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Sample records for artificial radioactive aerosols

  1. The Discovery of Artificial Radioactivity

    NASA Astrophysics Data System (ADS)

    Guerra, Francesco; Leone, Matteo; Robotti, Nadia

    2012-03-01

    We reconstruct Frédéric Joliot and Irène Curie's discovery of artificial radioactivity in January 1934 based in part on documents preserved in the Joliot-Curie Archives in Paris, France. We argue that their discovery followed from the convergence of two parallel lines of research, on the neutron and on the positron, that were focused on a well-defined experimental problem, the nuclear transmutation of aluminum and other light elements. We suggest that a key role was played by a suggestion that Francis Perrin made at the seventh Solvay Conference at the end of October 1933, that the alpha-particle bombardment of aluminum produces an intermediate unstable isotope of phosphorus, which then decays by positron emission. We also suggest that a further idea that Perrin published in December 1933, and the pioneering theory of beta decay that Enrico Fermi also first published in December 1933, established a new theoretical framework that stimulated Joliot to resume the researches that he and Curie had interrupted after the Solvay Conference, now for the first time using a Geiger-Müller counter to detect the positrons emitted when he bombarded aluminum with polonium alpha particles.

  2. Electrically Driven Technologies for Radioactive Aerosol Abatement

    SciTech Connect

    David W. DePaoli; Ofodike A. Ezekoye; Costas Tsouris; Valmor F. de Almeida

    2003-01-28

    The purpose of this research project was to develop an improved understanding of how electriexecy driven processes, including electrocoalescence, acoustic agglomeration, and electric filtration, may be employed to efficiently treat problems caused by the formation of aerosols during DOE waste treatment operations. The production of aerosols during treatment and retrieval operations in radioactive waste tanks and during thermal treatment operations such as calcination presents a significant problem of cost, worker exposure, potential for release, and increased waste volume.

  3. Hand calculations for transport of radioactive aerosols through sampling systems.

    PubMed

    Hogue, Mark; Thompson, Martha; Farfan, Eduardo; Hadlock, Dennis

    2014-05-01

    Workplace air monitoring programs for sampling radioactive aerosols in nuclear facilities sometimes must rely on sampling systems to move the air to a sample filter in a safe and convenient location. These systems may consist of probes, straight tubing, bends, contractions and other components. Evaluation of these systems for potential loss of radioactive aerosols is important because significant losses can occur. However, it can be very difficult to find fully described equations to model a system manually for a single particle size and even more difficult to evaluate total system efficiency for a polydispersed particle distribution. Some software methods are available, but they may not be directly applicable to the components being evaluated and they may not be completely documented or validated per current software quality assurance requirements. This paper offers a method to model radioactive aerosol transport in sampling systems that is transparent and easily updated with the most applicable models. Calculations are shown with the R Programming Language, but the method is adaptable to other scripting languages. The method has the advantage of transparency and easy verifiability. This paper shows how a set of equations from published aerosol science models may be applied to aspiration and transport efficiency of aerosols in common air sampling system components. An example application using R calculation scripts is demonstrated. The R scripts are provided as electronic attachments. PMID:24667389

  4. Room air monitor for radioactive aerosols

    DOEpatents

    Balmer, David K.; Tyree, William H.

    1989-04-11

    A housing assembly for use with a room air monitor for simultaneous collection and counting of suspended particles includes a casing containing a combination detector-preamplifier system at one end, a filter system at the other end, and an air flow system consisting of an air inlet formed in the casing between the detector-preamplifier system and the filter system and an air passageway extending from the air inlet through the casing and out the end opposite the detector-preamplifier combination. The filter system collects suspended particles transported directly through the housing by means of the air flow system, and these particles are detected and examined for radioactivity by the detector-pre The U.S. Government has rights in this invention pursuant to Contract No. DE-AC04-76DP03533 between the Department of Energy and Rockwell International Corporation.

  5. Room air monitor for radioactive aerosols

    DOEpatents

    Balmer, D.K.; Tyree, W.H.

    1987-03-23

    A housing assembly for use with a room air monitor for simultaneous collection and counting of suspended particles includes a casing containing a combination detector-preamplifier system at one end, a filter system at the other end, and an air flow system consisting of an air inlet formed in the casing between the detector-preamplifier system and the filter system and an air passageway extending from the air inlet through the casing and out the end opposite the detector-preamplifier combination. The filter system collects suspended particles transported directly through the housing by means of the air flow system, and these particles are detected and examined for radioactivity by the detector-preamplifier combination. 2 figs.

  6. EMSP Final Report: Electrically Driven Technologies for Radioactive Aerosol Abatement

    SciTech Connect

    DePaoli, D.W.

    2003-01-22

    The purpose of this research project was to develop an improved understanding of how electrically driven processes, including electrocoalescence, acoustic agglomeration, and electric filtration, may be employed to efficiently treat problems caused by the formation of aerosols during DOE waste treatment operations. The production of aerosols during treatment and retrieval operations in radioactive waste tanks and during thermal treatment operations such as calcination presents a significant problem of cost, worker exposure, potential for release, and increased waste volume. There was anecdotal evidence in the literature that acoustic agglomeration and electrical coalescence could be used together to change the size distribution of aerosol particles in such a way as to promote easier filtration and less frequent maintenance of filtration systems. As such, those electrically driven technologies could potentially be used as remote technologies for improved treatment; however, existing theoretical models are not suitable for prediction and design. To investigate the physics of such systems, and also to prototype a system for such processes, a collaborative project was undertaken between Oak Ridge National Laboratory (ORNL) and the University of Texas at Austin (UT). ORNL was responsible for the larger-scale prototyping portion of the project, while UT was primarily responsible for the detailed physics in smaller scale unit reactors. It was found that both electrical coalescence and acoustic agglomeration do in fact increase the rate of aggregation of aerosols. Electrical coalescence requires significantly less input power than acoustic agglomeration, but it is much less effective in its ability to aggregate/coalesce aerosols. The larger-scale prototype showed qualitatively similar results as the unit reactor tests, but presented more difficulty in interpretation of the results because of the complex multi-physics coupling that necessarily occur in all larger

  7. Natural and artificial radioactivity levels in Livingston Island (Antarctic regions)

    SciTech Connect

    Baeza, A.; Miro, C.; Paniagua, J.M.; Navarro, E.; Rodriguez, M.J.; Sanchez, F.

    1994-01-01

    Radioactive contamination of the sea and land is due, on the one hand, to fallout from atmospheric atomic explosions since 1945, and, on the other, to emissions produced by nuclear and radioactive facilities. Given its geographic position far distant from the aforementioned main sources of radioactive contamination, Antarctica should have the lowest levels that can be measured on the Earth of artificial radionuclides in the various receptor media which are characteristic of the trophic chain. In the case of Antarctica, these are melt-water, sea-water, mosses, algae, and lichens. With the aim of contributing basic information on the radiation levels present in the Antarctic ecosystem, we have identified and measured for the first time the radioactive levels of natural emitters (of cosmic and terrestrial origin) and man-made emitters in the aforementioned receptor media, in the vicinity of the Spanish Antarctic Base, Juan Carlos I, situated on Livingston Island in the South Shetland archipelago, Antarctic region. 22 refs., 1 fig., 3 tabs.

  8. Radioactivity of natural and artificial building materials - a comparative study.

    PubMed

    Szabó, Zs; Völgyesi, P; Nagy, H É; Szabó, Cs; Kis, Z; Csorba, O

    2013-04-01

    Building materials and their additives contain radioactive isotopes, which can increase both external and internal radioactive exposures of humans. In this study Hungarian natural (adobe) and artificial (brick, concrete, coal slag, coal slag concrete and gas silicate) building materials were examined. We qualified 40 samples based on their radium equivalent, activity concentration, external hazard and internal hazard indices and the determined threshold values of these parameters. Absorbed dose rate and annual effective dose for inhabitants living in buildings made of these building materials were also evaluated. The calculations are based on (226)Ra, (232)Th and (40)K activity concentrations determined by gamma-ray spectrometry. Measured radionuclide concentrations and hence, calculated indices and doses of artificial building materials show a rather disparate distribution compared to adobes. The studied coal slag samples among the artificial building materials have elevated (226)Ra content. Natural, i.e. adobe and also brick samples contain higher amount of (40)K compared to other artificial building materials. Correlation coefficients among radionuclide concentrations are consistent with the values in the literature and connected to the natural geochemical behavior of U, Th and K elements. Seven samples (coal slag and coal slag concrete) exceed any of the threshold values of the calculated hazard indices, however only three of them are considered to be risky to use according to the fact that the building material was used in bulk amount or in restricted usage. It is shown, that using different indices can lead to different conclusions; hence we recommend considering more of the indices at the same time when building materials are studied. Additionally, adding two times their statistical uncertainties to their values before comparing to thresholds should be considered for providing a more conservative qualification. We have defined radon hazard portion to point

  9. Measurements of Natural Radioactivity in Submicron Aerosols in Mexico City.

    NASA Astrophysics Data System (ADS)

    Gaffney, J. S.; Marley, N. A.; Sterling, K.; Sturchio, N. C.

    2003-12-01

    Natural radionuclides can be useful in evaluating the transport of ozone and aerosols in the troposphere. Beryllium-7, which is produced by cosmic ray interactions in the upper troposphere and lower stratosphere and becomes adsorbed on fine aerosols, can be a useful indicator of upper air transport into a region. Lead-210 is produced by the decay of radon-222 out-gassed into the lower atmosphere from ground-based uranium deposits. Potassium-40, found in soils, can act as a measure of wind-blown dust and also comes from burning of wood and other biomass that is enriched in this natural radioisotope. Thus, both lead-210 and potassium-40 can aid in identification of aerosols sourced in the lower atmosphere. As part of our continuing interest in the lifetimes and sources of aerosols and their radiative effects, we report here measurements of fine aerosol radioactivity in Mexico City, one of the largest megacities in the world. Samples were collected on quartz fiber filters by using cascade impactors (Sierra type, Anderson Instruments) and high-volume air samplers from the rooftop of the main laboratory of El Centro Nacional de Investigacion y Capacitacion Ambiental (CENICA). By using stage 4 of the impactor and timers, we were able to collect integrated samples of sizes > 1 micrometer and < 1 micrometer over 12-hr time periods daily for approximately one month in April 2003. Samples were counted at the University of Illinois at Chicago by using state-of-the-art gamma counting (beryllium-7, 477.6 keV; potassium-40, 1460.8 keV; lead-210, 46.5 keV). The beryllium-7 data indicate one possible upper-air transport event during April 2003. As expected, the lead-210 data indicate very little soil contribution to the fine aerosol. The potassium-40 data showed an increase in fine aerosol potassium during Holy Week that might be attributed to local combustion of biomass fuels. The data will be presented and discussed in light of future data analysis and comparison with other

  10. Level of natural and artificial radioactivity in Algeria.

    PubMed

    Baggoura, B; Noureddine, A; Benkrid, M

    1998-07-01

    A national environmental sampling program was carried out during 1993 to determine natural and artificial radionuclides contents in the (0-15 cm) upper layer of the soil. The main objective was to establish a radioactive reference level in the whole territory, since 131I, 134Cs and 137Cs were detected in most of the analysed samples collected right after the Chernobyl accident (May 1986). Soil samples were analysed by direct counting by gamma-ray spectrometry. In addition, terrestrial gamma-ray dose rates in air have been measured out of doors throughout Algeria. In each of the 48 administrative divisions of the country selected sites were chosen to collect soil samples and measure gamma-ray dose rates. The gamma-emitting radionuclides resulting from the radioactive decay of 238U and 232Th, 40K and 137Cs were detected in most of the analysed samples. Radioactivity concentrations in Bq kg-1 dry mass in soil samples of 226Ra, 214Pb, 214Bi, 212Pb, 228Ac, 40K and 137Cs range between (5-176), (2-107), (3-65), (2-97), (3-144), (36-1405) and (0.3-41) respectively. In addition, six selected soil samples were analysed to determine plutonium isotopes contents. Radioactivity concentrations in Bq kg-1 dry mass of 238Pu and 239 + 240Pu vary between (0.012-0.013) and (0.24-0.61) respectively. The dose rates in air measured over the whole country were found to range between 20 and 133 nGy h-1. Presence of 137Cs has been clearly observed. An approach has been made to determine its origin, considering the global fallout, the Chernobyl accident and the French nuclear bomb tests in the 60s as the main potential sources. It is concluded that Algeria has indeed been affected by the Chernobyl accident. PMID:9570102

  11. Distribution and clearance of radioactive aerosol on the nasal mucosa.

    PubMed

    McLean, J A; Bacon, J R; Mathews, K P; Thrall, J H; Banas, J M; Hedden, J; Bayne, N K

    1984-03-01

    The distribution and clearance of aerosolized radioactive technetium 99m pertechnate in physiologic buffered saline was analyzed in four human adult asymptomatic volunteers following delivery into one nostril in the same manner as for nasal challenge testing (i.e., 0.1 ml via a 251 DeVilbiss atomizer powered by a compressor delivering 0.10 +/- 0.01 gm/spray). For comparison, squeeze bottles and spray bottles from commercial sources, a 114 and a 127 DeVilbiss atomizer, and a pipette were employed. Lateral imagery via minicomputer processing was used to determine both distribution and clearance of the radiotracer. The counts after 1 minute were lower following pipette delivery than with the other devices. None yielded discernable , wide-spread distribution of aerosol throughout the nasal cavity. Following delivery from the 251 atomizer, mean clearance at 17 minutes was 60.0%. Similar clearance rates were obtained with the other spraying methods except for lower values with the squeeze bottle. Analysis of six hour clearance studies by linear regression showed a relatively rapid initial phase, which is probably due largely to mucociliary clearance, and a prolonged late phase related to the very slow disappearance of residual material located far anteriorly in the nose. Achieving good initial retention and rapid clearance of material deposited anteriorly in the nose are desirable attributes of devices employed for administering materials intranasally. PMID:6328631

  12. Artificial ultra-fine aerosol tracers for highway transect studies

    NASA Astrophysics Data System (ADS)

    Cahill, Thomas A.; Barnes, David E.; Wuest, Leann; Gribble, David; Buscho, David; Miller, Roger S.; De la Croix, Camille

    2016-07-01

    The persistent evidence of health impacts of roadway aerosols requires extensive information for urban planning to avoid putting populations at risk, especially in-fill projects. The required information must cover both highway aerosol sources as well as transport into residential areas under a variety of roadway configurations, traffic conditions, downwind vegetation, and meteorology. Such studies are difficult and expensive to do, but were easier in the past when there was a robust fine aerosol tracer uniquely tied to traffic - lead. In this report we propose and test a modern alternative, highway safety flare aerosols. Roadway safety flares on vehicles in traffic can provide very fine and ultra-fine aerosols of unique composition that can be detected quantitatively far downwind of roadways due to a lack of upwind interferences. The collection method uses inexpensive portable aerosol collection hardware and x-ray analysis protocols. The time required for each transect is typically 1 h. Side by side tests showed precision at ± 4%. We have evaluated this technique both by aerosol removal in vegetation in a wind tunnel and by tracking aerosols downwind of freeways as a function of season, highway configuration and vegetation coverage. The results show that sound walls for at-grade freeways cause freeway pollution to extend much farther downwind than standard models predict. The elevated or fill section freeway on a berm projected essentially undiluted roadway aerosols at distances well beyond 325 m, deep into residential neighborhoods. Canopy vegetation with roughly 70% cover reduced very fine and ultra-fine aerosols by up to a factor of 2 at distances up to 200 m downwind.

  13. Enrico Fermi's Discovery of Neutron-Induced Artificial Radioactivity: Neutrons and Neutron Sources

    NASA Astrophysics Data System (ADS)

    Guerra, Francesco; Leone, Matteo; Robotti, Nadia

    2006-09-01

    We reconstruct and analyze the path leading from James Chadwick’s discovery of the neutron in February 1932 through Frédéric Joliot and Irène Curie’s discovery of artificial radioactivity in January 1934 to Enrico Fermi’s discovery of neutron-induced artificial radioactivity in March 1934. We show, in particular, that Fermi’s innovative construction and use of radon-beryllium neutron sources permitted him to make his discovery.

  14. Breakdown of model aircraft radome dielectric shell in artificial charged aerosol clouds

    NASA Astrophysics Data System (ADS)

    Temnikov, A. G.; Chernenskii, L. L.; Orlov, A. V.; Antonenko, S. S.

    2011-10-01

    The breakdown of a model aircraft radome dielectric shell in artificial charged aqueous aerosol clouds has been experimentally studied. It is established that, in most cases, electric breakdown of a model shell takes place without explicit discharge development between a charged aqueous aerosol cloud and a model antenna arranged under the radome shell. The probabilities of the dielectric shell breakdown have been determined for various radome models. A possible mechanism of the shell breakdown in hollow dielectric radomes interacting with charged aqueous aerosol clouds and electric discharges in these clouds is proposed that takes into account the accumulation of charges of opposite signs on the internal and external surface of the radome.

  15. From OLS to VIIRS, an overview of nighttime satellite aerosol retrievals using artificial light sources

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Miller, S. D.; Reid, J. S.; Hyer, E. J.; McHardy, T. M.

    2015-12-01

    Compared to abundant daytime satellite-based observations of atmospheric aerosol, observations at night are relatively scarce. In particular, conventional satellite passive imaging radiometers, which offer expansive swaths of spatial coverage compared to non-scanning lidar systems, lack sensitivity to most aerosol types via the available thermal infrared bands available at night. In this talk, we make the fundamental case for the importance of nighttime aerosol information in forecast models, and the need to mitigate the existing nocturnal gap. We review early attempts at estimating nighttime aerosol optical properties using the modulation of stable artificial surface lights. Initial algorithm development using DMSP Operational Linescan System (OLS) has graduated to refined techniques based on the Suomi-NPP Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB). We present examples of these retrievals for selected cases and compare the results to available surface-based point-source validation data.

  16. Modeling Electrical Structure of the Artificial Charged Aerosol Cloud

    NASA Astrophysics Data System (ADS)

    Davydenko, S.; Iudin, D.; Klimashov, V.; Kostinskiy, A. J.; Syssoev, V.

    2014-12-01

    The electric structure of the unipolar charged aerosol cloud is considered. The cloud of the volume about 30 cubic meters is generated in the open atmosphere by the original aeroelectrical facility consisting of the source of the aquated ions and the high-voltage discharger. Representing the charge density distribution as a superposition of regular and irregular parts, a model of the electrical structure of the cloud is developed. The regular part is calculated under the stationary current approximation taking into account the source current structure, the shape of the cloud, and results of the multi-point measurements of the electric field and conductivity in the vicinity of the cloud. The irregular part describes random spatiotemporal fluctuations of the charge density which are assumed to be proportional to the aerosol number density. It is shown that a quasi-electrostatic field of the charged aerosol is characterized by significant spatial fluctuations showing the scale invariance. The mean-square fluctuations of the voltage between different parts of the cloud are proportional to the square root of its linear dimensions and may reach significant values even in the absence of the regular field. The basic parameters of the fluctuating spatial structure of the electric field inside the charged aerosol cloud are estimated. It is shown that the charge density fluctuations could lead to a significant (up to 2,5 times) local enhancement of the electric field as compared to the field of the regular part of the charge density. The above effect could serve as one of the important mechanisms of the spark initiation.

  17. Aerodynamic size associations of natural radioactivity with ambient aerosols

    SciTech Connect

    Bondietti, E.A.; Papastefanou, C.; Rangarajan, C.

    1986-04-01

    The aerodynamic size of /sup 214/Pb, /sup 212/Pb, /sup 210/Pb, /sup 7/Be, /sup 32/P, /sup 35/S (as SO/sub 4//sup 2 -/), and stable SO/sub 4//sup 2 -/ was measured using cascade impactors. The activity distribution of /sup 212/Pb and /sup 214/Pb, measured by alpha spectroscopy, was largely associated with aerosols smaller than 0.52 ..mu..m. Based on 46 measurements, the activity median aerodynamic diameter of /sup 212/Pb averaged 0.13 ..mu..m (sigma/sub g/ = 2.97), while /sup 214/Pb averaged 0.16 ..mu..m (sigma/sub g/ = 2.86). The larger median size of /sup 214/Pb was attributed to ..cap alpha..-recoil depletion of smaller aerosols following decay of aerosol-associated /sup 218/Po. Subsequent /sup 214/Pb condensation on all aerosols effectively enriches larger aerosols. /sup 212/Pb does not undergo this recoil-driven redistribution. Low-pressure impactor measurements indicated that the mass median aerodynamic diameter of SO/sub 4//sup 2 -/ was about three times larger than the activity median diameter /sup 212/Pb, reflecting differences in atmospheric residence times as well as the differences in surface area and volume distributions of the atmospheric aerosol. Cosmogenic radionuclides, especially /sup 7/Be, were associated with smaller aerosols than SO/sub 4//sup 2 -/ regardless of season, while /sup 210/Pb distributions in summer measurements were similar to sulfate but smaller in winter measurements. Even considering recoil following /sup 214/Po ..cap alpha..-decay, the avervage /sup 210/Pb labeled aerosol grows by about a factor of two during its atmospheric lifetime. The presence of 5 to 10% of the /sup 7/Be on aerosols greater than 1 ..mu..m was indicative of post-condensation growth, probably either in the upper atmosphere or after mixing into the boundary layer.

  18. PROGRESS REPORT. ELECTRICALLY DRIVEN TECHNOLOGIES FOR RADIOACTIVE AEROSOL ABATEMENT

    EPA Science Inventory

    The objective of this research program is to develop an improved understanding of how electrically driven processes, including electrocoalescence, acoustic agglomeration, and electric filtration may be employed to efficiently treat problems caused by the formation of aerosols dur...

  19. FINAL REPORT. ELECTRICALLY DRIVEN TECHNOLOGIES FOR RADIOACTIVE AEROSOL ABATEMENT

    EPA Science Inventory

    The objective of this research program was to develop an improved understanding of how electrically driven processes, including electrocoalescence, acoustic agglomeration, and electric filtration, may be employed to efficiently treat problems caused by aerosols formed during DOE ...

  20. Using artificial neural networks to retrieve the aerosol type from multi-spectral lidar data

    NASA Astrophysics Data System (ADS)

    Nicolae, Doina; Belegante, Livio; Talianu, Camelia; Vasilescu, Jeni

    2015-04-01

    Aerosols can influence the microphysical and macrophysical properties of clouds and hence impact the energy balance, precipitation and the hydrological cycle. They have different scattering and absorption properties depending on their origin, therefore measured optical properties can be used to retrieve their physical properties, as well as to estimate their chemical composition. Due to the measurement limitations (spectral, uncertainties, range) and high variability of the aerosol properties with environmental conditions (including mixing during transport), the identification of the aerosol type from lidar data is still not solved. However, ground, airborne and space-based lidars provide more and more observations to be exploited. Since 2000, EARLINET collected more than 20,000 aerosol vertical profiles under various meteorological conditions, concerning local or long-range transport of aerosols in the free troposphere. This paper describes the basic algorithm for aerosol typing from optical data using the benefits of artificial neural networks. A relevant database was built to provide sufficient training cases for the neural network, consisting of synthetic and measured aerosol properties. Synthetic aerosols were simulated starting from the microphysical properties of basic components, internally mixed in various proportions. The algorithm combines the GADS database (Global Aerosol DataSet) to OPAC model (Optical Properties of Aerosol and Clouds) and T-Matrix code in order to compute, in an iterative way, the intensive optical properties of each aerosol type. Both pure and mixed aerosol types were considered, as well as their particular non-sphericity and hygroscopicity. Real aerosol cases were picked up from the ESA-CALIPSO database, as well as EARLINET datasets. Specific selection criteria were applied to identify cases with accurate optical data and validated sources. Cross-check of the synthetic versus measured aerosol intensive parameters was performed in

  1. Note: Real time optical sensing of alpha-radiation emitting radioactive aerosols based on solid state nuclear track detector.

    PubMed

    Kulkarni, A; Ha, S; Joshirao, P; Manchanda, V; Bak, M S; Kim, T

    2015-06-01

    A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO3)4 ⋅ 5H2O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories. PMID:26133876

  2. Note: Real time optical sensing of alpha-radiation emitting radioactive aerosols based on solid state nuclear track detector

    SciTech Connect

    Kulkarni, A.; Bak, M. S. E-mail: moonsoo@skku.edu; Ha, S.; Joshirao, P.; Manchanda, V.; Kim, T. E-mail: moonsoo@skku.edu

    2015-06-15

    A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO{sub 3}){sub 4} ⋅ 5H{sub 2}O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories.

  3. Radioactive Aerosols as an Index of Air Pollution in the City of Thessaloniki, Greece

    NASA Astrophysics Data System (ADS)

    Ioannidou, A.; Papastefanou, C.

    2010-01-01

    This study summarizes results of an investigation done in order to find out how the radioactive aerosols of 7Be could serve as indicators of air pollution conditions. Beryllium-7 is a cosmic-ray produced radionuclide with an important fraction of its production to take place in the upper troposphere. Once it is formed is rapidly associated with submicron aerosol particles and participates in the formation and growth of the accumulation mode aerosols, which is a major reservoir of pollutants in the atmosphere. In order to define any influence of AMAD of 7Be aerosols by air pollution conditions, the aerodynamic size distribution of 7Be aerosols was determined by collecting samples at different locations in the suburban area of the city of Thessaloniki, including rural areas, industrial areas, high elevations, marine environment and the airport area. The aerodynamic size distribution of 7Be aerosols in different locations was obtained by using Andersen 1-ACFM cascade impactors and the Activity Median Aerodynamic Diameter (AMAD) was determined. Some dependency of the AMADs on height has been observed, while in near marine environment the 7Be activity size distribution was dominant in the upper size range of aerosol particles. Low AMADs as low as 0.62 to 0.74 μm of 7Be aerosols have been observed at locations characterized with relative low pollution, while it is concluded that in the activity size distribution of ambient aerosols, 7Be changes to larger particle sizes in the presence of pollutants, since low AMADs of 7Be aerosols have been observed at low polluted locations. Preliminary data of simultaneous measurements of 214Pb and 212Pb with gaseous air pollutants CO, NO, NOX, SO2 and total suspended particulate matter (TSP) show that radon decay products near the ground could be a useful index of air pollution potential conditions and transport processes in the boundary layer.

  4. Wavelength-Dependent Optical Absorption Properties of Artificial and Atmospheric Aerosol Measured by a Multi-Wavelength Photoacoustic Spectrometer

    NASA Astrophysics Data System (ADS)

    Utry, N.; Ajtai, T.; Pintér, M.; Bozóki, Z.; Szabó, G.

    2014-12-01

    Various aspects of the photoacoustic (PA) detection method are discussed from the point of view of developing it into a routine tool for measuring the wavelength-dependent optical absorption coefficient of artificial and atmospheric aerosol. The discussion includes the issues of calibration, cross-sensitivity to gaseous molecules, background PA signal subtraction, and size-dependent particle losses within the PA system. The results in this paper are based on a recently developed four-wavelength PA system, which has operational wavelengths in the near-infrared, in the visible, and in the ultraviolet. The measured spectra of artificial and atmospheric aerosol prove the outstanding applicability of the presented PA system.

  5. Using Artificial Sky Glow to Retrieve Night Time Aerosol Optical Depth

    NASA Astrophysics Data System (ADS)

    Aubé, M.; O'Neill, N. T.; Giguère, J.-D.; Royer, A.

    2009-04-01

    Measuring the Aerosol Optical Depth (AOD) is of particular importance in monitoring aerosol contributions to global radiative forcing. Most measuring methods are based on direct or indirect observation of sunlight and thus are only available for use during daylight hours. Attempts have been made to measure AOD behavior at night from star photometry, and more recently moon photometry. Star photometry method uses spectrally calibrated stars as reference targets this provides somewhat more flexibility than a sunphotometer but there are low-signal and calibration issues which can make these measurements problematic. Moon photometry is only possible when the moon is present in the sky. We suggest a complementary method, based on the observation of artificial hemispheric sky glow generated by light pollution. The methodology requires (1) the implementation of an heterogeneous 3D light pollution model and (2) the design of an automated light pollution spectrometer. This instrument designated as the Spectrometer for Aerosol Night Detection (SAND) is now in it's third version. Basically, SAND-3 is a CCD based, long-slit spectrometer with a non imaging optical head. SAND-3 is protected from inclement weather by a transparent acrylic dome; it can run autonomously with minimal maintenance. The system can be remotely controlled via a web browser or via a secure shell client. Preliminary field measurements acquired at the Mont-Mégantic astronomical observatory (Québec, Canada) and in Sherbrooke (Québec, Canada) will be reported. We will also show preliminary day/night (continuity) comparisons with AERONET/AEROCAN sunphotometer AOD measurements and nightime comparisons with aerosol backscatter lidar profiles acquired at the nearby optical observatory in Sherbrooke Québec, Canada. The performance and the potential of this approach will be discussed in conjunction with the implementation of the light pollution model.

  6. Ratio of aerosol and gases of radioactive chlorine and particle size distribution of aerosol formed by high-energy proton irradiation.

    PubMed

    Yokoyama, S; Sato, K; Manabe, K; Noguchi, H; Kaneko, H; Oki, Y; Iida, T; Tanaka, Su

    2007-01-01

    To estimate internal doses due to the inhalation of radionuclides produced by the nuclear spallation of the air nuclei in high-energy proton accelerator facilities, the physicochemical properties of radionuclides are very important. Thus, the ratio of aerosol and gases of 38Cl and 39Cl formed by irradiating argon gas-added air with a 48 MeV proton beam has been measured. Radionuclides of 38Cl and 39Cl exist as aerosol, acid gas and non-acid gas. The percentages of activity of 38Cl and 39Cl aerosols are about 80%. The number size distributions of non-radioactive aerosol were characterised by two peaks with diameters of 10-20 nm and larger than 20 nm. As a result predicted by a simple surface model, it was found that the activity size distribution of 38Cl aerosols can be regarded as that having a single peak at 120 nm. PMID:18033760

  7. Demolition and removal of radioactively contaminated concrete soil: Aerosol control and monitoring

    SciTech Connect

    Newton, G.J.; Hoover, M.D.; Grace, A.C. III

    1995-12-01

    From 1963 to 1985, two concrete-lined ponds were used to reduce the volume of radioactive liquids from the Institute`s research programs. Following withdrawal of the {open_quotes}hot ponds{close_quotes} from active use, the residual sludges and plastic liners of the ponds were removed and shipped to a radioactive waste disposal site. From 1987 to 1994, the concrete structures remained undisturbed pending environmental restoration on the site. Restoration began in 1994 and was completed in 1995. Restoration involved mechanical breakup and removal of the concrete structures and removal of areas of contaminated soils from the site. This report describes the design and results of the aerosol control and monitoring program that was conducted to ensure protection of workers and the environment during the restoration process. The aerosol control and monitoring strategy developed for remediation of the ITRI hot ponds was successful both in preventing dispersion of radioactive dusts and in demonstrating that exposures of workers and offsite releases were within statutory limits.

  8. Monitoring natural and artificial radioactivity enhancement in the Aegean Sea using floating measuring systems.

    PubMed

    Tsabaris, C

    2008-11-01

    In the present work, the enhancement of radioactivity due to rainfall in the Aegean Sea using floating measuring systems was observed and quantified. The data were acquired with a NaI underwater detection system, which was installed on a floating measuring system at a depth of 3m. The results of natural and artificial radioactivity are discussed taking into account the rainfall intensity and wind direction. The activity concentration of (214)Bi increased up to (991+/-102)Bq/m(3) after strong rainfall in the North Aegean Sea in winter (humid period) with east wind direction. On other hand, the maximum activity concentration reached the level of (110+/-10)Bq/m(3) in summer (dry period) during south winds. PMID:18495486

  9. Studying electromagnetic interference spectrum in antenna under aircraft radome using models with artificial charged aerosol clouds

    NASA Astrophysics Data System (ADS)

    Temnikov, A. G.; Gilyazov, M. Z.; Matveev, D. A.; Voronkova, A. Yu.; Chernenskii, L. L.; Orlov, A. V.

    2011-09-01

    The spectrum of electromagnetic interference that is induced by discharges in an antenna arranged under an aircraft radome in an artificial charged aqueous aerosol cloud has been experimentally studied. It is established that, among different possible variants of lightning-arrest radomes, the minimum level of the spectral density of interference signals in the antenna is provided by vertical stripe electrodes on the radome surface. The maximum characteristic frequencies of signals in a model spherical antenna are several times lower than those in model lightning diverters, while the flat model antennas of disk or rectangular shapes exhibit the opposite trend. It has been suggested that a significant role in determining the characteristics of the electromagnetic interference spectrum in weather radar antennas is played by currents of discharges generated by charges accumulated on the dielectric radome surface.

  10. Artificial and natural radioactivity in edible mushrooms from Sao Paulo, Brazil.

    PubMed

    de Castro, L P; Maihara, V A; Silva, P S C; Figueira, R C L

    2012-11-01

    Environmental biomonitoring has demonstrated that organisms such as crustaceans, fish and mushrooms are useful to evaluate and monitor both ecosystem contamination and quality. Particularly, some mushroom species have a high capacity to retain radionuclides and some toxic elements from the soil and the air. The potential of mushrooms to accumulate radionuclides in their fruit-bodies has been well documented. However, there are no studies that determine natural and artificial radionuclide composition in edible mushrooms, in Brazil. Artificial ((137)Cs) and natural radioactivity ((40)K, (22)(6)Ra, (2)(28)Ra) were determined in 17 mushroom samples from 3 commercialized edible mushroom species. The edible mushrooms collected were Agaricus sp., Pleurotus sp. and Lentinula sp. species. The activity measurements were carried out by gamma spectrometry. The levels of (137)Cs varied from 1.45 ± 0.04 to 10.6 ± 0.3 Bq kg(-1), (40)K levels varied from 461 ± 2 to 1535 ± 10 Bq kg(-1), (2)(26)Ra levels varied from 14 ± 3 to 66 ± 12 Bq kg(-1) and (228)Ra levels varied from 6.2 ± 0.2 to 54.2 ± 1.7 Bq kg(-1). (137)Cs levels in Brazilian mushrooms are in accordance with the radioactive fallout in the Southern Hemisphere. The artificial and natural activities determined in this study were found to be below the maximum permissible levels as established by national legislation. Thus, these mushroom species can be normally consumed by the population without any apparent risks to human health. PMID:22765964

  11. Radioactive isotopes in atmospheric aerosols over Russia and the Sea of Japan following nuclear accident at Fukushima Nr. 1 Daiichi Nuclear Power Station in March 2011.

    PubMed

    Neroda, Andrey S; Mishukov, Vasily F; Goryachev, Vladimir A; Simonenkov, Denis V; Goncharova, Anna A

    2014-04-01

    Artificial radionuclides, such as iodine-131 ((131)I), cesium-134 ((134)Cs), and cesium-137 ((137)Cs), as well as natural isotopes of beryllium-7 ((7)Be) and potassium-40 ((40)K) have been registered in atmospheric aerosols over Vladivostok selected from 11 March to 17 June 2011. Additionally, (134)Cs and (137)Cs were detected in atmospheric aerosols over Tomsk selected from 16 March to 17 June 2011. Artificial radionuclides were also discovered in atmospheric wet depositions sampled in Vladivostok from 3 to 17 May 2011. Moreover, these radionuclides have been registered in atmospheric aerosols over the sea surface of the Sea of Japan selected from 3 to 31 May 2011 during an expedition of the "Nadezhda" sailing ship. From 18 March to 15 April, an increase in concentrations of atmospheric aerosols over Vladivostok from 108.8 to 321.5 μg/m(3) has been registered. It was accompanied by increased activity concentrations of (134)Cs, (137)Cs, and the (131)I. During the period from 18 March to 15 April, activity concentrations of (137)Cs and (134)Cs in atmospheric aerosols increased 100 times compared with the minimum detectable concentration (MDC) level and peaked in the weekly sample gathered from 8 to 15 April (145.0 and 105.3 μBq/m(3), respectively). Variability of concentrations of natural isotopes of (7)Be and (40)K was not greater than 1 order of magnitude throughout the sampling period. Maximal values of (137)Cs and (134)Cs concentrations (1,281.5 ± 141 and 384.4 ± 42.3 μBq/m(3), respectively) in Tomsk were reached in samples taken from 1 to 2 April. For the atmospheric aerosol samples from the Sea of Japan, the largest concentration of (131)I (392.3 ± 215.7 μBq/m(3)) was detected from 13 to 19 May, while all other samples had much lower concentration values. Synoptic analysis of back trajectories movement of air masses showed that the radioactive cloud came to Vladivostok from the regions of Siberia and northeastern part of China. Synoptic

  12. Natural and artificial radionuclide measurements and radioactivity assessment of soil samples in eastern Sichuan province (China).

    PubMed

    Wang, Zhonghai; He, Jun; Du, Yu; He, Yang; Li, Zhiqian; Chen, Zhihua; Yang, Chaowen

    2012-07-01

    The activity concentrations of natural and artificial radionuclides were measured in the eastern region of Sichuan province (China). One hundred and ninety-three soil samples from this region were collected and analysed by high-purity germanium gamma spectrometry. The measured results show that the average radioactivity concentrations of (226)Ra, (232)Th, (40)K and (137)Cs in the soil samples are 26, 49, 440 and 6 Bq kg(-1), respectively. The calculated average radium equivalent activity is 130 Bq kg(-1), which is less than the recommended limit of 370 Bq kg(-1). The absorbed dose rate and annual effective dose are 60 nGy h(-1) and 74 µSv, respectively. This is the first time the absorbed dose rate in the east region of Sichuan has been mapped. Overall, the environmental radiation background is greater in the southern part of the area studied than in the northern. PMID:22128351

  13. Enrico Fermi's Discovery of Neutron-Induced Artificial Radioactivity:The Recovery of His First Laboratory Notebook

    NASA Astrophysics Data System (ADS)

    Acocella, Giovanni; Guerra, Francesco; Robotti, Nadia

    . We give a short description of the discovery of the first experimental notebook of Enrico Fermi (1901-1954) on his researches during March and April of 1934 on neutron-induced artificial radioactivity, and we point out its relevance for a proper historical and conceptual understanding of those researches.

  14. Metal complexes containing natural and and artificial radioactive elements and their applications.

    PubMed

    Kharissova, Oxana V; Méndez-Rojas, Miguel A; Kharisov, Boris I; Méndez, Ubaldo Ortiz; Martínez, Perla Elizondo

    2014-01-01

    Recent advances (during the 2007-2014 period) in the coordination and organometallic chemistry of compounds containing natural and artificially prepared radionuclides (actinides and technetium), are reviewed. Radioactive isotopes of naturally stable elements are not included for discussion in this work. Actinide and technetium complexes with O-, N-, N,O, N,S-, P-containing ligands, as well π-organometallics are discussed from the view point of their synthesis, properties, and main applications. On the basis of their properties, several mono-, bi-, tri-, tetra- or polydentate ligands have been designed for specific recognition of some particular radionuclides, and can be used in the processes of nuclear waste remediation, i.e., recycling of nuclear fuel and the separation of actinides and fission products from waste solutions or for analytical determination of actinides in solutions; actinide metal complexes are also usefulas catalysts forcoupling gaseous carbon monoxide,as well as antimicrobial and anti-fungi agents due to their biological activity. Radioactive labeling based on the short-lived metastable nuclide technetium-99m ((99m)Tc) for biomedical use as heart, lung, kidney, bone, brain, liver or cancer imaging agents is also discussed. Finally, the promising applications of technetium labeling of nanomaterials, with potential applications as drug transport and delivery vehicles, radiotherapeutic agents or radiotracers for monitoring metabolic pathways, are also described. PMID:25061724

  15. Lessons learned from case studies of inhalation exposures of workers to radioactive aerosols

    SciTech Connect

    Hoover, M.D.; Fencl, A.F.; Newton, G.J.

    1995-12-01

    Various Department of Energy requirements, rules, and orders mandate that lessons learned be identified, evaluated, shared, and incorporated into current practices. The recently issued, nonmandatory DOE standard for Development of DOE Lessons Learned Program states that a DOE-wide lessons learned program will {open_quotes}help to prevent recurrences of negative experiences, highlight best practices, and spotlight innovative ways to solve problems or perform work more safely, efficiently, and cost effectively.{close_quotes} Additional information about the lessons learned program is contained in the recently issued DOE handbook on Implementing U.S. Department of Energy Lessons Learned Programs and in October 1995 DOE SAfety Notice on Lessons Learned Programs. This report summarizes work in progress at ITRI to identify lessons learned for worker exposures to radioactive aerosols, and describes how this work will be incorporated into the DOE lessons learned program, including a new technical guide for measuring, modeling, and mitigating airborne radioactive particles. Follow-on work is focusing on preparation of {open_quotes}lessons learned{close_quotes} training materials for facility designers, managers, health protection professionals, line supervisors, and workers.

  16. Evaluation of Observed and Modelled Aerosol Lifetimes Using Radioactive Tracers of Opportunity and an Ensemble of 19 Global Models

    NASA Technical Reports Server (NTRS)

    Kristiansen, N. I.; Stohl, A.; Olivie, D. J. L.; Croft, B.; Sovde, O. A.; Klein, H.; Christoudias, T.; Kunkel, D.; Leadbetter, S. J.; Lee, Y. H.; Zhang, K.; Tsigaridis, K.; Bauer, S. E.; Faluvegi, G. S.; Shindell, D.

    2016-01-01

    Aerosols have important impacts on air quality and climate, but the processes affecting their removal from the atmosphere are not fully understood and are poorly constrained by observations. This makes modelled aerosol lifetimes uncertain. In this study, we make use of an observational constraint on aerosol lifetimes provided by radionuclide measurements and investigate the causes of differences within a set of global models. During the Fukushima Dai-Ichi nuclear power plant accident of March 2011, the radioactive isotopes cesium-137 (Cs-137) and xenon-133 (Xe-133) were released in large quantities. Cesium attached to particles in the ambient air, approximately according to their available aerosol surface area. Cs-137 size distribution measurements taken close to the power plant suggested that accumulation mode (AM) sulfate aerosols were the main carriers of cesium. Hence, Cs-137 can be used as a proxy tracer for the AM sulfate aerosol's fate in the atmosphere. In contrast, the noble gas Xe-133 behaves almost like a passive transport tracer. Global surface measurements of the two radioactive isotopes taken over several months after the release allow the derivation of a lifetime of the carrier aerosol. We compare this to the lifetimes simulated by 19 different atmospheric transport models initialized with identical emissions of Cs-137that were assigned to an aerosol tracer with each model's default properties of AM sulfate, and Xe-133 emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulfate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled Cs-137and Xe-133 concentrations sampled at the same location and times as station measurements allow a direct comparison between measured and modelled aerosol lifetime. The e-folding lifetime e, calculated from station measurement data taken between 2 and 9 weeks after the start of the emissions, is 14.3 days (95

  17. Evaluation of observed and modelled aerosol lifetimes using radioactive tracers of opportunity and an ensemble of 19 global models

    NASA Astrophysics Data System (ADS)

    Kristiansen, N. I.; Stohl, A.; Olivié, D. J. L.; Croft, B.; Søvde, O. A.; Klein, H.; Christoudias, T.; Kunkel, D.; Leadbetter, S. J.; Lee, Y. H.; Zhang, K.; Tsigaridis, K.; Bergman, T.; Evangeliou, N.; Wang, H.; Ma, P.-L.; Easter, R. C.; Rasch, P. J.; Liu, X.; Pitari, G.; Di Genova, G.; Zhao, S. Y.; Balkanski, Y.; Bauer, S. E.; Faluvegi, G. S.; Kokkola, H.; Martin, R. V.; Pierce, J. R.; Schulz, M.; Shindell, D.; Tost, H.; Zhang, H.

    2015-09-01

    Aerosols have important impacts on air quality and climate, but the processes affecting their removal from the atmosphere are not fully understood and are poorly constrained by observations. This makes modelled aerosol lifetimes uncertain. In this study, we make use of an observational constraint on aerosol lifetimes provided by radionuclide measurements and investigate the causes of differences within a set of global models. During the Fukushima Dai-Ichi nuclear power plant accident of March 2011, the radioactive isotopes cesium-137 (137Cs) and xenon-133 (133Xe) were released in large quantities. Cesium attached to particles in the ambient air, approximately according to their available aerosol surface area. 137Cs size distribution measurements taken close to the power plant suggested that accumulation-mode (AM) sulphate aerosols were the main carriers for the cesium. Hence, 137Cs can be used as a proxy tracer for the AM sulphate aerosol's fate in the atmosphere. In contrast, the noble gas 133Xe behaves almost like a passive transport tracer. Global surface measurements of the two radioactive isotopes taken over several months after the release allow the derivation of a lifetime of the carrier aerosol. We compare this to the lifetimes simulated by 19 different atmospheric transport models initialized with identical emissions of 137Cs that were assigned to an aerosol tracer with each model's default properties of AM sulphate, and 133Xe emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulphate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled 37Cs and 133Xe concentrations sampled at the same location and times as station measurements allow a direct comparison between measured and modelled aerosol lifetime. The e-folding lifetime τe, calculated from station measurement data taken between two and nine weeks after the start of the emissions, is 14.3 days

  18. Evaluation of observed and modelled aerosol lifetimes using radioactive tracers of opportunity and an ensemble of 19 global models

    NASA Astrophysics Data System (ADS)

    Kristiansen, N. I.; Stohl, A.; Olivié, D. J. L.; Croft, B.; Søvde, O. A.; Klein, H.; Christoudias, T.; Kunkel, D.; Leadbetter, S. J.; Lee, Y. H.; Zhang, K.; Tsigaridis, K.; Bergman, T.; Evangeliou, N.; Wang, H.; Ma, P.-L.; Easter, R. C.; Rasch, P. J.; Liu, X.; Pitari, G.; Di Genova, G.; Zhao, S. Y.; Balkanski, Y.; Bauer, S. E.; Faluvegi, G. S.; Kokkola, H.; Martin, R. V.; Pierce, J. R.; Schulz, M.; Shindell, D.; Tost, H.; Zhang, H.

    2016-03-01

    Aerosols have important impacts on air quality and climate, but the processes affecting their removal from the atmosphere are not fully understood and are poorly constrained by observations. This makes modelled aerosol lifetimes uncertain. In this study, we make use of an observational constraint on aerosol lifetimes provided by radionuclide measurements and investigate the causes of differences within a set of global models. During the Fukushima Dai-Ichi nuclear power plant accident of March 2011, the radioactive isotopes cesium-137 (137Cs) and xenon-133 (133Xe) were released in large quantities. Cesium attached to particles in the ambient air, approximately according to their available aerosol surface area. 137Cs size distribution measurements taken close to the power plant suggested that accumulation-mode (AM) sulfate aerosols were the main carriers of cesium. Hence, 137Cs can be used as a proxy tracer for the AM sulfate aerosol's fate in the atmosphere. In contrast, the noble gas 133Xe behaves almost like a passive transport tracer. Global surface measurements of the two radioactive isotopes taken over several months after the release allow the derivation of a lifetime of the carrier aerosol. We compare this to the lifetimes simulated by 19 different atmospheric transport models initialized with identical emissions of 137Cs that were assigned to an aerosol tracer with each model's default properties of AM sulfate, and 133Xe emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulfate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled 137Cs and 133Xe concentrations sampled at the same location and times as station measurements allow a direct comparison between measured and modelled aerosol lifetime. The e-folding lifetime τe, calculated from station measurement data taken between 2 and 9 weeks after the start of the emissions, is 14.3 days (95

  19. Determination of natural and artificial radioactivity in soil at North Lebanon province.

    PubMed

    El Samad, O; Baydoun, R; Nsouli, B; Darwish, T

    2013-11-01

    The concentrations of natural and artificial radionuclides at 57 sampling locations along the North Province of Lebanon are reported. The samples were collected from uncultivated areas in a region not previously reported. The samples were analyzed by gamma spectrometers with High Purity Germanium detectors of 30% and 40% relative efficiency. The activity concentrations of primordial naturally occurring radionuclides of (238)U, (232)Th, and (40)K varied between 4-73 Bq kg(-1), 5-50 Bq kg(-1), and 57-554 Bq kg(-1) respectively. The surface activity concentrations due to the presence of these radionuclides were calculated and Kriging-geostatistical method was used to plot the obtained data on the Lebanese radioactive map. The results for (238)U, (232)Th, and (40)K ranged from 0.2 kBq m(-2) to 9 kBq m(-2), from 0.2 kBq m(-2) to 3 kBq m(-2), and from 3 kBq m(-2) to 29 kBq m(-2) respectively. For the anthropogenic radionuclides, the activity concentrations of (137)Cs founded in soil ranged from 2 Bq kg(-1) to 113 Bq kg(-1), and the surface activity concentration from 0.1 kBq m(-2) to 5 kBq m(-2). The total absorbed gamma dose rates in air from natural and artificial radionuclides in these locations were calculated. The minimum value was 6 nGy h(-1) and the highest one was 135 nGy h(-1) with an average of 55 nGy h(-1) in which the natural terrestrial radiation contributes in 99% and the artificial radionuclides mainly (137)Cs contributes only in 1%. The total effective dose calculated varied in the range of 7 μSv y(-1) and 166 μSv y(-1) while the average value was 69 μSv y(-1) which is below the permissible limit 1000 μSv y(-1). PMID:23498968

  20. Radioactive aerosols released from the Chernobyl Shelter into the immediate environment.

    PubMed

    Garger, E K; Kashpur, V A; Li, W B; Tschiersch, J

    2006-07-01

    The release of radioactive particles through large gaps in the containment of the destroyed Chernobyl reactor was assessed during two measurement periods. In 1996-1999, a total radionuclide flow rate of 274 Bq s(-1) or 8.64 x 10(9) Bq year(-1) was determined. These releases were predominantly due to (137)Cs (78.5%), (90)Sr (21.1%), and (239+240)Pu (0.4%). The mean activity concentration in the aerosol measured directly at the gaps was about 240 mBq m(-3) with an activity median aerodynamic diameter (AMAD) of 2.4 microm for (137)Cs, 120 mBq m(-3) with an AMAD in the range 3.1-13 microm for (90)Sr, 1.8 mBq m(-3) with an AMAD in the range 3.5-11 microm for (239+240)Pu, and 2.0 mBq m(-3) with an AMAD of 1.5 microm for (241)Am. The resulting total inhalation dose rate calculated close to the gaps was about 100 nSv h(-1). In the near environment, the mean (137)Cs activity in the aerosol was 2.2 mBq m(-3) with an AMAD of 2.2 microm, which gave rise to an inhalation dose rate of about two orders of magnitude lower than the corresponding dose rate at the gaps. Occasionally, however, dose levels were measured in the near environment that were similar to those at the gaps. In 2000-2003, lower activity concentrations were observed. The decrease was more pronounced at the gaps than in the near environment. The results indicate that effective dose due to inhalation must be considered for the dose assessment of construction workers who will be deployed at the Chernobyl site to reconstruct the old or to build the new Shelter, in the future. PMID:16733725

  1. Influence of temperature and artificially-created physical barriers on the efficacy of synergized pyrethrin aerosol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flour mills in the United States are utilizing synergized pyrethrin aerosol for management of stored product insects. However, the dispersal of the aerosol within a facility may be hampered by barriers created from machinery and other equipment that block dispersion. Additionally, seasonal temperatu...

  2. An Improved Method for Estimating Aerosol Optical Thickness from Artificial Light Sources Observed by the Visible/Infrared Imaging Radiometer Suite Day/Night Band

    NASA Astrophysics Data System (ADS)

    McHardy, Theodore Mitchell

    Using Visible/Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) data, a method, dubbed the "variance method", is developed for retrieving nighttime aerosol optical thickness (AOT) values based on the dispersion of radiance values above an artificial light source. An improvement of a previous algorithm, this updated method derives a semi-quantitative indicator of nighttime AOT using artificial light sources. Nighttime AOT retrievals from the newly developed method are inter-compared with an interpolated value from late afternoon and early morning ground observations from four AErosol RObotic NETwork (AERONET) sites as well as column-integrated Aerosol Optical Depth (AOD) from one High Spectral Resolution LiDAR (HSRL) site at Huntsville, AL during the NASA Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaign, providing full diel coverage. This method does not account for lunar reflectance from either the surface or the aerosol layer. Sensitivity tests do no indicate large systematic or random errors associated with lunar illumination. VIIRS AOT retrievals yield a coefficient of determination (r2) of 0.60 and a root-mean-squared-error (RMSE) of 0.18 when compared against straddling daytime-averaged AERONET AOT values. Preliminary results suggest that artificial light sources can be used for estimating regional and global nighttime aerosol distributions in the future.

  3. State of radionuclides in seawater. Comparison of natural stable and artificial radioactive isotope s of mercury and zinc in natural waters of the arid zone of the USSR

    SciTech Connect

    Rakhmatov, U; Khikmatov, K; Kist, A.A.; Kulmatov, R.A.; Teshabaev, S.T.; Volkov, A.A.

    1986-09-01

    This paper studies the state of stable and artificial radioactive isotopes of merury and zinc in natural waters of the arid zone of the USSR by radioactivity and radiochemical methods. Convergent results have been obtained for the dissolved forms of mercury and zinc in natural waters of the arid zone in a comparison of the results of radioactivation analysis and laboratory simulation using the radionuclides mercury-203 and zinc-65.

  4. The technical basis for air pathway assessment of resuspended radioactive aerosols: LLNL experiences at seven sites around the world

    SciTech Connect

    Shinn, J.H.

    1993-09-01

    There is a large uncertainty in quantifying the inhalation pathway and the aerosol emission rate in human health assessments of radioactive-contamination sites. The need for site-specific assessments led to formation of our team of specialists at LLNL, who have participated in numerous field campaigns around the world. Our goal was to obtain all the information necessary for determining potential human exposures and to estimate source terms for turbulent transport of the emissions during both normal and disturbed soil conditions. That is, measurements were made of the key variables to quantify the suspended aerosols at the actual contamination sites, but different scenarios for habitation, site management, and site cleanup were included. The most notable locations of these site-investigations were the Marshall Islands (Bikini, Enewetak, and Rongelap), Nevada Test Site (GMX, Little Feller, Palanquin, and Plutonium Valley), Tonopah (Nevada--site of Roller Coaster), Savannah River Lab (South Carolina--H-Area site), Johnston Island (cleanup of rocket-impact site), Chernobyl (Ukraine--grass field end sandy beach sites near Nuclear Power Plant Unit 4), and Palomares (Spain--site of aircraft accident). This discussion will review the variables quantified, methods developed, general results, uncertainty of estimations, and recommendations for future research that are a result of our experience in these field studies.

  5. Debye-like shielding effect on low-cloud electricity by the radioactive aerosol after the Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Yamauchi, Masatoshi; Takeda, Masahiko; Makino, Masahiko; Owada, Takeshi

    2014-05-01

    The vertical (downward) component of the DC atmospheric electric field, or potential gradient (PG) at Kakioka, 150 km southwest of the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) was analyzed before and after the FNPP1 accident to examine whether the influence of floating radioactive is visible in the PG data under the rain cloud. We used one-minute PG data since 2006 (digital data is available), and obtained the following statistical tendencies. (1) Ten-minute averaged PG during or just before the rain during 13-31 March shows less excursion toward the negative (upward field) side after the accident in 2011 than the average from 2006 to 2013, (2) occurrence frequency of negative PG peaks of about -200 to -700 V/m (corresponding to light rain) is consistently low during March-April period after the accident than the average of the same months of the other years, and (3) time constant around the negative PG peaks during March-April period is shorter after the accident than before the accident beyond annual differences for peak PGs of -200 to -800 V/m (corresponding to light rain), while no difference is seen in May between 2011 and the other years. The end of April 2011 corresponds to the time when the floating radioactive materials significantly decreased. The results suggest that the radioactive aerosol that was originated from the FNPP1 accident might have affected the PG under electrified clouds during light rain. Since the effect is not seen during heavy rain or positive PG reflecting high clouds, it is quite possible that the increased ion density in the atmosphere, that is still very low compared to ordinary plasma, enhanced the Debye shielding effect over the negative charges at the lower part of the cloud.

  6. Artificial radioactivity in fuel peat and peat ash in Finland after the Chernobyl accident

    SciTech Connect

    Mustonen, R.A.; Reponen, A.R.; Jantunen, M.J.

    1989-04-01

    The accident at the Chernobyl nuclear power plant in April 1986 caused very uneven deposition of radionuclides in Finland. The deposited radionuclides were found in relatively high concentrations in fuel peat and especially in peat ash because a thin surface layer of peat-production bogs was extracted as fuel peat soon after the fallout occurred. Concentrations of artificial radionuclides in fuel peat and peat ash were measured at six peat-fired power plants in Finland throughout the heating season 1986-87. Concentrations of /sup 137/Cs in composite peat samples varied between 30 and 3600 Bq kg-1 dry weight and in ash samples between 600 and 68,000 Bq kg-1. High concentrations in peat ash caused some restrictions to the utilization of peat ash for various purposes.

  7. A cluster analysis of back trajectories to study the behaviour of radioactive aerosols in the south-east of Spain.

    PubMed

    Piñero-García, F; Ferro-García, M A; Chham, E; Cobos-Díaz, M; González-Rodelas, P

    2015-09-01

    This research is focused on the study of the influence of the air masses together with the local meteorological fluctuations on the amount of radioactive elements in aerosols at surface air of the southeastern of Iberian Peninsula. The radioactivity in aerosols has been determined by measuring the concentration activity of Gross β and (7)Be from January 4(th), 2011 to December 31(s)(t), 2013. The activity concentration (Bq/m(3)) of gross beta was measured by α/β Low-Level counter, whereas the activity concentration of (7)Be (Bq/m(3)) was detected by gamma spectrometry (Eγ = 477.6 KeV, Yield = 10.42%). The air mass origings have been set using k-means clustering analysis of daily 72-h kinematic 3D backward trajectories at 500 m, 1500 m and 3000 m of altitude. Finally, a multiple Regression Analysis (MRA) have been carried out in order to determine the influence of the origins and trajectories of the air masses and local meteorology variations on the evolution of Gross β and (7)Be activity concentration. In conclusion, the results of the current research demonstrate that the re-suspended mineral dust from Northern Africa transported by Mediterranean air masses at low altitude (500 m) and African air masses at high altitude (3000 m) increases the radioactivity concentration in aerosols at the surface atmosphere. In addition, the opposite influence of the Saharan intrusions at 1500 m of altitude on the behaviour of (7)Be aerosols deserves special attention. PMID:26070051

  8. Aerosol optical depth retrievals at the Izaña Atmospheric Observatory from 1941 to 2013 by using artificial neural networks

    NASA Astrophysics Data System (ADS)

    García, R. D.; García, O. E.; Cuevas, E.; Cachorro, V. E.; Barreto, A.; Guirado-Fuentes, C.; Kouremeti, N.; Bustos, J. J.; Romero-Campos, P. M.; de Frutos, A. M.

    2015-09-01

    This paper presents the reconstruction of the 73 year time series of the aerosol optical depth (AOD) at 500 nm at the subtropical high-mountain Izaña Atmospheric Observatory (IZO) located in Tenerife (Canary Islands, Spain). For this purpose, we have combined AOD estimates from artificial neural networks (ANNs) from 1941 to 2001 and AOD measurements directly obtained with a Precision Filter Radiometer (PFR) between 2003 and 2013. The analysis is limited to summer months (July-August-September), when the largest aerosol load is observed at IZO (Saharan mineral dust particles). The ANN AOD time series has been comprehensively validated against coincident AOD measurements performed with a solar spectrometer Mark-I (1984-2009) and AERONET (AErosol RObotic NETwork) CIMEL photometers (2004-2009) at IZO, obtaining a rather good agreement on a daily basis: Pearson coefficient, R, of 0.97 between AERONET and ANN AOD, and 0.93 between Mark-I and ANN AOD estimates. In addition, we have analyzed the long-term consistency between ANN AOD time series and long-term meteorological records identifying Saharan mineral dust events at IZO (synoptical observations and local wind records). Both analyses provide consistent results, with correlations larger than 85 %. Therefore, we can conclude the reconstructed AOD time series captures well the AOD variations and dust-laden Saharan air mass outbreaks at short-term and long-term time scales and, thus, it is suitable to be used in climate analysis.

  9. Aerosol optical depth retrievals at the Izaña Atmospheric Observatory from 1941 to 2013 by using artificial neural networks

    NASA Astrophysics Data System (ADS)

    García, R. D.; García, O. E.; Cuevas, E.; Cachorro, V. E.; Barreto, A.; Guirado-Fuentes, C.; Kouremeti, N.; Bustos, J. J.; Romero-Campos, P. M.; de Frutos, A. M.

    2016-01-01

    This paper presents the reconstruction of a 73-year time series of the aerosol optical depth (AOD) at 500 nm at the subtropical high-mountain Izaña Atmospheric Observatory (IZO) located in Tenerife (Canary Islands, Spain). For this purpose, we have combined AOD estimates from artificial neural networks (ANNs) from 1941 to 2001 and AOD measurements directly obtained with a Precision Filter Radiometer (PFR) between 2003 and 2013. The analysis is limited to summer months (July-August-September), when the largest aerosol load is observed at IZO (Saharan mineral dust particles). The ANN AOD time series has been comprehensively validated against coincident AOD measurements performed with a solar spectrometer Mark-I (1984-2009) and AERONET (AErosol RObotic NETwork) CIMEL photometers (2004-2009) at IZO, obtaining a rather good agreement on a daily basis: Pearson coefficient, R, of 0.97 between AERONET and ANN AOD, and 0.93 between Mark-I and ANN AOD estimates. In addition, we have analysed the long-term consistency between ANN AOD time series and long-term meteorological records identifying Saharan mineral dust events at IZO (synoptical observations and local wind records). Both analyses provide consistent results, with correlations > 85 %. Therefore, we can conclude that the reconstructed AOD time series captures well the AOD variations and dust-laden Saharan air mass outbreaks on short-term and long-term timescales and, thus, it is suitable to be used in climate analysis.

  10. Nuclear Aerosols: Direct Simulation and Elucidation of the Role of Multiple Components, Radioactivity, Charge, Shape and Spatial Inhomogeneity

    SciTech Connect

    Sudarshan K. Loyalka

    2008-10-12

    Nuclear aerosols can originate from severe core damae in light water reactors, core disruptive accidents in fast reactors, nuclear accidents during nuclear material transport, at waste disposal sites, or explosions. These aerosols evolve under natural transport processes as well as under the influence of engineered safety features. Such aerosols can be hazardous for the equipment inside the reactor, and when leaked into the environment, pose potential risks to the public. Hence, the origin, movement and distribution of these aerosols need to be studied and controlled.

  11. Effect of epicuticular wax crystals on the localization of artificially deposited sub-micron carbon-based aerosols on needles of Cryptomeria japonica.

    PubMed

    Nakaba, Satoshi; Yamane, Kenichi; Fukahori, Mie; Nugroho, Widyanto Dwi; Yamaguchi, Masahiro; Kuroda, Katsushi; Sano, Yuzou; Wuled Lenggoro, I; Izuta, Takeshi; Funada, Ryo

    2016-09-01

    Elucidation of the mechanism of adsorption of particles suspended in the gas-phase (aerosol) to the outer surfaces of leaves provides useful information for understanding the mechanisms of the effect of aerosol particles on the growth and physiological functions of trees. In the present study, we examined the localization of artificially deposited sub-micron-sized carbon-based particles on the surfaces of needles of Cryptomeria japonica, a typical Japanese coniferous tree species, by field-emission scanning electron microscopy. The clusters (aggregates) of carbon-based particles were deposited on the needle surface regions where epicuticular wax crystals were sparsely distributed. By contrast, no clusters of the particles were found on the needle surface regions with dense distribution of epicuticular wax crystals. Number of clusters of carbon-based particles per unit area showed statistically significant differences between regions with sparse epicuticular wax crystals and those with dense epicuticular wax crystals. These results suggest that epicuticular wax crystals affect distribution of carbon-based particles on needles. Therefore, densely distributed epicuticular wax crystals might prevent the deposition of sub-micron-sized carbon-based particles on the surfaces of needles of Cryptomeria japonica to retain the function of stomata. PMID:27294967

  12. Determination and mapping the spatial distribution of radioactivity of natural spring water in the Eastern Black Sea Region by using artificial neural network method.

    PubMed

    Yeşilkanat, Cafer Mert; Kobya, Yaşar

    2015-09-01

    In this study, radiological distribution of gross alpha, gross beta, (226)Ra, (232)Th, (40)K, and (137)Cs for a total of 40 natural spring water samples obtained from seven cities of the Eastern Black Sea Region was determined by artificial neural network (ANN) method. In the ANN method employed, the backpropagation algorithm, which estimates the backpropagation of the errors and results, was used. In the structure of ANN, five input parameters (latitude, longitude, altitude, major soil groups, and rainfall) were used for natural radionuclides and four input parameters (latitude, longitude, altitude, and rainfall) were used for artificial radionuclides, respectively. In addition, 75 % of the total data were used as the data of training and 25 % of them were used as test data in order to reveal the structure of each radionuclide. It has been seen that the results obtained explain the radiographic structure of the region very well. Spatial interpolation maps covering the whole region were created for each radionuclide including spots not measured by using these results. It has been determined that artificial neural network method can be used for mapping the spatial distribution of radioactivity with this study, which is conducted for the first time for the Black Sea Region. PMID:26307690

  13. Breast-milk radioactivity after a Tc-99m DTPA aerosol/Tc-99m MAA lung study

    SciTech Connect

    Mountford, P.J.; Hall, F.M.; Wells, C.P.; Coakley, A.J.

    1984-10-01

    Measurements were made of the concentration of Tc-99m activity in samples of breast milk following an administration of Tc-99m DTPA aerosol for a lung ventilation image and one of Tc-99m MAA for lung perfusion. The activity was 222 nCi/ml of milk (8.2 kBq/ml) at 2 hr after the MAA injection, and it was found to be excreted exponentially with an effective half-life of 4.6 hr. There was a small incorporation of Tc-99m into breast-milk protein. The authors conclude that the combined use of these two Tc-99m agents did not indicate the interruption of breast feeding beyond 24 hr after administration of the MAA, and that for an aerosol ventiliation study alone, breast feeding need not be interrupted for more than 4 hr after the test.

  14. Comparison of Tc-99m DTPA aerosol with radioactive gas ventilation imaging in patients (pts) with suspected pulmonary embolism (PE)

    SciTech Connect

    Alderson, P.O.; Kroop, S.A.; Biello, D.R.; Siegel, B.A.; Gottschalk, A.; Hoffer, P.B.; Ramanna, L.; Waxman, A.D.

    1984-01-01

    The utility of Tc-99m labeled DTPA aerosol (A) as a ventilation agent was compared to that of Xe-133 (Xe) or Kr-81m (Kr) gases in a series of 100 pts (age range 20-83, 53% women) undergoing ventilation-perfusion (V-P) imaging for suspected PE. The majority of pts had A and Xe studies in conjunction with P scans; 26 had A and Kr studies. All A studies were comprised of multiple 100K ct views performed prior to P scanning. Conventional Xe or Kr studies were then performed in conjunction with a multiview P scan. The studies were later reviewed by four independent readers who evaluated 100 V-P studies (100 A-P pairs, 100 gas-P pairs) and the accompanying chest radiographs and determined the probability of PE as none, low, high, or nondiagnostic (NDX). The A scans showed central hot spots in 27% of pts, but poor peripheral penetration in only 5%. Prominent lower lobe deposition was seen in 19 of the 66 pts who inhaled A upright, but in none who inhaled in the supine position. The A-P and gas-P scans were either both diagnostic or both NDX 82% of the time. There were 77% agreement between probability categories for A-P and Kr-P studies, and 74% agreement with Xe-P. These results were better than the inter-observer agreement for gas-P studies alone. Angiography revealed that 3 A-P studies were true negatives, 3 were true positives (pos), and one was a false pos (also pos by gas-P). The results suggest that commercially available DTPA aerosols provide comparable results to gas-P studies in pts with suspected PE.

  15. Emergency Protection from Aerosols

    SciTech Connect

    Cristy, G.A.

    2001-11-13

    Expedient methods were developed that could be used by an average person, using only materials readily available, to protect himself and his family from injury by toxic (e.g., radioactive) aerosols. The most effective means of protection was the use of a household vacuum cleaner to maintain a small positive pressure on a closed house during passage of the aerosol cloud. Protection factors of 800 and above were achieved.

  16. Radioactivity: A Natural Phenomenon.

    ERIC Educational Resources Information Center

    Ronneau, C.

    1990-01-01

    Discussed is misinformation people have on the subject of radiation. The importance of comparing artificial source levels of radiation to natural levels is emphasized. Measurements of radioactivity, its consequences, and comparisons between the risks induced by radiation in the environment and from artificial sources are included. (KR)

  17. Field tests using radioactive matter 2.

    PubMed

    Rulik, P; Prouza, Z; Hovorka, J; Beckova, V; Cespirova, I; Fronka, A; Helebrant, J; Hulka, J; Kuca, P; Skrkal, J

    2013-04-01

    Results of field tests with explosive dispersal of a radioactive substance (RaS) are presented. The paper deals with tests exploiting artificial obstacles as a continuation and expansion of the tests used in this study performed in free area described previously. The essential goal of the tests was to estimate the distribution of the released RaS in the case of intentional abuse of radioactive sources and to get a set of data applicable to testing physical or mathematical models of propagation. Effects of different geometrical and meteorological conditions on the distribution of dispersed RaS were studied via the assessment of dose rate, surface and volume activities, aerosol mass and activity aerodynamic diameters. The principal results can be summarised as follows: the prevalent proportion of the activity of the radionuclide dispersed by an explosion (born by the blast wave and by air convection) is transferred to the detection system/collecting pads essentially within the first minute. Enhanced aerosol mass concentrations were also detected within the same period. The RaS carried by the blast wave passed through the polygon (50 m) within <1 s. An expected crucial impact of meteorological conditions at the moment of the explosion and shortly after was proved by the tests. PMID:22923250

  18. Change of radioactive cesium (137Cs and 134Cs) content in cloud water at an elevated site in France, before and after the Fukushima nuclear accident: Comparison with radioactivity in rainwater and in aerosol particles

    NASA Astrophysics Data System (ADS)

    Masson, Olivier; de Vismes Ott, Anne; Bourcier, Laureline; Paulat, Pascal; Ribeiro, Mickael; Pichon, Jean-Marc; Sellegri, Karine; Gurriaran, Rodolfo

    2015-01-01

    Airborne cesium isotopes (134Cs and 137Cs) released during the Fukushima nuclear accident were transported all around the world attached to particles and reached France about 12 days after the first explosion. Concentration of cesium isotopes in cloud water sampled at the summit of the Puy de Dôme mountain (1465 m a.s.l.) increased by a factor of at least 40. During the following weeks, the concentrations decreased more slowly in cloud water than in rain and in rain compared with what was found on the aerosol phase. Cesium-134 was detectable in the aerosol phase, in rain and in cloud water for 3 months, 11 months and 18 months after the accident, respectively. These kinetics are consistent with the washout scavenging of aerosol in the lower layers of the atmosphere that leads to a relative depletion of Fukushima-labeled aerosols at ground level. Airborne particles at high altitudes, i.e. where clouds form, have a longer residence time. This finding has implications on the different time scales at which a contamination may be transferred to the ground, depending if it is transferred via dry or wet deposition. This study highlights that cloud water is a relevant type of environmental sample to attest the presence of radionuclides on a longer time scale than for the aerosol phase, provided that the metrology is able to lower usual detection limits. Rainout efficiency was computed for 137Cs.

  19. Independent Retrieval of Aerosol Type From Lidar

    NASA Astrophysics Data System (ADS)

    Nicolae, Doina; Vasilescu, Jeni; Talianu, Camelia; Dandocsi, Alexandru

    2016-06-01

    This paper presents an algorithm for aerosol typing from multiwavelength lidar data, based on Artificial Neural Networks. The aerosol model used to simulate optical properties for the training of the network is described. The algorithm is tested on real observations from ESA-CALIPSO database.

  20. Assessment of natural and artificial radioactivity levels and radiation hazards and their relation to heavy metals in the industrial area of Port Said city, Egypt.

    PubMed

    Attia, T E; Shendi, E H; Shehata, M A

    2015-02-01

    A detailed gamma ray spectrometry survey was carried out to make an action in environmental impact assessment of urbanization and industrialization on Port Said city, Egypt. The concentrations of the measured radioelements U-238, Th-232 in ppm, and K-40 %, in addition to the total counts of three selected randomly dumping sites (A, B, and C) were mapped. The concentration maps represent a base line for the radioactivity in the study area in order to detect any future radioactive contamination. These concentrations are ranging between 0.2 and 21 ppm for U-238 and 0.01 to 13.4 ppm for Th-232 as well as 0.15 to 3.8 % for K-40, whereas the total count values range from 8.7 to 123.6 uR. Moreover, the dose rate was mapped using the same spectrometer and survey parameters in order to assess the radiological effect of these radioelements. The dose rate values range from 0.12 to 1.61 mSv/year. Eighteen soil samples were collected from the sites with high radioelement concentrations and dose rates to determine the activity concentrations of Ra-226, Th-232, and K-40 using HPGe spectrometer. The activity concentrations of Ra-226, Th-232, and K-40 in the measured samples range from 18.03 to 398.66 Bq kg(-1), 5.28 to 75.7 Bq kg(-1), and 3,237.88 to 583.12 Bq kg(-1), respectively. In addition to analyze heavy metal for two high reading samples (a 1 and a 10) which give concentrations of Cd and Zn elements (a 1 40 ppm and a 10 42 ppm) and (a 1 0.90 ppm and a 10 0.97 ppm), respectively, that are in the range of phosphate fertilizer products that suggested a dumped man-made waste in site A. All indicate that the measured values for the soil samples in the two sites of three falls within the world ranges of soil in areas with normal levels of radioactivity, while site A shows a potential radiological risk for human beings, and it is important to carry out dose assessment program with a specifically detailed monitoring program periodically. PMID:25233912

  1. Artificial Limbs

    MedlinePlus

    ... you are missing an arm or leg, an artificial limb can sometimes replace it. The device, which ... activities such as walking, eating, or dressing. Some artificial limbs let you function nearly as well as ...

  2. Artificial Intelligence.

    ERIC Educational Resources Information Center

    Waltz, David L.

    1982-01-01

    Describes kinds of results achieved by computer programs in artificial intelligence. Topics discussed include heuristic searches, artificial intelligence/psychology, planning program, backward chaining, learning (focusing on Winograd's blocks to explore learning strategies), concept learning, constraint propagation, language understanding…

  3. Artificial Intelligence.

    ERIC Educational Resources Information Center

    Information Technology Quarterly, 1985

    1985-01-01

    This issue of "Information Technology Quarterly" is devoted to the theme of "Artificial Intelligence." It contains two major articles: (1) Artificial Intelligence and Law" (D. Peter O'Neill and George D. Wood); (2) "Artificial Intelligence: A Long and Winding Road" (John J. Simon, Jr.). In addition, it contains two sidebars: (1) "Calculating and…

  4. Radioactivity from Fukushima nuclear accident detected in Lisbon, Portugal.

    PubMed

    Carvalho, F P; Reis, M C; Oliveira, J M; Malta, M; Silva, L

    2012-12-01

    The radioactivity released from the Fukushima Dai-ichi nuclear accident was transported around the globe by atmospheric processes. Several artificial radionuclides were detected and measured in aerosols and atmospheric surface depositions in the Lisbon area during late March and early April 2011. The highest concentrations measured in aerosols were those of particulate (131)I, 1.39 ± 0.08 mBq m(-3). Cesium-134, (137)Cs and (132)Te were also determined but at lower concentrations. The total atmospheric depositions on the ground were higher on the first week of April with values for (131)I, (134)Cs, and (137)Cs of 0.92 ± 0.11, 0.59 ± 0.06, and 0.62 ± 0.12 Bq m(-2), respectively. The four artificial radionuclides measurable, (131)I, (132)Te (134)Cs, and (137)Cs, caused little radiation exposure to the members of the public, that was five orders of magnitude lower than the ionizing radiation effective dose limits for members of the public for one year (1 mSv y(-1)). PMID:22503401

  5. Organic aerosols

    SciTech Connect

    Penner, J.E.

    1994-01-01

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

  6. Aerosol Behavior Log-Normal Distribution Model.

    Energy Science and Technology Software Center (ESTSC)

    2001-10-22

    HAARM3, an acronym for Heterogeneous Aerosol Agglomeration Revised Model 3, is the third program in the HAARM series developed to predict the time-dependent behavior of radioactive aerosols under postulated LMFBR accident conditions. HAARM3 was developed to include mechanisms of aerosol growth and removal which had not been accounted for in the earlier models. In addition, experimental measurements obtained on sodium oxide aerosols have been incorporated in the code. As in HAARM2, containment gas temperature, pressure,more » and temperature gradients normal to interior surfaces are permitted to vary with time. The effects of reduced density on sodium oxide agglomerate behavior and of nonspherical shape of particles on aerosol behavior mechanisms are taken into account, and aerosol agglomeration due to turbulent air motion is considered. Also included is a capability to calculate aerosol concentration attenuation factors and to restart problems requiring long computing times.« less

  7. Study of radioactive contamination in silts and aerosols at Aldama City, Mexico, due to the operation of a yellow-cake processing plant.

    PubMed

    Montelongo, Michel Y; Herrera, Eduardo F; Ramirez, Elias; Carrillo, Jorge I; Campos, Alfredo; Gomez, Ramón; Montero, Maria E; Rodriguez, Luis M

    2015-08-01

    The city of Aldama, Chihuahua, Mexico is located 30 km NNE of Chihuahua city. Three high-volume collectors with PM10 heads were placed in specific locations in Aldama during the year 2011 to measure radioisotope concentrations in the air. The city area of 16 km² was divided into 64 squares of 500 × 500 m. At the vertices of the grid, silt samples were taken between January and June 2011, before the rains began. The concentrations of natural, cosmogenic, and anthropogenic radioactive isotopes were calculated in both filters and silts samples. The isotopes selected for the measurement were ²³⁸U, ²³²Th, (7)Be, ¹³⁷Cs, and ⁴⁰K. Measurements of PM10 and silts were performed during 2011, coinciding with the accident at Fukushima, Japan, on March 11. For this reason, we could see the ¹³⁷Cs in PM10 increase between April and July; with the arrival of the rains, the ¹³⁷Cs concentration began to decrease in the air. The concentration of PM10 measured by the equipment located at the Mexican Uranium plant (URAMEX, initials in Spanish) that was processing radioactive ores exceeded the standard values in February and March, when the air velocity increases. At City Hall, the concentration of PM10 surpassed the value of the standard between May and July. This increased concentration is likely due to increased automobile traffic because City Hall is located in the city center. At a private home, the concentration of PM10 surpassed the standard on several days during the year because the home is located on the outskirts of the city, where most of the streets are not paved. Due to the high concentrations of PM10, especially at the collection point located at the private home, it is necessary to start taking steps to mitigate their spread before they cause health problems in the younger population and in older adults. PMID:26211631

  8. Artificial Intelligence.

    ERIC Educational Resources Information Center

    Thornburg, David D.

    1986-01-01

    Overview of the artificial intelligence (AI) field provides a definition; discusses past research and areas of future research; describes the design, functions, and capabilities of expert systems and the "Turing Test" for machine intelligence; and lists additional sources for information on artificial intelligence. Languages of AI are also briefly…

  9. Artificial Intelligence.

    ERIC Educational Resources Information Center

    Smith, Linda C.; And Others

    1988-01-01

    A series of articles focuses on artificial intelligence research and development to enhance information systems and services. Topics discussed include knowledge base designs, expert system development tools, natural language processing, expert systems for reference services, and the role that artificial intelligence concepts should have in…

  10. Artificial intelligence

    SciTech Connect

    Firschein, O.

    1984-01-01

    This book presents papers on artificial intelligence. Topics considered include knowledge engineering, expert systems, applications of artificial intelligence to scientific reasoning, planning and problem solving, error recovery in robots through failure reason analysis, programming languages, natural language, speech recognition, map-guided interpretation of remotely-sensed imagery, and image understanding architectures.

  11. Artificial urushi.

    PubMed

    Kobayashi, S; Uyama, H; Ikeda, R

    2001-11-19

    A new concept for the design and laccase-catalyzed preparation of "artificial urushi" from new urushiol analogues is described. The curing proceeded under mild reaction conditions to produce the very hard cross-linked film (artificial urushi) with a high gloss surface. A new cross-linkable polyphenol was synthesized by oxidative polymerization of cardanol, a phenol derivative from cashew-nut-shell liquid, by enzyme-related catalysts. The polyphenol was readily cured to produce the film (also artificial urushi) showing excellent dynamic viscoelasticity. PMID:11763444

  12. Artificial noses.

    PubMed

    Stitzel, Shannon E; Aernecke, Matthew J; Walt, David R

    2011-08-15

    The mammalian olfactory system is able to detect many more odorants than the number of receptors it has by utilizing cross-reactive odorant receptors that generate unique response patterns for each odorant. Mimicking the mammalian system, artificial noses combine cross-reactive sensor arrays with pattern recognition algorithms to create robust odor-discrimination systems. The first artificial nose reported in 1982 utilized a tin-oxide sensor array. Since then, however, a wide range of sensor technologies have been developed and commercialized. This review highlights the most commonly employed sensor types in artificial noses: electrical, gravimetric, and optical sensors. The applications of nose systems are also reviewed, covering areas such as food and beverage quality control, chemical warfare agent detection, and medical diagnostics. A brief discussion of future trends for the technology is also provided. PMID:21417721

  13. Global Aerosols

    Atmospheric Science Data Center

    2013-04-19

    ... sizes and from multiple sources, including biomass burning, mineral dust, sea salt and regional industrial pollution. A color scale is ... desert source region. Deserts are the main sources of mineral dust, and MISR obtains aerosol optical depth at visible wavelengths ...

  14. Environmental radioactivity measurements in Greece following the Fukushima Daichi nuclear accident.

    PubMed

    Potiriadis, C; Kolovou, M; Clouvas, A; Xanthos, S

    2012-07-01

    Since the double disaster of the 9.0 magnitude earthquake and tsunami that affected hundreds of thousands of people and seriously damaged the Fukushima Daichi power plant in Japan on 11 March 2011, traces of radioactive emissions from Fukushima have spread across the entire northern hemisphere. The radioactive isotope of iodine (131)I that was generated by the nuclear accident in Fukushima arrived in Greece on 24 March 2011. Radioactive iodine is present in the air either as gas or bound to particles (aerosols). The maximum (131)I concentrations were measured between 3 and 5 April 2011. In aerosols the maximum (131)I values measured in Southern Greece (Athens) and Northern Greece (Thessaloniki) were 585±70 and 408±61 μΒq m(-3), respectively. (131)I concentrations in gas were about 3.5 times higher than in aerosols. Since 29 April 2011, the (131)I concentration has been below detection limits. Traces of (137)Cs and (134)Cs were also measured in the air filters with an activity ratio of (137)Cs/(134)Cs equal to 1 and (131)I/(137)Cs activity ratio of about 3. Since 16 May 2011, the (137)Cs concentration in air has been determined to be about the same as before the Fukushima accident. Traces of (131)I were also measured in grass and milk. The maximum measured activity of (131)I in sheep milk was about 2 Bq l(-1) which is 5000 times less than that measured in Greece immediately after the Chernobyl accident. The measured activity concentrations of artificial radionuclides in Greece due to the Fukushima release, have been very low, with no impact on human health. PMID:22090415

  15. Artificial Intelligence.

    ERIC Educational Resources Information Center

    Wash, Darrel Patrick

    1989-01-01

    Making a machine seem intelligent is not easy. As a consequence, demand has been rising for computer professionals skilled in artificial intelligence and is likely to continue to go up. These workers develop expert systems and solve the mysteries of machine vision, natural language processing, and neural networks. (Editor)

  16. Influence of Radioactivity on Surface Interaction Forces

    SciTech Connect

    Walker, Mark E; McFarlane, Joanna; Glasgow, David C; Chung, Eunhyea; Taboada Serrano, Patricia L; Yiacoumi, Sotira; Tsouris, Costas

    2010-01-01

    Although some differences have been observed, the transport behavior of radioactive aerosol particles has often been assumed to be analogous to the behavior of nonradioactive aerosols in dispersion models. However, radioactive particles can become electrostatically charged as a result of the decay process. Theories have been proposed to describe this self-charging phenomenon, which may have a significant effect on how these particles interact with one another and with charged surfaces in the environment. In this study, atomic force microscopy (AFM) was employed to quantify surface forces between a particle and a planar surface and to compare measurements with and without the involvement of radioactivity. The main objective of this work is to assess directly the effects of radioactivity on the surface interactions of radioactive aerosols via the measurement of the adhesion force. The adhesion force between a silicon nitride AFM tip and an activated gold substrate was measured so that any possible effects due to radioactivity could be observed. The adhesion force between the tip and the gold surface increased significantly when the gold substrate (25 mm{sup 2} surface area) was activated to a level of approximately 0.6 mCi. The results of this investigation will prompt further work into the effects of radioactivity in particle-surface interactions.

  17. Artificial Intelligence.

    PubMed

    Lawrence, David R; Palacios-González, César; Harris, John

    2016-04-01

    It seems natural to think that the same prudential and ethical reasons for mutual respect and tolerance that one has vis-à-vis other human persons would hold toward newly encountered paradigmatic but nonhuman biological persons. One also tends to think that they would have similar reasons for treating we humans as creatures that count morally in our own right. This line of thought transcends biological boundaries-namely, with regard to artificially (super)intelligent persons-but is this a safe assumption? The issue concerns ultimate moral significance: the significance possessed by human persons, persons from other planets, and hypothetical nonorganic persons in the form of artificial intelligence (AI). This article investigates why our possible relations to AI persons could be more complicated than they first might appear, given that they might possess a radically different nature to us, to the point that civilized or peaceful coexistence in a determinate geographical space could be impossible to achieve. PMID:26957450

  18. Tropospheric Aerosols

    NASA Astrophysics Data System (ADS)

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

    2003-12-01

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

  19. Artificial halos

    NASA Astrophysics Data System (ADS)

    Selmke, Markus

    2015-09-01

    Judged by their frequency and beauty, ice halos easily rival rainbows as a prominent atmospheric optics phenomenon. This article presents experimental halo demonstrations of varying complexity. Using a single commercially available hexagonal glass prism, a variety of artificial halos can be simulated. The experiments include laser beam path analysis, a modified classic spinning prism experiment, and a novel Monte-Carlo machine for three-dimensional rotations. Each of these experiments emulates different conditions of certain halo displays, and in combination, they allow a thorough understanding of these striking phenomena.

  20. Environmental radioactivity measurements and applications - Difficulties, current status and future trends

    NASA Astrophysics Data System (ADS)

    Anagnostakis, Marios J.

    2015-11-01

    For several decades natural and artificial radioactivity in the environment have been extensively studied all around the world. Nuclear accidents - mainly that of Chernobyl - have led to the development of the field of radioecology, while detector systems and techniques - with predominant that of γ-spectrometry - have been continuously developed through the years to meet researchers' needs. The study of natural radionuclides that was originally limited to 226Ra, 232Th and 40K was then extended to include radionuclides such as 234Th, 210Pb, 235U and 7Be, which allowed the study of radioactive equilibrium. Besides their importance from the radiation protection point of view, many radionuclides are also used as tracers of environmental processes, such as aerosol and transportation of air masses studies (7Be, 10Be, 22Na), soil erosion, sedimentation and geochronology (210Pb, 137Cs), marine ecosystems studies and studies related to climate change. All these studies require specialized samplings strategies and sampling preparation techniques as well as high quality measurements, while the improvement of detection limits is often of vital importance. This work is a review of environmental radioactivity measurements and applications, mainly focused in the field of γ-spectrometry, for which difficulties and limitations will be presented, together with future trends, new challenges and applications.

  1. Artificial Hydrogenases

    PubMed Central

    Barton, Bryan E.; Olsen, Matthew T.; Rauchfuss, Thomas B.

    2010-01-01

    Decades of biophysical study on the hydrogenase (H2ase) enzymes have yielded sufficient information to guide the synthesis of analogues of their active sites. Three families of enzymes serve as inspiration for this work: the [FeFe]-, [NiFe]-, and [Fe]-H2ases, all of which feature iron centers bound to both CO and thiolate. Artificial H2ases effect the oxidation of H2 of H2 and the reverse reaction, the reduction of protons. These reactions occur via the intermediacy of metal hydrides. The inclusion of amine bases within the catalysts is an important design feature that is emulated in related bioinspired catalysts. Continuing challenges are the low reactivity of H2 towards biomimetic H2ases. PMID:20356731

  2. Artificial rheotaxis

    PubMed Central

    Palacci, Jérémie; Sacanna, Stefano; Abramian, Anaïs; Barral, Jérémie; Hanson, Kasey; Grosberg, Alexander Y.; Pine, David J.; Chaikin, Paul M.

    2015-01-01

    Motility is a basic feature of living microorganisms, and how it works is often determined by environmental cues. Recent efforts have focused on developing artificial systems that can mimic microorganisms, in particular their self-propulsion. We report on the design and characterization of synthetic self-propelled particles that migrate upstream, known as positive rheotaxis. This phenomenon results from a purely physical mechanism involving the interplay between the polarity of the particles and their alignment by a viscous torque. We show quantitative agreement between experimental data and a simple model of an overdamped Brownian pendulum. The model notably predicts the existence of a stagnation point in a diverging flow. We take advantage of this property to demonstrate that our active particles can sense and predictably organize in an imposed flow. Our colloidal system represents an important step toward the realization of biomimetic microsystems with the ability to sense and respond to environmental changes. PMID:26601175

  3. Artificial rheotaxis.

    PubMed

    Palacci, Jérémie; Sacanna, Stefano; Abramian, Anaïs; Barral, Jérémie; Hanson, Kasey; Grosberg, Alexander Y; Pine, David J; Chaikin, Paul M

    2015-05-01

    Motility is a basic feature of living microorganisms, and how it works is often determined by environmental cues. Recent efforts have focused on developing artificial systems that can mimic microorganisms, in particular their self-propulsion. We report on the design and characterization of synthetic self-propelled particles that migrate upstream, known as positive rheotaxis. This phenomenon results from a purely physical mechanism involving the interplay between the polarity of the particles and their alignment by a viscous torque. We show quantitative agreement between experimental data and a simple model of an overdamped Brownian pendulum. The model notably predicts the existence of a stagnation point in a diverging flow. We take advantage of this property to demonstrate that our active particles can sense and predictably organize in an imposed flow. Our colloidal system represents an important step toward the realization of biomimetic microsystems with the ability to sense and respond to environmental changes. PMID:26601175

  4. Atmospheric Aerosols

    NASA Technical Reports Server (NTRS)

    Pueschel, R. F.; Lawless, James G. (Technical Monitor)

    1994-01-01

    Aerosols, defined as particles and droplets suspended in air, are always present in the atmosphere. They are part of the earth-atmosphere climate system, because they interact with both incoming solar and outgoing terrestrial radiation. They do this directly through scattering and absorption, and indirectly through effects on clouds. Submicrometer aerosols usually predominate in terms of number of particles per unit volume of air. They have dimensions close to the wavelengths of visible light, and thus scatter radiation from the sun very effectively. They are produced in the atmosphere by chemical reactions of sulfur-, nitrogen- and carbon-containing gases of both natural and anthropogenic origins. Light absorption is dominated by particles containing elemental carbon (soot), produced by incomplete combustion of fossil fuels and by biomass burning. Light-scattering dominates globally, although absorption can be significant at high latitudes, particularly over highly reflective snow- or ice-covered surfaces. Other aerosol substances that may be locally important are those from volcanic eruptions, wildfires and windblown dust.

  5. Radioactive Wastes.

    PubMed

    Choudri, B S; Baawain, Mahad

    2016-10-01

    Papers reviewed herein present a general overview of radioactive waste activities around the world in 2015. These include safety assessments, decommission and decontamination of nuclear facilities, fusion facilities, transportation and management solutions for the final disposal of low and high level radioactive wastes (LLW and HLW), interim storage and final disposal options for spent fuel (SF), and tritiated wastes, with a focus on environmental impacts due to the mobility of radionuclides in water, soil and ecosystem alongwith other progress made in the management of radioactive wastes. PMID:27620100

  6. Radioactive Wastes.

    PubMed

    Choudri, B S; Baawain, Mahad

    2015-10-01

    Papers reviewed herein present a general overview of radioactive waste activities around the world in 2014. These include safety assessments, decommission and decontamination of nuclear facilities, fusion facilities, transportation and management solutions for the final disposal of low and high level radioactive wastes (LLW and HLW), interim storage and final disposal options for spent fuel (SF), and tritiated wastes, with a focus on environmental impacts due to the mobility of radionuclides in water, soil and ecosystem alongwith other progress made in the management of radioactive wastes. PMID:26420096

  7. Artificial Respiration and Artificial Circulation

    PubMed Central

    Brook, Joseph; Brook, Morris H.; Lopez, Jose F.

    1965-01-01

    A training program in the newer methods of treatment of acute cardiopulmonary emergencies which was developed at the University Hospital, University of Saskatchewan, is reported. Artificial respiration by the chance rescuer, primary and secondary resuscitation, and post-resuscitation measures involving the use of special drugs and equipment by trained personnel are described. Figures and tables designed for wall-mounting and ready reference in an emergency situation are presented. Firstaid ventilatory adjuncts for use by trained personnel are classified and critically appraised, and the propriety of their use is emphasized. A plea is made to the medical profession and allied agencies to assume the responsibility of spreading knowledge of the new techniques more widely. Unless effective treatment is instituted early enough to prevent death or permanent anoxic damage to heart and brain, follow-through therapy will often be fruitless. PMID:14339303

  8. Radioactivity Calculations

    ERIC Educational Resources Information Center

    Onega, Ronald J.

    1969-01-01

    Three problems in radioactive buildup and decay are presented and solved. Matrix algebra is used to solve the second problem. The third problem deals with flux depression and is solved by the use of differential equations. (LC)

  9. Simulated Radioactivity

    ERIC Educational Resources Information Center

    Boettler, James L.

    1972-01-01

    Describes the errors in the sugar-cube experiment related to radioactivity as described in Project Physics course. The discussion considers some of the steps overlooked in the experiment and generalizes the theory beyond the sugar-cube stage. (PS)

  10. Concentrating Radioactivity

    ERIC Educational Resources Information Center

    Herrmann, Richard A.

    1974-01-01

    By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

  11. Investigating Methods for Nighttime Aerosol Optical Depth Retrieval Using the VIIRS Day/Night Band

    NASA Astrophysics Data System (ADS)

    McHardy, T. M.; Zhang, J.; Reid, J. S.; Hyer, E. J.

    2014-12-01

    Most of the existing aerosol sensitive passive sensors focus on detecting day time aerosol properties. The Visible/Infrared Imaging Radiometer Suite (VIIRS) contains a Day/Night Band (DNB) which is capable of remote sensing of aerosol signals at night. This brings an opportunity for studying nighttime aerosol optical properties at a high spatial and temporal resolution. Using VIIRS DNB data, several methods are developed for retrieving aerosol optical depth values over regions with artificial city lights. These methods are based on changes in diffuse scattering of artificial light due to particles in the atmosphere. The first method compares average radiance values of artificial light sources against that of nearby dark pixels. The second method examines the dispersion of radiance values above an artificial light source. The strengths and weaknesses of each method are investigated over selected artificial city light sources that are within close proximity to Aerosol Robotic Network (AERONET) sites. This study suggests that nighttime retrievals of aerosol properties at high spatial and temporal resolution using the VIIRS DNB may be viable in the future.

  12. Global Atmospheric Aerosol Modeling

    NASA Technical Reports Server (NTRS)

    Hendricks, Johannes; Aquila, Valentina; Righi, Mattia

    2012-01-01

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

  13. PERSPECTIVE: Fireworks and radioactivity

    NASA Astrophysics Data System (ADS)

    Breitenecker, Katharina

    2009-09-01

    both reaction products and unburnt constituents of a pyrotechnic mixture. One major environmental concern in pyrotechnics focuses on the emission of heavy metals. This is the topic discussed in the article by Georg Steinhauser and Andreas Musilek in this issue [4]. A possible interrelationship between respiratory effects and fireworks emissions of barium-rich aerosols was also raised last year [5]. In recent years the potential hazard of naturally occurring radioactive material has become of importance to the scientific community. Naturally occurring radionuclides can be of terrestrial or cosmological origin. Terrestrial radionuclides were present in the presolar cloud that later contracted in order to build our solar system. These radionuclides—mainly heavy metals—and their non-radioactive isotopes are nowadays fixed in the matrix of the Earth's structure. Usually, their percentage is quite small compared to their respective stable isotopes—though there are exceptions like in the case of radium. The problem with environmental pollution due to naturally occurring radioactive material begins when this material is concentrated due to mining and milling, and later further processed [6]. Environmental pollution due to radioactive material goes back as far as the Copper and Iron Ages, when the first mines were erected in order to mine ores (gold, silver, copper, iron, etc), resulting in naturally occurring radioactive material being set free with other dusts into the atmosphere. So where is the link between pyrotechnics and radioactivity? In this article presented by Georg Steinhauser and Andreas Musilek [4], the pyrotechnic ingredients barium nitrate and strontium nitrate are explored with respect to their chemical similarities to radium. The fundamental question, therefore, was whether radium can be processed together with barium and strontium. If so, the production and ignition of these pyrotechnic ingredients could cause atmospheric pollution with radium aerosols

  14. RADIOACTIVE BATTERY

    DOEpatents

    Birden, J.H.; Jordan, K.C.

    1959-11-17

    A radioactive battery which includes a capsule containing the active material and a thermopile associated therewith is presented. The capsule is both a shield to stop the radiations and thereby make the battery safe to use, and an energy conventer. The intense radioactive decay taking place inside is converted to useful heat at the capsule surface. The heat is conducted to the hot thermojunctions of a thermopile. The cold junctions of the thermopile are thermally insulated from the heat source, so that a temperature difference occurs between the hot and cold junctions, causing an electrical current of a constant magnitude to flow.

  15. Aerosol gels

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

  16. Radioactive wastes

    SciTech Connect

    Devarakonda, M.S.; Hickox, J.A.

    1996-11-01

    This paper provides a review of literature published in 1995 on the subject of radioactive wastes. Topics covered include: national programs; waste repositories; mixed wastes; decontamination and decommissioning; remedial actions and treatment; and environmental occurrence and transport of radionuclides. 155 refs.

  17. Radioactive Waste.

    ERIC Educational Resources Information Center

    Blaylock, B. G.

    1978-01-01

    Presents a literature review of radioactive waste disposal, covering publications of 1976-77. Some of the studies included are: (1) high-level and long-lived wastes, and (2) release and burial of low-level wastes. A list of 42 references is also presented. (HM)

  18. Aerosol typing - key information from aerosol studies

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  19. Sampling submicron T1 bacteriophage aerosols.

    PubMed

    Harstad, J B

    1965-11-01

    Liquid impingers, filter papers, and fritted bubblers were partial viable collectors of radioactive submicron T1 bacteriophage aerosols at 30, 55, and 85% relative humidity. Sampler differences for viable collection were due to incomplete physical collection (slippage) and killing of phage by the samplers. Dynamic aerosols of a mass median diameter of 0.2 mu were produced with a Dautrebande generator from concentrated aqueous purified phage suspensions containing extracellular soluble radioactive phosphate as a physical tracer. There was considerable destruction of phage by the Dautrebande generator; phage titers of the Dautrebande suspension decreased exponentially, but there was a progressive (linear) increase in tracer titers. Liquid impingers recovered the most viable phage but allowed considerable (30 to 48%) slippage, which varies inversely with the aerosol relative humidity. Filter papers were virtually complete physical collectors of submicron particles but were the most destructive. Fritted bubbler slippage was more than 80%. With all samplers, phage kill was highest at 85% relative humidity and lowest at 55% relative humidity. An electrostatic precipitator was used to collect aerosol samples for particle sizing with an electron microscope. The particle size was slightly larger at 85% relative humidity than at 30 or 55% relative humidity. PMID:5866038

  20. Do anthropogenic, continental or coastal aerosol sources impact on a marine aerosol signature at Mace Head?

    NASA Astrophysics Data System (ADS)

    O'Dowd, C.; Ceburnis, D.; Ovadnevaite, J.; Vaishya, A.; Rinaldi, M.; Facchini, M. C.

    2014-10-01

    Atmospheric aerosols have been sampled and characterised at the Mace Head north-east (NE) Atlantic atmospheric research station since 1958, with many interesting phenomena being discovered. However, with the range of new discoveries and scientific advances, there has been a range of concomitant criticisms challenging the representativeness of aerosol sampled at the station compared to that of aerosol over the pristine open-ocean. Two recurring criticisms relate to the lack of representativeness due to potentially enhanced coastal sources, possibly leading to artificially high values of aerosol concentrations, and to the influence of long-range transport of anthropogenic or continental aerosol and its potential dominance over, or perturbation of, a natural marine aerosol signal. Here, we review the results of previous experimental studies on marine aerosols over the NE Atlantic and at Mace Head with the aim of evaluating their representativeness relative to that of a pristine open-ocean aerosol, i.e. with negligible anthropogenic/continental influence. Particular focus is given to submicron organic matter (OM) aerosol. In summary, no correlation was found between OM and black carbon (BC) in marine air conforming to clean-air sampling criteria, either at BC levels of 0-15 or 15-50 ng m-3, suggesting that OM concentrations, up to observed peak values of 3.8 μg m-3, are predominantly natural in origin. Sophisticated carbon isotope analysis and aerosol mass spectral finger printing techniques corroborate the conclusion that there is a predominant natural source of OM, with 80% biogenic source apportionment being observed for general clean-air conditions, rising to ∼98% during specific primary marine organic plumes when peak OM mass concentrations > 3 μg m-3 are observed. Similarly, a maximum contribution of 20% OM mass coming from non-marine sources was established by dual carbon isotope analysis. Further, analysis of a series of experiments conducted at Mace Head

  1. Electrodynamic radioactivity detector for microparticles

    NASA Astrophysics Data System (ADS)

    Ward, T. L.; Davis, E. J.; Jenkins, R. W., Jr.; McRae, D. D.

    1989-03-01

    A new technique for the measurement of the radioactive decay of single microparticles has been demonstrated. Although the experiments were made with droplets of order 20 μm in diameter, microparticles in the range 0.1-100 μm can be accommodated. An electrodynamic balance and combination light-scattering photometer were used to measure the charge-loss rate and size of a charged microsphere suspended in a laser beam by superposed ac and dc electrical fields. The charged particle undergoes charge loss in the partially ionized gas atmosphere which results from radioactive decay of 14C-tagged compounds, and the rate of charge loss is proportional to the rate of decay here. The charge on a particle was determined by measuring the dc voltage necessary to stably suspend the particle against gravity while simultaneously determining the droplet size by light-scattering techniques. The parameters which affect the operation of the electrodynamic balance as a radioactivity detector are examined, and the limits of its sensitivity are explored. Radioactivity levels as low as 120 pCi have been measured, and it appears that by reducing the background contamination inside our balance activity levels on the order of 10 pCi can be detected. This new technique has application in the measurement of activity levels and source discrimination of natural and man-made aerosols and smokes and is also useful for studies involving specifically labeled radio-chemical probes.

  2. Aerosol mobility size spectrometer

    DOEpatents

    Wang, Jian; Kulkarni, Pramod

    2007-11-20

    A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

  3. Optical measurement of medical aerosol media parameters

    NASA Astrophysics Data System (ADS)

    Sharkany, Josif P.; Zhytov, Nikolay B.; Sichka, Mikhail J.; Lemko, Ivan S.; Pintye, Josif L.; Chonka, Yaroslav V.

    2000-07-01

    The problem of aerosol media parameters measurements are presented in the work and these media are used for the treatment of the patients with bronchial asthma moreover we show the results of the development and the concentration and dispersity of the particles for the long-term monitoring under such conditions when the aggressive surroundings are available. The system for concentration measurements is developed, which consists of two identical photometers permitting to carry out the measurements of the transmission changes and the light dispersion depending on the concentration of the particles. The given system permits to take into account the error, connected with the deposition of the salt particles on the optical windows and the mirrors in the course of the long-term monitoring. For the controlling of the dispersity of the aggressive media aerosols the optical system is developed and used for the non-stop analysis of the Fure-spectra of the aerosols which deposit on the lavsan film. The registration of the information is performed with the help of the rule of the photoreceivers or CCD-chamber which are located in the Fure- plane. With the help of the developed optical system the measurements of the concentration and dispersity of the rock-salt aerosols were made in the medical mines of Solotvino (Ukraine) and in the artificial chambers of the aerosol therapy.

  4. Inflatable artificial sphincter

    MedlinePlus

    ... works well. When you need to urinate, the cuff of the artificial sphincter can be relaxed so ... pain. An artificial sphincter has three parts: A cuff, which fits around your urethra, the tube that ...

  5. A Cough Aerosol Simulator for the Study of Disease Transmission by Human Cough-Generated Aerosols

    PubMed Central

    Lindsley, William G.; Reynolds, Jeffrey S.; Szalajda, Jonathan V.; Noti, John D.; Beezhold, Donald H.

    2015-01-01

    Aerosol particles expelled during human coughs are a potential pathway for infectious disease transmission. However, the importance of airborne transmission is unclear for many diseases. To better understand the role of cough aerosol particles in the spread of disease and the efficacy of different types of protective measures, we constructed a cough aerosol simulator that produces a humanlike cough in a controlled environment. The simulated cough has a 4.2 l volume and is based on coughs recorded from influenza patients. In one configuration, the simulator produces a cough aerosol containing particles from 0.1 to 100 µm in diameter with a volume median diameter (VMD) of 8.5 µm and a geometric standard deviation (GSD) of 2.9. In a second configuration, the cough aerosol has a size range of 0.1–30 µm, a VMD of 3.4 µm, and a GSD of 2.3. The total aerosol volume expelled during each cough is 68 µl. By generating a controlled and reproducible artificial cough, the simulator allows us to test different ventilation, disinfection, and personal protection scenarios. The system can be used with live pathogens, including influenza virus, which allows isolation precautions used in the healthcare field to be tested without risk of exposure for workers or patients. The information gained from tests with the simulator will help to better understand the transmission of infectious diseases, develop improved techniques for infection control, and improve safety for healthcare workers and patients. PMID:26500387

  6. Decontamination of protective clothing against radioactive contamination.

    PubMed

    Vošahlíková, I; Otáhal, P

    2014-11-01

    The aim of this study is to describe the experimental results of external surface mechanical decontamination of the studied materials forming selected suits. Seven types of personal protective suits declaring protection against radioactive aerosol contamination in different price ranges were selected for decontamination experiments. The outcome of this study is to compare the efficiency of a double-step decontamination process on various personal protective suits against radioactive contamination. A comparison of the decontamination effectiveness for the same type of suit, but for the different chemical mixtures ((140)La in a water-soluble or in a water-insoluble compound), was performed. PMID:25084793

  7. AEROSOL AND GAS MEASUREMENT

    EPA Science Inventory

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

  8. Aerosols and environmental pollution

    NASA Astrophysics Data System (ADS)

    Colbeck, Ian; Lazaridis, Mihalis

    2010-02-01

    The number of publications on atmospheric aerosols has dramatically increased in recent years. This review, predominantly from a European perspective, summarizes the current state of knowledge of the role played by aerosols in environmental pollution and, in addition, highlights gaps in our current knowledge. Aerosol particles are ubiquitous in the Earth’s atmosphere and are central to many environmental issues; ranging from the Earth’s radiative budget to human health. Aerosol size distribution and chemical composition are crucial parameters that determine their dynamics in the atmosphere. Sources of aerosols are both anthropogenic and natural ranging from vehicular emissions to dust resuspension. Ambient concentrations of aerosols are elevated in urban areas with lower values at rural sites. A comprehensive understanding of aerosol ambient characteristics requires a combination of measurements and modeling tools. Legislation for ambient aerosols has been introduced at national and international levels aiming to protect human health and the environment.

  9. Aerosol distribution apparatus

    DOEpatents

    Hanson, W.D.

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

  10. Solid aerosol generator

    DOEpatents

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

    1992-03-17

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

  11. Improved solid aerosol generator

    DOEpatents

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

    1988-07-19

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

  12. Solid aerosol generator

    DOEpatents

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

    1992-01-01

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

  13. Tropopsheric Aerosol Chemistry via Aerosol Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Worsnop, Douglas

    2008-03-01

    A broad overview of size resolved aerosol chemistry in urban, rural and remote regions is evolving from deployment of aerosol mass spectrometers (AMS) throughout the northern hemisphere. Using thermal vaporization and electron impact ionization as universal detector of non-refractory inorganic and organic composition, the accumulation of AMS results represent a library of mass spectral signatures of aerosol chemistry. For organics in particular, mass spectral factor analysis provides a procedure for classifying (and simplifying) complex mixtures composed of the hundreds or thousands of individual compounds. Correlations with parallel gas and aerosol measurements (e.g. GC/MS, HNMR, FTIR) supply additional chemical information needed to interpret mass spectra. The challenge is to separate primary and secondary; anthropogenic, biogenic and biomass burning sources - and subsequent - transformations of aerosol chemistry and microphysics.

  14. Reallocation in modal aerosol models: impacts on predicting aerosol radiative effects

    NASA Astrophysics Data System (ADS)

    Korhola, T.; Kokkola, H.; Korhonen, H.; Partanen, A.-I.; Laaksonen, A.; Lehtinen, K. E. J.; Romakkaniemi, S.

    2014-01-01

    Atmospheric models often represent the aerosol particle size distribution with a modal approach, in which particles are described with log-normal modes within predetermined size ranges. This approach reallocates particles numerically from one mode to another for example during particle growth, potentially leading to artificial changes in the aerosol size distribution. In this study we analysed how the modal reallocation affects climate-relevant variables: cloud droplet number concentration (CDNC), aerosol-cloud interaction parameter (ACI) and light extinction coefficient (qext). The ACI parameter gives the response of CDNC to a change in total aerosol number concentration. We compared these variables between a modal model (with and without reallocation routines) and a high resolution sectional model, which was considered a reference model. We analysed the relative differences in the chosen variables in four experiments designed to assess the influence of atmospheric aerosol processes. We find that limiting the allowed size ranges of the modes, and subsequent remapping of the distribution, leads almost always to an underestimation of cloud droplet number concentrations (by up to 100%) and an overestimation of light extinction (by up to 20%). On the other hand, the aerosol-cloud interaction parameter can be either over- or underestimated by the reallocating model, depending on the conditions. For example, in the case of atmospheric new particle formation events followed by rapid particle growth, the reallocation can cause on average a 10% overestimation of the ACI parameter. Thus it is shown that the reallocation affects the ability of a model to estimate aerosol climate effects accurately, and this should be taken into account when using and developing aerosol models.

  15. Complex measurements of aerosol and ion characteristics in the atmospheric boundary layer

    NASA Astrophysics Data System (ADS)

    Kikas, Iu. E.; Kolomiets, S. M.; Kornienko, V. I.; Mirme, A. A.; Sal'm, Ia. I.; Sergeev, I. Ia.; Tammet, Kh. F.

    Results of a comprehensive study of the characteristics of atmospheric ions and aerosols in the boundary layer during the summer season are reported. A study is also made of the kinetics of aerosol formation under conditions of high artificial ionization of the air by alpha and UV radiation. A high degree of correlation is shown to exist between atmospheric concentrations of medium ions and fine (less than 0.01 micron) aerosol. The results obtained support the radiation-chemical mechanism of aerosol formation.

  16. Aerosolization of two strains (ice+ and ice-) of Pseudomonas syringae in a Collison nebulizer at different temperatures

    NASA Astrophysics Data System (ADS)

    Pietsch, Renee; David, Ray; Marr, Linsey; Vinatzer, Boris; Schmale, David

    2015-04-01

    The aerosolization of microorganisms from aquatic environments is understudied. In this study, an ice nucleation active (ice+) strain and a non-ice nucleation active (ice-) strain of the bacterium Pseudomonas syringae were aerosolized from aqueous suspensions under artificial laboratory conditions using a Collison nebulizer. The aerosolization of P. syringae was not influenced by water temperatures between 5° and 30°C. In general, the culturability (viability) of P. syringae in aerosols increased with temperature between 5 and 30°C. The ice+ strain was aerosolized in greater numbers than the ice- strain at all temperatures studied, suggesting a possible connection between the ice nucleation phenotype and aerosol production. Together, our results suggest that P. syringae has the potential to be aerosolized from natural aquatic environments, such as streams, rivers, ponds, and lakes; known reservoirs of P. syringae. Future work is needed to elucidate the mechanisms of aerosolization of P. syringae from natural aquatic systems.

  17. Soils: man-caused radioactivity and radiation forecast

    SciTech Connect

    Gablin, Vassily

    2007-07-01

    Available in abstract form only. Full text of publication follows: One of the main tasks of the radiation safety guarantee is non-admission of the excess over critical radiation levels. In Russia they are man-caused radiation levels. Meanwhile any radiation measurement represents total radioactivity. That is why it is hard to assess natural and man-caused contributions to total radioactivity. It is shown that soil radioactivity depends on natural factors including radioactivity of rocks and cosmic radiation as well as man-caused factors including nuclear and non-nuclear technologies. Whole totality of these factors includes unpredictable (non-deterministic) factors - nuclear explosions and radiation accidents, and predictable ones (deterministic) - all the rest. Deterministic factors represent background radioactivity whose trends is the base of the radiation forecast. Non-deterministic factors represent man-caused radiation treatment contribution which is to be controlled. This contribution is equal to the difference in measured radioactivity and radiation background. The way of calculation of background radioactivity is proposed. Contemporary soils are complicated technologically influenced systems with multi-leveled spatial and temporary inhomogeneity of radionuclides distribution. Generally analysis area can be characterized by any set of factors of soil radioactivity including natural and man-caused factors. Natural factors are cosmic radiation and radioactivity of rocks. Man-caused factors are shown on Fig. 1. It is obvious that man-caused radioactivity is due to both artificial and natural emitters. Any result of radiation measurement represents total radioactivity i.e. the sum of activities resulting from natural and man-caused emitters. There is no gauge which could separately measure natural and man-caused radioactivity. That is why it is so hard to assess natural and man-caused contributions to soil radioactivity. It would have been possible if human

  18. Do anthropogenic or coastal aerosol sources impact on a clean marine aerosol signature at Mace Head?

    NASA Astrophysics Data System (ADS)

    O'Dowd, C.; Ceburnis, D.; Ovadnevaite, J.; Rinaldi, M.; Facchini, M. C.

    2013-03-01

    Atmospheric aerosols have been sampled and characterised at the Mace Head North East (N.E.) Atlantic atmospheric research station since 1958, with many interesting phenomena being discovered. However, with the range of new discoveries and scientific advances, there has been a range of concomitant criticisms challenging the representativeness of aerosol sampled at the station to that of aerosol over the open ocean. Two recurring criticisms relate to the lack of representativeness due to enhanced coastal sources, thereby leading to artificially high values to aerosol parameters, and to the influence of long-range transport of anthropogenic aerosol and its potential dominance over, or drowning-out of, a natural marine aerosol signal. Here we review the results of previous experimental studies into marine aerosols over the N.E. Atlantic and at Mace Head with the aim of evaluating their representativeness relative to that of an open ocean aerosol with negligible anthropogenic influence. Particular focus is given to organic matter (OM) aerosol. In summary, no correlation was found between OM and black carbon (BC) either at BC levels of 0-15 or 15-50 ng m-3, suggesting that OM concentrations up to peak values of 3.8 μg m-3 are predominantly natural in origin. Sophisticated carbon isotope analysis and aerosol mass spectral finger printing corroborate the natural source of OM with 80% biogenic source apportionment being observed for general clean air conditions, rising to 98% during specific primary marine organic plumes when peak concentrations >3 μg m-3 are observed. A range of other experiments are discussed which corroborate the dominance of a marine signal under Mace Head clean air criteria along. Further, analysis of a series of experiments conducted at Mace Head conclude that negligible coastal, surf zone, or tidal effects are discernible in the submicron size range for sampling heights of 7 m and above. The Mace Head clean air criteria ensures anthropogenic and

  19. PERSPECTIVE: Fireworks and radioactivity

    NASA Astrophysics Data System (ADS)

    Breitenecker, Katharina

    2009-09-01

    both reaction products and unburnt constituents of a pyrotechnic mixture. One major environmental concern in pyrotechnics focuses on the emission of heavy metals. This is the topic discussed in the article by Georg Steinhauser and Andreas Musilek in this issue [4]. A possible interrelationship between respiratory effects and fireworks emissions of barium-rich aerosols was also raised last year [5]. In recent years the potential hazard of naturally occurring radioactive material has become of importance to the scientific community. Naturally occurring radionuclides can be of terrestrial or cosmological origin. Terrestrial radionuclides were present in the presolar cloud that later contracted in order to build our solar system. These radionuclides—mainly heavy metals—and their non-radioactive isotopes are nowadays fixed in the matrix of the Earth's structure. Usually, their percentage is quite small compared to their respective stable isotopes—though there are exceptions like in the case of radium. The problem with environmental pollution due to naturally occurring radioactive material begins when this material is concentrated due to mining and milling, and later further processed [6]. Environmental pollution due to radioactive material goes back as far as the Copper and Iron Ages, when the first mines were erected in order to mine ores (gold, silver, copper, iron, etc), resulting in naturally occurring radioactive material being set free with other dusts into the atmosphere. So where is the link between pyrotechnics and radioactivity? In this article presented by Georg Steinhauser and Andreas Musilek [4], the pyrotechnic ingredients barium nitrate and strontium nitrate are explored with respect to their chemical similarities to radium. The fundamental question, therefore, was whether radium can be processed together with barium and strontium. If so, the production and ignition of these pyrotechnic ingredients could cause atmospheric pollution with radium aerosols

  20. Artificial Intelligence in Astronomy

    NASA Astrophysics Data System (ADS)

    Devinney, E. J.; Prša, A.; Guinan, E. F.; Degeorge, M.

    2010-12-01

    From the perspective (and bias) as Eclipsing Binary researchers, we give a brief overview of the development of Artificial Intelligence (AI) applications, describe major application areas of AI in astronomy, and illustrate the power of an AI approach in an application developed under the EBAI (Eclipsing Binaries via Artificial Intelligence) project, which employs Artificial Neural Network technology for estimating light curve solution parameters of eclipsing binary systems.

  1. An artificial muscle computer

    NASA Astrophysics Data System (ADS)

    Marc O'Brien, Benjamin; Alexander Anderson, Iain

    2013-03-01

    We have built an artificial muscle computer based on Wolfram's "2, 3" Turing machine architecture, the simplest known universal Turing machine. Our computer uses artificial muscles for its instruction set, output buffers, and memory write and addressing mechanisms. The computer is very slow and large (0.15 Hz, ˜1 m3); however by using only 13 artificial muscle relays, it is capable of solving any computable problem given sufficient memory, time, and reliability. The development of this computer shows that artificial muscles can think—paving the way for soft robots with reflexes like those seen in nature.

  2. The Impact of Geoengineering Aerosols on Stratospheric Temperature and Ozone

    NASA Technical Reports Server (NTRS)

    Heckendorn, P.; Weisenstein, D.; Fueglistaler, S.; Luo, B. P.; Rozanov, E.; Schraner, M.; Peter, T.; Thomason, L. W.

    2009-01-01

    Anthropogenic greenhouse gas emissions are warming the global climate at an unprecedented rate. Significant emission reductions will be required soon to avoid a rapid temperature rise. As a potential interim measure to avoid extreme temperature increase, it has been suggested that Earth's albedo be increased by artificially enhancing stratospheric sulfate aerosols. We use a 3D chemistry climate model, fed by aerosol size distributions from a zonal mean aerosol model, to simulate continuous injection of 1-10 Mt/a into the lower tropical stratosphere. In contrast to the case for all previous work, the particles are predicted to grow to larger sizes than are observed after volcanic eruptions. The reason is the continuous supply of sulfuric acid and hence freshly formed small aerosol particles, which enhance the formation of large aerosol particles by coagulation and, to a lesser extent, by condensation. Owing to their large size, these particles have a reduced albedo. Furthermore, their sedimentation results in a non-linear relationship between stratospheric aerosol burden and annual injection, leading to a reduction of the targeted cooling. More importantly, the sedimenting particles heat the tropical cold point tropopause and, hence, the stratospheric entry mixing ratio of H2O increases. Therefore, geoengineering by means of sulfate aerosols is predicted to accelerate the hydroxyl catalyzed ozone destruction cycles and cause a significant depletion of the ozone layer even though future halogen concentrations will be significantly reduced.

  3. The Impact of Geoengineering Aerosols on Stratospheric Temperature and Ozone

    NASA Technical Reports Server (NTRS)

    Heckendorn, P.; Weisenstein, D.; Fueglistaler, S.; Luo, B. P.; Rozanov, E.; Schraner, M.; Thomason, L. W.; Peter, T.

    2011-01-01

    Anthropogenic greenhouse gas emissions are warming the global climate at an unprecedented rate. Significant emission reductions will be required soon to avoid a rapid temperature rise. As a potential interim measure to avoid extreme temperature increase, it has been suggested that Earth's albedo be increased by artificially enhancing stratospheric sulfate aerosols. We use a 3D chemistry climate model, fed by aerosol size distributions from a zonal mean aerosol model. to simulate continuous injection of 1-10 Mt/a into the lower tropical stratosphere. In contrast to the case for all previous work, the particles are predicted to grow to larger sizes than are observed after volcanic eruptions. The reason is the continuous supply of sulfuric acid and hence freshly formed small aerosol particles, which enhance the formation of large aerosol particles by coagulation and, to a lesser extent, by condensation. Owing to their large size, these particles have a reduced albedo. Furthermore, their sedimentation results in a non-linear relationship between stratospheric aerosol burden and annual injection, leading to a reduction of the targeted cooling. More importantly, the sedimenting particles heat the tropical cold point tropopause and, hence, the stratospheric entry mixing ratio of H2O increases. Therefore, geoengineering by means of sulfate aerosols is predicted to accelerate the hydroxyl catalyzed ozone destruction cycles and cause a significant depletion of the ozone layer even though future halogen concentrations will he significantly reduced.

  4. Thermoluminescent aerosol analysis

    NASA Technical Reports Server (NTRS)

    Rogowski, R. S.; Long, E. R., Jr. (Inventor)

    1977-01-01

    A method for detecting and measuring trace amounts of aerosols when reacted with ozone in a gaseous environment was examined. A sample aerosol was exposed to a fixed ozone concentration for a fixed period of time, and a fluorescer was added to the exposed sample. The sample was heated in a 30 C/minute linear temperature profile to 200 C. The trace peak was measured and recorded as a function of the test aerosol and the recorded thermoluminescence trace peak of the fluorescer is specific to the aerosol being tested.

  5. Radiative Effects of Aerosols

    NASA Technical Reports Server (NTRS)

    Valero, Francisco P. J.

    1997-01-01

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

  6. Fire aerosol experiment and comparisons with computer code predictions

    NASA Astrophysics Data System (ADS)

    Gregory, W. S.; Nichols, B. D.; White, B. W.; Smith, P. R.; Leslie, I. H.; Corkran, J. R.

    1988-08-01

    Los Alamos National Laboratory, in cooperation with New Mexico State University, has carried on a series of tests to provide experimental data on fire-generated aerosol transport. These data will be used to verify the aerosol transport capabilities of the FIRAC computer code. FIRAC was developed by Los Alamos for the U.S. Nuclear Regulatory Commission. It is intended to be used by safety analysts to evaluate the effects of hypothetical fires on nuclear plants. One of the most significant aspects of this analysis deals with smoke and radioactive material movement throughout the plant. The tests have been carried out using an industrial furnace that can generate gas temperatures to 300 C. To date, we have used quartz aerosol with a median diameter of about 10 microns as the fire aerosol simulant. We also plan to use fire-generated aerosols of polystyrene and polymethyl methacrylate (PMMA). The test variables include two nominal gas flow rates (150 and 300 cu ft/min) and three nominal gas temperatures (ambient, 150 C, and 300 C). The test results are presented in the form of plots of aerosol deposition vs length of duct. In addition, the mass of aerosol caught in a high-efficiency particulate air (HEPA) filter during the tests is reported. The tests are simulated with the FIRAC code, and the results are compared with the experimental data.

  7. Artificial insemination in poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Artificial insemination is a relative simple yet powerful tool geneticists can employ for the propagation of economically important traits in livestock and poultry. In this chapter, we address the fundamental methods of the artificial insemination of poultry, including semen collection, semen evalu...

  8. Equine artificial insemination.

    PubMed

    Merkt, H

    1976-07-24

    The use and techniques of artificial insemination for horses in Germany over the last 30 years is described. Artificial insemination appears to produce pregnancy percentages equal to those from normal breeding methods and its continued availability under veterinary supervision is recommended in conditions where disease, disability or distance debar normal service. PMID:960520

  9. Onion artificial muscles

    NASA Astrophysics Data System (ADS)

    Chen, Chien-Chun; Shih, Wen-Pin; Chang, Pei-Zen; Lai, Hsi-Mei; Chang, Shing-Yun; Huang, Pin-Chun; Jeng, Huai-An

    2015-05-01

    Artificial muscles are soft actuators with the capability of either bending or contraction/elongation subjected to external stimulation. However, there are currently no artificial muscles that can accomplish these actions simultaneously. We found that the single layered, latticed microstructure of onion epidermal cells after acid treatment became elastic and could simultaneously stretch and bend when an electric field was applied. By modulating the magnitude of the voltage, the artificial muscle made of onion epidermal cells would deflect in opposing directions while either contracting or elongating. At voltages of 0-50 V, the artificial muscle elongated and had a maximum deflection of -30 μm; at voltages of 50-1000 V, the artificial muscle contracted and deflected 1.0 mm. The maximum force response is 20 μN at 1000 V.

  10. HOUSTON AEROSOL CHARACTERIZATION STUDY

    EPA Science Inventory

    An intensive field study of ambient aerosols was conducted in Houston between September 14 and October 14, 1978. Measurements at 12 sites were made using (1) two relocatable monitoring systems instrumented for aerosol and gaseous pollutants, (2) a network of high volume samplers ...

  11. Global Aerosol Observations

    Atmospheric Science Data Center

    2013-04-19

    ... atmosphere, directly influencing global climate and human health. Ground-based networks that accurately measure column aerosol amount and ... being used to improve Air Quality Models and for regional health studies. To assess the human-health impact of chronic aerosol exposure, ...

  12. Direct Aerosol Forcing Uncertainty

    DOE Data Explorer

    Mccomiskey, Allison

    2008-01-15

    Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

  13. Portable Aerosol Contaminant Extractor

    DOEpatents

    Carlson, Duane C.; DeGange, John J.; Cable-Dunlap, Paula

    2005-11-15

    A compact, portable, aerosol contaminant extractor having ionization and collection sections through which ambient air may be drawn at a nominal rate so that aerosol particles ionized in the ionization section may be collected on charged plate in the collection section, the charged plate being readily removed for analyses of the particles collected thereon.

  14. Radiative Effects of Aerosols

    NASA Technical Reports Server (NTRS)

    Valero, Francisco P. J.

    1996-01-01

    During the Atlantic Stratocumulus Transition Experiment (ASTEX) in June 1992, two descents in cloud-free regions allowed comparison of the change in aerosol optical depth as determined by an onboard total-direct-diffuse radiometer (TDDR) to the change calculated from measured size-resolved aerosol microphysics and chemistry. Both profiles included a pollution haze from Europe but the second also included the effect of a Saharan dust layer above the haze. The separate contributions of supermicrometer (coarse) and submicrometer (fine) aerosol were determined and thermal analysis of the pollution haze indicated that the fine aerosol was composed primarily of a sulfate/water mixture with a refractory soot-like core. The soot core increased the calculated extinction by about 10% in the most polluted drier layer relative to a pure sulfate aerosol but had significantly less effect at higher humidities. A 3 km descent through a boundary layer air mass dominated by pollutant aerosol with relative humidities (RH) 10-77% yielded a close agreement between the measured and calculated aerosol optical depths (550 nm) of 0.160 (+/- 0.07) and 0. 157 (+/- 0.034) respectively. During descent the aerosol mass scattering coefficient per unit sulfate mass varied from about 5 to 16 m(exp 2)/g and primarily dependent upon ambient RH. However, the total scattering coefficient per total fine mass was far less variable at about 4+/- 0.7 m(exp 2)/g. A subsequent descent through a Saharan dust layer located above the pollution aerosol layer revealed that both layers contributed similarly to aerosol optical depth. The scattering per unit mass of the coarse aged dust was estimated at 1.1 +/- 0.2 m(exp 2)/g. The large difference (50%) in measured and calculated optical depth for the dust layer exceeded measurements.

  15. Artificial ecosystem selection.

    PubMed

    Swenson, W; Wilson, D S; Elias, R

    2000-08-01

    Artificial selection has been practiced for centuries to shape the properties of individual organisms, providing Darwin with a powerful argument for his theory of natural selection. We show that the properties of whole ecosystems can also be shaped by artificial selection procedures. Ecosystems initiated in the laboratory vary phenotypically and a proportion of the variation is heritable, despite the fact that the ecosystems initially are composed of thousands of species and millions of individuals. Artificial ecosystem selection can be used for practical purposes, illustrates an important role for complex interactions in evolution, and challenges a widespread belief that selection is most effective at lower levels of the biological hierarchy. PMID:10890915

  16. Results and code prediction comparisons of lithium-air reaction and aerosol behavior tests

    SciTech Connect

    Jeppson, D.W.

    1986-03-01

    The Hanford Engineering Development Laboratory (HEDL) Fusion Safety Support Studies include evaluation of potential safety and environmental concerns associated with the use of liquid lithium as a breeder and coolant for fusion reactors. Potential mechanisms for volatilization and transport of radioactive metallic species associated with breeder materials are of particular interest. Liquid lithium pool-air reaction and aerosol behavior tests were conducted with lithium masses up to 100 kg within the 850-m/sup 3/ containment vessel in the Containment Systems Test Facility. Lithium-air reaction rates, aerosol generation rates, aerosol behavior and characterization, as well as containment atmosphere temperature and pressure responses were determined. Pool-air reaction and aerosol behavior test results were compared with computer code calculations for reaction rates, containment atmosphere response, and aerosol behavior. The volatility of potentially radioactive metallic species from a lithium pool-air reaction was measured. The response of various aerosol detectors to the aerosol generated was determined. Liquid lithium spray tests in air and in nitrogen atmospheres were conducted with lithium temperatures of about 427/sup 0/ and 650/sup 0/C. Lithium reaction rates, containment atmosphere response, and aerosol generation and characterization were determined for these spray tests.

  17. Characteristics of biological aerosols in dairy processing plants.

    PubMed

    Kang, Y J; Frank, J F

    1990-03-01

    The viable aerosol in dairy processing plant environments was characterized by using an Andersen six-stage sieve sampler and a Reuter centrifugal sampler. Artificially introduced Serratia marcescens were detected in the air during drain flooding and after rinsing the floor with a pressured water hose, thus illustrating the ability of a specific microorganism to be disseminated from drains and wet surfaces via physical disruption activities often observed in food plants. Once a high concentration of wet viable aerosol was generated, it took 40 or more min to return to the background level in the absence of forced ventilation or other activity. The greatest reduction in viable particles occurred during the first 10 min. Estimated mean aerosol particle sizes were decreased from approximately 4.6 to 3.2 mu with time lapse. The estimated mean aerosol particle sizes from actual dairy processing plant environments ranged from approximately 4.3 to 5.3 mu. In addition, a more heavily contaminated dairy processing environment contained larger aerosol particles. These results indicate that the RCS sampler will often overestimate the true aerosol concentration in highly contaminated air, because mean particle sizes are over 4 mu in diameter. PMID:2187913

  18. Introduction to artificial intelligence

    SciTech Connect

    Gevarter, W.B.

    1987-09-01

    The author discusses the development of artificial intelligence (AI). He explains the basic elements of AI: Heuristic search, knowledge representation, AI languages and tools, Natural Language Processing, computer vision, expert systems and problem solving and planning.

  19. Intelligence: Real or artificial?

    PubMed Central

    Schlinger, Henry D.

    1992-01-01

    Throughout the history of the artificial intelligence movement, researchers have strived to create computers that could simulate general human intelligence. This paper argues that workers in artificial intelligence have failed to achieve this goal because they adopted the wrong model of human behavior and intelligence, namely a cognitive essentialist model with origins in the traditional philosophies of natural intelligence. An analysis of the word “intelligence” suggests that it originally referred to behavior-environment relations and not to inferred internal structures and processes. It is concluded that if workers in artificial intelligence are to succeed in their general goal, then they must design machines that are adaptive, that is, that can learn. Thus, artificial intelligence researchers must discard their essentialist model of natural intelligence and adopt a selectionist model instead. Such a strategic change should lead them to the science of behavior analysis. PMID:22477051

  20. Artificial Sweeteners and Cancer

    MedlinePlus

    ... artificial sweeteners and cancer? Saccharin Studies in laboratory rats during the early 1970s linked saccharin with the ... cause cancer in laboratory animals .” Subsequent studies in rats showed an increased incidence of urinary bladder cancer ...

  1. Physics of Artificial Gravity

    NASA Technical Reports Server (NTRS)

    Bukley, Angie; Paloski, William; Clement, Gilles

    2006-01-01

    This chapter discusses potential technologies for achieving artificial gravity in a space vehicle. We begin with a series of definitions and a general description of the rotational dynamics behind the forces ultimately exerted on the human body during centrifugation, such as gravity level, gravity gradient, and Coriolis force. Human factors considerations and comfort limits associated with a rotating environment are then discussed. Finally, engineering options for designing space vehicles with artificial gravity are presented.

  2. Artificial light sources.

    PubMed

    Anderson, T F

    1986-04-01

    A wide variety of artificial light sources exists for use in the diagnosis and treatment of photosensitivity disorders. A discussion of the advantages and disadvantages of these light sources (including gas discharge arcs, fluorescent lamps, and other apparatus) illustrates the importance of matching the emission spectrum of the light source, the spectral response of the radiometer, and the photobiologic action spectrum. Environmental and occupational exposure to artificial light sources may contribute to photosensitivity disorders. PMID:3955892

  3. Stratospheric changes caused by geoengineering aerosols

    NASA Astrophysics Data System (ADS)

    Heckendorn, P.; Peter, T.; Weisenstein, D.; Luo, B. P.; Rozanov, E.; Fueglistaler, S.; Thomason, L. W.

    2010-05-01

    Anthropogenic greenhouse gas emissions are warming the global climate at an unprecedented rate. Significant emission reductions will be required soon to avoid a rapid temperature rise. One of the most prominent geoengineering ideas to counteract global warming is the increase of Earth's albedo by artificially enhancing stratospheric sulphate aerosols. This idea is based on the observed increase of atmospheric optical thickness after volcanic eruptions. The most straightforward method, from a technical point of view, is to inject sulphur in the tropical stratosphere. We use a 3D chemistry climate model, fed by aerosol size distributions from a zonal mean aerosol model, to simulate continuous injection of 1-10 Mt/a sulphur in form of SO2 into the lower tropical stratosphere. The volcanic and geoengineering forcings differ in terms of their radiative, chemical and dynamical impact on climate, mainly because the geoengineering forcing has to be continuously applied over a long period of time, whereas volcanic eruptions are single events, leading to a non-linear relationship between annual sulphur input and stratospheric sulphur burden. The reason is the continuous supply of sulphuric acid and hence freshly formed small aerosol particles, which enhance the formation of large aerosol particles by coagulation and, to a lesser extent, also by condensation. This shows the importance of investigating carefully the microphysics of the sulphate aerosols. The growth of the particles is sensitive to the injection region and the sulphur loading per injection time. The consequences of the formation of large particles lead to notable disadvantages. Larger particles are less efficient in cooling than small particles with the same mass. Furthermore, a large fraction of the emitted sulphur is lost rapidly by gravitational settling and subsequent tropospheric washout. Hence, larger sulphur amounts are needed to achieve a targeted cooling. Some particles are trapped in the tropopause

  4. Sugars in Antarctic aerosol

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  5. Heidegger and artificial intelligence

    SciTech Connect

    Diaz, G.

    1987-01-01

    The discipline of Artificial Intelligence, in its quest for machine intelligence, showed great promise as long as its areas of application were limited to problems of a scientific and situation neutral nature. The attempts to move beyond these problems to a full simulation of man's intelligence has faltered and slowed it progress, largely because of the inability of Artificial Intelligence to deal with human characteristic, such as feelings, goals, and desires. This dissertation takes the position that an impasse has resulted because Artificial Intelligence has never been properly defined as a science: its objects and methods have never been identified. The following study undertakes to provide such a definition, i.e., the required ground for Artificial Intelligence. The procedure and methods employed in this study are based on Heidegger's philosophy and techniques of analysis as developed in Being and Time. Results of this study show that both the discipline of Artificial Intelligence and the concerns of Heidegger in Being and Time have the same object; fundamental ontology. The application of Heidegger's conclusions concerning fundamental ontology unites the various aspects of Artificial Intelligence and provides the articulation which shows the parts of this discipline and how they are related.

  6. RADIO-ACTIVE TRANSDUCER

    DOEpatents

    Wanetick, S.

    1962-03-01

    ABS>ure the change in velocity of a moving object. The transducer includes a radioactive source having a collimated beam of radioactive particles, a shield which can block the passage of the radioactive beam, and a scintillation detector to measure the number of radioactive particles in the beam which are not blocked by the shield. The shield is operatively placed across the radioactive beam so that any motion normal to the beam will cause the shield to move in the opposite direction thereby allowing more radioactive particles to reach the detector. The number of particles detected indicates the acceleration. (AEC)

  7. Modelling artificial sea salt emission in large eddy simulations.

    PubMed

    Maalick, Z; Korhonen, H; Kokkola, H; Kühn, T; Romakkaniemi, S

    2014-12-28

    We study the dispersion of sea salt particles from artificially injected sea spray at a cloud-resolving scale. Understanding of how different aerosol processes affect particle dispersion is crucial when designing emission sources for marine cloud brightening. Compared with previous studies, we include for the first time an explicit treatment of aerosol water, which takes into account condensation, evaporation and their effect on ambient temperature. This enables us to capture the negative buoyancy caused by water evaporation from aerosols. Additionally, we use a higher model resolution to capture aerosol loss through coagulation near the source point. We find that, with a seawater flux of 15 kg s(-1), the cooling due to evaporation can be as much as 1.4 K, causing a delay in particle dispersion of 10-20 min. This delay enhances particle scavenging by a factor of 1.14 compared with simulations without aerosol water. We further show that both cooling and particle dispersion depend on the model resolution, with a maximum particle scavenging efficiency of 20% within 5 h after emission at maximum resolution of 50 m. Based on these results, we suggest further regional high-resolution studies which model several injection periods over several weeks. PMID:25404679

  8. Modelling artificial sea salt emission in large eddy simulations

    PubMed Central

    Maalick, Z.; Korhonen, H.; Kokkola, H.; Kühn, T.; Romakkaniemi, S.

    2014-01-01

    We study the dispersion of sea salt particles from artificially injected sea spray at a cloud-resolving scale. Understanding of how different aerosol processes affect particle dispersion is crucial when designing emission sources for marine cloud brightening. Compared with previous studies, we include for the first time an explicit treatment of aerosol water, which takes into account condensation, evaporation and their effect on ambient temperature. This enables us to capture the negative buoyancy caused by water evaporation from aerosols. Additionally, we use a higher model resolution to capture aerosol loss through coagulation near the source point. We find that, with a seawater flux of 15 kg s−1, the cooling due to evaporation can be as much as 1.4 K, causing a delay in particle dispersion of 10–20 min. This delay enhances particle scavenging by a factor of 1.14 compared with simulations without aerosol water. We further show that both cooling and particle dispersion depend on the model resolution, with a maximum particle scavenging efficiency of 20% within 5 h after emission at maximum resolution of 50 m. Based on these results, we suggest further regional high-resolution studies which model several injection periods over several weeks. PMID:25404679

  9. Biogenic amines in submicron marine aerosol (Invited)

    NASA Astrophysics Data System (ADS)

    Facchini, M.

    2010-12-01

    Ammonium salts of dimethyl and diethyl amine (DMA+ and DEA+) have been detected in size segregated marine samples collected in the North Atlantic over open ocean and at a coastal site. DMA+ and DEA+ peak in the accumulation mode range while very low concentration, close to detection limit, are observed in the coarse size fractions, as well as in sea spray aerosol artificially generated in the laboratory using sea water. These results indicate a secondary formation pathway. DMA+ and DEA+ represent up to 20% of secondary organic aerosol (SOA) in our samples , and to our knowledge they are the most abundant organic species besides MSA ever detected in clean marine aerosol . Maximum concentrations have been observed during spring and summer when the biological activity is high and in clean marine air masses, thus indicating biogenic sources. Total organic nitrogen (ON) concentration also peaks in the accumulation mode range and represents in our samples a fraction from 32 to 54 % of the total SOA. Ammonium salt formation from biogenic amines might be an important source of marine SOA and atmospheric nitrogen at the global scale with a seasonal variation connected to the oceanic biological productivity and an atmospheric cycle parallel to that of the organosulfur species.

  10. Neural network computer simulation of medical aerosols.

    PubMed

    Richardson, C J; Barlow, D J

    1996-06-01

    Preliminary investigations have been conducted to assess the potential for using artificial neural networks to simulate aerosol behaviour, with a view to employing this type of methodology in the evaluation and design of pulmonary drug-delivery systems. Details are presented of the general purpose software developed for these tasks; it implements a feed-forward back-propagation algorithm with weight decay and connection pruning, the user having complete run-time control of the network architecture and mode of training. A series of exploratory investigations is then reported in which different network structures and training strategies are assessed in terms of their ability to simulate known patterns of fluid flow in simple model systems. The first of these involves simulations of cellular automata-generated data for fluid flow through a partially obstructed two-dimensional pipe. The artificial neural networks are shown to be highly successful in simulating the behaviour of this simple linear system, but with important provisos relating to the information content of the training data and the criteria used to judge when the network is properly trained. A second set of investigations is then reported in which similar networks are used to simulate patterns of fluid flow through aerosol generation devices, using training data furnished through rigorous computational fluid dynamics modelling. These more complex three-dimensional systems are modelled with equal success. It is concluded that carefully tailored, well trained networks could provide valuable tools not just for predicting but also for analysing the spatial dynamics of pharmaceutical aerosols. PMID:8832491

  11. Abscess scan - radioactive

    MedlinePlus

    Radioactive abscess scan; Abscess scan; Indium Scan; Indium-labelled white blood cell scan ... the white blood cells are tagged with a radioactive substance called indium. The cells are then injected ...

  12. Radioactive iodine uptake

    MedlinePlus

    ... the testing center so that the amount of radioactivity in the thyroid gland can be measured. This ... The amount of radioactivity is very small, and there have been no documented side effects. The amount of iodine used is less than ...

  13. Radioactive diagnostic agent

    SciTech Connect

    Shigematsu, A.; Aihara, M.; Matsuda, M.; Suzuki, A.; Tsuya, A.

    1984-02-07

    A radioactive diagnostic agent for renal cortex, adrenal cortex, myocardium, brain stem, spinal nerve, etc., which comprises as an essential component monoiodoacetic acid wherein the iodine atom is radioactive.

  14. Volcanic Aerosol Radiative Properties

    NASA Technical Reports Server (NTRS)

    Lacis, Andrew

    2015-01-01

    Large sporadic volcanic eruptions inject large amounts of sulfur bearing gases into the stratosphere which then get photochemically converted to sulfuric acid aerosol droplets that exert a radiative cooling effect on the global climate system lasting for several years.

  15. Palaeoclimate: Aerosols and rainfall

    NASA Astrophysics Data System (ADS)

    Partin, Jud

    2015-03-01

    Instrumental records have hinted that aerosol emissions may be shifting rainfall over Central America southwards. A 450-year-long precipitation reconstruction indicates that this shift began shortly after the Industrial Revolution.

  16. Aerosol lenses propagation model.

    PubMed

    Tremblay, Grégoire; Roy, Gilles

    2011-09-01

    We propose a model based on the properties of cascading lenses modulation transfer function (MTF) to reproduce the irradiance of a screen illuminated through a dense aerosol cloud. In this model, the aerosol cloud is broken into multiple thin layers considered as individual lenses. The screen irradiance generated by these individual layers is equivalent to the point-spread function (PSF) of each aerosol lens. Taking the Fourier transform of the PSF as a MTF, we cascade the lenses MTF to find the cloud MTF. The screen irradiance is found with the Fourier transform of this MTF. We show the derivation of the model and we compare the results with the Undique Monte Carlo simulator for four aerosols at three optical depths. The model is in agreement with the Monte Carlo for all the cases tested. PMID:21886230

  17. MISR Aerosol Typing

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph A.

    2014-01-01

    AeroCom is an open international initiative of scientists interested in the advancement of the understanding of global aerosol properties and aerosol impacts on climate. A central goal is to more strongly tie and constrain modeling efforts to observational data. A major element for exchanges between data and modeling groups are annual meetings. The meeting was held September 20 through October 2, 1014 and the organizers would like to post the presentations.

  18. Monodisperse aerosol generator

    DOEpatents

    Ortiz, Lawrence W.; Soderholm, Sidney C.

    1990-01-01

    An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.

  19. RACORO aerosol data processing

    SciTech Connect

    Elisabeth Andrews

    2011-10-31

    The RACORO aerosol data (cloud condensation nuclei (CCN), condensation nuclei (CN) and aerosol size distributions) need further processing to be useful for model evaluation (e.g., GCM droplet nucleation parameterizations) and other investigations. These tasks include: (1) Identification and flagging of 'splash' contaminated Twin Otter aerosol data. (2) Calculation of actual supersaturation (SS) values in the two CCN columns flown on the Twin Otter. (3) Interpolation of CCN spectra from SGP and Twin Otter to 0.2% SS. (4) Process data for spatial variability studies. (5) Provide calculated light scattering from measured aerosol size distributions. Below we first briefly describe the measurements and then describe the results of several data processing tasks that which have been completed, paving the way for the scientific analyses for which the campaign was designed. The end result of this research will be several aerosol data sets which can be used to achieve some of the goals of the RACORO mission including the enhanced understanding of cloud-aerosol interactions and improved cloud simulations in climate models.

  20. Artificial consciousness, artificial emotions, and autonomous robots.

    PubMed

    Cardon, Alain

    2006-12-01

    Nowadays for robots, the notion of behavior is reduced to a simple factual concept at the level of the movements. On another hand, consciousness is a very cultural concept, founding the main property of human beings, according to themselves. We propose to develop a computable transposition of the consciousness concepts into artificial brains, able to express emotions and consciousness facts. The production of such artificial brains allows the intentional and really adaptive behavior for the autonomous robots. Such a system managing the robot's behavior will be made of two parts: the first one computes and generates, in a constructivist manner, a representation for the robot moving in its environment, and using symbols and concepts. The other part achieves the representation of the previous one using morphologies in a dynamic geometrical way. The robot's body will be seen for itself as the morphologic apprehension of its material substrata. The model goes strictly by the notion of massive multi-agent's organizations with a morphologic control. PMID:17016730

  1. [Clinico-radiometric studies of the eye in radioactive contamination].

    PubMed

    Mikhaĭlina, T N; Bazhin, A G

    1994-01-01

    The aim of the study was assessment of local and remote effects of radioactive substances on ocular media and development of measures to remove radionuclides from the eye. Radioactive substances getting into the eye in the form of aerosols, dust, or gaseous mixtures are unevenly distributed in it. The highest radioactivity was found on the skin of the eyelids and orbit, particularly so on the eyelashes and eyebrows, the least one on the cornea and in the conjunctival cavity. A follow-up of 8 to 17 years showed that timely removal of radionuclides from ocular surface prevented the development of specific symptoms and trophic changes of ocular media, of radiation cataracts among other things. The suggested method for washing the skin of the eyelids and orbital area from radioactive contaminants did not induce skin irritation, maceration, sense of discomfort, and is recommended for practice. PMID:8073571

  2. Photochemical Aging of Organic Aerosol Particles

    NASA Astrophysics Data System (ADS)

    Nizkorodov, S. A.; Bateman, A. P.; Dailo, M.; Do, T.; Mang, S. A.; Pan, X.; Underwood, J. S.; Walser, M. L.

    2007-05-01

    Secondary Organic Aerosol (SOA) particles are produced in the atmosphere as a result of oxidation of volatile organic compounds (VOC). Primary Organic Aerosol (POA) particles are directly emitted in the atmosphere by their sources. This research focuses on the mechanisms of direct photochemical processes taking place in model SOA and POA particles, the role of such processes in aging of organic aerosol particles, and the effect of photochemistry on particles' physicochemical properties. To address these questions, artificial SOA and POA particles are investigated with several laboratory-based approaches relying on cavity ring-down spectroscopy and mass-spectrometry. SOA particles generated by dark oxidation of d-Limonene, alpha-Pinene, and beta-Pinene by ozone are all found to absorb radiation in the tropospheric actinic window. The UV absorption photolyzes SOA constituents resulting in a release of small VOC molecules back in the gas-phase, and considerable change in SOA chemical composition. For terpenes featuring a terminal double bond, the main SOA photolysis products are invariably found to be formaldehyde and formic acid. Similar observations are obtained for products of ozonolysis of thin films of unsaturated fatty acids and self-assembled monolayers of unsaturated alkenes. For the case of fatty acids, a very detailed mechanism of ozonolysis and subsequent photolysis is proposed. The photolytic activity is primarily attributed to organic peroxides and aldehydes. These results convincingly demonstrate that photochemical processes occurring inside SOA and POA particles age the particles on time scales that are shorter than typical lifetimes of aerosol particles in the atmosphere.

  3. Artificial muscles on heat

    NASA Astrophysics Data System (ADS)

    McKay, Thomas G.; Shin, Dong Ki; Percy, Steven; Knight, Chris; McGarry, Scott; Anderson, Iain A.

    2014-03-01

    Many devices and processes produce low grade waste heat. Some of these include combustion engines, electrical circuits, biological processes and industrial processes. To harvest this heat energy thermoelectric devices, using the Seebeck effect, are commonly used. However, these devices have limitations in efficiency, and usable voltage. This paper investigates the viability of a Stirling engine coupled to an artificial muscle energy harvester to efficiently convert heat energy into electrical energy. The results present the testing of the prototype generator which produced 200 μW when operating at 75°C. Pathways for improved performance are discussed which include optimising the electronic control of the artificial muscle, adjusting the mechanical properties of the artificial muscle to work optimally with the remainder of the system, good sealing, and tuning the resonance of the displacer to minimise the power required to drive it.

  4. Doped Artificial Spin Ice

    NASA Astrophysics Data System (ADS)

    Olson Reichhardt, Cynthia; Libal, Andras; Reichhardt, Charles

    We examine square and kagome artificial spin ice for colloids confined in arrays of double-well traps. Unlike magnetic artificial spin ices, colloidal and vortex artificial spin ice realizations allow creation of doping sites through double occupation of individual traps. We find that doping square and kagome ice geometries produces opposite effects. For square ice, doping creates local excitations in the ground state configuration that produce a local melting effect as the temperature is raised. In contrast, the kagome ice ground state can absorb the doping charge without generating non-ground-state excitations, while at elevated temperatures the hopping of individual colloids is suppressed near the doping sites. These results indicate that in the square ice, doping adds degeneracy to the ordered ground state and creates local weak spots, while in the kagome ice, which has a highly degenerate ground state, doping locally decreases the degeneracy and creates local hard regions.

  5. An artificial molecular pump.

    PubMed

    Cheng, Chuyang; McGonigal, Paul R; Schneebeli, Severin T; Li, Hao; Vermeulen, Nicolaas A; Ke, Chenfeng; Stoddart, J Fraser

    2015-06-01

    Carrier proteins consume fuel in order to pump ions or molecules across cell membranes, creating concentration gradients. Their control over diffusion pathways, effected entirely through noncovalent bonding interactions, has inspired chemists to devise artificial systems that mimic their function. Here, we report a wholly artificial compound that acts on small molecules to create a gradient in their local concentration. It does so by using redox energy and precisely organized noncovalent bonding interactions to pump positively charged rings from solution and ensnare them around an oligomethylene chain, as part of a kinetically trapped entanglement. A redox-active viologen unit at the heart of a dumbbell-shaped molecular pump plays a dual role, first attracting and then repelling the rings during redox cycling, thereby enacting a flashing energy ratchet mechanism with a minimalistic design. Our artificial molecular pump performs work repetitively for two cycles of operation and drives rings away from equilibrium toward a higher local concentration. PMID:25984834

  6. An artificial molecular pump

    NASA Astrophysics Data System (ADS)

    Cheng, Chuyang; McGonigal, Paul R.; Schneebeli, Severin T.; Li, Hao; Vermeulen, Nicolaas A.; Ke, Chenfeng; Stoddart, J. Fraser

    2015-06-01

    Carrier proteins consume fuel in order to pump ions or molecules across cell membranes, creating concentration gradients. Their control over diffusion pathways, effected entirely through noncovalent bonding interactions, has inspired chemists to devise artificial systems that mimic their function. Here, we report a wholly artificial compound that acts on small molecules to create a gradient in their local concentration. It does so by using redox energy and precisely organized noncovalent bonding interactions to pump positively charged rings from solution and ensnare them around an oligomethylene chain, as part of a kinetically trapped entanglement. A redox-active viologen unit at the heart of a dumbbell-shaped molecular pump plays a dual role, first attracting and then repelling the rings during redox cycling, thereby enacting a flashing energy ratchet mechanism with a minimalistic design. Our artificial molecular pump performs work repetitively for two cycles of operation and drives rings away from equilibrium toward a higher local concentration.

  7. Artificial gravity experiment satellites

    NASA Astrophysics Data System (ADS)

    Harada, Tadashi

    1992-07-01

    An overview of the conceptual study of an artificial gravity experiment satellite based on the assumption of a launch by the H-2 launch vehicle with a target launch date in the Year 2000 is presented. While many satellites provided with artificial gravity have been reported in relation to a manned Mars exploration spacecraft mission, the review has been conducted on missions and test subjects only for experimental purposes. Mission requirements were determined based on the results of reviews on the mission, test subjects, and model missions. The system baseline and development plan were based on the results of a study on conceptual structure and scale of the system, including measures to generate artificial gravity. Approximate scale of the system and arm length, mission orbit, visibility of the operation orbit from ground stations in Japan, and satellite attitude on the mission orbit are outlined.

  8. Artificial intelligence in nanotechnology

    NASA Astrophysics Data System (ADS)

    Sacha, G. M.; Varona, P.

    2013-11-01

    During the last decade there has been increasing use of artificial intelligence tools in nanotechnology research. In this paper we review some of these efforts in the context of interpreting scanning probe microscopy, the study of biological nanosystems, the classification of material properties at the nanoscale, theoretical approaches and simulations in nanoscience, and generally in the design of nanodevices. Current trends and future perspectives in the development of nanocomputing hardware that can boost artificial-intelligence-based applications are also discussed. Convergence between artificial intelligence and nanotechnology can shape the path for many technological developments in the field of information sciences that will rely on new computer architectures and data representations, hybrid technologies that use biological entities and nanotechnological devices, bioengineering, neuroscience and a large variety of related disciplines.

  9. The Invigoration of Deep Convective Clouds Over the Atlantic: Aerosol Effect, Meteorology or Retrieval Artifact?

    NASA Technical Reports Server (NTRS)

    Koren, Ilan; Feingold, Graham; Remer, Lorraine A.

    2010-01-01

    Associations between cloud properties and aerosol loading are frequently observed in products derived from satellite measurements. These observed trends between clouds and aerosol optical depth suggest aerosol modification of cloud dynamics, yet there are uncertainties involved in satellite retrievals that have the potential to lead to incorrect conclusions. Two of the most challenging problems are addressed here: the potential for retrieved aerosol optical depth to be cloud-contaminated, and as a result, artificially correlated with cloud parameters; and the potential for correlations between aerosol and cloud parameters to be erroneously considered to be causal. Here these issues are tackled directly by studying the effects of the aerosol on convective clouds in the tropical Atlantic Ocean using satellite remote sensing, a chemical transport model, and a reanalysis of meteorological fields. Results show that there is a robust positive correlation between cloud fraction or cloud top height and the aerosol optical depth, regardless of whether a stringent filtering of aerosol measurements in the vicinity of clouds is applied, or not. These same positive correlations emerge when replacing the observed aerosol field with that derived from a chemical transport model. Model-reanalysis data is used to address the causality question by providing meteorological context for the satellite observations. A correlation exercise between the full suite of meteorological fields derived from model reanalysis and satellite-derived cloud fields shows that observed cloud top height and cloud fraction correlate best with model pressure updraft velocity and relative humidity. Observed aerosol optical depth does correlate with meteorological parameters but usually different parameters from those that correlate with observed cloud fields. The result is a near-orthogonal influence of aerosol and meteorological fields on cloud top height and cloud fraction. The results strengthen the case

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  11. AEROSOL CHARACTERIZATION WITH CENTRIFUCAL AEROSOL SPECTROMETERS: THEORY AND EXPERIMENT

    EPA Science Inventory

    A general mathematical model describing the motion of particles in aerosol centrifuges has been developed. t has been validated by comparisons of theoretically predicted calibration sites with experimental data from tests sizing aerosols in instruments of three different spiral d...

  12. Radioactivity and lung cancer-mathematical models of radionuclide deposition in the human lungs

    PubMed Central

    Sturm, Robert

    2011-01-01

    The human respiratory tract is regarded as pathway for radionuclides and other hazardous airborne materials to enter the body. Radioactive particles inhaled and deposited in the lungs cause an irradiation of bronchial/alveolar tissues. At the worst, this results in a malignant cellular transformation and, as a consequence of that, the development of lung cancer. In general, naturally occurring radionuclides (e.g., 222Rn, 40K) are attached to so-called carrier aerosols. The aerodynamic diameters of such radioactively labeled particles generally vary between several nanometers (ultrafine particles) and few micrometers, whereby highest particle fractions adopt sizes around 100 nm. Theoretical simulations of radioactive particle deposition in the human lungs were based on a stochastic lung geometry and a particle transport/deposition model using the random-walk algorithm. Further a polydisperse carrier aerosol (diameter: 1 nm–10 µm, ρ ≈ 1 g cm−3) with irregularly shaped particles and the effect of breathing characteristics and certain respiratory parameters on the transport of radioactive particles to bronchial/alveolar tissues were considered. As clearly shown by the results of deposition modeling, distribution patterns of radiation doses mainly depend on the size of the carrier aerosol. Ultrafine (< 10 nm) and large (> 2 µm) aerosol particles are preferentially deposited in the extrathoracic and upper bronchial region, whereas aerosol particles with intermediate size (10 nm–2 µm) may penetrate to deeper lung regions, causing an enhanced damage of the alveolar tissue by the attached radionuclides. PMID:22263097

  13. Artificial Intelligence and CALL.

    ERIC Educational Resources Information Center

    Underwood, John H.

    The potential application of artificial intelligence (AI) to computer-assisted language learning (CALL) is explored. Two areas of AI that hold particular interest to those who deal with language meaning--knowledge representation and expert systems, and natural-language processing--are described and examples of each are presented. AI contribution…

  14. Applications of artificial intelligence

    SciTech Connect

    Gilmore, J.F.

    1984-01-01

    This book presents papers given at a conference on expert systems and artificial intelligence. Topics considered at the conference included the location of multiple faults by diagnostic expert systems, knowledge-based systems, natural language, image processing, computer vision, and identification systems.

  15. The Artificial Planet

    NASA Astrophysics Data System (ADS)

    Glover, D. R.

    An interim milestone for interstellar space travel is proposed: the artificial planet. Interstellar travel will require breakthroughs in the areas of propulsion systems, energy systems, construction of large space structures, protection from space & radiation effects, space agriculture, closed environmental & life support systems, and many other areas. Many difficult problems can be attacked independently of the propulsion and energy challenges through a project to establish an artificial planet in our solar system. Goals of the project would include construction of a large space structure, development of space agriculture, demonstration of closed environmental & life support systems over long time periods, selection of gravity level for long-term spacecraft, demonstration of a self-sufficient colony, and optimization of space colony habitat. The artificial planet would use solar energy as a power source. The orbital location will be selected to minimize effects of the Earth, yet be close enough for construction, supply, and rescue operations. The artificial planet would start out as a construction station and evolve over time to address progressive goals culminating in a self-sufficient space colony.

  16. Micromachined Artificial Haircell

    NASA Technical Reports Server (NTRS)

    Liu, Chang (Inventor); Engel, Jonathan (Inventor); Chen, Nannan (Inventor); Chen, Jack (Inventor)

    2010-01-01

    A micromachined artificial sensor comprises a support coupled to and movable with respect to a substrate. A polymer, high-aspect ratio cilia-like structure is disposed on and extends out-of-plane from the support. A strain detector is disposed with respect to the support to detect movement of the support.

  17. Artificial intelligence and robotics

    SciTech Connect

    Peden, I.C.; Braddock, J.V.; Brown, W.; Langendorf, R.M.

    1982-09-01

    This report examines the state-of-the-art in artificial intelligence and robotics technologies and their potential in terms of Army needs. Assessment includes battlefield technology, research and technology insertions, management considerations and recommendations related to research and development personnel, and recommendations regarding the Army's involvement in the automated plant.

  18. Terahertz Artificial Dielectric Lens

    NASA Astrophysics Data System (ADS)

    Mendis, Rajind; Nagai, Masaya; Wang, Yiqiu; Karl, Nicholas; Mittleman, Daniel M.

    2016-03-01

    We have designed, fabricated, and experimentally characterized a lens for the THz regime based on artificial dielectrics. These are man-made media that mimic properties of naturally occurring dielectric media, or even manifest properties that cannot generally occur in nature. For example, the well-known dielectric property, the refractive index, which usually has a value greater than unity, can have a value less than unity in an artificial dielectric. For our lens, the artificial-dielectric medium is made up of a parallel stack of 100 μm thick metal plates that form an array of parallel-plate waveguides. The convergent lens has a plano-concave geometry, in contrast to conventional dielectric lenses. Our results demonstrate that this lens is capable of focusing a 2 cm diameter beam to a spot size of 4 mm, at the design frequency of 0.17 THz. The results further demonstrate that the overall power transmission of the lens can be better than certain conventional dielectric lenses commonly used in the THz regime. Intriguingly, we also observe that under certain conditions, the lens boundary demarcated by the discontinuous plate edges actually resembles a smooth continuous surface. These results highlight the importance of this artificial-dielectric technology for the development of future THz-wave devices.

  19. Database in Artificial Intelligence.

    ERIC Educational Resources Information Center

    Wilkinson, Julia

    1986-01-01

    Describes a specialist bibliographic database of literature in the field of artificial intelligence created by the Turing Institute (Glasgow, Scotland) using the BRS/Search information retrieval software. The subscription method for end-users--i.e., annual fee entitles user to unlimited access to database, document provision, and printed awareness…

  20. Terahertz Artificial Dielectric Lens

    PubMed Central

    Mendis, Rajind; Nagai, Masaya; Wang, Yiqiu; Karl, Nicholas; Mittleman, Daniel M.

    2016-01-01

    We have designed, fabricated, and experimentally characterized a lens for the THz regime based on artificial dielectrics. These are man-made media that mimic properties of naturally occurring dielectric media, or even manifest properties that cannot generally occur in nature. For example, the well-known dielectric property, the refractive index, which usually has a value greater than unity, can have a value less than unity in an artificial dielectric. For our lens, the artificial-dielectric medium is made up of a parallel stack of 100 μm thick metal plates that form an array of parallel-plate waveguides. The convergent lens has a plano-concave geometry, in contrast to conventional dielectric lenses. Our results demonstrate that this lens is capable of focusing a 2 cm diameter beam to a spot size of 4 mm, at the design frequency of 0.17 THz. The results further demonstrate that the overall power transmission of the lens can be better than certain conventional dielectric lenses commonly used in the THz regime. Intriguingly, we also observe that under certain conditions, the lens boundary demarcated by the discontinuous plate edges actually resembles a smooth continuous surface. These results highlight the importance of this artificial-dielectric technology for the development of future THz-wave devices. PMID:26973294

  1. Artificial limb connection

    NASA Technical Reports Server (NTRS)

    Owens, L. J.

    1974-01-01

    Connection simplifies and eases donning and removing artificial limb; eliminates harnesses and clamps; and reduces skin pressures by allowing bone to carry all tensile and part of compressive loads between prosthesis and stump. Because connection is modular, it is easily modified to suit individual needs.

  2. Terahertz Artificial Dielectric Lens.

    PubMed

    Mendis, Rajind; Nagai, Masaya; Wang, Yiqiu; Karl, Nicholas; Mittleman, Daniel M

    2016-01-01

    We have designed, fabricated, and experimentally characterized a lens for the THz regime based on artificial dielectrics. These are man-made media that mimic properties of naturally occurring dielectric media, or even manifest properties that cannot generally occur in nature. For example, the well-known dielectric property, the refractive index, which usually has a value greater than unity, can have a value less than unity in an artificial dielectric. For our lens, the artificial-dielectric medium is made up of a parallel stack of 100 μm thick metal plates that form an array of parallel-plate waveguides. The convergent lens has a plano-concave geometry, in contrast to conventional dielectric lenses. Our results demonstrate that this lens is capable of focusing a 2 cm diameter beam to a spot size of 4 mm, at the design frequency of 0.17 THz. The results further demonstrate that the overall power transmission of the lens can be better than certain conventional dielectric lenses commonly used in the THz regime. Intriguingly, we also observe that under certain conditions, the lens boundary demarcated by the discontinuous plate edges actually resembles a smooth continuous surface. These results highlight the importance of this artificial-dielectric technology for the development of future THz-wave devices. PMID:26973294

  3. Artificial intelligence. Second edition

    SciTech Connect

    Winston, P.H.

    1984-01-01

    This book introduces the basic concepts of the field of artificial intelligence. It contains material covering the latest advances in control, representation, language, vision, and problem solving. Problem solving in design and analysis systems is addressed. Mitcell's version-space learning procedure, Morevec's reduced-images stereo procedure, and the Strips problem solver are covered.

  4. Artificial Gravity Research Plan

    NASA Technical Reports Server (NTRS)

    Gilbert, Charlene

    2014-01-01

    This document describes the forward working plan to identify what countermeasure resources are needed for a vehicle with an artificial gravity module (intermittent centrifugation) and what Countermeasure Resources are needed for a rotating transit vehicle (continuous centrifugation) to minimize the effects of microgravity to Mars Exploration crewmembers.

  5. Artificial intelligence within AFSC

    NASA Technical Reports Server (NTRS)

    Gersh, Mark A.

    1990-01-01

    Information on artificial intelligence research in the Air Force Systems Command is given in viewgraph form. Specific research that is being conducted at the Rome Air Development Center, the Space Technology Center, the Human Resources Laboratory, the Armstrong Aerospace Medical Research Laboratory, the Armamant Laboratory, and the Wright Research and Development Center is noted.

  6. Aerosol chemistry in GLOBE

    NASA Technical Reports Server (NTRS)

    Clarke, Antony D.; Rothermel, Jeffry; Jarzembski, Maurice A.

    1993-01-01

    This task addresses the measurement and understanding of the physical and chemical properties of aerosol in remote regions that are responsible for aerosol backscatter at infrared wavelengths. Because it is representative of other clean areas, the remote Pacific is of extreme interest. Emphasis is on the determination size dependent aerosol properties that are required for modeling backscatter at various wavelengths and upon those features that may be used to help understand the nature, origin, cycling and climatology of these aerosols in the remote troposphere. Empirical relationships will be established between lidar measurements and backscatter derived from the aerosol microphysics as required by the NASA Doppler Lidar Program. This will include the analysis of results from the NASA GLOBE Survey Mission Flight Program. Additional instrument development and deployment will be carried out in order to extend and refine this data base. Identified activities include participation in groundbased and airborne experiments. Progress to date includes participation in, analysis of, and publication of results from Mauna Loa Backscatter Intercomparison Experiment (MABIE) and Global Backscatter Experiment (GLOBE).

  7. Biological aerosol background characterization

    NASA Astrophysics Data System (ADS)

    Blatny, Janet; Fountain, Augustus W., III

    2011-05-01

    To provide useful information during military operations, or as part of other security situations, a biological aerosol detector has to respond within seconds or minutes to an attack by virulent biological agents, and with low false alarms. Within this time frame, measuring virulence of a known microorganism is extremely difficult, especially if the microorganism is of unknown antigenic or nucleic acid properties. Measuring "live" characteristics of an organism directly is not generally an option, yet only viable organisms are potentially infectious. Fluorescence based instruments have been designed to optically determine if aerosol particles have viability characteristics. Still, such commercially available biological aerosol detection equipment needs to be improved for their use in military and civil applications. Air has an endogenous population of microorganisms that may interfere with alarm software technologies. To design robust algorithms, a comprehensive knowledge of the airborne biological background content is essential. For this reason, there is a need to study ambient live bacterial populations in as many locations as possible. Doing so will permit collection of data to define diverse biological characteristics that in turn can be used to fine tune alarm algorithms. To avoid false alarms, improving software technologies for biological detectors is a crucial feature requiring considerations of various parameters that can be applied to suppress alarm triggers. This NATO Task Group will aim for developing reference methods for monitoring biological aerosol characteristics to improve alarm algorithms for biological detection. Additionally, they will focus on developing reference standard methodology for monitoring biological aerosol characteristics to reduce false alarm rates.

  8. SURVIVAL OF BACTERIA DURING AEROSOLIZATION

    EPA Science Inventory

    One form of commercial application of microorganisms, including genetically engineered microorganisms is as an aerosol. To study the effect of aerosol-induced stress on bacterial survival, nonrecombinant spontaneous antibiotic-resistant mutants of four organisms, Enterobacter clo...

  9. Other medications for aerosol delivery.

    PubMed

    Rubin, Bruce K

    2006-01-01

    Although aerosol therapy is most commonly used to treat asthma and COPD, there are a large number of aerosol medications now used or in development for other diseases. Mucoactive agents have long been available by aerosol, but now we have truly effective drugs to improve effective airway clearance including dornase alfa, hyperosmolar saline, and aerosol surfactant. Inhaled antibiotics are available for the treatment of cystic fibrosis, bronchiectasis and other chronic airway infections. With the development of devices that can target aerosol to the deep lung, the opportunity to deliver medications systemically by the aerosol route has become a reality. Insulin, recently approved in the US as aerosol therapy, and other peptides are systemically absorbed from the distal airway and alveolus. Aerosol gene transfer therapy to correct abnormalities associated with cystic fibrosis, primary ciliary dyskinesia and other airway diseases also holds great potential. PMID:16798603

  10. Atmospheric Chemistry: Nature's plasticized aerosols

    NASA Astrophysics Data System (ADS)

    Ziemann, Paul J.

    2016-01-01

    The structure of atmospheric aerosol particles affects their reactivity and growth rates. Measurements of aerosol properties over the Amazon rainforest indicate that organic particles above tropical rainforests are simple liquid drops.

  11. MODIS 3km Aerosol Product: Algorithm and Global Perspective

    NASA Technical Reports Server (NTRS)

    Remer, L. A.; Mattoo, S.; Levy, R. C.; Munchak, L.

    2013-01-01

    After more than a decade of producing a nominal 10 km aerosol product based on the dark target method, the MODIS aerosol team will be releasing a nominal 3 km product as part of their Collection 6 release. The new product differs from the original 10 km product only in the manner in which reflectance pixels are ingested, organized and selected by the aerosol algorithm. Overall, the 3 km product closely mirrors the 10 km product. However, the finer resolution product is able to retrieve over ocean closer to islands and coastlines, and is better able to resolve fine aerosol features such as smoke plumes over both ocean and land. In some situations, it provides retrievals over entire regions that the 10 km product barely samples. In situations traditionally difficult for the dark target algorithm, such as over bright or urban surfaces the 3 km product introduces isolated spikes of artificially high aerosol optical depth (AOD) that the 10 km algorithm avoids. Over land, globally, the 3 km product appears to be 0.01 to 0.02 higher than the 10 km product, while over ocean, the 3 km algorithm is retrieving a proportionally greater number of very low aerosol loading situations. Based on collocations with ground-based observations for only six months, expected errors associated with the 3 km land product are determined to be greater than for the 10 km product: 0.05 0.25 AOD. Over ocean, the suggestion is for expected errors to be the same as the 10 km product: 0.03 0.05 AOD. The advantage of the product is on the local scale, which will require continued evaluation not addressed here. Nevertheless, the new 3 km product is expected to provide important information complementary to existing satellite-derived products and become an important tool for the aerosol community.

  12. Detection of Fukushima plume within regular Slovenian environmental radioactivity surveillance.

    PubMed

    Glavič-Cindro, D; Benedik, L; Kožar Logar, J; Vodenik, B; Zorko, B

    2013-11-01

    After the Fukushima accident aerosol and rain water samples collected within regular national monitoring programmes were carefully analysed. In rain water samples, aerosol and iodine filters collected in the second half of March and in April 2011 I-131, Cs-134 and Cs-137 were detected. In May 2011 the activities of I-131 and Cs-134 were close or below the detection limit and Cs-137 reached values from the period before the Fukushima accident. Additionally plutonium and americium activity concentrations in aerosol filters were analysed. These measured data were compared with measured data after the Chernobyl contamination in Slovenia in 1986. We can conclude that with adequate regular monitoring programmes influences of radioactivity contamination due to nuclear accidents worldwide can be properly assessed. PMID:23611815

  13. Physiological Considerations of Artificial Gravity

    NASA Technical Reports Server (NTRS)

    Cramer, D. B.

    1985-01-01

    Reasons for the development of artificial gravity environments on spacecraft are outlined. The physiological effects of weightlessness on the human cardiovascular skeletal, and vestibular systems are enumerated. Design options for creating artificial gravity environments are shown.

  14. Aerosol characterization with lidar methods

    NASA Astrophysics Data System (ADS)

    Sugimoto, Nobuo; Nishizawa, Tomoaki; Shimizu, Atsushi; Matsui, Ichiro

    2014-08-01

    Aerosol component analysis methods for characterizing aerosols were developed for various types of lidars including polarization-sensitive Mie scattering lidars, multi-wavelength Raman scattering lidars, and multi-wavelength highspectral- resolution lidars. From the multi-parameter lidar data, the extinction coefficients for four aerosol components can be derived. The microphysical parameters such as single scattering albedo and effective radius can be also estimated from the derived aerosol component distributions.

  15. Mexico City Aerosol Transect

    NASA Astrophysics Data System (ADS)

    Lewandowski, P. A.; Eichinger, W. E.; Prueger, J.; Holder, H. L.

    2007-12-01

    A radiative impact study was conducted in Mexico City during MILAGRO/MIRAGE campaign in March of 2006. On a day when the predominant wind was from the north to the south, authors measured radiative properties of the atmosphere in six locations across the city ranging from the city center, through the city south limits and the pass leading out of the city (causing pollutants to funnel through the area). A large change in aerosol optical properties has been noticed. The aerosol optical depth has generally increased outside of the city and angstrom coefficient has changed significantly towards smaller values. Aerosol size distribution was calculated using SkyRadPack. The total optical depths allowed coincidental lidar data to calculate total extinction profiles for all the locations for 1064nm.

  16. Aerosol Quality Monitor (AQUAM)

    NASA Astrophysics Data System (ADS)

    Liang, X.; Ignatov, A.

    2011-12-01

    The Advanced Clear-Sky Processor for Oceans (ACSPO) developed at NESDIS generates three products from AVHRR, operationally: clear sky radiances in all bands, and sea surface temperature (SST) derived from clear-sky brightness temperatures (BT) in Ch3B (centered at 3.7 μm), Ch4 (11 μm) and Ch5 (12 μm), and aerosol optical depths (AOD) derived from clear-sky reflectances in Ch1 (0.63), Ch2 (0.83) and Ch3A (1.61 μm). An integral part of ACSPO is the fast Community Radiative Transfer Model (CRTM), which calculates first-guess clear-sky BTs using global NCEP forecast atmospheric and Reynolds SST fields. Simulated BTs are employed in ACSPO for improved cloud screening, physical (RTM-based) SST inversions, and to monitor and validate satellite BTs. The model minus observation biases are monitored online in near-real time using the Monitoring IR Clear-sky radiances over Oceans for SST (MICROS; http://www.star.nesdis.noaa.gov/sod/sst/micros/). A persistent positive M-O bias is observed in MICROS, partly attributed to missing aerosol in CRTM input, causing "M" to be warmer than "O". It is thus necessary to include aerosols in CRTM and quantify their effects on AVHRR BTs and SSTs. However, sensitivity of thermal bands to aerosol is only minimal, and use of solar reflectance bands is preferable to evaluate the accuracy of CRTM modeling, with global aerosol fields as input (from e.g. Goddard Chemistry Aerosol Radiation and Transport, GOCART, or Navy Aerosol Analysis and Prediction System, NAAPS). Once available, the corresponding M-O biases in solar reflectance bands will be added to MICROS. Also, adding CRTM simulated reflectances in ACSPO would greatly improve cloud detection, help validate CRTM in the solar reflectance bands, and assist aerosol retrievals. Running CRTM with global aerosol as input is very challenging, computationally. While CRTM is being optimized to handle such global scattering computations, a near-real time web-based Aerosol Quality Monitor (AQUAM

  17. Cantera Aerosol Dynamics Simulator

    SciTech Connect

    Moffat, Harry

    2004-09-01

    The Cantera Aerosol Dynamics Simulator (CADS) package is a general library for aerosol modeling to address aerosol general dynamics, including formation from gas phase reactions, surface chemistry (growth and oxidation), bulk particle chemistry, transport by Brownian diffusion, thermophoresis, and diffusiophoresis with linkage to DSMC studies, and thermal radiative transport. The library is based upon Cantera, a C++ Cal Tech code that handles gas phase species transport, reaction, and thermodynamics. The method uses a discontinuous galerkin formulation for the condensation and coagulation operator that conserves particles, elements, and enthalpy up to round-off error. Both O-D and 1-D time dependent applications have been developed with the library. Multiple species in the solid phase are handled as well. The O-D application, called Tdcads (Time Dependent CADS) is distributed with the library. Tdcads can address both constant volume and constant pressure adiabatic homogeneous problems. An extensive set of sample problems for Tdcads is also provided.

  18. Indian aerosols: present status.

    PubMed

    Mitra, A P; Sharma, C

    2002-12-01

    This article presents the status of aerosols in India based on the research activities undertaken during last few decades in this region. Programs, like International Geophysical Year (IGY), Monsoon Experiment (MONEX), Indian Middle Atmospheric Program (IMAP) and recently conducted Indian Ocean Experiment (INDOEX), have thrown new lights on the role of aerosols in global change. INDOEX has proved that the effects of aerosols are no longer confined to the local levels but extend at regional as well as global scales due to occurrence of long range transportation of aerosols from source regions along with wind trajectories. The loading of aerosols in the atmosphere is on rising due to energy intensive activities for developmental processes and other anthropogenic activities. One of the significant observation of INDOEX is the presence of high concentrations of carbonaceous aerosols in the near persistent winter time haze layer over tropical Indian Ocean which have probably been emitted from the burning of fossil-fuels and biofuels in the source region. These have significant bearing on the radiative forcing in the region and, therefore, have potential to alter monsoon and hydrological cycles. In general, the SPM concentrations have been found to be on higher sides in ambient atmosphere in many Indian cities but the NOx concentrations have been found to be on lower side. Even in the haze layer over Indian Ocean and surrounding areas, the NOx concentrations have been reported to be low which is not conducive of O3 formation in the haze/smog layer. The acid rain problem does not seem to exist at the moment in India because of the presence of neutralizing soil dust in the atmosphere. But the high particulate concentrations in most of the cities' atmosphere in India are of concern as it can cause deteriorated health conditions. PMID:12492171

  19. Rearing insects on artificial diets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insects are reared in the laboratory for various purposes. They may be reared either on their natural food or artificial diets. Developing artificial diets may be difficult and time consuming but once optimized, artificial diets usually are simple to prepare and easy to use. Because they are process...

  20. Artificial Intelligence and Information Retrieval.

    ERIC Educational Resources Information Center

    Teodorescu, Ioana

    1987-01-01

    Compares artificial intelligence and information retrieval paradigms for natural language understanding, reviews progress to date, and outlines the applicability of artificial intelligence to question answering systems. A list of principal artificial intelligence software for database front end systems is appended. (CLB)

  1. Physiological Considerations of Artificial Gravity

    NASA Technical Reports Server (NTRS)

    Cramer, D. B.

    1985-01-01

    Weightlessness produces significant physiological changes. Whether these changes will stabilize or achieve medical significance is not clear. Artificial gravity is the physiological countermeasure, and the tether system represents an attractive approach to artificial gravity. The need for artificial gravity is examined.

  2. Radioactivity and food

    SciTech Connect

    Olszyna-Marzys, A.E. )

    1990-03-01

    Two topics relating to radioactivity and food are discussed: food irradiation for preservation purposes, and food contamination from radioactive substances. Food irradiation involves the use of electromagnetic energy (x and gamma rays) emitted by radioactive substances or produced by machine in order to destroy the insects and microorganisms present and prevent germination. The sanitary and economic advantages of treating food in this way are discussed. Numerous studies have confirmed that under strictly controlled conditions no undesirable changes take place in food that has been irradiated nor is radioactivity induced. Reference is made to the accident at the Chernobyl nuclear power station, which aroused public concern about irradiated food. The events surrounding the accident are reviewed, and its consequences with regard to contamination of different foods with radioactive substances, particularly iodine-131 and cesium-137, are described. Also discussed are the steps that have been taken by different international organizations to set limits on acceptable radioactivity in food.15 references.

  3. Global Aerosol Climatology Project.

    NASA Astrophysics Data System (ADS)

    Mishchenko, Michael; Penner, Joyce; Anderson, Donald

    2002-02-01

    This paper is concerned with uncertainties in the Advanced Very High Resolution Radiometer (AVHRR)-based retrieval of optical depth for heavy smoke aerosol plumes generated from forest fires that occurred in Canada due to a lack of knowledge on their optical properties (single-scattering albedo and asymmetry parameter). Typical values of the optical properties for smoke aerosols derived from such field experiments as Smoke, Clouds, and Radiation-Brazil (SCAR-B); Transport and Atmospheric Chemistry near the Equator-Atlantic (TRACE-A); Biomass Burning Airborne and Spaceborne Experiment in the Amazonas (BASE-A); and Boreal Ecosystem-Atmosphere Study (BOREAS) were first assumed for retrieving smoke optical depths. It is found that the maximum top-of-atmosphere (TOA) reflectance values calculated by models with these aerosol parameters are less than observations whose values are considerably higher. A successful retrieval would require an aerosol model that either has a substantially smaller asymmetry parameter (g < 0.4 versus g > 0.5), or higher single-scattering albedo ( 0.9 versus < 0.9), or both (e.g., g = 0.39 and = 0.91 versus g = 0.57 and = 0.87) than the existing models. Several potential causes were examined including small smoke particle size, low black carbon content, humidity effect, calibration errors, inaccurate surface albedo, mixture of cloud and aerosol layers, etc. A more sound smoke aerosol model is proposed that has a lower content of black carbon (mass ratio = 0.015) and smaller size (mean radius = 0.02 m for dry smoke particles), together with consideration of the effect of relative humidity. Ground-based observations of smoke suggest that for < 2.5 there is an increasing trend in and a decreasing trend in g with increases in , which is consistent with the results of satellite retrievals. Using these relationships as constraints, more plausible values of can be obtained for heavy smoke aerosol. The possibility of smoke-cloud mixtures is also

  4. Highly stable aerosol generator

    DOEpatents

    DeFord, H.S.; Clark, M.L.

    1981-11-03

    An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly. 2 figs.

  5. Highly stable aerosol generator

    DOEpatents

    DeFord, Henry S.; Clark, Mark L.

    1981-01-01

    An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly.

  6. Radioactive Waste Management Basis

    SciTech Connect

    Perkins, B K

    2009-06-03

    The purpose of this Radioactive Waste Management Basis is to describe the systematic approach for planning, executing, and evaluating the management of radioactive waste at LLNL. The implementation of this document will ensure that waste management activities at LLNL are conducted in compliance with the requirements of DOE Order 435.1, Radioactive Waste Management, and the Implementation Guide for DOE Manual 435.1-1, Radioactive Waste Management Manual. Technical justification is provided where methods for meeting the requirements of DOE Order 435.1 deviate from the DOE Manual 435.1-1 and Implementation Guide.

  7. Artificial neural superposition eye.

    PubMed

    Brückner, Andreas; Duparré, Jacques; Dannberg, Peter; Bräuer, Andreas; Tünnermann, Andreas

    2007-09-17

    We propose an ultra-thin imaging system which is based on the neural superposition compound eye of insects. Multiple light sensitive pixels in the footprint of each lenslet of this multi-channel configuration enable the parallel imaging of the individual object points. Together with the digital superposition of related signals this multiple sampling enables advanced functionalities for artificial compound eyes. Using this technique, color imaging and a circumvention for the trade-off between resolution and sensitivity of ultra-compact camera devices have been demonstrated in this article. The optical design and layout of such a system is discussed in detail. Experimental results are shown which indicate the attractiveness of microoptical artificial compound eyes for applications in the field of machine vision, surveillance or automotive imaging. PMID:19547555

  8. Influence of room geometry and ventilation rate on airflow and aerosol dispersion: implications for worker protection.

    PubMed

    Whicker, Jeffrey J; Wasiolek, Piotr T; Tavani, Rebecca A

    2002-01-01

    Knowledge of dispersion rates and patterns of radioactive aerosols and gases through workrooms is critical for understanding human exposure and for developing strategies for worker protection. The dispersion within rooms can be influenced by complex interactions between numerous variables, but especially ventilation design and room furnishings. For this study, dependence of airflow and aerosol dispersion on workroom geometry (furnishings) and ventilation rate were studied in an experimental room that was designed to approximate a plutonium laboratory. Three different configurations of simulated gloveboxes and two ventilation rates (approximately 6 and 12 air exchanges per hour) were studied. A sonic anemometer was used to measure airflow parameters including all three components of air velocity vectors and turbulence intensity distributions at multiple locations and heights. Aerosol dispersion rates and patterns were measured by releasing aerosols multiple times from six different locations. Aerosol particle concentrations resolved in time and space were measured using 16 multiplexed laser particle counters. Comparisons were made of air velocities, turbulence, and aerosol transport across different ventilation rates and room configurations. A strong influence of ventilation rate on aerosol dispersion rates and air velocity was found, and changes in room geometry had significant effects on aerosol dispersion rates and patterns. These results are important with regards to constant evaluation of placement of air sampling equipment, benchmarking numerical models of room airflow, and design of ventilation and room layouts with consideration of worker safety. PMID:11768799

  9. Geometrical Optics of Dense Aerosols

    SciTech Connect

    Hay, Michael J.; Valeo, Ernest J.; Fisch, Nathaniel J.

    2013-04-24

    Assembling a free-standing, sharp-edged slab of homogeneous material that is much denser than gas, but much more rare ed than a solid, is an outstanding technological challenge. The solution may lie in focusing a dense aerosol to assume this geometry. However, whereas the geometrical optics of dilute aerosols is a well-developed fi eld, the dense aerosol limit is mostly unexplored. Yet controlling the geometrical optics of dense aerosols is necessary in preparing such a material slab. Focusing dense aerosols is shown here to be possible, but the nite particle density reduces the eff ective Stokes number of the flow, a critical result for controlled focusing. __________________________________________________

  10. Measurement of natural and 137Cs radioactivity concentrations at Izmit Bay (Marmara Sea), Turkey

    NASA Astrophysics Data System (ADS)

    Öksüz, I.; Güray, R. T.; Özkan, N.; Yalçin, C.; Ergül, H. A.; Aksan, S.

    2016-03-01

    In order to determine the radioactivity level at Izmit Bay Marmara Sea, marine sediment samples were collected from five different locations. The radioactivity concentrations of naturally occurring 238U, 232Th and 40K isotopes and also that of an artificial isotope 137Cs were measured by using gamma-ray spectroscopy. Preliminary results show that the radioactivity concentrations of 238U and 232Th isotopes are lower than the average worldwide values while the radioactivity concentrations of the 40K are higher than the average worldwide value. A small amount of 137Cs contamination, which might be caused by the Chernobyl accident, was also detected.

  11. Radioactive pollution: Ocean environments. (Latest citations from Oceanic abstracts). Published Search

    SciTech Connect

    Not Available

    1994-04-01

    This bibliography contains citations concerning radioactive pollution of the marine environment. Distrubutions of radionuclides that indicate artificial radioactive contamination are discussed including iodine-131, various uranium isotopes, Cesium-137, Cobalt-60, Strontium-90, Ruthenium-160, and plutonium isotopes. Ecosystems considered include coral reefs and atolls, planktonic zones in the open ocean, salt marshes, estuaries, coastal waters, and the Mediterranean Sea. Sources of radioactive contamination examined include atomic bomb blasts, fossil fuel combustion, radioactive waste disposal, and nuclear accidents. Experimental simulation of radionuclide transport in marine biota is included. (Contains a minimum of 161 citations and includes a subject term index and title list.)

  12. Radioactive pollution: Ocean environments. (Latest citations from Oceanic abstracts). Published Search

    SciTech Connect

    1997-07-01

    This bibliography contains citations concerning radioactive pollution of the marine environment. Distrubutions of radionuclides that indicate artificial radioactive contamination are discussed including iodine-131, various uranium isotopes, Cesium-137, Cobalt-60, Strontium-90, Ruthenium-160, and plutonium isotopes. Ecosystems considered include coral reefs and atolls, planktonic zones in the open ocean, salt marshes, estuaries, coastal waters, and the Mediterranean Sea. Sources of radioactive contamination examined include atomic bomb blasts, fossil fuel combustion, radioactive waste disposal, and nuclear accidents. Experimental simulation of radionuclide transport in marine biota is included. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  13. Radioactive pollution: Oean environments. (Latest citations from Oceanic abstracts). Published Search

    SciTech Connect

    1995-02-01

    This bibliography contains citations concerning radioactive pollution of the marine environment. Distrubutions of radionuclides that indicate artificial radioactive contamination are discussed including iodine-131, various uranium isotopes, Cesium-137, Cobalt-60, Strontium-90, Ruthenium-160, and plutonium isotopes. Ecosystems considered include coral reefs and atolls, planktonic zones in the open ocean, salt marshes, estuaries, coastal waters, and the Mediterranean Sea. Sources of radioactive contamination examined include atomic bomb blasts, fossil fuel combustion, radioactive waste disposal, and nuclear accidents. Experimental simulation of radionuclide transport in marine biota is included. (Contains a minimum of 168 citations and includes a subject term index and title list.)

  14. Radioactive pollution: Ocean environments. (Latest citations from Oceanic abstracts). Published Search

    SciTech Connect

    1996-05-01

    This bibliography contains citations concerning radioactive pollution of the marine environment. Distrubutions of radionuclides that indicate artificial radioactive contamination are discussed including iodine-131, various uranium isotopes, Cesium-137, Cobalt-60, Strontium-90, Ruthenium-160, and plutonium isotopes. Ecosystems considered include coral reefs and atolls, planktonic zones in the open ocean, salt marshes, estuaries, coastal waters, and the Mediterranean Sea. Sources of radioactive contamination examined include atomic bomb blasts, fossil fuel combustion, radioactive waste disposal, and nuclear accidents. Experimental simulation of radionuclide transport in marine biota is included. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  15. Developing better artificial bones.

    PubMed

    Flinn, Edward D

    2003-01-01

    Researchers at the Center for Commercial Applications of Combustion in Space at the Colorado School of Mines are preparing the Space-DRUMS (Dynamically Responding Ultrasonic Matrix Systems) materials processing facility for transport to the International Space Station. The Space-DRUMS uses acoustic pressure beams to maintain the position of a suspended liquid or solid. Space-DRUMS will be used to extend experiments with tricalcium phosphate in the development of artificial bone material. PMID:12524712

  16. Artificial gravity Mars spaceship

    NASA Technical Reports Server (NTRS)

    Clark, Benton C.

    1989-01-01

    Experience gained in the study of artificial gravity for a manned trip to Mars is reviewed, and a snowflake-configured interplanetary vehicle cluster of habitat modules, descent vehicles, and propulsion systems is presented. An evolutionary design is described which permits sequential upgrading from five to nine crew members, an increase of landers from one to as many a three per mission, and an orderly, phased incorporation of advanced technologies as they become available.

  17. Applications Of Artificial Intelligence

    NASA Astrophysics Data System (ADS)

    Trivedi, Mohan M.; Gilmore, John F.

    1986-03-01

    Intelligence evolves out of matter, so said the Sankhya philosophers of ancient India. The discipline of artificial intelligence (Al), which was established some 30 years ago, has confirmed the validity of the above assertion. Recently, a number of AI applications have been successfully demonstrated, generating a great deal of excitement and interest in scientific and technical circles. In this special issue of Optical Engineering a representative set of applications that incorporate Al principles is presented.

  18. Whither Artificial Reproduction?

    PubMed Central

    Percival-Smith, Robin

    1985-01-01

    Artificial reproduction now offers sub fertile couples a number of options which raise scientific and ethical questions. This article discusses the Canadian and British experiences in formulating regulations and legislation in this important field. Current work on mammalian embryo research foretells the direction which human research will take. This article stresses the need for family physicians' participation in the ethical decisions that accompany these new developments. PMID:21274181

  19. Polish artificial heart program.

    PubMed

    El Fray, Miroslawa; Czugala, Monika

    2012-01-01

    Despite significant advances in the development of artificial heart substitutes, anthrombogenic materials and surfaces remain to be the main challenge for implants, which can prevent thrombosis that leads to rejection. The goal of material engineering is essentially to design polymeric materials of high durability and optimal thrombogenicity in mechanical heart prosthesis, being developed recently in a frame of the polish artificial heart program. For these reasons, various surface modifications are being continuously developed for a 'gold standard' material, which is a polyurethane (PU) thermoplastic elastomer and they will be shortly reviewed. However, new polymeric materials can meet medical word's attention if they are able to provide similar or better characteristics in term of bulk and surface properties. Specifically, if they will show appropriate surface topography, which is the most influential in determining the response of live tissues toward biomaterials. Nanostructured polyester thermoplastic elastomers of high biodurability as an alternative to PU materials for artificial heart are challenging new materials, and they will be discussed briefly. PMID:22110047

  20. [Liver and artificial liver].

    PubMed

    Chamuleau, R A

    1998-06-01

    Despite good results of orthotopic liver transplantation in patients with fulminant hepatic failure the need still exists for an effective and safe artificial liver, able to temporarily take over the complex liver function so as to bridge the gap with transplantation or regeneration. Attempts to develop non-biological artificial livers have failed, mostly when controlled clinical trials were performed. In the last decade several different types of bioartificial livers have been devised, in which the biocomponent consists of freshly isolated porcine hepatocytes or a human hepatoblastoma cell line. The majority use semipermeable hollow fibers known from artificial kidney devices. The liver cells may lie either inside or outside the lumen of these fibers. In vitro analysis of liver function and animal experimental work showing that the bioartificial liver increases survival justify clinical application. Bioartificial livers are connected to patients extracorporeally by means of plasmapheresis circuit for periods of about 6 hours. In different trials about 40 patients with severe liver failure have been treated. No important adverse effects have not been reported in these phase I trials. Results of controlled studies are urgently needed. As long as no satisfactory immortalised human liver cell line with good function is available, porcine hepatocytes will remain the first choice, provided transmission of porcine pathogens to man is prevented. PMID:9752034

  1. ACID AEROSOL MEASUREMENT WORKSHOP

    EPA Science Inventory

    This report documents the discussion and results of the U.S. EPA Acid Aerosol Measurement Workshop, conducted February 1-3, 1989, in Research Triangle Park, North Carolina. t was held in response to recommendations by the Clean Air Scientific Advisory Committee (CASAC) regarding ...

  2. EXPOSURES TO ACIDIC AEROSOLS

    EPA Science Inventory

    Ambient monitoring of acid aerosol in four U.S. cities and in a rural region of southern Ontario clearly show distinct periods of strong acidity. easurements made in Kingston, TN, and Stuebenville, OH, resulted in 24-hr H+ ion concentrations exceeding 100 nmole/m3 more than 10 ti...

  3. FORMATION OF PHOTOCHEMICAL AEROSOLS

    EPA Science Inventory

    The objective was to develop a better understanding of smog aerosol formation with particular reference to haze in the Southern California area. This study combined laboratory work with ambient air studies. Counting of particles by light scattering was the principle physical tech...

  4. MULTI-TECHNIQUE APPROACH TO MEASURE SIZE AND TIME RESOLVED ATMOSPHERIC AND RADIONUCLIDE AEROSOLS

    SciTech Connect

    Shutthanandan, V; Xie, YuLong; Disselkamp, Robert S; Laulainen, Nels S; Smith, Edward A; Thevuthasan, Suntharampillai

    2008-12-01

    Accurate quantifications of aerosol components are crucial to predict global atmospheric transport models. Recently developed International Monitoring System (IMS) network represents an opportunity to enhance comprehensive systematic aerosol observations on a global scale because it provides a global infrastructure. As such, a local pilot study utilizing several state-of-the-art instruments has been conducted at the peak of Rattlesnake Mountain, Washington, USA, during three month periods (June-August) in 2003 to explore this opportunity. In this study, routine aerosol samples were collected using a 3-stage Cascade Impactor Beam Analyzer (0.07 to 2.5 µm) with time resolution about 6 hours on long Teflon strips while radionuclide aerosols were collected using Radionuclide aerosol sampler/analyzer (RASA) developed at Pacific Northwest National Laboratory. The elemental composition and hydrogen concentration were measured using proton induced x-ray emission (PIXE) and proton elastic scattering analysis (PESA), respectively. In addition, short and long-lived radionuclides that exist in nature were measured with same time resolution (6 hours) using RASA. In this method, high-resolution gamma-ray spectra were analyzed for radionuclide concentration. Combination of trace radioactive and non-radioactive element analysis in aerosols makes this investigation unique.

  5. Radioactive waste disposal package

    DOEpatents

    Lampe, Robert F.

    1986-11-04

    A radioactive waste disposal package comprising a canister for containing vitrified radioactive waste material and a sealed outer shell encapsulating the canister. A solid block of filler material is supported in said shell and convertible into a liquid state for flow into the space between the canister and outer shell and subsequently hardened to form a solid, impervious layer occupying such space.

  6. Radioactive waste disposal package

    DOEpatents

    Lampe, Robert F.

    1986-01-01

    A radioactive waste disposal package comprising a canister for containing vitrified radioactive waste material and a sealed outer shell encapsulating the canister. A solid block of filler material is supported in said shell and convertible into a liquid state for flow into the space between the canister and outer shell and subsequently hardened to form a solid, impervious layer occupying such space.

  7. Radioactive Wastes. Revised.

    ERIC Educational Resources Information Center

    Fox, Charles H.

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. This booklet deals with the handling, processing and disposal of radioactive wastes. Among the topics discussed are: The Nature of Radioactive Wastes; Waste Management; and Research and Development. There are…

  8. Temporary Personal Radioactivity

    NASA Astrophysics Data System (ADS)

    Myers, Fred

    2012-11-01

    As part of a bone scan procedure to look for the spread of prostate cancer, I was injected with radioactive technetium. In an effort to occupy/distract my mind, I used a Geiger counter to determine if the radioactive count obeyed the inverse-square law as a sensor was moved away from my bladder by incremental distances.

  9. A Remote Radioactivity Experiment

    ERIC Educational Resources Information Center

    Jona, Kemi; Vondracek, Mark

    2013-01-01

    Imagine a high school with very few experimental resources and limited budgets that prevent the purchase of even basic laboratory equipment. For example, many high schools do not have the means of experimentally studying radioactivity because they lack Geiger counters and/or good radioactive sources. This was the case at the first high school one…

  10. Computational fluid dynamics analysis of aerosol deposition in pebble beds

    NASA Astrophysics Data System (ADS)

    Mkhosi, Margaret Msongi

    2007-12-01

    The Pebble Bed Modular Reactor is a high temperature gas cooled reactor which uses helium gas as a coolant. The reactor uses spherical graphite pebbles as fuel. The fuel design is inherently resistant to the release of the radioactive material up to high temperatures; therefore, the plant can withstand a broad spectrum of accidents with limited release of radionuclides to the environment. Despite safety features of the concepts, these reactors still contain large inventories of radioactive materials. The transport of most of the radioactive materials in an accident occurs in the form of aerosol particles. In this dissertation, the limits of applicability of existing computational fluid dynamics code FLUENT to the prediction of aerosol transport have been explored. The code was run using the Reynolds Averaged Navier-Stokes turbulence models to determine the effects of different turbulence models on the prediction of aerosol particle deposition. Analyses were performed for up to three unit cells in the orthorhombic configuration. For low flow conditions representing natural circulation driven flow, the laminar flow model was used and the results were compared with existing experimental data for packed beds. The results compares well with experimental data in the low flow regime. For conditions corresponding to normal operating of the reactor, analyses were performed using the standard k-ɛ turbulence model. From the inertial deposition results, a correlation that can be used to estimate the deposition of aerosol particles within pebble beds given inlet flow conditions has been developed. These results were converted into a dimensionless form as a function of a modified Stokes number. Based on results obtained in the laminar regime and for individual pebbles, the correlation developed for the inertial impaction component of deposition is believed to be credible. The form of the correlation developed also allows these results to be applied to pebble beds of different

  11. The influence of salt aerosol on alpha radiation detection by WIPP continuous air monitors

    SciTech Connect

    Bartlett, W.T.; Walker, B.A.

    1996-01-01

    Alpha continuous air monitors (CAMs) will be used at the Waste Isolation Pilot Plant (WIPP) to measure airborne transuranic radioactivity that might be present in air exhaust or in work-place areas. WIPP CAMs are important to health and safety because they are used to alert workers to airborne radioactivity, to actuate air-effluent filtration systems, and to detect airborne radioactivity so that the radioactivity can be confined in a limited area. In 1993, the Environmental Evaluation Group (EEG) reported that CAM operational performance was affected by salt aerosol, and subsequently, the WIPP CAM design and usage were modified. In this report, operational data and current theories on aerosol collection were reviewed to determine CAM quantitative performance limitations. Since 1993, the overall CAM performance appears to have improved, but anomalous alpha spectra are present when sampling-filter salt deposits are at normal to high levels. This report shows that sampling-filter salt deposits directly affect radon-thoron daughter alpha spectra and overall monitor efficiency. Previously it was assumed that aerosol was mechanically collected on the surface of CAM sampling filters, but this review suggests that electrostatic and other particle collection mechanisms are more important than previously thought. The mechanism of sampling-filter particle collection is critical to measurement of acute releases of radioactivity. 41 refs.

  12. Scoping studies: behavior and control of lithium and lithium aerosols

    SciTech Connect

    Jeppson, D W

    1982-01-01

    The HEDL scoping studies examining the behavior of lithium and lithium aerosols have been conducted to determine and examine potential safety and environmental issues for postulated accident conditions associated with the use of lithium as a fusion reactor blanket and/or coolant. Liquid lithium reactions with air, nitrogen, carbon dioxide and concretes have been characterized. The effectiveness of various powder extinguishing agents and methods of application were determined for lithium-air reactions. The effectiveness of various lithium aerosol collection methods were determined and the volatilization and transport of radioactive metals potentially associated with lithium-air reactions were evaluated. Liquid lithium atmosphere reactions can be safely controlled under postulated accident conditions, but special handling practices must be provided. Lithium-concrete reactions should be avoided because of the potential production of high temperatures, corrosive environment and hydrogen. Carbon microspheres are effective in extinguishing well established lithium-air reactions for the lithium quantities tested (up to 10 kg). Large mass loading of lithium aerosols can be efficiently collected with conventional air cleaning systems. Potentially radioactive species (cobalt, iron and manganese) will be volatilized in a lithium-air reaction in contact with neutron activated stainless steel.

  13. Particle size influences aerosol deposition in guinea pigs during bronchoconstriction

    SciTech Connect

    Praud, J.P.; Macquin-Mavier, I.; Wirquin, V.; Meignan, M.; Harf, A.

    1986-03-01

    The role of two factors determining the deposition of aerosols in the respiratory tract was investigated: the particle size and the nature of the airflow in the airways. An aerosol of Tc99 m-DTPA was generated, with a mass median aerodynamic diameter of either 3 ..mu..m (Bird nebulizer) or 0.5 ..mu..m (Jouan nebulizer). The vehicle was either saline (S) or histamine (H) at a concentration which was previously shown to induce a 50% decrease of specific airway conductance. Spontaneously breathing guinea pigs were exposed during 2 minutes to the aerosol, then killed and the radioactivity in the pharynx, the trachea, the large bronchi and the remaining parenchyma was measured. Results are evaluated as the percentage of total radioactivity in the respiratory tract (mean +/- SEM). Analysis of variance showed that there was a significant difference in the pattern of deposition for large particles (3 ..mu..m) during bronchoconstriction: the more proximal deposition can be ascribed to inertial impaction. Particle size should be clearly defined during histamine challenge in experimental animals.

  14. Artificial intelligence in hematology.

    PubMed

    Zini, Gina

    2005-10-01

    Artificial intelligence (AI) is a computer based science which aims to simulate human brain faculties using a computational system. A brief history of this new science goes from the creation of the first artificial neuron in 1943 to the first artificial neural network application to genetic algorithms. The potential for a similar technology in medicine has immediately been identified by scientists and researchers. The possibility to store and process all medical knowledge has made this technology very attractive to assist or even surpass clinicians in reaching a diagnosis. Applications of AI in medicine include devices applied to clinical diagnosis in neurology and cardiopulmonary diseases, as well as the use of expert or knowledge-based systems in routine clinical use for diagnosis, therapeutic management and for prognostic evaluation. Biological applications include genome sequencing or DNA gene expression microarrays, modeling gene networks, analysis and clustering of gene expression data, pattern recognition in DNA and proteins, protein structure prediction. In the field of hematology the first devices based on AI have been applied to the routine laboratory data management. New tools concern the differential diagnosis in specific diseases such as anemias, thalassemias and leukemias, based on neural networks trained with data from peripheral blood analysis. A revolution in cancer diagnosis, including the diagnosis of hematological malignancies, has been the introduction of the first microarray based and bioinformatic approach for molecular diagnosis: a systematic approach based on the monitoring of simultaneous expression of thousands of genes using DNA microarray, independently of previous biological knowledge, analysed using AI devices. Using gene profiling, the traditional diagnostic pathways move from clinical to molecular based diagnostic systems. PMID:16203606

  15. Artificial mismatch hybridization

    DOEpatents

    Guo, Zhen; Smith, Lloyd M.

    1998-01-01

    An improved nucleic acid hybridization process is provided which employs a modified oligonucleotide and improves the ability to discriminate a control nucleic acid target from a variant nucleic acid target containing a sequence variation. The modified probe contains at least one artificial mismatch relative to the control nucleic acid target in addition to any mismatch(es) arising from the sequence variation. The invention has direct and advantageous application to numerous existing hybridization methods, including, applications that employ, for example, the Polymerase Chain Reaction, allele-specific nucleic acid sequencing methods, and diagnostic hybridization methods.

  16. Artificial gravity field

    NASA Astrophysics Data System (ADS)

    Markley, Larry C.; Lindner, John F.

    Using computer algebra to run Einstein's equations "backward", from field to source rather than from source to field, we design an artificial gravity field for a space station or spaceship. Everywhere inside astronauts experience normal Earth gravity, while outside they float freely. The stress-energy that generates the field contains exotic matter of negative energy density but also relies importantly on pressures and shears, which we describe. The same techniques can be readily used to design other interesting spacetimes and thereby elucidate the connection between the source and field in general relativity.

  17. Plasmonic nanostructures: artificial molecules.

    PubMed

    Wang, Hui; Brandl, Daniel W; Nordlander, Peter; Halas, Naomi J

    2007-01-01

    This Account describes a new paradigm for the relationship between the geometry of metallic nanostructures and their optical properties. While the interaction of light with metallic nanoparticles is determined by their collective electronic or plasmon response, a compelling analogy exists between plasmon resonances of metallic nanoparticles and wave functions of simple atoms and molecules. Based on this insight, an entire family of plasmonic nanostructures, artificial molecules, has been developed whose optical properties can be understood within this picture: nanoparticles (nanoshells, nanoeggs, nanomatryushkas, nanorice), multi-nanoparticle assemblies (dimers, trimers, quadrumers), and a nanoparticle-over-metallic film, an electromagnetic analog of the spinless Anderson model. PMID:17226945

  18. Reduction of photosynthetically active radiation under extreme stratospheric aerosol loads

    SciTech Connect

    Gerstl, S.A.W.; Zardecki, A.

    1981-08-01

    The recently published hypothesis that the Cretaceous-Tertiary extinctions might be caused by an obstruction of sunlight is tested by model calculations. First we compute the total mass of stratospheric aerosols under normal atmospheric conditions for four different (measured) aerosol size distributions and vertical profiles. For comparison, the stratospheric dust masses after four volcanic eruptions are also evaluated. Detailed solar radiative transfer calculations are then performed for artificially increased aerosol amounts until the postulated darkness scenario is obtained. Thus we find that a total stratospheric aerosol mass between 1 and 4 times 10/sup 1/ g is sufficient to reduce photosynthesis to 10/sup -3/ of normal. We also infer from this result tha the impact of a 0.4- to 3-km-diameter asteroid or a close encounter with a Halley-size comet may deposit that amount of particulates into the stratosphere. The darkness scenario of Alvarez et al. is thus shown to be a possible extinction mechanism, even with smaller size asteroids of comets than previously estimated.

  19. The kinetics of aerosol particle formation and removal in NPP severe accidents

    NASA Astrophysics Data System (ADS)

    Zatevakhin, Mikhail A.; Arefiev, Valentin K.; Semashko, Sergey E.; Dolganov, Rostislav A.

    2016-06-01

    Severe Nuclear Power Plant (NPP) accidents are accompanied by release of a massive amount of energy, radioactive products and hydrogen into the atmosphere of the NPP containment. A valid estimation of consequences of such accidents can only be carried out through the use of the integrated codes comprising a description of the basic processes which determine the consequences. A brief description of a coupled aerosol and thermal-hydraulic code to be used for the calculation of the aerosol kinetics within the NPP containment in case of a severe accident is given. The code comprises a KIN aerosol unit integrated into the KUPOL-M thermal-hydraulic code. Some features of aerosol behavior in severe NPP accidents are briefly described.

  20. Aerosol Resuspension Model for MELCOR for Fusion and Very High Temperature Reactor Applications

    SciTech Connect

    B.J. Merrill

    2011-01-01

    Dust is generated in fusion reactors from plasma erosion of plasma facing components within the reactor’s vacuum vessel (VV) during reactor operation. This dust collects in cooler regions on interior surfaces of the VV. Because this dust can be radioactive, toxic, and/or chemically reactive, it poses a safety concern, especially if mobilized by the process of resuspension during an accident and then transported as an aerosol though out the reactor confinement building, and possibly released to the environment. A computer code used at the Idaho National Laboratory (INL) to model aerosol transport for safety consequence analysis is the MELCOR code. A primary reason for selecting MELCOR for this application is its aerosol transport capabilities. The INL Fusion Safety Program (FSP) organization has made fusion specific modifications to MELCOR. Recent modifications include the implementation of aerosol resuspension models in MELCOR 1.8.5 for Fusion. This paper presents the resuspension models adopted and the initial benchmarking of these models.

  1. Size-resolved parameterization of primary organic carbon in fresh marine aerosols

    SciTech Connect

    Long, Michael S; Keene, William C; Erickson III, David J

    2009-12-01

    Marine aerosols produced by the bursting of artificially generated bubbles in natural seawater are highly enriched (2 to 3 orders of magnitude based on bulk composition) in marine-derived organic carbon (OC). Production of size-resolved particulate OC was parameterized based on a Langmuir kinetics-type association of OC to bubble plumes in seawater and resulting aerosol as constrained by measurements of aerosol produced from highly productive and oligotrophic seawater. This novel approach is the first to account for the influence of adsorption on the size-resolved association between marine aerosols and OC. Production fluxes were simulated globally with an eight aerosol-size-bin version of the NCAR Community Atmosphere Model (CAM v3.5.07). Simulated number and inorganic sea-salt mass production fell within the range of published estimates based on observationally constrained parameterizations. Because the parameterization does not consider contributions from spume drops, the simulated global mass flux (1.5 x 10{sup 3} Tg y{sup -1}) is near the lower limit of published estimates. The simulated production of aerosol number (2.1 x 10{sup 6} cm{sup -2} s{sup -1}) and OC (49 Tg C y{sup -1}) fall near the upper limits of published estimates and suggest that primary marine aerosols may have greater influences on the physiochemical evolution of the troposphere, radiative transfer and climate, and associated feedbacks on the surface ocean than suggested by previous model studies.

  2. Graphical aerosol classification method using aerosol relative optical depth

    NASA Astrophysics Data System (ADS)

    Chen, Qi-Xiang; Yuan, Yuan; Shuai, Yong; Tan, He-Ping

    2016-06-01

    A simple graphical method is presented to classify aerosol types based on a combination of aerosol optical thickness (AOT) and aerosol relative optical thickness (AROT). Six aerosol types, including maritime (MA), desert dust (DD), continental (CO), sub-continental (SC), urban industry (UI) and biomass burning (BB), are discriminated in a two dimensional space of AOT440 and AROT1020/440. Numerical calculations are performed using MIE theory based on a multi log-normal particle size distribution, and the AROT ranges for each aerosol type are determined. More than 5 years of daily observations from 8 representative aerosol sites are applied to the method to confirm spatial applicability. Finally, 3 individual cases are analyzed according to their specific aerosol status. The outcomes indicate that the new graphical method coordinates well with regional characteristics and is also able to distinguish aerosol variations in individual situations. This technique demonstrates a novel way to estimate different aerosol types and provide information on radiative forcing calculations and satellite data corrections.

  3. Remote sensing of clouds and aerosols with cosmic rays

    NASA Astrophysics Data System (ADS)

    Neronov, Andrii; Malyshev, Denys; Dmytriiev, Anton

    2014-05-01

    Remote sensing of atmosphere is conventionally done via a study of extinction/scattering of light from natural (Sun, Moon) or artificial (laser) sources. Cherenkov emission from extensive air showers generated by cosmic rays provides one more natural light source distributed throughout the atmosphere. We show that Cherenkov light carries information on three-dimensional distribution of clouds and aerosols in the atmosphere and on the size distribution and scattering phase function of cloud/aerosol particles. Therefore, it could be used for the atmospheric sounding. The new atmospheric sounding method could be implemented via an adjustment of technique of imaging Cherenkov telescopes. The atmospheric sounding data collected in this way could be used both for atmospheric science and for the improvement of the quality of astronomical gamma-ray observations.

  4. Applicability of nonresonant artificial diamagnetics

    NASA Astrophysics Data System (ADS)

    Jelinek, L.; Lapine, M.; McPhedran, R. C.

    2014-09-01

    Artificial diamagnetics are prominent for achieving extraordinarily strong diamagnetism in a wide frequency range. However, as far as the magnetic fields outside the artificial medium are concerned, bulk conductors show a very similar pattern. The question arises whether the complicated internal structure of artificial diamagnetics can, to this end, be replaced by a simpler object. We show that for an electrically small body, internal structuring is likely to make the effective diamagnetic response weaker than that of a simple conducting object.

  5. Aerosol Observing System (AOS) Handbook

    SciTech Connect

    Jefferson, A

    2011-01-17

    The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

  6. Development of artificial empathy.

    PubMed

    Asada, Minoru

    2015-01-01

    We have been advocating cognitive developmental robotics to obtain new insight into the development of human cognitive functions by utilizing synthetic and constructive approaches. Among the different emotional functions, empathy is difficult to model, but essential for robots to be social agents in our society. In my previous review on artificial empathy (Asada, 2014b), I proposed a conceptual model for empathy development beginning with emotional contagion to envy/schadenfreude along with self/other differentiation. In this article, the focus is on two aspects of this developmental process, emotional contagion in relation to motor mimicry, and cognitive/affective aspects of the empathy. It begins with a summary of the previous review (Asada, 2014b) and an introduction to affective developmental robotics as a part of cognitive developmental robotics focusing on the affective aspects. This is followed by a review and discussion on several approaches for two focused aspects of affective developmental robotics. Finally, future issues involved in the development of a more authentic form of artificial empathy are discussed. PMID:25498950

  7. The total artificial heart

    PubMed Central

    Cook, Jason A.; Shah, Keyur B.; Quader, Mohammed A.; Cooke, Richard H.; Kasirajan, Vigneshwar; Rao, Kris K.; Smallfield, Melissa C.; Tchoukina, Inna

    2015-01-01

    The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient’s native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review. PMID:26793338

  8. Clinical assessment of a commercial aerosol delivery system for ventilation scanning by comparison with KR-81m

    SciTech Connect

    Wollmer, P.; Eriksson, L.; Andersson, A.C.

    1984-01-01

    Radioactive aerosols offer a means for steady state ventilation scanning in multiple views. The clinical use of radioaerosol techniques has been hampered by the lack of delivery systems producing sufficiently small particles. If the aerosol contains large particles, heavy deposition occurs in major airways, especially in patients with airways disease. The authors have assessed a new, commercial aerosol delivery system (Syntevent) by comparison with Kr-81m ventilation scanning in 23 patients with airways obstruction. An indirect comparison was also made with a settling bad technique. Ventilation scans in four projections were obtained during continuous inhalation of Kr-81m. Subsequently, the patient inhaled an aerosol labelled with In-113m from the Syntevent system, and aerosol ventilation scans were obtained in the same projections. Spirometry was performed to establish the degree of airways obstruction. The aerosol delineated the ventilated regions of the lungs adequately in all the patients. Deposition of aerosol in larger airways was seen in a few patients only, and this did not impede the interpretation of the scintigram. A quantitative analysis of the penetration of the aerosol to the periphery of the lung failed to demonstrate any significant correlation between particle penetration and airways obstruction. Aerosol penetration was significantly greater (p<0.001) with the Syntevent system than with a settling bag technique.

  9. Cantera Aerosol Dynamics Simulator

    Energy Science and Technology Software Center (ESTSC)

    2004-09-01

    The Cantera Aerosol Dynamics Simulator (CADS) package is a general library for aerosol modeling to address aerosol general dynamics, including formation from gas phase reactions, surface chemistry (growth and oxidation), bulk particle chemistry, transport by Brownian diffusion, thermophoresis, and diffusiophoresis with linkage to DSMC studies, and thermal radiative transport. The library is based upon Cantera, a C++ Cal Tech code that handles gas phase species transport, reaction, and thermodynamics. The method uses a discontinuous galerkinmore » formulation for the condensation and coagulation operator that conserves particles, elements, and enthalpy up to round-off error. Both O-D and 1-D time dependent applications have been developed with the library. Multiple species in the solid phase are handled as well. The O-D application, called Tdcads (Time Dependent CADS) is distributed with the library. Tdcads can address both constant volume and constant pressure adiabatic homogeneous problems. An extensive set of sample problems for Tdcads is also provided.« less

  10. Combined measurements of organic aerosol isotopic and chemical composition to investigate day-night differences in carbonaceous aerosol

    NASA Astrophysics Data System (ADS)

    Dusek, Ulrike; Holzinger, Rupert; Meijer, Harro A. J.; Röckmann, Thomas

    2014-05-01

    PM2.5 filter samples have been collected during the Pegasos (Mai, 2012) and Actris (June/July 2012) campaigns at the CESAR site near Cabauw, the Netherlands. This site lies in a rural location surrounded by major urban centers and highways and is a good location for measuring the regional aerosol contamination in the Netherlands. High volume filter samples were taken over several days, but the aerosol was collected on separate filters during day and night time periods. We analyzed these filters for carbon isotopes (14C and 13C) and detailed chemical composition of the organic fraction, which can be a powerful tool, for investigating sources and processing of the organic aerosol. Measurement of the radioactive carbon isotope 14C in aerosols can provide a direct estimate of the contribution of fossil fuel sources to aerosol carbon. The stable carbon isotopes 12C and 13C can be used to get information about sources and processing of organic aerosol. We use a method to measure d13C values of OC desorbed from the filter samples in He at different temperature steps. The chemical composition of the organic fraction at the same temperature steps can be determined using a Proton Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-ToF-MS). The PTR-MS method is applied to the filter samples as well to aerosol collected in situ by a impaction using a Collection-Thermal-Desorption Cell. First results show that the mass concentration of the carbonaceous aerosol is higher during night time than during day time, dominated by a strong increase of biogenic organic aerosol. This is at least partially caused by a shallow night time boundary layer combined with decreased traffic sources and increased condensation of semi-volatile biogenic gases during night-time. Evidence for the role of semi-volatile compounds in enhancing organic carbon (OC) night time concentrations comes from several observations: (1) semi-volatile OC with desorption temperatures lower than 250 °C increases

  11. Assimilation of Aerosol Optical Depths

    NASA Astrophysics Data System (ADS)

    Verver, Gé; Henzing, Bas

    Climate predictions are hampered by the large uncertainties involved in the estima- tion of the effects of atmospheric aerosol (IPCC,2001). These uncertainties are caused partly because sources and sinks as well as atmospheric processing of the different types of aerosol are not accurately known. Moreover, the climate impact (especially the indirect effect) of a certain distribution of aerosol is hard to quantify. There have been different approaches to reduce these uncertainties. In recent years intensive ob- servational campaigns such as ACE and INDOEX have been carried out, aiming to in- crease our knowledge of atmospheric processes that determine the fate of atmospheric aerosols and to quantify the radiation effects. With the new satellite instruments such as SCIAMACHY and OMI it will be possible in the near future to derive the ge- ographical distribution of the aerosol optical depths (AOD) and perhaps additional information on the occurrence of different aerosol types. The goal of the ARIA project (started in 2001) is to assimilate global satellite de- rived aerosol optical depth (AOD) in an off-line chemistry/transport model TM3. The TM3 model (Jeuken et al. 2001) describes sources, sinks, transformation and transport processes of different types of aerosol (mineral dust, carbon, sulfate, nitrate) that are relevant to radiative forcing. All meteorological input is provided by ECMWF. The assimilation procedure constrains the aerosol distribution produced by the model on the basis of aerosol optical depths observed by satellite. The product, i.e. an optimal estimation of global aerosol distribution, is then available for the calculation of radia- tive forcing. Error analyses may provide valuable information on deficiencies of the model. In the ARIA project it is tried to extract additional information on the type of aerosol present in the atmosphere by assimilating AOD at multiple wavelengths. First results of the ARIA project will be presented. The values

  12. Atmospheric aerosols: Their Optical Properties and Effects

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Measured properties of atmospheric aerosol particles are presented. These include aerosol size frequency distribution and complex retractive index. The optical properties of aerosols are computed based on the presuppositions of thermodynamic equilibrium and of Mie-theory.

  13. Measurement of radioactivity levels and assessment of radioactivity hazards of soil samples in Karaman, Turkey.

    PubMed

    Agar, O; Boztosun, I; Korkmaz, M E; Özmen, S F

    2014-12-01

    In this study, the levels of the natural and artificial radioactivity in soil samples collected from surrounding of Karaman in Turkey were measured. Activity concentrations of the concerned radionuclides were determined by gamma-ray spectrometry using a high-purity germanium detector with a relative efficiency of 40 % at 1.332 MeV. The results obtained for the (238)U series ((226)Ra, (214)Pb and (214)Bi), (232)Th series ((228)Ac), (40)K and fission product (137)Cs are discussed. To evaluate the radiological hazard of radioactivity in samples, the radium equivalent activity (Raeq), the absorbed dose rate (D), the annual effective dose and the external (Hex) and internal hazard index (Hin) were calculated and presented in comparison with the data collected from different areas in the world and Turkey. PMID:24587487

  14. Stratospheric aerosols - Observation and theory

    NASA Technical Reports Server (NTRS)

    Turco, R. P.; Whitten, R. C.; Toon, O. B.

    1982-01-01

    Important chemical and physical roles of aerosols are discussed, and properties of stratospheric aerosols as revealed by experimental data are described. In situ measurements obtained by mechanical collection and scattered-light detection yield the overall size distribution of the aerosols, and analyses of preserved aerosol precursor gases by wet chemical, cryogenic and spectroscopic techniques indicate the photochemical sources of particle mass. Aerosol chemical reactions including those of gaseous precursors, those in aqueous solution, and those on particle surfaces are discussed, in addition to aerosol microphysical processes such as nucleation, condensation/evaporation, coagulation and sedimentation. Models of aerosols incorporating such chemical and physical processes are presented, and simulations are shown to agree with measurements. Estimates are presented for the potential aerosol changes due to emission of particles and gases by aerospace operations and industrial consumption of fossil fuels, and it is demonstrated that although the climatic effects of existing levels of stratospheric aerosol pollution are negligible, potential increases in those levels might pose a future threat.

  15. Volcanic aerosols and lunar eclipses.

    PubMed

    Keen, R A

    1983-12-01

    The moon is visible during total lunar eclipses due to sunlight refracted into the earth's shadow by the atmosphere. Stratospheric aerosols can profoundly affect the brightness of the eclipsed moon. Observed brightnesses of 21 lunar eclipses during 1960-1982 are compared with theoretical calculations based on refraction by an aerosol-free atmosphere to yield globally averaged aerosol optical depths. Results indicate the global aerosol loading from the 1982 eruption of El Chichón is similar in magnitude to that from the 1963 Agung eruption. PMID:17776243

  16. Residence times of fine tropospheric aerosols as determined by {sup 210}Pb progeny.

    SciTech Connect

    Marley, N. A.; Gaffney, J. S.; Drayton, P. J.; Cunningham, M. M.; Mielcarek, C.; Ravelo, R.; Wagner, C.

    1999-10-05

    Fine tropospheric aerosols can play important roles in the radiative balance of the atmosphere. The fine aerosols can act directly to cool the atmosphere by scattering incoming solar radiation, as well as indirectly by serving as cloud condensation nuclei. Fine aerosols, particularly carbonaceous soots, can also warm the atmosphere by absorbing incoming solar radiation. In addition, aerosols smaller than 2.5 {micro}m have recently been implicated in the health effects of air pollution. Aerosol-active radioisotopes are ideal tracers for the study of atmospheric transport processes. The source terms of these radioisotopes are relatively well known, and they are removed from the atmosphere only by radioactive decay or by wet or dry deposition of the host aerosol. The progeny of the primordial radionuclide {sup 238}U are of particular importance to atmospheric studies. Uranium-238 is common throughout Earth's crust and decays to the inert gas {sup 222}Rn, which escapes into the atmosphere. Radon-222 decays by the series of alpha and beta emissions shown in Figure 1 to the long-lived {sup 210}Pb. Once formed, {sup 210}Pb becomes attached to aerosol particles with average attachment times of 40 s to 3 min.

  17. The Humidity Dependence of N2O5 Uptake to Citric Acid Aerosol Particles

    NASA Astrophysics Data System (ADS)

    Grzinic, G.; Bartels-Rausch, T.; Tuerler, A.; Ammann, M.

    2013-12-01

    Dinitrogen pentoxide is a significant reactive intermediate in the night time chemistry of nitrogen oxides. Depending on atmospheric conditions it can act either as a NO3 radical reservoir or as a major NOx sink by heterogeneous hydrolysis on aerosol surfaces. As such, it can influence tropospheric ozone production and therefore the oxidative capacity of the atmosphere. The heterogeneous loss of N2O5 to aerosol particles has remained uncertain, and reconciling lab and field data has demonstrated some gaps in our understanding of the detailed mechanism. We used the short-lived radioactive tracer 13N to study N2O5 uptake kinetics on aerosol particles in an aerosol flow reactor at ambient pressure, temperature and relative humidity. Citric acid, representing strongly oxidized polyfunctional organic compounds in atmospheric aerosols, has been chosen as a proxy due to its well established physical properties. Aerosol uptake measurements were performed with citric acid aerosols in a humidity range of 15-75 % RH, within which the uptake coefficient varies between about 0.001 and about 0.02. Taking into account the well established hygroscopic properties of citric acid, we interpret uptake in terms of disproportionation of N2O5 into nitrate ion and nitronium ion and reaction of the latter with liquid water.

  18. Understanding radioactive waste

    SciTech Connect

    Murray, R.L.

    1981-12-01

    This document contains information on all aspects of radioactive wastes. Facts are presented about radioactive wastes simply, clearly and in an unbiased manner which makes the information readily accessible to the interested public. The contents are as follows: questions and concerns about wastes; atoms and chemistry; radioactivity; kinds of radiation; biological effects of radiation; radiation standards and protection; fission and fission products; the Manhattan Project; defense and development; uses of isotopes and radiation; classification of wastes; spent fuels from nuclear reactors; storage of spent fuel; reprocessing, recycling, and resources; uranium mill tailings; low-level wastes; transportation; methods of handling high-level nuclear wastes; project salt vault; multiple barrier approach; research on waste isolation; legal requiremnts; the national waste management program; societal aspects of radioactive wastes; perspectives; glossary; appendix A (scientific American articles); appendix B (reference material on wastes). (ATT)

  19. Artificial organs: recent progress in artificial hearing and vision.

    PubMed

    Ifukube, Tohru

    2009-01-01

    Artificial sensory organs are a prosthetic means of sending visual or auditory information to the brain by electrical stimulation of the optic or auditory nerves to assist visually impaired or hearing-impaired people. However, clinical application of artificial sensory organs, except for cochlear implants, is still a trial-and-error process. This is because how and where the information transmitted to the brain is processed is still unknown, and also because changes in brain function (plasticity) remain unknown, even though brain plasticity plays an important role in meaningful interpretation of new sensory stimuli. This article discusses some basic unresolved issues and potential solutions in the development of artificial sensory organs such as cochlear implants, brainstem implants, artificial vision, and artificial retinas. PMID:19330498

  20. Container for radioactive materials

    DOEpatents

    Fields, Stanley R.

    1985-01-01

    A container for housing a plurality of canister assemblies containing radioactive material and disposed in a longitudinally spaced relation within a carrier to form a payload package concentrically mounted within the container. The payload package includes a spacer for each canister assembly, said spacer comprising a base member longitudinally spacing adjacent canister assemblies from each other and a sleeve surrounding the associated canister assembly for centering the same and conducting heat from the radioactive material in a desired flow path.

  1. Dynamic radioactive particle source

    DOEpatents

    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.

  2. Temporary Personal Radioactivity

    ERIC Educational Resources Information Center

    Myers, Fred

    2012-01-01

    As part of a bone scan procedure to look for the spread of prostate cancer, I was injected with radioactive technetium. In an effort to occupy/distract my mind, I used a Geiger counter to determine if the radioactive count obeyed the inverse-square law as a sensor was moved away from my bladder by incremental distances. (Contains 1 table and 2…

  3. Radioactive gold ring dermatitis

    SciTech Connect

    Miller, R.A.; Aldrich, J.E. )

    1990-08-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy.

  4. Aerosol optical depth and type retrieval using MSG/SEVIRI data

    NASA Astrophysics Data System (ADS)

    Mei, L.; Xue, Y.; Kokhanovsky, A. A.

    2012-04-01

    approximating the exact integrodifferential equation of radioactive transfer equations for radiant intensity by common differential equations for the upward and incident radiation fluxes, a MSG/SEVIRI multi-spectral for three series time algorithm to retrieve AOD and surface reflectance will be proposed. And then the proposed model will be used as a forward model, a new joint retrieval of the total column AOD and surface reflectance over land surface from MSG/SEVIRI observations with an optimal estimation approach will be obtained. As to the aerosol type, six pre-defined aerosol type were used, all aerosol type of each pixel in area of a certain area is statistic, and the type with the highest mean probability is taken as the best one for the area. And then we get the aerosol type in the whole study area; we should reprocess the AOD using the update aerosol type. The main point is to choose the best aerosol properties for define aerosol type during retrieving. Primary validation using AEORNET show that the good agreement between retrieval results and ground-based observation, the relative error compared with AERONET is around 0.3. Primary validation also demonstrates that the MSG retrieval provides larger coverage and a comparable result compared with MODIS product, meanwhile, it also provide aerosol type product. Although preliminary validation is encouraging, the difference in wavelength and time differences makes comparison difficult, and further validation is needed.

  5. Molecular artificial photosynthesis.

    PubMed

    Berardi, Serena; Drouet, Samuel; Francàs, Laia; Gimbert-Suriñach, Carolina; Guttentag, Miguel; Richmond, Craig; Stoll, Thibaut; Llobet, Antoni

    2014-11-21

    The replacement of fossil fuels by a clean and renewable energy source is one of the most urgent and challenging issues our society is facing today, which is why intense research has been devoted to this topic recently. Nature has been using sunlight as the primary energy input to oxidise water and generate carbohydrates (solar fuel) for over a billion years. Inspired, but not constrained, by nature, artificial systems can be designed to capture light and oxidise water and reduce protons or other organic compounds to generate useful chemical fuels. This tutorial review covers the primary topics that need to be understood and mastered in order to come up with practical solutions for the generation of solar fuels. These topics are: the fundamentals of light capturing and conversion, water oxidation catalysis, proton and CO2 reduction catalysis and the combination of all of these for the construction of complete cells for the generation of solar fuels. PMID:24473472

  6. Artificial Molecular Machines.

    PubMed

    Balzani; Credi; Raymo; Stoddart

    2000-10-01

    The miniaturization of components used in the construction of working devices is being pursued currently by the large-downward (top-down) fabrication. This approach, however, which obliges solid-state physicists and electronic engineers to manipulate progressively smaller and smaller pieces of matter, has its intrinsic limitations. An alternative approach is a small-upward (bottom-up) one, starting from the smallest compositions of matter that have distinct shapes and unique properties-namely molecules. In the context of this particular challenge, chemists have been extending the concept of a macroscopic machine to the molecular level. A molecular-level machine can be defined as an assembly of a distinct number of molecular components that are designed to perform machinelike movements (output) as a result of an appropriate external stimulation (input). In common with their macroscopic counterparts, a molecular machine is characterized by 1) the kind of energy input supplied to make it work, 2) the nature of the movements of its component parts, 3) the way in which its operation can be monitored and controlled, 4) the ability to make it repeat its operation in a cyclic fashion, 5) the timescale needed to complete a full cycle of movements, and 6) the purpose of its operation. Undoubtedly, the best energy inputs to make molecular machines work are photons or electrons. Indeed, with appropriately chosen photochemically and electrochemically driven reactions, it is possible to design and synthesize molecular machines that do work. Moreover, the dramatic increase in our fundamental understanding of self-assembly and self-organizational processes in chemical synthesis has aided and abetted the construction of artificial molecular machines through the development of new methods of noncovalent synthesis and the emergence of supramolecular assistance to covalent synthesis as a uniquely powerful synthetic tool. The aim of this review is to present a unified view of the field

  7. Artificial sweeteners - a review.

    PubMed

    Chattopadhyay, Sanchari; Raychaudhuri, Utpal; Chakraborty, Runu

    2014-04-01

    Now a days sugar free food are very much popular because of their less calorie content. So food industry uses various artificial sweeteners which are low in calorie content instead of high calorie sugar. U.S. Food and Drug Administration has approved aspartame, acesulfame-k, neotame, cyclamate and alitame for use as per acceptable daily intake (ADI) value. But till date, breakdown products of these sweeteners have controversial health and metabolic effects. On the other hand, rare sugars are monosaccharides and have no known health effects because it does not metabolize in our body, but shows same sweet taste and bulk property as sugar. Rare sugars have no such ADI value and are mainly produced by using bioreactor and so inspite of high demand, rare sugars cannot be produced in the desired quantities. PMID:24741154

  8. Compact artificial hand

    NASA Technical Reports Server (NTRS)

    Wiker, G. A.; Mann, W. A. (Inventor)

    1979-01-01

    A relatively simple, compact artificial hand, is described which includes hooks pivotally mounted on first frame to move together and apart. The first frame is rotatably mounted on a second frame to enable "turning at the wrist" movement without limitation. The second frame is pivotally mounted on a third frame to permit 'flexing at the wrist' movement. A hook-driving motor is fixed to the second frame but has a shaft that drives a speed reducer on the first frame which, in turn, drives the hooks. A second motor mounted on the second frame, turns a gear on the first frame to rotate the first frame and the hooks thereon. A third motor mounted on the third frame, turns a gear on a second frame to pivot it.

  9. Aerosol Absorption and Radiative Forcing

    NASA Technical Reports Server (NTRS)

    Stier, Philip; Seinfeld, J. H.; Kinne, Stefan; Boucher, Olivier

    2007-01-01

    We present a comprehensive examination of aerosol absorption with a focus on evaluating the sensitivity of the global distribution of aerosol absorption to key uncertainties in the process representation. For this purpose we extended the comprehensive aerosol-climate model ECHAM5-HAM by effective medium approximations for the calculation of aerosol effective refractive indices, updated black carbon refractive indices, new cloud radiative properties considering the effect of aerosol inclusions, as well as by modules for the calculation of long-wave aerosol radiative properties and instantaneous aerosol forcing. The evaluation of the simulated aerosol absorption optical depth with the AERONET sun-photometer network shows a good agreement in the large scale global patterns. On a regional basis it becomes evident that the update of the BC refractive indices to Bond and Bergstrom (2006) significantly improves the previous underestimation of the aerosol absorption optical depth. In the global annual-mean, absorption acts to reduce the shortwave anthropogenic aerosol top-of-atmosphere (TOA) radiative forcing clear-sky from -0.79 to -0.53 W m(sup -2) (33%) and all-sky from -0.47 to -0.13W m(sup -2 (72%). Our results confirm that basic assumptions about the BC refractive index play a key role for aerosol absorption and radiative forcing. The effect of the usage of more accurate effective medium approximations is comparably small. We demonstrate that the diversity in the AeroCom land-surface albedo fields contributes to the uncertainty in the simulated anthropogenic aerosol radiative forcings: the usage of an upper versus lower bound of the AeroCom land albedos introduces a global annual-mean TOA forcing range of 0.19W m(sup -2) (36%) clear-sky and of 0.12W m(sup -2) (92%) all-sky. The consideration of black carbon inclusions on cloud radiative properties results in a small global annual-mean all-sky absorption of 0.05W m(sup -2) and a positive TOA forcing perturbation of 0

  10. Studies of organic aerosol and aerosol-cloud interactions

    NASA Astrophysics Data System (ADS)

    Duong, Hanh To

    Atmospheric aerosols can influence society and the environment in many ways including altering the planet's energy budget, the hydrologic cycle, and public health. However, the Fourth Assessment Report of the Intergovernmental Panel on Climate Change indicates that the anthropogenic radiative forcing associated with aerosol effects on clouds has the highest uncertainty in the future climate predictions. This thesis focuses on the nature of the organic fraction of ambient particles and how particles interact with clouds using a combination of tools including aircraft and ground measurements, models, and satellite data. Fine aerosol particles typically contain between 20 - 90% organic matter by mass and a major component of this fraction includes water soluble organic carbon (WSOC). Consequently, water-soluble organic species can strongly influence aerosol water-uptake and optical properties. However, the chemical composition of this fraction is not well-understood. PILS-TOC was used to characterize WSOC in ambient aerosol in Los Angeles, California. The spatial distribution of WSOC was found to be influenced by (i) a wide range of aerosol sources within this urban metropolitan area, (ii) transport of pollutants by the characteristic daytime sea breeze trajectory, (iii) topography, and (iv) secondary production during transport. Meteorology is linked with the strength of many of these various processes. Many methods and instruments have been used to study aerosol-cloud interactions. Each observational platform is characterized by different temporal/spatial resolutions and operational principles, and thus there are disagreements between different studies for the magnitude of mathematical constructs used to represent the strength of aerosol-cloud interactions. This work points to the sensitivity of the magnitude of aerosol-cloud interactions to cloud lifetime and spatial resolution of measurements and model simulations. Failure to account for above-cloud aerosol layers

  11. Artificial Ligaments: Promise or Panacea?

    ERIC Educational Resources Information Center

    Lubell, Adele

    1987-01-01

    The Food and Drug Administration has approved a prosthetic ligament for limited use in persons with damaged anterior cruciate ligaments (ACL). This article addresses ligament repair, ACL tears, current treatment, development of the Gore-Tex artificial ligament, other artificial ligaments in process, and arguments for and against their use.…

  12. A Primer on Artificial Intelligence.

    ERIC Educational Resources Information Center

    Leal, Ralph A.

    A survey of literature on recent advances in the field of artificial intelligence provides a comprehensive introduction to this field for the non-technical reader. Important areas covered are: (1) definitions, (2) the brain and thinking, (3) heuristic search, and (4) programing languages used in the research of artificial intelligence. Some…

  13. In Pursuit of Artificial Intelligence.

    ERIC Educational Resources Information Center

    Watstein, Sarah; Kesselman, Martin

    1986-01-01

    Defines artificial intelligence and reviews current research in natural language processing, expert systems, and robotics and sensory systems. Discussion covers current commercial applications of artificial intelligence and projections of uses and limitations in library technical and public services, e.g., in cataloging and online information and…

  14. Generalized Adaptive Artificial Neural Networks

    NASA Technical Reports Server (NTRS)

    Tawel, Raoul

    1993-01-01

    Mathematical model of supervised learning by artificial neural network provides for simultaneous adjustments of both temperatures of neurons and synaptic weights, and includes feedback as well as feedforward synaptic connections. Extension of mathematical model described in "Adaptive Neurons For Artificial Neural Networks" (NPO-17803). Dynamics of neural network represented in new model by less-restrictive continuous formalism.

  15. Artificial Intelligence and Language Comprehension.

    ERIC Educational Resources Information Center

    National Inst. of Education (DHEW), Washington, DC. Basic Skills Group. Learning Div.

    The three papers in this volume concerning artificial intelligence and language comprehension were commissioned by the National Institute of Education to further the understanding of the cognitive processes that enable people to comprehend what they read. The first paper, "Artificial Intelligence and Language Comprehension," by Terry Winograd,…

  16. Instructional Applications of Artificial Intelligence.

    ERIC Educational Resources Information Center

    Halff, Henry M.

    1986-01-01

    Surveys artificial intelligence and the development of computer-based tutors and speculates on the future of artificial intelligence in education. Includes discussion of the definitions of knowledge, expert systems (computer systems that solve tough technical problems), intelligent tutoring systems (ITS), and specific ITSs such as GUIDON, MYCIN,…

  17. Spent fuel sabotage test program, characterization of aerosol dispersal : technical review and analysis supplement.

    SciTech Connect

    Durbin, Samuel G.; Lindgren, Eric Richard

    2009-07-01

    This project seeks to provide vital data required to assess the consequences of a terrorist attack on a spent fuel transportation cask. One such attack scenario involves the use of conical shaped charges (CSC), which are capable of damaging a spent fuel transportation cask. In the event of such an attack, the amount of radioactivity that may be released as respirable aerosols is not known with great certainty. Research to date has focused on measuring the aerosol release from single short surrogate fuel rodlets subjected to attack by a small CSC device in various aerosol chamber designs. The last series of three experiments tested surrogate fuel rodlets made with depleted uranium oxide ceramic pellets in a specially designed double chamber aerosol containment apparatus. This robust testing apparatus was designed to prevent any radioactive release and allow high level radioactive waste disposal of the entire apparatus following testing of actual spent fuel rodlets as proposed. DOE and Sandia reviews of the project to date identified a number of issues. The purpose of this supplemental report is to address and document the DOE review comments and to resolve the issues identified in the Sandia technical review.

  18. Conservative smoothing versus artificial viscosity

    SciTech Connect

    Guenther, C.; Hicks, D.L.; Swegle, J.W.

    1994-08-01

    This report was stimulated by some recent investigations of S.P.H. (Smoothed Particle Hydrodynamics method). Solid dynamics computations with S.P.H. show symptoms of instabilities which are not eliminated by artificial viscosities. Both analysis and experiment indicate that conservative smoothing eliminates the instabilities in S.P.H. computations which artificial viscosities cannot. Questions were raised as to whether conservative smoothing might smear solutions more than artificial viscosity. Conservative smoothing, properly used, can produce more accurate solutions than the von Neumann-Richtmyer-Landshoff artificial viscosity which has been the standard for many years. The authors illustrate this using the vNR scheme on a test problem with known exact solution involving a shock collision in an ideal gas. They show that the norms of the errors with conservative smoothing are significantly smaller than the norms of the errors with artificial viscosity.

  19. Aerosolization of a Human Norovirus Surrogate, Bacteriophage MS2, during Simulated Vomiting

    PubMed Central

    Tung-Thompson, Grace; Libera, Dominic A.; Koch, Kenneth L.; de los Reyes, Francis L.; Jaykus, Lee-Ann

    2015-01-01

    Human noroviruses (NoV) are the leading cause of acute gastroenteritis worldwide. Epidemiological studies of outbreaks have suggested that vomiting facilitates transmission of human NoV, but there have been no laboratory-based studies characterizing the degree of NoV release during a vomiting event. The purpose of this work was to demonstrate that virus aerosolization occurs in a simulated vomiting event, and to estimate the amount of virus that is released in those aerosols. A simulated vomiting device was constructed at one-quarter scale of the human body following similitude principles. Simulated vomitus matrices at low (6.24 mPa*s) and high (177.5 mPa*s) viscosities were inoculated with low (108 PFU/mL) and high (1010 PFU/mL) concentrations of bacteriophage MS2 and placed in the artificial “stomach” of the device, which was then subjected to scaled physiologically relevant pressures associated with vomiting. Bio aerosols were captured using an SKC Biosampler. In low viscosity artificial vomitus, there were notable differences between recovered aerosolized MS2 as a function of pressure (i.e., greater aerosolization with increased pressure), although this was not always statistically significant. This relationship disappeared when using high viscosity simulated vomitus. The amount of MS2 aerosolized as a percent of total virus “vomited” ranged from 7.2 x 10-5 to 2.67 x 10-2 (which corresponded to a range of 36 to 13,350 PFU total). To our knowledge, this is the first study to document and measure aerosolization of a NoV surrogate in a similitude-based physical model. This has implications for better understanding the transmission dynamics of human NoV and for risk modeling purposes, both of which can help in designing effective infection control measures. PMID:26287612

  20. AEROSOL EXPOSURE, PHYSICS, AND CHEMISTRY

    EPA Science Inventory

    A brief review is given of the "Knowledge" and the "Gaps in Knowledge" of aerosol exposure, physics and chemistry relevant to health effects of aerosols, and presented or discussed in platform or poster presentations at the Symposium on Particulate Air Pollution - Associations wi...

  1. Nanotechnology and pharmaceutical inhalation aerosols.

    PubMed

    Patel, A R; Vavia, P R

    2007-02-01

    Pharmaceutical inhalation aerosols have been playing a crucial role in the health and well being of millions of people throughout the world for many years. The technology's continual advancement, the ease of use and the more desirable pulmonary-rather-than-needle delivery for systemic drugs has increased the attraction for the pharmaceutical aerosol in recent years. But administration of drugs by the pulmonary route is technically challenging because oral deposition can be high, and variations in inhalation technique can affect the quantity of drug delivered to the lungs. Recent advances in nanotechnology, particularly drug delivery field have encouraged formulation scientists to expand their reach in solving tricky problems related to drug delivery. Moreover, application of nanotechnology to aerosol science has opened up a new category of pharmaceutical aerosols (collectively known as nanoenabled-aerosols) with added advantages and effectiveness. In this review, some of the latest approaches of nano-enabled aerosol drug delivery system (including nano-suspension, trojan particles, bioadhesive nanoparticles and smart particle aerosols) that can be employed successfully to overcome problems of conventional aerosol systems have been introduced. PMID:17375556

  2. Mount Saint Helens aerosol evolution

    NASA Technical Reports Server (NTRS)

    Oberbeck, V. R.; Farlow, N. H.; Snetsinger, K. G.; Ferry, G. V.; Fong, W.; Hayes, D. M.

    1982-01-01

    Stratospheric aerosol samples were collected using a wire impactor during the year following the eruption of Mt. St. Helens. Analysis of samples shows that aerosol volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.

  3. Preliminary aerosol generator design studies

    NASA Technical Reports Server (NTRS)

    Stampfer, J. F., Jr.

    1976-01-01

    The design and construction of a prototype vaporization generator for highly dispersed sodium chloride aerosols is described. The aerosol generating system is to be used in the Science Simulator of the Cloud Physics Laboratory Project and as part of the Cloud Physics Laboratory payload to be flown on the shuttle/spacelab.

  4. Aerosol in the Pacific troposphere

    NASA Technical Reports Server (NTRS)

    Clarke, Antony D.

    1989-01-01

    The use of near real-time optical techniques is emphasized for the measurement of mid-tropospheric aerosol over the Central Pacific. The primary focus is on measurement of the aerosol size distribution over the range of particle diameters from 0.15 to 5.0 microns that are essential for modeling CO2 backscatter values in support of the laser atmospheric wind sounder (LAWS) program. The measurement system employs a LAS-X (Laser Aerosol Spectrometer-PMS, Boulder, CO) with a custom 256 channel pulse height analyzer and software for detailed measurement and analysis of aerosol size distributions. A thermal preheater system (Thermo Optic Aerosol Descriminator (TOAD) conditions the aerosol in a manner that allows the discrimination of the size distribution of individual aerosol components such as sulfuric acid, sulfates and refractory species. This allows assessment of the relative contribution of each component to the BCO2 signal. This is necessary since the different components have different sources, exhibit independent variability and provide different BCO2 signals for a given mass and particle size. Field activities involve experiments designed to examine both temporal and spatial variability of these aerosol components from ground based and aircraft platforms.

  5. INDOOR AEROSOLS AND EXPOSURE ASSESSMENT

    EPA Science Inventory

    This chapter provides an overview of both indoor aerosol concentration measurements, and the considerations for assessment of exposure to aerosols in non-occupational settings. The fixed-location measurements of concentration at an outdoor location, while commuting inside an a...

  6. Mount St. Helens aerosol evolution

    NASA Technical Reports Server (NTRS)

    Oberbeck, V. R.; Farlow, N. H.; Fong, W.; Snetsinger, K. G.; Ferry, G. V.; Hayes, D. M.

    1982-01-01

    Stratospheric aerosol samples were collected using a wire impactor during the year following the eruption of Mount St. Helens. Analysis of samples shows that aerosol volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.

  7. Mount St. Helens aerosol evolution

    SciTech Connect

    Oberbeck, V.R.; Farlow, N.H.; Fong, W.; Snetsinger, K.G.; Ferry, G.V.; Hayes, D.M.

    1982-09-01

    Stratospheric aerosol samples were collected using a wire impactor during the year following the eruption of Mt. St. Helens. Analysis of samples show that aerosol volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.

  8. Mount St. Helens aerosol evolution

    SciTech Connect

    Oberbeck, V.R.; Farlow, N.H.

    1982-08-01

    Stratospheric aerosol samples were collected using a wire impactor during the year following the eruption of Mount St. Helens. Analysis of samples shows that aerosol volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.

  9. Background considerations in the analysis of PIXE spectra by Artificial Neural Systems.

    NASA Astrophysics Data System (ADS)

    Correa, R.; Morales, J. R.; Requena, I.; Miranda, J.; Barrera, V. A.

    2016-05-01

    In order to study the importance of background in PIXE spectra to determine elemental concentrations in atmospheric aerosols using artificial neural systems ANS, two independently trained ANS were constructed, one which considered as input the net number of counts in the peak, and another which included the background. In the training and validation phases thirty eight spectra of aerosols collected in Santiago, Chile, were used. In both cases the elemental concentration values were similar. This fact was due to the intrinsic characteristic of ANS operating with normalized values of the net and total number of counts under the peaks, something that was verified in the analysis of 172 spectra obtained from aerosols collected in Mexico city. Therefore, networks operating under the mode which include background can reduce time and cost when dealing with large number of samples.

  10. Thermophoretically Dominated Aerosol Coagulation

    NASA Astrophysics Data System (ADS)

    Rosner, Daniel E.; Arias-Zugasti, Manuel

    2011-01-01

    A theory of aerosol coagulation due to size-dependent thermophoresis is presented. This previously overlooked effect is important when local temperature gradients are large, the sol population is composed of particles of much greater thermal conductivity than the carrier gas, with mean diameters much greater than the prevailing gas mean free path, and an adequate “spread” in sizes (as in metallurgical mists or fumes). We illustrate this via a population-balance analysis of the evolution of an initially log-normal distribution when this mechanism dominates ordinary Brownian diffusion.

  11. Aerosol Remote Sensing

    NASA Technical Reports Server (NTRS)

    Lenoble, Jacqueline (Editor); Remer, Lorraine (Editor); Tanre, Didier (Editor)

    2012-01-01

    This book gives a much needed explanation of the basic physical principles of radia5tive transfer and remote sensing, and presents all the instruments and retrieval algorithms in a homogenous manner. For the first time, an easy path from theory to practical algorithms is available in one easily accessible volume, making the connection between theoretical radiative transfer and individual practical solutions to retrieve aerosol information from remote sensing. In addition, the specifics and intercomparison of all current and historical methods are explained and clarified.

  12. Proceedings of the workshop on radioactivity associated with coal use

    SciTech Connect

    Not Available

    1981-12-01

    A workshop on radioactivity in coal use was held on September 15 through 17, 1981, under the auspices of the US Department of Energy, Office of Environmental Programs, and the Los Alamos National Laboratory. The purpose of the workshop was to identify research issues associated with radioactivity resulting from the use of coal for electric power generation. The concensus of the 10 scientists participating in the workshop was that a moderate to strong need exists for research in solubility of fly ash in different fluids and for determination of radioactivity in construction materials. Several additional research issues were identified but were given a lower priority. Summaries of each presentation are included. Titles are: some effects of coal combustion on the radiation environment; radionuclides in western coal at Mound; low-level radiation in coals utilized and ashes produced at New York State electric utilities; radioactivity from coal use - where are the problems; chemistry of radionuclides in coal preparation; uranium daughters in natural atmospheric aerosols and coal-fired power plant emissions; possible contributions of coal extraction and utilization to radioactivity contributions in drinking water; and impact on water quality from radionuclides in coal. One paper has been abstracted separately for inclusion in the Energy Data Base. (DMC)

  13. Determining the basic characteristics of aerosols suitable for studies of deposition in the respiratory tract.

    PubMed

    Legáth, L; Naus, A; Halík, J

    1988-01-01

    Studies of aerosol particle deposition in the respiratory tract requires experimental inhalation of artificial model aerosols. The paper formulates some of the most important requirements for the properties of such aerosols. Several suitable fractions were prepared as part of a research project dealing with the use of microporous polymers for diagnostic purposes. 5 fractions of the polymer designated G-gel 60 with the particle size as stated by the manufacturer, ranging from 3 to 7 micron were evaluated using a 16-channel particle dispersity analyzer HIAC/ROYCO MT 3210 with the sensor 1200 and operated by a microprocessor, the equipment being coupled to an APPLE IIe computer. G-gel 60 particles introduced into the aerosol were characterized by the parameters CMAD, MMAD and sg both numerically and graphically. The measurement procedure was found to be very sensitive with respect to all fractions in evaluating the subtile differences between different lot numbers of the aerosol. G-gel 60 fractions characterized both numerically and graphically were compared with the known aerosols from paraffin oil and atmospheric air. The equipment MT 3210 enables prompt determination of the percentages of aerosol particles distribution by size class. The authors conclude that the procedure, both in its numerical and graphical versions, is particularly suitable for the diagnosis of aerosol particles deposition in the respiratory tract, offering a new application for HIAC/ROYCO in the field of medicine. In evaluating atmospheric aerosol in exhaled air, the number of particles was found to be below that in inhaled air, the difference being dependent on the choice of investigation methods. Percentual distribution of deposited particles following one minute ventilation proved to be at its maximum, as regards atmospheric aerosol, in the 0.30-0.50 micron range. The deposition curve was similar to already published curves, being characterized by an S-shaped pattern with maximum deposition

  14. Biodegradation of radioactive animals

    SciTech Connect

    Party, N.; Party, E.; Wilkerson, A.

    1995-06-01

    The two most common disposal alternatives for animals contaminated with radioactive materials are incineration and burial. For most of the country burial has entailed shipping the carcasses to a commercial disposal facility at Barnwell, South Carolina, where it was landfilled along with other solid radioactive waste. Unfortunately, since 30 June 1994, this facility accepts waste generated by the states of the Southeast Compact only. Therefore, burial is no longer an option for most of the country`s generators and incineration is an option only for those institutions which have, or have access to, an incinerator that is permitted to burn radioactive materials and that accepts animal carcasses with de minimis levels of radioactive contaminants. Many institutions, especially those in congested urban areas where the public does not support incineration, do not have viable outlets for radioactive animal carcasses. Interim, on-site storage poses problems of its own. Biodegradation of animal carcasses with dermestid beetles is an inexpensive approach to this waste management problem. 7 refs., 3 figs., 1 tab.

  15. Radioactivity in food crops

    SciTech Connect

    Drury, J.S.; Baldauf, M.F.; Daniel, E.W.; Fore, C.S.; Uziel, M.S.

    1983-05-01

    Published levels of radioactivity in food crops from 21 countries and 4 island chains of Oceania are listed. The tabulation includes more than 3000 examples of 100 different crops. Data are arranged alphabetically by food crop and geographical origin. The sampling date, nuclide measured, mean radioactivity, range of radioactivities, sample basis, number of samples analyzed, and bibliographic citation are given for each entry, when available. Analyses were reported most frequently for /sup 137/Cs, /sup 40/K, /sup 90/Sr, /sup 226/Ra, /sup 228/Ra, plutonium, uranium, total alpha, and total beta, but a few authors also reported data for /sup 241/Am, /sup 7/Be, /sup 60/Co, /sup 55/Fe, /sup 3/H, /sup 131/I, /sup 54/Mn, /sup 95/Nb, /sup 210/Pb, /sup 210/Po, /sup 106/Ru, /sup 125/Sb, /sup 228/Th, /sup 232/Th, and /sup 95/Zr. Based on the reported data it appears that radioactivity from alpha emitters in food crops is usually low, on the order of 0.1 Bq.g/sup -1/ (wet weight) or less. Reported values of beta radiation in a given crop generally appear to be several orders of magnitude greater than those of alpha emitters. The most striking aspect of the data is the great range of radioactivity reported for a given nuclide in similar food crops with different geographical origins.

  16. The Aerosol Coarse Mode Initiative

    NASA Astrophysics Data System (ADS)

    Arnott, W. P.; Adhikari, N.; Air, D.; Kassianov, E.; Barnard, J.

    2014-12-01

    Many areas of the world show an aerosol volume distribution with a significant coarse mode and sometimes a dominant coarse mode. The large coarse mode is usually due to dust, but sea salt aerosol can also play an important role. However, in many field campaigns, the coarse mode tends to be ignored, because it is difficult to measure. This lack of measurements leads directly to a concomitant "lack of analysis" of this mode. Because, coarse mode aerosols can have significant effects on radiative forcing, both in the shortwave and longwave spectrum, the coarse mode -- and these forcings -- should be accounted for in atmospheric models. Forcings based only on fine mode aerosols have the potential to be misleading. In this paper we describe examples of large coarse modes that occur in areas of large aerosol loading (Mexico City, Barnard et al., 2010) as well as small loadings (Sacramento, CA; Kassianov et al., 2012; and Reno, NV). We then demonstrate that: (1) the coarse mode can contribute significantly to radiative forcing, relative to the fine mode, and (2) neglecting the coarse mode may result in poor comparisons between measurements and models. Next we describe -- in general terms -- the limitations of instrumentation to measure the coarse mode. Finally, we suggest a new initiative aimed at examining coarse mode aerosol generation mechanisms; transport and deposition; chemical composition; visible and thermal IR refractive indices; morphology; microphysical behavior when deposited on snow and ice; and specific instrumentation needs. Barnard, J. C., J. D. Fast, G. Paredes-Miranda, W. P. Arnott, and A. Laskin, 2010: Technical Note: Evaluation of the WRF-Chem "Aerosol Chemical to Aerosol Optical Properties" Module using data from the MILAGRO campaign, Atmospheric Chemistry and Physics, 10, 7325-7340. Kassianov, E. I., M. S. Pekour, and J. C. Barnard, 2012: Aerosols in Central California: Unexpectedly large contribution of coarse mode to aerosol radiative forcing

  17. The artificial leaf.

    PubMed

    Nocera, Daniel G

    2012-05-15

    To convert the energy of sunlight into chemical energy, the leaf splits water via the photosynthetic process to produce molecular oxygen and hydrogen, which is in a form of separated protons and electrons. The primary steps of natural photosynthesis involve the absorption of sunlight and its conversion into spatially separated electron-hole pairs. The holes of this wireless current are captured by the oxygen evolving complex (OEC) of photosystem II (PSII) to oxidize water to oxygen. The electrons and protons produced as a byproduct of the OEC reaction are captured by ferrodoxin of photosystem I. With the aid of ferrodoxin-NADP(+) reductase, they are used to produce hydrogen in the form of NADPH. For a synthetic material to realize the solar energy conversion function of the leaf, the light-absorbing material must capture a solar photon to generate a wireless current that is harnessed by catalysts, which drive the four electron/hole fuel-forming water-splitting reaction under benign conditions and under 1 sun (100 mW/cm(2)) illumination. This Account describes the construction of an artificial leaf comprising earth-abundant elements by interfacing a triple junction, amorphous silicon photovoltaic with hydrogen- and oxygen-evolving catalysts made from a ternary alloy (NiMoZn) and a cobalt-phosphate cluster (Co-OEC), respectively. The latter captures the structural and functional attributes of the PSII-OEC. Similar to the PSII-OEC, the Co-OEC self-assembles upon oxidation of an earth-abundant metal ion from 2+ to 3+, may operate in natural water at room temperature, and is self-healing. The Co-OEC also activates H(2)O by a proton-coupled electron transfer mechanism in which the Co-OEC is increased by four hole equivalents akin to the S-state pumping of the Kok cycle of PSII. X-ray absorption spectroscopy studies have established that the Co-OEC is a structural relative of Mn(3)CaO(4)-Mn cubane of the PSII-OEC, where Co replaces Mn and the cubane is extended in a

  18. Amplification of large artificial chromosomes.

    PubMed Central

    Smith, D R; Smyth, A P; Moir, D T

    1990-01-01

    Yeast artificial chromosome cloning is an attractive technology for genomic mapping studies because very large DNA segments can be readily propagated. However, detailed analyses often require the extensive application of blotting-hybridization techniques because artificial chromosomes are normally present at only one copy per haploid genome. We have developed a cloning vector and host strain that alleviate this problem by permitting copy number amplification of artificial chromosomes. The vector includes a conditional centromere that can be turned on or off by changing the carbon source. Strong selective pressure for extra copies of the artificial chromosome can be applied by selecting for the expression of a heterologous thymidine kinase gene. When this system was used, artificial chromosomes ranging from about 100 to 600 kilobases in size were readily amplified 10- to 20-fold. The selective conditions did not induce obvious rearrangements in any of the clones tested. Reactivation of the centromere in amplified artificial chromosome clones resulted in stable maintenance of an elevated copy number for 20 generations. Applications of copy number control to various aspects of artificial chromosome analysis are addressed. Images PMID:2236036

  19. Radioactive pollution: ocean environments. January 1974-May 1989 (Citations from Oceanic Abstracts). Report for January 1974-May 1989

    SciTech Connect

    Not Available

    1989-06-01

    This bibliography contains citations concerning radioactive pollution of the marine environment. Distributions of radionuclides indicative of artificial radioactive contamination are discussed including iodine-131, various uranium isotopes, cesium-137, cobalt-60, strontium-90, ruthenium-160, and plutonium isotopes. Ecosystems considered include coral reefs and atolls, planktonic zones in the open ocean, salt marshes, estuaries, coastal waters, and the Mediterranean Sea. Sources of radioactive contamination examined include atomic bomb blasts, fossil-fuel combustion, radioactive waste disposal, and nuclear accidents. Experimental simulation of radionuclide transport in marine biota is included. (Contains 108 citations fully indexed and including a title list.)

  20. Radioactive mixed waste disposal

    SciTech Connect

    Jasen, W.G.; Erpenbeck, E.G.

    1993-02-01

    Various types of waste have been generated during the 50-year history of the Hanford Site. Regulatory changes in the last 20 years have provided the emphasis for better management of these wastes. Interpretations of the Atomic Energy Act of 1954 (AEA), the Resource Conservation and Recovery Act of 1976 (RCRA), and the Hazardous and Solid Waste Amendments (HSWA) have led to the definition of radioactive mixed wastes (RMW). The radioactive and hazardous properties of these wastes have resulted in the initiation of special projects for the management of these wastes. Other solid wastes at the Hanford Site include low-level wastes, transuranic (TRU), and nonradioactive hazardous wastes. This paper describes a system for the treatment, storage, and disposal (TSD) of solid radioactive waste.

  1. Radioactivity of Consumer Products

    NASA Astrophysics Data System (ADS)

    Peterson, David; Jokisch, Derek; Fulmer, Philip

    2006-11-01

    A variety of consumer products and household items contain varying amounts of radioactivity. Examples of these items include: FiestaWare and similar glazed china, salt substitute, bananas, brazil nuts, lantern mantles, smoke detectors and depression glass. Many of these items contain natural sources of radioactivity such as Uranium, Thorium, Radium and Potassium. A few contain man-made sources like Americium. This presentation will detail the sources and relative radioactivity of these items (including demonstrations). Further, measurements of the isotopic ratios of Uranium-235 and Uranium-238 in several pieces of china will be compared to historical uses of natural and depleted Uranium. Finally, the presenters will discuss radiation safety as it pertains to the use of these items.

  2. Artificial radionuclides in the atmosphere over Lithuania.

    PubMed

    Lujaniene, G; Aninkevicius, V; Lujanas, V

    2009-02-01

    Measurements of airborne radioactive aerosol concentration were carried out on the basis of 1-3 days samples after the Chernobyl disaster and during the period of 1992-2003. Transport of "hot" particles of different composition resulted in the high activity concentrations of (137)Cs, (238)Pu, (239,240)Pu and (241)Am in the atmosphere in Vilnius at the end of April 1986. The (240)Pu/(239)Pu atom ratio showed clear evidence of non-global plutonium originating from the Chernobyl accident in the atmosphere over Lithuania. The (240)Pu/(239)Pu atom ratio ranged from 0.14 to 0.40 in monthly samples in Vilnius in 1995-2003. An increase in activity concentration of (137)Cs by a factor of 100 (up to 300 microBq/m(3)) was found following forest fires in the Ukraine and Belarus. However, no transport of the Chernobyl plutonium was observed and the (240)Pu/(239)Pu atom ratio in samples collected during the forest fires was found to be 0.229 and 0.185, respectively. The exponential decrease in the (240)Pu/(239)Pu atom ratio from 0.30 to 0.19 (mean values) was observed in 1995-2003. PMID:17884261

  3. Inorganic Components of Atmospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Wexler, Anthony Stein

    The inorganic components comprise 15% to 50% of the mass of atmospheric aerosols. For about the past 10 years the mass of these components was predicted assuming thermodynamic equilibrium between the volatile aerosol -phase inorganic species NH_4NO _3 and NH_4Cl and their gas-phase counterparts NH_3, HNO_3, and HCl. In this thesis I examine this assumption and prove that (1) the time scales for equilibration between the gas and aerosol phases are often too long for equilibrium to hold, and (2) even when equilibrium holds, transport considerations often govern the size distribution of these aerosol components. Water can comprise a significant portion of atmospheric aerosols under conditions of high relative humidity, whereas under conditions of sufficiently low relative humidity atmospheric aerosols tend to be dry. The deliquescence point is the relative humidity where the aerosol goes from a solid dry phase to an aqueous or mixed solid-aqueous phase. In this thesis I derive the temperature dependence of the deliquescence point and prove that in multicomponent solutions the deliquescence point is lower than for corresponding single component solutions. These theories of the transport, thermodynamic, and deliquescent properties of atmospheric aerosols are integrated into an aerosol inorganics model, AIM. The predictions of AIM compare well to fundamental thermodynamic measurements. Comparison of the prediction of AIM to those of other aerosol equilibrium models shows substantial disagreement in the predicted water content at lower relative humidities. The disagreement is due the improved treatment in AIM of the deliquescence properties of multicomponent solutions. In the summer and fall of 1987 the California Air Resources Board conducted the Southern California Air Quality Study, SCAQS, during which atmospheric aerosols were measured in Los Angeles. The size and composition of the aerosol and the concentrations of their gas phase counterparts were measured. When the

  4. A new stochastic algorithm for inversion of dust aerosol size distribution

    NASA Astrophysics Data System (ADS)

    Wang, Li; Li, Feng; Yang, Ma-ying

    2015-08-01

    Dust aerosol size distribution is an important source of information about atmospheric aerosols, and it can be determined from multiwavelength extinction measurements. This paper describes a stochastic inverse technique based on artificial bee colony (ABC) algorithm to invert the dust aerosol size distribution by light extinction method. The direct problems for the size distribution of water drop and dust particle, which are the main elements of atmospheric aerosols, are solved by the Mie theory and the Lambert-Beer Law in multispectral region. And then, the parameters of three widely used functions, i.e. the log normal distribution (L-N), the Junge distribution (J-J), and the normal distribution (N-N), which can provide the most useful representation of aerosol size distributions, are inversed by the ABC algorithm in the dependent model. Numerical results show that the ABC algorithm can be successfully applied to recover the aerosol size distribution with high feasibility and reliability even in the presence of random noise.

  5. Artificial frustrated spin systems

    NASA Astrophysics Data System (ADS)

    Perrin, Y.; Chioar, I. A.; Nguyen, V. D.; Lacour, D.; Hehn, M.; Montaigne, F.; Canals, B.; Rougemaille, N.

    2015-09-01

    Complex architectures of nanostructures are routinely elaborated using bottom-up or nanofabrication processes. This technological capability allows scientists to engineer materials with properties that do not exist in nature, but also to manufacture model systems to explore fundamental issues in condensed matter physics. Two-dimensional frustrated arrays of magnetic nanostructures are one class of systems for which theoretical predictions can be tested experimentally. These systems have been the subject of intense research in the last few years and allowed the investigation of a rich physics and fascinating phenomena, such as the exploration of the extensively degenerate ground-state manifolds of spin ice systems, the evidence of new magnetic phases in purely two-dimensional lattices, and the observation of pseudoexcitations involving classical analogues of magnetic monopoles. We show here, experimentally and theoretically, that simple magnetic geometries can lead to unconventional, non-collinear spin textures. For example, kagome arrays of inplane magnetized nano-islands do not show magnetic order. Instead, these systems are characterized by spin textures with intriguing properties, such as chirality, coexistence of magnetic order and disorder, and charge crystallization. Magnetic frustration effects in lithographically patterned kagome arrays of nanomagnets with out-of-plane magnetization also lead to an unusal, and still unknown, magnetic ground state manifold. Besides the influence of the lattice geometry, the micromagnetic nature of the elements constituting the arrays introduce the concept of chiral magnetic monopoles, bringing additional complexity into the physics of artificial frustrated spin systems.

  6. Artificial dexterous hand

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan (Inventor)

    1990-01-01

    An artificial dexterous hand is provided for grasping and manipulating objects. The hand includes left and right thumbs that are operatively connected to an engagement assembly which causes movement of the left and right thumbs. The left thumb has a left thumb base and is movable about three separate first left thumb axes which run through the left thumb base. Correspondingly, the right thumb has a right thumb base and is movable about three separate first right thumb axes which run through the right thumb base. The engagement assembly has a gear assembly which is operatively connected to a motor assembly. Upon actuation by the motor assembly, the gear assembly causes movement of the left and right thumbs about the first left thumb axes and first right thumb axes respectively. The hand can also have a center finger which is operatively connected to the engagement assembly and which is interposed between the left and right thumbs. The finger has a finger base and is movable about two separate first finger axes running through the finger base. Therefore, upon actuation by the motor assembly, the gear assembly will also cause movement of the finger about the first finger axes.

  7. Artificial polarization components

    NASA Astrophysics Data System (ADS)

    Cescato, L.; Gluch, Ekkehard; Stork, Wilhelm; Streibl, Norbert

    1990-07-01

    High frequency surface relief structures are optically anisotropic and show interesting polarisation properties 1 . These properties can be used to produce polarizations components such as wave plates polarizers. polarizing beamsplitters etc. Our experimental results show that even gratings with relatively low spatial frequency ( periods A ) exhibit a strong phase retardation and can be used as quarter-wave plates. k INTRODUC11ON The artificial birefringence exhibited by ultrahigh frequency gratings of dielectric materials can be used to produce various polarization components2 . Such components have applications in integrated optics as well as in free space optics. In order to produce the high spatial frequencies complex processes such as electron-beam lithography and reactive ion etching are needed. We show in this paper that sinusoidal holographic gratings in photoresist exhibit also a strong phase ret even at relatively long periods. L EXPERIMENTAL MEASUREMENTS To obtain the phase retardation of a lower frequency ( period A ) grating a simple setup as used by Enger and 2 can be applied. In our case however there are three measurements necessary to obtain the phase retardation because transmission of the two perpendicularly polarized beams is different from each other. I GRATING PRODUCTION grating 2 3 4 5 6 7 8 9 period (pmj 0. 74 0. 74 0. 61 0. 54 0. 46 0. 32 0. 54 0. 54 0. 54 ne (sec) 60

  8. Nanostructured artificial nacre

    NASA Astrophysics Data System (ADS)

    Tang, Zhiyong; Kotov, Nicholas A.; Magonov, Sergei; Ozturk, Birol

    2003-06-01

    Finding a synthetic pathway to artificial analogs of nacre and bones represents a fundamental milestone in the development of composite materials. The ordered brick-and-mortar arrangement of organic and inorganic layers is believed to be the most essential strength- and toughness-determining structural feature of nacre. It has also been found that the ionic crosslinking of tightly folded macromolecules is equally important. Here, we demonstrate that both structural features can be reproduced by sequential deposition of polyelectrolytes and clays. This simple process results in a nanoscale version of nacre with alternating organic and inorganic layers. The macromolecular folding effect reveals itself in the unique saw-tooth pattern of differential stretching curves attributed to the gradual breakage of ionic crosslinks in polyelectrolyte chains. The tensile strength of the prepared multilayers approached that of nacre, whereas their ultimate Young modulus was similar to that of lamellar bones. Structural and functional resemblance makes clay- polyelectrolyte multilayers a close replica of natural biocomposites. Their nanoscale nature enables elucidation of molecular processes occurring under stress.

  9. Artificial dexterous hand

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan (Inventor)

    1990-01-01

    An artificial dexterous hand is provided for conformally engaging and manipulating objects. The hand includes an articulated digit which is connected to an engagement sub-assembly and has a first shape adaption mechanism associated with it. The digit has a digit base and first and second phalanges. The digit base is operatively interconnected to the first phalange by a base joint having a base pulley. The phalanges are operatively interconnected by a separate first phalange joint having a first phalange pulley. The engagement sub-assembly includes a tendon, which is received by the base pulley and by the first phalange pulley, and an actuation device for selectively tensioning the tendon. The first shape adaption mechanism is responsive to and receives the tendon. It is also situated between the base joint and the first phalange joint and is connected to the first phalange. Upon actuation by the actuation device, the phalanges are caused to pivot relative to the base joint and the second phalange is caused to pivot relative to the first phalange. At the same time, the first shape adaption mechanism controls the sequence of the aforementioned pivoting of the phalanges through application of braking force to the tendon.

  10. Aerosol Climate Interactions in Climate System Models

    NASA Astrophysics Data System (ADS)

    Kiehl, J. T.

    2002-12-01

    Aerosols are widely recognized as an important process in Earth's climate system. Observations over the past decade have improved our understanding of the physical and chemical properties of aerosols. Recently, field observations have highlighted the pervasiveness of absorbing aerosols in the atmosphere. These aerosols are of particular interest, since they alter the vertical distribution of shortwave radiative heating between the surface and atmosphere. Given this increased knowledge of aerosols from various field programs, interest is focusing on how to integrate this understanding into global climate models. These types of models provide the best tool available to comprehensively study the potential effects of aerosols on Earth's climate system. Results from climate system model simulations that include aerosol effects will be presented to illustrate key aerosol climate interactions. These simulations employ idealized and realistic distributions of absorbing aerosols. The idealized aerosol simulations provide insight into the role of aerosol shortwave absorption on the global hydrologic cycle. The realistic aerosol distributions provide insight into the local response of aerosol forcing in the Indian subcontinent region. Emphasis from these simulations will be on the hydrologic cycle, since water availability is of emerging global environmental concern. This presentation will also consider what more is needed to significantly improve our ability to model aerosol processes in climate system models. Uncertainty in aerosol climate interactions remains a major source of uncertainty in our ability to project future climate change. Focus will be on interactions between aerosols and various physical, chemical and biogeochemical aspects of the Earth system.

  11. International Cooperative for Aerosol Prediction Workshop on Aerosol Forecast Verification

    NASA Technical Reports Server (NTRS)

    Benedetti, Angela; Reid, Jeffrey S.; Colarco, Peter R.

    2011-01-01

    The purpose of this workshop was to reinforce the working partnership between centers who are actively involved in global aerosol forecasting, and to discuss issues related to forecast verification. Participants included representatives from operational centers with global aerosol forecasting requirements, a panel of experts on Numerical Weather Prediction and Air Quality forecast verification, data providers, and several observers from the research community. The presentations centered on a review of current NWP and AQ practices with subsequent discussion focused on the challenges in defining appropriate verification measures for the next generation of aerosol forecast systems.

  12. SAGE II aerosol data validation based on retrieved aerosol model size distribution from SAGE II aerosol measurements

    NASA Technical Reports Server (NTRS)

    Wang, Pi-Huan; Mccormick, M. P.; Mcmaster, L. R.; Chu, W. P.; Swissler, T. J.; Osborn, M. T.; Russell, P. B.; Oberbeck, V. R.; Livingston, J.; Rosen, J. M.

    1989-01-01

    Consideration is given to aerosol correlative measurements experiments for the Stratospheric Aerosol and Gas Experiment (SAGE) II, conducted between November 1984 and July 1986. The correlative measurements were taken with an impactor/laser probe, a dustsonde, and an airborne 36-cm lidar system. The primary aerosol quantities measured by the ground-based instruments are compared with those calculated from the aerosol size distributions from SAGE II aerosol extinction measurements. Good agreement is found between the two sets of measurements.

  13. Container for radioactive materials

    DOEpatents

    Fields, S.R.

    1984-05-30

    A container is claimed for housing a plurality of canister assemblies containing radioactive material. The several canister assemblies are stacked in a longitudinally spaced relation within a carrier to form a payload concentrically mounted within the container. The payload package includes a spacer for each canister assembly, said spacer comprising a base member longitudinally spacing adjacent canister assemblies from each other and sleeve surrounding the associated canister assembly for centering the same and conducting heat from the radioactive material in a desired flow path. 7 figures.

  14. AERONET: The Aerosol Robotic Network

    DOE Data Explorer

    The AERONET (AErosol RObotic NETwork) program is a federation of ground-based remote sensing aerosol networks established by NASA and LOA-PHOTONS (CNRS) and is greatly expanded by collaborators from national agencies, institutes, universities, individual scientists, and partners. The program provides a long-term, continuous and readily accessible public domain database of aerosol optical, mircrophysical and radiative properties for aerosol research and characterization, validation of satellite retrievals, and synergism with other databases. The network imposes standardization of instruments, calibration, processing and distribution. AERONET collaboration provides globally distributed observations of spectral aerosol optical Depth (AOD), inversion products, and precipitable water in diverse aerosol regimes. Aerosol optical depth data are computed for three data quality levels: Level 1.0 (unscreened), Level 1.5 (cloud-screened), and Level 2.0 (cloud screened and quality-assured). Inversions, precipitable water, and other AOD-dependent products are derived from these levels and may implement additional quality checks.[Copied from http://aeronet.gsfc.nasa.gov/new_web/system_descriptions.html

  15. Artificial intelligence: Principles and applications

    SciTech Connect

    Yazdami, M.

    1985-01-01

    The book covers the principles of AI, the main areas of application, as well as considering some of the social implications. The applications chapters have a common format structured as follows: definition of the topic; approach with conventional computing techniques; why 'intelligence' would provide a better approach; and how AI techniques would be used and the limitations. The contents discussed are: Principles of artificial intelligence; AI programming environments; LISP, list processing and pattern-making; AI programming with POP-11; Computer processing of natural language; Speech synthesis and recognition; Computer vision; Artificial intelligence and robotics; The anatomy of expert systems - Forsyth; Machine learning; Memory models of man and machine; Artificial intelligence and cognitive psychology; Breaking out of the chinese room; Social implications of artificial intelligence; and Index.

  16. Artificial photosynthesis for solar fuels.

    PubMed

    Styring, Stenbjörn

    2012-01-01

    This contribution was presented as the closing lecture at the Faraday Discussion 155 on artificial photosynthesis, held in Edinburgh Scotland, September 5-7 2011. The world needs new, environmentally friendly and renewable fuels to exchange for fossil fuels. The fuel must be made from cheap and "endless" resources that are available everywhere. The new research area of solar fuels aims to meet this demand. This paper discusses why we need a solar fuel and why electricity is not enough; it proposes solar energy as the major renewable energy source to feed from. The scientific field concerning artificial photosynthesis expands rapidly and most of the different scientific visions for solar fuels are briefly overviewed. Research strategies and the development of artificial photosynthesis research to produce solar fuels are overviewed. Some conceptual aspects of research for artificial photosynthesis are discussed in closer detail. PMID:22470985

  17. Artificial Reefs and Ocean Dumping.

    ERIC Educational Resources Information Center

    Glueck, Richard D.

    1983-01-01

    Activities and instructional strategies for two multigrade lessons are provided. Activity objectives include describing an artificial reef (such as a sunken ocean liner) as an ecosystem, knowing animal types in the ecosystem, and describing a food web. (JN)

  18. Inflatable artificial sphincter - series (image)

    MedlinePlus

    An artificial sphincter consists of three parts: a cuff that fits around the bladder neck a pressure regulating balloon a pump that inflates the cuff. To treat urinary incontinence, the cuff is placed ...

  19. Darwin, artificial selection, and poverty.

    PubMed

    Sanchez, Luis

    2010-03-01

    This paper argues that the processes of evolutionary selection are becoming increasingly artificial, a trend that goes against the belief in a purely natural selection process claimed by Darwin's natural selection theory. Artificial selection is mentioned by Darwin, but it was ignored by Social Darwinists, and it is all but absent in neo-Darwinian thinking. This omission results in an underestimation of probable impacts of artificial selection upon assumed evolutionary processes, and has implications for the ideological uses of Darwin's language, particularly in relation to poverty and other social inequalities. The influence of artificial selection on genotypic and phenotypic adaptations arguably represents a substantial shift in the presumed path of evolution, a shift laden with both biological and political implications. PMID:20812798

  20. Comparison of Artificial Compressibility Methods

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Housman, Jeffrey; Kwak, Dochan

    2004-01-01

    Various artificial compressibility methods for calculating the three-dimensional incompressible Navier-Stokes equations are compared. Each method is described and numerical solutions to test problems are conducted. A comparison based on convergence behavior, accuracy, and robustness is given.

  1. Aerosol growth in Titan's ionosphere.

    PubMed

    Lavvas, Panayotis; Yelle, Roger V; Koskinen, Tommi; Bazin, Axel; Vuitton, Véronique; Vigren, Erik; Galand, Marina; Wellbrock, Anne; Coates, Andrew J; Wahlund, Jan-Erik; Crary, Frank J; Snowden, Darci

    2013-02-19

    Photochemically produced aerosols are common among the atmospheres of our solar system and beyond. Observations and models have shown that photochemical aerosols have direct consequences on atmospheric properties as well as important astrobiological ramifications, but the mechanisms involved in their formation remain unclear. Here we show that the formation of aerosols in Titan's upper atmosphere is directly related to ion processes, and we provide a complete interpretation of observed mass spectra by the Cassini instruments from small to large masses. Because all planetary atmospheres possess ionospheres, we anticipate that the mechanisms identified here will be efficient in other environments as well, modulated by the chemical complexity of each atmosphere. PMID:23382231

  2. A fixed frequency aerosol albedometer.

    PubMed

    Thompson, Jonathan E; Barta, Nick; Policarpio, Danielle; Duvall, Richard

    2008-02-01

    A new method for the measurement of aerosol single scatter albedo (omega) at 532 nm was developed. The method employs cavity ring-down spectroscopy (CRDS) for measurement of aerosol extinction coefficient (b(ext)) and an integrating sphere nephelometer for determination of aerosol scattering coefficient (b(scat)). A unique feature of this method is that the extinction and scattering measurements are conducted simultaneously, on the exact same sample volume. Limits of detection (3s) for the extinction and scattering channel were 0.61 Mm(-1) and 2.7 Mm(-1) respectively. PMID:18542299

  3. eDPS Aerosol Collection

    SciTech Connect

    Venzie, J.

    2015-10-13

    The eDPS Aerosol Collection project studies the fundamental physics of electrostatic aerosol collection for national security applications. The interpretation of aerosol data requires understanding and correcting for biases introduced from particle genesis through collection and analysis. The research and development undertaken in this project provides the basis for both the statistical correction of existing equipment and techniques; as well as, the development of new collectors and analytical techniques designed to minimize unwanted biases while improving the efficiency of locating and measuring individual particles of interest.

  4. Actuator device for artificial leg

    NASA Technical Reports Server (NTRS)

    Burch, J. L. (Inventor)

    1976-01-01

    An actuator device is described for moving an artificial leg of a person having a prosthesis replacing an entire leg and hip joint. The device includes a first articulated hip joint assembly carried by the natural leg and a second articulated hip joint assembly carried by the prosthesis whereby energy from the movement of the natural leg is transferred by a compressible fluid from the first hip joint assembly to the second hip joint assembly for moving the artificial leg.

  5. An artificial gravity demonstration experiment

    NASA Technical Reports Server (NTRS)

    Rupp, C.; Lemke, L.; Penzo, P.

    1989-01-01

    An artificial gravity experiment which is tethered to a Delta second stage and which uses the Small Expendable Deployer System is proposed. Following tether deployment, the Delta vehicle performs the required spin-up maneuver and can then be passivated. A surplus reentry vehicle houses the artificial gravity life science experiments. When the experiments are completed, the reentry phase of the experiment is initiated by synchronizing the spin of the configuration with the required deorbit impulse.

  6. The total artificial heart.

    PubMed

    Meyer, A; Slaughter, M

    2011-09-01

    In the 1960s, cardiac surgeons and biomedical engineers pioneered the development of total artificial hearts (TAH) for the treatment of left and right heart failure. As we mark the 10th anniversary of the first implantation of the AbioCor device, the use of TAH has been limited, having failed to reach its envisioned potential and promise as an alternative therapy to heart transplantation. The Syncardia/CardioWest device, originally developed 30 years ago as the Jarvik TAH and later renamed the CardioWest TAH, continues to be used clinically in over 50 centers within the US and Europe having supported over 900 patients worldwide. Syncardia continues to develop TAH technology as evidenced by their recent introduction of a new portable pneumatic driver that enables patients to be discharged from the hospital. In contrast to TAH devices, continuous flow ventricular assist devices (VAD) have made tremendous technological strides and are rapidly gaining widespread clinical acceptance. The VAD technology has demonstrated extraordinary safety and reliability records through evolving technologies, advanced biocompatible materials, and improved patient management. Subsequently, the number of TAH implantations remains low compared to the growth in LVAD implants. Nonetheless, the Syncardia/CardioWest TAH remains an important and viable option for patients with severe biventricular failure and end organ dysfunction. Overall, a 79% survival rate has been achieved in patients supported with a Syncardia/CardioWest TAH as bridge-to-transplantation. In this review article, a brief history on the evolution of TAH devices, their current use and emerging use of evolving continuous flow VAD technology as chronic biventricular and TAH device systems are presented. PMID:21775941

  7. Radioactive Decay - An Analog.

    ERIC Educational Resources Information Center

    McGeachy, Frank

    1988-01-01

    Presents an analog of radioactive decay that allows the student to grasp the concept of half life and the exponential nature of the decay process. The analog is devised to use small, colored, plastic poker chips or counters. Provides the typical data and a graph which supports the analog. (YP)

  8. Detecting Illicit Radioactive Sources

    SciTech Connect

    McDonald, Joseph C.; Coursey, Bert; Carter, Michael

    2004-11-01

    Specialized instruments have been developed to detect the presence of illicit radioactive sources that may be used by terrorists in radiation dispersal devices, so-called ''dirty bombs'' or improvised nuclear devices. This article discusses developments in devices to detect and measure radiation.

  9. TABLE OF RADIOACTIVE ELEMENTS.

    SciTech Connect

    HOLDEN,N.E.

    2001-06-29

    For those chemical elements which have no stable nuclides with a terrestrial isotopic composition, the data on radioactive half-lives and relative atomic masses for the nuclides of interest and importance have been evaluated and the recommended values and uncertainties are listed.

  10. Viewer Makes Radioactivity "Visible"

    NASA Technical Reports Server (NTRS)

    Yin, L. I.

    1983-01-01

    Battery operated viewer demonstrates feasibility of generating threedimensional visible light simulations of objects that emit X-ray or gamma rays. Ray paths are traced for two pinhold positions to show location of reconstructed image. Images formed by pinholes are converted to intensified visible-light images. Applications range from radioactivity contamination surveys to monitoring radioisotope absorption in tumors.

  11. AIR RADIOACTIVITY MONITOR

    DOEpatents

    Bradshaw, R.L.; Thomas, J.W.

    1961-04-11

    The monitor is designed to minimize undesirable background buildup. It consists of an elongated column containing peripheral electrodes in a central portion of the column, and conduits directing an axial flow of radioactively contaminated air through the center of the column and pure air through the annular portion of the column about the electrodes. (AEC)

  12. The Charged Aerosol Release Experiment (CARE) Program

    NASA Astrophysics Data System (ADS)

    Bernhardt, Paul; Scales, Wayne; Sternovsky, Zoltan; Kelley, Michael; Hysell, David; Holzworth, Robert

    A new experiment called the Charged Aerosol Release Experiment (CARE) employs the release of dust in the upper atmosphere to form a dusty plasma in space. Two solid rocket motors strapped side-by-side in opposition will provide a pin-wheel high speed dust dispenser for the CARE experiment. A spherical dust cloud will form as a radial expansion around the CARE dust release module. The release will occur between 200 and 250 km altitude in the F-region where the 10 to 1000 nm diameter particles will become charged by electron attachment. As the charged dust particle stream through the ionosphere, plasma irregularities will be produced by streaming and fluid plasma instabilities. The plasma turbulence will driven by large electric fields at the surface of the cloud resulting from the separation of unmagnetized negatively charge dust from the background positive ions which are tied to magnetic field lines. In addition, two stream instabilities from the charge particles moving through the plasma will cause plasma wave structures. The effects of the CARE dust release will be diagnosed with in situ electric field booms, dust detectors, and Langmuir probes. Remote sensing of the CARE release will involve ground backscatter radars in the HF, VHF, and UHF frequency ranges. At late times, the dust cloud will settle into the mesosphere where an artificial mesospheric cloud will be formed. Satellite imagery using the AIM satellite will measure the long-term dispersal of the artificial dust cloud. The results of the CARE experiment will be compared with radar, optical and rocket measurements of natural polar mesospheric clouds.

  13. Survival of toxigenic Pasteurella multocida in aerosols and aqueous liquids.

    PubMed Central

    Thomson, C M; Chanter, N; Wathes, C M

    1992-01-01

    The survival of toxigenic Pasteurella multocida in air and liquids was studied to identify possible risk factors in the etiology of atrophic rhinitis. In aerosols, at low relative humidity (28%), the viability of toxigenic P. multocida 5 min after aerosolization was at least 22% of its initial value. Viability at low relative humidity declined to 8% after 45 min. Viability at high relative humidity (79%) was 69% after 5 min and declined to 2% after 45 min. Survival of toxigenic P. multocida in liquids depended on storage and constituents in the liquid. Toxigenic P. multocida became nonculturable 1 to 14 days after inoculation in water and artificial seawater, depending on the storage temperature. Toxigenic P. multocida stored at 37 degrees C could be detected for up to 6 days in pig slurry and more than 36 days in Bacto Tryptose broth and nasal lavages. However, in Bacto Tryptose broth and nasal lavages stored at 4 degrees C, P. multocida was detected for up to 14 days whereas at 15 and 37 degrees C it was detected for more than 49 days. These results suggest that aerosols and fomites can play a role in the transmission of atrophic rhinitis. PMID:1575496

  14. A study of regional-scale aerosol assimilation using a Stretch-NICAM

    NASA Astrophysics Data System (ADS)

    Misawa, S.; Dai, T.; Schutgens, N.; Nakajima, T.

    2013-12-01

    Although aerosol is considered to be harmful to human health and it became a social issue, aerosol models and emission inventories include large uncertainties. In recent studies, data assimilation is applied to aerosol simulation to get more accurate aerosol field and emission inventory. Most of these studies, however, are carried out only on global scale, and there are only a few researches about regional scale aerosol assimilation. In this study, we have created and verified an aerosol assimilation system on regional scale, in hopes to reduce an error associated with the aerosol emission inventory. Our aerosol assimilation system has been developed using an atmospheric climate model, NICAM (Non-hydrostaric ICosahedral Atmospheric Model; Satoh et al., 2008) with a stretch grid system and coupled with an aerosol transport model, SPRINTARS (Takemura et al., 2000). Also, this assimilation system is based on local ensemble transform Kalman filter (LETKF). To validate this system, we used a simulated observational data by adding some artificial errors to the surface aerosol fields constructed by Stretch-NICAM-SPRINTARS. We also included a small perturbation in original emission inventory. This assimilation with modified observational data and emission inventory was performed in Kanto-plane region around Tokyo, Japan, and the result indicates the system reducing a relative error of aerosol concentration by 20%. Furthermore, we examined a sensitivity of the aerosol assimilation system by varying the number of total ensemble (5, 10 and 15 ensembles) and local patch (domain) size (radius of 50km, 100km and 200km), both of which are the tuning parameters in LETKF. The result of the assimilation with different ensemble number 5, 10 and 15 shows that the larger the number of ensemble is, the smaller the relative error become. This is consistent with ensemble Kalman filter theory and imply that this assimilation system works properly. Also we found that assimilation system

  15. Wavelength dependence of aerosol extinction coefficient for stratospheric aerosols

    NASA Technical Reports Server (NTRS)

    Yue, Glenn K.

    1986-01-01

    A simple empirical formula for the wavelength dependence of the aerosol extinction coefficient is proposed. The relationship between the constants in the formula and the variable parameter in the aerosol size distribution is explicitly expressed. Good agreement is found between the extinction coefficients calculated from the proposed formula and that calculated from Mie theory. The proposed expression is shown to be better than the Angstroem formula commonly used by atmospheric scientists.

  16. Preliminary investigations toward nighttime aerosol optical depth retrievals from the VIIRS day/night band

    NASA Astrophysics Data System (ADS)

    Johnson, R. S.; Zhang, J.; Hyer, E. J.; Miller, S. D.; Reid, J. S.

    2013-01-01

    A great need exists for reliable nighttime aerosol products at high spatial and temporal resolution. In this concept demonstration study, using Visible/Infrared Imager/Radiometer Suite (VIIRS) Day/Night Band (DNB) observations on the Suomi National Polar-orbiting Partnership (NPP) satellite, a new method is proposed for retrieving nighttime aerosol optical depth (τ) using the contrast between regions with and without artificial surface lights. Evaluation of the retrieved τ values against daytime AERONET data from before and after the overpass of the VIIRS satellite over the Cape Verde, Grand Forks, and Alta Floresta AERONET stations yields a coefficient of determination (r2) of 0.71. This study suggests that the VIIRS DNB has the potential to provide useful nighttime aerosol detection and property retrievals.

  17. Preliminary investigations toward nighttime aerosol optical depth retrievals from the VIIRS Day/Night Band

    NASA Astrophysics Data System (ADS)

    Johnson, R. S.; Zhang, J.; Hyer, E. J.; Miller, S. D.; Reid, J. S.

    2013-05-01

    A great need exists for reliable nighttime aerosol products at high spatial and temporal resolution. In this concept demonstration study, using Visible/Infrared Imager/Radiometer Suite (VIIRS) Day/Night Band (DNB) observations on the Suomi National Polar-orbiting Partnership (NPP) satellite, a new method is proposed for retrieving nighttime aerosol optical depth (τ) using the contrast between regions with and without artificial surface lights. Evaluation of the retrieved τ values against daytime AERONET data from before and after the overpass of the VIIRS satellite over the Cape Verde, Grand Forks, and Alta Floresta AERONET stations yields a coefficient of determination (r2) of 0.71. This study suggests that the VIIRS DNB has the potential to provide useful nighttime aerosol detection and property retrievals.

  18. Environmental Radioactivity, Temperature, and Precipitation.

    ERIC Educational Resources Information Center

    Riland, Carson A.

    1996-01-01

    Reports that environmental radioactivity levels vary with temperature and precipitation and these effects are due to radon. Discusses the measurement of this environmental radioactivity and the theory behind it. (JRH)

  19. Aerosol Transmission of Filoviruses.

    PubMed

    Mekibib, Berhanu; Ariën, Kevin K

    2016-01-01

    Filoviruses have become a worldwide public health concern because of their potential for introductions into non-endemic countries through international travel and the international transport of infected animals or animal products. Since it was first identified in 1976, in the Democratic Republic of Congo (formerly Zaire) and Sudan, the 2013-2015 western African Ebola virus disease (EVD) outbreak is the largest, both by number of cases and geographical extension, and deadliest, recorded so far in medical history. The source of ebolaviruses for human index case(s) in most outbreaks is presumptively associated with handling of bush meat or contact with fruit bats. Transmission among humans occurs easily when a person comes in contact with contaminated body fluids of patients, but our understanding of other transmission routes is still fragmentary. This review deals with the controversial issue of aerosol transmission of filoviruses. PMID:27223296

  20. Aerosol Transmission of Filoviruses

    PubMed Central

    Mekibib, Berhanu; Ariën, Kevin K.

    2016-01-01

    Filoviruses have become a worldwide public health concern because of their potential for introductions into non-endemic countries through international travel and the international transport of infected animals or animal products. Since it was first identified in 1976, in the Democratic Republic of Congo (formerly Zaire) and Sudan, the 2013–2015 western African Ebola virus disease (EVD) outbreak is the largest, both by number of cases and geographical extension, and deadliest, recorded so far in medical history. The source of ebolaviruses for human index case(s) in most outbreaks is presumptively associated with handling of bush meat or contact with fruit bats. Transmission among humans occurs easily when a person comes in contact with contaminated body fluids of patients, but our understanding of other transmission routes is still fragmentary. This review deals with the controversial issue of aerosol transmission of filoviruses. PMID:27223296

  1. Aerosol lidar ``M4``

    SciTech Connect

    Shelevoy, C.D.; Andreev, Y.M. |

    1994-12-31

    Small carrying aerosol lidar in which is used small copper vapor laser ``Malachite`` as source of sounding optical pulses is described. The advantages of metal vapor laser and photon counting mode in acquisition system of lidar gave ability to get record results: when lidar has dimensions (1 x .6 x .3 m) and weight (65 kg), it provides the sounding of air industrial pollutions at up to 20 km range in scanning sector 90{degree}. Power feed is less than 800 Wt. Lidar can be disposed as stationary so on the car, helicopter, light plane. Results of location of smoke tails and city smog in situ experiments are cited. Showed advantages of work of acquisition system in photon counting mode when dynamic range of a signal is up to six orders.

  2. Stratospheric aerosol geoengineering

    SciTech Connect

    Robock, Alan

    2015-03-30

    The Geoengineering Model Intercomparison Project, conducting climate model experiments with standard stratospheric aerosol injection scenarios, has found that insolation reduction could keep the global average temperature constant, but global average precipitation would reduce, particularly in summer monsoon regions around the world. Temperature changes would also not be uniform; the tropics would cool, but high latitudes would warm, with continuing, but reduced sea ice and ice sheet melting. Temperature extremes would still increase, but not as much as without geoengineering. If geoengineering were halted all at once, there would be rapid temperature and precipitation increases at 5–10 times the rates from gradual global warming. The prospect of geoengineering working may reduce the current drive toward reducing greenhouse gas emissions, and there are concerns about commercial or military control. Because geoengineering cannot safely address climate change, global efforts to reduce greenhouse gas emissions and to adapt are crucial to address anthropogenic global warming.

  3. Airborne radioactive contamination monitoring

    SciTech Connect

    Whitley, C.R.; Adams, J.R.; Bounds, J.A.; MacArthur, D.W.

    1996-03-01

    Current technologies for the detection of airborne radioactive contamination do not provide real-time capability. Most of these techniques are based on the capture of particulate matter in air onto filters which are then processed in the laboratory; thus, the turnaround time for detection of contamination can be many days. To address this shortcoming, an effort is underway to adapt LRAD (Long-Range-Alpha-Detection) technology for real-time monitoring of airborne releases of alpa-emitting radionuclides. Alpha decays in air create ionization that can be subsequently collected on electrodes, producing a current that is proportional to the amount of radioactive material present. Using external fans on a pipe containing LRAD detectors, controlled samples of ambient air can be continuously tested for the presence of radioactive contamination. Current prototypes include a two-chamber model. Sampled air is drawn through a particulate filter and then through the first chamber, which uses an electrostatic filter at its entrance to remove ambient ionization. At its exit, ionization that occurred due to the presence of radon is collected and recorded. The air then passes through a length of pipe to allow some decay of short-lived radon species. A second chamber identical to the first monitors the remaining activity. Further development is necessary on air samples without the use of particulate filtering, both to distinguish ionization that can pass through the initial electrostatic filter on otherwise inert particulate matter from that produced through the decay of radioactive material and to separate both of these from the radon contribution. The end product could provide a sensitive, cost-effective, real-time method of determining the presence of airborne radioactive contamination.

  4. An improved method for retrieving nighttime aerosol optical thickness from the VIIRS Day/Night Band

    NASA Astrophysics Data System (ADS)

    McHardy, T. M.; Zhang, J.; Reid, J. S.; Miller, S. D.; Hyer, E. J.; Kuehn, R. E.

    2015-11-01

    Using Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) data, a method, dubbed the "variance method", is developed for retrieving nighttime aerosol optical thickness (τ) values through the examination of the dispersion of radiance values above an artificial light source. Based on the improvement of a previous algorithm, this updated method derives a semi-quantitative indicator of nighttime τ using artificial light sources. Nighttime τ retrievals from the newly developed method are inter-compared with an interpolated value from late afternoon and early morning ground observations from four AErosol RObotic NETwork (AERONET) sites as well as column-integrated τ from one High Spectral Resolution Lidar (HSRL) site at Huntsville, AL, during the NASA Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaign, providing full diel coverage. Sensitivity studies are performed to examine the effects of lunar illumination on VIIRS τ retrievals made via the variance method, revealing that lunar contamination may have a smaller impact than previously thought; however, the small sample size of this study limits the conclusiveness thus far. VIIRS τ retrievals yield a coefficient of determination (r2) of 0.60 and a root-mean-squared error (RMSE) of 0.18 when compared against straddling daytime-averaged AERONET τ values. Preliminary results suggest that artificial light sources can be used for estimating regional and global nighttime aerosol distributions in the future.

  5. Method for calcining radioactive wastes

    DOEpatents

    Bjorklund, William J.; McElroy, Jack L.; Mendel, John E.

    1979-01-01

    This invention relates to a method for the preparation of radioactive wastes in a low leachability form by calcining the radioactive waste on a fluidized bed of glass frit, removing the calcined waste to melter to form a homogeneous melt of the glass and the calcined waste, and then solidifying the melt to encapsulate the radioactive calcine in a glass matrix.

  6. Background stratospheric aerosol reference model

    NASA Technical Reports Server (NTRS)

    Mccormick, M. P.; Wang, P.

    1989-01-01

    In this analysis, a reference background stratospheric aerosol optical model is developed based on the nearly global SAGE 1 satellite observations in the non-volcanic period from March 1979 to February 1980. Zonally averaged profiles of the 1.0 micron aerosol extinction for the tropics and the mid- and high-altitudes for both hemispheres are obtained and presented in graphical and tabulated form for the different seasons. In addition, analytic expressions for these seasonal global zonal means, as well as the yearly global mean, are determined according to a third order polynomial fit to the vertical profile data set. This proposed background stratospheric aerosol model can be useful in modeling studies of stratospheric aerosols and for simulations of atmospheric radiative transfer and radiance calculations in atmospheric remote sensing.

  7. Stratospheric aerosols and climatic change

    NASA Technical Reports Server (NTRS)

    Baldwin, B.; Pollack, J. B.; Summers, A.; Toon, O. B.; Sagan, C.; Van Camp, W.

    1976-01-01

    Generated primarily by volcanic explosions, a layer of submicron silicate particles and particles made of concentrated sulfuric acids solution is present in the stratosphere. Flights through the stratosphere may be a future source of stratospheric aerosols, since the effluent from supersonic transports contains sulfurous gases (which will be converted to H2SO4) while the exhaust from Space Shuttles contains tiny aluminum oxide particles. Global heat balance calculations have shown that the stratospheric aerosols have made important contributions to some climatic changes. In the present paper, accurate radiative transfer calculations of the globally-averaged surface temperature (T) are carried out to estimate the sensitivity of the climate to changes in the number of stratospheric aerosols. The results obtained for a specified model atmosphere, including a vertical profile of the aerosols, indicate that the climate is unlikely to be affected by supersonic transports and Space Shuttles, during the next decades.

  8. Wind Power Charged Aerosol Generator

    SciTech Connect

    Marks, A.M.

    1980-07-01

    This describes experimental results on a Charged Aerosol Wind/Electric Power Generator, using Induction Electric Charging with a water jet issuing under water pressure from a small diameter (25-100 ..mu..m) orifice.

  9. The influence of salt aerosol on alpha radiation detection by WIPP continuous air monitors

    SciTech Connect

    Bartlett, W.T.; Walker, B.A.

    1997-08-01

    Waste Isolation Pilot Plant (WIPP) alpha continuous air monitor (CAM) performance was evaluated to determine if CAMs could detect accidental releases of transuranic radioactivity from the underground repository. Anomalous alpha spectra and poor background subtraction were observed and attributed to salt deposits on the CAM sampling filters. Microscopic examination of salt laden sampling filters revealed that aerosol particles were forming dendritic structures on the surface of the sampling filters. Alpha CAM detection efficiency decreased exponentially as salt deposits increased on the sampling filters, suggesting that sampling-filter salt was performing like a fibrous filter rather than a membrane filter. Aerosol particles appeared to penetrate the sampling-filter salt deposits and alpha particle energy was reduced. These findings indicate that alpha CAMs may not be able to detect acute releases of radioactivity, and consequently CAMs are not used as part of the WIPP dynamic confinement system. 12 refs., 12 figs., 1 tab.

  10. Method for producing monodisperse aerosols

    DOEpatents

    Ortiz, Lawrence W.; Soderholm, Sidney C.

    1990-01-01

    An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.

  11. AEROSOL, CLOUDS, AND CLIMATE CHANGE

    SciTech Connect

    SCHWARTZ, S.E.

    2005-09-01

    Earth's climate is thought to be quite sensitive to changes in radiative fluxes that are quite small in absolute magnitude, a few watts per square meter, and in relation to these fluxes in the natural climate. Atmospheric aerosol particles exert influence on climate directly, by scattering and absorbing radiation, and indirectly by modifying the microphysical properties of clouds and in turn their radiative effects and hydrology. The forcing of climate change by these indirect effects is thought to be quite substantial relative to forcing by incremental concentrations of greenhouse gases, but highly uncertain. Quantification of aerosol indirect forcing by satellite- or ground-based remote sensing has proved quite difficult in view of inherent large variation in the pertinent observables such as cloud optical depth, which is controlled mainly by liquid water path and only secondarily by aerosols. Limited work has shown instances of large magnitude of aerosol indirect forcing, with local instantaneous forcing upwards of 50 W m{sup 66}-2. Ultimately it will be necessary to represent aerosol indirect effects in climate models to accurately identify the anthropogenic forcing at present and over secular time and to assess the influence of this forcing in the context of other forcings of climate change. While the elements of aerosol processes that must be represented in models describing the evolution and properties of aerosol particles that serve as cloud condensation particles are known, many important components of these processes remain to be understood and to be represented in models, and the models evaluated against observation, before such model-based representations can confidently be used to represent aerosol indirect effects in climate models.

  12. N(2)O(5) reaction on submicron sea salt aerosol: kinetics, products, and the effect of surface active organics.

    PubMed

    Thornton, Joel A; Abbatt, Jonathan P D

    2005-11-10

    The reaction of N(2)O(5) on sea salt aerosol is a sink for atmospheric nitrogen oxides and a source of the Cl radical. We present room-temperature measurements of the N(2)O(5) loss rate on submicron artificial seawater (ASW) aerosol, performed with an entrained aerosol flow tube coupled to a chemical ionization mass spectrometer, as a function of aerosol phase (aqueous or partially crystalline), liquid water content, and size. We also present an analysis of the product growth kinetics showing that ClNO(2) is produced at a rate equal to N(2)O(5) loss, with an estimated lower limit yield of 50% at 50% relative humidity (RH). The reaction probability for N(2)O(5), gamma(N(2)(O)(5)), depends strongly on the particle phase, being 0.005 +/- 0.004 on partially crystalline ASW aerosol at 30% RH and 0.03 +/- 0.008 on aqueous ASW aerosol at 65% RH. At 50% RH, N(2)O(5) loss is relatively insensitive to particle size for radii greater than 100 nm, and gamma(N(2)(O)(5)) displays a statistically insignificant increase from 0.022 to approximately 0.03 for aqueous ASW aerosol over the RH range of 43-70%. We find that the presence of millimolar levels of hexanoic acid in the aerosol bulk decreases the gamma(N(2)(O)(5)) at 70% RH by a factor of 3-4 from approximately 0.025 to 0.008 +/- 0.004. This reduction is likely due to the partitioning of hexanoic acid to the gas-aerosol interface at a surface coverage that we estimate to be equivalent to a monolayer. This result is the first evidence that a monolayer coating of aqueous organic surfactant can slow the reactive uptake of atmospheric trace gases to aerosol. PMID:16838918

  13. Spent fuel sabotage aerosol test program :FY 2005-06 testing and aerosol data summary.

    SciTech Connect

    Gregson, Michael Warren; Brockmann, John E.; Nolte, O. (Fraunhofer institut fur toxikologie und experimentelle Medizin, Germany); Loiseau, O. (Institut de radioprotection et de Surete Nucleaire, France); Koch, W. (Fraunhofer institut fur toxikologie und experimentelle Medizin, Germany); Molecke, Martin Alan; Autrusson, Bruno (Institut de radioprotection et de Surete Nucleaire, France); Pretzsch, Gunter Guido (Gesellschaft fur anlagen- und Reaktorsicherheit, Germany); Billone, M. C. (Argonne National Laboratory, USA); Lucero, Daniel A.; Burtseva, T.; Brucher, W (Gesellschaft fur anlagen- und Reaktorsicherheit, Germany); Steyskal, Michele D.

    2006-10-01

    This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program has been underway for several years. This program provides source-term data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. This document focuses on an updated description of the test program and test components for all work and plans made, or revised, primarily during FY 2005 and about the first two-thirds of FY 2006. It also serves as a program status report as of the end of May 2006. We provide details on the significant findings on aerosol results and observations from the recently completed Phase 2 surrogate material tests using cerium oxide ceramic pellets in test rodlets plus non-radioactive fission product dopants. Results include: respirable fractions produced; amounts, nuclide content, and produced particle size distributions and morphology; status on determination of the spent fuel ratio, SFR (the ratio of respirable particles from real spent fuel/respirables from surrogate spent fuel, measured under closely matched test conditions, in a contained test chamber); and, measurements of enhanced volatile fission product species sorption onto respirable particles. We discuss progress and results for the first three, recently performed Phase 3 tests using depleted uranium oxide, DUO{sub 2}, test rodlets. We will also review the status of preparations and the final Phase 4 tests in this program, using short rodlets containing actual spent fuel from U.S. PWR reactors, with both high- and lower-burnup fuel. These data plus testing results and design are tailored to support and guide, follow-on computer modeling of aerosol dispersal hazards and radiological consequence

  14. Climate forcing by anthropogenic aerosols.

    PubMed

    Charlson, R J; Schwartz, S E; Hales, J M; Cess, R D; Coakley, J A; Hansen, J E; Hofmann, D J

    1992-01-24

    Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol in particular has imposed a major perturbation to this forcing. Both the direct scattering of shortwavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting a cooling influence on the planet. Current climate forcing due to anthropogenic sulfate is estimated to be -1 to -2 watts per square meter, globally averaged. This perturbation is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign. Thus, the aerosol forcing has likely offset global greenhouse warming to a substantial degree. However, differences in geographical and seasonal distributions of these forcings preclude any simple compensation. Aerosol effects must be taken into account in evaluating anthropogenic influences on past, current, and projected future climate and in formulating policy regarding controls on emission of greenhouse gases and sulfur dioxide. Resolution of such policy issues requires integrated research on the magnitude and geographical distribution of aerosol climate forcing and on the controlling chemical and physical processes. PMID:17842894

  15. Climate forcing by anthropogenic aerosols

    NASA Technical Reports Server (NTRS)

    Charlson, R. J.; Schwartz, S. E.; Hales, J. M.; Cess, R. D.; Coakley, J. A., Jr.; Hansen, J. E.; Hofmann, D. J.

    1992-01-01

    Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol, in particular, has imposed a major perturbation to this forcing. Both the direct scattering of short-wavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting a cooling influence on the planet. Current climate forcing due to anthropogenic sulfate is estimated to be -1 to -2 watts per square meter, globally averaged. This perturbation is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign. Thus, the aerosol forcing has likely offset global greenhouse warming to a substantial degree. However, differences in geographical and seasonal distributions of these forcings preclude any simple compensation. Aerosol effects must be taken into account in evaluating anthropogenic influences on past, current, and projected future climate and in formulating policy regarding controls on emission of greenhouse gases and sulfur dioxide. Resolution of such policy issues requires integrated research on the magnitude and geographical distribution of aerosol climate forcing and on the controlling chemical and physical processes.

  16. Satellite Remote Sensing: Aerosol Measurements

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph A.

    2013-01-01

    Aerosols are solid or liquid particles suspended in the air, and those observed by satellite remote sensing are typically between about 0.05 and 10 microns in size. (Note that in traditional aerosol science, the term "aerosol" refers to both the particles and the medium in which they reside, whereas for remote sensing, the term commonly refers to the particles only. In this article, we adopt the remote-sensing definition.) They originate from a great diversity of sources, such as wildfires, volcanoes, soils and desert sands, breaking waves, natural biological activity, agricultural burning, cement production, and fossil fuel combustion. They typically remain in the atmosphere from several days to a week or more, and some travel great distances before returning to Earth's surface via gravitational settling or washout by precipitation. Many aerosol sources exhibit strong seasonal variability, and most experience inter-annual fluctuations. As such, the frequent, global coverage that space-based aerosol remote-sensing instruments can provide is making increasingly important contributions to regional and larger-scale aerosol studies.

  17. Effect of ethanol on droplet size, efficiency of delivery, and clearance characteristics of technetium-99m DTPA aerosol.

    PubMed

    Sirr, S A; Juenemann, P J; Tom, H; Boudreau, R J; Chandler, R P; Loken, M K

    1985-06-01

    With recent technical advances in aerosol technology, the study of regional ventilation using [99mTc]DTPA aerosol has become increasingly popular. Using a cascade impactor, we have assessed droplet size distribution from a newly designed nebulizer. Delivery efficiency of [99mTc]DTPA aerosol to normal subjects was improved 70% with a 10% concentration of ethanol in the nebulizer. Using filter paper fixed to the delivery end of the aerosol device, and varying ethanol concentrations from 0-10%, an 87% increase of deposited radioactivity is measured. Use of higher concentration of ethanol to the nebulizer solution did not further improve delivery efficiency. The addition of ethanol did not alter clearance characteristics of [99mTc]DTPA from the lung nor did it affect droplet size distribution. PMID:3889235

  18. Effect of ethanol on droplet size, efficiency of delivery, and clearance characteristics of technetium-99m DTPA aerosol

    SciTech Connect

    Sirr, S.A.; Juenemann, P.J.; Tom, H.; Boudreau, R.J.; Chandler, R.P.; Loken, M.K.

    1985-06-01

    With recent technical advances in aerosol technology, the study of regional ventilation using (/sup 99m/Tc)DTPA aerosol has become increasingly popular. Using a cascade impactor, the authors have assessed droplet size distribution from a newly designed nebulizer. Delivery efficiency of (/sup 99m/Tc)DTPA aerosol to normal subjects was improved 70% with a 10% concentration of ethanol in the nebulizer. Using filter paper fixed to the delivery end of the aerosol device, and varying ethanol concentrations from 0-10%, an 87% increase of deposited radioactivity is measured. The addition of ethanol did not alter clearance characteristics of (/sup 99m/Tc)DTPA from the lung nor did it affect droplet size distribution.

  19. CALIPSO Observations of Aerosol Properties Near Clouds

    NASA Technical Reports Server (NTRS)

    Marshak, Alexander; Varnai, Tamas; Yang, Weidong

    2010-01-01

    Clouds are surrounded by a transition zone of rapidly changing aerosol properties. Characterizing this zone is important for better understanding aerosol-cloud interactions and aerosol radiative effects as well as for improving satellite measurements of aerosol properties. We present a statistical analysis of a global dataset of CALIPSO (Cloud-Aerosol Lidar and infrared Pathfinder Satellite Observation) Lidar observations over oceans. The results show that the transition zone extends as far as 15 km away from clouds and it is ubiquitous over all oceans. The use of only high confidence level cloud-aerosol discrimination (CAD) data confirms the findings. However, the results underline the need for caution to avoid biases in studies of satellite aerosol products, aerosol-cloud interactions, and aerosol direct radiative effects.

  20. Modeling of the dispersion of depleted uranium aerosol.

    PubMed

    Mitsakou, C; Eleftheriadis, K; Housiadas, C; Lazaridis, M

    2003-04-01

    Depleted uranium is a low-cost radioactive material that, in addition to other applications, is used by the military in kinetic energy weapons against armored vehicles. During the Gulf and Balkan conflicts concern has been raised about the potential health hazards arising from the toxic and radioactive material released. The aerosol produced during impact and combustion of depleted uranium munitions can potentially contaminate wide areas around the impact sites or can be inhaled by civilians and military personnel. Attempts to estimate the extent and magnitude of the dispersion were until now performed by complex modeling tools employing unclear assumptions and input parameters of high uncertainty. An analytical puff model accommodating diffusion with simultaneous deposition is developed, which can provide a reasonable estimation of the dispersion of the released depleted uranium aerosol. Furthermore, the period of the exposure for a given point downwind from the release can be estimated (as opposed to when using a plume model). The main result is that the depleted uranium mass is deposited very close to the release point. The deposition flux at a couple of kilometers from the release point is more than one order of magnitude lower than the one a few meters near the release point. The effects due to uncertainties in the key input variables are addressed. The most influential parameters are found to be atmospheric stability, height of release, and wind speed, whereas aerosol size distribution is less significant. The output from the analytical model developed was tested against the numerical model RPM-AERO. Results display satisfactory agreement between the two models. PMID:12705453

  1. Undiagnosed illnesses and radioactive warfare.

    PubMed

    Duraković, Asaf

    2003-10-01

    The internal contamination with depleted uranium (DU) isotopes was detected in British, Canadian, and United States Gulf War veterans as late as nine years after inhalational exposure to radioactive dust in the Persian Gulf War I. DU isotopes were also identified in a Canadian veteran's autopsy samples of lung, liver, kidney, and bone. In soil samples from Kosovo, hundreds of particles, mostly less than 5 microm in size, were found in milligram quantities. Gulf War I in 1991 resulted in 350 metric tons of DU deposited in the environment and 3-6 million grams of DU aerosol released into the atmosphere. Its legacy, Gulf War disease, is a complex, progressive, incapacitating multiorgan system disorder. The symptoms include incapacitating fatigue, musculoskeletel and joint pains, headaches, neuropsychiatric disorders, affect changes, confusion, visual problems, changes of gait, loss of memory, lymphadenopathies, respiratory impairment, impotence, and urinary tract morphological and functional alterations. Current understanding of its etiology seems far from being adequate. After the Afghanistan Operation Anaconda (2002), our team studied the population of Jalalabad, Spin Gar, Tora Bora, and Kabul areas, and identified civilians with the symptoms similar to those of Gulf War syndrome. Twenty-four-hour urine samples from 8 symptomatic subjects were collected by the following criteria: 1) the onset of symptoms relative to the bombing raids; 2) physical presence in the area of the bombing; and 3) clinical manifestations. Control subjects were selected among the sympotom-free residents in non-targeted areas. All samples were analyzed for the concentration and ratio of four uranium isotopes, (234)U, (235)U, (236)U and (238)U, by using a multicollector, inductively coupled plasma ionization mass spectrometry. The first results from the Jalalabad province revealed urinary excretion of total uranium in all subjects significantly exceeding the values in the nonexposed population

  2. International radioactive material recycling challenges

    SciTech Connect

    Greeves, John T.; Lieberman, James

    2007-07-01

    The paper explores current examples of successful International radioactive recycling programs and also explores operational regulatory and political challenges that need to be considered for expanding international recycling world-wide. Most countries regulations are fully consistent with the International Atomic Agency (IAEA) Code of Practice on the International Transboundary Movement of Radioactive Material and the IAEA Code of Conduct on the Safety and Security of Radioactive Sources. IAEA member States reported on the status of their efforts to control transboundary movement of radioactive material recently during the Joint Convention on the Safety of Spent Fuel management and on the Safety of Radioactive Waste Management meeting in May 2006. (authors)

  3. Holistic aerosol evaluation using synthesized aerosol aircraft measurements

    NASA Astrophysics Data System (ADS)

    Watson-Parris, Duncan; Reddington, Carly; Schutgens, Nick; Stier, Philip; Carslaw, Ken; Liu, Dantong; Allan, James; Coe, Hugh

    2016-04-01

    Despite ongoing efforts there are still large uncertainties in aerosol concentrations and loadings across many commonly used GCMs. This in turn leads to large uncertainties in the contributions of the direct and indirect aerosol forcing on climate. However, constraining these fields using earth observation data, although providing global coverage, is problematic for many reasons, including the large uncertainties in retrieving aerosol loadings. Additionally, the inability to retrieve aerosols in or around cloudy scenes leads to further sampling biases (Gryspeerdt 2015). Many in-situ studies have used regional datasets to attempt to evaluate the model uncertainties, but these are unable to provide an assessment of the models ability to represent aerosols properties on a global scale. Within the Global Aerosol Synthesis and Science Project (GASSP) we have assembled the largest collection of quality controlled, in-situ aircraft observations ever synthesized to a consistent format. This provides a global set of in-situ measurements of Cloud Condensation Nuclei (CCN) and Black Carbon (BC), amongst others. In particular, the large number of vertical profiles provided by this aircraft data allows us to investigate the vertical structure of aerosols across a wide range of regions and environments. These vertical distributions are particularly valuable when investigating the dominant processes above or below clouds where remote sensing data is not available. Here we present initial process-based assessments of the BC lifetimes and vertical distributions of CCN in the HadGEM-UKCA and ECHAM-HAM models using this data. We use point-by-point based comparisons to avoid the sampling issues associated with comparing spatio-temporal aggregations.

  4. Photochemical Activation of Chlorine by Iron and Iron Oxide Aerosol

    NASA Astrophysics Data System (ADS)

    Wittmer, J.; Zetzsch, C.

    2015-12-01

    The photochemical activation of chlorine by dissolved iron in sea-salt aerosol droplets and by highly dispersed Fe2O3 aerosol particles (mainly hematite, specific surface > 100 m2/g), exposed to gaseous HCl, was investigated in humidified air in a Teflon simulation chamber. Employing the radical-clock technique, we quantified the production of gaseous atomic Cl. When the artificial sea salt aerosols contained suspended Fe2O3 alone at pH 6, no significant Cl production could be observed, even if the dissolution of iron was forced by "weathering" (repeatedly freezing and thawing for five times). Adjusting the pH in the stock suspension to 2.6, 2.2, and 1.9 and equilibrating for one week resulted in a quantifiable amount of dissolved iron (0.03, 0.2, and 0.6 mmol/L, respectively) and in gaseous Cl production rates of ~1.6, 6, and 8 × 1021 atoms cm-2 h-1, respectively. Exposing the pure Fe2O3 aerosol in the absence of salt to various gaseous HCl concentrations resulted in rates ranging from 8 × 1020 Cl atoms cm-2 h-1 (at ~4 ppb HCl) to 5 × 1022 Cl atoms cm-2 h-1 (at ~350 ppb HCl) and confirmed the uptake and conversion of HCl to atomic Cl (at HCl to Cl conversion yields of 2-5 % mol/mol, depending on the relative humidity). The relevance for environmental processes in the atmosphere will be discussed.

  5. Multicomponent aerosol dynamics model UHMA: model development and validation

    NASA Astrophysics Data System (ADS)

    Korhonen, H.; Lehtinen, K. E. J.; Kulmala, M.

    2004-05-01

    A size-segregated aerosol dynamics model UHMA (University of Helsinki Multicomponent Aerosol model) was developed for studies of multicomponent tropospheric aerosol particles. The model includes major aerosol microphysical processes in the atmosphere with a focus on new particle formation and growth; thus it incorporates particle coagulation and multicomponent condensation, applying a revised treatment of condensation flux onto free molecular regime particles and the activation of nanosized clusters by organic vapours (Nano-Köhler theory), as well as recent parameterizations for binary H2SO4-H2O and ternary H2SO4-NH3-H2O homogeneous nucleation and dry deposition. The representation of particle size distribution can be chosen from three sectional methods: the hybrid method, the moving center method, and the retracking method in which moving sections are retracked to a fixed grid after a certain time interval. All these methods can treat particle emissions and atmospheric transport consistently, and are therefore suitable for use in large scale atmospheric models. In a test simulation against an accurate high resolution solution, all the methods showed reasonable treatment of new particle formation with 20 size sections although the hybrid and the retracking methods suffered from artificial widening of the distribution. The moving center approach, on the other hand, showed extra dents in the particle size distribution and failed to predict the onset of detectable particle formation. In a separate test simulation of an observed nucleation event, the model captured the key qualitative behaviour of the system well. Furthermore, its prediction of the organic volume fraction in newly formed particles, suggesting values as high as 0.5 for 3-4 nm particles and approximately 0.8 for 10 nm particles, agrees with recent indirect composition measurements.

  6. Radioactive ion detector

    DOEpatents

    Bower, Kenneth E.; Weeks, Donald R.

    1997-01-01

    Apparatus for detecting the presence, in aqueous media, of substances which emit alpha and/or beta radiation and determining the oxidation state of these radioactive substances, that is, whether they are in cationic or anionic form. In one embodiment, a sensor assembly has two elements, one comprised of an ion-exchange material which binds cations and the other comprised of an ion-exchange material which binds anions. Each ion-exchange element is further comprised of a scintillation plastic and a photocurrent generator. When a radioactive substance to which the sensor is exposed binds to either element and emits alpha or beta particles, photons produced in the scintillation plastic illuminate the photocurrent generator of that element. Sensing apparatus senses generator output and thereby indicates whether cationic species or anionic species or both are present and also provides an indication of species quantity.

  7. Radioactive ion detector

    DOEpatents

    Bower, K.E.; Weeks, D.R.

    1997-08-12

    Apparatus for detecting the presence, in aqueous media, of substances which emit alpha and/or beta radiation and determining the oxidation state of these radioactive substances, that is, whether they are in cationic or anionic form. In one embodiment, a sensor assembly has two elements, one comprised of an ion-exchange material which binds cations and the other comprised of an ion-exchange material which binds anions. Each ion-exchange element is further comprised of a scintillation plastic and a photocurrent generator. When a radioactive substance to which the sensor is exposed binds to either element and emits alpha or beta particles, photons produced in the scintillation plastic illuminate the photocurrent generator of that element. Sensing apparatus senses generator output and thereby indicates whether cationic species or anionic species or both are present and also provides an indication of species quantity. 2 figs.

  8. Test-Aerosol Generator For Calibrating Particle Counters

    NASA Technical Reports Server (NTRS)

    Mogan, Paul A.; Adams, Alois J.; Schwindt, Christian J.; Hodge, Timothy R.; Mallow, Tim J.; Duong, Anh A.; Bukauskas, Vyto V.

    1996-01-01

    Apparatus generates clean, stable aerosol stream for use in testing and calibrating laser-based aerosol-particle counter. Size and concentration of aerosol particles controlled to ensure accurate calibration. Cheap, widely available medical nebulizers used to generate aerosols.

  9. Biological Effects Of Artificial Illumination

    NASA Astrophysics Data System (ADS)

    Corth, Richard

    1980-10-01

    We are increasingly being warned of the possible effects of so called "polluted" light, that is light that differs in spectral content from that of sunlight. We should be concerned, we are told, because all animals and plants have evolved under this natural daylight and therefore any difference between that illuminant and the artificial illuminants that are on the market today, is suspect. The usual presentation of the differences between the sunlight and the artificial illuminants are as shown in Figure 1. Here we are shown the spectral power distribution of sunlight and Cool White fluorescent light. The spectral power distributions of each have been normalized to some convenient wavelength so that each can be seen and easily compared on the same figure. But this presentation is misleading for one does not experience artificial illuminants at the same intensity as one experiences sunlight. Sunlight intensities are ordinarily found to be in the 8000 to 10,000 footcandle range whereas artificial illuminants are rarely experienced at intensity levels greater than 100 footcandles. Therefore a representative difference between the two types of illumination conditions is more accurately represented as in Figure 2. Thus if evolutionary adaptations require that humans and other animals be exposed to sunlight to ensure wellbeing, it is clear that one must be exposed to sunlight intensities. It is not feasible to expect that artificially illuminated environments will be lit to the same intensity as sunlight

  10. Artificial gametes from stem cells

    PubMed Central

    Moreno, Inmaculada; Míguez-Forjan, Jose Manuel

    2015-01-01

    The generation of artificial gametes is a real challenge for the scientific community today. In vitro development of human eggs and sperm will pave the way for the understanding of the complex process of human gametogenesis and will provide with human gametes for the study of infertility and the onset of some inherited disorders. However, the great promise of artificial gametes resides in their future application on reproductive treatments for all these people wishing to have genetically related children and for which gamete donation is now their unique option of parenthood. This is the case of infertile patients devoid of suitable gametes, same sex couples, singles and those fertile couples in a high risk of transmitting serious diseases to their progeny. In the search of the best method to obtain artificial gametes, many researchers have successfully obtained human germ cell-like cells from stem cells at different stages of differentiation. In the near future, this field will evolve to new methods providing not only viable but also functional and safe artificial germ cells. These artificial sperm and eggs should be able to recapitulate all the genetic and epigenetic processes needed for the correct gametogenesis, fertilization and embryogenesis leading to the birth of a healthy and fertile newborn. PMID:26161331

  11. Artificial evolution: a new path for artificial intelligence?

    PubMed

    Husbands, P; Harvey, I; Cliff, D; Miller, G

    1997-06-01

    Recently there have been a number of proposals for the use of artificial evolution as a radically new approach to the development of control systems for autonomous robots. This paper explains the artificial evolution approach, using work at Sussex to illustrate it. The paper revolves around a case study on the concurrent evolution of control networks and visual sensor morphologies for a mobile robot. Wider intellectual issues surrounding the work are discussed, as is the use of more abstract evolutionary simulations as a new potentially useful tool in theoretical biology. PMID:9209759

  12. PROCESSING OF RADIOACTIVE WASTE

    DOEpatents

    Johnson, B.M. Jr.; Barton, G.B.

    1961-11-14

    A process for treating radioactive waste solutions prior to disposal is described. A water-soluble phosphate, borate, and/or silicate is added. The solution is sprayed with steam into a space heated from 325 to 400 deg C whereby a powder is formed. The powder is melted and calcined at from 800 to 1000 deg C. Water vapor and gaseous products are separated from the glass formed. (AEC)

  13. Table of radioactive elements

    SciTech Connect

    Holden, N.E.

    1985-01-01

    As has been the custom in the past, the Commission publishes a table of relative atomic masses and halflives of selected radionuclides. The information contained in this table will enable the user to calculate the atomic weight for radioactive materials with a variety of isotopic compositions. The atomic masses have been taken from the 1984 Atomic Mass Table. Some of the halflives have already been documented.

  14. MARE: Mars Radioactivity Experiment

    NASA Astrophysics Data System (ADS)

    di Lellis, A. M.; Capria, M. T.; Espinasse, S.; Magni, G.; Orosei, R.; Piccioni, G.; Federico, C.; Minelli, G.; Pauselli, C.; Scarpa, G.

    1999-09-01

    MARE is an experiment for the measurement of the beta and gamma radioactivity in space and in the Martian soil, both at the surface and in the subsurface. This will be accomplished by means of a dosimeter and a spectrometer. The radiation dose rate to which crews will be exposed is one of the hazards that has to be quantified before the human exploration of Mars may begin. Data for evaluating radioactivity levels at Martian surface are of great interest for environmental studies related to life in general. The dosimeter will be able to measure the beta and gamma radiation dose received, with a responsivity which is very close to that of a living organism. The dosimeter is based on thermo-luminescence pills which emit an optical signal proportional to the absorbed dose when heated. Radioactive elements ((40) K, (235) U, (238) U and (232) Th) can be used as a mean of tracing the evolution of a terrestrial planet. These radioactive elements are the source of the internal heat, which drives convection in the mantle. They have been redistributed in this process and they are now concentrated in the crust where they are accessible for study. Their different behavior during the fractionation process can be used as a mean to investigate the geochemical characteristic of Mars. The spectrometer, a scintillation radiation absorber system for single event counting, is capable of detecting gamma photons with energies between 200 KeV and 10 MeV. The detected events will be processed in such a way to allow the recognition of the spectral signature of different decay processes, and thus the identification and the measurement of the concentrations of different radionuclides in the Martian soil.

  15. Satellite Retrieval of Aerosol Properties

    NASA Astrophysics Data System (ADS)

    de Leeuw, G.; Robles Gonzalez, C.; Kusmierczyk-Michulec, J.; Decae, R.

    SATELLITE RETRIEVAL of AEROSOL PROPERTIES G. de Leeuw, C. Robles Gonzalez, J. Kusmierczyk-Michulec and R. Decae TNO Physics and Electronics Laboratory, The Hague, The Netherlands; deleeuw@fel.tno.nl Methods to retrieve aerosol properties over land and over sea were explored. The dual view offered by the ATSR-2 aboard ERS-2 was used by Veefkind et al., 1998. The retrieved AOD (aerosol optical depth) values compare favourably with collocated sun photometer measurements, with an accuracy of 0.06 +/- 0.05 in AOD. An algorithm developed for GOME on ERS-2 takes advantage of the low surface reflection in the UV (Veefkind et al., 2000). AOD values retrieved from ATSR-2 and GOME data over western Europe are consistent. The results were used to produce a map of mean AOD values over Europe for one month (Robles-Gonzalez et al., 2000). The ATSR-2 is al- gorithm is now extended with other aerosol types with the aim to apply it over the In- dian Ocean. A new algorithm is being developed for the Ozone Monitoring Instrument (OMI) to be launched in 2003 on the NASA EOS-AURA satellite. It is expected that, based on the different scattering and absorption properties of various aerosol types, five major aerosol classes can be distinguished. The experience with the retrieval of aerosol properties by using several wavelength bands is used to develop an algorithm for Sciamachy to retrieve aerosol properties both over land and over the ocean which takes advantage of the wavelengths from the UV to the IR. The variation of the AOD with wavelength is described by the Angstrom parameter. The AOD and the Angstrom parameter together yield information on the aerosol size distribution, integrated over the column. Analysis of sunphotometer data indicates a relation between the Angstrom parameter and the mass ratio of certain aerosols (black carbon, organic carbon and sea salt) to the total particulate matter. This relation has been further explored and was applied to satellite data over land to

  16. Artificial Gravity Research Project

    NASA Technical Reports Server (NTRS)

    Kamman, Michelle R.; Paloski, William H.

    2005-01-01

    Protecting the health, safety, and performance of exploration-class mission crews against the physiological deconditioning resulting from long-term weightlessness during transit and long-term hypogravity during surface operations will require effective, multi-system countermeasures. Artificial gravity (AG), which would replace terrestrial gravity with inertial forces generated by rotating the transit vehicle or by a human centrifuge device within the transit vehicle or surface habitat, has long been considered a potential solution. However, despite its attractiveness as an efficient, multi-system countermeasure and its potential for improving the environment and simplifying operational activities (e.g., WCS, galley, etc.), much still needs to be learned regarding the human response to rotating environments before AG can be successfully implemented. This paper will describe our approach for developing and implementing a rigorous AG Research Project to address the key biomedical research questions that must be answered before developing effective AG countermeasure implementation strategies for exploration-class missions. The AG Research Project will be performed at JSC, ARC, extramural academic and government research venues, and international partner facilities maintained by DLR and IMBP. The Project includes three major ground-based human research subprojects that will lead to flight testing of intermittent short-radius AG in ISS crewmembers after 201 0, continuous long-radius AG in CEV crews transiting to and from the Moon, and intermittent short-radius AG plus exercise in lunar habitats. These human ground-based subprojects include: 1) a directed, managed international short-radius project to investigate the multi-system effectiveness of intermittent AG in human subjects deconditioned by bed rest, 2) a directed, managed long-radius project to investigate the capacity of humans to live and work for extended periods in rotating environments, and 3) a focused

  17. Hydrogen bonding at the aerosol interface

    SciTech Connect

    Zhang, J.X.; Aiello, D.; Aker, P.M. )

    1995-01-12

    Morphology-dependent stimulated Raman scattering (MDSRS) has been used to monitor the degree of hydrogen bonding in water aerosols generated by a vibrating orifice aerosol generator (VOAG). The results show that aerosols created by a VOAG suffer extensive structural disruption and that the disruption is most pronounced at the aerosol surface. Laboratory aerosols prepared in this way do not appropriately mimic those found in the atmosphere, and the mass accommodation coefficients measured using such aerosols should not be used in global climate modeling calculations. 25 refs., 10 figs.

  18. Radioactive deposits of Nevada

    USGS Publications Warehouse

    Lovering, T.G.

    1953-01-01

    Thirty-five occurrences of radioactive rocks had been reported from Nevada prior to 1952. Twenty-five of these had been investigated by the U. S. Geological Survey and the U. S. Atomic Energy Commission. Of those investigated, uranium minerals were identified in 13; two contained a thorium mineral (monazite); the source of radioactivity on 7 properties was not ascertained; and one showed no abnormal radioactivity. Of the other reported occurrences, one is said to contain uraniferous hydrocarbons and 9 are placers containing thorian monazite. Pitchblende occurs at two localities; the East Walker River area, and the Stalin's Present prospect, where it is sparsely disseminated in tabular bodies cutting granitic rocks. Other uranium minerals found in the state include: carnotite, tyuyamunite, autunite, torbernite, gummite, uranophane, kasolite, and an unidentified mineral which may be dumontit. Monazite is the only thorium mineral of possible economic importance that has been reported. From an economic standpoint 9 only 4 of the properties examined showed reserves of uranium ore in 1952; these are: the Green Monster mine, which shipped 5 tons of ore to Marysvale, Utah, during 1951, the Majuba Hill mine, the Stalin's Present prospect, and the West Willys claim in the Washington district. Reserves of ore grade are small on all of these properties and probably cannot be developed commercially unless an ore-buying station is set up nearby. No estimate has been made of thorium reserves and no commercial deposits of thorium are known.

  19. Ice crystallization in ultrafine water-salt aerosols: nucleation, ice-solution equilibrium, and internal structure.

    PubMed

    Hudait, Arpa; Molinero, Valeria

    2014-06-01

    Atmospheric aerosols have a strong influence on Earth's climate. Elucidating the physical state and internal structure of atmospheric aqueous aerosols is essential to predict their gas and water uptake, and the locus and rate of atmospherically important heterogeneous reactions. Ultrafine aerosols with sizes between 3 and 15 nm have been detected in large numbers in the troposphere and tropopause. Nanoscopic aerosols arising from bubble bursting of natural and artificial seawater have been identified in laboratory and field experiments. The internal structure and phase state of these aerosols, however, cannot yet be determined in experiments. Here we use molecular simulations to investigate the phase behavior and internal structure of liquid, vitrified, and crystallized water-salt ultrafine aerosols with radii from 2.5 to 9.5 nm and with up to 10% moles of ions. We find that both ice crystallization and vitrification of the nanodroplets lead to demixing of pure water from the solutions. Vitrification of aqueous nanodroplets yields nanodomains of pure low-density amorphous ice in coexistence with vitrified solute rich aqueous glass. The melting temperature of ice in the aerosols decreases monotonically with an increase of solute fraction and decrease of radius. The simulations reveal that nucleation of ice occurs homogeneously at the subsurface of the water-salt nanoparticles. Subsequent ice growth yields phase-segregated, internally mixed, aerosols with two phases in equilibrium: a concentrated water-salt amorphous mixture and a spherical cap-like ice nanophase. The surface of the crystallized aerosols is heterogeneous, with ice and solution exposed to the vapor. Free energy calculations indicate that as the concentration of salt in the particles, the advance of the crystallization, or the size of the particles increase, the stability of the spherical cap structure increases with respect to the alternative structure in which a core of ice is fully surrounded by

  20. An effective technique for the storage of short lived radioactive gaseous waste.

    PubMed

    Schweiger, Lutz

    2011-09-01

    An effective technique is described to deal with volatile, short lived radioactive waste generated as a result of the routinely produced positron emission tomography (PET) radiopharmaceutical 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG). All radioactive gases and aerosols created during the synthesis are collected and stored safely in commercially available TEDLAR gas sampling bags. Once these collected PET by-products decay, the TEDLAR gas bags can be easily emptied and reused. This improved technique is effective, safe, reliable and economical. PMID:21592805

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

    NASA Astrophysics Data System (ADS)

    Zhang, Z.

    2015-12-01

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

  2. Study of Aerosol Chemical Composition Based on Aerosol Optical Properties

    NASA Astrophysics Data System (ADS)

    Berry, Austin; Aryal, Rudra

    2015-03-01

    We investigated the variation of aerosol absorption optical properties obtained from the CIMEL Sun-Photometer measurements over three years (2012-2014) at three AERONET sites GSFC; MD Science_Center and Tudor Hill, Bermuda. These sites were chosen based on the availability of data and locations that can receive different types of aerosols from land and ocean. These absorption properties, mainly the aerosol absorption angstrom exponent, were analyzed to examine the corresponding aerosol chemical composition. We observed that the retrieved absorption angstrom exponents over the two sites, GSFC and MD Science Center, are near 1 (the theoretical value for black carbon) and with low single scattering albedo values during summer seasons indicating presence of black carbon. Strong variability of aerosol absorption properties were observed over Tudor Hill and will be analyzed based on the air mass embedded from ocean side and land side. We will also present the seasonal variability of these properties based on long-range air mass sources at these three sites. Brent Holben, NASA GSFC, AERONET, Jon Rodriguez.

  3. AERONET - Aerosol Climatology From Megalopolis Aerosol Source Regions

    NASA Astrophysics Data System (ADS)

    Holben, B. N.; Eck, T. F.; Dubovik, O.; Smirnov, A.; Slutsker, I.; Artaxo, P.; Leyva, A.; Lu, D.; Sano, I.; Singh, R. P.; Quel, E.; Tanre, D.; Zibordi, G.

    2002-05-01

    AERONET is a globally distributed network of ~170 identical sun and sky scanning spectral radiometers expanded by federation with collaborating investigators that contribute to the AERONET public domain data-base. We will detail the current distribution and plans for expanded collaboration. Recent products available through the project database are important for assessment of human health as well as climate forcing issues. We will illustrate a summary of aerosol optical properties measured in Indian, East Asian, North American, South American and European megalopolis source regions. We will present monthly mean fine and coarse particle aerosol optical depth, particle size distributions and single scattering albedos. Each region represents a population in excess of 10 million inhabitants within a 200 km radius of the observation site that dictate the anthropogenic aerosol sources contributing to significantly diverse aerosol properties as a function of economic development and seasonally dependent meteorological processes. The diversity of the measured optical properties of urban aerosols illustrates the need for long-term regional monitoring that contribute to comparative assessments for health and climate change investigations.

  4. Nanobiocatalytic assemblies for artificial photosynthesis.

    PubMed

    Kim, Jae Hong; Nam, Dong Heon; Park, Chan Beum

    2014-08-01

    Natural photosynthesis, a solar-to-chemical energy conversion process, occurs through a series of photo-induced electron transfer reactions in nanoscale architectures that contain light-harvesting complexes, protein-metal clusters, and many redox biocatalysts. Artificial photosynthesis in nanobiocatalytic assemblies aims to reconstruct man-made photosensitizers, electron mediators, electron donors, and redox enzymes for solar synthesis of valuable chemicals through visible light-driven cofactor regeneration. The key requirement in the design of biocatalyzed artificial photosynthetic process is an efficient and forward electron transfer between each photosynthetic component. This review describes basic principles in combining redox biocatalysis with photocatalysis, and highlights recent research outcomes in the development of nanobiocatalytic assemblies that can mimic natural photosystems I and II, respectively. Current issues in biocatalyzed artificial photosynthesis and future perspectives will be briefly discussed. PMID:24832068

  5. Doped colloidal artificial spin ice

    NASA Astrophysics Data System (ADS)

    Libál, A.; Olson Reichhardt, C. J.; Reichhardt, C.

    2015-10-01

    We examine square and kagome artificial spin ice for colloids confined in arrays of double-well traps. Unlike magnetic artificial spin ices, colloidal and vortex artificial spin ice realizations allow creation of doping sites through double occupation of individual traps. We find that doping square and kagome ice geometries produces opposite effects. For square ice, doping creates local excitations in the ground state configuration that produce a local melting effect as the temperature is raised. In contrast, the kagome ice ground state can absorb the doping charge without generating non-ground-state excitations, while at elevated temperatures the hopping of individual colloids is suppressed near the doping sites. These results indicate that in the square ice, doping adds degeneracy to the ordered ground state and creates local weak spots, while in the kagome ice, which has a highly degenerate ground state, doping locally decreases the degeneracy and creates local hard regions.

  6. Bioengineering of Artificial Lymphoid Organs

    PubMed Central

    Nosenko, M. A.; Drutskaya, M. S.; Moisenovich, M. M.; Nedospasov, S. A.

    2016-01-01

    This review addresses the issue of bioengineering of artificial lymphoid organs.Progress in this field may help to better understand the nature of the structure-function relations that exist in immune organs. Artifical lymphoid organs may also be advantageous in the therapy or correction of immunodefficiencies, autoimmune diseases, and cancer. The structural organization, development, and function of lymphoid tissue are analyzed with a focus on the role of intercellular contacts and on the cytokine signaling pathways regulating these processes. We describe various polymeric materials, as scaffolds, for artificial tissue engineering. Finally, published studies in which artificial lymphoid organs were generated are reviewed and possible future directions in the field are discussed. PMID:27437136

  7. Artificial heart for humanoid robot

    NASA Astrophysics Data System (ADS)

    Potnuru, Akshay; Wu, Lianjun; Tadesse, Yonas

    2014-03-01

    A soft robotic device inspired by the pumping action of a biological heart is presented in this study. Developing artificial heart to a humanoid robot enables us to make a better biomedical device for ultimate use in humans. As technology continues to become more advanced, the methods in which we implement high performance and biomimetic artificial organs is getting nearer each day. In this paper, we present the design and development of a soft artificial heart that can be used in a humanoid robot and simulate the functions of a human heart using shape memory alloy technology. The robotic heart is designed to pump a blood-like fluid to parts of the robot such as the face to simulate someone blushing or when someone is angry by the use of elastomeric substrates and certain features for the transport of fluids.

  8. Artificial sweeteners: safe or unsafe?

    PubMed

    Qurrat-ul-Ain; Khan, Sohaib Ahmed

    2015-02-01

    Artificial sweeteners or intense sweeteners are sugar substitutes that are used as an alternative to table sugar. They are many times sweeter than natural sugar and as they contain no calories, they may be used to control weight and obesity. Extensive scientific research has demonstrated the safety of the six low-calorie sweeteners currently approved for use in foods in the U.S. and Europe (stevia, acesulfame-K, aspartame, neotame, saccharin and sucralose), if taken in acceptable quantities daily. There is some ongoing debate over whether artificial sweetener usage poses a health threat .This review article aims to cover thehealth benefits, and risks, of consuming artificial sweeteners, and discusses natural sweeteners which can be used as alternatives. PMID:25842566

  9. Computational aerodynamics and artificial intelligence

    NASA Technical Reports Server (NTRS)

    Kutler, P.; Mehta, U. B.

    1984-01-01

    Some aspects of artificial intelligence are considered and questions are speculated on, including how knowledge-based systems can accelerate the process of acquiring new knowledge in aerodynamics, how computational fluid dynamics may use 'expert' systems and how expert systems may speed the design and development process. The anatomy of an idealized expert system called AERODYNAMICIST is discussed. Resource requirements are examined for using artificial intelligence in computational fluid dynamics and aerodynamics. Considering two of the essentials of computational aerodynamics - reasoniing and calculating - it is believed that a substantial part of the reasoning can be achieved with artificial intelligence, with computers being used as reasoning machines to set the stage for calculating. Expert systems will probably be new assets of institutions involved in aeronautics for various tasks of computational aerodynamics.

  10. Computational aerodynamics and artificial intelligence

    NASA Technical Reports Server (NTRS)

    Mehta, U. B.; Kutler, P.

    1984-01-01

    The general principles of artificial intelligence are reviewed and speculations are made concerning how knowledge based systems can accelerate the process of acquiring new knowledge in aerodynamics, how computational fluid dynamics may use expert systems, and how expert systems may speed the design and development process. In addition, the anatomy of an idealized expert system called AERODYNAMICIST is discussed. Resource requirements for using artificial intelligence in computational fluid dynamics and aerodynamics are examined. Three main conclusions are presented. First, there are two related aspects of computational aerodynamics: reasoning and calculating. Second, a substantial portion of reasoning can be achieved with artificial intelligence. It offers the opportunity of using computers as reasoning machines to set the stage for efficient calculating. Third, expert systems are likely to be new assets of institutions involved in aeronautics for various tasks of computational aerodynamics.

  11. Modeling the Absorbing Aerosol Index

    NASA Technical Reports Server (NTRS)

    Penner, Joyce; Zhang, Sophia

    2003-01-01

    We propose a scheme to model the absorbing aerosol index and improve the biomass carbon inventories by optimizing the difference between TOMS aerosol index (AI) and modeled AI with an inverse model. Two absorbing aerosol types are considered, including biomass carbon and mineral dust. A priori biomass carbon source was generated by Liousse et al [1996]. Mineral dust emission is parameterized according to surface wind and soil moisture using the method developed by Ginoux [2000]. In this initial study, the coupled CCM1 and GRANTOUR model was used to determine the aerosol spatial and temporal distribution. With modeled aerosol concentrations and optical properties, we calculate the radiance at the top of the atmosphere at 340 nm and 380 nm with a radiative transfer model. The contrast of radiance at these two wavelengths will be used to calculate AI. Then we compare the modeled AI with TOMS AI. This paper reports our initial modeling for AI and its comparison with TOMS Nimbus 7 AI. For our follow-on project we will model the global AI with aerosol spatial and temporal distribution recomputed from the IMPACT model and DAO GEOS-1 meteorology fields. Then we will build an inverse model, which applies a Bayesian inverse technique to optimize the agreement of between model and observational data. The inverse model will tune the biomass burning source strength to reduce the difference between modelled AI and TOMS AI. Further simulations with a posteriori biomass carbon sources from the inverse model will be carried out. Results will be compared to available observations such as surface concentration and aerosol optical depth.

  12. MODIS Retrieval of Dust Aerosol

    NASA Technical Reports Server (NTRS)

    Remer, Lorraine A.; Kaufman, Yoram J.; Tanre, Didier

    2003-01-01

    The MODerate resolution Imaging Spectroradiometer (MODIS) currently aboard both the Terra and Aqua satellites produces a suite of products designed to characterize global aerosol distribution, optical thickness and particle size. Never before has a space-borne instrument been able to provide such detailed information, operationally, on a nearly global basis every day. The three years of Terra-MODIS data have been validated by comparing with co-located AERONET observations of aerosol optical thickness and derivations of aerosol size parameters. Some 8000 comparison points located at 133 AERONET sites around the globe show that the MODIS aerosol optical thickness retrievals are accurate to within the pre-launch expectations. However, the validation in regions dominated by desert dust is less accurate than in regions dominated by fine mode aerosol or background marine sea salt. The discrepancy is most apparent in retrievals of aerosol size parameters over ocean. In dust situations, the MODIS algorithm tends to under predict particle size because the reflectances at top of atmosphere measured by MODIS exhibit the stronger spectral signature expected by smaller particles. This pattern is consistent with the angular and spectral signature of non-spherical particles. All possible aerosol models in the MODIS Look-Up Tables were constructed from Mie theory, assuming a spherical shape. Using a combination of MODIS and AERONET observations, in regimes dominated by desert dust, we construct phase functions, empirically, with no assumption of particle shape. These new phase functions are introduced into the MODIS algorithm, in lieu of the original options for large dust-like particles. The results will be analyzed and examined.

  13. Aerosol can puncture device operational test plan

    SciTech Connect

    Leist, K.J.

    1994-05-03

    Puncturing of aerosol cans is performed in the Waste Receiving and Processing Facility Module 1 (WRAP 1) process as a requirement of the waste disposal acceptance criteria for both transuranic (TRU) waste and low-level waste (LLW). These cans have contained such things as paints, lubricating oils, paint removers, insecticides, and cleaning supplies which were used in radioactive facilities. Due to Westinghouse Hanford Company (WHC) Fire Protection concerns of the baseline system`s fire/explosion proof characteristics, a study was undertaken to compare the baseline system`s design to commercially available puncturing devices. While the study found no areas which might indicate a risk of fire or explosion, WHC Fire Protection determined that the puncturing system must have a demonstrated record of safe operation. This could be obtained either by testing the baseline design by an independent laboratory, or by substituting a commercially available device. As a result of these efforts, the commercially available Aerosolv can puncturing device was chosen to replace the baseline design. Two concerns were raised with the system. Premature blinding of the coalescing/carbon filter, due to its proximity to the puncture and draining operation; and overpressurization of the collection bottle due to its small volume and by blinding of the filter assembly. As a result of these concerns, testing was deemed necessary. The objective of this report is to outline test procedures for the Aerosolv.

  14. YAG aerosol lidar

    NASA Technical Reports Server (NTRS)

    Sullivan, R.

    1988-01-01

    The Global Atmospheric Backscatter Experiment (GLOBE) Mission, using the NASA DC-8 aircraft platform, is designed to provide the magnitude and statistical distribution of atmospheric backscatter cross section at lidar operating wavelengths. This is a fundamental parameter required for the Doppler lidar proposed to be used on a spacecraft platform for global wind field measurements. The prime measurements will be made by a CO2 lidar instrument in the 9 to 10 micron range. These measurements will be complemented with the Goddard YAG Aerosol Lidar (YAL) data in two wavelengths, 0.532 and 1.06 micron, in the visible and near-infrared. The YAL, is being designed to utilize as much existing hardware, as feasible, to minimize cost and reduce implementation time. The laser, energy monitor, telescope and detector package will be mounted on an optical breadboard. The optical breadboard is mounted through isolation mounts between two low boy racks. The detector package will utilize a photomultiplier tube for the 0.532 micron channel and a silicon avalanche photo detector (APD) for the 1.06 micron channel.

  15. Dispersion of aerosol particles in the atmosphere: Fukushima

    NASA Astrophysics Data System (ADS)

    Haszpra, Tímea; Lagzi, István; Tél, Tamás

    2013-04-01

    Investigation of dispersion and deposition of aerosol particles in the atmosphere is an essential issue, because they have an effect on the biosphere and atmosphere. Moreover, aerosol particles have different transport properties and chemical and physical transformations in the atmosphere compared to gas phase air pollutants. The motion of a particle is described by a set of ordinary differential equations. The large-scale dynamics in the horizontal direction can be described by the equations of passive scalar advection, but in the vertical direction a well-defined terminal velocity should be taken into account as a term added to the vertical wind component. In the planetary boundary layer turbulent diffusion has an important role in the particle dispersion, which is taken into account by adding stochastic terms to the deterministic equations above. Wet deposition is also an essential process in the lower levels of the atmosphere, however, its precise parameterization is a challenge. For the simulations the wind field and other necessary data were taken from the ECMWF ERA-Interim database. In the case of the Fukushima Daiichi nuclear disaster (March-April 2011) radioactive aerosol particles were also released in the planetary boundary layer. Simulations (included the continuous and varying emission from the nuclear power plant) will be presented for the period of 14-23 March. Results show that wet deposition also has to be taken into consideration in the lower levels of the atmosphere. Furthermore, dynamical system characteristics are evaluated for the aerosol particle dynamics. The escape rate of particles was estimated both with and without turbulent diffusion, and in both cases when there was no wet deposition and also when wet deposition was taken into consideration.

  16. ASSESSMENT OF RADIOACTIVE AND NON-RADIOACTIVE CONTAMINANTS FOUND IN LOW LEVEL RADIOACTIVE WASTE STREAMS

    SciTech Connect

    R.H. Little, P.R. Maul, J.S.S. Penfoldag

    2003-02-27

    This paper describes and presents the findings from two studies undertaken for the European Commission to assess the long-term impact upon the environment and human health of non-radioactive contaminants found in various low level radioactive waste streams. The initial study investigated the application of safety assessment approaches developed for radioactive contaminants to the assessment of nonradioactive contaminants in low level radioactive waste. It demonstrated how disposal limits could be derived for a range of non-radioactive contaminants and generic disposal facilities. The follow-up study used the same approach but undertook more detailed, disposal system specific calculations, assessing the impacts of both the non-radioactive and radioactive contaminants. The calculations undertaken indicated that it is prudent to consider non-radioactive, as well as radioactive contaminants, when assessing the impacts of low level radioactive waste disposal. For some waste streams with relatively low concentrations of radionuclides, the potential post-closure disposal impacts from non-radioactive contaminants can be comparable with the potential radiological impacts. For such waste streams there is therefore an added incentive to explore options for recycling the materials involved wherever possible.

  17. Artificial Life in Quantum Technologies

    PubMed Central

    Alvarez-Rodriguez, Unai; Sanz, Mikel; Lamata, Lucas; Solano, Enrique

    2016-01-01

    We develop a quantum information protocol that models the biological behaviours of individuals living in a natural selection scenario. The artificially engineered evolution of the quantum living units shows the fundamental features of life in a common environment, such as self-replication, mutation, interaction of individuals, and death. We propose how to mimic these bio-inspired features in a quantum-mechanical formalism, which allows for an experimental implementation achievable with current quantum platforms. This study paves the way for the realization of artificial life and embodied evolution with quantum technologies. PMID:26853918

  18. Rewritable artificial magnetic charge ice

    NASA Astrophysics Data System (ADS)

    Wang, Yong-Lei; Xiao, Zhi-Li; Snezhko, Alexey; Xu, Jing; Ocola, Leonidas E.; Divan, Ralu; Pearson, John E.; Crabtree, George W.; Kwok, Wai-Kwong

    2016-05-01

    Artificial ices enable the study of geometrical frustration by design and through direct observation. However, it has proven difficult to achieve tailored long-range ordering of their diverse configurations, limiting both fundamental and applied research directions. We designed an artificial spin structure that produces a magnetic charge ice with tunable long-range ordering of eight different configurations. We also developed a technique to precisely manipulate the local magnetic charge states and demonstrate write-read-erase multifunctionality at room temperature. This globally reconfigurable and locally writable magnetic charge ice could provide a setting for designing magnetic monopole defects, tailoring magnonics, and controlling the properties of other two-dimensional materials.

  19. Artificial Life in Quantum Technologies

    NASA Astrophysics Data System (ADS)

    Alvarez-Rodriguez, Unai; Sanz, Mikel; Lamata, Lucas; Solano, Enrique

    2016-02-01

    We develop a quantum information protocol that models the biological behaviours of individuals living in a natural selection scenario. The artificially engineered evolution of the quantum living units shows the fundamental features of life in a common environment, such as self-replication, mutation, interaction of individuals, and death. We propose how to mimic these bio-inspired features in a quantum-mechanical formalism, which allows for an experimental implementation achievable with current quantum platforms. This study paves the way for the realization of artificial life and embodied evolution with quantum technologies.

  20. Artificial Cells: Prospects for Biotechnology

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew; Deamer, David; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    A variety of techniques can now be used to alter the genome of a cell. Although these techniques are very powerful, they also have limitations related to cost and efficiency of scale. Artificial cells designed for specific applications combine properties of biological systems such as nano-scale efficiency, self-organization and adaptability at relatively low cost. Individual components needed for such structures have already been developed, and now the main challenge is to integrate them in functional microscopic compartments. It will then become possible to design and construct communities of artificial cells that can perform different tasks related to therapeutic and diagnostic applications.

  1. Artificial cells: prospects for biotechnology

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew; Deamer, David

    2002-01-01

    A variety of techniques can now be used to alter the genome of a cell. Although these techniques are very powerful, they have limitations related to cost and efficiency of scale. Artificial cells designed for specific applications combine properties of biological systems such as nanoscale efficiency, self-organization and adaptability at relatively low cost. Individual components needed for such structures have already been developed, and now the main challenge is to integrate them in functional microscopic compartments. It will then become possible to design and construct communities of artificial cells that can perform different tasks related to therapeutic and diagnostic applications.

  2. Joint Center for Artificial Photosynthesis

    ScienceCinema

    Koval, Carl; Lee, Kenny; Houle, Frances; Lewis, Nate

    2013-12-19

    The Joint Center for Artificial Photosynthesis (JCAP) is the nation's largest research program dedicated to the development of an artificial solar-fuel generation technology. Established in 2010 as a U.S. Department of Energy (DOE) Energy Innovation Hub, JCAP aims to find a cost-effective method to produce fuels using only sunlight, water, and carbon dioxide as inputs. JCAP brings together more than 140 top scientists and researchers from the California Institute of Technology and its lead partner, Berkeley Lab, along with collaborators from the SLAC National Accelerator Laboratory, and the University of California campuses at Irvine and San Diego.

  3. Joint Center for Artificial Photosynthesis

    SciTech Connect

    Koval, Carl; Lee, Kenny; Houle, Frances; Lewis, Nate

    2013-12-10

    The Joint Center for Artificial Photosynthesis (JCAP) is the nation's largest research program dedicated to the development of an artificial solar-fuel generation technology. Established in 2010 as a U.S. Department of Energy (DOE) Energy Innovation Hub, JCAP aims to find a cost-effective method to produce fuels using only sunlight, water, and carbon dioxide as inputs. JCAP brings together more than 140 top scientists and researchers from the California Institute of Technology and its lead partner, Berkeley Lab, along with collaborators from the SLAC National Accelerator Laboratory, and the University of California campuses at Irvine and San Diego.

  4. Detection of uranium and chemical state analysis of individual radioactive microparticles emitted from the Fukushima nuclear accident using multiple synchrotron radiation X-ray analyses.

    PubMed

    Abe, Yoshinari; Iizawa, Yushin; Terada, Yasuko; Adachi, Kouji; Igarashi, Yasuhito; Nakai, Izumi

    2014-09-01

    Synchrotron radiation (SR) X-ray microbeam analyses revealed the detailed chemical nature of radioactive aerosol microparticles emitted during the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, resulting in better understanding of what occurred in the plant during the early stages of the accident. Three spherical microparticles (∼2 μm, diameter) containing radioactive Cs were found in aerosol samples collected on March 14th and 15th, 2011, in Tsukuba, 172 km southwest of the FDNPP. SR-μ-X-ray fluorescence analysis detected the following 10 heavy elements in all three particles: Fe, Zn, Rb, Zr, Mo, Sn, Sb, Te, Cs, and Ba. In addition, U was found for the first time in two of the particles, further confirmed by U L-edge X-ray absorption near-edge structure (XANES) spectra, implying that U fuel and its fission products were contained in these particles along with radioactive Cs. These results strongly suggest that the FDNPP was damaged sufficiently to emit U fuel and fission products outside the containment vessel as aerosol particles. SR-μ-XANES spectra of Fe, Zn, Mo, and Sn K-edges for the individual particles revealed that they were present at high oxidation states, i.e., Fe(3+), Zn(2+), Mo(6+), and Sn(4+) in the glass matrix, confirmed by SR-μ-X-ray diffraction analysis. These radioactive materials in a glassy state may remain in the environment longer than those emitted as water-soluble radioactive Cs aerosol particles. PMID:25084242

  5. Factors Affecting Aerosol Radiative Forcing

    NASA Astrophysics Data System (ADS)

    Wang, Jingxu; Lin, Jintai; Ni, Ruijing

    2016-04-01

    Rapid industrial and economic growth has meant a large amount of aerosols in the atmosphere with strong radiative forcing (RF) upon the climate system. Over parts of the globe, the negative forcing of aerosols has overcompensated for the positive forcing of greenhouse gases. Aerosol RF is determined by emissions and various chemical-transport-radiative processes in the atmosphere, a multi-factor problem whose individual contributors have not been well quantified. In this study, we analyze the major factors affecting RF of secondary inorganic aerosols (SIOAs, including sulfate, nitrate and ammonium), primary organic aerosol (POA), and black carbon (BC). We analyze the RF of aerosols produced by 11 major regions across the globe, including but not limited to East Asia, Southeast Asia, South Asia, North America, and Western Europe. Factors analyzed include population size, per capita gross domestic production (GDP), emission intensity (i.e., emissions per unit GDP), chemical efficiency (i.e., mass per unit emissions) and radiative efficiency (i.e., RF per unit mass). We find that among the 11 regions, East Asia produces the largest emissions and aerosol RF, due to relatively high emission intensity and a tremendous population size. South Asia produce the second largest RF of SIOA and BC and the highest RF of POA, in part due to its highest chemical efficiency among all regions. Although Southeast Asia also has large emissions, its aerosol RF is alleviated by its lowest chemical efficiency. The chemical efficiency and radiative efficiency of BC produced by the Middle East-North Africa are the highest across the regions, whereas its RF is lowered by a small per capita GDP. Both North America and Western Europe have low emission intensity, compensating for the effects on RF of large population sizes and per capita GDP. There has been a momentum to transfer industries to Southeast Asia and South Asia, and such transition is expected to continue in the coming years. The

  6. The Effect of Aerosol Hygroscopicity and Volatility on Aerosol Optical Properties During Southern Oxidant and Aerosol Study

    NASA Astrophysics Data System (ADS)

    Khlystov, A.; Grieshop, A. P.; Saha, P.; Subramanian, R.

    2014-12-01

    Secondary organic aerosol (SOA) from biogenic sources can influence optical properties of ambient aerosol by altering its hygroscopicity and contributing to light absorption directly via formation of brown carbon and indirectly by enhancing light absorption by black carbon ("lensing effect"). The magnitude of these effects remains highly uncertain. A set of state-of-the-art instruments was deployed at the SEARCH site near Centerville, AL during the Southern Oxidant and Aerosol Study (SOAS) campaign in summer 2013 to measure the effect of relative humidity and temperature on aerosol size distribution, composition and optical properties. Light scattering and absorption by temperature- and humidity-conditioned aerosols was measured using three photo-acoustic extinctiometers (PAX) at three wavelengths (405 nm, 532 nm, and 870 nm). The sample-conditioning system provided measurements at ambient RH, 10%RH ("dry"), 85%RH ("wet"), and 200 C ("TD"). In parallel to these measurements, a long residence time temperature-stepping thermodenuder (TD) and a variable residence time constant temperature TD in combination with three SMPS systems and an Aerosol Chemical Speciation Monitor (ACSM) were used to assess aerosol volatility and kinetics of aerosol evaporation. We will present results of the on-going analysis of the collected data set. We will show that both temperature and relative humidity have a strong effect on aerosol optical properties. SOA appears to increase aerosol light absorption by about 10%. TD measurements suggest that aerosol equilibrated fairly quickly, within 2 s. Evaporation varied substantially with ambient aerosol loading and composition and meteorology.

  7. Optical Characterization of Metallic Aerosols

    NASA Technical Reports Server (NTRS)

    Sun, Wenbo; Lin, Bing

    2005-01-01

    Airborne metallic particulates from industry and urban sources are highly conducting aerosols. The characterization of these pollutant particles is important for environment monitoring and protection. Because these metallic particulates are highly reflective, their effect on local weather or regional radiation budget may also need to be studied. In this work, light scattering characteristics of these metallic aerosols are studied using exact solutions on perfectly conducting spherical and cylindrical particles. It is found that for perfectly conducting spheres and cylinders, when scattering angle is larger than approx. 90 deg. the linear polarization degree of the scattered light is very close to zero. This light scattering characteristics of perfectly conducting particles is significantly different from that of other aerosols. When these perfectly conducting particles are immersed in an absorbing medium, this light scattering characteristics does not show significant change. Therefore, measuring the linear polarization of scattered lights at backward scattering angles can detect and distinguish metallic particulates from other aerosols. This result provides a great potential of metallic aerosol detection and monitoring for environmental protection.

  8. Mesoscale Variations of Tropospheric Aerosols(.

    NASA Astrophysics Data System (ADS)

    Anderson, Theodore L.; Charlson, Robert J.; Winker, David M.; Ogren, John A.; Holmén, Kim

    2003-01-01

    Tropospheric aerosols are calculated to cause global-scale changes in the earth's heat balance, but these forcings are space/time integrals over highly variable quantities. Accurate quantification of these forcings will require an unprecedented synergy among satellite, airborne, and surface-based observations, as well as models. This study considers one aspect of achieving this synergy-the need to treat aerosol variability in a consistent and realistic way. This need creates a requirement to rationalize the differences in spatiotemporal resolution and coverage among the various observational and modeling approaches. It is shown, based on aerosol optical data from diverse regions, that mesoscale variability (specifically, for horizontal scales of 40-400 km and temporal scales of 2-48 h) is a common and perhaps universal feature of lower-tropospheric aerosol light extinction. Such variation is below the traditional synoptic or `airmass' scale (where the aerosol is often assumed to be essentially homogeneous except for plumes from point sources) and below the scales that are readily resolved by chemical transport models. The present study focuses on documenting this variability. Possible physical causes and practical implications for coordinated observational strategies are also discussed.

  9. Center for Aerosol Research (AEROCENTER)

    NASA Technical Reports Server (NTRS)

    Kleidman, Richard; Kaufman, Yoram; Lau, William K. M. (Technical Monitor)

    2001-01-01

    The newly established Center for Aerosol Research (AEROCENTER) located at the NASA/Goddard Space Flight Center in Greenbelt MD is dedicated to fostering interdisciplinary research in all aspects of aerosol science. AEROCENTER will be an incubator for innovative new analysis of existing data and ideas for new space missions. The plan is to tap and harvest ideas from a broad international and interdisciplinary science community and to incorporate these ideas into NASA's aerosol research effort for understanding and predicting the aerosol effect on climate and the environment. In order to achieve this goal the center aims to host several established and developing scientists for a period of 3-6 months each year. AEROCENTER will also develop a new technical infrastructure that will integrate the present aerosol research activities and data resources of GSFC/Greenbelt and GSFC/GISS, increase efficiency in the use of NASA remote sensing data, and increase the involvement of a larger national and international scientific community. The center aims to institutionalize and extend the present knowledge base within NASA into a national resource for the education and research communities.

  10. MISR Level 2 Aerosol and Land Versioning

    Atmospheric Science Data Center

    2013-04-01

    ... Current F12_0022 (aerosol), F07_0022 (land) 12/01/2007 Data Product Specification Rev Q ... AEROSOL: Revised Dark Water algorithm to use a common subregion location across all channels. Revised ...

  11. Aerosol Climate Time Series in ESA Aerosol_cci

    NASA Astrophysics Data System (ADS)

    Popp, Thomas; de Leeuw, Gerrit; Pinnock, Simon

    2016-04-01

    Within the ESA Climate Change Initiative (CCI) Aerosol_cci (2010 - 2017) conducts intensive work to improve algorithms for the retrieval of aerosol information from European sensors. Meanwhile, full mission time series of 2 GCOS-required aerosol parameters are completely validated and released: Aerosol Optical Depth (AOD) from dual view ATSR-2 / AATSR radiometers (3 algorithms, 1995 - 2012), and stratospheric extinction profiles from star occultation GOMOS spectrometer (2002 - 2012). Additionally, a 35-year multi-sensor time series of the qualitative Absorbing Aerosol Index (AAI) together with sensitivity information and an AAI model simulator is available. Complementary aerosol properties requested by GCOS are in a "round robin" phase, where various algorithms are inter-compared: fine mode AOD, mineral dust AOD (from the thermal IASI spectrometer, but also from ATSR instruments and the POLDER sensor), absorption information and aerosol layer height. As a quasi-reference for validation in few selected regions with sparse ground-based observations the multi-pixel GRASP algorithm for the POLDER instrument is used. Validation of first dataset versions (vs. AERONET, MAN) and inter-comparison to other satellite datasets (MODIS, MISR, SeaWIFS) proved the high quality of the available datasets comparable to other satellite retrievals and revealed needs for algorithm improvement (for example for higher AOD values) which were taken into account for a reprocessing. The datasets contain pixel level uncertainty estimates which were also validated and improved in the reprocessing. For the three ATSR algorithms the use of an ensemble method was tested. The paper will summarize and discuss the status of dataset reprocessing and validation. The focus will be on the ATSR, GOMOS and IASI datasets. Pixel level uncertainties validation will be summarized and discussed including unknown components and their potential usefulness and limitations. Opportunities for time series extension

  12. Method for volatility measurements on polydisperse aerosol

    NASA Astrophysics Data System (ADS)

    Schmid, Otmar; Hagen, Donald E.; Whitefield, Philip D.; Hopkins, Alfred R.; Eimer, Ben

    2000-08-01

    We describe a method for measuring the amount of volatile material in the aerosol phase using a thermal discriminator. This method, which requires the measurement of the particle size distributions of the heated (through discriminator) and non-heated (bypassing discriminator) sample aerosol, includes the effects due to both particle loss and partially volatile aerosols. Tests with polydisperse internally mixed, i.e. partially volatile, aerosol (not shown here) indicate a high degree of accuracy of this method even for ultrafine particles.

  13. Study of proton radioactivities

    SciTech Connect

    Davids, C.N.; Back, B.B.; Henderson, D.J.

    1995-08-01

    About a dozen nuclei are currently known to accomplish their radioactive decay by emitting a proton. These nuclei are situated far from the valley of stability, and mark the very limits of existence for proton-rich nuclei: the proton drip line. A new 39-ms proton radioactivity was observed following the bombardment of a {sup 96}Ru target by a beam of 420-MeV {sup 78}Kr. Using the double-sided Si strip detector implantation system at the FMA, a proton group having an energy of 1.05 MeV was observed, correlated with the implantation of ions having mass 167. The subsequent daughter decay was identified as {sup 166}Os by its characteristic alpha decay, and therefore the proton emitter is assigned to the {sup 167}Ir nucleus. Further analysis showed that a second weak proton group from the same nucleus is present, indicating an isomeric state. Two other proton emitters were discovered recently at the FMA: {sup 171}Au and {sup 185}Bi, which is the heaviest known proton radioactivity. The measured decay energies and half-lives will enable the angular momentum of the emitted protons to be determined, thus providing spectroscopic information on nuclei that are beyond the proton drip line. In addition, the decay energy yields the mass of the nucleus, providing a sensitive test of mass models in this extremely proton-rich region of the chart of the nuclides. Additional searches for proton emitters will be conducted in the future, in order to extend our knowledge of the location of the proton drip line.

  14. Sensitivity of depositions to the size and hygroscopicity of Cs-bearing aerosols released from the Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Kajino, Mizuo; Adachi, Kouji; Sekiyama, Tsuyoshi; Zaizen, Yuji; Igarashi, Yasuhito

    2014-05-01

    We recently revealed that the microphysical properties of aerosols carrying the radioactive Cs released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) at an early stage (March 14-15, 2011) of the accident could be very different from what we assumed previously: super-micron and non-hygroscopic at the early stage, whereas sub-micron and hygroscopic afterwards (at least later than March 20-22). In the study, two sensitivity simulations with the two different aerosol microphysical properties were conducted using a regional scale meteorology- chemical transport model (NHM-Chem). The impact of the difference was quite significant. 17% (0.001%) of the radioactive Cs fell onto the ground by dry (wet) deposition processes, and the rest was deposited into the ocean or was transported out of the model domain, which is central and northern part of the main land of Japan, under the assumption that Cs-bearing aerosols are non-hygroscopic and super-micron. On the other hand, 5.7% (11.3%) fell onto the ground by dry (wet) deposition, for the cases under the assumption that the Cs-bearing aerosols are hygroscopic and sub-micron. For the accurate simulation of the deposition of radionuclides, knowledge of the aerosol microphysical properties is essential as well as the accuracy of the simulated wind fields and precipitation patterns.

  15. Artificial Video for Video Analysis

    ERIC Educational Resources Information Center

    Gallis, Michael R.

    2010-01-01

    This paper discusses the use of video analysis software and computer-generated animations for student activities. The use of artificial video affords the opportunity for students to study phenomena for which a real video may not be easy or even possible to procure, using analysis software with which the students are already familiar. We will…

  16. Hydrogen production: Catalysing artificial photosynthesis

    NASA Astrophysics Data System (ADS)

    Mao, Samuel S.; Shen, Shaohua

    2013-12-01

    Efficient photocatalytic splitting of water to realize carbon-free production of hydrogen from sunlight remains a challenge. New precious-metal-free molecular catalysts in semiconductor-based, visible-light-driven water-splitting systems are promising for realizing practical artificial photosynthesis.

  17. Worldwide variations in artificial skyglow.

    PubMed

    Kyba, Christopher C M; Tong, Kai Pong; Bennie, Jonathan; Birriel, Ignacio; Birriel, Jennifer J; Cool, Andrew; Danielsen, Arne; Davies, Thomas W; Outer, Peter N den; Edwards, William; Ehlert, Rainer; Falchi, Fabio; Fischer, Jürgen; Giacomelli, Andrea; Giubbilini, Francesco; Haaima, Marty; Hesse, Claudia; Heygster, Georg; Hölker, Franz; Inger, Richard; Jensen, Linsey J; Kuechly, Helga U; Kuehn, John; Langill, Phil; Lolkema, Dorien E; Nagy, Matthew; Nievas, Miguel; Ochi, Nobuaki; Popow, Emil; Posch, Thomas; Puschnig, Johannes; Ruhtz, Thomas; Schmidt, Wim; Schwarz, Robert; Schwope, Axel; Spoelstra, Henk; Tekatch, Anthony; Trueblood, Mark; Walker, Constance E; Weber, Michael; Welch, Douglas L; Zamorano, Jaime; Gaston, Kevin J

    2015-01-01

    Despite constituting a widespread and significant environmental change, understanding of artificial nighttime skyglow is extremely limited. Until now, published monitoring studies have been local or regional in scope, and typically of short duration. In this first major international compilation of monitoring data we answer several key questions about skyglow properties. Skyglow is observed to vary over four orders of magnitude, a range hundreds of times larger than was the case before artificial light. Nearly all of the study sites were polluted by artificial light. A non-linear relationship is observed between the sky brightness on clear and overcast nights, with a change in behavior near the rural to urban landuse transition. Overcast skies ranged from a third darker to almost 18 times brighter than clear. Clear sky radiances estimated by the World Atlas of Artificial Night Sky Brightness were found to be overestimated by ~25%; our dataset will play an important role in the calibration and ground truthing of future skyglow models. Most of the brightly lit sites darkened as the night progressed, typically by ~5% per hour. The great variation in skyglow radiance observed from site-to-site and with changing meteorological conditions underlines the need for a long-term international monitoring program. PMID:25673335

  18. Thinking, Creativity, and Artificial Intelligence.

    ERIC Educational Resources Information Center

    DeSiano, Michael; DeSiano, Salvatore

    This document provides an introduction to the relationship between the current knowledge of focused and creative thinking and artificial intelligence. A model for stages of focused and creative thinking gives: problem encounter/setting, preparation, concentration/incubation, clarification/generation and evaluation/judgment. While a computer can…

  19. Artificial Intelligence and Expert Systems.

    ERIC Educational Resources Information Center

    Lawlor, Joseph

    Artificial intelligence (AI) is the field of scientific inquiry concerned with designing machine systems that can simulate human mental processes. The field draws upon theoretical constructs from a wide variety of disciplines, including mathematics, psychology, linguistics, neurophysiology, computer science, and electronic engineering. Some of the…

  20. Artificial Intelligence and Science Education.

    ERIC Educational Resources Information Center

    Good, Ron

    1987-01-01

    Defines artificial intelligence (AI) in relation to intelligent computer-assisted instruction (ICAI) and science education. Provides a brief background of AI work, examples of expert systems, examples of ICAI work, and addresses problems facing AI workers that have implications for science education. Proposes a revised model of the Karplus/Renner…

  1. Artificial neural networks in medicine

    SciTech Connect

    Keller, P.E.

    1994-07-01

    This Technology Brief provides an overview of artificial neural networks (ANN). A definition and explanation of an ANN is given and situations in which an ANN is used are described. ANN applications to medicine specifically are then explored and the areas in which it is currently being used are discussed. Included are medical diagnostic aides, biochemical analysis, medical image analysis and drug development.

  2. Artificial-Satellite-Analysis Program

    NASA Technical Reports Server (NTRS)

    Kwok, Johnny H.

    1989-01-01

    Artificial Satellite Analysis Program (ASAP) is general orbit-predicting computer program incorporating sufficient orbit-modeling accuracy for design and planning of missions and analysis of maneuvers. Suitable for study of planetary-orbit missions with spacecraft trajectories of reconnaissance (flyby) and exploratory (mapping) nature. Not written for specific mission and intended use for almost any planetary orbiting mission. Written in FORTRAN 77.

  3. Artificial Intelligence Assists Ultrasonic Inspection

    NASA Technical Reports Server (NTRS)

    Schaefer, Lloyd A.; Willenberg, James D.

    1992-01-01

    Subtle indications of flaws extracted from ultrasonic waveforms. Ultrasonic-inspection system uses artificial intelligence to help in identification of hidden flaws in electron-beam-welded castings. System involves application of flaw-classification logic to analysis of ultrasonic waveforms.

  4. WASTEWATER TREATMENT BY ARTIFICIAL WETLANDS

    EPA Science Inventory

    Studies of artificial wetlands at Santee, California demonstrated the capacity of wetlands systems for integrated secondary and advanced treatment of municipal wastewaters. When receiving a blend of primary and secondary wastewaters at a blend ratio of 1:2 (6 cm per day: 12 cm pe...

  5. Radioactive and magnetic investigations

    NASA Technical Reports Server (NTRS)

    Heye, D.; Beiersdorf, H.

    1979-01-01

    Age and growth pattern determination of manganese nodules were explored. Two methods are discussed: (1) measurement of the presence of radioactive iodine isotopes; which is effective only up to 3.105 years, and (2) measurements of magnetism. The growth rates of three nodules were determined. The surface of the nodule was recent, and the overall age of the nodule could be determined with accuracy of better than 30%. Measurement of paleomagnetic effect was attempted to determine wider age ranges, however, the measured sign changes could not be interpreted as paleomagnetic reversals.

  6. Radioactive waste material disposal

    DOEpatents

    Forsberg, Charles W.; Beahm, Edward C.; Parker, George W.

    1995-01-01

    The invention is a process for direct conversion of solid radioactive waste, particularly spent nuclear fuel and its cladding, if any, into a solidified waste glass. A sacrificial metal oxide, dissolved in a glass bath, is used to oxidize elemental metal and any carbon values present in the waste as they are fed to the bath. Two different modes of operation are possible, depending on the sacrificial metal oxide employed. In the first mode, a regenerable sacrificial oxide, e.g., PbO, is employed, while the second mode features use of disposable oxides such as ferric oxide.

  7. Material for radioactive protection

    DOEpatents

    Taylor, R.S.; Boyer, N.W.

    A boron containing burn resistant, low-level radiation protection material useful, for example, as a liner for radioactive waste disposal and storage, a component for neutron absorber, and a shield for a neutron source is described. The material is basically composed of borax in the range of 25 to 50%, coal tar in the range of 25 to 37.5%, with the remainder being an epoxy resin mix. A preferred composition is 50% borax, 25% coal tar and 25% epoxy resin. The material is not susceptible to burning and is about 1/5 the cost of existing radiation protection material utilized in similar applications.

  8. RADIOACTIVE MATERIALS SENSORS

    SciTech Connect

    Mayo, Robert M.; Stephens, Daniel L.

    2009-09-15

    Providing technical means to detect, prevent, and reverse the threat of potential illicit use of radiological or nuclear materials is among the greatest challenges facing contemporary science and technology. In this short article, we provide brief description and overview of the state-of-the-art in sensor development for the detection of radioactive materials, as well as an identification of the technical needs and challenges faced by the detection community. We begin with a discussion of gamma-ray and neutron detectors and spectrometers, followed by a description of imaging sensors, active interrogation, and materials development, before closing with a brief discussion of the unique challenges posed in fielding sensor systems.

  9. Radioactive waste material disposal

    DOEpatents

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

    1995-10-24

    The invention is a process for direct conversion of solid radioactive waste, particularly spent nuclear fuel and its cladding, if any, into a solidified waste glass. A sacrificial metal oxide, dissolved in a glass bath, is used to oxidize elemental metal and any carbon values present in the waste as they are fed to the bath. Two different modes of operation are possible, depending on the sacrificial metal oxide employed. In the first mode, a regenerable sacrificial oxide, e.g., PbO, is employed, while the second mode features use of disposable oxides such as ferric oxide. 3 figs.

  10. Simpler radioactive wastewater processing.

    PubMed

    Rodríguez, José Canga; Luh, Volker

    2011-11-01

    José Canga Rodríguez, key account manager, Pharmaceutical and Life Sciences, EnviroChemie, and Volker Luh, CEO of EnviroDTS, describe the development, and recent successful application, of a new technology for dealing safely and effectively with the radioactive "wastewater" generated by patients who have undergone radiotherapy in nuclear medicine facilities. The BioChroma process provides what is reportedly not only a more flexible means than traditional "delay and decay" systems of dealing with this "by-product" of medical treatment, but also one that requires less plant space, affords less risk of leakage or cross-contamination, and is easier to install. PMID:22368885

  11. Study for radionuclide transfer ratio of aerosols generated during heat cutting

    SciTech Connect

    Iguchi, Yukihiro; Baba, Tsutomu; Kawakami, Hiroto; Kitahara, Takashi; Watanabe, Atsushi; Kodama, Mitsuhiro

    2007-07-01

    The metallic elements with a low melting point and high vapor pressure seemed to transfer in aerosols selectively at dismantling reactor internals using heat cutting. Therefore, the arc melting tests of neutron irradiated zirconium alloy were conducted to investigate the radionuclide transfer behavior of aerosols generated during the heat cutting of activated metals. The arc melting test was conducted using a tungsten inert gas welding machine in an inert gas or air atmosphere. The radioactive aerosols were collected by filter and charcoal filter. The test sample was obtained from Zry-2 fuel cladding irradiated in a Japanese boiling water reactor for five fuel cycles. The activity analysis, chemical composition measurement and scanning electron microscope observation of aerosols were carried out. Some radionuclides were enriched in the aerosols generated in an inert gas atmosphere and the radionuclide transfer ratio did not change remarkably by the presence of air. The transfer ratio of Sb-125 was almost the same as that of Co-60. It was expected that Sb-125 was enriched from other elements since Sb is an element with a low melting point and high vapor pressure compared with the base metal (Zr). In the viewpoint of the environmental impact assessment, it became clear that the influence if Sb-125 is comparable to Co-60. The transfer ratio of Mn-54 was one order higher compared with other radionuclides. The results were discussed on the basis of thermal properties and oxide formation energy of the metallic elements. (authors)

  12. Air ions and aerosol science

    NASA Astrophysics Data System (ADS)

    Tammet, Hannes

    1996-03-01

    Collaboration between Gas Discharge and Plasma Physics, Atmospheric Electricity, and Aerosol Science is a factor of success in the research of air ions. The concept of air ion as of any carrier of electrical current through the air is inherent to Atmospheric Electricity under which a considerable statistical information about the air ion mobility spectrum is collected. A new model of air ion size-mobility correlation has been developed proceeding from Aerosol Science and joining the methods of neighboring research fields. The predicted temperature variation of the mobility disagrees with the commonly used Langevin rule for the reduction of air ion mobilities to the standard conditions. Concurrent errors are too big to be neglected in applications. The critical diameter distinguishing cluster ions and charged aerosol particles has been estimated to be 1.4-1.8 nm.

  13. Measurements of Semi-volatile Aerosol and Its Effect on Aerosol Optical Properties During Southern Oxidant and Aerosol Study

    NASA Astrophysics Data System (ADS)

    Khlystov, A.; Grieshop, A. P.; Saha, P.; Subramanian, R.

    2013-12-01

    Semi-volatile compounds, including particle-bound water, comprise a large part of aerosol mass and have a significant influence on aerosol lifecycle and its optical properties. Understanding the properties of semi-volatile compounds, especially those pertaining to gas/aerosol partitioning, is of critical importance for our ability to predict concentrations and properties of ambient aerosol. A set of state-of-the-art instruments was deployed at the SEARCH site near Centerville, AL during the Southern Oxidant and Aerosol Study (SOAS) campaign in summer 2013 to measure the effect of temperature and relative humidity on aerosol size distribution, composition and optical properties. Light scattering and absorption by temperature- and humidity-conditioned aerosols was measured using three photo-acoustic extinctiometers (PAX) at three wavelengths (405 nm, 532 nm, and 870 nm). In parallel to these measurements, a long residence time temperature-stepping thermodenuder and a variable residence time constant temperature thermodenuder in combination with three SMPS systems and an Aerosol Chemical Speciation Monitor (ACSM) were used to assess aerosol volatility and kinetics of aerosol evaporation. It was found that both temperature and relative humidity have a strong effect on aerosol optical properties. The variable residence time thermodenuder data suggest that aerosol equilibrated fairly quickly, within 2 s, in contrast to other ambient observations. Preliminary analysis show that approximately 50% and 90% of total aerosol mass evaporated at temperatures of 100 C and 180C, respectively. Evaporation varied substantially with ambient aerosol loading and composition and meteorology. During course of this study, T50 (temperatures at which 50% aerosol mass evaporates) varied from 60 C to more than 120 C.

  14. Aerosol Measurement and Processing System (AMAPS)

    Atmospheric Science Data Center

    2016-03-22

    Description:  Access aerosol data from MISR and MODIS Subset Level-2 MISR granules by parameter and by space/time region Extract MISR aerosol data for overflights of specific geographic regions or ground site ... or concerns. Details:  Aerosol Measurement and Processing System (AMAPS) Screenshot:  ...

  15. Chemical Properties of Combustion Aerosols: An Overview

    EPA Science Inventory

    A wide variety of pyrogenic and anthropogenic sources emit fine aerosols to the atmosphere. The physical and chemical properties of these aerosols are of interest due to their influence on climate, human health, and visibility. Aerosol chemical composition is remarkably complex. ...

  16. Meeting Review: Airborne Aerosol Inlet Workshop

    NASA Technical Reports Server (NTRS)

    Baumgardner, Darrel; Huebert, Barry; Wilson, Chuck

    1991-01-01

    Proceedings from the Airborne Aerosol Inlet Workshop are presented. The two central topics of discussion were the role of aerosols in atmospheric processes and the difficulties in characterizing aerosols. The following topics were discussed during the working sessions: airborne observations to date; identification of inlet design issues; inlet modeling needs and directions; objectives for aircraft experiments; and future laboratory and wind tunnel studies.

  17. ATI TDA 5A aerosol generator evaluation

    SciTech Connect

    Gilles, D.A.

    1998-07-27

    Oil based aerosol ``Smoke`` commonly used for testing the efficiency and penetration of High Efficiency Particulate Air filters (HEPA) and HEPA systems can produce flammability hazards that may not have been previously considered. A combustion incident involving an aerosol generator has caused an investigation into the hazards of the aerosol used to test HEPA systems at Hanford.

  18. Levels of radioactivity in Qatar

    SciTech Connect

    Al-Thani, A.A.; Abdul-Majid, S.; Mohammed, K.

    1995-12-31

    The levels of natural and man-made radioactivity in soil and seabed were measured in Qatar to assess radiation exposure levels and to evaluate any radioactive contamination that may have reached the country from fallout or due to the Chernobyl accident radioactivity release. Qatar peninsula is located on the Arabian Gulf, 4500 km from Chernobyl, and has an area of {approximately}11,600 km{sup 2} and a population of {approximately}600,000.

  19. Reconstruction of passive open-path FTIR ambient spectra using meteorological measurements and its application for detection of aerosol cloud drift.

    PubMed

    Kira, Oz; Dubowski, Yael; Linker, Raphael

    2015-07-27

    Remote sensing of atmospheric aerosols is of great importance to public and environmental health. This research promotes a simple way of detecting an aerosol cloud using a passive Open Path FTIR (OP-FTIR) system, without utilizing radiative transfer models and without relying on an artificial light source. Meteorological measurements (temperature, relative humidity and solar irradiance), and chemometric methods (multiple linear regression and artificial neural networks) together with previous cloud-free OP-FTIR measurements were used to estimate the ambient spectrum in real time. The cloud detection process included a statistical comparison between the estimated cloud-free signal and the measured OP-FTIR signal. During the study we were able to successfully detect several aerosol clouds (water spray) in controlled conditions as well as during agricultural pesticide spraying in an orchard. PMID:26367691

  20. Aerosol Transport Over Equatorial Africa

    NASA Technical Reports Server (NTRS)

    Gatebe, C. K.; Tyson, P. D.; Annegarn, H. J.; Kinyua, A. M.; Piketh, S.; King, M.; Helas, G.

    1999-01-01

    Long-range and inter-hemispheric transport of atmospheric aerosols over equatorial Africa has received little attention so far. Most aerosol studies in the region have focussed on emissions from rain forest and savanna (both natural and biomass burning) and were carried out in the framework of programs such as DECAFE (Dynamique et Chimie Atmospherique en Foret Equatoriale) and FOS (Fires of Savanna). Considering the importance of this topic, aerosols samples were measured in different seasons at 4420 meters on Mt Kenya and on the equator. The study is based on continuous aerosol sampling on a two stage (fine and coarse) streaker sampler and elemental analysis by Particle Induced X-ray Emission. Continuous samples were collected for two seasons coinciding with late austral winter and early austral spring of 1997 and austral summer of 1998. Source area identification is by trajectory analysis and sources types by statistical techniques. Major meridional transports of material are observed with fine-fraction silicon (31 to 68 %) in aeolian dust and anthropogenic sulfur (9 to 18 %) being the major constituents of the total aerosol loading for the two seasons. Marine aerosol chlorine (4 to 6 %), potassium (3 to 5 %) and iron (1 to 2 %) make up the important components of the total material transport over Kenya. Minimum sulfur fluxes are associated with recirculation of sulfur-free air over equatorial Africa, while maximum sulfur concentrations are observed following passage over the industrial heartland of South Africa or transport over the Zambian/Congo Copperbelt. Chlorine is advected from the ocean and is accompanied by aeolian dust recirculating back to land from mid-oceanic regions. Biomass burning products are transported from the horn of Africa. Mineral dust from the Sahara is transported towards the Far East and then transported back within equatorial easterlies to Mt Kenya. This was observed during austral summer and coincided with the dying phase of 1997/98 El

  1. Determinants of Low Cloud Properties - An Artificial Neural Network Approach Using Observation Data Sets

    NASA Astrophysics Data System (ADS)

    Andersen, Hendrik; Cermak, Jan

    2015-04-01

    This contribution studies the determinants of low cloud properties based on the application of various global observation data sets in machine learning algorithms. Clouds play a crucial role in the climate system as their radiative properties and precipitation patterns significantly impact the Earth's energy balance. Cloud properties are determined by environmental conditions, as cloud formation requires the availability of water vapour ("precipitable water") and condensation nuclei in sufficiently saturated conditions. A main challenge in the research of aerosol-cloud interactions is the separation of aerosol effects from meteorological influence. To gain understanding of the processes that govern low cloud properties in order to increase accuracy of climate models and predictions of future changes in the climate system is thus of great importance. In this study, artificial neural networks are used to relate a selection of predictors (meteorological parameters, aerosol loading) to a set of predictands (cloud microphysical and optical properties). As meteorological parameters, wind direction and velocity, sea level pressure, static stability of the lower troposphere, atmospheric water vapour and temperature at the surface are used (re-analysis data by the European Centre for Medium-Range Weather Forecasts). In addition to meteorological conditions, aerosol loading is used as a predictor of cloud properties (MODIS collection 6 aerosol optical depth). The statistical model reveals significant relationships between predictors and predictands and is able to represent the aerosol-cloud-meteorology system better than frequently used bivariate relationships. The most important predictors can be identified by the additional error when excluding one predictor at a time. The sensitivity of each predictand to each of the predictors is analyzed.

  2. Coming Soon: A Wearable Artificial Kidney?

    MedlinePlus

    ... gov/news/fullstory_159246.html Coming Soon: A Wearable Artificial Kidney? Small trial suggests device might be ... themselves of clunky machines, moving about with a "wearable artificial kidney" instead. That's the promise of a ...

  3. Artificial Intelligence Databases: A Survey and Comparison.

    ERIC Educational Resources Information Center

    Stern, David

    1990-01-01

    Identifies and describes online databases containing references to materials on artificial intelligence, robotics, and expert systems, and compares them in terms of scope and usage. Recommendations for conducting online searches on artificial intelligence and related fields are offered. (CLB)

  4. Performance evaluation of the pilot-scale, double-shell tank ventilation system using simulated aerosol streams

    SciTech Connect

    Brouns, T.M.; Peterson, M.E.

    1989-12-01

    Radioactive waste slurries are currently being stored in underground tanks on the Hanford Site. The slurries that are being stored in the double-shell tanks (DSTs) are various mixtures of radioactive solids, liquids, and aqueous wastes. The tanks must be maintained at a negative pressure relative to atmospheric pressure to safeguard against pressurization and the subsequent leakage of entrained radioactive aerosols to the environment. A ventilation system must be capable of withdrawing the total volume of off gas generated from the tanks while maintaining the tanks at a negative pressure. Westinghouse Hanford Company (WHC) has identified a need to improve the efficiency of the ventilation system being used on the tank farms to meet the more restrictive release limits for radioactive isotopes. Kaiser Engineers Hanford Company (KEH) has been contracted by WHC to design the new ventilation system for the existing tank farms. WHC contracted the Pacific Northwest Laboratory (PNL) to fabricate and test the prototypic pilot-scale design prior to finalizing the design of the ventilation system. The PNL has conducted tests to determine (1) the effectiveness of the system for removal of vapors condensable at 35{degrees}F, (2) the effectiveness for removal of soluble and insoluble aerosols, and (3) the life span of the mist eliminators to be used in the new system. The results of extensive testing of the pilot-scale system with condensables and both soluble and insoluble aerosols are presented in this report. 7 refs., 25 figs., 8 tabs.

  5. Background stratospheric aerosol reference model

    NASA Astrophysics Data System (ADS)

    McCormick, M. P.; Wang, Pi-Huan

    Nearly global SAGE I satellite observations in the nonvolcanic period from March 1979 to February 1980 are used to produce a reference background stratospheric aerosol optical model. Zonally average profiles of the 1.0-micron aerosol extinction for the tropics, midlatitudes, and high latitudes for both hemispheres are given in graphical and tabulated form for the different seasons. A third order polynomial fit to the vertical profile data set is used to derive analytic expressions for the seasonal global means and the yearly global mean. The results have application to the simulation of atmospheric radiative transfer and radiance calculations in atmospheric remote sensing.

  6. Real time infrared aerosol analyzer

    DOEpatents

    Johnson, Stanley A.; Reedy, Gerald T.; Kumar, Romesh

    1990-01-01

    Apparatus for analyzing aerosols in essentially real time includes a virtual impactor which separates coarse particles from fine and ultrafine particles in an aerosol sample. The coarse and ultrafine particles are captured in PTFE filters, and the fine particles impact onto an internal light reflection element. The composition and quantity of the particles on the PTFE filter and on the internal reflection element are measured by alternately passing infrared light through the filter and the internal light reflection element, and analyzing the light through infrared spectrophotometry to identify the particles in the sample.

  7. Numerical Modelling of Gelating Aerosols

    SciTech Connect

    Babovsky, Hans

    2008-09-01

    The numerical simulation of the gel phase transition of an aerosol system is an interesting and demanding task. Here, we follow an approach first discussed in [6, 8] which turns out as a useful numerical tool. We investigate several improvements and generalizations. In the center of interest are coagulation diffusion systems, where the aerosol dynamics is supplemented with diffusive spreading in physical space. This leads to a variety of scenarios (depending on the coagulation kernel and the diffusion model) for the spatial evolution of the gelation area.

  8. Generation of a monodispersed aerosol

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

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

  9. Strategy to use the Terra Aerosol Information to Derive the Global Aerosol Radiative Forcing of Climate

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram J.; Tanre, Didier; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Terra will derive the aerosol optical thickness and properties. The aerosol properties can be used to distinguish between natural and human-made aerosol. In the polar orbit Terra will measure aerosol only once a day, around 10:30 am. How will we use this information to study the global radiative impacts of aerosol on climate? We shall present a strategy to address this problem. It includes the following steps: - From the Terra aerosol optical thickness and size distribution model we derive the effect of aerosol on reflection of solar radiation at the top of the atmosphere. In a sensitivity study we show that the effect of aerosol on solar fluxes can be derived 10 times more accurately from the MODIS data than derivation of the optical thickness itself. Applications to data over several regions will be given. - Using 1/2 million AERONET global data of aerosol spectral optical thickness we show that the aerosol optical thickness and properties during the Terra 10:30 pass are equivalent to the daily average. Due to the aerosol lifetime of several days measurements at this time of the day are enough to assess the daily impact of aerosol on radiation. - Aerosol impact on the top of the atmosphere is only part of the climate question. The INDOEX experiment showed that addressing the impact of aerosol on climate, requires also measurements of the aerosol forcing at the surface. This can be done by a combination of measurements of MODIS and AERONET data.

  10. Aerosolization, Chemical Characterization, Hygroscopicity and Ice Formation of Marine Biogenic Particles

    NASA Astrophysics Data System (ADS)

    Alpert, P. A.; Radway, J.; Kilthau, W.; Bothe, D.; Knopf, D. A.; Aller, J. Y.

    2013-12-01

    The oceans cover the majority of the earth's surface, host nearly half the total global primary productivity and are a major source of atmospheric aerosol particles. However, effects of biological activity on sea spray generation and composition, and subsequent cloud formation are not well understood. Our goal is to elucidate these effects which will be particularly important over nutrient rich seas, where microorganisms can reach concentrations of 10^9 per mL and along with transparent exopolymer particles (TEP) can become aerosolized. Here we report the results of mesocosm experiments in which bubbles were generated by two methods, either recirculating impinging water jets or glass frits, in natural or artificial seawater containing bacteria and unialgal cultures of three representative phytoplankton species, Thalassiosira pseudonana, Emiliania huxleyi, and Nannochloris atomus. Over time we followed the size distribution of aerosolized particles as well as their hygroscopicity, heterogeneous ice nucleation potential, and individual physical-chemical characteristics. Numbers of cells and the mass of dissolved and particulate organic carbon (DOC, POC), TEP (which includes polysaccharide-containing microgels and nanogels >0.4 μm in diameter) were determined in the bulk water, the surface microlayer, and aerosolized material. Aerosolized particles were also impacted onto substrates for ice nucleation and water uptake experiments, elemental analysis using computer controlled scanning electron microscopy and energy dispersive analysis of X-rays (CCSEM/EDX), and determination of carbon bonding with scanning transmission X-ray microscopy and near-edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Regardless of bubble generation method, the overall concentration of aerosol particles, TEP, POC and DOC increased as concentrations of bacterial and phytoplankton cells increased, stabilized, and subsequently declined. Particles <100 nm generated by means of jets

  11. Radioactive waste processing apparatus

    DOEpatents

    Nelson, Robert E.; Ziegler, Anton A.; Serino, David F.; Basnar, Paul J.

    1987-01-01

    Apparatus for use in processing radioactive waste materials for shipment and storage in solid form in a container is disclosed. The container includes a top, and an opening in the top which is smaller than the outer circumference of the container. The apparatus includes an enclosure into which the container is placed, solution feed apparatus for adding a solution containing radioactive waste materials into the container through the container opening, and at least one rotatable blade for blending the solution with a fixing agent such as cement or the like as the solution is added into the container. The blade is constructed so that it can pass through the opening in the top of the container. The rotational axis of the blade is displaced from the center of the blade so that after the blade passes through the opening, the blade and container can be adjusted so that one edge of the blade is adjacent the cylindrical wall of the container, to insure thorough mixing. When the blade is inside the container, a substantially sealed chamber is formed to contain vapors created by the chemical action of the waste solution and fixant, and vapors emanating through the opening in the container.

  12. Radioactivity in Urals

    NASA Astrophysics Data System (ADS)

    Interest in the problems due to the radioactive contamination of the environment has been frequently stimulated by rumors of an occurrence of severe contamination of lakes and rivers in areas of the Ural Mountains. Occasional evidence appearing in publications and provided by Soviet emigrants has been pieced together and seems to suggest that there is an ideal opportunity for groundwater geochemists and others to evaluate such major radioactivity in the environment. The reasons that such a study probably will not take place is that the contamination may have been caused for the most part by a nuclear explosion in a Soviet weapons plant.F. Parker, an environmental scientist at Vanderbilt University, in a study for the Department of Energy, deduced that a large explosion occurred in 1958 at a nuclear fuels reprocessing plant at Kyshtym in the Ural Mountains, according to a recent report (Science, July 8, 1983). The report refers to the original interpretations of Z. Medvedev, a Soviet geneticist, who concluded that nuclear fallout has contaminated a very extensive area around Kyshtym.

  13. Introduction to Concepts in Artificial Neural Networks

    NASA Technical Reports Server (NTRS)

    Niebur, Dagmar

    1995-01-01

    This introduction to artificial neural networks summarizes some basic concepts of computational neuroscience and the resulting models of artificial neurons. The terminology of biological and artificial neurons, biological and machine learning and neural processing is introduced. The concepts of supervised and unsupervised learning are explained with examples from the power system area. Finally, a taxonomy of different types of neurons and different classes of artificial neural networks is presented.

  14. Use Of Cosmogenic 35S To Trace The Uptake Process Of SO2 In Aerosols In The Atmosphere

    NASA Astrophysics Data System (ADS)

    Abramian, A.; Corbin, A.

    2008-12-01

    Environmental issues, such as acid rain and global warming, are linked to increased sulfur emissions and sulfate production in the atmosphere. Sulfate aerosol particles act as cloud condensation nuclei and can reduce the greenhouse effect by the indirect effect. Our understanding of the chemical and photochemical processes that govern the chemical transformations and transport of sulfur compounds in the atmosphere is still incomplete due to the complex, multivalent nature of sulfur and uncertainties in aerosol chemistry and transport (particularly trans-oceanic). We explore the use of cosmogenically produced 35S (half-life~87 days) to trace the uptake of SO2 gas into aerosols, as a function of aerosol size, in two different environments by simultaneously collecting and measuring [35SO42- ]and [35SO2]. These measurements can in turn be used to understand the time scales of SO2 oxidation to SO42-, aerosol 'age' and boundary layer dynamics. Aerosol samples are collected on glass fiber filters twice a week at Scripps Institute of Oceanography Pier in La Jolla, CA and the San Fernando Valley, CA for a 21-day period. SO2 (g) was collected on KOH impregnated filters placed after a 4-stage aerosol filter stack. We present preliminary results for both fine and coarse aerosol sulfate [35SO4] as well as [35SO2]. These measurements were done using low-noise liquid scintillation spectroscopy. By measuring the activity of each sample repeatedly over a period of 100 days, the exponential decay of 35S was observed, confirming the identity of the radioactive signal. The coastal and inland measurements are compared and implications for the atmospheric chemistry of SO2 and SO4 are discussed. Finally, we assess the potential of using [35SO4]/[nss-SO4] as a tracer of primary sulfate and trans-oceanic transport by coupling the measurements of the cation (Na+, Ca2+, K+, Mg2+, NH4+) and anion (Cl, NO3, SO4) concentrations in the aerosols.

  15. Solar fuels via artificial photosynthesis.

    PubMed

    Gust, Devens; Moore, Thomas A; Moore, Ana L

    2009-12-21

    Because sunlight is diffuse and intermittent, substantial use of solar energy to meet humanity's needs will probably require energy storage in dense, transportable media via chemical bonds. Practical, cost effective technologies for conversion of sunlight directly into useful fuels do not currently exist, and will require new basic science. Photosynthesis provides a blueprint for solar energy storage in fuels. Indeed, all of the fossil-fuel-based energy consumed today derives from sunlight harvested by photosynthetic organisms. Artificial photosynthesis research applies the fundamental scientific principles of the natural process to the design of solar energy conversion systems. These constructs use different materials, and researchers tune them to produce energy efficiently and in forms useful to humans. Fuel production via natural or artificial photosynthesis requires three main components. First, antenna/reaction center complexes absorb sunlight and convert the excitation energy to electrochemical energy (redox equivalents). Then, a water oxidation complex uses this redox potential to catalyze conversion of water to hydrogen ions, electrons stored as reducing equivalents, and oxygen. A second catalytic system uses the reducing equivalents to make fuels such as carbohydrates, lipids, or hydrogen gas. In this Account, we review a few general approaches to artificial photosynthetic fuel production that may be useful for eventually overcoming the energy problem. A variety of research groups have prepared artificial reaction center molecules. These systems contain a chromophore, such as a porphyrin, covalently linked to one or more electron acceptors, such as fullerenes or quinones, and secondary electron donors. Following the excitation of the chromophore, photoinduced electron transfer generates a primary charge-separated state. Electron transfer chains spatially separate the redox equivalents and reduce electronic coupling, slowing recombination of the charge

  16. Aerosols of Mongolian arid area

    NASA Astrophysics Data System (ADS)

    Golobokova, L.; Marinayte, I.; Zhamsueva, G.

    2012-04-01

    Sampling was performed in July-August 2005-2010 at Station Sain Shand (44°54'N, 110°07'E) in the Gobi desert (1000 m a.s.l.), West Mongolia. Aerosol samples were collected with a high volume sampler PM 10 (Andersen Instruments Inc., USA) onto Whatman-41 filters. The substance was extracted from the filters by de-ionized water. The solution was screened through an acetate-cellulose filter with 0.2 micron pore size. Ions of ammonium, sodium, potassium, magnesium, and calcium, as well as sulphate ions, nitrate ions, hydrocarbonate, chloride ions were determined in the filtrate by means of an atomic adsorption spectrometer Carl Zeiss Jena (Germany), a high performance liquid chromatographer «Milichrome A-02» (Russia), and an ionic chromatographer ICS-3000 (Dionex, USA). The PAH fraction was separated from aerosol samples using hexane extraction at room temperature under UV environment. The extract was concentrated to 0.1-0.2 ml and analysed by a mass-spectrometer "Agilent, GC 6890, MSD 5973 Network". Analysis of concentrations of aerosols components, their correlation ratios, and meteorological modeling show that the main factor affecting chemical composition of aerosols is a flow of contaminants transferred by air masses to the sampling area mainly from the south and south-east, as well as wind conditions of the area, dust storms in particular. Sulphate, nitrate, and ammonium are major ions in aerosol particles at Station Sain Shand. Dust-borne aerosol is known to be a sorbent for both mineral and organic admixtures. Polycyclic aromatic hydrocarbons (PAH) being among superecotoxicants play an important role among resistant organic substances. PAH concentrations were determined in the samples collected in 2010. All aerosol samples contained dominant PAHs with 5-6 benzene rings ( (benze(k)fluoranthen, benze(b)flouranthen, benze(a)pyren, benze(?)pyren, perylene, benze(g,h,i)perylene, and indene(1,2,3-c,d)pyrene). Their total quantity varied between 42 and 90

  17. 21 CFR 886.3200 - Artificial eye.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Artificial eye. 886.3200 Section 886.3200 Food and... OPHTHALMIC DEVICES Prosthetic Devices § 886.3200 Artificial eye. (a) Identification. An artificial eye is a device resembling the anterior portion of the eye, usually made of glass or plastic, intended to...

  18. 21 CFR 886.3200 - Artificial eye.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Artificial eye. 886.3200 Section 886.3200 Food and... OPHTHALMIC DEVICES Prosthetic Devices § 886.3200 Artificial eye. (a) Identification. An artificial eye is a device resembling the anterior portion of the eye, usually made of glass or plastic, intended to...

  19. Artificial Intelligence and Its Importance in Education.

    ERIC Educational Resources Information Center

    Tilmann, Martha J.

    Artificial intelligence, or the study of ideas that enable computers to be intelligent, is discussed in terms of what it is, what it has done, what it can do, and how it may affect the teaching of tomorrow. An extensive overview of artificial intelligence examines its goals and applications and types of artificial intelligence including (1) expert…

  20. Imaging of radioactive material and its host particle from the nuclear power plant accident in Japan by using imaging plate and electron microscopy

    NASA Astrophysics Data System (ADS)

    Adachi, Kouji; Zaizen, Yuji; Kimura, Tohru; Sakoh, Hiroshi; Igarashi, Yasuhito

    2013-04-01

    The Fukushima Daiichi Nuclear Power Plant accident in Japan on March, 2012, dispersed radioactive materials. In the Meteorological Research Institute, where locates 170 km south west from the power plant, we collected two types of filter aerosol samples and wet and dry deposition particles before and after the accident. Using these samples, we analyzed 1) radioactivity using an imaging plate (IP), which visualizes the radioactivity of samples in a two-dimensional plane with space resolution ~0.05 mm and 2) shape and compositions of particles that host radioactive materials using a scanning electron microscope (SEM) with energy-dispersive X-ray spectrometer (EDS). From the samples collected on March 15 and 21, we found radioactive spots on the filter samples using the IP, suggesting that radioactive materials, presumably Cs, were carried from the power plant. Radioactivity was also detected over the aggregates of dust particles in wet and dry deposition samples collected from March 2011. We did not find any detectable radioactive materials after the April when using the IP. We further investigated the radioactive spots using the SEM to identify the host particles of the radioactive materials and to detect radioactive materials from the EDS analysis. From the SEM analysis, we found that the particles on the filters include sulfate, mineral dust, and metals, but there were no particular particles or materials in the radioactive spots comparing to those in other area. The result suggests that the radioactive materials are hosted on the surface of other particles or inside them. We, so far, did not obtain any evidences that the radioactive materials are particulate with larger than 0.1 micro meter. Further analysis will need to identify the source of radioactive spots from individual particles using a manipulator as well as SEM and IP. Such studies will reveal where the radioactive materials exist in the environment, how they resuspend in the air, and how they could

  1. A thermoluminescent method for aerosol characterization

    NASA Technical Reports Server (NTRS)

    Long, E. R., Jr.; Rogowski, R. S.

    1976-01-01

    A thermoluminescent method has been used to study the interactions of aerosols with ozone. The preliminary results show that ozone reacts with many compounds found in aerosols, and that the thermoluminescence curves obtained from ozonated aerosols are characteristic of the aerosol. The results suggest several important applications of the thermoluminescent method: development of a detector for identification of effluent sources; a sensitive experimental tool for study of heterogeneous chemistry; evaluation of importance of aerosols in atmospheric chemistry; and study of formation of toxic, electronically excited species in airborne particles.

  2. Aerosol Microtops II sunphotometer observations over Ukraine

    NASA Astrophysics Data System (ADS)

    Bovchaliuk, V.; Bovchaliuk, A.; Milinevsky, G.; Danylevsky, V.; Sosonkin, M.; Goloub, Ph.

    2013-08-01

    Atmospheric aerosols and their impact on climate study are based on measurements by networks of ground-based instruments, satellite sensors, and measurements on portable sunphotometers. This paper presents the preliminary aerosol characteristics obtained during 2009-2012 using portable multi-wavelength Microtops II sunphotometer. Measurements were collected at different Ukraine sites in Kyiv, Odesa, Lugansk, Rivne, Chornobyl regions. The main aerosol characteristics, namely aerosol optical thickness (AOT) and Angstroem exponent, have been retrieved and analyzed. Aerosol data processing, filtering and calibration techniques are discussed in the paper.

  3. Contribution of methane to aerosol carbon mass

    NASA Astrophysics Data System (ADS)

    Bianchi, F.; Barmet, P.; Stirnweis, L.; El Haddad, I.; Platt, S. M.; Saurer, M.; Lötscher, C.; Siegwolf, R.; Bigi, A.; Hoyle, C. R.; DeCarlo, P. F.; Slowik, J. G.; Prévôt, A. S. H.; Baltensperger, U.; Dommen, J.

    2016-09-01

    Small volatile organic compounds (VOC) such as methane (CH4) have long been considered non-relevant to aerosol formation due to the high volatility of their oxidation products. However, even low aerosol yields from CH4, the most abundant VOC in the atmosphere, would contribute significantly to the total particulate carbon budget. In this study, organic aerosol (OA) mass yields from CH4 oxidation were evaluated at the Paul Scherrer Institute (PSI) smog chamber in the presence of inorganic and organic seed aerosols. Using labeled 13C methane, we could detect its oxidation products in the aerosol phase, with yields up to 0.09

  4. The Many Problems with Geoengineering Using Stratospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Robock, Alan

    2009-05-01

    In response to the global warming problem, there has been a recent renewed call for geoengineering ``solutions'' involving injecting particles into the stratosphere or blocking sunlight with satellites between the Sun and Earth. While volcanic eruptions have been suggested as innocuous examples of stratospheric aerosols cooling the planet, the volcano analog actually argues against geoengineering because of ozone depletion and regional hydrologic and temperature responses. In this talk, I consider the suggestion to create an artificial stratospheric aerosol layer. No systems to conduct geoengineering now exist, but a comparison of different proposed stratospheric injection schemes, airplanes, balloons, artillery, and a space elevator, shows that using airplanes would not be that expensive. We simulated the climate response to both tropical and Arctic stratospheric injection of sulfate aerosol precursors using a comprehensive atmosphere-ocean general circulation model, the National Aeronautics and Space Administration Goddard Institute for Space Studies ModelE. We simulated the injection of SO2 and the model converts it to sulfate aerosols, transports them and removes them through dry and wet deposition, and calculates the climate response to the radiative forcing from the aerosols. We conducted simulations of future climate with the Intergovernmental Panel on Climate Change A1B business-as-usual scenario both with and without geoengineering, and compare the results. We found that if there were a way to continuously inject SO2 into the lower stratosphere, it would produce global cooling. Acid deposition from the sulfate would not be enough to disturb most ecosystems. Tropical SO2 injection would produce sustained cooling over most of the world, with more cooling over continents. Arctic SO2 injection would not just cool the Arctic. But both tropical and Arctic SO2 injection would disrupt the Asian and African summer monsoons, reducing precipitation to the food supply

  5. Review of models applicable to accident aerosols

    SciTech Connect

    Glissmeyer, J.A.

    1983-07-01

    Estimations of potential airborne-particle releases are essential in safety assessments of nuclear-fuel facilities. This report is a review of aerosol behavior models that have potential applications for predicting aerosol characteristics in compartments containing accident-generated aerosol sources. Such characterization of the accident-generated aerosols is a necessary step toward estimating their eventual release in any accident scenario. Existing aerosol models can predict the size distribution, concentration, and composition of aerosols as they are acted on by ventilation, diffusion, gravity, coagulation, and other phenomena. Models developed in the fields of fluid mechanics, indoor air pollution, and nuclear-reactor accidents are reviewed with this nuclear fuel facility application in mind. The various capabilities of modeling aerosol behavior are tabulated and discussed, and recommendations are made for applying the models to problems of differing complexity.

  6. Aerosol generation by raindrop impact on soil

    NASA Astrophysics Data System (ADS)

    Joung, Young Soo; Buie, Cullen R.

    2015-01-01

    Aerosols are investigated because of their significant impact on the environment and human health. To date, windblown dust and sea salt from sea spray through bursting bubbles have been considered the chief mechanisms of environmental aerosol dispersion. Here we investigate aerosol generation from droplets hitting wettable porous surfaces including various classifications of soil. We demonstrate that droplets can release aerosols when they influence porous surfaces, and these aerosols can deliver elements of the porous medium to the environment. Experiments on various porous media including soil and engineering materials reveal that knowledge of the surface properties and impact conditions can be used to predict when frenzied aerosol generation will occur. This study highlights new phenomena associated with droplets on porous media that could have implications for the investigation of aerosol generation in the environment.

  7. Standard aerosols for particle velocimeters

    NASA Technical Reports Server (NTRS)

    Deepark, A.; Ozarski, R.; Thomson, J. A. L.

    1976-01-01

    System consists of laser-scattering counter (LSC) and photographic system. Photographic system provides absolute method of measuring aerosol size-distribution independently of their light scattering properties. LSC comprises 1-mW He/Ne laser, input optics, collecting optics, photodetector, and signal-processing electronics.

  8. PIXE Analysis of Indoor Aerosols

    NASA Astrophysics Data System (ADS)

    Johnson, Christopher; Turley, Colin; Moore, Robert; Battaglia, Maria; Labrake, Scott; Vineyard, Michael

    2011-10-01

    We have performed a proton-induced X-ray emission (PIXE) analysis of aerosol samples collected in academic buildings at Union College to investigate the air quality in these buildings and the effectiveness of their air filtration systems. This is also the commissioning experiment for a new scattering chamber in the Union College Ion-Beam Analysis Laboratory. The aerosol samples were collected on Kapton foils using a nine-stage cascade impactor that separates particles according to their aerodynamic size. The foils were bombarded with beams of 2.2-MeV protons from the Union College 1.1-MV Pelletron Accelerator and the X-ray products were detected with an Amptek silicon drift detector. After subtracting the contribution from the Kapton foils, the X-ray energy spectra of the aerosol samples were analyzed using GUPIX software to determine the elemental concentrations of the samples. We will describe the collection of the aerosol samples, discuss the PIXE analysis, and present the results.

  9. Immunization by a bacterial aerosol.

    PubMed

    Garcia-Contreras, Lucila; Wong, Yun-Ling; Muttil, Pavan; Padilla, Danielle; Sadoff, Jerry; Derousse, Jessica; Germishuizen, Willem Andreas; Goonesekera, Sunali; Elbert, Katharina; Bloom, Barry R; Miller, Rich; Fourie, P Bernard; Hickey, Anthony; Edwards, David

    2008-03-25

    By manufacturing a single-particle system in two particulate forms (i.e., micrometer size and nanometer size), we have designed a bacterial vaccine form that exhibits improved efficacy of immunization. Microstructural properties are adapted to alter dispersive and aerosol properties independently. Dried "nanomicroparticle" vaccines possess two axes of nanoscale dimensions and a third axis of micrometer dimension; the last one permits effective micrometer-like physical dispersion, and the former provides alignment of the principal nanodimension particle axes with the direction of airflow. Particles formed with this combination of nano- and micrometer-scale dimensions possess a greater ability to aerosolize than particles of standard spherical isotropic shape and of similar geometric diameter. Here, we demonstrate effective application of this biomaterial by using the live attenuated tuberculosis vaccine bacille Calmette-Guérin (BCG). Prepared as a spray-dried nanomicroparticle aerosol, BCG vaccine exhibited high-efficiency delivery and peripheral lung targeting capacity from a low-cost and technically simple delivery system. Aerosol delivery of the BCG nanomicroparticle to normal guinea pigs subsequently challenged with virulent Mycobacterium tuberculosis significantly reduced bacterial burden and lung pathology both relative to untreated animals and to control animals immunized with the standard parenteral BCG. PMID:18344320

  10. Airborne Atmospheric Aerosol Measurement System

    NASA Astrophysics Data System (ADS)

    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).

  11. Zero-gravity aerosol behavior

    NASA Technical Reports Server (NTRS)

    Edwards, H. W.

    1981-01-01

    The feasibility and scientific benefits of a zero gravity aerosol study in an orbiting laboratory were examined. A macroscopic model was devised to deal with the simultaneous effects of diffusion and coagulation of particles in the confined aerosol. An analytical solution was found by treating the particle coagulation and diffusion constants as ensemble parameters and employing a transformation of variables. The solution was used to carry out simulated zero gravity aerosol decay experiments in a compact cylindrical chamber. The results demonstrate that the limitations of physical space and time imposed by the orbital situation are not prohibitive in terms of observing the history of an aerosol confined under zero gravity conditions. While the absence of convective effects would be a definite benefit for the experiment, the mathematical complexity of the problem is not greatly reduced when the gravitational term drops out of the equation. Since the model does not deal directly with the evolution of the particle size distribution, it may be desirable to develop more detailed models before undertaking an orbital experiment.

  12. Near UV Aerosol Group Report

    NASA Technical Reports Server (NTRS)

    Torres, Omar

    2013-01-01

    2012-13 Report of research on aerosol and cloud remote sensing using UV observations. The document was presented at the 2013 AEROCENTER Annual Meeting held at the GSFC Visitors Center, May 31, 2013. The Organizers of the meeting are posting the talks to the public Aerocentr website, after the meeting.

  13. Aerosol backscatter studies supporting LAWS

    NASA Technical Reports Server (NTRS)

    Rothermel, Jeffry

    1989-01-01

    Optimized Royal Signals and Radar Establishment (RSRE), Laser True Airspeed System (LATAS) algorithm for low backscatter conditions was developed. The algorithm converts backscatter intensity measurements from focused continuous-wave (CW) airborne Doppler lidar into backscatter coefficients. The performance of optimized algorithm under marginal backscatter signal conditions was evaluated. The 10.6 micron CO2 aerosol backscatter climatologies were statistically analyzed. Climatologies reveal clean background aerosol mode near 10(exp -10)/kg/sq m/sr (mixing ratio units) through middle and upper troposhere, convective mode associated with planetary boundary layer convective activity, and stratospheric mode associated with volcanically-generated aerosols. Properties of clean background mode are critical to design and simulation studies of Laser Atmospheric Wind Sounder (LAWS), a MSFC facility Instrument on the Earth Observing System (Eos). Previous intercomparisons suggested correlation between aerosol backscatter at CO2 wavelength and water vapor. Field measurements of backscatter profiles with MSFC ground-based Doppler lidar system (GBDLS) were initiated in late FY-88 to coincide with independent program of local rawinsonde releases and overflights by Multi-spectral Atmospheric Mapping Sensor (MAMS), a multi-channel infrared radiometer capable of measuring horizontal and vertical moisture distributions. Design and performance simulation studies for LAWS would benefit from the existence of a relationship between backscatter and water vapor.

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    additions of important diagnostic information. At the same time as we have introduced algorithm changes, we have also accounted for upstream changes including: new instrument calibration, revised land-sea masking, and changed cloud masking. Upstream changes also impact the coverage and global statistics of the retrieved AOD. Although our responsibility is to the DT code and products, we have also added a product that merges DT and DB product over semi-arid land surfaces to provide a more gap-free dataset, primarily for visualization purposes. Preliminary validation shows that compared to surface-based sunphotometer data, the C6, Level 2 (along swath) DT-products compare at least as well as those from C5. C6 will include new diagnostic information about clouds in the aerosol field, including an aerosol cloud mask at 500 m resolution, and calculations of the distance to the nearest cloud from clear pixels. Finally, we have revised the strategy for aggregating and averaging the Level 2 (swath) data to become Level 3 (gridded) data. All together, the changes to the DT algorithms will result in reduced global AOD (by 0.02) over ocean and increased AOD (by 0.02) over land, along with changes in spatial coverage. Changes in calibration will have more impact to Terras time series, especially over land. This will result in a significant reduction in artificial differences in the Terra and Aqua datasets, and will stabilize the MODIS data as a target for AEROCOM studie

  15. Stefan Meyer: Pioneer of Radioactivity

    NASA Astrophysics Data System (ADS)

    Reiter, Wolfgang L.

    2001-03-01

    Stefan Meyer was one of the pioneers in radioactivity research and director of the Vienna Radium Institute, the first institution in the world devoted exclusively to radioactivity. I give here a biographical sketch of Meyer and of some of his colleagues and an overview of the research activities at the Radium Institute.

  16. Radioactive elements in stellar atmospheres

    SciTech Connect

    Gopka, Vira; Yushchenko, Alexander; Goriely, Stephane; Shavrina, Angelina; Kang, Young Woon

    2006-07-12

    The identification of lines of radioactive elements (Tc, Pm and elements with 83radioactive decay of Th and U in the upper levels of stellar atmospheres, contamination of stellar atmosphere by recent SN explosion, and spallation reactions.

  17. Rewritable artificial magnetic charge ice.

    PubMed

    Wang, Yong-Lei; Xiao, Zhi-Li; Snezhko, Alexey; Xu, Jing; Ocola, Leonidas E; Divan, Ralu; Pearson, John E; Crabtree, George W; Kwok, Wai-Kwong

    2016-05-20

    Artificial ices enable the study of geometrical frustration by design and through direct observation. However, it has proven difficult to achieve tailored long-range ordering of their diverse configurations, limiting both fundamental and applied research directions. We designed an artificial spin structure that produces a magnetic charge ice with tunable long-range ordering of eight different configurations. We also developed a technique to precisely manipulate the local magnetic charge states and demonstrate write-read-erase multifunctionality at room temperature. This globally reconfigurable and locally writable magnetic charge ice could provide a setting for designing magnetic monopole defects, tailoring magnonics, and controlling the properties of other two-dimensional materials. PMID:27199423

  18. Fuel-powered artificial muscles.

    PubMed

    Ebron, Von Howard; Yang, Zhiwei; Seyer, Daniel J; Kozlov, Mikhail E; Oh, Jiyoung; Xie, Hui; Razal, Joselito; Hall, Lee J; Ferraris, John P; Macdiarmid, Alan G; Baughman, Ray H

    2006-03-17

    Artificial muscles and electric motors found in autonomous robots and prosthetic limbs are typically battery-powered, which severely restricts the duration of their performance and can necessitate long inactivity during battery recharge. To help solve these problems, we demonstrated two types of artificial muscles that convert the chemical energy of high-energy-density fuels to mechanical energy. The first type stores electrical charge and uses changes in stored charge for mechanical actuation. In contrast with electrically powered electrochemical muscles, only half of the actuator cycle is electrochemical. The second type of fuel-powered muscle provides a demonstrated actuator stroke and power density comparable to those of natural skeletal muscle and generated stresses that are over a hundred times higher. PMID:16543453

  19. Artificial graphene with tunable interactions.

    PubMed

    Uehlinger, Thomas; Jotzu, Gregor; Messer, Michael; Greif, Daniel; Hofstetter, Walter; Bissbort, Ulf; Esslinger, Tilman

    2013-11-01

    We create an artificial graphene system with tunable interactions and study the crossover from metallic to Mott insulating regimes, both in isolated and coupled two-dimensional honeycomb layers. The artificial graphene consists of a two-component spin mixture of an ultracold atomic Fermi gas loaded into a hexagonal optical lattice. For strong repulsive interactions, we observe a suppression of double occupancy and measure a gapped excitation spectrum. We present a quantitative comparison between our measurements and theory, making use of a novel numerical method to obtain Wannier functions for complex lattice structures. Extending our studies to time-resolved measurements, we investigate the equilibration of the double occupancy as a function of lattice loading time. PMID:24237536

  20. Economic reasoning and artificial intelligence.

    PubMed

    Parkes, David C; Wellman, Michael P

    2015-07-17

    The field of artificial intelligence (AI) strives to build rational agents capable of perceiving the world around them and taking actions to advance specified goals. Put another way, AI researchers aim to construct a synthetic homo economicus, the mythical perfectly rational agent of neoclassical economics. We review progress toward creating this new species of machine, machina economicus, and discuss some challenges in designing AIs that can reason effectively in economic contexts. Supposing that AI succeeds in this quest, or at least comes close enough that it is useful to think about AIs in rationalistic terms, we ask how to design the rules of interaction in multi-agent systems that come to represent an economy of AIs. Theories of normative design from economics may prove more relevant for artificial agents than human agents, with AIs that better respect idealized assumptions of rationality than people, interacting through novel rules and incentive systems quite distinct from those tailored for people. PMID:26185245

  1. Torsional Carbon Nanotube Artificial Muscles

    NASA Astrophysics Data System (ADS)

    Foroughi, Javad; Spinks, Geoffrey M.; Wallace, Gordon G.; Oh, Jiyoung; Kozlov, Mikhail E.; Fang, Shaoli; Mirfakhrai, Tissaphern; Madden, John D. W.; Shin, Min Kyoon; Kim, Seon Jeong; Baughman, Ray H.

    2011-10-01

    Rotary motors of conventional design can be rather complex and are therefore difficult to miniaturize; previous carbon nanotube artificial muscles provide contraction and bending, but not rotation. We show that an electrolyte-filled twist-spun carbon nanotube yarn, much thinner than a human hair, functions as a torsional artificial muscle in a simple three-electrode electrochemical system, providing a reversible 15,000° rotation and 590 revolutions per minute. A hydrostatic actuation mechanism, as seen in muscular hydrostats in nature, explains the simultaneous occurrence of lengthwise contraction and torsional rotation during the yarn volume increase caused by electrochemical double-layer charge injection. The use of a torsional yarn muscle as a mixer for a fluidic chip is demonstrated.

  2. Determination of the bioaccessible fraction of metals in urban aerosol using simulated lung fluids

    NASA Astrophysics Data System (ADS)

    Coufalík, Pavel; Mikuška, Pavel; Matoušek, Tomáš; Večeřa, Zbyněk

    2016-09-01

    Determination of the bioaccessible fraction of metals in atmospheric aerosol is a significant issue with respect to air pollution in the urban environment. The aim of this work was to compare of metal bioaccessibility determined according to the extraction yields of six simulated lung fluids. Aerosol samples of the PM1 fraction were collected in Brno, Czech Republic. The total contents of Cd, Ce, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn in the samples were determined and their enrichment factors were calculated. The bioaccessible proportions of elements were determined by means of extraction in Gamble's solution, Gamble's solution with dipalmitoyl phosphatidyl choline (DPPC), artificial lysosomal fluid, saline, water, and in a newly proposed solution based on DPPC, referred to as "Simulated Alveoli Fluid" (SAF). The chemical composition and surface tension of the simulated lung fluids were the main parameters influencing extraction yields. Gamble's solutions and the newly designed solution of SAF exhibited the lowest extraction efficiency, and also had the lowest surface tensions. The bioaccessibility of particulate metals should be assessed by synthetic lung fluids with a low surface tension, which simulate better the behavior and composition of native lung surfactant. The bioaccessibility of metals in aerosol assessed by means of the extraction in water or artificial lysosomal fluid can be overestimated.

  3. Reconstitution of Heme Enzymes with Artificial Metalloporphyrinoids.

    PubMed

    Oohora, K; Hayashi, T

    2016-01-01

    An important strategy used in engineering of hemoproteins to generate artificial enzymes involves replacement of heme with an artificial cofactor after removal of the native heme cofactor under acidic conditions. Replacement of heme in an enzyme with a nonnatural metalloporphyrinoid can significantly alter the reactivity of the enzyme. This chapter describes the design and synthesis of three types of artificial metalloporphyrinoid cofactors consisting of mono-, di-, and tri-anionic ligands (tetradehydrocorrin, porphycene, and corrole, respectively). In addition, practical procedures for the preparation of apo-hemoproteins, incorporation of artificial cofactors, and characterization techniques are presented. Furthermore, the representative catalytic activities of artificial enzymes generated by reconstitution of hemoproteins are summarized. PMID:27586344

  4. Aerosol Absorption Measurements in MILAGRO.

    NASA Astrophysics Data System (ADS)

    Gaffney, J. S.; Marley, N. A.; Arnott, W. P.; Paredes-Miranda, L.; Barnard, J. C.

    2007-12-01

    During the month of March 2006, a number of instruments were used to determine the absorption characteristics of aerosols found in the Mexico City Megacity and nearby Valley of Mexico. These measurements were taken as part of the Department of Energy's Megacity Aerosol Experiment - Mexico City (MAX-Mex) that was carried out in collaboration with the Megacity Interactions: Local and Global Research Observations (MILAGRO) campaign. MILAGRO was a joint effort between the DOE, NSF, NASA, and Mexican agencies aimed at understanding the impacts of a megacity on the urban and regional scale. A super-site was operated at the Instituto Mexicano de Petroleo in Mexico City (designated T-0) and at the Universidad Technologica de Tecamac (designated T-1) that was located about 35 km to the north east of the T-0 site in the State of Mexico. A third site was located at a private rancho in the State of Hidalgo approximately another 35 km to the northeast (designated T-2). Aerosol absorption measurements were taken in real time using a number of instruments at the T-0 and T-1 sites. These included a seven wavelength aethalometer, a multi-angle absorption photometer (MAAP), and a photo-acoustic spectrometer. Aerosol absorption was also derived from spectral radiometers including a multi-filter rotating band spectral radiometer (MFRSR). The results clearly indicate that there is significant aerosol absorption by the aerosols in the Mexico City megacity region. The absorption can lead to single scattering albedo reduction leading to values below 0.5 under some circumstances. The absorption is also found to deviate from that expected for a "well-behaved" soot anticipated from diesel engine emissions, i.e. from a simple 1/lambda wavelength dependence for absorption. Indeed, enhanced absorption is seen in the region of 300-450 nm in many cases, particularly in the afternoon periods indicating that secondary organic aerosols are contributing to the aerosol absorption. This is likely due

  5. Heavy fragment radioactivities

    SciTech Connect

    Price, P.B.

    1987-12-10

    This recently discovered mode of radioactive decay, like alpha decay and spontaneous fission, is believed to involve tunneling through the deformation-energy barrier between a very heavy nucleus and two separated fragments the sum of whose masses is less than the mass of the parent nucleus. In all known cases the heavier of the two fragments is close to doubly magic /sup 208/Pb, and the lighter fragment has even Z. Four isotopes of Ra are known to emit /sup 14/C nuclei; several isotopes of U as well as /sup 230/Th and /sup 231/Pa emit Ne nuclei; and /sup 234/U exhibits four hadronic decay modes: alpha decay, spontaneous fission, Ne decay and Mg decay.

  6. Comparison of Artificial Compressibility Methods

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Housman, Jeffrey; Kwak, Dochan

    2003-01-01

    Various artificial compressibility methods for calculating three-dimensional, steady and unsteady, laminar and turbulent, incompressible Navier-Stokes equations are compared in this work. Each method is described in detail along with appropriate physical and numerical boundary conditions. Analysis of well-posedness and numerical solutions to test problems for each method are provided. A comparison based on convergence behavior, accuracy, stability and robustness is used to establish the relative positive and negative characteristics of each method.

  7. Automated Scheduling Via Artificial Intelligence

    NASA Technical Reports Server (NTRS)

    Biefeld, Eric W.; Cooper, Lynne P.

    1991-01-01

    Artificial-intelligence software that automates scheduling developed in Operations Mission Planner (OMP) research project. Software used in both generation of new schedules and modification of existing schedules in view of changes in tasks and/or available resources. Approach based on iterative refinement. Although project focused upon scheduling of operations of scientific instruments and other equipment aboard spacecraft, also applicable to such terrestrial problems as scheduling production in factory.

  8. Artificial anisotropy and polarizing filters

    NASA Astrophysics Data System (ADS)

    Flory, Francois; Escoubas, Ludovic; Lazarides, Basile

    2002-06-01

    The calculated spectral transmittance of a multilayer laser mirror is used to determine the effective index of the single layer equivalent to the multilayer stack. We measure the artificial anisotropy of photoresist thin films whose structure is a one-dimensional, subwavelength grating obtained from interference fringes. The limitation of the theory of the first-order effective index homogenization is discussed. We designed normal-incidence, polarizing coating and a polarization rotator by embedding anisotropic films in simple multilayer structures.

  9. The MODIS Aerosol Algorithm, Products and Validation

    NASA Technical Reports Server (NTRS)

    Remer, L. A.; Kaufman, Y. J.; Tanre, D.; Mattoo, S.; Chu, D. A.; Martins, J. V.; Li, R.-R.; Ichoku, C.; Levy, R. C.; Kleidman, R. G.

    2003-01-01

    The MODerate resolution Imaging Spectroradiometer (MODIS) aboard both NASA's Terra and Aqua satellites is making near global daily observations of the earth in a wide spectral range. These measurements are used to derive spectral aerosol optical thickness and aerosol size parameters over both land and ocean. The aerosol products available over land include aerosol optical thickness at three visible wavelengths, a measure of the fraction of aerosol optical thickness attributed to the fine mode and several derived parameters including reflected spectral solar flux at top of atmosphere. Over ocean, the aerosol optical thickness is provided in seven wavelengths from 0.47 microns to 2.13 microns. In addition, quantitative aerosol size information includes effective radius of the aerosol and quantitative fraction of optical thickness attributed to the fine mode. Spectral aerosol flux, mass concentration and number of cloud condensation nuclei round out the list of available aerosol products over the ocean. The spectral optical thickness and effective radius of the aerosol over the ocean are validated by comparison with two years of AERONET data gleaned from 133 AERONET stations. 8000 MODIS aerosol retrievals colocated with AERONET measurements confirm that one-standard deviation of MODIS optical thickness retrievals fall within the predicted uncertainty of delta tauapproximately equal to plus or minus 0.03 plus or minus 0.05 tau over ocean and delta tay equal to plus or minus 0.05 plus or minus 0.15 tau over land. 271 MODIS aerosol retrievals co-located with AERONET inversions at island and coastal sites suggest that one-standard deviation of MODIS effective radius retrievals falls within delta r_eff approximately equal to 0.11 microns. The accuracy of the MODIS retrievals suggests that the product can be used to help narrow the uncertainties associated with aerosol radiative forcing of global climate.

  10. Seasonality of Forcing by Carbonaceous Aerosols

    NASA Astrophysics Data System (ADS)

    Habib, G.; Bond, T.; Rasch, P. J.; Coleman, D.

    2006-12-01

    Aerosols can influence the energy balance of Earth-Atmosphere system with profound effect on regional climate. Atmospheric processes, such as convection, scavenging, wet and dry deposition, govern the lifetime and location of aerosol; emissions affect its quantity and location. Both affect climate forcing. Here we investigate the effect of seasonality in emissions and atmospheric processes on radiative forcing by carbonaceous aerosols, focusing on aerosol from fossil fuel and biofuel. Because aerosol lifetime is seasonal, ignoring the seasonality of sources such as residential biofuel may introduce a bias in aerosol burden and therefore in predicted climate forcing. We present a global emission inventory of carbonaceous aerosols with seasonality, and simulate atmospheric concentrations using the Community Atmosphere Model (CAM). We discuss where and when the seasonality of emissions and atmospheric processes has strong effects on atmospheric burden, lifetime, climate forcing and aerosol optical depth (AOD). Previous work has shown that aerosol forcing is higher in summer than in winter, and has identified the importance of aerosol above cloud in determining black carbon forcing. We show that predicted cloud height is a very important factor in determining normalized radiative forcing (forcing per mass), especially in summer. This can affect the average summer radiative forcing by nearly 50%. Removal by cloud droplets is the dominant atmospheric cleansing mechanism for carbonaceous aerosols. We demonstrate the modeled seasonality of removal processes and compare the importance of scavenging by warm and cold clouds. Both types of clouds contribute significantly to aerosol removal. We estimate uncertainty in direct radiative forcing due to scavenging by tagging the aerosol which has experienced cloud interactions. Finally, seasonal variations offer an opportunity to assess modeled processes when a single process dominates variability. We identify regions where aerosol

  11. Radioactive waste processing apparatus

    DOEpatents

    Nelson, R.E.; Ziegler, A.A.; Serino, D.F.; Basnar, P.J.

    1985-08-30

    Apparatus for use in processing radioactive waste materials for shipment and storage in solid form in a container is disclosed. The container includes a top, and an opening in the top which is smaller than the outer circumference of the container. The apparatus includes an enclosure into which the container is placed, solution feed apparatus for adding a solution containing radioactive waste materials into the container through the container opening, and at least one rotatable blade for blending the solution with a fixing agent such as cement or the like as the solution is added into the container. The blade is constructed so that it can pass through the opening in the top of the container. The rotational axis of the blade is displaced from the center of the blade so that after the blade passes through the opening, the blade and container can be adjusted so that one edge of the blade is adjacent the cylindrical wall of the container, to insure thorough mixing. When the blade is inside the container, a substantially sealed chamber is formed to contain vapors created by the chemical action of the waste solution and fixant, and vapors emanating through the opening in the container. The chamber may be formed by placing a removable extension over the top of the container. The extension communicates with the apparatus so that such vapors are contained within the container, extension and solution feed apparatus. A portion of the chamber includes coolant which condenses the vapors. The resulting condensate is returned to the container by the force of gravity.

  12. Miniature curved artificial compound eyes

    PubMed Central

    Floreano, Dario; Pericet-Camara, Ramon; Viollet, Stéphane; Ruffier, Franck; Brückner, Andreas; Leitel, Robert; Buss, Wolfgang; Menouni, Mohsine; Expert, Fabien; Juston, Raphaël; Dobrzynski, Michal Karol; L’Eplattenier, Geraud; Recktenwald, Fabian; Mallot, Hanspeter A.; Franceschini, Nicolas

    2013-01-01

    In most animal species, vision is mediated by compound eyes, which offer lower resolution than vertebrate single-lens eyes, but significantly larger fields of view with negligible distortion and spherical aberration, as well as high temporal resolution in a tiny package. Compound eyes are ideally suited for fast panoramic motion perception. Engineering a miniature artificial compound eye is challenging because it requires accurate alignment of photoreceptive and optical components on a curved surface. Here, we describe a unique design method for biomimetic compound eyes featuring a panoramic, undistorted field of view in a very thin package. The design consists of three planar layers of separately produced arrays, namely, a microlens array, a neuromorphic photodetector array, and a flexible printed circuit board that are stacked, cut, and curved to produce a mechanically flexible imager. Following this method, we have prototyped and characterized an artificial compound eye bearing a hemispherical field of view with embedded and programmable low-power signal processing, high temporal resolution, and local adaptation to illumination. The prototyped artificial compound eye possesses several characteristics similar to the eye of the fruit fly Drosophila and other arthropod species. This design method opens up additional vistas for a broad range of applications in which wide field motion detection is at a premium, such as collision-free navigation of terrestrial and aerospace vehicles, and for the experimental testing of insect vision theories. PMID:23690574

  13. Miniature curved artificial compound eyes.

    PubMed

    Floreano, Dario; Pericet-Camara, Ramon; Viollet, Stéphane; Ruffier, Franck; Brückner, Andreas; Leitel, Robert; Buss, Wolfgang; Menouni, Mohsine; Expert, Fabien; Juston, Raphaël; Dobrzynski, Michal Karol; L'Eplattenier, Geraud; Recktenwald, Fabian; Mallot, Hanspeter A; Franceschini, Nicolas

    2013-06-01

    In most animal species, vision is mediated by compound eyes, which offer lower resolution than vertebrate single-lens eyes, but significantly larger fields of view with negligible distortion and spherical aberration, as well as high temporal resolution in a tiny package. Compound eyes are ideally suited for fast panoramic motion perception. Engineering a miniature artificial compound eye is challenging because it requires accurate alignment of photoreceptive and optical components on a curved surface. Here, we describe a unique design method for biomimetic compound eyes featuring a panoramic, undistorted field of view in a very thin package. The design consists of three planar layers of separately produced arrays, namely, a microlens array, a neuromorphic photodetector array, and a flexible printed circuit board that are stacked, cut, and curved to produce a mechanically flexible imager. Following this method, we have prototyped and characterized an artificial compound eye bearing a hemispherical field of view with embedded and programmable low-power signal processing, high temporal resolution, and local adaptation to illumination. The prototyped artificial compound eye possesses several characteristics similar to the eye of the fruit fly Drosophila and other arthropod species. This design method opens up additional vistas for a broad range of applications in which wide field motion detection is at a premium, such as collision-free navigation of terrestrial and aerospace vehicles, and for the experimental testing of insect vision theories. PMID:23690574

  14. Bioinspired artificial single ion pump.

    PubMed

    Zhang, Huacheng; Hou, Xu; Zeng, Lu; Yang, Fu; Li, Lin; Yan, Dadong; Tian, Ye; Jiang, Lei

    2013-10-30

    Bioinspired artificial functional nanochannels for intelligent molecular and ionic transport control at the nanoscale have wide potential applications in nanofluidics, energy conversion, and biosensors. Although various smart passive ion transport properties of ion channels have been artificially realized, it is still hugely challenging to achieve high level intelligent ion transport features in biological ion pumps. Here we show a unique bioinspired single ion pump based on a cooperative pH response double-gate nanochannel, whose gates could be opened and closed alternately/simultaneously under symmetric/asymmetric pH environments. With the stimulation of the double-gate nanochannel by continuous switching of the symmetric/asymmetric pH stimuli, the bioinspired system systematically realized three key ionic transport features of biological ion pumps, including an alternating gates ion pumping process under symmetric pH stimuli, transformation of the ion pump into an ion channel under asymmetric pH stimuli, and a fail-safe ion pumping feature under both symmetric and asymmetric pH stimuli. The ion pumping processes could well be reproduced under a concentration gradient. With the advantages of the extraordinary ionic transport functions of biological ion pumps, the bioinspired ion pump should find widespread applicability in active transportation-controlling smart nanofluidic devices, efficient energy conversions, and seawater desalinization, and open the way to design and develop novel bioinspired intelligent artificial nanochannel materials. PMID:23773031

  15. Periplasmic Screening for Artificial Metalloenzymes.

    PubMed

    Jeschek, M; Panke, S; Ward, T R

    2016-01-01

    Artificial metalloenzymes represent an attractive means of combining state-of-the-art transition metal catalysis with the benefits of natural enzymes. Despite the tremendous recent progress in this field, current efforts toward the directed evolution of these hybrid biocatalysts mainly rely on the laborious, individual purification of protein variants rendering the throughput, and hence the outcome of these campaigns feeble. We have recently developed a screening platform for the directed evolution of artificial metalloenzymes based on the streptavidin-biotin technology in the periplasm of the Gram-negative bacterium Escherichia coli. This periplasmic compartmentalization strategy comprises a number of compelling advantages, in particular with respect to artificial metalloenzymes, which lead to a drastic increase in the throughput of screening campaigns and additionally are of unique value for future in vivo applications. Therefore, we highlight here the benefits of this strategy and intend to propose a generalized guideline for the development of novel transition metal-based biocatalysts by directed evolution in order to extend the natural enzymatic repertoire. PMID:27586348

  16. Artificial life: The coming evolution

    SciTech Connect

    Farmer, J.D. Santa Fe Inst., NM ); Belin, A.d'A. )

    1990-01-01

    Within fifty to a hundred years a new class of organisms is likely to emerge. These organisms will be artificial in the sense that they will originally be designed by humans. However, they will reproduce, and will evolve into something other than their initial form; they will be alive'' under any reasonable definition of the word. These organisms will evolve in a fundamentally different manner than contemporary biological organisms, since their reproduction will be under at least partial conscious control, giving it a Lamarckian component. The pace of evolutionary change consequently will be extremely rapid. The advent of artificial life will be the most significant historical event since the emergence of human beings. The impact on humanity and the biosphere could be enormous, larger than the industrial revolution, nuclear weapons, or environmental pollution. We must take steps now to shape the emergence of artificial organisms; they have potential to be either the ugliest terrestrial disaster, or the most beautiful creation of humanity. 22 refs., 3 figs.

  17. Artificial multilayers and nanomagnetic materials

    PubMed Central

    SHINJO, Teruya

    2013-01-01

    The author has been actively engaged in research on nanomagnetic materials for about 50 years. Nanomagnetic materials are comprised of ferromagnetic systems for which the size and shape are controlled on a nanometer scale. Typical examples are ultrafine particles, ultrathin films, multilayered films and nano-patterned films. In this article, the following four areas of the author’s studies are described. (1) Mössbauer spectroscopic studies of nanomagnetic materials and interface magnetism. (2) Preparation and characterization of metallic multilayers with artificial superstructures. (3) Giant magnetoresistance (GMR) effect in magnetic multilayers. (4) Novel properties of nanostructured ferromagnetic thin films (dots and wires). A subject of particular interest in the author’s research was the artificially prepared multilayers consisting of metallic elements. The motivation to initiate the multilayer investigation is described and the physical properties observed in the artificial multilayers are introduced. The author’s research was initially in the field of pure physical science and gradually extended into applied science. His achievements are highly regarded not only from the fundamental point of view but also from the technological viewpoint. PMID:23391605

  18. Beller Lecture: Artificial Ferroic Systems

    NASA Astrophysics Data System (ADS)

    Heyderman, Laura

    In artificial ferroic systems, novel functionality is engineered through the combination of structured ferroic materials and the control of the interactions between the different components. I will present two classes of these systems, beginning with hybrid mesoscopic structures incorporating two different ferromagnetic layers whose static and dynamic behaviour result from the mutual imprint of the magnetic domain configurations. Here we have demonstrated a new vortex core reversal mechanism, which occurs when it is displaced across domain boundaries with a magnetic field. I will then describe our progress on artificial spin ice, consisting of arrays of dipolar-coupled nanomagnets arranged in frustrated geometries. We have employed photoemission electron microscopy to observe the behaviour of emergent magnetic monopoles in an array of nanomagnets placed on the kagome lattice. We have also created artificial spin ice with fluctuating magnetic moments and observed the evolution of magnetic configurations with time. This has provided a means to study relaxation processes with a controlled route to the lowest-energy state. Recently, we have demonstrated with muon spin relaxation that these magnetic metamaterials can support thermodynamic phase transitions, and future directions include the incorporation of novel magnetic materials such as ultrathin magnetic films, the investigation of 3D structures, as well as the implementation of x-ray resonant magnetic scattering to study magnetic correlations in smaller nanomagnets and at faster timescales

  19. Particle Deposition in a Child Respiratory Tract Model: In Vivo Regional Deposition of Fine and Ultrafine Aerosols in Baboons

    PubMed Central

    Albuquerque-Silva, Iolanda; Vecellio, Laurent; Durand, Marc; Avet, John; Le Pennec, Déborah; de Monte, Michèle; Montharu, Jérôme; Diot, Patrice; Cottier, Michèle; Dubois, Francis; Pourchez, Jérémie

    2014-01-01

    To relate exposure to adverse health effects, it is necessary to know where particles in the submicron range deposit in the respiratory tract. The possibly higher vulnerability of children requires specific inhalation studies. However, radio-aerosol deposition experiments involving children are rare because of ethical restrictions related to radiation exposure. Thus, an in vivo study was conducted using three baboons as a child respiratory tract model to assess regional deposition patterns (thoracic region vs. extrathoracic region) of radioactive polydisperse aerosols ([d16–d84], equal to [0.15 µm–0.5 µm], [0.25 µm–1 µm], or [1 µm–9 µm]). Results clearly demonstrated that aerosol deposition within the thoracic region and the extrathoraic region varied substantially according to particle size. High deposition in the extrathoracic region was observed for the [1 µm–9 µm] aerosol (72%±17%). The [0.15 µm–0.5 µm] aerosol was associated almost exclusively with thoracic region deposition (84%±4%). Airborne particles in the range of [0.25 µm–1 µm] showed an intermediate deposition pattern, with 49%±8% in the extrathoracic region and 51%±8% in the thoracic region. Finally, comparison of baboon and human inhalation experiments for the [1 µm–9 µm] aerosol showed similar regional deposition, leading to the conclusion that regional deposition is species-independent for this airborne particle sizes. PMID:24787744

  20. Using the OMI Aerosol Index and Absorption Aerosol Optical Depth to Evaluate the NASA MERRA Aerosol Reanalysis.

    NASA Astrophysics Data System (ADS)

    Buchard, V.; da Silva, A. M., Jr.; Colarco, P. R.; Darmenov, A.; Govindaraju, R.

    2014-12-01

    A radiative transfer interface has been developed to simulate the UV Aerosol Index (AI) from the NASA Goddard Earth Observing System version 5 (GEOS-5) aerosol assimilated fields. The purpose of this work is to use the AI derived from the Ozone Monitoring Instrument (OMI) measurements as independent validation for the Modern Era Retrospective analysis for Research and Applications Aerosol Reanalysis (MERRAero). In this presentation we show comparisons of model produced AI with the corresponding OMI measurements during several months of 2007 characterized by a good sampling of dust and biomass burning events. In parallel, model produced Absorption Aerosol Optical Depth (AAOD) were compared to OMI AAOD for the same period, identifying regions where the model representation of absorbing aerosols were deficient. Since AI is dependent on aerosol concentration, optical properties and altitude of the aerosol layer, we make use of complementary observations to fully diagnose the model, including AOD from the Multi-angle Imaging SpectroRadiometer (MISR) and the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors, aerosol retrievals from the Aerosol Robotic Network (AERONET) and attenuated backscatter coefficients from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission to ascertain misplacement of plume height by the model.