Nowadays, growing attention has been paid to the pulmonary region as a target for the delivery of peptide and protein drugs, especially macromolecules with systemic effect like insulin, since the pulmonary route exhibits numerous benefits to be an alternative for repeated injection. Furthermore, encapsulation of insulin into liposomal carriers is an attractive way to increase drug retention time and control the drug release in the lung; however, its long-term stability during storage in the reservoir and the process of aerosolization might be suspected when practically applied. Thus, the aim of this study was to design and characterize dry powder inhalation of insulin-loaded liposomes prepared by novel spray-freeze-drying method for enhanced pulmonary delivery. Process variables such as compressed air pressure, pump speed, and concentration were optimized for parameters such as mean particle diameter, moisture content, and fine particle fraction of the produced powders. Influence of different kinds and amounts of lyoprotectants was also evaluated for the best preservation of the drug entrapped in the liposome bilayers after the dehydration-rehydration cycle. The in vivo study of intratracheal instillation of insulin-loaded liposomes to diabetic rats showed successful hypoglycemic effect with low blood glucose level and long-lasting period and a relative pharmacological bioavailability as high as 38.38% in the group of 8 IU/kg dosage.

  16. Exposure of spray-men to dieldrin in residual spraying.

    PubMed

    FLETCHER, T E; PRESS, J M; WILSON, D B

    1959-01-01

    A study of the exposure of spray-men to dieldrin was made in a pilot scheme of residual spraying in the Taveta-Pare area of East Africa. A detailed work study was completed on the operators, and sources of contamination were enumerated. Filter paper pads were placed on the skin and outside clothing and the pick-up was estimated chemically. A spray-man, while using the daily average of 2.12 kg (4.7 pounds) of dieldrin and observing the protective measures laid down, received a dermal exposure of 1.8 mg of dieldrin per kg of body-weight per day. This was possibly reduced somewhat by washing with soap and water upon completion of each day's work. The sixteen spray-men and assistants were exposed for 180 days per year and there was an interim period of 2 months between spray cycles. No clinical symptoms of poisoning were observed.Comparison is made with certain programmes where dieldrin poisoning has occurred. Attention is drawn to the reduced time of exposure in the Taveta-Pare scheme, personal washing, the great value of protective clothing and of its daily washing in soap and water and the need to use a dilute suspension of wettable powder for spraying.

  17. Modifications Of A Commercial Spray Gun

    NASA Technical Reports Server (NTRS)

    Allen, Peter B.

    1993-01-01

    Commercial spray gun modified to increase spray rate and make sprayed coats more nearly uniform. Consists of gun head and pneumatic actuator. Actuator opens valves for two chemical components, called "A" and "B," that react to produce foam. Components flow through orifices, into mixing chamber in head. Mixture then flows through control orifice to spray tip. New spray tip tapered to reduce area available for accumulation of foam and makes tip easier to clean.

  18. Spatial and temporal distribution of airborne Bacillus thuringiensis var. kurstaki during an aerial spray program for gypsy moth eradication.

    PubMed Central

    Teschke, K; Chow, Y; Bartlett, K; Ross, A; van Netten, C

    2001-01-01

    We measured airborne exposures to the biological insecticide Bacillus thuringiensis var. kurstaki (Btk) during an aerial spray program to eradicate gypsy moths on the west coast of Canada. We aimed to determine whether staying indoors during spraying reduced exposures, to determine the rate of temporal decay of airborne concentrations, and to determine whether drift occurred outside the spray zone. During spraying, the average culturable airborne Btk concentration measured outdoors within the spray zone was 739 colony-forming units (CFU)/m3 of air. Outdoor air concentrations decreased over time, quickly in an initial phase with a half time of 3.3 hr, and then more slowly over the following 9 days, with an overall half-time of about 2.4 days. Inside residences during spraying, average concentrations were initially 2-5 times lower than outdoors, but at 5-6 hr after spraying began, indoor concentrations exceeded those outdoors, with an average of 244 CFU/m3 vs. 77 CFU/m3 outdoors, suggesting that the initial benefits of remaining indoors during spraying may not persist as outside air moves indoors with normal daily activities. There was drift of culturable Btk throughout a 125- to 1,000-meter band outside the spray zone where measurements were made, a consequence of the fine aerosol sizes that remained airborne (count median diameters of 4.3 to 7.2 microm). Btk concentrations outside the spray zone were related to wind speed and direction, but not to distance from the spray zone. PMID:11171524

  19. AEROSOL AND GAS MEASUREMENT

    EPA Science Inventory

    Measurements provide fundamental information for evaluating and managing the impact of aerosols on air quality. Specific measurements of aerosol concentration and their physical and chemical properties are required by different users to meet different user-community needs. Befo...

  20. Spray nozzle for fire control

    NASA Astrophysics Data System (ADS)

    Papavergos, Panayiotis G.

    1990-09-01

    The design of a spray nozzle for fire control is described. It produces a spray of gas and liquid having an oval transverse cross section and it comprises a mixing chamber with an oval transverse cross section adapted to induce a toroidal mixing pattern in pressurized gas and liquid introduced to the mixing chamber through a plurality of inlets. In a preferred embodiment the mixing chamber is toroidal. The spray nozzle produces an oval spray pattern for more efficient wetting of narrow passages and is suitable for fire control systems in vehicles or other confined spaces. Vehicles to which this invention may be applied include trains, armoured vehicles, ships, hovercraft, submarines, oil rigs, and most preferably, aircraft.

  1. Electrostatic application of antimicrobial sprays to sanitize food handling and processing surfaces for enhanced food safety

    NASA Astrophysics Data System (ADS)

    Lyons, Shawn M.; Harrison, Mark A.; Law, S. Edward

    2011-06-01

    Human illnesses and deaths caused by foodborne pathogens (e.g., Salmonella enterica, Listeria monocytogenes, Escherichia coli O157:H7, etc.) are of increasing concern globally in maintaining safe food supplies. At various stages of the food production, processing and supply chain antimicrobial agents are required to sanitize contact surfaces. Additionally, during outbreaks of contagious pathogenic microorganisms (e.g., H1N1 influenza), public health requires timely decontamination of extensive surfaces within public schools, mass transit systems, etc. Prior publications verify effectiveness of air-assisted, induction-charged (AAIC) electrostatic spraying of various chemical and biological agents to protect on-farm production of food crops...typically doubling droplet deposition efficiency with concomitant increases in biological control efficacy. Within a biosafety facility this present work evaluated the AAIC electrostatic-spraying process for application of antimicrobial liquids onto various pathogen-inoculated food processing and handling surfaces as a food safety intervention strategy. Fluoroanalysis of AAIC electrostatic sprays (-7.2 mC/kg charge-to-mass ratio) showed significantly greater (p<0.05) mass of tracer active ingredient (A.I.) deposited onto target surfaces at various orientations as compared both to a similar uncharged spray nozzle (0 mC/kg) and to a conventional hydraulic-atomizing nozzle. Per unit mass of A.I. dispensed toward targets, for example, A.I. mass deposited by AAIC electrostatic sprays onto difficult to coat backsides was 6.1-times greater than for similar uncharged sprays and 29.0-times greater than for conventional hydraulic-nozzle sprays. Even at the 56% reduction in peracetic acid sanitizer A.I. dispensed by AAIC electrostatic spray applications, they achieved equal or greater CFU population reductions of Salmonella on most target orientations and materials as compared to uncharged sprays and conventional full-rate hydraulic

  2. Analysis of optical trap mediated aerosol coalescence

    NASA Astrophysics Data System (ADS)

    Mistry, N. S.; Power, R.; Anand, S.; McGloin, D.; Almohamedi, A.; Downie, M.; Reid, J. P.; Hudson, A. J.

    2012-10-01

    The use of optical tweezers for the analysis of aerosols is valuable for understanding the dynamics of atmospherically relevant particles. However to be able to make accurate measurements that can be directly tied to real-world phenomena it is important that we understand the influence of the optical trap on those processes. One process that is seemingly straightforward to study with these techniques is binary droplet coalescence, either using dual beam traps, or by particle collision with a single trapped droplet. This binary coalescence is also of interest in many other processes that make use of dense aerosol sprays such as spray drying and the use of inhalers for drug delivery in conditions such as asthma or hay fever. In this presentation we discuss the use of high speed (~5000 frames per second) video microscopy to track the dynamics of particles as they approach and interact with a trapped aqueous droplet and develop this analysis further by considering elastic light scattering from droplets as they undergo coalescence. We find that we are able to characterize the re-equilibration time of droplets of the same phase after they interact and that the trajectories taken by airborne particles influenced by an optical trap are often quite complex. We also examine the role of parameters such as the salt concentration of the aqueous solutions used and the influence of laser wavelength.

  3. Aerosol distribution apparatus

    DOEpatents

    Hanson, W.D.

    An apparatus for uniformly distributing an aerosol to a plurality of filters mounted in a plenum, wherein the aerosol and air are forced through a manifold system by means of a jet pump and released into the plenum through orifices in the manifold. The apparatus allows for the simultaneous aerosol-testing of all the filters in the plenum.

  4. Improved solid aerosol generator

    DOEpatents

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1988-07-19

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  5. Solid aerosol generator

    DOEpatents

    Prescott, Donald S.; Schober, Robert K.; Beller, John

    1992-01-01

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates.

  6. Solid aerosol generator

    DOEpatents

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1992-03-17

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration is disclosed. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  7. Charge generation associated with liquid spraying in tank cleaning and comparable processes - preliminary experiments

    NASA Astrophysics Data System (ADS)

    Blum, Carsten; Losert, Oswald F. J.

    2015-10-01

    The BG RCI has initiated investigations in order to improve the data basis for assessing the ignition hazard by electrostatic charging processes associated with the spraying of liquids. On the base of preliminary experiments, we established procedures for measurements of electric field strength and charging current in the presence of aerosol particles. Results obtained with three different nozzle types, variation of pressure and with built-in deflecting plate are presented.

  8. OCEANFILMS-2: Representing coadsorption of saccharides in marine films and potential impacts on modeled marine aerosol chemistry

    SciTech Connect

    Burrows, Susannah M.; Gobrogge, Eric; Fu, Li; Link, Katie; Elliott, Scott M.; Wang, Hongfei; Walker, Rob

    2016-08-10

    Here we show that the addition of chemical interactions of soluble polysaccharides with a surfactant monolayer improves agreement of modeled sea spray chemistry with observed marine aerosol chemistry. In particular, the fraction of hydroxyl functional groups in modeled sea spray organic matter is increased, improving agreement with FTIR observations of marine aerosol composition. The overall organic fraction of submicron sea spray also increases, allowing organic mass fractions in the range 0.5 – 0.7 for submicron sea spray particles over highly active phytoplankton blooms. We show results from Sum Frequency Generation (SFG) experiments that support the modeling approach, by demonstrating that soluble polysaccharides can strongly adsorb to a lipid monolayer via columbic interactions under appropriate conditions.

  9. Satellite remote sensing of aerosols generated by the Island of Nauru

    NASA Astrophysics Data System (ADS)

    Henderson, Bradley G.; Chylek, Petr; Porch, William M.; Dubey, Manvendra K.

    2006-11-01

    We use imagery from the Multispectral Thermal Imager (MTI) to search for aerosols generated by the Island of Nauru, an island located in the tropical western Pacific Ocean. Nauru frequently displays linear cloud trails for many kilometers downwind of the island, and this study was intended to investigate the presence of aerosols as an aid to understanding those features. The study had three components: (1) a search for specific aerosol plumes, (2) a comparison of downwind and upwind aerosol loading to look for asymmetries, and (3) application of matched filters to increase the visibility of aerosol plumes. The plume search resulted in the finding of three aerosol plumes, two of which are presented as imagery and also radiance profiles. The comparison of downwind and upwind reflectance spectra demonstrated that the radiance is slightly higher downwind of the island, and the residual spectra (downwind minus upwind) have a spectrum consistent with sea salt aerosol. Application of clutter-matched filters to MTI imagery accentuated the upper (near source) sections of an aerosol plume when utilizing a single-scatter albedo signature for coarse-grained sea salt aerosol. We combine our observations with models from the literature to describe a simple mechanism by which Nauru aerosols are created by wave breaking and wind tearing of sea spray and then entrained by island-influenced wind motions.

  10. Experimental Infection of Cynomolgus Macaques (Macaca fascicularis) with Aerosolized Monkeypox Virus

    DTIC Science & Technology

    2010-09-01

    Aerobiological Sciences for conducting the aerosol sprays of animals, the personnel of the Veterinary Medicine Division for the care and handling of the...disease: the inside story of eradicating a worldwide killer. Amherst, N.Y.: Prometheus Books. 23. Swearengen JR (2006) Biodefense: research methodology

  11. Aerosol algorithm evaluation within aerosol-CCI

    NASA Astrophysics Data System (ADS)

    Kinne, Stefan; Schulz, Michael; Griesfeller, Jan

    Properties of aerosol retrievals from space are difficult. Even data from dedicated satellite sensors face contaminations which limit the accuracy of aerosol retrieval products. Issues are the identification of complete cloud-free scenes, the need to assume aerosol compositional features in an underdetermined solution space and the requirement to characterize the background at high accuracy. Usually the development of aerosol is a slow process, requiring continuous feedback from evaluations. To demonstrate maturity, these evaluations need to cover different regions and seasons and many different aerosol properties, because aerosol composition is quite diverse and highly variable in space and time, as atmospheric aerosol lifetimes are only a few days. Three years ago the ESA Climate Change Initiative started to support aerosol retrieval efforts in order to develop aerosol retrieval products for the climate community from underutilized ESA satellite sensors. The initial focus was on retrievals of AOD (a measure for the atmospheric column amount) and of Angstrom (a proxy for aerosol size) from the ATSR and MERIS sensors on ENVISAT. The goal was to offer retrieval products that are comparable or better in accuracy than commonly used NASA products of MODIS or MISR. Fortunately, accurate reference data of ground based sun-/sky-photometry networks exist. Thus, retrieval assessments could and were conducted independently by different evaluation groups. Here, results of these evaluations for the year 2008 are summarized. The capability of these newly developed retrievals is analyzed and quantified in scores. These scores allowed a ranking of competing efforts and also allow skill comparisons of these new retrievals against existing and commonly used retrievals.

  12. Microchip sonic spray ionization.

    PubMed

    Pól, Jaroslav; Kauppila, Tiina J; Haapala, Markus; Saarela, Ville; Franssila, Sami; Ketola, Raimo A; Kotiaho, Tapio; Kostiainen, Risto

    2007-05-01

    The first microchip version of sonic spray ionization (SSI) as an atmospheric pressure ionization source for mass spectrometry (MS) is presented. The microchip used for SSI has recently been developed in our laboratory, and it has been used before as an atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) source. Now the ionization is achieved simply by applying high (sonic) speed nebulizer gas, without heat, corona discharge, or high voltage. The microchip SSI was applied to the analysis of tetra-N-butylammonium, verapamil, testosterone, angiotensin I, and ibuprofen. The limits of detection were in the range of 15 nM to 4 microM. The technique was found to be highly dependent on the position of the chip toward the mass spectrometer inlet, and on the gas and the sample solution flow rates. The microchip SSI provided dynamic linearity following a pattern similar to that used with electrospray, good quantitative repeatability (RSD=16%), and long-term signal stability.

  13. Aerosol tests conducted at Aberdeen Proving Grounds MD.

    SciTech Connect

    Brockmann, John E.; Lucero, Daniel A.; Servantes, Brandon Lee; Hankins, Matthew Granholm

    2012-06-01

    Test data are reported that demonstrate the deposition from a spray dispersion system (Illinois Tool Works inductively charging rotary atomization nozzle) for application of decontamination solution to various surfaces in the passenger cabin of a Boeing 737 aircraft. The decontamination solution (EnviroTru) was tagged with a known concentration of fluorescein permitting determination of both airborne decontaminant concentration and surface deposited decontaminant solution so that the effective deposition rates and surface coverage could be determined and correlated with the amount of material sprayed. Six aerosol dispersion tests were conducted. In each test, aluminum foil deposition coupons were set out throughout the passenger area and the aerosol was dispersed. The aerosol concentration was measured with filter samplers as well as with optical techniques Average aerosol deposition ranged from 3 to 15 grams of decontamination solution per square meter. Some disagreement was observed between various instruments utilizing different measurement principles. These results demonstrate a potentially effective method to disperse decontaminant to interior surfaces of a passenger aircraft.

  14. Investigation of Viability of Pantoea agglomerans (Formerly Erwinia herbicola) After Aerosolization From Media Containing Enriching and Coating Chemicals

    DTIC Science & Technology

    2008-02-01

    issue in aerosol testing of vegetative cells, which might be found in the environment. The viability of this bacterial strain has usually been poor during...the foliage of pear trees, when the powder was sprayed to protect the orchard from fire blight . Costa et al. (2002) tested the effects of spray... bacterial growth conditions and after-growth treatments used in the experiments described in this section were prepared as follows: * Eh in TSB: An Eh

  15. Plasma Sprayed Hydroxyapatite Coatings: Influence of Spraying Power on Microstructure

    SciTech Connect

    Mohd, S. M.; Abd, M. Z.; Abd, A. N.

    2010-03-11

    The plasma sprayed hydroxyapatite (HA) coatings are used on metallic implants to enhance the bonding between the implant and bone in human body. The coating process was implemented at different spraying power for each spraying condition. The coatings formed from a rapid solidification of molten and partly molten particles that impact on the surface of substrate at high velocity and high temperature. The study was concentrated on different spraying power that is between 23 to 31 kW. The effect of different power on the coatings microstructure was investigated using scanning electron microscope (SEM) and phase composition was evaluated using X-ray diffraction (XRD) analysis. The coatings surface morphology showed distribution of molten, partially melted particles and some micro-cracks. The produced coatings were found to be porous as observed from the cross-sectional morphology. The coatings XRD results indicated the presence of crystalline phase of HA and each of the patterns was similar to the initial powder. Regardless of different spraying power, all the coatings were having similar XRD patterns.

  16. Evaporation of droplets in a Champagne wine aerosol

    NASA Astrophysics Data System (ADS)

    Ghabache, Elisabeth; Liger-Belair, Gérard; Antkowiak, Arnaud; Séon, Thomas

    2016-04-01

    In a single glass of champagne about a million bubbles nucleate on the wall and rise towards the surface. When these bubbles reach the surface and rupture, they project a multitude of tiny droplets in the form of a particular aerosol holding a concentrate of wine aromas. Based on the model experiment of a single bubble bursting in idealized champagnes, the key features of the champagne aerosol are identified. In particular, we show that film drops, critical in sea spray for example, are here nonexistent. We then demonstrate that compared to a still wine, champagne fizz drastically enhances the transfer of liquid into the atmosphere. There, conditions on bubble radius and wine viscosity that optimize aerosol evaporation are provided. These results pave the way towards the fine tuning of flavor release during sparkling wine tasting, a major issue for the sparkling wine industry.

  17. Evaporation of droplets in a Champagne wine aerosol

    PubMed Central

    Ghabache, Elisabeth; Liger-Belair, Gérard; Antkowiak, Arnaud; Séon, Thomas

    2016-01-01

    In a single glass of champagne about a million bubbles nucleate on the wall and rise towards the surface. When these bubbles reach the surface and rupture, they project a multitude of tiny droplets in the form of a particular aerosol holding a concentrate of wine aromas. Based on the model experiment of a single bubble bursting in idealized champagnes, the key features of the champagne aerosol are identified. In particular, we show that film drops, critical in sea spray for example, are here nonexistent. We then demonstrate that compared to a still wine, champagne fizz drastically enhances the transfer of liquid into the atmosphere. There, conditions on bubble radius and wine viscosity that optimize aerosol evaporation are provided. These results pave the way towards the fine tuning of flavor release during sparkling wine tasting, a major issue for the sparkling wine industry. PMID:27125240

  18. The optical manipulation and characterisation of aerosol particles

    NASA Astrophysics Data System (ADS)

    Reid, Jonathan P.

    2008-08-01

    Aerosols play a crucial role in many areas of science, ranging from atmospheric chemistry and physics, to pharmaceutical aerosols and drug delivery to the lungs, to combustion science and spray drying. The development of new methods for characterising the properties and dynamics of aerosol particles is of crucial importance if the complex role that particles play is to be more fully understood. Optical tweezers provide a valuable new tool to address fundamental questions in aerosol science. Single or multiple particles 1-15 μm in diameter can be manipulated for indefinite timescales. Linear and non-linear Raman and fluorescence spectroscopies can be used to probe particle composition, phase, component mixing state, and size. In particular, size can be determined with nanometre accuracy, allowing accurate measurements of the thermodynamic properties of aerosols, the kinetics of particle transformation and of light absorption. Further, the simultaneous manipulation of multiple particles in parallel optical traps provides a method for performing comparative measurements on particles of different composition. We will present some latest work in which optical tweezers are used to characterise aerosol dynamics, demonstrating that optical tweezers can find application in studies of hygroscopicity, the mixing state of different chemical components, including the phase separation of immiscible phases, and the kinetics of chemical transformation.

  19. Development of a Paper Spray Mass Spectrometry Cartridge with Integrated Solid Phase Extraction for Bioanalysis.

    PubMed

    Zhang, Chengsen; Manicke, Nicholas E

    2015-06-16

    A novel paper spray cartridge with an integrated solid phase extraction (SPE) column is described. The cartridge performs extraction and pre-concentration, as well as sample ionization by paper spray, from complex samples such as plasma. The cartridge allows for selective enrichment of target molecules from larger sample volumes and removal of the matrix, which significantly improved the signal intensity of target compounds in plasma samples by paper spray ionization. Detection limits, quantitative performance, recovery, ionization suppression, and the effects of sample volume were evaluated for five drugs: carbamazepine, atenolol, sulfamethazine, diazepam, and alprazolam. Compared with direct paper spray analysis of dried plasma spots, paper spray analysis using the integrated solid phase extraction improved the detection limits significantly by a factor of 14-70, depending on the drug. The improvement in detection limits was, in large part, due to the capability of analyzing larger sample volumes. In addition, ionization suppression was found to be lower and recovery was higher for paper spray with integrated SPE, as compared to direct paper spray analysis. By spiking an isotopically labeled internal standard into the plasma sample, a linear calibration curve for the drugs was obtained from the limit of detection (LOD) to 1 μg/mL, indicating that this method can be used for quantitative analysis. The paper spray cartridge with integrated SPE could prove valuable for analytes that ionize poorly, in applications where lower detection limits are required, or on portable mass spectrometers. The improved performance comes at the cost of requiring a more complex paper spray cartridge and requiring larger sample volumes than those used in typical direct paper spray ionization.

  20. Impact of Local Pollution Versus Long Range Transported Aerosols on Clouds and Precipitation over California

    NASA Astrophysics Data System (ADS)

    Prather, K. A.

    2015-12-01

    Aerosols form cloud droplets and ice crystals in clouds and can profoundly impact precipitation processes. In-situ aircraft measurements of the composition of individual cloud residuals have been used to study the impact of different aerosol sources including sea spray, dust, soot, and biomass burning on cloud microphysics and precipitation processes. Aircraft studies in 2011 as part of the CalWater project showed that long range transport of dust aerosols from as far away as Africa and biological particles can lead to an increase in the amount of snowfall over California. This presentation will describe results from CalWater-2015 involving aircraft and ground-based measurements at a coastal site. A discussion of the aerosol sources measured in clouds will be presented detailing the relative impacts of local versus long range transported pollution aerosols over California.

  1. Comparison of the performance between a spray gun and a spray boom in ornamentals.

    PubMed

    Foqué, D; Nuyttens, D

    2011-01-01

    Flemish greenhouse growers predominantly use handheld spray guns and spray lances for their crop protection purposes although these techniques are known for their heavy workload and their high operator exposure risks. Moreover, when these techniques are compared with spray boom equipment, they are often found to be less effective. On the other hand, handheld spraying techniques are less expensive and more flexible to use. Additionally, many Flemish growers are convinced that a high spray volume and spray pressure is needed to assure a good plant protection. The aim of this work was to evaluate and compare the spray deposition, penetration and uniformity between a manually pulled horizontal spray boom and a spray gun under controlled laboratory conditions. In total, six different spray application techniques were evaluated. In general, the total deposition results were comparable between the spray boom and the spray gun applications but the boom applications resulted in a more uniform spray distribution over the crop. On a plant level, the spray distribution was not uniform for the different techniques with highest deposits on the upper side of the top leaves. Using spray guns at a higher spray pressure did not improve spray penetration and deposition on the bottom side of the leaves. From the different nozzle types, the XR 80 03 gave the best results. Plant density clearly affected crop penetration and deposition on the bottom side of the leaves.

  2. Aerosol effects and corrections in the Halogen Occultation Experiment

    NASA Technical Reports Server (NTRS)

    Hervig, Mark E.; Russell, James M., III; Gordley, Larry L.; Daniels, John; Drayson, S. Roland; Park, Jae H.

    1995-01-01

    The eruptions of Mt. Pinatubo in June 1991 increased stratospheric aerosol loading by a factor of 30, affecting chemistry, radiative transfer, and remote measurements of the stratosphere. The Halogen Occultation Experiment (HALOE) instrument on board Upper Atmosphere Research Satellite (UARS) makes measurements globally for inferring profiles of NO2, H2O, O3, HF, HCl, CH4, NO, and temperature in addition to aerosol extinction at five wavelengths. Understanding and removing the aerosol extinction is essential for obtaining accurate retrievals from the radiometer channels of NO2, H2O and O3 in the lower stratosphere since these measurements are severely affected by contaminant aerosol absorption. If ignored, aerosol absorption in the radiometer measurements is interpreted as additional absorption by the target gas, resulting in anomalously large mixing ratios. To correct the radiometer measurements for aerosol effects, a retrieved aerosol extinction profile is extrapolated to the radiometer wavelengths and then included as continuum attenuation. The sensitivity of the extrapolation to size distribution and composition is small for certain wavelength combinations, reducing the correction uncertainty. The aerosol corrections extend the usable range of profiles retrieved from the radiometer channels to the tropopause with results that agree well with correlative measurements. In situations of heavy aerosol loading, errors due to aerosol in the retrieved mixing ratios are reduced to values of about 15, 25, and 60% in H2O, O3, and NO2, respectively, levels that are much less than the correction magnitude.

  3. SPRAY CALCINATION REACTOR

    DOEpatents

    Johnson, B.M.

    1963-08-20

    A spray calcination reactor for calcining reprocessin- g waste solutions is described. Coaxial within the outer shell of the reactor is a shorter inner shell having heated walls and with open regions above and below. When the solution is sprayed into the irner shell droplets are entrained by a current of gas that moves downwardly within the inner shell and upwardly between it and the outer shell, and while thus being circulated the droplets are calcined to solids, whlch drop to the bottom without being deposited on the walls. (AEC) H03 H0233412 The average molecular weights of four diallyl phthalate polymer samples extruded from the experimental rheometer were redetermined using the vapor phase osmometer. An amine curing agent is required for obtaining suitable silver- filled epoxy-bonded conductive adhesives. When the curing agent was modified with a 47% polyurethane resin, its effectiveness was hampered. Neither silver nor nickel filler impart a high electrical conductivity to Adiprenebased adhesives. Silver filler was found to perform well in Dow-Corning A-4000 adhesive. Two cascaded hot-wire columns are being used to remove heavy gaseous impurities from methane. This purified gas is being enriched in the concentric tube unit to approximately 20% carbon-13. Studies to count low-level krypton-85 in xenon are continuing. The parameters of the counting technique are being determined. The bismuth isotopes produced in bismuth irradiated for polonium production are being determined. Preliminary data indicate the presence of bismuth207 and bismuth-210m. The light bismuth isotopes are probably produced by (n,xn) reactions bismuth-209. The separation of uranium-234 from plutonium-238 solutions was demonstrated. The bulk of the plutonium is removed by anion exchange, and the remainder is extracted from the uranium by solvent extraction techniques. About 99% of the plutonium can be removed in each thenoyltrifluoroacetone extraction. The viscosity, liquid density, and

  4. Miniature paint-spray gun for recessed areas

    NASA Technical Reports Server (NTRS)

    Vanasse, M. A.

    1968-01-01

    Miniature spray gun regulates paints and other liquids to spray at close range, facilitating spraying of remote or recessed areas. Individual valves for regulating air pressure and paint maximizes atomization for low pressure spraying.

  5. Characterization of aerosols above the Northern Adriatic Sea: Case studies of offshore and onshore wind conditions

    NASA Astrophysics Data System (ADS)

    Piazzola, J.; Mihalopoulos, N.; Canepa, E.; Tedeschi, G.; Prati, P.; Zarmpas, P.; Bastianini, M.; Missamou, T.; Cavaleri, L.

    2016-05-01

    Aerosol particles in coastal areas result from a complex mixing between sea spray aerosols locally generated at the sea surface by the wind-waves interaction processes and a continental component resulting from natural and/or anthropogenic sources. This paper presents a physical and chemical analysis of the aerosol data acquired from May to September 2014 in the Adriatic Sea. Aerosol distributions were measured on the Acqua Alta platform located 15 km off the coast of Venice using two Particle Measuring System probes and a chemical characterization was made using an Ion Chromatography analysis (IC). Our aim is to study both the sea-spray contribution and the anthropogenic influence in the coastal aerosol of this Mediterranean region. To this end, we focus on a comparison between the present data and the aerosol size distributions measured south of the French Mediterranean coast. For air masses of marine origin transported by southern winds on the French coast and by the Sirocco in the Adriatic, we note a good agreement between the concentrations of super-micrometer aerosols measured in the two locations. This indicates a similar sea surface production of sea-spray aerosols formed by bubble bursting processes in the two locations. In contrast, the results show larger concentrations of submicron particles in the North-Western Mediterranean compared to the Adriatic, which result probably from a larger anthropogenic background for marine conditions. In contrast, for a coastal influence, the chemical analysis presented in the present paper seems to indicate a larger importance of the anthropogenic impact in the Northern Adriatic compared to the North-Western Mediterranean.

  6. Selective and conventional house-spraying of DDT and bendiocarb against Anopheles pseudopunctipennis in southern Mexico.

    PubMed

    Casas, M; Torres, J L; Bown, D N; Rodríguez, M H; Arredondo-Jiménez, J I

    1998-12-01

    Indoor feeding behaviors and mortalities of Anopheles pseudopunctipennis females were evaluated following contact with selective (bands covering mosquitoes' preferred resting areas) and full applications of DDT and bendiocarb on indoor sprayable surfaces. The DDT residues provoked strong avoidance behavior. To a lesser degree, mosquitoes were also repelled by bendiocarb-sprayed surfaces. Because of strong irritancy/repellency, unfed mosquitoes were driven outdoors in proportionally higher numbers. The resting time on selectively or fully DDT-sprayed huts was greatly reduced in comparison to bendiocarb-sprayed huts. Although unfed mosquitoes tended to rest on non-DDT-sprayed surfaces in the selectively treated hut, the man-biting rate was similar with both types of treatments. Unfed mosquitoes were repelled less from selectively bendiocarb-treated surfaces. Similar reductions in postfed resting times were observed on all surfaces suggesting that once fed, mosquitoes rested on sprayed surfaces for shorter intervals of time. Engorged mosquitoes had normal resting behavior (pre- and postspray) within the range of preferred resting heights in both DDT- and bendiocarb-sprayed huts, but the proportion of mosquitoes fed in the DDT-treated huts was lower. Selective spraying of walls was as effective as spraying the complete walls with both insecticides, but DDT was more effective in reducing mosquito-human contact. These studies show that by more effectively targeting vector behavior, a cost-effective alternative to traditional control techniques can be achieved.

  7. Model evaluation of marine primary organic aerosol emission schemes

    NASA Astrophysics Data System (ADS)

    Gantt, B.; Johnson, M. S.; Meskhidze, N.; Sciare, J.; Ovadnevaite, J.; Ceburnis, D.; O'Dowd, C. D.

    2012-09-01

    In this study, several marine primary organic aerosol (POA) emission schemes have been evaluated using the GEOS-Chem chemical transport model in order to provide guidance for their implementation in air quality and climate models. These emission schemes, based on varying dependencies of chlorophyll a concentration ([chl a]) and 10 m wind speed (U10), have large differences in their magnitude, spatial distribution, and seasonality. Model comparison with weekly and monthly mean values of the organic aerosol mass concentration at two coastal sites shows that the source function exclusively related to [chl a] does a better job replicating surface observations. Sensitivity simulations in which the negative U10 and positive [chl a] dependence of the organic mass fraction of sea spray aerosol are enhanced show improved prediction of the seasonality of the marine POA concentrations. A top-down estimate of submicron marine POA emissions based on the parameterization that compares best to the observed weekly and monthly mean values of marine organic aerosol surface concentrations has a global average emission rate of 6.3 Tg yr-1. Evaluation of existing marine POA source functions against a case study during which marine POA contributed the major fraction of submicron aerosol mass shows that none of the existing parameterizations are able to reproduce the hourly-averaged observations. Our calculations suggest that in order to capture episodic events and short-term variability in submicron marine POA concentration over the ocean, new source functions need to be developed that are grounded in the physical processes unique to the organic fraction of sea spray aerosol.

  8. Microgravity experiments and numerical studies on ethanol/air spray flames

    NASA Astrophysics Data System (ADS)

    Thimothée, Romain; Chauveau, Christian; Halter, Fabien; Nicoli, Colette; Haldenwang, Pierre; Denet, Bruno

    2017-01-01

    Spray flames are known to exhibit amazing features in comparison with single-phase flames. The weightless situation offers the conditions in which the spray characteristics can be well controlled before and during combustion. The article reports on a joint experimental/numerical work that concerns ethanol/air spray flames observed in a spherical chamber using the condensation technique of expansion cooling (based on the Wilson cloud chamber principle), under microgravity. We describe the experimental set-up and give details on the creation of a homogeneous and nearly monosized aerosol. Different optical diagnostics are employed successfully to measure the relevant parameters of two-phase combustion. A classical shadowgraphy system is used to track the flame speed propagation and allow us to observe the flame front instability. The complete characterization of the aerosol is performed with a laser diffraction particle size analyser by measuring the droplet diameter and the droplet density number, just before ignition. A laser tomography device allows us to measure the temporal evolution of the droplet displacement during flame propagation, as well as to identify the presence of droplets in the burnt gases. The numerical modelling is briefly recalled. In particular, spray-flame propagation is schematized by the combustion spread in a 2-D lattice of fuel droplets surrounded by an initial gaseous mixture of fuel vapour and air. In its spherical expansion, the spray flame presents a corrugated front pattern, while the equivalent single-phase flame does not. From a numerical point of view, the same phenomena of wrinkles are also observed in the simulations. The front pattern pointed out by the numerical approach is identified as of Darrieus-Landau (DL) type. The droplets are found to trigger the instability. Then, we quantitatively compare experimental data with numerical predictions on spray-flame speed. The experimental results show that the spray-flame speed is of the

  9. Environmental Technology Verification Report: Pesticide spray drift reduction technologies--Evaluation of the verification protocol for low and high speed wind tunnel testing

    EPA Science Inventory

    Pesticide spray drift is defined as the movement of spray droplets through the air at the time of application or soon thereafter from the target site to any non- or off-target site, excluding pesticide movements by erosion, migration, volatility, or windblown soil particles after...

  10. [Antibacterial effect of Ankerplast Spray].

    PubMed

    Oehring, H; Karl, P; Döring, K; Herrberger, U

    1979-04-01

    The diffusion test yielded no satisfactory results. In the tube test, both the spray and the solvent (in a dilution of 1:4 and 1:8, respectively) proved to be bacteriostatically active against enterococci, Staphylococcus aureus, Escheria coli, Proteus, and Pseudomonas aeruginosa. These germs were killed within 30 minutes in the test for bactericidal activity, whereas the reference substance (1% phenol) required 1--2 hours, except against the last-named germ. Even the copolymer exerted a bactericidal effect, it is true, but only within 8 or 24 hours. The following results were obtained from the spray test with agar plate cultures: Streptococcus viridans species, streptococci, Diplococcus pneumoniae, Escheria coli, and Proteus were killed, whereas others survived under the plastic film for up to 9 days. Klebsiella and Pseudomonas aeruginosa had grown through the film within 7 days. In vivo experiments demonstrated a very potent antibacterial activity on the skin under the spray film.

  11. The 2016 Thermal Spray Roadmap

    NASA Astrophysics Data System (ADS)

    Vardelle, Armelle; Moreau, Christian; Akedo, Jun; Ashrafizadeh, Hossein; Berndt, Christopher C.; Berghaus, Jörg Oberste; Boulos, Maher; Brogan, Jeffrey; Bourtsalas, Athanasios C.; Dolatabadi, Ali; Dorfman, Mitchell; Eden, Timothy J.; Fauchais, Pierre; Fisher, Gary; Gaertner, Frank; Gindrat, Malko; Henne, Rudolf; Hyland, Margaret; Irissou, Eric; Jordan, Eric H.; Khor, Khiam Aik; Killinger, Andreas; Lau, Yuk-Chiu; Li, Chang-Jiu; Li, Li; Longtin, Jon; Markocsan, Nicolaie; Masset, Patrick J.; Matejicek, Jiri; Mauer, Georg; McDonald, André; Mostaghimi, Javad; Sampath, Sanjay; Schiller, Günter; Shinoda, Kentaro; Smith, Mark F.; Syed, Asif Ansar; Themelis, Nickolas J.; Toma, Filofteia-Laura; Trelles, Juan Pablo; Vassen, Robert; Vuoristo, Petri

    2016-12-01

    Considerable progress has been made over the last decades in thermal spray technologies, practices and applications. However, like other technologies, they have to continuously evolve to meet new problems and market requirements. This article aims to identify the current challenges limiting the evolution of these technologies and to propose research directions and priorities to meet these challenges. It was prepared on the basis of a collection of short articles written by experts in thermal spray who were asked to present a snapshot of the current state of their specific field, give their views on current challenges faced by the field and provide some guidance as to the R&D required to meet these challenges. The article is divided in three sections that deal with the emerging thermal spray processes, coating properties and function, and biomedical, electronic, aerospace and energy generation applications.

  12. Spray coated nanosilver functional layers

    NASA Astrophysics Data System (ADS)

    Krzemiński, J.; Szałapak, J.; Dybowska-Sarapuk, L.; Jakubowska, M.

    2016-09-01

    Silver coatings are highly conductive functional layers. There are many different ways to product the silver coating but most of them need vacuum or high temperature. Spray coating is a technique that is free of this disadvantages - it doesn't need a cleanroom or high temperature. What's more the layer thickness is about 10 μm. In this article the spray coating process of silver nanolayer is described. Four different inks were tested and measured. The layer resistance was measured and show as a graph. After the layer resistance was measured the adhesion test was performed. The pull-off test was performed on testing machine with special self made module. To conclude the article include the test and measurements of spray coated nanosilver functional layers. The layers was examined for the current conductivity and adhesion force.

  13. Advanced Technologies for the Improvement of Spray Application Techniques in Spanish Viticulture: An Overview

    PubMed Central

    Gil, Emilio; Arnó, Jaume; Llorens, Jordi; Sanz, Ricardo; Llop, Jordi; Rosell-Polo, Joan R.; Gallart, Montserrat; Escolà, Alexandre

    2014-01-01

    Spraying techniques have been undergoing continuous evolution in recent decades. This paper presents part of the research work carried out in Spain in the field of sensors for characterizing vineyard canopies and monitoring spray drift in order to improve vineyard spraying and make it more sustainable. Some methods and geostatistical procedures for mapping vineyard parameters are proposed, and the development of a variable rate sprayer is described. All these technologies are interesting in terms of adjusting the amount of pesticides applied to the target canopy. PMID:24451462

  14. Spray casting project final report

    SciTech Connect

    Churnetski, S.R.; Thompson, J.E.

    1996-08-01

    Lockheed Martin Energy Systems, Inc. (Energy Systems), along with other participating organizations, has been exploring the feasibility of spray casting depleted uranium (DU) to near-net shape as a waste minimization effort. Although this technology would be useful in a variety of applications where DU was the material of choice, this effort was aimed primarily at gamma-shielding components for use in storage and transportation canisters for high-level radioactive waste, particularly in the Multipurpose Canister (MPC) application. In addition to the waste-minimization benefits, spray casting would simplify the manufacturing process by allowing the shielding components for MPC to be produced as a single component, as opposed to multiple components with many fabrication and assembly steps. In earlier experiments, surrogate materials were used to simulate the properties (specifically reactivity and density) of DU. Based on the positive results from those studies, the project participants decided that further evaluation of the issues and concerns that would accompany spraying DU was warranted. That evaluation occupied substantially all of Fiscal Year 1995, yielding conceptual designs for both an intermediate facility and a production facility and their associated engineering estimates. An intermediate facility was included in this study to allow further technology development in spraying DU. Although spraying DU to near-net shape seems to be feasible, a number of technical, engineering, and safety issues would need to be evaluated before proceeding with a production facility. This report is intended to document the results from the spray-casting project and to provide information needed by anyone interested in proceeding to the next step.

  15. Natural aerosols explain seasonal and spatial patterns of Southern Ocean cloud albedo

    PubMed Central

    McCoy, Daniel T.; Burrows, Susannah M.; Wood, Robert; Grosvenor, Daniel P.; Elliott, Scott M.; Ma, Po-Lun; Rasch, Phillip J.; Hartmann, Dennis L.

    2015-01-01

    Atmospheric aerosols, suspended solid and liquid particles, act as nucleation sites for cloud drop formation, affecting clouds and cloud properties—ultimately influencing the cloud dynamics, lifetime, water path, and areal extent that determine the reflectivity (albedo) of clouds. The concentration Nd of droplets in clouds that influences planetary albedo is sensitive to the availability of aerosol particles on which the droplets form. Natural aerosol concentrations affect not only cloud properties themselves but also modulate the sensitivity of clouds to changes in anthropogenic aerosols. It is shown that modeled natural aerosols, principally marine biogenic primary and secondary aerosol sources, explain more than half of the spatiotemporal variability in satellite-observed Nd. Enhanced Nd is spatially correlated with regions of high chlorophyll a, and the spatiotemporal variability in Nd is found to be driven primarily by high concentrations of sulfate aerosol at lower Southern Ocean latitudes (35o to 45oS) and by organic matter in sea spray aerosol at higher latitudes (45o to 55oS). Biogenic sources are estimated to increase the summertime mean reflected solar radiation in excess of 10 W m–2 over parts of the Southern Ocean, which is comparable to the annual mean increases expected from anthropogenic aerosols over heavily polluted regions of the Northern Hemisphere. PMID:26601216

  16. Natural aerosols explain seasonal and spatial patterns of Southern Ocean cloud albedo.

    PubMed

    McCoy, Daniel T; Burrows, Susannah M; Wood, Robert; Grosvenor, Daniel P; Elliott, Scott M; Ma, Po-Lun; Rasch, Phillip J; Hartmann, Dennis L

    2015-07-01

    Atmospheric aerosols, suspended solid and liquid particles, act as nucleation sites for cloud drop formation, affecting clouds and cloud properties-ultimately influencing the cloud dynamics, lifetime, water path, and areal extent that determine the reflectivity (albedo) of clouds. The concentration N d of droplets in clouds that influences planetary albedo is sensitive to the availability of aerosol particles on which the droplets form. Natural aerosol concentrations affect not only cloud properties themselves but also modulate the sensitivity of clouds to changes in anthropogenic aerosols. It is shown that modeled natural aerosols, principally marine biogenic primary and secondary aerosol sources, explain more than half of the spatiotemporal variability in satellite-observed N d. Enhanced N d is spatially correlated with regions of high chlorophyll a, and the spatiotemporal variability in N d is found to be driven primarily by high concentrations of sulfate aerosol at lower Southern Ocean latitudes (35(o) to 45(o)S) and by organic matter in sea spray aerosol at higher latitudes (45(o) to 55(o)S). Biogenic sources are estimated to increase the summertime mean reflected solar radiation in excess of 10 W m(-2) over parts of the Southern Ocean, which is comparable to the annual mean increases expected from anthropogenic aerosols over heavily polluted regions of the Northern Hemisphere.

  17. Natural Aerosols Explain Seasonal and Spatial Patterns of Southern Ocean Cloud Albedo

    SciTech Connect

    McCoy, Daniel; Burrows, Susannah M.; Wood, R.; Grosvenor, Daniel P.; Elliott, Scott; Ma, Po-Lun; Rasch, Philip J.; Hartmann, Dennis L.

    2015-07-17

    Small particles called aerosols act as nucleation sites for cloud drop formation, affecting clouds and cloud properties – ultimately influencing the cloud dynamics, lifetime, water path and areal extent that determine the reflectivity (albedo) of clouds. The concentration Nd of droplets in clouds that influences planetary albedo is sensitive to the availability of aerosol particles on which the droplets form. Natural aerosol concentrations not only affect cloud properties themselves, but also modulate the sensitivity of clouds to changes in anthropogenic aerosols. Here, it is shown that modeled natural aerosols, principally marine biogenic primary and secondary aerosol sources, explain more than half of the spatiotemporal variability in satellite-observed Nd. Enhanced Nd over regions of high biological activity is found to be driven primarily by high concentrations of sulfate aerosol at lower Southern Ocean latitudes (35-45°S) and by organic matter in sea spray aerosol at higher latitudes (45-55°S). Biogenic sources are estimated to increase the summertime mean reflected solar radiation in excess of 10 W m-2 over parts of the Southern Ocean, which is comparable to the annual mean increases expected from anthropogenic aerosols over heavily polluted regions of the Northern Hemisphere.

  18. "Teaching" an Industrial Robot To Spray

    NASA Technical Reports Server (NTRS)

    Evans, A. R.; Sweet, G. K.

    1982-01-01

    Teaching device, consisting of spacer rod or tube with three-pointed tip and line level, is used during pattern "teach-in" to make sure that robot manipulator holds spray gun perpendicular to surface to be sprayed and at right distance from it. For slanted surfaces angle adapter is added between spacer rod and line-level indicator. Angle is determined by slope of surface to be sprayed, thus allowing a perpendicular spray pattern against even slanted surfaces.

  19. Thermal Spray Coatings for Coastal Infrastructure

    SciTech Connect

    Holcomb, G.R.; Covino, BernardS. Jr.; Cramer, S.D.; Bullard, S.J.

    1997-11-01

    Several protection strategies for coastal infrastructure using thermal-spray technology are presented from research at the Albany Research Center. Thermal-sprayed zinc coatings for anodes in impressed current cathodic protection systems are used to extend the service lives of reinforced concrete bridges along the Oregon coast. Thermal-sprayed Ti is examined as an alternative to the consumable zinc anode. Sealed thermal-sprayed Al is examined as an alternative coating to zinc dust filled polyurethane paint for steel structures.

  20. Feedback enhanced plasma spray tool

    DOEpatents

    Gevelber, Michael Alan; Wroblewski, Donald Edward; Fincke, James Russell; Swank, William David; Haggard, Delon C.; Bewley, Randy Lee

    2005-11-22

    An improved automatic feedback control scheme enhances plasma spraying of powdered material through reduction of process variability and providing better ability to engineer coating structure. The present inventors discovered that controlling centroid position of the spatial distribution along with other output parameters, such as particle temperature, particle velocity, and molten mass flux rate, vastly increases control over the sprayed coating structure, including vertical and horizontal cracks, voids, and porosity. It also allows improved control over graded layers or compositionally varying layers of material, reduces variations, including variation in coating thickness, and allows increasing deposition rate. Various measurement and system control schemes are provided.

  1. Influence of the spray velocity on arc-sprayed coating structures

    NASA Astrophysics Data System (ADS)

    Steffens, H.-D.; Nassenstein, K.

    1999-09-01

    Thermal spray processes such as plasma spraying and HVOF have gained markets due to a steady process of development of materials and equipment. One disadvantage of thermal spray processes is that costs must be competitive compared to techniques such as PTA and electroplating. In order to reduce costs, the more economical spray processes like conventional wire flame spraying, as well as arc spraying, are becoming more popular. There are modern arc spray gun designs on the market that meet the requirements of modern coating properties, for example aviation overhaul applications as well as the processing of cored wires. Nevertheless, the physical basis of arc spraying is well known. The aim of the present investigation is to show how the influence of spray velocity (not particle velocity) affects coating structure with respect to arc spray parameters.

  2. Overview of Aerosol Distribution

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram

    2005-01-01

    Our knowledge of atmospheric aerosols (smoke, pollution, dust or sea salt particles, small enough to be suspended in the air), their evolution, composition, variability in space and time and interaction with clouds and precipitation is still lacking despite decades of research. Understanding the global aerosol system is fundamental for progress in climate change and hydrological cycle research. While a single instrument was used to demonstrate 50 years ago that the global CO2 levels are rising, posing threat of global warming, we need an array of satellites and field measurements coupled with chemical transport models to understand the global aerosol system. This complexity of the aerosol problem results from their short lifetime (1 week) and variable chemical composition. A new generation of satellites provides exciting opportunities to measure the global distribution of aerosols, distinguishing natural from anthropogenic aerosol and measuring their interaction with clouds and climate. I shall discuss these topics and application of the data to air quality monitoring.

  3. How to Use Nasal Pump Sprays

    MedlinePlus

    Using Nasal Pump SpraysBlow your nose gently before using the spray. Prime the pump bottle by spraying it into the air a ... Breathe in quickly while squeezing down on the pump bottle one time. Repeat in other nostril. Do ...

  4. Spray Deposition: A Fundamental Study of Droplet Impingement, Spreading and Consolidation

    DTIC Science & Technology

    1989-12-01

    Consoadation: Only a portion of the droplets reach the substrate; this fraction is defined as the target efficiency of the spray, 1- t . Furthermore, only a...adheres is termed the sticking efficiency, ’Is. Deposit yield is determined by the product of these two efficiencies. lI t depends upon the size of...Foundation, New York, NY, ed. T . Giamei, p.593,1988 * P. Mathur, D. Wei and D. Apelian, "Modeling of the Solidification Process During Spray Casting

  5. Aerosol, radiation, and climate

    NASA Technical Reports Server (NTRS)

    Pollack, J. B.

    1983-01-01

    Airborne, spaceborne, and ground-based measurements are used to study the radiative and climatic effects of aerosols. The data, which are modelled with a hierarchy of radiation and climate models, and their implications are summarized. Consideration is given to volcanic aerosols, polar stratospheric clouds, and the Arctic haze. It is shown that several types of aerosols (volcanic particles and the Arctic haze) cause significant alterations to the radiation budget of the regions where they are located.

  6. Production of Highly Charged Pharmaceutical Aerosols Using a New Aerosol Induction Charger

    PubMed Central

    Golshahi, Laleh; Longest, P. Worth; Holbrook, Landon; Snead, Jessica; Hindle, Michael

    2015-01-01

    Purpose Properly charged particles can be used for effective lung targeting of pharmaceutical aerosols. The objective of this study was to characterize the performance of a new induction charger that operates with a mesh nebulizer for the production of highly charged submicrometer aerosols to bypass the mouth-throat and deliver clinically relevant doses of medications to the lungs. Methods Variables of interest included combinations of model drug (i.e. albuterol sulfate) and charging excipient (NaCl) as well as strength of the charging field (1–5 kV/cm). Aerosol charge and size were measured using a modified electrical low pressure impactor system combined with high performance liquid chromatography. Results At the approximate mass median aerodynamic diameter (MMAD) of the aerosol (~ 0.4 μm), the induction charge on the particles was an order of magnitude above the field and diffusion charge limit. The nebulization rate was 439.3 ± 42.9 μl/min, which with a 0.1 % w/v solution delivered 419.5 ± 34.2 μg of medication per minute. A new correlation was developed to predict particle charge produced by the induction charger. Conclusions The combination of the aerosol induction charger and predictive correlations will allow for the practical generation and control of charged submicrometer aerosols for targeting deposition within the lungs. PMID:25823649

  7. Evaluation of AERONET Aerosol Retrievals

    NASA Astrophysics Data System (ADS)

    Schuster, G. L.; Dubovik, O.; Rutledge, C. K.

    2001-12-01

    The aerosol robotic network (AERONET) program provides aerosol retrievals at ground-based sunphotometer sites throughout the world. The aerosol size distributions and refractive index retrievals at two locations have been converted to phase functions and single-scattering albedo using Mie theory. These optical properties are incorporated into a discrete-ordinates radiative transfer model and calculations are compared to independent measurements obtained at the surface. The independent measurements include principle plane radiances from sunphotometer data and narrowband irradiances from multi-filter rotating shadowband radiometer (MFRSR) and rotating shadowband spectroradiometer (RSS) data. The two locations represent radically different environments. The Atmospheric Radiation Measurement (ARM) program Central Facility (CF) represents a rural continental environment, while the CERES (Clouds and the Earth's Radiant Energy System) Ocean Validation Experiment (COVE) site represents a coastal marine environment. Both sites exhibit good agreement between the model calculations and the principle plane radiances for the year 2000 (generally better than 15 percent at optical depths greater than 0.1). A comparison with RSS measurements in July 2000 at the ARM Central Facility shows an irradiance error of 12 percent or better at tested wavelenghs longer than 500 nm. Comparisons with MFRSR data fared less well, however, indicating a discrepancy between the instruments. Inspection of 28 whole-sky imager (WSI) files coincidental with all AERONET quality-controlled retrievals during 7 days reveals that no clouds were obstructing the almucantar field of view and that indeed the whole sky was clear during this period, indicating a degree of robustness in the AERONET cloud screening. Additionally, the size distributions were evaluated at COVE with hourly-averaged wind speed and direction. Linear regression indicates that the coarse mode column-integrated surface area increases from

  8. A comparison between spray drying and spray freeze drying for dry powder inhaler formulation of drug-loaded lipid-polymer hybrid nanoparticles.

    PubMed

    Wang, Yajie; Kho, Katherine; Cheow, Wean Sin; Hadinoto, Kunn

    2012-03-15

    Lipid-polymer hybrid nanoparticles - polymeric nanoparticles enveloped by lipid layers - have emerged as a potent therapeutic nano-carrier alternative to liposomes and polymeric nanoparticles. Herein we perform comparative studies of employing spray drying (SD) and spray freeze drying (SFD) to produce inhalable dry-powder form of drug-loaded lipid-polymer hybrid nanoparticles. Poly(lactic-co-glycolic acid), lecithin, and levofloxacin are employed as the polymer, lipid, and drug models, respectively. The hybrid nanoparticles are transformed into micro-scale nanoparticle aggregates (or nano-aggregates) via SD and SFD, where the effects of (1) different excipients (i.e. mannitol, polyvinyl alcohol (PVA), and leucine), and (2) nanoparticle to excipient ratio on nano-aggregate characteristics (e.g. size, flowability, aqueous reconstitution, aerosolization efficiency) are examined. In both methods, PVA is found more effective than mannitol for aqueous reconstitution, whereas hydrophobic leucineis needed to achieve effective aerosolization as it reduces nano-aggregate agglomeration. Using PVA, both methods are equally capable of producing nano-aggregates having size, density, flowability, yield and reconstitutibility in the range ideal for inhaled delivery. Nevertheless, nano-aggregates produced by SFD are superior to SD in terms of their aerosolization efficiency manifested in the higher emitted dose and fine particle fraction with lower mass median aerodynamic diameter.

  9. Radiative Effects of Aerosols

    NASA Technical Reports Server (NTRS)

    Valero, Francisco P. J.

    1997-01-01

    During the Atlantic Stratocumulus Transition Experiment (ASTEX) in June 1992, two descents in cloud-free regions allowed comparison of the change in aerosol optical depth as determined by an onboard total-direct-diffuse radiometer (TDDR) to the change calculated from measured size resolved aerosol microphysics and chemistry. Both profiles included pollution haze layer from Europe but the second also included the effect of a Saharan dust layer above the haze. The separate contributions of supermicrometer (coarse) and submicrometer (fine) aerosol were determined and thermal analysis of the pollution haze indicated that the fine aerosol was composed primarily of a sulfate/water mixture with a refractory soot-like core.

  10. Influence of Cold-Sprayed, Warm-Sprayed, and Plasma-Sprayed Layers Deposition on Fatigue Properties of Steel Specimens

    NASA Astrophysics Data System (ADS)

    Cizek, J.; Matejkova, M.; Dlouhy, I.; Siska, F.; Kay, C. M.; Karthikeyan, J.; Kuroda, S.; Kovarik, O.; Siegl, J.; Loke, K.; Khor, Khiam Aik

    2015-06-01

    Titanium powder was deposited onto steel specimens using four thermal spray technologies: plasma spray, low-pressure cold spray, portable cold spray, and warm spray. The specimens were then subjected to strain-controlled cyclic bending test in a dedicated in-house built device. The crack propagation was monitored by observing the changes in the resonance frequency of the samples. For each series, the number of cycles corresponding to a pre-defined specimen cross-section damage was used as a performance indicator. It was found that the grit-blasting procedure did not alter the fatigue properties of the steel specimens (1% increase as compared to as-received set), while the deposition of coatings via all four thermal spray technologies significantly increased the measured fatigue lives. The three high-velocity technologies led to an increase of relative lives to 234% (low-pressure cold spray), 210% (portable cold spray), and 355% (warm spray) and the deposition using plasma spray led to an increase of relative lives to 303%. The observed increase of high-velocity technologies (cold and warm spray) could be attributed to a combination of homogeneous fatigue-resistant coatings and induction of peening stresses into the substrates via the impingement of the high-kinetic energy particles. Given the intrinsic character of the plasma jet (low-velocity impact of semi/molten particles) and the mostly ceramic character of the coating (oxides, nitrides), a hypothesis based on non-linear coatings behavior is provided in the paper.

  11. Multi-Nozzle Spray Cooling in a Closed Loop (POSTPRINT)

    DTIC Science & Technology

    2011-03-01

    facing upward, (b) vertical, and (c) horizontal facing downward. The thermal performance of the horizontal facing downward surface was the best. A...transfer, closed loop, CHF 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT: SAR 18. NUMBER OF PAGES 12 19a. NAME OF...the spray target surface, namely (a) horizontal facing upward, (b) vertical, and (c) horizontal facing downward. The thermal performance of the

  12. No Heat Spray Drying Technology

    SciTech Connect

    Beetz, Charles

    2016-06-15

    No Heat Spray Drying Technology. ZoomEssence has developed our Zooming™ spray drying technology that atomizes liquids to powders at ambient temperature. The process of drying a liquid into a powder form has been traditionally achieved by mixing a heated gas with an atomized (sprayed) fluid within a vessel (drying chamber) causing the solvent to evaporate. The predominant spray drying process in use today employs air heated up to 400° Fahrenheit to dry an atomized liquid into a powder. Exposing sensitive, volatile liquid ingredients to high temperature causes molecular degradation that negatively impacts solubility, stability and profile of the powder. In short, heat is detrimental to many liquid ingredients. The completed award focused on several areas in order to advance the prototype dryer to a commercial scale integrated pilot system. Prior to the award, ZoomEssence had developed a prototype ‘no-heat’ dryer that firmly established the feasibility of the Zooming™ process. The award focused on three primary areas to improve the technology: (1) improved ability to formulate emulsions for specific flavor groups and improved understanding of the relationship of emulsion properties to final dry particle properties, (2) a new production atomizer, and (3) a dryer controls system.

  13. Plasma Spraying Reclaims Compressor Housings

    NASA Technical Reports Server (NTRS)

    Leissler, George W.; Yuhas, John S.

    1991-01-01

    Plasma-spraying process used to build up material in worn and pitted areas. Newly applied material remachined to specified surface contours. Effective technique for addition of metal to out-of-tolerance magnesium-alloy turbine-engine compressor housings.

  14. Electrokinetically pumped high pressure sprays

    DOEpatents

    Schoeniger, Joseph S.; Paul, Phillip H.; Schoeniger, Luke

    2005-11-01

    An electrokinetic pump capable of producing high pressure is combined with a nozzle having a submicron orifice to provide a high pressure spray device. Because of its small size, the device can be contained within medical devices such as an endoscope for delivering biological materials such as DNA, chemo therapeutic agents, or vaccines to tissues and cells.

  15. Electrokinetically pumped high pressure sprays

    DOEpatents

    Schoeniger, Joseph S.; Paul, Phillip H.; Schoeniger, Luke

    2002-01-01

    An electrokinetic pump capable of producing high pressure is combined with a nozzle having a submicron orifice to provide a high pressure spray device. Because of its small size, the device can be contained within medical devices such as an endoscope for delivering biological materials such as DNA, chemo therapeutic agents, or vaccines to tissues and cells.

  16. Aqueous-Spray Cleaning System

    NASA Technical Reports Server (NTRS)

    Morgan, Gene E.; Hoult, William S.; Simpson, Gareth L.

    1996-01-01

    Simple aqueous-spray cleaning system with overall dimensions comparable to large kitchen refrigerator constructed for use in cleaning hardware in shop. Made of commercially available parts and materials. Incorporates economical cleaner-and-rinse-recycling subsystem, as well as programmable logic-controller device for either manual or automatic operation.

  17. Checklist of Safe Work Practices for Spray Polyurethane Foam (SPF) for Contractors, Incluyendo la Versión de Español

    EPA Pesticide Factsheets

    A contractor checklist aimed at helping spray polyurethane foam (SPF) professional contractors protect themselves, workers and others. Guía de las prácticas seguras en el lugar de trabajo para la aplicación del aerosol de espuma aislante de poliuretano.

  18. Eye-Safe Lidar System for Pesticide Spray Drift Measurement

    PubMed Central

    Gregorio, Eduard; Rocadenbosch, Francesc; Sanz, Ricardo; Rosell-Polo, Joan R.

    2015-01-01

    Spray drift is one of the main sources of pesticide contamination. For this reason, an accurate understanding of this phenomenon is necessary in order to limit its effects. Nowadays, spray drift is usually studied by using in situ collectors which only allow time-integrated sampling of specific points of the pesticide clouds. Previous research has demonstrated that the light detection and ranging (lidar) technique can be an alternative for spray drift monitoring. This technique enables remote measurement of pesticide clouds with high temporal and distance resolution. Despite these advantages, the fact that no lidar instrument suitable for such an application is presently available has appreciably limited its practical use. This work presents the first eye-safe lidar system specifically designed for the monitoring of pesticide clouds. Parameter design of this system is carried out via signal-to-noise ratio simulations. The instrument is based on a 3-mJ pulse-energy erbium-doped glass laser, an 80-mm diameter telescope, an APD optoelectronic receiver and optomechanically adjustable components. In first test measurements, the lidar system has been able to measure a topographic target located over 2 km away. The instrument has also been used in spray drift studies, demonstrating its capability to monitor the temporal and distance evolution of several pesticide clouds emitted by air-assisted sprayers at distances between 50 and 100 m. PMID:25658395

  19. Eye-safe lidar system for pesticide spray drift measurement.

    PubMed

    Gregorio, Eduard; Rocadenbosch, Francesc; Sanz, Ricardo; Rosell-Polo, Joan R

    2015-02-04

    Spray drift is one of the main sources of pesticide contamination. For this reason, an accurate understanding of this phenomenon is necessary in order to limit its effects. Nowadays, spray drift is usually studied by using in situ collectors which only allow time-integrated sampling of specific points of the pesticide clouds. Previous research has demonstrated that the light detection and ranging (lidar) technique can be an alternative for spray drift monitoring. This technique enables remote measurement of pesticide clouds with high temporal and distance resolution. Despite these advantages, the fact that no lidar instrument suitable for such an application is presently available has appreciably limited its practical use. This work presents the first eye-safe lidar system specifically designed for the monitoring of pesticide clouds. Parameter design of this system is carried out via signal-to-noise ratio simulations. The instrument is based on a 3-mJ pulse-energy erbium-doped glass laser, an 80-mm diameter telescope, an APD optoelectronic receiver and optomechanically adjustable components. In first test measurements, the lidar system has been able to measure a topographic target located over 2 km away. The instrument has also been used in spray drift studies, demonstrating its capability to monitor the temporal and distance evolution of several pesticide clouds emitted by air-assisted sprayers at distances between 50 and 100 m.

  20. Aerodynamic Focusing Of High-Density Aerosols

    SciTech Connect

    Ruiz, D. E.; Fisch, Nathaniel

    2014-02-24

    High-density micron-sized particle aerosols might form the basis for a number of applications in which a material target with a particular shape might be quickly ionized to form a cylindrical or sheet shaped plasma. A simple experimental device was built in order to study the properties of high-density aerosol focusing for 1 m silica spheres. Preliminary results recover previous findings on aerodynamic focusing at low densities. At higher densities, it is demonstrated that the focusing properties change in a way which is consistent with a density dependent Stokes number.

  1. A View of Earth's Aerosol System from Space to Your Office Chair

    NASA Technical Reports Server (NTRS)

    Colarco, Peter

    2008-01-01

    Aerosols are tiny particles and droplets suspended in the air. Each day you breathe in about 10 billion of them, about a half a million per breath. They are formed in nature by volcanoes, dust storms, sea spray, and emissions from vegetation. Humans create aerosols and alter their natural sources by burning fossil fuels and modifying land cover. Fires are another important source of aerosols; some are natural, such as wildfires started by lightning strikes, while others are from human-caused burning of vegetation for cooking, heating, and land clearing. Aerosols have complex effects on Earth's climate. In general, they cool the surface by reflecting (scattering) radiation from the sun back into space. Dust and smoke absorb solar radiation and heat the atmosphere where they are concentrated. Aerosols change the properties of clouds. Indeed, it would be very difficult to form clouds in the atmosphere without aerosols to act as 'seeds' for water to condense on. In aerosol polluted environments clouds tend to have smaller droplets than clouds formed in cleaner environments; these polluted clouds appear brighter from space because they reflect more sunlight, and they may persist longer and not rain as intensely. Aerosols also affect local air quality and visibility. Data collected by NASA satellites over the past decade have provided an unprecedented view of Earth's aerosol distribution and dramatically increased our understanding of where aerosols come from and just how far they travel in the atmosphere. In this talk I will discuss observations of aerosols from space and how they inform numerical transport models attempting to simulate the global aerosol system.

  2. Size analysis of suspension inhalation aerosols by inertial separation methods.

    PubMed

    Hallworth, G W; Andrews, U G

    1976-12-01

    The particle size distribution of beclomethasone dipropionate (BDP) aerosols delivered from pressurized metered dose suspension inhalers has been measured with three cascaded inertial separation instruments, the Casella Cascade Impactor, Multistage Liquid Impinger and Cascade Centripeter. Various methods for collecting the emitted aerosol before measurement have been examined. A bent glass tubular 'throat', used as a simulated oro-pharynx, collects 35-60% of the emitted dose by impingement of the wet spray cone in the throat. The aerosol passing through the throat has a similar but somewhat finer size distribution to that collected by firing directly into a large flask. The three cascaded instruments give similar results which in the Multistage Liquid Impinger also resemble those given by a salbutamol inhaler. The mass fraction (35-60%) emitted from the oral adaptor which is of a size capable of deep lung penetration ( less than 4 mum) is much higher than the fraction (10-16%) found in the lungs of dogs after inhalation of aerosol. The size distributions resemble those determined by microscopy and are expressed as aerodynamic sizes, thus showing that the particles approximate to unit density spheres. The performance of two simpler devices, Kirk's apparatus and the Harwell size selective air sampler are also assessed, the latter shows some promise for the simple evaluation of the respirable fraction of inhalation aerosols.

  3. Supercritical Saltwater Spray for Marine Cloud Brightening (MCB)

    NASA Astrophysics Data System (ADS)

    Neukermans, A.; Cooper, G. F.; Foster, J.; Galbraith, L. K.; Johnston, D.; Ormond, B.; Wang, Q.

    2012-12-01

    Solar Radiation Management (SRM), including both stratospheric sulfur aerosol delivery and MCB, has emerged as the leading contender for geoengineering. Field research in MCB would require a technique capable of producing 1017 salt nuclei/sec from a single source on a seagoing vessel. Spraying supercritical saltwater has emerged as a viable technology, at least for research purposes. Under optimum conditions a single 50-μm nozzle produces 1014 suitable nuclei/sec. Power consumption is high (1-2 MW), but 95% of the required energy is in the form of heat that can probably be obtained from wasted ship-engine heat. While its implementation is conceptually simple, the corrosive nature of supercritical saltwater makes the material requirements very demanding. Progress on this work is detailed.

  4. Effectiveness of Spray-Based Decontamination Methods for ...

    EPA Pesticide Factsheets

    Report The objective of this project was to assess the effectiveness of spray-based common decontamination methods for inactivating Bacillus (B.) atrophaeus (surrogate for B. anthracis) spores and bacteriophage MS2 (surrogate for foot and mouth disease virus [FMDV]) on selected test surfaces (with or without a model agricultural soil load). Relocation of viable viruses or spores from the contaminated coupon surfaces into aerosol or liquid fractions during the decontamination methods was investigated. This project was conducted to support jointly held missions of the U.S. Department of Homeland Security (DHS) and the U.S. Environmental Protection Agency (EPA). Within the EPA, the project supports the mission of EPA’s Homeland Security Research Program (HSRP) by providing relevant information pertinent to the decontamination of contaminated areas resulting from a biological incident.

  5. Stable isotopes measurements reveal dual carbon pools contributing to organic matter enrichment in marine aerosol

    PubMed Central

    Ceburnis, Darius; Masalaite, Agne; Ovadnevaite, Jurgita; Garbaras, Andrius; Remeikis, Vidmantas; Maenhaut, Willy; Claeys, Magda; Sciare, Jean; Baisnée, Dominique; O’Dowd, Colin D.

    2016-01-01

    Stable carbon isotope ratios in marine aerosol collected over the Southern Indian Ocean revealed δ13C values ranging from −20.0‰ to −28.2‰. The isotope ratios exhibited a strong correlation with the fractional organic matter (OM) enrichment in sea spray aerosol. The base-level isotope ratio of −20.0‰ is characteristic of an aged Dissolved Organic Matter (DOM) pool contributing a relatively homogeneous background level of DOM to oceanic waters. The range of isotope ratios, extending down to −28.2‰, is characteristic of more variable, stronger, and fresher Particulate Organic Matter (POM) pool driven by trophic level interactions. We present a conceptual dual-pool POM-DOM model which comprises a ‘young’ and variable POM pool which dominates enrichment in sea-spray and an ‘aged’ but invariant DOM pool which is, ultimately, an aged end-product of processed ‘fresh’ POM. This model is harmonious with the preferential enrichment of fresh colloidal and nano-gel lipid-like particulate matter in sea spray particles and the observed depleted δ13C ratio resulting from isotope equilibrium fractionation coupled with enhanced plankton photosynthesis in cold water (−2 °C to +8 °C). These results re-assert the hypothesis that OM enrichment in sea-spray is directly linked to primary production and, consequently, can have implications for climate-aerosol-cloud feedback systems. PMID:27819297

  6. Stable isotopes measurements reveal dual carbon pools contributing to organic matter enrichment in marine aerosol

    NASA Astrophysics Data System (ADS)

    Ceburnis, Darius; Masalaite, Agne; Ovadnevaite, Jurgita; Garbaras, Andrius; Remeikis, Vidmantas; Maenhaut, Willy; Claeys, Magda; Sciare, Jean; Baisnée, Dominique; O’Dowd, Colin D.

    2016-11-01

    Stable carbon isotope ratios in marine aerosol collected over the Southern Indian Ocean revealed δ13C values ranging from ‑20.0‰ to ‑28.2‰. The isotope ratios exhibited a strong correlation with the fractional organic matter (OM) enrichment in sea spray aerosol. The base-level isotope ratio of ‑20.0‰ is characteristic of an aged Dissolved Organic Matter (DOM) pool contributing a relatively homogeneous background level of DOM to oceanic waters. The range of isotope ratios, extending down to ‑28.2‰, is characteristic of more variable, stronger, and fresher Particulate Organic Matter (POM) pool driven by trophic level interactions. We present a conceptual dual-pool POM-DOM model which comprises a ‘young’ and variable POM pool which dominates enrichment in sea-spray and an ‘aged’ but invariant DOM pool which is, ultimately, an aged end-product of processed ‘fresh’ POM. This model is harmonious with the preferential enrichment of fresh colloidal and nano-gel lipid-like particulate matter in sea spray particles and the observed depleted δ13C ratio resulting from isotope equilibrium fractionation coupled with enhanced plankton photosynthesis in cold water (‑2 °C to +8 °C). These results re-assert the hypothesis that OM enrichment in sea-spray is directly linked to primary production and, consequently, can have implications for climate-aerosol-cloud feedback systems.

  7. Development of variable-rate precision spraying systems for tree crop production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Excessive pesticides are often applied to target and non-target areas in orchards and nurseries, resulting in greater production costs, worker exposure to unnecessary pesticide risks, and adverse contamination of the environment. To improve spray application efficiency, two types of variable-rate pr...

  8. Direct Aerosol Forcing Uncertainty

    DOE Data Explorer

    Mccomiskey, Allison

    2008-01-15

    Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

  9. Global Aerosol Observations

    Atmospheric Science Data Center

    2013-04-19

    ... atmosphere, directly influencing global climate and human health. Ground-based networks that accurately measure column aerosol amount and ... being used to improve Air Quality Models and for regional health studies. To assess the human-health impact of chronic aerosol exposure, ...

  10. Portable Aerosol Contaminant Extractor

    DOEpatents

    Carlson, Duane C.; DeGange, John J.; Cable-Dunlap, Paula

    2005-11-15

    A compact, portable, aerosol contaminant extractor having ionization and collection sections through which ambient air may be drawn at a nominal rate so that aerosol particles ionized in the ionization section may be collected on charged plate in the collection section, the charged plate being readily removed for analyses of the particles collected thereon.

  11. Ganges valley aerosol experiment.

    SciTech Connect

    Kotamarthi, V.R.; Satheesh, S.K.

    2011-08-01

    In June 2011, the Ganges Valley Aerosol Experiment (GVAX) began in the Ganges Valley region of India. The objective of this field campaign is to obtain measurements of clouds, precipitation, and complex aerosols to study their impact on cloud formation and monsoon activity in the region.

  12. Background Maritime Aerosol: Their Optical Thickness and Scattering Properties

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram J.; Smirnov, Alexander; Holben, Brent N.; Dubovik, Oleg; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The effect of human induced change in the aerosol concentration and properties, or the aerosol response to climate change (e.g. droughts producing fires or dust) should be measured relative to a "background aerosol". How to define this background aerosol, so that it is both measurable and useful? Here we use 10 stations located in the Pacific, Atlantic and Indian Oceans to answer this question. Using a data set of the spectral optical thickness measured by the Aerosol Robotic network (AERONET), extending 1-3 years, we find the background conditions for these stations. The oceanic background aerosol is the result of ocean emission and spray, and some residual long lived continental aerosol. Its source is very broadly spread and is expected to vary little in time. Pollution or dust sources are from specific locations, emitted and transported to the measuring site in specific combination of meteorological conditions. Therefore they are expected to vary with time. It follows that the background aerosol can be identified as the median for conditions with small variations. To define the background we compute the median of N consequent measurements. We use N=50 that in average cloudy conditions corresponds to 2-3 days of measurements and N=100 (4-5 days). Most high polluted or dusty conditions correspond to data sequences with high standard deviation (greater than 0.02 in optical thickness) and are excluded. From the remaining N point running medians with low standard deviations we derive again the median. This excludes those rare cases of pollution or dust that is stable during the N measurements. The results show that the background aerosol over the Pacific Ocean is characterize by optical thickness of 0.055 at 500 nm and Angstrom exponent of 0.74. Over the Atlantic Ocean the values are 0.070 and 1.1 respectively, with little influence of the assumed value of N (50 or 100). The derivation of the background uses 20,000 and 5000 medians respectively that passed the

  13. Chamber for Aerosol Deposition of Bioparticles

    NASA Technical Reports Server (NTRS)

    Kern, Roger; Kirschner, Larry

    2008-01-01

    Laboratory apparatus is depicted that is a chamber for aerosol deposition of bioparticles on surfaces of test coupons. It is designed for primary use in inoculating both flat and three-dimensional objects with approximately reproducible, uniform dispersions of bacterial spores of the genus Bacillus so that the objects could be used as standards for removal of the spores by quantitative surface sampling and/or cleaning processes. The apparatus is also designed for deposition of particles other than bacterial spores, including fungal spores, viruses, bacteriophages, and standard micron-sized beads. The novelty of the apparatus lies in the combination of a controllable nebulization system with a settling chamber large enough to contain a significant number of test coupons. Several companies market other nebulizer systems, but none are known to include chambers for deposition of bioparticles to mimic the natural fallout of bioparticles. The nebulization system is an expanded and improved version of commercially available aerosol generators that include nebulizers and drying columns. In comparison with a typical commercial aerosol generator, this system includes additional, higher-resolution flowmeters and an additional pressure regulator. Also, unlike a typical commercial aerosol generator, it includes stopcocks for separately controlling flows of gases to the nebulizer and drying column. To maximize the degree of uniformity of dispersion of bioaerosol, the chamber is shaped as an axisymmetrical cylinder and the aerosol generator is positioned centrally within the chamber and aimed upward like a fountain. In order to minimize electric charge associated with the aerosol particles, the drying column is made of aluminum, the drying column is in direct contact with an aluminum base plate, and three equally spaced Po-210 antistatic strips are located at the exit end of the drying column. The sides and top of the chamber are made of an acrylic polymer; to prevent

  14. Simulated consumer exposure to propellant HCFC 22 (chlorodifluoromethane) in aerosol personal products.

    PubMed

    Hartop, P J; Adams, M G

    1989-02-01

    Summary The potential human exposure to the aerosol propellant HCFC 22 (chlorodifluoromethane) arising from its use in personal products has been assessed. HCFC 22 concentrations were measured in the 'breathing zone' of an experimental manikin and an 'accompanying child' designed to simulate human use of hairsprays, body sprays and antiperspirants in a closed room. Results were expressed as the 10-min time-weighted average concentration in the air (TWA 10) and as the peak concentration in the 'breathing zone' of the 'user'. Following a 10-s use of hairspray containing approximately 20-40% HCFC 22, TWA10 values for an adult user and child were 64-116 ppm and 44-100 ppm, respectively. Use of an aerosol body spray containing 20-65% HCFC 22 for 5-20 s gave rise to TWA10 values of 32-411 ppm for an adult user and 20-395 ppm for a child. A 4-s use of an antiperspirant containing approximately 20-40% HCFC 22 sprayed at a distance of 10-30 cm from the breathing zone of the adult user generated TWA 10 values in the range of 14-34 ppm for both the adult user and child. Opening the door of the room prior to hairspray and antiperspirant spraying slightly reduced these TWA 10 values. The peak values recorded in these studies for the adult user were 208 ppm for hairspray, 1415 ppm for body sprays and 82 ppm for antiperspirants.

  15. Radiative Effects of Aerosols

    NASA Technical Reports Server (NTRS)

    Valero, Francisco P. J.

    1996-01-01

    During the Atlantic Stratocumulus Transition Experiment (ASTEX) in June 1992, two descents in cloud-free regions allowed comparison of the change in aerosol optical depth as determined by an onboard total-direct-diffuse radiometer (TDDR) to the change calculated from measured size-resolved aerosol microphysics and chemistry. Both profiles included a pollution haze from Europe but the second also included the effect of a Saharan dust layer above the haze. The separate contributions of supermicrometer (coarse) and submicrometer (fine) aerosol were determined and thermal analysis of the pollution haze indicated that the fine aerosol was composed primarily of a sulfate/water mixture with a refractory soot-like core. The soot core increased the calculated extinction by about 10% in the most polluted drier layer relative to a pure sulfate aerosol but had significantly less effect at higher humidities. A 3 km descent through a boundary layer air mass dominated by pollutant aerosol with relative humidities (RH) 10-77% yielded a close agreement between the measured and calculated aerosol optical depths (550 nm) of 0.160 (+/- 0.07) and 0. 157 (+/- 0.034) respectively. During descent the aerosol mass scattering coefficient per unit sulfate mass varied from about 5 to 16 m(exp 2)/g and primarily dependent upon ambient RH. However, the total scattering coefficient per total fine mass was far less variable at about 4+/- 0.7 m(exp 2)/g. A subsequent descent through a Saharan dust layer located above the pollution aerosol layer revealed that both layers contributed similarly to aerosol optical depth. The scattering per unit mass of the coarse aged dust was estimated at 1.1 +/- 0.2 m(exp 2)/g. The large difference (50%) in measured and calculated optical depth for the dust layer exceeded measurements.

  16. Air detoxification with nanosize TiO2 aerosol tested on mice.

    PubMed

    Besov, A S; Krivova, N A; Vorontsov, A V; Zaeva, O B; Kozlov, D V; Vorozhtsov, A B; Parmon, V N; Sakovich, G V; Komarov, V F; Smirniotis, P G; Eisenreich, N

    2010-01-15

    A method for fast air purification using high concentration aerosol of TiO(2) nanoparticles is evaluated in a model chemical catastrophe involving toxic vapors of diisopropyl fluorophosphate (DFP). Mice are used as human model in a closed 100 dm(3) chamber. Exposure of mice to 37 ppm of DFP vapor for 15 min resulted in acute poisoning. Spraying TiO(2) aerosol in 2 min after the start of exposure to DFP vapors resulted in quick removal of DFP vapors from the chamber's air. Animals did not show signs of poisoning after the decontamination experiment and exposure to TiO(2) aerosol alone. Reactive oxygen species (ROS) and antioxidant activity (AOA) of mice blood plasma were measured for animals exposed to sound of aerosol generator, DFP vapors, TiO(2) aerosol and DFP vapors+TiO(2) aerosol. Reduced ROS and increased AOA were found for mice exposure to sound, DFP and TiO(2) aerosol. Exposure to DFP and decontamination with TiO(2) nanoparticles resulted in decreased AOA in 48 h following the exposure. The results suggest that application of TiO(2) aerosol is a powerful method of air purification from toxic hydrolysable compounds with moderate health aftermaths and requires further study and optimization.

  17. Pharmaceutical aerosols for the treatment and prevention of Tuberculosis

    PubMed Central

    Hanif, Shumaila N. M.; Garcia-Contreras, Lucila

    2012-01-01

    Historically, pharmaceutical aerosols have been employed for the treatment of obstructive airway diseases, such as asthma and chronic obstructive pulmonary disease, but in the past decades their use has been expanded to treat lung infections associated with cystic fibrosis and other respiratory diseases. Tuberculosis (TB) is acquired after inhalation of aerosol droplets containing the bacilli from the cough of infected individuals. Even though TB affects other organs, the lungs are the primary site of infection, which makes the pulmonary route an ideal alternative route to administer vaccines or drug treatments. Optimization of formulations and delivery systems for anti-TB vaccines and drugs, as well as the proper selection of the animal model to evaluate those is of paramount importance if novel vaccines or drug treatments are to be successful. Pharmaceutical aerosols for patient use are generated from metered dose inhalers, nebulizers, and dry powder inhalers (DPIs). In addition to the advantages of providing more efficient delivery of the drug, low cost, and portability, pharmaceutical dry powder aerosols are more stable than inhalable liquid dosage forms and do not require refrigeration. Methods to manufacture dry powders in respirable sizes include micronization, spray drying, and other proprietary technologies. Inhalable dry powders are characterized in terms of their drug content, particle size, and dispersibility to ensure deposition in the appropriate lung region and effective aerosolization from the device. These methods will be illustrated as they were applied for the manufacture and characterization of powders containing anti-tubercular agents and vaccines for pulmonary administration. The influence of formulation, selection of animal model, method of aerosol generation, and administration on the efficacy demonstrated in a given study will be illustrated by the evaluation of pharmaceutical aerosols of anti-TB drugs and vaccines in guinea pigs by our

  18. Tantalum/Copper X-Ray Targets

    NASA Technical Reports Server (NTRS)

    Waters, William J.; Edmonds, Brian

    1993-01-01

    Lewis Research Center developed unique solution to subsidiary problem of fabrication of x-ray target. Plasma spraying enabled fabrication of lightweight, high-performance targets. Power settings, atmosphere-control settings, rate of deposition, and other spraying parameters developed. Thin coats of tantalum successfully deposited on copper targets. Targets performed successfully in tests and satisfied all criteria expressed in terms of critical parameters. Significantly reduces projected costs of fabrication of targets and contributes to development of improved, long-lived, lightweight x-ray system.

  19. Aqueous aerosol SOA formation: impact on aerosol physical properties.

    PubMed

    Woo, Joseph L; Kim, Derek D; Schwier, Allison N; Li, Ruizhi; McNeill, V Faye

    2013-01-01

    Organic chemistry in aerosol water has recently been recognized as a potentially important source of secondary organic aerosol (SOA) material. This SOA material may be surface-active, therefore potentially affecting aerosol heterogeneous activity, ice nucleation, and CCN activity. Aqueous aerosol chemistry has also been shown to be a potential source of light-absorbing products ("brown carbon"). We present results on the formation of secondary organic aerosol material in aerosol water and the associated changes in aerosol physical properties from GAMMA (Gas-Aerosol Model for Mechanism Analysis), a photochemical box model with coupled gas and detailed aqueous aerosol chemistry. The detailed aerosol composition output from GAMMA was coupled with two recently developed modules for predicting a) aerosol surface tension and b) the UV-Vis absorption spectrum of the aerosol, based on our previous laboratory observations. The simulation results suggest that the formation of oligomers and organic acids in bulk aerosol water is unlikely to perturb aerosol surface tension significantly. Isoprene-derived organosulfates are formed in high concentrations in acidic aerosols under low-NO(x) conditions, but more experimental data are needed before the potential impact of these species on aerosol surface tension may be evaluated. Adsorption of surfactants from the gas phase may further suppress aerosol surface tension. Light absorption by aqueous aerosol SOA material is driven by dark glyoxal chemistry and is highest under high-NO(x) conditions, at high relative humidity, in the early morning hours. The wavelength dependence of the predicted absorption spectra is comparable to field observations and the predicted mass absorption efficiencies suggest that aqueous aerosol chemistry can be a significant source of aerosol brown carbon under urban conditions.

  20. Antibody immobilization using pneumatic spray: comparison with the avidin-biotin bridge immobilization method.

    PubMed

    Figueroa, Jhon; Magaña, Sonia; Lim, Daniel V; Schlaf, Rudy

    2012-12-14

    The formation of a thin antibody film on a glass surface using pneumatic spray was investigated as a potential immobilization technique for capturing pathogenic targets. Goat-Escherichia coli O157:H7 IgG films were made by pneumatic spray and compared against the avidin-biotin bridge immobilized films by assaying with green fluorescent protein (GFP) transformed E. coli O157:H7 cells and fluorescent reporter antibodies. Functionality, stability, and immobilization of the films were tested. The pneumatic spray films had lower fluorescence intensity values than the avidin-biotin bridge films but resulted in similar detection for E. coli O157:H7 at 10(5)-10(7)cells/ml sample concentrations with no detection of non-E. coli O157:H7 strains. Both methods also resulted in similar percent capture efficiencies. The results demonstrated that immobilization of antibody via pneumatic spray did not render the antibody non-functional and produced stable antibody films. The amount of time necessary for immobilization of the antibody was reduced significantly from 24h for the avidin-biotin bridge to 7 min using the pneumatic spray technique, with additional benefits of greatly reduced use of materials and chemicals. The pneumatic spray technique promises to be an alternative for the immobilization of antibodies on glass slides for capturing pathogenic targets and use in biosensor type devices.

  1. CFD Simulation of Aerial Crop Spraying

    NASA Astrophysics Data System (ADS)

    Omar, Zamri; Qiang, Kua Yong; Mohd, Sofian; Rosly, Nurhayati

    2016-11-01

    Aerial crop spraying, also known as crop dusting, is made for aerial application of pesticides or fertilizer. An agricultural aircraft which is converted from an aircraft has been built to combine with the aerial crop spraying for the purpose. In recent years, many studies on the aerial crop spraying were conducted because aerial application is the most economical, large and rapid treatment for the crops. The main objective of this research is to study the airflow of aerial crop spraying system using Computational Fluid Dynamics. This paper is focus on the effect of aircraft speed and nozzle orientation on the distribution of spray droplet at a certain height. Successful and accurate of CFD simulation will improve the quality of spray during the real situation and reduce the spray drift. The spray characteristics and efficiency are determined from the calculated results of CFD. Turbulence Model (k-ɛ Model) is used for the airflow in the fluid domain to achieve a more accurate simulation. Furthermore, spray simulation is done by setting the Flat-fan Atomizer Model of Discrete Phase Model (DPM) at the nozzle exit. The interaction of spray from each flat-fan atomizer can also be observed from the simulation. The evaluation of this study is validation and grid dependency study using field data from industry.

  2. Predictions of spray combustion interactions

    NASA Technical Reports Server (NTRS)

    Shuen, J. S.; Solomon, A. S. P.; Faeth, G. M.

    1984-01-01

    Mean and fluctuating phase velocities; mean particle mass flux; particle size; and mean gas-phase Reynolds stress, composition and temperature were measured in stationary, turbulent, axisymmetric, and flows which conform to the boundary layer approximations while having well-defined initial and boundary conditions in dilute particle-laden jets, nonevaporating sprays, and evaporating sprays injected into a still air environment. Three models of the processes, typical of current practice, were evaluated. The local homogeneous flow and deterministic separated flow models did not provide very satisfactory predictions over the present data base. In contrast, the stochastic separated flow model generally provided good predictions and appears to be an attractive approach for treating nonlinear interphase transport processes in turbulent flows containing particles (drops).

  3. Sprays and Cartan projective connections

    NASA Astrophysics Data System (ADS)

    Saunders, D. J.

    2004-10-01

    Around 80 years ago, several authors (for instance H. Weyl, T.Y. Thomas, J. Douglas and J.H.C. Whitehead) studied the projective geometry of paths, using the methods of tensor calculus. The principal object of study was a spray, namely a homogeneous second-order differential equation, or more generally a projective equivalence class of sprays. At around the same time, E. Cartan studied the same topic from a different point of view, by imagining a projective space attached to a manifold, or, more generally, attached to a `manifold of elements'; the infinitesimal `glue' may be interpreted in modern language as a Cartan projective connection on a principal bundle. This paper describes the geometrical relationship between these two points of view.

  4. Vacuum Plasma Sprayed Metallic Coatings

    NASA Astrophysics Data System (ADS)

    Shankar, S.; Koenig, D. E.; Dardi, L. E.

    1981-10-01

    Recognizing the fundamental cost advantage, technical capabilities, and compositional flexibility of reduced pressure (vacuum) plasma spraying compared to other overlay coating methods, an advanced, second generation, closed chamber deposition process called VPX (a Howmet trademark) was developed. An automated experimental facility for coating gas turbine engine components was also constructed. This paper describes several important features of the process and equipment. It shows that the use of optimized spray parameters combined with an appropriate schedule of relative orientations between the gun and work-piece can be used to produce dense and highly reproducible coatings of either uniform or controlled thickness distributions. The chemical composition, microstructure, and interfacial characteristics of typical MCrAlY coatings are reported. Some effects of operating procedures and MCrAlY chemical composition on coating density are noted. The results of mechanical property and burner rig tests of coated material are also described.

  5. Variable Gravity Effects on the Cooling Performance of a Single Phase Confined Spray

    NASA Technical Reports Server (NTRS)

    Michalak, Travis; Yerkes, Kirk; Baysinger, Karri; McQuillen, John

    2005-01-01

    The objective of this paper is to discuss the testing of a spray cooling experiment designed to be flown on NASA's KC-135 Reduced Gravity Testing Platform. Spray cooling is an example of a thermal management technique that may be utilized in high flux heat acquisition and high thermal energy transport concepts. Many researchers have investigated the utility of spray cooling for the thermal management of devices generating high heat fluxes. However, there has been little research addressing the physics and ultimate performance of spray cooling in a variable gravity environment. An experimental package, consisting of a spray chamber coupled to a fluid delivery loop system, was fabricated for variable gravity flight tests. The spray chamber contains two opposing nozzles spraying on target Indium Tin Oxide (ITO) heaters. These heaters are mounted on glass pedestals, which are part of a sump system to remove unconstrained liquid from the test chamber. Liquid is collected in the sumps and returned to the fluid delivery loop. Thermocouples mounted in and around the pedestals are used to determine both the heat loss through the underside of the IT0 heater and the heat extracted by the spray. A series of flight tests were carried out aboard the KC-135, utilizing the ability of the aircraft to produce various gravity conditions. During the flight tests, for a fixed flow rate, heat input was varied at 20, 30, 50, and 80W with variable gravities of 0.01, 0.16, 0.36, and 1.8g. Flight test data was compared to terrestrial baseline data in addition to analytical and numerical solutions to evaluate the heat transfer in the heater and support structure . There were significant differences observed in the spray cooling performance as a result of variable gravity conditions and heat inputs. In general, the Nussult number at the heater surface was found to increase with decreasing gravity conditions for heat loads greater than 30W.

  6. High Power Density Spray Cooling

    DTIC Science & Technology

    1989-07-01

    to subcooled flow boiling . Above this point, the percentage of heat removal attributed to evaporation increases. After the majority of the coolant is...concerning the spray characteristics Was obtained using a laser phase Doppler system . Table 5.1.1: Nozzle characteristics Nozzle Orifice Flow Rate (1/hr...in section 6.2.1. A study of the air/droplet inpingetmet flow field on the surface clearly shows the advantages of such a system . The air jet on

  7. Uniform-droplet spray forming

    SciTech Connect

    Blue, C.A.; Sikka, V.K.; Chun, Jung-Hoon; Ando, T.

    1997-04-01

    The uniform-droplet process is a new method of liquid-metal atomization that results in single droplets that can be used to produce mono-size powders or sprayed-on to substrates to produce near-net shapes with tailored microstructure. The mono-sized powder-production capability of the uniform-droplet process also has the potential of permitting engineered powder blends to produce components of controlled porosity. Metal and alloy powders are commercially produced by at least three different methods: gas atomization, water atomization, and rotating disk. All three methods produce powders of a broad range in size with a very small yield of fine powders with single-sized droplets that can be used to produce mono-size powders or sprayed-on substrates to produce near-net shapes with tailored microstructures. The economical analysis has shown the process to have the potential of reducing capital cost by 50% and operating cost by 37.5% when applied to powder making. For the spray-forming process, a 25% savings is expected in both the capital and operating costs. The project is jointly carried out at Massachusetts Institute of Technology (MIT), Tuffs University, and Oak Ridge National Laboratory (ORNL). Preliminary interactions with both finished parts and powder producers have shown a strong interest in the uniform-droplet process. Systematic studies are being conducted to optimize the process parameters, understand the solidification of droplets and spray deposits, and develop a uniform-droplet-system (UDS) apparatus appropriate for processing engineering alloys.

  8. Magnesium Repair by Cold Spray

    DTIC Science & Technology

    2008-05-01

    were conducted using microstructural analysis, hardness, bond strength, and corrosion testing. 15. SUBJECT TERMS Cold spray, magnesium, aluminum ... corrosion pitting are the primary causes for removing the components from service. In addition, any repair must be confined to nonstructural areas of...unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT The U.S. Army has experienced significant corrosion problems with magnesium alloys that are used to

  9. Overview of the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Forcing on the Mediterranean Climate (ChArMEx/ADRIMED) summer 2013 campaign

    NASA Astrophysics Data System (ADS)

    Mallet, M.; Dulac, F.; Formenti, P.; Nabat, P.; Sciare, J.; Roberts, G.; Pelon, J.; Ancellet, G.; Tanré, D.; Parol, F.; Denjean, C.; Brogniez, G.; di Sarra, A.; Alados-Arboledas, L.; Arndt, J.; Auriol, F.; Blarel, L.; Bourrianne, T.; Chazette, P.; Chevaillier, S.; Claeys, M.; D'Anna, B.; Derimian, Y.; Desboeufs, K.; Di Iorio, T.; Doussin, J.-F.; Durand, P.; Féron, A.; Freney, E.; Gaimoz, C.; Goloub, P.; Gómez-Amo, J. L.; Granados-Muñoz, M. J.; Grand, N.; Hamonou, E.; Jankowiak, I.; Jeannot, M.; Léon, J.-F.; Maillé, M.; Mailler, S.; Meloni, D.; Menut, L.; Momboisse, G.; Nicolas, J.; Podvin, T.; Pont, V.; Rea, G.; Renard, J.-B.; Roblou, L.; Schepanski, K.; Schwarzenboeck, A.; Sellegri, K.; Sicard, M.; Solmon, F.; Somot, S.; Torres, B.; Totems, J.; Triquet, S.; Verdier, N.; Verwaerde, C.; Waquet, F.; Wenger, J.; Zapf, P.

    2016-01-01

    The Chemistry-Aerosol Mediterranean Experiment (ChArMEx; target="_blank">http://charmex.lsce.ipsl.fr) is a collaborative research program federating international activities to investigate Mediterranean regional chemistry-climate interactions. A special observing period (SOP-1a) including intensive airborne measurements was performed in the framework of the Aerosol Direct Radiative Impact on the regional climate in the MEDiterranean region (ADRIMED) project during the Mediterranean dry season over the western and central Mediterranean basins, with a focus on aerosol-radiation measurements and their modeling. The SOP-1a took place from 11 June to 5 July 2013. Airborne measurements were made by both the ATR-42 and F-20 French research aircraft operated from Sardinia (Italy) and instrumented for in situ and remote-sensing measurements, respectively, and by sounding and drifting balloons, launched in Minorca. The experimental setup also involved several ground-based measurement sites on islands including two ground-based reference stations in Corsica and Lampedusa and secondary monitoring sites in Minorca and Sicily. Additional measurements including lidar profiling were also performed on alert during aircraft operations at EARLINET/ACTRIS stations at Granada and Barcelona in Spain, and in southern Italy. Remote-sensing aerosol products from satellites (MSG/SEVIRI, MODIS) and from the AERONET/PHOTONS network were also used. Dedicated meso-scale and regional modeling experiments were performed in relation to this observational effort. We provide here an overview of the different surface and aircraft observations deployed during the ChArMEx/ADRIMED period and of associated modeling studies together with an analysis of the synoptic conditions that determined the aerosol emission and transport. Meteorological conditions observed during this campaign (moderate temperatures and southern flows) were not favorable to producing high

  10. Coanda-assisted Spray Manipulation

    NASA Astrophysics Data System (ADS)

    Mabey, Katie; Smith, Barton; Archibald, Reid; West, Brian

    2009-11-01

    An overview of research on a flow control technique called Coanda-assisted Spray Manipulation (CSM) is presented. CSM uses a high-momentum control jet under the influence of the Coanda effect to vector a high volume-flow jet or spray. Actuators provide the capability of moving the location of applied control flow making rotary or arbitrary motion of the vectored flow possible. The presented work includes a fundamental isothermal study on the effects of rotation speed and Reynolds number on a vectored jet using a belt-driven CSM actuator. Three-component velocity data were acquired for three Reynolds numbers and three rotation speeds using timed resolved high-speed stereo Particle Image Velocimetry. A second CSM system with 16 pneumatically-driven control ports has been retrofitted to a flame spray gun. This combination provides the capability to rapidly alter the direction of applied metal powders. High speed video of this process will also be presented. Finally, a fundamental study on the pneumatic system's response to minor losses and connection lines of varying lengths is presented.

  11. Factors determining the most efficient spray distribution for marine cloud brightening

    PubMed Central

    Connolly, P. J.; McFiggans, G. B.; Wood, R.; Tsiamis, A.

    2014-01-01

    We investigate the sensitivity of marine cloud brightening to the properties of the added salt particle distribution using a cloud parcel model, with an aim to address the question of, ‘what is the most efficient particle size distribution that will produce a desired cooling effect?’ We examine the effect that altering the aerosol particle size distribution has on the activation and growth of drops, i.e. the Twomey effect alone, and do not consider macrophysical cloud responses that may enhance or mitigate the Twomey effect. For all four spray generation methods considered, Rayleigh jet; Taylor cone jet; supercritical fluid; and effervescent spray, salt particles within the median dry diameter range Dm=30–100 nm are the most effective range of sizes. The Rayleigh jet method is also the most energy efficient overall. We also find that care needs to be taken when using droplet activation parametrizations: for the concentrations considered, Aitken particles do not result in a decrease in the total albedo, as was found in a recent study, and such findings are likely to be a result of the parametrizations' inability to simulate the effect of swollen aerosol particles. Our findings suggest that interstitial aerosol particles play a role in controlling the albedo rather than just the activated cloud drops, which is an effect that the parametrization methods do not consider. PMID:25404674

  12. Factors determining the most efficient spray distribution for marine cloud brightening.

    PubMed

    Connolly, P J; McFiggans, G B; Wood, R; Tsiamis, A

    2014-12-28

    We investigate the sensitivity of marine cloud brightening to the properties of the added salt particle distribution using a cloud parcel model, with an aim to address the question of, 'what is the most efficient particle size distribution that will produce a desired cooling effect?' We examine the effect that altering the aerosol particle size distribution has on the activation and growth of drops, i.e. the Twomey effect alone, and do not consider macrophysical cloud responses that may enhance or mitigate the Twomey effect. For all four spray generation methods considered, Rayleigh jet; Taylor cone jet; supercritical fluid; and effervescent spray, salt particles within the median dry diameter range Dm=30-100 nm are the most effective range of sizes. The Rayleigh jet method is also the most energy efficient overall. We also find that care needs to be taken when using droplet activation parametrizations: for the concentrations considered, Aitken particles do not result in a decrease in the total albedo, as was found in a recent study, and such findings are likely to be a result of the parametrizations' inability to simulate the effect of swollen aerosol particles. Our findings suggest that interstitial aerosol particles play a role in controlling the albedo rather than just the activated cloud drops, which is an effect that the parametrization methods do not consider.

  13. Future aerosol reductions and widening of the northern tropical belt

    NASA Astrophysics Data System (ADS)

    Allen, Robert J.; Ajoku, Osinachi

    2016-06-01

    Observations show that the tropical belt has widened over the past few decades, a phenomenon associated with poleward migration of subtropical dry zones and large-scale atmospheric circulation. Although part of this signal is related to natural climate variability, studies have identified an externally forced contribution primarily associated with greenhouse gases (GHGs) and stratospheric ozone loss. Here we show that the increase in aerosols over the twentieth century has led to contraction of the northern tropical belt, thereby offsetting part of the widening associated with the increase in GHGs. Over the 21st century, however, when aerosol emissions are projected to decrease, the effects of aerosols and GHGs reinforce one another, both contributing to widening of the northern tropical belt. Models that have larger aerosol forcing, by including aerosol indirect effects on cloud albedo and lifetime, yield significantly larger Northern Hemisphere (NH) tropical widening than models with direct aerosol effects only. More targeted simulations show that future reductions in aerosols can drive NH tropical widening as large as greenhouse gases, and idealized simulations show the importance of NH midlatitude aerosol forcing. Mechanistically, the 21st century reduction in aerosols peaks near 40°N, which results in a corresponding maximum increase in surface solar radiation, NH midlatitude tropospheric warming amplification, and a poleward shift in the latitude of maximum baroclinicity, implying a corresponding shift in atmospheric circulation. If models with aerosol indirect effects better represent the real world, then future aerosol changes are likely to be an important -- if not dominant -- driver of NH tropical belt widening.

  14. Infrared spectroscopy of aerosols

    NASA Astrophysics Data System (ADS)

    Mentel, Th.; Sebald, H.

    2003-04-01

    In our large Aerosol Chamber at the FZ Jülich we apply HR FTIR absorption spectroscopy for the determination of trace gases. In the FTIR spectra we also observe broad absorptions of several 10 to a few 100 cm-1 widths that arise from species in the condensed aerosol phase: liquid H_2O, NO_3^-, SO_42-, HSO_4^-, or dicarboxylic acids. Moreover, the aerosol droplets caused extinctions over several 1000 cm-1 by IR scattering. This allows for in-situ observation of changes in the condensed aerosol phase e.g. on HNO_3 uptake, like the shift of the sulfate/bisulfate equilibrium or the growth by water condensation. The IR absorptions of the condensed aerosol phase provide useful extra information in process studies, if they can be quantified. Therefore the absorption cross section, respective, the absorption index which is the imaginary part of the complex refractive index is needed. We set up an aerosol flow tube in which IR spectroscopy on a 8 m light path and aerosol size distribution measurements in the range from 20 nm - 10 μm can be performed simultaneously. We measured sulfate aerosols at several relative humidities (dry, metastable, deliquescent). We will demonstrate an iterative procedure based on Mie calculations and Kramers Kronig transformation to retrieve the absorption index from the observed IR spectra and the corresponding size distribution (for dry ammonium sulfate). We will compare resulting absorption indices for aqueous sodium bisulfate aerosols at several relative humidties with thermodynamic model calculations for the Na^+/H^+/HSO_4^-/SO_42-/H_2O system.

  15. Wire Whip Keeps Spray Nozzle Clean

    NASA Technical Reports Server (NTRS)

    Carroll, H. R.

    1982-01-01

    Air-turbine-driven wire whip is clamped near spray-gun mount. When spray gun is installed, wire whip is in position to remove foam buildup from nozzle face. Two lengths of wire 1 to 2 inches long and about 0.03 inch in thickness are used. Foam spray would be prevented from accumulating on nozzle face by increasing purge flow and cutting vortex-generating grooves inside cap and on nozzle flats.

  16. Planar Droplet Sizing in Dense Sprays

    DTIC Science & Technology

    2013-04-01

    Transactions of the ASME 121(3): 409-414. Sick, V. and B. Stojkovic (2001). "Attenuation effects on imaging diagnostics of hollow - cone sprays ...considered in the data processing method. Imaging of the scattered light from the spray was performed by a 12bit CCD camera ( Model PCO sensical QE...the spray was performed using a laser power meter. The motorised linear stage was acquired from Thorlabs MTS50 models (Figure 5). The positioning

  17. Spray combustion model improvement study, 1

    NASA Technical Reports Server (NTRS)

    Chen, C. P.; Kim, Y. M.; Shang, H. M.

    1993-01-01

    This study involves the development of numerical and physical modeling in spray combustion. These modeling efforts are mainly motivated to improve the physical submodels of turbulence, combustion, atomization, dense spray effects, and group vaporization. The present mathematical formulation can be easily implemented in any time-marching multiple pressure correction methodologies such as MAST code. A sequence of validation cases includes the nonevaporating, evaporating and_burnin dense_sprays.

  18. Liquid spray cooling of a heated surface

    NASA Technical Reports Server (NTRS)

    Grissom, W. M.; Wierum, F. A.

    1981-01-01

    The lowest surface temperature possible for the existance of spray evaporative cooling is determined experimentally to be a linear function of the impinging spray mass flux. A conduction-controlled analytical model of droplet evaporation gives fairly good agreement with experimental measurements at atmospheric pressure. At reduced pressures droplet evaporation rates are decreased significantly such that an optimum operating pressure exists for each desired surface heat flux. The initiation of the 'Leidenfrost state' provides the upper surface temperature bound for spray evaporative cooling.

  19. Plasma sprayed ceria-containing interlayer

    DOEpatents

    Schmidt, Douglas S.; Folser, George R.

    2006-01-10

    A plasma sprayed ceria-containing interlayer is provided. The interlayer has particular application in connection with a solid oxide fuel cell used within a power generation system. The fuel cell advantageously comprises an air electrode, a plasma sprayed interlayer disposed on at least a portion of the air electrode, a plasma sprayed electrolyte disposed on at least a portion of the interlayer, and a fuel electrode applied on at least a portion of the electrolyte.

  20. The MESSy aerosol submodel MADE3 (v2.0b): description and a box model test

    NASA Astrophysics Data System (ADS)

    Kaiser, J. C.; Hendricks, J.; Righi, M.; Riemer, N.; Zaveri, R. A.; Metzger, S.; Aquila, V.

    2014-01-01

    We introduce MADE3 (Modal Aerosol Dynamics model for Europe, adapted for global applications, 3rd generation), an aerosol dynamics submodel for application within the MESSy framework (Modular Earth Submodel System). MADE3 builds on the predecessor aerosol submodels MADE and MADE-in. Its main new features are the explicit representation of coarse particle interactions both with other particles and with condensable gases, and the inclusion of hydrochloric acid (HCl)/chloride (Cl) partitioning between the gas and condensed phases. The aerosol size distribution is represented in the new submodel as a superposition of nine lognormal modes: one for fully soluble particles, one for insoluble particles, and one for mixed particles in each of three size ranges (Aitken, accumulation, and coarse mode size ranges). In order to assess the performance of MADE3 we compare it to its predecessor MADE and to the much more detailed particle-resolved aerosol model PartMC-MOSAIC in a box model simulation of an idealised marine boundary layer test case. MADE3 and MADE results are very similar, except in the coarse mode, where the aerosol is dominated by sea spray particles. Cl is reduced in MADE3 with respect to MADE due to the HCl/Cl partitioning that leads to Cl removal from the sea spray aerosol in our test case. Additionally, aerosol nitrate concentration is higher in MADE3 due to the condensation of nitric acid on coarse particles. MADE3 and PartMC-MOSAIC show substantial differences in the fine particle size distributions (sizes ≲ 2 μm) that could be relevant when simulating climate effects on a global scale. Nevertheless, the agreement between MADE3 and PartMC-MOSAIC is very good when it comes to coarse particle size distribution, and also in terms of aerosol composition. Considering these results and the well-established ability of MADE in reproducing observed aerosol loadings and composition, MADE3 seems suitable for application within a global model.

  1. The Messy Aerosol Submodel MADE3 (v2.0b): Description and a Box Model Test

    NASA Technical Reports Server (NTRS)

    Kaiser, J. C.; Hendricks, J.; Righi, M.; Riemer, N.; Zaveri, R. A.; Metzger, S.; Aquila, Valentina

    2014-01-01

    We introduce MADE3 (Modal Aerosol Dynamics model for Europe, adapted for global applications, 3rd generation), an aerosol dynamics submodel for application within the MESSy framework (Modular Earth Submodel System). MADE3 builds on the predecessor aerosol submodels MADE and MADE-in. Its main new features are the explicit representation of coarse particle interactions both with other particles and with condensable gases, and the inclusion of hydrochloric acid (HCl)chloride (Cl) partitioning between the gas and condensed phases. The aerosol size distribution is represented in the new submodel as a superposition of nine lognormal modes: one for fully soluble particles, one for insoluble particles, and one for mixed particles in each of three size ranges (Aitken, accumulation, and coarse mode size ranges). In order to assess the performance of MADE3 we compare it to its predecessor MADE and to the much more detailed particle-resolved aerosol model PartMC-MOSAIC in a box model simulation of an idealized marine boundary layer test case. MADE3 and MADE results are very similar, except in the coarse mode, where the aerosol is dominated by sea spray particles. Cl is reduced in MADE3 with respect to MADE due to the HClCl partitioning that leads to Cl removal from the sea spray aerosol in our test case. Additionally, aerosol nitrate concentration is higher in MADE3 due to the condensation of nitric acid on coarse particles. MADE3 and PartMC- MOSAIC show substantial differences in the fine particle size distributions (sizes about 2 micrometers) that could be relevant when simulating climate effects on a global scale. Nevertheless, the agreement between MADE3 and PartMC-MOSAIC is very good when it comes to coarse particle size distribution, and also in terms of aerosol composition. Considering these results and the well-established ability of MADE in reproducing observed aerosol loadings and composition, MADE3 seems suitable for application within a global model.

  2. Modeling Multi-Arc Spraying Systems

    NASA Astrophysics Data System (ADS)

    Bobzin, K.; Öte, M.

    2016-06-01

    The use of plasma as energy source in thermal spraying enables among others the processing of feed stock materials with very high melting temperatures as coating materials. New generation multi-arc plasma spraying systems are widely spread and promise several advantages in comparison to the conventional single-arc systems. Numerical modeling of multi-arc plasma spraying offers the possibility to increase the understanding about this process. This study focuses on the numerical modeling of three-cathode spraying systems, introducing the recent activities in this field and discussing the numerical aspects which influence the prediction power of the models.

  3. Dynamic characteristics of pulsed supersonic fuel sprays

    NASA Astrophysics Data System (ADS)

    Pianthong, K.; Matthujak, A.; Takayama, K.; Milton, B. E.; Behnia, M.

    2008-06-01

    This paper describes the dynamic characteristics of pulsed, supersonic liquid fuel sprays or jets injected into ambient air. Simple, single hole nozzles were employed with the nozzle sac geometries being varied. Different fuel types, diesel fuel, bio-diesel, kerosene, and gasoline were used to determine the effects of fuel properties on the spray characteristics. A vertical two-stage light gas gun was employed as a projectile launcher to provide a high velocity impact to produce the liquid jet. The injection pressure was around 0.88-1.24 GPa in all cases. The pulsed, supersonic fuel sprays were visualized by using a high-speed video camera and shadowgraph method. The spray tip penetration and velocity attenuation and other characteristics were examined and are described here. An instantaneous spray tip velocity of 1,542 m/s (Mach number 4.52) was obtained. However, this spray tip velocity can be sustained for only a very short period (a few microseconds). It then attenuates very quickly. The phenomenon of multiple high frequency spray pulses generated by a single shot impact and the changed in the angle of the shock structure during the spray flight, which had already been observed in previous studies, is again noted. Multiple shock waves from the conical nozzle spray were also clearly captured.

  4. Pulsed spray structure and atomisation techniques

    NASA Astrophysics Data System (ADS)

    Yule, A. J.

    1987-08-01

    The process of atomisation from diesel injectors is found to persist for a significant proportion of the spray length before impaction on the cylinder wall. Both aerodynamic shear and cavitation appear to be of importance for the liquid jet breakdown. In addition cyclic variations are found in the atomisation and penetration of sprays. The transient nature of the spray initial conditions can cause pile up and coagulation of droplets at the leading edge of the spray pulse for certain cases. Improved modeling of diesel injection requires recognition of these phenomena and this is supported by both modeling and experimental data which have been obtained under realistic engine conditions in a specially developed rig.

  5. Wind tunnel and field evaluation of drift from aerial spray applications with multiple spray formulations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact of different spray tank modifiers into an active ingredient spray mixture on spray atomization and in-field behavior under aerial application conditions were examined. Wind tunnel tests demonstrated that active ingredient solutions potentially results in significantly different atomizati...

  6. Spray drift reduction evaluations of spray nozzles using a standardized testing protocol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development and testing of drift reduction technologies has come to the forefront of application research in the past few years in the United States. Drift reduction technologies (DRTs) can be spray nozzles, sprayer modifications, spray delivery assistance, spray property modifiers (adjuvants),...

  7. Volcanic Aerosol Radiative Properties

    NASA Technical Reports Server (NTRS)

    Lacis, Andrew

    2015-01-01

    Large sporadic volcanic eruptions inject large amounts of sulfur bearing gases into the stratosphere which then get photochemically converted to sulfuric acid aerosol droplets that exert a radiative cooling effect on the global climate system lasting for several years.

  8. Palaeoclimate: Aerosols and rainfall

    NASA Astrophysics Data System (ADS)

    Partin, Jud

    2015-03-01

    Instrumental records have hinted that aerosol emissions may be shifting rainfall over Central America southwards. A 450-year-long precipitation reconstruction indicates that this shift began shortly after the Industrial Revolution.

  9. [Factors influencing particle measurement of aerosols and their retention in the lung].

    PubMed

    Le Bouffant, L

    1977-01-01

    The dimensional characteristics of the particles of an aerosol depend on the means used for producing them. Mechanical spray and ultrasonic dispersion give polydispersed particles. On the other hand, centrifugal atomization produces a monodispersed aerosol. Particle retention in the lung system depends on the particle diameter. In addition, retention varies according to the respiratory characteristics: it is minimal for about 15 inspirations per minute. Using iron-59 labeled particles, it was shown that the degree of retention varies considerably from one individual to the other and accessibility to the depths of the lungs is decreased under the effect of certain lesions. Bronchial retention appears to be increased in smokers.

  10. Combined electron-beam and ozone treatment of wastewater in the aerosol flow

    NASA Astrophysics Data System (ADS)

    Pikaev, A. K.; Podzorova, E. A.; Bakhtin, O. M.

    1997-01-01

    Combined electron-beam and ozone method for purification and disinfection of wastewater in the aerosol flow is considered. The method consists in spraying the wastewater and subsequent electron-beam treatment of the produced aerosol flow in the presence of ozone. The results of the study on the purification of municipal wastewater by this method with using pilot plant based on low-energy electron accelerator (energy 0.3 MeV, maximum electron-beam power 15 kW) are described. The output of the plant is 500 m 3/day. The data on economic feasibility of the method are presented.

  11. Emergency Protection from Aerosols

    SciTech Connect

    Cristy, G.A.

    2001-11-13

    Expedient methods were developed that could be used by an average person, using only materials readily available, to protect himself and his family from injury by toxic (e.g., radioactive) aerosols. The most effective means of protection was the use of a household vacuum cleaner to maintain a small positive pressure on a closed house during passage of the aerosol cloud. Protection factors of 800 and above were achieved.

  12. Monodisperse aerosol generator

    DOEpatents

    Ortiz, Lawrence W.; Soderholm, Sidney C.

    1990-01-01

    An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.

  13. RACORO aerosol data processing

    SciTech Connect

    Elisabeth Andrews

    2011-10-31

    The RACORO aerosol data (cloud condensation nuclei (CCN), condensation nuclei (CN) and aerosol size distributions) need further processing to be useful for model evaluation (e.g., GCM droplet nucleation parameterizations) and other investigations. These tasks include: (1) Identification and flagging of 'splash' contaminated Twin Otter aerosol data. (2) Calculation of actual supersaturation (SS) values in the two CCN columns flown on the Twin Otter. (3) Interpolation of CCN spectra from SGP and Twin Otter to 0.2% SS. (4) Process data for spatial variability studies. (5) Provide calculated light scattering from measured aerosol size distributions. Below we first briefly describe the measurements and then describe the results of several data processing tasks that which have been completed, paving the way for the scientific analyses for which the campaign was designed. The end result of this research will be several aerosol data sets which can be used to achieve some of the goals of the RACORO mission including the enhanced understanding of cloud-aerosol interactions and improved cloud simulations in climate models.

  14. Aerosol Production from the Great Lakes Surface

    NASA Astrophysics Data System (ADS)

    Slade, J. H.; Mwaniki, G.; Bertman, S. B.; Vanreken, T. M.; Shepson, P. B.

    2009-12-01

    It is well understood that oceans generate airborne particulate matter from mechanical processes such as sea spray and bubble bursting. These particles are primarily composed of salts and other nonvolatile inorganic material; however, the organic mass fraction can vary by location and the extent of biological activity. The size distributions of aerosols in these environments depend greatly on relative humidity with diameters ranging from typically several hundred nanometers to several micrometers. There has been much less discussion of particle formation from fresh water ecosystems, a hub for organic activity, and thus a more likely medium for organic aerosol production. We investigated particle formation over the Great Lakes during the summer of 2009 as a part of the Community Atmosphere-Biosphere Interactions Experiments (CABINEX) at the University of Michigan Biological Station (UMBS) in Pellston, MI. With a scanning mobility particle sizer (SMPS) aboard Purdue University’s Airborne Laboratory for Atmospheric Research (ALAR) for size-distribution analysis of accumulation-mode aerosol, we conducted vertical profiles above Lake Michigan and the UMBS deciduous forest, and transects across the peninsula between Lakes Michigan and Huron to study particle formation, transport, and deposition. Preliminary results reveal a well-mixed troposphere above the forest with a mode ~0.1 μm, while in several cases, the total particle concentration over Lake Michigan is an order of magnitude greater than over the forest. There is a consistent bimodal distribution of particle sizes over Lake Michigan the lowest of which is centered at ~0.025 μm, suggesting the possibility of new particle formation. This mode is consistent with the presence of breaking waves on the lake’s surface, and this mode and the vertical structure depend greatly on wind speed. We present here evidence for new particle production from breaking waves on fresh water lakes, and discuss the results

  15. Sub-Antarctic marine aerosol: dominant contributions from biogenic sources

    NASA Astrophysics Data System (ADS)

    Schmale, J.; Schneider, J.; Nemitz, E.; Tang, Y. S.; Dragosits, U.; Blackall, T. D.; Trathan, P. N.; Phillips, G. J.; Sutton, M.; Braban, C. F.

    2013-09-01

    Biogenic influences on the composition and characteristics of aerosol were investigated on Bird Island (54°00' S, 38°03' W) in the South Atlantic during November and December 2010. This remote marine environment is characterised by large seabird and seal colonies. The chemical composition of the submicron particles, measured by an aerosol mass spectrometer (AMS), was 21% non-sea-salt sulfate, 2% nitrate, 8% ammonium, 22% organics and 47% sea salt including sea salt sulfate. A new method to isolate the sea spray signature from the high-resolution AMS data was applied. Generally, the aerosol was found to be less acidic than in other marine environments due to the high availability of ammonia, from local fauna emissions. By positive matrix factorisation five different organic aerosol (OA) profiles could be isolated: an amino acid/amine factor (AA-OA, 18% of OA mass), a methanesulfonic acid OA factor (MSA-OA, 25%), a marine oxygenated OA factor (M-OOA, 41%), a sea spray OA fraction (SS-OA, 7%) and locally produced hydrocarbon-like OA (HOA, 9%). The AA-OA was dominant during the first two weeks of November and found to be related with the hatching of penguins in a nearby colony. This factor, rich in nitrogen (N : C ratio = 0.13), has implications for the biogeochemical cycling of nitrogen in the area as particulate matter is often transported over longer distances than gaseous N-rich compounds. The MSA-OA was mainly transported from more southerly latitudes where phytoplankton bloomed. The bloom was identified as one of three sources for particulate sulfate on Bird Island, next to sea salt sulfate and sulfate transported from South America. M-OOA was the dominant organic factor and found to be similar to marine OA observed at Mace Head, Ireland. An additional OA factor highly correlated with sea spray aerosol was identified (SS-OA). However, based on the available data the type of mixture, internal or external, could not be determined. Potassium was not associated

  16. Comparison Between Sodium Nitrite & Sodium Hydroxide Spray Accident

    SciTech Connect

    WILLIAMS, J.C.; HEY, B.E.

    2001-11-07

    The purpose of this analysis is to compare the consequences of an 8 molar NaNO2 spray leak to the Tank Farm Final Safety Analysis Report (FSAR) evaluation of sprays of up to 19 molar (50%) NaOH. Four conditions were evaluated. These are: a spray during transfers from a one-inch pipe, a spray resulting from a truck tank Crack, a spray resulting from a truck tank rupture, and a spray in the 204-AR Waste Unloading Facility.

  17. Spray forming lead strip. Final report

    SciTech Connect

    McHugh, K.

    1996-04-10

    A cooperative research project was conducted between the Idaho National Engineering Laboratory (INEL) and Johnson Controls, Inc. (JCI) to adapt the INEL spray forming process to produce near-net-shape lead alloy strip. The emphasis of the work was to spray form lead strip samples at INEL, using a variety of spray conditions, for characterization at JCI. An existing glove box apparatus was modified at INEL to spray form lead. The main spray forming components were housed inside the glove box. They included a spray nozzle, tundish (crucible), substrate assembly, gas heater and furnaces to heat the nozzle and tundish. To spray form metal strip, liquid metal was pressure-fed at a controlled rate through a series of circular orifices that span the width of the nozzle. There the metal contacted high velocity, high temperature inert gas (nitrogen) which atomized the molten material into fine droplets, entrained the droplets in a directed flow, and deposited them onto glass plates that were swept through the spray plume to form strip samples. In-flight convection cooling of the droplets followed by conduction and convection cooling at the substrate resulted in rapid solidification of the deposit. During operation, the inside of the glove box was purged with an inert gas to limit the effects of in-flight oxidation of the particles and spray-formed strips, as well as to protect personnel from exposure to airborne lead particulate. Remote controls were used to start/stop the spray and control the speed and position of the substrate. In addition, substrate samples were loaded into the substrate translator manually using the gloved side ports of the box. In this way, the glove box remained closed during a series of spray trials, and was opened only when loading the crucible with a lead charge or when removing lead strip samples for shipment to JCI.

  18. Assessing the Dynamics of Organic Aerosols over the North Atlantic Ocean

    PubMed Central

    Kasparian, Jérôme; Hassler, Christel; Ibelings, Bas; Berti, Nicolas; Bigorre, Sébastien; Djambazova, Violeta; Gascon-Diez, Elena; Giuliani, Grégory; Houlmann, Raphaël; Kiselev, Denis; de Laborie, Pierric; Le, Anh-Dao; Magouroux, Thibaud; Neri, Tristan; Palomino, Daniel; Pfändler, Stéfanie; Ray, Nicolas; Sousa, Gustavo; Staedler, Davide; Tettamanti, Federico; Wolf, Jean-Pierre; Beniston, Martin

    2017-01-01

    The influence of aerosols on climate is highly dependent on the particle size distribution, concentration, and composition. In particular, the latter influences their ability to act as cloud condensation nuclei, whereby they impact cloud coverage and precipitation. Here, we simultaneously measured the concentration of aerosols from sea spray over the North Atlantic on board the exhaust-free solar-powered vessel “PlanetSolar”, and the sea surface physico-chemical parameters. We identified organic-bearing particles based on individual particle fluorescence spectra. Organic-bearing aerosols display specific spatio-temporal distributions as compared to total aerosols. We propose an empirical parameterization of the organic-bearing particle concentration, with a dependence on water salinity and sea-surface temperature only. We also show that a very rich mixture of organic aerosols is emitted from the sea surface. Such data will certainly contribute to providing further insight into the influence of aerosols on cloud formation, and be used as input for the improved modeling of aerosols and their role in global climate processes. PMID:28361985

  19. Assessing the Dynamics of Organic Aerosols over the North Atlantic Ocean.

    PubMed

    Kasparian, Jérôme; Hassler, Christel; Ibelings, Bas; Berti, Nicolas; Bigorre, Sébastien; Djambazova, Violeta; Gascon-Diez, Elena; Giuliani, Grégory; Houlmann, Raphaël; Kiselev, Denis; de Laborie, Pierric; Le, Anh-Dao; Magouroux, Thibaud; Neri, Tristan; Palomino, Daniel; Pfändler, Stéfanie; Ray, Nicolas; Sousa, Gustavo; Staedler, Davide; Tettamanti, Federico; Wolf, Jean-Pierre; Beniston, Martin

    2017-03-31

    The influence of aerosols on climate is highly dependent on the particle size distribution, concentration, and composition. In particular, the latter influences their ability to act as cloud condensation nuclei, whereby they impact cloud coverage and precipitation. Here, we simultaneously measured the concentration of aerosols from sea spray over the North Atlantic on board the exhaust-free solar-powered vessel "PlanetSolar", and the sea surface physico-chemical parameters. We identified organic-bearing particles based on individual particle fluorescence spectra. Organic-bearing aerosols display specific spatio-temporal distributions as compared to total aerosols. We propose an empirical parameterization of the organic-bearing particle concentration, with a dependence on water salinity and sea-surface temperature only. We also show that a very rich mixture of organic aerosols is emitted from the sea surface. Such data will certainly contribute to providing further insight into the influence of aerosols on cloud formation, and be used as input for the improved modeling of aerosols and their role in global climate processes.

  20. Influence of Surface Seawater and Atmospheric Conditions on the Ccn Activity of Ocean-Derived Aerosol

    NASA Astrophysics Data System (ADS)

    Quinn, P.; Bates, T. S.; Russell, L. M.; Frossard, A. A.; Keene, W. C.; Kieber, D. J.; Hakala, J. P.

    2012-12-01

    Ocean-derived aerosols are produced from direct injection into the atmosphere (primary production) and gas-to-particle conversion in the atmosphere (secondary production). These different production mechanisms result in a broad range of particle sizes that has implications for the impact of ocean-derived aerosol on climate. The chemical composition of ocean-derived aerosols is a result of a complex mixture of inorganic sea salt and organic matter including polysaccharides, proteins, amino acids, microorganisms and their fragments, and secondary oxidation products. Both production mechanisms and biological processes in the surface ocean impact the ability of ocean-derived aerosol to act as cloud condensation nuclei (CCN). In addition, CCN activity can be impacted by atmospheric processing that modifies particle size and composition after the aerosol is emitted from the ocean. To understand relationships between production mechanism, surface ocean biology, and atmospheric processing, measurements were made of surface ocean chlorophyll and dissolved organic matter; nascent sea spray aerosol freshly emitted from the ocean surface; and ambient marine aerosol. These measurements were made along the coast of California and in the North Atlantic between the northeast US and Bermuda. These regions include both eutrophic and oligotraphic waters and, thus, provide for observations over a wide range of ocean conditions.

  1. New Satellite Measurements of Aerosol Direct Radiative Forcing from MODIS, MISR, and POLDER

    NASA Technical Reports Server (NTRS)

    Kaufman, Y.

    2000-01-01

    New set of satellites, MODIS and MISR launched on EOS-Terra and POLDER launched on ADEOS-1, and scheduled for ADEOS-II and PARASOL in orbit with EOS-AQUA, open exciting opportunities to measure aerosol and their radiative forcing of climate. Each of these instruments has a different approach to invert remote sensing data to derive the aerosol properties. MODIS is using wide spectral range 0.47-2.1 micron. MISR is using narrower spectral range (0.44 to 0.87 micron) but observing the same spot from 9 different angles along the satellite track. POLDER using similar wavelengths, uses two dimensional view with a wide angle optics and adds polarization to the inversion process. Among these instruments, we expect to measure the global distribution of aerosol, to distinguish small pollution particles from large particles from deserts and ocean spray. We shall try to measure the aerosol absorption of solar radiation, and their refractive index that indicates the effect of liquid water on the aerosol size and interaction with sunlight. The radiation field measured by these instruments in variety of wavelengths and angles, is also used to derive the effect of the aerosol on reflection of sunlight spectral fluxes to space. When combined with flux measurements at the ground, it gives a complete characterization of the effect of aerosol on solar illumination, heating in the atmosphere and reflection to space.

  2. Characterization of ice-nucleating bacteria using on-line electron impact ionization aerosol mass spectrometry.

    PubMed

    Wolf, R; Slowik, J G; Schaupp, C; Amato, P; Saathoff, H; Möhler, O; Prévôt, A S H; Baltensperger, U

    2015-04-01

    The mass spectral signatures of airborne bacteria were measured and analyzed in cloud simulation experiments at the AIDA (Aerosol Interaction and Dynamics in the Atmosphere) facility. Suspensions of cultured cells in pure water were sprayed into the aerosol and cloud chambers forming an aerosol which consisted of intact cells, cell fragments and residual particles from the agar medium in which the bacteria were cultured. The aerosol particles were analyzed with a high-resolution time-of-flight aerosol mass spectrometer equipped with a newly developed PM2.5 aerodynamic lens. Positive matrix factorization (PMF) using the multilinear engine (ME-2) source apportionment was applied to deconvolve the bacteria and agar mass spectral signatures. The bacteria mass fraction contributed between 75 and 95% depending on the aerosol generation, with the remaining mass attributed to agar. We present mass spectra of Pseudomonas syringae and Pseudomonas fluorescens bacteria typical for ice-nucleation active bacteria in the atmosphere to facilitate the distinction of airborne bacteria from other constituents in ambient aerosol, e.g. by PMF/ME-2 source apportionment analyses. Nitrogen-containing ions were the most salient feature of the bacteria mass spectra, and a combination of C4 H8 N(+) (m/z 70) and C5 H12 N(+) (m/z 86) may be used as marker ions.

  3. Splattering during turbulent liquid jet impingement on solid targets

    SciTech Connect

    Bhunia, S.K.; Lienhard, J.H. V . Dept. of Mechanical Engineering)

    1994-06-01

    In turbulent liquid jet impingement, a spray of droplets often breaks off of the liquid layer formed on the target. This splattering of liquid alters the efficiencies of jet impingement heat transfer processes and chemical containment safety devices, and leads to problems of aerosol formation in jet impingement cleaning processes. In this paper, the authors present a more complete study of splattering and improved correlations that extend and supersede the previous reports on this topic. The authors report experimental results on the amount of splattering for jets of water, isopropanol-water solutions, and soap-water mixtures. Jets were produced by straight tube nozzles of diameter 0.8--5.8 mm, with fully developed turbulent pipe-flow upstream of the nozzle exist. These experiments cover Weber numbers between 130--31,000, Reynolds numbers between 2,700--98,000, and nozzle-to-target separations of 0.2 [<=]l/d[<=]125. Splattering of up to 75 percent of the incoming jet liquid is observed. The results show that only the Weber number and l/d affect the fraction of jet liquid splattered. The presence of surfactants does not alter the splattering. A new correlation for the onset condition for splattering is given. In addition, the authors establish the range of applicability of the model of Lienhard et al. and the authors provide a more accurate set of coefficients for their correlation.

  4. Investigating the Influence of Sea Spray Particle Composition on Water Uptake

    NASA Astrophysics Data System (ADS)

    Cappa, C. D.; Forestieri, S.; Cornwell, G.; Helgestad, T.; Moore, K.; Lee, C.; Novak, G.; Sultana, C. M.; Wang, X.; Bertram, T. H.; Prather, K. A.

    2015-12-01

    Sea spray aerosol (SSA) particles influence climate by scattering solar radiation and serving as cloud seeds. Their specific influence depends, in part, on the extent to which they interact with water, which depends importantly on particle composition. The composition of freshly-emitted SSA particles is connected to the water (ocean) composition—especially biological activity—and the SSA production mechanism. Results from both field measurements and a suite of laboratory mesocosm experiments utilizing real ocean water and stimulated phytoplankton blooms with realistic simulated wave breaking will be discussed to demonstrate the complex relationships between nascent SSA particle water uptake and particle and source water composition.

  5. Preparation and characterization of microparticles of piroxicam by spray drying and spray chilling methods

    PubMed Central

    Dixit, M.; Kini, A.G.; Kulkarni, P.K.

    2010-01-01

    Piroxicam, an anti-inflammatory drug, exhibits poor water solubility and flow properties, poor dissolution and poor wetting. Consequently, the aim of this study was to improve the dissolution of piroxicam. Microparticles containing piroxicam were produced by spray drying, using isopropyl alcohol and water in the ratio of 40:60 v/v as solvent system, and spray chilling technology by melting the drug and chilling it with a pneumatic nozzle to enhance dissolution rate. The prepared formulations were evaluated for in vitro dissolution and solubility. The prepared drug particles were characterized by scanning electron microscopy (SEM), differential scanning calorimeter, X-ray diffraction and Fourier transform infrared spectroscopy. Dissolution profile of the spray dried microparticles was compared with spray-chilled microparticles, pure and recrystallized samples. Spray dried microparticles and spray chilled microparticles exhibited decreased crystallinity and improved micromeritic properties. The dissolution of the spray dried microparticle and spray chilled particles were improved compared with recrystallized and pure sample of piroxicam. Consequently, it was believed that spray drying of piroxicam is a useful tool to improve dissolution but not in case of spray chilling. This may be due to the degradation of drug or variations in the resonance structure or could be due to minor distortion of bond angles. Hence, this spray drying technique can be used for formulation of tablets of piroxicam by direct compression with directly compressible tablet excipients. PMID:21589797

  6. Disposition of aerosolized liposomal amphotericin B.

    PubMed

    Lambros, M P; Bourne, D W; Abbas, S A; Johnson, D L

    1997-09-01

    Amphotericin B (AmB) is an important drug for the treatment of fungal infection, but toxicity limits the lung tissue doses which may be achieved through intravenous administration. Although incorporation of AmB in liposomes reduces these effects and increases the therapeutic index for intravenous administration, targeted delivery to lung tissues via inhaled liposomal AmB aerosol may be a more effective approach. Aerosolization of liposomal amphotericin B targets the lungs, the organs first infested by many fungi. Development of optimal aerosolized liposomal AmB therapies requires a better understanding of the effect that liposome surface charge has on lung clearance kinetics. In this work we evaluated the clearance kinetics and organ distribution of inhaled liposomal AmB in male Balb/C mice. Mice were exposed via nose only to AmB-containing liposomal aerosols having positive, negative, or neutral surface charge characteristics. The formulations were aerosolized using a Collison nebulizer. Groups of animals were euthanized at predetermined times and the lungs and other organs were analyzed for AmB. AmB was not detected in serum and other organs such as kidneys, liver, and brain. The disposition of neutral and positive liposomal amphotericin B in lungs followed biexponential kinetics. The alpha and beta phase half-lives for positive liposomes were 1.3 and 15.1 days, respectively, and 2.3 and 22 days for neutral liposomes. AmB delivered via negative liposomes exhibited monoexponential clearance with a half-life of 4.5 days. These results suggest that toxic side effects in nontarget tissues are minimal and may indicate a potential for long term protection against fungal infections.

  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. Die-away kinetics of aerosolized bacteria from sprinkler application of wastewater.

    PubMed Central

    Teltsch, B; Shuval, H I; Tadmor, J

    1980-01-01

    A methodology for estimating, under field conditions, the microbial die-away constant (lambda) is presented. This constant may be used in predicting the aerosolized pathogenic microorganism concentrations downwind from a wastewater spray or aeration site by means of modified atmospheric diffusion equations. The mean lambda of Escherichia coli for very early morning runs was 8.8 X 10(-3)s-1, and that for afternoon runs was 6.6 X 10(-2)s-1. PMID:6996614

  9. Spray Gun With Constant Mixing Ratio

    NASA Technical Reports Server (NTRS)

    Simpson, William G.

    1987-01-01

    Conceptual mechanism mounted in handle of spray gun maintains constant ratio between volumetric flow rates in two channels leading to spray head. With mechanism, possible to keep flow ratio near 1:1 (or another desired ratio) over range of temperatures, orifice or channel sizes, or clogging conditions.

  10. Non-Markov effects in intersecting sprays

    NASA Astrophysics Data System (ADS)

    Panchagnula, Mahesh; Kumaran, Dhivyaraja; Deevi, Sri Vallabha; Tangirala, Arun

    2016-11-01

    Sprays have been assumed to follow a Markov process. In this study, we revisit that assumption relying on experimental data from intersecting and non-intersecting sprays. A phase Doppler Particle Analyzer (PDPA) is used to measure particle diameter and velocity at various axial locations in the intersection region of two sprays. Measurements of single sprays, with one nozzle turned off alternatively are also obtained at the same locations. This data, treated as an unstructured time series is classified into three bins each for diameter (small, medium, large) and velocity (slow, medium, fast). Conditional probability analysis on this binned data showed a higher static correlation between droplet velocities, while diameter correlation is significantly alleviated (reduced) in intersecting sprays, compared to single sprays. Further analysis using serial correlation measures: auto-correlation function (ACF) and partial auto-correlation function (PACF) shows that the lagged correlations in droplet velocity are enhanced while those in the droplet diameter are significantly debilitated in intersecting sprays. We show that sprays are not necessarily Markov processes and that memory persists, even though curtailed to fewer lags in case of size, and enhanced in case of droplet velocity.

  11. Spray Deflector For Water-Jet Machining

    NASA Technical Reports Server (NTRS)

    Cawthon, Michael A.

    1989-01-01

    Disk on water-jet-machining nozzle protects nozzle and parts behind it from erosion by deflected spray. Consists of stainless-steel backing with neoprene facing deflecting spray so it does not reach nut or other vital parts of water-jet apparatus.

  12. Impact of electrostatic and conventional sprayers characteristics on dispersion of barrier spray.

    PubMed

    Farooq, Muhammad; Walker, Todd W; Heintschel, Bryan P; Hoffmann, Wesley C; Fritz, Bradley K; Smith, Vincent L; Robinson, Cathy A; English, Trey

    2010-12-01

    A study was conducted to analyze the performance of 3 electrostatic (Electrolon BP-2.5, Spectrum Electrostatic 4010, and Spectrum Electrostatic head on a Stihl 420) and 2 conventional (Buffalo Turbine CSM2 and Stihl 420) sprayers for barrier sprays to suppress an adult mosquito population in an enclosed area. Sprayer characteristics such as charge-mass ratio, air velocity, flow rate, and droplet spectra were measured while spraying water. Dispersion of the spray cloud from these sprayers was determined using coverage on water-sensitive cards at various heights (0.5 m, 1.0 m, 1.5 m, 2.0 m, 2.5 m, and 3.0 m) and depths (1 m, 3 m, and 5 m) into the under-forest vegetation while spraying bifenthrin (Talstar 7.9% AI; FMC Corporation, Philadelphia, PA) at the rate of 21.8 ml/300 m of treated row. The charge-mass ratio data show that Electrostatic head on a Stihl 420 did not impart enough charge to the droplets to be considered as an electrostatic sprayer. In general, the charged spray cloud moved down toward the ground. The Electrolon BP 2.5 had significantly lower spray coverage on cards, indicating lack of spray dispersion. This sprayer had the lowest air velocity and did not have the air capacity needed to deliver droplets close to the target for electrostatic force to affect deposition. The analysis shows that these 2 sprayers are not a suitable choice for barrier sprays on vegetation. The results indicate that the Buffalo Turbine is suitable for barriers wider than 3 m, and the Spectrum 4010 and Stihl 420 are suitable for 1-3-m-wide barriers.

  13. The change of depolarization of backscattering light from the polar stratospheric aerosol layer

    NASA Technical Reports Server (NTRS)

    Iwasaka, Y.

    1985-01-01

    The change of polarization properties of scattered light strongly depends on the non-spherisity of target particles. It should be helpful information for the study of stratospheric aerosols to know the non-spherisity of stratospheric aerosol particles. The change of the total backscatter depolarization ratio of the stratospheric aerosol layer measured at Syowa Station (69.00 deg S, 39.35 deg E), Antarctica is described.

  14. Combustion of liquid sprays at high pressures

    NASA Technical Reports Server (NTRS)

    Shearer, A. J.; Faeth, G. M.

    1977-01-01

    The combustion of pressure atomized fuel sprays in high pressure stagnant air was studied. Measurements were made of flame and spray boundaries at pressures in the range 0.1-9 MPa for methanol and n-pentane. At the higher test pressure levels, critical phenomena are important. The experiments are compared with theoretical predictions based on a locally homogeneous two-phase flow model. The theory correctly predicted the trends of the data, but underestimates flame and spray boundaries by 30-50 percent, indicating that slip is still important for the present experiments (Sauter mean diameters of 30 microns at atmospheric pressure under cold flow conditions). Since the sprays are shorter at high pressures, slip effects are still important even though the density ratio of the phases approach one another as the droplets heat up. The model indicates the presence of a region where condensed water is present within the spray and provides a convenient means of treating supercritical phenomena.

  15. Tapered plug foam spray apparatus

    NASA Technical Reports Server (NTRS)

    Allen, Peter B. (Inventor)

    1996-01-01

    A two-component foam spray gun is readily disassembled for cleaning. It includes a body (1) with reactant (12, 14) and purge gas (16) inlet ports. A moldable valve packing (32) inside the body has a tapered conical interior surface (142), and apertures which match the reactant ports. A valve/tip (40) has a conical outer surface (48) which mates with the valve packing (32). The valve/tip (40) is held in place by a moldable packing washer (34), held at non-constant pressure by a screw (36, 38). The interior of the valve/tip (40) houses a removable mixing chamber (50). The mixing chamber (50) has direct flow orifices (60) and an auxiliary flow path (58, 60) which ameliorate pressure surges. The spray gun can be disassembled for cleaning without disturbing the seal, by removing the valve/tip (40) to the rear, thereby breaking it free of the conical packing. Rotation of the valve/tip (40) relative to the body (1) shuts off the reactant flow, and starts the purge gas flow.

  16. Atmospheric Chemistry: Nature's plasticized aerosols

    NASA Astrophysics Data System (ADS)

    Ziemann, Paul J.

    2016-01-01

    The structure of atmospheric aerosol particles affects their reactivity and growth rates. Measurements of aerosol properties over the Amazon rainforest indicate that organic particles above tropical rainforests are simple liquid drops.

  17. Palaeoclimate: Aerosols shift lake ecosystem

    NASA Astrophysics Data System (ADS)

    Dowsett, Harry J.

    2017-02-01

    Anthropogenic aerosols over the Chinese Loess Plateau have diminished monsoon precipitation and concomitant soil erosion that plagues the region. Now, a reconstruction documents the differences between historical warming events and the present, highlighting the paradoxical implications of decreasing atmospheric aerosols.

  18. Aerosol chemistry in GLOBE

    NASA Technical Reports Server (NTRS)

    Clarke, Antony D.; Rothermel, Jeffry; Jarzembski, Maurice A.

    1993-01-01

    This task addresses the measurement and understanding of the physical and chemical properties of aerosol in remote regions that are responsible for aerosol backscatter at infrared wavelengths. Because it is representative of other clean areas, the remote Pacific is of extreme interest. Emphasis is on the determination size dependent aerosol properties that are required for modeling backscatter at various wavelengths and upon those features that may be used to help understand the nature, origin, cycling and climatology of these aerosols in the remote troposphere. Empirical relationships will be established between lidar measurements and backscatter derived from the aerosol microphysics as required by the NASA Doppler Lidar Program. This will include the analysis of results from the NASA GLOBE Survey Mission Flight Program. Additional instrument development and deployment will be carried out in order to extend and refine this data base. Identified activities include participation in groundbased and airborne experiments. Progress to date includes participation in, analysis of, and publication of results from Mauna Loa Backscatter Intercomparison Experiment (MABIE) and Global Backscatter Experiment (GLOBE).

  19. ISS Ambient Air Quality: Updated Inventory of Known Aerosol Sources

    NASA Technical Reports Server (NTRS)

    Meyer, Marit

    2014-01-01

    Spacecraft cabin air quality is of fundamental importance to crew health, with concerns encompassing both gaseous contaminants and particulate matter. Little opportunity exists for direct measurement of aerosol concentrations on the International Space Station (ISS), however, an aerosol source model was developed for the purpose of filtration and ventilation systems design. This model has successfully been applied, however, since the initial effort, an increase in the number of crewmembers from 3 to 6 and new processes on board the ISS necessitate an updated aerosol inventory to accurately reflect the current ambient aerosol conditions. Results from recent analyses of dust samples from ISS, combined with a literature review provide new predicted aerosol emission rates in terms of size-segregated mass and number concentration. Some new aerosol sources have been considered and added to the existing array of materials. The goal of this work is to provide updated filtration model inputs which can verify that the current ISS filtration system is adequate and filter lifetime targets are met. This inventory of aerosol sources is applicable to other spacecraft, and becomes more important as NASA considers future long term exploration missions, which will preclude the opportunity for resupply of filtration products.

  20. MODIS Aerosol Optical Depth Bias Adjustment Using Machine Learning Algorithms

    NASA Astrophysics Data System (ADS)

    Albayrak, A.; Wei, J. C.; Petrenko, M.; Lary, D. J.; Leptoukh, G. G.

    2011-12-01

    Over the past decade, global aerosol observations have been conducted by space-borne sensors, airborne instruments, and ground-base network measurements. Unfortunately, quite often we encounter the differences of aerosol measurements by different well-calibrated instruments, even with a careful collocation in time and space. The differences might be rather substantial, and need to be better understood and accounted for when merging data from many sensors. The possible causes for these differences come from instrumental bias, different satellite viewing geometries, calibration issues, dynamically changing atmospheric and the surface conditions, and other "regressors", resulting in random and systematic errors in the final aerosol products. In this study, we will concentrate on the subject of removing biases and the systematic errors from MODIS (both Terra and Aqua) aerosol product, using Machine Learning algorithms. While we are assessing our regressors in our system when comparing global aerosol products, the Aerosol Robotic Network of sun-photometers (AERONET) will be used as a baseline for evaluating the MODIS aerosol products (Dark Target for land and ocean, and Deep Blue retrieval algorithms). The results of bias adjustment for MODIS Terra and Aqua are planned to be incorporated into the AeroStat Giovanni as part of the NASA ACCESS funded AeroStat project.

  1. Liposomal aerosols in the management of pulmonary infections.

    PubMed

    Gilbert, B E

    1996-01-01

    The combination of liposomes and aerosols has been utilized to directly target the lungs with chemotherapeutic agents that might not have been used because of low solubility or toxicity. There are a variety of antibacterials, antifungals, and antivirals that have good in vitro activity, but are not effective because of their systemic toxicity and/or poor penetration into the lungs. Incorporation of many lipophilic drugs into liposomes decreases their toxicity without affecting effectiveness, thus increasing the therapeutic index. We have focused on aerosol delivery of amphotericin B (ampB) for the treatment of pulmonary and systemic fungal diseases. We have tested a variety of ampB-lipid formulations for the optimal treatment regimen for Cryptococcus and Candida infections in mouse models. The AeroTech II nebulizer (MMADs of 1.8-2.2 microns) produced aerosols with the highest concentrations in the breathable range. Pharmacokinetic studies revealed that pulmonary drug was present for hours to weeks. AmBisome retained its anticryptococcal activity even when animals were challenged 14 days after aerosol treatment. Aerosols may also be effective in systemic diseases. In our Candida-mouse model, systemic candidiasis and mortality were reduced by aerosolized ampB-liposome treatment. The ability to utilize lipophilic drugs, to deliver high concentrations of drug directly to the site of infection, and to reduce toxicity makes aerosol liposomes an attractive, alternative route of administration.

  2. Reducing the Uncertainties in Direct Aerosol Radiative Forcing

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph A.

    2011-01-01

    Airborne particles, which include desert and soil dust, wildfire smoke, sea salt, volcanic ash, black carbon, natural and anthropogenic sulfate, nitrate, and organic aerosol, affect Earth's climate, in part by reflecting and absorbing sunlight. This paper reviews current status, and evaluates future prospects for reducing the uncertainty aerosols contribute to the energy budget of Earth, which at present represents a leading factor limiting the quality of climate predictions. Information from satellites is critical for this work, because they provide frequent, global coverage of the diverse and variable atmospheric aerosol load. Both aerosol amount and type must be determined. Satellites are very close to measuring aerosol amount at the level-of-accuracy needed, but aerosol type, especially how bright the airborne particles are, cannot be constrained adequately by current techniques. However, satellite instruments can map out aerosol air mass type, which is a qualitative classification rather than a quantitative measurement, and targeted suborbital measurements can provide the required particle property detail. So combining satellite and suborbital measurements, and then using this combination to constrain climate models, will produce a major advance in climate prediction.

  3. The Impact of Geoengineering Aerosols on Stratospheric Temperature and Ozone

    NASA Technical Reports Server (NTRS)

    Heckendorn, P.; Weisenstein, D.; Fueglistaler, S.; Luo, B. P.; Rozanov, E.; Schraner, M.; Thomason, L. W.; Peter, T.

    2011-01-01

    Anthropogenic greenhouse gas emissions are warming the global climate at an unprecedented rate. Significant emission reductions will be required soon to avoid a rapid temperature rise. As a potential interim measure to avoid extreme temperature increase, it has been suggested that Earth's albedo be increased by artificially enhancing stratospheric sulfate aerosols. We use a 3D chemistry climate model, fed by aerosol size distributions from a zonal mean aerosol model. to simulate continuous injection of 1-10 Mt/a into the lower tropical stratosphere. In contrast to the case for all previous work, the particles are predicted to grow to larger sizes than are observed after volcanic eruptions. The reason is the continuous supply of sulfuric acid and hence freshly formed small aerosol particles, which enhance the formation of large aerosol particles by coagulation and, to a lesser extent, by condensation. Owing to their large size, these particles have a reduced albedo. Furthermore, their sedimentation results in a non-linear relationship between stratospheric aerosol burden and annual injection, leading to a reduction of the targeted cooling. More importantly, the sedimenting particles heat the tropical cold point tropopause and, hence, the stratospheric entry mixing ratio of H2O increases. Therefore, geoengineering by means of sulfate aerosols is predicted to accelerate the hydroxyl catalyzed ozone destruction cycles and cause a significant depletion of the ozone layer even though future halogen concentrations will he significantly reduced.

  4. The Impact of Geoengineering Aerosols on Stratospheric Temperature and Ozone

    NASA Technical Reports Server (NTRS)

    Heckendorn, P.; Weisenstein, D.; Fueglistaler, S.; Luo, B. P.; Rozanov, E.; Schraner, M.; Peter, T.; Thomason, L. W.

    2009-01-01

    Anthropogenic greenhouse gas emissions are warming the global climate at an unprecedented rate. Significant emission reductions will be required soon to avoid a rapid temperature rise. As a potential interim measure to avoid extreme temperature increase, it has been suggested that Earth's albedo be increased by artificially enhancing stratospheric sulfate aerosols. We use a 3D chemistry climate model, fed by aerosol size distributions from a zonal mean aerosol model, to simulate continuous injection of 1-10 Mt/a into the lower tropical stratosphere. In contrast to the case for all previous work, the particles are predicted to grow to larger sizes than are observed after volcanic eruptions. The reason is the continuous supply of sulfuric acid and hence freshly formed small aerosol particles, which enhance the formation of large aerosol particles by coagulation and, to a lesser extent, by condensation. Owing to their large size, these particles have a reduced albedo. Furthermore, their sedimentation results in a non-linear relationship between stratospheric aerosol burden and annual injection, leading to a reduction of the targeted cooling. More importantly, the sedimenting particles heat the tropical cold point tropopause and, hence, the stratospheric entry mixing ratio of H2O increases. Therefore, geoengineering by means of sulfate aerosols is predicted to accelerate the hydroxyl catalyzed ozone destruction cycles and cause a significant depletion of the ozone layer even though future halogen concentrations will be significantly reduced.

  5. Screening for inhibitors of histone deacetylase by incorporating a spraying method to micro-arrayed compound screening.

    PubMed

    Sabet, R S; Marcotte, P; Glaser, K; Burns, D J; Warrior, U; Groebe, D R

    2004-03-01

    We have developed a method of spraying assay reagents onto a target gel in the Micro-Arrayed Compound Screening ( micro ARCS) format. After application of target gels to compound sheets, subsequent reagents can be applied by spraying onto the target gel. The spraying method conserves on assay reagents by up to 10-fold, eliminates the need for casting additional agarose gels, and increases the throughput of a screen by 3-fold. To demonstrate the efficacy of applying the spraying method to micro ARCS, we screened over 600,000 compounds for inhibitors of histone deacetylase (HDAC). Commercially available HDAC substrate and reaction developer were sprayed directly onto the gel to initiate the reaction and to amplify the signal, respectively. Picks in the primary screen were retested at a density of 384 compounds per sheet in the micro ARCS format. IC(50) values for active compounds were confirmed in a 96-well plate assay. The screen identified several small molecule inhibitors of the enzyme, including members of several classes of known HDAC inhibitors. The combination of the high-density format of micro ARCS, the efficiency of the spraying method, and a timed sequence of adding assay reagents permitted a screening throughput of 200,000 tests an hour. We present the details of the screening format and the analysis of the hits from the screen.

  6. Chemical aerosol Raman detector

    NASA Astrophysics Data System (ADS)

    Aggarwal, R. L.; Farrar, L. W.; Di Cecca, S.; Amin, M.; Perkins, B. G.; Clark, M. L.; Jeys, T. H.; Sickenberger, D. W.; D'Amico, F. M.; Emmons, E. D.; Christesen, S. D.; Kreis, R. J.; Kilper, G. K.

    2017-03-01

    A sensitive chemical aerosol Raman detector (CARD) has been developed for the trace detection and identification of chemical particles in the ambient atmosphere. CARD includes an improved aerosol concentrator with a concentration factor of about 40 and a CCD camera for improved detection sensitivity. Aerosolized isovanillin, which is relatively safe, has been used to characterize the performance of the CARD. The limit of detection (SNR = 10) for isovanillin in 15 s has been determined to be 1.6 pg/cm3, which corresponds to 6.3 × 109 molecules/cm3 or 0.26 ppb. While less sensitive, CARD can also detect gases. This paper provides a more detailed description of the CARD hardware and detection algorithm than has previously been published.

  7. Spray deposition inside tree canopies from a newly developed variable-rate air assisted sprayer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional spray applications in orchards and ornamental nurseries are not target-oriented, resulting in significant waste of pesticides and contamination of the environment. To address this problem, a variable-rate air-assisted sprayer implementing laser scanning technology was developed to apply...

  8. Heat Flux Analysis of a Reacting Thermite Spray Impingent on a Substrate

    SciTech Connect

    Eric S. Collins; Michelle L. Pantoya; Michael A. Daniels; Daniel J. Prentice; Eric D. Steffler; Steven P. D'Arche

    2012-03-01

    Spray combustion from a thermite reaction is a new area of research relevant to localized energy generation applications, such as welding or cutting. In this study, we characterized the heat flux of combustion spray impinging on a target from a nozzle for three thermite mixtures. The reactions studied include aluminum (Al) with iron oxide (Fe2O3), Al with copper oxide (CuO), and Al with molybdenum oxide (MoO3). Several standoff distances (i.e., distance from the nozzle exit to the target) were analyzed. A fast response heat flux sensor was engineered for this purpose and is discussed in detail. Results correlated substrate damage to a threshold heat flux of 4550 W/cm2 for a fixed-nozzle configuration. Also, higher gas-generating thermites were shown to produce a widely dispersed spray and be less effective at imparting kinetic energy damage to a target. These results provide an understanding of the role of thermal and physical properties (i.e., such as heat of combustion, gas generation, and particle size) on thermite spray combustion performance measured by damaging a target substrate.

  9. EPA Reaches Agreement with Manufacturer to Stop Use of TCE in Spray Fixative Products Used on Arts and Crafts/EPA also taking regulatory action to reduce exposure to this chemical

    EPA Pesticide Factsheets

    WASHINGTON - The U.S. Environmental Protection Agency (EPA) has reached an agreement with a manufacturer to voluntarily phase-out the use of trichloroethylene (TCE) in an aerosol arts and crafts spray fixative product as part of EPA's ongoing efforts

  10. Global estimation of above-cloud aerosols using spaceborne LIDAR

    NASA Astrophysics Data System (ADS)

    Chand, D.; Wood, R.; Anderson, T. L.; Satheesh, S. K.; Leahy, L.

    2008-12-01

    Estimates of global mean direct climate forcing by absorbing aerosols located above boundary layer clouds are large, uncertain, and almost entirely unconstrained by observations. Spaceborne lidar offers a new opportunity of estimating the aerosols at global scale. Here we use two recently available techniques quantifying the above-cloud aerosols using liquid water clouds as lidar targets from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) [Chand et al., 2008]. Both methods can quantify aerosols above clouds and are based on their self-calibrating techniques. We used one year of global data between 70N-70S to show that day time calibration constants are different than night time calibrations constants. A clear latitudinal dependence is observed in the calibrations constants in CALIPSO observations. Using these 'self-calibration' constants, aerosol optical depth (AOD) and angstrom exponent (AE) of 'above- cloud' aerosols are quantified. Biomass burning is a major source of fine mode aerosols in different regions of world. For example, it is observed that June is the onset of the biomass burning fires in Southern Africa, peaking in August and September and then slowly decreasing until November, with a corresponding signature in aerosol optical depth. Layers with aerosol optical depth greater than 0.3 are commonly observed up to several thousand kilometers away from Africa over the Atlantic Ocean. The 'above-cloud' AOD as high as 1.5 is observed in the peak months. Despite of large variations is AOD, mean AE of these aerosols is about 1.6, without any systematic variability away from the source region. The results estimating the aerosols above clouds, including other regions at global scale, will be presented in the AGU meeting. Chand, D., T. L. Anderson, R. Wood, R. J. Charlson, Y. Hu, Z. Liu, and M. Vaughan (2008), Quantifying above-cloud aerosol using spaceborne lidar for improved understanding of cloudy-sky direct climate forcing, J

  11. Multi- year Arctic and Antarctic aerosol chemical characterization

    NASA Astrophysics Data System (ADS)

    Udisti, Roberto; Becagli, Silvia; Caiazzo, Laura; Calzolai, Giulia; Cappelletti, David; Giardi, Fabio; Grotti, Marco; Malandrino, Mery; Nava, Silvia; Severi, Mirko; Traversi, Rita

    2016-04-01

    Long term measurements of aerosol chemical composition in polar region are particularly relevant to investigate potential climatic effects of atmospheric components arising from both natural and anthropogenic emissions. In order to improve our knowledge on the atmospheric load and chemical composition of polar aerosol, several measurements and sampling campaigns were carried out both in Antarctica and in the Arctic since 2005.The main results are here reported. As regard as Antarctica, a continuous all-year-round sampling of size-segregated aerosol was carried from 2005 to 2013 at Dome C (East Antarctica; 75° 60' S, 123° 200' E, 3220 m a.s.l. and 1100 km away from the nearest coast). Aerosol was collected by PM10 and PM2.5 samplers and by multi-stage impactors (Dekati 4-stage impactor). Chemical analysis was carried out by Ion Chromatography (ions composition) and ICP-MS (trace metals). Sea spray showed a sharp seasonal pattern, with winter (Apr-Nov) concentrations about ten times larger than summer (Dec-Mar). Besides, in winter, sea spray particles are mainly sub micrometric, while the summer size-mode is around 1-2 um. Meteorological analysis and air mass back trajectory reconstructions allowed the identification of two major air mass pathways: micrometric fractions for transport from the closer Indian-Pacific sector, and sub-micrometric particles for longer trajectories over the Antarctic Plateau. The markers of oceanic biogenic emission (methanesulfonic acid - MSA, and non-sea-salt sulphate) exhibit a seasonal cycle with summer maxima (Nov-Mar). Their size distributions show two modes (0.4- 0.7 um and 1.1-2.1 um) in early summer and just one sub-micrometric mode in full summer. The two modes are related to different transport pathways. In early summer, air masses came primarily from the Indian Ocean and spent a long time over the continent. The transport of sulphur compounds is related to sea spray aerosols and the resulting condensation of H2SO4 and MSA over

  12. Stratospheric Aerosol Measurements

    NASA Technical Reports Server (NTRS)

    Pueschel, Rudolf, F.; Gore, Warren J. (Technical Monitor)

    1998-01-01

    Stratospheric aerosols affect the atmospheric energy balance by scattering and absorbing solar and terrestrial radiation. They also can alter stratospheric chemical cycles by catalyzing heterogeneous reactions which markedly perturb odd nitrogen, chlorine and ozone levels. Aerosol measurements by satellites began in NASA in 1975 with the Stratospheric Aerosol Measurement (SAM) program, to be followed by the Stratospheric Aerosol and Gas Experiment (SAGE) starting in 1979. Both programs employ the solar occultation, or Earth limb extinction, techniques. Major results of these activities include the discovery of polar stratospheric clouds (PSCs) in both hemispheres in winter, illustrations of the impacts of major (El Chichon 1982 and Pinatubo 1991) eruptions, and detection of a negative global trend in lower stratospheric/upper tropospheric aerosol extinction. This latter result can be considered a triumph of successful worldwide sulfur emission controls. The SAGE record will be continued and improved by SAGE III, currently scheduled for multiple launches beginning in 2000 as part of the Earth Observing System (EOS). The satellite program has been supplemented by in situ measurements aboard the ER-2 (20 km ceiling) since 1974, and from the DC-8 (13 km ceiling) aircraft beginning in 1989. Collection by wire impactors and subsequent electron microscopic and X-ray energy-dispersive analyses, and optical particle spectrometry have been the principle techniques. Major findings are: (1) The stratospheric background aerosol consists of dilute sulfuric acid droplets of around 0.1 micrometer modal diameter at concentration of tens to hundreds of monograms per cubic meter; (2) Soot from aircraft amounts to a fraction of one percent of the background total aerosol; (3) Volcanic eruptions perturb the sulfuric acid, but not the soot, aerosol abundance by several orders of magnitude; (4) PSCs contain nitric acid at temperatures below 195K, supporting chemical hypotheses

  13. Highly stable aerosol generator

    SciTech Connect

    DeFord, Henry S.; Clark, Mark L.

    1981-01-01

    An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly.

  14. Highly stable aerosol generator

    DOEpatents

    DeFord, H.S.; Clark, M.L.

    1981-11-03

    An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly. 2 figs.

  15. LSPRAY-IV: A Lagrangian Spray Module

    NASA Technical Reports Server (NTRS)

    Raju, M. S.

    2012-01-01

    LSPRAY-IV is a Lagrangian spray solver developed for application with parallel computing and unstructured grids. It is designed to be massively parallel and could easily be coupled with any existing gas-phase flow and/or Monte Carlo Probability Density Function (PDF) solvers. The solver accommodates the use of an unstructured mesh with mixed elements of either triangular, quadrilateral, and/or tetrahedral type for the gas flow grid representation. It is mainly designed to predict the flow, thermal and transport properties of a rapidly vaporizing spray. Some important research areas covered as a part of the code development are: (1) the extension of combined CFD/scalar-Monte- Carlo-PDF method to spray modeling, (2) the multi-component liquid spray modeling, and (3) the assessment of various atomization models used in spray calculations. The current version contains the extension to the modeling of superheated sprays. The manual provides the user with an understanding of various models involved in the spray formulation, its code structure and solution algorithm, and various other issues related to parallelization and its coupling with other solvers.

  16. Assessing effects of esfenvalerate aerosol applications on resident populations of Tribolium castaneum (Herbst), the red flour beetle, through direct and indirect sampling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Small-scale field sheds were infested with resident populations of the red flour beetle, Tribolium castaneum (Herbst), and either left untreated or treated every two or four weeks with an aerosol spray of esfenvalerate (Conquer ®). The sheds were infested by placing flour food patches underneath she...

  17. 40 CFR 61.146 - Standard for spraying.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... spray applied shall comply with the following requirements: (a) For spray-on application on buildings... Microscopy, except as provided in paragraph (c) of this section. (b) For spray-on application of materials... requirements of this paragraph. (2) Discharge no visible emissions to the outside air from spray-on...

  18. DRIFTSIM, A Computer Program for Estimating Spray Drift Distances

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the severe problems with spraying pesticides is the spray drift. Drift is a problem if chemicals are sprayed too close to residential areas, livestock facilities, bodies of water, or sensitive crops. Complaints regarding spray drift are routinely brought to state departments of agriculture,...

  19. Ground-based Network and Supersite Measurements for Studying Aerosol Properties and Aerosol-Cloud Interactions

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee; Holben, Brent N.

    2008-01-01

    From radiometric principles, it is expected that the retrieved properties of extensive aerosols and clouds from reflected/emitted measurements by satellite (and/or aircraft) should be consistent with those retrieved from transmitted/emitted radiance observed at the surface. Although space-borne remote sensing observations contain large spatial domain, they are often plagued by contamination of surface signatures. Thus, ground-based in-situ and remote-sensing measurements, where signals come directly from atmospheric constituents, the sun, and the Earth-atmosphere interactions, provide additional information content for comparisons that confirm quantitatively the usefulness of the integrated surface, aircraft, and satellite datasets. The development and deployment of AERONET (AErosol RObotic NETwork) sunphotometer network and SMART-COMMIT (Surface-sensing Measurements for Atmospheric Radiative Transfer - Chemical, Optical & Microphysical Measurements of In-situ Troposphere) mobile supersite are aimed for the optimal utilization of collocated ground-based observations as constraints to yield higher fidelity satellite retrievals and to determine any sampling bias due to target conditions. To characterize the regional natural and anthropogenic aerosols, AERONET is an internationally federated network of unique sunphotometry that contains more than 250 permanent sites worldwide. Since 1993, there are more than 480 million aerosol optical depth observations and about 15 sites have continuous records longer than 10 years for annual/seasonal trend analyses. To quantify the energetics of the surface-atmosphere system and the atmospheric processes, SMART-COMMIT instrument into three categories: flux radiometer, radiance sensor and in-situ probe. Through participation in many satellite remote-sensing/retrieval and validation projects over eight years, SMART-COMMIT have gradually refine( and been proven vital for field deployment. In this paper, we will demonstrate the

  20. High-efficiency particulate air filter test stand and aerosol generator for particle loading studies.

    PubMed

    Arunkumar, R; Hogancamp, Kristina U; Parsons, Michael S; Rogers, Donna M; Norton, Olin P; Nagel, Brian A; Alderman, Steven L; Waggoner, Charles A

    2007-08-01

    This manuscript describes the design, characterization, and operational range of a test stand and high-output aerosol generator developed to evaluate the performance of 30 x 30 x 29 cm(3) nuclear grade high-efficiency particulate air (HEPA) filters under variable, highly controlled conditions. The test stand system is operable at volumetric flow rates ranging from 1.5 to 12 standard m(3)/min. Relative humidity levels are controllable from 5%-90% and the temperature of the aerosol stream is variable from ambient to 150 degrees C. Test aerosols are produced through spray drying source material solutions that are introduced into a heated stainless steel evaporation chamber through an air-atomizing nozzle. Regulation of the particle size distribution of the aerosol challenge is achieved by varying source solution concentrations and through the use of a postgeneration cyclone. The aerosol generation system is unique in that it facilitates the testing of standard HEPA filters at and beyond rated media velocities by consistently providing, into a nominal flow of 7 standard m(3)/min, high mass concentrations (approximately 25 mg/m(3)) of dry aerosol streams having count mean diameters centered near the most penetrating particle size for HEPA filters (120-160 nm). Aerosol streams that have been generated and characterized include those derived from various concentrations of KCl, NaCl, and sucrose solutions. Additionally, a water insoluble aerosol stream in which the solid component is predominantly iron (III) has been produced. Multiple ports are available on the test stand for making simultaneous aerosol measurements upstream and downstream of the test filter. Types of filter performance related studies that can be performed using this test stand system include filter lifetime studies, filtering efficiency testing, media velocity testing, evaluations under high mass loading and high humidity conditions, and determination of the downstream particle size distributions.

  1. Development of a model for characterizing pneumatically generated primary aerosols for inductively coupled plasma emission spectrometry

    SciTech Connect

    Msimanga, N.D.G.

    1992-01-01

    The study of aerosols plays a key role in the development of analytical atomic spectroscopy. While work has been carried out with Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) to improve transport efficiency, analyte signal, limits of detection, and to reduce matrix interferences, little study has focused on sample introduction processes. This study has focused on the characterization and optimization of pneumatic nebulizers used for liquid sample introduction to the ICP. Pneumatic nebulization is the most common means of sample introduction in atomic spectrometry. The pneumatic nebulizers most commonly used today for ICP spectrometry are the cross-flow type or all-glass concentric nebulizers. Aerosols undergo certain processes after the primary formation process before reaching the atomizer, the secondary and tertiary stages. In this work all three stages were looked at, focusing on the primary aerosols. The primary aerosol is the first stage in the formation of the aerosols and takes place at the tip of the nebulizer, as the liquid stream is shattered by the gas flow. The drop size diameters of primary aerosols were measured using a Fraunhofer Laser Diffraction instrument. The Sauter mean diameter (D3.2), which describes the volume of the aerosol with a given surface area, was determined for nebulizers at spray chambers operated under a variety of conditions. The characterization and optimization of sample introduction involved a study of aerosol technology, a study of different instruments for measuring the mean drop size, a description of the instrument, and the influence of some parameters on the D3.2. An empirical model summarizing the characteristics of the primary aerosols is proposed. Modeling is carried out using nonlinear software. The data for modelling were acquired using water, n-butanol, and methanol as the liquid solvents. The model was tested on data obtained from nebulizers with different cross-sectional areas.

  2. New Insights On The Link Between Oceanic Vegetation and Marine Organic Aerosol

    NASA Astrophysics Data System (ADS)

    Facchini, M.; Rinaldi, M.; Decesari, S.; Finessi, E.; Carbone, C.; Fuzzi, S.; Ceburnis, D.; O'Dowd, C.

    2008-12-01

    Until a few years ago the link between vegetation and aerosol particles in marine environment was centered on the DMS emission from phytoplankton and the sulphur cycle. More recently, observation carried out in the North Atlantic as well as in other marine locations evidenced a seasonal dependence of sub micron particle chemical composition on biological oceanic activity and a potentially important marine aerosol organic component from primary and/or secondary formation processes associated to marine vegetation and its seasonal cycle. Here we show recent results obtained within the EC project MAP which allowed to discriminate primary and secondary organic marine aerosol components of biogenic origin. Bubble-mediated experiments carried out during phytoplankton blooms in the North Atlantic revealed that organic carbon in nascent submicron spray particles was highly enriched in the finest fraction, constituting up to 77 % in mass of the aerosol in the 0.125-0.25 micrometer size range and was almost entirely water insoluble (96% on average). 1H NMR analysis showed that WIOM in nascent marine aerosol forms from aggregation of lipopolysaccharides exuded by phytoplankton. Being marine aerosol WIOC mainly associated to primary production mechanisms, a direct consequence of this observation is that the water soluble fraction (WSOC) is mainly accounted for by secondary organic aerosol. This fact was also clearly evidenced by the analysis of the WSOC fraction of marine aerosol samples collected during MAP. The aerosol WSOC was dominated by MSA and two organic N species (ammonium salts of biogenic amines) and by several oxygenated species (mainly carboxylic acids and ketons). These results evidence the important contribution of organic nitrogen in North Atlantic marine SOA.

  3. Spray-formed tooling and aluminum strip

    SciTech Connect

    McHugh, K.M.

    1995-11-01

    Spray forming is an advanced materials processing technology that converts a bulk liquid metal to a near-net-shape solid by depositing atomized droplets onto a suitably shaped substrate. By combining rapid solidification processing with product shape control, spray forming can reduce manufacturing costs while improving product quality. De Laval nozzles offer an alternative method to the more conventional spray nozzle designs. Two applications are described: high-volume production of aluminum alloy strip, and the production of specialized tooling, such as injection molds and dies, for rapid prototyping.

  4. Diazinon residues in insects from sprayed tobacco

    USGS Publications Warehouse

    Stromborg, K.L.; Beyer, W.N.; Kolbe, E.

    1982-01-01

    Pooled samples of tobacco hornworms collected from a field sprayed with 0.84 kg/ha of diazinon were analyzed for residues at various intervals after application. No residues of the toxic metabolite diazoxon were detected (sensitivity 0.5 ppm) in any sample. Only one sample exceeded 1.0 ppm of the parent compound and was collected 4 hours after spraying. Residues declined over time (P<0.01) and none were detected (sensitivity 0.1 ppm) 18 days after spraying. the potential hazard to birds eating these insects appeared to be minimal.

  5. Laser Sheet Dropsizing of dense sprays

    NASA Astrophysics Data System (ADS)

    Le Gal, P.; Farrugia, N.; Greenhalgh, D. A.

    1999-02-01

    A new technique has been developed that produces instantaneous or time-averaged two-dimensional images of Sauter Mean Diameter from a spray. Laser Sheet Dropsizing (LSD) combines elastic and inelastic light scattered from a laser sheet. Compared with Phase Doppler Anemometry (PDA), the new technique offers advantages in increased spatial and temporal resolution and more rapid spray characterisation. Moreover, the technique can also be applied to dense sprays. Successful implementation requires careful calibration, particularly of the effect of dye concentration on the dropsize dependence of the inelastic scattered light.

  6. Organophosphate residues in grasshoppers from sprayed rangelands

    USGS Publications Warehouse

    Stromborg, K.L.; McEwen, L.C.; Lamont, Thair

    1984-01-01

    Grasshoppers (Orthoptera) were collected in pastures that had been sprayed with malathion and acephate to estimate the secondary exposure of insectivorous birds to these pesticides. Residues of malathion were below 3 ppm at 30 'and 54 hours after spraying and no malaoxon was detected. In contrast, acephate was found at 8 and 9 ppm 4 hours after spray; 3-5 ppm of the toxic metabolite methamidophos were also detected at that time. By 53 hours postspray, acephate levels declined to 2 ppm and methamidophos to less than 1 ppm. These results suggest that although malathion may not be a hazard to insectivorous species. acephate may be hazardous through metabolic transformation to methamidophos.

  7. Laser Doppler velocimeter aerial spray measurements

    NASA Technical Reports Server (NTRS)

    Zalay, A. D.; Eberle, W. R.; Howle, R. E.; Shrider, K. R.

    1978-01-01

    An experimental research program for measuring the location, spatial extent, and relative concentration of airborne spray clouds generated by agricultural aircraft is described. The measurements were conducted with a ground-based laser Doppler velocimeter. The remote sensing instrumentation, experimental tests, and the results of the flight tests are discussed. The cross section of the aerial spray cloud and the observed location, extent, and relative concentration of the airborne particulates are presented. It is feasible to use a mobile laser Doppler velocimeter to track and monitor the transport and dispersion of aerial spray generated by an agricultural aircraft.

  8. Environmental and human health risks of aerosolized silver nanoparticles.

    PubMed

    Quadros, Marina E; Marr, Linsey C

    2010-07-01

    Silver nanoparticles (AgNPs) are gaining attention from the academic and regulatory communities, not only because of their antimicrobial effects and subsequent product applications, but also because of their potential health and environmental risks. Whereas AgNPs in the aqueous phase are under intensive study, those in the atmosphere have been largely overlooked, although it is well established that inhalation of nanoparticles is associated with adverse health effects. This review summarizes the present state of knowledge concerning airborne AgNPs to shed light on the possible environmental exposure scenarios that may accompany the production and popularization of silver nanotechnology consumer products. The current understanding of the toxicity of AgNPs points toward a potential threat via the inhalation exposure route. Nanoparticle size, chemical composition, crystal structure, surface area, and the rate of silver ion release are expected to be important variables in determining toxicity. Possible routes of aerosolization of AgNPs from the production, use, and disposal of existing consumer products are presented. It is estimated that approximately 14% of silver nanotechnology products that have been inventoried could potentially release silver particles into the air during use, whether through spraying, dry powder dispersion, or other methods. In laboratory and industrial settings, six methods of aerosolization have been used to produce airborne AgNPs: spray atomization, liquid-flame spray, thermal evaporation-condensation, chemical vaporization, dry powder dispersion, and manual handling. Fundamental uncertainties remain about the fate of AgNPs in the environment, their short- and long-term health effects, and the specific physical and chemical properties of airborne particles that are responsible for health effects. Thus, to better understand the risks associated with silver nanotechnology, it is vital to understand the conditions under which AgNPs could become

  9. Large-scale sodium spray fire code validation (SOFICOV) test

    SciTech Connect

    Jeppson, D.W.; Muhlestein, L.D.

    1985-01-01

    A large-scale, sodium, spray fire code validation test was performed in the HEDL 850-m/sup 3/ Containment System Test Facility (CSTF) as part of the Sodium Spray Fire Code Validation (SOFICOV) program. Six hundred fifty eight kilograms of sodium spray was sprayed in an air atmosphere for a period of 2400 s. The sodium spray droplet sizes and spray pattern distribution were estimated. The containment atmosphere temperature and pressure response, containment wall temperature response and sodium reaction rate with oxygen were measured. These results are compared to post-test predictions using SPRAY and NACOM computer codes.

  10. Influence of formulation and preparation process on ambroxol hydrochloride dry powder inhalation characteristics and aerosolization properties.

    PubMed

    Ren, Yachao; Yu, Chaoqun; Meng, Kangkang; Tang, Xing

    2008-09-01

    The objective of this study is to evaluate the influence of formulation and preparation process on ambroxol hydrochloride (AH) dry powder inhalation (DPI) characteristics and aerosolization properties. Spray-dried samples of AH, AH/leucine, and AH/leucine/mannitol were prepared from their corresponding water solutions under the same conditions to study the influence of the composition, and the AH/leucine/mannitol (2.5/0.5/1 by weight) formulation was used for investigation of the effect of the preparation process. Following spray-drying, the resulting powders were characterized using scanning electron microscopy, laser diffraction, tapped density, and angle of repose measurements, and the aerosolization performance was determined using a twin-stage liquid impinger. AH/leucine/mannitol (2.5/0.5/1 by weight) obtained by cospray-drying improved the AH aerosolization properties. The AH/leucine/mannitol (2.5/0.5/1 by weight) preparation exhibited the following properties: 62.34% yield, 0.34 g/cm(3) tap density, 2.71 microm d(ae), 33.45 degrees angle of repose, and 30.93% respirable fraction. The influence of the preparation process on DPI characteristics and aerosolization properties was relatively small, but the influence of the composition was relatively large. Optimization of DPI can be achieved by selecting the most appropriate formulation and preparation process.

  11. Size-Resolved Chemical Analysis of Individual Atmospheric Aerosols near Barrow, Alaska

    NASA Astrophysics Data System (ADS)

    Gunsch, M.; Barrett, T. E.; Sheesley, R. J.; Pratt, K.

    2015-12-01

    Climate change is having noticeable impacts on the Arctic with increasing temperatures and decreasing sea ice coverage. Loss of sea ice is leading to development of oil and gas extraction activities and increased shipping in the Arctic. Arctic aerosol emissions are expected to increase with increasing anthropogenic activities and production of sea spray aerosol. These particles have significant climate effects, including interacting with radiation, forming cloud droplets and ice crystals, and depositing onto surfaces. Given the complexity and evolving nature of atmospheric particles, as well as the challenges associated with Arctic measurements, significant uncertainties remain in our understanding of particle sources, evolution, and impacts in the Arctic. To investigate the size and chemistry of individual particles in real-time, an aerosol time-of-flight mass spectrometer (ATOFMS) was deployed to Barrow, Alaska during August-September 2015. Parallel size-resolved number concentration measurements allow the quantification of number and mass concentrations of particles from various sources, including sea spray aerosol, biomass burning, and diesel combustion, for example.

  12. Solvent vapor exposures in booth spray painting and spray glueing, and associated operations.

    PubMed

    Whitehead, L W; Ball, G L; Fine, L J; Langolf, G D

    1984-11-01

    Time-weighted average exposures for all solvents present at detectable levels were obtained for eighty-nine solvent-using workers and thirty-six control-group (unexposed) workers in seven plants of three companies applying paints and glues, primarily by spraying. Over twenty solvents were quantified if detected. Concentrations of specific solvents and cumulative fractions of TLVs were measured for various job types. All spray painting and most spray glueing was conducted in operating spray booths. Only low to moderate exposures were observed, with one TWA exceeding the cumulative TLV and three additional TWAs exceeding 50 percent of the cumulative TLV. It may be concluded that solvent TWA exposures in spraying of paints and glues are often well-controlled by common spray booths, and further, that other solvent-use operations including light-duty solvent wiping and manual paint mixing do not frequently produce high exposures (relative to TLV levels) in the presence of ordinary general room ventilation.

  13. Representation of the vaporization behavior of turbulent polydisperse sprays by 'equivalent' monodisperse sprays

    NASA Technical Reports Server (NTRS)

    Aggarwal, S. K.; Shuen, J. S.

    1987-01-01

    The concept of using an equivalent monodisperse spray to represent the vaporization behavior of polydisperse sprays has been examined by numerically solving two turbulent vaporizing sprays. One involves the injection of Freon-11 in a still environment, whereas the other is a methanol spray in a still but hot environment. The use of three different mean sizes, namely, Sauter mean diameter, volume median diameter, and surface-area mean diameter, has been investigated. Results indicate a good degree of correlation between the polydisperse spray and its equivalent monodisperse sprays represented by the volume median diameter and the Sauter mean diameter, the former giving slightly better results. The surface-area mean diameter does not provide as good a correlation as the other two mean diameters.

  14. Representation of the vaporization behavior of turbulent polydisperse sprays by equivalent monodisperse sprays

    NASA Technical Reports Server (NTRS)

    Aggarwal, S. K.; Shuen, J. S.

    1986-01-01

    The concept of using an equivalent monodisperse spray to represent the vaporization behavior of polydisperse sprays has been examined by numerically solving two turbulent vaporizing sprays. One involves the injection of Freon-11 in a still environment, whereas the other is a methanol spray in a still but hot environment. The use of three different mean sizes, namely, Sauter mean diameter, volume median diameter, and surface-area mean diameter, has been investigated. Results indicate a good degree of correlation between the polydisperse spray and its equivalent monodisperse sprays represented by the volume median diameter and the Sauter mean diameter, the former giving slightly better results. The surface-area mean diameter does not provide as good a correlation as the other two mean diameters.

  15. Visual characterization of heated water spray jet breakup induced by full cone spray nozzles

    NASA Astrophysics Data System (ADS)

    Naz, M. Y.; Sulaiman, S. A.; Ariwahjoedi, B.; Zilati, K.

    2015-03-01

    The present work with specific objectives places a greater emphasis on measurements of the breakup lengths and phenomenological analysis of a hot water jet under reduced pumping pressures in still environment. Therefore, visual and comparative studies are conducted on full cone jet disintegration of heated water for low pumping pressures. A further analysis of the grabbed images confirms the strong influence of the input processing parameters on full cone spray patternation. It is also predicted that the heated liquids generate a dispersed spray pattern by utilizing partial evaporation of the spraying medium. The radial spray cone width and angle do not vary significantly with increasing Reynolds and Weber numbers at early injection phases, leading to enhanced macroscopic spray propagation. The discharge coefficient, mean flow rate, and mean flow velocity are significantly influenced by the load pressure, but less affected by the temperature. The fine scale image analysis also predicts toroidal-shaped vortex formation in the spray structure near the water boiling point.

  16. Influence of aircraft vortices on spray cloud behavior.

    PubMed

    Mickle, R E

    1996-06-01

    For small droplet spraying, the spray cloud is initially entrained into the wingtip vortices so that the ultimate fate of the spray is controlled by the motion of these vortices. In close to 100 aerial sprays, the emitted spray cloud has been mapped using a scanning laser system that displays diffusion and transport of the spray cloud. Results detailing the concentrations within the spray cloud in space and time are given for sprays in parallel and crosswinds. Wind direction is seen to potentially alter the vortex motion and hence the fate of the spray cloud. In crosswind spraying, the vortex behavior associated with the 2 wings is found to differ, which leads to enhanced deposition from the upwind wing and enhanced drift from the downwind wing.

  17. Metered Cryospray™: a novel uniform, controlled, and consistent in vivo application of liquid nitrogen cryogenic spray

    PubMed Central

    Mulcahey, Thomas I; Coad, James E; Fan, Wei Li; Grasso, Daniel J; Hanley, Brian M; Hawkes, Heather V; McDermott, Sean A; O’Connor, John P; Sheets, Ellen E; Vadala, Charles J

    2017-01-01

    In this article, a novel cryotherapy approach using a uniform, controlled, and consistent in vivo application of liquid nitrogen (LN2) spray as a Metered Cryospray™ (MCS) process is described. Although MCS may be used for many potential clinical applications, this paper focuses on the development that led to the controlled and consistent delivery of radial LN2 cryogen spray in order to generate a uniform circumferential effect and how the amount of MCS can be adapted to specifically ablate targeted diseases within a patient’s lumen such as an airway or esophagus. PMID:28255257

  18. Evaluation of Convergent Spray Technology(TM) Spray Process for Roof Coating Application

    NASA Technical Reports Server (NTRS)

    Scarpa, J.; Creighton, B.; Hall, T.; Hamlin, K.; Howard, T.

    1998-01-01

    The overall goal of this project was to demonstrate the feasibility of(CST) Convergent Spray Technology (Trademark) for the roofing industry. This was accomplished by producing an environmentally compliant coating utilization recycled materials, a CST(Trademark) spray process portable application cart, and hand-held applicator with a CST(Trademark) spray process nozzle. The project culminated with application of this coating to a nine hundred sixty square foot metal for NASA Marshall Space Flight Center (MSFC) in Huntsville, Alabama.

  19. Improvement of Representation of the Cloud-Aerosol Interaction in Large-Scale Models

    SciTech Connect

    Khain, Alexander; Phillips, Vaughan; Pinsky, Mark; Lynn, Barry

    2016-12-20

    The main achievements reached under the DOE award DE-SC0006788 are described. It is shown that the plan of the Project is completed. Unique results concerning cloud-aerosol interaction are obtained. It is shown that aerosols affect intensity of hurricanes. The effects of small aerosols on formation of ice in anvils of deep convective clouds are discovered, for the first time the mechanisms of drizzle formation are found and described quantitatively. Mechanisms of formation of warm rain are clarified and the dominating role of adiabatic processes and turbulence are stressed. Important results concerning the effects of sea spray on intensity of clouds and tropical cyclones are obtained. A novel methods of calculation of hail formation has been developed and implemented.

  20. Spatially resolved measurements of size and velocity distributions of aerosol droplets from a direct injection nebulizer

    SciTech Connect

    Shum, S.C.K.; Johnson, S.K.; Pang, H.M.; Houk, R.S. )

    1993-05-01

    Aerosol droplet sizes and velocities from a direct injection nebulizer (DIN) are measured with radial and axial spatial resolution by phase Doppler particle analysis (PDPA). The droplets on the central axis of the spray become finer and their size becomes more uniform when [approx]20% methanol is added to the usual aqueous solvent. This could explain why the analyte signal is a maximum at this solvent composition when the DIN is used for inductively coupled plasma-mass spectrometry (ICP-MS). Mean droplet velocities are 12 to 22 m s[sup [minus]1] with standard deviations of [plus minus]4 to [plus minus]7 m s[sup [minus]1]. The outer fringes of the aerosol plume tend to be enriched in large droplets. The Sauter mean diameter (D[sub 3,2]) and velocity of the droplets also vary substantially with axial position in the aerosol plume. 35 refs., 10 figs., 1 tab.

  1. Characterization of a Quadrotor Unmanned Aircraft System for Aerosol-Particle-Concentration Measurements.

    PubMed

    Brady, James M; Stokes, M Dale; Bonnardel, Jim; Bertram, Timothy H

    2016-02-02

    High-spatial-resolution, near-surface vertical profiling of atmospheric chemical composition is currently limited by the availability of experimental platforms that can sample in constrained environments. As a result, measurements of near-surface gradients in trace gas and aerosol particle concentrations have been limited to studies conducted from fixed location towers or tethered balloons. Here, we explore the utility of a quadrotor unmanned aircraft system (UAS) as a sampling platform to measure vertical and horizontal concentration gradients of trace gases and aerosol particles at high spatial resolution (1 m) within the mixed layer (0-100 m). A 3D Robotics Iris+ autonomous quadrotor UAS was outfitted with a sensor package consisting of a two-channel aerosol optical particle counter and a CO2 sensor. The UAS demonstrated high precision in both vertical (±0.5 m) and horizontal positions (±1 m), highlighting the potential utility of quadrotor UAS drones for aerosol- and trace-gas measurements within complex terrain, such as the urban environment, forest canopies, and above difficult-to-access areas such as breaking surf. Vertical profiles of aerosol particle number concentrations, acquired from flights conducted along the California coastline, were used to constrain sea-spray aerosol-emission rates from coastal wave breaking.

  2. Direct morphological comparison of vacuum plasma sprayed and detonation gun sprayed hydroxyapatite coatings for orthopaedic applications.

    PubMed

    Gledhill, H C; Turner, I G; Doyle, C

    1999-02-01

    Hydroxyapatite coatings on titanium substrates were produced using two thermal spray techniques vacuum plasma spraying and detonation gun spraying. X-ray diffraction was used to compare crystallinity and residual stresses in the coatings. Porosity was measured using optical microscopy in conjunction with an image analysis system. Scanning electron microscopy and surface roughness measurements were used to characterise the surface morphologies of the coatings. The vacuum plasma sprayed coatings were found to have a lower residual stress, a higher crystallinity and a higher level of porosity than the detonation gun coatings. It is concluded that consideration needs to be given to the significance of such variations within the clinical context.

  3. Aerosol contributions to speleothem geochemistry

    NASA Astrophysics Data System (ADS)

    Dredge, J. A.; Fairchild, I. J.; Harrison, R.; Woodhead, J. D.; Hellstrom, J.

    2011-12-01

    The term "aerosols" encompasses the suspension of both fine solid or liquid particles within a gaseous medium. Aerosols become suspended into the earth's atmosphere through a multitude of processes both natural and anthropogenic. Atmospheric aerosols enter cave networks as a result of cave ventilation processes and are either deposited, or cycled and removed from the system. Speleothem offer a multiproxy palaeoclimate resource; many of the available proxies have been extensively investigated and utilised for palaeoclimatic reconstructions in a range of studies. The potential contribution of aerosols to speleothem chemistry and their applicability for palaeoenvironmental reconstructions remains untested and the extent of their value as an addition to palaeoclimate sciences unknown. Aerosols through incorporation into speleothem may provide a novel palaeoenvironmental resource. The aerosol component of interest is that which is transported into the cave atmosphere and deposited and are available for incorporation into precipitated calcite. Aerosol deposition and therefore distribution in the cave has shown to be a complex function of ventilation and changing environmental factors. Through detailed monitoring aerosols have been detected, identified, characterised and quantified to determine their prominence in the cave system. Investigations are on a case study basis, searching for suitable aerosol proxies of environmentally significant emission processes. Case studies include: Palaeofires at Yarrangobilly Caves, Australia; anthropogenic emissions at St Michaels Cave, Gibraltar and Cheddar gorge, UK; and drip water aerosol production and geochemical addition in Obir cave, Austria. Monitoring has allowed for the temporal and spatial determination of aerosols in karst networks. Speleothem samples will be analysed in combination with in-situ monitoring to determine incorporation factors and record preservation. By understanding how aerosols are transmitted within the

  4. Retrieval of Aerosol Within Cloud Fields Using the MODIS Airborne Simulator (MAS)

    NASA Astrophysics Data System (ADS)

    Munchak, L. A.; Levy, R. C.; Mattoo, S.; Patadia, F.; Wilcox, E. M.; Marshak, A.

    2015-12-01

    Passive satellite remote sensing has become essential for obtaining global information about aerosol properties, including aerosol optical depth (AOD) and aerosol fine mode fraction (FMF). However, due to the spatial resolution of satellite aerosol products (typically 3 km and larger), observing aerosol within dense partly cloudy fields is difficult from space. Here, we apply an adapted version of the MODIS Collection 6 dark target algorithm to the 50-meter MODIS airborne simulator retrieved reflectances measured during the SEAC4RS campaign during 2013 to robustly retrieve aerosol with a 500 m resolution. We show good agreement with AERONET and MODIS away from cloud, suggesting that the algorithm is working as expected. However, closer to cloud, significant AOD increases are observed. We investigate the cause of these AOD increases, including examining the potential for undetected cloud contamination, reflectance increases due to unconsidered 3D radiative effects, and the impact of humidification on aerosol properties. In combination with other sensors that flew in SEAC4RS, these high-resolution observations of aerosol in partly cloudy fields can be used to characterize the radiative impact of the "twilight zone" between cloud and aerosol which is typically not considered in current estimates of direct aerosol radiative forcing.

  5. LSPRAY-III: A Lagrangian Spray Module

    NASA Technical Reports Server (NTRS)

    Raju, M. S.

    2008-01-01

    LSPRAY-III is a Lagrangian spray solver developed for application with parallel computing and unstructured grids. It is designed to be massively parallel and could easily be coupled with any existing gas-phase flow and/or Monte Carlo Probability Density Function (PDF) solvers. The solver accommodates the use of an unstructured mesh with mixed elements of either triangular, quadrilateral, and/or tetrahedral type for the gas flow grid representation. It is mainly designed to predict the flow, thermal and transport properties of a rapidly vaporizing spray because of its importance in aerospace application. The manual provides the user with an understanding of various models involved in the spray formulation, its code structure and solution algorithm, and various other issues related to parallelization and its coupling with other solvers. With the development of LSPRAY-III, we have advanced the state-of-the-art in spray computations in several important ways.

  6. LSPRAY-V: A Lagrangian Spray Module

    NASA Technical Reports Server (NTRS)

    Raju, M. S.

    2015-01-01

    LSPRAY-V is a Lagrangian spray solver developed for application with unstructured grids and massively parallel computers. It is mainly designed to predict the flow, thermal and transport properties of a rapidly vaporizing spray encountered over a wide range of operating conditions in modern aircraft engine development. It could easily be coupled with any existing gas-phase flow and/or Monte Carlo Probability Density Function (PDF) solvers. The manual provides the user with an understanding of various models involved in the spray formulation, its code structure and solution algorithm, and various other issues related to parallelization and its coupling with other solvers. With the development of LSPRAY-V, we have advanced the state-of-the-art in spray computations in several important ways.

  7. Plasma-Sprayed Photocatalytic Zinc Oxide Coatings

    NASA Astrophysics Data System (ADS)

    Navidpour, A. H.; Kalantari, Y.; Salehi, M.; Salimijazi, H. R.; Amirnasr, M.; Rismanchian, M.; Azarpour Siahkali, M.

    2017-03-01

    Fabrication of semiconductor coatings with photocatalytic action for photodegradation of organic pollutants is highly desirable. In this research, pure zinc oxide, which is well known for its promising photocatalytic activity, was deposited on stainless-steel plates by plasma spraying. The phase composition and microstructure of the deposited films were studied by x-ray diffraction analysis and scanning electron microscopy, respectively. Despite the low-energy conditions of the plasma spraying process, the zinc oxide coatings showed good mechanical integrity on the substrate. Their photocatalytic activity was evaluated using aqueous solution of methylene blue at concentration of 5 mg L-1. The results showed the potential of the plasma spraying technique to deposit zinc oxide coatings with photocatalytic action under ultraviolet illumination. Ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy confirmed that the plasma spraying method could deposit zinc oxide films with higher photoabsorption ability relative to the initial powder.

  8. Spray drying formulation of amorphous solid dispersions.

    PubMed

    Singh, Abhishek; Van den Mooter, Guy

    2016-05-01

    Spray drying is a well-established manufacturing technique which can be used to formulate amorphous solid dispersions (ASDs) which is an effective strategy to deliver poorly water soluble drugs (PWSDs). However, the inherently complex nature of the spray drying process coupled with specific characteristics of ASDs makes it an interesting area to explore. Numerous diverse factors interact in an inter-dependent manner to determine the final product properties. This review discusses the basic background of ASDs, various formulation and process variables influencing the critical quality attributes (CQAs) of the ASDs and aspects of downstream processing. Also various aspects of spray drying such as instrumentation, thermodynamics, drying kinetics, particle formation process and scale-up challenges are included. Recent advances in the spray-based drying techniques are mentioned along with some future avenues where major research thrust is needed.

  9. Turbulent group reaction model of spray dryer

    SciTech Connect

    Ma, H.K.; Huang, H.S.; Chiu, H.H.

    1987-01-01

    A turbulent group reaction model consisting of several sub-models was developed for the prediction of SO/sub 2/ removal efficiency in spray dryers. Mathematical models are developed on the basis of Eulerian-type turbulent Navier-Stokes equations for both gas and condensed phases with interphase transport considerations. The group reaction number, G, is defined as the ratio of the SO/sub 2/ absorption rate to a reference convective mass flux. This number represents the fraction of SO/sub 2/ absorbed into the lime slurry. The model is incorporated into a computer code which permits the investigation of spray dryer design concepts and operating conditions. Hence, it provides a theoretical basis for spray dryer performance optimization and scale-up. This investigation can be a practical guide to achieve high SO/sub 2/ removal efficiency in a spray dryer.

  10. Nasal Sprays: How to Use Them Correctly

    MedlinePlus

    ... two different kinds of containers: pressurized canisters and pump bottles.Steps for using a pressurized canisterGently blow ... after using the spray.Steps for using a pump bottleGently blow your nose to clear it of ...

  11. Dynamics of flare sprays. [in sun

    NASA Technical Reports Server (NTRS)

    Tandberg-Hanssen, E.; Martin, S. F.; Hansen, R. T.

    1980-01-01

    During solar cycle No. 20 new insight into the flare-spray phenomenon has been attained due to several innovations in solar optical-observing techniques (higher spatial resolution cinema-photography, tunable passband filters, multislit spectroscopy and extended angular field coronagraphs). From combined analysis of 13 well-observed sprays which occurred between 1969-1974 it is concluded that (1) the spray material originates from a preexisting active region filament which undergoes increased absorption some tens of minutes prior to the abrupt chromospheric brightening at the 'flare-start', and (2) the spray material is confined within a steadily expanding, loop-shaped (presumable magnetically controlled) envelope with part of the materials draining back down along one or both legs of the loop.

  12. LSPRAY-II: A Lagrangian Spray Module

    NASA Technical Reports Server (NTRS)

    Raju, M. S.

    2004-01-01

    LSPRAY-II is a Lagrangian spray solver developed for application with parallel computing and unstructured grids. It is designed to be massively parallel and could easily be coupled with any existing gas-phase flow and/or Monte Carlo Probability Density Function (PDF) solvers. The solver accommodates the use of an unstructured mesh with mixed elements of either triangular, quadrilateral, and/or tetrahedral type for the gas flow grid representation. It is mainly designed to predict the flow, thermal and transport properties of a rapidly vaporizing spray because of its importance in aerospace application. The manual provides the user with an understanding of various models involved in the spray formulation, its code structure and solution algorithm, and various other issues related to parallelization and its coupling with other solvers. With the development of LSPRAY-II, we have advanced the state-of-the-art in spray computations in several important ways.

  13. Comparison of UNL laser imaging and sizing system and a phase Doppler system for analyzing sprays from a NASA nozzle

    NASA Technical Reports Server (NTRS)

    Alexander, Dennis R.

    1990-01-01

    Research was conducted on characteristics of aerosol sprays using a P/DPA and a laser imaging/video processing system on a NASA MOD-1 air assist nozzle being evaluated for use in aircraft icing research. Benchmark tests were performed on monodispersed particles and on the NASA MOD-1 nozzle under identical lab operating conditions. The laser imaging/video processing system and the P/DPA showed agreement on a calibration tests in monodispersed aerosol sprays of + or - 2.6 micron with a standard deviation of + or - 2.6 micron. Benchmark tests were performed on the NASA MOD-1 nozzle on the centerline and radially at 0.5 inch increments to the outer edge of the spray plume at a distance 2 ft downstream from the exit nozzle. Comparative results at two operation conditions of the nozzle are presented for the two instruments. For the 1st case studied, the deviation in arithmetic mean diameters determined by the two instruments was in a range of 0.1 to 2.8 micron, and the deviation in Sauter mean diameters varied from 0 to 2.2 micron. Severe operating conditions in the 2nd case resulted in the arithmetic mean diameter deviating from 1.4 to 7.1 micron and the deviation in the Sauter mean diameters ranging from 0.4 to 6.7 micron.

  14. Induction of Silencing in Plants by High-Pressure Spraying of In vitro-Synthesized Small RNAs

    PubMed Central

    Dalakouras, Athanasios; Wassenegger, Michèle; McMillan, John N.; Cardoza, Vinitha; Maegele, Ira; Dadami, Elena; Runne, Miriam; Krczal, Gabi; Wassenegger, Michael

    2016-01-01

    In this report, we describe a method for the delivery of small interfering RNAs (siRNAs) into plant cells. In vitro synthesized siRNAs that were designed to target the coding region of a GREEN FLUORESCENT PROTEIN (GFP) transgene were applied by various methods onto GFP-expressing transgenic Nicotiana benthamiana plants to trigger RNA silencing. In contrast to mere siRNA applications, including spraying, syringe injection, and infiltration of siRNAs that all failed to induce RNA silencing, high pressure spraying of siRNAs resulted in efficient local and systemic silencing of the GFP transgene, with comparable efficiency as was achieved with biolistic siRNA introduction. High-pressure spraying of siRNAs with sizes of 21, 22, and 24 nucleotides (nt) led to local GFP silencing. Small RNA deep sequencing revealed that no shearing of siRNAs was detectable by high-pressure spraying. Systemic silencing was basically detected upon spraying of 22 nt siRNAs. Local and systemic silencing developed faster and more extensively upon targeting the apical meristem than spraying of mature leaves. PMID:27625678

  15. Nanofiber spraying method using a supplementary electrode

    NASA Astrophysics Data System (ADS)

    Kim, GeunHyung; Kim, WanDoo

    2006-07-01

    Using a supplementary electrode, electrospun poly(ɛ-carprolactone) fibers were deposited on various substrates with different electrical properties. The ability to coat the substrates was independent of the surface electric resistance of the substrates. This was due to the charge reduction of the sprayed fibers, which resulted from passing through the supplementary electrode. The sprayed fibers might find applications in smart textiles, advanced coating technology, and as biomedical wound dressings.

  16. Plasma spray forming metals, intermetallics, and composites

    NASA Astrophysics Data System (ADS)

    Sampath, Sanjay; Herman, Herbert

    1993-07-01

    Plasma spray processing is a droplet deposition method that combines the steps of melting, rapid solidification, and consolidation into a single step. The versatility of the technology enables the processing of freestanding bulk, near-net shapes of a wide range of alloys, intermetallics, ceramics, and composites, while still retaining the benefits of rapid solidification processing. In particular, it is possible to produce dense forms through vacuum plasma spraying.

  17. Laser modification of thermally sprayed coatings

    NASA Astrophysics Data System (ADS)

    Uglov, A. A.; Fomin, A. D.; Naumkin, A. O.; Pekshev, P. Iu.; Smurov, I. Iu.

    1987-08-01

    Experimental results are reported on the modification of thermally sprayed coatings on steels and aluminum alloys using pulsed YAG and CW CO2 lasers. In particular, results obtained for self-fluxing Ni9CrBSi powders, ZRO2 ceramic, and titanium are examined. It is shown that the laser treatment of thermally sprayed coatings significantly improves their physicomechanical properties; it also makes it possible to obtain refractory coatings on low-melting substrates with good coating-substrate adhesion.

  18. Ice Nuclei Emissions From Sea Spray Produced By Realistically Simulated Breaking Waves

    NASA Astrophysics Data System (ADS)

    Sullivan, R. C.; DeMott, P. J.; Ruppel, M. J.; Franc, G.; Hill, T.; Collins, D. B.; Cuadra-Rodriguez, L. A.; Guasco, T.; Kim, M. J.; Ault, A. P.; Grassian, V. H.; Prather, K. A.

    2012-12-01

    Breaking waves were used to generate realistic sea spray aerosol in the laboratory for the first time to study the chemical and cloud nucleation properties of marine-derived particles. Ice nuclei (IN) concentrations were measured online from the large wave channel, and from a smaller wave tank, during the collaborative CAICE experiment at Scripps Institution of Oceanography. These represent the first such measurements of ice nucleation isolated to sea spray aerosol under controlled but realistic laboratory conditions. The wave channel and small wave tank were filled with coarsely filtered sea water pumped from the nearby Pacific Ocean. Various types of bacteria, phytoplankton, and/or algae were added to the tanks to simulate marine biology. In a multiday mesocosm experiment, growth media was also added to stimulate a marine bloom event. Ice nuclei concentrations were strongly dependent on the cloud processing temperature, and required a combination of both online and higher sample volume offline collection methods to successfully characterize IN concentrations at the warmest ice nucleation temperatures. A clear relation between ice nuclei concentrations at lower temperatures below -30 °C and heterotrophic bacteria concentrations in the seawater was found. The IN concentration was also impaired by increasing concentrations of total organic carbon. IN did not correlate with chlorophyll concentrations, though this is the indicator typically used to predict changes in ocean biology and chemistry and the resulting alteration of sea spray aerosol properties. Spectromicroscopic analysis of collected ice crystals was used to investigate what particle compositions were likely responsible for the observed ice nucleation activity. These measurements suggest characteristic ice nuclei activation at lower average temperatures than typically observed for Northern Hemisphere ambient aerosols. The marine bio-particles observed here displayed weaker ice nucleation ability than

  19. American Association for Aerosol Research (AAAR) `95

    SciTech Connect

    1995-12-31

    The Fourteenth annual meeting of the American Association for Aerosol Research was held October 9-13, 1995 at Westin William Penn Hotel in Pittsburgh, PA. This volume contains the abstracts of the papers and poster sessions presented at this meeting, grouped by the session in which they were presented as follows: Radiation Effects; Aerosol Deposition; Collision Simulations and Microphysical Behavior; Filtration Theory and Measurements; Materials Synthesis; Radioactive and Nuclear Aerosols; Aerosol Formation, Thermodynamic Properties, and Behavior; Particle Contamination Issues in the Computer Industry; Pharmaceutical Aerosol Technology; Modeling Global/Regional Aerosols; Visibility; Respiratory Deposition; Biomass and Biogenic Aerosols; Aerosol Dynamics; Atmospheric Aerosols.

  20. New model for light propagation in highly inhomogeneous polydisperse turbid media with applications in spray diagnostics

    NASA Astrophysics Data System (ADS)

    Berrocal, Edouard; Meglinski, Igor; Jermy, Mark

    2005-11-01

    Modern optical diagnostics for quantitative characterization of polydisperse sprays and other aerosols which contain a wide range of droplet size encounter difficulties in the dense regions due to the multiple scattering of laser radiation with the surrounding droplets. The accuracy and efficiency of optical measurements can only be improved if the radiative transfer within such polydisperse turbid media is understood. A novel Monte Carlo code has been developed for modeling of optical radiation propagation in inhomogeneous polydisperse scattering media with typical drop size ranging from 2 μm to 200 μm in diameter. We show how strong variations of both particle size distribution and particle concentration within a 3D scattering medium can be taken into account via the Monte Carlo approach. A new approximation which reduces ~20 times the computational memory space required to determine the phase function is described. The approximation is verified by considering four log-normal drop size distributions. It is found valid for particle sizes in the range of 10-200 μm with increasing errors, due to additional photons scattered at large angles, as the number of particles below than 10 μm increases. The technique is applied to the simulation of typical planar Mie imaging of a hollow cone spray. Simulated and experimental images are compared and shown to agree well. The code has application in developing and testing new optical diagnostics for complex scattering media such as dense sprays.