WorldWideScience

Sample records for airborne particles

  1. Mutagenicity of airborne particles.

    Science.gov (United States)

    Chrisp, C E; Fisher, G L

    1980-09-01

    The physical and chemical properties of airborne particles are important for the interpretation of their potential biologic significance as genotoxic hazards. For polydisperse particle size distributions, the smallest, most respirable particles are generally the most mutagenic. Particulate collection for testing purposes should be designed to reduce artifact formation and allow condensation of mutagenic compounds. Other critical factors such as UV irradiation, wind direction, chemical reactivity, humidity, sample storage, and temperature of combustion are important. Application of chemical extraction methods and subsequent class fractionation techniques influence the observed mutagenic activity. Particles from urban air, coal fly ash, automobile and diesel exhaust, agricultural burning and welding fumes contain primarily direct-acting mutagens. Cigarette smoke condensate, smoke from charred meat and protein pyrolysates, kerosene soot and cigarette smoke condensates contain primarily mutagens which require metabolic activation. Fractionation coupled with mutagenicity testing indicates that the most potent mutagens are found in the acidic fractions of urban air, coal fly ash, and automobile diesel exhaust, whereas mutagens in rice straw smoke and cigarette smoke condensate are found primarily in the basic fractions. The interaction of the many chemical compounds in complex mixtures from airborne particles is likely to be important in determining mutagenic or comutagenic potentials. Because the mode of exposure is generally frequent and prolonged, the presence of tumor-promoting agents in complex mixtures may be a major factor in evaluation of the carcinogenic potential of airborne particles.

  2. Airborne Soil Organic Particles Generated by Precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bingbing; Harder, Henning T.; Kelly, Stephen T.; Piens, Dominique` Y.; China, Swarup; Kovarik, Libor; Keiluweit, Marco; Arey, Bruce W.; Gilles, Mary K.; Laskin, Alexander

    2016-05-02

    Airborne organic particles play a critical role in the Earth’s climate1, public health2, air quality3, and hydrological and carbon cycles4. These particles exist in liquid, amorphous semi-solid, or solid (glassy) phase states depending on their composition and ambient conditions5. However, sources and formation mechanisms for semi- solid and solid organic particles are poorly understood and typically neglected in atmospheric models6. Here we report field evidence for airborne solid organic particles generated by a “raindrop” mechanism7 pertinent to atmosphere – land surface interactions (Fig. 1). We find that after rain events at Southern Great Plains, Oklahoma, USA, submicron solid particles, with a composition consistent with soil organic matter, contributed up to 60% of atmospheric particles in number. Subsequent experiments indicate that airborne soil organic particles are ejected from the surface of soils caused by intensive rains or irrigation. Our observations suggest that formation of these particles may be a widespread phenomenon in ecosystems where soils are exposed to strong, episodic precipitation events such as agricultural systems and grasslands8. Chemical imaging and micro-spectroscopy analysis of their physico-chemical properties suggests that airborne soil organic particles may have important impacts on cloud formation and efficiently absorb solar radiation and hence, are an important type of particles.

  3. Airborne soil organic particles generated by precipitation

    Science.gov (United States)

    Wang, Bingbing; Harder, Tristan H.; Kelly, Stephen T.; Piens, Dominique S.; China, Swarup; Kovarik, Libor; Keiluweit, Marco; Arey, Bruce W.; Gilles, Mary K.; Laskin, Alexander

    2016-06-01

    Airborne organic particles play a critical role in Earth's climate, public health, air quality, and hydrological and carbon cycles. However, sources and formation mechanisms for semi-solid and solid organic particles are poorly understood and typically neglected in atmospheric models. Laboratory evidence suggests that fine particles can be formed from impaction of mineral surfaces by droplets. Here, we use chemical imaging of particles collected following rain events in the Southern Great Plains, Oklahoma, USA and after experimental irrigation to show that raindrop impaction of soils generates solid organic particles. We find that after rain events, sub-micrometre solid particles, with a chemical composition consistent with soil organic matter, contributed up to 60% of atmospheric particles. Our irrigation experiments indicate that intensive water impaction is sufficient to cause ejection of airborne soil organic particles from the soil surface. Chemical imaging and micro-spectroscopy analysis of particle physico-chemical properties suggest that these particles may have important impacts on cloud formation and efficiently absorb solar radiation. We suggest that raindrop-induced formation of solid organic particles from soils may be a widespread phenomenon in ecosystems such as agricultural systems and grasslands where soils are exposed to strong, episodic precipitation events.

  4. Study of airborne particles generated by the impact of droplets

    International Nuclear Information System (INIS)

    A liquid droplet impinging onto surfaces occurs in many industrial and natural processes. The study of this phenomenon is fundamental in order to determine the potential sources of contamination in the case of scenarios of liquid falls such as dripping. There are very few data in the literature in the case of the impact of millimeter-size droplets. The purpose of our work is to study experimentally the particle emission during the impact of droplets onto a liquid film. Experiments were conducted to study the influence of the velocity and the diameter of the droplets, the height of the liquid film, the surface tension and viscosity of the liquid on the airborne particles. Our results, original, have made it possible to examine the relevance of existing relations, describing the transition between deposition and splash regimes, in order to determine the presence or not of airborne particles. The micro droplets produced, with diameters less than fifty micrometers, are characterised in terms of total mass and size distribution. Our results also show the influence of a combination of several factors on the production of airborne particles. For this reason, it is interesting to use dimensionless numbers, to describe the relationship between the inertial, viscosity and surface tension forces, in order to understand physically the emission of airborne particles. (author)

  5. Analysis of the dynamic interaction between SVOCs and airborne particles

    DEFF Research Database (Denmark)

    Liu, Cong; Shi, Shanshan; Weschler, Charles J.;

    2013-01-01

    A proper quantitative understanding of the dynamic interaction between gas-phase semivolatile organic compounds (SVOCs) and airborne particles is important for human exposure assessment and risk evaluation. Questions regarding how to properly address gas/particle interactions have introduced...... be reasonably neglected for particles with diameters between 0.01 and 10 μm if the particulate organic matter is in the liquid phase. A lumped description therefore can be applied to determine, with greater accuracy than in previous studies, the timescale required to attain gas/particle equilibrium...

  6. Acoustic Resonator Optimisation for Airborne Particle Manipulation

    Science.gov (United States)

    Devendran, Citsabehsan; Billson, Duncan R.; Hutchins, David A.; Alan, Tuncay; Neild, Adrian

    Advances in micro-electromechanical systems (MEMS) technology and biomedical research necessitate micro-machined manipulators to capture, handle and position delicate micron-sized particles. To this end, a parallel plate acoustic resonator system has been investigated for the purposes of manipulation and entrapment of micron sized particles in air. Numerical and finite element modelling was performed to optimise the design of the layered acoustic resonator. To obtain an optimised resonator design, careful considerations of the effect of thickness and material properties are required. Furthermore, the effect of acoustic attenuation which is dependent on frequency is also considered within this study, leading to an optimum operational frequency range. Finally, experimental results demonstrated good particle levitation and capture of various particle properties and sizes ranging to as small as 14.8 μm.

  7. [Investigation of Carbonaceous Airborne Particles by Scanning Proton Microprobe].

    Science.gov (United States)

    Bao, Liang-man; Liu, Jiang-feng; Lei, Qian-tao; Li, Xiao-lin; Zhang, Gui-lin; Li, Yan

    2016-01-15

    Carbonaceous particles are an important component of the atmospheric aerosol particles and important for global climate change, air quality and human health. The PM₁₀ single particles from two environmental monitor locations and seven pollution emission sources were analyzed using scanning proton microprobe (SPM) techniques. The concentration of carbon in individual particles was quantitatively determined by proton non-Rutherford elastic backscattering spectrometry (EBS). The results of this investigation showed that carbonaceous particles were dominant in the pollution sources of coal and oil combustions, diesel busexhaust and automobile exhaust, while inorganic particles were dominant in the sources of steel industry, cement dust and soil dust. Carbonaceous matter was enriched in particles from the city center, while mineral matter was the main component of airborne particles in the industrial area. Elemental mapping of single aerosol particles yielded important information on the chemical reactions of aerosol particles. The micro-PIXE (particle induced X-ray emission) maps of S, Ca and Fe of individual carbonaceous particles showed that sulfuration reaction occurred between SO₂and mineral particles, which increased the sulfur content of particles. PMID:27078933

  8. New Methods for Personal Exposure Monitoring for Airborne Particles.

    Science.gov (United States)

    Koehler, Kirsten A; Peters, Thomas M

    2015-12-01

    Airborne particles have been associated with a range of adverse cardiopulmonary outcomes, which has driven its monitoring at stationary central sites throughout the world. Individual exposures, however, can differ substantially from concentrations measured at central sites due to spatial variability across a region and sources unique to the individual, such as cooking or cleaning in homes, traffic emissions during commutes, and widely varying sources encountered at work. Personal monitoring with small, battery-powered instruments enables the measurement of an individual's exposure as they go about their daily activities. Personal monitoring can substantially reduce exposure misclassification and improve the power to detect relationships between particulate pollution and adverse health outcomes. By partitioning exposures to known locations and sources, it may be possible to account for variable toxicity of different sources. This review outlines recent advances in the field of personal exposure assessment for particulate pollution. Advances in battery technology have improved the feasibility of 24-h monitoring, providing the ability to more completely attribute exposures to microenvironment (e.g., work, home, commute). New metrics to evaluate the relationship between particulate matter and health are also being considered, including particle number concentration, particle composition measures, and particle oxidative load. Such metrics provide opportunities to develop more precise associations between airborne particles and health and may provide opportunities for more effective regulations. PMID:26385477

  9. Flow analysis of airborne particles in a hospital operating room

    Science.gov (United States)

    Faeghi, Shiva; Lennerts, Kunibert

    2016-06-01

    Preventing airborne infections during a surgery has been always an important issue to deliver effective and high quality medical care to the patient. One of the important sources of infection is particles that are distributed through airborne routes. Factors influencing infection rates caused by airborne particles, among others, are efficient ventilation and the arrangement of surgical facilities inside the operating room. The paper studies the ventilation airflow pattern in an operating room in a hospital located in Tehran, Iran, and seeks to find the efficient configurations with respect to the ventilation system and layout of facilities. This study uses computational fluid dynamics (CFD) and investigates the effects of different inflow velocities for inlets, two pressurization scenarios (equal and excess pressure) and two arrangements of surgical facilities in room while the door is completely open. The results show that system does not perform adequately when the door is open in the operating room under the current conditions, and excess pressure adjustments should be employed to achieve efficient results. The findings of this research can be discussed in the context of design and controlling of the ventilation facilities of operating rooms.

  10. Dry deposition of large, airborne particles onto a surrogate surface

    Science.gov (United States)

    Kim, Eugene; Kalman, David; Larson, Timothy

    Simultaneous measurements of particle dry deposition flux and airborne number concentration in the open atmosphere were made using three different types of artificially generated particles in the size range 10-100 μm - perlite, diatomaceous earth and glass beads. A combination of gravimetric analysis, automated microscopy and sonic anemometry provided size-resolved estimates of both the inertial and gravitational components of the quasi-laminar layer particle deposition velocity, ( Vd) b, as a function of size. Eddy inertial deposition efficiency ( ηdI) was determined as a function of dimensionless eddy Stokes number (Stk e). In the range 3PNL-SA-6721, Pacific Northwest Laboratories, Richland, WA), used in several regulatory models, significantly under-predicted (up to seven times) ( Vd) b for large particles ( da>10 μm).

  11. Particle sizing of airborne radioactivity field measurements at Olympic Dam

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, S.B.; Wilkis, M.; O`Brein, R.; Ganakas, G.

    1993-12-01

    On July 1, 1991 the Australian Radiation Laboratory (ARL) commenced a two year project entitled - Particle sizing of airborne radioactivity, funded by a Mining and Quarrying Occupational Health and Safety Committee - grant (submission No. 9138). This study was set out to measure airborne radioactivity size distributions in an underground uranium mine, in order to provide better estimates of the health risks associated with inhalation of airborne radiation in the work place. These measurements included both active and passive measurement of radon gas, continuous and spot sample of radon daughter levels, as well as wire screen diffusion battery measurements of the radon daughter size distributions. The results of measurements at over 50 sites within the mine are reported, together with the calculated dose conversion factors derived from the older dosimetric models and from the new ICRP lung model using the computer code RADEP. The results showed that the ventilation is relatively uniform within the mine and the radon daughter concentrations are kept to less than 20% of the equilibrium concentration. The radon and radon daughter concentrations showed marked variability with both time and position within the mine. It is concluded that the present radiation protection methods and dose conversion factors used in Australia provide a good estimate of the radiation risk for the inhalation of radon progeny. 29 refs., 8 tabs., 9 figs.

  12. Microvolumetric determination of inorganic and organic sulphur in airborne particles

    Energy Technology Data Exchange (ETDEWEB)

    Moehnle, K.; Krivan, V.; Grallath, E.

    1984-02-01

    A reductive procedure for the determination of sulphur was modified and applied to the analysis of airborne particles. It is based on the reduction of the given sulphur forms with the mixture HI/HCOOH/H/sub 3/PO/sub 2//Sb/sub 2/O/sub 3/ to hydrogen sulphide, which is transferred into a NaOH solution and determined by microtitration with Cd/sup 2 +/ using dithizone as indicator. Examination of the behaviour of the different sulphur forms in the reduction mixture showed that the inorganic sulphur was converted to H/sub 2/S whereas the organic remained in the reaction flask. This makes possible the differentiation between inorganic and organic sulphur when one part of the sample is directly reacted with the mixture and the other one is oxidatively decomposed (Schoeniger), and then the total sulphur determined with the same procedure. The method was used for the analysis of a number of airborne particle samples of different origin, and the results were compared with those of some instrumental techniques.

  13. Measurement of airborne particle concentrations near the Sunset Crater volcano, Arizona.

    Science.gov (United States)

    Benke, Roland R; Hooper, Donald M; Durham, James S; Bannon, Donald R; Compton, Keith L; Necsoiu, Marius; McGinnis, Ronald N

    2009-02-01

    Direct measurements of airborne particle mass concentrations or mass loads are often used to estimate health effects from the inhalation of resuspended contaminated soil. Airborne particle mass concentrations were measured using a personal sampler under a variety of surface-disturbing activities within different depositional environments at both volcanic and nonvolcanic sites near the Sunset Crater volcano in northern Arizona. Focused field investigations were performed at this analog site to improve the understanding of natural and human-induced processes at Yucca Mountain, Nevada. The level of surface-disturbing activity was found to be the most influential factor affecting the measured airborne particle concentrations, which increased over three orders of magnitude relative to ambient conditions. As the surface-disturbing activity level increased, the particle size distribution and the majority of airborne particle mass shifted from particles with aerodynamic diameters less than 10 mum (0.00039 in) to particles with aerodynamic diameters greater than 10 mum (0.00039 in). Under ambient conditions, above average wind speeds tended to increase airborne particle concentrations. In contrast, stronger winds tended to decrease airborne particle concentrations in the breathing zone during light and heavy surface-disturbing conditions. A slight increase in the average airborne particle concentration during ambient conditions was found above older nonvolcanic deposits, which tended to be finer grained than the Sunset Crater tephra deposits. An increased airborne particle concentration was realized when walking on an extremely fine-grained deposit, but the sensitivity of airborne particle concentrations to the resuspendible fraction of near-surface grain mass was not conclusive in the field setting when human activities disturbed the bulk of near-surface material. Although the limited sample size precluded detailed statistical analysis, the differences in airborne particle

  14. An introduction to data analysis of airborne particle composition

    International Nuclear Information System (INIS)

    A major problem facing air quality management personnel is the identification of sources of airborne particles and the quantitative apportionment of the aerosol mass to those sources. The ability to collect particle samples and analyze these samples for a suite of elements by such techniques as neutron activation analysis or x-ray fluorescence provides that data for the problem of resolving a series of complex mixtures into its components based on the profiles of the elements emitted by the various sources in the airshed. If all of the sources and their composition profiles are known, then the mass balance model becomes a multiple regression problem. If a series of samples have been analyzed without substantial information being available on the sources, factor analysis methods can be employed. In both situations, there are limits to the identification of specific sources or the location of the sources. Thus, other methods that combine chemical with meteorological data have been developed to assist in spatial identification of pollutant sources. There are also limitations to the ability of any statistical method to resolve sources in real world problems. The physical and statistical basis of these methods and their application to representative problems are reviewed in this report. (author). 42 refs, 5 figs, 5 tabs

  15. Determination of thorium and uranium particles in monazite airborne

    International Nuclear Information System (INIS)

    The work is the determination of the Mass Median Aerodynamic Diameter of Airborne particles of Th and U, produced during the milling of monazite in Monozite Sand Plants. The air samples was collected using a Cascade Impactor from Delron DCI-6 with a flux of 12,5 1/min and cut-off diametes of 0,5, 1,0, 4,0, 8,0 and 16,0 μm. Each stage of the cascate impactor was analysed by measuring the X rays induced in collision with 2 MeV protons acellereted by a 4 MV Van de Graaff acceletor located at University Catolic, PUC, RJ. The MMAD found for Th and U was of 1,15 μm with a geometric standard desviation of 2,0. Take in acount that there are more thorium than uranium in the brazilian monazite, and the 232Th 238U are thr principal isotopes at the Th and U natural radioative decay series, we considered the mass and the activity distribution as equal. The mean concentration of Th (17,0 Bq/m3) record in the air was 42% above 3/10 of international limit for concentration of oxides of thorium in the air, while the concentration of U remaind below 1/10 of the limit for concentration of U3O8 in the air. (author)

  16. Discussion on National Standard GB 6167 "Methods for Testing the Performance of Airborne Particle Counter"

    Institute of Scientific and Technical Information of China (English)

    刘俊杰; 朱能; 王君山

    2003-01-01

    Airborne particle counters are used widely to test the air cleanliness of cleanrooms. The current Chinese national standard of airborne particle counter calibration, GB6167-85, Methods for Testing the Performance of Dust Particle Counter, has kept the same for more than 10 years. It is necessary to be amended in time.This paper discusses the differences between Chinese airborne particle counter calibration procedure and other new calibration procedures in other countries, and points out the defects of current Chinese national standard.The draft of revised Chinese National Standard is also introduced. The new revised standard, Methods for Testing the Performance of Airborne Particle Counter, covers two level calibrations:primary and secondary. Primary calibration procedure includes testing 6 kinds of performances: sample airflow rate, false counting, particle size accuracy and resolution, particle counting stability, counting efficiency and particle concentration limit. Secondary calibration is a relative comparing test method to verify the counting accuracy of calibrated airborne particle counters. Finally, how to keep the calibration traceability is suggested.

  17. Self-refreshing characteristics of an airborne particle sensor using a bridged paddle oscillator

    Science.gov (United States)

    Choi, Eunsuk; Lee, Seung-Beck; Park, Bonghyun; Sul, Onejae

    2016-05-01

    We report on the self-refreshing characteristics of a micromachined airborne particle sensor. The sensor consists of a bridge-type beam having an oscillating paddle-type particle collector at its center. When a positive potential is applied to the paddle, the sensor is able to attract and collect negatively charged airborne particles while oscillating close to its resonant frequency and thereby measure their density from the change in the oscillating phase at ˜10 pg resolution. When the applied potential is removed, the collected particles are detached from the sensor due to momentum transfer from the oscillating paddle, thus demonstrating a self-refreshing capability.

  18. Partitioning of phthalates among the gas phase, airborne particles and settled dust in indoor environments

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Salthammer, Tunga; Fromme, Hermann

    2008-01-01

    A critical evaluation of human exposure to phthalate esters in indoor environments requires the determination of their distribution among the gas phase, airborne particles and settled dust. If sorption from the gas phase is the dominant mechanism whereby a given phthalate is associated with both....... The particle concentration, C-particle, of a given phthalate was calculated from its total airborne concentration and the concentration of airborne particles (PM4). This required knowledge of the particle-gas partition coefficient, K., which was estimated from either the saturation vapor pressure (p...... concentrations, the gas-phase concentrations of phthalates can also be estimated and, subsequently, the contribution of each of these compartments to indoor phthalate exposures....

  19. Airborne contamination of forest soils by carbonaceous particles from industrial coal processing

    OpenAIRE

    Schmidt, M. W. I.; Knicker, Heike; Hatcher, Patrick G.; Kögel-Knabner, I.

    2000-01-01

    In the German Ruhr-area industrial coal processing emitted large amounts of carbonaceous particles for a century until 1970. Our objectives were to detect the presence of airborne carbonaceous particles and assess their impact on the chemical structure of soil organic matter in two forest soils (Podzols) with potential sources of carbonaceous particles approximately 10 to 30 km away. Contamination was not visible macroscopicaily. Organic matter was characterized in bulk soils and in particle-...

  20. Ventilation conditions and air-borne bacteria and particles in operating theatres: proposed safe economies.

    OpenAIRE

    Clark, R. P.; Reed, P. J.; Seal, D V; Stephenson, M. L.

    1985-01-01

    Concentrations of air-borne bacteria and particles have been measured in turbulently ventilated operating theatres in full flow, half flow and zero flow conditions. Increased air-borne challenge produced by human activity and by mechanical cleaning procedures is demonstrated: die-away of this contamination is shown to be related to the ventilation rate. Ventilation can be reduced or turned off at night and during weekends, and cleaning can also be carried out, without increased risk of infect...

  1. ELECTROHYDRODYNAMIC ENHANCED TRANSPORT AND TRAPPING OF AIRBORNE PARTICLES TO A MICROFLUIDIC AIR-LIQUID INTERFACE

    OpenAIRE

    Sandström, Niklas; Frisk, Thomas; Stemme, Göran; van der Wijngaart, Wouter

    2008-01-01

    We introduce a novel approach for greatly improved transport and trapping of airborne sample to a microfluidic analysis system by integrating an electrohydrodynamic (EHD) air pump with a microfluidic air-liquid interface. In our system, a negative corona discharge partially ionizes the air around a sharp electrode tip while the electrostatic field accelerates airborne particles towards an electrically grounded liquid surface, where they absorb. The air-liquid interface is fixated at the micro...

  2. On Airborne Wear Particles Emissions ofCommercial Disc Brake Materials– A Pin on Disc Simulation

    OpenAIRE

    Söderberg, Anders; Wahlström, Jens; Olander, Lars; Jansson, Anders; Olofsson, Ulf

    2008-01-01

    A novel test method was used to study the concentration and size distribution of airborne wear particles from disc brake materials. A pin-on-disc tribometer equipped with particle counting instruments was used as test equipment. Four different nonasbestoses-organic (NAO) linings for the U.S. market and four different low metallic linings for the EU market were tested against material from gray cast iron rotors. The result indicates that the low metallic linings are more aggressive to the roto...

  3. Direct Characterization of Airborne Particles Associated with Arsenic-rich Mine Tailings: Particle Size Mineralogy and Texture

    Energy Technology Data Exchange (ETDEWEB)

    M Corriveau; H Jamieson; M Parsons; J Campbell; A Lanzirotti

    2011-12-31

    Windblown and vehicle-raised dust from unvegetated mine tailings can be a human health risk. Airborne particles from As-rich abandoned Au mine tailings from Nova Scotia, Canada have been characterized in terms of particle size, As concentration, As oxidation state, mineral species and texture. Samples were collected in seven aerodynamically fractionated size ranges (0.5-16 {micro}m) using a cascade impactor deployed at three tailings fields. All three sites are used for recreational activities and off-road vehicles were racing on the tailings at two mines during sample collection. Total concentrations of As in the <8 {micro}m fraction varied from 65 to 1040 ng/m{sup 3} of air as measured by proton-induced X-ray emission (PIXE) analysis. The same samples were analysed by synchrotron-based microfocused X-ray absorption near-edge spectroscopy ({micro}XANES) and X-ray diffraction ({micro}XRD) and found to contain multiple As-bearing mineral species, including Fe-As weathering products. The As species present in the dust were similar to those observed in the near-surface tailings. The action of vehicles on the tailings surface may disaggregate material cemented with Fe arsenate and contribute additional fine-grained As-rich particles to airborne dust. Results from this study can be used to help assess the potential human health risks associated with exposure to airborne particles from mine tailings.

  4. Particle size analysis in estimating the significance of airborne contamination

    International Nuclear Information System (INIS)

    In this report information on pertinent methods and techniques for analysing particle size distributions is compiled. The principles underlying the measurement methods are described, and the merits of different methods in relation to the information being sought and to their usefulness in the laboratory and in the field are explained. Descriptions on sampling methods, gravitational and inertial particle separation methods, electrostatic sizing devices, diffusion batteries, optical sizing techniques and autoradiography are included. Finally, the report considers sampling for respirable activity and problems related to instrument calibration

  5. Experimentally determined human respiratory tract deposition of airborne particles at a busy street

    DEFF Research Database (Denmark)

    Löndahl, Jakob; Massling, Andreas; Swietlicki, Erik;

    2009-01-01

    Traffic is one of the major sources of harmful airborne particles worldwide. To relate exposure to adverse health effects it is important to determine the deposition probability of the inhaled particles in the human respiratory tract. The size-dependent deposition of 12-580 nm particles was measu......Traffic is one of the major sources of harmful airborne particles worldwide. To relate exposure to adverse health effects it is important to determine the deposition probability of the inhaled particles in the human respiratory tract. The size-dependent deposition of 12-580 nm particles...... was measured with a novel setup in 9 healthy subjects breathing by mouth on the windward side of a busy street in Copenhagen, Denmark. The aerosol was characterized both at the curbside and, to obtain the background concentration, at rooftop level. Particle hygroscopicity, a key parameter affecting respiratory...... investigated previously (equal inhaled mass concentrations). This was because the traffic exhaust particles had both a higher deposition probability and a higher number and surface area concentration per unit mass. To validate the results, the respiratory tract deposition was estimated by using the well...

  6. Retention of airborne particles in granular bed filters

    International Nuclear Information System (INIS)

    A literature survey was made on theoretical models for the prediction of particle retention in sand beds. Also data on observed retention was collected from the literature. Based on this information, a semi-empirical model was compiled. Comparison of the model with published retention data shows a general agreement. (Auth.)

  7. Direct characterization of airborne particles associated with arsenic-rich mine tailings: Particle size, mineralogy and texture

    Energy Technology Data Exchange (ETDEWEB)

    Corriveau, M.C. [Department of Geological Sciences and Geological Engineering, Queen' s University, Kingston, Ontario, K7L 3N6 (Canada); Jamieson, H.E., E-mail: jamieson@geol.queensu.ca [Department of Geological Sciences and Geological Engineering, Queen' s University, Kingston, Ontario, K7L 3N6 (Canada); Parsons, M.B. [Geological Survey of Canada (Atlantic), Natural Resources Canada, Dartmouth, Nova Scotia, B2Y 4A2 (Canada); Campbell, J.L. [Guelph-Waterloo Physics Institute, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Lanzirotti, A. [Center for Advanced Radiation Sources, University of Chicago, Chicago, IL 60637 (United States)

    2011-09-15

    Highlights: > Airborne dust from As-rich gold mine tailings used for recreation was collected. > Total concentrations of arsenic in the <8 {mu}m fraction varied from 65 to 1040 ng/m{sup 3}. > Multiple As minerals in dust are comparable with near-surface tailings samples. - Abstract: Windblown and vehicle-raised dust from unvegetated mine tailings can be a human health risk. Airborne particles from As-rich abandoned Au mine tailings from Nova Scotia, Canada have been characterized in terms of particle size, As concentration, As oxidation state, mineral species and texture. Samples were collected in seven aerodynamically fractionated size ranges (0.5-16 {mu}m) using a cascade impactor deployed at three tailings fields. All three sites are used for recreational activities and off-road vehicles were racing on the tailings at two mines during sample collection. Total concentrations of As in the <8 {mu}m fraction varied from 65 to 1040 ng/m{sup 3} of air as measured by proton-induced X-ray emission (PIXE) analysis. The same samples were analysed by synchrotron-based microfocused X-ray absorption near-edge spectroscopy ({mu}XANES) and X-ray diffraction ({mu}XRD) and found to contain multiple As-bearing mineral species, including Fe-As weathering products. The As species present in the dust were similar to those observed in the near-surface tailings. The action of vehicles on the tailings surface may disaggregate material cemented with Fe arsenate and contribute additional fine-grained As-rich particles to airborne dust. Results from this study can be used to help assess the potential human health risks associated with exposure to airborne particles from mine tailings.

  8. Evaluation of cell sorting aerosols and containment by an optical airborne particle counter.

    Science.gov (United States)

    Xie, Mike; Waring, Michael T

    2015-08-01

    Understanding aerosols produced by cell sorting is critical to biosafety risk assessment and validation of containment efficiency. In this study an Optical Airborne Particle Counter was used to analyze aerosols produced by the BD FACSAria and to assess the effectiveness of its aerosol containment. The suitability of using this device to validate containment was directly compared to the Glo-Germ method put forth by the International Society for Advancement of Cytometry (ISAC) as a standard for testing. It was found that high concentrations of aerosols ranging from 0.3 µm to 10 µm can be detected in failure mode, with most less than 5 µm. In most cases, while numerous aerosols smaller than 5 µm were detected by the Optical Airborne Particle Counter, no Glo-Germ particles were detected, indicating that small aerosols are under-evaluated by the Glo-Germ method. The results demonstrate that the Optical Airborne Particle Counter offers a rapid, economic, and quantitative analysis of cell sorter aerosols and represents an improved method over Glo-Germ for the task of routine validation and monitoring of aerosol containment for cell sorting. PMID:26012776

  9. Allergens in Paved Road Dust and Airborne Particles

    OpenAIRE

    Miguel, Ann G.; Cass, Glen R.; Glovsky, M. Michael; Weiss, Jay

    1999-01-01

    Paved road dust present on the surface of streets in Southern California consists of a complex mixture of soil dust, deposited motor vehicle exhaust particles, tire dust, brake lining wear dust, plant fragments, and other biological materials. The research presented here shows that allergens from at least 20 different source materials are found in the paved road dust. These include pollens and pollen fragments, animal dander, and molds. When paved road dust is resuspended into the atmosphere ...

  10. Characterization of individual airborne particles in Taiyuan City, China

    OpenAIRE

    Xie, R. K.; Seip, H. M.; L. Liu; Zhang, D.S.

    2009-01-01

    Taiyuan, the capital of Shanxi province, China, is one of the most polluted cities in the world. To characterize the ambient particulate pollution, samples of particulates with aerodynamic diameter less than 10 µm (PM10) were collected during a 6-day campaign. Individual particles were analyzed by Scanning Electron Microscope with Energy-Dispersive Spectrometer (SEM-EDS) to determine their chemical composition. Meanwhile, photomicrographs were obtained from SEM to aid in particles’ source ide...

  11. Concentrations and Sources of Airborne Particles in a Neonatal Intensive Care Unit

    Science.gov (United States)

    Licina, Dusan; Bhangar, Seema; Brooks, Brandon; Baker, Robyn; Firek, Brian; Tang, Xiaochen; Morowitz, Michael J.; Banfield, Jillian F.; Nazaroff, William W.

    2016-01-01

    Premature infants in neonatal intensive care units (NICUs) have underdeveloped immune systems, making them susceptible to adverse health consequences from air pollutant exposure. Little is known about the sources of indoor airborne particles that contribute to the exposure of premature infants in the NICU environment. In this study, we monitored the spatial and temporal variations of airborne particulate matter concentrations along with other indoor environmental parameters and human occupancy. The experiments were conducted over one year in a private-style NICU. The NICU was served by a central heating, ventilation and air-conditioning (HVAC) system equipped with an economizer and a high-efficiency particle filtration system. The following parameters were measured continuously during weekdays with 1-min resolution: particles larger than 0.3 μm resolved into 6 size groups, CO2 level, dry-bulb temperature and relative humidity, and presence or absence of occupants. Altogether, over sixteen periods of a few weeks each, measurements were conducted in rooms occupied with premature infants. In parallel, a second monitoring station was operated in a nearby hallway or at the local nurses’ station. The monitoring data suggest a strong link between indoor particle concentrations and human occupancy. Detected particle peaks from occupancy were clearly discernible among larger particles and imperceptible for submicron (0.3–1 μm) particles. The mean indoor particle mass concentrations averaged across the size range 0.3–10 μm during occupied periods was 1.9 μg/m3, approximately 2.5 times the concentration during unoccupied periods (0.8 μg/m3). Contributions of within-room emissions to total PM10 mass in the baby rooms averaged 37–81%. Near-room indoor emissions and outdoor sources contributed 18–59% and 1–5%, respectively. Airborne particle levels in the size range 1–10 μm showed strong dependence on human activities, indicating the importance of indoor

  12. Concentrations and Sources of Airborne Particles in a Neonatal Intensive Care Unit.

    Directory of Open Access Journals (Sweden)

    Dusan Licina

    Full Text Available Premature infants in neonatal intensive care units (NICUs have underdeveloped immune systems, making them susceptible to adverse health consequences from air pollutant exposure. Little is known about the sources of indoor airborne particles that contribute to the exposure of premature infants in the NICU environment. In this study, we monitored the spatial and temporal variations of airborne particulate matter concentrations along with other indoor environmental parameters and human occupancy. The experiments were conducted over one year in a private-style NICU. The NICU was served by a central heating, ventilation and air-conditioning (HVAC system equipped with an economizer and a high-efficiency particle filtration system. The following parameters were measured continuously during weekdays with 1-min resolution: particles larger than 0.3 μm resolved into 6 size groups, CO2 level, dry-bulb temperature and relative humidity, and presence or absence of occupants. Altogether, over sixteen periods of a few weeks each, measurements were conducted in rooms occupied with premature infants. In parallel, a second monitoring station was operated in a nearby hallway or at the local nurses' station. The monitoring data suggest a strong link between indoor particle concentrations and human occupancy. Detected particle peaks from occupancy were clearly discernible among larger particles and imperceptible for submicron (0.3-1 μm particles. The mean indoor particle mass concentrations averaged across the size range 0.3-10 μm during occupied periods was 1.9 μg/m3, approximately 2.5 times the concentration during unoccupied periods (0.8 μg/m3. Contributions of within-room emissions to total PM10 mass in the baby rooms averaged 37-81%. Near-room indoor emissions and outdoor sources contributed 18-59% and 1-5%, respectively. Airborne particle levels in the size range 1-10 μm showed strong dependence on human activities, indicating the importance of indoor

  13. Indoor and outdoor airborne particles. An in vitro study on mutagenic potential and toxicological implications.

    OpenAIRE

    Houdt, van, R.

    1988-01-01

    IntroductionAir pollution components are present as gases and as particulate matter. As particle deposition takes place in various parts of the respiratory system particulate matter may have other toxicological implications than gaseous pollutants, which all may penetrate in the lower part of the respiratory tract. In addition, suspended particulate matter represents a group of pollutants of variable physical as well as chemical composition. Therefore airborne particulate matter cannot be reg...

  14. Predicting emissions of SVOCs from polymeric materials and their interaction with airborne particles.

    Science.gov (United States)

    Xu, Ying; Little, John C

    2006-01-15

    A model that predicts the emission rate of volatile organic compounds (VOCs) from building materials is extended and used to predict the emission rate of semivolatile organic compounds (SVOCs) from polymeric materials. Reasonable agreement between model predictions and gas-phase di-2-ethylhexyl phthalate (DEHP) concentrations is achieved using data collected in a previous experimental study that measured emissions of DEHP from vinyl flooring in two very different chambers. While emissions of highly volatile VOCs are subject to "internal" control (the material-phase diffusion coefficient), emissions of the very low volatility SVOCs are subject to "external" control (partitioning into the gas phase, the convective mass-transfer coefficient, and adsorption onto interior surfaces). The effect of SVOCs partitioning onto airborne particles is also examined. The DEHP emission rate is increased when the gas-phase concentration is high, and especially when partitioning to the airborne particles is strong. Airborne particles may play an important role in inhalation exposure as well as in transporting SVOCs well beyond the source. Although more rigorous validation is needed, the model should help elucidate the mechanisms governing emissions of phthalate plasticizers, brominated flame retardants, biocides, and other SVOCs from a wide range of building materials and consumer products. PMID:16468389

  15. Approximation for the absorption coefficient of airborne atmospheric aerosol particles in terms of measurable bulk properties

    OpenAIRE

    HÄNEL, GOTTFRIED; Dlugi, Ralph

    2011-01-01

    The absorption coefficient of airborne atmospheric aerosol particles can be approximated by where λ is the wavelength of radiation, n — ik is the mean complex refractive index, ρ the mean bulk density, and M/Vk the mass of the particles per unit volume of air. This approximation gives good results at relative humidities between 0 and 0.95 for the wavelengths of radiation between 0.55 μm and 2.0 μm and between 9.25 μm and 12.0 μm. Basing on this approximation it is possible to determine the s...

  16. Capability of a Portable Chromatic Unit for Monitoring Airborne Particles over Wide Urban Areas

    Directory of Open Access Journals (Sweden)

    M. A. Aceves-Fernandez

    2009-01-01

    Full Text Available Investigations are described into the use of a compact, portable unit, using polychromatic scattered light, for the preliminary monitoring airborne PM 2–10 particulates over widespread urban areas subjected to vehicular traffic. The monitoring unit has been used at a city centre bus terminus, at sites along an urban bus corridor and outside a local school adjacent to an air quality monitoring station. Holistic results are presented which demonstrate the use of the unit for the preliminary identification of locations and conditions with elevated levels of PM 2–10 particles which can be investigated in greater detail with particle-specific, high-precision instruments.

  17. A review of airborne particle sampling with special reference to long-lived radioactive dust

    International Nuclear Information System (INIS)

    This report reviews some basic aspects related to the sampling of airborne particles with special reference to Long-Lived Radioactive Dust (LLRD). The report covers a number of areas of practical interest such as the production of aerosols, the dynamics of suspended particles, the physical and chemical characteristics and properties of dust clouds, and the inhalation and measurement of dust. It is followed with a brief review of dust sampling instrumentation, and with a short account of the work done on LLRD in Canada with a few references to work done outside this country. (34 figs., 7 tabs., 117 refs.)

  18. Use of GSR particle analysis program on an analytical SEM to identify sources of emission of airborne particles

    International Nuclear Information System (INIS)

    Full text: High concentrations of airborne particles, in particular PM10 (particulate matter 10, but has been little used in Australia for airborne particulates. Two sets of 15 mm PM10 samples were collected in March and April 2000 from two sites in Brisbane, one within a suburb and one next to an arterial road. The particles were collected directly onto double-sided carbon tapes with a cascade impactor attached to a high-volume PM10 sampler. The carbon tapes were analysed in a JEOL 840 SEM equipped with a Be-window energy-dispersive X-ray detector and Moran Scientific microanalysis system. An automated Gun Shot Residue (GSR) program was used together with backscattered electron imaging to characterise and analyse individual particulates. About 6,000 particles in total were analysed for each set of impactor samples. Due to limitations of useful pixel size, only particles larger than about 0.5 μm could be analysed. The size, shape and estimated elemental composition (from Na to Pb) of the particles were subjected to non-hierarchical cluster analysis and the characteristics of the clusters were related to their possible sources of emission. Both samples resulted in similar particle clusters. The particles could be classified into three main categories non-spherical (58% of the total number of analysed particles, shape factor >1 1), spherical (15%) and 'carbonaceous' (27%, ie with unexplained % of elemental mass >75%). Non-spherical particles were mainly sea salt and soil particles, and a small amount of iron, lead and mineral dust. The spherical particles were mainly sea salt particles and flyash, and a small amount of iron, lead and secondary sulphate dust. The carbonaceous particles included carbon material mixed with secondary aerosols, roadside dust, sea salt or industrial dust. The arterial road sample also contained more roadside dust and less secondary aerosols than the suburb sample. Current limitations with this method are the minimum particle size

  19. Cloud particle size distributions measured with an airborne digital in-line holographic instrument

    Directory of Open Access Journals (Sweden)

    J. P. Fugal

    2009-03-01

    Full Text Available Holographic data from the prototype airborne digital holographic instrument HOLODEC (Holographic Detector for Clouds, taken during test flights are digitally reconstructed to obtain the size (equivalent diameters in the range 23 to 1000 μm, three-dimensional position, and two-dimensional profile of ice particles and then ice particle size distributions and number densities are calculated using an automated algorithm with minimal user intervention. The holographic method offers the advantages of a well-defined sample volume size that is not dependent on particle size or airspeed, and offers a unique method of detecting shattered particles. The holographic method also allows the volume sample rate to be increased beyond that of the prototype HOLODEC instrument, limited solely by camera technology.

    HOLODEC size distributions taken in mixed-phase regions of cloud compare well to size distributions from a PMS FSSP probe also onboard the aircraft during the test flights. A conservative algorithm for detecting shattered particles utilizing the particles depth-position along the optical axis eliminates the obvious ice particle shattering events from the data set. In this particular case, the size distributions of non-shattered particles are reduced by approximately a factor of two for particles 15 to 70 μm in equivalent diameter, compared to size distributions of all particles.

  20. Comparison of deposited surface area of airborne ultrafine particles generated from two welding processes.

    Science.gov (United States)

    Gomes, J F; Albuquerque, P C; Miranda, Rosa M; Santos, Telmo G; Vieira, M T

    2012-09-01

    This article describes work performed on the assessment of the levels of airborne ultrafine particles emitted in two welding processes metal-active gas (MAG) of carbon steel and friction-stir welding (FSW) of aluminium in terms of deposited area in alveolar tract of the lung using a nanoparticle surface area monitor analyser. The obtained results showed the dependence from process parameters on emitted ultrafine particles and clearly demonstrated the presence of ultrafine particles, when compared with background levels. The obtained results showed that the process that results on the lower levels of alveolar-deposited surface area is FSW, unlike MAG. Nevertheless, all the tested processes resulted in important doses of ultrafine particles that are to be deposited in the human lung of exposed workers.

  1. Characterization and Control of Airborne Particles Emitted During Production of Epoxy / Carbon Nanotube Nanocomposites

    Science.gov (United States)

    Cena, Lorenzo G.; Peters, Thomas M.

    2016-01-01

    This work characterized airborne particles that were generated from the weighing of bulk, multi-wall carbon nanotubes (CNTs) and the manual sanding of epoxy test samples reinforced with CNTs. It also evaluated the effectiveness of three local exhaust ventilation (LEV) conditions (no LEV, custom fume hood, and biosafety cabinet) for control of particles generated during sanding of CNT-epoxy nanocomposites. Particle number and respirable mass concentrations were measured using an optical particle counter (OPC) and a condensation particle counter (CPC), and particle morphology was assessed by transmission electron microscopy. The ratios of the geometric mean (GM) concentrations measured during the process to that measured in the background (P/B ratios) were used as indices of the impact of the process and the LEVs on observed concentrations. Processing CNT-epoxy nanocomposites materials released respirable size airborne particles (P/B ratio: weighing = 1.79; sanding = 5.90) but generally no nanoparticles (P/B ratiô1). The particles generated during sanding were predominately micron-sized with protruding CNTs and very different from bulk CNTs that tended to remain in large (>1 μm) tangled clusters. Respirable mass concentrations in the operator’s breathing zone were lower when sanding was performed in the biological safety cabinet (GM = 0.20 μg/m3) compared to those with no LEV (GM = 2.68 μg/m3) or those when sanding was performed inside the fume hood (GM = 21.4 μg/m3; p-value < 0.0001). The poor performance of the custom fume hood used in this study may have been exacerbated by its lack of a front sash and rear baffles and its low face velocity (0.39 m/sec). PMID:21253981

  2. A review of methods for sampling large airborne particles and associated radioactivity

    International Nuclear Information System (INIS)

    Radioactive particles, tens of μm or more in diameter, are unlikely to be emitted directly from nuclear facilities with exhaust gas cleansing systems, but may arise in the case of an accident or where resuspension from contaminated surfaces is significant. Such particles may dominate deposition and, according to some workers, may contribute to inhalation doses. Quantitative sampling of large airborne particles is difficult because of their inertia and large sedimentation velocities. The literature describes conditions for unbiased sampling and the magnitude of sampling errors for idealised sampling inlets in steady winds. However, few air samplers for outdoor use have been assessed for adequacy of sampling. Many size selective sampling methods are found in the literature but few are suitable at the low concentrations that are often encountered in the environment. A number of approaches for unbiased sampling of large particles have been found in the literature. Some are identified as meriting further study, for application in the measurement of airborne radioactivity. (author)

  3. A Lagrangian particle model to predict the airborne spread of foot-and-mouth disease virus

    Science.gov (United States)

    Mayer, D.; Reiczigel, J.; Rubel, F.

    Airborne spread of bioaerosols in the boundary layer over a complex terrain is simulated using a Lagrangian particle model, and applied to modelling the airborne spread of foot-and-mouth disease (FMD) virus. Two case studies are made with study domains located in a hilly region in the northwest of the Styrian capital Graz, the second largest town in Austria. Mountainous terrain as well as inhomogeneous and time varying meteorological conditions prevent from application of so far used Gaussian dispersion models, while the proposed model can handle these realistically. In the model, trajectories of several thousands of particles are computed and the distribution of virus concentration near the ground is calculated. This allows to assess risk of infection areas with respect to animal species of interest, such as cattle, swine or sheep. Meteorological input data like wind field and other variables necessary to compute turbulence were taken from the new pre-operational version of the non-hydrostatic numerical weather prediction model LMK ( Lokal-Modell-Kürzestfrist) running at the German weather service DWD ( Deutscher Wetterdienst). The LMK model provides meteorological parameters with a spatial resolution of about 2.8 km. To account for the spatial resolution of 400 m used by the Lagrangian particle model, the initial wind field is interpolated upon the finer grid by a mass consistent interpolation method. Case studies depict a significant influence of local wind systems on the spread of virus. Higher virus concentrations at the upwind side of the hills and marginal concentrations in the lee are well observable, as well as canalization effects by valleys. The study demonstrates that the Lagrangian particle model is an appropriate tool for risk assessment of airborne spread of virus by taking into account the realistic orographic and meteorological conditions.

  4. Measurements of Ultra-fine and Fine Aerosol Particles over Siberia: Large-scale Airborne Campaigns

    Science.gov (United States)

    Arshinov, Mikhail; Paris, Jean-Daniel; Stohl, Andreas; Belan, Boris; Ciais, Philippe; Nédélec, Philippe

    2010-05-01

    In this paper we discuss the results of in-situ measurements of ultra-fine and fine aerosol particles carried out in the troposphere from 500 to 7000 m in the framework of several International and Russian State Projects. Number concentrations of ultra-fine and fine aerosol particles measured during intensive airborne campaigns are presented. Measurements carried over a great part of Siberia were focused on particles with diameters from 3 to 21 nm to study new particle formation in the free/upper troposphere over middle and high latitudes of Asia, which is the most unexplored region of the Northern Hemisphere. Joint International airborne surveys were performed along the following routes: Novosibirsk-Salekhard-Khatanga-Chokurdakh-Pevek-Yakutsk-Mirny-Novosibirsk (YAK-AEROSIB/PLARCAT2008 Project) and Novosibirsk-Mirny-Yakutsk-Lensk-Bratsk-Novosibirsk (YAK-AEROSIB Project). The flights over Lake Baikal was conducted under Russian State contract. Concentrations of ultra-fine and fine particles were measured with automated diffusion battery (ADB, designed by ICKC SB RAS, Novosibirsk, Russia) modified for airborne applications. The airborne ADB coupled with CPC has an additional aspiration unit to compensate ambient pressure and changing flow rate. It enabled to classify nanoparticles in three size ranges: 3-6 nm, 6-21 nm, and 21-200 nm. To identify new particle formation events we used similar specific criteria as Young et al. (2007): (1) N3-6nm >10 cm-3, (2) R1=N3-6/N621 >1 and R2=N321/N21200 >0.5. So when one of the ratios R1 or R2 tends to decrease to the above limits the new particle formation is weakened. It is very important to notice that space scale where new particle formation was observed is rather large. All the events revealed in the FT occurred under clean air conditions (low CO mixing ratios). Measurements carried out in the atmospheric boundary layer over Baikal Lake did not reveal any event of new particle formation. Concentrations of ultra

  5. Identifying airborne metal particles sources near an optoelectronic and semiconductor industrial park

    Science.gov (United States)

    Chen, Ho-Wen; Chen, Wei-Yea; Chang, Cheng-Nan; Chuang, Yen-Hsun; Lin, Yu-Hao

    2016-06-01

    The recently developed Central Taiwan Science Park (CTSP) in central Taiwan is home to an optoelectronic and semiconductor industrial cluster. Therefore, exploring the elemental compositions and size distributions of airborne particles emitted from the CTSP would help to prevent pollution. This study analyzed size-fractionated metal-rich particle samples collected in upwind and downwind areas of CTSP during Jan. and Oct. 2013 by using micro-orifice uniform deposited impactor (MOUDI). Correlation analysis, hierarchical cluster analysis and particle mass-size distribution analysis are performed to identify the source of metal-rich particle near the CTSP. Analyses of elemental compositions and particle size distributions emitted from the CTSP revealed that the CTSP emits some metals (V, As, In Ga, Cd and Cu) in the ultrafine particles (pollution index for optoelectronic and semiconductor emission in the CTSP. Meanwhile, the ratios of As/Ga concentration at the particle size of 0.32 μm demonstrates that humans near the CTSP would be potentially exposed to GaAs ultrafine particles. That is, metals such as Ga and As and other metals that are not regulated in Taiwan are potentially harmful to human health.

  6. Occupational exposure to airborne particles and other pollutants in an aviation base

    International Nuclear Information System (INIS)

    The occupational exposure to airborne particles and other pollutants in a high performance jet engine airport was investigated. Three spatial scales were considered: i) a downwind receptor site, ii) close to the airstrip, iii) personal monitoring. Particle number, surface area, mass concentrations and distributions were measured as well as inorganic and organic fractions, ionic fractions and Polycyclic Aromatic Hydrocarbons. Particle number distribution measured at a receptor site presents a mode of 80 nm and an average total concentration of 6.5 × 103 part. cm−3; the chemical analysis shows that all the elements may be attributed to long-range transport from the sea. Particle number concentrations in the proximity of the airstrip show short term peaks during the working day mainly related to takeoff, landing and pre-flight operations of jet engines. Personal exposure of workers highlights a median number concentration of 2.5 × 104 part. cm−3 and 1.7 × 104 part. cm−3 for crew chief and hangar operator. - Highlights: ► Air quality measures were performed at different spatial scales in an aviation base. ► Exposure to Polycyclic Aromatic Hydrocarbons was estimated. ► Particles at downwind receptor site show a marine origin typical of a coastal site. ► Main exposure peaks are related to pre-flight operations of jet engine aircrafts. ► Crew chief are exposed to highest concentrations even if these were not worrisome. - A negligible impact of a high performance jet engine airport, in terms of airborne particles and other pollutants, was measured through an experimental campaign at three spatial scales.

  7. A microfluidics-based on-chip impinger for airborne particle collection.

    Science.gov (United States)

    Mirzaee, I; Song, M; Charmchi, M; Sun, H

    2016-06-21

    Capturing airborne particles from air into a liquid is a critical process for the development of many sensors and analytical systems. A miniaturized airborne particle sampling device (microimpinger) has been developed in this research. The microimpinger relies on a controlled bubble generation process produced by driving air through microchannel arrays. The particles confined in the microscale bubbles are captured in the sampling liquid while the bubbles form, are released and travel in a millimetre-scale sealed liquid reservoir. The microchannel arrays in the impinger are fabricated using a soft-lithography method with polydimethylsiloxane (PDMS) as the structural material. To prevent air leakage at the connections, a PDMS-only sealing technique is successfully developed. The hydrophobicity of the microchannel surface is found to be critical for generating continuous and stable bubbles in the bubbling process. A Teflon layer is coated on the walls of a microchannel array by vapor deposition which effectively increases the hydrophobicity of the PDMS. The collection efficiency of the microimpinger is measured by counting different sizes of fluorescent polystyrene latex particles on polycarbonate membrane filters. Collection efficiencies above 90% are achieved. Furthermore, the particle capturing mechanisms during the injection, formation and rise of a single microbubble are investigated by a computational fluid dynamics (CFD) model. The Navier-Stokes equations are solved along with the use of the volume-of-fluid (VOF) method to capture the bubble deformations and the particles are tracked using a Lagrangian equation of motion. The model is also employed to study the effect of bubble size on the collection efficiency of the microimpinger. PMID:27185303

  8. A real-time monitoring system for airborne particle shape and size analysis

    Science.gov (United States)

    Kaye, P. H.; Alexander-Buckley, K.; Hirst, E.; Saunders, S.; Clark, J. M.

    1996-08-01

    This paper describes a new instrument for the study of airborne particles. The instrument performs a rapid analysis of the transient spatial intensity distribution of laser-light scattered by individual aerosol particles drawn from an ambient environment and uses this to characterize the particles in terms of both size and shape parameters. Analyses are carried out at peak particle throughput rates of up to 10,000 particles per second, and semiquantitative data relating to the size and shape (or more correctly asymmetry) spectra of the sampled particles are provided to the user via a graphical display which is refreshed or updated at 5-s intervals. In addition to the real-time display of data, continuous data recording allows subsequent replay of measurements at either normal or high speed. Preliminary experimental results are given for aerosols of both spherical and nonspherical particle types, and these suggest the instrument may find use in environmental monitoring of aerosols or clouds where some real-time semiquantitative assessment of particulate size and shape spectra may be desirable as an aid to characterizing the aerosol and its constituent particulate species.

  9. Characterization of Exposures to Airborne Nanoscale Particles During Friction Stir Welding of Aluminum

    Science.gov (United States)

    Pfefferkorn, Frank E.; Bello, Dhimiter; Haddad, Gilbert; Park, Ji-Young; Powell, Maria; Mccarthy, Jon; Bunker, Kristin Lee; Fehrenbacher, Axel; Jeon, Yongho; Virji, M. Abbas; Gruetzmacher, George; Hoover, Mark D.

    2010-01-01

    Friction stir welding (FSW) is considered one of the most significant developments in joining technology over the last half century. Its industrial applications are growing steadily and so are the number of workers using this technology. To date, there are no reports on airborne exposures during FSW. The objective of this study was to investigate possible emissions of nanoscale (<100 nm) and fine (<1 μm) aerosols during FSW of two aluminum alloys in a laboratory setting and characterize their physicochemical composition. Several instruments measured size distributions (5 nm to 20 μm) with 1-s resolution, lung deposited surface areas, and PM2.5 concentrations at the source and at the breathing zone (BZ). A wide range aerosol sampling system positioned at the BZ collected integrated samples in 12 stages (2 nm to 20 μm) that were analyzed for several metals using inductively coupled plasma mass spectrometry. Airborne aerosol was directly collected onto several transmission electron microscope grids and the morphology and chemical composition of collected particles were characterized extensively. FSW generates high concentrations of ultrafine and submicrometer particles. The size distribution was bimodal, with maxima at ∼30 and ∼550 nm. The mean total particle number concentration at the 30 nm peak was relatively stable at ∼4.0 × 105 particles cm−3, whereas the arithmetic mean counts at the 550 nm peak varied between 1500 and 7200 particles cm−3, depending on the test conditions. The BZ concentrations were lower than the source concentrations by 10–100 times at their respective peak maxima and showed higher variability. The daylong average metal-specific concentrations were 2.0 (Zn), 1.4 (Al), and 0.24 (Fe) μg m−3; the estimated average peak concentrations were an order of magnitude higher. Potential for significant exposures to fine and ultrafine aerosols, particularly of Al, Fe, and Zn, during FSW may exist, especially in larger scale industrial

  10. Characterization of exposures to airborne nanoscale particles during friction stir welding of aluminum.

    Science.gov (United States)

    Pfefferkorn, Frank E; Bello, Dhimiter; Haddad, Gilbert; Park, Ji-Young; Powell, Maria; McCarthy, Jon; Bunker, Kristin Lee; Fehrenbacher, Axel; Jeon, Yongho; Virji, M Abbas; Gruetzmacher, George; Hoover, Mark D

    2010-07-01

    Friction stir welding (FSW) is considered one of the most significant developments in joining technology over the last half century. Its industrial applications are growing steadily and so are the number of workers using this technology. To date, there are no reports on airborne exposures during FSW. The objective of this study was to investigate possible emissions of nanoscale (<100 nm) and fine (<1 microm) aerosols during FSW of two aluminum alloys in a laboratory setting and characterize their physicochemical composition. Several instruments measured size distributions (5 nm to 20 microm) with 1-s resolution, lung deposited surface areas, and PM(2.5) concentrations at the source and at the breathing zone (BZ). A wide range aerosol sampling system positioned at the BZ collected integrated samples in 12 stages (2 nm to 20 microm) that were analyzed for several metals using inductively coupled plasma mass spectrometry. Airborne aerosol was directly collected onto several transmission electron microscope grids and the morphology and chemical composition of collected particles were characterized extensively. FSW generates high concentrations of ultrafine and submicrometer particles. The size distribution was bimodal, with maxima at approximately 30 and approximately 550 nm. The mean total particle number concentration at the 30 nm peak was relatively stable at approximately 4.0 x 10(5) particles cm(-3), whereas the arithmetic mean counts at the 550 nm peak varied between 1500 and 7200 particles cm(-3), depending on the test conditions. The BZ concentrations were lower than the source concentrations by 10-100 times at their respective peak maxima and showed higher variability. The daylong average metal-specific concentrations were 2.0 (Zn), 1.4 (Al), and 0.24 (Fe) microg m(-3); the estimated average peak concentrations were an order of magnitude higher. Potential for significant exposures to fine and ultrafine aerosols, particularly of Al, Fe, and Zn, during FSW may

  11. Immunochemical quantification and particle size distribution of airborne papain in a meat portioning facility.

    Science.gov (United States)

    Swanson, M C; Boiano, J M; Galson, S K; Grauvogel, L W; Reed, C E

    1992-01-01

    The use of enzymes in industry continues to expand. With this increased use comes a concerted need to better understand potential respiratory health hazards to exposed workers and to quantify exposure levels that cause impaired health. To this end, projects were undertaken by the National Institute for Occupational Safety and Health (NIOSH) Health Hazard Evaluations Program and Cole Associates whereby this information was collected. Data concerning medical evaluation and aspects of industrial hygiene are the subjects of two separate reports from these respective groups. This method/results report includes a description of (1) a sensitive immunoradiometric assay for the quantification of airborne papain and its particle size distribution, (2) measurement of papain from both general area and personal breathing zone air samples obtained from a meat processing plant that used this immunochemical analysis, (3) a sampling strategy, and (4) an improved air sample processing technique. Airborne papain was measured at levels ranging from low nanogram to microgram per cubic meter concentrations. Approximately half of the papain activity was associated with particles having an aerodynamic diameter of less than 9.4 microns. These data point to a need for containment and controls in the manufacture and use of such compounds. This approach can be considered by the hygienist as an effective tool to be used in conjunction with epidemiologic studies to help set standards that are practical, safe, and maintained. PMID:1590216

  12. Measurement of the electrostatic charge in airborne particles: II - particle charge distribution of different aerosols

    Directory of Open Access Journals (Sweden)

    M. V. Rodrigues

    2006-03-01

    Full Text Available This work gives sequence to the study on the measurement of the electrostatic charges in aerosols. The particle charge classifier developed for this purpose and presented in the previous paper (Marra and Coury, 2000 has been used here to measure the particle charge distribution of a number of different aerosols. The charges acquired by the particles were naturally derived from the aerosol generation procedure itself. Two types of aerosol generators were used: the vibrating orifice generator and turntable Venturi plate generator. In the vibrating orifice generator, mono-dispersed particles were generated by a solution of water/ethanol/methylene blue, while in the rotating plate generator, six different materials were utilized. The results showed no clear dependence between electric charge and particle diameter for the mono-dispersed aerosol. However, for the poly-dispersed aerosols, a linear dependence between particle size and charge could be noticed.

  13. A Semi-Empirical Airborne Particle Erosion Model for Polyesteric Matrix Fiberglass Composites

    Directory of Open Access Journals (Sweden)

    Valeriu DRAGAN

    2013-12-01

    Full Text Available The paper deals with the mathematical modeling of the airborne solid particle erosion rate of composite materials, in particular non-oriented fiberglass reinforced polyesteric matrices. Using the mathematical tool of non-linear regression, based on experimental data available in the state of the art, an algebraic equation has been determined to estimate the relative erosion rate of such composites. The formulation is tailored so that it relates to classical erosion models such as Finnie’s, Bitter’s or Tulsa angle dependent model which can be implemented into commercial computational fluid dynamics software. Although the implementation - per se - is not described herein, the model proposed can be useful in estimating the global effect of solid particle erosion on composite materials in this class. Further theoretical developments may add to the model the capacity to evaluate the erosion rate for a wider class of matrices as well as more types of weavings.

  14. The effect of airborne particles and weather conditions on pediatric respiratory infections in Cordoba, Argentine

    International Nuclear Information System (INIS)

    We studied the effect of estimated PM10 on respiratory infections in children from Cordoba, Argentine as well as the influence of weather factors, socio-economic conditions and education. We analyzed upper and lower respiratory infections and applied a time-series analysis with a quasi-Poisson distribution link function. To control for seasonally varying factors we fitted cubic smoothing splines of date. We also examined community-specific parameters and differences in susceptibility by sex. We found a significant association between particles and respiratory infections. This relationship was affected by mean temperature, atmospheric pressure and wind speed. These effects were stronger in fall, winter and spring for upper respiratory infections while for lower respiratory infections the association was significant only during spring. Low socio-economic conditions and low education levels increased the risk of respiratory infections. These findings add useful information to understand the influence of airborne particles on children health in developing countries. - Highlights: ► Few information is available on children respiratory health from developing countries. ► We modeled the association between PM10 and children's respiratory infections. ► We checked the influence of weather factors, socio-economic conditions, education and sex. ► Temperature, pressure and wind speed modified the effect of particles. ► Low socio-economic conditions and low education levels increased the risk of infections. - The concentration of airborne particles as well as low socio-economic conditions and low education levels are significant risk factors for upper and lower respiratory infections in children from Cordoba, Argentine.

  15. Laboratory testing of airborne brake wear particle emissions using a dynamometer system under urban city driving cycles

    Science.gov (United States)

    Hagino, Hiroyuki; Oyama, Motoaki; Sasaki, Sousuke

    2016-04-01

    To measure driving-distance-based mass emission factors for airborne brake wear particulate matter (PM; i.e., brake wear particles) related to the non-asbestos organic friction of brake assembly materials (pads and lining), and to characterize the components of brake wear particles, a brake wear dynamometer with a constant-volume sampling system was developed. Only a limited number of studies have investigated brake emissions under urban city driving cycles that correspond to the tailpipe emission test (i.e., JC08 or JE05 mode of Japanese tailpipe emission test cycles). The tests were performed using two passenger cars and one middle-class truck. The observed airborne brake wear particle emissions ranged from 0.04 to 1.4 mg/km/vehicle for PM10 (particles up to 10 μm (in size), and from 0.04 to 1.2 mg/km/vehicle for PM2.5. The proportion of brake wear debris emitted as airborne brake wear particles was 2-21% of the mass of wear. Oxygenated carbonaceous components were included in the airborne PM but not in the original friction material, which indicates that changes in carbon composition occurred during the abrasion process. Furthermore, this study identified the key tracers of brake wear particles (e.g., Fe, Cu, Ba, and Sb) at emission levels comparable to traffic-related atmospheric environments.

  16. Treatment of airborne asbestos and asbestos-like microfiber particles using atmospheric microwave air plasma

    International Nuclear Information System (INIS)

    Highlights: → We use atmospheric microwave air plasma to treat ceramic fiber and stainless fiber as asbestos alike micro fiber particle. → Spheroidization of certain type of ceramic fiber and stainless fiber particle. → The evaluation of the treated particles by the fiber vanishing rate. → Good fiber vanishing rate is observed for fiber particle with diameter below 10 μm. → The treatment of pure asbestos and a suggestion of the use of this method for the treatment airborne asbestos. - Abstract: Atmospheric microwave air plasma was used to treat asbestos-like microfiber particles that had two types of ceramic fiber and one type of stainless fiber. The treated particles were characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). The experiment results showed that one type of ceramic fiber (Alumina:Silica = 1:1) and the stainless fiber were spheroidized, but the other type of ceramic fiber (Alumina:Silica = 7:3) was not. The conversion of the fibers was investigated by calculating the equivalent diameter, the aspect ratio, and the fiber content ratio. The fiber content ratio in various conditions showed values near zero. The relationship between the normalized fiber vanishing rate and the energy needed to melt the particles completely per unit surface area of projected particles, which is defined as η, was examined and seen to indicate that the normalized fiber vanishing rate decreased rapidly with the increase in η. Finally, some preliminary experiments for pure asbestos were conducted, and the analysis via XRD and phase-contrast microscopy (PCM) showed the availability of the plasma treatment.

  17. Treatment of airborne asbestos and asbestos-like microfiber particles using atmospheric microwave air plasma

    Energy Technology Data Exchange (ETDEWEB)

    Averroes, A., E-mail: aulia.a.aa@m.titech.ac.jp [Department of Chemical Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan); Sekiguchi, H. [Department of Chemical Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan); Sakamoto, K. [Street Design Corporation, 6-9-30 Shimo odanaka, Kawasaki-shi, Kanagawa 211-0041 (Japan)

    2011-11-15

    Highlights: {yields} We use atmospheric microwave air plasma to treat ceramic fiber and stainless fiber as asbestos alike micro fiber particle. {yields} Spheroidization of certain type of ceramic fiber and stainless fiber particle. {yields} The evaluation of the treated particles by the fiber vanishing rate. {yields} Good fiber vanishing rate is observed for fiber particle with diameter below 10 {mu}m. {yields} The treatment of pure asbestos and a suggestion of the use of this method for the treatment airborne asbestos. - Abstract: Atmospheric microwave air plasma was used to treat asbestos-like microfiber particles that had two types of ceramic fiber and one type of stainless fiber. The treated particles were characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). The experiment results showed that one type of ceramic fiber (Alumina:Silica = 1:1) and the stainless fiber were spheroidized, but the other type of ceramic fiber (Alumina:Silica = 7:3) was not. The conversion of the fibers was investigated by calculating the equivalent diameter, the aspect ratio, and the fiber content ratio. The fiber content ratio in various conditions showed values near zero. The relationship between the normalized fiber vanishing rate and the energy needed to melt the particles completely per unit surface area of projected particles, which is defined as {eta}, was examined and seen to indicate that the normalized fiber vanishing rate decreased rapidly with the increase in {eta}. Finally, some preliminary experiments for pure asbestos were conducted, and the analysis via XRD and phase-contrast microscopy (PCM) showed the availability of the plasma treatment.

  18. Airborne bacteria transported with Sahara dust particles from Northern Africa to the European Alps

    Science.gov (United States)

    Lazzaro, A.; Meola, M.

    2015-12-01

    The Sahara Desert is the most important source of aerosols transported across the Mediterranean towards Europe. Airborne microorganisms associated with aerosols may be transported over long distances and act as colonizers of distant habitats. However, little is known on the composition and viability of such microorganisms, due to difficulties related to their detection, collection and isolation. Here we describe an in-depth assessment of the bacterial communities associated with Sahara dust (SD) particles deposited on snow. Two distinct SD events reaching the European Alps in February and May 2014 were preserved as distinct ochre-coloured layers within the snowpack. In June 2014, we collected samples from a snow profile at 3621 m a.s.l. close to the Jungfraujoch (Swiss Alps). SD particles were analyzed by Scanning Electron Microscopy and Energy-Dispersive X-Ray Spectroscopy (SEM-EDX). Backward trajectories were calculated using the NOAA HYSPLIT model. Bacterial communities were charac-terized by MiSeq Illumina sequencing of the 16S rRNA gene. Microbial physiological profiles were assessed by incubation of samples on BIOLOG plates. The SD-layers were generally enriched in illite and kaolinite particles as compared to the adjacent snow layers. The source of SD could be traced back to Algeria. We observed distinct bacterial community structures in the SD-layers as compared to the clean snow layers. While sporulating bacteria were not enriched in the SD-layers, low abundant (Deinococcus-Thermus appeared to be specific bioindicators for SD. Both phyla are adapted to arid oligotrophic environments and UV radiation and thus are well suited to survive the harsh conditions of long-distance airborne transport. Our results show that bacteria are viable and metabolically active after the trek to the European Alps.

  19. Chemical and isotopic properties and origin of coarse airborne particles collected by passive samplers in industrial, urban, and rural environments

    Science.gov (United States)

    Guéguen, Florence; Stille, Peter; Dietze, Volke; Gieré, Reto

    2012-12-01

    Passive air samplers have been installed in industrial, urban, rural and remote forested environments in order to collect coarse airborne particles for subsequent chemical characterization. To identify principal polluting sources, isotopic tracers, such as Sr, Nd and Pb isotopic ratios, have been used. The mass deposition rates (MDRs) of trace metals, determined for each of the studied environments, clearly indicate that industrial and traffic sites are especially affected by air pollution. Elements such as V, Pb, Fe, Cr, Co, Mo, Cd, Ni, As, Sb and Zn are notably enriched in samples from industrial zones, whereas V, Mn, Ba, Sr, Al, U, Th, rare earth elements (REE), Zr, Y, Cs, Rb, Sb, Sn and Cu are principal components of the airborne particles collected close to areas influenced by heavy traffic. The chemical/isotopic baseline composition derived from the airborne particles is the result of mixing of particles from different industrial sources, traffic and fertilizers. The monthly analysis of trace-metal MDRs of the collected airborne particle samples from different stations around the industrial zone allows for the detection of distinct atmospheric dust-deposition events during the year, characterized by high MDRs. "Natural" dusts from regional soil re-suspension, including from more distant regions like the Sahara desert, might overprint the regional atmospheric baseline composition, as suggested by trace metal trajectories in ternary diagrams and by Sr, Nd and Pb isotope data.

  20. Assessment of oxidative DNA damage formation by organic complex mixtures from airborne particles PM(10).

    Science.gov (United States)

    Gábelová, Alena; Valovicová, Zuzana; Lábaj, Juraj; Bacová, Gabriela; Binková, Blanka; Farmer, Peter B

    2007-07-01

    The free radical generating activity of airborne particulate matter (PM(10)) has been proposed as a primary mechanism in biological activity of ambient air pollution. In an effort to determine the impact of the complex mixtures of extractable organic matter (EOM) from airborne particles on oxidative damage to DNA, the level of 8-oxo-2'-deoxyguanosine (8-oxodG), the most prevalent and stable oxidative lesion, was measured in the human metabolically competent cell line Hep G2. Cultured cells were exposed to equivalent EOM concentrations (5-150microg/ml) and oxidative DNA damage was analyzed using a modified single cell gel electrophoresis (SCGE), which involves the incubation of whole cell DNA with repair specific DNA endonuclease, which cleaves oxidized DNA at the sites of 8-oxodG. EOMs were extracted from PM(10) collected daily (24h intervals) in three European cities: Prague (Czech Republic, two monitoring sites, Libus and Smíchov), Kosice (Slovak Republic) and Sofia (Bulgaria) during 3-month sampling periods in the winter and summer seasons. No substantial time- and dose-dependent increase of oxidative DNA lesions was detected in EOM-treated cells with the exception of the EOM collected at the monitoring site Kosice, summer sampling. In this case, 2h cell exposure to EOM resulted in a slight but significant increase of oxidative DNA damage at three from total of six concentrations. The mean 8-oxodG values at these concentrations ranged from 15.3 to 26.1 per 10(6) nucleotides with a value 3.5 per 10(6) nucleotides in untreated cells. B[a]P, the positive control, induced a variable but insignificant increase of oxidative DNA damage in Hep G2 cell (approximately 1.6-fold increase over control value). Based on these data we believe that EOM samples extracted from airborne particle PM(10) play probably only a marginal role in oxidative stress generation and oxidative lesion formation to DNA. However, adsorbed organic compounds can undergo various interactions

  1. Characterisation of airborne particles and associated organic components produced from incense burning.

    Science.gov (United States)

    Chuang, Hsiao-Chi; Jones, Tim; Chen, Yang; Bell, Jennifer; Wenger, John; BéruBé, Kelly

    2011-12-01

    Airborne particles generated from the burning of incense have been characterized in order to gain an insight into the possible implications for human respiratory health. Physical characterization performed using field-emission scanning electron microscopy showed incense particulate smoke mainly consisted of soot particles with fine and ultrafine fractions in various aggregated forms. A range of organic compounds present in incense smoke have been identified using derivatisation reactions coupled with gas chromatography-mass spectrometry analysis. A total of 19 polar organic compounds were positively identified in the samples, including the biomass burning markers levoglucosan, mannosan and galactosan, as well as a number of aromatic acids and phenols. Formaldehyde was among 12 carbonyl compounds detected and predominantly associated with the gas phase, whereas six different quinones were also identified in the incense particulate smoke. The nano-structured incense soot particles intermixed with organics (e.g. formaldehyde and quinones) could increase the oxidative capacity. When considering the worldwide prevalence of incense burning and resulting high respiratory exposures, the oxygenated organics identified in this study have significant human health implications, especially for susceptible populations.

  2. Alternate particle removal technologies for the Airborne Activity Confinement System at the Savannah River Site

    International Nuclear Information System (INIS)

    This report presents a review of the filtration technologies available for the removal of particulate material from a gas stream. It was undertaken to identify alternate filtration technologies that may be employed in the Airborne Activity Confinement System (AACS) at the Savannah River Plant. This report is organized into six sections: (1) a discussion of the aerosol source term and its definition, (2) a short discussion of particle and gaseous contaminant removal mechanisms, (3) a brief overview of particle removal technologies, (4) a discussion of the existing AACS and its potential shortcomings, (5) an enumeration of issues to be addressed in upgrading the AACS, and, (6) a detailed discussion of the identified technologies. The purpose of this report is to identity available options to the existing particle removal system. This system is in continuous operation during routine operation of the reactor. As will be seen, there are a number of options and the selection of any technology or combination of technologies will depend on the design aerosol source term (yet to be appropriately defined) as well as the flow requirements and configuration. This report does not select a specific technology. It focuses on particulate removal and qualitatively on the removal of radio-iodine and mist elimination. Candidate technologies have been selected from industrial and nuclear gas cleaning applications

  3. Alternate particle removal technologies for the Airborne Activity Confinement System at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Brockmann, J.E.; Adkins, C.L.J.; Gelbard, F. (Sandia National Labs., Albuquerque, NM (United States))

    1991-09-01

    This report presents a review of the filtration technologies available for the removal of particulate material from a gas stream. It was undertaken to identify alternate filtration technologies that may be employed in the Airborne Activity Confinement System (AACS) at the Savannah River Plant. This report is organized into six sections: (1) a discussion of the aerosol source term and its definition, (2) a short discussion of particle and gaseous contaminant removal mechanisms, (3) a brief overview of particle removal technologies, (4) a discussion of the existing AACS and its potential shortcomings, (5) an enumeration of issues to be addressed in upgrading the AACS, and, (6) a detailed discussion of the identified technologies. The purpose of this report is to identity available options to the existing particle removal system. This system is in continuous operation during routine operation of the reactor. As will be seen, there are a number of options and the selection of any technology or combination of technologies will depend on the design aerosol source term (yet to be appropriately defined) as well as the flow requirements and configuration. This report does not select a specific technology. It focuses on particulate removal and qualitatively on the removal of radio-iodine and mist elimination. Candidate technologies have been selected from industrial and nuclear gas cleaning applications.

  4. Determination of chemical composition of individual airborne particles by SEM/EDX and micro-Raman spectrometry: A review

    Science.gov (United States)

    Stefaniak, E. A.; Buczynska, A.; Novakovic, V.; Kuduk, R.; Van Grieken, R.

    2009-04-01

    The strategies for sampling and analysis by SEM/EDX and micro-Raman spectrometry for individual airborne particles analysis as applied at the University of Antwerp (Belgium) by the MITAC group have been reviewed. Microbeam techniques provide detailed information concerning the origin, formation, transport, reactivity, transformation reactions and environmental impact of particulate matter. Moreover, some particles of certain chemical properties have been recognized as a threat for human health and cultural heritage objects. However, the small sizes of particles result in specific problems with respect to single particle analysis. Development of equipment and software for improvement of analysis and quantification are reported.

  5. Association of the mutagenicity of airborne particles with the direct emission from combustion processes investigated in Osaka, Japan

    Science.gov (United States)

    Kameda, Takayuki; Sanukida, Satoshi; Inazu, Koji; Hisamatsu, Yoshiharu; Maeda, Yasuaki; Takenaka, Norimichi; Bandow, Hiroshi

    The association of the direct-acting mutagenicity of soluble organic fraction of airborne particles toward Salmonella typhimurium YG1024 strain with the direct emission was investigated at a roadside and at a residential area in Osaka, Japan. The direct-acting mutagenicity was evaluated as mutagenic activity per unit volume of ambient air (rev m -3) and/or that per airborne particulate weight collected on a filter (rev mg -1). The annual or diurnal changes of the mutagenicity of airborne particles at the residential site showed similar patterns to those of some gaseous pollutants such as NO 2 and SO 2, which were emitted from combustion processes. This result indicates that the mutagenicity is mainly attributable to the primary emissions. From the analysis of the relationship between the wind sector and the mutagenic intensity, rev m -3 and rev mg -1 values were strongly affected by the emissions from the fixed sources and from the mobile sources, respectively. The rev m -3 value and concentration of 1-nitropyrene (1-NP) in unit per m 3 at the roadside were a factor of 2.6 and 2.8 higher than those at the residential site, respectively, but the rev mg -1 value and concentration of 1-NP in unit per mg at the roadside were substantially comparable to those at the residential area. These observations suggest that the characteristics of the airborne particles can be attributed to the automotive emissions even at the suburban area.

  6. Instrument for Long-Path Spectral Extinction Measurements in Air: Application to Sizing of Airborne Particles

    Science.gov (United States)

    Paganini, Enrico; Trespidi, Franco; Ferri, Fabio

    2001-08-01

    A novel instrument that is capable of taking spectral extinction measurements over long optical paths (approximately 1 -100 m) in the UV, visible, and IR ranges is described. The instrument is fully automated, and the extinction spectrum is acquired in almost real time (approximately 5 -10 s) with a resolution of ~3 nm. Its sensitivity and accuracy were estimated by tests carried out in a clean room that showed that, for optical paths between 50 and 100 m, the extinction coefficient can be detected at levels of ~10-5 m-1 . Tests carried out on calibrated latex particles showed that, when it was combined with an appropriate inversion method, the technique could be profitably applied to characterize airborne particulate distributions. By carrying out measurements over optical paths of ~100 m, the instrument is also capable of detecting extinction coefficients that are due to aerosol concentrations well below the limits imposed by the European Economic Community for atmospheric pollution (150 g /m3 ). Scaled over optical paths of ~10 m, the limit imposed for particle emissions from industrial plants (10 mg /m3 ) can also be detected sensitively.

  7. MEMS-based silicon cantilevers with integrated electrothermal heaters for airborne ultrafine particle sensing

    Science.gov (United States)

    Wasisto, Hutomo Suryo; Merzsch, Stephan; Waag, Andreas; Peiner, Erwin

    2013-05-01

    The development of low-cost and low-power MEMS-based cantilever sensors for possible application in hand-held airborne ultrafine particle monitors is described in this work. The proposed resonant sensors are realized by silicon bulk micromachining technology with electrothermal excitation, piezoresistive frequency readout, and electrostatic particle collection elements integrated and constructed in the same sensor fabrication process step of boron diffusion. Built-in heating resistor and full Wheatstone bridge are set close to the cantilever clamp end for effective excitation and sensing, respectively, of beam deflection. Meanwhile, the particle collection electrode is located at the cantilever free end. A 300 μm-thick, phosphorus-doped silicon bulk wafer is used instead of silicon-on-insulator (SOI) as the starting material for the sensors to reduce the fabrication costs. To etch and release the cantilevers from the substrate, inductively coupled plasma (ICP) cryogenic dry etching is utilized. By controlling the etching parameters (e.g., temperature, oxygen content, and duration), cantilever structures with thicknesses down to 10 - 20 μm are yielded. In the sensor characterization, the heating resistor is heated and generating thermal waves which induce thermal expansion and further cause mechanical bending strain in the out-of-plane direction. A resonant frequency of 114.08 +/- 0.04 kHz and a quality factor of 1302 +/- 267 are measured in air for a fabricated rectangular cantilever (500x100x13.5 μm3). Owing to its low power consumption of a few milliwatts, this electrothermal cantilever is suitable for replacing the current external piezoelectric stack actuator in the next generation of the miniaturized cantilever-based nanoparticle detector (CANTOR).

  8. The white-light humidified optical particle spectrometer (WHOPS – a novel airborne system to characterize aerosol hygroscopicity

    Directory of Open Access Journals (Sweden)

    B. Rosati

    2014-07-01

    3% and maximal deviation of 9% for GFs at RH = 95%. First airborne measurements in the Netherlands observed GFs (mean value of the GF distribution at RH = 95% between 1.74 and 2.67 with a median of 1.94 for particles with a dry diameter of 500 nm. This corresponds to hygroscopicity parameters (κ between 0.21 and 0.93 with a median of 0.33. The GF distributions indicate externally mixed particles covering the whole range of GFs between ~ 1.0–3.0. On average ~ 74% of the particles were "more hygroscopic" with GFs > 1.5, ~ 15% were non- or slightly hygroscopic with GF 2, indicating influence of sea salt particles, consistent with previous ground-based particle hygroscopicity measurements in this area. The mean dry effective index of refraction for 500 nm particles was found to be rather constant with a value of 1.42 ± 0.04.

  9. Application examples of APC-03-2 and APC-03-2A airborne particle counters under various contamination conditions

    International Nuclear Information System (INIS)

    Several application examples of the airborne particle counters APC-03-2 and APC-03-2A for monitoring particle size distribution and concentration in air and other gases are described. The computer controlled fast data evaluation and storage provide efficient presentation of the measured data in a variety of table- and histogram-forms, presenting of alarm levels for each size range, observation of alarm history, etc. The device can be applied not only for clean room monitoring and laminar box testing, but also for measuring contamination in health care facilities in workshops using hazardous airborne compounds (e.g. in pharmacology), and in toxicology where the concentration of the contamination may be very high. (author)

  10. Beryllium solubility in occupational airborne particles: Sequential extraction procedure and workplace application.

    Science.gov (United States)

    Rousset, Davy; Durand, Thibaut

    2016-01-01

    Modification of an existing sequential extraction procedure for inorganic beryllium species in the particulate matter of emissions and in working areas is described. The speciation protocol was adapted to carry out beryllium extraction in closed-face cassette sampler to take wall deposits into account. This four-step sequential extraction procedure aims to separate beryllium salts, metal, and oxides from airborne particles for individual quantification. Characterization of the beryllium species according to their solubility in air samples may provide information relative to toxicity, which is potentially related to the different beryllium chemical forms. Beryllium salts (BeF(2), BeSO(4)), metallic beryllium (Bemet), and beryllium oxide (BeO) were first individually tested, and then tested in mixtures. Cassettes were spiked with these species and recovery rates were calculated. Quantitative analyses with matched matrix were performed using inductively coupled plasma mass spectrometry (ICP-MS). Method Detection Limits (MDLs) were calculated for the four matrices used in the different extraction steps. In all cases, the MDL was below 4.2 ng/sample. This method is appropriate for assessing occupational exposure to beryllium as the lowest recommended threshold limit values are 0.01 µg.m(-3) in France([) (1) (]) and 0.05 µg.m(-3) in the USA.([ 2 ]) The protocol was then tested on samples from French factories where occupational beryllium exposure was suspected. Beryllium solubility was variable between factories and among the same workplace between different tasks. PMID:26327570

  11. Health effects of daily airborne particle dose in children: Direct association between personal dose and respiratory health effects

    International Nuclear Information System (INIS)

    Air pollution is a widespread health problem associated with respiratory symptoms. Continuous exposure monitoring was performed to estimate alveolar and tracheobronchial dose, measured as deposited surface area, for 103 children and to evaluate the long-term effects of exposure to airborne particles through spirometry, skin prick tests and measurement of exhaled nitric oxide (eNO). The mean daily alveolar deposited surface area dose received by children was 1.35 × 103 mm2. The lowest and highest particle number concentrations were found during sleeping and eating time. A significant negative association was found between changes in pulmonary function tests and individual dose estimates. Significant differences were found for asthmatics, children with allergic rhinitis and sensitive to allergens compared to healthy subjects for eNO. Variation is a child's activity over time appeared to have a strong impact on respiratory outcomes, which indicates that personal monitoring is vital for assessing the expected health effects of exposure to particles. -- Highlights: •Particle dose was estimated through personal monitoring on more than 100 children. •We focused on real-time daily dose of particle alveolar deposited surface area. •Spirometry, skin prick and exhaled Nitric Oxide tests were performed. •Negative link was found between changes in pulmonary functions and individual doses. •A child's lifestyle appeared to have a strong impact on health respiratory outcomes. -- The respiratory health effects of daily airborne particle dose on children through personal monitoring

  12. Characterizing the impact of urban emissions on regional aerosol particles; airborne measurements during the MEGAPOLI experiment

    Directory of Open Access Journals (Sweden)

    E. J. Freney

    2013-09-01

    Full Text Available The MEGAPOLI experiment took place in July 2009. The aim of this campaign was to study the aging and reactions of aerosol and gas-phase emissions in the city of Paris. Three ground-based measurement sites and several mobile platforms including instrument equipped vehicles and the ATR-42 aircraft were involved. We present here the variations in particle- and gas-phase species over the city of Paris using a combination of high-time resolution measurements aboard the ATR-42 aircraft. Particle chemical composition was measured using a compact time-of-flight aerosol mass spectrometer (C-ToF-AMS giving detailed information of the non-refractory submicron aerosol species. The mass concentration of BC, measured by a particle absorption soot photometer (PSAP, was used as a marker to identify the urban pollution plume boundaries. Aerosol mass concentrations and composition were affected by air-mass history, with air masses that spent longest time over land having highest fractions of organic aerosol and higher total mass concentrations. The Paris plume is mainly composed of organic aerosol (OA, black carbon and nitrate aerosol, as well as high concentrations of anthropogenic gas-phase species such as toluene, benzene, and NOx. Using BC and CO as tracers for air-mass dilution, we observe the ratio of ΔOA / ΔBC and ΔOA / ΔCO increase with increasing photochemical age (−log(NOx / NOy. Plotting the equivalent ratios for the Positive Matrix Factorization (PMF resolved species (LV-OOA, SV-OOA, and HOA illustrate that the increase in OA is a result of secondary organic aerosol (SOA. Within Paris the changes in the ΔOA / ΔCO are similar to those observed during other studies in Mexico city, Mexico and in New England, USA. Using the measured VOCs species together with recent organic aerosol formation yields we predicted ~ 50% of the measured organics. These airborne measurements during the MEGAPOLI experiment show that urban emissions contribute to the

  13. Airborne measurements over the boreal forest of southern Finland during new particle formation events in 2009 and 2010

    Energy Technology Data Exchange (ETDEWEB)

    Schobesberger, S.; Vaananen, R.; Leino, K. [Helsinki Univ. (Finland). Dept. of Physics, Division of Atmospheric Sciences] [and others

    2013-06-01

    We conducted airborne observations of aerosol physical properties over the southern Finland boreal forest environment. The aim was to investigate the lower tropospheric aerosol (up to 4-km altitude) over an area of 250 by 200 km, in particular during new particle formation (NPF) events, and to address the spatial variability of aerosol number concentration and number size distribution. The regional NPF events, detected both airborne and at the ground, with air masses originating from the Arctic or northern Atlantic Ocean were studied throughout the boundary layer and throughout the area covered. Three suitable case studies are presented in more detail. In two of these studies, the concentrations of nucleation mode particles (3-10 nm in diameter) were found considerably higher (up to a factor of 30) in the upper parts of the planetary boundary layer compared to ground-based measurements during the nucleation events. The observed vertical variation can be connected to boundary layer dynamics and interactions between the boundary layer and the lower free troposphere, likely yielding high concentrations of newly formed aerosol particles. Our results suggest that nucleation does not necessarily occur close to the surface. In one presented case we found evidence of NPF occurring in a limited area above cloud, in the complete absence of a regional NPF event. (orig.)

  14. Airborne instruments to measure atmospheric aerosol particles, clouds and radiation: A cook's tour of mature and emerging technology

    Science.gov (United States)

    Baumgardner, D.; Brenguier, J. L.; Bucholtz, A.; Coe, H.; DeMott, P.; Garrett, T. J.; Gayet, J. F.; Hermann, M.; Heymsfield, A.; Korolev, A.; Krämer, M.; Petzold, A.; Strapp, W.; Pilewskie, P.; Taylor, J.; Twohy, C.; Wendisch, M.; Bachalo, W.; Chuang, P.

    2011-10-01

    An overview is presented of airborne systems for in situ measurements of aerosol particles, clouds and radiation that are currently in use on research aircraft around the world. Description of the technology is at a level sufficient for introducing the basic principles of operation and an extensive list of references for further reading is given. A number of newer instruments that implement emerging technology are described and the review concludes with a description of some of the most important measurement challenges that remain. This overview is a synthesis of material from a reference book that is currently in preparation and that will be published in 2012 by Wiley.

  15. PHIPS-HALO: the airborne Particle Habit Imaging and Polar Scattering probe - Part 1: Design and operation

    Science.gov (United States)

    Abdelmonem, Ahmed; Järvinen, Emma; Duft, Denis; Hirst, Edwin; Vogt, Steffen; Leisner, Thomas; Schnaiter, Martin

    2016-07-01

    The number and shape of ice crystals present in mixed-phase and ice clouds influence the radiation properties, precipitation occurrence and lifetime of these clouds. Since clouds play a major role in the climate system, influencing the energy budget by scattering sunlight and absorbing heat radiation from the earth, it is necessary to investigate the optical and microphysical properties of cloud particles particularly in situ. The relationship between the microphysics and the single scattering properties of cloud particles is usually obtained by modelling the optical scattering properties from in situ measurements of ice crystal size distributions. The measured size distribution and the assumed particle shape might be erroneous in case of non-spherical ice particles. There is a demand to obtain both information correspondently and simultaneously for individual cloud particles in their natural environment. For evaluating the average scattering phase function as a function of ice particle habit and crystal complexity, in situ measurements are required. To this end we have developed a novel airborne optical sensor (PHIPS-HALO) to measure the optical properties and the corresponding microphysical parameters of individual cloud particles simultaneously. PHIPS-HALO has been tested in the AIDA cloud simulation chamber and deployed in mountain stations as well as research aircraft (HALO and Polar 6). It is a successive version of the laboratory prototype instrument PHIPS-AIDA. In this paper we present the detailed design of PHIPS-HALO, including the detection mechanism, optical design, mechanical construction and aerodynamic characterization.

  16. Toxic effects of indoor and outdoor airborne particles relevant to carcinogenesis.

    NARCIS (Netherlands)

    Heussen, G.A.H.

    1993-01-01

    The mutagenicity of indoor and outdoor airborne particulate matter (APM) has been demonstrated by previous in vitro studies (Alink et al., 1983; Van Houdt et al., 1984, 1986, 1987). The aim of the present thesis was to contribute to a better understanding of the mode of action of AIM in the pathogen

  17. Particle Size Distribution of Airborne Microorganisms and Pathogens during an Intense African Dust Event in the Eastern Mediterranean

    Science.gov (United States)

    Polymenakou, Paraskevi N.; Mandalakis, Manolis; Stephanou, Euripides G.; Tselepides, Anastasios

    2008-01-01

    Background The distribution of microorganisms, and especially pathogens, over airborne particles of different sizes has been ignored to a large extent, but it could have significant implications regarding the dispersion of these microorganisms across the planet, thus affecting human health. Objectives We examined the microbial quality of the aerosols over the eastern Mediterranean region during an African storm to determine the size distribution of microorganisms in the air. Methods We used a five-stage cascade impactor for bioaerosol collection in a coastal city on the eastern Mediterranean Sea during a north African dust storm. Bacterial communities associated with aerosol particles of six different size ranges were characterized following molecular culture–independent methods, regardless of the cell culturability (analysis of 16S rRNA genes). Results All 16S rDNA clone libraries were diverse, including sequences commonly found in soil and marine ecosystems. Spore-forming bacteria such as Firmicutes dominated large particle sizes (> 3.3 μm), whereas clones affiliated with Actinobacteria (found commonly in soil) and Bacteroidetes (widely distributed in the environment) gradually increased their abundance in aerosol particles of reduced size (< 3.3 μm). A large portion of the clones detected at respiratory particle sizes (< 3.3 μm) were phylogenetic neighbors to human pathogens that have been linked to several diseases. Conclusions The presence of aerosolized bacteria in small size particles may have significant implications to human health via intercontinental transportation of pathogens. PMID:18335093

  18. Comparison of Three Real-Time Measurement Methods for Airborne Ultrafine Particles in the Silicon Alloy Industry

    Directory of Open Access Journals (Sweden)

    Ida Teresia Kero

    2016-09-01

    Full Text Available The aim of this study was to compare the applicability and the correlation between three commercially available instruments capable of detection, quantification, and characterization of ultrafine airborne particulate matter in the industrial setting of a tapping area in a silicon alloy production plant. The number concentration of ultrafine particles was evaluated using an Electric Low Pressure Impactor (ELPITM, a Fast Mobility Particle Sizer (FMPSTM, and a Condensation Particle Counter (CPC. The results are discussed in terms of particle size distribution and temporal variations linked to process operations. The instruments show excellent temporal covariation and the correlation between the FMPS and ELPI is good. The advantage of the FMPS is the excellent time- and size resolution of the results. The main advantage of the ELPI is the possibility to collect size-fractionated samples of the dust for subsequent analysis by, for example, electron microscopy. The CPC does not provide information about the particle size distribution and its correlation to the other two instruments is somewhat poor. Nonetheless, the CPC gives basic, real-time information about the ultrafine particle concentration and can therefore be used for source identification.

  19. Comparison of Three Real-Time Measurement Methods for Airborne Ultrafine Particles in the Silicon Alloy Industry.

    Science.gov (United States)

    Kero, Ida Teresia; Jørgensen, Rikke Bramming

    2016-01-01

    The aim of this study was to compare the applicability and the correlation between three commercially available instruments capable of detection, quantification, and characterization of ultrafine airborne particulate matter in the industrial setting of a tapping area in a silicon alloy production plant. The number concentration of ultrafine particles was evaluated using an Electric Low Pressure Impactor (ELPI(TM)), a Fast Mobility Particle Sizer (FMPS(TM)), and a Condensation Particle Counter (CPC). The results are discussed in terms of particle size distribution and temporal variations linked to process operations. The instruments show excellent temporal covariation and the correlation between the FMPS and ELPI is good. The advantage of the FMPS is the excellent time- and size resolution of the results. The main advantage of the ELPI is the possibility to collect size-fractionated samples of the dust for subsequent analysis by, for example, electron microscopy. The CPC does not provide information about the particle size distribution and its correlation to the other two instruments is somewhat poor. Nonetheless, the CPC gives basic, real-time information about the ultrafine particle concentration and can therefore be used for source identification.

  20. Comparison of Three Real-Time Measurement Methods for Airborne Ultrafine Particles in the Silicon Alloy Industry

    Science.gov (United States)

    Kero, Ida Teresia; Jørgensen, Rikke Bramming

    2016-01-01

    The aim of this study was to compare the applicability and the correlation between three commercially available instruments capable of detection, quantification, and characterization of ultrafine airborne particulate matter in the industrial setting of a tapping area in a silicon alloy production plant. The number concentration of ultrafine particles was evaluated using an Electric Low Pressure Impactor (ELPITM), a Fast Mobility Particle Sizer (FMPSTM), and a Condensation Particle Counter (CPC). The results are discussed in terms of particle size distribution and temporal variations linked to process operations. The instruments show excellent temporal covariation and the correlation between the FMPS and ELPI is good. The advantage of the FMPS is the excellent time- and size resolution of the results. The main advantage of the ELPI is the possibility to collect size-fractionated samples of the dust for subsequent analysis by, for example, electron microscopy. The CPC does not provide information about the particle size distribution and its correlation to the other two instruments is somewhat poor. Nonetheless, the CPC gives basic, real-time information about the ultrafine particle concentration and can therefore be used for source identification. PMID:27598180

  1. Comparison of Three Real-Time Measurement Methods for Airborne Ultrafine Particles in the Silicon Alloy Industry.

    Science.gov (United States)

    Kero, Ida Teresia; Jørgensen, Rikke Bramming

    2016-01-01

    The aim of this study was to compare the applicability and the correlation between three commercially available instruments capable of detection, quantification, and characterization of ultrafine airborne particulate matter in the industrial setting of a tapping area in a silicon alloy production plant. The number concentration of ultrafine particles was evaluated using an Electric Low Pressure Impactor (ELPI(TM)), a Fast Mobility Particle Sizer (FMPS(TM)), and a Condensation Particle Counter (CPC). The results are discussed in terms of particle size distribution and temporal variations linked to process operations. The instruments show excellent temporal covariation and the correlation between the FMPS and ELPI is good. The advantage of the FMPS is the excellent time- and size resolution of the results. The main advantage of the ELPI is the possibility to collect size-fractionated samples of the dust for subsequent analysis by, for example, electron microscopy. The CPC does not provide information about the particle size distribution and its correlation to the other two instruments is somewhat poor. Nonetheless, the CPC gives basic, real-time information about the ultrafine particle concentration and can therefore be used for source identification. PMID:27598180

  2. Airborne spectral radiation measurements to derive solar radiative forcing of Saharan dust mixed with biomass burning smoke particles

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, S.; Bierwirth, E.; Wendisch, M. (Leipzig Inst. for Meteorology (LIM), Univ. of Leipzig, Leipzig (Germany)), e-mail: s.bauer@uni-leipzig.de; Esselborn, M.; Petzold, A.; Trautmann, T. (Deutsches Zentrum fur Luft- und Raumfahrt (DLR), Oberpfaffenhofen (Germany)); Macke, A. (Leibniz Inst. for Tropospheric Research (IfT) (Germany))

    2011-09-15

    Airborne measurements of upward solar spectral irradiances were performed during the second Saharan Mineral dUst experiMent (SAMUM-2) campaign based on the Cape Verde Islands. Additionally, airborne high resolution lidar measurements of vertical profiles of particle extinction coefficients were collected in parallel to the radiation data. Aerosol layers of Saharan dust, partly mixed with biomass-burning smoke, were probed. With corresponding radiative transfer simulations the single scattering albedo and the asymmetry parameter of the aerosol particles were derived although with high uncertainty. The broad-band aerosol solar radiative forcing at the top of atmosphere was calculated and examined as a function of the aerosol types. However, due to uncertainties in both the measurements and the calculations the chemical composition cannot be identified. In addition, a mostly measurement-based method to derive the broad-band aerosol solar radiative forcing was used. This approach revealed clear differences of broad-band net irradiances as a function of the aerosol optical depth. The data were used to identify different aerosol types from different origins. Higher portions of biomass-burning smoke lead to larger broad-band net irradiances

  3. Airborne Biogenic Particles in the Snow of the Cities of the Russian Far East as Potential Allergic Compounds

    Directory of Open Access Journals (Sweden)

    Kirill S. Golokhvast

    2014-01-01

    Full Text Available This paper presents an analysis of airborne biogenic particles (1 mkm–1 mm found in the snow in several cities of the Russian Far East during 2010–2013. The most common was vegetational terraneous detritus (fragments of tree and grass leaves followed by animal hair, small insects and their fragments, microorganisms of aeroplankton, and equivocal biological garbage. Specific components were found in samples from locations close to bodies of water such as fragments of algae and mollusc shells and, marine invertebrates (needles of sea urchins and shell debris of arthropods. In most locations across the Far East (Vladivostok, Khabarovsk, Blagoveshchensk, and Ussuriysk, the content of biogenic particles collected in the winter did not exceed 10% of the total particulate matter, with the exception of Birobidzhan and the nature reserve Bastak, where it made up to 20%. Most of all biogenic compounds should be allergic: hair, fragments of tree and grass leaves, insects, and microorganisms.

  4. Airborne biogenic particles in the snow of the cities of the Russian Far East as potential allergic compounds.

    Science.gov (United States)

    Golokhvast, Kirill S

    2014-01-01

    This paper presents an analysis of airborne biogenic particles (1 mkm-1 mm) found in the snow in several cities of the Russian Far East during 2010-2013. The most common was vegetational terraneous detritus (fragments of tree and grass leaves) followed by animal hair, small insects and their fragments, microorganisms of aeroplankton, and equivocal biological garbage. Specific components were found in samples from locations close to bodies of water such as fragments of algae and mollusc shells and, marine invertebrates (needles of sea urchins and shell debris of arthropods). In most locations across the Far East (Vladivostok, Khabarovsk, Blagoveshchensk, and Ussuriysk), the content of biogenic particles collected in the winter did not exceed 10% of the total particulate matter, with the exception of Birobidzhan and the nature reserve Bastak, where it made up to 20%. Most of all biogenic compounds should be allergic: hair, fragments of tree and grass leaves, insects, and microorganisms. PMID:25140327

  5. Observations of the spectral dependence of linear particle depolarization ratio of aerosols using NASA Langley airborne High Spectral Resolution Lidar

    Science.gov (United States)

    Burton, S. P.; Hair, J. W.; Kahnert, M.; Ferrare, R. A.; Hostetler, C. A.; Cook, A. L.; Harper, D. B.; Berkoff, T. A.; Seaman, S. T.; Collins, J. E.; Fenn, M. A.; Rogers, R. R.

    2015-12-01

    Linear particle depolarization ratio is presented for three case studies from the NASA Langley airborne High Spectral Resolution Lidar-2 HSRL-2). Particle depolarization ratio from lidar is an indicator of non-spherical particles and is sensitive to the fraction of non-spherical particles and their size. The HSRL-2 instrument measures depolarization at three wavelengths: 355, 532, and 1064 nm. The three measurement cases presented here include two cases of dust-dominated aerosol and one case of smoke aerosol. These cases have partial analogs in earlier HSRL-1 depolarization measurements at 532 and 1064 nm and in literature, but the availability of three wavelengths gives additional insight into different scenarios for non-spherical particles in the atmosphere. A case of transported Saharan dust has a spectral dependence with a peak of 0.30 at 532 nm with smaller particle depolarization ratios of 0.27 and 0.25 at 1064 and 355 nm, respectively. A case of aerosol containing locally generated wind-blown North American dust has a maximum of 0.38 at 1064 nm, decreasing to 0.37 and 0.24 at 532 and 355 nm, respectively. The cause of the maximum at 1064 nm is inferred to be very large particles that have not settled out of the dust layer. The smoke layer has the opposite spectral dependence, with the peak of 0.24 at 355 nm, decreasing to 0.09 and 0.02 at 532 and 1064 nm, respectively. The depolarization in the smoke case may be explained by the presence of coated soot aggregates. We note that in these specific case studies, the linear particle depolarization ratio for smoke and dust-dominated aerosol are more similar at 355 nm than at 532 nm, having possible implications for using the particle depolarization ratio at a single wavelength for aerosol typing.

  6. Size distribution of airborne particle-bound polybrominated diphenyl ethers and its implications for dry and wet deposition.

    Science.gov (United States)

    Luo, Pei; Ni, Hong-Gang; Bao, Lian-Jun; Li, Shao-Meng; Zeng, Eddy Y

    2014-12-01

    Size distribution of particles in part dictates the environmental behavior of particle-bound organic pollutants in the atmosphere. The present study was conducted to examine the potential mechanisms responsible for the distribution of organic pollutants in size fractionated particles and their environmental implications, using an e-waste recycling zone in South China as a case study. Size-fractionated atmospheric particles were collected at the heights of 1.5, 5, and 20 m near two residential apartments and analyzed for polybrominated diphenyl ethers (PBDEs). The concentrations of particle-bound ΣPBDE (sum of 18 PBDE congeners) were significantly greater at 5 and 20 m than those at 1.5 m. The size-fractionated distributions of airborne ΣPBDE displayed trimodal peaks in 0.10–0.18, 1.8–3.2, and 10–18 μm at 1.5 m but only an unimodal peak in 1.0–1.8 μm at 20 m height. Emission sources, resuspension of dust and soil, and volatility of PBDEs were important factors influencing the size distribution of particle-bound PBDEs. The dry deposition fluxes of particle-bound PBDE estimated from the measured data in the present study were approximately twice the estimated wet deposition fluxes, with a total deposition flux of 3000 ng m(–2) d(–1). The relative contributions of particles to dry and wet deposition fluxes were also size-dependent, e.g., coarse (aerodynamic diameters (Dp) > 1.8 μm) and fine (Dp deposition fluxes of PBDEs, respectively.

  7. The physicochemical characterisation of microscopic airborne particles in south Wales: A review of the locations and methodologies

    International Nuclear Information System (INIS)

    As part of the NERC-URGENT thematic programme, research was undertaken into the physicochemistry and bioreactivity of microscopic airborne particulate matter in south Wales. This paper reviews the collecting and characterisation methods used in the research; some of the results obtained are shown as examples. Four main collecting locations were chosen: Cardiff (urban); Port Talbot (urban/industrial); Park Slip West coal opencast pit (industrial/rural); the Black Mountains (rural/background). Collections initially used a 30-l/min Negretti PM1 filter collection system, however in the later stages of the project increased use was made of a 1100-l/min impaction system (nicknamed the super-sucker). This latter device was developed at Harvard University USA, however was adapted and optimised at Cardiff University. Methods for the extraction of PM1 off polycarbonate filters and polyurethane substrates were developed, with particular attention being paid to minimise physical or chemical changes during the extraction, and the extracts being in an appropriate state for bioreactivity assessment. Physicochemical characterisation of the PM1 included the empirical measurement of shape and size using electron microscopy and semi-automated image analysis. The determinations of the water-soluble and -insoluble chemical components were undertaken by ion chromatography and inductive coupled plasma-mass spectrometry. The bioreactivity of south Wales airborne particles is not covered by this review

  8. Particle number size distribution in the eastern Mediterranean: Formation and growth rates of ultrafine airborne atmospheric particles

    Science.gov (United States)

    Kopanakis, I.; Chatoutsidou, S. E.; Torseth, K.; Glytsos, T.; Lazaridis, M.

    2013-10-01

    Particle number concentration was measured between June 2009 and June 2010 at Akrotiri research station in a rural/suburban region of western Crete (Greece). Overall, the available data covered 157 days during the aforementioned period of measurements. The objectives were to study the number size distribution characteristics of ambient aerosols and furthermore to identify new particle formation events and to evaluate particle formation rates and growth rates of the newborn particles. Aerosol particles with mobility diameters between 10 and 1100 nm were measured using a Scanning Mobility Particle Sizer (SMPS) system. Measurements were performed at ambient relative humidities. The median total particle number concentration was 525 #/cm3 whereas the number concentration ranged between 130 #/cm3 and 9597 #/cm3. The average percentage of particles with diameters between 10 nm and 100 nm (N10-100) to total particles was 53% during summer and spring, but reached 80% during winter. Maximum average contribution of nano-particles (10 nm heating. Furthermore, back trajectories (HYSPLIT model) showed that different air mass origins are linked to different levels of particle number concentrations, with higher values associated with air masses passing from polluted areas before reaching the Akrotiri station. Modal analysis of the measured size distribution data revealed a strong nucleation mode during winter (15-25 nm), which can be correlated with emissions from local sources (domestic heating). The nucleation mode was observed also during the spring campaigns and was partly linked to new particle formation events. On the contrary, an accumulation mode (80-120 nm) prevailed in the measurements during summer campaigns, when the station area was influenced by polluted air masses arriving mainly from Eastern Europe. In total, 13 new particle formation events were recorded during the 157 days of measurements. Nucleation events were associated with low values of N100 particle number

  9. Effect of indoor-generated airborne particles on radon progeny dynamics.

    Science.gov (United States)

    Trassierra, C Vargas; Stabile, L; Cardellini, F; Morawska, L; Buonanno, G

    2016-08-15

    In order to investigate the interaction between radon progeny and particles, an experimental campaign was carried out in a radon chamber at the Italian National Institute of Ionizing Radiation Metrology, quantifying the amount of attached and unattached radon daughters present in air, as well as the equilibrium factor in the presence of particles generated through indoor sources. A fixed radon concentration was maintained, while particles were generated using incense sticks, mosquito coils and gas combustion. Aerosols were characterized in terms of particle concentrations and size distributions. Simultaneously, radon concentration and attached/unattached potential alpha energy concentration in the air were continuously monitored by two different devices, based on alpha spectroscopy techniques. The presence of particles was found to affect the attached fraction of radon decay products, in such a way that the particles acted as a sink for radionuclides. In terms of sources which emit large particles (e.g. incense, mosquito coils), which greatly increase particle surface area concentrations, the Equilibrium Factor was found to double with respect to the background level before particle generation sessions. On the contrary, the radon decay product dynamics were not influenced by gas combustion processes, mainly due to the small surface area of the particles emitted. PMID:27131455

  10. 激光尘埃粒子计数器反射腔偏差分析%Error Analysis of Reflecting mirror of Airborne Particle Counter

    Institute of Scientific and Technical Information of China (English)

    王卫芳

    2011-01-01

    目前激光尘埃粒子计数器的应用非常广泛,但各方面参数的选择还都不是很完善。将激光尘埃粒子计器的反射腔工作原理建立了几何模型,用数学公式表达出气溶胶粒子偏离焦点后在反射腔上的偏差,为实际生产和使用提供了依据。%Recently,The Airborne Particle Counter is used widely,however,its choose of parameters is not very perfect.In this particle,a geometric model of mirror in Airborne Particle Counter was established,expressed in mathematical formula for error in reflect cavity besause of Particles off the focus,This will offer some references to practices.

  11. "EUROPART". Airborne particles in the indoor environment. A European interdisciplinary review of scientific evidence on associations between exposure to particles in buildings and health effects

    DEFF Research Database (Denmark)

    Schneider, T.; Sundell, Jan; Bischof, W.;

    2003-01-01

    The relevance of particle mass, surface area or number concentration as risk indicators for health effects in non-industrial buildings has been assessed by a European interdisciplinary group of researchers (called EUROPART) by reviewing papers identified in Medline, Toxline, and OSH. Studies...... dealing with dermal effects or cancer or specifically addressing environmental tobacco smoke, house dust-mite, cockroach or animal allergens, microorganisms and pesticides were excluded. A total of 70 papers were reviewed, and eight were identified for the final review: Five experimental studies involving...... mainly healthy subjects, two cross-sectional office studies and one longitudinal study among elderly on cardiovascular effects. From most studies, no definite conclusions could be drawn. Overall, the group concluded that there is inadequate scientific evidence that airborne, indoor particulate mass...

  12. Characterization of Airborne Particles Collected from Car Engine Air Filters Using SEM and EDX Techniques

    Science.gov (United States)

    Heredia Rivera, Birmania; Gerardo Rodriguez, Martín

    2016-01-01

    Particulate matter accumulated on car engine air-filters (CAFs) was examined in order to investigate the potential use of these devices as efficient samplers for collecting street level air that people are exposed to. The morphology, microstructure, and chemical composition of a variety of particles were studied using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). The particulate matter accumulated by the CAFs was studied in two categories; the first was of removed particles by friction, and the second consisted of particles retained on the filters. Larger particles with a diameter of 74–10 µm were observed in the first category. In the second one, the detected particles had a diameter between 16 and 0.7 µm. These particles exhibited different morphologies and composition, indicating mostly a soil origin. The elemental composition revealed the presence of three groups: mineral (clay and asphalt), metallic (mainly Fe), and biological particles (vegetal and animal debris). The palynological analysis showed the presence of pollen grains associated with urban plants. These results suggest that CAFs capture a mixture of atmospheric particles, which can be analyzed in order to monitor urban air. Thus, the continuous availability of large numbers of filters and the retroactivity associated to the car routes suggest that these CAFs are very useful for studying the high traffic zones within a city. PMID:27706087

  13. Characterization of Airborne Particles Collected from Car Engine Air Filters Using SEM and EDX Techniques

    Directory of Open Access Journals (Sweden)

    Birmania Heredia Rivera

    2016-10-01

    Full Text Available Particulate matter accumulated on car engine air-filters (CAFs was examined in order to investigate the potential use of these devices as efficient samplers for collecting street level air that people are exposed to. The morphology, microstructure, and chemical composition of a variety of particles were studied using scanning electron microscopy (SEM and energy-dispersive X-ray (EDX. The particulate matter accumulated by the CAFs was studied in two categories; the first was of removed particles by friction, and the second consisted of particles retained on the filters. Larger particles with a diameter of 74–10 µm were observed in the first category. In the second one, the detected particles had a diameter between 16 and 0.7 µm. These particles exhibited different morphologies and composition, indicating mostly a soil origin. The elemental composition revealed the presence of three groups: mineral (clay and asphalt, metallic (mainly Fe, and biological particles (vegetal and animal debris. The palynological analysis showed the presence of pollen grains associated with urban plants. These results suggest that CAFs capture a mixture of atmospheric particles, which can be analyzed in order to monitor urban air. Thus, the continuous availability of large numbers of filters and the retroactivity associated to the car routes suggest that these CAFs are very useful for studying the high traffic zones within a city.

  14. Airborne dust and soil particles at the Phoenix landing site, Mars

    DEFF Research Database (Denmark)

    Madsen, M. B.; Drube, L.; Goetz, W.;

    . Because of the multiple background colors of the iSweeps the effect of the translucence of thin dust layers can be studied. This is used to estimate the rate of dust accumulation and will be used to evaluate light scattering properties of the particles. Some particles raised by the retro-rockets during...

  15. LOAC (Light Optical Particle Counter): a new small aerosol counter with particle characterization capabilities for surface and airborne measurements

    Science.gov (United States)

    Renard, Jean-Baptiste; Berthet, Gwenael; Jégou, Fabrice; Jeannot, Matthieu; Jourdain, Line; Dulac, François; Mallet, Marc; Dupont, Jean-Charles; Thaury, Claire; Tonnelier, Thierry; Verdier, Nicolas; Charpentier, Patrick

    2013-04-01

    The determination of the size distribution of tropospheric and stratospheric aerosols with conventional optical counters is difficult when different natures of particles are present (droplets, soot, mineral dust, secondary organic or mineral particles...). Also, a light and cheap aerosol counter that can be used at ground, onboard drones or launched under all kinds of atmospheric balloons can be very useful during specific events as volcanic plumes, desert dust transport or local pollution episodes. These goals can be achieved thanks to a new generation of aerosol counter, called LOAC (Light Optical Aerosol Counter). The instrument was developed in the frame of a cooperation between French scientific laboratories (CNRS), the Environnement-SA and MeteoModem companies and the French Space Agency (CNES). LOAC is a small optical particle counter/sizer of ~250 grams, having a low electrical power consumption. The measurements are conducted at two scattering angles. The first one, at 12°, is used to determine the aerosol particle concentrations in 19 size classes within a diameter range of 0.3-100 micrometerers. At such an angle close to forward scattering, the signal is much more intense and the measurements are the least sensitive to the particle nature. The second angle is at 60°, where the scattered light is strongly dependent on the particle refractive index and thus on the nature of the aerosols. The ratio of the measurements at the two angles is used to discriminate between the different types of particles dominating the nature of the aerosol particles in the different size classes. The sensor particularly discriminates wet or liquid particles, soil dust and soot. Since 2011, we have operated LOAC in various environments (Arctic, Mediterranean, urban and peri-urban…) under different kinds of balloons including zero pressure stratospheric, tethered, drifting tropospheric, and meteorological sounding balloons. For the last case, the total weight of the gondola

  16. The future of airborne sulfur-containing particles in the absence of fossil fuel sulfur dioxide emissions.

    Science.gov (United States)

    Perraud, Véronique; Horne, Jeremy R; Martinez, Andrew S; Kalinowski, Jaroslaw; Meinardi, Simone; Dawson, Matthew L; Wingen, Lisa M; Dabdub, Donald; Blake, Donald R; Gerber, R Benny; Finlayson-Pitts, Barbara J

    2015-11-01

    Sulfuric acid (H2SO4), formed from oxidation of sulfur dioxide (SO2) emitted during fossil fuel combustion, is a major precursor of new airborne particles, which have well-documented detrimental effects on health, air quality, and climate. Another precursor is methanesulfonic acid (MSA), produced simultaneously with SO2 during the atmospheric oxidation of organosulfur compounds (OSCs), such as dimethyl sulfide. In the present work, a multidisciplinary approach is used to examine how contributions of H2SO4 and MSA to particle formation will change in a large coastal urban area as anthropogenic fossil fuel emissions of SO2 decline. The 3-dimensional University of California Irvine-California Institute of Technology airshed model is used to compare atmospheric concentrations of gas phase MSA, H2SO4, and SO2 under current emissions of fossil fuel-associated SO2 and a best-case futuristic scenario with zero fossil fuel sulfur emissions. Model additions include results from (i) quantum chemical calculations that clarify the previously uncertain gas phase mechanism of formation of MSA and (ii) a combination of published and experimental estimates of OSC emissions, such as those from marine, agricultural, and urban processes, which include pet waste and human breath. Results show that in the zero anthropogenic SO2 emissions case, particle formation potential from H2SO4 will drop by about two orders of magnitude compared with the current situation. However, particles will continue to be generated from the oxidation of natural and anthropogenic sources of OSCs, with contributions from MSA and H2SO4 of a similar order of magnitude. This could be particularly important in agricultural areas where there are significant sources of OSCs.

  17. Airborne measurements of nucleation mode particles I: coastal nucleation and growth rates

    Directory of Open Access Journals (Sweden)

    C. D. O'Dowd

    2007-01-01

    Full Text Available A light aircraft was equipped with a bank of Condensation Particle Counters (CPCs (50% cut from 3–5.4–9.6 nm and a nano-Scanning Mobility Particle Sizer (nSMPS and deployed along the west coast of Ireland, in the vicinity of Mace Head. The objective of the exercise was to provide high resolution micro-physical measurements of the coastal nucleation mode in order to map the spatial extent of new particle production regions and to evaluate the evolution, and associated growth rates of the coastal nucleation-mode aerosol plume. Results indicate that coastal new particle production is occurring over most areas along the land-sea interface with peak concentrations at the coastal plume-head in excess of 106 cm−3. Pseudo-Lagrangian studies of the coastal plume evolution illustrated significant growth of new particles to sizes in excess of 8 nm approximately 10 km downwind of the source region. Close to the plume head (<1 km growth rates can be as high as 123–171 nm h−1, decreasing gradually to 53–72 nm h−1 at 3 km. Further along the plume, at distances up to 10 km, the growth rates are calculated to be 17–32 nm h−1. Growth rates of this magnitude suggest that after a couple of hours, coastal nucleation mode particles can reach significant sizes where they can contribution to the regional aerosol loading.

  18. Fabrication and characterization of thermally actuated micromechanical resonators for airborne particle mass sensing: II. Device fabrication and characterization

    International Nuclear Information System (INIS)

    This paper, the second of two parts, presents extensive measurement and characterization results on fabricated thermally actuated single-crystal silicon MEMS resonators analyzed in part I. The resonators have been fabricated using a single mask process on SOI substrates. Resonant frequencies in a few hundreds of kHz to a few MHz and equivalent motional conductances as high as 102 mA V−1 have been measured for the fabricated resonators. The measurement results have been compared to the resonator characteristics predicted by the model developed in part I showing a good agreement between the two. Despite the relatively low frequencies, high quality factors (Q) of the order of a few thousand have been measured for the resonators under atmospheric pressure. The mass sensitivities of some of the resonators were characterized by embedding them in a custom-made test setup and deposition of artificially generated aerosol particles with known size and composition. The resulting measured mass sensitivities are of the order of tens to hundreds of Hz ng−1 and are in agreement with the expected values based on the resonator's physical dimensions. Finally, measurement of mass density of arbitrary airborne particles in the surrounding lab environment has been demonstrated

  19. Airborne observations of aerosol microphysical properties and particle ageing processes in the troposphere above Europe

    Directory of Open Access Journals (Sweden)

    T. Hamburger

    2012-12-01

    Full Text Available In-situ measurements of aerosol microphysical properties were performed in May 2008 during the EUCAARI-LONGREX campaign. Two aircraft, the FAAM BAe-146 and DLR Falcon 20, operated from Oberpfaffenhofen, Germany. A comprehensive data set was obtained comprising the wider region of Europe north of the Alps throughout the whole tropospheric column. Prevailing stable synoptic conditions enabled measurements of accumulating emissions inside the continental boundary layer reaching a maximum total number concentration of 19 000 particles cm−3 stp. Ultra-fine particles as indicators for nucleation events were observed within the boundary layer during high pressure conditions and after updraft of emissions induced by frontal passages above 8 km altitude in the upper free troposphere. Aerosol ageing processes during air mass transport are analysed using trajectory analysis. The ratio of particles containing a non-volatile core (250 °C to the total aerosol number concentration was observed to increase within the first 12 to 48 h from the particle source from 50 to 85% due to coagulation. Aged aerosol also features an increased fraction of accumulation mode particles of approximately 40% of the total number concentration. The presented analysis provides an extensive data set of tropospheric aerosol microphysical properties on a continental scale which can be used for atmospheric aerosol models and comparisons of satellite retrievals.

  20. Airborne observations of aerosol microphysical properties and particle ageing processes in the troposphere above Europe

    Science.gov (United States)

    Hamburger, T.; McMeeking, G.; Minikin, A.; Petzold, A.; Coe, H.; Krejci, R.

    2012-12-01

    In-situ measurements of aerosol microphysical properties were performed in May 2008 during the EUCAARI-LONGREX campaign. Two aircraft, the FAAM BAe-146 and DLR Falcon 20, operated from Oberpfaffenhofen, Germany. A comprehensive data set was obtained comprising the wider region of Europe north of the Alps throughout the whole tropospheric column. Prevailing stable synoptic conditions enabled measurements of accumulating emissions inside the continental boundary layer reaching a maximum total number concentration of 19 000 particles cm-3 stp. Ultra-fine particles as indicators for nucleation events were observed within the boundary layer during high pressure conditions and after updraft of emissions induced by frontal passages above 8 km altitude in the upper free troposphere. Aerosol ageing processes during air mass transport are analysed using trajectory analysis. The ratio of particles containing a non-volatile core (250 °C) to the total aerosol number concentration was observed to increase within the first 12 to 48 h from the particle source from 50 to 85% due to coagulation. Aged aerosol also features an increased fraction of accumulation mode particles of approximately 40% of the total number concentration. The presented analysis provides an extensive data set of tropospheric aerosol microphysical properties on a continental scale which can be used for atmospheric aerosol models and comparisons of satellite retrievals.

  1. Lung deposition predictions of airborne particles and the emergence of contemporary diseases Part-I

    Directory of Open Access Journals (Sweden)

    Khan A

    2011-05-01

    Full Text Available Inhaled particles can cause a variety of pulmonary illnesses such as asthma, bronchitis, chronic obstructive pulmonary diseases (COPD and even secondary organismic diseases. Thus, predictions of inhaled aerosol deposition in the respiratory tract are essential not only to assess their possible consequences but also to optimize drug delivery using pharmaceutical aerosols. Deposition of inhaled aerosols is a complex phenomenon that depends on the physico-chemical properties of the particles, lung anatomy, and respiratory patterns of the subject. Hence, the prediction of particle deposition for an individual person poses real challenges. Different conceptual particle deposition models are employed for the estimation of deposition fraction in different region of the lung. However, these deposition fractions vary with the above mentioned parameters in addition to the modeling and computational technique. Part-I of this review article briefly describes the deposition behaviour of inhaled particulate matter and the currently available approaches for the prediction of aerosol deposition in the respiratory tract. Part-II continues this thread and provides a broad view of the health-related issues of particle exposure.

  2. Standard Practice for Continuous Sizing and Counting of Airborne Particles in Dust-Controlled Areas and Clean Rooms Using Instruments Capable of Detecting Single Sub-Micrometre and Larger Particles

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice covers the determination of the particle concentration, by number, and the size distribution of airborne particles in dust-controlled areas and clean rooms, for particles in the size range of approximately 0.01 to 5.0 m. Particle concentrations not exceeding 3.5 106 particles/m3 (100 000/ft 3) are covered for all particles equal to and larger than the minimum size measured. 1.2 This practice uses an airborne single particle counting device (SPC) whose operation is based on measuring the signal produced by an individual particle passing through the sensing zone. The signal must be directly or indirectly related to particle size. Note 1The SPC type is not specified here. The SPC can be a conventional optical particle counter (OPC), an aerodynamic particle sizer, a condensation nucleus counter (CNC) operating in conjunction with a diffusion battery or differential mobility analyzer, or any other device capable of counting and sizing single particles in the size range of concern and of sampling...

  3. Automated classification of single airborne particles from two-dimensional angle-resolved optical scattering (TAOS) patterns by non-linear filtering

    Science.gov (United States)

    Crosta, Giovanni Franco; Pan, Yong-Le; Aptowicz, Kevin B.; Casati, Caterina; Pinnick, Ronald G.; Chang, Richard K.; Videen, Gorden W.

    2013-12-01

    Measurement of two-dimensional angle-resolved optical scattering (TAOS) patterns is an attractive technique for detecting and characterizing micron-sized airborne particles. In general, the interpretation of these patterns and the retrieval of the particle refractive index, shape or size alone, are difficult problems. By reformulating the problem in statistical learning terms, a solution is proposed herewith: rather than identifying airborne particles from their scattering patterns, TAOS patterns themselves are classified through a learning machine, where feature extraction interacts with multivariate statistical analysis. Feature extraction relies on spectrum enhancement, which includes the discrete cosine FOURIER transform and non-linear operations. Multivariate statistical analysis includes computation of the principal components and supervised training, based on the maximization of a suitable figure of merit. All algorithms have been combined together to analyze TAOS patterns, organize feature vectors, design classification experiments, carry out supervised training, assign unknown patterns to classes, and fuse information from different training and recognition experiments. The algorithms have been tested on a data set with more than 3000 TAOS patterns. The parameters that control the algorithms at different stages have been allowed to vary within suitable bounds and are optimized to some extent. Classification has been targeted at discriminating aerosolized Bacillus subtilis particles, a simulant of anthrax, from atmospheric aerosol particles and interfering particles, like diesel soot. By assuming that all training and recognition patterns come from the respective reference materials only, the most satisfactory classification result corresponds to 20% false negatives from B. subtilis particles and <11% false positives from all other aerosol particles. The most effective operations have consisted of thresholding TAOS patterns in order to reject defective ones

  4. Indoor and outdoor airborne particles. An in vitro study on mutagenic potential and toxicological implications.

    NARCIS (Netherlands)

    Houdt, van J.J.

    1988-01-01

    IntroductionAir pollution components are present as gases and as particulate matter. As particle deposition takes place in various parts of the respiratory system particulate matter may have other toxicological implications than gaseous pollutants, which all may penetrate in the low

  5. Airborne observations of aerosol microphysical properties and particle ageing processes in the troposphere above Europe

    Directory of Open Access Journals (Sweden)

    T. Hamburger

    2012-08-01

    Full Text Available In-situ measurements of aerosol microphysical properties were performed in May 2008 during the EUCAARI-LONGREX campaign. Two aircraft, the FAAM BAe-146 and DLR Falcon 20, operated from Oberpfaffenhofen, Germany. A comprehensive data set was obtained comprising the wider region of Europe north of the Alps throughout the whole tropospheric column. Prevailing stable synoptic conditions enabled measurements of accumulating emissions inside the continental boundary layer reaching a maximum total number concentration of 19 000 particles cm−3 stp. Nucleation events were observed within the boundary layer during high pressure conditions and after updraft of emissions induced by frontal passages above 8 km altitude in the upper free troposphere. Aerosol ageing processes during air mass transport are analysed using trajectory analysis. The ratio of particles containing a non-volatile core (250 °C to the total aerosol number concentration was observed to increase within the first 12 to 48 h from the particle source from 50 to 85% due to coagulation. Aged aerosol also features an increased fraction of accumulation mode particles of approximately 40% of the total number concentration. The presented analysis provides an extensive data set of tropospheric aerosol microphysical properties on a continental scale which can be used for atmospheric aerosol models and comparisons of satellite retrievals.

  6. Treatment of airborne asbestos and asbestos-like microfiber particles using atmospheric microwave air plasma.

    Science.gov (United States)

    Averroes, A; Sekiguchi, H; Sakamoto, K

    2011-11-15

    Atmospheric microwave air plasma was used to treat asbestos-like microfiber particles that had two types of ceramic fiber and one type of stainless fiber. The treated particles were characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). The experiment results showed that one type of ceramic fiber (Alumina:Silica=1:1) and the stainless fiber were spheroidized, but the other type of ceramic fiber (Alumina:Silica=7:3) was not. The conversion of the fibers was investigated by calculating the equivalent diameter, the aspect ratio, and the fiber content ratio. The fiber content ratio in various conditions showed values near zero. The relationship between the normalized fiber vanishing rate and the energy needed to melt the particles completely per unit surface area of projected particles, which is defined as η, was examined and seen to indicate that the normalized fiber vanishing rate decreased rapidly with the increase in η. Finally, some preliminary experiments for pure asbestos were conducted, and the analysis via XRD and phase-contrast microscopy (PCM) showed the availability of the plasma treatment.

  7. Effect of atmospheric electricity on dry deposition of airborne particles from atmosphere

    Science.gov (United States)

    Tammet, H.; Kimmel, V.; Israelsson, S.

    The electric mechanism of dry deposition is well known in the case of unattached radon daughter clusters that are unipolar charged and of high mobility. The problematic role of the electric forces in deposition of aerosol particles is theoretically examined by comparing the fluxes of particles carried by different deposition mechanisms in a model situation. The electric mechanism of deposition appears essential for particles of diameter 10-200 nm in conditions of low wind speed. The electric flux of fine particles can be dominant on the tips of leaves and needles even in a moderate atmospheric electric field of a few hundred V m -1 measured over the plane ground surface. The electric deposition is enhanced under thunderclouds and high voltage power lines. Strong wind suppresses the relative role of the electric deposition when compared with aerodynamic deposition. When compared with diffusion deposition the electric deposition appears less uniform: the precipitation particulate matter on the tips of leaves and especially on needles of top branches of conifer trees is much more intensive than on the ground surface and electrically shielded surfaces of plants. The knowledge of deposition geometry could improve our understanding of air pollution damage to plants.

  8. Heterogeneous reaction of N2O5 with airborne TiO2 particles and the implication for stratospheric particle injection

    Science.gov (United States)

    Tang, Mingjin; Abraham, Luke; Braesicke, Peter; Cox, Tony; McGregor, James; Pope, Francis; Pyle, John; Rkiouak, Laylla; Telford, Paul; Watson, Matt; Kalberer, Markus

    2014-05-01

    Injection of aerosol particles (or their precursors) into the stratosphere to scatter solar radiation back into space, has been suggested as a solar-radiation management (SRM) scheme for the mitigation for global warming. TiO2 has recently been highlighted as a possible candidate aerosol because of its high light scattering ability with a refractive index of 2.5 (Pope et al. 2012). The impact of particles injection on stratospheric ozone requires systematical assessment via laboratory and modelling studies. In this work, the heterogeneous reaction of airborne sub-micrometre TiO2 particles with N2O5 has been investigated at room temperature and different relative humidities (RH), using an atmospheric pressure aerosol flow tube. The uptake coefficient of N2O5 onto TiO2, γ(N2O5), was determined to be ~1.0×10-3 at low RH, and increase to ~3×10-3 at 60% RH. The dependence of γ(N2O5) on RH can be explained by the water adsorption isotherm of TiO2 particles. In addition, the uptake of N2O5 onto TiO2 aerosol particles has been included in the UKCA chemistry-climate model to assess the effect of N2O5 uptake onto TiO2 particles on the stratospheric composition. We construct a case study based on the eruption of Mt. Pinatubo, comparing the effects of TiO2 to those from the volcanic sulfate and to the situation with only background amount of aerosol. The changes in reactive nitrogen species and ozone due to the heterogeneous reaction of TiO2 with N2O5 are assessed relative to sulfate aerosol impacts. Pope, F. D., Braesicke, P., Grainger, R. G., Kalberer, M., Watson, I. M., Davidson, P. J., and Cox, R. A.: Stratospheric aerosol particles and solar-radiation management, Nature Clim. Change, 2, 713-719, 2012

  9. Airborne measurements of trace gas and aerosol particle emissions from biomass burning in Amazonia

    Directory of Open Access Journals (Sweden)

    P. Guyon

    2005-05-01

    Full Text Available As part of the LBA-SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia – Smoke, Aerosols, Clouds, Rainfall, and Climate 2002 campaign, we studied the emission of carbon monoxide (CO, carbon dioxide (CO2, and aerosol particles from Amazonian deforestation fires using an instrumented aircraft. Emission ratios for aerosol number (CN relative to CO (ERCN/CO fell in the range 14–32 cm-3 ppb-1 for most of the time, in agreement with values usually found from tropical savanna fires. The number of particles emitted per amount biomass burned was found to be dependant on the fire condition (combustion efficiency. Variability in the ERCN/CO between fires was similar to the variability caused by variations in combustion behavior within each individual fire. This was confirmed by observations of CO-to-CO2 emission ratios (ERCO/CO2, which stretched across the same wide range of values for individual fires as for all the fires observed during the sampling campaign, indicating that flaming and smoldering phases are present simultaneously in deforestation fires. Emission factors (EF for CO and aerosol particles were computed and a correction was applied for the residual smoldering combustion (RSC fraction of emissions that are not sampled by the aircraft. The correction, previously unpublished for tropical deforestation fires, suggested an EF about one and a half to twice as large for these species. Vertical transport of biomass-burning plumes from the boundary layer (BL to the cloud detrainment layer (CDL and the free troposphere (FT was found to be a very common phenomenon. We observed a 20% loss in particle number as a result of this vertical transport and subsequent cloud processing, attributable to in-cloud coagulation. This small loss fraction suggests that this mode of transport is very efficient in terms of particle numbers and occurs mostly via non

  10. Airborne measurements of trace gas and aerosol particle emissions from biomass burning in Amazonia

    Directory of Open Access Journals (Sweden)

    P. Guyon

    2005-01-01

    Full Text Available As part of the LBA-SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia - Smoke, Aerosols, Clouds, Rainfall, and Climate 2002 campaign, we studied the emission of carbon monoxide (CO, carbon dioxide (CO2, and aerosol particles from Amazonian deforestation fires using an instrumented aircraft. Emission ratios for aerosol number (CN relative to CO (ERCN/CO fell in the range 14-32 cm-3 ppb-1 in most of the investigated smoke plumes. Particle number emission ratios have to our knowledge not been previously measured in tropical deforestation fires, but our results are in agreement with values usually found from tropical savanna fires. The number of particles emitted per amount biomass burned was found to be dependent on the fire conditions (combustion efficiency. Variability in ERCN/CO between fires was similar to the variability caused by variations in combustion behavior within each individual fire. This was confirmed by observations of CO-to-CO2 emission ratios (ERCO/CO2, which stretched across the same wide range of values for individual fires as for all the fires observed during the sampling campaign, reflecting the fact that flaming and smoldering phases are present simultaneously in deforestation fires. Emission factors (EF for CO and aerosol particles were computed and a correction was applied for the residual smoldering combustion (RSC fraction of emissions that are not sampled by the aircraft, which increased the EF by a factor of 1.5-2.1. Vertical transport of smoke from the boundary layer (BL to the cloud detrainment layer (CDL and the free troposphere (FT was found to be a very common phenomenon. We observed a 20% loss in particle number as a result of this vertical transport and subsequent cloud processing, attributable to in-cloud coagulation. This small loss fraction suggests that this mode of transport is very efficient in terms of particle numbers and occurs mostly via non-precipitating clouds. The detrained aerosol

  11. Aerobyologic monitoring in urban and extra urban areas : analysis of airborne fungal particle concentration; Indagini aerobiologiche in ambiente urbano ed extraurbano componente fungina aerodiffusa

    Energy Technology Data Exchange (ETDEWEB)

    Bari, A. [ENEA, Saluggia (Italy). Centro Ricerche Energia; Caramiello, R.; Fossa, V.; Potenza, A. [Turin Univ. (Italy), Dip. di Biologia Vegetale

    1995-12-01

    In the environmental monitoring studies carried out by ENEA (Italian Agency for New Technologies, Energy and the Environment) a research about air quality of Turin and Saluggia (VC) has started in collaboration with the University of Turin. This research concerns the study of pollen and airborne fungal particle concentrations in the atmosphere. In the last few years the interest in airborne spores and hyphal fragments has increased. Indeed these particles play a very important role in allergic reactions, in several other human diseases, and in plant pathology. The incidence and the risk of infections by airborne fungal spores are correlated to the general climate and to the local micro climatic conditions; a complete aerosporological knowledge can be in many cases a useful indicator for infection risks. In this study the concentrations of airborne fungal spores in two different stations (urban station, Turin; and rural station, Saluggia (VC)) has been evaluated and compared, only for the year 1992, in order to verify the influence of climatic conditions and of floristic and vegetational aspects. In order to establish the correlations between the climate and the airborne fungal data, the results of aerosporogical analysis, relative to the Turin station, are reported. This investigation cover a six year period, three of which under standard climatic conditions and three with considerable peculiarities. A comparative evaluation of the efficiency in the collection of aerobiological particles (pollen and spores) by natural traps (mosses) has been attempted in Saluggia. The results obtained by this palinological analysis have been compared with the composition of the local flora and the data monitored by a spore-trap (volumetric pollen trap) positioned on the roof of a building in the ENEA Research Center of Saluggia.

  12. Phthalates in PM2.5 airborne particles in the Moravian-Silesian Region, Czech Republic

    Directory of Open Access Journals (Sweden)

    Jana Růžičková

    2016-03-01

    Full Text Available Industrial area of the Moravian-Silesian Region (the Czech Republic is highly polluted by air contaminants, especially emissions of particulate matter. Samples of PM2.5 particles were analysed by pyrolysis gas chromatography with mass spectrometric detection. Concentrations of phthalates were determined for the winter season, transitional period and the summer season. The relative concentrations of phthalates in PM2.5 particles have the same proportion in both heating and non-heating season: di(2ethylexyl phthalate > di-n-butyl phthalate > diisononyl phthalate > diethyl phthalate. The most common increase in concentration in the winter season is from 5 to 10 times higher; the maximum of average concentration was 44 times higher than in the non-heating season.

  13. Airborne measurements of trace gas and aerosol particle emissions from biomass burning in Amazonia

    OpenAIRE

    Guyon, P; Frank, G. P.; M. Welling; D. Chand; Artaxo, P.; L. Rizzo; Nishioka, G.; Kolle, O.; Fritsch, H.; Silva Dias, M. A. F.; L. V. Gatti; Cordova, A. M.; Andreae, M.O.

    2005-01-01

    As part of the LBA-SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia – Smoke, Aerosols, Clouds, Rainfall, and Climate) 2002 campaign, we studied the emission of carbon monoxide (CO), carbon dioxide (CO2), and aerosol particles from Amazonian deforestation fires using an instrumented aircraft. Emission ratios for aerosol number (CN) relative to CO (ERCN/CO) fell in the range 14–32 cm-3&nbs...

  14. Measurement of Soluble and Total Hexavalent Chromium in the Ambient Airborne Particles in New Jersey

    Science.gov (United States)

    Huang, Lihui; Yu, Chang Ho; Hopke, Philip K.; Lioy, Paul J.; Buckley, Brian T.; Shin, Jin Young; Fan, Zhihua (Tina)

    2015-01-01

    Hexavalent chromium (Cr(VI)) in ambient airborne particulate matter (PM) is a known pulmonary carcinogen and may have both soluble and insoluble forms. The sum of the two forms is defined as total Cr(VI). Currently, there were no methods suitable for large-scale monitoring of total Cr(VI) in ambient PM. This study developed a method to measure total Cr(VI) in ambient PM. This method includes PM collection using a Teflon filter, microwave extraction with 3% Na2CO3-2% NaOH at 95°C for 60 minutes, and Cr(VI) analysis by 1,5-diphenylcarbazide colorimetry at 540 nm. The recoveries of total Cr(VI) were 119.5 ± 10.4% and 106.3 ± 16.7% for the Cr(VI)-certified reference materials, SQC 012 and SRM 2700, respectively. Total Cr(VI) in the reference urban PM (NIST 1648a) was 26.0 ± 3.1 mg/kg (%CV = 11.9%) determined by this method. The method detection limit was 0.33 ng/m3. This method and the one previously developed to measure ambient Cr(VI), which is soluble in pH ~9.0 aqueous solution, were applied to measure Cr(VI) in ambient PM10 collected from three urban areas and one suburban area in New Jersey. The total Cr(VI) concentrations were 1.05–1.41 ng/m3 in the winter and 0.99–1.56 ng/m3 in the summer. The soluble Cr(VI) concentrations were 0.03–0.19 ng/m3 in the winter and 0.12–0.37 ng/m3 in the summer. The summer mean ratios of soluble to total Cr(VI) were 14.3–43.7%, significantly higher than 4.2–14.4% in the winter. The winter concentrations of soluble and total Cr(VI) in the suburban area were significantly lower than in the three urban areas. The results suggested that formation of Cr(VI) via atmospheric chemistry may contribute to the higher soluble Cr(VI) concentrations in the summer. PMID:26120324

  15. Selection of filter media used for monitoring airborne alpha-emitting particles in a radiological emergency

    International Nuclear Information System (INIS)

    We have developed on air monitor for alpha-emitting particles released to the atmosphere at an accident of nuclear reprocessing plant. Selection of a suitable filter for the monitor is considerably important in order to achieve the high-sensitive measurement of radioactive concentration. We have examined surface collection efficiencies and pressure drops for the various filters that are commercially available in Japan. It was found that the PTFE membrane filter with backing had superior performance to the others, that is, a high surface collection efficiency and low pressure drop. (author)

  16. Concentration and particle size of airborne toxic algae (brevetoxin) derived from ocean red tide events.

    Science.gov (United States)

    Cheng, Yung Sung; McDonald, Jacob D; Kracko, Dean; Irvin, C Mitch; Zhou, Yue; Pierce, Richard H; Henry, Michael S; Bourdelaisa, Andrea; Naar, Jerome; Baden, Daniel G

    2005-05-15

    Red tides in the Gulf of Mexico are formed by blooms of the dinoflagellate Karenia brevis, which produces brevetoxins (PbTx). Brevetoxins can be transferred from water to air in the wind-powered whitecapped waves during red tide episodes. Inhalation exposure to marine aerosol containing PbTx causes respiratory problems. A liquid chromatograph/ tandem mass spectrometric method was developed for the detection and quantitation of several PbTxs in ambient samples collected during red tide events. This method was complemented by a previously developed antibody assay that analyzes the entire class of PbTx compounds. The method showed good linearity, accuracy, and reproducibility, allowing quantitation of PbTx compounds in the 10 pg/m3 range. Air concentrations of PbTxs and brevenal for individual samples ranged from 0.01 to 80 ng/m3. The particle size showed a single mode with a mass median diameter between 6 and 10 microm, which was consistent for all of the PbTx species that were measured. Our results imply that individual PbTxs were from the same marine aerosol or from marine aerosol that was produced from the same process. The particle size indicated the likelihood of high deposition efficiency in the respiratory tract with the majority of aerosol deposited in the upper airways and small but not insignificant deposition in the lower airways. PMID:15954221

  17. Rural measurements of the chemical composition of airborne particles in the Eastern United States

    International Nuclear Information System (INIS)

    Quantitative measurements of particulate composition was made at three rural sites: in central South Dakota, on the Louisiana Gulf Coastal, and in the Blue Ridge Mountains of Virginia. The first two sites were selected to determine background concentrations in continental polar and maritime tropical air masses, respectively, which affect the eastern United State during the summer. The Virginia site was selected as a receptor site, downwind of the midwestern source area. The South Dakota data established the background concentrations. These concentrations were similar to the levels in Louisiana when air parcels arrived from the Gulf of Mexico, without recently passing over the United States. Levels of fine particles (diameters less than 2.5 μm) were highest in Virginia and were due chiefly to sulfate. Using trajectory and statistical analyses, it is shown that the residence time of an air parcel over the midwestern source area was the most important variable in determining the sulface levels in the Blue Ridge Mountains

  18. 最小二乘法在尘埃粒子计数器中的应用%Application of Least Square Method in the Airborne Particle Counter

    Institute of Scientific and Technical Information of China (English)

    杨娟; 卞保民; 何幼权; 贺安之

    2001-01-01

    分析了导致尘埃粒子计数器标定过程非常复杂的原因,提出将最小二乘法用于尘埃粒子计数器标定过程中的方法,有利于提高仪器标定的一致性并降低劳动强度。文中给出了用最小二乘法对国产激光尘埃粒子计数器进行标定的实验结果。%The reasons that lead to the complication in the process of demarcating the airborne particle counter is anal-ysed in this paper. And the Least Square Method is introduced, which can increase effectively the consistency of the in-strument demarcation and decrease the labor intensity. Experimental results calculated by the Least Square Method hasbeen performed with laser airborne particle counter.

  19. Organic compounds present in airborne particles stimulate superoxide production and DNA fragmentation: role of NOX and xanthine oxidase in animal tissues.

    Science.gov (United States)

    Busso, Iván Tavera; Silva, Guillermo Benjamín; Carreras, Hebe Alejandra

    2016-08-01

    Suspended particulate matter trigger the production of reactive oxygen species. However, most of the studies dealing with oxidative damage of airborne particles focus on the effects of individual compounds and not real mixtures. In order to study the enzymatic superoxide production resulting from the exposition to a complex mixture, we derived organic extracts from airborne particles collected daily in an urban area and exposed kidney, liver, and heart mammal tissues. After that, we measured DNA damage employing the comet assay. We observed that in every tissue, NADPH oxidase and xanthine oxidase were involved in O2 (-) production when they were exposed to the organic extracts, as the lucigenin's chemiluminescence decays when enzymes were inhibited. The same trend was observed with the percentage of cells with comets, since DNA damage was higher when they were exposed to same experimental conditions. Our data allow us to hypothesize that these enzymes play an important role in the oxidative stress produced by PAHs and that there is a mechanism involving them in the O2 (-)generation. PMID:27180836

  20. Observation and Discussion of the Latest Airborne Particle Counter of Hach Company%美国哈希公司尘埃粒子计数器最新动态观察与探讨

    Institute of Scientific and Technical Information of China (English)

    刘柳; 梁毅

    2012-01-01

    以美国哈希公司生产的METONE3411便携式尘埃粒子计数器为例,介绍了目前制药工业洁净区空气悬浮粒子的控制和监测方面的最新技术动向,并探讨其应用。%This paper introduces the current pharmaceutical airborne particle control and monitoring of the latest technology trends,using MET ONE 3411 portable airborne particle counters produced by Hath Company as an example, and discussed its application.

  1. Airborne Coarse Mode Aerosol Measurements with the CAS-DPOL Instrument: Effects of Particle Shape and Refractive Index and Implications for Radiative Transfer Estimate

    Science.gov (United States)

    Sauer, D. N.; Weinzierl, B.; Gasteiger, J.; Spanu, A.; Freudenthaler, V.; Gross, S.

    2015-12-01

    Each year huge amounts of mineral dust are mobilized in deserts and arid regions of the world and transported over large distances forming thick elevated aerosol layers with a substantial fraction of coarse mode particles. Optical properties of mineral dust, including the absorptive refractive index of some components, cause a significant effect on the atmospheric radiative energy balance from optical to infrared wavelengths. The aerosol characteristics, in particular its coarse mode size distribution, are modified during long-range transport by aging and deposition processes. This also affects the aerosol optical properties and therefore the effect on the atmospheric radiative energy budget. In-situ measurements of aerosol microphysical properties are essential to characterize those effects in order to be implemented in global climate models in parametrized form. However, in-situ measurements of airborne coarse mode aerosols such as mineral dust and volcanic ash are challenging and the measurements are usually affected by substantial uncertainties. In this work we use airborne measurements of mineral dust from our optical light-scattering spectrometer CAS-DPOL during SALTRACE 2013 to discuss the analysis of such data. We cover the effects of varying refractive index and particle shapes and develop recommendations for the configuration of the CAS-DPOL for aerosol studies. We also present an inversion method to derive coarse mode size distributions from light-scattering probes for mixtures of non-spherical, absorbing aerosols. The size distributions retrieved from the in-situ measurements are then validated using an independent analysis with a combination of sun-photometer and lidar data. We apply these methods to investigate the Saharan mineral dust particle size distributions measured on both sides of the Atlantic Ocean and discuss the influence of aerosol aging on the atmospheric radiative energy budget. With this example we also assess how the uncertainties

  2. Vertical wind retrieved by airborne lidar and analysis of island induced gravity waves in combination with numerical models and in situ particle measurements

    Science.gov (United States)

    Chouza, Fernando; Reitebuch, Oliver; Jähn, Michael; Rahm, Stephan; Weinzierl, Bernadett

    2016-04-01

    This study presents the analysis of island induced gravity waves observed by an airborne Doppler wind lidar (DWL) during SALTRACE. First, the instrumental corrections required for the retrieval of high spatial resolution vertical wind measurements from an airborne DWL are presented and the measurement accuracy estimated by means of two different methods. The estimated systematic error is below -0.05 m s-1 for the selected case of study, while the random error lies between 0.1 and 0.16 m s-1 depending on the estimation method. Then, the presented method is applied to two measurement flights during which the presence of island induced gravity waves was detected. The first case corresponds to a research flight conducted on 17 June 2013 in the Cabo Verde islands region, while the second case corresponds to a measurement flight on 26 June 2013 in the Barbados region. The presence of trapped lee waves predicted by the calculated Scorer parameter profiles was confirmed by the lidar and in situ observations. The DWL measurements are used in combination with in situ wind and particle number density measurements, large-eddy simulations (LES), and wavelet analysis to determine the main characteristics of the observed island induced trapped waves.

  3. Airborne exposures to PAH and PM2.5 particles for road paving workers applying conventional asphalt and crumb rubber modified asphalt.

    Science.gov (United States)

    Watts, R R; Wallingford, K M; Williams, R W; House, D E; Lewtas, J

    1998-01-01

    Personal exposure monitoring was conducted for road paving workers in three states. A research objective was to characterize and compare occupational exposures to fine respirable particles (asphalt and asphalt containing crumb rubber from shredded tires. Workers not exposed to asphalt fume were also included for comparison (to support the biomarker component of this study). The rubber content of the crumb rubber modified (CRM) asphalt at the three study sites was 12, 15, and 20%. A comparison of some specific job categories from two sites indicates greater potential carcinogenic PAH exposures during CRM asphalt work, however, the site with the greatest overall exposures did not indicate any differences for specific jobs. A statistical analysis of means for fine particle, pyrene and total carcinogenic PAH personal exposure shows, with two exceptions, there were no differences in exposures for these three measurement variables. One site shows significantly elevated pyrene exposure for CRM asphalt workers and another site similarly shows greater carcinogenic PAH exposure for CRM asphalt workers. Conventional and CRM asphalt worker airborne exposures to the PAH carcinogen marker, BaP, were very low with concentrations comparable to ambient air in many cities. However, this study demonstrates that asphalt road paving workers are exposed to elevated airborne concentrations of a group of unknown compounds that likely consist of the carcinogenic PAHs benz(a)anthracene, chrysene and methylated derivatives of both. The research described in this article has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. PMID:9577752

  4. Comparison of physicochemical properties between fine (PM2.5) and coarse airborne particles at cold season in Korea.

    Science.gov (United States)

    Choung, Sungwook; Oh, Jungsun; Han, Weon Shik; Chon, Chul-Min; Kwon, Youngsang; Kim, Do Yeon; Shin, Woosik

    2016-01-15

    Although it has been well-known that atmospheric aerosols affect negatively the local air quality, human health, and climate changes, the chemical and physical properties of atmospheric aerosols are not fully understood yet. This study experimentally measured the physiochemical characteristics of fine and coarse aerosol particles at the suburban area to evaluate relative contribution to environmental pollution in consecutive seasons of autumn and winter, 2014-2015, using XRD, SEM-EDX, XNI, ICP-MS, and TOF-SIMS. For these experimental works, the fine and coarse aerosols were collected by the high volume air sampler for 7 days each season. The fine particles contain approximately 10 μg m(-3) of carbonaceous aerosols consisting of 90% organic and 10% elemental carbon. The spherical-shape carbonaceous particles were observed for the coarse samples as well. Interestingly, the coarse particles in winter showed the increased frequency of carbon-rich particles with high contents of heavy metals. These results suggest that, for the cold season, the coarse particles could contribute relatively more to the conveyance of toxic contaminants compared to the fine particles in the study area. However, the fine particles showed acidic properties so that their deposition to surface may cause facilitate the increase of mobility for toxic heavy metals in soil and groundwater environments. The fine and coarse particulate matters, therefore, should be monitored separately with temporal variation to evaluate the impact of atmospheric aerosols to environmental pollution and human health. PMID:26476059

  5. Performance of a scanning mobility particle sizer in measuring diverse types of airborne nanoparticles: Multi-walled carbon nanotubes, welding fumes, and titanium dioxide spray.

    Science.gov (United States)

    Chen, Bean T; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared; Friend, Sherri; Stone, Samuel; Keane, Michael

    2016-07-01

    Direct-reading instruments have been widely used for characterizing airborne nanoparticles in inhalation toxicology and industrial hygiene studies for exposure/risk assessments. Instruments using electrical mobility sizing followed by optical counting, e.g., scanning or sequential mobility particle spectrometers (SMPS), have been considered as the "gold standard" for characterizing nanoparticles. An SMPS has the advantage of rapid response and has been widely used, but there is little information on its performance in assessing the full spectrum of nanoparticles encountered in the workplace. In this study, an SMPS was evaluated for its effectiveness in producing "monodisperse" aerosol and its adequacy in characterizing overall particle size distribution using three test aerosols, each mimicking a unique class of real-life nanoparticles: singlets of nearly spherical titanium dioxide (TiO2), agglomerates of fiber-like multi-walled carbon nanotube (MWCNT), and aggregates that constitutes welding fume (WF). These aerosols were analyzed by SMPS, cascade impactor, and by counting and sizing of discrete particles by scanning and transmission electron microscopy. The effectiveness of the SMPS to produce classified particles (fixed voltage mode) was assessed by examination of the resulting geometric standard deviation (GSD) from the impactor measurement. Results indicated that SMPS performed reasonably well for TiO2 (GSD = 1.3), but not for MWCNT and WF as evidenced by the large GSD values of 1.8 and 1.5, respectively. For overall characterization, results from SMPS (scanning voltage mode) exhibited particle-dependent discrepancies in the size distribution and total number concentration compared to those from microscopic analysis. Further investigation showed that use of a single-stage impactor at the SMPS inlet could distort the size distribution and underestimate the concentration as shown by the SMPS, whereas the presence of vapor molecules or atom clusters in some test

  6. Performance of a scanning mobility particle sizer in measuring diverse types of airborne nanoparticles: Multi-walled carbon nanotubes, welding fumes, and titanium dioxide spray.

    Science.gov (United States)

    Chen, Bean T; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared; Friend, Sherri; Stone, Samuel; Keane, Michael

    2016-07-01

    Direct-reading instruments have been widely used for characterizing airborne nanoparticles in inhalation toxicology and industrial hygiene studies for exposure/risk assessments. Instruments using electrical mobility sizing followed by optical counting, e.g., scanning or sequential mobility particle spectrometers (SMPS), have been considered as the "gold standard" for characterizing nanoparticles. An SMPS has the advantage of rapid response and has been widely used, but there is little information on its performance in assessing the full spectrum of nanoparticles encountered in the workplace. In this study, an SMPS was evaluated for its effectiveness in producing "monodisperse" aerosol and its adequacy in characterizing overall particle size distribution using three test aerosols, each mimicking a unique class of real-life nanoparticles: singlets of nearly spherical titanium dioxide (TiO2), agglomerates of fiber-like multi-walled carbon nanotube (MWCNT), and aggregates that constitutes welding fume (WF). These aerosols were analyzed by SMPS, cascade impactor, and by counting and sizing of discrete particles by scanning and transmission electron microscopy. The effectiveness of the SMPS to produce classified particles (fixed voltage mode) was assessed by examination of the resulting geometric standard deviation (GSD) from the impactor measurement. Results indicated that SMPS performed reasonably well for TiO2 (GSD = 1.3), but not for MWCNT and WF as evidenced by the large GSD values of 1.8 and 1.5, respectively. For overall characterization, results from SMPS (scanning voltage mode) exhibited particle-dependent discrepancies in the size distribution and total number concentration compared to those from microscopic analysis. Further investigation showed that use of a single-stage impactor at the SMPS inlet could distort the size distribution and underestimate the concentration as shown by the SMPS, whereas the presence of vapor molecules or atom clusters in some test

  7. Performance of a Scanning Mobility Particle Sizer in Measuring Diverse Types of Airborne Nanoparticles: Multi-Walled Carbon Nanotubes, Welding Fumes, and Titanium Dioxide Spray

    Science.gov (United States)

    Chen, Bean T.; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared; Friend, Sherri; Stone, Samuel; Keane, Michael

    2016-01-01

    Direct-reading instruments have been widely used for characterizing airborne nanoparticles in inhalation toxicology and industrial hygiene studies for exposure/risk assessments. Instruments using electrical mobility sizing followed by optical counting, e.g., scanning or sequential mobility particle spectrometers (SMPS), have been considered as the “gold standard” for characterizing nanoparticles. An SMPS has the advantage of rapid response and has been widely used, but there is little information on its performance in assessing the full spectrum of nanoparticles encountered in the workplace. In this study, an SMPS was evaluated for its effectiveness in producing “monodisperse” aerosol and its adequacy in characterizing overall particle size distribution using three test aerosols, each mimicking a unique class of real-life nanoparticles: singlets of nearly spherical titanium dioxide (TiO2), agglomerates of fiber-like multi-walled carbon nanotube (MWCNT), and aggregates that constitutes welding fume (WF). These aerosols were analyzed by SMPS, cascade impactor, and by counting and sizing of discrete particles by scanning and transmission electron microscopy. The effectiveness of the SMPS to produce classified particles (fixed voltage mode) was assessed by examination of the resulting geometric standard deviation (GSD) from the impactor measurement. Results indicated that SMPS performed reasonably well for TiO2 (GSD = 1.3), but not for MWCNT and WF as evidenced by the large GSD values of 1.8 and 1.5, respectively. For overall characterization, results from SMPS (scanning voltage mode) exhibited particle-dependent discrepancies in the size distribution and total number concentration compared to those from microscopic analysis. Further investigation showed that use of a single-stage impactor at the SMPS inlet could distort the size distribution and underestimate the concentration as shown by the SMPS, whereas the presence of vapor molecules or atom clusters in

  8. Airborne and ground-based measurements of the trace gases and particles emitted by prescribed fires in the United States

    Directory of Open Access Journals (Sweden)

    I. R. Burling

    2011-06-01

    Full Text Available We measured the emission factors for 19 trace gas species and particulate matter (PM2.5 from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as conifer forest understory in the southeastern US and Sierra Nevada mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass burning to date and the only published emission factors for temperate oak savanna fuels. This study helps close the gap in emissions data available for temperate zone fires relative to tropical biomass burning. We present the first field measurements of the biomass burning emissions of glycolaldehyde, a possible precursor for aqueous phase secondary organic aerosol formation. We also measured the emissions of phenol, another aqueous phase secondary organic aerosol precursor. Our data confirm previous observations that urban deposition can impact the NOx emission factors and thus subsequent plume chemistry. For two fires, we measured both the emissions in the convective smoke plume from our airborne platform and the unlofted residual smoldering combustion emissions with our ground-based platform. The smoke from residual smoldering combustion was characterized by emission factors for hydrocarbon and oxygenated organic species that were up to ten times higher than in the lofted plume, including high 1,3-butadiene and isoprene concentrations which were not observed in the lofted plume. This should be considered in modeling the air quality impacts of smoke that disperses at ground level. We also show that the often ignored unlofted emissions can significantly impact estimates of total emissions. Preliminary evidence suggests large emissions of monoterpenes in the residual smoldering smoke. These data should lead to an improved capacity to model the impacts of biomass burning in similar temperate ecosystems.

  9. Airborne and ground-based measurements of the trace gases and particles emitted by prescribed fires in the United States

    Directory of Open Access Journals (Sweden)

    I. R. Burling

    2011-12-01

    Full Text Available We have measured emission factors for 19 trace gas species and particulate matter (PM2.5 from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as conifer forest understory in the southeastern US and Sierra Nevada mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass burning to date and the only published emission factors for temperate oak savanna fuels. This study helps to close the gap in emissions data available for temperate zone fires relative to tropical biomass burning. We present the first field measurements of the biomass burning emissions of glycolaldehyde, a possible precursor for aqueous phase secondary organic aerosol formation. We also measured the emissions of phenol, another aqueous phase secondary organic aerosol precursor. Our data confirm previous observations that urban deposition can impact the NOx emission factors and thus subsequent plume chemistry. For two fires, we measured both the emissions in the convective smoke plume from our airborne platform and the unlofted residual smoldering combustion emissions with our ground-based platform. The smoke from residual smoldering combustion was characterized by emission factors for hydrocarbon and oxygenated organic species that were up to ten times higher than in the lofted plume, including high 1,3-butadiene and isoprene concentrations which were not observed in the lofted plume. This should be considered in modeling the air quality impacts for smoke that disperses at ground level. We also show that the often ignored unlofted emissions can significantly impact estimates of total emissions. Preliminary evidence suggests large emissions of monoterpenes in the residual smoldering smoke. These data should lead to an improved capacity to model the impacts of biomass burning in similar temperate ecosystems.

  10. Airborne and ground-based measurements of the trace gases and particles emitted from prescribed fires in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Burling, Ian; Yokelson, Robert J.; Akagi, Sheryl; Urbanski, Shawn; Wold, Cyle E.; Griffith, David WT; Johnson, Timothy J.; Reardon, James; Weise, David

    2011-12-07

    We measured the emission factors for 19 trace gas species and particulate matter (PM2.5) from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass burning to date and the only published emission factors for temperate oak savanna fuels. This study helps close the gap in emissions data available for temperate zone fires relative to tropical biomass burning. We present the first field measurements of the biomass burning emissions of glycolaldehyde, a possible precursor for aqueous phase secondary organic aerosol formation. We also measured the emissions of phenol, another aqueous phase secondary organic aerosol precursor. Our data confirm previous suggestions that urban deposition can impact the NOx emission factors and thus subsequent plume chemistry. For two fires, we measured the emissions in the convective smoke plume from our airborne platform at the same time the unlofted residual smoldering combustion emissions were measured with our ground-based platform after the flame front passed through. The smoke from residual smoldering combustion was characterized by emission factors for hydrocarbon and oxygenated organic species that were up to ten times higher than in the lofted plume, including significant 1,3-butadiene and isoprene concentrations which were not observed in the lofted plume. This should be considered in modeling the air quality impacts of smoke that disperses at ground level, and we show that the normally-ignored unlofted emissions can also significantly impact estimates of total emissions. Preliminary evidence of large emissions of monoterpenes was seen in the residual smoldering spectra, but we have not yet quantified these emissions. These data should lead to an improved capacity to model the impacts of biomass burning in similar

  11. Exposure to Airborne Particles and Volatile Organic Compounds from Polyurethane Molding, Spray Painting, Lacquering, and Gluing in a Workshop

    Directory of Open Access Journals (Sweden)

    Bjarke Mølgaard

    2015-04-01

    Full Text Available Due to the health risk related to occupational air pollution exposure, we assessed concentrations and identified sources of particles and volatile organic compounds (VOCs in a handcraft workshop producing fishing lures. The work processes in the site included polyurethane molding, spray painting, lacquering, and gluing. We measured total VOC (TVOC concentrations and particle size distributions at three locations representing the various phases of the manufacturing and assembly process. The mean working-hour TVOC concentrations in three locations studied were 41, 37, and 24 ppm according to photo-ionization detector measurements. The mean working-hour particle number concentration varied between locations from 3000 to 36,000 cm−3. Analysis of temporal and spatial variations of TVOC concentrations revealed that there were at least four substantial VOC sources: spray gluing, mold-release agent spraying, continuous evaporation from various lacquer and paint containers, and either spray painting or lacquering (probably both. The mold-release agent spray was indirectly also a major source of ultrafine particles. The workers’ exposure can be reduced by improving the local exhaust ventilation at the known sources and by increasing the ventilation rate in the area with the continuous source.

  12. Exposure to airborne particles and volatile organic compounds from polyurethane molding, spray painting, lacquering, and gluing in a workshop.

    Science.gov (United States)

    Mølgaard, Bjarke; Viitanen, Anna-Kaisa; Kangas, Anneli; Huhtiniemi, Marika; Larsen, Søren Thor; Vanhala, Esa; Hussein, Tareq; Boor, Brandon E; Hämeri, Kaarle; Koivisto, Antti Joonas

    2015-04-02

    Due to the health risk related to occupational air pollution exposure, we assessed concentrations and identified sources of particles and volatile organic compounds (VOCs) in a handcraft workshop producing fishing lures. The work processes in the site included polyurethane molding, spray painting, lacquering, and gluing. We measured total VOC (TVOC) concentrations and particle size distributions at three locations representing the various phases of the manufacturing and assembly process. The mean working-hour TVOC concentrations in three locations studied were 41, 37, and 24 ppm according to photo-ionization detector measurements. The mean working-hour particle number concentration varied between locations from 3000 to 36,000 cm-3. Analysis of temporal and spatial variations of TVOC concentrations revealed that there were at least four substantial VOC sources: spray gluing, mold-release agent spraying, continuous evaporation from various lacquer and paint containers, and either spray painting or lacquering (probably both). The mold-release agent spray was indirectly also a major source of ultrafine particles. The workers' exposure can be reduced by improving the local exhaust ventilation at the known sources and by increasing the ventilation rate in the area with the continuous source.

  13. Compositae dermatitis from airborne parthenolide

    DEFF Research Database (Denmark)

    Paulsen, E.; Christensen, Lars Porskjær; Andersen, K.E.

    2007-01-01

    suspected of causing airborne contact allergy, and its most important allergen is the sesquiterpene lactone (SQL) parthenolide (PHL). OBJECTIVES: The aims of this study were to (i) assess the allergenicity of feverfew-derived monoterpenes and sesquiterpenes and their oxidized products in feverfew......-allergic patients and (ii) re-assess the role of PHL and other SQLs in airborne contact allergy. PATIENTS AND METHODS: Feverfew-allergic patients were patch tested with extracts and fractions containing volatile monoterpenes and sesquiterpenes as well as extracts of airborne particles from flowering feverfew plants...

  14. Real-time detection and characterization of individual flowing airborne biological particles: fluorescence spectra and elastic scattering measurements

    Science.gov (United States)

    Pan, Yongle; Holler, Stephen; Chang, Richard K.; Hill, Steven C.; Pinnick, Ronald G.; Niles, Stanley; Bottiger, Jerold R.; Bronk, Burt V.

    1999-11-01

    Real-time methods which is reagentless and could detect and partially characterize bioaerosols are of current interest. We present a technique for real-time measurement of UV-excited fluorescence spectra and two-dimensional angular optical scattering (TAOS) from individual flowing biological aerosol particles. The fluorescence spectra have been observed from more than 20 samples including Bacillus subtilis, Escherichia coli, Erwinia herbicola, allergens, dust, and smoke. The S/N and resolution of the spectra are sufficient for observing small lineshape differences among the same type of bioaerosol prepared under different conditions. The additional information from TAOS regarding particle size, shape, and granularity has the potential of aiding in distinguishing bacterial aerosols from other aerosols, such as diesel and cigarette smoke.

  15. Mineralogical characteristics of airborne particles collected in Beijing during a severe Asian dust storm period in spring 2002

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Asian dust storm (ADS) samples were collected on March 20,2002 in Beijing,China. High-resolution field emission scanning electron microscopy with energy dispersive X-ray detector (FESEM-EDX) and X-ray diffraction (XRD) were used to study the morphology,chemical compositions,number-size dis-tributions and mineralogical compositions of ADS particles. The mineral particles were major compo-nents in the ADS samples,accounting for 94% by number. The XRD analysis indicated that the dust particles were dominated by clay (40.3%),and quartz (19.5%),followed by plagioclase (8.4%),calcite (7.5%),K-feldspar (1.5%),hematite (0.9%),pyrite (0.9%),hornblende (0.4%) and gypsum (0.3%),with a certain amount of noncrystalline materials (20.3%). Clay minerals were mainly illite/smectite mixed lay-ers (78%),followed by illite (9%),kaolinite (6%),and chlorite (7%). In addition to these main minerals,FESEM-EDX also detected some trace minerals,such as dolomite,pyrite,thenardite,as well as heavy minerals represented by rutile,ilmenite and apatite. The mineralogical compositions of the 2002-03-20 Asian dust storm and the Saharan dust plumes were similar but the clay mineralogy showed a great distinction,with the illite/smectite mixed layers being common in the Asian dust storm but illite being common in the Saharan dust plumes.

  16. Airborne studies of emissions from savanna fires in southern Africa. 1. Aerosol emissions measured with a laser optical particle counter

    Science.gov (United States)

    Le Canut, P.; Andreae, M. O.; Harris, G. W.; Wienhold, F. G.; Zenker, T.

    1996-10-01

    During the SAFARI-92 experiment (Southern Africa Fire Atmosphere Research Initiative, September-October 1992), we flew an instrumented DC-3 aircraft through plumes from fires in various southern African savanna ecosystems. Some fires had been managed purposely for scientific study (e.g., those in Kruger National Park, South Africa), while the others were "fires of opportunity" which are abundant during the burning season in southern Africa. We obtained the aerosol (0.1-3.0 μm diameter) number and mass emission ratios relative to carbon monoxide and carbon dioxide from 21 individual fires. The average particle number emission ratio ΔN/ΔCO (Δ: concentrations in plume minus background concentrations) varied between 14 ± 2 cm-3 ppb-1 for grasslands and 23 ± 7 cm-3 ppb-1 for savannas. An exceptionally high value of 43 ± 4 cm-3 ppb-1 was measured for a sugarcane fire. Similarly, the mass emission ratio ΔM/ΔCO varied from 36 ± 6 ng m-3 ppb-1 to 83 ± 45 ng m-3 ppb-1, respectively, with again an exceptionally high value of 124 ± 14 ng m-3 ppb-1 for the sugarcane fire. The number and mass emission ratios relative to CO depended strongly upon the fire intensity. Whereas the emission ratios varied greatly from one fire to the other, the aerosol number and volume distributions as a function of particle size were very consistent. The average background aerosol size distribution was characterized by three mass modes (0.2-0.4 μm, ≈1.0 μm, and ≈2.0 μm diameter). On the other hand, the aerosol size distribution in the smoke plumes showed only two mass modes, one centered in the interval 0.2-0.3 μm and the other above 2 μm diameter. From our mean emission factor (4 ± 1 g kg-1 dm) we estimate that savanna fires release some 11-18 Tg aerosol particles in the size range 0.1-3.0 μm annually, a somewhat lower amount than emitted from tropical forest fires. Worldwide, savanna fires emit some 3-8 × 1027 particles (in the same size range) annually, which is expected

  17. Airborne urban particles (Milan winter-PM2.5) cause mitotic arrest and cell death: Effects on DNA, mitochondria, AhR binding and spindle organization

    Energy Technology Data Exchange (ETDEWEB)

    Gualtieri, Maurizio [Applied Cell Biology and Particles Effects, Department of Environmental Science, University Milano-Bicocca, Piazza della Scienza 1, 20126 Milano (Italy); Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo (Norway); Ovrevik, Johan [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo (Norway); Mollerup, Steen [Section for Toxicology, National Institute of Occupational Health, N-0033 Oslo (Norway); Asare, Nana [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo (Norway); Longhin, Eleonora [Applied Cell Biology and Particles Effects, Department of Environmental Science, University Milano-Bicocca, Piazza della Scienza 1, 20126 Milano (Italy); Dahlman, Hans-Jorgen [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo (Norway); Camatini, Marina [Applied Cell Biology and Particles Effects, Department of Environmental Science, University Milano-Bicocca, Piazza della Scienza 1, 20126 Milano (Italy); Centre Research POLARIS, Department of Environmental Science, University Milano-Bicocca, Piazza della Scienza 1, 20126 Milano (Italy); Holme, Jorn A., E-mail: jorn.holme@fhi.no [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, N-0403 Oslo (Norway)

    2011-08-01

    Highlights: {yields} PM2.5 induces mitotic arrest in BEAS-2B cells. {yields} PM2.5 induces DNA damage and activates DNA damage response. {yields} AhR regulated genes (Cyp1A1, Cyp1B1 and AhRR) are upregulated after PM exposure. {yields} Mitotic spindle assembly is perturbed in PM exposed cells. - Abstract: Airborne particulate matter (PM) is considered to be an important contributor to lung diseases. In the present study we report that Milan winter-PM2.5 inhibited proliferation in human bronchial epithelial cells (BEAS-2B) by inducing mitotic arrest. The cell cycle arrest was followed by an increase in mitotic-apoptotic cells, mitotic slippage and finally an increase in 'classical' apoptotic cells. Exposure to winter-PM10 induced only a slight effect which may be due to the presence of PM2.5 in this fraction while pure combustion particles failed to disturb mitosis. Fewer cells expressing the mitosis marker phospho-histone H3 compared to cells with condensed chromosomes, suggest that PM2.5 induced premature mitosis. PM2.5 was internalized into the cells and often localized in laminar organelles, although particles without apparent plasma membrane covering were also seen. In PM-containing cells mitochondria and lysosomes were often damaged, and in mitotic cells fragmented chromosomes often appeared. PM2.5 induced DNA strands breaks and triggered a DNA-damage response characterized by increased phosphorylation of ATM, Chk2 and H2AX; as well as induced a marked increase in expression of the aryl hydrocarbon receptor (AhR)-regulated genes, CYP1A1, CYP1B1 and AhRR. Furthermore, some disturbance of the organization of microtubules was indicated. It is hypothesized that the induced mitotic arrest and following cell death was due to a premature chromosome condensation caused by a combination of DNA, mitochondrial and spindle damage.

  18. Airborne urban particles (Milan winter-PM2.5) cause mitotic arrest and cell death: Effects on DNA, mitochondria, AhR binding and spindle organization

    International Nuclear Information System (INIS)

    Highlights: → PM2.5 induces mitotic arrest in BEAS-2B cells. → PM2.5 induces DNA damage and activates DNA damage response. → AhR regulated genes (Cyp1A1, Cyp1B1 and AhRR) are upregulated after PM exposure. → Mitotic spindle assembly is perturbed in PM exposed cells. - Abstract: Airborne particulate matter (PM) is considered to be an important contributor to lung diseases. In the present study we report that Milan winter-PM2.5 inhibited proliferation in human bronchial epithelial cells (BEAS-2B) by inducing mitotic arrest. The cell cycle arrest was followed by an increase in mitotic-apoptotic cells, mitotic slippage and finally an increase in 'classical' apoptotic cells. Exposure to winter-PM10 induced only a slight effect which may be due to the presence of PM2.5 in this fraction while pure combustion particles failed to disturb mitosis. Fewer cells expressing the mitosis marker phospho-histone H3 compared to cells with condensed chromosomes, suggest that PM2.5 induced premature mitosis. PM2.5 was internalized into the cells and often localized in laminar organelles, although particles without apparent plasma membrane covering were also seen. In PM-containing cells mitochondria and lysosomes were often damaged, and in mitotic cells fragmented chromosomes often appeared. PM2.5 induced DNA strands breaks and triggered a DNA-damage response characterized by increased phosphorylation of ATM, Chk2 and H2AX; as well as induced a marked increase in expression of the aryl hydrocarbon receptor (AhR)-regulated genes, CYP1A1, CYP1B1 and AhRR. Furthermore, some disturbance of the organization of microtubules was indicated. It is hypothesized that the induced mitotic arrest and following cell death was due to a premature chromosome condensation caused by a combination of DNA, mitochondrial and spindle damage.

  19. Study on Size Distributions of Airborne Particles by Aircraft Observation in Spring over Eastern Coastal Areas of China

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; LIU Hongjie; YUE Xin; LI Hong; CHEN Jianhua; TANG Dagang

    2005-01-01

    The authors studied the size distributions of particles at an altitude of 2000 m by aircraft observation over eastern costal areas of China from Zhuhai, Guangdong to Dalian, Liaoning (0.47-30 μm, 57 channels,including number concentration distribution, surface area concentration distribution and mass concentration distribution). In these cities, the average daily concentrations of PM10 are very high. They are among the most heavily polluted cities in China. The main pollution sources are anthropogenic activities such as wood, coal and oil burning. The observed size distributions show a broad spectrum and unique multi-peak characteristics, indicating no significant impacts of individual sources from urban areas. These results are far different from the distribution type at ground level. It may reflect the comprehensive effect of the regional pollution characteristics. Monitoring results over big cities could to some extent reflect their pollution characteristics.

  20. Europart - Airborne particles in the indoor environment. A European interdisciplinary review of scientific evidence on associations between exposure to particles in buildings and health effects

    DEFF Research Database (Denmark)

    Schneider, T.; Sundell, Jan; Bischof, W.;

    2002-01-01

    The relevance of particle mass, surface area or number concentration as risk indicators for health effects in non-industrial buildings has been assessed by a European interdisciplinary group of researchers by reviewing papers identified in Medline, Toxline, and OSH. Studies dealing with dermal...... effects or cancer or specifically addressing environmental tobacco smoke, major allergens, and pesticides were excluded. Seventy-six papers were identified for evaluation and eight of these were judged to be conclusive and included in the final review: five experimental studies, two cross-sectional office...... studies, and a longitudinal study among elderly with cardiovascular conditions. Given the limited and inconclusive scientific evidence, the group concluded that indoor particulate mass or number concentrations cannot be used as generally applicable risk indicators of health effects in non...

  1. Monitoring and evaluation techniques for airborne contamination

    Energy Technology Data Exchange (ETDEWEB)

    Xia Yihua [China Inst. of Atomic Energy, Beijing (China)

    1997-06-01

    Monitoring and evaluation of airborne contamination are of great importance for the purpose of protection of health and safety of workers in nuclear installations. Because airborne contamination is one of the key sources to cause exposure to individuals by inhalation and digestion, and to cause diffusion of contaminants in the environment. The main objectives of monitoring and evaluation of airborne contamination are: to detect promptly a loss of control of airborne material, to help identify those individuals and predict exposure levels, to assess the intake and dose commitment to the individuals, and to provide sufficient documentation of airborne radioactivity. From the viewpoint of radiation protection, the radioactive contaminants in air can be classified into the following types: airborne aerosol, gas and noble gas, and volatile gas. In this paper, the following items are described: sampling methods and techniques, measurement and evaluation, and particle size analysis. (G.K.)

  2. Evaluation of fluorescent particle counter in detecting airborne bacteria%荧光粒子计数器在空气细菌监测中的应用评价

    Institute of Scientific and Technical Information of China (English)

    张艳; 马筱玲; 尹美玲; 郑海洋; 顾学军; 谢少清; 荚恒敏; 张亮; 张为俊

    2014-01-01

    Objective Airborne transmission is the main approach of nosocomial infection.Closely related to the nosocomial infection rate is the air purification of hospital environment,especially the operating theatres and patients concentrated area.Routine monitoring of hospital air is the key to reduce the incidence of hospital infection.But it's quite necessary to do a bacteria culture if using traditional airborne bacterial detection method,which will take 2~3 days and delay in results.Laser-induced fluorescence spectroscopy was first used to detect airborne biological particles and non-biological particles in the mid of 1 990s.The aim of this study is to explore the ap-plication value of fluorescent particle counter in monitoring airborne bacteria.Methods The number of biological particles was dynami-cally monitored by the fluorescent particle counter in the blood collection room,and compared with the bacterial culture counts which was collected by impacting air sampler;SPSS1 3.0 software was used to calculate the correlation coefficient r between the number of bi-ological particles and airborne bacteria.Results There was a significant correlation between the number of biological particles and the number of airborne bacteria(r=0.889);the number of airborne bacteria was below 500 cfu·m-3 in non-treatment time and increased in other condition,and it didn’t meet the requirements of national hygienic standard for disinfection.Conclusions The number of bio-logical particles detected by fluorescent particle counter can be used to indicate the number of airborne bacteria,thus hopefully,the dy-namic monitoring of airborne bacteria can be achieved.%目的:空气是医院内感染传播的主要途径,医院内环境尤其是手术室及患者集中地区的空气净化程度和医院感染发生率密切相关,对医院空气进行常规监测是降低医院感染发生的关键所在。但是传统的空气细菌检测方法需要进行细菌培养,耗时2~3 d,

  3. Expert workshop traffic-caused airborne particles in urban areas; Experten-Workshop 'Verkehrsbedingte Feinstaeube in der Stadt'

    Energy Technology Data Exchange (ETDEWEB)

    Lanzendorf, Martin; Birmili, Wolfram; Franke, Patrick

    2006-07-15

    The proceedings of the expert workshop on traffic-caused airborne particulates in urban regions include the following contributions: epidemiology of ultra-fine particulates, ultra-fine particulates and their impacts in human health, environmental particulates in the urban atmosphere: properties and future requirement of measuring methods; ultra-fine particulates from traffic emissions - problems of measuring site selection for the evaluation of human exposure, modeling of PMx emissions in the context of environmental compatibility assessments and mitigation planning, traffic-caused particulates - need for action and remedial actions from the sight of the Federal environment Agency, traffic-related measures for the reduction of urban particulate exposure and their impact on the planning of air pollution prevention, strategic environmental assessment as an instrument for the airborne particulate consideration within the traffic and regional planning.

  4. THE BIMODAL DISTRIBUTION: DEVELOPMENT OF THE CONCEPT OF FINE AND COARSE PARTICLES AS SEPARATE AND DISTINCT COMPONENTS OF AIRBORNE PARTICULATE MATTER

    Science.gov (United States)

    In the early 1970s, it was understood that combustion particles were formed mostly in sizes below 1 um diameter, and windblown dust was suspended in sizes mostly above 1 um diameter. However, particle size distribution was thought of as a single mode. Particles were thought to f...

  5. Modeling for Airborne Contamination

    International Nuclear Information System (INIS)

    The objective of Modeling for Airborne Contamination (referred to from now on as ''this report'') is to provide a documented methodology, along with supporting information, for estimating the release, transport, and assessment of dose to workers from airborne radioactive contaminants within the Monitored Geologic Repository (MGR) subsurface during the pre-closure period. Specifically, this report provides engineers and scientists with methodologies for estimating how concentrations of contaminants might be distributed in the air and on the drift surfaces if released from waste packages inside the repository. This report also provides dose conversion factors for inhalation, air submersion, and ground exposure pathways used to derive doses to potentially exposed subsurface workers. The scope of this report is limited to radiological contaminants (particulate, volatile and gaseous) resulting from waste package leaks (if any) and surface contamination and their transport processes. Neutron activation of air, dust in the air and the rock walls of the drift during the preclosure time is not considered within the scope of this report. Any neutrons causing such activation are not themselves considered to be ''contaminants'' released from the waste package. This report: (1) Documents mathematical models and model parameters for evaluating airborne contaminant transport within the MGR subsurface; and (2) Provides tables of dose conversion factors for inhalation, air submersion, and ground exposure pathways for important radionuclides. The dose conversion factors for air submersion and ground exposure pathways are further limited to drift diameters of 7.62 m and 5.5 m, corresponding to the main and emplacement drifts, respectively. If the final repository design significantly deviates from these drift dimensions, the results in this report may require revision. The dose conversion factors are further derived by using concrete of sufficient thickness to simulate the drift

  6. Analysis on Measurement Calibration Specifications for Light-scattering Airborne Particle Counter%光散射尘埃粒子计数器的计量校准规范浅析

    Institute of Scientific and Technical Information of China (English)

    高志良; 季启政; 王慧; 袁亚飞

    2013-01-01

    光散射尘埃粒子计数器作为监测洁净环境的最主要仪器,已在各领域被广泛应用,其自身性能质量也越来越被关注.近年来,国内外形成了多种光散射尘埃粒子计数器计量校准方法,其相互之间均存在着一定差异,这给仪器生产厂家以及计量机构带来了一定困难.本文简要分析了光散射尘埃粒子计数器相关国内外技术标准的研究现状,并重点对国内目前使用较为广泛的JJF 1190和GJB/J 5416标准进行了对比分析.%As the main equipment to monitor the clean space,the light-scattering airborne particle counter has been widely used and caught more attention on its capability.In recent years,many kinds of measurements of the airborne particle counter have been made,which brings troubles to the manufacturing corporations and measurement organizations.This paper introduces the domestic and international counter measurement standards,and focuses on the comparison and analysis of domestic standards JJF 1190 and GJB/J 5416.

  7. Airborne exposure and estimated bioavailability of arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Yager, J.W. [Electric Power Research Inst., Madison, WI (United States); Clewell, H.J. III [ICF Consulting, Fairfax, VA (United States); Hicks, J. [Geomatrix, (United States)

    2000-07-01

    A pilot group of workers were used in a study to determine the relationship between exposure to arsenic present in fly ash particles and urinary excretion of inorganic arsenic and its methylated metabolites. Arsenic was measured in the breathing zone of workers during full shift work schedules and daily urine samples were collected to determine the concentration of arsenic and its metabolites. Airborne particle size distribution samples were collected on six-stage personal cascade impactors. Previous studies of airborne exposure to arsenic in copper smelters predict urinary values nearly three times higher than those seen in exposure to arsenic in fly ash. The results suggest that differences in biological uptake of airborne arsenic probably depend on characteristics such as solubility, particle size and distribution and matrix composition of the arsenic compounds.

  8. Effect of airborne particle abrasion protocols on surface topography of Y-TZP ceramic Efeito do protocolo de jateamento com partículas na topografia da superfície de uma cerâmica Y-TZP

    Directory of Open Access Journals (Sweden)

    J. R. C. Queiroz

    2012-06-01

    Full Text Available This study aimed to evaluate Y-TZP surface after different airborne particle abrasion protocols. Seventy-six Y-TZP ceramic blocks (5×4×4 mm³ were sintered and polished. Specimens were randomly divided into 19 groups (n=4 according to control group and 3 factors: a protocol duration (2 and 4 s; b particle size (30 µm, alumina coated silica particle; 45 µm, alumina particle; and 145 µm, alumina particle and; c pressure (1.5, 2.5 and 4.5 bar. Airborne particle abrasion was performed following a strict protocol. For qualitative and quantitative results, topography surfaces were analyzed in a digital optical profilometer (Interference Microscopic, using different roughness parameters (Ra, Rq, Rz, X-crossing, Mr1, Mr2 and Sdr and 3D images. Surface roughness also was analyzed following the primer and silane applications on Y-TZP surfaces. One-way ANOVA revealed that treatments (application period, particle size and pressure of particle blasting provided significant difference for all roughness parameters. The Tukey test determined that the significant differences between groups were different among roughness parameters. In qualitative analysis, the bonding agent application reduced roughness, filing the valleys in the surface. The protocols performed in this study verified that application period, particle size and pressure influenced the topographic pattern and amplitude of roughness.O objetivo deste estudo foi avaliar a superfície de uma cerâmica à base de zircônia tetragonal estabilizada por ítria (Y-TZP após diferentes protocolos de jateamento com partículas. Setenta e seis blocos cerâmicos de Y-TZP (5 x 4 x 4 mm³ foram sinterizados e polidos. As amostras foram randomicamente divididas em 19 grupos (n=4 sendo um controle e 18 grupos utilizando 3 fatores: a tempo (2 e 4 s; b tamanho de partícula (30 µm - partículas de alumina revestida por sílica; 45 µm - partículas de alumina; 145 µm - partículas de alumina e; c pressão (1

  9. Study of airborne particles during the impact of droplets on a dry surface or on a liquid film; Etude de la mise en suspension de micro-gouttelettes lors de l'impact d'une goutte sur une surface seche ou sur un film liquide

    Energy Technology Data Exchange (ETDEWEB)

    Motzkus, C.; Gensdarmes, F. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Service d' Etudes et de Recherches en Aerodispersion des polluants et en Confinement, 91 - Gif sur Yvette (France); Motzkus, C.; Gehin, E. [Paris-12 Univ., Centre d' Etudes et de Recherches en Thermique, Environnement et Systeme, 94 - Creteil (France)

    2007-07-01

    The safety analyses of the nuclear facilities require extensive knowledge on the airborne micro-droplet, in order to assess the potential sources of contamination in the case of hypothetical scenarios of accidental falls of liquids caused by leakage or discharge from a container. There are very few data in the literature in the case of the impaction of millimeter-size droplets on the airborne particles. The objective of our work is to study experimentally the emission of the particles during the impaction on a dry or wet plane surface, in order to understand the mechanisms leading to the airborne icles. First experiments are carried out in order to study the airborne particles produced by the free falls of droplet according to the fall height. These results are faced with a semi empirical correlation, which describes the transition between deposition and splash. In the case of a dripping of 3.84 mm-diameter droplets, our results show that the splash occurs for a fall height above 30 cm, which leads to resuspension fractions between 1,9 10{sup -6} at 46 cm and 7,5 10{sup -6} at 80 cm. (authors)

  10. Measuring airborne microorganisms and dust from livestock houses

    NARCIS (Netherlands)

    Yang Zhao, Yang

    2011-01-01

      Airborne transmission has been suspected to be responsible for epidemics of highly infectious disease in livestock production. In such transmission, the pathogenic microorganisms may associate with dust particles. However, the extent to which airborne transmission plays a role in the spread

  11. Airborne in-situ investigations of the Eyjafjallajökull volcanic ash plume on Iceland and over north-western Germany with light aircrafts and optical particle counters

    Science.gov (United States)

    Weber, K.; Eliasson, J.; Vogel, A.; Fischer, C.; Pohl, T.; van Haren, G.; Meier, M.; Grobéty, B.; Dahmann, D.

    2012-03-01

    During the time period of the eruption of the Icelandic volcano Eyjafjallajökull in April/May 2010 the Duesseldorf University of Applied Sciences has performed 14 research flights in situations with and without the volcanic ash plume over Germany. In parallel to the research flights in Germany three measurement flights have been performed by the University of Iceland in May 2010 over the western part of Iceland. During two of these flights the outskirts of the eruption plume were entered directly, delivering most direct measurements within the eruption plume during this eruptive event. For all the measurement flights reported here, light durable piston-motor driven aircrafts were used, which were equipped with optical particle counters for in-situ measurements. Real-time monitoring of the particle concentrations was possible during the flights. As different types of optical particle counters have been used in Iceland and Germany, the optical particle counters have been re-calibrated after the flights to the same standard using gravimetric reference methods and original Eyjafjallajökull volcanic ash samples. In-situ measurement results with high spatial resolution, directly from the eruption plume in Iceland as well as from the dispersed and several days old plume over Germany, are therefore presented here for the first time. They are normalized to the same ash concentration calibration standard. Moreover, airborne particles could be sampled directly out of the eruption plume in Iceland as well as during the flights over Germany. During the research flights over Iceland from 9 May 2011 to 11 May 2011 the ash emitted from the vent of the volcano turned out to be concentrated in a narrow well-defined plume of about 10 km width at a distance of 45-60 km away from the vent. Outside this plume the airborne ash concentrations could be proved to be below 50 μg m -3 over western Iceland. However, by entering the outskirts of the plume directly the research aircraft could

  12. Airborne single particle mass spectrometers (SPLAT II & miniSPLAT) and new software for data visualization and analysis in a geo-spatial context.

    Science.gov (United States)

    Zelenyuk, Alla; Imre, Dan; Wilson, Jacqueline; Zhang, Zhiyuan; Wang, Jun; Mueller, Klaus

    2015-02-01

    Understanding the effect of aerosols on climate requires knowledge of the size and chemical composition of individual aerosol particles-two fundamental properties that determine an aerosol's optical properties and ability to serve as cloud condensation or ice nuclei. Here we present our aircraft-compatible single particle mass spectrometers, SPLAT II and its new, miniaturized version, miniSPLAT that measure in-situ and in real-time the size and chemical composition of individual aerosol particles with extremely high sensitivity, temporal resolution, and sizing precision on the order of a monolayer. Although miniSPLAT's size, weight, and power consumption are significantly smaller, its performance is on par with SPLAT II. Both instruments operate in dual data acquisition mode to measure, in addition to single particle size and composition, particle number concentrations, size distributions, density, and asphericity with high temporal resolution. We also present ND-Scope, our newly developed interactive visual analytics software package. ND-Scope is designed to explore and visualize the vast amount of complex, multidimensional data acquired by our single particle mass spectrometers, along with other aerosol and cloud characterization instruments on-board aircraft. We demonstrate that ND-Scope makes it possible to visualize the relationships between different observables and to view the data in a geo-spatial context, using the interactive and fully coupled Google Earth and Parallel Coordinates displays. Here we illustrate the utility of ND-Scope to visualize the spatial distribution of atmospheric particles of different compositions, and explore the relationship between individual particle compositions and their activity as cloud condensation nuclei.

  13. Airborne Single Particle Mass Spectrometers (SPLAT II & miniSPLAT) and New Software for Data Visualization and Analysis in a Geo-Spatial Context

    Science.gov (United States)

    Zelenyuk, Alla; Imre, Dan; Wilson, Jacqueline; Zhang, Zhiyuan; Wang, Jun; Mueller, Klaus

    2015-02-01

    Understanding the effect of aerosols on climate requires knowledge of the size and chemical composition of individual aerosol particles—two fundamental properties that determine an aerosol's optical properties and ability to serve as cloud condensation or ice nuclei. Here we present our aircraft-compatible single particle mass spectrometers, SPLAT II and its new, miniaturized version, miniSPLAT that measure in-situ and in real-time the size and chemical composition of individual aerosol particles with extremely high sensitivity, temporal resolution, and sizing precision on the order of a monolayer. Although miniSPLAT's size, weight, and power consumption are significantly smaller, its performance is on par with SPLAT II. Both instruments operate in dual data acquisition mode to measure, in addition to single particle size and composition, particle number concentrations, size distributions, density, and asphericity with high temporal resolution. We also present ND-Scope, our newly developed interactive visual analytics software package. ND-Scope is designed to explore and visualize the vast amount of complex, multidimensional data acquired by our single particle mass spectrometers, along with other aerosol and cloud characterization instruments on-board aircraft. We demonstrate that ND-Scope makes it possible to visualize the relationships between different observables and to view the data in a geo-spatial context, using the interactive and fully coupled Google Earth and Parallel Coordinates displays. Here we illustrate the utility of ND-Scope to visualize the spatial distribution of atmospheric particles of different compositions, and explore the relationship between individual particle compositions and their activity as cloud condensation nuclei.

  14. The Distribution of PM10 and PM2.5 Dust Particles Diameter in Airborne at the Cement Factory Neighboring Area, Citeureup - Bogor

    International Nuclear Information System (INIS)

    The distribution analysis in PM10 and PM2.5 dust particle diameter has been carried out at residence area around the cement factory, Citeureup - Bogor to estimate deposition of dust particles that is accepted by public. The dust particles were sampled at the dwellings by using a cascade impactor on four wind directions and 500, 1000, 1500, 2000, 2500, and 3000 m radius from the Plant one as the center of the cement factory at Citeureup - Bogor. Measurements at the north direction were the Gunung Putri, Kranggan, Bojong Nangka villages, and Gunung Putri dwellings. The south directions were Tarikolot and Pasir Mukti villages. The west directions were guest house, Puspanegara, Puspasari, and Citatah villages. The northwest directions were Puspanegara, Gunung Putri, Puspasari, and Kranggan villages. The analysis result showed that the diameter distribution of PM10 dust particles at outdoor is ranging from 0.4 to 4.7 μm, and has the weight percentage is high in average approximate 17.91 % of total dust weight on 500, 1000, 1500, 2000, 2500, and 3000 m radius. The distributions of indoor PM2.5 dust particles diameter show a stable 12.27 % weight percentage of total dust weight from 0.4 to 2.1 μm. (author)

  15. BioAerosol Mass Spectrometry: Reagentless Detection of Individual Airborne Spores and Other Bioagent Particles Based on Laser Desorption/Ionization Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Steele, Paul Thomas [Univ. of California, Davis, CA (United States)

    2004-09-01

    Better devices are needed for the detection of aerosolized biological warfare agents. Advances in the ongoing development of one such device, the BioAerosol Mass Spectrometry (BAMS) system, are described here in detail. The system samples individual, micrometer-sized particles directly from the air and analyzes them in real-time without sample preparation or use of reagents. At the core of the BAMS system is a dual-polarity, single-particle mass spectrometer with a laser based desorption and ionization (DI) system. The mass spectra produced by early proof-of-concept instruments were highly variable and contained limited information to differentiate certain types of similar biological particles. The investigation of this variability and subsequent changes to the DI laser system are described. The modifications have reduced the observed variability and thereby increased the usable information content in the spectra. These improvements would have little value without software to analyze and identify the mass spectra. Important improvements have been made to the algorithms that initially processed and analyzed the data. Single particles can be identified with an impressive level of accuracy, but to obtain significant reductions in the overall false alarm rate of the BAMS instrument, alarm decisions must be made dynamically on the basis of multiple analyzed particles. A statistical model has been developed to make these decisions and the resulting performance of a hypothetical BAMS system is quantitatively predicted. The predictions indicate that a BAMS system, with reasonably attainable characteristics, can operate with a very low false alarm rate (orders of magnitude lower than some currently fielded biodetectors) while still being sensitive to small concentrations of biological particles in a large range of environments. Proof-of-concept instruments, incorporating some of the modifications described here, have already performed well in independent testing.

  16. BioAerosol Mass Spectrometry: Reagentless Detection of Individual Airborne Spores and Other Bioagent Particles Based on Laser Desorption/Ionization Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Steele, P T

    2004-07-20

    Better devices are needed for the detection of aerosolized biological warfare agents. Advances in the ongoing development of one such device, the BioAerosol Mass Spectrometry (BAMS) system, are described here in detail. The system samples individual, micrometer-sized particles directly from the air and analyzes them in real-time without sample preparation or use of reagents. At the core of the BAMS system is a dual-polarity, single-particle mass spectrometer with a laser based desorption and ionization (DI) system. The mass spectra produced by early proof-of-concept instruments were highly variable and contained limited information to differentiate certain types of similar biological particles. The investigation of this variability and subsequent changes to the DI laser system are described. The modifications have reduced the observed variability and thereby increased the usable information content in the spectra. These improvements would have little value without software to analyze and identify the mass spectra. Important improvements have been made to the algorithms that initially processed and analyzed the data. Single particles can be identified with an impressive level of accuracy, but to obtain significant reductions in the overall false alarm rate of the BAMS instrument, alarm decisions must be made dynamically on the basis of multiple analyzed particles. A statistical model has been developed to make these decisions and the resulting performance of a hypothetical BAMS system is quantitatively predicted. The predictions indicate that a BAMS system, with reasonably attainable characteristics, can operate with a very low false alarm rate (orders of magnitude lower than some currently fielded biodetectors) while still being sensitive to small concentrations of biological particles in a large range of environments. Proof-of-concept instruments, incorporating some of the modifications described here, have already performed well in independent testing.

  17. Microwaves in Airborne Surveillance

    OpenAIRE

    Christopher, S.

    2013-01-01

    The use of microwave spectrum is widespread due to its convenience. Therefore, enormous amount of information is available in the free space channel. Obviously, mining this channel for surveillance is quite common. Airborne surveillance offers significant advantages in military operations. This paper talks of the usage of microwaves in airborne surveillance systems, in general, and in the Indian airborne early warning and control (AEW&C) System, in particular. It brings out the multiple s...

  18. Airborne Single Observer Passive Location Based on Krill Herd Immune Particle Filter%磷虾群免疫粒子滤波的机载单站无源定位算法

    Institute of Scientific and Technical Information of China (English)

    张智; 姜秋喜; 徐梁昊

    2015-01-01

    In order to improve the positioning accuracy of airborne single observer passive location,a novel particle filter based on krill herd immune algorithm is proposed,while the krill herd optimization method is introduced into the resampling process. The particles are moved to the high likelihood area, through the induced motion,foraging movement and random diffusion behaviors. Then the effect of the degeneracy problem is reduced. Meanwhile,the mutation operation of the artificial immune algorithm is adopted to avoid the premature phenomenon. The diversity of the particles is improved,and the impoverishment problem is solved. Simulation results indicated that the novel algorithm improve the performance of the positioning accuracy and convergence velocity.%为了进一步提高机载单站无源定位的精度,将磷虾群优化思想引入到粒子滤波的重采样阶段,提出了一种磷虾群免疫粒子滤波算法。该算法利用磷虾的受诱导运动、觅食以及随机扩散行为,将粒子导向高似然区域,有效缓解了粒子退化问题。同时,其采用了人工免疫算法的变异操作,避免了早熟现象的出现,提高了粒子的多样性,克服了粒子贫化问题。仿真结果表明,新算法改善了机载单站无源定位的定位精度以及收敛速度。

  19. Airborne infections and modern building technology

    Energy Technology Data Exchange (ETDEWEB)

    LaForce, F.M.

    1986-01-01

    Over the last 30 yr an increased appreciation of the importance of airborne infection has evolved. The concept of droplet nuclei, infectious particles from 0.5 to 3 ..mu.. which stay suspended in air for long periods of time, has been accepted as an important determinant of infectivity. Important airborne pathogens in modern buildings include legionella pneumophila, Aspergillus sp., thermophilic actinomycetes, Mycobacterium tuberculosis, measles, varicella and rubella. Perhaps, the most important microbiologic threat to most buildings is L. pneumophila. This organism can multiply in water cooling systems and contaminate effluent air which can be drawn into a building and efficiently circulated throughout by existing ventilation systems. Hospitals are a special problem because of the concentration of immunosuppressed patients who are uniquely susceptible to airborne diseases such as aspergillosis, and the likelihood that patients ill from diseases that can be spread via the airborne route will be concentrated. Humidifiers are yet another problem and have been shown to be important in several outbreaks of allergic alveolitis and legionellosis. Control of airborne infections is largely an effort at identifying and controlling reservoirs of infection. This includes regular biocide treatment of cooling towers and evaporative condensers and identification and isolation of patients with diseases that may be spread via the airborne route.

  20. 空中颗粒物对直流电晕放电影响研究现状:颗粒物空间电荷效应%Current Status of Study on the Effects of Airborne Particles on DC Corona Discharge:Space-charge Effect of Particles

    Institute of Scientific and Technical Information of China (English)

    陆家榆; 何堃; 马晓倩; 鞠勇; 谢莉

    2015-01-01

    Airborne suspended particles trapping electrons and ions give rise to space charges, which has an impact on DC corona discharge and electromagnetic environment of high voltage DC(HVDC) transmission lines. This is called space- charge effect of airborne suspended particles. Presently, severe air pollution and frequent occurrence of sand-dust, fog and haze are increasingly raging through China. The space-charge effect of airborne suspended particles charged by corona discharge will complicate the electromagnetic environment of HVDC transmission lines which is one of the important aspects impacting on the determination of the configuration parameters of the transmission lines. This makes the research on the effects of airborne suspended particles on electromagnetic environment of HVDC transmission lines crucial. Firstly, A detailed review on the research on the space charge-effect of suspended particles in the field of power transmission from the aspects of space charge density, charge of particles, total field ion current density at the ground level was conducted. Further, a summary of the research on the space charge effect in the fields of electrostatic precipitation, corona discharge of two- phase mixture of gas and solid, and dust plasma was presented. In the end, this paper pointed out the problems needed to be solved and gives the suggestions for the future research.%颗粒物捕获电子或离子以空间电荷形式对直流电晕放电产生影响。当前我国的大气污染日益严重,沙尘和霾天气频发。污染物中悬浮颗粒物荷电后带来的空间电荷效应将使高压直流输电线路周围的电磁环境复杂化,因此开展空中悬浮颗粒物对高压直流输电线路电磁环境影响的研究对指导直流输电线路的工程设计具有重要意义。该文对输电线路关于颗粒物空间电荷效应的研究历史进行回顾,并从空间电荷密度分布、颗粒物荷电量及其分布、地面合成电场和

  1. Modelling airborne dispersion of coarse particulate material

    International Nuclear Information System (INIS)

    Methods of modelling the airborne dispersion and deposition of coarse particulates are presented, with the emphasis on the heavy particles identified as possible constituents of releases from damaged AGR fuel. The first part of this report establishes the physical characteristics of the irradiated particulate in airborne emissions from AGR stations. The second part is less specific and describes procedures for extending current dispersion/deposition models to incorporate a coarse particulate component: the adjustment to plume spread parameters, dispersion from elevated sources and dispersion in conjunction with building effects and plume rise. (author)

  2. Airborne Particulate Threat Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Patrick Treado; Oksana Klueva; Jeffrey Beckstead

    2008-12-31

    Aerosol threat detection requires the ability to discern between threat agents and ambient background particulate matter (PM) encountered in the environment. To date, Raman imaging technology has been demonstrated as an effective strategy for the assessment of threat agents in the presence of specific, complex backgrounds. Expanding our understanding of the composition of ambient particulate matter background will improve the overall performance of Raman Chemical Imaging (RCI) detection strategies for the autonomous detection of airborne chemical and biological hazards. Improving RCI detection performance is strategic due to its potential to become a widely exploited detection approach by several U.S. government agencies. To improve the understanding of the ambient PM background with subsequent improvement in Raman threat detection capability, ChemImage undertook the Airborne Particulate Threat Assessment (APTA) Project in 2005-2008 through a collaborative effort with the National Energy Technology Laboratory (NETL), under cooperative agreement number DE-FC26-05NT42594. During Phase 1 of the program, a novel PM classification based on molecular composition was developed based on a comprehensive review of the scientific literature. In addition, testing protocols were developed for ambient PM characterization. A signature database was developed based on a variety of microanalytical techniques, including scanning electron microscopy, FT-IR microspectroscopy, optical microscopy, fluorescence and Raman chemical imaging techniques. An automated particle integrated collector and detector (APICD) prototype was developed for automated collection, deposition and detection of biothreat agents in background PM. During Phase 2 of the program, ChemImage continued to refine the understanding of ambient background composition. Additionally, ChemImage enhanced the APICD to provide improved autonomy, sensitivity and specificity. Deliverables included a Final Report detailing our

  3. Promoting smoke-free homes: a novel behavioral intervention using real-time audio-visual feedback on airborne particle levels.

    Directory of Open Access Journals (Sweden)

    Neil E Klepeis

    Full Text Available Interventions are needed to protect the health of children who live with smokers. We pilot-tested a real-time intervention for promoting behavior change in homes that reduces second hand tobacco smoke (SHS levels. The intervention uses a monitor and feedback system to provide immediate auditory and visual signals triggered at defined thresholds of fine particle concentration. Dynamic graphs of real-time particle levels are also shown on a computer screen. We experimentally evaluated the system, field-tested it in homes with smokers, and conducted focus groups to obtain general opinions. Laboratory tests of the monitor demonstrated SHS sensitivity, stability, precision equivalent to at least 1 µg/m(3, and low noise. A linear relationship (R(2 = 0.98 was observed between the monitor and average SHS mass concentrations up to 150 µg/m(3. Focus groups and interviews with intervention participants showed in-home use to be acceptable and feasible. The intervention was evaluated in 3 homes with combined baseline and intervention periods lasting 9 to 15 full days. Two families modified their behavior by opening windows or doors, smoking outdoors, or smoking less. We observed evidence of lower SHS levels in these homes. The remaining household voiced reluctance to changing their smoking activity and did not exhibit lower SHS levels in main smoking areas or clear behavior change; however, family members expressed receptivity to smoking outdoors. This study established the feasibility of the real-time intervention, laying the groundwork for controlled trials with larger sample sizes. Visual and auditory cues may prompt family members to take immediate action to reduce SHS levels. Dynamic graphs of SHS levels may help families make decisions about specific mitigation approaches.

  4. Characterization of airborne uranium from test firing of XM774 ammunition

    International Nuclear Information System (INIS)

    Pacific Northwest Laboratory conducted experiments at Aberdeen Proving Grounds, Maryland, to characterize the airborne depleted uranium (DU) resulting from the test firings of 105-mm, APFSDS-T XM774 ammunition. The goal was to obtain data pertinent to evaluations of human inhalation exposure to the airborne DU. Data was desired concerning the following: (1) size distribution of airborne DU; (2) quantity of airborne DU; (3) dispersion of airborne DU from the target vicinity; (4) amount of DU deposited on the ground; (5) solubility of airborne DU compounds in lung fluid; and (6) oxide forms of airborne and fallout DU. The experiments involved extensive air sampling for total airborne DU particulates and respirable DU particles both above the targets and at distances downwind. Fallout and fragments were collected around the target area. High-speed movies of the smoke generated from the impact of the penetrators were taken to estimate the cloud volumes. Results of the experiments are presented

  5. Airborne wind energy

    CERN Document Server

    Ahrens, Uwe; Schmehl, Roland

    2013-01-01

    This reference offers an overview of the field of airborne wind energy. As the first book of its kind, it provides a consistent compilation of the fundamental theories, a compendium of current research and development activities as well as economic and regulatory aspects. In five parts, the book demonstrates the relevance of Airborne Wind Energy and the role that this emerging field of technology can play for the transition towards a renewable energy economy. Part I on 'Fundamentals' contains seven general chapters explaining the principles of airborne wind energy and its different variants, o

  6. Airborne plutonium-239 and americium-241 concentrations measured from the 125-meter Hanford Meteorological Tower

    International Nuclear Information System (INIS)

    Airborne plutonium-239 and americium-241 concentrations and fluxes were measured at six heights from 1.9 to 122 m on the Hanford meteorological tower. The data show that plutonium-239 was transported on nonrespirable and small particles at all heights. Airborne americium-241 concentrations on small particles were maximum at the 91 m height

  7. Hypersensitivity of prediabetic JCR:LA-cp rats to fine airborne combustion particle-induced direct and noradrenergic-mediated vascular contraction.

    Science.gov (United States)

    Proctor, Spencer D; Dreher, Kevin L; Kelly, Sandra E; Russell, James C

    2006-04-01

    Particulate matter with mean aerodynamic diameter JCR:LA-cp rat. Residual oil fly ash leachate (ROFA-L) was studied using aortic rings from young-adult, obese, insulin-resistant rats and lean normal rats in vitro. Contractile response to phenylephrine and relaxant response to acetylcholine were determined in the presence and absence of L-NAME (N(G)-nitro-L-arginine methyl ester). In a separate series of studies, the direct contractile effects of ROFA-L on repeated exposure were determined. ROFA-L (12.5 microg ml(-1)) increased phenylephrine-mediated contraction in obese (p < 0.05), but not in lean rat aortae, with the effect being exacerbated by L-NAME, and it reduced acetylcholine-mediated relaxation of both obese and lean aortae (p < 0.0001). Initial exposure of aortae to ROFA-L caused a small contractile response (<0.05 g), which was markedly greater on second exposure in the obese (approximately 0.6 g, p < 0.0001) aortae but marginal in lean (approximately 0.1 g) aortae. Our data demonstrate that bioavailable constituents of oil combustion particles enhance noradrenergic-mediated vascular contraction, impair endothelium-mediated relaxation, and induce direct vasocontraction in prediabetic rats. These observations provide the first direct evidence of the causal properties of PM(2.5) and identify the pathophysiological role of the early prediabetic state in susceptibility to environmentally induced cardiovascular disease. These are important implications for public health and public policy.

  8. Effect of an Air Cleaner with Electrostatic Filter on the Removal of Airborne House Dust Mite Allergens

    OpenAIRE

    Agrawal, Santosh Rani; Kim, Hak-Joon; Lee, Yong Won; Sohn, Jung-Ho; Lee, Jae Hyun; Kim, Yong-Jin; Lee, Sung-Hwa; Hong, Chein-Soo; Park, Jung-Won

    2010-01-01

    Purpose The effects of air cleaners on the removal of airborne indoor allergens, especially house dust mites (HDM), are still controversial. The objective of this study is to evaluate the effect of an air cleaner with an electrostatic filter on the removal of airborne mite allergens. Materials and Methods A dried HDM culture medium that contained mite body particles and excretions was dispersed in a chamber equipped with an electrostatic air cleaner. The number of airborne particles was recor...

  9. Airborne Fraunhofer Line Discriminator

    Science.gov (United States)

    Gabriel, F. C.; Markle, D. A.

    1969-01-01

    Airborne Fraunhofer Line Discriminator enables prospecting for fluorescent materials, hydrography with fluorescent dyes, and plant studies based on fluorescence of chlorophyll. Optical unit design is the coincidence of Fraunhofer lines in the solar spectrum occurring at the characteristic wavelengths of some fluorescent materials.

  10. Microwaves in Airborne Surveillance

    Directory of Open Access Journals (Sweden)

    S. Christopher

    2013-03-01

    Full Text Available The use of microwave spectrum is widespread due to its convenience. Therefore, enormous amount of information is available in the free space channel. Obviously, mining this channel for surveillance is quite common. Airborne surveillance offers significant advantages in military operations. This paper talks of the usage of microwaves in airborne surveillance systems, in general, and in the Indian airborne early warning and control (AEW&C System, in particular. It brings out the multiple sub-systems onboard the aircraft comprising the AEW&C system and their spectral coverage. Co-location of several systems has its own problems and resolving them in terms of geometric location, frequency band and time of operation are covered. AEW&C, being an airborne system, has several other requirements  including minimal weight, volume and power considerations, lightning protection, streamlining, structural integrity, thermal management, vibration tolerance, corrosion prevention, erosion resistance, static charge discharge capability, bird strike resilience, etc. The methods adopted to cater to all these requirements in the microwave systems that are used in the AEW&C system are discussed. Paper ultimately speaks of the microwave systems that are designed and developed for the Indian AEW&C system to surmount these unusual constraints.Defence Science Journal, 2013, 63(2, pp.138-144, DOI:http://dx.doi.org/10.14429/dsj.63.4255

  11. International Symposium on Airborne Geophysics

    Science.gov (United States)

    Mogi, Toru; Ito, Hisatoshi; Kaieda, Hideshi; Kusunoki, Kenichiro; Saltus, Richard W.; Fitterman, David V.; Okuma, Shigeo; Nakatsuka, Tadashi

    2006-05-01

    Airborne geophysics can be defined as the measurement of Earth properties from sensors in the sky. The airborne measurement platform is usually a traditional fixed-wing airplane or helicopter, but could also include lighter-than-air craft, unmanned drones, or other specialty craft. The earliest history of airborne geophysics includes kite and hot-air balloon experiments. However, modern airborne geophysics dates from the mid-1940s when military submarine-hunting magnetometers were first used to map variations in the Earth's magnetic field. The current gamut of airborne geophysical techniques spans a broad range, including potential fields (both gravity and magnetics), electromagnetics (EM), radiometrics, spectral imaging, and thermal imaging.

  12. Determination of airborne nanoparticles from welding operations.

    Science.gov (United States)

    Gomes, João Fernando Pereira; Albuquerque, Paula Cristina Silva; Miranda, Rosa Maria Mendes; Vieira, Maria Teresa Freire

    2012-01-01

    The aim of this study is to assess the levels of airborne ultrafine particles emitted in welding processes (tungsten inert gas [TIG], metal active gas [MAG] of carbon steel, and friction stir welding [FSW] of aluminum) in terms of deposited area in pulmonary alveolar tract using a nanoparticle surface area monitor (NSAM) analyzer. The obtained results showed the dependence of process parameters on emitted ultrafine particles and demonstrated the presence of ultrafine particles compared to background levels. Data indicated that the process that resulted in the lowest levels of alveolar deposited surface area (ADSA) was FSW, followed by TIG and MAG. However, all tested processes resulted in significant concentrations of ultrafine particles being deposited in humans lungs of exposed workers.

  13. Sedimentation behavior of indoor airborne microparticles

    Institute of Scientific and Technical Information of China (English)

    LI Ming; WU Chao; PAN Wei

    2008-01-01

    Experiments on the behavior of airborne microparticle sediments and their adhesion on glass slides were conducted in a laboratory located on the first floor of a teaching building. Clean tiles and glass slides were placed at different angles (0°, 45° and 90°) with respect to the horizontal plane in the laboratory. The sedimentation of microparticles was investigated at certain time intervals (1 d, 3 d, 10 d and 30 d). The results of testing, at day 30, show that the diameters of particles on the horizontal tiles varied from 20 to 80 μm; few particles with diameter less than 0.5 μm or greater than 100 μm were found. The amount of particle sediment on all the slides increased along over time, while the average diameter of particles was not correlated with time, nor with the angle of placement. The maximum particle size, the total particle surface area, the total perimeter of all particles and the cover ratio of light (the proportion of total area of particles to the observed area of the slides surfaces) did not change significantly within the first 10 days. Inspection of all the samples for the last 20 days, however, showed that these variables increased substantially with the passage of time and were in reverse proportion to the placement angles, which indicates a concentration of particles, as well as physical and chemical changes.

  14. An Analysis of Measurement Calibration Specifications for Light-scattering Airborne Particle Counter%能量色散X射线荧光法快速检测玩具中铅方法的问题分析及应对措施

    Institute of Scientific and Technical Information of China (English)

    李学云; 陈子凡; 勾正伦; 彭首创

    2013-01-01

    结合美国和欧盟在X射线荧光光谱法检测玩具中铅的报告和标准方法,对X射线荧光光谱仪进行了分类剖析,列举能量色散X射线荧光光谱仪检测玩具中铅的优势,分析现阶段还存在的问题,结合理论和实践对问题逐一提出应对措施,为建立X射线荧光光谱法检测玩具中铅的标准方法提供正确方向和理论基础.%As the main equipment to monitor the clean space,the light-scattering airborne particle counter has been widely used and caught more attention on its capability.In recent years,many kinds of measurements of the airborne particle counter have been made,which brings troubles to the manufacturing corporations and measurement organizations.This paper introduces the domestic and international counter measurement standards,and focuses on the comparison and analysis of domestic standards JJF 1190 and GJB/J 5416.

  15. MLS airborne antenna research

    Science.gov (United States)

    Yu, C. L.; Burnside, W. D.

    1975-01-01

    The geometrical theory of diffraction was used to analyze the elevation plane pattern of on-aircraft antennas. The radiation patterns for basic elements (infinitesimal dipole, circumferential and axial slot) mounted on fuselage of various aircrafts with or without radome included were calculated and compared well with experimental results. Error phase plots were also presented. The effects of radiation patterns and error phase plots on the polarization selection for the MLS airborne antenna are discussed.

  16. Airborne wireless communication systems, airborne communication methods, and communication methods

    Science.gov (United States)

    Deaton, Juan D.; Schmitt, Michael J.; Jones, Warren F.

    2011-12-13

    An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

  17. ASHRAE IAQ 2010: Airborne infection controlventilation, IAQ & energy

    DEFF Research Database (Denmark)

    Sekhar, Chandra; Olesen, Bjarne W.

    2012-01-01

    . • Knowledge that proximity to an infected person affects infection rate, but the continued lack of certainty about whether that is due to large "ballistic" droplets or just a higher concentration of smaller airborne particles. Besides the papers from the IAQ 2010 conference mentioned above, this special issue...

  18. Airborne silica levels in an urban area

    International Nuclear Information System (INIS)

    In order to evaluate the exposure levels of the general population we studied the concentrations of silica particles in the inhalable particulate fraction (PM10) in different meteorological-climate periods in an urban area of Rome. In order to determine the concentration and the granulometric spectrum of silica particles, PM10 sampled by a cascade impactor was analysed by X-ray diffractometry (XRD) and by scanning electron microscopy equipped with a thin-window system for X-ray microanalysis (SEM/EDX). Over the period September 2004-October 2005 the abundance of silica particles as evaluated by SEM/EDX ranged from 1.6 to 10.4% of the total PM10 particulate, with a weight concentration of free crystalline silica, evaluated by XRD, in the range 0.25-2.87 μg/m3. The mean diameter of silica particles ranged from 0.3 to 10.5 μm, with more than 87% of particles having a diameter of less than 2.5 μm. The correlations between SEM/EDX and XRD data seem to suggest that the airborne silica particles in the urban location studied were mainly in the form crystalline silica. A strong relationship was found between the meteorological-climate conditions and the concentration level of free crystalline silica. This result suggests that the Southern winds from the Sahara desert carry an important amount of silica particles into Mediterranean Europe

  19. Airborne field strength monitoring

    Directory of Open Access Journals (Sweden)

    J. Bredemeyer

    2007-06-01

    Full Text Available In civil and military aviation, ground based navigation aids (NAVAIDS are still crucial for flight guidance even though the acceptance of satellite based systems (GNSS increases. Part of the calibration process for NAVAIDS (ILS, DME, VOR is to perform a flight inspection according to specified methods as stated in a document (DOC8071, 2000 by the International Civil Aviation Organization (ICAO. One major task is to determine the coverage, or, in other words, the true signal-in-space field strength of a ground transmitter. This has always been a challenge to flight inspection up to now, since, especially in the L-band (DME, 1GHz, the antenna installed performance was known with an uncertainty of 10 dB or even more. In order to meet ICAO's required accuracy of ±3 dB it is necessary to have a precise 3-D antenna factor of the receiving antenna operating on the airborne platform including all losses and impedance mismatching. Introducing precise, effective antenna factors to flight inspection to achieve the required accuracy is new and not published in relevant papers yet. The authors try to establish a new balanced procedure between simulation and validation by airborne and ground measurements. This involves the interpretation of measured scattering parameters gained both on the ground and airborne in comparison with numerical results obtained by the multilevel fast multipole algorithm (MLFMA accelerated method of moments (MoM using a complex geometric model of the aircraft. First results will be presented in this paper.

  20. The Development of Airborne Data for Assessing Models (ADAM) - A central repository of airborne field campaign data archives

    Science.gov (United States)

    Chen, G.; Kleb, M. M.; Aknan, A. A.; Brown, C. C.; Mangosing, D. C.; Thornhill, A.; Rinsland, P. L.

    2010-12-01

    NASA, NOAA, and NSF have conducted over 30 airborne campaigns during the past three decades aimed at gaining an understanding of the tropospheric chemical and physical processes related to climate change and air-quality issues. In recent years, the scientific value of this accumulated airborne data has been increasingly recognized for use in satellite validation and model assessment and evaluation activities. In addition to the high spatial-temporal resolutions, the airborne data, especially from the more recent studies, offers a comprehensive view of the atmosphere through a large suite of the simultaneously observed atmospheric species/parameters, ranging from photochemical precursors to products as well as particle chemical, microphysical, and optical properties. To better facilitate the model assessment and evaluation activities, we are actively engaged in the development of a web-based central airborne data archive: ADAM (Airborne Data for Assessing Models). This effort is sponsored by the NASA MEaSUREs program and is intended to archive data from tropospheric chemistry airborne field campaign since the 1980s. The principal design philosophy of the ADAM web site is to provide an intuitive user interface that allows users to browse, visualize, subset (both spatially and temporally), merge, and download the airborne data, as well as providing adequate metadata associated with the data archive. A working version of the web site which shows the ADAM user interface and functionalities will be presented. Also presented are conventions to establish common names for the atmospheric variables which are often observed during airborne campaigns as well as the approaches to handle missing data and limit of detections. This presentation is intended to serve the purpose of getting feedback from the broad atmospheric community, including both modelers and measurement experts.

  1. Airborne monitoring system

    International Nuclear Information System (INIS)

    A complete system for tracking, mapping, and performing a composition analysis of a radioactive plume and contaminated area was developed at the NRCN. The system includes two major units : An airborne unit for monitoring and a ground station for analyzing. The airborne unit is mounted on a helicopter and includes file following. Four radiation sensor, two 2'' x 2'' Nal (Tl) sensors horizontally separated by lead shield for mapping and spectroscopy, and two Geiger Mueller (GM) tubes as part of the safety system. A multichannel analyzer card is used for spectroscopy. A navigation system, based on GPS and a barometric altitude meter, is used to locate the plume or ground data. The telemetry system, consisting of a transceiver and a modem, transfers all the data in real time to the ground station. An industrial PC (Field Works) runs a dedicated C++ Windows application to manage the acquired data. An independent microprocessor based backup system includes a recorder, display, and key pad. The ground station is based on an industrial PC, a telemetry system, a color printer and a modem to communicate with automatic meteorology stations in the relevant area. A special software controls the ground station. Measurement results are analyzed in the ground station to estimate plume parameters including motion, location, size, velocity, and perform risk assessment. (authors)

  2. Development of airborne remote sensing data assimilation system

    International Nuclear Information System (INIS)

    In this paper, an airborne remote sensing data assimilation system for China Airborne Remote Sensing System is introduced. This data assimilation system is composed of a land surface model, data assimilation algorithms, observation data and fundamental parameters forcing the land surface model. In this data assimilation system, Variable Infiltration Capacity hydrologic model is selected as the land surface model, which also serves as the main framework of the system. Three-dimensional variation algorithm, four-dimensional variation algorithms, ensemble Kalman filter and Particle filter algorithms are integrated in this system. Observation data includes ground observations and remotely sensed data. The fundamental forcing parameters include soil parameters, vegetation parameters and the meteorological data

  3. Ultrafine Condensation Particle Counter Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-01

    The Model 3776 Ultrafine Condensation Particle Counter (UCPC; pictured in Appendix A) is designed for researchers interested in airborne particles smaller than 20 nm. With sensitivity to particles down to 2.5 nm in diameter, this UCPC is ideally suited for atmospheric and climate research, particle formation and growth studies, combustion and engine exhaust research, and nanotechnology research.

  4. Airborne Cloud Computing Environment (ACCE)

    Science.gov (United States)

    Hardman, Sean; Freeborn, Dana; Crichton, Dan; Law, Emily; Kay-Im, Liz

    2011-01-01

    Airborne Cloud Computing Environment (ACCE) is JPL's internal investment to improve the return on airborne missions. Improve development performance of the data system. Improve return on the captured science data. The investment is to develop a common science data system capability for airborne instruments that encompasses the end-to-end lifecycle covering planning, provisioning of data system capabilities, and support for scientific analysis in order to improve the quality, cost effectiveness, and capabilities to enable new scientific discovery and research in earth observation.

  5. Airborne particulate discriminator

    Science.gov (United States)

    Creek, Kathryn Louise; Castro, Alonso; Gray, Perry Clayton

    2009-08-11

    A method and apparatus for rapid and accurate detection and discrimination of biological, radiological, and chemical particles in air. A suspect aerosol of the target particulates is treated with a taggant aerosol of ultrafine particulates. Coagulation of the taggant and target particles causes a change in fluorescent properties of the cloud, providing an indication of the presence of the target.

  6. Dispersion model for airborne particulates inside a building

    International Nuclear Information System (INIS)

    An empirical model has been developed for the spread of airborne radioactive particles after they are released inside a building. The model has been useful in performing safety analyses of actinide materials facilities at the Savannah River Plant (SRP). These facilities employ the multiple-air-zone concept; that is, ventilation air flows from rooms or areas of least radioactive material hazard, through zones of increasing hazard, to a treatment system. A composite of the data for dispersion of airborne activity during 12 actual case incidents at SRP forms the basis for this model. These incidents occurred during approximately 90 plant-years of experience at SRP with the chemical and metallurgical processing of purified neptunium and plutonium after their recovery from irradiated uranium. The model gives ratios of the airborne activity concentrations in rooms and corridors near the site of the release. The multiple-air-zone concept has been applied to many designs of nuclear facilities as a safety feature to limit the spread of airborne activity from a release. The model illustrates the limitations of this concept: it predicts an apparently anomalous behavior of airborne particulates; namely, a small migration against the flow of the ventilation air

  7. Biophysical influence of airborne carbon nanomaterials on natural pulmonary surfactant.

    Science.gov (United States)

    Valle, Russell P; Wu, Tony; Zuo, Yi Y

    2015-05-26

    Inhalation of nanoparticles (NP), including lightweight airborne carbonaceous nanomaterials (CNM), poses a direct and systemic health threat to those who handle them. Inhaled NP penetrate deep pulmonary structures in which they first interact with the pulmonary surfactant (PS) lining at the alveolar air-water interface. In spite of many research efforts, there is a gap of knowledge between in vitro biophysical study and in vivo inhalation toxicology since all existing biophysical models handle NP-PS interactions in the liquid phase. This technical limitation, inherent in current in vitro methodologies, makes it impossible to simulate how airborne NP deposit at the PS film and interact with it. Existing in vitro NP-PS studies using liquid-suspended particles have been shown to artificially inflate the no-observed adverse effect level of NP exposure when compared to in vivo inhalation studies and international occupational exposure limits (OELs). Here, we developed an in vitro methodology called the constrained drop surfactometer (CDS) to quantitatively study PS inhibition by airborne CNM. We show that airborne multiwalled carbon nanotubes and graphene nanoplatelets induce a concentration-dependent PS inhibition under physiologically relevant conditions. The CNM aerosol concentrations controlled in the CDS are comparable to those defined in international OELs. Development of the CDS has the potential to advance our understanding of how submicron airborne nanomaterials affect the PS lining of the lung.

  8. Ultrafine particles in the atmosphere

    CERN Document Server

    Brown, L M; Harrison, R M; Maynard, A D; Maynard, R L

    2003-01-01

    Following the recognition that airborne particulate matter, even at quite modest concentrations, has an adverse effect on human health, there has been an intense research effort to understand the mechanisms and quantify the effects. One feature that has shone through is the important role of ultrafine particles as a contributor to the adverse effects of airborne particles. In this volume, many of the most distinguished researchers in the field provide a state-of-the-art overview of the scientific and medical research on ultrafine particles. Contents: Measurements of Number, Mass and Size Distr

  9. Characterisation of airborne dust in a gold mine

    International Nuclear Information System (INIS)

    Samples of airborne dust were collected from a gold mine using a single orifice cascade impactor. The size fractionated dust samples were analysed by Particle Induced X-ray Emission (PIXE) and Electron Probe X-ray Micro-Analysis (EPXMA). Results on chemical composition of the sub-micron, inhalable dust were obtained. In addition ot quartz dust, a large fraction consisted of chlorine containing particles. The filter grade efficiency of a spray cooling chamber was calculated as a function of particle size

  10. Three Color Particle Optical Extinction Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design, build and test a multi-color (red, green, blue) particle optical extinction monitor suitable for use in either land or airborne applications....

  11. South African Airborne Operations

    Directory of Open Access Journals (Sweden)

    McGill Alexander

    2012-02-01

    Full Text Available Airborne operations entail the delivery of ground troops and their equipment by air to their area of operations. They can also include the subsequent support of these troops and their equipment by air. Historically, and by definition, this would encompass delivery by fixed-wing powered aircraft, by glider, by parachute or by helicopter. Almost any troops can be delivered by most of these means. However, the technical expertise and physical as well as psychological demands required by parachuting have resulted in specialist troops being selected and trained for this role. Some of the material advantages of using parachute troops, or paratroops, are: the enormous strategic reach provided by the long-distance transport aircraft used to convey them; the considerable payload which these aircraft are capable of carrying; the speed with which the parachute force can deploy; and the fact that no infrastructure such as airfields are required for their arrival. Perhaps most attractively to cash-strapped governments, the light equipment scales of parachute units’ makes them economical to establish and maintain. There are also less tangible advantages: the soldiers selected are invariably volunteers with a willingness or even desire to tackle challenges; their selection and training produces tough, confident and aggressive troops, psychologically geared to face superior odds and to function independently from other units; and their initiative and self-reliance combined with a high level of physical fitness makes them suitable for a number of different and demanding roles.

  12. Airborne transuranium elements

    International Nuclear Information System (INIS)

    This paper reports on a new kind of alpha-particle air monitor which is based on the concept of alpha energy range discrimination (AERD). With the help of a specially designed sandwich detector, an on-line discrimination between alpha and beta particles of natural and artificial origin can be performed. The high flow rate of approximately 50-60 m3 h-1 allows reliable surveillance even of large volumes. Typical results are presented, and the properties of the AERD technique are compared with those of competing methods

  13. [Airborne Fungal Aerosol Concentration and Distribution Characteristics in Air- Conditioned Wards].

    Science.gov (United States)

    Zhang, Hua-ling; Feng, He-hua; Fang, Zi-liang; Wang, Ben-dong; Li, Dan

    2015-04-01

    The effects of airborne fungus on human health in the hospital environment are related to not only their genera and concentrations, but also their particle sizes and distribution characteristics. Moreover, the mechanisms of aerosols with different particle sizes on human health are different. Fungal samples were obtained in medicine wards of Chongqing using a six-stage sampler. The airborne fungal concentrations, genera and size distributions of all the sampling wards were investigated and identified in detail. Results showed that airborne fungal concentrations were not correlated to the diseases or personnel density, but were related to seasons, temperature, and relative humidity. The size distribution rule had roughly the same for testing wards in winter and summer. The size distributions were not related with diseases and seasons, the percentage of airborne fungal concentrations increased gradually from stage I to stage III, and then decreased dramatically from stage V to stage VI, in general, the size of airborne fungi was a normal distribution. There was no markedly difference for median diameter of airborne fungi which was less 3.19 μm in these wards. There were similar dominant genera in all wards. They were Aspergillus spp, Penicillium spp and Alternaria spp. Therefore, attention should be paid to improve the filtration efficiency of particle size of 1.1-4.7 μm for air conditioning system of wards. It also should be targeted to choose appropriate antibacterial methods and equipment for daily hygiene and air conditioning system operation management.

  14. Distribution and identification of culturable airborne microorganisms in a Swiss milk processing facility.

    Science.gov (United States)

    Brandl, Helmut; Fricker-Feer, Claudia; Ziegler, Dominik; Mandal, Jyotshna; Stephan, Roger; Lehner, Angelika

    2014-01-01

    Airborne communities (mainly bacteria) were sampled and characterized (concentration levels and diversity) at 1 outdoor and 6 indoor sites within a Swiss dairy production facility. Air samples were collected on 2 sampling dates in different seasons, one in February and one in July 2012 using impaction bioaerosol samplers. After cultivation, isolates were identified by mass spectrometry (matrix-assisted laser desorption/ionization-time-of-flight) and molecular (sequencing of 16S rRNA and rpoB genes) methods. In general, total airborne particle loads and total bacterial counts were higher in winter than in summer, but remained constant within each indoor sampling site at both sampling times (February and July). Bacterial numbers were generally very low (airborne microflora, with Bacillus and Staphylococcus being the most frequent genera identified. Overall, the culturable microflora community showed a composition typical and representative for the specific location. Bacterial counts were highly correlated with total airborne particles in the size range 1 to 5 µm, indicating that a simple surveillance system based upon counting of airborne particles could be implemented. The data generated in this study could be used to evaluate the effectiveness of the dairy plant's sanitation program and to identify potential sources of airborne contamination, resulting in increased food safety.

  15. Wavelet Based Fractal Analysis of Airborne Pollen

    CERN Document Server

    Degaudenzi, M E

    1999-01-01

    The most abundant biological particles in the atmosphere are pollen grains and spores. Self protection of pollen allergy is possible through the information of future pollen contents in the air. In spite of the importance of airborne pol len concentration forecasting, it has not been possible to predict the pollen concentrations with great accuracy, and about 25% of the daily pollen forecasts have resulted in failures. Previous analysis of the dynamic characteristics of atmospheric pollen time series indicate that the system can be described by a low dimensional chaotic map. We apply the wavelet transform to study the multifractal characteristics of an a irborne pollen time series. We find the persistence behaviour associated to low pollen concentration values and to the most rare events of highest pollen co ncentration values. The information and the correlation dimensions correspond to a chaotic system showing loss of information with time evolution.

  16. Airborne Measurements of Coarse Mode Aerosol Composition and Abundance

    Science.gov (United States)

    Froyd, K. D.; Murphy, D. M.; Brock, C. A.; Ziemba, L. D.; Anderson, B. E.; Wilson, J. C.

    2015-12-01

    Coarse aerosol particles impact the earth's radiative balance by direct scattering and absorption of light and by promoting cloud formation. Modeling studies suggest that coarse mode mineral dust and sea salt aerosol are the dominant contributors to aerosol optical depth throughout much of the globe. Lab and field studies indicate that larger aerosol particles tend to be more efficient ice nuclei, and recent airborne measurements confirm the dominant role of mineral dust on cirrus cloud formation. However, our ability to simulate coarse mode particle abundance in large scale models is limited by a lack of validating measurements above the earth's surface. We present airborne measurements of coarse mode aerosol abundance and composition over several mid-latitude, sub-tropical, and tropical regions from the boundary layer to the stratosphere. In the free troposphere the coarse mode constitutes 10-50% of the total particulate mass over a wide range of environments. Above North America mineral dust typically dominates the coarse mode, but biomass burning particles and sea salt also contribute. In remote environments coarse mode aerosol mainly consists of internally mixed sulfate-organic particles. Both continental and marine convection can enhance coarse aerosol mass through direct lofting of primary particles and by secondary accumulation of aerosol material through cloud processing.

  17. Mismatch in aeroallergens and airborne grass pollen concentrations

    Science.gov (United States)

    Plaza, M. P.; Alcázar, P.; Hernández-Ceballos, M. A.; Galán, C.

    2016-11-01

    An accurate estimation of the allergen concentration in the atmosphere is essential for allergy sufferers. The major cause of pollinosis all over Europe is due to grass pollen and Phl p 5 has the highest rates of sensitization (>50%) in patients with grass pollen-induced allergy. However, recent research has shown that airborne pollen does not always offer a clear indicator of exposure to aeroallergens. This study aims to evaluate relations between airborne grass pollen and Phl p 5 concentrations in Córdoba (southern Spain) and to study how meteorological parameters influence these atmospheric records. Monitoring was carried out from 2012 to 2014. Hirst-type volumetric spore trap was used for pollen collection, following the protocol recommended by the Spanish Aerobiology Network (REA). Aeroallergen sampling was performed using a low-volume cyclone sampler, and allergenic particles were quantified by ELISA assay. Besides, the influence of main meteorological factors on local airborne pollen and allergen concentrations was surveyed. A significant correlation was observed between grass pollen and Phl p 5 allergen concentrations during the pollen season, but with some sporadic discrepancy episodes. The cumulative annual Pollen Index also varied considerably. A significant correlation has been obtained between airborne pollen and minimum temperature, relative humidity and precipitation, during the three studied years. However, there is no clear relationship between allergens and weather variables. Our findings suggest that the correlation between grass pollen and aeroallergen Phl p 5 concentrations varies from year-to-year probably related to a complex interplay of meteorological variables.

  18. Personal exposure to airborne dust and microorganisms in agricultural environments.

    Science.gov (United States)

    Lee, Shu-An; Adhikari, Atin; Grinshpun, Sergey A; McKay, Roy; Shukla, Rakesh; Reponen, Tiina

    2006-03-01

    Airborne dust and microorganisms are associated with respiratory diseases and increased mortality and morbidity. Farmers are at high risk of exposure to both of these hazards. Very limited information, however, is available on the combined exposures to both hazards on different types of farms. Moreover, most of the previous studies have measured the mass concentration of particles ignoring the particle size. In this study, farmers' exposure to airborne dust and microorganisms was studied using our newly developed personal sampling system. Particle number concentration and size distribution were measured with an optical particle counter. Simultaneously, particles were collected on a filter and analyzed for microorganisms. The field measurements were conducted in animal confinements (swine, poultry, and dairy) and during grain harvesting (corn and soybean). The results show the following average concentrations on the workers' breathing zone: 1.7 x 10(6) to 2.9 x 10(7) particles/m(3) for total dust, 0.9 x 10(3) to 3.9 x 10(4) spores/m(3) for total fungal spores, 0.3 x 10(3) to 3.6 x 10(4)CFU/m(3) for culturable fungal spores, 0.3 x 10(4) to 3.3 x 10(8) CFU/m(3) for culturable bacteria, and limit of detection (LOD) to 2.8 x 10(3) CFU/m(3) for culturable actinomycetes in animal confinements. The respective concentrations were 4.4 x 10(6) to 5.8 x 10(7) particles/m(3), 3.4 x 10(4) to 6.1 x 10(6) spores/m(3), 8.2 x 10(4) to 7.4 x 10(6) CFU/m(3), 0.4 x 10(5) to 1.4 x 10(6) CFU/m(3), and LOD to 2.6 x 10(4) CFU/m(3) during grain harvesting. The highest contribution of large particles (3-10 microm) in total particles was found during grain harvesting, whereas the size distribution was dominated by smaller particles (particles between 2-10 microm was found to be fungal spores. The results indicate that an increase in the concentration of large dust particles (2-10 microm) during grain harvesting was partially attributed to the increase in the concentration of the fungal spores

  19. Toxicity to chicken embryos of organic extracts from airborne particulates separated into five sizes

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, H.

    1988-07-01

    The chicken embryo assay has been used for research on the toxicity of complex extracts derived from different environmental sources, as well as of individual compounds. However, only a few studies have been made on the toxicological effects of extracts derived from airborne particulate matter in chicken embryo. These studies showed that the toxic effect was due to the polycyclic aromatic hydrocarbons (PAHs) in the particles, although their structure and quantity were the factors determining the extent of the toxicity. Airborne particulate matter is composed of particles of different sizes, which can be separated into five classes according to their size by an Andersen high-volume sampler. Each class contained many kinds of compounds such as PAHs. In this study, airborne particulate matter was extracted according to particle size, the extracts analyzed for PAHs, and tested for embryotoxicity.

  20. Airborne gamma-ray spectrometry

    DEFF Research Database (Denmark)

    Hovgaard, Jens

    A new method - Noise Adjusted Singular Value Decomposition, NASVD - for processing gamma-ray spectra has been developed as part of a Ph.D. project. By using this technique one is able to decompose a large set of data - for example from airborne gamma-ray surveys - into a few spectral components. ...

  1. Routing architecture and security for airborne networks

    Science.gov (United States)

    Deng, Hongmei; Xie, Peng; Li, Jason; Xu, Roger; Levy, Renato

    2009-05-01

    Airborne networks are envisioned to provide interconnectivity for terrestial and space networks by interconnecting highly mobile airborne platforms. A number of military applications are expected to be used by the operator, and all these applications require proper routing security support to establish correct route between communicating platforms in a timely manner. As airborne networks somewhat different from traditional wired and wireless networks (e.g., Internet, LAN, WLAN, MANET, etc), security aspects valid in these networks are not fully applicable to airborne networks. Designing an efficient security scheme to protect airborne networks is confronted with new requirements. In this paper, we first identify a candidate routing architecture, which works as an underlying structure for our proposed security scheme. And then we investigate the vulnerabilities and attack models against routing protocols in airborne networks. Based on these studies, we propose an integrated security solution to address routing security issues in airborne networks.

  2. Dynamic radioactive particle source

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E.; Gauss, Adam Benjamin; Justus, Alan Lawrence

    2012-06-26

    A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

  3. Improved IMMPF Tracking Methods for Airborne Laser Communication

    Directory of Open Access Journals (Sweden)

    Yang Cao

    2014-01-01

    Full Text Available Tracking system offers the prerequisite and guarantee for airborne laser communication, it is vital for tracking methods to determine the tracking accuracy. Because of diversity of maneuvering forms and high nonlinear problem, it is impossible to accurately describe the movement of airborne platform with the simple model and the traditional filtering method, it is necessary to adopt Interacting Multiple Model (IMM methods for tracking system. The Particle Filter (PF can deal with nonlinear/non-Gaussian problems, it can be introduced into IMM framework. However, the realization of PF have a larger amount of computation, in order to solve computational complexity, the parallel structure of data processing is proposed. Through theoretical analysis and computer simulation, improved PF effectively reduces the workload; the performance of improved IMMPF is much superior to other methods.

  4. Airborne contamination during blow-fill-seal pharmaceutical production.

    Science.gov (United States)

    Whyte, W; Matheis, W; Dean-Netcher, M; Edwards, A

    1998-01-01

    The routes of airborne contamination, during Blow-Fill-Seal (BFS) production, were studied using tracer gas, particles and bacteria. The prevention of airborne contamination, by the air shower at the point of fill, was effective (> 99.2% efficient). However, microbe-carrying particles could gain access, by deposition or air exchange, when the containers were cut open and before they shuttled under the protection of the air shower. The use of SF6 tracer gas demonstrated that when the air shower was not on, 50% of the air within the containers came from the area round the machine. When the air shower was switched on, only about 5% of the air came from the surroundings. Airborne microbial contamination of containers is in proportion to: the number of airborne microbes around the machine, the time the container is open, the neck area and the amount of air left within the container. The likely microbial contamination rate can be calculated from a model incorporating these variables. Microbial contamination of containers during BFS manufacturing is normally very low, but by increasing the naturally occurring bacteria in the air of the production rooms by about 100-fold, it was possible to verify the accuracy of this model. The contamination model agrees well with the observation that microbial contamination levels of between 1 in 10(5) and in 10(7) will be found when small containers (< 10 ml) are filled in conventionally ventilated rooms. To achieve similar contamination rates when filling of larger bottles, it is likely that unidirectional flow, or barrier technology will be required. PMID:9691671

  5. Influence of Asian dust particles on immune adjuvant effects and airway inflammation in asthma model mice.

    Directory of Open Access Journals (Sweden)

    Jun Kurai

    Full Text Available An Asian dust storm (ADS contains airborne particles that affect conditions such as asthma, but the mechanism of exacerbation is unclear. The objective of this study was to compare immune adjuvant effects and airway inflammation induced by airborne particles collected on ADS days and the original ADS soil (CJ-1 soil in asthma model mice.Airborne particles were collected on ADS days in western Japan. NC/Nga mice were co-sensitized by intranasal instillation with ADS airborne particles and/or Dermatophagoides farinae (Df, and with CJ-1 soil and/or Df for 5 consecutive days. Df-sensitized mice were stimulated with Df challenge intranasally at 7 days after the last Df sensitization. At 24 hours after challenge, serum allergen specific antibody, differential leukocyte count and inflammatory cytokines in bronchoalveolar lavage fluid (BALF were measured, and airway inflammation was examined histopathologically.Co-sensitization with ADS airborne particles and Df increased the neutrophil and eosinophil counts in BALF. Augmentation of airway inflammation was also observed in peribronchiolar and perivascular lung areas. Df-specific serum IgE was significantly elevated by ADS airborne particles, but not by CJ-1 soil. Levels of interleukin (IL-5, IL-13, IL-6, and macrophage inflammatory protein-2 were higher in BALF in mice treated with ADS airborne particles.These results suggest that substances attached to ADS airborne particles that are not in the original ADS soil may play important roles in immune adjuvant effects and airway inflammation.

  6. Vascular effects of ultrafine particles in persons with type 2 diabetes

    Science.gov (United States)

    BACKGROUND: Diabetes confers an increased risk for cardiovascular effects of airborne particles. OBJECTIVE: We hypothesized that inhalation of elemental carbon ultrafine particles (UFP) would activate blood platelets and vascular endothelium in people with type 2 diabetes. ...

  7. Electrospray Collection of Airborne Contaminants Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In stark contrast to current stagnation-based methods for capturing airborne particulates and biological aerosols, our demonstrated, cost-effective electrospray...

  8. Requirements for airborne vector gravimetry

    Science.gov (United States)

    Schwarz, K. P.; Colombo, O.; Hein, G.; Knickmeyer, E. T.

    1992-01-01

    The objective of airborne vector gravimetry is the determination of the full gravity disturbance vector along the aircraft trajectory. The paper briefly outlines the concept of this method using a combination of inertial and GPS-satellite data. The accuracy requirements for users in geodesy and solid earth geophysics, oceanography and exploration geophysics are then specified. Using these requirements, accuracy specifications for the GPS subsystem and the INS subsystem are developed. The integration of the subsystems and the problems connected with it are briefly discussed and operational methods are indicated that might reduce some of the stringent accuracy requirements.

  9. Geophex Airborne Unmanned Survey System

    Energy Technology Data Exchange (ETDEWEB)

    Won, I.J.; Keiswetter, D. [Geophex, Ltd., Raleigh, NC (United States)

    1995-10-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits rapid geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected.

  10. Airborne Research Experience for Educators

    Science.gov (United States)

    Costa, V. B.; Albertson, R.; Smith, S.; Stockman, S. A.

    2009-12-01

    The Airborne Research Experience for Educators (AREE) Program, conducted by the NASA Dryden Flight Research Center Office of Education in partnership with the AERO Institute, NASA Teaching From Space Program, and California State University Fullerton, is a complete end-to-end residential research experience in airborne remote sensing and atmospheric science. The 2009 program engaged ten secondary educators who specialize in science, technology, engineering or mathematics in a 6-week Student Airborne Research Program (SARP) offered through NSERC. Educators participated in collection of in-flight remote sensor data during flights aboard the NASA DC-8 as well as in-situ research on atmospheric chemistry (bovine emissions of methane); algal blooms (remote sensing to determine location and degree of blooms for further in-situ analysis); and crop classification (exploration of how drought conditions in Central California have impacted almond and cotton crops). AREE represents a unique model of the STEM teacher-as-researcher professional development experience because it asks educators to participate in a research experience and then translate their experiences into classroom practice through the design, implementation, and evaluation of instructional materials that emphasize the scientific research process, inquiry-based investigations, and manipulation of real data. Each AREE Master Educator drafted a Curriculum Brief, Teachers Guide, and accompanying resources for a topic in their teaching assignment Currently, most professional development programs offer either a research experience OR a curriculum development experience. The dual nature of the AREE model engaged educators in both experiences. Educators’ content and pedagogical knowledge of STEM was increased through the review of pertinent research articles during the first week, attendance at lectures and workshops during the second week, and participation in the airborne and in-situ research studies, data

  11. Chemical Microsensor Instrument for UAV Airborne Atmospheric Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Makel Engineering, Inc. (MEI) proposes to develop a miniaturized Airborne Chemical Microsensor Instrument (ACMI) suitable for real-time, airborne measurements of...

  12. SIMULATION STUDY ON AIRBORNE SAR ECHO SIGNAL

    Institute of Scientific and Technical Information of China (English)

    Bao Houbing; Liu Zhao

    2004-01-01

    Through analyzing the influence on echo signal by factors of kinematical parameters of airborne SAR platform and radar antenna direction, this letter, on the basis of classical SAR echo signal analogue algorithm, puts forward certain airborne SAR echo signal analogue algorithm of distance directional frequency domain pulse coherent accumulation, and goes through simulation. The simulation results have proved the effectiveness of this algorithm.

  13. The Continuous wavelet in airborne gravimetry

    Science.gov (United States)

    Liang, X.; Liu, L.

    2013-12-01

    Airborne gravimetry is an efficient method to recover medium and high frequency band of earth gravity over any region, especially inaccessible areas, which can measure gravity data with high accuracy,high resolution and broad range in a rapidly and economical way, and It will play an important role for geoid and geophysical exploration. Filtering methods for reducing high-frequency errors is critical to the success of airborne gravimetry due to Aircraft acceleration determination based on GPS.Tradiontal filters used in airborne gravimetry are FIR,IIR filer and so on. This study recommends an improved continuous wavelet to process airborne gravity data. Here we focus on how to construct the continuous wavelet filters and show their working principle. Particularly the technical parameters (window width parameter and scale parameter) of the filters are tested. Then the raw airborne gravity data from the first Chinese airborne gravimetry campaign are filtered using FIR-low pass filter and continuous wavelet filters to remove the noise. The comparison to reference data is performed to determinate external accuracy, which shows that continuous wavelet filters applied to airborne gravity in this thesis have good performances. The advantages of the continuous wavelet filters over digital filters are also introduced. The effectiveness of the continuous wavelet filters for airborne gravimetry is demonstrated through real data computation.

  14. Resuscitation effects of catalase on airborne bacteria.

    OpenAIRE

    Marthi, B; Shaffer, B. T.; Lighthart, B; Ganio, L

    1991-01-01

    Catalase incorporation into enumeration media caused a significant increase (greater than 63%) in the colony-forming abilities of airborne bacteria. Incubation for 30 to 60 min of airborne bacteria in collection fluid containing catalase caused a greater than 95% increase in colony-forming ability. However, catalase did not have any effects on enumeration at high relative humidities (80 to 90%).

  15. A Simple Method for Collecting Airborne Pollen

    Science.gov (United States)

    Kevan, Peter G.; DiGiovanni, Franco; Ho, Rong H.; Taki, Hisatomo; Ferguson, Kristyn A.; Pawlowski, Agata K.

    2006-01-01

    Pollination is a broad area of study within biology. For many plants, pollen carried by wind is required for successful seed set. Airborne pollen also affects human health. To foster studies of airborne pollen, we introduce a simple device--the "megastigma"--for collecting pollen from the air. This device is flexible, yielding easily obtained data…

  16. A system for airborne SAR interferometry

    DEFF Research Database (Denmark)

    Madsen, Søren Nørvang; Skou, Niels; Granholm, Johan;

    1996-01-01

    Interferometric synthetic aperture radar (INSAR) systems have already demonstrated that elevation maps can be generated rapidly with single pass airborne across-track interferometry systems (XTT), and satellite repeat track interferometry (RTT) techniques have been used to map both elevation......) the status of the airborne interferometry activities at DCRS, including the present system configuration, recent results, and some scientific applications of the system....

  17. Elemental composition of airborne dust in the shale shaker house during an offshore drilling operation

    DEFF Research Database (Denmark)

    Hansen, A.B.; Larsen, E.; Hansen, L.V.;

    1991-01-01

    chrome lignosulphonate and chrome lignite, was circulated between the borehole and the Shale Shaker House. The concentration of airborne dust in the atmosphere was determined and the elemental composition of the particles analysed by both PIXE (proton-induced X-ray emission) and ICP-MS (inductively......During 2 days of an offshore drilling operation in the North Sea, 16 airborne dust samples from the atmosphere of the Shale Shaker House were collected onto filters. During this operation, drilling mud composed of a water slurry of barite (BaSO4) together with minor amounts of additives, among them...

  18. Condensation Particle Counter Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-01

    The Model 3772 CPC is a compact, rugged, and full-featured instrument that detects airborne particles down to 10 nm in diameter, at an aerosol flow rate of 1.0 lpm, over a concentration range from 0 to 1x104 #/cc. This CPC is ideally suited for applications without high concentration measurements, such as basic aerosol research, filter and air-cleaner testing, particle counter calibrations, environmental monitoring, mobile aerosol studies, particle shedding and component testing, and atmospheric and climate studies.

  19. Tracing airborne particles after Japan's nuclear plant explosion

    Science.gov (United States)

    Takemura, Toshihiko; Nakamura, Hisashi; Nakajima, Teruyuki

    2011-11-01

    The powerful Tohoku earthquake and consequent tsunami that occurred off the east coast of Japan on 11 March 2011 devastated dozens of coastal cities and towns, causing the loss of more than 15,000 lives and leaving close to 4000 people still missing. Although nuclear reactors at the Fukushima Daiichi Nuclear Power Plant, located on the Pacific coast, stopped their operation automatically upon the occurrence of the Mw 9.0 quake [Showstack, 2011], the cooling system for nuclear fuel broke down. From 12 to 16 March, vapor and hydrogen blasts destroyed the buildings that had contained the reactors, resulting in the release into the atmosphere of radioactive materials such as sulfur-35, iodine-131, cesium-134, and cesium-137, which collectively can cause harmful health effects such as tissue damage and increased risk of cancer (particularly in children), depending on dose. Most of those materials emitted from the power plant rained out onto the grounds within its vicinity and forced tens of thousands within a 20-kilometer radius to evacuate (residents to the northwest of the site within about 40 kilometers also were moved from their homes). Some of the radioactive materials were transported and then detected at such distant locations as North America and Europe, although the level of radiation dose was sufficiently low not to affect human health in any significant manner.

  20. Morphology, chemical composition, and bacterial concentration of airborne particulate matter in rabbit farms

    Directory of Open Access Journals (Sweden)

    Elisa Adell

    2012-12-01

    Full Text Available Livestock houses are major sources of airborne particulate matter (PM, which can originate from manure, feed, feathers, skin and bedding and may contain and transport microorganisms. Improved knowledge of particle size, morphology, chemical and microbiological composition of PM in livestock houses can help identify major sources of PM and contribute to the development of appropriate source-specific reduction techniques. In rabbit production systems, however, there is limited information on specific particle characteristics. The objective of this study was to characterise airborne PM in rabbit farms in terms of morphology, chemical compositions and bacterial concentration in different size fractions. Size-fractioned PM was sampled in the air of 2 rabbit farms, 1 for fattening rabbits and 1 for reproductive does, using a virtual cascade impactor, which simultaneously collected total suspended PM (TSP, PM10 and PM2.5 size fractions. Airborne PM samples were examined by light microscopy and scanning electron microscopy combined with energy dispersive X-ray analysis. Representative samples from potential sources of PM were also collected and examined. Additionally, a methodology to extract bacteria from the collected samples of airborne PM was developed to determine the bacterial concentration per PM size fraction. Results showed that airborne PM in rabbit farms is highly complex in particle morphology, especially in size. Broken skin flakes, disintegrated particles from feed or faecal material from mechanical fracture are the main sources of airborne PM in rabbit farms. Major elements found in rabbit airborne PM were S, Ca, Mg, Na and Cl. Bacterial concentrations ranged from 1.7×104 to 1.6×106 colony forming units (CFU/m3 (TSP; from 3.6×103 to 3.0×104 CFU/m3 (PM10; and from 3.1×103 to 1.6×104 CFU/m3 (PM2.5. Our results will improve the knowledge on essential particle characteristics necessary to understand PM’s origin in rabbit farms and

  1. Airborne gamma ray spectrometer surveying

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) in its role as collector and disseminator of information on nuclear techniques has long had an interest in gamma ray spectrometer methods and has published a number of Technical Reports on various aspects of the subject. At an Advisory Group Meeting held in Vienna in November 1986 to review appropriate activities the IAEA could take following the Chernobyl accident, it was recommended that preparation begin on a new Technical Report on airborne gamma ray spectrometer surveying, taking into account the use of the technique for environmental monitoring as well as for nuclear emergency response requirements. Shortly thereafter the IAEA became the lead organization in the Radioelement Geochemical Mapping section of the International Geological Correlation Programme/United Nations Educational, Scientific and Cultural Organization (UNESCO) Project on International Geochemical Mapping. These two factors led to the preparation of the present Technical Report. 18 figs, 4 tabs

  2. Removal of airborne microorganisms emitted from a wastewater treatment oxidation ditch by adsorption on activated carbon

    Institute of Scientific and Technical Information of China (English)

    Lin Li; Min Gao; Junxin Liu; Xuesong Guo

    2011-01-01

    Bioaerosol emissions from wastewater and wastewater treatment processes are a significant subgroup of atmospheric aerosols.Most previous work has focused on the evaluation of their biological risks.In this study, however, the adsorption method was applied to reduce airborne microorganisms generated from a pilot scale wastewater treatment facility with oxidation ditch.Results showed adsorption on granule activated carbon (GAC) was an efficient method for the purification of airborne microorganisms.The GAC itself had a maximum adsorption capacity of 2217 CFU/g for airborne bacteria and 225 CFU/g for fungi with a flow rate of 1.50 m3/hr.Over 85%of airborne bacteria and fungi emitted from thc oxidation ditch were adsorbed within 80 hr of continuous operation mode.Most of them had a particle size of 0.65-4.7 μm.Those airborne microorganisms with small particle size were apt to be adsorbed.The SEM/EDAX,BET and Boehm's titration methods were applied to analyse the physicochemical characteristics of the GAC.Relationships between GAC surface characteristics and its adsorption performance demonstrated that porous structure, large surface area, and hydrophobicity rendered GAC an effective absorber of airborne microorganisms.Two regenerate methods, ultraviolet irradiation and high pressure vapor, were compared for the regeneration of used activated carbon.High pressure vapor was an effective technique as it totally destroyed the microorganisms adhered to the activated carbon.Microscopic observation was also carried out to investigate original and used adsorbents.

  3. Predictors of airborne endotoxin in the home.

    OpenAIRE

    Park, J. H.; Spiegelman, D L; Gold, D R; Burge, H A; Milton, D K

    2001-01-01

    We identified home characteristics associated with the level of airborne endotoxin in 111 Boston-area homes enrolled in a cohort study of home exposures and childhood asthma, and we developed a predictive model to estimate airborne endotoxin. We measured endotoxin in family-room air and in dust from the baby's bed, family room, bedroom, and kitchen floor. Level of airborne endotoxin was weakly correlated (r < 0.3) with level of endotoxin in each of the four types of dust samples and was signi...

  4. Airborne Digital Camera. A digital view from above; Airborne Digital Camera. Der digitale Blick von oben

    Energy Technology Data Exchange (ETDEWEB)

    Roeser, H.P. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Berlin (Germany). Inst. fuer Weltraumsensorik und Planetenerkundung

    1999-09-01

    The Airborne Digital Camera is based on the WAOSS camera of the MARS-96 mission. The camera will provide a new basis for airborne photogrammetry and remote exploration. The ADC project aims at the development of the first commercial digital airborne camera. [German] Die Wurzeln des Projektes Airborne Digital Camera (ADC) liegen in der Mission MARS-96. Die hierfuer konzipierte Marskamera WAOSS lieferte die Grundlage fuer das innovative Konzept einer digitalen Flugzeugkamera. Diese ist auf dem Weg, die flugzeuggestuetzte Photogrammetrie und Fernerkundung auf eine technologisch voellig neue Basis zu stellen. Ziel des Projektes ADC ist die Entwicklung der ersten kommerziellen digitalen Luftbildkamera. (orig.)

  5. Miniaturized Airborne Imaging Central Server System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a miniaturized airborne imaging central server system (MAICSS). MAICSS is designed as a high-performance computer-based electronic backend that...

  6. Miniaturized Airborne Imaging Central Server System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a miniaturized airborne imaging central server system (MAICSS). MAICSS is designed as a high-performance-computer-based electronic backend that...

  7. Regenerable Lunar Airborne Dust Filter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Effective methods are needed to control pervasive Lunar Dust within spacecraft and surface habitations. Once inside, airborne transmission is the primary mode of...

  8. Airborne Multi-Gas Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mesa Photonics proposes to develop an Airborne Multi-Gas Sensor (AMUGS) based upon two-tone, frequency modulation spectroscopy (TT-FMS). Mesa Photonics has...

  9. Reconfigurable Weather Radar for Airborne Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Intelligent Automation, Inc (IAI) and its university partner, University of Oklahoma (OU), Norman, propose a forward-looking airborne environment sensor based on...

  10. Software for airborne radiation monitoring system

    International Nuclear Information System (INIS)

    The Airborne Radiation Monitoring System monitors radioactive contamination in the air or on the ground. The contamination source can be a radioactive plume or an area contaminated with radionuclides. This system is composed of two major parts: Airborne Unit carried by a helicopter, and Ground Station carried by a truck. The Airborne software is intended to be the core of a computerized airborne station. The software is written in C++ under MS-Windows with object-oriented methodology. It has been designed to be user-friendly: function keys and other accelerators are used for vital operations, a help file and help subjects are available, the Human-Machine-Interface is plain and obvious. (authors)

  11. Airborne Infrared Search and Track Systems

    Directory of Open Access Journals (Sweden)

    Hari Babu Srivastava

    2007-09-01

    Full Text Available Infrared search and track (IRST systems are required for fighter aircraft to enable them to passively search, detect, track, classify, and prioritise multiple airborne targets under all aspects, look-up, look-down, and co-altitude conditions and engage them at as long ranges as possible. While the IRST systems have been proven in performance for ground-based and naval-based platforms, it is still facing some technical problems for airborne applications. These problems arise from uncertainty in target signature, atmospheric effects, background clutter (especially dense and varying clouds, signal and data processing algorithms to detect potential targets at long ranges and some hardware limitations such as large memory requirement to store and process wide field of view data. In this paper, an overview of airborne IRST as a system has been presented with detailed comparative simulation results of different detectionitracking algorithms and the present status of airborne IRSTs

  12. Particle Suspension Mechanisms - Supplemental Material

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, M B

    2011-03-03

    This supplemental material provides a brief introduction to particle suspension mechanisms that cause exfoliated skin cells to become and remain airborne. The material presented here provides additional context to the primary manuscript and serves as background for designing possible future studies to assess the impact of skin cells as a source of infectious aerosols. This introduction is not intended to be comprehensive and interested readers are encouraged to consult the references cited.

  13. The JAC airborne EM system : AEM-05

    OpenAIRE

    Levaniemi, H.; Beamish, D; Hautaniemi, H.; Kurimo, M.; Suppala, I.; Vironmaki, J.; Cuss, R.J.; Lahti, M; Tartaras, E.

    2009-01-01

    This paper describes the airborne electromagnetic (AEM) system operated by the Joint Airborne geoscience Capability (JAC), a partnership between the Finnish and British Geological Surveys. The system is a component of a 3-in-1, fixed-wing facility acquiring magnetic gradiometer and full spectrum radiometric data alongside the wing-tip, frequency-domain AEM measurements. The AEM system has recently (2005) been upgraded from 2 to 4 frequencies and now provides a bandwidth from 900 Hz to 25 kHz....

  14. Challenges and Opportunities of Airborne Metagenomics

    KAUST Repository

    Behzad, H.

    2015-05-06

    Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles.

  15. Downscaling of Airborne Wind Energy Systems

    Science.gov (United States)

    Fechner, Uwe; Schmehl, Roland

    2016-09-01

    Airborne wind energy systems provide a novel solution to harvest wind energy from altitudes that cannot be reached by wind turbines with a similar nominal generator power. The use of a lightweight but strong tether in place of an expensive tower provides an additional cost advantage, next to the higher capacity factor and much lower total mass. This paper investigates the scaling effects of airborne wind energy systems. The energy yield of airborne wind energy systems, that work in pumping mode of operation is at least ten times higher than the energy yield of conventional solar systems. For airborne wind energy systems the yield is defined per square meter wing area. In this paper the dependency of the energy yield on the nominal generator power for systems in the range of 1 kW to 1 MW is investigated. For the onshore location Cabauw, The Netherlands, it is shown, that a generator of just 1.4 kW nominal power and a total system mass of less than 30 kg has the theoretical potential to harvest energy at only twice the price per kWh of large scale airborne wind energy systems. This would make airborne wind energy systems a very attractive choice for small scale remote and mobile applications as soon as the remaining challenges for commercialization are solved.

  16. Challenges and opportunities of airborne metagenomics.

    Science.gov (United States)

    Behzad, Hayedeh; Gojobori, Takashi; Mineta, Katsuhiko

    2015-05-06

    Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles.

  17. Particle Pollution

    Science.gov (United States)

    ... Your Health Particle Pollution Public Health Issues Particle Pollution Recommend on Facebook Tweet Share Compartir Particle pollution ... see them in the air. Where does particle pollution come from? Particle pollution can come from two ...

  18. Airborne Atmospheric Aerosol Measurement System

    Science.gov (United States)

    Ahn, K.; Park, Y.; Eun, H.; Lee, H.

    2015-12-01

    It is important to understand the atmospheric aerosols compositions and size distributions since they greatly affect the environment and human health. Particles in the convection layer have been a great concern in global climate changes. To understand these characteristics satellite, aircraft, and radio sonde measurement methods have usually been used. An aircraft aerosol sampling using a filter and/or impactor was the method commonly used (Jay, 2003). However, the flight speed particle sampling had some technical limitations (Hermann, 2001). Moreover, the flight legal limit, altitude, prohibited airspace, flight time, and cost was another demerit. To overcome some of these restrictions, Tethered Balloon Package System (T.B.P.S.) and Recoverable Sonde System(R.S.S.) were developed with a very light optical particle counter (OPC), impactor, and condensation particle counter (CPC). Not only does it collect and measure atmospheric aerosols depending on altitudes, but it also monitors the atmospheric conditions, temperature, humidity, wind velocity, pressure, GPS data, during the measurement (Eun, 2013). In this research, atmospheric aerosol measurement using T.B.P.S. in Ansan area is performed and the measurement results will be presented. The system can also be mounted to an unmanned aerial vehicle (UAV) and create an aerial particle concentration map. Finally, we will present measurement data using Tethered Balloon Package System (T.B.P.S.) and R.S.S (Recoverable Sonde System).

  19. Air pollution dry deposition: radioisotopes as particles and volatiles

    International Nuclear Information System (INIS)

    This study focuses on determining volcanic ash and ambient airborne solids concentrations at various sampling sites subsequent to the Mt. St. Helens' eruption in order to develop an experimental basis for models predicting removal of airborne particles and gases by dry deposition onto outdoor surfaces. In addition, deposition rates were determined using dual tracer techniques in the field and in a wind tunnel in the laboratory

  20. Airborne high spectral resolution lidar observation of pollution aerosol during EUCAARI-LONGREX

    OpenAIRE

    Groß, S.; M. Esselborn; F. Abicht; Wirth, M.; Fix, A.(Laboratory of Mathematical Physics, Tomsk Polytechnic University, Tomsk, Russia); Minikin, A.

    2012-01-01

    Airborne high spectral resolution lidar observations over Europe during the EUCAARI field experiment in May 2008 are analysed with respect to spatial distribution and optical properties of continental pollution aerosol. Continental aerosol is characterized by its depolarisation and lidar ratio. Mean values of 6%±1% for the particle linear depolarisation ratio, and 56 sr±6 sr for the lidar ratio were found for pollution aerosol. Both, lidar ratio and depolarisation ...

  1. Airborne high spectral resolution lidar observation of pollution aerosol during EUCAARI-LONGREX

    OpenAIRE

    Groß, Silke; Esselborn, Michael; Abicht, Florian; Wirth, Martin; Fix, Andreas; Minikin, Andreas

    2013-01-01

    Airborne high spectral resolution lidar observations over Europe during the EUCAARI-LONGREX field experiment in May 2008 are analysed with respect to the optical properties of continental pollution aerosol. Continental pollution aerosol is characterized by its depolarisation and lidar ratio. Over all, the measurements of the lidar ratio and the particle linear depolarization ratio of pollution aerosols provide a narrow range of values. Therefore, this data set allows for a distinct characteri...

  2. Second generation dichotomous sampler for large-scale monitoring of airborne particulate matter

    Energy Technology Data Exchange (ETDEWEB)

    Loo, B.W.; Adachi, R.S.; Cork, C.P.; Goulding, F.S.; Jaklevic, J.M.; Landis, D.A.; Searles, W.L.

    1979-01-01

    The differences which exist between fine (< 2.5 ..mu..m) and coarse (> 2.5 ..mu..m) airborne particles with respect to their origin, chemical properties, and environmental impact, call for their separate collection and analysis. An automated dichotomous sampler (ADS), equipped with a high efficiency single-stage virtual impactor and a microprocessor-based controller to self-correct fault conditions including filter overload, has been developed as a model for commercial production.

  3. Mapping permafrost with airborne electromagnetics

    Science.gov (United States)

    Minsley, B. J.; Ball, L. B.; Bloss, B. R.; Kass, A.; Pastick, N.; Smith, B. D.; Voss, C. I.; Walsh, D. O.; Walvoord, M. A.; Wylie, B. K.

    2014-12-01

    Permafrost is a key characteristic of cold region landscapes, yet detailed assessments of how the subsurface distribution of permafrost impacts the environment, hydrologic systems, and infrastructure are lacking. Data acquired from several airborne electromagnetic (AEM) surveys in Alaska provide significant new insight into the spatial extent of permafrost over larger areas (hundreds to thousands of square kilometers) than can be mapped using ground-based geophysical methods or through drilling. We compare several AEM datasets from different areas of interior Alaska, and explore the capacity of these data to infer geologic structure, permafrost extent, and related hydrologic processes. We also assess the impact of fires on permafrost by comparing data from different burn years within similar geological environments. Ultimately, interpretations rely on understanding the relationship between electrical resistivity measured by AEM surveys and the physical properties of interest such as geology, permafrost, and unfrozen water content in the subsurface. These relationships are often ambiguous and non-unique, so additional information is useful for reducing uncertainty. Shallow (upper ~1m) permafrost and soil characteristics identified from remotely sensed imagery and field observations help to constrain and aerially extend near-surface AEM interpretations, where correlations between the AEM and remote sensing data are identified using empirical multivariate analyses. Surface nuclear magnetic resonance (sNMR) measurements quantify the contribution of unfrozen water at depth to the AEM-derived electrical resistivity models at several locations within one survey area. AEM surveys fill a critical data gap in the subsurface characterization of permafrost environments and will be valuable in future mapping and monitoring programs in cold regions.

  4. System for particle concentration and detection

    Science.gov (United States)

    Morales, Alfredo M.; Whaley, Josh A.; Zimmerman, Mark D.; Renzi, Ronald F.; Tran, Huu M.; Maurer, Scott M.; Munslow, William D.

    2013-03-19

    A new microfluidic system comprising an automated prototype insulator-based dielectrophoresis (iDEP) triggering microfluidic device for pathogen monitoring that can eventually be run outside the laboratory in a real world environment has been used to demonstrate the feasibility of automated trapping and detection of particles. The system broadly comprised an aerosol collector for collecting air-borne particles, an iDEP chip within which to temporarily trap the collected particles and a laser and fluorescence detector with which to induce a fluorescence signal and detect a change in that signal as particles are trapped within the iDEP chip.

  5. Airborne and ground based CCN spectral characteristics: Inferences from CAIPEEX - 2011

    Science.gov (United States)

    Varghese, Mercy; Prabha, Thara V.; Malap, Neelam; Resmi, E. A.; Murugavel, P.; Safai, P. D.; Axisa, Duncan; Pandithurai, G.; Dani, K.

    2016-01-01

    A first time comprehensive study of Cloud Condensation Nuclei (CCN) and associated spectra from both airborne and ground campaigns of the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) conducted over the rain shadow region of Western Ghats during September and October 2011 is illustrated. Observations of CCN spectra during clean, polluted and highly polluted conditions indicated significant differences between airborne and ground observations. Vertical variation of CCN concentration is illustrated from airborne observations in the clean, polluted and highly polluted conditions with different air mass characteristics. The cloud base CCN number concentrations are three times less than that of the surface measurements at different supersaturations. Diurnal variations of the ground based CCN number concentration and activation diameter showed bimodality. Atmospheric mixing in the wet conditions is mainly through mechanical mixing. The dry conditions favored convective mixing and were dominated by more CCN than the wet conditions. New particle formation and growth events have been observed and were found more often on days with convective mixing. The average critical activation diameter (at 0.6% SS) observed at the ground is approximately 60 nm and availability of a large number of particles below this limit was due to the new particle formation. Observations give convincing evidence that the precipitable water and liquid water path is inversely proportional to surface CCN number concentration, and this relationship is largely dictated by the meteorological conditions.

  6. Method for measuring the size distribution of airborne rhinovirus

    Energy Technology Data Exchange (ETDEWEB)

    Russell, M.L.; Goth-Goldstein, R.; Apte, M.G.; Fisk, W.J.

    2002-01-01

    About 50% of viral-induced respiratory illnesses are caused by the human rhinovirus (HRV). Measurements of the concentrations and sizes of bioaerosols are critical for research on building characteristics, aerosol transport, and mitigation measures. We developed a quantitative reverse transcription-coupled polymerase chain reaction (RT-PCR) assay for HRV and verified that this assay detects HRV in nasal lavage samples. A quantitation standard was used to determine a detection limit of 5 fg of HRV RNA with a linear range over 1000-fold. To measure the size distribution of HRV aerosols, volunteers with a head cold spent two hours in a ventilated research chamber. Airborne particles from the chamber were collected using an Andersen Six-Stage Cascade Impactor. Each stage of the impactor was analyzed by quantitative RT-PCR for HRV. For the first two volunteers with confirmed HRV infection, but with mild symptoms, we were unable to detect HRV on any stage of the impactor.

  7. Lunar Airborne Dust Toxicity Hazard Assessments (Invited)

    Science.gov (United States)

    Cooper, B. L.; McKay, D. S.; Taylor, L. A.; Wallace, W. T.; James, J.; Riofrio, L.; Gonzalez, C. P.

    2009-12-01

    The Lunar Airborne Dust Toxicity Assessment Group (LADTAG) is developing data to set the permissible limits for human exposure to lunar dust. This standard will guide the design of airlocks and ports for EVA, as well as the requirements for filtering and monitoring the atmosphere in habitable vehicles, rovers and other modules. LADTAG’s recommendation for permissible exposure limits will be delivered to the Constellation Program in late 2010. The current worst-case exposure limit of 0.05 mg/m3, estimated by LADTAG in 2006, reflects the concern that lunar dust may be as toxic as quartz dust. Freshly-ground quartz is known to be more toxic than un-ground quartz dust. Our research has shown that the surfaces of lunar soil grains can be more readily activated by grinding than quartz. Activation was measured by the amount of free radicals generated—activated simulants generate Reactive Oxygen Species (ROS) i.e., production of hydroxyl free radicals. Of the various influences in the lunar environment, micrometeorite bombardment probably creates the most long-lasting reactivity on the surfaces of grains, although solar wind impingement and short-wavelength UV radiation also contribute. The comminution process creates fractured surfaces with unsatisfied bonds. When these grains are inhaled and carried into the lungs, they will react with lung surfactant and cells, potentially causing tissue damage and disease. Tests on lunar simulants have shown that dissolution and leaching of metals can occur when the grains are exposed to water—the primary component of lung fluid. However, simulants may behave differently than actual lunar soils. Rodent toxicity testing will be done using the respirable fraction of actual lunar soils (particles with physical size of less than 2.5 micrometers). We are currently separating the fine material from the coarser material that comprises >95% of the mass of each soil sample. Dry sieving is not practical in this size range, so a new system

  8. Trace elements in airborne particulates in South Africa

    International Nuclear Information System (INIS)

    Airborne particulate materials were monitored continously with calendar month sampling periods at 5 rural/background, 4 rural/developing/peri-urban, 6 urban and 7 industrial sites in South Africa. Concentrations of Al, Br, Ca, Cs, Cd, Cl, Co, Cr, Cu, Eu, Fe, K, Mg, Mn, Na, Ni, Pb, Rb, S, Sb, Sc, Se, Ti, V and Zn were determined with neutron activation analysis (NAA), atomic absorption spectroscopy (AAS) and particle-induced X-ray emission spectroscopy (PIXE) employed on a complementary basis. A review of sources of airborne trace elements is given. The monitoring program, sampling, sample-handling procedures, as well as the analytical methods used, are discussed in detail. The results of related studies, i.e. effects of filter materials; sampling rates and geometry; determinations of collection efficiencies; particle size ranges; effects of internal flux monitors on the precision and accuracy of NAA; trace impurities in blank materials; quality control by routine analysis of reference materials; comparison of results obtained by NAA, AAS, and PIXE analysis; are given, as is a review of air-pollution control and research policy in South Africa and of ambient air quality standards. Results are discussed in terms of general patterns in trace-element concentrations and enrichments, the general pattern in population centres, the variability of monthly concentrations, and in terms of long-term trends at background, rural, developing, peri-urban, urban and industrial sites. Cases of concern in respect of increasing concentrations are pointed out, as are the constantly high Pb levels at urban sites

  9. Airborne Microalgae: Insights, Opportunities, and Challenges.

    Science.gov (United States)

    Tesson, Sylvie V M; Skjøth, Carsten Ambelas; Šantl-Temkiv, Tina; Löndahl, Jakob

    2016-04-01

    Airborne dispersal of microalgae has largely been a blind spot in environmental biological studies because of their low concentration in the atmosphere and the technical limitations in investigating microalgae from air samples. Recent studies show that airborne microalgae can survive air transportation and interact with the environment, possibly influencing their deposition rates. This minireview presents a summary of these studies and traces the possible route, step by step, from established ecosystems to new habitats through air transportation over a variety of geographic scales. Emission, transportation, deposition, and adaptation to atmospheric stress are discussed, as well as the consequences of their dispersal on health and the environment and state-of-the-art techniques to detect and model airborne microalga dispersal. More-detailed studies on the microalga atmospheric cycle, including, for instance, ice nucleation activity and transport simulations, are crucial for improving our understanding of microalga ecology, identifying microalga interactions with the environment, and preventing unwanted contamination events or invasions. PMID:26801574

  10. Airborne space laser communication system and experiments

    Science.gov (United States)

    Li, Xiao-Ming; Zhang, Li-zhong; Meng, Li-Xin

    2015-11-01

    Airborne space laser communication is characterized by its high speed, anti-electromagnetic interference, security, easy to assign. It has broad application in the areas of integrated space-ground communication networking, military communication, anti-electromagnetic communication. This paper introduce the component and APT system of the airborne laser communication system design by Changchun university of science and technology base on characteristic of airborne laser communication and Y12 plan, especially introduce the high communication speed and long distance communication experiment of the system that among two Y12 plans. In the experiment got the aim that the max communication distance 144Km, error 10-6 2.5Gbps - 10-7 1.5Gbps capture probability 97%, average capture time 20s. The experiment proving the adaptability of the APT and the high speed long distance communication.

  11. Sandia Multispectral Airborne Lidar for UAV Deployment

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, J.W.; Hargis,Jr. P.J.; Henson, T.D.; Jordan, J.D.; Lang, A.R.; Schmitt, R.L.

    1998-10-23

    Sandia National Laboratories has initiated the development of an airborne system for W laser remote sensing measurements. System applications include the detection of effluents associated with the proliferation of weapons of mass destruction and the detection of biological weapon aerosols. This paper discusses the status of the conceptual design development and plans for both the airborne payload (pointing and tracking, laser transmitter, and telescope receiver) and the Altus unmanned aerospace vehicle platform. Hardware design constraints necessary to maintain system weight, power, and volume limitations of the flight platform are identified.

  12. Attenuation of airborne debris from LMFBR accidents

    International Nuclear Information System (INIS)

    Experimental and theoretical studies have been performed to characterize the behavior of airborne particulates (aerosols) expected to be produced by hypothetical core disassembly accidents (HCDA's) in liquid metal fast breeder reactors (LMFBR's). These aerosol studies include work on aerosol transport in a 20-m high, 850-m3 closed vessel at moderate concentrations; aerosol transport in a small vessel under conditions of high concentration (approximately 1,000 g/m3), high turbulence, and high temperature (approximately 20000C); and aerosol transport through various leak paths. These studies have shown that tittle, if any, airborne debris from LMFBR HCDA's would reach the atmosphere exterior to an intact reactor containment building. (author)

  13. Detection and enumeration of airborne biocontaminants.

    Science.gov (United States)

    Stetzenbach, Linda D; Buttner, Mark P; Cruz, Patricia

    2004-06-01

    The sampling and analysis of airborne microorganisms has received attention in recent years owing to concerns with mold contamination in indoor environments and the threat of bioterrorism. Traditionally, the detection and enumeration of airborne microorganisms has been conducted using light microscopy and/or culture-based methods; however, these analyses are time-consuming, laborious, subjective and lack sensitivity and specificity. The use of molecular methods, such as quantitative polymerase chain reaction amplification, can enhance monitoring strategies by increasing sensitivity and specificity, while decreasing the time required for analysis.

  14. Airborne radioactivity surveys in geologic exploration

    Science.gov (United States)

    Moxham, R.M.

    1958-01-01

    The value of airborne radioactivity surveys in guiding uranium exploration has been well established. Recent improvements in circuitry and development of semiquantitative analytical techniques permit a more comprehensive evaluation of the geologic distribution of radioactive materials that may prove useful in exploration for other minerals and in regional geologic studies. It is shown that placer deposits of heavy minerals can be detected from the air, and that the geometric configuration and average grade of the surficial part of the deposit can be approximated. Uranium-bearing phosphorite deposits may be similarly evaluated. Airborne surveys over the Coastal Plain area, Texas, show that

  15. Attenuation of airborne debris from LMFBR accidents

    International Nuclear Information System (INIS)

    Experimental and theoretical studies have been performed to characterize the behavior of airborne particulates (aerosols) expected to be produced by hypothetical core disassembly accidents (HCDA's) in liquid metal fast breeder reactors (LMFBR's). These aerosol studies include work on aerosol transport in a 20-m high, 850-m3 closed vessel at moderate concentrations; aerosol transport in a small vessel under conditions of high concentration (approx. 1000 g/m3), high turbulence, and high temperature (approx. 20000C); and aerosol transport through various leak paths. These studies have shown that little, if any, airborne debris from LMFBR HCDA's would reach the atmosphere exterior to an intact reactor containment building

  16. ASSESSMENT OF BAGGING OPERATORS EXPOSURE TO WITH PVC AIRBORNE PARTICULATES

    Directory of Open Access Journals (Sweden)

    H. Asilian, M. Nasseri Nejad, S. B. Mortazavi, M. J. Jafari, A. Khavanin, A. R. Dehdashti

    2008-07-01

    Full Text Available Dust consists of tiny solid particles carried by air currents. These particles are formed by many different processes. One of these processes is polymerization of inert plastic such as Polyvinyl Chloride production plant. According to the Occupational Health and Safety Assessment Series requirements, section 4.4.6, occupational health and safety risks must be defined and controlled where needed. This field study was conducted to evaluate the occupational exposure of packaging operators to airborne polyvinyl chloride dust in order to health risk assessment and recommend feasible controlling methods. The mass concentration of polyvinyl chloride particulate was measured in two fractions according to the particle size that expressed as total and respirable particulates. The Air Sampling Methods, Methods for the Determination of Hazardous Substances 14/3, of Health and Safety Executive were used as a standard sampling protocol. The average mass concentrations for respirable and total particulates were measured 3.54±0.3 mg/m3 and 11.89±0.8 mg/m3 respectively. Also health risks of studied condition were estimated as significant level, category one, therefore the risk must be reduced below the standard level. According to the work requirements to reduce the emission rate and mitigate the health risk exposure, a local exhaust ventilation system design was recommended for bag-filters of hopper tank.

  17. 14 CFR 135.175 - Airborne weather radar equipment requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... Aircraft and Equipment § 135.175 Airborne weather radar equipment requirements. (a) No person may operate a... conditions that can be detected with airborne weather radar equipment, may reasonably be expected along...

  18. 14 CFR 125.223 - Airborne weather radar equipment requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... Equipment Requirements § 125.223 Airborne weather radar equipment requirements. (a) No person may operate an airplane governed by this part in passenger-carrying operations unless approved airborne weather...

  19. 14 CFR 121.357 - Airborne weather radar equipment requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... § 121.357 Airborne weather radar equipment requirements. (a) No person may operate any transport... December 31, 1964, unless approved airborne weather radar equipment has been installed in the airplane....

  20. Aerosol Remote Sensing Applications for Airborne Multiangle, Multispectral Shortwave Radiometers

    Science.gov (United States)

    von Bismarck, Jonas; Ruhtz, Thomas; Starace, Marco; Hollstein, André; Preusker, René; Fischer, Jürgen

    2010-05-01

    Aerosol particles have an important impact on the surface net radiation budget by direct scattering and absorption (direct aerosol effect) of solar radiation, and also by influencing cloud formation processes (semi-direct and indirect aerosol effects). To study the former, a number of multispectral sky- and sunphotometers have been developed at the Institute for Space Sciences of the Free University of Berlin in the past two decades. The latest operational developments were the multispectral aureole- and sunphotometer FUBISS-ASA2, the zenith radiometer FUBISS-ZENITH, and the nadir polarimeter AMSSP-EM, all designed for a flexible use on moving platforms like aircraft or ships. Currently the multiangle, multispectral radiometer URMS/AMSSP (Universal Radiation Measurement System/ Airborne Multispectral Sunphotometer and Polarimeter) is under construction for a Wing-Pod of the high altitude research aircraft HALO operated by DLR. The system is expected to have its first mission on HALO in 2011. The algorithms for the retrieval of aerosol and trace gas properties from the recorded multidirectional, multispectral radiation measurements allow more than deriving standard products, as for instance the aerosol optical depth and the Angstrom exponent. The radiation measured in the solar aureole contains information about the aerosol phasefunction and therefore allows conclusions about the particle type. Furthermore, airborne instrument operation allows vertically resolved measurements. An inversion algorithm, based on radiative transfer simulations and additionally including measured vertical zenith-radiance profiles, allows conclusions about the aerosol single scattering albedo and the relative soot fraction in aerosol layers. Ozone column retrieval is performed evaluating measurements from pixels in the Chappuis absorption band. A retrieval algorithm to derive the water-vapor column from the sunphotometer measurements is currently under development. Of the various airborne

  1. Airborne Gravity: NGS' Airborne Gravity Data for AN01 (2009-2010)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2009-2010 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

  2. Precision Rectification of Airborne SAR Image

    DEFF Research Database (Denmark)

    Dall, Jørgen; Liao, M.; Zhang, Zhe;

    1997-01-01

    A simple and direct procedure for the rectification of a certain class of airborne SAR data is presented. The relief displacements of SAR data are effectively removed by means of a digital elevation model and the image is transformed to the ground coordinate system. SAR data from the Danish EMISAR...

  3. Experimental airborne transmission of PRRS virus

    DEFF Research Database (Denmark)

    Kristensen, C.S.; Bøtner, Anette; Takai, H.;

    2004-01-01

    A series of three experiments, differing primarily in airflow volume, were performed to evaluate the likelihood of airborne transmission of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) from infected to non-infected pigs. Pigs were housed in two units (unit A and unit B) located 1 m...

  4. Topology optimized cloak for airborne sound

    DEFF Research Database (Denmark)

    Andkjær, Jacob Anders; Sigmund, Ole

    2013-01-01

    Directional acoustic cloaks that conceal an aluminum cylinder for airborne sound waves are presented in this paper. Subwavelength cylindrical aluminum inclusions in air constitute the cloak design to aid practical realizations. The positions and radii of the subwavelength cylinders are determined...

  5. Use of airborne vehicles as research platforms

    OpenAIRE

    Gratton, GB

    2012-01-01

    This is the accepted version of the following chapter: Gratton, G. 2012. Use of Airborne Vehicles as Research Platforms. Encyclopedia of Aerospace Engineering, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/9780470686652.eae604/full. Copyright @ John Wiley & Sons 2012.

  6. Airborne laser sensors and integrated systems

    Science.gov (United States)

    Sabatini, Roberto; Richardson, Mark A.; Gardi, Alessandro; Ramasamy, Subramanian

    2015-11-01

    The underlying principles and technologies enabling the design and operation of airborne laser sensors are introduced and a detailed review of state-of-the-art avionic systems for civil and military applications is presented. Airborne lasers including Light Detection and Ranging (LIDAR), Laser Range Finders (LRF), and Laser Weapon Systems (LWS) are extensively used today and new promising technologies are being explored. Most laser systems are active devices that operate in a manner very similar to microwave radars but at much higher frequencies (e.g., LIDAR and LRF). Other devices (e.g., laser target designators and beam-riders) are used to precisely direct Laser Guided Weapons (LGW) against ground targets. The integration of both functions is often encountered in modern military avionics navigation-attack systems. The beneficial effects of airborne lasers including the use of smaller components and remarkable angular resolution have resulted in a host of manned and unmanned aircraft applications. On the other hand, laser sensors performance are much more sensitive to the vagaries of the atmosphere and are thus generally restricted to shorter ranges than microwave systems. Hence it is of paramount importance to analyse the performance of laser sensors and systems in various weather and environmental conditions. Additionally, it is important to define airborne laser safety criteria, since several systems currently in service operate in the near infrared with considerable risk for the naked human eye. Therefore, appropriate methods for predicting and evaluating the performance of infrared laser sensors/systems are presented, taking into account laser safety issues. For aircraft experimental activities with laser systems, it is essential to define test requirements taking into account the specific conditions for operational employment of the systems in the intended scenarios and to verify the performance in realistic environments at the test ranges. To support the

  7. Regional airborne flux measurements in Europe

    Science.gov (United States)

    Gioli, B.; Miglietta, F.; Vaccari, F. P.; Zaldei, A.; Hutjes, R. W. A.

    2003-04-01

    The problem of identifying the spatial and temporal distribution of sources and sinks of atmospheric CO2 is the subject of considerable scientific and political debate. Even if it is now possible to estimate within reasonable accuracy the sink strength of European forests at the local scale, difficulties still exist in determining the partitioning of the sinks at the global and regional scales. The aim of the EU-project RECAB (Regional Assessment of the Carbon Balance in Europe) that is coordinated by Alterra, Wageningen (NL), is to bridge the gap between local scale flux measurements and continental scale inversion models by a generic modelling effort and measurement program, focussing on a limited number of selected regions in Europe for which previous measurements exists. This required the establishment of a European facility for airborne measurement of surface fluxes of CO2 at very low altitude, and a research aircraft capable of performing airborne eddy covariance measurements has been acquired by this project and used on several occasions at the different RECAB sites. The aircraft is the italian Sky Arrows ERA (Environmental Research Aircraft) equipped with the NOAA/ARA Mobile Flux Platform (MFP), and a commercial open-path infrared gas analyser. Airborne eddy covariance measurements were made from June 2001 onwards in Southern Spain near Valencia (June and December 2001), in Central Germany near Jena (July 2001), in Sweden near Uppsala (August 2001), in The Netherlands near Wageningen (January and July 2002) and in Italy near Rome (June 2002). Flux towers were present at each site to provide a validation of airborne eddy covariance measurements. This contribution reports some validation results based on the comparison between airborne and ground based flux measurements and some regional scale results for different locations and different seasons, in a wide range of meteorological and ecological settings.

  8. Direct analysis of airborne mite allergen (Der f1) in the residential atmosphere by chemifluorescent immunoassay using bioaerosol sampler.

    Science.gov (United States)

    Miyajima, Kumiko; Suzuki, Yurika; Miki, Daisuke; Arai, Moeka; Arakawa, Takahiro; Shimomura, Hiroji; Shiba, Kiyoko; Mitsubayashi, Kohji

    2014-06-01

    Dermatophagoides farinae allergen (Der f1) is one of the most important indoor allergens associated with allergic diseases in humans. Mite allergen Der f1 is usually associated with particles of high molecular weight; thus, Der f1 is generally present in settled dust. However, a small quantity of Der f1 can be aerosolized and become an airborne component. Until now, a reliable method of detecting airborne Der f1 has not been developed. The aim of this study was to develop a fiber-optic chemifluorescent immunoassay for the detection of airborne Der f1. In this method, the Der f1 concentration measured on the basis of the intensity of fluorescence amplified by an enzymatic reaction between the labeled enzyme by a detection antibody and a fluorescent substrate. The measured Der f1 concentration was in the range from 0.49 to 250 ng/ml and a similar range was found by enzyme-linked immunosorbent assay (ELISA). This method was proved to be highly sensitive to Der f1 compared with other airborne allergens. For the implementation of airborne allergen measurement in a residential environment, a bioaerosol sampler was constructed. The airborne allergen generated by a nebulizer was conveyed to a newly sampler we developed for collecting airborne Der f1. The sampler was composed of polymethyl methacrylate (PMMA) cells for gas/liquid phases and some porous membranes which were sandwiched in between the two phases. Der f1 in air was collected by the sampler and measured using the fiber-optic immunoassay system. The concentration of Der f1 in aerosolized standards was in the range from 0.125 to 2.0 mg/m(3) and the collection rate of the device was approximately 0.2%.

  9. The International SubMillimetre Airborne Radiometer (ISMAR) - First results from the STICCS and COSMIC campaigns

    Science.gov (United States)

    Mendrok, Jana; Eriksson, Patrick; Fox, Stuart; Brath, Manfred; Buehler, Stefan

    2016-04-01

    Multispectral millimeter- and submillimeter-wave observations bear the potential to measure properties of non-thin ice clouds like mass content and mean particle size. The next generation of European meteorological satellites, the MetOp-SG series, will carry the first satellite-borne submillimeter sounder, the Ice Cloud Imager (ICI). An airborne demonstrator, the International SubMillimetre Airborne Radiometer (ISMAR), is operated together with other remote sensing instruments and in-situ probes on the FAAM aircraft. Scientific measurements from two campaings in the North Atlantic region, STICCS and COSMIC, are available so far. Here we will introduce the ISMAR instrument, present the acquired measurements from the STICCS and COSMIC campaigns and show some first results. This will include estimation of instrument performance, first analysis of clear-sky and cloudy cases and discussion of selected features observed in the measurements (e.g. polarisation signatures).

  10. The relationships between air pollutants, meteorological parameters and concentration of airborne fungal spores

    Energy Technology Data Exchange (ETDEWEB)

    Grinn-Gofron, Agnieszka, E-mail: agofr@univ.szczecin.p [Department of Plant Taxonomy and Phytogeography, Faculty of Natural Science, University of Szczecin, Waska 13 Street, 71-415 Szczecin (Poland); Strzelczak, Agnieszka [Department of Food Process Engineering, Faculty of Food Science and Fisheries, West Pomeranian University of Technology, Szczecin (Poland); Wolski, Tomasz [Physical Oceanography Laboratory, University of Szczecin (Poland)

    2011-02-15

    Fungal spores are an important component of bioaerosol and also considered to act as indicator of the level of atmospheric bio-pollution. Therefore, better understanding of these phenomena demands a detailed survey of airborne particles. The objective of this study was to examine the dependence of two the most important allergenic taxa of airborne fungi - Alternaria and Cladosporium - on meteorological parameters and air pollutant concentrations during three consecutive years (2006-2008). This study is also an attempt to create artificial neural network (ANN) forecasting models useful in the prediction of aeroallergen abundance. There were statistically significant relationships between spore concentration and environmental parameters as well as pollutants, confirmed by the Spearman's correlation rank analysis and high performance of the ANN models obtained. The concentrations of Cladosporium and Alternaria spores can be predicted with quite good accuracy from meteorological conditions and air pollution recorded three days earlier. - ANN models predict airspore contents from weather conditions and air pollutant.

  11. Measurement of airborne fission products in Chapel Hill, NC, USA from the Fukushima I reactor accident

    CERN Document Server

    MacMullin, S; Green, M P; Henning, R; Holmes, R; Vorren, K; Wilkerson, J F

    2011-01-01

    We present measurements of airborne fission products in Chapel Hill, NC, USA, from 62 days following the March 11, 2011, accident at the Fukushima I Nuclear Power Plant. Airborne particle samples were collected daily in air filters and radio-assayed with two high-purity germanium (HPGe) detectors. The fission products I-131 and Cs-137 were measured with maximum activities of 4.2 +/- 0.6 mBq/m^2 and 0.42 +/- 0.07 mBq/m^2 respectively. Additional activity from I-131, I-132, Cs-134, Cs-136, Cs-137 and Te-132 were measured in the same air filters using a low-background HPGe detector at the Kimballton Underground Research Facility (KURF).

  12. Airborne Measurements of Aerosol Size Distributions During PACDEX

    Science.gov (United States)

    Rogers, D. C.; Gandrud, B.; Campos, T.; Kok, G.; Stith, J.

    2007-12-01

    The Pacific Dust Experiment (PACDEX) is an airborne project that attempts to characterize the indirect aerosol effect by tracing plumes of dust and pollution across the Pacific Ocean. This project occurred during April-May 2007 and used the NSF/NCAR HIAPER research aircraft. When a period of strong generation of dust particles and pollution was detected by ground-based and satellite sensors, then the aircraft was launched from Colorado to Alaska, Hawaii, and Japan. Its mission was to intercept and track these plumes from Asia, across the Pacific Ocean, and ultimately to the edges of North America. For more description, see the abstract by Stith and Ramanathan (this conference) and other companion papers on PACDEX. The HIAPER aircraft carried a wide variety of sensors for measuring aerosols, cloud particles, trace gases, and radiation. Sampling was made in several weather regimes, including clean "background" air, dust and pollution plumes, and regions with cloud systems. Altitude ranges extended from 100 m above the ocean to 13.4 km. This paper reports on aerosol measurements made with a new Ultra-High Sensitivity Aerosol Spectrometer (UHSAS), a Radial Differential Mobility Analyzer (RDMA), a water-based CN counter, and a Cloud Droplet Probe (CDP). These cover the size range 10 nm to 10 um diameter. In clear air, dust was detected with the UHSAS and CDP. Polluted air was identified with high concentrations of carbon monoxide, ozone, and CN. Aerosol size distributions will be presented, along with data to define the context of weather regimes.

  13. Determination of airborne isocyanate exposure: considerations in method selection.

    Science.gov (United States)

    Streicher, R P; Reh, C M; Key-Schwartz, R J; Schlecht, P C; Cassinelli, M E; O'Connor, P F

    2000-01-01

    To assess worker isocyanate exposures in a variety of processes involving the manufacture and use of surface coatings, polyurethane foams, adhesives, resins, elastomers, binders, and sealants, it is important to be able to measure airborne reactive isocyanate-containing compounds. Choosing the correct methodology can be difficult. Isocyanate species, including monomers, prepolymers, oligomers, and polyisocyanates, are capable of producing irritation to the skin, eyes, mucous membranes, and respiratory tract. The most common adverse health effect is respiratory sensitization, and to a lesser extent dermal sensitization and hypersensitivity pneumonitis. Furthermore, isocyanate species formed during polyurethane production or thermal degradation may also produce adverse health effects. Isocyanate measurement is complicated by the fact that isocyanates may be in the form of vapors or aerosols of various particle size; the species of interest are reactive and therefore unstable; few pure analytical standards exist; and high analytical sensitivity is needed. There are numerous points in the sampling and analytical procedures at which errors can be introduced. The factors to be considered for selecting the most appropriate methodology for a given workplace include collection, derivatization, sample preparation, separation, identification, and quantification. This article discusses these factors in detail and presents a summary of method selection criteria based on the isocyanate species, its physical state, particle size, cure rate, and other factors. PMID:10976685

  14. Skin Damage Mechanisms Related to Airborne Particulate Matter Exposure.

    Science.gov (United States)

    Magnani, Natalia D; Muresan, Ximena M; Belmonte, Giuseppe; Cervellati, Franco; Sticozzi, Claudia; Pecorelli, Alessandra; Miracco, Clelia; Marchini, Timoteo; Evelson, Pablo; Valacchi, Giuseppe

    2016-01-01

    Epidemiological studies suggest a correlation between increased airborne particulate matter (PM) and adverse health effects. The mechanisms of PM-health effects are believed to involve oxidative stress and inflammation. To evaluate the ability of PM promoting skin tissue damage, one of the main organs exposed to outdoor pollutants, we analyzed the effect of concentrated ambient particles (CAPs) in a reconstructed human epidermis (RHE) model. RHE tissues were exposed to 25 or 100 µg/ml CAPs for 24 or 48 h. Data showed that RHE seems to be more susceptible to CAPs-induced toxicity after 48 h exposure than after 24 h. We found a local reactive O(2) species (ROS) production increase generated from metals present on the particle, which contributes to lipids oxidation. Furthermore, as a consequence of altered redox status, NFkB nucleus translocation was increase upon CAPs exposure, as well as cyclooxygenase 2 and cytochrome P450 levels, which may be involved in the inflammatory response initiated by PM. CAPs also triggered an apoptotic process in skin. Surprisingly, by transition electron microscopy analysis we showed that CAPs were able to penetrate skin tissues. These findings contribute to the understanding of the cutaneous pathophysiological mechanisms initiated by CAPs exposure, where oxidative stress and inflammation may play predominant roles. PMID:26507108

  15. Cleanroom airborne particulate limits and 70% isopropyl alcohol: a lingering problem for pharmaceutical manufacturing?

    Science.gov (United States)

    Eaton, Tim

    2009-01-01

    Seventy percent isopropyl alcohol (70% IPA) in water for injection is extensively utilised within pharmaceutical cleanrooms for glove and surface disinfection. When supplied in pressurised containers and delivered as an aerosol, it has been demonstrated that large quantities of 70% IPA particles are generated that remain airborne for substantial periods of time. Within non-unidirectional airflow cleanroom areas, such particles are likely to be recorded by the particle monitoring system. Consequently, the derived operational limits for particles will almost certainly be at "artificially high" levels and any particle generating activities with contamination potential may be masked. These high particle levels may not comply with the requirements of Annex 1 of the European Unions Guide to Good Manufacturing Practices (EU GGMP) and the United States Food and Drug Administration (FDA) Aseptic Processing Guideline. This is the case predominantly for the larger particles (> or =5 microm), the monitoring of which is exclusively required by the Annex 1 guide. However, by using canisters that deliver the 70% IPA as a stream, large quantities of particles are not generated and more meaningful and compliant operational levels can be obtained. Additionally, the EU GGMP's Annex 1 continuing requirement to monitor particles > or =5 microm appears to have little value or scientific justification and restricts further harmonisation of the European guide with the US FDA Aseptic Processing Guideline.

  16. Analyzing Options for Airborne Emergency Wireless Communications

    Energy Technology Data Exchange (ETDEWEB)

    Michael Schmitt; Juan Deaton; Curt Papke; Shane Cherry

    2008-03-01

    In the event of large-scale natural or manmade catastrophic events, access to reliable and enduring commercial communication systems is critical. Hurricane Katrina provided a recent example of the need to ensure communications during a national emergency. To ensure that communication demands are met during these critical times, Idaho National Laboratory (INL) under the guidance of United States Strategic Command has studied infrastructure issues, concerns, and vulnerabilities associated with an airborne wireless communications capability. Such a capability could provide emergency wireless communications until public/commercial nodes can be systematically restored. This report focuses on the airborne cellular restoration concept; analyzing basic infrastructure requirements; identifying related infrastructure issues, concerns, and vulnerabilities and offers recommended solutions.

  17. Geoid of Nepal from airborne gravity survey

    DEFF Research Database (Denmark)

    Forsberg, René; Olesen, Arne Vestergaard; Einarsson, Indriði;

    2011-01-01

    An airborne gravity survey of Nepal was carried out December 2010 in a cooperation between DTU-Space, Nepal Survey Department, and NGA, USA. The entire country was flown with survey lines spaced 6 nm with a King Air aircraft, with a varying flight altitude from 4 to 10 km. The survey operations...... were a major challenge due to excessive jet streams at altitude as well as occasional excessive mountain waves. Despite the large 400 mGal+ range of gravity anomaly changes from the Indian plains to the Tibetan Plateau, results appear accurate to a few mGal, with proper evaluation from cross...... as well as recent GPS-heights of Mt. Everest. The new airborne data also provide an independent validation of GOCE gravity field results at the local ~100 km resolution scale....

  18. Comprehensive characterization of indoor airborne bacterial profile

    Institute of Scientific and Technical Information of China (English)

    P.L.Chan; P.H.F.Yu; Y.W.Cheng; C.Y.Chan; P.K.Wong

    2009-01-01

    This is the first detailed characterization of the air-borne bacterial profiles in indoor environments and two restaurants were selected for this study.Fifteen genera of bacteria were isolated from each restaurant and identified by three different bacterial identification systems including MIDI, Biolog and Riboprinter?.The dominant bacteria of both restaurants were Gram-positive bacteria in which Micrococcus and Bacillus species were the most abundant species.Most bacteria identified were representative species of skin and respiratory tract of human, and soil.Although the bacterial levels in these restaurants were below the limit of the Hong Kong Indoor Air Quality Objective (HKIAQO) Level 1 standard (i.e., < 500 cfu/m3), the majority of these bacteria were opportunistic pathogens.These results suggested that the identity of airborne bacteria should also be included in the IAQ to ensure there is a safety guideline for the public.

  19. Simulating City-level Airborne Infectious Diseases

    CERN Document Server

    Shan, Mei; Yifan, Zhu; Zhenghu, Zu; Tao, Zheng; Boukhanovsky, A V; Sloot, P M A

    2012-01-01

    With the exponential growth in the world population and the constant increase in human mobility, the danger of outbreaks of epidemics is rising. Especially in high density urban areas such as public transport and transfer points, where people come in close proximity of each other, we observe a dramatic increase in the transmission of airborne viruses and related pathogens. It is essential to have a good understanding of the `transmission highways' in such areas, in order to prevent or to predict the spreading of infectious diseases. The approach we take is to combine as much information as is possible, from all relevant sources and integrate this in a simulation environment that allows for scenario testing and decision support. In this paper we lay out a novel approach to study Urban Airborne Disease spreading by combining traffic information, with geo-spatial data, infection dynamics and spreading characteristics.

  20. Simulating city-level airborne infectious diseases

    OpenAIRE

    Mei, S.; Chen, B; Zhu, Y; Lees, M.H.; Boukhanovsky, A.V.; Sloot, P.M.A.

    2015-01-01

    With the exponential growth in the world population and the constant increase in human mobility, the possible impact of outbreaks of epidemics on cities is increasing, especially in high-density urban areas such as public transportation and transfer points. The volume and proximity of people in these areas can lead to an observed dramatic increase in the transmission of airborne viruses and related pathogens. Due to the critical role these areas play in transmission, it is vital that we have ...

  1. Airborne Chemical Sensing with Mobile Robots

    Science.gov (United States)

    Lilienthal, Achim J.; Loutfi, Amy; Duckett, Tom

    2006-01-01

    Airborne chemical sensing with mobile robots has been an active research area since the beginning of the 1990s. This article presents a review of research work in this field, including gas distribution mapping, trail guidance, and the different subtasks of gas source localisation. Due to the difficulty of modelling gas distribution in a real world environment with currently available simulation techniques, we focus largely on experimental work and do not consider publications that are purely based on simulations.

  2. Airborne laser altimeter measurements of landscape topography

    International Nuclear Information System (INIS)

    Measurements of topography can provide a wealth of information on landscape properties for managing hydrologic and geologic systems and conserving natural and agricultural resources. This article discusses the application of an airborne laser altimeter to measure topography and other landscape surface properties. The airborne laser altimeter makes 4000 measurements per second with a vertical recording resolution of 5 cm. Data are collected digitally with a personal computer. A video camera, borehole sighted with the laser, records an image for locating flight lines. GPS data are used to locate flight line positions on the landscape. Laser data were used to measure vegetation canopy topography, height, cover, and distribution and to measure microtopography of the land surface and gullies with depths of 15–20 cm. Macrotopography of landscape profiles for segments up to 4 km were in agreement with available topographic maps but provided more detail. Larger gullies with and without vegetation, and stream channel cross sections and their associated floodplains have also been measured and reported in other publications. Landscape segments for any length could be measured for either micro- or macrotopography. Airborne laser altimeter measurements of landscape profiles can provide detailed information on landscape properties or specific needs that will allow better decisions on the design and location of structures (i.e., roads, pipe, and power lines) and for improving the management and conservation of natural and agricultural landscapes. (author)

  3. Airborne multispectral detection of regrowth cotton fields

    Science.gov (United States)

    Westbrook, John K.; Suh, Charles P.-C.; Yang, Chenghai; Lan, Yubin; Eyster, Ritchie S.

    2015-01-01

    Effective methods are needed for timely areawide detection of regrowth cotton plants because boll weevils (a quarantine pest) can feed and reproduce on these plants beyond the cotton production season. Airborne multispectral images of regrowth cotton plots were acquired on several dates after three shredding (i.e., stalk destruction) dates. Linear spectral unmixing (LSU) classification was applied to high-resolution airborne multispectral images of regrowth cotton plots to estimate the minimum detectable size and subsequent growth of plants. We found that regrowth cotton fields can be identified when the mean plant width is ˜0.2 m for an image resolution of 0.1 m. LSU estimates of canopy cover of regrowth cotton plots correlated well (r2=0.81) with the ratio of mean plant width to row spacing, a surrogate measure of plant canopy cover. The height and width of regrowth plants were both well correlated (r2=0.94) with accumulated degree-days after shredding. The results will help boll weevil eradication program managers use airborne multispectral images to detect and monitor the regrowth of cotton plants after stalk destruction, and identify fields that may require further inspection and mitigation of boll weevil infestations.

  4. MITAS: multisensor imaging technology for airborne surveillance

    Science.gov (United States)

    Thomas, John D.

    1991-08-01

    MITAS, a unique and low-cost solution to the problem of collecting and processing multisensor imaging data for airborne surveillance operations has been developed, MITAS results from integrating the established and proven real-time video processing, target tracking, and sensor management software of TAU with commercially available image exploitation and map processing software. The MITAS image analysis station (IAS) supports airborne day/night reconnaissance and surveillance missions involving low-altitude collection platforms employing a suite of sensors to perform reconnaissance functions against a variety of ground and sea targets. The system will detect, locate, and recognize threats likely to be encountered in support of counternarcotic operations and in low-intensity conflict areas. The IAS is capable of autonomous, near real-time target exploitation and has the appropriate communication links to remotely located IAS systems for more extended analysis of sensor data. The IAS supports the collection, fusion, and processing of three main imaging sensors: daylight imagery (DIS), forward looking infrared (FLIR), and infrared line scan (IRLS). The MITAS IAS provides support to all aspects of the airborne surveillance mission, including sensor control, real-time image enhancement, automatic target tracking, sensor fusion, freeze-frame capture, image exploitation, target data-base management, map processing, remote image transmission, and report generation.

  5. Cryospheric Applications of Modern Airborne Photogrammetry

    Science.gov (United States)

    Nolan, M.

    2014-12-01

    Airborne photogrammetry is undergoing a renaissance. Lower-cost equipment, more powerful software, and simplified methods have lowered the barriers-to-entry significantly and now allow repeat-mapping of cryospheric dynamics that were previously too expensive to consider. The current state-of-the-art is the ability to use an airborne equipment package costing less than $20,000 to make topographic maps on landscape-scales at 10 cm pixel size with a vertical repeatability of about 10 cm. Nearly any surface change on the order of decimeters can be measured using these techniques through analysis of time-series of such maps. This presentation will discuss these new methods and their application to cryospheric dynamics such as the measurement of snow depth, coastal erosion, valley-glacier volume-change, permafrost thaw, frost heave of infrastructure, river bed geomorphology, and aufeis melt. Because of the expense of other airborne methods, by necessity measurements of these dynamics are currently most often made on the ground along benchmark transects that are then extrapolated to the broader scale. The ability to directly measure entire landscapes with equal or higher accuracy than transects eliminates the need to extrapolate them and the ability to do so at lower costs than transects may revolutionize the way we approach studying change in the cryosphere, as well as our understanding of the cryosphere itself.

  6. Airborne Tactical Free-Electron Laser

    Energy Technology Data Exchange (ETDEWEB)

    Whitney, Roy; Neil, George

    2007-02-01

    The goal of 100 kilowatts (kW) of directed energy from an airborne tactical platform has proved challenging due to the size and weight of most of the options that have been considered. However, recent advances in Free-Electron Lasers appear to offer a solution along with significant tactical advantages: a nearly unlimited magazine, time structures for periods from milliseconds to hours, radar like functionality, and the choice of the wavelength of light that best meets mission requirements. For an Airborne Tactical Free-Electron Laser (ATFEL) on a platforms such as a Lockheed C-130J-30 and airships, the two most challenging requirements, weight and size, can be met by generating the light at a higher harmonic, aggressively managing magnet weights, managing cryogenic heat loads using recent SRF R&D results, and using FEL super compact design concepts that greatly reduce the number of components. The initial R&D roadmap for achieving an ATFEL is provided in this paper. Performing this R&D is expected to further reduce the weight, size and power requirements for the FELs the Navy is currently developing for shipboard applications, as well as providing performance enhancements for the strategic airborne MW class FELs. The 100 kW ATFEL with its tactical advantages may prove sufficiently attractive for early advancement in the queue of deployed FELs.

  7. Use of direct versus indirect preparation data for assessing risk associated with airborne exposures at asbestos-contaminated sites.

    Science.gov (United States)

    Goldade, Mary Patricia; O'Brien, Wendy Pott

    2014-01-01

    At asbestos-contaminated sites, exposure assessment requires measurement of airborne asbestos concentrations; however, the choice of preparation steps employed in the analysis has been debated vigorously among members of the asbestos exposure and risk assessment communities for many years. This study finds that the choice of preparation technique used in estimating airborne amphibole asbestos exposures for risk assessment is generally not a significant source of uncertainty. Conventionally, the indirect preparation method has been less preferred by some because it is purported to result in false elevations in airborne asbestos concentrations, when compared to direct analysis of air filters. However, airborne asbestos sampling in non-occupational settings is challenging because non-asbestos particles can interfere with the asbestos measurements, sometimes necessitating analysis via indirect preparation. To evaluate whether exposure concentrations derived from direct versus indirect preparation techniques differed significantly, paired measurements of airborne Libby-type amphibole, prepared using both techniques, were compared. For the evaluation, 31 paired direct and indirect preparations originating from the same air filters were analyzed for Libby-type amphibole using transmission electron microscopy. On average, the total Libby-type amphibole airborne exposure concentration was 3.3 times higher for indirect preparation analysis than for its paired direct preparation analysis (standard deviation = 4.1), a difference which is not statistically significant (p = 0.12, two-tailed, Wilcoxon signed rank test). The results suggest that the magnitude of the difference may be larger for shorter particles. Overall, neither preparation technique (direct or indirect) preferentially generates more precise and unbiased data for airborne Libby-type amphibole concentration estimates. The indirect preparation method is reasonable for estimating Libby-type amphibole exposure and

  8. Influence of negative pressurization on airborne microbial and radon levels

    Energy Technology Data Exchange (ETDEWEB)

    Kalliokoski, P.; Korhonen, P.; Kokotti, H.; Pasanen, A.L.; Rautiala, S.; Rantamaeki, J.

    1999-07-01

    The negative pressure inside a building is the main driving force for the entry of both radon and fungal spores. This study was conducted to test the suitability of depressurization to facilitate simultaneously the detection of fungal growth within the lower parts of building envelope and the risk of radon entry. Pressure difference was increased in three steps to 24--28 Pa in two wooden buildings known to suffer from long-term water damages. At the end, pulses of negative pressure were generated. Airborne viable fungal counts, radon and particle counts were followed during the tests together with the ventilation rate and particle count. The absolute concentrations of the impurities studied did not increase significantly or even decreased during the tests due to enhanced ventilation. However, when the increase in the ventilation rate was taken into consideration it was found that the entry rate of all the contaminants increased. The changes were larger in the tighter building where the radon entry rate increased systematically with the pressure difference reaching finally 13.8-fold level compared to the initial value. In the less tight building, the corresponding highest radon entry rate ratio was 9.5. Very large increases, up to 42-fold, were observed in the viable spore count ratio in the tighter building during the tests. In the leaky building, the changes were again considerably smaller; the maximum ratio was 4.2. Increases in particle emissions were smaller than those observed in fungal counts. The pulses were less effective than continuous depressurization. The results show that negative pressurization can be used to increase the release of fungal spores in order to detect hidden fungal growth. This kind of test is especially effective if there are no major leaks in the clean part of the building envelope. The method allows simultaneous rapid checking of need for radon mitigation.

  9. Comprehensive airborne characterization of aerosol from a major bovine source

    Directory of Open Access Journals (Sweden)

    H. Jonsson

    2008-09-01

    Full Text Available We report an extensive airborne characterization of aerosol downwind of a massive bovine source in the San Joaquin Valley (California on two flights during July 2007. The Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS Twin Otter probed chemical composition, particle size distribution, mixing state, sub- and supersaturated water uptake behavior, light scattering properties, and the interrelationship between these parameters and meteorology. Total PM1.0 levels and concentrations of organics, nitrate, and ammonium were enhanced in the plume from the source as compared to the background aerosol. Organics dominated the plume aerosol mass (~56–64%, followed either by sulfate or nitrate, and then ammonium. Particulate amines were detected in the plume aerosol by a particle-into-liquid sampler (PILS and via mass spectral markers in the Aerodyne C-ToF-AMS. Amines were found to be a significant atmospheric base even in the presence of ammonia; particulate amine concentrations are estimated as at least 14–23% of that of ammonium in the plume. Enhanced sub- and supersaturated water uptake and reduced refractive indices were coincident with lower organic mass fractions, higher nitrate mass fractions, and the detection of amines. The likelihood of suppressed droplet growth owing to kinetic limitations from hydrophobic organic material is explored. After removing effects associated with size distribution and mixing state, the normalized activated fraction of cloud condensation nuclei (CCN increased as a function of the subsaturated hygroscopic growth factor, with the highest activated fractions being consistent with relatively lower organic mass fractions and higher nitrate mass fractions. Subsaturated hygroscopic growth factors for the organic fraction of the aerosol are estimated based on employing the Zdanovskii-Stokes Robinson (ZSR mixing rule. Representative values for a parameterization treating particle water

  10. Comprehensive airborne characterization of aerosol from a major bovine source

    Directory of Open Access Journals (Sweden)

    A. Sorooshian

    2008-06-01

    Full Text Available We report an extensive airborne characterization of aerosol downwind of a massive bovine source in the San Joaquin Valley (California on two flights during July 2007. The Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS Twin Otter probed chemical composition, particle size distribution, mixing state, sub- and supersaturated water uptake behavior, light scattering properties, and the interrelationship between these parameters and meteorology. Total PM1.0 levels and concentrations of organics, nitrate, and ammonium were enhanced in the plume from the source as compared to the background aerosol. Organics dominated the plume aerosol mass (~56–64%, followed either by sulfate or nitrate, and then ammonium. Particulate amines were detected in the plume aerosol by a particle-into-liquid sampler (PILS and via mass spectral markers in the Aerodyne cToF-AMS. Amines were found to be a significant atmospheric base even in the presence of ammonia; particulate amine concentrations are estimated as at least 14–23% of that of ammonium in the plume. Enhanced sub- and supersaturated water uptake and reduced refractive indices were coincident with lower organic mass fractions, higher nitrate mass fractions, and the detection of amines. Kinetic limitations due to hydrophobic organic material are shown to have likely suppressed droplet growth. After removing effects associated with size distribution and mixing state, the normalized activated fraction of cloud condensation nuclei (CCN increased as a function of the subsaturated hygroscopic growth factor, with the highest activated fractions being consistent with relatively lower organic mass fractions and higher nitrate mass fractions. Subsaturated hygroscopic growth factors for the organic fraction of the aerosol are estimated based on employing the Zdanovskii-Stokes Robinson (ZSR mixing rule. Representative values for a parameterization treating particle water uptake in both the

  11. Airborne EM applied to environmental geoscience in the UK

    OpenAIRE

    Beamish, D

    2002-01-01

    The British Geological Survey (BGS) has been highlighting the need for modern, multi-sensor airborne geophysical data in the UK. Here David Beamish, geophysicist with the BGS, describes the first trial airborne electromagnetic data acquired and its relevance to environmental geoscience. The lack of modern, multi-sensor (magnetic, radiometric and electromagnetic) data represents one of the most serious gaps in the geoscience knowledge base of the UK, and a national, high resolution airborne su...

  12. High-Performance Airborne Optical Carbon Dioxide Analyzer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Environmental species measurement on airborne atmospheric research craft is a demanding application for optical sensing techniques. Yet optical techniques offer...

  13. Interim report: airborne plutonium studies for the HEDL Plutonium Fuels Laboratory

    International Nuclear Information System (INIS)

    This report describes data and findings for two studies. The objective of the first is to provide a valid estimate of the alpha activity concentration of the gaseous effluents emitted from the Plutonium Fuels Laboratory. Particulates from large volume samples (millions of cubic ft.) continuously extracted from the E4 duct have shown the alpha activity concentrations to be greater than 2 orders of magnitude below the most restrictive limits for plutonium isotopes listed in Appendix B 10 CFR 20. Currently, samples are continuously extracted at approximately 50 cm for 90 days and indicate alpha activity concentrations of around 5 x 10-6 dpm per ft3. The second study proposes to evaluate the behavior of particles airborne in ''inerted'' gloveboxes. The size distributions and alpha activity concentrations of airborne activity in the Mixing-Blending glovebox have been evaluated during selected fuel fabrication operations. Samples were collected by inserting the collection equipment (cascade impactors or filters) into the glovebox. Samples were collected during mixing blending operations during 2 periods with varying enrichment levels. A maximum airborne concentration of 2.4 x 108 dpm/ft3 was measured with concentrations decaying to 102 to 103 dpm/ft3 after a few days of inactivity

  14. Airborne gamma anomalies in the Elbe Valley near Koenigstein, Germany - Origin and variation with time

    International Nuclear Information System (INIS)

    In 1982, an airborne gamma spectrometer survey was undertaken by SDAG WISMUT which was directed at the detection of further uranium mineralization in Saxony and Thuringia. Anomalies outlined along the Elbe river near the existing Koenigstein uranium mine were attributed to one or a combination of the following causes: radioactive residues from uranium processing facilities located upstream, temporary accumulation of Rn-decay products attached to dust particles in the atmosphere at the time of the survey, and radioactive waters emerging from uraniferous rocks along tectonic structures. In 1994, WISMUT GmbH re-evaluated the survey to determine the need for implementing cleanup measures. Subsequent to the verification of the original airborne data, ground surveys were undertaken that included gamma spectrometry, percussion probing and river sediment sampling. The new results did not confirm the magnitude of most of the 1982 airborne anomalies. The general decline of the radioactivity pointed out by the 1994 ground measurements is interpreted to be a result of the partial erosion and dilution of radionuclides in fluvial sediments as well as burial by additional river sediments since. Additional anomalous copper and zinc concentrations are attributed to sources other than mining. The ground follow-up delineated a new anomalous zone that is caused by radionuclides discharged with treated process and mine water. It is the only area, which may require further investigations and possible remedial action. (author)

  15. Black pine (Pinus nigra) barks as biomonitors of airborne mercury pollution.

    Science.gov (United States)

    Chiarantini, Laura; Rimondi, Valentina; Benvenuti, Marco; Beutel, Marc W; Costagliola, Pilario; Gonnelli, Cristina; Lattanzi, Pierfranco; Paolieri, Mario

    2016-11-01

    Tree barks are relevant interfaces between plants and the external environment, and can effectively retain airborne particles and elements at their surface. In this paper we have studied the distribution of mercury (Hg) in soils and in black pine (Pinus nigra) barks from the Mt. Amiata Hg district in southern Tuscany (Italy), where past Hg mining and present-day geothermal power plants affect local atmospheric Hg concentration, posing serious environmental concerns. Barks collected in heavily Hg-polluted areas of the district display the highest Hg concentration ever reported in literature (8.6mg/kg). In comparison, barks of the same species collected in local reference areas and near geothermal power plants show much lower (range 19-803μg/kg) concentrations; even lower concentrations are observed at a "blank" site near the city of Florence (5-98μg/kg). Results show a general decrease of Hg concentration from bark surface inwards, in accordance with a deposition of airborne Hg, with minor contribution from systemic uptake from soils. Preliminary results indicate that bark Hg concentrations are comparable with values reported for lichens in the same areas, suggesting that tree barks may represent an additional useful tool for biomonitoring of airborne Hg. PMID:27341111

  16. Contribution of airborne microbes to bacterial production and N2 fixation in seawater upon aerosol deposition

    Science.gov (United States)

    Rahav, Eyal; Ovadia, Galit; Paytan, Adina; Herut, Barak

    2016-01-01

    Aerosol deposition may supply a high diversity of airborne microbes, which can affect surface microbial composition and biological production. This study reports a diverse microbial community associated with dust and other aerosol particles, which differed significantly according to their geographical air mass origin. Microcosm bioassay experiments, in which aerosols were added to sterile (0.2 µm filtered and autoclaved) SE Mediterranean Sea (SEMS) water, were performed to assess the potential impact of airborne bacteria on bacterial abundance, production, and N2 fixation. Significant increase was observed in all parameters within a few hours, and calculations suggest that airborne microbes can account for one third in bacterial abundance and 50-100% in bacterial production and N2-fixation rates following dust/aerosol amendments in the surface SEMS. We show that dust/aerosol deposition can be a potential source of a wide array of microorganisms, which may impact microbial composition and food web dynamics in oligotrophic marine systems such as the SEMS.

  17. Automated Counting of Airborne Asbestos Fibers by a High-Throughput Microscopy (HTM Method

    Directory of Open Access Journals (Sweden)

    Hwataik Han

    2011-07-01

    Full Text Available Inhalation of airborne asbestos causes serious health problems such as lung cancer and malignant mesothelioma. The phase-contrast microscopy (PCM method has been widely used for estimating airborne asbestos concentrations because it does not require complicated processes or high-priced equipment. However, the PCM method is time-consuming and laborious as it is manually performed off-site by an expert. We have developed a high-throughput microscopy (HTM method that can detect fibers distinguishable from other spherical particles in a sample slide by image processing both automatically and quantitatively. A set of parameters for processing and analysis of asbestos fiber images was adjusted for standard asbestos samples with known concentrations. We analyzed sample slides containing airborne asbestos fibers collected at 11 different workplaces following PCM and HTM methods, and found a reasonably good agreement in the asbestos concentration. Image acquisition synchronized with the movement of the robotic sample stages followed by an automated batch processing of a stack of sample images enabled us to count asbestos fibers with greatly reduced time and labors. HTM should be a potential alternative to conventional PCM, moving a step closer to realization of on-site monitoring of asbestos fibers in air.

  18. Particle-Particle-String Vertex

    OpenAIRE

    Ishibashi, Nobuyuki

    1996-01-01

    We study a theory of particles interacting with strings. Considering such a theory for Type IIA superstring will give some clue about M-theory. As a first step toward such a theory, we construct the particle-particle-string interaction vertex generalizing the D-particle boundary state.

  19. Resuspension of uranium-plutonium oxide particles from burning Plexiglas

    International Nuclear Information System (INIS)

    Nuclear fuel materials such as Uranium-Plutonium oxide must be handled remotely in gloveboxes because of their radiotoxicity. These gloveboxes are frequently constructed largely of combustible Plexiglas sheet. To estimate the potential airborne spread of radioactive contamination in the event of a glovebox fire, the resuspension of particles from burning Plexiglas was investigated. (author)

  20. Diversity and Composition of Airborne Fungal Community Associated with Particulate Matters in Beijing during Haze and Non-haze Days.

    Science.gov (United States)

    Yan, Dong; Zhang, Tao; Su, Jing; Zhao, Li-Li; Wang, Hao; Fang, Xiao-Mei; Zhang, Yu-Qin; Liu, Hong-Yu; Yu, Li-Yan

    2016-01-01

    To assess the diversity and composition of airborne fungi associated with particulate matters (PMs) in Beijing, China, a total of 81 PM samples were collected, which were derived from PM2.5, PM10 fractions, and total suspended particles during haze and non-haze days. The airborne fungal community in these samples was analyzed using the Illumina Miseq platform with fungi-specific primers targeting the internal transcribed spacer 1 region of the large subunit rRNA gene. A total of 797,040 reads belonging to 1633 operational taxonomic units were observed. Of these, 1102 belonged to Ascomycota, 502 to Basidiomycota, 24 to Zygomycota, and 5 to Chytridiomycota. The dominant orders were Pleosporales (29.39%), Capnodiales (27.96%), Eurotiales (10.64%), and Hypocreales (9.01%). The dominant genera were Cladosporium, Alternaria, Fusarium, Penicillium, Sporisorium, and Aspergilus. Analysis of similarities revealed that both particulate matter sizes (R = 0.175, p = 0.001) and air quality levels (R = 0.076, p = 0.006) significantly affected the airborne fungal community composition. The relative abundance of many fungal genera was found to significantly differ among various PM types and air quality levels. Alternaria and Epicoccum were more abundant in total suspended particles samples, Aspergillus in heavy-haze days and PM2.5 samples, and Malassezia in PM2.5 samples and heavy-haze days. Canonical correspondence analysis and permutation tests showed that temperature (p < 0.01), NO2 (p < 0.01), PM10 (p < 0.01), SO2(p < 0.01), CO (p < 0.01), and relative humidity (p < 0.05) were significant factors that determine airborne fungal community composition. The results suggest that diverse airborne fungal communities are associated with particulate matters and may provide reliable data for studying the responses of human body to the increasing level of air pollution in Beijing.

  1. Environmental releases from fuel cycle facility: part 1: radionuclide resuspension vs. stack releases on ambient airborne uranium and thorium levels

    International Nuclear Information System (INIS)

    Airborne activity levels of uranium and thorium series were measured in the vicinity (1.1 km) of a uranium (UF4) processing plant, located in Malvési, south of France. Regarding its impact on the environment, this facility is characterized by its routine atmospheric releases of uranium and by the emission of radionuclide-labelled particles from a storage pond filled with waste water or that contain dried sludge characterized by traces of plutonium and thorium (230Th). This study was performed during a whole year (November 2009–November 2010) and based on weekly aerosol sampling. Thanks to ICP-MS results, it was possible to perform investigations of uranium and thorium decay product concentration in the air. The number of aerosol filters sampled (50) was sufficient to establish a relationship between airborne radionuclide variations and the wind conditions. As expected, the more the time spent in the plume, the higher the ambient levels. The respective contributions of atmospheric releases and resuspension from local soil and waste ponds on ambient dust load and uranium-bearing aerosols were estimated. Two shutdown periods dedicated to facility servicing made it possible to estimate the resuspension contribution and to specify its origin (local or regional) according to the wind direction and remote background concentration. Airborne uranium mainly comes from the emission stack and, to a minor extent (∼20%), from wind resuspension of soil particles from the surrounding fields and areas devoted to waste storage. Moreover, weighed activity levels were clearly higher during operational periods than for shutdown periods. - Highlights: • Airborne activity levels of uranium and thorium were determined at about 1 km from the smokestack of a UF4 facility. • During shutdown periods all the airborne activity can be ascribed to local resuspension of formerly deposited radionuclides. • During production periods, the respective contribution of resuspension

  2. Comprehensive simultaneous shipboard and airborne characterization of exhaust from a modern container ship at sea.

    Science.gov (United States)

    Murphy, Shane M; Agrawal, Harshit; Sorooshian, Armin; Padró, Luz T; Gates, Harmony; Hersey, Scott; Welch, W A; Lung, H; Miller, J W; Cocker, David R; Nenes, Athanasios; Jonsson, Haflidi H; Flagan, Richard C; Seinfeld, John H

    2009-07-01

    We report the first joint shipboard and airborne study focused on the chemical composition and water-uptake behavior of particulate ship emissions. The study focuses on emissions from the main propulsion engine of a Post-Panamax class container ship cruising off the central coast of California and burning heavy fuel oil. Shipboard sampling included micro-orifice uniform deposit impactors (MOUDI) with subsequent off-line analysis, whereas airborne measurements involved a number of real-time analyzers to characterize the plume aerosol, aged from a few seconds to over an hour. The mass ratio of particulate organic carbon to sulfate at the base of the ship stack was 0.23 +/- 0.03, and increased to 0.30 +/- 0.01 in the airborne exhaust plume, with the additional organic mass in the airborne plume being concentrated largely in particles below 100 nm in diameter. The organic to sulfate mass ratio in the exhaust aerosol remained constant during the first hour of plume dilution into the marine boundary layer. The mass spectrum of the organic fraction of the exhaust aerosol strongly resembles that of emissions from other diesel sources and appears to be predominantly hydrocarbon-like organic (HOA) material. Background aerosol which, based on air mass back trajectories, probably consisted of aged ship emissions and marine aerosol, contained a lower organic mass fraction than the fresh plume and had a much more oxidized organic component. A volume-weighted mixing rule is able to accurately predict hygroscopic growth factors in the background aerosol but measured and calculated growth factors do not agree for aerosols in the ship exhaust plume. Calculated CCN concentrations, at supersaturations ranging from 0.1 to 0.33%, agree well with measurements in the ship-exhaust plume. Using size-resolved chemical composition instead of bulk submicrometer composition has little effect on the predicted CCN concentrations because the cutoff diameter for CCN activation is larger than the

  3. Gas-borne particles with tunable and highly controlled characteristics for nanotoxicology studies

    OpenAIRE

    Messing, Maria; Svensson, Christian; Meuller, Bengt; Deppert, Knut; Pagels, Joakim; Rissler, Jenny

    2012-01-01

    For nanotoxicology investigations of air-borne particles to provide relevant results it is ever so important that the particle exposure of, for example cells, closely resembles the “real” exposure situation, that the dosimetry is well defined, and that the characteristics of the deposited nanoparticles are known in detail. By synthesizing the particles in the gas-phase and directly depositing them on lung cells the particle deposition conditions in the lung is closely mimicked. In this work w...

  4. Even Shallower Exploration with Airborne Electromagnetics

    Science.gov (United States)

    Auken, E.; Christiansen, A. V.; Kirkegaard, C.; Nyboe, N. S.; Sørensen, K.

    2015-12-01

    Airborne electromagnetics (EM) is in many ways undergoing the same type rapid technological development as seen in the telecommunication industry. These developments are driven by a steadily increasing demand for exploration of minerals, groundwater and geotechnical targets. The latter two areas demand shallow and accurate resolution of the near surface geology in terms of both resistivity and spatial delineation of the sedimentary layers. Airborne EM systems measure the grounds electromagnetic response when subject to either a continuous discrete sinusoidal transmitter signal (frequency domain) or by measuring the decay of currents induced in the ground by rapid transmission of transient pulses (time domain). In the last decade almost all new developments of both instrument hardware and data processing techniques has focused around time domain systems. Here we present a concept for measuring the time domain response even before the transient transmitter current has been turned off. Our approach relies on a combination of new instrument hardware and novel modeling algorithms. The newly developed hardware allows for measuring the instruments complete transfer function which is convolved with the synthetic earth response in the inversion algorithm. The effect is that earth response data measured while the transmitter current is turned off can be included in the inversion, significantly increasing the amount of available information. We demonstrate the technique using both synthetic and field data. The synthetic examples provide insight on the physics during the turn off process and the field examples document the robustness of the method. Geological near surface structures can now be resolved to a degree that is unprecedented to the best of our knowledge, making airborne EM even more attractive and cost-effective for exploration of water and minerals that are crucial for the function of our societies.

  5. Evaluation of airborne respirable particulate matter and polycyclic aromatic hydrocarbon exposure of asphalt workers

    Directory of Open Access Journals (Sweden)

    Teresa Cirillo

    2007-12-01

    Full Text Available

    Introduction: Assessment of exposure to the airborne respirable particles (PM10 and polycyclic aromatic hydrocarbons (PAHs of asphalt manufacturing and road paving workers in the Campania region (Italy.

    Materials and Methods: A study was carried out during 2006 and involved 5 firms producing and employing bitumen in road paving activities. The workers studied were categorized on the basis of their job as workers in bitumen manufacturing, in road paving and in workers not exposed at bitumen fume considered like controls.

    Results: In the manufacturing plants the average concentrations of airborne PM10 were 1125±445 ìg/m3 in the HMA manufacturing workers’ areas; 314±81 ìg/m3 in the process surveyors’ cabins and 92±27 ìg/m3 in the controls’ areas (administrative offices. Within the breathing zones of the worker, the average PAHs levels in air were as follows: 367±198 ng/m3 for HMA manufacturing workers; 348±172 ng/m3 for process surveyors; 21±2 ng/m3 for the controls. At the road paving sites the average airborne PM10 levels were 1435±325 ìg/m3 for roller operators; 1610±356 ìg/m3 for paver operators; 319±108 ìg/m for the controls (traffic controllers. PAHs in the breathing zones were 1220±694 ng/m3 for the paver operators; 1360±575 ng/m3 for the roller operators’ and 139±135 ng/m3 for the traffic controllers’. The results show that the more consistent hazard for asphalt workers’ health is derived from exposure to airborne PM10 both in exposed and in non-exposed (controls workers.

  6. Using proximate analysis to characterize airborne dust generation from bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Page, S.J.; Organiscak, J.A. [NIOSH, Pittsburgh, PA (United States). Pittsburgh Research Lab.

    2002-06-01

    Laboratory crushing experiments were conducted on a range of low to high volatile bituminous coals to investigate the various factors influencing airborne respirable dust generation. Bituminous coal samples from 8 mines (5 U.S. and 3 Polish) were uniformly prepared and processed through a double roll crusher located in a low air velocity wind tunnel. Experimental factors studied included inherent coal seam constituents, specific energy of crushing, product size characteristics, dust cloud electrostatic field, and specific quantity of airborne respirable dust generated. A combination of factors is associated with the generation of airborne respirable dust. One factor involved is the effect of coal rank, described by the inherent moist fuel ratio, on the product size characteristics. However, since coals of high moist fuel ratio (high rank) are generally more extensively cleated, it is suggested that the degree of cleating is directly responsible for the quantity of respirable-sized particles produced in the crushed product material for eastern U.S. coals. This is implied by the relationship of ash content and at least one mineral constituent (pyrite, determined from pyritic sulfur analysis) to the percentage of airborne respirable dust. A clear delineation of coals, based on well-known proximate analysis characteristics, that generate the most respirable dust appears to be possible. It was also shown that the dust-generating characteristics of coals could be reasonably described by both the moist fuel ratio and the Hardgrove Grindability Index (HGI). These results show a clear distinction between eastern and western U.S. coals. However, no consistent distinction for Polish coal was observed.

  7. Development and calibration of real-time PCR for quantification of airborne microorganisms in air samples

    Science.gov (United States)

    An, Hey Reoun; Mainelis, Gediminas; White, Lori

    This manuscript describes the coupling of bioaerosol collection and the use of real-time PCR (RT-PCR) to quantify the airborne bacteria. The quantity of collected bacteria determined by RT-PCR is compared with conventional quantification techniques, such as culturing, microscopy and airborne microorganism counting by using optical particle counter (OPC). Our data show that an experimental approach used to develop standard curves for use with RT-PCR is critical for accurate sample quantification. Using universal primers we generated 12 different standard curves which were used to quantify model organism Escherichia coli (Migula) Catellani from air samples. Standard curves prepared using a traditional approach, where serially diluted genomic DNA extracted from pure cultured bacteria were used in PCR reaction as a template DNA yielded significant underestimation of sample quantities compared to airborne microorganism concentration as measured by an OPC. The underestimation was especially pronounced when standard curves were built using colony forming units (CFUs). In contrast, the estimate of cell concentration in an air sample by RT-PCR was more accurate (˜60% compared to the airborne microorganism concentration) when the standard curve was built using aerosolized E. coli. The accuracy improved even further (˜100%) when air samples used to build the standard curves were diluted first, then the DNA extracted from each dilution was amplified by the RT-PCR—to mimic the handling of air samples with unknown and possibly low concentration. Therefore, our data show that standard curves used for quantification by RT-PCR needs to be prepared using the same environmental matrix and procedures as handling of the environmental sample in question. Reliance on the standard curves generated with cultured bacterial suspension (a traditional approach) may lead to substantial underestimation of microorganism quantities in environmental samples.

  8. Airborne Pollen Grains Of Afyon, Turkey

    Institute of Scientific and Technical Information of China (English)

    Adem BICAKCI; Süheyla ERGUN; Sevcan TATLIDIL; Hulusi MALYER; Sabri OZYURT; Ahmet AKKAYA; Nihat SAPAN

    2002-01-01

    The airborne pollen grains of Afyon have been studied for a two-year period (1999-2000) with a Durham sampler. A total of 14 367 pollen grains belonging to 40 taxa have been identified and recorded with some unidentified ones. Of them, 6 732 were identified in 1999 and 7 635 in 2000. Of the total pollen grains, 69.67% were arboreal, 26.64% non-arboreal and 3.68 % unidentified. The majority of the investigated pollen grains were from Pinus, Gramineae, Cupressaceae, Platanus, Chenopodiaceae/Amaranthaceae, Quercus, Ailanthus, Moraceae, Juglans, Salix, Cedrus and Rosaceae. The highest level of pollen grains was in May.

  9. Voxel inversion of airborne EM data

    DEFF Research Database (Denmark)

    Fiandaca, Gianluca G.; Auken, Esben; Christiansen, Anders Vest C A.V.C.;

    2013-01-01

    We present a geophysical inversion algorithm working directly in a voxel grid disconnected from the actual measuring points, which allows for straightforward integration of different data types in joint inversion, for informing geological/hydrogeological models directly and for easier incorporation...... for jointly inverting airborne and ground-based geophysical data. Furthermore, geological and groundwater models most often refer to a regular voxel grid not correlated to the geophysical model space, and incorporating the geophysical data into the geological/hydrological modelling grids is problematic. We...... present a voxel grid inversion routine that overcomes these problems and we discuss in detail the algorithm implementation....

  10. 1. Airborne 2. Hangár

    OpenAIRE

    Johnson, Christy

    2008-01-01

    Hangár, Bakelit Multi Art Center 7th L1 Dance Festival, Budapest, Hungary Installation, 2008 AIRBORNE (projection-sound-monitor installation) was sited in the Hangár, B.A.C. as part of the 7th L1 Dance Festival in Budapest, Hungary (March 2008). This work continues Johnson's interest in and use of 'found' material (16mm wind tunnel footage), and performative methods (sound recording of Channel 9 on United Airlines). This immersive work explores the turbulence of suspension and sets ...

  11. Analysis of airborne pollen grains in Denizli

    OpenAIRE

    GÜVENSEN, Aykut; ÇELİK, Ali; TOPUZ, Bülent; ÖZTÜRK, Münir

    2013-01-01

    Airborne pollen distribution in Denizli Province was measured volumetrically during 2 consecutive years, 2005 and 2006, on a weekly basis. A total of 11,981 pollen grains/m3 belonging to 42 taxa were determined. In 2005 the total was 5368 pollen grains/m3 and in 2006 it was 6613 pollen grains/m3. Among the taxa recorded, 26 belonged to arboreal and 16 to nonarboreal taxa. At the end of the 2 years total pollen counts comprised 79.68% arboreal, 19.48% nonarboreal, and 0.84% unidentified taxa. ...

  12. Mutagenicity of airborne particulates in the rubber industry.

    Science.gov (United States)

    Barański, B; Indulski, J; Janik-Spiechowicz, E; Palus, J

    1989-12-01

    The aim of this work was to evaluate the mutagenic activity of airborne particulate matter in the rubber industry. Air was sucked through Whatman glass-fibre filters with Staplex pumps and adsorbed substances and fume particles were extracted with acetone or toluene for 2 h in a ultrasonic cleaner. After separation of the insoluble solid phase by filtration, solvent was evaporated at a temperature of 70 degrees C in an argon atmosphere. The residue was stored at -20 degrees C. Mutagenicity was determined by the Salmonella plate incorporation assay with the tester strain TA98 and activity is related either to the weight of aerosol (rev mg-1) or to the volume of atmospheric sample (rev m-3). The fumes emitted from the tyre tread line, calender feeding, and tyre vulcanizing processes, showed the highest mutagenic activity (55-211 rev mg-1, + S9). At these and at other workplaces (extruder mill, carbon black station, mixer loading), mutagenic activity related to the volume of air was in the range of 22-158 rev m-3, + S9. The results indicate the need to reduce and monitor mutagenic contamination in order to increase the safety of work in the rubber industry. PMID:2693511

  13. Airborne particulate soiling of terrestrial photovoltaic modules and cover materials

    Science.gov (United States)

    Hoffman, A. R.; Maag, C. R.

    1980-01-01

    Results are presented for the first phase of a photovoltaic-module soiling study that was carried out with NASA participation to investigate the problem of the electrical performance degradation of flat-plate photovoltaic modules exposed at outdoor sites that is due to the accumulation of airborne particulates on sensitive optical surfaces. The results were obtained in both field and laboratory soiling experiments, as well as in materials field experiments using candidate encapsulants and top covers. It is concluded that: (1) the electrical performance degradation shows a significant time and site dependence, ranging from 2% to 60% power loss; (2) the rate of particulate accumulation appears to be largely material independent when natural removal processes do not dominate; (3) the effectiveness of natural removal processes, especially rain, is strongly material dependent; (4) top-cover materials of glass and plexiglass retain fewer particles than silicone rubber; and (5) high module voltages relative to ground do not appear to affect the rate of dirt accumulation on modules.

  14. Modelling airborne concentration and deposition rate of maize pollen

    Science.gov (United States)

    Jarosz, Nathalie; Loubet, Benjamin; Huber, Laurent

    2004-10-01

    The introduction of genetically modified (GM) crops has reinforced the need to quantify gene flow from crop to crop. This requires predictive tools which take into account meteorological conditions, canopy structure as well as pollen aerodynamic characteristics. A Lagrangian Stochastic (LS) model, called SMOP-2D (Stochastic Mechanistic model for Pollen dispersion and deposition in 2 Dimensions), is presented. It simulates wind dispersion of pollen by calculating individual pollen trajectories from their emission to their deposition. SMOP-2D was validated using two field experiments where airborne concentration and deposition rate of pollen were measured within and downwind from different sized maize (Zea mays) plots together with micrometeorological measurements. SMOP-2D correctly simulated the shapes of the concentration profiles but generally underestimated the deposition rates in the first 10 m downwind from the source. Potential explanations of this discrepancy are discussed. Incorrect parameterisation of turbulence in the transition from the crop to the surroundings is probably the most likely reason. This demonstrates that LS models for particle transfer need to be coupled with air-flow models under complex terrain conditions.

  15. Particle deposition in ventilation ducts

    Energy Technology Data Exchange (ETDEWEB)

    Sippola, Mark R.

    2002-09-01

    Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on

  16. Quantification of bitumen particles in aerosol and soil samples using HP-GPC

    DEFF Research Database (Denmark)

    Fauser, Patrik; Tjell, Jens Christian; Mosbæk, Hans;

    2000-01-01

    A method for identifying and quantifying bitumen particles, generated from the wear of roadway asphalts, in aerosol and soil samples has been developed. Bitumen is found to be the only contributor to airborne particles containing organic molecules with molecular weights larger than 2000 g pr. mol...

  17. Moving Target Indication for Multi-channel Airborne Radar Systems

    NARCIS (Netherlands)

    Lidicky, L.

    2010-01-01

    Moving target indication (MTI) using radar is of great interest in civil and military applications. Its uses include airborne or space-borne surveillance of ground moving vehicles (cars, trains) or ships at sea, for instance. Airborne (space-borne) radar offers several advantages when compared to op

  18. Monitoring of airborne radioactivity (radon, thoron and daughters; radioactive dust)

    International Nuclear Information System (INIS)

    The processes resulting in airborne radioactivity from uranium and thorium ores are discussed. Measurement methods for radioactive dust, radon and thoron gas and radon and thoron daughters are described and assessed. The monitoring equipment required for measurement of airborne radioactivity is described

  19. 14 CFR 135.173 - Airborne thunderstorm detection equipment requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne thunderstorm detection equipment... Aircraft and Equipment § 135.173 Airborne thunderstorm detection equipment requirements. (a) No person may... the aircraft is equipped with either approved thunderstorm detection equipment or approved...

  20. Detection in Urban Scenario Using Combined Airborne Imaging Sensors

    NARCIS (Netherlands)

    Renhorn, I.; Axelsson, M.; Benoist, K.W.; Bourghys, D.; Boucher, Y.; Xavier Briottet, X.; Sergio De CeglieD, S. De; Dekker, R.J.; Dimmeler, A.; Dost, R.; Friman, O.; Kåsen, I.; Maerker, J.; Persie, M. van; Resta, S.; Schwering, P.B.W.; Shimoni, M.; Vegard Haavardsholm, T.

    2012-01-01

    The EDA project “Detection in Urban scenario using Combined Airborne imaging Sensors” (DUCAS) is in progress. The aim of the project is to investigate the potential benefit of combined high spatial and spectral resolution airborne imagery for several defense applications in the urban area. The proje

  1. Detection in Urban Scenario using Combined Airborne Imaging Sensors

    NARCIS (Netherlands)

    Renhorn, I.; Axelsson, M.; Benoist, K.W.; Bourghys, D.; Boucher, Y.; Xavier Briottet, X.; Sergio De CeglieD, S. De; Dekker, R.J.; Dimmeler, A.; Dost, R.; Friman, O.; Kåsen, I.; Maerker, J.; Persie, M. van; Resta, S.; Schwering, P.B.W.; Shimoni, M.; Vegard Haavardsholm, T.

    2012-01-01

    The EDA project “Detection in Urban scenario using Combined Airborne imaging Sensors” (DUCAS) is in progress. The aim of the project is to investigate the potential benefit of combined high spatial and spectral resolution airborne imagery for several defense applications in the urban area. The proje

  2. SOFIA's Airborne Astronomy Ambassadors: An External Evaluation of Cycle 1

    Science.gov (United States)

    Phillips, Michelle

    2015-01-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) represents a partnership between NASA and the German Aerospace Center (DLR). The observatory itself is a Boeing 747 SP that has been modified to serve as the world's largest airborne research observatory. The SOFIA Airborne Astronomy Ambassadors (AAA) program is a component of SOFIA's…

  3. Estimate of airborne release of plutonium from Babcock and Wilcox plant as a result of severe wind hazard and earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Mishima, J.; Schwendiman, L.C.; Ayer, J.E.

    1978-10-01

    As part of an interdisciplinary study to evaluate the potential radiological consequences of wind hazard and earthquake upon existing commercial mixed oxide fuel fabrication plants, the potential mass airborne releases of plutonium (source terms) from such events are estimated. The estimated souce terms are based upon the fraction of enclosures damaged to three levels of severity (crush, puncture penetrate, and loss of external filter, in order of decreasing severity), called damage ratio, and the airborne release if all enclosures suffered that level of damage. The discussion of damage scenarios and source terms is divided into wind hazard and earthquake scenarios in order of increasing severity. The largest airborne releases from the building were for cases involving the catastrophic collapse of the roof over the major production areas--wind hazard at 110 mph and earthquakes with peak ground accelerations of 0.20 to 0.29 g. Wind hazards at higher air velocities and earthquakes with higher ground acceleration do not result in significantly greater source terms. The source terms were calculated as additional mass of respirable particles released with time up to 4 days; and, under these assumptions, approximately 98% of the mass of material of concern is made airborne from 2 h to 4 days after the event. The overall building source terms from the damage scenarios evaluated are shown in a table. The contribution of individual areas to the overall building source term is presented in order of increasing severity for wind hazard and earthquake.

  4. Stellar Occultations from Airborne Platforms: 1988 to 2016

    Science.gov (United States)

    Bosh, Amanda S.; Dunham, Edward W.; Zuluaga, Carlos; Levine, Stephen; Person, Michael J.; Van Cleve, Jeffrey E.

    2016-10-01

    Observing a stellar occultation by a solar system body with an airborne telescope requires precise positioning of the observer within the shadow cast onto the Earth. For small bodies like Pluto and Kuiper Belt objects, smaller than the Earth, the challenge is particularly intense, with the accuracy of the astrometric and flight planning determining whether the observation succeeds or fails. From our first airborne occultation by Pluto in 1988 aboard the Kuiper Airborne Observatory (KAO), to our most recent event by Pluto in 2015 aboard the Stratospheric Observatory for Infrared Astronomy (SOFIA), we have refined our astrometric and flight planning systems to the point where we can now place an airborne observer into the small central flash zone. We will discuss the history of airborne observation of occultations while detailing the improvements in the astrometric processes. Support for this work was provided by NASA SSO grant NNX15AJ82G to Lowell Observatory.

  5. Airborne gamma radiation soil moisture measurements over short flight lines

    Science.gov (United States)

    Peck, Eugene L.; Carrol, Thomas R.; Lipinski, Daniel M.

    1990-01-01

    Results are presented on airborne gamma radiation measurements of soil moisture condition, carried out along short flight lines as part of the First International Satellite Land Surface Climatology Project Field Experiment (FIFE). Data were collected over an area in Kansas during the summers of 1987 and 1989. The airborne surveys, together with ground measurements, provide the most comprehensive set of airborne and ground truth data available in the U.S. for calibrating and evaluating airborne gamma flight lines. Analysis showed that, using standard National Weather Service weights for the K, Tl, and Gc radiation windows, the airborne soil moisture estimates for the FIFE lines had a root mean square error of no greater than 3.0 percent soil moisture. The soil moisture estimates for sections having acquisition time of at least 15 sec were found to be reliable.

  6. Calibration Matters: Advances in Strapdown Airborne Gravimetry

    Science.gov (United States)

    Becker, D.

    2015-12-01

    Using a commercial navigation-grade strapdown inertial measurement unit (IMU) for airborne gravimetry can be advantageous in terms of cost, handling, and space consumption compared to the classical stable-platform spring gravimeters. Up to now, however, large sensor errors made it impossible to reach the mGal-level using such type IMUs as they are not designed or optimized for this kind of application. Apart from a proper error-modeling in the filtering process, specific calibration methods that are tailored to the application of aerogravity may help to bridge this gap and to improve their performance. Based on simulations, a quantitative analysis is presented on how much IMU sensor errors, as biases, scale factors, cross couplings, and thermal drifts distort the determination of gravity and the deflection of the vertical (DOV). Several lab and in-field calibration methods are briefly discussed, and calibration results are shown for an iMAR RQH unit. In particular, a thermal lab calibration of its QA2000 accelerometers greatly improved the long-term drift behavior. Latest results from four recent airborne gravimetry campaigns confirm the effectiveness of the calibrations applied, with cross-over accuracies reaching 1.0 mGal (0.6 mGal after cross-over adjustment) and DOV accuracies reaching 1.1 arc seconds after cross-over adjustment.

  7. CO2 Budget and Rectification Airborne Study

    Science.gov (United States)

    Grainger, C. A.

    2004-01-01

    The main purpose of this award was to supply a platform for the airborne measurements of gases associated with the CO2 Budget and Regional Airborne Study (COBRA). The original program was to consist of three field programs: the first was to be in 1999, the second in 2000, and the third in 2001. At the end of the second field program, it was agreed that the science could better be served by making the measurements in northern Brazil, rather than in North America. The final North American program would be postponed until after two field programs in Brazil. A substantial amount of effort was diverted into making plans and preparations for the Brazil field programs. The Brazil field programs were originally scheduled to take place in the Fall of 2002 and Spring of 2003. Carrying out the field program in Brazil was going to logistically much more involved than a program in the US. Shipping of equipment, customs, and site preparations required work to begin many months prior to the actual measurement program. Permission to fly in that country was also not trivial and indeed proved to be a major obstacle. When we were not able to get permission to fly in Brazil for the 2002 portion of the experiment, the program was pushed back to 2003. When permission by the Brazilian government was not given in time for a Spring of 2003 field program, the experiment was postponed again to begin in the Fall of 2003.

  8. Architecture and Algorithms for an Airborne Network

    CERN Document Server

    Sen, Arunabha; Silva, Tiffany; Das, Nibedita; Kundu, Anjan

    2010-01-01

    The U.S. Air Force currently is in the process of developing an Airborne Network (AN) to provide support to its combat aircrafts on a mission. The reliability needed for continuous operation of an AN is difficult to achieve through completely infrastructure-less mobile ad hoc networks. In this paper we first propose an architecture for an AN where airborne networking platforms (ANPs - aircrafts, UAVs and satellites) form the backbone of the AN. In this architecture, the ANPs can be viewed as mobile base stations and the combat aircrafts on a mission as mobile clients. The combat aircrafts on a mission move through a space called air corridor. The goal of the AN design is to form a backbone network with the ANPs with two properties: (i) the backbone network remains connected at all times, even though the topology of the network changes with the movement of the ANPs, and (ii) the entire 3D space of the air corridor is under radio coverage at all times by the continuously moving ANPs. In addition to proposing an...

  9. Laser Systems For Use With Airborne Platforms

    Science.gov (United States)

    Jepsky, Joseph

    1984-10-01

    This paper describes a family of airborne laser systems in use for terrain profiling, surveying, mapping, altimetry, collision avoidance and shipboard landing systems using fixed and rotary wing aircraft as the platforms. The laser altimeter has also been used in systems compatible with the Army T-16 and. T-22 carrier missiles (platform). Both pulsed gallium arsenide and Nd:YAG (neodymium-doped, yttrium-aluminum-garnet) laser rangefinders have been used for these applications. All of these systems use ACCI's advanced measurement techniques that permit range accuracies of 8 cm, single shot, 1 cm averaged, to be achieved. Pulse rates up to 4 Khz are employed for airborne profiling. This high data density rate provides 1 data point every 2" along the aircraft flight line at aircraft speed of 500 knots. Scanning modes for some applications are employed. Systems have been integrated with all current inertial navigation systems (Litton, Ferranti and Honeywell), as well as a number of microwave positioning systems. Removal of aircraft motion from the laser range measurements by use of an accelerometer is described. Flight data from a number of program performed by U.S. and Canadian Federal Agencies, in addition to those of commercial surveying and mapping companies are described.

  10. Airborne multidimensional integrated remote sensing system

    Science.gov (United States)

    Xu, Weiming; Wang, Jianyu; Shu, Rong; He, Zhiping; Ma, Yanhua

    2006-12-01

    In this paper, we present a kind of airborne multidimensional integrated remote sensing system that consists of an imaging spectrometer, a three-line scanner, a laser ranger, a position & orientation subsystem and a stabilizer PAV30. The imaging spectrometer is composed of two sets of identical push-broom high spectral imager with a field of view of 22°, which provides a field of view of 42°. The spectral range of the imaging spectrometer is from 420nm to 900nm, and its spectral resolution is 5nm. The three-line scanner is composed of two pieces of panchromatic CCD and a RGB CCD with 20° stereo angle and 10cm GSD(Ground Sample Distance) with 1000m flying height. The laser ranger can provide height data of three points every other four scanning lines of the spectral imager and those three points are calibrated to match the corresponding pixels of the spectral imager. The post-processing attitude accuracy of POS/AV 510 used as the position & orientation subsystem, which is the aerial special exterior parameters measuring product of Canadian Applanix Corporation, is 0.005° combined with base station data. The airborne multidimensional integrated remote sensing system was implemented successfully, performed the first flying experiment on April, 2005, and obtained satisfying data.

  11. Auxiliary DCP data acquisition system. [airborne system

    Science.gov (United States)

    Snyder, R. V.

    1975-01-01

    An airborne DCP Data Aquisition System has been designed to augment the ERTS satellite data recovery system. The DCP's are data collection platforms located at pertinent sites. With the appropriate sensors they are able to collect, digitally encode and transmit environmental parameters to the ERTS satellite. The satellite in turn relays these transmissions to a ground station for processing. The satellite is available for such relay duty a minimum of two times in a 24-hour period. The equipment is to obtain continuous DCP data during periods of unusual environmental activity--storms, floods, etc. Two circumstances contributed to the decision to design such a system; (1) Wallops Station utilizes surveillance aircraft in support of rocket launches and also in support of earth resources activities; (2) the area in which Wallops is located, the Delaware and Chesapeake Bay areas, are fertile areas for DCP usage. Therefore, by developing an airborne DCP receiving station and installing it on aircraft more continuous DCP data can be provided from sites in the surrounding areas at relatively low cost.

  12. APEX - the Hyperspectral ESA Airborne Prism Experiment

    Directory of Open Access Journals (Sweden)

    Koen Meuleman

    2008-10-01

    Full Text Available The airborne ESA-APEX (Airborne Prism Experiment hyperspectral mission simulator is described with its distinct specifications to provide high quality remote sensing data. The concept of an automatic calibration, performed in the Calibration Home Base (CHB by using the Control Test Master (CTM, the In-Flight Calibration facility (IFC, quality flagging (QF and specific processing in a dedicated Processing and Archiving Facility (PAF, and vicarious calibration experiments are presented. A preview on major applications and the corresponding development efforts to provide scientific data products up to level 2/3 to the user is presented for limnology, vegetation, aerosols, general classification routines and rapid mapping tasks. BRDF (Bidirectional Reflectance Distribution Function issues are discussed and the spectral database SPECCHIO (Spectral Input/Output introduced. The optical performance as well as the dedicated software utilities make APEX a state-of-the-art hyperspectral sensor, capable of (a satisfying the needs of several research communities and (b helping the understanding of the Earth’s complex mechanisms.

  13. The Next Generation Airborne Polarimetric Doppler Radar

    Science.gov (United States)

    Vivekanandan, J.; Lee, Wen-Chau; Loew, Eric; Salazar, Jorge; Chandrasekar, V.

    2013-04-01

    NCAR's Electra Doppler radar (ELDORA) with a dual-beam slotted waveguide array using dual-transmitter, dual-beam, rapid scan and step-chirped waveform significantly improved the spatial scale to 300m (Hildebrand et al. 1996). However, ELDORA X-band radar's penetration into precipitation is limited by attenuation and is not designed to collect polarimetric measurements to remotely estimate microphysics. ELDORA has been placed on dormancy because its airborne platform (P3 587) was retired in January 2013. The US research community has strongly voiced the need to continue measurement capability similar to the ELDORA. A critical weather research area is quantitative precipitation estimation/forecasting (QPE/QPF). In recent years, hurricane intensity change involving eye-eyewall interactions has drawn research attention (Montgomery et al., 2006; Bell and Montgomery, 2006). In the case of convective precipitation, two issues, namely, (1) when and where convection will be initiated, and (2) determining the organization and structure of ensuing convection, are key for QPF. Therefore collocated measurements of 3-D winds and precipitation microphysics are required for achieving significant skills in QPF and QPE. Multiple radars in dual-Doppler configuration with polarization capability estimate dynamical and microphysical characteristics of clouds and precipitation are mostly available over land. However, storms over complex terrain, the ocean and in forest regions are not observable by ground-based radars (Bluestein and Wakimoto, 2003). NCAR/EOL is investigating potential configurations for the next generation airborne radar that is capable of retrieving dynamic and microphysical characteristics of clouds and precipitation. ELDORA's slotted waveguide array radar is not compatible for dual-polarization measurements. Therefore, the new design has to address both dual-polarization capability and platform requirements to replace the ELDORA system. NCAR maintains a C-130

  14. Nucleation and capture of condensible airborne contaminants in an aqueous scrubbing system

    International Nuclear Information System (INIS)

    The fate of condensible contaminants in an aqueous scrubbing system was evaluated. Knowledge of the behavior of volatile fission product compounds is important in evaluating the effectiveness of emergency air cleaning systems proposed for use in containment systems of breeder reactor plants. When a high temperature air stream passes through a spray quench chamber, very large cooling rates occur in the drop boundary layers. These large cooling rates cause large supersaturations in airborne concentrations of condensible contaminants, and one predicts that most condensation would take place through homogeneous nucleation. The very small particles formed would agglomerate, and attach to sodium aerosol particles which would be present. In the study the overall removal efficiency of volatile fission product species (typified by NaI, SeO2, and Sb2O3) in an air cleaning train (quench chamber, venturi scrubber, and fibrous bed) was theoretically evaluated. The overall removal efficiency of condensible materials was found to be lower than that for sodium compound aerosols because the freshly condensed particles would be smaller in size. For a base case, a removal efficiency of 99.97 percent was predicted for condensible materials. The fibrous bed scrubber exhibited superior particle removal characteristics for small particles compared to the quench chamber and venturi scrubber. Its removal efficiency exceeded 97 percent for even the most penetrating particle size (about 0.4 micron aerodynamic diameter). Therefore, all condensible fission products would be removed with efficiencies exceeding 97 percent

  15. Optimization of an air–liquid interface exposure system for assessing toxicity of airborne nanoparticles

    Science.gov (United States)

    Latvala, Siiri; Hedberg, Jonas; Möller, Lennart; Odnevall Wallinder, Inger; Karlsson, Hanna L.

    2016-01-01

    Abstract The use of refined toxicological methods is currently needed for characterizing the risks of airborne nanoparticles (NPs) to human health. To mimic pulmonary exposure, we have developed an air–liquid interface (ALI) exposure system for direct deposition of airborne NPs on to lung cell cultures. Compared to traditional submerged systems, this allows more realistic exposure conditions for characterizing toxicological effects induced by airborne NPs. The purpose of this study was to investigate how the deposition of silver NPs (AgNPs) is affected by different conditions of the ALI system. Additionally, the viability and metabolic activity of A549 cells was studied following AgNP exposure. Particle deposition increased markedly with increasing aerosol flow rate and electrostatic field strength. The highest amount of deposited particles (2.2 μg cm–2) at cell‐free conditions following 2 h exposure was observed for the highest flow rate (390 ml min–1) and the strongest electrostatic field (±2 kV). This was estimated corresponding to deposition efficiency of 94%. Cell viability was not affected after 2 h exposure to clean air in the ALI system. Cells exposed to AgNPs (0.45 and 0.74 μg cm–2) showed significantly (P < 0.05) reduced metabolic activities (64 and 46%, respectively). Our study shows that the ALI exposure system can be used for generating conditions that were more realistic for in vitro exposures, which enables improved mechanistic and toxicological studies of NPs in contact with human lung cells.Copyright © 2016 The Authors Journal of Applied Toxicology Published by John Wiley & Sons Ltd. PMID:26935862

  16. Characteristics of an airborne demonstrator for MERLIN

    Science.gov (United States)

    Amediek, A.; Büdenbender, C.; Ehret, G.; Fix, A.; Kiemle, C.; Quatrevalet, M.; Wirth, M.; Dieter, H.; Löhring, J.; Klein, V.

    2012-12-01

    After three years development time, first test measurements on DLR's (Deutsches Zentrum für Luft- und Raumfahrt) CO2 and CH4 airborne Lidar have started. It is an integrated path differential absorption (IPDA) lidar for the simultaneous measurement of CO2 and CH4 columns, designed for operation onboard the new German research aircraft HALO. In the framework of the project "CHARM-F", funded by the German ministry of education and research, the lidar was developed in collaboration with Fraunhofer Institut für Lasertechnik and Kayser-Threde. Due to the special features of the aircraft, such as the maximum flight altitude of 15 km and its long range, as well as the special design of the lidar, the system is particularly suitable to be an airborne demonstrator for the French-German MERLIN project, a spaceborne IPDA lidar sounder for methane. The layout of the receiver optics allows a large field of view, i.e. a large laser footprint on ground is possible, comparable to the size obtained by a spaceborne system. So, important features that come along with ground reflectivity issues, such as albedo variations on different spatial scales, can be taken into account in the same way and can be investigated in detail. Furthermore, two detector types are used, PIN photodiodes and APDs, each with specially adapted telescopes, to compare their respective properties. The basic design of the transmitter is identical to the one envisaged for MERLIN. Also important subsystems of the presented lidar, like wavelengths stabilization and output power monitoring, can serve as demonstrators for the satellite system. The main features of the airborne system are: Two almost identical laser systems for CH4 and CO2. Nd:YAG lasers serve as the pump sources for optical parametric oscillators (OPO), injection seeded by laser diodes, to generate the desired online and offline wavelengths in single mode operation. The online wavelength is tuned to an absorption line of the measured trace gas, the

  17. Alternative analysis of airborne laser data collected within conventional multi-parameter airborne geophysical surveys

    Science.gov (United States)

    Ahl, Andreas; Supper, R.; Motschka, K.; Schattauer, I.

    2010-05-01

    For the interpretation of airborne gamma-ray spectrometry as well as airborne electromagnetics it is of great importance to determine the distance between the geophysical sensor and the ground surface. Since radar altimeters do not penetrate vegetation, laser altimeters became popular in airborne geophysics over the past years. Currently the airborne geophysical platform of the Geological Survey of Austria (GBA) is equipped with a Riegl LD90-3800VHS-FLP high resolution laser altimeter, measuring the distances according to the first and the last reflected pulse. The goal of the presented study was to explore the possibilities of deriving additional information about the survey area from the laser data and to determine the accuracy of such results. On one hand the difference between the arrival time of the first and the last reflected pulse can be used to determine the height of the vegetation. This parameter is for example important for the correction of damping effects on airborne gamma-ray measurements caused by vegetation. Moreover especially for groundwater studies at catchment scale, this parameter can also be applied to support the spatial assessment of evapotranspiration. In combination with the altitude above geoid, determined by a GPS receiver, a rough digital elevation model of the survey area can be derived from the laser altimetry. Based on a data set from a survey area in the northern part of Austria, close to the border with the Czech Republic, the reliability of such a digital elevation model and the calculated vegetation height was tested. In this study a mean deviation of -1.4m, with a standard deviation of ±3.4m, between the digital elevation model from Upper Austria (25m spatial resolution) and the determined elevation model was determined. We also found an obvious correlation between the calculated vegetation heights greater 15m and the mapped forest published by the ‘Department of Forest Inventory' of the ‘Federal Forest Office' of Austria

  18. Evaluating airborne and ground based gamma spectrometry methods for detecting particulate radioactivity in the environment: A case study of Irish Sea beaches

    International Nuclear Information System (INIS)

    In several places, programmes are in place to locate and recover radioactive particles that have the potential to cause detrimental health effects in any member of the public who may encounter them. A model has been developed to evaluate the use of mobile gamma spectrometry systems within such programmes, with particular emphasis on large volume (16 l) NaI(Tl) detectors mounted in low flying helicopters. This model uses a validated Monte Carlo code with assessment of local geochemistry and natural and anthropogenic background radiation concentrations and distributions. The results of the model, applied to the example of particles recovered from beaches in the vicinity of Sellafield, clearly show the ability of rapid airborne surveys conducted at 75 m ground clearance and 120 kph speeds to demonstrate the absence of sources greater than 5 MBq 137Cs within large areas (10–20 km2 h−1), and identify areas requiring further ground based investigation. Lowering ground clearance for airborne surveys to 15 m whilst maintaining speeds covering 1–2 km2 h−1 can detect buried 137Cs sources of 0.5 MBq or greater activity. A survey design to detect 100 kBq 137Cs sources at 10 cm depth has also been defined, requiring surveys at −1 ground speed. The response of airborne systems to the Sellafield particles recovered to date has also been simulated, and the proportion of the existing radiocaesium background in the vicinity of the nuclear site has been established. Finally the rates of area coverage and sensitivities of both airborne and ground based approaches are compared, demonstrating the ability of airborne systems to increase the rate of particle recovery in a cost effective manner. The potential for equipment and methodological developments to improve performance are discussed. -- Highlights: ► Validated Monte Carlo simulations used to model mobile gamma spectrometry response to radioactive particless. ► Detection limits for airborne and ground based surveys

  19. Biomass Burning Airborne and Spaceborne Experiment in the Amazonas (BASE-A)

    Science.gov (United States)

    Kaufman, Y. J.; Setzer, A.; Ward, D.; Tanre, D.; Holben, B. N.; Menzel, P.; Pereira, M. C.; Rasmussen, R.

    1992-01-01

    Results are presented on measurements of the trace gas and particulate matter emissions due to biomass burning during deforestation and grassland fires in South America, conducted as part of the Biomass Burning Airborne and Spaceborne Experiment in the Amazonas in September 1989. Field observations by an instrumented aircraft were used to estimate concentrations of O3, CO2, CO, CH4, and particulate matter. Fires were observed from satellite imagery, and the smoke optical thickness, particle size, and profiles of the extinction coefficient were measured from the aircraft and from the ground. Four smoke plumes were sampled, three vertical profiles were measured, and extensive ground measurements of smoke optical characteristics were carried out for different smoke types. The simultaneous measurements of the trace gases, smoke particles, and the distribution of fires were used to correlate biomass burning with the elevated levels of ozone.

  20. Airborne laser: a tool to study landscape surface features

    International Nuclear Information System (INIS)

    Landscape surface features related to erosion and hydrology were measured using an airborne laser profiler. The airborne laser profiler made 4,000 measurements per second with a recording accuracy of 5 cm (1.9 inches) on a single measurement. Digital data from the laser are recorded and analyzed with a personal computer. These airborne laser profiles provide information on surface landscape features. Topography and canopy heights, cover, and distribution of natural vegetation were determined in studies in South Texas. Laser measurements of shrub cover along flightlines were highly correlated (R2 = 0.98) with ground measurements made with line-intercept methods. Stream channel cross sections on Goodwin Creek in Mississippi were measured quickly and accurately with airborne laser data. Airborne laser profile data were used to measure small gullies in a level fallow field and in field with mature soybeans. While conventional ground-based techniques can be used to make these measurements, airborne laser profiler techniques allow data to be collected quickly, at a high density, and in areas that are essentially inaccessible for ground surveys. Airborne laser profiler data can quantify landscape features related to erosion and runoff, and the laser proler has the potential to be a useful tool for providing other data for studying and managing natural resources

  1. Endotoxin in Size-Separated Metal Working Fluid Aerosol Particles.

    Science.gov (United States)

    Dahlman-Höglund, Anna; Lindgren, Åsa; Mattsby-Baltzer, Inger

    2016-08-01

    Patients with airway symptoms working in metal working industries are increasing, despite efforts to improve the environmental air surrounding the machines. Our aim was to analyse the amount of endotoxin in size-separated airborne particles of metal working fluid (MWF) aerosol, by using the personal sampler Sioutas cascade impactor, to compare filter types, and to compare the concentration of airborne endotoxin to that of the corresponding MWFs. In a pilot field study, aerosols were collected in two separate machine halls on totally 10 occasions, using glass fibre and polytetrafluoroethylene (PTFE) filters in parallel at each station. Airborne endotoxin was distributed over all size fractions. While a major part was found in the largest size fraction (72%, 2.5-10 µm), up to 8% of the airborne endotoxin was detected in the smallest size fraction (efficiency of the filter types, a significantly higher median endotoxin level was found with glass fibres filters collecting the largest particle-size fraction (1.2-fold) and with PTFE filters collecting the smallest ones (5-fold). The levels of endotoxin in the size-separated airborne particle fractions correlated to those of the MWFs supporting the aerosol-generating machines. Our study indicates that a significant part of inhalable aerosols of MWFs consists of endotoxin-containing particles below the size of intact bacteria, and thus small enough to readily reach the deepest part of the lung. Combined with other chemical irritants of the MWF, exposure to MWF aerosols containing endotoxin pose a risk to respiratory health problems. PMID:27268595

  2. Polarization resolved angular optical scattering of aerosol particles

    Science.gov (United States)

    Redding, B.; Pan, Y.; Wang, C.; Videen, G.; Cao, Hui

    2014-05-01

    Real-time detection and identification of bio-aerosol particles are crucial for the protection against chemical and biological agents. The strong elastic light scattering properties of airborne particles provides a natural means for rapid, non-invasive aerosol characterization. Recent theoretical predictions suggested that variations in the polarization dependent angular scattering cross section could provide an efficient means of classifying different airborne particles. In particular, the polarization dependent scattering cross section of aggregate particles is expected to depend on the shape of the primary particles. In order to experimentally validate this prediction, we built a high throughput, sampling system, capable of measuring the polarization resolved angular scattering cross section of individual aerosol particles flowing through an interrogating volume with a single shot of laser pulse. We calibrated the system by comparing the polarization dependent scattering cross section of individual polystyrene spheres with that predicted by Mie theory. We then used the system to study different particles types: Polystyrene aggregates composed 500 nm spheres and Bacillus subtilis (BG, Anthrax simulant) spores composed of elongated 500 nm × 1000 nm cylinder-line particles. We found that the polarization resolved scattering cross section depends on the shape of the constituent elements of the aggregates. This work indicates that the polarization resolved scattering cross section could be used for rapid discrimination between different bio-aerosol particles.

  3. Airborne radioactivity surveys for phosphate in Florida

    Science.gov (United States)

    Moxham, Robert M.

    1954-01-01

    Airborne radioactivity surveys totaling 5, 600 traverse miles were made in 10 areas in Florida, which were thought to be geologically favorable for deposits of uraniferous phosphate. Abnormal radioactivity was recorded in 8 of the 10 areas surveyed. The anomalies are located in Bradford, Clay, Columbia, DeSoto, Dixie, Lake, Marion, Orange, Sumter, Taylor, and Union Counties. Two of the anomalies were investigated briefly on the ground. One resulted from a deposit of river-pebble phosphate in the Peace River valley; the river-pebble samples contain an average of 0.013 percent equivalent uranium. The other anomaly resulted from outcrops of leached phosphatic rock containing as much as 0. 016 percent equivalent uranium. Several anomalies in other areas were recorded at or near localities where phosphate deposits have been reported.

  4. Airborne gravimetry, altimetry, and GPS navigation errors

    Science.gov (United States)

    Colombo, Oscar L.

    1992-01-01

    Proper interpretation of airborne gravimetry and altimetry requires good knowledge of aircraft trajectory. Recent advances in precise navigation with differential GPS have made it possible to measure gravity from the air with accuracies of a few milligals, and to obtain altimeter profiles of terrain or sea surface correct to one decimeter. These developments are opening otherwise inaccessible regions to detailed geophysical mapping. Navigation with GPS presents some problems that grow worse with increasing distance from a fixed receiver: the effect of errors in tropospheric refraction correction, GPS ephemerides, and the coordinates of the fixed receivers. Ionospheric refraction and orbit error complicate ambiguity resolution. Optimal navigation should treat all error sources as unknowns, together with the instantaneous vehicle position. To do so, fast and reliable numerical techniques are needed: efficient and stable Kalman filter-smoother algorithms, together with data compression and, sometimes, the use of simplified dynamics.

  5. Spatial dynamics of airborne infectious diseases

    CERN Document Server

    Robinson, M; Drossinos, Y

    2011-01-01

    Disease outbreaks, such as those of Severe Acute Respiratory Syndrome in 2003 and the 2009 pandemic A(H1N1) influenza, have highlighted the potential for airborne transmission in indoor environments. Respirable pathogen-carrying droplets provide a vector for the spatial spread of infection with droplet transport determined by diffusive and convective processes. An epidemiological model describing the spatial dynamics of disease transmission is presented. The effects of an ambient airflow, as an infection control, are incorporated leading to a delay equation, with droplet density dependent on the infectious density at a previous time. It is found that small droplets ($\\sim 0.4\\ \\mu$m) generate a negligible infectious force due to the small viral load and the associated duration they require to transmit infection. In contrast, larger droplets ($\\sim 4\\ \\mu$m) can lead to an infectious wave propagating through a fully susceptible population or a secondary infection outbreak for a localised susceptible population...

  6. Digital Logarithmic Airborne Gamma Ray Spectrometer

    CERN Document Server

    Zeng, GuoQiang; Li, Chen; Tan, ChengJun; Ge, LiangQuan; Gu, Yi; Cheng, Feng

    2014-01-01

    A new digital logarithmic airborne gamma ray spectrometer is designed in this study. The spectrometer adopts a high-speed and high-accuracy logarithmic amplifier (LOG114) to amplify the pulse signal logarithmically and to improve the utilization of the ADC dynamic range, because the low-energy pulse signal has a larger gain than the high-energy pulse signal. The spectrometer can clearly distinguish the photopeaks at 239, 352, 583, and 609keV in the low-energy spectral sections after the energy calibration. The photopeak energy resolution of 137Cs improves to 6.75% from the original 7.8%. Furthermore, the energy resolution of three photopeaks, namely, K, U, and Th, is maintained, and the overall stability of the energy spectrum is increased through potassium peak spectrum stabilization. Thus, effectively measuring energy from 20keV to 10MeV is possible.

  7. Particle therapy

    Energy Technology Data Exchange (ETDEWEB)

    Raju, M.R.

    1993-09-01

    Particle therapy has a long history. The experimentation with particles for their therapeutic application got started soon after they were produced in the laboratory. Physicists played a major role in proposing the potential applications in radiotherapy as well as in the development of particle therapy. A brief review of the current status of particle radiotherapy with some historical perspective is presented and specific contributions made by physicists will be pointed out wherever appropriate. The rationale of using particles in cancer treatment is to reduce the treatment volume to the target volume by using precise dose distributions in three dimensions by using particles such as protons and to improve the differential effects on tumors compared to normal tissues by using high-LET radiations such as neutrons. Pions and heavy ions combine the above two characteristics.

  8. Photothermal Infrared Spectroscopy of Airborne Samples with Mechanical String Resonators

    DEFF Research Database (Denmark)

    Yamada, Shoko; Schmid, Silvan; Larsen, Tom;

    2013-01-01

    -scale airborne samples. Airborne sample material is directly collected on the microstring with an efficient nondiffusion limited sampling method based on inertial impaction. Resonance frequency shifts, proportional to the absorbed heat in the microstring, are recorded as monochromatic IR light is scanned over...... the mid-infrared range. As a proof-of-concept, we sample and analyze polyvinylpyrrolidone (PVP) and the IR spectrum measured by photothermal spectroscopy matches the reference IR spectrum measured by an FTIR spectrometer. We further identify the organic surface coating of airborne TiO2 nanoparticles...

  9. NASA Langley Airborne High Spectral Resolution Lidar Instrument Description

    Science.gov (United States)

    Harper, David B.; Cook, Anthony; Hostetler, Chris; Hair, John W.; Mack, Terry L.

    2006-01-01

    NASA Langley Research Center (LaRC) recently developed the LaRC Airborne High Spectral Resolution Lidar (HSRL) to make measurements of aerosol and cloud distribution and optical properties. The Airborne HSRL has undergone as series of test flights and was successfully deployed on the Megacity Initiative: Local and Global Research Observations (MILAGRO) field mission in March 2006 (see Hair et al. in these proceedings). This paper provides an overview of the design of the Airborne HSRL and descriptions of some key subsystems unique to this instrument.

  10. Control of Airborne Infectious Diseases in Ventilated Spaces

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    2009-01-01

    We protect ourselves from airborne cross-infection in the indoor environment by supplying fresh air to a room by natural or mechanical ventilation. The air is distributed in the room according to different principles: mixing ventilation, displacement ventilation, etc. A large amount of air...... is supplied to the room to ensure a dilution of airborne infection. Analyses of the flow in the room show that there are a number of parameters that play an important role in minimizing airborne cross-infection. The air flow rate to the room must be high, and the air distribution pattern can be designed...

  11. Particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Kamal, Anwar

    2014-09-01

    Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook teaches particle physics very didactically. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams lead to a better understanding of the explanations. The content of the book covers all important topics of particle physics: Elementary particles are classified from the point of view of the four fundamental interactions. The nomenclature used in particle physics is explained. The discoveries and properties of known elementary particles and resonances are given. The particles considered are positrons, muon, pions, anti-protons, strange particles, neutrino and hadrons. The conservation laws governing the interactions of elementary particles are given. The concepts of parity, spin, charge conjugation, time reversal and gauge invariance are explained. The quark theory is introduced to explain the hadron structure and strong interactions. The solar neutrino problem is considered. Weak interactions are classified into various types, and the selection rules are stated. Non-conservation of parity and the universality of the weak interactions are discussed. Neutral and charged currents, discovery of W and Z bosons and the early universe form important topics of the electroweak interactions. The principles of high energy accelerators including colliders are elaborately explained. Additionally, in the book detectors used in nuclear and particle physics are described. This book is on the upper undergraduate level.

  12. Particle physics

    International Nuclear Information System (INIS)

    Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook teaches particle physics very didactically. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams lead to a better understanding of the explanations. The content of the book covers all important topics of particle physics: Elementary particles are classified from the point of view of the four fundamental interactions. The nomenclature used in particle physics is explained. The discoveries and properties of known elementary particles and resonances are given. The particles considered are positrons, muon, pions, anti-protons, strange particles, neutrino and hadrons. The conservation laws governing the interactions of elementary particles are given. The concepts of parity, spin, charge conjugation, time reversal and gauge invariance are explained. The quark theory is introduced to explain the hadron structure and strong interactions. The solar neutrino problem is considered. Weak interactions are classified into various types, and the selection rules are stated. Non-conservation of parity and the universality of the weak interactions are discussed. Neutral and charged currents, discovery of W and Z bosons and the early universe form important topics of the electroweak interactions. The principles of high energy accelerators including colliders are elaborately explained. Additionally, in the book detectors used in nuclear and particle physics are described. This book is on the upper undergraduate level.

  13. Particle Physics

    CERN Document Server

    Martin, B R

    2008-01-01

    An essential introduction to particle physics, with coverage ranging from the basics through to the very latest developments, in an accessible and carefully structured text. Particle Physics: Third Edition is a revision of a highly regarded introduction to particle physics. In its two previous editions this book has proved to be an accessible and balanced introduction to modern particle physics, suitable for those students needed a more comprehensive introduction to the subject than provided by the 'compendium' style physics books. In the Third Edition the standard mod

  14. Airborne forward pointing UV Rayleigh lidar for remote clear air turbulence (CAT) detection: system design and performance

    CERN Document Server

    Vrancken, Patrick; Ehret, Gerhard; Barny, Hervé; Rondeau, Philippe; Veerman, Henk

    2016-01-01

    A high-performance airborne UV Rayleigh lidar system was developed within the European project DELICAT. With its forward-pointing architecture it aims at demonstrating a novel detection scheme for clear air turbulence (CAT) for an aeronautics safety application. Due to its occurrence in clear and clean air at high altitudes (aviation cruise flight level), this type of turbulence evades microwave radar techniques and in most cases coherent Doppler lidar techniques. The present lidar detection technique relies on air density fluctuations measurement and is thus independent of backscatter from hydrometeors and aerosol particles. The subtle air density fluctuations caused by the turbulent air flow demand exceptionally high stability of the setup and in particular of the detection system. This paper describes an airborne test system for the purpose of demonstrating this technology and turbulence detection method: a high-power UV Rayleigh lidar system is installed on a research aircraft in a forward-looking configu...

  15. Advances and perspectives in bathymetry by airborne lidar

    Science.gov (United States)

    Zhou, Guoqing; Wang, Chenxi; Li, Mingyan; Wang, Yuefeng; Ye, Siqi; Han, Caiyun

    2015-12-01

    In this paper, the history of the airborne lidar and the development stages of the technology are reviewed. The basic principle of airborne lidar and the method of processing point-cloud data were discussed. At present, single point laser scanning method is widely used in bathymetric survey. Although the method has high ranging accuracy, the data processing and hardware system is too much complicated and expensive. For this reason, this paper present a kind of improved dual-frequency method for bathymetric and sea surface survey, in this method 176 units of 1064nm wavelength laser has been used by push-broom scanning and due to the airborne power limits still use 532nm wavelength single point for bathymetric survey by zigzag scanning. We establish a spatial coordinates for obtaining the WGS-84 of point cloud by using airborne POS system.

  16. Airborne Gravity: NGS' Gravity Data for CN02 (2013 & 2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Nebraska collected in 2013 & 2014 over 3 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical...

  17. Airborne Gravity: NGS' Gravity Data for EN06 (2016)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Maine, Canada, and the Atlantic Ocean collected in 2012 over 2 surveys. This data set is part of the Gravity for the Re-definition of the...

  18. Thermal Mapping Airborne Simulator for Small Satellite Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A high performance, inexpensive, airborne simulator that will serve as the prototype for a small satellite based imaging system capable of mapping thermal anomalies...

  19. A Web-Based Airborne Remote Sensing Telemetry Server Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A Web-based Airborne Remote Sensing Telemetry Server (WARSTS) is proposed to integrate UAV telemetry and web-technology into an innovative communication, command,...

  20. Airborne Magnetic Trackline and Survey Data (Vector and Scalar Observations)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA National Centers for Environmental Information (formerly National Geophysical Data Center) receive airborne magnetic survey data from US and non-US...

  1. Research on airborne infrared leakage detection of natural gas pipeline

    Science.gov (United States)

    Tan, Dongjie; Xu, Bin; Xu, Xu; Wang, Hongchao; Yu, Dongliang; Tian, Shengjie

    2011-12-01

    An airborne laser remote sensing technology is proposed to detect natural gas pipeline leakage in helicopter which carrying a detector, and the detector can detect a high spatial resolution of trace of methane on the ground. The principle of the airborne laser remote sensing system is based on tunable diode laser absorption spectroscopy (TDLAS). The system consists of an optical unit containing the laser, camera, helicopter mount, electronic unit with DGPS antenna, a notebook computer and a pilot monitor. And the system is mounted on a helicopter. The principle and the architecture of the airborne laser remote sensing system are presented. Field test experiments are carried out on West-East Natural Gas Pipeline of China, and the results show that airborne detection method is suitable for detecting gas leak of pipeline on plain, desert, hills but unfit for the area with large altitude diversification.

  2. Airborne Wide Area Imager for Wildfire Mapping and Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An autonomous airborne imaging system for earth science research, disaster response, and fire detection is proposed. The primary goal is to improve information to...

  3. Airborne Wide Area Imager for Wildfire Mapping and Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An advanced airborne imaging system for fire detection/mapping is proposed. The goal of the project is to improve control and management of wildfires in order to...

  4. Airborne Gravity: NGS' Gravity Data for ES03 (2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Maryland, Pennsylvania, New Jersey, West Virginia, Virginia, Delaware, and the Atlantic Ocean collected in 2013 over 1 survey. This data...

  5. Airborne Gravity: NGS' Gravity Data for EN08 (2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for New York, Vermont, New Hampshire, Massachusettes, Maine, and Canada collected in 2013 over 1 survey. This data set is part of the Gravity...

  6. Airborne Gravity: NGS' Gravity Data for TS01 (2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Puerto Rico and the Virgin Islands collected in 2009 over 1 survey. This data set is part of the Gravity for the Re-definition of the...

  7. Airborne Gravity: NGS' Gravity Data for ES01 (2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Florida, the Bahamas, and the Atlantic Ocean collected in 2013 over 1 survey. This data set is part of the Gravity for the Re-definition...

  8. Airborne Gravity: NGS' Gravity Data for CN03 (2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Nebraska collected in 2014 over one survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

  9. Airborne Gravity: NGS' Gravity Data for EN05 (2012)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Minnesota, Wisconsin, and Michigan collected in 2012 over 1 survey. This data set is part of the Gravity for the Re-definition of the...

  10. Airborne Gravity: NGS' Gravity Data for CS06 (2012 & 2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Texas collected in 2012 & 2013 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical...

  11. Airborne Gravity: NGS' Gravity Data for EN09 (2016)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Massachusetts, Connecticut, Rhode Island, New Hampshire, New York, and the Atlantic Ocean collected in 2012 over 1 survey. This data set...

  12. Airborne Gravity: NGS' Gravity Data for AN03 (2010)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2010 and 2012 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical...

  13. Airborne Gravity: NGS' Gravity Data for EN04 (2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Michigan and Lake Huron collected in 2012 over 1 survey. This data set is part of the Gravity for the Re-definition of the American...

  14. Airborne Gravity: NGS' Gravity Data for AS02 (2010)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2010 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

  15. Airborne Gravity: NGS' Gravity Data for EN10 (2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for New York, Pennsylvania, New Jersey, Connecticut and the Atlantic Ocean collected in 2013 over 1 survey. This data set is part of the...

  16. Airborne Gravity: NGS' Gravity Data for CS03 (2009)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Texas and Louisiana collected in 2009 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical...

  17. Airborne Gravity: NGS' Gravity Data for EN01 (2011)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for New York, Canada, and Lake Ontario collected in 2011 over 1 survey. This data set is part of the Gravity for the Re-definition of the...

  18. Airborne Gravity: NGS' Gravity Data for CS01 (2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alabama and Florida collected in 2008 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical...

  19. Airborne Gravity: NGS' Gravity Data for PN01 (2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for California and Oregon collected in 2011 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical...

  20. Levels and spatial distribution of airborne chemical elements in a heavy industrial area located in the north of Spain.

    Science.gov (United States)

    Lage, J; Almeida, S M; Reis, M A; Chaves, P C; Ribeiro, T; Garcia, S; Faria, J P; Fernández, B G; Wolterbeek, H T

    2014-01-01

    The adverse health effects of airborne particles have been subjected to intense investigation in recent years; however, more studies on the chemical characterization of particles from pollution emissions are needed to (1) identify emission sources, (2) better understand the relative toxicity of particles, and (3) pinpoint more targeted emission control strategies and regulations. The main objective of this study was to assess the levels and spatial distribution of airborne chemical elements in a heavy industrial area located in the north of Spain. Instrumental and biomonitoring techniques were integrated and analytical methods for k0 instrumental neutron activation analysis and particle-induced x-ray emission were used to determine element content in aerosol filters and lichens. Results indicated that in general local industry contributed to the emissions of As, Sb, Cu, V, and Ni, which are associated with combustion processes. In addition, the steelwork emitted significant quantities of Fe and Mn and the cement factory was associated with Ca emissions. The spatial distribution of Zn and Al also indicated an important contribution of two industries located outside the studied area. PMID:25072718

  1. The next generation airborne polarimetric Doppler weather radar

    OpenAIRE

    Vivekanandan, J.; W.-C. Lee; E. Loew; Salazar, J. L.; Grubišić, V.; J. Moore; Tsai, P

    2014-01-01

    Results from airborne field deployments emphasized the need to obtain concurrently high temporal and spatial resolution measurements of 3-D winds and microphysics. A phased array radar on an airborne platform using dual-polarization antenna has the potential for retrieving high resolution, collocated 3-D winds and microphysical measurements. Recently, ground-based phased array radar (PAR) demonstrated the high time resolution estimation of accurate Doppler velocity and reflecti...

  2. The next generation airborne polarimetric Doppler weather radar

    OpenAIRE

    Vivekanandan, J.; W.-C. Lee; E. Loew; Salazar, J. L.; Grubišić, V.; J. Moore; Tsai, P

    2014-01-01

    Results from airborne field deployments emphasized the need to obtain concurrently high temporal and spatial resolution measurements of 3-D winds and microphysics. A phased array radar on an airborne platform using dual-polarization antenna has the potential for retrieving high-resolution, collocated 3-D winds and microphysical measurements. Recently, ground-based phased array radar (PAR) has demonstrated the high time-resolution estimation of accurate Doppler velocity and...

  3. Airborne geophysical mapping of environmental features - examples from Northern Ireland

    OpenAIRE

    Young, Michael; Appleton, James; Beamish, David; Cuss, Robert; Van Dam, Christiaan; Jones, David; Lahti, Mari; Miles, Jon; Rawlins, Barry; Scheib, Catherine

    2007-01-01

    The Geological Survey of Northern Ireland completed a low-level regional airborne geophysical survey of Northern Ireland during 2005-6 as part of the Tellus Project. The survey was flown by the Joint Airborne Geoscience Capability, a partnership of the British Geological Survey and the Geological Survey of Finland. The aircraft, a De Havilland Twin Otter, was equipped with two magnetometer sensors, a four-frequency electromagnetic system and a 256-channel gamma-ray spectrometer. The traverse-...

  4. User definition and mission requirements for unmanned airborne platforms, revised

    Science.gov (United States)

    Kuhner, M. B.; Mcdowell, J. R.

    1979-01-01

    The airborne measurement requirements of the scientific and applications experiment user community were assessed with respect to the suitability of proposed strawman airborne platforms. These platforms provide a spectrum of measurement capabilities supporting associated mission tradeoffs such as payload weight, operating altitude, range, duration, flight profile control, deployment flexibility, quick response, and recoverability. The results of the survey are used to examine whether the development of platforms is warranted and to determine platform system requirements as well as research and technology needs.

  5. Airborne flux measurements of biogenic isoprene over California

    OpenAIRE

    Misztal, P. K.; T. Karl; Weber, R.; Jonsson, H. H.; Guenther, A. B.; A. H. Goldstein

    2014-01-01

    © Author(s) 2014. CC Attribution 3.0 License. Biogenic isoprene fluxes were measured onboard the CIRPAS Twin Otter aircraft as part of the California Airborne Biogenic volatile organic compound (BVOC) Emission Research in Natural Ecosystem Transects (CABERNET) campaign during June 2011. The airborne virtual disjunct eddy covariance (AvDEC) approach used measurements from a proton transfer reaction mass spectrometer (PTR-MS) and a wind radome probe to directly determine fluxes of isoprene over...

  6. Airborne flux measurements of biogenic volatile organic compounds over California

    OpenAIRE

    Misztal, P. K.; T. Karl; Weber, R.; Jonsson, H. H.; Guenther, A. B.; A. H. Goldstein

    2014-01-01

    Biogenic Volatile Organic Compound (BVOC) fluxes were measured onboard the CIRPAS Twin Otter aircraft as part of the California Airborne BVOC Emission Research in Natural Ecosystem Transects (CABERNET) campaign during June 2011. The airborne virtual disjunct eddy covariance (AvDEC) approach used measurements from a PTR-MS and a wind radome probe to directly determine fluxes of isoprene, MVK + MAC, methanol, monoterpenes, and MBO over ∼10 000 km of flight...

  7. Calibration for Radiation Protection Equipment for the Measuring Airborne Tritium

    Institute of Scientific and Technical Information of China (English)

    CHEN; Xi-lin; SHEN; En-wei; WEI; Ke-xin; WANG; Kong-zhao; LI; Hou-wen; GE; Jian-an; LV; Xiao-xia

    2012-01-01

    <正>Monitoring airborne tritium is an important routine work in heavy water reactor nuclear power stations and the units related with tritium. Nowadays direct measuring instruments like hand carrying tritium monitors are more often used in routine workshop environment check. Need for calibrating such monitors was suggested. A trial work about the calibration for radiation protection equipment for measuring airborne tritium was carried out with a domestic standard EJ/T 1077-1998 equivalent that of IEC 710.

  8. Ultrafine particle characteristics in seven industrial plants.

    Science.gov (United States)

    Elihn, Karine; Berg, Peter

    2009-07-01

    Ultrafine particles are considered as a possible cause of some of the adverse health effects caused by airborne particles. In this study, the particle characteristics were measured in seven Swedish industrial plants, with a special focus on the ultrafine particle fraction. Number concentration, size distribution, surface area concentration, and mass concentration were measured at 10 different job activities, including fettling, laser cutting, welding, smelting, core making, moulding, concreting, grinding, sieving powders, and washing machine goods. A thorough particle characterization is necessary in workplaces since it is not clear yet which choice of ultrafine particle metric is the best to measure in relation to health effects. Job activities were given a different order of rank depending on what particle metric was measured. An especially high number concentration (130 x 10(3) cm(-3)) and percentage of ultrafine particles (96%) were found at fettling of aluminium, whereas the highest surface area concentration (up to 3800 mum(2) cm(-3)) as well as high PM10 (up to 1 mg m(-3)) and PM1 (up to 0.8 mg m(-3)) were found at welding and laser cutting of steel. The smallest geometric mean diameter (22 nm) was found at core making (geometric standard deviation: 1.9). PMID:19447849

  9. Miniaturized Airborne Imaging Central Server System

    Science.gov (United States)

    Sun, Xiuhong

    2011-01-01

    In recent years, some remote-sensing applications require advanced airborne multi-sensor systems to provide high performance reflective and emissive spectral imaging measurement rapidly over large areas. The key or unique problem of characteristics is associated with a black box back-end system that operates a suite of cutting-edge imaging sensors to collect simultaneously the high throughput reflective and emissive spectral imaging data with precision georeference. This back-end system needs to be portable, easy-to-use, and reliable with advanced onboard processing. The innovation of the black box backend is a miniaturized airborne imaging central server system (MAICSS). MAICSS integrates a complex embedded system of systems with dedicated power and signal electronic circuits inside to serve a suite of configurable cutting-edge electro- optical (EO), long-wave infrared (LWIR), and medium-wave infrared (MWIR) cameras, a hyperspectral imaging scanner, and a GPS and inertial measurement unit (IMU) for atmospheric and surface remote sensing. Its compatible sensor packages include NASA s 1,024 1,024 pixel LWIR quantum well infrared photodetector (QWIP) imager; a 60.5 megapixel BuckEye EO camera; and a fast (e.g. 200+ scanlines/s) and wide swath-width (e.g., 1,920+ pixels) CCD/InGaAs imager-based visible/near infrared reflectance (VNIR) and shortwave infrared (SWIR) imaging spectrometer. MAICSS records continuous precision georeferenced and time-tagged multisensor throughputs to mass storage devices at a high aggregate rate, typically 60 MB/s for its LWIR/EO payload. MAICSS is a complete stand-alone imaging server instrument with an easy-to-use software package for either autonomous data collection or interactive airborne operation. Advanced multisensor data acquisition and onboard processing software features have been implemented for MAICSS. With the onboard processing for real time image development, correction, histogram-equalization, compression, georeference, and

  10. Experimental studies on particle emissions from cruising ship, their characteristic properties, transformation and atmospheric lifetime in the marine boundary layer

    OpenAIRE

    Petzold, A.; Hasselbach, J.; P. Lauer; Baumann, R.; Franke, K.; Gurk, C.; H. Schlager; Weingartner, E.

    2008-01-01

    Particle emissions from ship engines and their atmospheric transformation in the marine boundary layer (MBL) were investigated in engine test bed studies and in airborne measurements of expanding ship plumes. During the test rig studies, detailed aerosol microphysical and chemical properties were measured in the exhaust gas of a serial MAN B&W seven-cylinder four-stroke marine diesel engine under various load conditions. The emission studies were complemented by airborne aerosol transform...

  11. Experimental studies on particle emissions from cruising ship, their characteristic properties, transformation and atmospheric lifetime in the marine boundary layer

    OpenAIRE

    Petzold, A.; Hasselbach, J.; P. Lauer; Baumann, R.; Franke, K.; Gurk, C.; H. Schlager; Weingartner, E.

    2007-01-01

    Particle emissions from ship engines and their atmospheric transformation in the marine boundary layer (MBL) were investigated in engine test bed studies and in airborne measurements of expanding ship plumes. During the test rig studies, detailed aerosol microphysical and chemical properties were measured in the exhaust gas of a serial MAN B{&}W seven-cylinder four-stroke marine diesel engine under various load conditions. The emission studies were complemented by airborne aerosol transfo...

  12. Experimental studies on particle emissions from cruising ship, their characteristic properties, transformation and atmospheric lifetime in the marine boundary layer

    OpenAIRE

    Petzold, A.; Hasselbach, J.; P. Lauer; Baumann, R.; Franke, K.; Gurk, C.; H. Schlager; Weingartner, E.

    2007-01-01

    Particle emissions from ship engines and their atmospheric transformation in the marine boundary layer (MBL) were investigated in engine test bed studies and in airborne measurements of expanding ship plumes. During the test rig studies, detailed aerosol microphysical and chemical properties were measured in the exhaust gas of a serial MAN B&W seven-cylinder four-stroke marine diesel engine under various load conditions. The emission studies were complemented by airborne aer...

  13. Overview of the Airborne Tropical TRopopause EX

    Science.gov (United States)

    Singh, Hanwant B.; Jensen, Eric J.; Pfister, Leonhard

    2014-01-01

    The NASA Airborne Tropical TRopopause EXperiment (ATTREX) is a series of airborne campaigns focused on understanding physical processes in the Tropical Tropopause Layer (TTL) and their role in atmospheric chemistry and climate. ATTREX is using the high-altitude, long-duration NASA Global Hawk Unmanned Air System to make in situ and remote-sensing measurements spanning the Pacific. A particular ATIREX emphasis is to better understand the dehydration of air as it passes through the cold tropical tropopause region. The ATTREX payload contains 12 in situ and remote sensing instruments that measure water vapor, clouds, multiple gaseous tracers (CO, CO2, CH4, NMHC, SF6, CFCs, N2O), reactive chemical compounds (O3, BrO, NO2), meteorological parameters, and radiative fluxes. ATTREX flight series have been conducted in the fall of 2011 from Armstrong Flight Research Center (AFRC) in California, in the winter of 2013 from AFRC, and in the winter/spring of 2014 from Guam. The first two f light series provided extensive sampling of the central and eastern Pacific, whereas the last flight series permitted sampling in the western Pacific. The sampling strategy has primarily involved repeated ascents and descents through the depth of the TTL (about 13-19 km). Over 100 TTL profiles were obtained on each flight series. The ATTREX dataset includes TTL water vapor measurements with unprecedented accuracy, ice crystal size distributions and habits. The cloud and water measurements provide unique information about TTL cloud formation, the persistence of supersaturation with respect to ice, and dehydration. The plethora of tracers measured on the Global Hawk flights are providing unique information about TTL transport pathways and time scales. The meteorological measurements are revealing dynamical phenomena controlling the TTL thermal structure, and the radiation measurements are providing information about heating rates associated with TTL clouds and water vapor. This presentation

  14. Locating spilled oil with airborne laser fluorosensors

    Science.gov (United States)

    Brown, Carl E.; Fingas, Mervin F.; Nelson, Robert D.; Mullin, Joseph V.

    1999-02-01

    Locating oil in marine and terrestrial environments is a daunting task. There are commercially available off the shelf (COTS) sensors with a wide field-of-view (FOV) which can be used to map the overall extent of the spill. These generic sensors, however, lack the specificity required to positively identify oil and related products. The problem is exacerbated along beach and shoreline environments where a variety of organic and inorganic substrates are present. One sensor that can detect and classify oil in these environments is the laser fluorosensor. Laser fluorosensors have been under development by several agencies around the world for the past two decades. Environment Canada has been involved with laser fluorosensor development since the early 1990s. The prototype system was known as the Laser Environmental Airborne Fluorosensor (LEAF). The LEAF has recently been modified to provide real-time oil spill detection and classification. Fluorescence spectra are collected and analyzed at the rate of 100 Hz. Geo-referenced maps showing the locations of oil contamination are produced in real-time onboard the aircraft. While the LEAF has proven to be an excellent prototype sensor and a good operational tool, it has some deficiencies when it comes to oil spill response operations. A consortium including Environment Canada and the Minerals Management Service has recently funded the development of a new fluorosensor, called the Scanning Laser Environmental Airborne Fluorosensor (SLEAF). The SLEAF was designed to detect and map oil in shoreline environments where other non-specific sensors experience difficulty. Oil tends to pile up in narrow bands along the high tide line on beaches. A nadir-looking, small footprint sensor such as the LEAF would have difficulty locating oil in this situation. The SLEAF employs a pair of conical scanning mirrors to direct the laser beam in a circular pattern below the aircraft. With a sampling rate of 400 Hz and real-time spectral analysis

  15. POTENTIAL OF AIRBORNE IMAGING SPECTROSCOPY AT CZECHGLOBE

    Directory of Open Access Journals (Sweden)

    J. Hanuš

    2016-06-01

    Full Text Available Ecosystems, their services, structures and functions are affected by complex environmental processes, which are both natural and human-induced and globally changing. In order to understand how ecosystems behave in globally changing environment, it is important to monitor the current status of ecosystems and their structural and functional changes in time and space. An essential tool allowing monitoring of ecosystems is remote sensing (RS. Many ecosystems variables are being translated into a spectral response recorded by RS instruments. It is however important to understand the complexity and synergies of the key ecosystem variables influencing the reflected signal. This can be achieved by analysing high resolution RS data from multiple sources acquired simultaneously from the same platform. Such a system has been recently built at CzechGlobe - Global Change Research Institute (The Czech Academy of Sciences. CzechGlobe has been significantly extending its research infrastructure in the last years, which allows advanced monitoring of ecosystem changes at hierarchical levels spanning from molecules to entire ecosystems. One of the CzechGlobe components is a laboratory of imaging spectroscopy. The laboratory is now operating a new platform for advanced remote sensing observations called FLIS (Flying Laboratory of Imaging Spectroscopy. FLIS consists of an airborne carrier equipped with passive RS systems. The core instrument of FLIS is a hyperspectral imaging system provided by Itres Ltd. The hyperspectral system consists of three spectroradiometers (CASI 1500, SASI 600 and TASI 600 that cover the reflective spectral range from 380 to 2450 nm, as well as the thermal range from 8 to 11.5 μm. The airborne platform is prepared for mounting of full-waveform laser scanner Riegl-Q780 as well, however a laser scanner is not a permanent part of FLIS. In 2014 the installation of the hyperspectral scanners was completed and the first flights were carried out

  16. Potential of Airborne Imaging Spectroscopy at Czechglobe

    Science.gov (United States)

    Hanuš, J.; Fabiánek, T.; Fajmon, L.

    2016-06-01

    Ecosystems, their services, structures and functions are affected by complex environmental processes, which are both natural and human-induced and globally changing. In order to understand how ecosystems behave in globally changing environment, it is important to monitor the current status of ecosystems and their structural and functional changes in time and space. An essential tool allowing monitoring of ecosystems is remote sensing (RS). Many ecosystems variables are being translated into a spectral response recorded by RS instruments. It is however important to understand the complexity and synergies of the key ecosystem variables influencing the reflected signal. This can be achieved by analysing high resolution RS data from multiple sources acquired simultaneously from the same platform. Such a system has been recently built at CzechGlobe - Global Change Research Institute (The Czech Academy of Sciences). CzechGlobe has been significantly extending its research infrastructure in the last years, which allows advanced monitoring of ecosystem changes at hierarchical levels spanning from molecules to entire ecosystems. One of the CzechGlobe components is a laboratory of imaging spectroscopy. The laboratory is now operating a new platform for advanced remote sensing observations called FLIS (Flying Laboratory of Imaging Spectroscopy). FLIS consists of an airborne carrier equipped with passive RS systems. The core instrument of FLIS is a hyperspectral imaging system provided by Itres Ltd. The hyperspectral system consists of three spectroradiometers (CASI 1500, SASI 600 and TASI 600) that cover the reflective spectral range from 380 to 2450 nm, as well as the thermal range from 8 to 11.5 μm. The airborne platform is prepared for mounting of full-waveform laser scanner Riegl-Q780 as well, however a laser scanner is not a permanent part of FLIS. In 2014 the installation of the hyperspectral scanners was completed and the first flights were carried out with all

  17. Assessment of airborne dust associated with chemical plant: A case study

    Directory of Open Access Journals (Sweden)

    Pattajoshi P

    2006-01-01

    Full Text Available The process of alumina production involves refining of bauxite ore into tri-hydrated alumina (Al2O3, 3H2O by chemical method followed by process of calcinations. This method possesses various kinds of dust hazards in its work environment amongst the people involved. Poor health of industrial employees in India is due to its occupational environment (Park & Park, 1970, which is a major concern now-a-days. Attempts have been made to recognize the potential sources of airborne dust and to assess the dust load upon exposed workers at different work sites of alumina plants by comparing the observations with the standard values called ′Threshold Limit Values′ (T.L.V. assigned by the international body ACGIH (American Conference of Governmental and Industrial Hygienists, USA, and also permissible exposure limit values prescribed in the second schedule Section F of Factories Act (Amendment, 1987. Alumina plant operation includes various physical operations like crushing, grinding, conveying, loading, transporting, etc., which generate finer particles. It can cause serious health hazards on inhalation, depending upon its size, shape, constituents and duration of exposure. Out of all these parameters, concentration of respirable fraction of airborne dust (0.5 to 5.0 micron size and its free silica content have been reported to cause lung fibrosis as well as occupational disorders. In the present study, attempts have been made to make a survey of respirable fraction of the airborne dust (that remains suspended in air for quite an appreciable time associated with various operations according to job profiles. It also outlines the probable control measures in order to provide a healthy working environment. Present work aims at identifying and evaluating the degree of workplace dust with special reference to respirable fraction and for recommending suitable suggestive control measures for an effective management of occupational environment.

  18. Analytical Methods INAA and PIXE Applied to Characterization of Airborne Particulate Matter in Bandung, Indonesia

    Directory of Open Access Journals (Sweden)

    D.D. Lestiani

    2011-08-01

    Full Text Available Urbanization and industrial growth have deteriorated air quality and are major cause to air pollution. Air pollution through fine and ultra-fine particles is a serious threat to human health. The source of air pollution must be known quantitatively by elemental characterization, in order to design the appropriate air quality management. The suitable methods for analysis the airborne particulate matter such as nuclear analytical techniques are hardly needed to solve the air pollution problem. The objectives of this study are to apply the nuclear analytical techniques to airborne particulate samples collected in Bandung, to assess the accuracy and to ensure the reliable of analytical results through the comparison of instrumental neutron activation analysis (INAA and particles induced X-ray emission (PIXE. Particle samples in the PM2.5 and PM2.5-10 ranges have been collected in Bandung twice a week for 24 hours using a Gent stacked filter unit. The result showed that generally there was a systematic difference between INAA and PIXE results, which the values obtained by PIXE were lower than values determined by INAA. INAA is generally more sensitive and reliable than PIXE for Na, Al, Cl, V, Mn, Fe, Br and I, therefore INAA data are preffered, while PIXE usually gives better precision than INAA for Mg, K, Ca, Ti and Zn. Nevertheless, both techniques provide reliable results and complement to each other. INAA is still a prospective method, while PIXE with the special capabilities is a promising tool that could contribute and complement the lack of NAA in determination of lead, sulphur and silicon. The combination of INAA and PIXE can advantageously be used in air pollution studies to extend the number of important elements measured as key elements in source apportionment.

  19. Honey Bees (Apis mellifera, L. as Active Samplers of Airborne Particulate Matter.

    Directory of Open Access Journals (Sweden)

    Ilaria Negri

    Full Text Available Honey bees (Apis mellifera L. are bioindicators of environmental pollution levels. During their wide-ranging foraging activity, these hymenopterans are exposed to pollutants, thus becoming a useful tool to trace the environmental contaminants as heavy metals, pesticides, radionuclides and volatile organic compounds. In the present work we demonstrate that bees can also be used as active samplers of airborne particulate matter. Worker bees were collected from hives located in a polluted postmining area in South West Sardinia (Italy that is also exposed to dust emissions from industrial plants. The area is included in an official list of sites of national interest for environmental remediation, and has been characterized for the effects of pollutants on the health of the resident population. The head, wings, hind legs and alimentary canal of the bees were investigated with Scanning Electron Microscopy coupled with X-ray spectroscopy (SEM-EDX. The analyses pointed to specific morphological and chemical features of the particulate, and resulted into the identification of three categories of particles: industry-, postmining-, and soil-derived. With the exception of the gut, all the analyzed body districts displayed inorganic particles, mostly concentrated in specific areas of the body (i.e. along the costal margin of the fore wings, the medial plane of the head, and the inner surface of the hind legs. The role of both past mining activities and the industrial activity close to the study area as sources of the particulate matter is also discussed. We conclude that honey bees are able to collect samples of the main airborne particles emitted from different sources, therefore could be an ideal tool for monitoring such a kind of pollutants.

  20. Size-resolved culturable airborne bacteria sampled in rice field, sanitary landfill, and waste incineration sites.

    Science.gov (United States)

    Heo, Yongju; Park, Jiyeon; Lim, Sung-Il; Hur, Hor-Gil; Kim, Daesung; Park, Kihong

    2010-08-01

    Size-resolved bacterial concentrations in atmospheric aerosols sampled by using a six stage viable impactor at rice field, sanitary landfill, and waste incinerator sites were determined. Culture-based and Polymerase Chain Reaction (PCR) methods were used to identify the airborne bacteria. The culturable bacteria concentration in total suspended particles (TSP) was found to be the highest (848 Colony Forming Unit (CFU)/m(3)) at the sanitary landfill sampling site, while the rice field sampling site has the lowest (125 CFU/m(3)). The closed landfill would be the main source of the observed bacteria concentration at the sanitary landfill. The rice field sampling site was fully covered by rice grain with wetted conditions before harvest and had no significant contribution to the airborne bacteria concentration. This might occur because the dry conditions favor suspension of soil particles and this area had limited personnel and vehicle flow. The respirable fraction calculated by particles less than 3.3 mum was highest (26%) at the sanitary landfill sampling site followed by waste incinerator (19%) and rice field (10%), which showed a lower level of respiratory fraction compared to previous literature values. We identified 58 species in 23 genera of culturable bacteria, and the Microbacterium, Staphylococcus, and Micrococcus were the most abundant genera at the sanitary landfill, waste incinerator, and rice field sites, respectively. An antibiotic resistant test for the above bacteria (Micrococcus sp., Microbacterium sp., and Staphylococcus sp.) showed that the Staphylococcus sp. had the strongest resistance to both antibiotics (25.0% resistance for 32 microg ml(-1) of Chloramphenicol and 62.5% resistance for 4 microg ml(-1) of Gentamicin).

  1. Elementary Particles

    Science.gov (United States)

    Parham, R.

    1974-01-01

    Presents the text of a speech given to a conference of physics teachers in which the full spectrum of elementary particles is given, along with their classification. Also includes some teaching materials available on this topic. (PEB)

  2. An intercomparison of airborne VOC measurements

    International Nuclear Information System (INIS)

    During the Texas Air Quality Study (TexAQS) 2000 ambient air samples were analyzed on-board the NSF/NCAR ELECTRA research aircraft by two VOC measurement techniques: 1) an in-situ gas chromatograph named TACOH (Tropospheric Airborne Chromatograph for Oxy-hydrocarbons and Hydrocarbons), operated by NOAA's Aeronomy Laboratory, and 2) a chemical ionization mass spectrometer named PTR-MS (Proton-Transfer-Reaction Mass Spectrometer) and operated by the University of Innsbruck. The sample protocols were quite different for the two methods: the TACOH system collected air samples for 15-60 sec (depending upon altitude) every 15 min, the PTR-MS system monitored selected VOCs on a time-shared basis for 2 sec respectively, once every 4-20 sec, depending upon the number of monitored species. Simultaneous measurements of acetaldehyde, isoprene, the sum of acetone and propanal, the sum of methyl vinyl ketone and methacrolein (PTR-MS does not distinguish between isobaric species) and toluene show good agreement despite being performed in the complex and highly polluted Houston air matrix. (author)

  3. Collaboration Portals for NASA's Airborne Field Campaigns

    Science.gov (United States)

    Conover, Helen; Kulkami, Ajinkya; Garrett, Michele; Goodman, Michael; Peterson, Walter Arthur; Drewry, Marilyn; Hardin, Danny M.; He, Matt

    2011-01-01

    The University of Alabama in Huntsville (UAH), in collaboration with the Global Hydrology Resource Center, a NASA Earth Science Data Center, has provided information management for a number of NASA Airborne Field campaigns, both hurricane science investigations and satellite instrument validation. Effective field campaign management requires communication and coordination tools, including utilities for personnel to upload and share flight plans, weather forecasts, a variety of mission reports, preliminary science data, and personal photos. Beginning with the Genesis and Rapid Intensification Processes (GRIP) hurricane field campaign in 2010, we have provided these capabilities via a Drupal-based collaboration portal. This portal was reused and modified for the Midlatitude Continental Convective Clouds Experiment (MC3E), part of the Global Precipitation Measurement mission ground validation program. An end goal of these development efforts is the creation of a Drupal profile for field campaign management. This presentation will discuss experiences with Drupal in developing and using these collaboration portals. Topics will include Drupal modules used, advantages and disadvantages of working with Drupal in this context, and how the science teams used the portals in comparison with other communication and collaboration tools.

  4. Airborne electromagnetic imaging of discontinuous permafrost

    Science.gov (United States)

    Minsley, B.J.; Abraham, J.D.; Smith, B.D.; Cannia, J.C.; Voss, C.I.; Jorgenson, M.T.; Walvoord, M.A.; Wylie, B.K.; Anderson, L.; Ball, L.B.; Deszcz-Pan, M.; Wellman, T.P.; Ager, T.A.

    2012-01-01

    The evolution of permafrost in cold regions is inextricably connected to hydrogeologic processes, climate, and ecosystems. Permafrost thawing has been linked to changes in wetland and lake areas, alteration of the groundwater contribution to streamflow, carbon release, and increased fire frequency. But detailed knowledge about the dynamic state of permafrost in relation to surface and groundwater systems remains an enigma. Here, we present the results of a pioneering ???1,800 line-kilometer airborne electromagnetic survey that shows sediments deposited over the past ???4 million years and the configuration of permafrost to depths of ???100 meters in the Yukon Flats area near Fort Yukon, Alaska. The Yukon Flats is near the boundary between continuous permafrost to the north and discontinuous permafrost to the south, making it an important location for examining permafrost dynamics. Our results not only provide a detailed snapshot of the present-day configuration of permafrost, but they also expose previously unseen details about potential surface-groundwater connections and the thermal legacy of surface water features that has been recorded in the permafrost over the past ???1,000 years. This work will be a critical baseline for future permafrost studies aimed at exploring the connections between hydrogeologic, climatic, and ecological processes, and has significant implications for the stewardship of Arctic environments. ?? 2012 by the American Geophysical Union.

  5. Evaluation of principal cannabinoids in airborne particulates

    Energy Technology Data Exchange (ETDEWEB)

    Balducci, C., E-mail: balducci@iia.cnr.it [Italian National Research Council, Institute for Atmospheric Pollution (CNR-IIA), Monterotondo Stazione (Italy); Nervegna, G.; Cecinato, A. [Italian National Research Council, Institute for Atmospheric Pollution (CNR-IIA), Monterotondo Stazione (Italy)

    2009-05-08

    The determination of delta(9)-tetrahydrocannabinol ({Delta}{sup 9}-THC), cannabidiol (CND) and cannabinol (CNB), primary active components in cannabis preparation, was carried out on airborne particulates by applying a specific procedure consisting of soot extraction by ultrasonic bath, purification by solvent partitioning, derivatization with N-(t-butyldimethylsilyl)-N-methyl-trifluoroacetamide, and separation/detection through gas chromatography coupled with tandem mass spectrometry. The optimized procedure was found suitable for measuring the three psychotropic substances at concentrations ranging from ca. 0.001 to ca. 5.0 ng cm{sup -3} of air, with recoveries always higher than 82%, accuracy >7.3% and precision >90%. Application of the procedure performed on field in Rome and Bari, Italy, demonstrated that all three compounds contaminate the air in Italian cities whereas in Algiers, Algeria, only cannabinol, the most stable in the atmosphere, exceeded the limit of quantification of the method. The relative percentages of the three cannabinoids in general reproduced those typical of the Cannabis sativa plant and were very different from those found in human blood, urine and sweat.

  6. Palinocam Network: airborne pollen vigilance in Madrid

    Directory of Open Access Journals (Sweden)

    Patricia Cervigón Morales

    2005-12-01

    Full Text Available Asthma Regional Programme started to give up in 1992 with four big areas. Palinocam network project was first set up in Madrid as a part of Asthma Regional Programme, comprised in a wider Environmental Subprogram: Palynological Network of Madrid Region (PALINOCAM NETWORK.Palynological network is a multidisciplinary organization which has been working since 1993. In that moment an Experts Committee was created with This Experts Committee is coordinated by the Public Health Institute, under the technical Direction of Faculty of Pharmacy and is integrated by all of the involved institutions. This juridical framework is completed with individual agreements signed between the Councils and the Public Health Department, and with a Collaboration Agreement signed with the Madrid ́s Complutense University Faculty of Pharmacy.This network main aim is to watch for aerobiological content in Madrid's air, for a best knowledge of patients expositions in each geographical area in en different moment. This information has a great interest for Public Health.Palinocam Network is a useful tool in Public Health for offering information of aerobiological levels by Internet and Telephonic Service yearly .In this way allergic patients, sanitarians and media can know the most frequent pollen types in each season and its airborne level.

  7. Airborne chemistry: acoustic levitation in chemical analysis.

    Science.gov (United States)

    Santesson, Sabina; Nilsson, Staffan

    2004-04-01

    This review with 60 references describes a unique path to miniaturisation, that is, the use of acoustic levitation in analytical and bioanalytical chemistry applications. Levitation of small volumes of sample by means of a levitation technique can be used as a way to avoid solid walls around the sample, thus circumventing the main problem of miniaturisation, the unfavourable surface-to-volume ratio. Different techniques for sample levitation have been developed and improved. Of the levitation techniques described, acoustic or ultrasonic levitation fulfils all requirements for analytical chemistry applications. This technique has previously been used to study properties of molten materials and the equilibrium shape()and stability of liquid drops. Temperature and mass transfer in levitated drops have also been described, as have crystallisation and microgravity applications. The airborne analytical system described here is equipped with different and exchangeable remote detection systems. The levitated drops are normally in the 100 nL-2 microL volume range and additions to the levitated drop can be made in the pL-volume range. The use of levitated drops in analytical and bioanalytical chemistry offers several benefits. Several remote detection systems are compatible with acoustic levitation, including fluorescence imaging detection, right angle light scattering, Raman spectroscopy, and X-ray diffraction. Applications include liquid/liquid extractions, solvent exchange, analyte enrichment, single-cell analysis, cell-cell communication studies, precipitation screening of proteins to establish nucleation conditions, and crystallisation of proteins and pharmaceuticals. PMID:14762640

  8. Multiple model adaptive tracking of airborne targets

    Science.gov (United States)

    Norton, John E.

    1988-12-01

    Over the past ten years considerable work has been accomplished at the Air Force Institute of Technology (AFIT) towards improving the ability of tracking airborne targets. Motivated by the performance advantages in using established models of tracking environment variables within a Kalman filter, an advanced tracking algorithm has been developed based on adaptive estimation filter structures. A multiple model bank of filters that have been designed for various target dynamics, which each accounting for atmospheric disturbance of the Forward Looking Infrared (FLIR) sensor data and mechanical vibrations of the sensor platform, outperforms a correlator tracker. The bank of filters provides the estimation capability to guide the pointing mechanisms of a shared aperture laser/sensor system. The data is provided to the tracking algorithm via an (8 x 8)-pixel tracking Field of View (FOV) from the FLIR image plane. Data at each sample period is compared by an enhanced correlator to a target template. These offsets are measurements to a bank of linear Kalman filters which provide estimates of the target's location in azimuth and elevation coordinates based on a Gauss-Markov acceleration model, and a reduced form of the atmospheric jitter model for the disturbance in the IR wavefront carrying future measurements.

  9. Airborne radiometric: Data evaluation and calibration

    International Nuclear Information System (INIS)

    The airborne geophysical system of the BGR (German Geological Survey) consists of a helicopter equipped with an electromagnetic system with two transmittors and two receivers, a proton resonance magnetometer and a 16 L NaJ-crystal with four channel recording. All these data together with navigation data and flight altitude above ground are recorded each second on a nine track magnetic tape for further data evaluation. Different corrections have to be applied to the rough data such as: smoothing by means of a digital filter to reduce statistical noise, altitude correction, Compton-correction, and drift correction (cross-profile evaluation). Then the corrected measuring data are combined with the navigation data in order to be able to produce iso-line maps. The final results are presented as: line plots for U, Th, and K (and EM-data and magnetometer data); actual flight line plots; iso-line maps for U, Th, and K; iso-line maps for conductivity; depth of conducting layer; and magnetometry maps. The procedures of correction and evaluation of the above mentioned data as well as the calibration of the NaJ-detector in terms of ppm U, Th, and %K are dicussed in the paper. (author)

  10. Diversity and seasonal dynamics of airborne archaea

    Science.gov (United States)

    Fröhlich-Nowoisky, J.; Ruzene Nespoli, C.; Pickersgill, D. A.; Galand, P. E.; Müller-Germann, I.; Nunes, T.; Gomes Cardoso, J.; Almeida, S. M.; Pio, C.; Andreae, M. O.; Conrad, R.; Pöschl, U.; Després, V. R.

    2014-11-01

    Archaea are widespread and abundant in many terrestrial and aquatic environments, and are thus outside extreme environments, accounting for up to ~10% of the prokaryotes. Compared to bacteria and other microorganisms, however, very little is known about the abundance, diversity, and dispersal of archaea in the atmosphere. By means of DNA analysis and Sanger sequencing targeting the 16S rRNA (435 sequences) and amoA genes in samples of air particulate matter collected over 1 year at a continental sampling site in Germany, we obtained first insights into the seasonal dynamics of airborne archaea. The detected archaea were identified as Thaumarchaeota or Euryarchaeota, with soil Thaumarchaeota (group I.1b) being present in all samples. The normalized species richness of Thaumarchaeota correlated positively with relative humidity and negatively with temperature. This together with an increase in bare agricultural soil surfaces may explain the diversity peaks observed in fall and winter. The detected Euryarchaeota were mainly predicted methanogens with a low relative frequency of occurrence. A slight increase in their frequency during spring may be linked to fertilization processes in the surrounding agricultural fields. Comparison with samples from the Cape Verde islands (72 sequences) and from other coastal and continental sites indicates that the proportions of Euryarchaeota are enhanced in coastal air, which is consistent with their suggested abundance in marine surface waters. We conclude that air transport may play an important role in the dispersal of archaea, including assumed ammonia-oxidizing Thaumarchaeota and methanogens.

  11. Higgs particles

    International Nuclear Information System (INIS)

    The theoretical work on models of the electroweak interaction and simple grand unified models with a nonstandard set of Higgs particles is reviewed. Emphasis is placed on light and even strictly massless Higgs particles: Goldstone and pseudo-Goldstone bosons. It is shown that such bosons arise in a natural way in the theory if the Higgs particles are in fact composite. The low-energy effective Lagrangian of these particles is studied. A detailed study is made of the problem of CP breaking in a strong interaction and of a natural solution of this problem through the introduction of a pseudo-Goldstone particle: an axion. The theory of the ''standard'' axion and its experimental status are reviewed. Possible ''invisible'' and ''visualized'' axions are discussed, as are certain astrophysical aspects of the existence of an axion. By analogy with the axion, an analysis is made of another hypothetical particle: the strictly massless Goldstone boson or arion. Model-independent properties of the arion are determined. The similarity between the arion fields and magnetic fields and the differences between these fields are shown. Possible methods for detecting an arion field are discussed. An experiment which has set a limit on the strength of the arion interaction is described. Neutral Goldstone bosons whose emission is accompanied by changes in fermion flavors (''familons'') are discussed. Two versions of the theory with a Goldstone boson (a majoron) which arises upon a spontaneous breaking of lepton number are described

  12. The Efficiency of Biofilters at Mitigating Airborne MRSA from a Swine Nursery.

    Science.gov (United States)

    Ferguson, D D; Smith, T C; Donham, K J; Hoff, S J

    2015-10-01

    Our prior studies have been in agreement with other researchers in detecting airborne methicillin-resistant Staphylococcus aureus (MRSA) inside and downwind of a swine housing facility. MRSA emitted in the exhaust air of swine facilities creates a potential risk of transmission of these organisms to people in the general area of these facilities as well as to other animals. This study investigated a possible means of reducing those risks. We investigated the efficiency of biofilters to remove MRSA from the exhaust air of a swine building. Two types of biofilter media (hardwood chips and western red cedar shredded bark) were evaluated. Efficiency was measured by assessing both viable MRSA (viable cascade impactor) and dust particles (optical particle courter) in the pre-filtered and post-filtered air of a functioning swine production facility. Our study revealed that hardwood chips were respectively 92% and 88% efficient in removing viable MRSA and total dust particles. Western red cedar was 95% efficient in removing viable MRSA and 86% efficient in removing dust particles. Our findings suggest that biofilters can be used as effective engineering controls to mitigate the transmission of aerosolized MRSA in the exhaust air of enclosed swine housing facilities.

  13. The microphysical properties of small ice particles measured during MACPEX

    Science.gov (United States)

    Schmitt, C. G.; Schnaiter, M.; Heymsfield, A.; Bansemer, A.; Hirst, E.

    2012-12-01

    During the Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) field campaign, the Small Ice Detector version 3 (SID-3) and the NCAR Video Ice Particle Sampler (VIPS) probes were operated onboard the NASA WB-57 aircraft to measure the microphysical properties of small ice particles in midlatitude cirrus clouds. The VIPS was optimized to measure the particle size distribution and projected area properties of ice particles between 20 and 200 microns and measurements agreed well with other microphysical probes. SID-3 measures the forward light scattering pattern from ice particles in the 1 to 100 micron size range. Forward scattering patterns can be used to characterize ice particle shape as well as surface roughness. Scattering patterns appear to be 'speckled' when particles have surface roughness and/or are polycrystalline. Scattering patterns can be used to identify quasi-spherical ice particles as well as particles which are sublimating. Sublimating crystals, spherical ice particles, and particles with surface roughness were all observed by SID-3 during MACPEX. Observed particle properties will be correlated to concurrent atmospheric observations. Measurements from the controlled environment of the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) cloud chamber will be related to atmospheric particle measurements.

  14. Accuracy of chemical analysis of airborne particulates: results of an intercomparison exercise

    International Nuclear Information System (INIS)

    Since suitable standard reference materials for chemical analysis of airborne particulates are not available, an intercomparison exercise was carried out among 40 interested laboratories in order to evaluate the accuracy of various trace analysis techniques for this specific application. Six hundred grams of airborne particulates were collected from the inlet filters of the air conditioning installation of a hotel in the center of Milan. The sample was sieved to remove coarser particles, thoroughly mixed, and distributed in 1 to 5 gram aliquots. The homogeneity was checked by relative measurements carried out by three independent techniques. For 40 elements no inhomogeneity was found to exceed the analytical error, which was estimated to be approximately 10 percent. The data of the analytical exercise are being collected and evaluated. Results are available for 56 elements, but to date only 33 have been determined by more than one technique. Activation analysis, emission spectroscopy, atomic absorption, x-ray fluorescence and various wet chemical methods contributed to the intercomparison. No result was received from mass spectroscopic methods and, although analyses were specifically encouraged, very few results were received on the organic components. From a first approximate evaluation a good agreement was found for Al, Fe, Zn, Mn, Ca, Pb, Cl, S, Si, Ti, Mn, while for the other elements no definite conclusion can yet be drawn. An attempt will be made to interpret important cases of systematic errors, a few of which are already evident

  15. Impact of banning of two-stroke engines on airborne particulate matter concentrations in Dhaka, Bangladesh.

    Science.gov (United States)

    Begum, Bilkis A; Biswas, Swapan K; Hopke, Philip K

    2006-01-01

    Vehicular air pollution is common in growing metropolitan areas throughout the world. Vehicular emissions of fine particles are particularly harmful because they occur near ground level, close to where people live and work. Two-stroke engines represented an important contribution to the motor vehicle emissions where they constitute approximately half of the total vehicle fleet in Dhaka city. Two-stroke engines have lower fuel efficiency than four-stroke engines, and they emit as much of an order of magnitude and more particulate matter (PM) than four-stroke engines of similar size. To eliminate their impact on air quality, the government of Bangladesh promulgated an order banning all two-stroke engines from the roads in Dhaka starting on December 31, 2002. The effect of the banning of two-stroke engines on airborne PM was studied at the Farm Gate air quality-monitoring station in Dhaka (capital of Bangladesh), a hot spot with very high-pollutant concentrations because of its proximity to major roadways. The samples were collected using a "Gent" stacked filter unit in two fractions of 0-2.2 microm and 2.2-10 microm sizes. Samples of fine and coarse fractions of airborne PM collected from 2000 to 2004 were studied. It has been found that the fine PM and black carbon concentrations decreased from the previous years because of the banning of two-stroke engine baby taxies.

  16. Radiative flux measurements during the Airborne Tropical Tropopause Experiment (ATTREX) Guam Deployment.

    Science.gov (United States)

    Kindel, B. C.; Pilewskie, P.; Schmidt, S.

    2015-12-01

    The Airborne Tropical Tropopause Experiment was a field program utilizing the NASA Global Hawk aircraft, to make extensive measurements of tropical tropopause layer (TTL) over the Pacific Ocean. In February and March of 2014, the NASA Global Hawk was deployed to Guam and flew six long duration science flights. The aircraft was outfitted with a suite of instruments to study the composition of the TTL. Measurements included: water vapor amount, cloud particle size and shape, various gaseous species (e.g. CO, CH4, CO2, O3), and radiation measurements. The radiation measurements were comprised of the Solar Spectral Flux Radiometer (SSFR) that made spectrally resolved measurements of upwelling and downwelling solar irradiance from 350 to 2200 nm and thermal broadband (4μm to 42 μm) upwelling and downwelling irradiance. Once airborne, the Global Hawk made numerous vertical profiles (14 - 18 km) through the TTL. In this work we present results of combined solar spectral irradiance and broadband thermal irradiance measurements. Solar spectral measurements are correlated, wavelength-by-wavelength, with broadband thermal measurements. The radiative impact in the TTL of water vapor and cirrus clouds are examined both in the solar and thermal wavelengths from both upwelling and downwelling irradiances. The spectral measurements are used in an attempt to attribute physical mechanisms to the thermal (spectrally integrated) measurements. Measurements of heating rates are also presented, highlighting the difficultly in obtaining reliable results from aircraft measurements.

  17. Effects of studded tires on roadside airborne dust pollution in Niigata, Japan

    Science.gov (United States)

    Fukuzaki, Norio; Yanaka, Takaaki; Urushiyama, Yoshio

    Two series of dust samples, collected by Andersen impactors (denoted by AN) and low-volume air samplers (denoted by LV), were investigated with respect to roadside airborne dusts collected in two different periods in 1983. These were the periods (i) with studded tires (February and March) and (ii) without studded tires (October). Multi-element determinations of these samples were made by neutron activation analysis and atomic absorption spectrometry. The total concentration of AN in roadside air for period (i) was about three times higher than for the period without studded tires. The lithophilic elements such as Na, Al, K, Ca, Ti, Fe and Th, and component-metal elements of stud tip, W and Ta, produced a significant increase in atmospheric concentration in winter. The contribution of pavement material, one of the most interesting components of airborne particles in this study, was related to total AN and LV by the chemical element balance method. It made up only 16 percent (9.1 μgm -3) of AN in October, compared with 46 percent (70.2 μgm -3) in February. It was also observed that the atmospheric concentrations of pavement debris to total LV decreased with the distance from the road to each sampling site.

  18. The Ebb and Flow of Airborne Pathogens: Monitoring and Use in Disease Management Decisions.

    Science.gov (United States)

    Mahaffee, Walter F; Stoll, Rob

    2016-05-01

    Perhaps the earliest form of monitoring the regional spread of plant disease was a group of growers gathering together at the market and discussing what they see in their crops. This type of reporting continues to this day through regional extension blogs, by crop consultants and more formal scouting of sentential plots in the IPM PIPE network (http://www.ipmpipe.org/). As our knowledge of plant disease epidemiology has increased, we have also increased our ability to detect and monitor the presence of pathogens and use this information to make management decisions in commercial production systems. The advent of phylogenetics, next-generation sequencing, and nucleic acid amplification technologies has allowed for development of sensitive and accurate assays for pathogen inoculum detection and quantification. The application of these tools is beginning to change how we manage diseases with airborne inoculum by allowing for the detection of pathogen movement instead of assuming it and by targeting management strategies to the early phases of the epidemic development when there is the greatest opportunity to reduce the rate of disease development. While there are numerous advantages to using data on inoculum presence to aid management decisions, there are limitations in what the data represent that are often unrecognized. In addition, our understanding of where and how to effectively monitor airborne inoculum is limited. There is a strong need to improve our knowledge of the mechanisms that influence inoculum dispersion across scales as particles move from leaf to leaf, and everything in between.

  19. Antimicrobial durability of air filters coated with airborne Sophora flavescens nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Chong, Eui-seok; Hwang, Gi Byoung [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Nho, Chu Won [Functional Food Center, Korea Institute of Science and Technology (KIST Gangneung Institute), Gangneung, Gangwon-do 210-340 (Korea, Republic of); Kwon, Bo Mi [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Lee, Jung Eun [Biosafety Research Team, National Institute of Environmental Research, Kyungseo-Dong, Seo-Gu, Incheon 404-170 (Korea, Republic of); Seo, SungChul [Department of Environmental Health, College of Medicine, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul 136-701 (Korea, Republic of); Bae, Gwi-Nam, E-mail: gnbae@kist.re.kr [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Jung, Jae Hee, E-mail: jaehee@kist.re.kr [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

    2013-02-01

    Airborne biological particles containing viruses, bacteria, and/or fungi can be toxic and cause infections and allergy symptoms. Recently, natural materials such as tea tree oil and Sophora flavescens have shown promising antimicrobial activity when applied as air filter media. Although many of these studies demonstrated excellent antimicrobial efficacy, only a few of them considered external environmental effects such as the surrounding humidity, temperature, and natural degradation of chemicals, all of which can affect the antimicrobial performance of these natural materials. In this study, we investigated the antimicrobial durability of air filters containing airborne nanoparticles from S. flavescens for 5 months. Antimicrobial tests and quantitative chemical analyses were performed every 30 days. Morphological changes in the nanoparticles were also evaluated by scanning electron microscopy. The major antimicrobial compounds remained stable and active for ∼ 90 days at room temperature. After about 90 days, the quantities of major antimicrobial compounds decreased noticeably with a consequent decrease in antimicrobial activity. These results are promising for the implementation of new technologies using natural antimicrobial products and provide useful information regarding the average life expectancy of antimicrobial filters using nanoparticles of S. flavescens. - Graphical abstract: Variations in (a) the concentrations of major antimicrobial chemical compounds on S. flavescens nanoparticle-coated filters: kurarinone, kuraridin, and sophoraflavanone-G and (b) the inactivation rate of antimicrobial filters as a function of time.

  20. Open Source Software Reuse in the Airborne Cloud Computing Environment

    Science.gov (United States)

    Khudikyan, S. E.; Hart, A. F.; Hardman, S.; Freeborn, D.; Davoodi, F.; Resneck, G.; Mattmann, C. A.; Crichton, D. J.

    2012-12-01

    Earth science airborne missions play an important role in helping humans understand our climate. A challenge for airborne campaigns in contrast to larger NASA missions is that their relatively modest budgets do not permit the ground-up development of data management tools. These smaller missions generally consist of scientists whose primary focus is on the algorithmic and scientific aspects of the mission, which often leaves data management software and systems to be addressed as an afterthought. The Airborne Cloud Computing Environment (ACCE), developed by the Jet Propulsion Laboratory (JPL) to support Earth Science Airborne Program, is a reusable, multi-mission data system environment for NASA airborne missions. ACCE provides missions with a cloud-enabled platform for managing their data. The platform consists of a comprehensive set of robust data management capabilities that cover everything from data ingestion and archiving, to algorithmic processing, and to data delivery. Missions interact with this system programmatically as well as via browser-based user interfaces. The core components of ACCE are largely based on Apache Object Oriented Data Technology (OODT), an open source information integration framework at the Apache Software Foundation (ASF). Apache OODT is designed around a component-based architecture that allows for selective combination of components to create highly configurable data management systems. The diverse and growing community that currently contributes to Apache OODT fosters on-going growth and maturation of the software. ACCE's key objective is to reduce cost and risks associated with developing data management systems for airborne missions. Software reuse plays a prominent role in mitigating these problems. By providing a reusable platform based on open source software, ACCE enables airborne missions to allocate more resources to their scientific goals, thereby opening the doors to increased scientific discovery.

  1. Assessing deposition of airborne particulates and gases in the Selkirk area using lichens growing on tree trunks : non-technical summary

    International Nuclear Information System (INIS)

    An independent study was conducted to address the public concern regarding airborne emissions from Manitoba Hydro's coal-fired electricity generating station located in the Selkirk area. This document is a non-technical summary of the report issued by Ecostem Ltd. Since there are no air quality monitoring stations in the study area which covers more than 1,000 square km, Ecostem used lichens as biological indicators of historical deposition of airborne dust and gases. The sources of airborne dust and gases include urban centres, agriculture, pesticides, fertilizers, waste burning, vehicle use and manufacturing. Lichens have been commonly used as indicators since 1866. They provide useful information because they are long-lived, are not mobile, acquire most of their nutrients from the atmosphere, retain the airborne deposition they initially trap, and they can accumulate airborne particles year round. It is possible to obtain a record of the chemicals that have been present in the air by simply analyzing the lichen tissue. This study used the concentrations of various chemical elements in lichen tissue and the distribution and abundance of lichen species to see if airborne particulates were substantially elevated in the Selkirk area and if so, to determine if the coal-fired generating station was the apparent source of the pollution. A total of 62 stations and lichens on more than 400 trees were sampled. Sulphur, a fingerprint for gaseous emissions from the generating station, had tissue concentrations that were 1.32 times higher. Statistical analysis suggests that barium, boron and strontium were the clearest fingerprint elements for generating station emissions. Tissue concentrations of antimony, arsenic, cadmium, chromium, copper, iron, lead, manganese, mercury, molybdenum, nickel, selenium, silver, thallium, tin, vanadium and zinc were examined further because they are considered to be toxic. It was noted that a conclusion regarding human health cannot be made

  2. Experiments to quantify airborne release from packages with dispersible radioactive materials under accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Martens, R.; Lange, F. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Schwertnergasse 1, 50667 Koeln (Germany); Koch, W.; Nolte, O. [Fraunhofer-Institut fuer Toxikologie und Experimentelle Medizin (ITEM), Nikolai-Fuchs-Str.1, 30625 Hannover (Germany)

    2005-07-01

    For transport or handling accidents involving packages with radioactive materials and the assessment of potential radiological consequences, for the review of current requirements of the IAEA Transport Regulations, and for their possible further development reliable release data following mechanical impact are required. Within this context a research project was carried out which extends the basis for a well-founded examination of the contemporary system of requirements of 'Low Specific Activity' (LSA)-type materials and allows for its further development where appropriate. This project comprises a prior system-analytical examination and an experimental programme aiming at improving the general physical understanding of the release process as well as the quantity and the characteristics of airborne released material for non-fixed dispersible LSA-II material upon mechanical impact. Impaction experiments applying small, medium and real sized specimens of different dispersible materials revealed that the release behaviour of dispersible powders strongly depends upon material properties, e.g. particle size distribution and cohesion forces. The highest experimentally determined release fraction of respirable mass (AED < 10 {mu}m) amounted to about 2 % and was obtained for 2 kg of un-contained easily dispersible pulverized fly ash (PFA). For larger un-contained PFA specimen the release fraction decreases. However, packaging containing powdery material substantially reduces the airborne release fraction. The measured airborne release fractions for a 200 l drum with Type A certificate containing PFA were about a factor of 50 to 100 lower than for un-contained material. For a drop height of 9 m the airborne release fraction amounted to about 4 x 10{sup -5}. This value should be applicable for most of transport and handling accidents with mechanical impact. For a metal container of Type IP-2 or better which contains powder masses of 100 kg or more this release

  3. Validation of Airborne CO2 Laser Measurements

    Science.gov (United States)

    Browell, E. V.; Dobler, J. T.; Kooi, S.; Fenn, M. A.; Choi, Y.; Vay, S. A.; Harrison, F. W.; Moore, B.; Zaccheo, T. S.

    2010-12-01

    This paper discusses the flight test validation of a unique, multi-frequency, intensity-modulated, single-beam laser absorption spectrometer (LAS) that operates near 1.57 μm for remote column CO2 measurements. This laser system is under development for a future space-based mission to determine the global distribution of regional-scale CO2 sources and sinks, which is the objective of the NASA Active Sensing of CO2 Emissions during Nights, Days, and Seasons (ASCENDS) mission. A prototype of this LAS system, called the Multi-frequency Fiber Laser Lidar (MFLL), was developed by ITT, and it has been flight tested in nine airborne campaigns since May 2005. This paper focuses on the most recent results obtained over the last two years of flight-testing where the MFLL remote CO2 column measurements were evaluated against airborne in situ CO2 profile measurements traceable to World Meteorological Organization standards. A comprehensive multiple-aircraft flight test program was conducted over Oklahoma and Virginia in July-August 2009. The MFLL obtained surface reflectance and average CO2 column variations along the 50-km flight legs over the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Central Facility (CF) in Lamont, Oklahoma; over rural Virginia and North Carolina; and over the Chesapeake Bay. For a flight altitude of 4.6 km, the average signal to noise ratio (SNR) for a 1-s CO2 column measurement was found to be 760, which is the equivalent of a CO2 mixing ratio precision of 0.60 ppmv, and for a 10-s average the SNR was found to be 2002 or 0.20 ppmv. Absolute comparisons of MFLL-derived and in situ-derived CO2 column measurements were made for all daytime flights conducted over Oklahoma and Virginia with an average agreement to within 0.32 ppmv. A major ASCENDS flight test campaign was conducted using the NASA DC-8 during 6-18 July 2010. The MFLL system and associated in situ CO2 instrumentation were operated on DC-8 flights over the Central Valley

  4. Recent advances in airborne radiometric technology

    International Nuclear Information System (INIS)

    Since its inception, the DOE Remote Sensing Laboratory has made dramatic innovations in airborne radiometric technology. In the past few years there have been at least four major changes in operational philosophy. (1) The helicopter is now the prime radiation survey vehicle. Surveys are conducted at low speed and low altitude, with lines spaced only a few hundred feet apart. Radiation anomalies and subtle changes in background can be readily identified. (2) Much greater emphasis is now placed on accurate, detailed analysis and interpretation of radiation data. Dramatic improvements in survey hardware and software provide much more data of considerably better quality. (3) Recent Laboratory research has been concentrated on error-free, positive identification of point radiation sources. In the past, the extent and magnitude of dispersed sources were the major concerns. (4) Integrated remote sensing has been strongly emphasized at the Laboratory in recent years. This involves the simultaneous use of radiation detectors, aerial cameras, and the multispectral scanner imagery. The synergistic effects of such data correlation are of significantly greater value in analyzing the terrestrial environment. Many of the changes in operational philosophy are directly traceable to new or dramatically improved hardware and software employed at the Laboratory. Six items have been instrumental in the above technological advances: (1) the UHF Transponder System and its predecessor, the Microwave Ranging System; (2) Model IC of the REDAR data acquisition system; (3) the development of the search algorithm; (4) continued improvements in the REDACA data analysis system; (5) deployment of polyscin sodium iodide radiation detectors; and (6) development of the Graphic Overview System

  5. BioSAR Airborne Biomass Sensing System

    Energy Technology Data Exchange (ETDEWEB)

    Graham, R.L.; Johnson, P.

    2007-05-24

    This CRADA was developed to enable ORNL to assist American Electronics, Inc. test a new technology--BioSAR. BioSAR is a an airborne, low frequency (80-120 MHz {approx} FM radio frequencies) synthetic aperture radar (SAR) technology which was designed and built for NASA by ZAI-Amelex under Patrick Johnson's direction. At these frequencies, leaves and small branches are nearly transparent and the majority of the energy reflected from the forest and returned to the radar is from the tree trunks. By measuring the magnitude of the back scatter, the volume of the tree trunk and therefore the biomass of the trunks can be inferred. The instrument was successfully tested on tropical rain forests in Panama. Patrick Johnson, with American Electronics, Inc received a Phase II SBIR grant from DOE Office of Climate Change to further test and refine the instrument. Mr Johnson sought ORNL expertise in measuring forest biomass in order for him to further validate his instrument. ORNL provided ground truth measurements of forest biomass at three locations--the Oak Ridge Reservation, Weyerhaeuser Co. commercial pine plantations in North Carolina, and American Energy and Power (AEP) Co. hardwood forests in southern Ohio, and facilitated flights over these forests. After Mr. Johnson processed the signal data from BioSAR instrument, the processed data were given to ORNL and we attempted to derive empirical relationships between the radar signals and the ground truth forest biomass measurements using standard statistical techniques. We were unsuccessful in deriving such relationships. Shortly before the CRADA ended, Mr Johnson discovered that FM signal from local radio station broadcasts had interfered with the back scatter measurements such that the bulk of the signal received by the BioSAR instrument was not backscatter from the radar but rather was local radio station signals.

  6. Progress in georeferencing airborne laser altimeter measurements

    Energy Technology Data Exchange (ETDEWEB)

    Vaughn, C.R. [NASA/GSFC Wallops Flight Facility, Wallops Island, VA (United States); Bufton, J.L. [NASA/Goddard Space Flight Facility, Greenbelt, MD (United States)

    1996-10-01

    The NASA/Goddard Space Flight Center, including its Wallops Flight Facility, has conducted a series of airborne missions to collect transacts of pulsed-laser measured distances to the Earth`s surface. The primary purpose of these missions was to geolocate the points where the laser hit the earth. We present how we make these measurements with sufficient accuracy that a point on the earth can be geolocated in height to about 10 cm with-respect-to the WGS-84 ellipsoid. We give particular attention to determining the instantaneous spatial orientation of the laser beam and its transit time to the earth and back to the receiver. We also discuss the difficulty in assessing the accuracy of the ellipsoidal latitude and longitude of the point. From 1991 through 1994 we flew a nadir-pointing system in either a P3-B Orion or a T-39 Sabreline aircraft owned and operated by the Wallops Flight Facility. Flights in 1993 at an altitude of 500 to 600 meters over Lake Crowley, California (the Long Valley reservoir) gave a mean lake height that agreed to better than 10 cm with an accurate tide gage at the dam - after the local geoid undulation was removed from the laser data. In 1995 we built a new pulsed-laser ranger that raster-scans at 60 times per second, operates at a 523 run wavelength, fires 5000 pulses per second, and produces a 12 degrees wide scan line. We present preliminary results from this system. 5 refs., 5 figs.

  7. Forest Delineation Based on Airborne LIDAR Data

    Directory of Open Access Journals (Sweden)

    Norbert Pfeifer

    2012-03-01

    Full Text Available The delineation of forested areas is a critical task, because the resulting maps are a fundamental input for a broad field of applications and users. Different national and international forest definitions are available for manual or automatic delineation, but unfortunately most definitions lack precise geometrical descriptions for the different criteria. A mandatory criterion in forest definitions is the criterion of crown coverage (CC, which defines the proportion of the forest floor covered by the vertical projection of the tree crowns. For loosely stocked areas, this criterion is especially critical, because the size and shape of the reference area for calculating CC is not clearly defined in most definitions. Thus current forest delineations differ and tend to be non-comparable because of different settings for checking the criterion of CC in the delineation process. This paper evaluates a new approach for the automatic delineation of forested areas, based on airborne laser scanning (ALS data with a clearly defined method for calculating CC. The new approach, the ‘tree triples’ method, is based on defining CC as a relation between the sum of the crown areas of three neighboring trees and the area of their convex hull. The approach is applied and analyzed for two study areas in Tyrol, Austria. The selected areas show a loosely stocked forest at the upper timberline and a fragmented forest on the hillside. The fully automatic method presented for delineating forested areas from ALS data shows promising results with an overall accuracy of 96%, and provides a beneficial tool for operational applications.

  8. Airborne Lidar Point Cloud Density Indices

    Science.gov (United States)

    Shih, P. T.; Huang, C.-M.

    2006-12-01

    Airborne lidar is useful for collecting a large volume and high density of points with three dimensional coordinates. Among these points are terrain points, as well as those points located aboveground. For DEM production, the density of the terrain points is an important quality index. While the penetration rate of laser points is dependent on the surface type characteristics, there are also different ways to present the point density. Namely, the point density could be measured by subdividing the surveyed area into cells, then computing the ratio of the number of points in each respective cell to its area. In this case, there will be one density value for each cell. The other method is to construct the TIN, and count the number of triangles in the cell, divided by the area of the cell. Aside from counting the number of triangles, the area of the largest, or the 95% ranking, triangle, could be used as an index as well. The TIN could also be replaced by Voronoi diagrams (Thiessen Polygon), and a polygon with even density could be derived from human interpretation. The nature of these indices is discussed later in this research paper. Examples of different land cover types: bare earth, built-up, low vegetation, low density forest, and high density forest; are extracted from point clouds collected in 2005 by ITRI under a contract from the Ministry of the Interior. It is found that all these indices are capable of reflecting the differences of the land cover type. However, further investigation is necessary to determine which the most descriptive one is.

  9. Spacecraft Maximum Allowable Concentrations for Airborne Contaminants

    Science.gov (United States)

    James, John T.

    2008-01-01

    The enclosed table lists official spacecraft maximum allowable concentrations (SMACs), which are guideline values set by the NASA/JSC Toxicology Group in cooperation with the National Research Council Committee on Toxicology (NRCCOT). These values should not be used for situations other than human space flight without careful consideration of the criteria used to set each value. The SMACs take into account a number of unique factors such as the effect of space-flight stress on human physiology, the uniform good health of the astronauts, and the absence of pregnant or very young individuals. Documentation of the values is given in a 5 volume series of books entitled "Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants" published by the National Academy Press, Washington, D.C. These books can be viewed electronically at http://books.nap.edu/openbook.php?record_id=9786&page=3. Short-term (1 and 24 hour) SMACs are set to manage accidental releases aboard a spacecraft and permit risk of minor, reversible effects such as mild mucosal irritation. In contrast, the long-term SMACs are set to fully protect healthy crewmembers from adverse effects resulting from continuous exposure to specific air pollutants for up to 1000 days. Crewmembers with allergies or unusual sensitivity to trace pollutants may not be afforded complete protection, even when long-term SMACs are not exceeded. Crewmember exposures involve a mixture of contaminants, each at a specific concentration (C(sub n)). These contaminants could interact to elicit symptoms of toxicity even though individual contaminants do not exceed their respective SMACs. The air quality is considered acceptable when the toxicity index (T(sub grp)) for each toxicological group of compounds is less than 1, where T(sub grp), is calculated as follows: T(sub grp) = C(sub 1)/SMAC(sub 1) + C(sub 2/SMAC(sub 2) + ...+C(sub n)/SMAC(sub n).

  10. Airborne Gravity Data Enhances NGS Experimental Gravimetric Geoid in Alaska

    Science.gov (United States)

    Holmes, S. A.; Childers, V. A.; Li, X.; Roman, D. R.

    2014-12-01

    The U.S. National Geodetic Survey [NGS], through their Gravity for the Redefinition of the American Vertical Datum [GRAV-D] program, continues to update its gravimetry holdings by flying new airborne gravity surveys over a large fraction of the USA and its territories. By 2022, NGS intends that all orthometric heights in the USA will be determined in the field by using a reliable national gravimetric geoid model to transform from geodetic heights obtained from GPS. Several airborne campaigns have already been flown over Alaska and its coastline. Some of this Alaskan coastal data have been incorporated into a new NGS experimental geoid model - xGEOID14. The xGEOID14 model is the first in a series of annual experimental geoid models that will incorporate NGS GRAV-D airborne data. This series provides a useful benchmark for assessing and improving current techniques by which the airborne and land-survey data are filtered and cleaned, and then combined with satellite gravity models, elevation data (etc.) with the ultimate aim of computing a geoid model that can support a national physical height system by 2022. Here we will examine the NGS GRAV-D airborne data in Alaska, and assess its contribution to xGEOID14. Future prospects for xGEOID15 will also be considered.

  11. Detection Range of Airborne Magnetometers in Magnetic Anomaly Detection

    Directory of Open Access Journals (Sweden)

    Chengjing Li

    2015-11-01

    Full Text Available Airborne magnetometers are utilized for the small-range search, precise positioning, and identification of the ferromagnetic properties of underwater targets. As an important performance parameter of sensors, the detection range of airborne magnetometers is commonly set as a fixed value in references regardless of the influences of environment noise, target magnetic properties, and platform features in a classical model to detect airborne magnetic anomalies. As a consequence, deviation in detection ability analysis is observed. In this study, a novel detection range model is proposed on the basis of classic detection range models of airborne magnetometers. In this model, probability distribution is applied, and the magnetic properties of targets and the environment noise properties of a moving submarine are considered. The detection range model is also constructed by considering the distribution of the moving submarine during detection. A cell-averaging greatest-of-constant false alarm rate test method is also used to calculate the detection range of the model at a desired false alarm rate. The detection range model is then used to establish typical submarine search probabilistic models. Results show that the model can be used to evaluate not only the effects of ambient magnetic noise but also the moving and geomagnetic features of the target and airborne detection platform. The model can also be utilized to display the actual operating range of sensor systems.

  12. Glass characterization to assess the airborne sound isolation

    International Nuclear Information System (INIS)

    The main contribution of this paper is the formulation of an alternative to experimental determination of loss factor and, consequently, to improve the predictions of airborne sound insulation for any type of monolithic or laminated glass. In addition, a review of the standards related to measurement of mechanical parameters of glass is carried out, with particular interest in laminated glass Indeed, one of the problems that arise in the current context of building acoustics is to meet the requirements of facades airborne sound insulation of existing Building Technical Code (BTC). It is known that the blind and the hollow part of the facade should be distinguished. The weakest part regarding to airborne sound insulation is the empty one (consisting of glass, woodwork and other elements). Choosing an adequate woodwork makes the glass surface become the limiting factor. The Constructive Elements Catalog (CEC) of the BTC, the UNE-EN 12758:2011 standard, as well as some, increasingly, data vendors provide information about airborne sound insulation for monolithic glass, laminated glass and double glazing. In the case of laminated glass, these data are limited only to those with a single intermediate layer, and also nonacoustic. Can therefore be said that there is a gap of knowledge in this regard. To obtain reliable predictions of airborne sound insulation of multilayer partitions, such as laminated glass, mechanical characteristics must be known, being loss factor one of the most important. (Author) 7 refs.

  13. SURVEY OF AIRBORNE POLLEN IN HUBEI PROVINCE OF CHINA

    Institute of Scientific and Technical Information of China (English)

    Guang-hui Liu; Rong-fei Zhu; Wei Zhang; Wen-jing Li; Zhong-xi Wang; Huan Chen

    2008-01-01

    Objective To study the genera and seasonal distribution of airborne pollen in Hubei province of China,and its relationship with pollinosis.Methods From November 2003 to October 2004,an airborne pollen investigation was performed in 16 chosen areas in 12 cities of Hubei province using gravity sedimentation technique.Meanwhile,univalent skin prick tests of pollens were performed and the invasion season was studied on 2 300 patients with pollinosis.Among them,352 eases underwent the airway responsiveness measurements,and the correlation between airway responsiveness and results of pollen count was analyzed.Results A total of 61 pollen genera were observed and 257 520 pollens were collected.The peak of airborne pollen distribution occurred in two seasons each year:spring (March and April) and autumn (from August to October).The attack of pollinosis corresponded to the peak of pollen distribution.There was a significantly negative relationship between the provocation dose causing a 20% decrease of forced expiratory volume in one second (FEV1) from baseline and airborne pollen concentration (r=-0.6829,P<0.05).Conclusion This study provides useful information for airborne pollen epidemiology of Hubei province,and it provides important insights to clinical prevention,diagnosis,and treatment of pollen-related allergic diseases.

  14. Initial evaluation of airborne water vapour measurements by the IAGOS-GHG CRDS system

    Science.gov (United States)

    Filges, Annette; Gerbig, Christoph; Smit, Herman G. J.; Krämer, Martina; Spelten, Nicole

    2013-04-01

    Accurate and reliable airborne measurements of water vapour are still a challenge. Presently, no airborne humidity sensor exists that covers the entire range of water vapour content between the surface and the upper troposphere/lower stratosphere (UT/LS) region with sufficient accuracy and time resolution. Nevertheless , these data are a pre-requisite to study the underlying processes in the chemistry and physics of the atmosphere. The DENCHAR project (Development and Evaluation of Novel Compact Hygrometer for Airborne Research) addresses this deficit by developing and characterizing novel or improved compact airborne hygrometers for different airborne applications within EUFAR (European Facility for Airborne Research). As part of the DENCHAR inter-comparison campaign in Hohn (Germany), 23 May - 1 June 2011, a commercial gas analyzer (G2401-m, Picarro Inc.,US), based on cavity ring-down spectroscopy (CRDS), was installed on a Learjet to measure water vapour, CO2, CH4 and CO. The CRDS components are identical to those chosen for integration aboard commercial airliner within IAGOS (In-service Aircraft for a Global Observing System). Thus the campaign allowed for the initial assessment validation of the long-term IAGOS H2O measurements by CRDS against reference instruments with a long performance record (FISH, the Fast In-situ Stratospheric Hygrometer, and CR2 frostpoint hygrometer, both research centre Juelich). The inlet system, a one meter long 1/8" FEP-tube connected to a Rosemount TAT housing (model 102BX, deiced) installed on a window plate of the aircraft, was designed to eliminate sampling of larger aerosols, ice particles, and water droplets, and provides about 90% of ram-pressure. In combination with a lowered sample flow of 0.1 slpm (corresponding to a 4 second response time), this ensured a fully controlled sample pressure in the cavity of 140 torr throughout an aircraft altitude operating range up to 12.5 km without the need of an upstream sampling pump

  15. Nanotoxicology: An Emerging Discipline Evolving from Studies of Ultrafine Particles

    OpenAIRE

    Oberdörster, Günter; Oberdörster, Eva; Oberdörster, Jan

    2005-01-01

    Although humans have been exposed to airborne nanosized particles (NSPs; < 100 nm) throughout their evolutionary stages, such exposure has increased dramatically over the last century due to anthropogenic sources. The rapidly developing field of nanotechnology is likely to become yet another source through inhalation, ingestion, skin uptake, and injection of engineered nanomaterials. Information about safety and potential hazards is urgently needed. Results of older bio-kinetic studies with N...

  16. Source Apportionment of Fine Particles in Xinzhen, Beijing

    Institute of Scientific and Technical Information of China (English)

    JIN; Xiang-chun; ZHANG; Gui-ying; XIAO; Cai-jin; WANG; Ping-sheng; WANG; Xing-hua; HUA; Long; YAO; Yong-gang; YUAN; Guo-jun; NI; Bang-fa

    2013-01-01

    As the capital city of China,Beijing often suffers from hazy weather recently.In order to improve air quality,it is of great importance to perform source apportionment and source trajectory.A total of 140airborne particulate matter samples were collected at Xinzhen from May,2007 to July,2013 and their chemical compositions were analyzed by Particle Induced X-ray Emission(PIXE)and Energy Disperse-X

  17. Microcomputer-controlled system for measuring atmospheric particle fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, R.; Murphy, C.E. Jr.

    1985-01-01

    A Hiac/Royco Model 4102 optical airborne particle counter equipped with the Model 1200 sensor was interfaced to an existing data acquisition system. Due to the location of the instruments and data transmission problems, special interfaces and software solutions were required to achieve data transmission and instrument control integrity. System design, instrument operation, and the software and hardware solutions required for operation are described.

  18. Particle physics

    CERN Document Server

    Martin, Brian R

    2017-01-01

    An accessible and carefully structured introduction to Particle Physics, including important coverage of the Higgs Boson and recent progress in neutrino physics. Fourth edition of this successful title in the Manchester Physics series. Includes information on recent key discoveries including : An account of the discovery of exotic hadrons, beyond the simple quark model; Expanded treatments of neutrino physics and CP violation in B-decays; An updated account of ‘physics beyond the standard model’, including the interaction of particle physics with cosmology; Additional problems in all chapters, with solutions to selected problems available on the book’s website; Advanced material appears in optional starred sections.

  19. Reducing airborne pathogens and dust in commercial hatching cabinets with an electrostatic space charge system.

    Science.gov (United States)

    Mitchell, B W; Waltman, W D

    2003-01-01

    Commercial hatcheries typically infuse hydrogen peroxide or formaldehyde gas into hatching cabinets to reduce airborne pathogens that may lead to disease transmission during the hatch. A nonchemical option, an electrostatic space charge system (ESCS), was customized for full-sized commercial hatching cabinets and was tested extensively in broiler hatcheries. The ESCS cleans air by transferring a strong negative electrostatic charge to dust and microorganisms that are aerosolized during the hatch and collecting the charged particles on grounded plates or surfaces. In studies with three poultry companies, the ESCS resulted in significant (P or = 0.05) from those with formaldehyde, and in 93%-96% lower Enterobacteriaceae than with no treatment or with hydrogen peroxide treatment (P hatchery. PMID:12887184

  20. The calibration of portable and airborne gamma-ray spectrometers - theory, problems, and facilities

    International Nuclear Information System (INIS)

    A gamma-ray spectrometer for use in geological exploration possesses four stripping ratios and three window sensitivities which must be determined to make the instrumentation applicable for field assay or airborne measurement of potassium, uranium, and thorium contents in the ground. Survey organizations in many parts of the world perform the instrument calibration using large pads of concrete which simulate a plane ground of known radioelement concentration. Calibration and monitoring trials with twelve facilities in ten countries prove that moisture absorption, radon exhalation, and particle-size effects can offset a radiometric grade assigned to concrete whose aggregate contains an embedded radioactive mineral. These and other calibration problems are discussed from a combined theoretical and practical viewpoint. (author)

  1. Characterization of airborne particulate matter in the metropolitan region of Belo Horizonte

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Fernanda V.F.; Ardisson, Jose Domingos; Rodrigues, Paulo Cesar H.; Brito, Walter de; Macedo, Waldemar Augusto A.; Jacomino, Vanusa Maria F., E-mail: ferufv@yahoo.com.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    In this work soil samples, iron ore and airborne atmospheric particulate matter (PM) in the Metropolitan Region of Belo Horizonte (MRBH), State of Minas Gerais, Brazil, are investigated with the aim of identifying if the sources of the particulate matter are of natural origin, such as, resuspension of particles from soil, or due to anthropogenic origins from mining and processing of iron ore. Samples were characterized by powder X-ray diffraction, X-ray fluorescence and {sup 57}Fe-Moessbauer spectroscopy. The results showed that soil samples studied are rich in quartz and have low contents of iron mainly iron oxide with low crystallinity. The samples of iron ore and PM have high concentration of iron, predominantly well crystallized hematite. {sup 57}Fe-Moessbauer spectroscopy confirmed the presence of similar iron oxides in samples of PM and in the samples of iron ore, indicating the anthropogenic origin in the material present in atmosphere of the study area. (author)

  2. Trace element determination in the airborne particulate matter of Bangkok and Samutprakan by INAA

    International Nuclear Information System (INIS)

    During October 1995 - January 1996, 66 samples of airborne particulate matter were collected from Bangkok and Samutprakan provinces. Samples of the particle sizes of 2.5 - 10 microns (33 samples) and less than 2.5 microns (33 samples) were determined for elemental concentration of 34 elements. A comparative study of the data from both sampling size was initiated to investigate the trends, source and origin of the aerosols by comparing the concentration, enrichment factor (E F) and coarse/ fine ratio. The results show Al, Fe, Sc are from crustal elements, Ca, K, Mn, V has moderate high E F and As, Br, Cd, Cu, Ni, Sb, Se and Zn has rather high E F. Comparison between the two sites yields higher levels of As and Sb at Samutprakan appearly due to smelting or other industries nearby. Higher level of Br might be due to the heavier of transportation of trucks in and out of the city

  3. First Study Of HEPA Filter Prototype Performance To Control The Airborne Pollution

    International Nuclear Information System (INIS)

    This paper will report the efficiency test result of the filtration tool prototype of High Efficiency Particulate Air (HEPA filter) for low temperature, to control the airborne pollution of aerosol particle of solid and liquid. The prototype design of HEPA filter was based on the characteristic data of filter material (fibrous diameter, density, filter thickness), flow rate of air and first pressure drop. From the result of laboratory scale test, using DOP/PSL aerosol with 0,3 mum diameter and the flow rate of 3,78 m exp.3/min, was obtained filtration efficiency revolve between 89,90 and 99,94 % for the filter prototype of A, B, C, and D. the efficiency estimation of theory with filtration programme and the experiment was different amount 1 %. The value of the prototype efficiency of D filter was not far different with AAF-USA filter and its price is cheaper 30 % than the price of AAF-USA filter

  4. Design and construct optimum dosimeter to detect airborne radon and thoron gas: Experimental study

    Science.gov (United States)

    Ismail, Asaad H.; Jaafar, Mohamad S.

    2011-02-01

    Aim of this work is to design and select optimum dimension of a radon and thoron dosimeter within the measure optimum value of the calibration factor, using CR-39 Nuclear Track Detectors (NTDs). The results show that the best dimension to detect and measure real values of airborne radon and thoron concentrations is 6 cm and 7 cm for diameter and height, respectively. Calibration factors (K) for radon and thoron at this dimension were 2.68 ± 0.03 cm and 0.83 ± 0.01 cm, respectively, and these factors relatively depend on the detector efficiency. Therefore, the efficiency of CR-39NTDs to register alpha particles and their effects on the calibration factor estimated. It is found that the calibration factor increased exponentially with detector efficiency. Moreover, detector efficiency was equal to 80.3 ± 1.23% at the optimum dosimeter.

  5. Multi-Target Detection from Full-Waveform Airborne Laser Scanner Using Phd Filter

    Science.gov (United States)

    Fuse, T.; Hiramatsu, D.; Nakanishi, W.

    2016-06-01

    We propose a new technique to detect multiple targets from full-waveform airborne laser scanner. We introduce probability hypothesis density (PHD) filter, a type of Bayesian filtering, by which we can estimate the number of targets and their positions simultaneously. PHD filter overcomes some limitations of conventional Gaussian decomposition method; PHD filter doesn't require a priori knowledge on the number of targets, assumption of parametric form of the intensity distribution. In addition, it can take a similarity between successive irradiations into account by modelling relative positions of the same targets spatially. Firstly we explain PHD filter and particle filter implementation to it. Secondly we formulate the multi-target detection problem on PHD filter by modelling components and parameters within it. At last we conducted the experiment on real data of forest and vegetation, and confirmed its ability and accuracy.

  6. Data fusion techniques for object space classification using airborne laser data and airborne digital photographs

    Science.gov (United States)

    Park, Joong Yong

    The objective of this research is to investigate possible strategies for the fusion of airborne laser data with passive optical data for object space classification. A significant contribution of our work is the development and implementation of a data-level fusion technique, direct digital image georeferencing (DDIG). In DDIG, we use navigation data from an integrated system (composed of global positioning system (GPS) and inertial measurement unit (IMU)) to project three-dimensional data points measured with the University of Florida's airborne laser swath mapping (ALSM) system onto digital aerial photographs. As an underlying math model, we use the familiar collinearity condition equations. After matching the ALSM object space points to their corresponding image space pixels, we resample the digital photographs using cubic convolution techniques. We call the resulting images pseudo-ortho-rectified images (PORI) because they are orthographic at the ground surface but still exhibit some relief displacement for elevated objects; and because they have been resampled using a interpolation technique. Our accuracy tests on these PORI images show that they are planimetrically correct to about 0.4 meters. This accuracy is sufficient to remove most of the effects of the central perspective projection and enable a meaningful fusion of the RGB data with the height and intensity data produced by the laser. PORI images may also be sufficiently accurate for many other mapping applications, and may in some applications be an attractive alternative to traditional photogrammetric techniques. A second contribution of our research is the development of several strategies for the fusion of data from airborne laser and camera systems. We have conducted our work within the sensor fusion paradigm formalized in the optical engineering community. Our work explores the fusion of these two types of data for precision mapping applications. Specifically, we combine three different types of

  7. Airborne peptidoglycans as a supporting indicator of bacterial contamination in a metal processing plant

    Directory of Open Access Journals (Sweden)

    Marcin Cyprowski

    2016-06-01

    Full Text Available Objectives: The aim of this study was to assess exposure to airborne endotoxins and peptidoglycans (PGs as well as possibility of using PGs as a surrogate measure of bacterial exposure in workplaces in a metal processing plant. Material and Methods: Personal dosimetry (N = 11 was used to obtain data on concentrations of viable bacteria, total number of bioaerosol particles, endotoxins and peptidoglycans. To investigate the size distributions of aerosol particles responsible for transport of endotoxins and PGs, air samples (N = 5 were additionally collected using the 8-stage cascade impactor. Endotoxins and PGs were assayed with the Limulus amebocyte lysate (LAL test and a kinetic version of the silkworm larvae plasma (SLP test, respectively. Results: Median concentrations of airborne PGs (14.6 ng/m3, endotoxins (0.2 ng/m3, viable bacteria (1.16×103 CFU/m3 and the total number of bioaerosol particles (1.81×106 cells/m3 were determined. Qualitative analysis revealed presence of 19 bacterial species belonging to 14 genera. The calculations showed strong, significant correlations (p < 0.05 between endotoxins, viable bacteria (r = 0.75 and the total number of bioaerosol particle concentrations (r = 0.76 as well as between PGs and the total number of bioaerosol particle concentrations (r = 0.72. Size distribution analysis showed that the highest concentrations of bacterial aerosols occurred in the range of 2.1–3.3 μm. In the case of endotoxins, an increase of concentrations in 2 ranges of aerodynamic diameters: 1.1–3.3 μm and 5.8–9 μm was shown. For PGs there was a visible gradual increase of their concentrations in the range 2.1–9 μm. Conclusions: Peptidoglycans can be treated as a supporting indicator of bacterial contamination in metal processing plants, particularly when an assessment of an immunotoxic potential of microbiological hazards needs to be performed. However, to be extrapolated to other occupational and non

  8. An investigation of cirrus cloud properties using airborne lidar

    Science.gov (United States)

    Yorks, John Edward

    The impact of cirrus clouds on the Earth's radiation budget remains a key uncertainty in assessing global radiative balance and climate change. Composed of ice, and located in the cold upper troposphere, cirrus clouds can cause large warming effects because they are relatively transmissive to short-wave solar radiation, but absorptive of long wave radiation. Our ability to model radiative effects of cirrus clouds is inhibited by uncertainties in cloud optical properties. Studies of mid-latitude cirrus properties have revealed notable differences compared to tropical anvil cirrus, likely a consequence of varying dynamic formation mechanisms. Cloud-aerosol lidars provide critical information about the vertical structure of cirrus for climate studies. For this dissertation, I helped develop the Airborne Cloud-Aerosol Transport System (ACATS), a Doppler wind lidar system at NASA Goddard Space Flight Center (GSFC). ACATS is also a high spectral resolution lidar (HSRL), uniquely capable of directly resolving backscatter and extinction properties of a particle from high-altitude aircraft. The first ACATS science flights were conducted out of Wallops Island, VA in September of 2012 and included coincident measurements with the Cloud Physics Lidar (CPL) instrument. In this dissertation, I provide an overview of the ACATS method and instrument design, describe the ACATS retrieval algorithms for cloud and aerosol properties, explain the ACATS HSRL retrieval errors due to the instrument calibration, and use the coincident CPL data to validate and evaluate ACATS cloud and aerosol retrievals. Both the ACATS HSRL and standard backscatter retrievals agree well with coincident CPL retrievals. Mean ACATS and CPL extinction profiles for three case studies demonstrate similar structure and agree to within 25 percent for cirrus clouds. The new HSRL retrieval algorithms developed for ACATS have direct application to future spaceborne missions. Furthermore, extinction and particle wind

  9. Mutagenicity and antimutigenicity studies of air borne particles from Guangzhou

    Energy Technology Data Exchange (ETDEWEB)

    Liming Qian; Ying He; Jieming Chen [Guangzhou Normal Univ. (China)] [and others

    1997-10-01

    Guangzhou is a city of 6 million in south China. In the past decade, air pollution in Guangzhou become serious. The incidence of lung cancer increased, showing a significant correlation with the air pollution. The authors performed a series of studies of airborne particles from Guangzhou. We studied the mutagenicity of the airborne particles from the city, analysed the correlations between the mutagenicity of the organic extracts of air pollutants and meteorological condition and compared the antimutagenic effects of TP (tea polyphenols) and CHL (chlorophyllin) towards the extracts. The above studies are summarized as following: (1) the extracts of airborne particles showed very strong mutagenicity in E. Coli PQ37 and Salmonella typhimurium TA98, without S9 mix; (2) the mutagenicity of the extracts was correlated to the meteorological conditions; (3) the analysis of the effects of meteorological conditions on the mutagenicity resulted in different conclusions if different meteorological data (sampling time and periods) were used. It might be an explanation for those surprising different conclusions of the related studies appeared last few years. (4) there were no significant effect of pH (3.5-7.0) and temperature (100-200{degrees}C) on the antimutigenicity of TP and CHL, showing no deteriorate effects of the conditions of common use of the 2 antimutagens.

  10. Particle Physics

    CERN Multimedia

    2005-01-01

    While biomedicine and geoscience use grids to bring together many different sub-disciplines, particle physicists use grid computing to increase computing power and storage resources, and to access and analyze vast amounts of data collected from detectors at the world's most powerful accelerators (1 page)

  11. Airborne lidar detection of subsurface oceanic scattering layers

    Science.gov (United States)

    Hoge, Frank E.; Wright, C. Wayne; Krabill, William B.; Buntzen, Rodney R.; Gilbert, Gary D.

    1988-01-01

    The airborne lidar detection and cross-sectional mapping of submerged oceanic scattering layers are reported. The field experiment was conducted in the Atlantic Ocean southeast of Assateague Island, VA. NASA's Airborne Oceanographic Lidar was operated in the bathymetric mode to acquire on-wavelength 532-nm depth-resolved backscatter signals from shelf/slope waters. Unwanted laser pulse reflection from the air-water interface was minimized by spatial filtering and off-nadir operation. The presence of thermal stratification over the shelf was verified by the deployment of airborne expendable bathythermographs. Optical beam transmission measurements acquired from a surface truthing vessel indicated the presence of a layer of turbid water near the sea floor over the inner portion of the shelf.

  12. Polar gravity fields from GOCE and airborne gravity

    DEFF Research Database (Denmark)

    Forsberg, René; Olesen, Arne Vestergaard; Yidiz, Hasan;

    2011-01-01

    Airborne gravity, together with high-quality surface data and ocean satellite altimetric gravity, may supplement GOCE to make consistent, accurate high resolution global gravity field models. In the polar regions, the special challenge of the GOCE polar gap make the error characteristics...... of combination models especially sensitive to the correct merging of satellite and surface data. We outline comparisons of GOCE to recent airborne gravity surveys in both the Arctic and the Antarctic. The comparison is done to new 8-month GOCE solutions, as well as to a collocation prediction from GOCE gradients...... in Antarctica. It is shown how the enhanced gravity field solutions improve the determination of ocean dynamic topography in both the Arctic and in across the Drake Passage. For the interior of Antarctica, major airborne gravity programs are currently being carried out, and there is an urgent need...

  13. Problems of radome design for modern airborne radar

    Science.gov (United States)

    Rulf, B.

    1985-01-01

    The operation of airborne radar involves a discrimination between targets and ground clutter. A solution of the resulting problems requires the design of antennas with special characteristics. Efforts of the antenna designer, however, will be defeated if the antenna is protected by a radome which fails to provide the same high performance as the antenna. The present investigation is concerned with problems arising in the design of high-performance radomes, taking into account two important airborne radar systems. The first example involves the E-3A (AWACS), the most modern airborne surveillance radar system now in operation. The second example is related to a typical fire-control radar in a modern tactical aircraft.

  14. Measuring canopy structure with an airborne laser altimeter

    International Nuclear Information System (INIS)

    Quantification of vegetation patterns and properties is needed to determine their role on the landscape and to develop management plans to conserve our natural resources. Quantifying vegetation patterns from the ground, or by using aerial photography or satellite imagery is difficult, time consuming, and often expensive. Digital data from an airborne laser altimeter offer an alternative method to quantify selected vegetation properties and patterns of forest and range vegetation. Airborne laser data found canopy heights varied from 2 to 6 m within even-aged pine forests. Maximum canopy heights measured with the laser altimeter were significantly correlated to measurements made with ground-based methods. Canopy shape could be used to distinguish deciduous and evergreen trees. In rangeland areas, vegetation heights, spatial patterns, and canopy cover measured with the laser altimeter were significantly related with field measurements. These studies demonstrate the potential of airborne laser data to measure canopy structure and properties for large areas quickly and quantitatively

  15. Airborne bacteria in the atmosphere: Presence, purpose, and potential

    Science.gov (United States)

    Smets, Wenke; Moretti, Serena; Denys, Siegfried; Lebeer, Sarah

    2016-08-01

    Numerous recent studies have highlighted that the types of bacteria present in the atmosphere often show predictable patterns across space and time. These patterns can be driven by differences in bacterial sources of the atmosphere and a wide range of environmental factors, including UV intensity, precipitation events, and humidity. The abundance of certain bacterial taxa is of interest, not only for their ability to mediate a range of chemical and physical processes in the atmosphere, such as cloud formation and ice nucleation, but also for their implications -both beneficial and detrimental-for human health. Consequently, the widespread importance of airborne bacteria has stimulated the search for their applicability. Improving air quality, modelling the dispersal of airborne bacteria (e.g. pathogens) and biotechnological purposes are already being explored. Nevertheless, many technological challenges still need to be overcome to fully understand the roles of airborne bacteria in our health and global ecosystems.

  16. The airborne survey of natural gamma radiation level in China

    Energy Technology Data Exchange (ETDEWEB)

    Mingkao, Hu; Renkang, Gu; Jiangqi, Fang; Chongtao, Qiu [Airborne Survey and Remote Sensing Center of Nuclear Industry, Shijiazhuang (China)

    2002-07-01

    Airborne survey of natural gamma radiation level is a fast and effective method for evaluating environment radiation. This paper introduces some results about the investigation of gamma radiation level using airborne gamma ray spectrometer and associated NaI(Tl) crystal detector system by Airborne Survey and Remote Sensing Center of Nuclear Industry. The results of the natural radiation level in the regions surrounding Qinshan Nuclear Power Plant and Shanghai City were showed and analyzed emphatically. Air absorbed dose rate belongs to normal to low. The average is 52.6 nGy/h in Qinshan and 52.2 nGy/h in Shanghai. Among, the maximum is up to 72.5 nGy/h in the mountain forest, the second is approximately 68.4 nGy/h in town, 50{approx}60 nGy/h in cropland, and 25 nGy/h in beach.

  17. Analysis of the origin and composition of airborne particulate pollution

    International Nuclear Information System (INIS)

    Methods were developed for determination of airborne particulate pollution sources and origins from airborne particulate measurements, analyses of particulate constituents and routine meteorological measurements. The results obtained provide the basis for quantification of the long- and short-time impacts of these pollution sources on immission. The methods were tested in a densely populated urban area (West Berlin) and in a rural district (Waldhof, District of Uelzen) by collecting airborne particulates (fine and coarse particulates) at six measuring points by use of dichotomous collectors and high-volume collectors. The measurements were taken twice a day from November 1989 to November 1990. Analyses were made of the compounds and of the constituents Al, Fe, Si, Ca, Mg, K, Na, As, Cd, Cu, Ni, Sb, Se, V, Zn, Cl-, NO-3, SO2-4, NH+4, organic carbons (OC) and inorganic elementary (EC) carbons. (orig.). 104 refs., 66 tabs., 79 figs

  18. Risk factors for injuries during airborne static line operations.

    Science.gov (United States)

    Knapik, Joseph J; Steelman, Ryan

    2014-01-01

    US Army airborne operations began in World War II. Continuous improvements in parachute technology, aircraft exit procedures, and ground landing techniques have reduced the number of injuries over time from 27 per 1,000 descents to about 6 per 1,000 jumps. Studies have identified a number of factors that put parachutists at higher injury risk, including high wind speeds, night jumps, combat loads, higher temperatures, lower fitness, heavier body weight, and older age. Airborne injuries can be reduced by limiting risker training (higher wind speeds, night jumps, combat load) to the minimum necessary for tactical and operational proficiency. Wearing a parachute ankle brace (PAB) will reduce ankle injuries without increasing other injuries and should be considered by all parachutists, especially those with prior ankle problems. A high level of upper body muscular endurance and aerobic fitness is not only beneficial for general health but also associated with lower injury risk during airborne training.

  19. Contribution to the study of particle resuspension kinetics during thermal degradation of polymers

    Energy Technology Data Exchange (ETDEWEB)

    Ouf, F.-X., E-mail: francois-xavier.ouf@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire, Laboratoire de Physique et de Métrologie des Aérosols, B.P. 68, 91192 Gif-Sur-Yvette Cedex (France); Delcour, S. [Institut de Radioprotection et de Sûreté Nucléaire, Laboratoire de Physique et de Métrologie des Aérosols, B.P. 68, 91192 Gif-Sur-Yvette Cedex (France); Ecole des Mines d’Alès, Centre des Matériaux (CMGD)-Pôle Matériaux Polymères Avancés, 6 Avenue de Clavières, 30319 Alès Cedex (France); Azema, N. [Ecole des Mines d’Alès, Centre des Matériaux (CMGD)-Pôle Matériaux Polymères Avancés, 6 Avenue de Clavières, 30319 Alès Cedex (France); Coppalle, A. [CNRS UMR 6614-CORIA, Université et INSA de Rouen, 76801, BP-12, Sant Etienne du Rouvray (France); and others

    2013-04-15

    Highlights: ► We experiment the airborne release of particles during thermal degradation of polymers. ► A “peak of release” was identified during the first instances of thermal stress of Plexiglas. ► The duration of the peak of release was linked to the heat flux applied to the Plexiglas. ► Heat flux has a low influence on the airborne release fraction (ARF). ► The influence of the diameter of particles on the ARF depends on polymer. -- Abstract: Experimental results are reported on the resuspension of particles deposited on polymer samples representative of glove boxes used in the nuclear industry, under thermal degradation. A parametric study was carried out on the effects of heat flux, air flow rate, fuel type and particle size distribution. Small-scale experiments were conducted on 10 cm × 10 cm PolyMethyl MethAcrylate (PMMA) and PolyCarbonate (PC) samples covered with aluminium oxide particles with physical geometric diameters of 0.7 and 3.6 μm. It was observed for both polymer (fuel) samples that heat flux has no effect on the airborne release fraction (ARF), whereas particle size is a significant parameter. In the case of the PMMA sample, ARF values for 0.7 and 3.6 μm diameter particles range from 12.2% (±6.2%) to 2.1% (±0.6%), respectively, whereas the respective values for the PC sample range from 3.2% (±0.8%) to 6.9% (±3.9%). As the particle diameter increases, a significant decrease in particle release is observed for the PMMA sample, whereas an increase is observed for the PC sample. Furthermore, a peak airborne release rate is observed during the first instants of PMMA exposure to thermal stress. An empirical relationship has been proposed between the duration of this peak release and the external heat flux.

  20. Airborne Synthetic Aperature Radar (AIRSAR) on left rear fuselage of DC-8 Airborne Laboratory

    Science.gov (United States)

    1998-01-01

    A view of the Airborne Synthetic Aperature Radar (AIRSAR) antenna on the left rear fuselage of the DC-8. The AIRSAR captures images of the ground from the side of the aircraft and can provide precision digital elevation mapping capabilities for a variety of studies. The AIRSAR is one of a number of research systems that have been added to the DC-8. NASA is using a DC-8 aircraft as a flying science laboratory. The platform aircraft, based at NASA's Dryden Flight Research Center, Edwards, Calif., collects data for many experiments in support of scientific projects serving the world scientific community. Included in this community are NASA, federal, state, academic and foreign investigators. Data gathered by the DC-8 at flight altitude and by remote sensing have been used for scientific studies in archeology, ecology, geography, hydrology, meteorology, oceanography, volcanology, atmospheric chemistry, soil science and biology.

  1. Shiftable Leading Point Method for High Accuracy Registration of Airborne and Terrestrial LiDAR Data

    OpenAIRE

    Liang Cheng; Lihua Tong; Yang Wu; Yanming Chen; Manchun Li

    2015-01-01

    A new automated approach to the high-accuracy registration of airborne and terrestrial LiDAR data is proposed, which has three primary steps. Firstly, airborne and terrestrial LiDAR data are used to extract building corners, known as airborne corners and terrestrial corners, respectively. Secondly, an initial matching relationship between the terrestrial corners and airborne corners is automatically derived using a matching technique based on maximum matching corner pairs with minimum errors ...

  2. Quantitative DNA Analyses for Airborne Birch Pollen.

    Directory of Open Access Journals (Sweden)

    Isabell Müller-Germann

    Full Text Available Birch trees produce large amounts of highly allergenic pollen grains that are distributed by wind and impact human health by causing seasonal hay fever, pollen-related asthma, and other allergic diseases. Traditionally, pollen forecasts are based on conventional microscopic counting techniques that are labor-intensive and limited in the reliable identification of species. Molecular biological techniques provide an alternative approach that is less labor-intensive and enables identification of any species by its genetic fingerprint. A particularly promising method is quantitative Real-Time polymerase chain reaction (qPCR, which can be used to determine the number of DNA copies and thus pollen grains in air filter samples. During the birch pollination season in 2010 in Mainz, Germany, we collected air filter samples of fine (<3 μm and coarse air particulate matter. These were analyzed by qPCR using two different primer pairs: one for a single-copy gene (BP8 and the other for a multi-copy gene (ITS. The BP8 gene was better suitable for reliable qPCR results, and the qPCR results obtained for coarse particulate matter were well correlated with the birch pollen forecasting results of the regional air quality model COSMO-ART. As expected due to the size of birch pollen grains (~23 μm, the concentration of DNA in fine particulate matter was lower than in the coarse particle fraction. For the ITS region the factor was 64, while for the single-copy gene BP8 only 51. The possible presence of so-called sub-pollen particles in the fine particle fraction is, however, interesting even in low concentrations. These particles are known to be highly allergenic, reach deep into airways and cause often severe health problems. In conclusion, the results of this exploratory study open up the possibility of predicting and quantifying the pollen concentration in the atmosphere more precisely in the future.

  3. Innovativ Airborne Sensors for Disaster Management

    Science.gov (United States)

    Altan, M. O.; Kemper, G.

    2016-06-01

    Disaster management by analyzing changes in the DSM before and after the "event". Advantage of Lidar is that beside rain and clouds, no other weather conditions limit their use. As an active sensor, missions in the nighttime are possible. The new mid-format cameras that make use CMOS sensors (e.g. Phase One IXU1000) can capture data also under poor and difficult light conditions and might will be the first choice for remotely sensed data acquisition in aircrafts and UAVs. UAVs will surely be more and more part of the disaster management on the detailed level. Today equipped with video live cams using RGB and Thermal IR, they assist in looking inside buildings and behind. Thus, they can continue with the aerial survey where airborne anomalies have been detected.

  4. Manual of respiratory protection against airborne radioactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Caplin, J.L.; Held, B.J.; Catlin, R.J.

    1976-10-01

    The manual supplements Regulatory Guide 8.15, ''Acceptable Programs for Respiratory Protection''. It provides broad guidance for the planned use of respirators to protect individuals from airborne radioactive materials that might be encountered during certain operations. The guidance is intended for use by management in establishing and supervising programs and by operating personnel in implementing programs. Guidance is primarily directed to the use of respirators to prevent the inhalation of airborne radioactive materials. Protection against other modes of intake (e.g., absorption, swallowing, wound injection) is, in general, not covered nor is the use of protective equipment for head, eye, or skin protection.

  5. Airborne bathymetric charting using pulsed blue-green lasers

    Science.gov (United States)

    Kim, H. H.

    1977-01-01

    Laboratory and airborne experiments have proven the feasibility and demonstrated the techniques of an airborne pulsed laser system for rapidly mapping coastal water bathymetry. Water depths of 10 plus or minus 0.25 m were recorded in waters having an effective attenuation coefficient of 0.175 m. A 2-MW peak power Nd:YAG pulsed laser was flown at an altitude of 600 m. An advanced system, incorporating a mirror scanner, a high pulsed rate laser, and a good signal processor, could survey coastal zones at the rate of several square miles per hour.

  6. An airborne microwave radiometer and measurements of cloud liquid water

    Institute of Scientific and Technical Information of China (English)

    LEI Hengchi; JIN Dezhen; WEI Chong; SHEN Zhilai

    2003-01-01

    A single-channel (9.5 mm) airborne microwave radiometer with one antenna is developed. The retrieval methods and primary observation results of cloud liquid water and super-cooled cloud liquid water are discussed. The aircraft experiments show that the cloud liquid water and super-cooled liquid water can be sensitively monitored at some level of accuracy by the radiometer. The results of cloud liquid water content are reasonable and correspond well with the surface radar echo intensity. The design of the airborne radiometer and its retrieval methods are feasible, giving it application value.

  7. Issues relating to airborne applications of HTS SQUIDs

    CERN Document Server

    Foley, C P; Binks, R A; Lam, S H K; Du, J; Tilbrook, D L; Mitchell, E E; MacFarlane, J C; Lee, J B; Turner, R; Downey, M; Maddever, A

    2002-01-01

    Airborne application of HTS SQUIDs is the most difficult environment for their successful deployment. In order to operate with the sensitivity required for a particular application, there are many issues to be addressed such as the need for very wide dynamic range electronics, motion noise elimination, immunity to large changing magnetic fields and cultural noise sources. This paper reviews what is necessary to achieve an airborne system giving examples in geophysical mineral exploration. It will consider issues relating to device design and fabrication, electronics, dewar design, suspension system requirements and noise elimination methods.

  8. Airborne campaigns for CryoSat prelaunch calibration and validation

    DEFF Research Database (Denmark)

    Skourup, Henriette; Hanson, Susanne; Hvidegaard, Sine Munk;

    2011-01-01

    After the successful launch of CryoSat-2 in April 2010, the first direct validation campaign of the satellite is planned for spring 2011. DTU Space has been involved in ESA’s CryoSat Validation Experiment (CryoVEx) with airborne activities since 2003. To validate the prelaunch performance...... of the CryoSat radar altimeter (SIRAL), an airborne version of the SIRAL altimeter (ASIRAS) has been flown together with a laser scanner in 2006 and 2008. Of particular interest is to study the penetration depth of the radar altimeter over both land- and sea ice. This can be done by comparing the radar...

  9. EUFAR training opportunities to advance European airborne research

    Science.gov (United States)

    Reusen, I.; Brenguier, J.-L.; Brown, P.; Wendish, M.

    2009-04-01

    EUFAR, EUropean Facilities for Airborne Research, is an FP7 project (http://www.eufar.net) funded by the European Commission with 33 partners that aims at providing and improving the access to European airborne facilities (i.e. aircraft, airborne instruments, data processing centres) for researchers in environmental and geo-sciences through Networking Activities, Transnational Access and Joint Research Activities. This paper reports on the training opportunities within EUFAR for European researchers. In EUFAR three types of training opportunities are offered: 1) Participate in training courses (ET-TC) 2) Join an existing field campaign (ET-EC) 3) Participate in the design of a new field campaign (ET-TA), in the frame of EUFAR Transnational Access and tutored by more experienced researchers. During the 4-year EUFAR project (2008-2012), 4 training courses covering the complete chain from acquisition to interpretation of airborne data and images will be organised during spring/summer for early-stage researchers as well as university lecturers (new in FP7 EUFAR) in airborne research. The training courses will have an equal focus on theory and practical training/demonstration and each training course will be accompanied by a "student" airborne field campaign. Participants will be trained by top-class scientists, aircraft and/or instrument operators and each participant will get the opportunity to design his/her own experiment and to participate to that flight experiment. Furthermore, researchers have the opportunity to join an existing field campaign and work with more experienced researchers, aircraft and/or instrument operators. The list of airborne field campaigns open to join and the eligibility criteria, can be consulted at the EUFAR website. Finally, researchers have the opportunity to participate in the design of a new field campaign in the frame of EUFAR Transnational Access (TA). TA provides access to either aircraft or instrumentation that are not otherwise

  10. Parametric estimation of time varying baselines in airborne interferometric SAR

    DEFF Research Database (Denmark)

    Mohr, Johan Jacob; Madsen, Søren Nørvang

    1996-01-01

    A method for estimation of time varying spatial baselines in airborne interferometric synthetic aperture radar (SAR) is described. The range and azimuth distortions between two images acquired with a non-linear baseline are derived. A parametric model of the baseline is then, in a least square...... sense, estimated from image shifts obtained by cross correlation of numerous small patches throughout the image. The method has been applied to airborne EMISAR imagery from the 1995 campaign over the Storstrommen Glacier in North East Greenland conducted by the Danish Center for Remote Sensing. This has...

  11. Airborne spread of foot-and-mouth disease - Model intercomparison

    DEFF Research Database (Denmark)

    Gloster, John; Jones, Andrew; Redington, Alison;

    2010-01-01

    Foot-and-mouth disease virus (FMDV) spreads by direct contact between animals, by animal products (milk, meat and semen), by mechanical transfer on people or fomites and by the airborne route, with the relative importance of each mechanism depending on the particular outbreak characteristics....... Atmospheric dispersion models have been developed to assess airborne spread of FMDV in a number of countries, including the UK, Denmark, Australia, New Zealand, USA and Canada. These models were compared at a Workshop hosted by the Institute for Animal Health/Met Office in 2008. Each modeller was provided...

  12. Airborne pollution. Compendium of studies presenting analysis and data

    International Nuclear Information System (INIS)

    Problems of emission and transport of radioactive matter into the atmosphere and the subsequent exposure pathways are dealt with in the survey. The description of emissions is based on both measured and theoretically elaborated parameters, the latter being applicable only to nuclides such as noble gases. The diffusion of airborne substances is dealt with in terms of the most common Gauss distribution models, taking into consideration local effects. Questions on exposure pathways of the airborne pollution are examined. The dose rate factors required for the calculation of submersion for all nuclides in question, considering the shielding effects of differently thick skin and superposition of tissue are discussed. (DG)

  13. Airborne brake wear debris: size distributions, composition, and a comparison of dynamometer and vehicle tests.

    Science.gov (United States)

    Sanders, Paul G; Xu, Ning; Dalka, Tom M; Maricq, M Matti

    2003-09-15

    Particle size distributions of light-duty vehicle brake wear debris are reported with careful attention paid to avoid sampling biases. Electrical low-pressure impactor and micro-orifice uniform deposit impactor measurements yield consistent size distributions, and the net particulate matter mass from each method is in good agreement with gravimetric filter measurements. The mass mean diameter of wear debris from braking events representative of urban driving is 6 microm, and the number-weighted mean is 1-2 microm for three currently used classes of lining materials: low metallic, semimetallic, and non-asbestos organic (NAO). In contrast, the wear rates are very material dependent, both in number and mass of particles, with 3-4 times higher emissions observed from the low metallic linings as compared to the semimetallic and NAO linings. Wind tunnel and test track measurements demonstrate the appearance of micron size particles that correlate with braking events, with approximately 50% of the wear debris being airborne for the test vehicle in this study. Elemental analysis of the wear debris reveals a consistent presence of the elements Fe, Cu, and Ba in both dynamometer and test track samples. PMID:14524436

  14. The physical and chemical evolution of aerosols in smelter and power plant plumes: an airborne study

    Energy Technology Data Exchange (ETDEWEB)

    Banic, C.; Leaitch, W.R.; Strawbridge, K.; Tanabe, R.; Wong, H.; Gariepy, C.; Simonetti, A.; Nejedly, Z.; Campbell, J.L.; Lu, J.; Skeaff, J.; Paktunc, D.; MacPherson, J.I.; Daggupaty, S.; Geonac' h, H.; Chatt, A.; Lamoureux, M. [Environmental Canada, Toronto, ON (Canada)

    2006-06-15

    National and international concern about the health effects and continued use of Pb, Cd, As and Hg as well as other metals has defined a need for improved estimates of the long-term risks to ecosystems and human health from metals released from mining, metallurgical and energy production activities. A research aircraft was used to determine the microphysical and chemical properties of airborne particulate metal emissions from the Nanticoke coal-fired power-generating station located on the north shore of Lake Erie, Ontario, and the Horne copper smelter at Rouyn-Noranda, Quebec. These properties are critical to the determination of the deposition rates of the metals emitted, and hence the potential for these species to have impacts on local or distant ecosystems. An overview of the measurements made during the study is given. The size distributions of particles emitted from the stacks and observed within 5 km of the point of emission are briefly described. After dilution by ambient air, the concentration of particles smaller than 0.135 {mu}m in diameter in the plumes is tens of thousands per cubic centimetre, far exceeding the concentrations found in ambient air. However, in the size range 0.135 to 3 {mu}m diameter the plumes generally contribute about one to four times more particles than present in ambient air.

  15. Particle physics

    CERN Document Server

    Kennedy, Eugene

    2012-01-01

    Stimulated by the Large Hadron Collider and the search for the elusive Higgs Boson, interest in particle physics continues at a high level among scientists and the general public. This book includes theoretical aspects, with chapters outlining the generation model and a charged Higgs boson model as alternative scenarios to the Standard Model. An introduction is provided to postulated axion photon interactions and associated photon dispersion in magnetized media. The complexity of particle physics research requiring the synergistic combination of theory, hardware and computation is described in terms of the e-science paradigm. The book concludes with a chapter tackling potential radiation hazards associated with extremely weakly interacting neutrinos if produced in copious amounts with future high-energy muon-collider facilities.

  16. Environmental releases from fuel cycle facility: part 1: radionuclide resuspension vs. stack releases on ambient airborne uranium and thorium levels.

    Science.gov (United States)

    Masson, Olivier; Pourcelot, Laurent; Boulet, Béatrice; Cagnat, Xavier; Videau, Gérard

    2015-03-01

    Airborne activity levels of uranium and thorium series were measured in the vicinity (1.1 km) of a uranium (UF4) processing plant, located in Malvési, south of France. Regarding its impact on the environment, this facility is characterized by its routine atmospheric releases of uranium and by the emission of radionuclide-labelled particles from a storage pond filled with waste water or that contain dried sludge characterized by traces of plutonium and thorium ((230)Th). This study was performed during a whole year (November 2009-November 2010) and based on weekly aerosol sampling. Thanks to ICP-MS results, it was possible to perform investigations of uranium and thorium decay product concentration in the air. The number of aerosol filters sampled (50) was sufficient to establish a relationship between airborne radionuclide variations and the wind conditions. As expected, the more the time spent in the plume, the higher the ambient levels. The respective contributions of atmospheric releases and resuspension from local soil and waste ponds on ambient dust load and uranium-bearing aerosols were estimated. Two shutdown periods dedicated to facility servicing made it possible to estimate the resuspension contribution and to specify its origin (local or regional) according to the wind direction and remote background concentration. Airborne uranium mainly comes from the emission stack and, to a minor extent (∼20%), from wind resuspension of soil particles from the surrounding fields and areas devoted to waste storage. Moreover, weighed activity levels were clearly higher during operational periods than for shutdown periods.

  17. Environmental releases from fuel cycle facility: part 1: radionuclide resuspension vs. stack releases on ambient airborne uranium and thorium levels.

    Science.gov (United States)

    Masson, Olivier; Pourcelot, Laurent; Boulet, Béatrice; Cagnat, Xavier; Videau, Gérard

    2015-03-01

    Airborne activity levels of uranium and thorium series were measured in the vicinity (1.1 km) of a uranium (UF4) processing plant, located in Malvési, south of France. Regarding its impact on the environment, this facility is characterized by its routine atmospheric releases of uranium and by the emission of radionuclide-labelled particles from a storage pond filled with waste water or that contain dried sludge characterized by traces of plutonium and thorium ((230)Th). This study was performed during a whole year (November 2009-November 2010) and based on weekly aerosol sampling. Thanks to ICP-MS results, it was possible to perform investigations of uranium and thorium decay product concentration in the air. The number of aerosol filters sampled (50) was sufficient to establish a relationship between airborne radionuclide variations and the wind conditions. As expected, the more the time spent in the plume, the higher the ambient levels. The respective contributions of atmospheric releases and resuspension from local soil and waste ponds on ambient dust load and uranium-bearing aerosols were estimated. Two shutdown periods dedicated to facility servicing made it possible to estimate the resuspension contribution and to specify its origin (local or regional) according to the wind direction and remote background concentration. Airborne uranium mainly comes from the emission stack and, to a minor extent (∼20%), from wind resuspension of soil particles from the surrounding fields and areas devoted to waste storage. Moreover, weighed activity levels were clearly higher during operational periods than for shutdown periods. PMID:25613358

  18. Visualization of Air Particle Dynamics in an Engine Inertial Particle Separator

    Science.gov (United States)

    Wolf, Jason; Zhang, Wei

    2015-11-01

    Unmanned Aerial Vehicles (UAVs) are regularly deployed around the world in support of military, civilian and humanitarian efforts. Due to their unique mission profiles, these advanced UAVs utilize various internal combustion engines, which consume large quantities of air. Operating these UAVs in areas with high concentrations of sand and dust can be hazardous to the engines, especially during takeoff and landing. In such events, engine intake filters quickly become saturated and clogged with dust particles, causing a substantial decrease in the UAVs' engine performance and service life. Development of an Engine Air Particle Separator (EAPS) with high particle separation efficiency is necessary for maintaining satisfactory performance of the UAVs. Inertial Particle Separators (IPS) have been one common effective method but they experience complex internal particle-laden flows that are challenging to understand and model. This research employs an IPS test rig to simulate dust particle separation under different flow conditions. Soda lime glass spheres with a mean diameter of 35-45 microns are used in experiments as a surrogate for airborne particulates encountered during flight. We will present measurements of turbulent flow and particle dynamics using flow visualization techniques to understand the multiphase fluid dynamics in the IPS device. This knowledge can contribute to design better performing IPS systems for UAVs. Cleveland State University, Cleveland, Ohio, 44115.

  19. Airborne Remote Sensing of River Flow and Morphology

    Science.gov (United States)

    Zuckerman, S.; Anderson, S. P.; McLean, J.; Redford, R.

    2014-12-01

    River morphology, surface slope and flow are some of the fundamental measurements required for surface water monitoring and hydrodynamic research. This paper describes a method of combining bathymetric lidar with space-time processing of mid-wave infrared (MWIR) imagery to simultaneously measure bathymetry, currents and surface slope from an airborne platform. In May 2014, Areté installed a Pushbroom Imaging Lidar for Littoral Surveillance (PILLS) and a FLIR SC8000 MWIR imaging system sampling at 2 Hz in a small twin-engine aircraft. Data was collected over the lower Colorado River between Picacho Park and Parker. PILLS is a compact bathymetric lidar based on streak-tube sensor technology. It provides channel and bank topography and water surface elevation at 1 meter horizontal scales and 25 cm vertical accuracy. Surface currents are derived from the MWIR imagery by tracking surface features using a cross correlation algorithm. This approach enables the retrieval of currents along extended reaches at the forward speed of the aircraft with spatial resolutions down to 5 m with accuracy better than 10 cm/s. The fused airborne data captures current and depth variability on scales of meters over 10's of kilometers collected in just a few minutes. The airborne MWIR current retrievals are combined with the bathymetric lidar data to calculate river discharge which is then compared with real-time streamflow stations. The results highlight the potential for improving our understanding of complex river environments with simultaneous collections from multiple airborne sensors.

  20. AIRBORNE PESTICIDES AND POPULATION DECLINES OF A CALIFORNIA ALPINE FROG

    Science.gov (United States)

    The mountain yellow-legged frog (Rana muscosa) has disappeared from most of its historic localities in the Sierra Nevada of California, and airborne pesticides from the Central Valley have been implicated as a causal agent. To determine the distribution and temporal variation of ...

  1. First demonstration of an X-band airborne FMCW SAR

    NARCIS (Netherlands)

    Meta, A.; Hakkaart, P.; Zwan, F. van der; Hoogeboom, P.; Ligthart, L.P.

    2006-01-01

    At the Delft University of Technology, an X-band airborne FMCW SAR demonstrator system has been designed anddeveloped. The combination of Frequency Modulated Continuous Wave (FMCW) technology and Synthetic Aperture Technique (SAR) has led to a compact, low power consuming imaging system with high re

  2. Health Effects of Airborne Particulate Matter Trace Elements

    Institute of Scientific and Technical Information of China (English)

    XIANG GAO; QI YU; LI-MIN CHEN

    2005-01-01

    The effects of airborne particulate matter (PM) trace elements on health are widely concerned nowadays. Many achievements have been made while many unknowns exist. This article reports the recent research progresses, describes the effects of exposure to PM trace elements on health epidemiological evidence, toxicology findings, and raises some questions for future studies.

  3. Airborne Gravity: NGS' Gravity Data for CS08 (2015)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for CS08 collected in 2006 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum (GRAV-D)...

  4. Experimental Evaluation of a Coplanar Airborne Separation Display

    NARCIS (Netherlands)

    Ellerbroek, J.; Brantegem, K. C. R.; Van Paassen, M. M.; Mulder, M.

    2013-01-01

    Two experiments, an active conflict resolution task and a passive situation awareness assessment, were conducted that compared two versions of a constraint-based coplanar airborne separation assistance display. A baseline display showed a maneuver space based on 2-D projections of traffic and perfor

  5. Airborne Gamma-Ray Survey in Latvia 1995/96

    DEFF Research Database (Denmark)

    Bargholz, Kim

    1998-01-01

    Based on Airborne Gamma-Ray Spectrometry measurements performed with the Danish AGS equipment in 1995 and 1996 maps of the natural radioactivity have been produdced for selected areas in Latvia. The calibration of the quipment have been improved by comparisons with soil sample measurements....

  6. Detection and tracking of humans from an airborne platform

    NARCIS (Netherlands)

    Eekeren, A.W.M. van; Dijk, J.; Burghouts, G.

    2014-01-01

    Airborne platforms are recording large amounts of video data. Extracting the events which are needed to see is a timedemanding task for analysts. The reason for this is that the sensors record hours of video data in which only a fraction of the footage contains events of interest. For the analyst, i

  7. ALGORITMA ESTIMASI KANDUNGAN KLOROFIL TANAMAN PADI DENGAN DATA AIRBORNE HYPERSPECTRAL

    Directory of Open Access Journals (Sweden)

    Abdi Sukmono

    2015-02-01

    Full Text Available Klorofil merupakan pigmen yang paling penting dalam proses fotosintesis. Tanaman sehat yang mampu tumbuh maksimum umumnya  memiliki jumlah klorofil yang lebih besar daripada tanaman yang tidak sehat. Dalam Estimasi kandungan klorofil tanaman padi dengan airborne hyperspectral dibutuhkan algoritma khusus untuk mendaaptkan akurasi yang baik. Objek dari penelitian ini mengembangkan reflektan in situ menjadi model algoritma   estimasi kandungan klorofil tanaman padi untuk airborne hyperspectral.  Dalam penelitian ini beberapa indeks vegetasi seperti normalized difference vegetation index (NDVI, modified simple ratio (MSR  , modified/transformed chlorophyll absorption ratio index (MCARI, TCARI dan bentuk integrasi (MCARI/OSAVI and TCARI/OSAVI digunakan untuk membentuk model estimasi dengan metode regresi linear. Selain itu juga digunakan  Blue/Green/Yellow/Red Edge Absorption Clhorophyll Index. Dari proses regresi di dapatkan tiga ground model yang mempunyai korelasi kuat (R2≥0.5 terhadap klorofil tanaman padi. Ketiga model tersebut yaitu MSR (705,750 dengan R2 sebesar 0.51, TCARI/OSAVI (705, 750 dengan R2 sebesar 0.52 dan REACL 2 dengan R2 sebesar 0.57. Dari ketiga tersebut dipilih groun model terbaik REACL 2 untuk di upscalling ke model algoritma airborne hyperspectral.  Pembentukan algoritma dengan data airborne hyperspectral sensor Hymap dan REACL 2 menghasilkan model algoritma ( Klorofil (SPAD unit = 3.031((B22-B18/(B18-B13 + 31.596 dengan R2 sebesar 0.78

  8. Analysis of Membrane Lipids of Airborne Micro-Organisms

    Science.gov (United States)

    MacNaughton, Sarah

    2006-01-01

    A method of characterization of airborne micro-organisms in a given location involves (1) large-volume filtration of air onto glass-fiber filters; (2) accelerated extraction of membrane lipids of the collected micro-organisms by use of pressurized hot liquid; and (3) identification and quantitation of the lipids by use of gas chromatography and mass spectrometry. This method is suitable for use in both outdoor and indoor environments; for example, it can be used to measure airborne microbial contamination in buildings ("sick-building syndrome"). The classical approach to analysis of airborne micro-organisms is based on the growth of cultureable micro-organisms and does not provide an account of viable but noncultureable micro-organisms, which typically amount to more than 90 percent of the micro-organisms present. In contrast, the present method provides an account of all micro-organisms, including cultureable, noncultureable, aerobic, and anaerobic ones. The analysis of lipids according to this method makes it possible to estimate the number of viable airborne micro-organisms present in the sampled air and to obtain a quantitative profile of the general types of micro-organisms present along with some information about their physiological statuses.

  9. Citrus greening detection using airborne hyperspectral and multispectral imaging techniques

    Science.gov (United States)

    Hyperspectral imaging can provide unique spectral signatures for diseased vegetation. Airborne multispectral and hyperspectral imaging can be used to detect potentially infected trees over a large area for rapid detection of infected zones. This paper proposes a method to detect the citrus greening...

  10. Segmentation and classification of airborne laser scanner data

    NARCIS (Netherlands)

    Sithole, G.

    2005-01-01

    Various methods have been developed to measure the physical presence of objects in a landscape with high positional accuracy. A new method that has been gaining popularity is Airborne Laser Scanning (ALS). ALS works by scanning a landscape (the collection of ground, buildings, vegetation, etc.,) in

  11. Tree filtering for high density airborne LiDAR data

    NARCIS (Netherlands)

    Abd Rahman, M.Z.; Gorte, B.G.H.

    2008-01-01

    A high resolution Airborne LiDAR data creates better opportunity for an individual tree measurement and provides valuable results for more precise forest inventory. This paper presents tree filtering approach that able to separate dominant tree and undergrowth vegetation. The results can be used for

  12. Reducing Statistical Noise in Airborne Gamma-Ray Data

    DEFF Research Database (Denmark)

    Hovgaard, Jens; Grasty, R. L.

    1997-01-01

    By using the Noise Adjusted Singular Value Decomposition (NASVD) technique it is possible to reconstruct the measured airborne gamma-ray spectra with a noise content that is significant smaller than the noise contained in the original measured spectra. The method can be used for improving the out...

  13. ANIMAL MODELS FOR ASSESSING THE NEUROBEHAVIORAL IMPACT OF AIRBORNE POLLUTANTS

    Science.gov (United States)

    There has been a long-standing tradition of experimentation on laboratory animals and the behavioral effects of airborne pollutants. hese studies provide a scientific basis for investigating many of the pressing issues on indoor-air pollution. everal different procedures are revi...

  14. Quality Assurance Program Plan for radionuclide airborne emissions monitoring

    International Nuclear Information System (INIS)

    This Quality Assurance Program Plan (QAPP) describes the quality assurance requirements and responsibilities for radioactive airborne emissions measurements activities from regulated stacks are controlled at the Hanford Site. Detailed monitoring requirements apply to stacks exceeding 1% of the standard of 10 mrem annual effective dose equivalent to the maximally exposed individual from operations of the Hanford Site

  15. Immune Alterations in Rats Exposed to Airborne Lunar Dust

    Science.gov (United States)

    Crucian, Brian; Quiriarte, Heather; Nelman, Mayra; Lam, Chiu-wing; James, John T.; Sams, Clarence

    2014-01-01

    The lunar surface is covered by a layer of fine, reactive dust. Very little is known regarding the toxicity of lunar dust on human physiology. This study assessed the toxicity of airborne lunar dust exposure in rats on pulmonary and systemic immune parameters.

  16. Methane airborne measurements and comparison to global models during BARCA

    NARCIS (Netherlands)

    Beck, Veronika; Chen, Huilin; Gerbig, Christoph; Bergamaschi, Peter; Bruhwiler, Lori; Houweling, Sander; Rockmann, Thomas; Kolle, Olaf; Steinbach, Julia; Koch, Thomas; Sapart, Celia J.; van der Veen, Carina; Frankenberg, Christian; Andreae, Meinrat O.; Artaxo, Paulo; Longo, Karla M.; Wofsy, Steven C.

    2012-01-01

    Tropical regions, especially the Amazon region, account for large emissions of methane (CH4). Here, we present CH4 observations from two airborne campaigns conducted within the BARCA (Balanco Atmosferico Regional de Carbono na Amazonia) project in the Amazon basin in November 2008 (end of the dry se

  17. Fire Airborne Simulator Arrangement: in progress status report

    OpenAIRE

    Di Stefano, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Buongiorno, M. F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Amici, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Romeo, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Badiali, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Mari, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione AC, Roma, Italia; Pippi, I.; IFAC-CNR, Firenze, Italia; Marcoionni, P.; IFAC-CNR, Firenze, Italia; Cherubini, G.; Galileo Avionica, Campi Bisenzio Italia; Lindermeier, E.; DLR, Germany

    2004-01-01

    The FASA project in collaboration with the DLR and the financing of ASI was started in order to combine bi-spectral imager and high-resolution FTIR- spectrometer (MIROR) for airborne remote sensing and gas analyis of high temperature events such as volcanoes and wild fires.

  18. SGA-WZ: A New Strapdown Airborne Gravimeter

    Directory of Open Access Journals (Sweden)

    Kaidong Zhang

    2012-07-01

    Full Text Available Inertial navigation systems and gravimeters are now routinely used to map the regional gravitational quantities from an aircraft with mGal accuracy and a spatial resolution of a few kilometers. However, airborne gravimeter of this kind is limited by the inaccuracy of the inertial sensor performance, the integrated navigation technique and the kinematic acceleration determination. As the GPS technique developed, the vehicle acceleration determination is no longer the limiting factor in airborne gravity due to the cancellation of the common mode acceleration in differential mode. A new airborne gravimeter taking full advantage of the inertial navigation system is described with improved mechanical design, high precision time synchronization, better thermal control and optimized sensor modeling. Apart from the general usage, the Global Positioning System (GPS after differentiation is integrated to the inertial navigation system which provides not only more precise altitude information along with the navigation aiding, but also an effective way to calculate the vehicle acceleration. Design description and test results on the performance of the gyroscopes and accelerations will be emphasized. Analysis and discussion of the airborne field test results are also given.

  19. A comparison of stable platform and strapdown airborne gravity

    DEFF Research Database (Denmark)

    Glennie, C.L.; Schwarz, K.P.; Bruton, A.M.;

    2000-01-01

    To date, operational airborne gravity results have been obtained using either a damped two-axis stable platform gravimeter system such as the LaCoste and Romberg (LCR) S-model marine gravimeter or a strapdown inertial navigation system (INS), showing comparable accuracies. In June 1998 three flight...

  20. DOMECair: An Airborne Campaign in Antarctica Supporting SMOS Calibration

    DEFF Research Database (Denmark)

    Skou, Niels; Kristensen, Steen Savstrup; Søbjærg, Sten Schmidl;

    2013-01-01

    In search for a stable, well characterized terrestrial calibration target for SMOS, an airborne campaign was carried out in January 2013 over the Dome C area of Antarctica, and the surface was measured by an L-band radiometer. The focus was on homogeneity, and an area of 350 × 350 km around...