WorldWideScience

Sample records for prevailing atmospheric conditions

  1. Hygienic features of working conditions prevailing in X-ray cabinets

    International Nuclear Information System (INIS)

    Usol'tsev, V.I.; Serebryanyj, V.A.

    1975-01-01

    The results of an investigation of 352 x-ray cabinets showed that their personnel is subjected to simultaneous action of a number of factors: discomfortable microclimate, small concentrations of ozone and nitrogen oxides (within 0.1 of the maximum permissible concentration). The hands of the personnel, especially those of the x-ray laboratory assistants are contaminated with lead (2.38mg in the hands washings). Therefore the assessment of labour conditions prevailing in an x-ray cabinet and the accomplishment of measures of their provement should be carried out with due regards to all the complex of the above mentioned factors besides the ionizing radiation

  2. Evaluation of operational numerical weather predictions in relation to the prevailing synoptic conditions

    Science.gov (United States)

    Pytharoulis, Ioannis; Tegoulias, Ioannis; Karacostas, Theodore; Kotsopoulos, Stylianos; Kartsios, Stergios; Bampzelis, Dimitrios

    2015-04-01

    The Thessaly plain, which is located in central Greece, has a vital role in the financial life of the country, because of its significant agricultural production. The aim of DAPHNE project (http://www.daphne-meteo.gr) is to tackle the problem of drought in this area by means of Weather Modification in convective clouds. This problem is reinforced by the increase of population and the water demand for irrigation, especially during the warm period of the year. The nonhydrostatic Weather Research and Forecasting model (WRF), is utilized for research and operational purposes of DAPHNE project. The WRF output fields are employed by the partners in order to provide high-resolution meteorological guidance and plan the project's operations. The model domains cover: i) Europe, the Mediterranean sea and northern Africa, ii) Greece and iii) the wider region of Thessaly (at selected periods), at horizontal grid-spacings of 15km, 5km and 1km, respectively, using 2-way telescoping nesting. The aim of this research work is to investigate the model performance in relation to the prevailing upper-air synoptic circulation. The statistical evaluation of the high-resolution operational forecasts of near-surface and upper air fields is performed at a selected period of the operational phase of the project using surface observations, gridded fields and weather radar data. The verification is based on gridded, point and object oriented techniques. The 10 upper-air circulation types, which describe the prevailing conditions over Greece, are employed in the synoptic classification. This methodology allows the identification of model errors that occur and/or are maximized at specific synoptic conditions and may otherwise be obscured in aggregate statistics. Preliminary analysis indicates that the largest errors are associated with cyclonic conditions. Acknowledgments This research work of Daphne project (11SYN_8_1088) is co-funded by the European Union (European Regional Development Fund

  3. A quantitative genetic model of reciprocal altruism: a condition for kin or group selection to prevail.

    Science.gov (United States)

    Aoki, K

    1983-01-01

    A condition is derived for reciprocal altruism to evolve by kin or group selection. It is assumed that many additively acting genes of small effect and the environment determine the probability that an individual is a reciprocal altruist, as opposed to being unconditionally selfish. The particular form of reciprocal altruism considered is TIT FOR TAT, a strategy that involves being altruistic on the first encounter with another individual and doing whatever the other did on the previous encounter in subsequent encounters with the same individual. Encounters are restricted to individuals of the same generation belonging to the same kin or breeding group, but first encounters occur at random within that group. The number of individuals with which an individual interacts is assumed to be the same within any kin or breeding group. There are 1 + i expected encounters between two interacting individuals. On any encounter, it is assumed that an individual who behaves altruistically suffers a cost in personal fitness proportional to c while improving his partner's fitness by the same proportion of b. Then, the condition for kin or group selection to prevail is [Formula: see text] if group size is sufficiently large and the group mean and the within-group genotypic variance of the trait value (i.e., the probability of being a TIT-FOR-TAT strategist) are uncorrelated. Here, C, Vb, and Tb are the population mean, between-group variance, and between-group third central moment of the trait value and r is the correlation between the additive genotypic values of interacting kin or of individuals within the same breeding group. The right-hand side of the above inequality is monotone decreasing in C if we hold Tb/Vb constant, and kin and group selection become superfluous beyond a certain threshold value of C. The effect of finite group size is also considered in a kin-selection model. PMID:6575395

  4. Analysis of the Effect of Prevailing Weather Conditions on the Occurrence of Grain Dust Explosions.

    Science.gov (United States)

    Sanghi, Achint; Ambrose, R P Kingsly

    2016-07-27

    Grain dust explosions have been occurring in the U.S. for the past twenty years. In the past ten years, there have been an average of ten explosions a year, resulting in nine fatalities and 93 injuries. In more than half of these cases, the ignition source remains unidentified. The effect of ambient humidity on the likelihood of a dust explosion has been discussed for many years. However, no investigation into a possible link between the two has been carried out. In this study, we analyzed local weather data and grain dust explosions during the period 2006 to 2014 to measure potential relationships between the two events. The 84 analyzed explosions do not show any trend with regard to prevailing temperatures, or relative or absolute humidity. In addition, the ignition source could not be identified in 54 of the incidents. The majority of grain dust explosion incidents occurred at grain elevator facilities, where the dust generation potential was high compared with grain processing industries. Copyright© by the American Society of Agricultural Engineers.

  5. Oxidative conditions prevail in severe IUGR with vascular disease and Doppler anomalies.

    Science.gov (United States)

    Maisonneuve, Emeline; Delvin, Edgard; Edgard, Annie; Morin, Lucie; Dubé, Johanne; Boucoiran, Isabelle; Moutquin, Jean-Marie; Fouron, Jean-Claude; Klam, Stephanie; Levy, Emile; Leduc, Line

    2015-08-01

    Intrauterine growth restriction (IUGR) and prenatal exposure to oxidative stress are thought to lead to increased risks of cardiovascular disease later in life. The objective of the present study was to document whether cord blood oxidative stress biomarkers vary with the severity of IUGR and of vascular disease in the twin pregnancy model in which both fetuses share the same maternal environment. This prospective cohort study involved dichorionic twin pairs, with one co-twin with IUGR. Oxidative stress biomarkers were measured in venous cord blood samples from each neonate of 32 twin pairs, and compared, according to severity of IUGR (IUGR <5th percentile), Doppler anomalies of the umbilical artery and early onset IUGR (in the second trimester) of the growth restricted twin. Oxidized Low-Density Lipoproteins (oxLDL) and Malondialdehyde (MDA) concentrations were increased proportionally in cases of severe IUGR. OxLDL concentrations were also increased in cases of IUGR with Doppler anomaly. Our data indicate that severe IUGR, is related to a derangement in redox balance, illustrated by increased venous cord blood oxidative stress biomarkers concentrations. Severe IUGR and IUGR with abnormal Doppler can be translated into conditions with intense oxidative stress.

  6. Atmospheric particle formation in spatially and temporally varying conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lauros, J.

    2011-07-01

    Atmospheric particles affect the radiation balance of the Earth and thus the climate. New particle formation from nucleation has been observed in diverse atmospheric conditions but the actual formation path is still unknown. The prevailing conditions can be exploited to evaluate proposed formation mechanisms. This study aims to improve our understanding of new particle formation from the view of atmospheric conditions. The role of atmospheric conditions on particle formation was studied by atmospheric measurements, theoretical model simulations and simulations based on observations. Two separate column models were further developed for aerosol and chemical simulations. Model simulations allowed us to expand the study from local conditions to varying conditions in the atmospheric boundary layer, while the long-term measurements described especially characteristic mean conditions associated with new particle formation. The observations show statistically significant difference in meteorological and back-ground aerosol conditions between observed event and non-event days. New particle formation above boreal forest is associated with strong convective activity, low humidity and low condensation sink. The probability of a particle formation event is predicted by an equation formulated for upper boundary layer conditions. The model simulations call into question if kinetic sulphuric acid induced nucleation is the primary particle formation mechanism in the presence of organic vapours. Simultaneously the simulations show that ignoring spatial and temporal variation in new particle formation studies may lead to faulty conclusions. On the other hand, the theoretical simulations indicate that short-scale variations in temperature and humidity unlikely have a significant effect on mean binary water sulphuric acid nucleation rate. The study emphasizes the significance of mixing and fluxes in particle formation studies, especially in the atmospheric boundary layer. The further

  7. Effect of Atmospheric Conditions on LIBS Spectra

    OpenAIRE

    Effenberger, Andrew J.; Scott, Jill R.

    2010-01-01

    Laser-induced breakdown spectroscopy (LIBS) is typically performed at ambient Earth atmospheric conditions. However, interest in LIBS in other atmospheric conditions has increased in recent years, especially for use in space exploration (e.g., Mars and Lunar) or to improve resolution for isotopic signatures. This review focuses on what has been reported about the performance of LIBS in reduced pressure environments as well as in various gases other than air.

  8. Effect of Atmospheric Conditions on LIBS Spectra

    Science.gov (United States)

    Effenberger, Andrew J.; Scott, Jill R.

    2010-01-01

    Laser-induced breakdown spectroscopy (LIBS) is typically performed at ambient Earth atmospheric conditions. However, interest in LIBS in other atmospheric conditions has increased in recent years, especially for use in space exploration (e.g., Mars and Lunar) or to improve resolution for isotopic signatures. This review focuses on what has been reported about the performance of LIBS in reduced pressure environments as well as in various gases other than air. PMID:22399914

  9. The Prevailing Weather and Traffic Conditions in the Evaluation of a Future ECA in the Mediterranean Sea. A view into the Western Mediterranean

    Directory of Open Access Journals (Sweden)

    Marcella Castells i Sanabra

    2014-03-01

    Full Text Available Appendix III of MARPOL's Annex VI sets out the criteria and procedures for designating an emission control area (ECA.These criteria includes: a clear delineation of the proposed ECA; types of emissions proposed for control, land and sea areas at risk; emission quantification and impact assessment; prevailing weather conditions; data and quality on marine traffic; land based measures concurrent with the ECA adoption and the relative costs of reducing emissions from ships. This paper analyses the climate parameter together with traffic conditions: prevailing weather conditions as a parameter to be kept in mind for the adoption of a future ECA in the Mediterranean Sea. Preliminary results would show how marine emissions coming from existing traffic will impact the sea and land ecology in the Mediterranean area.

  10. Analysis of the prevailing standard and technical documents for their applicability under conditions of the 'Ukrytie' operation and technical proposals relating to the elaboration of new ones concerning fire safety

    International Nuclear Information System (INIS)

    Nazarenko, B.S.; Emets, V.G.

    1998-01-01

    An analysis of the prevailing laws and standards and technical documents (STD) to ensure safe operation of nuclear power installations, with requirements of nuclear, radiation and fire safety taken into account, has been performed. Proposals on application of some items of prevailing STD under conditions of the 'Ukrytie' operation are presented. Also given are technical proposals on correction of the prevailing operational standard documents and elaboration of special STD

  11. Effects of prevailing conditions during second Palestinian uprising on solid waste management system in Nablus city in Palestine.

    Science.gov (United States)

    Arafat, Hassan A; Al-Khatib, Issam A; Zahra, Abdulsalam Abu

    2006-08-01

    Since the start of the second Palestinian uprising (Al-Aqsa Intifada), and due to the Israeli activities, curfews, closures, and military checkpoints imposed since 2000, the quality of social services rendered by Nablus city has been gradually deteriorating. Solid waste management in Nablus city was badly affected by these conditions, and this situation is negatively affecting health and damaging the environment. Most of these cases were due to reasons beyond the capability of the municipality with its limited resources. This study revealed that some of the important municipal solid waste (MSW) equipment had been damaged during the uprising. The workforce in the MSW system was reduced and certain MSW-related development projects and activities have been frozen due to the current conditions. The city's medical waste incinerator had been phased out and the number of special medical containers had been reduced from 16 to 10. Some MSW compressing trucks had been out of use with no substitute. Another important figure is the number of waste collection workers which decreased from 420 to 301, although the city is growing in premises as well as population. The created unsanitary solid waste transfer station is now a pollution source on its own, causing an ugly scene at the eastern entrance of Nablus city. There should be a comprehensive and urgent solution for this problem and the needed resources should be invested.

  12. Complex interplay of body condition, life history, and prevailing environment shapes immune defenses of garter snakes in the wild.

    Science.gov (United States)

    Palacios, Maria G; Cunnick, Joan E; Bronikowski, Anne M

    2013-01-01

    The immunocompetence "pace-of-life" hypothesis proposes that fast-living organisms should invest more in innate immune defenses and less in adaptive defenses compared to slow-living ones. We found some support for this hypothesis in two life-history ecotypes of the snake Thamnophis elegans; fast-living individuals show higher levels of innate immunity compared to slow-living ones. Here, we optimized a lymphocyte proliferation assay to assess the complementary prediction that slow-living snakes should in turn show stronger adaptive defenses. We also assessed the "environmental" hypothesis that predicts that slow-living snakes should show lower levels of immune defenses (both innate and adaptive) given the harsher environment they live in. Proliferation of B- and T-lymphocytes of free-living individuals was on average higher in fast-living than slow-living snakes, opposing the pace-of-life hypothesis and supporting the environmental hypothesis. Bactericidal capacity of plasma, an index of innate immunity, did not differ between fast-living and slow-living snakes in this study, contrasting the previously documented pattern and highlighting the importance of annual environmental conditions as determinants of immune profiles of free-living animals. Our results do not negate a link between life history and immunity, as indicated by ecotype-specific relationships between lymphocyte proliferation and body condition, but suggest more subtle nuances than those currently proposed.

  13. The PREVAIL Study

    DEFF Research Database (Denmark)

    Evans, Christopher P; Higano, Celestia S; Keane, Thomas

    2016-01-01

    BACKGROUND: Enzalutamide, an oral androgen receptor inhibitor, significantly improved overall survival (OS) and radiographic progression-free survival (rPFS) versus placebo in the PREVAIL trial of men with chemotherapy-naïve metastatic castration-resistant prostate cancer. OBJECTIVE: To assess...... in men with chemotherapy-naïve metastatic castration-resistant prostate cancer, with or without visceral disease, low- or high-volume bone disease, or lymph node only disease. PATIENT SUMMARY: Patients with metastatic castration-resistant prostate cancer-including those with or without visceral disease...

  14. Exoplanetary Atmospheres-Chemistry, Formation Conditions, and Habitability.

    Science.gov (United States)

    Madhusudhan, Nikku; Agúndez, Marcelino; Moses, Julianne I; Hu, Yongyun

    2016-12-01

    Characterizing the atmospheres of extrasolar planets is the new frontier in exoplanetary science. The last two decades of exoplanet discoveries have revealed that exoplanets are very common and extremely diverse in their orbital and bulk properties. We now enter a new era as we begin to investigate the chemical diversity of exoplanets, their atmospheric and interior processes, and their formation conditions. Recent developments in the field have led to unprecedented advancements in our understanding of atmospheric chemistry of exoplanets and the implications for their formation conditions. We review these developments in the present work. We review in detail the theory of atmospheric chemistry in all classes of exoplanets discovered to date, from highly irradiated gas giants, ice giants, and super-Earths, to directly imaged giant planets at large orbital separations. We then review the observational detections of chemical species in exoplanetary atmospheres of these various types using different methods, including transit spectroscopy, Doppler spectroscopy, and direct imaging. In addition to chemical detections, we discuss the advances in determining chemical abundances in these atmospheres and how such abundances are being used to constrain exoplanetary formation conditions and migration mechanisms. Finally, we review recent theoretical work on the atmospheres of habitable exoplanets, followed by a discussion of future outlook of the field.

  15. Atmospheric conditions important for the assessment of population exposure

    International Nuclear Information System (INIS)

    Vidic, S.

    2005-01-01

    Atmospheric distribution of a pollutant can be predicted using numerical weather prediction models and atmospheric dispersion models. The first provides prediction on the evaluation of the meteorological fields for specified time period and the second uses this information to determine the evolution of the dispersing cloud in time and space. There is a number of conditions and features that limit the performance of both models, as they contain a degree of parametrisation that may be a source of error. This paper discusses influential parameters and conditions.(author)

  16. Transport of radionuclides in the atmosphere during complex meteorological conditions

    International Nuclear Information System (INIS)

    Antic, D.; Telenta, B.

    1991-01-01

    Radionuclides from various sources (nuclear and fossil fuel power plants, nuclear facilities, medical facilities, etc.) are being released to the atmosphere. The meteorological conditions determine the atmospheric turbulence, dispersion, and removal processes of the radionuclides. A two-dimensional version of the cloud model based on the Klemp-Wilhelmson dynamic and Lin et al.'s microphysics and thermodynamics has been adapted and used to simulate the transport of radionuclides emitted from a power plant or other source to the atmosphere. Calculations of the trajectories and radii for a few puffs are included in this paper. These numerical investigations show that the presented model can be used for the transport simulation of radionuclides and for the assessment of the radiological impact of power plants and other sources in safety assessments and comparative studies. Because it can simulate puff trajectories, this model is especially valuable in the presence of complex meteorological conditions

  17. ATMOSPHERIC CIRCULATION OF HOT JUPITERS: INSENSITIVITY TO INITIAL CONDITIONS

    International Nuclear Information System (INIS)

    Liu Beibei; Showman, Adam P.

    2013-01-01

    The ongoing characterization of hot Jupiters has motivated a variety of circulation models of their atmospheres. Such models must be integrated starting from an assumed initial state, which is typically taken to be a wind-free, rest state. Here, we investigate the sensitivity of hot-Jupiter atmospheric circulation to initial conditions with shallow-water models and full three-dimensional models. Those models are initialized with zonal jets, and we explore a variety of different initial jet profiles. We demonstrate that, in both classes of models, the final, equilibrated state is independent of initial condition—as long as frictional drag near the bottom of the domain and/or interaction with a specified planetary interior are included so that the atmosphere can adjust angular momentum over time relative to the interior. When such mechanisms are included, otherwise identical models initialized with vastly different initial conditions all converge to the same statistical steady state. In some cases, the models exhibit modest time variability; this variability results in random fluctuations about the statistical steady state, but we emphasize that, even in these cases, the statistical steady state itself does not depend on initial conditions. Although the outcome of hot-Jupiter circulation models depend on details of the radiative forcing and frictional drag, aspects of which remain uncertain, we conclude that the specification of initial conditions is not a source of uncertainty, at least over the parameter range explored in most current models.

  18. Design of Multijunction Photovoltaic Cells Optimized for Varied Atmospheric Conditions

    Directory of Open Access Journals (Sweden)

    C. Zhang

    2014-01-01

    Full Text Available Band gap engineering provides an opportunity to not only provide higher overall conversion efficiencies of the reference AM1.5 spectra but also customize PV device design for specific geographic locations and microenvironments based on atmospheric conditions characteristic to that particular location. Indium gallium nitride and other PV materials offer the opportunity for limited bandgap engineering to match spectra. The effects of atmospheric conditions such as aerosols, cloud cover, water vapor, and air mass have been shown to cause variations in spectral radiance that alters PV system performance due to both overrating and underrating. Designing PV devices optimized for spectral radiance of a particular region can result in improved PV system performance. This paper presents a new method for designing geographically optimized PV cells with using a numerical model for bandgap optimization. The geographic microclimate spectrally resolved solar flux for twelve representative atmospheric conditions for the incident radiation angle (zenith angle of 48.1° and fixed array angle of 40° is used to iteratively optimize the band gap for tandem, triple, and quad-layer of InGaN-based multijunction cells. The results of this method are illustrated for the case study of solar farms in the New York region and discussed.

  19. Behaviour of lactic acid bacteria populations in Pecorino di Carmasciano cheese samples submitted to environmental conditions prevailing in the gastrointestinal tract: evaluation by means of a polyphasic approach.

    Science.gov (United States)

    Ricciardi, Annamaria; Blaiotta, Giuseppe; Di Cerbo, Alessandro; Succi, Mariantonietta; Aponte, Maria

    2014-06-02

    The survival of the autochthonous microflora, of samples collected during Pecorino di Carmasciano cheese manufacturing, was evaluated along the passage through a model mimicking the gastro-intestinal tract. The aim was the selection of lactic acid bacteria potentially able to arrive alive and metabolically active to the colon. The dynamics of lactic microbiota, throughout simulated digestion of cheese samples, were evaluated by means of an approach PCR-DGGE-based. Dominant species after cheese digestion could be related to the Lactobacillus plantarum and Lactobacillus casei groups. Sixty-three strains, which survived to simulated gastro-intestinal transit, were further evaluated for technological features and tolerance to human digestion in several experimental conditions, according to routinely used protocols. Bacterial survival appeared to be, more than strain-specific, strongly affected by experimental conditions, i.e. some strains showed an acceptable survival when resuspended in skim milk but not in ewe milk and vice versa. Nevertheless according to data, one gram of fresh Pecorino di Carmasciano cheese may convey to human colon about the same amount of viable LAB of a probiotic drink. Although it cannot be assumed that lactobacilli introduced with Pecorino have beneficial effects on the host, the healthy impact of autochthonous lactic acid bacteria of naturally fermented food has a broad consensus in the current literature. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Alteration of municipal and industrial slags under atmospheric conditions

    Science.gov (United States)

    Rafał Kowalski, Piotr; Michalik, Marek

    2014-05-01

    The Waste Management System in Poland is being consequently built since 1998. After important changes in legislation, local governments have taken over the duty of waste collection. New points of selective collection of wastes have been opened and new sorting and composting plants were built. The last stage of introducing the Waste Management System is construction of waste incineration power plants. From nine installations which were planned, six are now under construction and they will start operating within the next two years. It is assumed that the consumption of raw wastes for these installations will reach 974 thousand tons per year. These investments will result in increased slags and ashes production. Now in Poland several local waste incinerators are operating and predominant amount of produced incineration residues is landfilled. These materials are exposed to atmospheric conditions in time of short term storage (just after incineration) and afterwards for a longer period of time on the landfill site. During the storage of slags low temperature mineral transformations and chemical changes may occur and also some components can be washed out. These materials are stored wet because of the technological processes. The aim of this study is to investigate the influence of storage in atmospheric conditions on slags from incineration of industrial and municipal wastes. The experiment started in January 2013. During this period slag samples from incineration of industrial and municipal wastes were exposed to atmospheric conditions. Samples were collected after 6 and 12 months. Within this time the pH value was measured monthly, and during the experimental period remained constant on the level of 9.5. After 6 months of exposure only slight changes in mineral compositions were observed in slags. The results of XRD analysis of municipal slags showed increase in content of carbonate minerals in comparison to the raw slag samples. In industrial slags, a decrease in

  1. Epistaxis: Prevailing Factors and Treatment

    Directory of Open Access Journals (Sweden)

    Secchi, Myrian Marajó Dal

    2009-12-01

    Full Text Available Introduction: The epistaxis is one the most frequent otorhinolaryngologic emergencies in the medical practice. It is a benign affection, but the refractory cases require hospital admission. Objective: To evaluate prevailing factors in patients with epistaxis and treatment. Form of study: Retrospective study. Method: 60 patients with diagnosis of epistaxis were evaluated and they needed hospital admission between 2005 and 2006. Results: The main prevailing factors were: Systemic arterial hypertension 36% (n= 22, trauma 16% (n=10 and coagulopathy 5% (n=3. The treatment was the use of nasal splint: anterior 58% (n=35 and antero-posterior 27% (n=16, the electrocauterization of the identified bloody point 7% (n=4, endoscopic arterial bandage 8% (n=5 in severe epistaxis. For the patients with antero-posterior splint with recurrence of bleeding in the first 24 hours (five patients, after clinical stabilization, an arterial bandage was indicated by endoscopic means; four patients had systemic arterial hypertension and in one patient no prevailing factor was identified. Conclusion: The main associated prevailing factors were systemic arterial hypertension, trauma and coagulopathy. The treatment depends on the type, severity and cause of bleeding, initially the anterior and antero-posterior splint for bleeding control. The early endoscopic arterial bandage is indicated in patients with severe epistaxis and prevailing factors, and prolonged admission and morbidities associated with nasal splint should be avoided.

  2. Theoretical predictions of arsenic and selenium species under atmospheric conditions

    Energy Technology Data Exchange (ETDEWEB)

    Monahan-Pendergast, M.T.; Przybylek, M.; Lindblad, M.; Wilcox, J. [Worcester Polytechnic Institute, Worcester, MA (United States). Dept. of Chemical Engineering

    2008-03-15

    Thermochemical properties of arsenic and selenium species thought to be released into the atmosphere during the coal combustion were examined using ab initio methods. At various levels of theory, calculated geometries and vibrational frequencies of the species were compared with experimental data, where available. Through a comparison of equilibrium constants for a series of gaseous arsenic and selenium oxidation reactions involving OH and HO{sub 2}, five thermodynamically favored reactions were found. In addition, it was determined that all favored reactions were more likely to go to completion tinder tropospheric, rather than stratospheric, conditions.

  3. Documentation of Atmospheric Conditions During Observed Rising Aircraft Wakes

    Science.gov (United States)

    Zak, J. Allen; Rodgers, William G., Jr.

    1997-01-01

    Flight tests were conducted in the fall of 1995 off the coast of Wallops Island, Virginia in order to determine characteristics of wake vortices at flight altitudes. A NASA Wallops Flight Facility C130 aircraft equipped with smoke generators produced visible wakes at altitudes ranging from 775 to 2225 m in a variety of atmospheric conditions, orientations (head wind, cross wind), and airspeeds. Meteorological and aircraft parameters were collected continuously from a Langley Research Center OV-10A aircraft as it flew alongside and through the wake vortices at varying distances behind the C130. Meteorological data were also obtained from special balloon observations made at Wallops. Differential GPS capabilities were on each aircraft from which accurate altitude profiles were obtained. Vortices were observed to rise at distances beyond a mile behind the C130. The maximum altitude was 150 m above the C130 in a near neutral atmosphere with significant turbulence. This occurred from large vertical oscillations in the wakes. There were several cases when vortices did not descend after a very short initial period and remained near generation altitude in a variety of moderately stable atmospheres and wind shears.

  4. CARBON-RICH GIANT PLANETS: ATMOSPHERIC CHEMISTRY, THERMAL INVERSIONS, SPECTRA, AND FORMATION CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Madhusudhan, Nikku [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Mousis, Olivier [Institut UTINAM, CNRS-UMR 6213, Observatoire de Besancon, BP 1615, F-25010 Besancon Cedex (France); Johnson, Torrence V. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Lunine, Jonathan I., E-mail: nmadhu@astro.princeton.edu [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States)

    2011-12-20

    The recent inference of a carbon-rich atmosphere, with C/O {>=} 1, in the hot Jupiter WASP-12b motivates the exotic new class of carbon-rich planets (CRPs). We report a detailed study of the atmospheric chemistry and spectroscopic signatures of carbon-rich giant (CRG) planets, the possibility of thermal inversions in their atmospheres, the compositions of icy planetesimals required for their formation via core accretion, and the apportionment of ices, rock, and volatiles in their envelopes. Our results show that CRG atmospheres probe a unique region in composition space, especially at high temperature (T). For atmospheres with C/O {>=} 1, and T {approx}> 1400 K in the observable atmosphere, most of the oxygen is bound up in CO, while H{sub 2}O is depleted and CH{sub 4} is enhanced by up to two or three orders of magnitude each, compared to equilibrium compositions with solar abundances (C/O = 0.54). These differences in the spectroscopically dominant species for the different C/O ratios cause equally distinct observable signatures in the spectra. As such, highly irradiated transiting giant exoplanets form ideal candidates to estimate atmospheric C/O ratios and to search for CRPs. We also find that the C/O ratio strongly affects the abundances of TiO and VO, which have been suggested to cause thermal inversions in highly irradiated hot Jupiter atmospheres. A C/O = 1 yields TiO and VO abundances of {approx}100 times lower than those obtained with equilibrium chemistry assuming solar abundances, at P {approx} 1 bar. Such a depletion is adequate to rule out thermal inversions due to TiO/VO even in the most highly irradiated hot Jupiters, such as WASP-12b. We estimate the compositions of the protoplanetary disk, the planetesimals, and the envelope of WASP-12b, and the mass of ices dissolved in the envelope, based on the observed atmospheric abundances. Adopting stellar abundances (C/O = 0.44) for the primordial disk composition and low-temperature formation conditions

  5. Persistency of atmospheric diffusion conditions in Angra dos Reis - Brazil

    International Nuclear Information System (INIS)

    Nicolli, D.

    1981-12-01

    Based on a 2 year observation period, the diffusion conditions at the Almirante Alvaro Alberto N.P.P. site, in Angra dos Reis, are analized with respect to persistency as a function of the wind direction, the Pasquill stability class and the time of the day. The Pasquill stability class relates to the bulk vertical temperature gradient measured between 2m and 50m in the atmosphere; the wind direction is measured at 50m height. The persistency is defined in this report as the probability that the wind direction will remain longer than a given time in a sector without change in the diffusion category by more than a certain stage. During the day the persistency is mostly affected by the sea breeze with predominance of the unstable and neutral categories. At night the stable categories dominate. The alternating sea and land breezes disturb daily the trade wind field resulting in low persistency of the diffusion conditions. (Author) [pt

  6. The effects of atmospheric optical conditions on perceived scenic beauty

    Science.gov (United States)

    Latimer, Douglas A.; Hogo, Henry; Daniel, Terry C.

    This paper describes the results from the first year of a currently on-going study, the objective of which is to investigate the relationships between atmospheric optical conditions and human perceptions of scenic beauty. Color photographs and atmospheric optical measurements, using telephotometers and nephelometers, were taken in the western U.S.A. (Grand Canyon National Park and Mt. Lemmon near Tucson, Arizona) and in the eastern United States (Great Smoky Mountains and Shenandoah national parks). Over 1300 individual observers rated color slides for either visual air quality or scenic beauty using a 10-point rating scale. Ratings were transformed to indices using standard psychophysical techniques. Relationships between these perceptual indices and physical parameters characteristic of the given landscape represented in the color slides were investigated using scatter plots, correlation analysis, and multiple linear regression. Physical parameters included visual range, horizon sky chromaticity and luminance, solar zenith and scattering angles, and cloud conditions. Results show that observers' ratings of visual air quality and scenic beauty are sensitive to visual range, sky color, and scattering angle. However, in some of the areas investigated, scenic beauty ratings were not affected by changes in visual range. The sensitivity of the scenic beauty of a vista to changes in the extinction coefficient may be useful for establishing visibility goals and priorities.

  7. Atmospheric conditions create freeways, detours and tailbacks for migrating birds.

    Science.gov (United States)

    Shamoun-Baranes, Judy; Liechti, Felix; Vansteelant, Wouter M G

    2017-07-01

    The extraordinary adaptations of birds to contend with atmospheric conditions during their migratory flights have captivated ecologists for decades. During the 21st century technological advances have sparked a revival of research into the influence of weather on migrating birds. Using biologging technology, flight behaviour is measured across entire flyways, weather radar networks quantify large-scale migratory fluxes, citizen scientists gather observations of migrant birds and mechanistic models are used to simulate migration in dynamic aerial environments. In this review, we first introduce the most relevant microscale, mesoscale and synoptic scale atmospheric phenomena from the point of view of a migrating bird. We then provide an overview of the individual responses of migrant birds (when, where and how to fly) in relation to these phenomena. We explore the cumulative impact of individual responses to weather during migration, and the consequences thereof for populations and migratory systems. In general, individual birds seem to have a much more flexible response to weather than previously thought, but we also note similarities in migratory behaviour across taxa. We propose various avenues for future research through which we expect to derive more fundamental insights into the influence of weather on the evolution of migratory behaviour and the life-history, population dynamics and species distributions of migrant birds.

  8. Filter Media Tests Under Simulated Martian Atmospheric Conditions

    Science.gov (United States)

    Agui, Juan H.

    2016-01-01

    Human exploration of Mars will require the optimal utilization of planetary resources. One of its abundant resources is the Martian atmosphere that can be harvested through filtration and chemical processes that purify and separate it into its gaseous and elemental constituents. Effective filtration needs to be part of the suite of resource utilization technologies. A unique testing platform is being used which provides the relevant operational and instrumental capabilities to test articles under the proper simulated Martian conditions. A series of tests were conducted to assess the performance of filter media. Light sheet imaging of the particle flow provided a means of detecting and quantifying particle concentrations to determine capturing efficiencies. The media's efficiency was also evaluated by gravimetric means through a by-layer filter media configuration. These tests will help to establish techniques and methods for measuring capturing efficiency and arrestance of conventional fibrous filter media. This paper will describe initial test results on different filter media.

  9. Ozonation of isoproturon adsorbed on silica particles under atmospheric conditions

    Science.gov (United States)

    Pflieger, Maryline; Grgić, Irena; Kitanovski, Zoran

    2012-12-01

    The results on heterogeneous ozonation of a phenylurea pesticide, isoproturon, under atmospheric conditions are presented for the first time in the present study. The study was carried out using an experimental device previously adopted and validated for the heterogeneous reactivity of organics toward ozone (Pflieger et al., 2011). Isoproturon was adsorbed on silica particles via a liquid-to-solid equilibrium with a load far below a monolayer (0.02% by weight/surface coverage of 0.5%). The rate constants were estimated by measuring the consumption of the organic (dark, T = 26 °C, RH isoproturon on the aerosol surface does not affect the kinetics of ozonation, indicating that both compounds are adsorbed on different surface sites of silica particles.

  10. A thermal model for photovoltaic panels under varying atmospheric conditions

    International Nuclear Information System (INIS)

    Armstrong, S.; Hurley, W.G.

    2010-01-01

    The response of the photovoltaic (PV) panel temperature is dynamic with respect to the changes in the incoming solar radiation. During periods of rapidly changing conditions, a steady state model of the operating temperature cannot be justified because the response time of the PV panel temperature becomes significant due to its large thermal mass. Therefore, it is of interest to determine the thermal response time of the PV panel. Previous attempts to determine the thermal response time have used indoor measurements, controlling the wind flow over the surface of the panel with fans or conducting the experiments in darkness to avoid radiative heat loss effects. In real operating conditions, the effective PV panel temperature is subjected to randomly varying ambient temperature and fluctuating wind speeds and directions; parameters that are not replicated in controlled, indoor experiments. A new thermal model is proposed that incorporates atmospheric conditions; effects of PV panel material composition and mounting structure. Experimental results are presented which verify the thermal behaviour of a photovoltaic panel for low to strong winds.

  11. 12 CFR 747.603 - Prevailing party.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Prevailing party. 747.603 Section 747.603 Banks... in NCUA Board Adjudications § 747.603 Prevailing party. An eligible applicant may be a “prevailing... dismissed. In appropriate situations an applicant may also have prevailed if the outcome of the proceeding...

  12. Financing Educational Facility Construction: Prevailing Wage Litigation.

    Science.gov (United States)

    Goldblatt, Steven M.; Wood, R. Craig

    This chapter presents an up-to-date analysis of prevailing state wage laws that affect educational facility construction or renovation and highlights relevant prevailing wage litigation in many states. Currently, 13 states have no prevailing wage laws for public works. The other 37 states and the District of Columbia do have prevailing wage laws…

  13. Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia

    Science.gov (United States)

    Prtenjak, Maja Telišman; Srnec, Lidija; Peternel, Renata; Madžarević, Valentina; Hrga, Ivana; Stjepanović, Barbara

    2012-11-01

    We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002-2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m3) for our analysis: period A (3-4 September 2002) and period B (6-7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002-2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m3. Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration.

  14. Computer Modeling of the Effects of Atmospheric Conditions on Sound Signatures

    Science.gov (United States)

    2016-02-01

    simulation. 11 5. References 1. Attenborough K. Sound propagation in the atmosphere. In: Rossing TD, editor. Springer handbook of...ARL-TR-7602 ● FEB 2016 US Army Research Laboratory Computer Modeling of the Effects of Atmospheric Conditions on Sound ...Laboratory Computer Modeling of the Effects of Atmospheric Conditions on Sound Signatures by Sarah Wagner Science and Engineering Apprentice

  15. PREVAIL: latest electron optics results

    Science.gov (United States)

    Pfeiffer, Hans C.; Golladay, Steven D.; Gordon, Michael S.; Kendall, Rodney A.; Lieberman, Jon E.; Rockrohr, James D.; Stickel, Werner; Yamaguchi, Takeshi; Okamoto, Kazuya; Umemoto, Takaaki; Shimizu, Hiroyasu; Kojima, Shinichi; Hamashima, Muneki

    2002-07-01

    The PREVAIL electron optics subsystem developed by IBM has been installed at Nikon's facility in Kumagaya, Japan, for integration into the Nikon commercial EPL stepper. The cornerstone of the electron optics design is the Curvilinear Variable Axis Lens (CVAL) technique originally demonstrated with a proof of concept system. This paper presents the latest experimental results obtained with the electron optical subsystem at Nikon's facility. The results include micrographs illustrating proper CVAL operation through the spatial resolution achieved over the entire optical field of view. They also include data on the most critical issue of the EPL exposure approach: subfield stitching. The methodology of distortion correction will be described and both micrographs and metrology data of stitched subfields will be presented. This paper represents a progress report of the IBM/Nikon alliance activity on EPL.

  16. The height of the atmospheric boundary layer during unstable conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gryning, S.E.

    2005-11-01

    The height of the convective atmospheric boundary layer, also called the mixed-layer, is one of the fundamental parameters that characterise the structure of the atmosphere near the ground. It has many theoretical and practical applications such as the prediction of air pollution concentrations, surface temperature and the scaling of turbulence. However, as pointed out by Builtjes (2001) in a review paper on Major Twentieth Century Milestones in Air Pollution Modelling and Its Application, the weakest point in meteorology data is still the determination of the height of the mixed-layer, the so-called mixing height. A simple applied model for the height of the mixed-layer over homogeneous terrain is suggested in chapter 2. It is based on a parameterised budget for the turbulent kinetic energy. In the model basically three terms - the spin-up term and the production of mechanical and convective turbulent kinetic energy - control the growth of the mixed layer. The interplay between the three terms is related to the meteorological conditions and the height of the mixed layer. A stable layer, the so-called entrainment zone, which is confined between the mixed layer and the free air above, caps the mixed layer. A parameterisation of the depth of the entrainment zone is also suggested, and used to devise a combined model for the height of the mixed layer and the entrainment zone. Another important aspect of the mixed layer development exists in coastal areas where an internal boundary layer forms downwind from the coastline. A model for the growth of the internal boundary layer is developed in analogy with the model for mixed layer development over homogeneous terrain. The strength of this model is that it can operate on a very fine spatial resolution with minor computer resources. Chapter 3 deals with the validation of the models. It is based in parts on data from the literature, and on own measurements. For the validation of the formation of the internal boundary layer

  17. 12 CFR 263.102 - Prevailing party.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Prevailing party. 263.102 Section 263.102 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM RULES... Prevailing party. Only an eligible applicant that prevailed on the merits of an adversary proceeding may...

  18. 12 CFR 308.173 - Prevailing party.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Prevailing party. 308.173 Section 308.173 Banks....173 Prevailing party. (a) General rule. An eligible applicant who, following an adversary adjudication has gained victory on the merits in the proceeding is a “prevailing party”. An eligible applicant may...

  19. Effects of Prevailing Winds on Turbidity of a Shallow Estuary

    OpenAIRE

    Cho, Hyun Jung

    2007-01-01

    Estuarine waters are generally more turbid than lakes or marine waters due to greater algal mass and continual re-suspension of sediments. The varying effects of diurnal and seasonal prevailing winds on the turbidity condition of a wind-dominated estuary were investigated by spatial and statistical analyses of wind direction, water level, turbidity, chlorophyll a, and PAR (Photosynthetically Active Radiation) collected in Lake Pontchartrain, Louisiana, USA. The prolonged prevailing winds were...

  20. Atmospheric corrosion in Gran Canaria specifically meteorological and pollution conditions

    International Nuclear Information System (INIS)

    Gonzalez, J.E.G.; Valles, M.L.; Mirza R, J.C.

    1998-01-01

    Carbon steel, copper, zinc and aluminium samples were exposed in different sizes with known ambient parameters in Gran Canaria Island and atmospheric corrosion was investigated. Weight-loss measurements used to determine corrosion damage were complemented with metallographic and XP S determination in order to characterize the structure and morphology of surface corrosion products. The ambient aggressiveness could be well evaluated from meteorological and pollution data. All atmospheric corrosion and environmental data were statistically processed for establishing general corrosion damage functions for carbon steel, copper, aluminium and zinc in terms of Gran Canaria extreme meteorological and pollution parameters. (Author)

  1. Ocean-atmosphere interaction and synoptic weather conditions in ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    turbances over oceans. On the other hand, these disturbances have an impact on the oceanic mixed layer, causing changes in the SST. This complex feed back process between the sea surface and the atmospheric disturbances is important in deter- mining the life span of the synoptic scale events. (Paul et al 1992). In view ...

  2. The role of ions in particle nucleation under atmospheric conditions

    DEFF Research Database (Denmark)

    Enghoff, Martin B.; Pedersen, J. O. P.; Bondo, T.

    2008-01-01

    Aerosol nucleation has been studied experimentally in purified, atmospheric air, containing trace amounts of water vapor, ozone, and sulfur dioxide. The results are compared with model calculations. It is found that an increase in ionization by a factor of 10 increases the production rate of stable...

  3. Evaluation of carbon diffusion in heat treatment of H13 tool steel under different atmospheric conditions

    OpenAIRE

    Ramezani, Maziar; Pasang, Timotius; Chen, Zhan; Neitzert, Thomas; Au, Dominique

    2015-01-01

    Although the cost of the heat treatment process is only a minor portion of the total production cost, it is arguably the most important and crucial stage on the determination of material quality. In the study of the carbon diffusion in H13 steel during austenitization, a series of heat treatment experiments had been conducted under different atmospheric conditions and length of treatment. Four austenitization atmospheric conditions were studied, i.e., heat treatment without atmospheric contro...

  4. Thermophysical Properties Measurement of High-Temperature Liquids Under Microgravity Conditions in Controlled Atmospheric Conditions

    Science.gov (United States)

    Watanabe, Masahito; Ozawa, Shumpei; Mizuno, Akotoshi; Hibiya, Taketoshi; Kawauchi, Hiroya; Murai, Kentaro; Takahashi, Suguru

    2012-01-01

    Microgravity conditions have advantages of measurement of surface tension and viscosity of metallic liquids by the oscillating drop method with an electromagnetic levitation (EML) device. Thus, we are preparing the experiments of thermophysical properties measurements using the Materials-Science Laboratories ElectroMagnetic-Levitator (MSL-EML) facilities in the international Space station (ISS). Recently, it has been identified that dependence of surface tension on oxygen partial pressure (Po2) must be considered for industrial application of surface tension values. Effect of Po2 on surface tension would apparently change viscosity from the damping oscillation model. Therefore, surface tension and viscosity must be measured simultaneously in the same atmospheric conditions. Moreover, effect of the electromagnetic force (EMF) on the surface oscillations must be clarified to obtain the ideal surface oscillation because the EMF works as the external force on the oscillating liquid droplets, so extensive EMF makes apparently the viscosity values large. In our group, using the parabolic flight levitation experimental facilities (PFLEX) the effect of Po2 and external EMF on surface oscillation of levitated liquid droplets was systematically investigated for the precise measurements of surface tension and viscosity of high temperature liquids for future ISS experiments. We performed the observation of surface oscillations of levitated liquid alloys using PFLEX on board flight experiments by Gulfstream II (G-II) airplane operated by DAS. These observations were performed under the controlled Po2 and also under the suitable EMF conditions. In these experiments, we obtained the density, the viscosity and the surface tension values of liquid Cu. From these results, we discuss about as same as reported data, and also obtained the difference of surface oscillations with the change of the EMF conditions.

  5. Polythiophene films obtained by polymerization under atmospheric pressure plasma conditions

    Energy Technology Data Exchange (ETDEWEB)

    Teslaru, T.; Topala, I., E-mail: ionut.topala@uaic.ro; Dobromir, M.; Pohoata, V.; Curecheriu, L.; Dumitrascu, N.

    2016-02-01

    The present work describes the experimental arrangement used to initiate polymerization reactions of thiophene monomer based on a dielectric barrier discharge with plane – parallel geometry, working at atmospheric pressure in argon, in turn to obtain conductive polymeric films for different applications. The resulting plasma polymerized polythiophene (pPTh) film was characterized by FT-IR, UV–Vis, XPS spectroscopy, AFM and contact angle measurements. Characterization of pPTh films showed a higher hydrophobic character and roughness, as compared with films obtained by chemical methods, and the thickness is depending on polymerization duration. Also it can conclude that our samples represent oxidised state of pPTh. As a possible application, it analysed in situ the iodine absorption phenomenon in the pPTh matrix and its time evolution by UV–Vis spectroscopy. The presence of iodine 3d{sub 5/2} and 3d{sub 3/2} peaks in the pPTh sample after absorption was identified by XPS spectroscopy. The hydrophobic pPTh film is transformed in a super hydrophilic film after absorption of iodine vapors. - Highlights: • We obtained polythiophene films (pPTh) by atmospheric pressure plasma technique. • The pPTh films showed a hydrophobic character and conducting properties. • The pPTh films were used as sensor for iodine vapors in biological environment.

  6. Evidence for the existence of supercooled ethane droplets under conditions prevalent in Titan's atmosphere.

    Science.gov (United States)

    Sigurbjörnsson, Omar F; Signorell, Ruth

    2008-11-07

    Recent evidence for ethane clouds and condensation in Titan's atmosphere raise the question whether liquid ethane condensation nuclei and supercooled liquid ethane droplets exist under the prevalent conditions. We present laboratory studies on the phase behaviour of pure ethane aerosols and ethane aerosols formed in the presence of other ice nuclei under conditions relevant to Titan's atmosphere. Combining bath gas cooling with infrared spectroscopy, we find evidence for the existence of supercooled liquid ethane aerosol droplets. The observed homogeneous freezing rates imply that supercooled ethane could be a long-lived species in ethane-rich regions of Titan's atmosphere similar to supercooled water in the Earth's atmosphere.

  7. Separation and Conditioning of Mars Atmospheric Gases via TSA

    Science.gov (United States)

    Finn, John E.; Luna, Bernadette (Technical Monitor)

    2000-01-01

    Space and planetary exploration almost always presents interesting and unusual engineering challenges. Separations engineering for chemical processes that are critical to humans working in space is no exception. The challenges are becoming clearer as we make the transition from concepts and planning to hardware development, and as we understand better the constraints and environments in which the processes must perform. The coming decade will see a robotic Mars exploration program that has recovered from recent setbacks and is building a knowledge and technology base for human exploration. One of the missions will carry a small chemical pilot plant for demonstrating the manufacture of rocket propellants and life support consumables from the low-pressure (0.01 atm) Martian atmosphere. By manufacturing and storing the fuel and consumables needed for human-return missions in situ, launch mass and landed mass are reduced by tons and missions become far less expensive. The front-end to the pilot plant is a solid-state atmosphere acquisition and separation unit based on temperature-swing adsorption (TSA). The unit produces purified and pressurized (to 1.0 atm) carbon dioxide to downstream reactors that will make methane and oxygen. The unit also produces a nitrogen-argon mixture as a valuable by-product for life support, inflatable structures, and propellant pressurization. With nighttime temperatures falling to -100 degrees C, power availability restricted to a few watts, and flawless operation critical to success, the dusty Martian surface is a difficult place to operate a remote plant. This talk will focus on how this TSA separation process is designed and implemented for this application, and how it might be used in the more distant future for human exploration.

  8. Ecosystem-atmosphere exchange of carbon in a heathland under future climatic conditions

    DEFF Research Database (Denmark)

    Selsted, Merete Bang

    on ecosystem-atmosphere exchange of carbon in a heathland under future climatic conditions, shows that extended summer drought in combination with elevated temperature will ensure permanent dryer soil conditions, which decreases carbon turnover, while elevated atmospheric CO2 concentrations will increase...... carbon turnover. In the full future climate scenario, carbon turnover is over all expected to increase and the heathland to become a source of atmospheric CO2. The methodology of static chamber CO2 flux measurements and applying the technology in a FACE (free air CO2 enrichment) facility is a challenge...... on the atmospheric CO2 concentration. Photosynthesis and respiration run in parallel during measurements of net ecosystem exchange, and these measurements should therefore be performed with care to both the atmospheric CO2 concentration and the CO2 soil-atmosphere gradient....

  9. Transport of Chemical Vapors from Subsurface Sources to Atmosphere as Affected by Shallow Subsurface and Atmospheric Conditions

    Science.gov (United States)

    Rice, A. K.; Smits, K. M.; Hosken, K.; Schulte, P.; Illangasekare, T. H.

    2012-12-01

    Understanding the movement and modeling of chemical vapor through unsaturated soil in the shallow subsurface when subjected to natural atmospheric thermal and mass flux boundary conditions at the land surface is of importance to applications such as landmine detection and vapor intrusion into subsurface structures. New, advanced technologies exist to sense chemical signatures at the land/atmosphere interface, but interpretation of these sensor signals to make assessment of source conditions remains a challenge. Chemical signatures are subject to numerous interactions while migrating through the unsaturated soil environment, attenuating signal strength and masking contaminant source conditions. The dominant process governing movement of gases through porous media is often assumed to be Fickian diffusion through the air phase with minimal or no quantification of other processes contributing to vapor migration, such as thermal diffusion, convective gas flow due to the displacement of air, expansion/contraction of air due to temperature changes, temporal and spatial variations of soil moisture and fluctuations in atmospheric pressure. Soil water evaporation and interfacial mass transfer add to the complexity of the system. The goal of this work is to perform controlled experiments under transient conditions of soil moisture, temperature and wind at the land/atmosphere interface and use the resulting dataset to test existing theories on subsurface gas flow and iterate between numerical modeling efforts and experimental data. Ultimately, we aim to update conceptual models of shallow subsurface vapor transport to include conditionally significant transport processes and inform placement of mobile sensors and/or networks. We have developed a two-dimensional tank apparatus equipped with a network of sensors and a flow-through head space for simulation of the atmospheric interface. A detailed matrix of realistic atmospheric boundary conditions was applied in a series of

  10. Modified atmospheric conditions controlling fungal growth on cheese

    DEFF Research Database (Denmark)

    Nielsen, Per Væggemose

    1997-01-01

    Effective control of fungal growth on cheese under storage conditions is of great concern for the dairy industry. Therefore we designed a research project together with the Danish dairy industry on modelling fungal growth on cheese as affected by the combined effect of storage conditions (O2 and CO......2 level, relative humidity and temperature) and the composition of the cheese. All fungal species commonly found on cheese, starter cultures as well as contaminants, were examined.The most important factors influencing fungal growth are temperature, water activity of the medium and the carbon...... a competitive advantage over other fungi in moist conditions with high carbon dioxide levels, such as inside a roquefort cheese or in gas tight grain storage. The key to success in food packaging is to recognise the food ecosystem, as it enables us to identify which micro...

  11. Prevailing Torque Locking Feature in Threaded Fasteners Using Anaerobic Adhesive

    Science.gov (United States)

    Hernandez, Alan; Hess, Daniel P.

    2016-01-01

    This paper presents results from tests to assess the use of anaerobic adhesive for providing a prevailing torque locking feature in threaded fasteners. Test procedures are developed and tests are performed on three fastener materials, four anaerobic adhesives, and both unseated assembly conditions. Five to ten samples are tested for each combination. Tests for initial use, reuse without additional adhesive, and reuse with additional adhesive are performed for all samples. A 48-hour cure time was used for all initial use and reuse tests. Test data are presented as removal torque versus removal angle with the specification required prevailing torque range added for performance assessment. Percent specification pass rates for the all combinations of fastener material, adhesive, and assembly condition are tabulated and reveal use of anaerobic adhesive as a prevailing torque locking feature is viable. Although not every possible fastener material and anaerobic adhesive combination provides prevailing torque values within specification, any combination can be assessed using the test procedures presented. Reuse without additional anaerobic adhesive generally provides some prevailing torque, and in some cases within specification. Reuse with additional adhesive often provides comparable removal torque data as in initial use.

  12. Measurement of forest condition and response along the Pennsylvania atmospheric deposition gradent

    Science.gov (United States)

    D.D. David; J.M. Skelly; J.A. Lynch; L.H. McCormick; B.L. Nash; M. Simini; E.A. Cameron; J.R. McClenahen; R.P. Long

    1991-01-01

    Research in the oak-hickory forest of northcentral Pennsylvania is being conducted to detect anomalies in forest condition that may be due to atmospheric deposition, with the intent that such anomalies will be further studied to determine the role, if any, of atmospheric deposition. This paper presents the status of research along a 160-km gradient of sulfate/nitrate...

  13. Response in atmospheric circulation and sources of Greenland precipitation to glacial boundary conditions

    DEFF Research Database (Denmark)

    Langen, Peter Lang; Vinther, Bo Møllesøe

    2009-01-01

    The response in northern hemisphere atmospheric circulation and the resulting changes in moisture sources for Greenland precipitation to glacial boundary conditions are studied in NCAR's CCM3 atmospheric general circulation model fitted with a moisture tracking functionality. We employ both...... seasonality, condensation temperatures and source temperatures are assessed. Udgivelsesdato: June 2009...

  14. Surface layer conditions of the atmosphere over western Bay of Bengal during Monex

    Digital Repository Service at National Institute of Oceanography (India)

    Anto, A.F.; Rao, L.V.G.; Somayajulu, Y.K.

    Based on surface meteorological data and wave data collected from 2 stations in the western Bay of Bengal in July 1979, surface layer (SL) conditions of the atmosphere for different situations of surface circulations and the associated sea surface...

  15. Atmospheric conditions of intense thaws in the Polish lowlands

    Energy Technology Data Exchange (ETDEWEB)

    Bednorz, Ewa [Adam Mickiewicz Univ., Poznan (Poland). Dept. of Climatology

    2012-02-15

    Synoptic conditions of daily changes in the snow cover depth by {>=} 5 cm were analyzed. Negative pressure anomalies appear over the North Atlantic and Scandinavia, which means low pressure systems moving over Europe along a northerly path. At the same time, positive pressure anomalies appear over the Mediterranean, indicating the expansion of the Azorean High. Such distribution of anomalies increases the horizontal baric gradient, which results in the intensification of the western and south western flow and stronger than usual winds from the SW quadrant. Transport of warm and humid air masses from the south-west brings about thaw-conducive conditions in central Europe: an increase in temperature and a considerable increase in the content of precipitable water, which means abundant precipitation. Different circulation types favorable for intense thawing were distinguished using the method of the hierarchical grouping. Two of them are characterized by the presence of deep and widespread cyclonal systems located north, north-west or west of the researched area. Less frequently, the decrease in the depth of snow cover occurs in the presence of the high located west over the Atlantic Ocean, which brings air masses from the north western direction. Such situations occur most frequently towards the end of winter. (orig.)

  16. Model test study of evaporation mechanism of sand under constant atmospheric condition

    OpenAIRE

    CUI, Yu Jun; DING, Wenqi; SONG, Weikang

    2014-01-01

    The evaporation mechanism of Fontainebleau sand using a large-scale model chamber is studied. First, the evaporation test on a layer of water above sand surface is performed under various atmospheric conditions, validating the performance of the chamber and the calculation method of actual evaporation rate by comparing the calculated and measured cumulative evaporations. Second,the evaporation test on sand without water layer is conducted under constant atmospheric condition. Both the evoluti...

  17. CFD Modeling of Non-Neutral Atmospheric Boundary Layer Conditions

    DEFF Research Database (Denmark)

    Koblitz, Tilman

    model results. A method is developed how to simulate the time-dependant non-neutral ABL flow over complex terrain: a precursor simulation is used to specify unsteady inlet boundary conditions on complex terrain domains. The advantage of the developed RANS model framework is its general applicability...... characteristics of neutral and non-neutral ABL flow. The developed ABL model significantly improves the predicted flow fields over both flat and complex terrain, when compared against neutral models and measurements....... cost than e.g. using large-eddy simulations. The developed ABL model is successfully validated using a range of different test cases with increasing complexity. Data from several large scale field campaigns, wind tunnel experiments, and previous numerical simulations is presented and compared against...

  18. Atmospheric-radiation boundary conditions for high-frequency waves in time-distance helioseismology

    Science.gov (United States)

    Fournier, D.; Leguèbe, M.; Hanson, C. S.; Gizon, L.; Barucq, H.; Chabassier, J.; Duruflé, M.

    2017-12-01

    The temporal covariance between seismic waves measured at two locations on the solar surface is the fundamental observable in time-distance helioseismology. Above the acoustic cut-off frequency ( 5.3 mHz), waves are not trapped in the solar interior and the covariance function can be used to probe the upper atmosphere. We wish to implement appropriate radiative boundary conditions for computing the propagation of high-frequency waves in the solar atmosphere. We consider recently developed and published radiative boundary conditions for atmospheres in which sound-speed is constant and density decreases exponentially with radius. We compute the cross-covariance function using a finite element method in spherical geometry and in the frequency domain. The ratio between first- and second-skip amplitudes in the time-distance diagram is used as a diagnostic to compare boundary conditions and to compare with observations. We find that a boundary condition applied 500 km above the photosphere and derived under the approximation of small angles of incidence accurately reproduces the "infinite atmosphere" solution for high-frequency waves. When the radiative boundary condition is applied 2 Mm above the photosphere, we find that the choice of atmospheric model affects the time-distance diagram. In particular, the time-distance diagram exhibits double-ridge structure when using a Vernazza Avrett Loeser atmospheric model.

  19. Under What Conditions Can Equilibrium Gas-Particle Partitioning Be Expected to Hold in the Atmosphere?

    Science.gov (United States)

    Mai, Huajun; Shiraiwa, Manabu; Flagan, Richard C; Seinfeld, John H

    2015-10-06

    The prevailing treatment of secondary organic aerosol formation in atmospheric models is based on the assumption of instantaneous gas-particle equilibrium for the condensing species, yet compelling experimental evidence indicates that organic aerosols can exhibit the properties of highly viscous, semisolid particles, for which gas-particle equilibrium may be achieved slowly. The approach to gas-particle equilibrium partitioning is controlled by gas-phase diffusion, interfacial transport, and particle-phase diffusion. Here we evaluate the controlling processes and the time scale to achieve gas-particle equilibrium as a function of the volatility of the condensing species, its surface accommodation coefficient, and its particle-phase diffusivity. For particles in the size range of typical atmospheric organic aerosols (∼50-500 nm), the time scale to establish gas-particle equilibrium is generally governed either by interfacial accommodation or particle-phase diffusion. The rate of approach to equilibrium varies, depending on whether the bulk vapor concentration is constant, typical of an open system, or decreasing as a result of condensation into the particles, typical of a closed system.

  20. Atmospheric degradation mechanism of organic sulfur compounds

    Energy Technology Data Exchange (ETDEWEB)

    Benter, T; Arsene, C

    2002-02-01

    In the present work a detailed product study has been performed on the OH radical initiated oxidation of dimethyl sulphide and dimethyl sulphoxide, under different conditions of temperature, partial pressure of oxygen and NO{sub x} concentration, in order to better define the degradation mechanism of the above compounds under conditions which prevail in the atmosphere. (orig.)

  1. Ecosystem-atmosphere exchange of carbon in a heathland under future climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bang Selsted, M

    2010-07-15

    Global change is a reality. Atmospheric CO{sub 2} levels are rising as well as mean global temperature and precipitation patterns are changing. These three environmental factors have separately and in combination effect on ecosystem processes. Terrestrial ecosystems hold large amounts of carbon, why understanding plant and soil responses to such changes are necessary, as ecosystems potentially can ameliorate or accelerate global change. To predict the feedback of ecosystems to the atmospheric CO{sub 2} concentrations experiments imitating global change effects are therefore an important tool. This work on ecosystem-atmosphere exchange of carbon in a heathland under future climatic conditions, shows that extended summer drought in combination with elevated temperature will ensure permanent dryer soil conditions, which decreases carbon turnover, while elevated atmospheric CO{sub 2} concentrations will increase carbon turnover. In the full future climate scenario, carbon turnover is over all expected to increase and the heathland to become a source of atmospheric CO{sub 2}. The methodology of static chamber CO{sub 2} flux measurements and applying the technology in a FACE (free air CO{sub 2} enrichment) facility is a challenge. Fluxes of CO{sub 2} from soil to atmosphere depend on a physical equilibrium between those two medias, why it is important to keep the CO{sub 2} gradient between soil and atmosphere unchanged during measurement. Uptake to plants via photosynthesis depends on a physiological process, which depends strongly on the atmospheric CO{sub 2} concentration. Photosynthesis and respiration run in parallel during measurements of net ecosystem exchange, and these measurements should therefore be performed with care to both the atmospheric CO{sub 2} concentration and the CO{sub 2} soil-atmosphere gradient. (author)

  2. Influence factor analysis of atmospheric electric field monitoring near ground under different weather conditions

    International Nuclear Information System (INIS)

    Wan, Haojiang; Wei, Guanghui; Cui, Yaozhong; Chen, Yazhou

    2013-01-01

    Monitoring of atmospheric electric field near ground plays a critical role in atmospheric environment detecting and lightning warning. Different environmental conditions (e.g. buildings, plants, weather, etc.) have different influences on the data's coherence in an atmospheric electric field detection network. In order to study the main influence factors of atmospheric electric field monitoring under different weather conditions, with the combination of theoretical analysis and experiments, the electric field monitoring data on the ground and on the top of a building are compared in fair weather and thunderstorm weather respectively in this paper. The results show that: In fair weather, the field distortion due to the buildings is the main influence factor on the electric field monitoring. In thunderstorm weather, the corona ions produced from the ground, besides the field distortion due to the buildings, can also influence the electric field monitoring results.

  3. Description of Atmospheric Conditions at the Pierre Auger Observatory using the Global Data Assimilation System (GDAS)

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, P.; /Lisbon, IST; Aglietta, M.; /Turin U. /INFN, Turin; Ahlers, M.; /Wisconsin U., Madison; Ahn, E.J.; /Fermilab; Albuquerque, I.F.M.; /Sao Paulo U.; Allard, D.; /APC, Paris; Allekotte, I.; /Buenos Aires, CONICET; Allen, J.; /New York U.; Allison, P.; /Ohio State U.; Almela, A.; /Natl. Tech. U., San Nicolas /Buenos Aires, CONICET; Alvarez Castillo, J.; /Mexico U., ICN /Santiago de Compostela U.

    2012-01-01

    Atmospheric conditions at the site of a cosmic ray observatory must be known for reconstructing observed extensive air showers. The Global Data Assimilation System (GDAS) is a global atmospheric model predicated on meteorological measurements and numerical weather predictions. GDAS provides altitude-dependent profiles of the main state variables of the atmosphere like temperature, pressure, and humidity. The original data and their application to the air shower reconstruction of the Pierre Auger Observatory are described. By comparisons with radiosonde and weather station measurements obtained on-site in Malargue and averaged monthly models, the utility of the GDAS data is shown.

  4. PBMC: Pre-conditioned Backward Monte Carlo code for radiative transport in planetary atmospheres

    Science.gov (United States)

    García Muñoz, A.; Mills, F. P.

    2017-08-01

    PBMC (Pre-Conditioned Backward Monte Carlo) solves the vector Radiative Transport Equation (vRTE) and can be applied to planetary atmospheres irradiated from above. The code builds the solution by simulating the photon trajectories from the detector towards the radiation source, i.e. in the reverse order of the actual photon displacements. In accounting for the polarization in the sampling of photon propagation directions and pre-conditioning the scattering matrix with information from the scattering matrices of prior (in the BMC integration order) photon collisions, PBMC avoids the unstable and biased solutions of classical BMC algorithms for conservative, optically-thick, strongly-polarizing media such as Rayleigh atmospheres.

  5. STEEL CORROSION AT 600°C IN SINGLE AND DUAL CONDITION IN OXYFUEL ATMOSPHERE

    Directory of Open Access Journals (Sweden)

    Daniel Massari de Souza Coelho

    2014-10-01

    Full Text Available Coal-fired power plants using the Oxyfuel process are being developed to produce electricity with zero CO2 emission. Steels used in this and other processes are often exposed to different atmospheres in each side of the material, especially in heat exchangers and solid oxide fuel cells. Some studies have shown that steels exposed to different hydrogen partial pressures in each side have a different corrosion behavior from steels exposed to a single atmosphere condition. In this investigation, two experimental steels were studied at 600°C and 1 atm in dual atmospheres containing water vapor in one side and flue gas in the other and they were compared to steels oxidized in single atmospheres. The gas composition used is similar to the ones found in Oxyfuel coal power plants, where there is a great concentration of CO2, and also H2O and SO2. Analyses were made using SEM and TEM.

  6. Assessing the Impacts of Atmospheric Conditions under Climate Change on Air Quality Profile over Hong Kong

    Science.gov (United States)

    Hei Tong, Cheuk

    2017-04-01

    Small particulates can cause long term impairment to human health as they can penetrate deep and deposit on the wall of the respiratory system. Under the projected climate change as reported by literature, atmospheric stability, which has strong effects on vertical mixing of air pollutants and thus air quality Hong Kong, is also varying from near to far future. In addition to domestic emission, Hong Kong receives also significant concentration of cross-boundary particulates that their natures and movements are correlated with atmospheric condition. This study aims to study the relation of atmospheric conditions with air quality over Hong Kong. Past meteorological data is based on Modern Era Retrospective Analysis for Research and Applications (MERRA) reanalysis data. Radiosonde data provided from HKO are also adopted in testing and validating the data. Future meteorological data is simulated by the Weather Research and Forecasting Model (WRF), which dynamically downscaled the past and future climate under the A1B scenario simulated by ECHAM5/MPIOM. Air quality data is collected on one hand from the ground station data provided by Environment Protection Department, with selected stations revealing local emission and trans-boundary emission respectively. On the other hand, an Atmospheric Light Detection and Ranging (LiDAR), which operates using the radar principle to detect Rayleigh and Mie scattering from atmospheric gas and aerosols, has also been adopted to measure vertical aerosol profile, which has been observed tightly related to the high level meteorology. Data from scattered signals are collected, averaged or some episode selected for characteristic comparison with the atmospheric stability indices and other meteorological factors. The relation between atmospheric conditions and air quality is observed by statistical analysis, and statistical models are built based on the stability indices to project the changes in sulphur dioxide, ozone and particulate

  7. Evaluation of carbon diffusion in heat treatment of H13 tool steel under different atmospheric conditions

    Directory of Open Access Journals (Sweden)

    Maziar Ramezani

    2015-04-01

    Full Text Available Although the cost of the heat treatment process is only a minor portion of the total production cost, it is arguably the most important and crucial stage on the determination of material quality. In the study of the carbon diffusion in H13 steel during austenitization, a series of heat treatment experiments had been conducted under different atmospheric conditions and length of treatment. Four austenitization atmospheric conditions were studied, i.e., heat treatment without atmospheric control, heat treatment with stainless steel foil wrapping, pack carburization heat treatment and vacuum heat treatment. The results showed that stainless steel foil wrapping could restrict decarburization process, resulting in a constant hardness profile as vacuum heat treatment does. However, the tempering characteristic between these two heat treatment methods is different. Results from the gas nitrided samples showed that the thickness and the hardness of the nitrided layer is independent of the carbon content in H13 steel.

  8. Initial conditions and ENSO prediction using a coupled ocean-atmosphere model

    Science.gov (United States)

    Larow, T. E.; Krishnamurti, T. N.

    1998-01-01

    A coupled ocean-atmosphere initialization scheme using Newtonian relaxation has been developed for the Florida State University coupled ocean-atmosphere global general circulation model. The initialization scheme is used to initialize the coupled model for seasonal forecasting the boreal summers of 1987 and 1988. The atmosphere model is a modified version of the Florida State University global spectral model, resolution T-42. The ocean general circulation model consists of a slightly modified version of the Hamburg's climate group model described in Latif (1987) and Latif et al. (1993). The coupling is synchronous with information exchanged every two model hours. Using ECMWF atmospheric daily analysis and observed monthly mean SSTs, two, 1-year, time-dependent, Newtonian relaxation were performed using the coupled model prior to conducting the seasonal forecasts. The coupled initializations were conducted from 1 June 1986 to 1 June 1987 and from 1 June 1987 to 1 June 1988. Newtonian relaxation was applied to the prognostic atmospheric vorticity, divergence, temperature and dew point depression equations. In the ocean model the relaxation was applied to the surface temperature. Two, 10-member ensemble integrations were conducted to examine the impact of the coupled initialization on the seasonal forecasts. The initial conditions used for the ensembles are the ocean's final state after the initialization and the atmospheric initial conditions are ECMWF analysis. Examination of the SST root mean square error and anomaly correlations between observed and forecasted SSTs in the Niño-3 and Niño-4 regions for the 2 seasonal forecasts, show closer agreement between the initialized forecast than two, 10-member non-initialized ensemble forecasts. The main conclusion here is that a single forecast with the coupled initialization outperforms, in SST anomaly prediction, against each of the control forecasts (members of the ensemble) which do not include such an initialization

  9. Wake meandering under non-neutral atmospheric stability conditions – theory and facts

    DEFF Research Database (Denmark)

    Larsen, Gunner Chr.; Machefaux, Ewan; Chougule, Abhijit S.

    2015-01-01

    This paper deals with modelling of wake dynamics under influence of atmospheric stability conditions different from neutral. In particular, it is investigated how the basic split in turbulent scales, on which the Dynamic Wake Meandering model is based, can be utilized to include atmospheric...... stability effects in this model. This is done partly by analyzing a large number of turbulence spectra obtained from sonic measurements, partly by analyzing dedicated full-scale LiDAR measurements from which wake dynamics can be directly resolved. The theory behind generalizing the Dynamic Wake Meandering...

  10. Numberical Calculations of Atmospheric Conditions over Tibetan Plateau by Using WRF Model

    International Nuclear Information System (INIS)

    Qian, Xuan; Yao, Yongqiang; Wang, Hongshuai; Liu, Liyong; Li, Junrong; Yin, Jia

    2015-01-01

    The wind field, precipitable water vapor are analyzed by using the mesoscale numerical model WRF over Tibetan Plateau, and the aerosol is analyzed by using WRF- CHEM model. The spatial and vertical distributions of the relevant atmospheric factors are summarized, providing truth evidence for selecting and further evaluating an astronomical site. It has been showed that this method could provide good evaluation of atmospheric conditions. This study serves as a further demonstration towards astro-climate regionalization, and provides with essential database for astronomical site survey over Tibetan Plateau. (paper)

  11. Interaction of oxides of nitrogen and aromatic hydrocarbons under simulated atmospheric conditions

    International Nuclear Information System (INIS)

    Obrien, R.J.; Green, P.J.; Doty, R.A.; Vanderzanden, J.W.; Easton, R.R.; Irwin, R.P.

    1979-01-01

    The reactions of nitrogen oxides with aromatic hydrocarbons under simulated atmospheric conditions are investigated. Gaseous reaction products formed when toluene is irradiated under simulated atmospheric conditions in the presence of nitrogen oxides were analyzed by gas chromatography. Reaction products detected include acetylene, water, acetaldehyde, acetone, toluene, benzaldehyde, ortho-, meta- and para-cresol, benzyl nitrate and meta- and para-nitrotoluene. Reaction mechanisms yielding the various products are illustrated. The assumption that all the nitrogen oxides observed to be lost from the reaction products can be accounted for by nitric acid formation in the absence of ozone formation is verified by a model in which the hydroxyl radical is assumed to be the only means of removing toluene. Under conditions in which ozone is formed, nitrogen oxide loss is accounted for by ozone formation in addition to nitric acid formation

  12. Oblique radiation lateral open boundary conditions for a regional climate atmospheric model

    Science.gov (United States)

    Cabos Narvaez, William; De Frutos Redondo, Jose Antonio; Perez Sanz, Juan Ignacio; Sein, Dmitry

    2013-04-01

    The prescription of lateral boundary conditions in regional atmospheric models represent a very important issue for limited area models. The ill-posed nature of the open boundary conditions makes it necessary to devise schemes in order to filter spurious wave reflections at boundaries, being desirable to have one boundary condition per variable. On the other side, due to the essentially hyperbolic nature of the equations solved in state of the art atmospheric models, external data is required only for inward boundary fluxes. These circumstances make radiation lateral boundary conditions a good choice for the filtering of spurious wave reflections. Here we apply the adaptive oblique radiation modification proposed by Mikoyada and Roseti to each of the prognostic variables of the REMO regional atmospheric model and compare it to the more common normal radiation condition used in REMO. In the proposed scheme, special attention is paid to the estimation of the radiation phase speed, essential to detecting the direction of boundary fluxes. One of the differences with the classical scheme is that in case of outward propagation, the adaptive nudging imposed in the boundaries allows to minimize under and over specifications problems, adequately incorporating the external information.

  13. Critical review: Copper runoff from outdoor copper surfaces at atmospheric conditions.

    Science.gov (United States)

    Hedberg, Yolanda S; Hedberg, Jonas F; Herting, Gunilla; Goidanich, Sara; Odnevall Wallinder, Inger

    2014-01-01

    This review on copper runoff dispersed from unsheltered naturally patinated copper used for roofing and facades summarizes and discusses influencing factors, available literature, and predictive models, and the importance of fate and speciation for environmental risk assessment. Copper runoff from outdoor surfaces is predominantly governed by electrochemical and chemical reactions and is highly dependent on given exposure conditions (size, inclination, geometry, degree of sheltering, and orientation), surface parameters (age, patina composition, and thickness), and site-specific environmental conditions (gaseous pollutants, chlorides, rainfall characteristics (amount, intensity, pH), wind direction, temperature, time of wetness, season). The corrosion rate cannot be used to assess the runoff rate. The extent of released copper varies largely between different rain events and is related to dry and wet periods, dry deposition prior to the rain event and prevailing rain and patina characteristics. Interpretation and use of copper runoff data for environmental risk assessment and management need therefore to consider site-specific factors and focus on average data of long-term studies (several years). Risk assessments require furthermore that changes in copper speciation, bioavailability aspects, and potential irreversible retention on solid surfaces are considered, factors that determine the environmental fate of copper runoff from outdoor surfaces.

  14. Efficacy of passive sampler collection for atmospheric NO2 isotopes under simulated environmental conditions.

    Science.gov (United States)

    Coughlin, Justin G; Yu, Zhongjie; Elliott, Emily M

    2017-07-30

    Nitrogen oxides or NO x (NO x = NO + NO 2 ) play an important role in air quality, atmospheric chemistry, and climate. The isotopic compositions of anthropogenic and natural NO 2 sources are wide-ranging, and they can be used to constrain sources of ambient NO 2 and associated atmospheric deposition of nitrogen compounds. While passive sample collection of NO 2 isotopes has been used in field studies to determine NO x source influences on atmospheric deposition, this approach has not been evaluated for accuracy or precision under different environmental conditions. The efficacy of NO 2 passive sampler collection for NO 2 isotopes was evaluated under varied temperature and relative humidity (RH) conditions in a dynamic flux chamber. The precision and accuracy of the filter NO 2 collection as nitrite (NO 2 - ) for isotopic analysis were determined using a reference NO 2 gas tank and through inter-calibration with a modified EPA Method 7. The bacterial denitrifer method was used to convert 20 μM of collected NO 2 - or nitrate (NO 3 - ) into N 2 O and was carried out on an Isoprime continuous flow isotope ratio mass spectrometer. δ 15 N-NO 2 values determined from passive NO 2 collection, in conditions of 11-34 °C, 1-78% RH, have an overall accuracy and precision of ±2.1 ‰, and individual run precision of ±0.6 ‰. δ 18 O-NO 2 values obtained from passive NO 2 sampler collection, under the same conditions, have an overall precision of ± 1.3 ‰. Suitable conditions for passive sampler collection of NO 2 isotopes are in environments ranging from 11 to 34 °C and 1 to 78% RH. The passive NO 2 isotope measurement technique provides an accurate method to determine variations in atmospheric δ 15 N-NO 2 values and a precise method for determining atmospheric δ 18 O-NO 2 values. The ability to measure NO 2 isotopes over spatial gradients at the same temporal resolution provides a unique perspective on the extent and seasonality of fluctuations in atmospheric NO 2

  15. Necessary conditions for the initiation and propagation of nuclear-detonation waves in plane atmospheres

    International Nuclear Information System (INIS)

    Weaver, T.A.; Wood, L.

    1979-01-01

    The basic conditions for the initiation of a nuclear-detonation wave in an atmosphere having plane symmetry (e.g., a thin, layered fluid envelope on a planet or star) are developed. Two classes of such a detonation are identified: those in which the temperature of the plasma is comparable to that of the electromagnetic radiation permeating it, and those in which the temperature of the plasma is much higher. Necessary conditions are developed for the propagation of such detonation waves for an arbitrarily great distance. The contribution of fusion chain reactions to these processes is evaluated. By means of these considerations, it is shown that neither the atmosphere nor oceans of the Earth may be made to undergo propagating nuclear detonation under any circumstances

  16. Study of the relations between cloud properties and atmospheric conditions using ground-based digital images

    Science.gov (United States)

    Bakalova, Kalinka

    The aerosol constituents of the earth atmosphere are of great significance for the radiation budget and global climate of the planet. They are the precursors of clouds that in turn play an essential role in these processes and in the hydrological cycle of the Earth. Understanding the complex aerosol-cloud interactions requires a detailed knowledge of the dynamical processes moving the water vapor through the atmosphere, and of the physical mechanisms involved in the formation and growth of cloud particles. Ground-based observations on regional and short time scale provide valuable detailed information about atmospheric dynamics and cloud properties, and are used as a complementary tool to the global satellite observations. The objective of the present paper is to study the physical properties of clouds as displayed in ground-based visible images, and juxtapose them to the specific surface and atmospheric meteorological conditions. The observations are being carried out over the urban area of the city of Sofia, Bulgaria. The data obtained from visible images of clouds enable a quantitative description of texture and morphological features of clouds such as shape, thickness, motion, etc. These characteristics are related to cloud microphysical properties. The changes of relative humidity and the horizontal visibility are considered to be representative of the variations of the type (natural/manmade) and amount of the atmospheric aerosols near the earth surface, and potentially, the cloud drop number concentration. The atmospheric dynamics is accounted for by means of the values of the atmospheric pressure, temperature, wind velocity, etc., observed at the earth's surface. The advantage of ground-based observations of clouds compared to satellite ones is in the high spatial and temporal resolution of the obtained data about the lowermost cloud layer, which in turn is sensitive to the meteorological regimes that determine cloud formation and evolution. It turns out

  17. Atmospheric propagation of high power laser radiation at different weather conditions

    OpenAIRE

    Pargmann, Carsten; Hall, Thomas; Duschek, Frank; Handke, Jürgen

    2016-01-01

    Applications based on the propagation of high power laser radiation through the atmosphere are limited in range and effect, due to weather dependent beam wandering, beam deterioration, and scattering processes. Security and defense related application examples are countermeasures against hostile projectiles and the powering of satellites and aircrafts. For an examination of the correlations between weather condition and laser beam characteristics DLR operates at Lampoldshausen a 130 m long fr...

  18. Exchange of nitrogen dioxide (NO2) between plants and the atmosphere under laboratory and field conditions

    Science.gov (United States)

    Breuninger, C.; Meixner, F. X.; Thielmann, A.; Kuhn, U.; Dindorf, T.; Kesselmeier, J.

    2012-04-01

    Nitric oxide (NO), nitrogen dioxide (NO2), often denoted as nitrogen oxides (NOx), and ozone (O3) are considered as most important compounds in atmospheric chemistry. In remote areas NOx concentration is related to biological activities of soils and vegetation. The emitted NOx will not entirely be subject of long range transport through the atmosphere. Aside oxidation of NO2 by the OH radical (forming HNO3), a considerable part of it is removed from the atmosphere through the uptake of NO2 by plants. The exchange depends on stomatal activity and on NO2 concentrations in ambient air. It is known that NO2 uptake by plants represents a large NO2 sink, but the magnitude and the NO2 compensation point concentration are still under discussion. Our dynamic chamber system allows exchange measurements of NO2 under field conditions (uncontrolled) as well as studies under controlled laboratory conditions including fumigation experiments. For NO2 detection we used a highly NO2 specific blue light converter (photolytic converter) with subsequent chemiluminescence analysis of the generated NO. Furthermore, as the exchange of NO2 is a complex interaction of transport, chemistry and plant physiology, in our field experiments we determined fluxes of NO, NO2, O3, CO2 and H2O. For a better knowledge of compensation point values for the bi-directional NO2 exchange we investigated a primary representative of conifers, Picea abies, under field and laboratory conditions, and re-analyzed older field data of the deciduous tree Quercus robur.

  19. Modeling Daily Rainfall Conditional on Atmospheric Predictors: An application to Western Greece

    Science.gov (United States)

    Langousis, Andreas; Kaleris, Vassilios

    2013-04-01

    Due to its intermittent and highly variable character, daily precipitation is the least well reproduced hydrologic variable by both General Circulation Models (GCMs) and Limited Area Models (LAMs). To that extent, several statistical procedures (usually referred to as downscaling schemes) have been suggested to generate synthetic rainfall time series conditional on predictor variables that are descriptive of the atmospheric circulation at the mesoscale. In addition to be more accurately simulated by GCMs and LAMs, large-scale atmospheric predictors are important indicators of the local weather. Currently used downscaling methods simulate rainfall series using either stable statistical relationships (usually referred to as transfer functions) between certain characteristics of the rainfall process and mesoscale atmospheric predictor variables, or simple stochastic schemes (e.g. properly transformed autoregressive models) with parameters that depend on the large-scale atmospheric conditions. The latter are determined by classifying large-scale circulation patterns into broad categories of weather states, using empirical or theoretically based classification schemes, and modeled by resampling from those categories; a process usually referred to as weather generation. In this work we propose a statistical framework to generate synthetic rainfall timeseries at a daily level, conditional on large scale atmospheric predictors. The latter include the mean sea level pressure (MSLP), the magnitude and direction of upper level geostrophic winds, and the 500 hPa geopotential height, relative vorticity and divergence. The suggested framework operates in continuous time, avoiding the use of transfer functions, and weather classification schemes. The suggested downscaling approach is validated using atmospheric data from the ERA-Interim archive (see http://www.ecmwf.int/research/era/do/get/index), and daily rainfall data from Western Greece, for the 14-year period from 01 October

  20. Fretting Wear Damage Mechanism of Uranium under Various Atmosphere and Vacuum Conditions

    Directory of Open Access Journals (Sweden)

    Zhengyang Li

    2018-04-01

    Full Text Available A fretting wear experiment with uranium has been performed on a linear reciprocating tribometer with ball-on-disk contact. This study focused on the fretting behavior of the uranium under different atmospheres (Ar, Air (21% O2 + 78% N2, and O2 and vacuum conditions (1.05 and 1 × 10−4 Pa. Evolution of friction was assessed by coefficient of friction (COF and friction-dissipated energy. The oxide of the wear surface was evaluated by Raman spectroscopy. The result shows that fretting wear behavior presents strong atmosphere and vacuum condition dependence. With increasing oxygen content, the COF decreases due to abrasive wear and formation of oxide film. The COF in the oxygen condition is at least 0.335, and it has a maximum wear volume of about 1.48 × 107 μm3. However, the COF in a high vacuum condition is maximum about 1.104, and the wear volume is 1.64 × 106 μm3. The COF in the low vacuum condition is very different: it firstly increased and then decreased rapidly to a steady value. It is caused by slight abrasive wear and the formation of tribofilm after thousands of cycles.

  1. Impact of atmospheric release in stable night meteorological conditions; can emergency models predict dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Connan, O.; Hebert, D.; Solier, L.; Voiseux, C.; Lamotte, M.; Laguionie, P.; Maro, D.; Thomas, L. [IRSN/PRP-ENV/SERIS/LRC (France)

    2014-07-01

    Atmospheric dispersion of pollutant or radionuclides in stratified meteorological condition, i.e. especially when weather conditions are very stable, mainly at night, is still poorly understood and not well apprehended by the operational atmospheric dispersion models. However, correctly predicting the dispersion of a radioactive plume, and estimating the radiological consequences for the population, following an unplanned atmospheric release of radionuclides are crucial steps in an emergency response. To better understand dispersion in these special weather conditions, IRSN performed a series of 22 air sampling campaigns between 2010 and 2013 in the vicinity of the La Hague nuclear reprocessing plant (AREVA - NC, France), at distances between 200 m and 3000 m from the facility. Krypton-85 ({sup 85}Kr), a b-and g-emitting radionuclide, released during the reprocessing of spent nuclear fuel was used as a non-reactive tracer of radioactive plumes. Experimental campaigns were realized in stability class stable or very stable (E or F according to Pasquill classification) 18 times, and in neutral conditions (D according to Pasquill classification) 4 times. During each campaign, Krypton-85 real time measurement were made to find the plume around the plant, and then integrated samples (30 min) were collected in bag perpendicularly to the assumed wind direction axis. After measurement by gamma spectrometry, we have, when it was possible, estimate the point of impact and the width of the plume. The objective was to estimate the horizontal dispersion (width) of the plume at ground level in function of the distance and be able to calculate atmospheric transfer coefficients. In a second step, objective was to conclude on the use of common model and on their uncertainties. The results will be presented in terms of impact on the near-field. They will be compared with data obtained in previous years in neutral atmospheric conditions, and finally the results will be confronted with

  2. Atmospheric conditions measured by a wireless sensor network on the local scale

    Science.gov (United States)

    Lengfeld, K.; Ament, F.

    2010-09-01

    Atmospheric conditions close to the surface, like temperature, wind speed and humidity, vary on small scales because of surface heterogeneities. Therefore, the traditional measuring approach of using a single, highly accurate station is of limited representativeness for a larger domain, because it is not able to determine these small scale variabilities. However, both the variability and the domain averages are important information for the development and validation of atmospheric models and soil-vegetation-atmosphere-transfer (SVAT) schemes. Due to progress in microelectronics it is possible to construct networks of comparably cheap meteorological stations with moderate accuracy. Such a network provides data in high spatial and temporal resolution. The EPFL Lausanne developed such a network called SensorScope, consisting of low cost autonomous stations. Each station observes air and surface temperature, humidity, wind direction and speed, incoming solar radiation, precipitation, soil moisture and soil temperature and sends the data via radio communication to a base station. This base station forwards the collected data via GSM/GPRS to a central server. The first measuring campaign took place within the FLUXPAT project in August 2009. We deployed 15 stations as a twin transect near Jülich, Germany. To test the quality of the low cost sensors we compared two of them to more accurate reference systems. It turned out, that although the network sensors are not highly accurate, the measurements are consistent. Consequently an analysis of the pattern of atmospheric conditions is feasible. The transect is 2.3 km long and covers different types of vegetation and a small river. Therefore, we analyse the influence of different land surfaces and the distance to the river on meteorological conditions. For example, we found a difference in air temperature of 0.8°C between the station closest to and the station farthest from the river. The decreasing relative humidity with

  3. The effect of the atmospheric condition on the extensive air shower analysis at the Telescope Array experiment

    International Nuclear Information System (INIS)

    Kobayashi, Y.; Tsunesada, Y.; Tokuno, H.; Kakimoto, F.; Tomida, T.

    2011-01-01

    The accuracies in determination of air shower parameters such as longitudinal profiles or primary energies with the fluorescence detection technique are strongly dependent on atmospheric conditions of the molecular and aerosol components. Moreover, air fluorescence photon yield depends on the atmospheric density, and the transparency of the air for fluorescence photons depends on the atmospheric conditions from EAS to FDs. In this paper, we describe the atmospheric monitoring system in the Telescope Array (TA experiment), and the impact of the atmospheric conditions in air shower reconstructions. The systematic uncertainties of the determination of the primary cosmic ray energies and of the measurement of depth of maximum development (X max ) of EASs due to atmospheric variance are evaluated by Monte Carlo simulation.

  4. Soil-plant-atmosphere conditions regulating convective cloud formation above southeastern US pine plantations.

    Science.gov (United States)

    Manoli, Gabriele; Domec, Jean-Christophe; Novick, Kimberly; Oishi, Andrew Christopher; Noormets, Asko; Marani, Marco; Katul, Gabriel

    2016-06-01

    Loblolly pine trees (Pinus taeda L.) occupy more than 20% of the forested area in the southern United States, represent more than 50% of the standing pine volume in this region, and remove from the atmosphere about 500 g C m-2 per year through net ecosystem exchange. Hence, their significance as a major regional carbon sink can hardly be disputed. What is disputed is whether the proliferation of young plantations replacing old forest in the southern United States will alter key aspects of the hydrologic cycle, including convective rainfall, which is the focus of the present work. Ecosystem fluxes of sensible (Hs) and latent heat (LE) and large-scale, slowly evolving free atmospheric temperature and water vapor content are known to be first-order controls on the formation of convective clouds in the atmospheric boundary layer. These controlling processes are here described by a zero-order analytical model aimed at assessing how plantations of different ages may regulate the persistence and transition of the atmospheric system between cloudy and cloudless conditions. Using the analytical model together with field observations, the roles of ecosystem Hs and LE on convective cloud formation are explored relative to the entrainment of heat and moisture from the free atmosphere. Our results demonstrate that cloudy-cloudless regimes at the land surface are regulated by a nonlinear relation between the Bowen ratio Bo=Hs/LE and root-zone soil water content, suggesting that young/mature pines ecosystems have the ability to recirculate available water (through rainfall predisposition mechanisms). Such nonlinearity was not detected in a much older pine stand, suggesting a higher tolerance to drought but a limited control on boundary layer dynamics. These results enable the generation of hypotheses about the impacts on convective cloud formation driven by afforestation/deforestation and groundwater depletion projected to increase following increased human population in the

  5. Determination atmospheric conditions by evaluating clearness index, turbidity and brightness of the sky

    International Nuclear Information System (INIS)

    Kandilli, C.

    2005-01-01

    There are fifteen different sky types which range from totally overcast sky to low turbidity clear sky have been defined by CIE (International Commission on Illumination). For the applications of solar energy engineering and day lighting purposes, it has a great importance to determine the physical characteristics of atmosphere and the sky type. The most important parameters which define the sky type are clearness index, turbidity and brightness. In this study, the parameters of clearness index, turbidity and brightness of the sky belong to Izmir was calculated and their relations with solar radiation and its components were represented according to 10 years data (1994-2004) of meteorology station of Ege University Solar Energy Institute. In this study, clearness index, turbidity, sky clearness and brightness were evaluated to put forward the effects of the these parameters on the atmospheric condition for designing and engineering purposes

  6. Sorption activity investigation of ultrafine powders of high temperature melting point compounds in atmospheric pressure conditions

    International Nuclear Information System (INIS)

    Rudneva, V.V.

    2006-01-01

    A study is made in saturation with gas in the air for ultradispersed chromium carbonitride and boride powders synthesized in a nitrogen plasma jet according to three variants: from elements, from oxides, from chromium trichloride. It is established that in the air on temperature increasing the powders adsorb considerable amounts of oxygen and water vapor. This results in surface oxidation of powder particles and a loss in specific combination of properties. Preliminary vacuum heat treatment is shown to decrease sharply the rate of atmospheric gas adsorption. The quantity of adsorbed gases is dependent on a carbon monoxide concentration in a particle surface layer and the availability of adsorption centers. The number of such centers in the layer can be controlled by vacuum heat treatment conditions. The interaction of the powders with atmospheric gases is concluded to be of adsorption-diffusion nature [ru

  7. Neutral molecular cluster formation of sulfuric acid–dimethylamine observed in real time under atmospheric conditions

    CERN Document Server

    Kürten, Andreas; Simon, Mario; Sipilä, Mikko; Sarnela, Nina; Junninen, Heikki; Adamov, Alexey; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Donahue, Neil M; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Hutterli, Manuel; Kangasluoma, Juha; Kirkby, Jasper; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud P; Riccobono, Francesco; Rissanen, Matti P; Rondo, Linda; Schobesberger, Siegfried; Seinfeld, John H; Steiner, Gerhard; Tomé, António; Tröstl, Jasmin; Winkler, Paul M; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Baltensperger, Urs; Carslaw, Kenneth S; Kulmala, Markku; Worsnop, Douglas R; Curtius, Joachim

    2014-01-01

    For atmospheric sulfuric acid (SA) concentrations the presence of dimethylamine (DMA) at mixing ratios of several parts per trillion by volume can explain observed boundary layer new particle formation rates. However, the concentration and molecular composition of the neutral (uncharged) clusters have not been reported so far due to the lack of suitable instrumentation. Here we report on experiments from the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research revealing the formation of neutral particles containing up to 14 SA and 16 DMA molecules, corresponding to a mobility diameter of about 2 nm, under atmospherically relevant conditions. These measurements bridge the gap between the molecular and particle perspectives of nucleation, revealing the fundamental processes involved in particle formation and growth. The neutral clusters are found to form at or close to the kinetic limit where particle formation is limited only by the collision rate of SA molecules. Even tho...

  8. Cleaning and air conditioning device for atmosphere in thermonuclear reactor chamber

    International Nuclear Information System (INIS)

    Ishida, Seiji.

    1993-01-01

    The device of the present invention removes tritium efficiently and attains ventilation and conditioning of a great amount of air flow. That is, there are disposed a humidity separator, a filter, a heater, a catalyst filled layer, a water jetting type humidifying heat insulation cooler and a cooler in this order from an inlet side (upstream) of contaminated room atmospheric gases. The catalyst filled layer, etc. are incorporated integrally into the ventilation air conditioning facility for ventilating air in the chamber of the thermonuclear reactor, to clean a tritium atmosphere at the same time. Accordingly, the device is made compact as a whole. A limit for the air flow rate owing to the use of the conventional catalyst tower and adsorbing tower is eliminated. Then a ventilating air conditioning for a great flow rate can be attained. Tritium is removed by cooling and dehumidification without using any adsorbent. Accordingly, an adsorbing tower is no more necessary and conventional regeneration operation is not required. As a result, space for installation is reduced, the system is simplified and the cost for construction and facility can be reduced. (I.S.)

  9. Modelling of the diffusion of pollutants in the atmosphere under varying conditions in large cultivated regions

    International Nuclear Information System (INIS)

    Wueneke, C.D.; Schultz, H.

    1975-01-01

    The most important routines of a numerical code based on the particle-in-cell-method for calculating the transport and the turbulent dispersion of inert and radio-active pollutants in the atmosphere have been programmed and have been tested successfully on the CDC computer CYBER 73/76 of the Regional Computer Centre for Niedersachsen in Hanover. Compared to the Gaussian plume model such a numerical code based on the particle-in-cell-method offers several advantages for the computation of the diffusion under varying conditions in large cultivated regions. (orig.) [de

  10. Forest condition and chemical characteristics of atmospheric depositions: research and monitoring network in Lombardy

    Directory of Open Access Journals (Sweden)

    Flaminio DI GIROLAMO

    2002-09-01

    Full Text Available Since 1987, the Regional Forestry Board of Lombardy and the Water Research Institute of the National Research Council have been carrying out surveys of forest conditions and the response of the ecosystem to environmental factors. The study approach is based on a large number of permanent plots for extensive monitoring (Level 1. At this level, crown condition is assessed annually, and soil condition and the nutritional status of forests surveyed. Some of the permanent plots were selected for intensive monitoring (Level 2, focussing mainly on the impact of atmospheric pollution on forest ecosystems. Level 2 monitoring also includes increment analyses, ground vegetation assessment, atmospheric deposition, soil solution analyses and climatic observations. This paper summarises the main results of a pluriannual research, which provides a general picture of the state of forest health in the region and focuses on more detailed investigations, described as case studies. Modified wet and dry samplers which use a water surface to collect dry deposition were used in a pluriannual field campaign at five sites in alpine and prealpine areas, to measure the total atmospheric depositions and to evaluate the nitrogen and sulphate exceedances of critical loads. Throughfall and bulk precipitation chemistry were studied for five years (June 1994-May 1999 at two high elevation forest sites (Val Gerola and Val Masino which were known to differ in terms of tree health, as assessed by live crown condition. Results indicated a higher contribution from the dry deposition of N-NO3 -, N-NH4 + and H+ and considerable canopy leaching of Ca2+, K+ and weak organic acids at Val Gerola, where the symptoms of damage were more evident. In the area of Val Masino (SO, included since 1997 in the national CONECOFOR network, investigations focused on the effectiveness of the biological compartment in modifying fluxes of atmospheric elements, and on the role of nitrogen both as an

  11. Nocturnal surface ozone enhancement over Portugal during winter: Influence of different atmospheric conditions

    KAUST Repository

    Kulkarni, Pavan S.

    2016-09-24

    Four distinct nocturnal surface ozone (NSO) enhancement events were observed, with NSO concentration exceeding 80μg/m3, at multiple ozone (O3) monitoring stations (32 sites) in January, November and December between year 2000–2010, in Portugal. The reasonable explanation for the observed bimodal pattern of surface ozone with enhanced NSO concentration during nighttime has to be transport processes, as the surface ozone production ceases at nighttime. Simultaneous measurements of O3 at multiple stations during the study period in Portugal suggest that horizontal advection alone cannot explain the observed NSO enhancement. Thus, detailed analysis of the atmospheric conditions, simulated with the Weather Research and Forecasting (WRF) model, were performed to evaluate the atmospheric mechanisms responsible for NSO enhancement in the region. Simulations revealed that each event occurred as a result of one or the combination of different atmospheric processes such as, passage of a cold front followed by a subsidence zone; passage of a moving surface trough, with associated strong horizontal wind speed and vertical shear; combination of vertical and horizontal transport at the synoptic scale; formation of a low level jet with associated vertical mixing below the jet stream. The study confirmed that large-scale flow pattern resulting in enhanced vertical mixing in the nocturnal boundary layer, plays a key role in the NSO enhancement events, which frequently occur over Portugal during winter months. © 2016 Elsevier Ltd

  12. Numerical experiments on the atmospheric response to cold Equatorial Pacific conditions ('La Nina') during northern summer

    International Nuclear Information System (INIS)

    Storch, H. von; Schriever, D.; Arpe, K.; Branstator, G.W.; Legnani, R.; Ulbrich, U.

    1993-01-01

    The effect of cold conditions in the central and eastern Equatorial Pacific during Northern Summer is examined in a series of numerical experiments with the low resolution (T21) atmospheric general circulation model ECHAM2. Anomalous sea surface temperatures (SST) as observed in June 1988 were prescribed and the effect on the global circulation is examined. In the model atmosphere, the anomalous cold water in the Equatorial Pacific excites a strong and stable response over the tropical Central and East Pacific. From here stationary Rossby waves radiate into both hemispheres. The Northern Hemisphere wave train is weak and affects only the Northeast Pacific area; the Southern Hemisphere wave train arches from the Central Pacific over the southern tip of South America to the South Atlantic. This response is not only present in the basic anomaly experiment with the T21 GCM but also in experiments with SST anomalies confined to the tropics and with an envelope-formulation of the SST anomalies, in experiments with a linear model, and in high resolution (T42) model experiments. The model output is also compared to the actually observed atmospheric state in June 1988. (orig./KW)

  13. Nocturnal surface ozone enhancement over Portugal during winter: Influence of different atmospheric conditions

    KAUST Repository

    Kulkarni, Pavan S.; Dasari, Hari Prasad; Sharma, Ashish; Bortoli, D.; Salgado, Rui; Silva, A.M.

    2016-01-01

    Four distinct nocturnal surface ozone (NSO) enhancement events were observed, with NSO concentration exceeding 80μg/m3, at multiple ozone (O3) monitoring stations (32 sites) in January, November and December between year 2000–2010, in Portugal. The reasonable explanation for the observed bimodal pattern of surface ozone with enhanced NSO concentration during nighttime has to be transport processes, as the surface ozone production ceases at nighttime. Simultaneous measurements of O3 at multiple stations during the study period in Portugal suggest that horizontal advection alone cannot explain the observed NSO enhancement. Thus, detailed analysis of the atmospheric conditions, simulated with the Weather Research and Forecasting (WRF) model, were performed to evaluate the atmospheric mechanisms responsible for NSO enhancement in the region. Simulations revealed that each event occurred as a result of one or the combination of different atmospheric processes such as, passage of a cold front followed by a subsidence zone; passage of a moving surface trough, with associated strong horizontal wind speed and vertical shear; combination of vertical and horizontal transport at the synoptic scale; formation of a low level jet with associated vertical mixing below the jet stream. The study confirmed that large-scale flow pattern resulting in enhanced vertical mixing in the nocturnal boundary layer, plays a key role in the NSO enhancement events, which frequently occur over Portugal during winter months. © 2016 Elsevier Ltd

  14. Federal Prevailing Rate Advisory Committee (FPRAC) Annual Reports

    Data.gov (United States)

    Office of Personnel Management — Annual reports of the Federal Prevailing Rate Advisory Committee (FPRAC), which studies the prevailing (market) rate system for wages and other matters pertinent to...

  15. Stepping towards new parameterizations for non-canonical atmospheric surface-layer conditions

    Science.gov (United States)

    Calaf, M.; Margairaz, F.; Pardyjak, E.

    2017-12-01

    Representing land-atmosphere exchange processes as a lower boundary condition remains a challenge. This is partially a result of the fact that land-surface heterogeneity exists at all spatial scales and its variability does not "average" out with decreasing scales. Such variability need not rapidly blend away from the boundary thereby impacting the near-surface region of the atmosphere. Traditionally, momentum and energy fluxes linking the land surface to the flow in NWP models have been parameterized using atmospheric surface layer (ASL) similarity theory. There is ample evidence that such representation is acceptable for stationary and planar-homogeneous flows in the absence of subsidence. However, heterogeneity remains a ubiquitous feature eliciting appreciable deviations when using ASL similarity theory, especially in scalars such moisture and air temperature whose blending is less efficient when compared to momentum. The focus of this project is to quantify the effect of surface thermal heterogeneity with scales Ο(1/10) the height of the atmospheric boundary layer and characterized by uniform roughness. Such near-canonical cases describe inhomogeneous scalar transport in an otherwise planar homogeneous flow when thermal stratification is weak or absent. In this work we present a large-eddy simulation study that characterizes the effect of surface thermal heterogeneities on the atmospheric flow using the concept of dispersive fluxes. Results illustrate a regime in which the flow is mostly driven by the surface thermal heterogeneities, in which the contribution of the dispersive fluxes can account for up to 40% of the total sensible heat flux. Results also illustrate an alternative regime in which the effect of the surface thermal heterogeneities is quickly blended, and the dispersive fluxes provide instead a quantification of the flow spatial heterogeneities produced by coherent turbulent structures result of the surface shear stress. A threshold flow

  16. Evaluate prevailing climate change on Great Lakes water levels

    International Nuclear Information System (INIS)

    Islam, M.

    2009-01-01

    'Full text:'In this paper, results of a comprehensive water mass balance modeling for the Great Lakes against prevailing and different anticipated climate change scenarios would be presented. Modeling is done in evaluating the changes in the lake storages and then changes in the lake's water level considering present condition, uncertainty and variability of climate and hydrologic conditions in the future. Inflow-outflow and consequent changes in the five Great Lake's storages are simulated for the last 30 years and then projected to evaluate the changes in the lake storages for the next 50 years. From the predicted changes in the lake storage data, water level is calculated using mass to linear conversion equation. Modeling and analysis results are expected to be helpful in understanding the possible impacts of the climate change on the Great Lakes water environment and preparing strategic plan for the sustainable management of lake's water resources. From the recent past, it is observed that there is a depleting trend in the lakes water level and hence there is a potential threat to lake's water environment and uncertainty of the availability of quality and quantity of water for the future generations, especially against prevailing and anticipated climate changes. For this reason, it is an urgent issue of understanding and quantifying the potential impacts of climate change on the Great Lake's water levels and storages. (author)

  17. Influence of different land surfaces on atmospheric conditions measured by a wireless sensor network

    Science.gov (United States)

    Lengfeld, Katharina; Ament, Felix

    2010-05-01

    Atmospheric conditions close to the surface, like temperature, wind speed and humidity, vary on small scales because of surface heterogeneities. Therefore, the traditional measuring approach of using a single, highly accurate station is of limited representativeness for a larger domain, because it is not able to determine these small scale variabilities. However, both the variability and the domain averages are important information for the development and validation of atmospheric models and soil-vegetation-atmosphere-transfer (SVAT) schemes. Due to progress in microelectronics it is possible to construct networks of comparably cheap meteorological stations with moderate accuracy. Such a network provides data in high spatial and temporal resolution. The EPFL Lausanne developed such a network called SensorScope, consisting of low cost autonomous stations. Each station observes air and surface temperature, humidity, wind direction and speed, incoming solar radiation, precipitations, soil moisture and soil temperature and sends the data via radio communication to a base station. This base station forwards the collected data via GSM/GPRS to a central server. Within the FLUXPAT project in August 2009 we deployed 15 stations as a twin transect near Jülich, Germany. One aim of this first experiment was to test the quality of the low cost sensors by comparing them to more accurate reference measurements. It turned out, that although the network is not highly accurate, the measurements are consistent. Consequently an analysis of the pattern of atmospheric conditions is feasible. For example, we detect a variability of ± 0.5K in the mean temperature at a distance of only 2.3 km. The transect covers different types of vegetation and a small river. Therefore, we analyzed the influence of different land surfaces and the distance to the river on meteorological conditions. On the one hand, some results meet our expectations, e.g. the relative humidity decreases with increasing

  18. 29 CFR 505.3 - Prevailing minimum compensation.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Prevailing minimum compensation. 505.3 Section 505.3 Labor... HUMANITIES § 505.3 Prevailing minimum compensation. (a)(1) In the absence of an alternative determination...)(2) of this section, the prevailing minimum compensation required to be paid under the Act to the...

  19. 29 CFR 4.51 - Prevailing in the locality determinations.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Prevailing in the locality determinations. 4.51 Section 4.51... Procedures § 4.51 Prevailing in the locality determinations. (a) Information considered. The minimum monetary... benefits contained in collective bargaining agreements where they have been determined to prevail in a...

  20. 26 CFR 301.7430-5 - Prevailing party.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Prevailing party. 301.7430-5 Section 301.7430-5... Prevailing party. (a) In general. For purposes of an award of reasonable administrative costs under section... prevailing party only if— (1) The position of the Internal Revenue Service was not substantially justified...

  1. THE QUANTITATIVE COMPONENT’S DIAGNOSIS OF THE ATMOSPHERIC PRECIPITATION CONDITION IN BAIA MARE URBAN AREA

    Directory of Open Access Journals (Sweden)

    S. ZAHARIA

    2012-12-01

    Full Text Available The atmospheric precipitation, an essential meteorological element for defining the climatic potential of a region, presents through its general and local particularities a defining influence for the evolution of the other climatic parameters, conditioning the structure of the overall geographic landscape. Their quantitative parameters sets up the regional natural setting and differentiation of water resources, soil, vegetation and fauna, in the same time influencing the majority of human activities’ aspects, through the generated impact over the agriculture, transportation, construction, for tourism etc. Especially, through the evolution of the related climatic parameters (production type, quantity, duration, frequency, intensity and their spatial and temporal fluctuations, the pluviometric extremes set out the maxim manifestation of the energy gap of the hydroclimatic hazards/risks which induce unfavourable or even damaging conditions for the human activities’ progress. Hence, the production of atmospheric precipitation surpluses conditions the triggering, or reactivation of some intense erosion processes, landslides, and last but not least, floods. Just as dangerous are the adverse amounts of precipitation or their absence on longer periods, determining the appearance of droughts, aridity phenomena, which if associated with the sharp anthropic pressure over the environment, favours the expansion of desertification, with the whole process of the arising negative effects. In this context, this paper aims to perform the diagnosis of atmospheric precipitation condition in Baia Mare urban area, through its quantitative component, in multiannual condition (1971-2007, underlining through the results of the analyzed climatic data and their interpretation, the main characteristics that define it. The data bank from Baia Mare station from the National Meteorological Administration network, representative for the chosen study area, was used. Baia

  2. Assessment of a surface-layer parameterization scheme in an atmospheric model for varying meteorological conditions

    Directory of Open Access Journals (Sweden)

    T. J. Anurose

    2014-06-01

    Full Text Available The performance of a surface-layer parameterization scheme in a high-resolution regional model (HRM is carried out by comparing the model-simulated sensible heat flux (H with the concurrent in situ measurements recorded at Thiruvananthapuram (8.5° N, 76.9° E, a coastal station in India. With a view to examining the role of atmospheric stability in conjunction with the roughness lengths in the determination of heat exchange coefficient (CH and H for varying meteorological conditions, the model simulations are repeated by assigning different values to the ratio of momentum and thermal roughness lengths (i.e. z0m/z0h in three distinct configurations of the surface-layer scheme designed for the present study. These three configurations resulted in differential behaviour for the varying meteorological conditions, which is attributed to the sensitivity of CH to the bulk Richardson number (RiB under extremely unstable, near-neutral and stable stratification of the atmosphere.

  3. Molecular dynamics simulation of the local concentration and structure in multicomponent aerosol nanoparticles under atmospheric conditions.

    Science.gov (United States)

    Karadima, Katerina S; Mavrantzas, Vlasis G; Pandis, Spyros N

    2017-06-28

    Molecular dynamics (MD) simulations were employed to investigate the local structure and local concentration in atmospheric nanoparticles consisting of an organic compound (cis-pinonic acid or n-C 30 H 62 ), sulfate and ammonium ions, and water. Simulations in the isothermal-isobaric (NPT) statistical ensemble under atmospheric conditions with a prespecified number of molecules of the abovementioned compounds led to the formation of a nanoparticle. Calculations of the density profiles of all the chemical species in the nanoparticle, the corresponding radial pair distribution functions, and their mobility inside the nanoparticle revealed strong interactions developing between sulfate and ammonium ions. However, sulfate and ammonium ions prefer to populate the central part of the nanoparticle under the simulated conditions, whereas organic molecules like to reside at its outer surface. Sulfate and ammonium ions were practically immobile; in contrast, the organic molecules exhibited appreciable mobility at the outer surface of the nanoparticle. When the organic compound was a normal alkane (e.g. n-C 30 H 62 ), a well-organized (crystalline-like) phase was rapidly formed at the free surface of the nanoparticle and remained separate from the rest of the species.

  4. Periodic variations of atmospheric electric field on fair weather conditions at YBJ, Tibet

    Science.gov (United States)

    Xu, Bin; Zou, Dan; Chen, Ben Yuan; Zhang, Jin Ye; Xu, Guo Wang

    2013-05-01

    Observations of atmospheric electric field on fair weather conditions from the plateau station, YBJ, Tibet (90°31‧50″ E, 30°06‧38″ N), over the period from 2006 to 2011, are presented in this work. Its periodic modulations are analyzed in frequency-domain by Lomb-Scargle Periodogram method and in time-domain by folding method. The results show that the fair weather atmospheric electric field intensity is modulated weakly by annual cycle, solar diurnal cycle and its several harmonic components. The modulating amplitude of annual cycle is bigger than that of solar diurnal cycle. The annual minimum/maximum nearly coincides with spring/autumn equinox. The detailed spectrum analysis show that the secondary peaks (i.e. sidereal diurnal cycle and semi-sidereal diurnal cycle) nearly disappear along with their primary peaks when the primary signals are subtracted from electric field data sequence. The average daily variation curve exhibits dual-fluctuations, and has obviously seasonal dependence. The mean value is bigger in summer and autumn, but smaller in spring and winter. The daytime fluctuation is affected by the sunrise and sunset effect, the occurring time of which have a little shift with seasons. However, the nightly one has a great dependence on season conditions.

  5. Atmospheric conditions and weather regimes associated with extreme winter dry spells over the Mediterranean basin

    Science.gov (United States)

    Raymond, Florian; Ullmann, Albin; Camberlin, Pierre; Oueslati, Boutheina; Drobinski, Philippe

    2018-06-01

    Very long dry spell events occurring during winter are natural hazards to which the Mediterranean region is extremely vulnerable, because they can lead numerous impacts for environment and society. Four dry spell patterns have been identified in a previous work. Identifying the main associated atmospheric conditions controlling the dry spell patterns is key to better understand their dynamics and their evolution in a changing climate. Except for the Levant region, the dry spells are generally associated with anticyclonic blocking conditions located about 1000 km to the Northwest of the affected area. These anticyclonic conditions are favourable to dry spell occurrence as they are associated with subsidence of cold and dry air coming from boreal latitudes which bring low amount of water vapour and non saturated air masses, leading to clear sky and absence of precipitation. These extreme dry spells are also partly related to the classical four Euro-Atlantic weather regimes are: the two phases of the North Atlantic Oscillation, the Scandinavian "blocking" or "East-Atlantic", and the "Atlantic ridge". Only the The "East-Atlantic", "Atlantic ridge" and the positive phase of the North Atlantic Oscillation are frequently associated with extremes dry spells over the Mediterranean basin but they do not impact the four dry spell patterns equally. Finally long sequences of those weather regimes are more favourable to extreme dry spells than short sequences. These long sequences are associated with the favourable prolonged and reinforced anticyclonic conditions

  6. Effects of Prevailing Winds on Turbidity of a Shallow Estuary

    Directory of Open Access Journals (Sweden)

    Hyun Jung Cho

    2007-06-01

    Full Text Available Estuarine waters are generally more turbid than lakes or marine waters due to greater algal mass and continual re-suspension of sediments. The varying effects of diurnal and seasonal prevailing winds on the turbidity condition of a wind-dominated estuary were investigated by spatial and statistical analyses of wind direction, water level, turbidity, chlorophyll a, and PAR (Photosynthetically Active Radiation collected in Lake Pontchartrain, Louisiana, USA. The prolonged prevailing winds were responsible for the long-term, large-scale turbidity pattern of the estuary, whereas the short-term changes in wind direction had differential effects on turbidity and water level in varying locations. There were temporal and spatial changes in the relationship between vertical light attenuation coefficient (Kd and turbidity, which indicate difference in phytoplankton and color also affect Kd. This study demonstrates that the effect of wind on turbidity and water level on different shores can be identified through system-specific analyses of turbidity patterns.

  7. Atmospheric dispersion characteristics of radioactive materials according to the local weather and emission conditions

    Energy Technology Data Exchange (ETDEWEB)

    An, Hye Yeon; Kang, Yoon Hee; Kim, Yoo Keun [Pusan National University, Busan (Korea, Republic of); Song, Sang Keun [Jeju National University, Jeju (Korea, Republic of)

    2016-12-15

    This study evaluated the atmospheric dispersion of radioactive material according to local weather conditions and emission conditions. Local weather conditions were defined as 8 patterns that frequently occur around the Kori Nuclear Power Plant and emission conditions were defined as 6 patterns from a combination of emission rates and the total number of particles of the {sup 137}Cs, using the WRF/HYSPLIT modeling system. The highest mean concentration of {sup 137}Cs occurred at 0900 LST under the ME4{sub 1} (main wind direction: SSW, daily average wind speed: 2.8 ms{sup -1}), with a wide region of its high concentration due to the continuous wind changes between 0000 and 0900 LST; under the ME3 (NE, 4.1 ms{sup -1}), the highest mean concentration of {sup 137}Cs occurred at 1500 and 2100 LST with a narrow dispersion along a strong northeasterly wind. In the case of ME4{sub 4} (S, 2.7 ms{sup -1}), the highest mean concentration of {sup 137}Cs occurred at 0300 LST because {sup 137}Cs stayed around the KNPP under low wind speed and low boundary layer height. As for the emission conditions, EM1{sub 3} and EM2{sub 3} that had the maximum total number of particles showed the widest dispersion of {sup 137}Cs, while its highest mean concentration was estimated under the EM1{sub 1} considering the relatively narrow dispersion and high emission rate. This study showed that even though an area may be located within the same radius around the Kori Nuclear Power Plant, the distribution and levels of {sup 137}Cs concentration vary according to the change in time and space of weather conditions (the altitude of the atmospheric boundary layer, the horizontal and vertical distribution of the local winds, and the precipitation levels), the topography of the regions where {sup 137}Cs is dispersed, the emission rate of {sup 137}Cs, and the number of emitted particles.

  8. Suspended Particulates Concentration (PM10 under Unstable Atmospheric Conditions over Subtropical Urban Area (Qena, Egypt

    Directory of Open Access Journals (Sweden)

    M. El-Nouby Adam

    2013-01-01

    Full Text Available The main purpose of this study is to evaluate the suspended particulates (PM10 in the atmosphere under unstable atmospheric conditions. The variation of PM10 was investigated and primary statistics were employed. The results show that, the PM10 concentrations values ranged from 6.00 to 646.74 μg m−3. The average value of PM10 is equal to 114.32 μg m−3. The high values were recorded in April and May (155.17 μg m−3 and 171.82 μg m−3, respectively and the low values were noted in February and December (73.86 μg m−3 and 74.05 μg m−3, respectively. The average value of PM10 of the hot season (125.35 × 10−6 g m−3 was higher than its value for the cold season (89.27 μg m−3. In addition, the effect of weather elements (air temperature, humidity and wind on the concentration of PM10 was determined. The multiple R between PM10 and these elements ranged from 0.05 to 0.47 and its value increased to reach 0.73 for the monthly average of the database used. Finally, the PM10 concentrations were grouped depending on their associated atmospheric stability class. These average values were equal to 122.80 ± 9 μg m−3 (highly unstable or convective, 109.37 ± 12 μg m−3 (moderately unstable and 104.42 ± 15 μg m−3 (slightly unstable.

  9. Convective transport in ATM simulations and its relation to the atmospheric stability conditions

    Science.gov (United States)

    Kusmierczyk-Michulec, Jolanta

    2017-04-01

    The International Monitoring System (IMS) developed by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is a global system of monitoring stations, using four complementary technologies: seismic, hydroacoustic, infrasound and radionuclide. Data from all stations, belonging to IMS, are collected and transmitted to the International Data Centre (IDC) in Vienna, Austria. The radionuclide network comprises 80 stations, of which more than 60 are certified. The aim of radionuclide stations is a global monitoring of radioactive aerosols and radioactive noble gases, in particular xenon isotopes, supported by the atmospheric transport modeling (ATM). One of the important noble gases, monitored on a daily basis, is radioxenon. It can be produced either during a nuclear explosion with a high fission yield, and thus be considered as an important tracer to prove the nuclear character of an explosion, or be emitted from nuclear power plants (NPPs) or from isotope production facilities (IPFs). To investigate the transport of xenon emissions, the Provisional Technical Secretariat (PTS) operates an Atmospheric Transport Modelling (ATM) system based on the Lagrangian Particle Dispersion Model FLEXPART. To address the question whether including the convective transport in ATM simulations will change the results significantly, the differences between the outputs with the convective transport turned off and turned on, were computed and further investigated taking into account the atmospheric stability conditions. For that purpose series of 14 days forward simulations, with convective transport and without it, released daily in the period January 2011 to February 2012, were analysed. The release point was at the ANSTO facility in Australia. The unique opportunity of having access to both daily emission values for ANSTO as well as measured Xe-133 activity concentration (AC) values at the IMS stations, gave a chance to validate the simulations.

  10. Low-energy-electron interactions with DNA: approaching cellular conditions with atmospheric experiments

    International Nuclear Information System (INIS)

    Alizadeh, E.; Sanche, L.

    2014-01-01

    A novel technique has been developed to investigate low energy electron (LEE)-DNA interactions in the presence of small biomolecules (e.g., N 2 , O 2 , H 2 O) found near DNA in the cell nucleus, in order to simulate cellular conditions. In this technique, LEEs are emitted from a metallic surface exposed by soft X-rays and interact with DNA thin films at standard ambient temperature and pressure (SATP). Whereas atmospheric N 2 had little effect on the yields of LEE-induced single and double strand breaks, both O 2 and H 2 O considerably modified and increased such damage. The highest yields were obtained when DNA is embedded in a combined O 2 and H 2 O atmosphere. In this case, the amount of additional double strand breaks was supper-additive. The effect of modifying the chemical and physical stability of DNA by platinum-based chemotherapeutic agents (Pt-drugs) including cisplatin, carboplatin and oxaliplatin was also investigated with this technique. The results obtained provide information on the role played by subexcitation-energy electrons and dissociative electron attachment in the radiosensitization of DNA by Pt-drugs, which is an important step to unravel the mechanisms of radiosensitization of these agents in chemo-radiation cancer therapy. (authors)

  11. Low-energy-electron interactions with DNA: approaching cellular conditions with atmospheric experiments

    Science.gov (United States)

    Alizadeh, Elahe; Sanche, Léon

    2014-04-01

    A novel technique has been developed to investigate low energy electron (LEE)-DNA interactions in the presence of small biomolecules (e.g., N2, O2, H2O) found near DNA in the cell nucleus, in order to simulate cellular conditions. In this technique, LEEs are emitted from a metallic surface exposed by soft X-rays and interact with DNA thin films at standard ambient temperature and pressure (SATP). Whereas atmospheric N2 had little effect on the yields of LEE-induced single and double strand breaks, both O2 and H2O considerably modified and increased such damage. The highest yields were obtained when DNA is embedded in a combined O2 and H2O atmosphere. In this case, the amount of additional double strand breaks was supper-additive. The effect of modifying the chemical and physical stability of DNA by platinum-based chemotherapeutic agents (Pt-drugs) including cisplatin, carboplatin and oxaliplatin was also investigated with this technique. The results obtained provide information on the role played by subexcitation-energy electrons and dissociative electron attachment in the radiosensitization of DNA by Pt-drugs, which is an important step to unravel the mechanisms of radiosensitisation of these agents in chemoradiation cancer therapy.

  12. On the analytic and numeric optimisation of airplane trajectories under real atmospheric conditions

    Science.gov (United States)

    Gonzalo, J.; Domínguez, D.; López, D.

    2014-12-01

    From the beginning of aviation era, economic constraints have forced operators to continuously improve the planning of the flights. The revenue is proportional to the cost per flight and the airspace occupancy. Many methods, the first started in the middle of last century, have explore analytical, numerical and artificial intelligence resources to reach the optimal flight planning. In parallel, advances in meteorology and communications allow an almost real-time knowledge of the atmospheric conditions and a reliable, error-bounded forecast for the near future. Thus, apart from weather risks to be avoided, airplanes can dynamically adapt their trajectories to minimise their costs. International regulators are aware about these capabilities, so it is reasonable to envisage some changes to allow this dynamic planning negotiation to soon become operational. Moreover, current unmanned airplanes, very popular and often small, suffer the impact of winds and other weather conditions in form of dramatic changes in their performance. The present paper reviews analytic and numeric solutions for typical trajectory planning problems. Analytic methods are those trying to solve the problem using the Pontryagin principle, where influence parameters are added to state variables to form a split condition differential equation problem. The system can be solved numerically -indirect optimisation- or using parameterised functions -direct optimisation-. On the other hand, numerical methods are based on Bellman's dynamic programming (or Dijkstra algorithms), where the fact that two optimal trajectories can be concatenated to form a new optimal one if the joint point is demonstrated to belong to the final optimal solution. There is no a-priori conditions for the best method. Traditionally, analytic has been more employed for continuous problems whereas numeric for discrete ones. In the current problem, airplane behaviour is defined by continuous equations, while wind fields are given in a

  13. Optical aging observation in suspended core tellurite microstructured fibers under atmospheric conditions

    Science.gov (United States)

    Strutynski, C.; Mouawad, O.; Picot-Clémente, J.; Froidevaux, P.; Désévédavy, F.; Gadret, G.; Jules, J.-C.; Kibler, B.; Smektala, F.

    2017-11-01

    Tellurite glasses are good candidates for the development of broadband supercontinuum (SC) laser sources in the 1-5 μm range. At the moment, beside very few exceptions, SC generation in TeO2-based microstructured optical fibers (MOFs) is limited to 3 μm in the mid-infrared (MIR). We present here an observation of an optical aging occurring in six-hole suspended-core tellurite MOFs. When exposed to atmospheric conditions, such fibers show an alteration of their transmission between 3 and 4 μm. This aging phenomenon leads to the growth of strong additional losses in this wavelengths range over time. Impact of the transmission degradation on spectral broadening is studied through numerical simulations of SC generation.

  14. Pressure and Humidity Measurements at the MSL Landing Site Supported by Modeling of the Atmospheric Conditions

    Science.gov (United States)

    Harri, A.; Savijarvi, H. I.; Schmidt, W.; Genzer, M.; Paton, M.; Kauhanen, J.; Atlaskin, E.; Polkko, J.; Kahanpaa, H.; Kemppinen, O.; Haukka, H.

    2012-12-01

    The Mars Science Laboratory (MSL) called Curiosity Rover landed safely on the Martian surface at the Gale crater on 6th August 2012. Among the MSL scientific objectives are investigations of the Martian environment that will be addressed by the Rover Environmental Monitoring Station (REMS) instrument. It will investigate habitability conditions at the Martian surface by performing a versatile set of environmental measurements including accurate observations of pressure and humidity of the Martian atmosphere. This paper describes the instrumental implementation of the MSL pressure and humidity measurement devices and briefly analyzes the atmospheric conditions at the Gale crater by modeling efforts using an atmospheric modeling tools. MSL humidity and pressure devices are based on proprietary technology of Vaisala, Inc. Humidity observations make use of Vaisala Humicap® relative humidity sensor heads and Vaisala Barocap® sensor heads are used for pressure observations. Vaisala Thermocap® temperature sensors heads are mounted in a close proximity of Humicap® and Barocap® sensor heads to enable accurate temperature measurements needed for interpretation of Humicap® and Barocap® readings. The sensor heads are capacitive. The pressure and humidity devices are lightweight and are based on a low-power transducer controlled by a dedicated ASIC. The transducer is designed to measure small capacitances in order of a few pF with resolution in order of 0.1fF (femtoFarad). The transducer design has a good spaceflight heritage, as it has been used in several previous missions, for example Mars mission Phoenix as well as the Cassini Huygens mission. The humidity device has overall dimensions of 40 x 25 x 55 mm. It weighs18 g, and consumes 15 mW of power. It includes 3 Humicap® sensor heads and 1 Thermocap®. The transducer electronics and the sensor heads are placed on a single multi-layer PCB protected by a metallic Faraday cage. The Humidity device has measurement range

  15. On the formation of sulphuric acid – amine clusters in varying atmospheric conditions and its influence on atmospheric new particle formation

    Directory of Open Access Journals (Sweden)

    I. K. Ortega

    2012-10-01

    Full Text Available Sulphuric acid is a key component in atmospheric new particle formation. However, sulphuric acid alone does not form stable enough clusters to initiate particle formation in atmospheric conditions. Strong bases, such as amines, have been suggested to stabilize sulphuric acid clusters and thus participate in particle formation. We modelled the formation rate of clusters with two sulphuric acid and two amine molecules (JA2B2 at varying atmospherically relevant conditions with respect to concentrations of sulphuric acid ([H2SO4], dimethylamine ([DMA] and trimethylamine ([TMA], temperature and relative humidity (RH. We also tested how the model results change if we assume that the clusters with two sulphuric acid and two amine molecules would act as seeds for heterogeneous nucleation of organic vapours (other than amines with higher atmospheric concentrations than sulphuric acid. The modelled formation rates JA2B2 were functions of sulphuric acid concentration with close to quadratic dependence, which is in good agreement with atmospheric observations of the connection between the particle formation rate and sulphuric acid concentration. The coefficients KA2B2 connecting the cluster formation rate and sulphuric acid concentrations as JA2B2=KA2B2[H2SO4]2 turned out to depend also on amine concentrations, temperature and relative humidity. We compared the modelled coefficients KA2B2 with the corresponding coefficients calculated from the atmospheric observations (Kobs from environments with varying temperatures and levels of anthropogenic influence. By taking into account the modelled behaviour of JA2B2 as a function of [H2SO4], temperature and RH, the atmospheric particle formation rate was reproduced more closely than with the traditional semi-empirical formulae based on sulphuric acid concentration only. The formation rates of clusters with two sulphuric acid and two amine molecules with different amine compositions (DMA or TMA or one of both had

  16. Correlation between meteorological conditions and the concentration of radionuclides in the ground layer of atmospheric air

    International Nuclear Information System (INIS)

    Krajny, E.; Osrodka, L.; Wojtylak, M.; Michalik, B.; Skowronek, J.

    2001-01-01

    The main goal of this work was to find correlation between the concentrations of radionuclides in outdoor air and the meteorological conditions like: atmospheric pressure, wind velocity and amount of precipitation. Because the sampling period of radionuclides concentrations in air was relatively long (7 days), the average levels of meteorological parameters have been calculated within the same time. Data of radionuclide concentrations and meteorological data have been analyzed in order to find statistical correlation. The regression analysis and one of AI methods, known as neural network, were applied. In general, analysis of the gathered data does not show any strong correlation between the meteorological conditions and the concentrations of the radionuclides in air. A slightly stronger correlation we found for radionuclides with relatively short half-lives. The only positive correlation has been found between the 7 Be concentration and air temperature (at the significance level α = 0.05). In our opinion, the lack of correlation was caused by a too long sampling time in measurements of radionuclides in outdoor air (a whole week). Results of analysis received by means of the artificial neuron network are better. We were able to find certain groups of meteorological conditions, related with the corresponding concentrations of particular radionuclides in air. Preliminary measurements of radon progeny concentration support the thesis that the link between changes of meteorological parameters and concentrations of radionuclides in ambient air must exist. (author)

  17. Lipid oxidation and color changes of goose meat stored under vacuum and modified atmosphere conditions.

    Science.gov (United States)

    Orkusz, A; Haraf, G; Okruszek, A; Werenska-Sudnik, M

    2017-03-01

    The objective of the work was to investigate the color and lipid oxidation changes of goose breast meat packaged in vacuum and modified atmosphere (MA) conditions consisting of 80% O2, 20% CO2, and stored in refrigerated conditions at 4°C. Color stability was monitored by determining total heme pigments concentration; relative concentration of myoglobin, oxymyoglobin, and metmyoglobin; parameters of color L*, a*, b*, and sensory evaluation of the surface color. Lipid stability was measured by determining thiobarbituric acid reactive substances (TBARS). The samples were examined in 24 h after slaughter (unpacked muscles) and on d 4, 7, 9, 11 of storage (muscles packed in vacuum and in MA). Through the time of storage, samples packed in MA had higher TBARS values in comparison to the meat packed in vacuum. For samples packed in two types of atmospheres, the total pigments concentration decreased gradually within 11 d of storage. It was observed that relative metmyoglobin concentration increased whereas relative oxymyoglobin concentration decreased in total heme pigments in the MA stored muscle. The relative concentration of all three myoglobin forms sample packed in vacuum remained unchanged. The color parameters (L*, a*, b*) did not change for 11 d of storage for the vacuum packed meat. The value of the color parameter a* decreased and the value of the color parameters L* and b* increased in the samples packaged in MA. The data prove that if you store goose meat in MA (consisting of 80% O2, 20% CO2) or vacuum, the unchanged surface color is preserved for 9 and 11 day, respectively.Vacuum appears to be a better method as regards the maintaining of lipid stability in goose meat. © 2016 Poultry Science Association Inc.

  18. Sulphation of oil shale ash under atmospheric and pressurized combustion conditions

    International Nuclear Information System (INIS)

    Kuelaots, I.; Yrjas, P.; Hupa, M.; Ots, A.

    1995-01-01

    One of the main problems in conventional combustion boilers firing pulverized oil shale is the corrosion and fouling of heating surfaces, which is caused by sulphur compounds. Another major problem, from the environmental point of view, are the high SO 2 emissions. Consequently, the amount of sulphur in flue gases must be reduced. One alternative to lower the SO 2 , concentration is the use of new technologies, such as pressurized fluidized bed combustion (PFBC). In FBC processes, the sulphur components are usually removed by the addition of limestone (CaCO 3 ) or dolomite (CaCO 3 x MgCO 3 ) into the bed. The calcium in these absorbents react with SO 2 , producing solid CaSO 4 . However, when burning oil shale, there would be no need to add limestone or dolomite into the bed, due to the initially high limestone content in the fuel (molar ratio Ca/S =10). The capture of sulphur by oil shale ashes has been studied using a pressurized thermogravimetric apparatus (PTGA). The chosen experimental conditions were typical for atmospheric and pressurized fluidized bed combustion. Four different materials were tested - one cyclone ash from an Estonian oil shale boiler, two size fractions of Estonian oil shale and, one fraction of Israeli oil shale. The cyclone ash was found to be the poorest sulphur absorbent. In general, the results from the sulphur capture experiments under both atmospheric and pressurized fluidized bed conditions showed that the oil shale can capture not only its own sulphur but also significant amounts of additional sulphur from another fuel if the fuels are mixed together. (author)

  19. The Titan Sky Simulator ™ - Testing Prototype Balloons in Conditions Approximating those in Titan's Atmosphere

    Science.gov (United States)

    Nott, Julian

    This paper will describe practical work flying prototype balloons in the "The Titan Sky Simulator TM " in conditions approximating those found in Titan's atmosphere. Saturn's moon, Titan, is attracting intense scientific interest. This has led to wide interest in exploring it with Aerobots, balloons or airships. Their function would be similar to the Rovers exploring Mars, but instead of moving laboriously across the rough terrain on wheels, they would float freely from location to location. To design any balloon or airship it is essential to know the temperature of the lifting gas as this influences the volume of the gas, which in turn influences the lift. To determine this temperature it is necessary to know how heat is transferred between the craft and its surroundings. Heat transfer for existing balloons is well understood. However, Titan conditions are utterly different from those in which balloons have ever been flown, so heat transfer rates cannot currently be calculated. In particular, thermal radiation accounts for most heat transfer for existing balloons but over Titan heat transfer will be dominated by convection. To be able to make these fundamental calculations, it is necessary to get fundamental experimental data. This is being obtained by flying balloons in a Simulator filled with nitrogen gas at very low temperature, about 95° K / minus 180° C, typical of Titan's temperatures. Because the gas in the Simulator is so cold, operating at atmospheric pressure the density is close to that of Titan's atmosphere. "The Titan Sky Simulator TM " has an open interior approximately 4.5 meter tall and 2.5 meters square. It has already been operated at 95° K/-180° C. By the time of the Conference it is fully expected to have data to present from actual balloons flying at this temperature. Perhaps the most important purpose of this testing is to validate numerical [computational fluid dynamics] models being developed by Tim Colonius of Caltech. These numerical

  20. 29 CFR 1918.94 - Ventilation and atmospheric conditions (See also § 1918.2, definitions of Hazardous cargo...

    Science.gov (United States)

    2010-07-01

    ....94 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING General Working Conditions... 29 Labor 7 2010-07-01 2010-07-01 false Ventilation and atmospheric conditions (See also § 1918.2...

  1. Effect Analysis on the Radiation Dose Rate of Nagasaki Atomic Bomb Survivors by Atmospheric Condition

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Ji Sun; Kim, Jong Kyung [Hanyang University, Seoul (Korea, Republic of); Shin, Chang Ho [Innovative Technology Center for Radiation Safety, Seoul (Korea, Republic of); Kim, Do Heon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    The Dosimetry System 2002 (DS02) had been established to evaluate the radiation doses for the atomic bomb survivors in Hiroshima and Nagasaki. The radiation effects of neutrons and gamma-rays emitted from the atomic bombs detonated at both cities were analyzed, and two types of radiation transport codes (i.e., MCNP4C and DORT) were employed in their studies. It was specifically investigated for contribution of each type of radiations to total dose. However, it is insufficient to examine the effects by various environmental factors such as weather conditions, because their calculations were only performed under certain condition at the times of the bombings. In addition, the scope of them does not include acute radiation injury of the atomic bomb survivors in spite of important information for investigating hazard of unexpected radiation accident. Therefore, this study analyzed the contribution of primary and secondary effects (i.e., skyshine and groundshine) of neutrons emitted from the Nagasaki atomic bomb. These analyses were performed through a series of radiation transport calculations by using MCNPX 2.6.0 code with variations of atmospheric density. The acute radiation injury by prompt neutrons was also evaluated as a function of distance from the hypocenter, where hypocenter is the point on the ground directly beneath the epicenter which is the burst point of the bomb in air

  2. A comparative modeling study of a dual tracer experiment in a large lysimeter under atmospheric conditions

    Science.gov (United States)

    Stumpp, C.; Nützmann, G.; Maciejewski, S.; Maloszewski, P.

    2009-09-01

    SummaryIn this paper, five model approaches with different physical and mathematical concepts varying in their model complexity and requirements were applied to identify the transport processes in the unsaturated zone. The applicability of these model approaches were compared and evaluated investigating two tracer breakthrough curves (bromide, deuterium) in a cropped, free-draining lysimeter experiment under natural atmospheric boundary conditions. The data set consisted of time series of water balance, depth resolved water contents, pressure heads and resident concentrations measured during 800 days. The tracer transport parameters were determined using a simple stochastic (stream tube model), three lumped parameter (constant water content model, multi-flow dispersion model, variable flow dispersion model) and a transient model approach. All of them were able to fit the tracer breakthrough curves. The identified transport parameters of each model approach were compared. Despite the differing physical and mathematical concepts the resulting parameters (mean water contents, mean water flux, dispersivities) of the five model approaches were all in the same range. The results indicate that the flow processes are also describable assuming steady state conditions. Homogeneous matrix flow is dominant and a small pore volume with enhanced flow velocities near saturation was identified with variable saturation flow and transport approach. The multi-flow dispersion model also identified preferential flow and additionally suggested a third less mobile flow component. Due to high fitting accuracy and parameter similarity all model approaches indicated reliable results.

  3. Future changes in atmospheric condition for the baiu under RCP scenarios

    Science.gov (United States)

    Okada, Y.; Takemi, T.; Ishikawa, H.

    2015-12-01

    This study focuses on atmospheric circulation fields during the baiu in Japan with global warming projection experimental data conducted using a 20-km mesh global atmospheric model (MRI-AGCM3.2) under Representative Concentration Pathways (RCP) scenarios. This model also used 4 different sea surface temperature (SST) initial conditions. Support of this dataset is provided by the Meteorological Research Institute (MRI). The baiu front indicated by the north-south gradient of moist static energy moves northward in present-day climate, whereas this northward shift in future climate simulations is very slow during May and June. In future late baiu season, the baiu front stays in the northern part of Japan even in August. As a result, the rich water vapor is transported around western Japan and the daily precipitation amount will increase in August. This northward shift of baiu front is associated with the westward expansion of the enhanced the North Pacific subtropical high (NPSH) into Japan region. However, the convective activity around northwest Pacific Ocean is inactive and is unlikely to occur convective jump (CJ). These models show that the weak trough exists in upper troposphere around Japan. Therefore, the cold advection stays in the northern part of Japan during June. In July, the front due to the strengthening of the NPSH moves northward, and then it stays until August. This feature is often found between the clustered SSTs, Cluster 2 and 3. The mean field of future August also show the inflow of rich water vapor content to Japan islands. In this model, the extreme rainfall suggested tends to almost increase over the Japan islands during future summer. This work was conducted under the Program for Risk Information on Climate Change supported by the Ministry of Education, Culture, Sports, Science, and Technology-Japan (MEXT).

  4. Remote Raman - laser induced breakdown spectroscopy (LIBS) geochemical investigation under Venus atmospheric conditions

    Energy Technology Data Exchange (ETDEWEB)

    Clegg, Sanuel M [Los Alamos National Laboratory; Barefield, James E [Los Alamos National Laboratory; Humphries, Seth D [Los Alamos National Laboratory; Wiens, Roger C [Los Alamos National Laboratory; Vaniman, D. T. [Los Alamos National Laboratory; Sharma, S. K. [UNIV OF HAWAII; Misra, A. K. [UNIV OF HAWAII; Dyar, M. D. [MT. HOLYOKE COLLEGE; Smrekar, S. E. [JET PROPULSION LAB.

    2010-12-13

    The extreme Venus surface temperatures ({approx}740 K) and atmospheric pressures ({approx}93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. and Sharma et al. demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachyandesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to

  5. Ecosystem-atmosphere exchange of carbon in a heathland under future climatic conditions

    DEFF Research Database (Denmark)

    Selsted, Merete Bang

    understanding plant and soil responses to such changes are necessary, as ecosystems potentially can ameliorate or accelerate global change. To predict the feedback of ecosystems to the atmospheric CO2 concentrations experiments imitating global change effects are therefore an important tool. This work....... Fluxes of CO2 from soil to atmosphere depend on a physical equilibrium between those two medias, why it is important to keep the CO2 gradient between soil and atmosphere unchanged during measurement. Uptake to plants via photosynthesis depends on a physiological process, which depends strongly...... on the atmospheric CO2 concentration. Photosynthesis and respiration run in parallel during measurements of net ecosystem exchange, and these measurements should therefore be performed with care to both the atmospheric CO2 concentration and the CO2 soil-atmosphere gradient....

  6. Relation between the Atmospheric Boundary Layer and Impact Factors under Severe Surface Thermal Conditions

    Directory of Open Access Journals (Sweden)

    Yinhuan Ao

    2017-01-01

    Full Text Available This paper reported a comprehensive analysis on the diurnal variation of the Atmospheric Boundary Layer (ABL in summer of Badain Jaran Desert and discussed deeply the effect of surface thermal to ABL, including the Difference in Surface-Air Temperature (DSAT, net radiation, and sensible heat, based on limited GPS radiosonde and surface observation data during two intense observation periods of experiments. The results showed that (1 affected by topography of the Tibetan Plateau, the climate provided favorable external conditions for the development of Convective Boundary Layer (CBL, (2 deep CBL showed a diurnal variation of three- to five-layer structure in clear days and five-layer ABL structure often occurred about sunset or sunrise, (3 the diurnal variation of DSAT influenced thickness of ABL through changes of turbulent heat flux, (4 integral value of sensible heat which rapidly converted by surface net radiation had a significant influence on the growth of CBL throughout daytime. The cumulative effect of thick RML dominated the role after CBL got through SBL in the development stage, especially in late summer, and (5 the development of CBL was promoted and accelerated by the variation of wind field and distribution of warm advection in high and low altitude.

  7. Study on chemical buffering property of GMZ sodium bentonite under atmospheric condition

    International Nuclear Information System (INIS)

    Wen Zhijian

    2012-01-01

    At present, the deep geological disposal is regarded as the most reasonable and effective way to safely disposal the high-level radioactive wastes in the world. The conceptual model of HLW geological disposal in China is based on a multi-barrier system that combines an isolating geological environment with an engineered barrier system. The buffer is one of the engineered barrier materials and GMZ Na-bentonite is selected as the basic material. One of the most important functions related to buffer is the chemical buffering, which means buffering the changes in pore water chemistry. This paper presents the experiments of GMZ-1 Na-bentonite reacted with distilled water under atmospheric condition. The batch tests and results discussion are reported. Na and Mg in batch test solution are co-provided by interlayer cations of montmorillonite and solids dissolution, K and Ca are provided by dissolution of solids. The result is a pre-requisite for predicting near-field nuclide migration and assesses the long-term stability of the engineered barrier materials. (author)

  8. Instrumentation for comparing night sky quality and atmospheric conditions of CTA site candidates

    International Nuclear Information System (INIS)

    Fruck, C.; Schweizer, T.; Häfner, D.; Lorentz, E.; Teshima, M.; Gaug, M.; Ernenwein, J.-P.; Costantini, H.; Mandát, D.; Pech, M.; Bulik, T.; Cieslar, M.; Dominik, M.; Ebr, J.; Garczarczyk, M.; Pareschi, G.; Puerto-Giménez, I.

    2015-01-01

    Many atmospheric and climatic criteria have to be taken into account for the selection of a suitable site for the next generation of imaging air-shower Cherenkov telescopes, the ''Cherenkov Telescope Array'' CTA. Such data are not available with sufficient precision, thus a comparison of the proposed sites and final decision based on a comprehensive characterization is impossible. Identical cross-calibrated instruments have been developed which allow for precise comparison between sites, the cross-validation of existing data, and the ground-validation of satellite data. The site characterization work package of the CTA consortium opted to construct and deploy 9 copies of an autonomous multi-purpose weather sensor, incorporating an infrared cloud sensor, a newly developed sensor for measuring the light of the night sky, and an All-Sky-Camera, the whole referred to as Autonomous Tool for Measuring Observatory Site COnditions PrEcisely (ATMOSCOPE). We present here the hardware that was combined into the ATMOSCOPE and characterize its performance

  9. Characterization of transient discharges under atmospheric-pressure conditions applying nitrogen photoemission and current measurements

    International Nuclear Information System (INIS)

    Keller, Sandra; Rajasekaran, Priyadarshini; Bibinov, Nikita; Awakowicz, Peter

    2012-01-01

    The plasma parameters such as electron distribution function and electron density of three atmospheric-pressure transient discharges namely filamentary and homogeneous dielectric barrier discharges in air, and the spark discharge of an argon plasma coagulation (APC) system are determined. A combination of numerical simulation as well as diagnostic methods including current measurement and optical emission spectroscopy (OES) based on nitrogen emissions is used. The applied methods supplement each other and resolve problems, which arise when these methods are used individually. Nitrogen is used as a sensor gas and is admixed in low amount to argon for characterizing the APC discharge. Both direct and stepwise electron-impact excitation of nitrogen emissions are included in the plasma-chemical model applied for characterization of these transient discharges using OES where ambiguity arises in the determination of plasma parameters under specific discharge conditions. It is shown that the measured current solves this problem by providing additional information useful for the determination of discharge-specific plasma parameters. (paper)

  10. Maximum Evaporation Rates of Water Droplets Approaching Obstacles in the Atmosphere Under Icing Conditions

    Science.gov (United States)

    Lowell, H. H.

    1953-01-01

    When a closed body or a duct envelope moves through the atmosphere, air pressure and temperature rises occur ahead of the body or, under ram conditions, within the duct. If cloud water droplets are encountered, droplet evaporation will result because of the air-temperature rise and the relative velocity between the droplet and stagnating air. It is shown that the solution of the steady-state psychrometric equation provides evaporation rates which are the maximum possible when droplets are entrained in air moving along stagnation lines under such conditions. Calculations are made for a wide variety of water droplet diameters, ambient conditions, and flight Mach numbers. Droplet diameter, body size, and Mach number effects are found to predominate, whereas wide variation in ambient conditions are of relatively small significance in the determination of evaporation rates. The results are essentially exact for the case of movement of droplets having diameters smaller than about 30 microns along relatively long ducts (length at least several feet) or toward large obstacles (wings), since disequilibrium effects are then of little significance. Mass losses in the case of movement within ducts will often be significant fractions (one-fifth to one-half) of original droplet masses, while very small droplets within ducts will often disappear even though the entraining air is not fully stagnated. Wing-approach evaporation losses will usually be of the order of several percent of original droplet masses. Two numerical examples are given of the determination of local evaporation rates and total mass losses in cases involving cloud droplets approaching circular cylinders along stagnation lines. The cylinders chosen were of 3.95-inch (10.0+ cm) diameter and 39.5-inch 100+ cm) diameter. The smaller is representative of icing-rate measurement cylinders, while with the larger will be associated an air-flow field similar to that ahead of an airfoil having a leading-edge radius

  11. Coal devolatilization and char conversion under suspension fired conditions in O2/N2 and O2/CO2 atmospheres

    DEFF Research Database (Denmark)

    Jensen, Anker Degn; Brix, Jacob; Jensen, Peter Arendt

    2010-01-01

    have been carried out in an electrically heated entrained flow reactor that is designed to simulate the conditions in a suspension fired boiler. Coal devolatilized in N2 and CO2 atmospheres provided similar results regarding char morphology, char N2-BET surface area and volatile yield. This strongly......The aim of the present investigation is to examine differences between O2/N2 and O2/CO2 atmospheres during devolatilization and char conversion of a bituminous coal at conditions covering temperatures between 1173 K and 1673 K and inlet oxygen concentrations between 5 and 28 vol.%. The experiments...

  12. Changes in atmospheric circulation between solar maximum and minimum conditions in winter and summer

    Science.gov (United States)

    Lee, Jae Nyung

    2008-10-01

    Statistically significant climate responses to the solar variability are found in Northern Annular Mode (NAM) and in the tropical circulation. This study is based on the statistical analysis of numerical simulations with ModelE version of the chemistry coupled Goddard Institute for Space Studies (GISS) general circulation model (GCM) and National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis. The low frequency large scale variability of the winter and summer circulation is described by the NAM, the leading Empirical Orthogonal Function (EOF) of geopotential heights. The newly defined seasonal annular modes and its dynamical significance in the stratosphere and troposphere in the GISS ModelE is shown and compared with those in the NCEP/NCAR reanalysis. In the stratosphere, the summer NAM obtained from NCEP/NCAR reanalysis as well as from the ModelE simulations has the same sign throughout the northern hemisphere, but shows greater variability at low latitudes. The patterns in both analyses are consistent with the interpretation that low NAM conditions represent an enhancement of the seasonal difference between the summer and the annual averages of geopotential height, temperature and velocity distributions, while the reverse holds for high NAM conditions. Composite analysis of high and low NAM cases in both the model and observation suggests that the summer stratosphere is more "summer-like" when the solar activity is near a maximum. This means that the zonal easterly wind flow is stronger and the temperature is higher than normal. Thus increased irradiance favors a low summer NAM. A quantitative comparison of the anti-correlation between the NAM and the solar forcing is presented in the model and in the observation, both of which show lower/higher NAM index in solar maximum/minimum conditions. The summer NAM in the troposphere obtained from NCEP/NCAR reanalysis has a dipolar zonal structure with maximum

  13. 29 CFR 525.10 - Prevailing wage rates.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Prevailing wage rates. 525.10 Section 525.10 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR REGULATIONS EMPLOYMENT OF WORKERS WITH DISABILITIES UNDER SPECIAL CERTIFICATES § 525.10 Prevailing wage rates. (a) A...

  14. Spectroscopic study of the water-soluble organic matter isolated from atmospheric aerosols collected under different atmospheric conditions

    International Nuclear Information System (INIS)

    Duarte, Regina M.B.O.; Pio, Casimiro A.; Duarte, Armando C.

    2005-01-01

    The composition of the water-soluble organic matter from fine aerosols collected in a rural location during two different meteorological conditions (summer and autumn) was investigated by UV-vis, synchronous fluorescence (with Δλ = 20 nm), FT-IR and CPMAS- 13 C NMR spectroscopies. A seasonal variation in the concentration of total carbon, organic carbon and water-soluble organic carbon was confirmed, with higher values during the autumn and lower values during the summer season. The chemical characterisation of the water-soluble organic matter showed that both samples are dominated by a high content of aliphatic structures, carboxyl groups and aliphatic carbons single bonded to one oxygen or nitrogen atom. However, the autumn sample exhibits a higher aromatic content than the summer sample, plus signals due to carbons of phenol, ketones and methoxyl groups. These signals were attributed to lignin breakdown products which are likely to be released during wood combustion processes. The obtained results put into evidence the major contribution of biomass burning processes in domestic fireplaces during low temperature conditions into both the concentration and the bulk chemical properties of the WSOC from fine aerosols

  15. Response of the Water Level in a Well to Earth Tides and Atmospheric Loading Under Unconfined Conditions

    Science.gov (United States)

    Rojstaczer, Stuart; Riley, Francis S.

    1990-08-01

    The response of the water level in a well to Earth tides and atmospheric loading under unconfined conditions can be explained if the water level is controlled by the aquifer response averaged over the saturated depth of the well. Because vertical averaging tends to diminish the influence of the water table, the response is qualitatively similar to the response of a well under partially confined conditions. When the influence of well bore storage can be ignored, the response to Earth tides is strongly governed by a dimensionless aquifer frequency Q'u. The response to atmospheric loading is strongly governed by two dimensionless vertical fluid flow parameters: a dimensionless unsaturated zone frequency, R, and a dimensionless aquifer frequency Qu. The differences between Q'u and Qu are generally small for aquifers which are highly sensitive to Earth tides. When Q'u and Qu are large, the response of the well to Earth tides and atmospheric loading approaches the static response of the aquifer under confined conditions. At small values of Q'u and Qu, well response to Earth tides and atmospheric loading is strongly influenced by water table drainage. When R is large relative to Qu, the response to atmospheric loading is strongly influenced by attenuation and phase shift of the pneumatic pressure signal in the unsaturated zone. The presence of partial penetration retards phase advance in well response to Earth tides and atmospheric loading. When the theoretical response of a phreatic well to Earth tides and atmospheric loading is fit to the well response inferred from cross-spectral estimation, it is possible to obtain estimates of the pneumatic diffusivity of the unsaturated zone and the vertical hydraulic conductivity of the aquifer.

  16. Experimental evidence for the role of ions in particle nucleation under atmospheric conditions

    DEFF Research Database (Denmark)

    Svensmark, Henrik; Pedersen, Jens Olaf Pepke; Marsh, N.D.

    2007-01-01

    Experimental studies of aerosol nucleation in air, containing trace amounts of ozone, sulphur dioxide and water vapour at concentrations relevant for the Earth's atmosphere, are reported. The production of new aerosol particles is found to be proportional to the negative ion density and yields...... nucleation rates of the order of 0.1 1 cm(-3) s(-1). This suggests that the ions are active in generating an atmospheric reservoir of small thermodynamically stable clusters, which are important for nucleation processes in the atmosphere and ultimately for cloud formation....

  17. Simulation of Electrical Discharge Initiated by a Nanometer-Sized Probe in Atmospheric Conditions

    International Nuclear Information System (INIS)

    Chen Ran; Chen Chilai; Liu Youjiang; Wang Huanqin; Kong Deyi; Ma Yuan; Cada Michael; Brugger Jürgen

    2013-01-01

    In this paper, a two-dimensional nanometer scale tip-plate discharge model has been employed to study nanoscale electrical discharge in atmospheric conditions. The field strength distributions in a nanometer scale tip-to-plate electrode arrangement were calculated using the finite element analysis (FEA) method, and the influences of applied voltage amplitude and frequency as well as gas gap distance on the variation of effective discharge range (EDR) on the plate were also investigated and discussed. The simulation results show that the probe with a wide tip will cause a larger effective discharge range on the plate; the field strength in the gap is notably higher than that induced by the sharp tip probe; the effective discharge range will increase linearly with the rise of excitation voltage, and decrease nonlinearly with the rise of gap length. In addition, probe dimension, especially the width/height ratio, affects the effective discharge range in different manners. With the width/height ratio rising from 1:1 to 1:10, the effective discharge range will maintain stable when the excitation voltage is around 50 V. This will increase when the excitation voltage gets higher and decrease as the excitation voltage gets lower. Furthermore, when the gap length is 5 nm and the excitation voltage is below 20 V, the diameter of EDR in our simulation is about 150 nm, which is consistent with the experiment results reported by other research groups. Our work provides a preliminary understanding of nanometer scale discharges and establishes a predictive structure-behavior relationship

  18. Atmospheric conditions associated with extreme fire activity in the Western Mediterranean region.

    Science.gov (United States)

    Amraoui, Malik; Pereira, Mário G; DaCamara, Carlos C; Calado, Teresa J

    2015-08-15

    Active fire information provided by TERRA and AQUA instruments on-board sun-synchronous polar MODIS platform is used to describe fire activity in the Western Mediterranean and to identify and characterize the synoptic patterns of several meteorological fields associated with the occurrence of extreme fire activity episodes (EEs). The spatial distribution of the fire pixels during the period of 2003-2012 leads to the identification of two most affected sub-regions, namely the Northern and Western parts of the Iberian Peninsula (NWIP) and Northern Africa (NAFR). The temporal distribution of the fire pixels in these two sub-regions is characterized by: (i) high and non-concurrent inter- and intra-annual variability with maximum values during the summer of 2003 and 2005 in NWIP and 2007 and 2012 in NAFR; and, (ii) high intra-annual variability dominated by a prominent annual cycle with a main peak centred in August in both sub-regions and a less pronounced secondary peak in March only evident in NWIP region. The 34 EEs identified were grouped according to the location, period of occurrence and spatial configuration of the associated synoptic patterns into 3 clusters (NWIP-summer, NWIP-winter and NAFR-summer). Results from the composite analysis reveal similar fire weather conditions (statistically significant positive anomalies of air temperature and negative anomalies of air relative humidity) but associated with different circulation patterns at lower and mid-levels of the atmosphere associated with the occurrence of EEs in each cluster of the Western Mediterranean region. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Evidence for the role of organics in aerosol particle formation under atmospheric conditions

    International Nuclear Information System (INIS)

    Metzger, A.; Dommen, J.; Duplissy, J.; Prevot, A.S.H.; Weingartner, E.; Baltensperger, U.; Verheggen, B.; Riipinen, I.; Kulmala, M.; Spracklen, D.V.; Carslaw, K.S.

    2010-01-01

    New particle formation in the atmosphere is an important parameter in governing the radiative forcing of atmospheric aerosols. However, detailed nucleation mechanisms remain ambiguous, as laboratory data have so far not been successful in explaining atmospheric nucleation. We investigated the formation of new particles in a smog chamber simulating the photochemical formation of H2SO4 and organic condensable species. Nucleation occurs at H2SO4 concentrations similar to those found in the ambient atmosphere during nucleation events. The measured particle formation rates are proportional to the product of the concentrations of H2SO4 and an organic molecule. This suggests that only one H2SO4 molecule and one organic molecule are involved in the rate-limiting step of the observed nucleation process. Parameterizing this process in a global aerosol model results in substantially better agreement with ambient observations compared to control runs.

  20. A Numerical Study of Nonlinear Nonhydrostatic Conditional Symmetric Instability in a Convectively Unstable Atmosphere.

    Science.gov (United States)

    Seman, Charles J.

    1994-06-01

    Nonlinear nonhydrostatic conditional symmetric instability (CSI) is studied as an initial value problem using a two-dimensional (y, z)nonlinear, nonhydrostatic numerical mesoscale/cloud model. The initial atmosphere for the rotating, baroclinic (BCF) simulation contains large convective available potential energy (CAPE). Analytical theory, various model output diagnostics, and a companion nonrotating barotropic (BTNF) simulation are used to interpret the results from the BCF simulation. A single warm moist thermal initiates convection for the two 8-h simulations.The BCF simulation exhibited a very intricate life cycle. Following the initial convection, a series of discrete convective cells developed within a growing mesoscale circulation. Between hours 4 and 8, the circulation grew upscale into a structure resembling that of a squall-line mesoscale convective system (MCS). The mesoscale updrafts were nearly vertical and the circulation was strongest on the baroclinically cool side of the initial convection, as predicted by a two-dimensional Lagrangian parcel model of CSI with CAPE. The cool-side mesoscale circulation grew nearly exponentially over the last 5 h as it slowly propagated toward the warm air. Significant vertical transport of zonal momentum occurred in the (multicellular) convection that developed, resulting in local subgeostrophic zonal wind anomalies aloft. Over time, geostrophic adjustment acted to balance these anomalies. The system became warm core, with mesohigh pressure aloft and mesolow pressure at the surface. A positive zonal wind anomaly also formed downstream from the mesohigh.Analysis of the BCF simulation showed that convective momentum transport played a key role in the evolution of the simulated MCS, in that it fostered the development of the nonlinear CSI on mesoscale time scales. The vertical momentum transport in the initial deep convection generated a subgeostrophic zonal momentum anomaly aloft; the resulting imbalance in pressure

  1. A case for 'prevailing ecology' as premium determinant in home ...

    African Journals Online (AJOL)

    A case for 'prevailing ecology' as premium determinant in home-based child care ... Ewe mothers located in Dzemeni a migrant, lakeside community in Ghana. ... It builds a case from the analysis of definitions and concepts in care literature.

  2. Study and Optimization on graft polymerization under normal pressure and air atmospheric conditions, and its application to metal adsorbent

    International Nuclear Information System (INIS)

    Ueki, Yuji; Chandra Dafader, Nirmal; Hoshina, Hiroyuki; Seko, Noriaki; Tamada, Masao

    2012-01-01

    Radiation-induced graft polymerization of glycidyl methacrylate (GMA) onto non-woven polyethylene (NWPE) fabric was achieved under normal pressure and air atmospheric conditions, without using unique apparatus such as glass ampoules or vacuum lines. To attain graft polymerization under normal pressure and air atmospheric conditions, the effects of the pre-irradiation dose, pre-irradiation atmosphere, pre-irradiation temperature, de-aeration of GMA-emulsion, grafting atmosphere in a reactor, and dissolved oxygen (DO) concentration in GMA-emulsion on the degree of grafting (Dg) were investigated in detail. It was found that the DO concentration had the strongest influence, the pre-irradiation dose, de-aeration of emulsion and grafting atmosphere had a relatively strong impact, and the pre-irradiation atmosphere and pre-irradiation temperature had the least effect on Dg. The optimum DO concentration before grafting was 2.0 mg/L or less. When a polyethylene bottle was used as a reactor instead of a glass ampoule, graft polymerization under normal pressure and air atmospheric conditions could be achieved under the following conditions; the pre-irradiation dose was more than 50 kGy, the volume ratio of GMA-emulsion to air was 50:1 or less, and the DO concentration in GMA-emulsion during grafting was below 2.0 mg/L. Under these grafting conditions, Dg was controlled within a range of up to 362%. The prepared GMA–grafted NWPE (GMA–g-NWPE) fabric was modified with a phosphoric acid to obtain an adsorbent for heavy metal ions. In the column-mode adsorption tests of Pb(II), the adsorption performance of the produced phosphorylated GMA–g-NWPE fabric (fibrous metal adsorbent) was not essentially dependent on the flow rate of the feed. The breakthrough points of 200, 500, and 1000 h −1 in space velocity were 483, 477 and 462 bed volumes, and the breakthrough capacities of the three flow rates were 1.16, 1.15 and 1.16 mmol-Pb(II)/g-adsorbent.

  3. Study and Optimization on graft polymerization under normal pressure and air atmospheric conditions, and its application to metal adsorbent

    Science.gov (United States)

    Ueki, Yuji; Chandra Dafader, Nirmal; Hoshina, Hiroyuki; Seko, Noriaki; Tamada, Masao

    2012-07-01

    Radiation-induced graft polymerization of glycidyl methacrylate (GMA) onto non-woven polyethylene (NWPE) fabric was achieved under normal pressure and air atmospheric conditions, without using unique apparatus such as glass ampoules or vacuum lines. To attain graft polymerization under normal pressure and air atmospheric conditions, the effects of the pre-irradiation dose, pre-irradiation atmosphere, pre-irradiation temperature, de-aeration of GMA-emulsion, grafting atmosphere in a reactor, and dissolved oxygen (DO) concentration in GMA-emulsion on the degree of grafting (Dg) were investigated in detail. It was found that the DO concentration had the strongest influence, the pre-irradiation dose, de-aeration of emulsion and grafting atmosphere had a relatively strong impact, and the pre-irradiation atmosphere and pre-irradiation temperature had the least effect on Dg. The optimum DO concentration before grafting was 2.0 mg/L or less. When a polyethylene bottle was used as a reactor instead of a glass ampoule, graft polymerization under normal pressure and air atmospheric conditions could be achieved under the following conditions; the pre-irradiation dose was more than 50 kGy, the volume ratio of GMA-emulsion to air was 50:1 or less, and the DO concentration in GMA-emulsion during grafting was below 2.0 mg/L. Under these grafting conditions, Dg was controlled within a range of up to 362%. The prepared GMA-grafted NWPE (GMA-g-NWPE) fabric was modified with a phosphoric acid to obtain an adsorbent for heavy metal ions. In the column-mode adsorption tests of Pb(II), the adsorption performance of the produced phosphorylated GMA-g-NWPE fabric (fibrous metal adsorbent) was not essentially dependent on the flow rate of the feed. The breakthrough points of 200, 500, and 1000 h-1 in space velocity were 483, 477 and 462 bed volumes, and the breakthrough capacities of the three flow rates were 1.16, 1.15 and 1.16 mmol-Pb(II)/g-adsorbent.

  4. Shoppers’ Perception on Physical Condition of Shopping Centers’ Atmosphere at Different Lifecycle

    Directory of Open Access Journals (Sweden)

    Astrid Kusumowidagdo

    2012-08-01

    Full Text Available Shopping center with atmospheric stimuli design needs to be well formulated in marketing strategy to expose its competitive advantage. As a result, most designs included in the marketing tactic scheme pay more attention to all factors related to the lifestyle in order to make designs exist and be appreciated by the society. Design is one of the key factors of shopping center to gain its success. This research aimed to find out to what extent the visitors perception is different towards shopping centers which has different lifecycles. The research studied two things, first was exploratory research intended to find the embodiment of atmospheric (atmospheric variables.The second research was done in a quantitative method, (multiple regression. This research studied the perception of a hundred mall visitors regarding how the variables of the interior atmosphere affected their shopping habit. The independent variables in the research were the exterior features and building configuration, interior features and supporting facilities. The dependent variable was the the visitor behavior. As a conclusion, the atmospheric interior design of a mall that is embodied in its interior element supported the hypothesis which said that existence of experience which felt differently according to visitor perception at shopping centers in different lifecyle.

  5. Attribution of soil moisture dynamics - Initial conditions vs. atmospheric forcing and the role of climate change

    Science.gov (United States)

    Orth, Rene; Seneviratne, Sonia I.

    2014-05-01

    conditions versus the atmospheric forcing for monthly soil moisture variations. We find that initial soil moisture anomalies are overall more important than the forcing, even if less pronounced in summer. Especially in southern Europe we show high drought forecasting potential, whereas the forcing is more important in Central and North-eastern Europe.

  6. Nb-TiO{sub 2}/polymer hybrid solar cells with photovoltaic response under inert atmosphere conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lira-Cantu, Monica; Khoda Siddiki, Mahbube; Munoz-Rojas, David; Amade, Roger [Centre d' Investigacio en Nanociencia i Nanotecnologia (CIN2, CSIC), Laboratory of Nanostructured Materials for Photovoltaic Energy, Campus UAB, Barcelona (Spain); Gonzalez-Pech, Natalia I. [Centre d' Investigacio en Nanociencia i Nanotecnologia (CIN2, CSIC), Laboratory of Nanostructured Materials for Photovoltaic Energy, Campus UAB, Barcelona (Spain); Instituto Tecnologico y de Estudios Superiores de Monterrey (ITESM), Ave. Eugenio Garza Sada, 64640 Monterrey, N.L. (Mexico)

    2010-07-15

    Hybrid Solar Cells (HSC) applying Nb-TiO{sub 2} in direct contact with a conducting organic polymer, MEH-PPV, show higher stability than the bare TiO{sub 2}-based HSC when analyzed under inert atmosphere conditions. IPCE analyses revealed that inert atmospheres affect directly the semiconductor oxide in the first stages of the analyses but photovoltaic performance stabilizes after several hours. A 20 wt% Nb-doped TiO{sub 2} presented the highest stability and photovoltaic properties. The behavior has been attributed to the solubility limit of Nb within the TiO{sub 2} beyond 20 wt% doping level where the co-existence of NbO{sub 2} is observed. The HSCs were analyzed under controlled N{sub 2} atmosphere and 1000 W/m{sup 2} (AM 1.5) irradiation. (author)

  7. Familiar units prevail over statistical cues in word segmentation.

    Science.gov (United States)

    Poulin-Charronnat, Bénédicte; Perruchet, Pierre; Tillmann, Barbara; Peereman, Ronald

    2017-09-01

    In language acquisition research, the prevailing position is that listeners exploit statistical cues, in particular transitional probabilities between syllables, to discover words of a language. However, other cues are also involved in word discovery. Assessing the weight learners give to these different cues leads to a better understanding of the processes underlying speech segmentation. The present study evaluated whether adult learners preferentially used known units or statistical cues for segmenting continuous speech. Before the exposure phase, participants were familiarized with part-words of a three-word artificial language. This design allowed the dissociation of the influence of statistical cues and familiar units, with statistical cues favoring word segmentation and familiar units favoring (nonoptimal) part-word segmentation. In Experiment 1, performance in a two-alternative forced choice (2AFC) task between words and part-words revealed part-word segmentation (even though part-words were less cohesive in terms of transitional probabilities and less frequent than words). By contrast, an unfamiliarized group exhibited word segmentation, as usually observed in standard conditions. Experiment 2 used a syllable-detection task to remove the likely contamination of performance by memory and strategy effects in the 2AFC task. Overall, the results suggest that familiar units overrode statistical cues, ultimately questioning the need for computation mechanisms of transitional probabilities (TPs) in natural language speech segmentation.

  8. Description of atmospheric conditions at the Pierre Auger Observatory using the Global Data Assimilation System (GDAS)

    Czech Academy of Sciences Publication Activity Database

    Abreu, P.; Aglietta, M.; Ahlers, M.; Boháčová, Martina; Chudoba, Jiří; Ebr, Jan; Mandát, Dušan; Nečesal, Petr; Nožka, Libor; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovancová, Jaroslava; Schovánek, Petr; Šmída, R.; Trávníček, Petr; Vícha, Jakub

    2012-01-01

    Roč. 35, č. 9 (2012), s. 591-607 ISSN 0927-6505 R&D Projects: GA MŠk LC527; GA MŠk(CZ) 1M06002; GA AV ČR KJB100100904; GA AV ČR KJB300100801; GA MŠk(CZ) LA08016 Institutional research plan: CEZ:AV0Z10100502; CEZ:AV0Z10100522 Keywords : cosmic rays * extensive air shower s * atmospheric monitoring * atmospheric models Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.777, year: 2012 http://www.sciencedirect.com/science/article/pii/S0927650511002271

  9. Reactions of CF3O radicals with selected alkenes and aromatics under atmospheric conditions

    DEFF Research Database (Denmark)

    Kelly, C.; Sidebottom, H.W.; Treacy, J.

    1994-01-01

    Rate data for the reactions of CF3O radicals with alkenes and aromatic compounds have been determined at 298 K using a relative rate method. The data are analyzed in terms of structure-reactivity relationships, and their importance to the atmospheric chemistry of CF3O discussed.......Rate data for the reactions of CF3O radicals with alkenes and aromatic compounds have been determined at 298 K using a relative rate method. The data are analyzed in terms of structure-reactivity relationships, and their importance to the atmospheric chemistry of CF3O discussed....

  10. Effect of Nock-Ten Tropical Cyclone on Atmospheric Condition and Distribution of Rainfall in Gorontalo, Ternate, and Sorong Regions

    Science.gov (United States)

    Lumbangaol, A.; Serhalawan, Y. R.; Endarwin

    2017-12-01

    Nock-Ten Tropical Cyclone is an atmospheric phenomenon that has claimed many lives in the Philippines. This super-typhoon cyclone grows in the Western Pacific Ocean, North of Papua. With the area directly contiguous to the trajectory of Nock-Ten Tropical Cyclone growth, it is necessary to study about the growth activity of this tropical cyclones in Indonesia, especially in 3 different areas, namely Gorontalo, Ternate, and Sorong. This study was able to determine the impact of Nock-Ten Tropical Cyclone on atmospheric dynamics and rainfall growth distribution based on the stages of tropical cyclone development. The data used in this study include Himawari-8 IR channel satellite data to see the development stage and movement track of Tropical Cyclone Nock-Ten, rainfall data from TRMM 3B42RT satellite product to know the rain distribution in Gorontalo, Ternate, and Sorong, and reanalysis data from ECMWF such as wind direction and speed, vertical velocity, and relative vorticity to determine atmospheric conditions at the time of development of the Nock-Ten Tropical Cyclone. The results of data analysis processed using GrADS application showed the development stage of Nock-Ten Tropical Cyclone has effect of changes in atmospheric dynamics condition and wind direction pattern. In addition, tropical cyclones also contribute to very light to moderate scale intensity during the cycle period of tropical cyclone development in all three regions.

  11. Approximate analytical solution to diurnal atmospheric boundary-layer growth under well-watered conditions

    Science.gov (United States)

    The system of governing equations of a simplified slab model of the uniformly-mixed, purely convective, diurnal atmospheric boundary layer (ABL) is shown to allow immediate solutions for the potential temperature and specific humidity as functions of the ABL height and net radiation when expressed i...

  12. Estimations of Atmospheric Conditions for Input to the Radar Performance Surface

    Science.gov (United States)

    2007-12-01

    distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) This study addresses the support of non- acoustic ASW operations by...BLANK v ABSTRACT This study addresses the support of non- acoustic ASW operations by timely atmospheric and ocean surface descriptions on features...24 Figure 12. Infrared Radiation Pyrometers , model KT15.82, Wintronics 2007

  13. Dependence of positive and negative sprite morphology on lightning characteristics and upper atmospheric ambient conditions

    Science.gov (United States)

    Qin, Jianqi; Celestin, Sebastien; Pasko, Victor P.

    2013-05-01

    Carrot sprites, exhibiting both upward and downward propagating streamers, and columniform sprites, characterized by predominantly vertical downward streamers, represent two distinct morphological classes of lightning-driven transient luminous events in the upper atmosphere. It is found that positive cloud-to-ground lightning discharges (+CGs) associated with large charge moment changes (QhQ) tend to produce carrot sprites with the presence of a mesospheric region where the electric field exceeds the value 0.8Ek and persists for >˜2 ms, whereas those associated with small QhQ are only able to produce columniform sprites. Columniform sprites may also appear in the periphery of a sprite halo produced by +CGs associated with large QhQ. For a sufficiently large QhQ, the time dynamics of the QhQ determines the specific shape of the carrot sprites. In the case when the sufficiently large QhQ is produced mainly by an impulsive return stroke, strong electric field is produced at high altitudes and manifests as a bright halo, and the corresponding conductivity enhancement lowers/enhances the probability of streamer initiation inside/below the sprite halo. A more impulsive return stroke leads to a more significant conductivity enhancement (i.e., a brighter halo). This conductivity enhancement also leads to fast decay and termination of the upper diffuse region of carrot sprites because it effectively screens out the electric field at high altitudes. On the contrary, if the sufficiently large QhQ is produced by a weak return stroke (i.e., a dim halo) accompanied by intense continuing current, the lightning-induced electric field at high altitudes persists at a level that is comparable to Ek, and therefore an extensive upper diffuse region can develop. Furthermore, we demonstrate that `negative sprites' (produced by -CGs) should be necessarily carrot sprites and most likely accompanied by a detectable halo, since the initiation of upward positive streamers is always easier

  14. Assessing the impacts of seasonal and vertical atmospheric conditions on air quality over the Pearl River Delta region

    Science.gov (United States)

    Tong, Cheuk Hei Marcus; Yim, Steve Hung Lam; Rothenberg, Daniel; Wang, Chien; Lin, Chuan-Yao; Chen, Yongqin David; Lau, Ngar Cheung

    2018-05-01

    Air pollution is an increasingly concerning problem in many metropolitan areas due to its adverse public health and environmental impacts. Vertical atmospheric conditions have strong effects on vertical mixing of air pollutants, which directly affects surface air quality. The characteristics and magnitude of how vertical atmospheric conditions affect surface air quality, which are critical to future air quality projections, have not yet been fully understood. This study aims to enhance understanding of the annual and seasonal sensitivities of air pollution to both surface and vertical atmospheric conditions. Based on both surface and vertical meteorological characteristics provided by 1994-2003 monthly dynamic downscaling data from the Weather and Research Forecast Model, we develop generalized linear models (GLMs) to study the relationships between surface air pollutants (ozone, respirable suspended particulates, and sulfur dioxide) and atmospheric conditions in the Pearl River Delta (PRD) region. Applying Principal Component Regression (PCR) to address multi-collinearity, we study the contributions of various meteorological variables to pollutants' concentration levels based on the loading and model coefficient of major principal components. Our results show that relatively high pollutant concentration occurs under relatively low mid-level troposphere temperature gradients, low relative humidity, weak southerly wind (or strong northerly wind) and weak westerly wind (or strong easterly wind). Moreover, the correlations vary among pollutant species, seasons, and meteorological variables at various altitudes. In general, pollutant sensitivity to meteorological variables is found to be greater in winter than in other seasons, and the sensitivity of ozone to meteorology differs from that of the other two pollutants. Applying our GLMs to anomalous air pollution episodes, we find that meteorological variables up to mid troposphere (∼700 mb) play an important role in

  15. Adaptive Artificial intelligence based fuzzy logic MPPTcontrol for stande-alone photovoltaic system under different atmospheric conditions

    Directory of Open Access Journals (Sweden)

    Zaghba Layachi

    2015-08-01

    Full Text Available there is an increased need for analysing the effect of atmospheric variables on photovoltaic (PV production and performance. The outputs from the different PV cells in different atmospheric conditions, such as irradiation and temperature , differ from each other evidencing knowledge deficiency in PV systems [14]. Maximum power point tracking (MPPT methods are used to maximize the PV array output power by tracking continuously the maximum power point (MPP. Among all MPPT methods existing in the literature, perturb and observe (P&O is the most commonly used for its simplicity and ease of implementation; however, it presents drawbacks such as slow response speed, oscillation around the MPP in steady state, and even tracking in wrong way under rapidly changing atmospheric conditions. In order to allow a functioning around the optimal point Mopt, we have inserted a DC-DC converter (Buck–Boost for a better matching between the PV and the load. This paper, we study the Maximum power point tracking using adaptive Intelligent fuzzy logic and conventional (P&O control for stande-alone photovoltaic Array system .In particular, the performances of the controllers are analyzed under variation weather conditions with are constant temperature and variable irradiation. The proposed system is simulated by using MATLAB-SIMULINK. According to the results, fuzzy logic controller has shown better performance during the optimization.

  16. The Influence of atmospheric conditions to probabilistic calculation of impact of radiology accident on PWR 1000 MWe

    International Nuclear Information System (INIS)

    Pande Made Udiyani; Sri Kuntjoro

    2015-01-01

    The calculation of the radiological impact of the fission products releases due to potential accidents that may occur in the PWR (Pressurized Water Reactor) is required in a probabilistic. The atmospheric conditions greatly contribute to the dispersion of radionuclides in the environment, so that in this study will be analyzed the influence of atmospheric conditions on probabilistic calculation of the reactor accidents consequences. The objective of this study is to conduct an analysis of the influence of atmospheric conditions based on meteorological input data models on the radiological consequences of PWR 1000 MWe accidents. Simulations using PC-Cosyma code with probabilistic calculations mode, the meteorological data input executed cyclic and stratified, the meteorological input data are executed in the cyclic and stratified, and simulated in Muria Peninsula and Serang Coastal. Meteorological data were taken every hour for the duration of the year. The result showed that the cumulative frequency for the same input models for Serang coastal is higher than the Muria Peninsula. For the same site, cumulative frequency on cyclic input models is higher than stratified models. The cyclic models provide flexibility in determining the level of accuracy of calculations and do not require reference data compared to stratified models. The use of cyclic and stratified models involving large amounts of data and calculation repetition will improve the accuracy of statistical calculation values. (author)

  17. Physical modeling of flow over an axisymmetric knoll under neutral atmospheric conditions

    International Nuclear Information System (INIS)

    Cliff, W.C.; Smith, J.D.

    1980-02-01

    A glass-walled hydraulic (water) flume was used to model physically air flow near an axisymmetric knoll in a neutral atmospheric boundary layer. The knoll was a 1:250 scale model. An upstream velocity profile (1/7 power law), characteristic of a neutral atmospheric boundary layer, was produced by locating a 10-cm-high (4-in.) trip near the flume entrance and by appropriately roughening the flume floor. Mean velocity, rms velocity, and turbulence intensity profiles were measured at locations near the knoll using an existing laser Doppler anemometer system. The flow accelerated over the knoll and produced a relatively uniform velocity profile at the crest. The measured velocity profile was in close agreement with a theoretical velocity profile developed using potential flow theory and an upstream power law velocity profile. The turbulence intensity decreased at the crest of the knoll as a result of the flow acceleration

  18. Do atmospheric conditions influence the first episode of primary spontaneous pneumothorax?

    Science.gov (United States)

    Heyndrickx, Maxime; Le Rochais, Jean-Philippe; Icard, Philippe; Cantat, Olivier; Zalcman, Gérard

    2015-09-01

    Several studies suggest that changes in airway pressure may influence the onset of primary spontaneous pneumothorax (PSP). The aim of this study was to investigate the influence of atmospheric changes on the onset of the first episode of PSP. We retrospectively analysed cases of pneumothorax admitted to our department between 1 January 2009 and 31 October 2013. Patients with recurrent pneumothorax, traumatic pneumothorax, older than 35 years or presenting history of underlying pulmonary disease were excluded. Meteorological data were collected from the Météo-France archives. Variation (Δ) of mean atmospheric pressure, and relative humidity, were calculated for each day between the day at which symptoms began (D-day), the day before first symptoms (D-1), 2 days before the first symptoms (D-2) and 3 days before the first symptoms (D-3). Six hundred and thirty-eight cases of pneumothorax were observed during the period of this study; 106 of them (16.6%) were a first episode of PSP. We did not observe any significant differences between days with or without PSP admission for any of the weather parameters that we tested. We could not find any thresholds in the variation of atmospheric pressure that could be used to determine the probability of PSP occurrence. Variation of atmospheric pressure, relative humidity, rainfall, wind speed and temperature were not significantly related to the onset of the first episode of PSP in healthy patients. These results suggest that the scientific community should focus on other possible aetiological factors than airway pressure modifications. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  19. Review Article: Atmospheric conditions inducing extreme precipitation over the eastern and western Mediterranean

    Science.gov (United States)

    Dayan, U.; Nissen, K.; Ulbrich, U.

    2015-11-01

    This review discusses published studies of heavy rainfall events over the Mediterranean Basin, combining them in a more general picture of the dynamic and thermodynamic factors and processes that produce heavy rain storms. It distinguishes the western and eastern Mediterranean in order to point out specific regional peculiarities. The crucial moisture for developing intensive convection over these regions can be originated not only from the adjacent Mediterranean Sea but also from distant upwind sources. Transport from remote sources is usually in the mid-tropospheric layers and associated with specific features and patterns of the larger-scale circulations. The synoptic systems (tropical and extratropical) that account for most of the major extreme precipitation events and the coupling of circulation and extreme rainfall patterns are presented. Heavy rainfall over the Mediterranean Basin is caused at times in concert by several atmospheric processes working at different atmospheric scales, such as local convection, upper synoptic-scale-level troughs, and mesoscale convective systems. Under tropical air-mass intrusions, convection generated by static instability seems to play a more important role than synoptic-scale vertical motions. Locally, the occurrence of torrential rains and their intensity is dependent on factors such as temperature profiles and implied instability, atmospheric moisture, and lower-level convergence.

  20. Vets prevail online intervention reduces PTSD and depression in veterans with mild-to-moderate symptoms.

    Science.gov (United States)

    Hobfoll, Stevan E; Blais, Rebecca K; Stevens, Natalie R; Walt, Lisa; Gengler, Richard

    2016-01-01

    Despite heightened rates of depression and posttraumatic stress disorder (PTSD) among in Iraq/Afghanistan veterans, the majority of distressed veterans will not receive mental health care. Overcoming barriers to mental health services requires innovative approaches to broaden the reach of evidence-based treatment. The current study examined the efficacy and acceptability of an innovative and dynamic online cognitive-behavioral therapy intervention for PTSD and depression called Vets Prevail. A randomized clinical trial conducted between 2011 and 2013 assessed changes in PTSD and depression in veterans with mild-to-moderate distress. Veterans randomized to Vets Prevail (n = 209) were aged 34.2 ± 7.6 years, mostly male (81.3%), and nonminority (73.7%). Veterans randomized to adjustment as usual (n = 94) were aged 34.7 ± 8.9, mostly male (81.9%), and White (67.0%). Veterans completed the PTSD Checklist-Military Version and the Center for Epidemiological Studies Depression scale (10-item version) postintervention and at 12-week follow-up. Veterans in the Vets Prevail condition reported significantly greater reductions in PTSD, t(250) = 3.24, p = .001 (Mreduction = 5.51, SD = 9.63), and depression, t(252) = 4.37, p = .001 (Mreduction = 2.31, SD = 5.34), at 12-week follow-up compared with veterans in the adjustment as usual condition (PTSD Mreduction = 1.00, SD = 7.32; depression Mreduction = 0.48, SD = 4.95), with moderate effect sizes for PTSD (Cohen's d = 0.42) and depression (Cohen's d = 0.56). Exploratory analysis shows that Vets Prevail may be effective regardless of combat trauma exposure, gender, and ethnic minority status. Vets Prevail circumvents many barriers to care and effectively addresses the dire mental health needs of veterans. (c) 2015 APA, all rights reserved).

  1. Radiation effects on the laser ablative shockwaves from aluminum under atmospheric conditions

    International Nuclear Information System (INIS)

    Sai Shiva, S.; Leela, C.H.; Prem Kiran, P.; Sijoy, C.D.; Chaturvedi, Shashank

    2015-01-01

    The evolution of laser ablative shockwaves (LASW) from Aluminum under atmospheric pressures is numerically modeled using a one-dimensional, three-temperature (electron, ion and thermal radiation temperatures), non-equilibrium, radiation hydrodynamic (RHD) model. The governing RHD equations in Lagrangian form are solved by using an implicit scheme. Similarly, the energy relaxation between the electrons and ions and the electrons and thermal radiation are determined implicitly. Apart from these, the energy equation takes into account the flux-limited electron thermal heat flux. The RHD equations are closed by using a two temperature QEOS model for the Al. The MULTI-fs code is modified to incorporate the nanosecond laser absorption model via the photoionization (PI) and the inverse bremsstrahlung (IB) processes. The spatio-temporal evolution of the laser ablative shockwaves generated by focusing a second harmonic (532 nm, 7ns) of Nd:YAG laser on to Aluminum target under atmospheric pressures in air is captured using a shadowgraphy technique. These measurements are made from 200 ns to 10 μs after the laser pulse with a temporal resolution of 1.5 ns. We report the details of the RHD model and compare the simulated and experimental results for input laser energies in the range of 25 - 175 mJ per pulse. The evolution of the plasma parameters like electron density, charge states and the shockwaves launched into the ambient atmosphere due to expanding plasma plume are compared. The role of thermal radiation on the evolution of LASW from Al is discussed. (author)

  2. Beam wandering statistics of twin thin laser beam propagation under generalized atmospheric conditions.

    Science.gov (United States)

    Pérez, Darío G; Funes, Gustavo

    2012-12-03

    Under the Geometrics Optics approximation is possible to estimate the covariance between the displacements of two thin beams after they have propagated through a turbulent medium. Previous works have concentrated in long propagation distances to provide models for the wandering statistics. These models are useful when the separation between beams is smaller than the propagation path-regardless of the characteristics scales of the turbulence. In this work we give a complete model for these covariances, behavior introducing absolute limits to the validity of former approximations. Moreover, these generalizations are established for non-Kolmogorov atmospheric models.

  3. Comparative evaluation of thermal decomposition behavior and thermal stability of powdered ammonium nitrate under different atmosphere conditions.

    Science.gov (United States)

    Yang, Man; Chen, Xianfeng; Wang, Yujie; Yuan, Bihe; Niu, Yi; Zhang, Ying; Liao, Ruoyu; Zhang, Zumin

    2017-09-05

    In order to analyze the thermal decomposition characteristics of ammonium nitrate (AN), its thermal behavior and stability under different conditions are studied, including different atmospheres, heating rates and gas flow rates. The evolved decomposition gases of AN in air and nitrogen are analyzed with a quadrupole mass spectrometer. Thermal stability of AN at different heating rates and gas flow rates are studied by differential scanning calorimetry, thermogravimetric analysis, paired comparison method and safety parameter evaluation. Experimental results show that the major evolved decomposition gases in air are H 2 O, NH 3 , N 2 O, NO, NO 2 and HNO 3 , while in nitrogen, H 2 O, NH 3 , NO and HNO 3 are major components. Compared with nitrogen atmosphere, lower initial and end temperatures, higher heat flux and broader reaction temperature range are obtained in air. Meanwhile, higher air gas flow rate tends to achieve lower reaction temperature and to reduce thermal stability of AN. Self-accelerating decomposition temperature of AN in air is much lower than that in nitrogen. It is considered that thermostability of AN is influenced by atmosphere, heating rate and gas flow rate, thus changes of boundary conditions will influence its thermostability, which is helpful to its safe production, storage, transportation and utilization. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Improvement in Simulation of Eurasian Winter Climate Variability with a Realistic Arctic Sea Ice Condition in an Atmospheric GCM

    Science.gov (United States)

    Lim, Young-Kwon; Ham, Yoo-Geun; Jeong, Jee-Hoon; Kug, Jong-Seong

    2012-01-01

    The present study investigates how much a realistic Arctic sea ice condition can contribute to improve simulation of the winter climate variation over the Eurasia region. Model experiments are set up using different sea ice boundary conditions over the past 24 years (i.e., 1988-2011). One is an atmospheric model inter-comparison (AMIP) type of run forced with observed sea-surface temperature (SST), sea ice, and greenhouse gases (referred to as Exp RSI), and the other is the same as Exp RSI except for the sea ice forcing, which is a repeating climatological annual cycle (referred to as Exp CSI). Results show that Exp RSI produces the observed dominant pattern of Eurasian winter temperatures and their interannual variation better than Exp CSI (correlation difference up to approx. 0.3). Exp RSI captures the observed strong relationship between the sea ice concentration near the Barents and Kara seas and the temperature anomaly across Eurasia, including northeastern Asia, which is not well captured in Exp CSI. Lagged atmospheric responses to sea ice retreat are examined using observations to understand atmospheric processes for the Eurasian cooling response including the Arctic temperature increase, sea-level pressure increase, upper-level jet weakening and cold air outbreak toward the mid-latitude. The reproducibility of these lagged responses by Exp RSI is also evaluated.

  5. Improvement in simulation of Eurasian winter climate variability with a realistic Arctic sea ice condition in an atmospheric GCM

    International Nuclear Information System (INIS)

    Lim, Young-Kwon; Ham, Yoo-Geun; Jeong, Jee-Hoon; Kug, Jong-Seong

    2012-01-01

    The present study investigates how much a realistic Arctic sea ice condition can contribute to improve simulation of the winter climate variation over the Eurasia region. Model experiments are set up using different sea ice boundary conditions over the past 24 years (i.e., 1988–2011). One is an atmospheric model inter-comparison (AMIP) type of run forced with observed sea-surface temperature (SST), sea ice, and greenhouse gases (referred to as Exp RSI), and the other is the same as Exp RSI except for the sea ice forcing, which is a repeating climatological annual cycle (referred to as Exp CSI). Results show that Exp RSI produces the observed dominant pattern of Eurasian winter temperatures and their interannual variation better than Exp CSI (correlation difference up to ∼0.3). Exp RSI captures the observed strong relationship between the sea ice concentration near the Barents and Kara seas and the temperature anomaly across Eurasia, including northeastern Asia, which is not well captured in Exp CSI. Lagged atmospheric responses to sea ice retreat are examined using observations to understand atmospheric processes for the Eurasian cooling response including the Arctic temperature increase, sea-level pressure increase, upper-level jet weakening and cold air outbreak toward the mid-latitude. The reproducibility of these lagged responses by Exp RSI is also evaluated. (letter)

  6. Inhibition treatment of the corrosion of lead artefacts in atmospheric conditions and by acetic acid vapour: use of sodium decanoate

    International Nuclear Information System (INIS)

    Rocca, E.; Rapin, C.; Mirambet, F.

    2004-01-01

    The efficiency of linear sodium decanoate, CH 3 (CH 2 ) 8 COONa (noted NaC 10 ), as corrosion inhibitor of lead was determined by electrochemical techniques in two corrosive mediums: ASTM D1384 standard water and acetic acid-enriched solutions. Best results were obtained with 0.05 mol l -1 of NaC 10 solution. In these conditions, the inhibition efficiency can be estimated of 99.9%. The corrosion inhibition effect was confirmed by cyclic atmospheric tests in a climatic chamber in two different conditions: water saturated vapour, and acid acetic enriched vapour simulating the atmosphere in the wooden displays in museums. Surface analyses by SEM and X-ray diffraction indicate that the metal protection is due to the formation of a protective layer mainly composed of lead decanoate Pb(C 10 ) 2 (metallic soap). This inhibition treatment was applied on objects of metallic cultural heritage: gallo-roman sarcophagus in lead. Electrochemical methods confirm the efficiency of treatment on archaeological materials. In conclusion, this inhibitor treatment seems to be very promising against the atmospheric corrosion and the corrosion by organic acid vapour in museums

  7. MPAS Atmospheric Boundary Layer Simulation under Selected Stability Conditions: Evaluation Using the SWIFT Datasen

    Energy Technology Data Exchange (ETDEWEB)

    Kotamarthi, V. Rao [Argonne National Lab. (ANL), Argonne, IL (United States); Feng, Yan [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-10-12

    Modeling the transition from mesoscale to microscale is necessary in order to model different processes that affect a wind farm and to develop forecasting tools that operate at the farm scale. The mesoscale-to-microscale coupling (MMC) project is an A2e (Atmosphere-toelectrons) coordinated activity for developing modeling capabilities at the wind farm scale. By moving the focus of the research from a single wind turbine to the collection of turbines that comprise a wind farm, A2e extends the range of spatial and timescales that need representation in a model from tens of meters to hundreds of kilometers and timescales from a few seconds to days (Bokharaie et al. 2016). In the atmosphere, these scales are represented by mesoscale-tomicroscale models. The modeling available at these scales has differed in its representation of various physical processes. The MMC group is responsible for evaluating existing models at these scales and recommending a set of options for coupling the mesoscale and microscale with the best-performing models. The group was organized in 2015 and will explore options for coupling strategies with real-world test problems in fiscal year (FY) 2017. The model of choice for this exercise is WRF (Weather Research Forecasting) for mesoscale and WRF-LES (Large Eddy Simulation) for microscale simulations. The MPAS (Model Prediction Across Scales) variable mesh model that can be continuously refined; it has dynamic core and physics options adopted from WRF, which offer an alternative platform for modeling the mesoscale.

  8. Comparison of toluene removal in air at atmospheric conditions by different corona discharges.

    Science.gov (United States)

    Schiorlin, Milko; Marotta, Ester; Rea, Massimo; Paradisi, Cristina

    2009-12-15

    Different types of corona discharges, produced by DC of either polarity (+/-DC) and positive pulsed (+pulsed) high voltages, were applied to the removal of toluene via oxidation in air at room temperature and atmospheric pressure. Mechanistic insight was obtained through comparison of the three different corona regimes with regard to process efficiency, products, response to the presence of humidity and, for DC coronas, current/voltage characteristics coupled with ion analysis. Process efficiency increases in the order +DC toluene conversion and product selectivity were achieved, CO(2) and CO accounting for about 90% of all reacted carbon. Ion analysis, performed by APCI-MS (Atmospheric Pressure Chemical Ionization-Mass Spectrometry), provides a powerful rationale for interpreting current/voltage characteristics of DC coronas. All experimental findings are consistent with the proposal that in the case of +DC corona toluene oxidation is initiated by reactions with ions (O(2)(+*), H(3)O(+) and their hydrates, NO(+)) both in dry as well as in humid air. In contrast, with -DC no evidence is found for any significant reaction of toluene with negative ions. It is also concluded that in humid air OH radicals are involved in the initial stage of toluene oxidation induced both by -DC and +pulsed corona.

  9. Growing importance of atmospheric water demands on the hydrologcial condition of East Asia

    Science.gov (United States)

    Park, C. E.; Ho, C. H.; Jeong, S. J.; Park, H.

    2015-12-01

    As global temperature increases, enhanced exchange of fresh water between the surface and atmosphere expected to make dry regions drier and wet regions wetter. This concept is well fitted for the ocean, but oversimplified for the land. How the climate change causes the complex patterns of the continental dryness change is one of challenging questions. Here we investigate the observed dryness changes of the land surface by examining the quantitative influence of several climate parameters on the background aridity changes over East Asia, containing various climate regimes from cold-arid to warm-humid regions, using observations of 189 stations covering the period from 1961 to 2010. Overall mean aridity trend is changed from negative to positive around early 1990s. The turning of dryness trend is largely influenced by sharp increase in atmospheric water demands, regardless of the background climate. The warming induced increase in water demands is larger in warm-humid regions than in cold-arid region due to the Clausius-Clapeyron relation between air temperature and saturation vapor pressure. The results show the drying of anthropogenic warming already begins and influences on the patterns of dryness change over the land surface.

  10. Effect of Shadowing on Survival of Bacteria under Conditions Simulating the Martian Atmosphere and UV Radiation▿ †

    Science.gov (United States)

    Osman, Shariff; Peeters, Zan; La Duc, Myron T.; Mancinelli, Rocco; Ehrenfreund, Pascale; Venkateswaran, Kasthuri

    2008-01-01

    Spacecraft-associated spores and four non-spore-forming bacterial isolates were prepared in Atacama Desert soil suspensions and tested both in solution and in a desiccated state to elucidate the shadowing effect of soil particulates on bacterial survival under simulated Martian atmospheric and UV irradiation conditions. All non-spore-forming cells that were prepared in nutrient-depleted, 0.2-μm-filtered desert soil (DSE) microcosms and desiccated for 75 days on aluminum died, whereas cells prepared similarly in 60-μm-filtered desert soil (DS) microcosms survived such conditions. Among the bacterial cells tested, Microbacterium schleiferi and Arthrobacter sp. exhibited elevated resistance to 254-nm UV irradiation (low-pressure Hg lamp), and their survival indices were comparable to those of DS- and DSE-associated Bacillus pumilus spores. Desiccated DSE-associated spores survived exposure to full Martian UV irradiation (200 to 400 nm) for 5 min and were only slightly affected by Martian atmospheric conditions in the absence of UV irradiation. Although prolonged UV irradiation (5 min to 12 h) killed substantial portions of the spores in DSE microcosms (∼5- to 6-log reduction with Martian UV irradiation), dramatic survival of spores was apparent in DS-spore microcosms. The survival of soil-associated wild-type spores under Martian conditions could have repercussions for forward contamination of extraterrestrial environments, especially Mars. PMID:18083857

  11. Effect of Light Intensities and Atmospheric Gas Conditions on Biohydrogen Production of Microalgae Isolated from Fisheries Wastewater

    Directory of Open Access Journals (Sweden)

    Mujalin Pholchan

    2017-06-01

    Full Text Available Recently, the fishery farming industry has been developed rapidly due to increasing demand and consumption as well as the depletion of wild fish resources. Production processes in the industry usually generate large amounts of wastewater containing high nutrients, posing a threat to downstream water. However, phytoplankton removal techniques commonly used to counteract the threat, though appearing to have low efficiency, are timeconsuming and less sustainable. Microalgae are photosynthetic microorganisms that convert solar energy into hydrogen. Using the isolated algae from fish farms as a source of renewable energy production could be a promising choice for handling fisheries wastewater in a more efficient manner. However, hydrogen production processes from algae still need more studies as their efficiencies vary between algae species and growth factors. In this work, the efficiency of hydrogen production from Scenedesmus accuminatus and Arthrospira platensis harvested from fish farms under three different light intensity conditions and three atmospheric gas conditions was determined. The results showed that the best conditions for hydrogen production from both species included 24 h darkness and carbon dioxide addition. Under the atmospheric gas combination of 99% argon and 1% carbon dioxide, S. accuminatus could produce hydrogen gas as high as 0.572 mol H2/mgCh h within 12 h, while the highest hydrogen production (0.348 mol H2/mgCh h obtained from A. platensis was found under the atmospheric gas mixture of 98% argon and 2% carbon dioxide. Interestingly, S. accuminatus appeared to produce more hydrogen than A. platensis under the same conditions.

  12. Effects of atmospheric pressure conditions on flow rate of an elastomeric infusion pump.

    Science.gov (United States)

    Wang, Jong; Moeller, Anna; Ding, Yuanpang Samuel

    2012-04-01

    The effects of pressure conditions, both hyperbaric and hypobaric, on the flow rate of an elastomeric infusion pump were investigated. The altered pressure conditions were tested with the restrictor outlet at two different conditions: (1) at the same pressure condition as the Infusor elastomeric balloon and (2) with the outlet exposed to ambient conditions. Five different pressure conditions were tested. These included ambient pressure (98-101 kilopascals [kPa]) and test pressures controlled to be 10 or 20 kPa below or 75 or 150 kPa above the ambient pressure. A theoretical calculation based on the principles of fluid mechanics was also used to predict the pump's flow rate at various ambient conditions. The conditions in which the Infusor elastomeric pump and restrictor outlet were at the same pressure gave rise to average flow rates within the ±10% tolerance of the calculated target flow rate of 11 mL/hr. The flow rate of the Infusor pump decreased when the pressure conditions changed from hypobaric to ambient. The flow rate increased when the pressure conditions changed from hyperbaric to ambient. The flow rate of the Infusor elastomeric pump was not affected when the balloon reservoir and restrictor outlet were at the same pressure. The flow rate varied from 58.54% to 377.04% of the labeled flow rate when the pressure applied to the reservoir varied from 20 kPa below to 150 kPa above the pressure applied to the restrictor outlet, respectively. The maximum difference between observed flow rates and those calculated by applying fluid mechanics was 4.9%.

  13. Pool boiling of water on nano-structured micro wires at sub-atmospheric conditions

    Science.gov (United States)

    Arya, Mahendra; Khandekar, Sameer; Pratap, Dheeraj; Ramakrishna, S. Anantha

    2016-09-01

    Past decades have seen active research in enhancement of boiling heat transfer by surface modifications. Favorable surface modifications are expected to enhance boiling efficiency. Several interrelated mechanisms such as capillarity, surface energy alteration, wettability, cavity geometry, wetting transitions, geometrical features of surface morphology, etc., are responsible for change in the boiling behavior of modified surfaces. Not much work is available on pool boiling at low pressures on microscale/nanoscale geometries; low pressure boiling is attractive in many applications wherein low operating temperatures are desired for a particular working fluid. In this background, an experimental setup was designed and developed to investigate the pool boiling performance of water on (a) plain aluminum micro wire (99.999 % pure) and, (b) nano-porous alumina structured aluminum micro wire, both having diameter of 250 µm, under sub-atmospheric pressure. Nano-structuring on the plain wire surface was achieved via anodization. Two samples, A and B of anodized wires, differing by the degree of anodization were tested. The heater length scale (wire diameter) was much smaller than the capillary length scale. Pool boiling characteristics of water were investigated at three different sub-atmospheric pressures of 73, 123 and 199 mbar (corresponding to T sat = 40, 50 and 60 °C). First, the boiling characteristics of plain wire were measured. It was noticed that at sub-atmospheric pressures, boiling heat transfer performance for plain wire was quite low due to the increased bubble sizes and low nucleation site density. Subsequently, boiling performance of nano-structured wires (both Sample A and Sample B) was compared with plain wire and it was noted that boiling heat transfer for the former was considerably enhanced as compared to the plain wire. This enhancement is attributed to increased nucleation site density, change in wettability and possibly due to enhanced pore scale

  14. Modelling the autoxidation of myoglobin in fresh meat under modified atmosphere packing conditions

    DEFF Research Database (Denmark)

    Tofteskov, Jon; Hansen, Jesper Schmidt; Bailey, Nicholas

    2017-01-01

    pigment concentration data is obtained, but only by substantially increasing the value of the oxygen consumption rate. Application of the model to meat stored at 5 °C shows that the metmyoglobin layer forms under the surface over a time scale of 24 h; The metmyoglobin layer forms deeper inside the meat......Modified atmosphere packing (MAP) is a technique to increase the shelf life of fresh meat. Continuing development of MAP requires better understanding of the physical and chemical processes taking place, in particular the diffusion of oxygen and its reaction with myoglobin. We model these processes...... proportional to the logarithm of the headspace oxygen partial pressure, thus improving the colour appearance of the meat....

  15. A numerical study for the assessment of pollutant dispersion from Kostolac B power plant to Viminacium for different atmospheric conditions

    Directory of Open Access Journals (Sweden)

    Kozić Mirko S.

    2015-01-01

    Full Text Available The level of pollution concentration to the archaeological site Viminacium caused by the stack of Kostolac B power plant is analyzed using CFD software. The wind is directed from the stack toward Viminacium-Archaeological Site, Therma and Viminacium - Museum. Three different meteorological conditions resulting in fanning, fumigating and looping plume are modelled. The temperature gradient as the most important factor defining the conditions of the atmosphere is included through the appropriate boundary conditions. It is shown that concentrations of the pollutants on the objects of Viminacium are very low. It can be attributed to the stack height and high temperature of the smoke at its exit. It also indicates that other sources of pollution such as open ash dumps and acid rain should be checked.

  16. Muscodor albus Volatiles Control Toxigenic Fungi under Controlled Atmosphere (CA Storage Conditions

    Directory of Open Access Journals (Sweden)

    Gordon Braun

    2012-11-01

    Full Text Available Muscodor albus, a biofumigant fungus, has the potential to control post-harvest pathogens in storage. It has been shown to produce over 20 volatile compounds with fungicidal, bactericidal and insecticidal properties. However, M. albus is a warm climate endophyte, and its biofumigant activity is significantly inhibited at temperatures below 5 °C. Conidia of seven mycotoxin producing fungi, Aspergillus carbonarius, A. flavus, A. niger, A. ochraceus, Penicillium verrucosum, Fusarium culmorum and F. graminearum, were killed or prevented from germinating by exposure to volatiles from 2 g M. albus-colonized rye grain per L of headspace in sealed glass jars for 24 h at 20 °C. Two major volatiles of M. albus, isobutyric acid (IBA and 2-methyl-1-butanol (2MB at 50 µL/L and 100 µL/L, respectively, gave differential control of the seven fungi when applied individually at 20 °C. When the fungi were exposed to both IBA and 2MB together, an average of 94% of the conidia were killed or suppressed. In a factorial experiment with controlled atmosphere storage (CA at 3 °C and 72 h exposure to four concentrations of IBA and 2MB combinations, 50 µL/L IBA plus 100 µL/L 2MB killed or suppressed germination of the conidia of all seven fungi. Controlled atmosphere had no significant effect on conidial viability or volatile efficacy. Major volatiles of M. albus may have significant potential to control plant pathogens in either ambient air or CA storage at temperatures below 5 °C. However, combinations of volatiles may be required to provide a broader spectrum of control than individual volatiles.

  17. PREVAIL: IBM's e-beam technology for next generation lithography

    Science.gov (United States)

    Pfeiffer, Hans C.

    2000-07-01

    PREVAIL - Projection Reduction Exposure with Variable Axis Immersion Lenses represents the high throughput e-beam projection approach to NGL which IBM is pursuing in cooperation with Nikon Corporation as alliance partner. This paper discusses the challenges and accomplishments of the PREVAIL project. The supreme challenge facing all e-beam lithography approaches has been and still is throughput. Since the throughput of e-beam projection systems is severely limited by the available optical field size, the key to success is the ability to overcome this limitation. The PREVAIL technique overcomes field-limiting off-axis aberrations through the use of variable axis lenses, which electronically shift the optical axis simultaneously with the deflected beam so that the beam effectively remains on axis. The resist images obtained with the Proof-of-Concept (POC) system demonstrate that PREVAIL effectively eliminates off- axis aberrations affecting both resolution and placement accuracy of pixels. As part of the POC system a high emittance gun has been developed to provide uniform illumination of the patterned subfield and to fill the large numerical aperture projection optics designed to significantly reduce beam blur caused by Coulomb interaction.

  18. Is the Economic Crisis Challenging the Prevailing Gender Regime?

    DEFF Research Database (Denmark)

    Leschke, Janine; Jepsen, Maria

    2014-01-01

    and analysing the corresponding position of women and men in paid and unpaid work, the paper contains an in-depth discussion of the short- and medium-term policy responses to the crisis. Our analysis shows that independent of the prevailing gender regime, scant public attention has been directed to gender...

  19. Evaluation of Haney-Type Surface Thermal Boundary Conditions Using a Coupled Atmosphere and Ocean Model

    National Research Council Canada - National Science Library

    Chu, Peter C; Chen, Yuchun; Lu, Shihua

    2001-01-01

    ... (Russell et al,, 1995) was used to verify the validity of Haney-type surface thermal boundary condition, which linearly connects net downward surface heat flux Q to air / sea temperature difference DeltaT by a relaxation coefficient K...

  20. A modified surface-resistance approach for representing bare-soil evaporation: wind tunnel experiments under various atmospheric conditions

    International Nuclear Information System (INIS)

    Yamanaka, T.; Takeda, A.; Sugita, F.

    1997-01-01

    A physically based (i.e., nonempirical) representation of surface-moisture availability is proposed, and its applicability is investigated. This method is based on the surface-resistance approaches, and it uses the depth of evaporating surface rather than the water content of the surface soil as the determining factor of surface-moisture availability. A simple energy-balance model including this representation is developed and tested against wind tunnel experiments under various atmospheric conditions. This model can estimate not only the latent heat flux but also the depth of the evaporating surface simultaneously by solving the inverse problem of energy balance at both the soil surface and the evaporating surface. It was found that the depth of the evaporating surface and the latent heat flux estimated by the model agreed well with those observed. The agreements were commonly found out under different atmospheric conditions. The only limitation of this representation is that it is not valid under conditions of drastic change in the radiation input, owing to the influence of transient phase transition of water in the dry surface layer. The main advantage of the approach proposed is that it can determine the surface moisture availability on the basis of the basic properties of soils instead of empirical fitting, although further investigations on its practical use are needed

  1. Demonstration of intradyne BPSK optical free-space transmission in representative atmospheric turbulence conditions for geostationary uplink channel.

    Science.gov (United States)

    Surof, Janis; Poliak, Juraj; Calvo, Ramon Mata

    2017-06-01

    Binary phase-shift keying optical transmission in the C-band with coherent intradyne reception is demonstrated over a long-range (10.45 km) link through the atmosphere. The link emulates representative channel conditions for geostationary optical feeder uplinks in satellite communications. The digital signal processing used in recovering the transmitted data and the performed measurements are described. Finally, the bit error rate results for 10 Gbit/s, 20 Gbit/s, and 30 Gbit/s of the outdoor experiments are presented and compared with back-to-back measurements and theory.

  2. Experimental study of the influence of atmospheric conditions on the performance of natural draft dry cooling towers

    International Nuclear Information System (INIS)

    Markoczy, G.; Staempfli, E.

    1977-08-01

    The heat dissipation of cooling towers is influenced by atmospheric conditions. In order to establish these influences EIR conducted measurements on a natural draft dry cooling tower. During two measuring campaigns with a duration of total 10 weeks the performance of the cooling tower, the ambient air temperatures, the wind velocities and directions as well as air temperature at the top of the tower and in front of the heat exchangers were continuously measured and registered. The results achieved enable the quantitative description of the influence of the ambient air temperature, wind and temperature inversion on the performance of natural draft dry cooling towers. (Auth.)

  3. Evaluation of air gap membrane distillation process running under sub-atmospheric conditions: Experimental and simulation studies

    KAUST Repository

    Alsaadi, Ahmad S.; Francis, Lijo; Maab, Husnul; Amy, Gary L.; Ghaffour, NorEddine

    2015-01-01

    The importance of removing non-condensable gases from air gap membrane distillation (AGMD) modules in improving the water vapor flux is presented in this paper. Additionally, a previously developed AGMD mathematical model is used to predict to the degree of flux enhancement under sub-atmospheric pressure conditions. Since the mathematical model prediction is expected to be very sensitive to membrane distillation (MD) membrane resistance when the mass diffusion resistance is eliminated, the permeability of the membrane was carefully measured with two different methods (gas permeance test and vacuum MD permeability test). The mathematical model prediction was found to highly agree with the experimental data, which showed that the removal of non-condensable gases increased the flux by more than three-fold when the gap pressure was maintained at the saturation pressure of the feed temperature. The importance of staging the sub-atmospheric AGMD process and how this could give better control over the gap pressure as the feed temperature decreases are also highlighted in this paper. The effect of staging on the sub-atmospheric AGMD flux and its relation to membrane capital cost are briefly discussed.

  4. Evaluation of air gap membrane distillation process running under sub-atmospheric conditions: Experimental and simulation studies

    KAUST Repository

    Alsaadi, Ahmad S.

    2015-04-16

    The importance of removing non-condensable gases from air gap membrane distillation (AGMD) modules in improving the water vapor flux is presented in this paper. Additionally, a previously developed AGMD mathematical model is used to predict to the degree of flux enhancement under sub-atmospheric pressure conditions. Since the mathematical model prediction is expected to be very sensitive to membrane distillation (MD) membrane resistance when the mass diffusion resistance is eliminated, the permeability of the membrane was carefully measured with two different methods (gas permeance test and vacuum MD permeability test). The mathematical model prediction was found to highly agree with the experimental data, which showed that the removal of non-condensable gases increased the flux by more than three-fold when the gap pressure was maintained at the saturation pressure of the feed temperature. The importance of staging the sub-atmospheric AGMD process and how this could give better control over the gap pressure as the feed temperature decreases are also highlighted in this paper. The effect of staging on the sub-atmospheric AGMD flux and its relation to membrane capital cost are briefly discussed.

  5. Heterogeneous Reactions between Toluene and NO2 on Mineral Particles under Simulated Atmospheric Conditions.

    Science.gov (United States)

    Niu, Hejingying; Li, Kezhi; Chu, Biwu; Su, Wenkang; Li, Junhua

    2017-09-05

    Heterogeneous reactions between organic and inorganic gases with aerosols are important for the study of smog occurrence and development. In this study, heterogeneous reactions between toluene and NO 2 with three atmospheric mineral particles in the presence or absence of UV light were investigated. The three mineral particles were SiO 2 , α-Fe 2 O 3 , and BS (butlerite and szmolnokite). In a dark environment, benzaldehyde was produced on α-Fe 2 O 3 . For BS, nitrotoluene and benzaldehyde were obtained. No aromatic products were produced in the absence of NO 2 in the system. In the presence of UV irradiation, benzaldehyde was detected on the SiO 2 surface. Identical products were produced in the presence and absence of UV light over α-Fe 2 O 3 and BS. UV light promoted nitrite to nitrate on mineral particles surface. On the basisi of the X-ray photoelectron spectroscopy (XPS) results, a portion of BS was reduced from Fe 3+ to Fe 2+ with the adsorption of toluene or the reaction with toluene and NO 2 . Sulfate may play a key role in the generation of nitrotoluene on BS particles. From this research, the heterogeneous reactions between organic and inorganic gases with aerosols that occur during smog events will be better understood.

  6. Effect of atmospheric pressure plasma treatment condition on adhesion of ramie fibers to polypropylene for composite

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying [College of Material and Textile Engineering, Jiaxing University, Jiaxing 314033 (China); Center for Plasma-Aided Manufacturing, Madison, WI 53706 (United States); School of Human Ecology, University of Wisconsin-Madison, Madison, WI 53706 (United States); Manolache, Sorin [Center for Plasma-Aided Manufacturing, Madison, WI 53706 (United States); US Forest Products Laboratory, Madison, WI 53726 (United States); Qiu, Yiping, E-mail: ypqiu@dhu.edu.cn [College of Textiles, Donghua University, Shanghai 201620 (China); Sarmadi, Majid, E-mail: majidsar@wisc.edu [Center for Plasma-Aided Manufacturing, Madison, WI 53706 (United States); School of Human Ecology, University of Wisconsin-Madison, Madison, WI 53706 (United States); Materials Science Program, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2016-02-28

    Graphical abstract: - Highlights: • The continuous ethanol flow technique can successfully modify ramie fiber surface with an increase in IFSS value up to 50%. • Response surface methodology was applied to design the plasma treatment parameters for ramie fiber modification. • The ethanol flow rate was the most influential treatment parameter in plasma modification process. - Abstract: In order to improve the interfacial adhesion between hydrophilic ramie fibers and hydrophobic polypropylene (PP) matrices, ramie fibers are modified by atmospheric pressure dielectric barrier discharge (DBD) plasma with our continuous ethanol flow technique in helium environment. A central composite design of experiments with different plasma processing parameter combinations (treatment current, treatment time and ethanol flow rate) is applied to find the most influential parameter and to obtain the best modification effect. Field emission scanning electron microscope (SEM) shows the roughened surfaces of ramie fibers from the treated groups due to plasma etching effect. Dynamic contact angle analysis (DCAA) demonstrates that the wettability of the treated fibers drastically decreases. Microbond pullout test shows that the interfacial shear strength (IFSS) between treated ramie fibers and PP matrices increases significantly. Residual gas analysis (RGA) confirms the creation of ethyl groups during plasma treatment. This study shows that our continuous ethanol flow technique is effective in the plasma modification process, during which the ethanol flow rate is the most influential parameter but all parameters have simultaneous influence on plasma modification effect of ramie fibers.

  7. Quality of Meat ( from Male Fallow Deer ( Packaged and Stored under Vacuum and Modified Atmosphere Conditions

    Directory of Open Access Journals (Sweden)

    N. Piaskowska

    2016-12-01

    Full Text Available This study evaluated the effect of vacuum and modified atmosphere (40% CO2+60% N2, MA packaging on the chemical composition, physicochemical properties and sensory attributes of chill-stored meat from 10 fallow deer (Dama dama bucks at 17 to 18 months of age. The animals were hunter-harvested in the forests of north-eastern Poland. During carcass dressing (48 to 54 h post mortem, both musculus longissimus muscles were cut out. Each muscle was divided into seven sections which were allocated to three groups: 0, A, and B. Samples 0 were immediately subjected to laboratory analyses. Samples A were vacuum-packaged, and samples B were packaged in MA. Packaged samples were stored for 7, 14, and 21 days at 2°C. The results of the present study showed that the evaluated packaging systems had no significant effect on the quality of fallow deer meat during chilled storage. However, vacuum-packaged meat samples were characterised by greater drip loss. Vacuum and MA packaging contributed to preserving the desired physicochemical properties and sensory attributes of meat during 21 days of storage. Regardless of the packaging method used, undesirable changes in the colour, water-holding capacity and juiciness of meat, accompanied by tenderness improvement, were observed during chilled storage.

  8. Prolonged silicon carbide integrated circuit operation in Venus surface atmospheric conditions

    Directory of Open Access Journals (Sweden)

    Philip G. Neudeck

    2016-12-01

    Full Text Available The prolonged operation of semiconductor integrated circuits (ICs needed for long-duration exploration of the surface of Venus has proven insurmountably challenging to date due to the ∼ 460 °C, ∼ 9.4 MPa caustic environment. Past and planned Venus landers have been limited to a few hours of surface operation, even when IC electronics needed for basic lander operation are protected with heavily cumbersome pressure vessels and cooling measures. Here we demonstrate vastly longer (weeks electrical operation of two silicon carbide (4H-SiC junction field effect transistor (JFET ring oscillator ICs tested with chips directly exposed (no cooling and no protective chip packaging to a high-fidelity physical and chemical reproduction of Venus’ surface atmosphere. This represents more than 100-fold extension of demonstrated Venus environment electronics durability. With further technology maturation, such SiC IC electronics could drastically improve Venus lander designs and mission concepts, fundamentally enabling long-duration enhanced missions to the surface of Venus.

  9. Dissolution rates of unirradiated UO2, UO2 doped with 233U, and spent fuel under normal atmospheric conditions and under reducing conditions using an isotope dilution method

    International Nuclear Information System (INIS)

    Ollila, Kaija; Albinsson, Yngve; Oversby, Virginia; Cowper, Mark

    2003-10-01

    The experimental results given in this report allow us to draw the following conclusions. 1) Tests using unirradiated fuel pellet materials from two different manufacturers gave very different dissolution rates under air atmosphere testing. Tests for fragments of pellets from different pellets made by the same manufacturer gave good agreement. This indicates that details of the manufacturing process have a large effect on the behavior of unirradiated UO 2 in dissolution experiments. Care must be taken in interpreting differences in results obtained in different laboratories because the results may be affected by manufacturing effects. 2) Long-term tests under air atmosphere have begun to show the effects of precipitation. Further testing will be needed before the samples reach steady state. 3) Testing of unirradiated UO 2 in systems containing an iron strip to produce reducing conditions gave [U] less than detection limits ( 235 U added as spike was recovered, indicating that 90% of the spike had precipitated onto the solid sample or the iron strip. 9) Tests of UO 2 pellet materials containing 233 U to provide an alpha decay activity similar to that expected for spent fuel 3000 and 10,000 years after disposal showed that the pellet materials behaved as expected under air atmosphere conditions, showing that the manufacturing method was successful. 10) Early testing of the 233 U-doped materials under reducing conditions showed relatively rapid (30 minute) dissolution of small amounts of U at the start of the puff test procedure. Results of analyses of an acidified fraction of the same solutions after 1 or 2 weeks holding indicate that the solutions were inhomogeneous, indicating the presence of colloidal material or small grains of solid. 11) Samples from the 233 U-doped tests initially indicated dissolution of solid during the first week of testing, with some indication of more rapid dissolution of the material with the higher doping. 12) The second cycle of testing

  10. Interactions between vegetation, atmospheric turbulence and clouds under a wide range of background wind conditions

    NARCIS (Netherlands)

    Sikma, M.; Ouwersloot, H.G.; Pedruzo-Bagazgoitia, X.; Heerwaarden, van C.C.; Vilà-Guerau de Arellano, J.

    2018-01-01

    The effects of plant responses to cumulus (Cu) cloud shading are studied from free convective to shear-driven boundary-layer conditions. By using a large-eddy simulation (LES) coupled to a plant physiology embedded land-surface submodel, we study the vegetation-cloud feedbacks for a wide range (44)

  11. Choosing the best meteorological conditions for atmospheric diffusion experiments at the Angra site

    International Nuclear Information System (INIS)

    Nicolli, D.; Thomas, P.

    1983-01-01

    The most appropriate meteorological conditions and time of the day advisable for carrying out diffusion experiments at the Angra site are described. Two emission points were defined, and the sampling area was determined with easy access to the complex terrain taken into consideration. The onsite meteorological measuring system is briefly described. (Author) [pt

  12. Preincubation of Penicillium commune conidia under modified atmosphere conditions: Influence on growth potential as determined by an impedimetric method

    DEFF Research Database (Denmark)

    Haasum, Iben; Nielsen, Per Væggemose

    1996-01-01

    The combined effect of preincubation time, relative humidity (r.h.), headspace carbon dioxide (CO2) and oxygen (O2) on subsequent growth potential of conidia from Penicillium commune was studied using Response Surface Modelling (RSM). Native conidia were preincubated under modified atmosphere...... conditions in sealed vials for 14, 35 and 56 d. Lag time and growth rates were determined using impedance microbiology on a Bactometer. Conidia survived and some swelling was observed during all experimental preincubation conditions. Regression analysis of the subsequent growth responses showed that relative...... humidity in the vials was the most significant factor affecting lag time of the conidia after preincubation for 14 and 35 d. Storage for 35 d extended lag times by 15 h when the level of r.h. was increased from 41% to 80%. After prolonged storage (56 d) r.h and CO2 levels elicited a significant effect...

  13. The effect of atmospheric thermal conditions and urban thermal pollution on all-cause and cardiovascular mortality in Bangladesh

    International Nuclear Information System (INIS)

    Burkart, Katrin; Schneider, Alexandra; Breitner, Susanne; Khan, Mobarak Hossain; Kraemer, Alexander; Endlicher, Wilfried

    2011-01-01

    This study assessed the effect of temperature and thermal atmospheric conditions on all-cause and cardiovascular mortality in Bangladesh. In particular, differences in the response to elevated temperatures between urban and rural areas were investigated. Generalized additive models (GAMs) for daily death counts, adjusted for trend, season, day of the month and age were separately fitted for urban and rural areas. Breakpoint models were applied for determining the increase in mortality above and below a threshold (equivalent) temperature. Generally, a 'V'-shaped (equivalent) temperature-mortality curve with increasing mortality at low and high temperatures was observed. Particularly, urban areas suffered from heat-related mortality with a steep increase above a specific threshold. This adverse heat effect may well increase with ongoing urbanization and the intensification of the urban heat island due to the densification of building structures. Moreover, rising temperatures due to climate change could aggravate thermal stress. - Highlights: → Temperature exhibits a strong influence on mortality in Bangladesh. → Mortality increases at low and high end of the temperature range. → Temperature is increased in the urban area of Dhaka, particular during summer. → Urban areas are facing increased risk of heat-related mortality. → Urbanization and climate change are likely to increase heat-related mortality. - Mortality in Bangladesh is strongly affected by thermal atmospheric conditions with particularly urban areas facing excess mortality above a specific threshold temperature.

  14. An atmospheric pressure flow reactor: Gas phase kinetics and mechanism in tropospheric conditions without wall effects

    Science.gov (United States)

    Koontz, Steven L.; Davis, Dennis D.; Hansen, Merrill

    1988-01-01

    A new type of gas phase flow reactor, designed to permit the study of gas phase reactions near 1 atm of pressure, is described. A general solution to the flow/diffusion/reaction equations describing reactor performance under pseudo-first-order kinetic conditions is presented along with a discussion of critical reactor parameters and reactor limitations. The results of numerical simulations of the reactions of ozone with monomethylhydrazine and hydrazine are discussed, and performance data from a prototype flow reactor are presented.

  15. Machine-Learning Techniques for the Determination of Attrition of Forces Due to Atmospheric Conditions

    Science.gov (United States)

    2018-02-01

    selected as a proof of concept due to its vast number of data points. While this report does note some trends associated with temperature and dew...separate data sets for helicopters and airplanes, while selectively requesting the event IDs, descriptions of events, light conditions, temperature , dew...weather events) and the error rate for that class . The rows are labeled for the actual occurrence of those events. Thus, for every row–column

  16. Analytical constraints on layered gas trapping and smoothing of atmospheric variability in ice under low-accumulation conditions

    Directory of Open Access Journals (Sweden)

    K. Fourteau

    2017-12-01

    Full Text Available We investigate for the first time the loss and alteration of past atmospheric information from air trapping mechanisms under low-accumulation conditions through continuous CH4 (and CO measurements. Methane concentration changes were measured over the Dansgaard–Oeschger event 17 (DO-17,  ∼  60 000 yr BP in the Antarctic Vostok 4G-2 ice core. Measurements were performed using continuous-flow analysis combined with laser spectroscopy. The results highlight many anomalous layers at the centimeter scale that are unevenly distributed along the ice core. The anomalous methane mixing ratios differ from those in the immediate surrounding layers by up to 50 ppbv. This phenomenon can be theoretically reproduced by a simple layered trapping model, creating very localized gas age scale inversions. We propose a method for cleaning the record of anomalous values that aims at minimizing the bias in the overall signal. Once the layered-trapping-induced anomalies are removed from the record, DO-17 appears to be smoother than its equivalent record from the high-accumulation WAIS Divide ice core. This is expected due to the slower sinking and densification speeds of firn layers at lower accumulation. However, the degree of smoothing appears surprisingly similar between modern and DO-17 conditions at Vostok. This suggests that glacial records of trace gases from low-accumulation sites in the East Antarctic plateau can provide a better time resolution of past atmospheric composition changes than previously expected. We also developed a numerical method to extract the gas age distributions in ice layers after the removal of the anomalous layers based on comparison with a weakly smoothed record. It is particularly adapted for the conditions of the East Antarctic plateau, as it helps to characterize smoothing for a large range of very low-temperature and low-accumulation conditions.

  17. PREVAIL-EPL alpha tool electron optics subsystem

    Science.gov (United States)

    Pfeiffer, Hans C.; Dhaliwal, Rajinder S.; Golladay, Steven D.; Doran, Samuel K.; Gordon, Michael S.; Kendall, Rodney A.; Lieberman, Jon E.; Pinckney, David J.; Quickle, Robert J.; Robinson, Christopher F.; Rockrohr, James D.; Stickel, Werner; Tressler, Eileen V.

    2001-08-01

    The IBM/Nikon alliance is continuing pursuit of an EPL stepper alpha tool based on the PREVAIL technology. This paper provides a status report of the alliance activity with particular focus on the Electron Optical Subsystem developed at IBM. We have previously reported on design features of the PREVAIL alpha system. The new state-of-the-art e-beam lithography concepts have since been reduced to practice and turned into functional building blocks of a production level lithography tool. The electron optical alpha tool subsystem has been designed, build, assembled and tested at IBM's Semiconductor Research and Development Center (SRDC) in East Fishkill, New York. After demonstrating subsystem functionality, the electron optical column and all associated control electronics hardware and software have been shipped during January 2001 to Nikon's facility in Kumagaya, Japan, for integration into the Nikon commercial e-beam stepper alpha tool. Early pre-shipment results obtained with this electron optical subsystem are presented.

  18. Kinetics and dynamics of nanosecond streamer discharge in atmospheric-pressure gas bubble suspended in distilled water under saturated vapor pressure conditions

    KAUST Repository

    Sharma, Ashish; Levko, Dmitry; Raja, Laxminarayan L; Cha, Min

    2016-01-01

    We perform computational studies of nanosecond streamer discharges generated in helium bubbles immersed in distilled water under atmospheric pressure conditions. The model takes into account the presence of water vapor in the gas bubble

  19. The influence of atmospheric conditions on the cooling tower plume of nuclear power station; Uticaj atmosferskih uslova na perjanicu rashladnih tornjeva nuklearne elektrane

    Energy Technology Data Exchange (ETDEWEB)

    Vehauc, A [Boris Kidric Institute of nuclear sciences, Vinca, Belgrade (Yugoslavia)

    1978-07-01

    The paper deals with the effect of atmospheric conditions - relative humidity, wind velocity, temperature and temperature gradient on the visible plume. For estimating cooling tower plumes, used was made of verified mathematical model. (author)

  20. A STUDY ON LEGIONELLA PNEUMOPHILA, WATER CHEMISTRY, AND ATMOSPHERIC CONDITIONS IN COOLING TOWERS AT THE SAVANNAH RIVER SITE

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.; Brigmon, R.

    2009-10-20

    elevated Legionella concentrations when the dew point temperature was high--a summertime occurrence. However, analysis of the three years of Legionella monitoring data of the 14 different SRS Cooling Towers demonstrated that elevated concentrations are observed at all temperatures and seasons. The objective of this study is to evaluate the ecology of L. pneumophila including serogroups and population densities, chemical, and atmospheric data, on cooling towers at SRS to determine whether relationships exist among water chemistry, and atmospheric conditions. The goal is to more fully understand the conditions which inhibit or encourage L. pneumophila growth and supply this data and associated recommendations to SRS Cooling Tower personnel for improved management of operation. Hopefully this information could then be used to help control L. pneumophila growth more effectively in SRS cooling tower water.

  1. Kinetics and Mechanism of the Reaction of Hydoxyl Radicals with Acetonitrile under Atmospheric Conditions

    Science.gov (United States)

    Hynes, A. J.; Wine, P. H.

    1997-01-01

    scheme to extract kinetic information about the adduct reations with O2 and branching ratios for OH regeneration. A plausible mechanism for OH regeneration in (2) involves OH addition to the nitrogen atom followed by O2 addition to the cyano carbon atom, isomeriazation and decomposition to D2CO + DOCN + OH. Our results suggest that the OH + CH3CN reaction occurs via a complex mechanism involving both bimolecular and termolecular pathways, analogous to the mechanisms for the the important atmospheric reactions of OH with CO and HNO3.

  2. Influence of Last Glacial Maximum boundary conditions on the global water isotope distribution in an atmospheric general circulation model

    Directory of Open Access Journals (Sweden)

    T. Tharammal

    2013-03-01

    Full Text Available To understand the validity of δ18O proxy records as indicators of past temperature change, a series of experiments was conducted using an atmospheric general circulation model fitted with water isotope tracers (Community Atmosphere Model version 3.0, IsoCAM. A pre-industrial simulation was performed as the control experiment, as well as a simulation with all the boundary conditions set to Last Glacial Maximum (LGM values. Results from the pre-industrial and LGM simulations were compared to experiments in which the influence of individual boundary conditions (greenhouse gases, ice sheet albedo and topography, sea surface temperature (SST, and orbital parameters were changed each at a time to assess their individual impact. The experiments were designed in order to analyze the spatial variations of the oxygen isotopic composition of precipitation (δ18Oprecip in response to individual climate factors. The change in topography (due to the change in land ice cover played a significant role in reducing the surface temperature and δ18Oprecip over North America. Exposed shelf areas and the ice sheet albedo reduced the Northern Hemisphere surface temperature and δ18Oprecip further. A global mean cooling of 4.1 °C was simulated with combined LGM boundary conditions compared to the control simulation, which was in agreement with previous experiments using the fully coupled Community Climate System Model (CCSM3. Large reductions in δ18Oprecip over the LGM ice sheets were strongly linked to the temperature decrease over them. The SST and ice sheet topography changes were responsible for most of the changes in the climate and hence the δ18Oprecip distribution among the simulations.

  3. Ruthenium release modelling in air and steam atmospheres under severe accident conditions using the MAAP4 code

    International Nuclear Information System (INIS)

    Beuzet, Emilie; Lamy, Jean-Sylvestre; Perron, Hadrien; Simoni, Eric; Ducros, Gérard

    2012-01-01

    Highlights: ► We developed a new modelling of fuel oxidation and ruthenium release in the EDF version of the MAAP4 code. ► We validated this model against some VERCORS experiments. ► Ruthenium release prediction quantitatively and qualitatively well reproduced under air and steam atmospheres. - Abstract: In a nuclear power plant (NPP), a severe accident is a low probability sequence that can lead to core fusion and fission product (FP) release to the environment (source term). For instance during a loss-of-coolant accident, water vaporization and core uncovery can occur due to decay heat. These phenomena enhance core degradation and, subsequently, molten materials can relocate to the lower head of the vessel. Heat exchange between the debris and the vessel may cause its rupture and air ingress. After lower head failure, steam and air entering in the vessel can lead to degradation and oxidation of materials that are still intact in the core. Indeed, Zircaloy-4 cladding oxidation is very exothermic and fuel interaction with the cladding material can decrease its melting temperature by several hundred of Kelvin. FP release can thus be increased, noticeably that of ruthenium under oxidizing conditions. Ruthenium is of particular interest because of its high radio-toxicity due to 103 Ru and 106 Ru isotopes and its ability to form highly volatile compounds, even at room temperature, such as gaseous ruthenium tetra-oxide (RuO 4 ). It is consequently of great need to understand phenomena governing steam and air oxidation of the fuel and ruthenium release as prerequisites for the source term issues. A review of existing data on these phenomena shows relatively good understanding. In terms of oxygen affinity, the fuel is oxidized before ruthenium, from UO 2 to UO 2+x . Its oxidation is a rate-controlling surface exchange reaction with the atmosphere, so that the stoichiometric deviation and oxygen partial pressure increase. High temperatures combined with the presence

  4. Synoptic-scale atmospheric conditions associated with flash flooding in watersheds of the Catskill Mountains, New York, USA

    Science.gov (United States)

    Teale, N. G.; Quiring, S. M.

    2015-12-01

    Understanding flash flooding is important in unfiltered watersheds, such as portions of the New York City water supply system (NYCWSS), as water quality is degraded by turbidity associated with flooding. To further understand flash flooding in watersheds of the NYCWSS, synoptic-scale atmospheric conditions most frequently associated with flash flooding between 1987 and 2013 were examined. Flash floods were identified during this time period using USGS 15-minute discharge data at the Esopus Creek near Allaben, NY and Neversink River at Claryville, NY gauges. Overall, 25 flash floods were detected, occurring over 17 separate flash flood days. These flash flood days were compared to the days on which flash flood warnings encompassing the study area was issued by the National Weather Service. The success rate for which the flash flood warnings for Ulster County coincided with flash flood in the study watershed was 0.09, demonstrating the highly localized nature of flash flooding in the Catskill Mountain region. The synoptic-scale atmospheric patterns influencing the study area were characterized by a principal component analysis and k-means clustering of NCEP/NCAR 500 mb geopotential height reanalysis data. This procedure was executed in Spatial Synoptic Typer Tools 4.0. While 17 unique synoptic patterns were identified, only 3 types were strongly associated with flash flooding events. A strong southwesterly flow suggesting advection of moisture from the Atlantic Ocean and Gulf of Mexico is shown in composites of these 3 types. This multiscalar study thereby links flash flooding in the NYCWSS with synoptic-scale atmospheric circulation.Understanding flash flooding is important in unfiltered watersheds, such as portions of the New York City water supply system (NYCWSS), as water quality is degraded by turbidity associated with flooding. To further understand flash flooding in watersheds of the NYCWSS, synoptic-scale atmospheric conditions most frequently associated with

  5. Elevated Atmospheric CO2 and Warming Stimulates Growth and Nitrogen Fixation in a Common Forest Floor Cyanobacterium under Axenic Conditions

    Directory of Open Access Journals (Sweden)

    Zoë Lindo

    2017-03-01

    Full Text Available The predominant input of available nitrogen (N in boreal forest ecosystems originates from moss-associated cyanobacteria, which fix unavailable atmospheric N2, contribute to the soil N pool, and thereby support forest productivity. Alongside climate warming, increases in atmospheric CO2 concentrations are expected in Canada’s boreal region over the next century, yet little is known about the combined effects of these factors on N fixation by forest floor cyanobacteria. Here we assess changes in N fixation in a common forest floor, moss-associated cyanobacterium, Nostoc punctiforme Hariot, under elevated CO2 conditions over 30 days and warming combined with elevated CO2 over 90 days. We measured rates of growth and changes in the number of specialized N2 fixing heterocyst cells, as well as the overall N fixing activity of the cultures. Elevated CO2 stimulated growth and N fixation overall, but this result was influenced by the growth stage of the cyanobacteria, which in turn was influenced by our temperature treatments. Taken together, climate change factors of warming and elevated CO2 are expected to stimulate N2 fixation by moss-associated cyanobacteria in boreal forest systems.

  6. Standard practice for measurement of time-of-wetness on surfaces exposed to wetting conditions as in atmospheric corrosion testing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1989-01-01

    1.1 This practice covers a technique for monitoring time-of-wetness (TOW) on surfaces exposed to cyclic atmospheric conditions which produce depositions of moisture. 1.2 The practice is also applicable for detecting and monitoring condensation within a wall or roof assembly and in test apparatus. 1.3 Exposure site calibration or characterization can be significantly enhanced if TOW is measured for comparison with other sites, particularly if this data is used in conjunction with other site-specific instrumentation techniques. 1.4 The values stated in SI units are to be regarded as the standard. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  7. The effect of atmospheric thermal conditions and urban thermal pollution on all-cause and cardiovascular mortality in Bangladesh.

    Science.gov (United States)

    Burkart, Katrin; Schneider, Alexandra; Breitner, Susanne; Khan, Mobarak Hossain; Krämer, Alexander; Endlicher, Wilfried

    2011-01-01

    This study assessed the effect of temperature and thermal atmospheric conditions on all-cause and cardiovascular mortality in Bangladesh. In particular, differences in the response to elevated temperatures between urban and rural areas were investigated. Generalized additive models (GAMs) for daily death counts, adjusted for trend, season, day of the month and age were separately fitted for urban and rural areas. Breakpoint models were applied for determining the increase in mortality above and below a threshold (equivalent) temperature. Generally, a 'V'-shaped (equivalent) temperature-mortality curve with increasing mortality at low and high temperatures was observed. Particularly, urban areas suffered from heat-related mortality with a steep increase above a specific threshold. This adverse heat effect may well increase with ongoing urbanization and the intensification of the urban heat island due to the densification of building structures. Moreover, rising temperatures due to climate change could aggravate thermal stress. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. 3-D laser confocal microscopy study of the oxidation of NdFeB magnets in atmospheric conditions

    Science.gov (United States)

    Meakin, J. P.; Speight, J. D.; Sheridan, R. S.; Bradshaw, A.; Harris, I. R.; Williams, A. J.; Walton, A.

    2016-08-01

    Neodymium iron boron (NdFeB) magnets are used in a number of important applications, such as generators in gearless wind turbines, motors in electric vehicles and electronic goods (e.g.- computer hard disk drives, HDD). Hydrogen can be used as a processing gas to separate and recycle scrap sintered Nd-Fe-B magnets from end-of-life products to form a powder suitable for recycling. However, the magnets are likely to have been exposed to atmospheric conditions prior to processing, and any oxidation could lead to activation problems for the hydrogen decrepitation reaction. Many previous studies on the oxidation of NdFeB magnets have been performed at elevated temperatures; however, few studies have been formed under atmospheric conditions. In this paper a combination of 3-D laser confocal microscopy and Raman spectroscopy have been used to assess the composition, morphology and rate of oxidation/corrosion on scrap sintered NdFeB magnets. Confocal microscopy has been employed to measure the growth of surface reaction products at room temperature, immediately after exposure to air. The results showed that there was a significant height increase at the triple junctions of the Nd-rich grain boundaries. Using Raman spectroscopy, the product was shown to consist of Nd2O3 and formed only on the Nd-rich triple junctions. The diffusion coefficient of the triple junction reaction product growth at 20 °C was determined to be approximately 4 × 10-13 cm2/sec. This value is several orders of magnitude larger than values derived from the diffusion controlled oxide growth observations at elevated temperatures in the literature. This indicates that the growth of the room temperature oxidation products are likely defect enhanced processes at the NdFeB triple junctions.

  9. Production of gasoline fraction from bio-oil under atmospheric conditions by an integrated catalytic transformation process

    International Nuclear Information System (INIS)

    Zhang, Zhaoxia; Bi, Peiyan; Jiang, Peiwen; Fan, Minghui; Deng, Shumei; Zhai, Qi; Li, Quanxin

    2015-01-01

    This work aimed to develop an integrated process for production of gasoline fraction bio-fuels from bio-oil under atmospheric conditions. This novel transformation process included the catalytic cracking of bio-oil to light olefins and the subsequent synthesis of liquid hydrocarbon bio-fuels from light olefins with two reactors in series. The yield of bio-fuel was up to 193.8 g/(kg bio-oil) along with a very low oxygen content, high RONs (research octane numbers), high LHVs (lower heating values) and low benzene content under the optimizing reaction conditions. Coke deposition seems to be the main cause of catalyst deactivation in view of the fact that the deactivated catalysts was almost recovered by on-line treating the used catalyst with oxygen. The integrated transformation potentially provides a useful way for the development of gasoline range hydrocarbon fuels using renewable lignocellulose biomass. - Graphical abstract: An integrated process for production of gasoline fraction bio-fuels from bio-oil through the catalytic cracking of bio-oil to light olefins followed by the synthesis of liquid hydrocarbon bio-fuels from light olefins in series. - Highlights: • A new route for production of gasoline-range bio-fuels from bio-oil was achieved. • The process was an integrated catalytic transformation at atmospheric pressure. • Bio-oil is converted into light olefins and then converted to biofuel in series. • C_6–C_1_0 bio-fuels derived from bio-oil had high RONs and LHVs.

  10. Extreme storm surges in the south of Brazil: atmospheric conditions and shore erosion

    Directory of Open Access Journals (Sweden)

    Cláudia Klose Parise

    2009-09-01

    Full Text Available The region under study is regularly subject to the occurrence of storms associated with frontal systems and extratropical cyclones, since it is located near one of the cyclogenetic regions in South America. These storms can generate storm surges that cause anomalous high sea level rises on Cassino Beach. The use of reanalysis data along with an efficient technique for the location of the cyclone, using a vorticity threshold, has provided a new classification based upon the trajectories of events that produce positive sea level variation. Three patterns have been identified: 1 Cyclogenesis to the south of Argentina with displacement to the east and a trajectory between 47.5ºS and 57.5ºS; 2 Cyclogenesis to the south of Uruguay with displacement to the east and a trajectory between 35ºS and 42.5ºS; and 3 Cyclogenesis to the south of Uruguay with displacement to the southeast and a trajectory between 35ºS and 57.5ºS. Maximum water level elevation above the mean sea level and beach erosion were associated, respectively, with winter and summer storms. Cassino beach displayed a seasonal morphological behavior, with short periods of episodic erosion associated with winter storm events followed by long periods of accretion characterized by the dominance of fair weather conditions.Marés meteorológicas que geram sobre-elevações do nível do mar são freqüentes na costa do Rio Grande do Sul e respondem às variações ocorridas na atmosfera. Torna-se importante, dessa maneira, definir padrões meteorológicos sinóticos responsáveis por gerar eventos de marés meteorológicas intensas na Praia do Cassino como objetivo desse trabalho. O uso de dados de reanálise associados a uma técnica eficiente de localização do ciclone, aplicando o conceito de vorticidade, permitiu definir uma nova classificação com base na trajetória de ciclones extratropicais responsáveis pela subida do nível do mar. Três padrões de trajetórias foram

  11. 3-D laser confocal microscopy study of the oxidation of NdFeB magnets in atmospheric conditions

    International Nuclear Information System (INIS)

    Meakin, J.P.; Speight, J.D.; Sheridan, R.S.; Bradshaw, A.; Harris, I.R.; Williams, A.J.; Walton, A.

    2016-01-01

    Highlights: • Room temperature atmospheric oxidation behaviour of sintered NdFeB. • 3D laser confocal microscopy measurement of oxide phase growth. • Significant height increase of oxide phase only observed at triple points. • Raman spectroscopy identified oxide phase to be Nd 2 O 3 . • Diffusion coefficient determined to be 4 × 10 −13 cm 2 /s. - Abstract: Neodymium iron boron (NdFeB) magnets are used in a number of important applications, such as generators in gearless wind turbines, motors in electric vehicles and electronic goods (e.g.— computer hard disk drives, HDD). Hydrogen can be used as a processing gas to separate and recycle scrap sintered Nd-Fe-B magnets from end-of-life products to form a powder suitable for recycling. However, the magnets are likely to have been exposed to atmospheric conditions prior to processing, and any oxidation could lead to activation problems for the hydrogen decrepitation reaction. Many previous studies on the oxidation of NdFeB magnets have been performed at elevated temperatures; however, few studies have been formed under atmospheric conditions. In this paper a combination of 3-D laser confocal microscopy and Raman spectroscopy have been used to assess the composition, morphology and rate of oxidation/corrosion on scrap sintered NdFeB magnets. Confocal microscopy has been employed to measure the growth of surface reaction products at room temperature, immediately after exposure to air. The results showed that there was a significant height increase at the triple junctions of the Nd-rich grain boundaries. Using Raman spectroscopy, the product was shown to consist of Nd 2 O 3 and formed only on the Nd-rich triple junctions. The diffusion coefficient of the triple junction reaction product growth at 20 °C was determined to be approximately 4 × 10 −13 cm 2 /sec. This value is several orders of magnitude larger than values derived from the diffusion controlled oxide growth observations at elevated

  12. 3-D laser confocal microscopy study of the oxidation of NdFeB magnets in atmospheric conditions

    Energy Technology Data Exchange (ETDEWEB)

    Meakin, J.P., E-mail: jxm764@bham.ac.uk; Speight, J.D.; Sheridan, R.S.; Bradshaw, A.; Harris, I.R.; Williams, A.J.; Walton, A.

    2016-08-15

    Highlights: • Room temperature atmospheric oxidation behaviour of sintered NdFeB. • 3D laser confocal microscopy measurement of oxide phase growth. • Significant height increase of oxide phase only observed at triple points. • Raman spectroscopy identified oxide phase to be Nd{sub 2}O{sub 3}. • Diffusion coefficient determined to be 4 × 10{sup −13} cm{sup 2}/s. - Abstract: Neodymium iron boron (NdFeB) magnets are used in a number of important applications, such as generators in gearless wind turbines, motors in electric vehicles and electronic goods (e.g.— computer hard disk drives, HDD). Hydrogen can be used as a processing gas to separate and recycle scrap sintered Nd-Fe-B magnets from end-of-life products to form a powder suitable for recycling. However, the magnets are likely to have been exposed to atmospheric conditions prior to processing, and any oxidation could lead to activation problems for the hydrogen decrepitation reaction. Many previous studies on the oxidation of NdFeB magnets have been performed at elevated temperatures; however, few studies have been formed under atmospheric conditions. In this paper a combination of 3-D laser confocal microscopy and Raman spectroscopy have been used to assess the composition, morphology and rate of oxidation/corrosion on scrap sintered NdFeB magnets. Confocal microscopy has been employed to measure the growth of surface reaction products at room temperature, immediately after exposure to air. The results showed that there was a significant height increase at the triple junctions of the Nd-rich grain boundaries. Using Raman spectroscopy, the product was shown to consist of Nd{sub 2}O{sub 3} and formed only on the Nd-rich triple junctions. The diffusion coefficient of the triple junction reaction product growth at 20 °C was determined to be approximately 4 × 10{sup −13} cm{sup 2}/sec. This value is several orders of magnitude larger than values derived from the diffusion controlled oxide growth

  13. Response characteristics of HPR1000 primary circuit under different working conditions of the atmospheric relief system after SBLOCA

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Danting, E-mail: suidanting@163.com [School of Nuclear Science and Engineering, North China Electric Power University, Beijing (China); Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy, North China Electric Power University, Beijing (China); Lu, Daogang [School of Nuclear Science and Engineering, North China Electric Power University, Beijing (China); Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy, North China Electric Power University, Beijing (China); Shang, Changzhong; Wei, Yuanyuan [China Nuclear Power Design Co., ltd (ShenZhen), Shenzhen (China); Zhang, Xianjie [School of Nuclear Science and Engineering, North China Electric Power University, Beijing (China); Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy, North China Electric Power University, Beijing (China)

    2017-04-01

    Highlights: • Response of HPR1000 under different VDA conditions after SBLOCA was investigated. • Activation of VDA can trigger ACCU SI earlier with a critical point exists. • VDA capability design should compromise the critical point with reactivity feedback. - Abstract: To cope with SBLOCA in absence of High-Head Safety Injection (HHSI) from design of HPR1000, atmospheric relief system (originally named as VDA in French) is uniquely designed to help to trigger Middle Head Safety Injection (MHSI) or Low Head Safety Injection (LHSI) earlier through cooling primary system quickly after SBLOCA. To make the best use of VDA decay heat removal capability, primary and secondary system of HPR1000 was modeled with RELAP5/SCDAP computer code. After steady-state initialization, a cold leg 30 mm break SBLOCA was simulated with six simulation conditions and five additional cases including availability of ACCU, different VDA discharge locations and area. Response characteristics of primary loop under different VDA working conditions are investigated. Pressurizer pressure decreases rapidly to lower level to trigger the reactor scram, VDA activation and accumulator safety injection sequently. Peak cladding temperature is 899.45 K occurring at 222 s, which is far below the safety limit. Activation of VDA can trigger ACCU SI earlier with a critical point, while positive reactivity will be introduced due to negative moderator temperature effect and Doppler effect. Larger VDA discharge capability will introduce larger reactivity feedback, as well as induce lower core level and SG level. It's suggested that VDA discharge condition should be chosen before the critical point, with the compromise with reactivity feedback introduced due to the negative moderator temperature effect.

  14. Response characteristics of HPR1000 primary circuit under different working conditions of the atmospheric relief system after SBLOCA

    International Nuclear Information System (INIS)

    Sui, Danting; Lu, Daogang; Shang, Changzhong; Wei, Yuanyuan; Zhang, Xianjie

    2017-01-01

    Highlights: • Response of HPR1000 under different VDA conditions after SBLOCA was investigated. • Activation of VDA can trigger ACCU SI earlier with a critical point exists. • VDA capability design should compromise the critical point with reactivity feedback. - Abstract: To cope with SBLOCA in absence of High-Head Safety Injection (HHSI) from design of HPR1000, atmospheric relief system (originally named as VDA in French) is uniquely designed to help to trigger Middle Head Safety Injection (MHSI) or Low Head Safety Injection (LHSI) earlier through cooling primary system quickly after SBLOCA. To make the best use of VDA decay heat removal capability, primary and secondary system of HPR1000 was modeled with RELAP5/SCDAP computer code. After steady-state initialization, a cold leg 30 mm break SBLOCA was simulated with six simulation conditions and five additional cases including availability of ACCU, different VDA discharge locations and area. Response characteristics of primary loop under different VDA working conditions are investigated. Pressurizer pressure decreases rapidly to lower level to trigger the reactor scram, VDA activation and accumulator safety injection sequently. Peak cladding temperature is 899.45 K occurring at 222 s, which is far below the safety limit. Activation of VDA can trigger ACCU SI earlier with a critical point, while positive reactivity will be introduced due to negative moderator temperature effect and Doppler effect. Larger VDA discharge capability will introduce larger reactivity feedback, as well as induce lower core level and SG level. It's suggested that VDA discharge condition should be chosen before the critical point, with the compromise with reactivity feedback introduced due to the negative moderator temperature effect.

  15. Atmospheric Dispersion Modeling of 137Cs generated from Nuclear Spent Fuel under Hypothetic Accidental Condition in the BNPP Area

    Science.gov (United States)

    Lee, Jongkuk; Lee, Kwan-Hee; Yook, Daesik; Kim, Sung Il; Lee, Byung Soo

    2016-04-01

    This study presents the results of atmosphere dispersion modeling using CALPUFF code that are based on computational simulation to evaluate the environmental characteristics of the Barakah nuclear power plant (BNPP) in west area of UAE. According to meteorological data analysis (2012~2013), the winds from the north(7.68%) and west(9.05%) including NNW(41.63%), NW(28.55%), and WNW(6.31%) winds accounted for more than 90% of the wind directions. East(0.2%) and south(0.6%) direction wind, including ESE(0.31%), SE(0.38%), and SSE(0.38%) were rarely distributed during the simulation period. Seasonal effects were not showed. However, a discrepancy in the tendency between daytime and night-time was observed. Approximately 87% of the wind speed was distributed below 5.4m/s (17%, 47% and 23% between the speeds of 0.5-1.8m/s 1.8-3.3m/s and 3.3-5.4m/s, respectively) during the annual period. Seasonal wind speed distribution results presented very similar pattern of annual distribution. Wind speed distribution of day and night, on the other hand, had a discrepancy with annual modeling results than seasonal distribution in some sections. The results for high wind speed (more than 10.8m/s) showed that this wind blew from the west. This high wind speed is known locally as the 'Shamal', which occurs rarely, lasting one or two days with the strongest winds experienced in association with gust fronts and thunderstorms. Six variations of cesium-137 (137Cs) dispersion test were simulated under hypothetic severe accidental condition. The 137Cs dispersion was strongly influenced by the direction and speed of the main wind. From the test cases, east-south area of the BNPP site was mainly influenced by 137Cs dispersion. A virtual receptor was set and calculated for observation of the 137Cs movement and accumulation. Surface roughness tests were performed for the analysis of topographic conditions. According to the surface condition, there are various surface roughness length. Four types

  16. Rainfall Downscaling Conditional on Upper-air Atmospheric Predictors: Improved Assessment of Rainfall Statistics in a Changing Climate

    Science.gov (United States)

    Langousis, Andreas; Mamalakis, Antonis; Deidda, Roberto; Marrocu, Marino

    2015-04-01

    To improve the level skill of Global Climate Models (GCMs) and Regional Climate Models (RCMs) in reproducing the statistics of rainfall at a basin level and at hydrologically relevant temporal scales (e.g. daily), two types of statistical approaches have been suggested. One is the statistical correction of climate model rainfall outputs using historical series of precipitation. The other is the use of stochastic models of rainfall to conditionally simulate precipitation series, based on large-scale atmospheric predictors produced by climate models (e.g. geopotential height, relative vorticity, divergence, mean sea level pressure). The latter approach, usually referred to as statistical rainfall downscaling, aims at reproducing the statistical character of rainfall, while accounting for the effects of large-scale atmospheric circulation (and, therefore, climate forcing) on rainfall statistics. While promising, statistical rainfall downscaling has not attracted much attention in recent years, since the suggested approaches involved complex (i.e. subjective or computationally intense) identification procedures of the local weather, in addition to demonstrating limited success in reproducing several statistical features of rainfall, such as seasonal variations, the distributions of dry and wet spell lengths, the distribution of the mean rainfall intensity inside wet periods, and the distribution of rainfall extremes. In an effort to remedy those shortcomings, Langousis and Kaleris (2014) developed a statistical framework for simulation of daily rainfall intensities conditional on upper air variables, which accurately reproduces the statistical character of rainfall at multiple time-scales. Here, we study the relative performance of: a) quantile-quantile (Q-Q) correction of climate model rainfall products, and b) the statistical downscaling scheme of Langousis and Kaleris (2014), in reproducing the statistical structure of rainfall, as well as rainfall extremes, at a

  17. MISTRAL V1.1.1: assessing doses from atmospheric releases in normal and off-normal conditions

    International Nuclear Information System (INIS)

    David Kerouanton; Patrick Devin; Malvina Rennesson

    2006-01-01

    Protecting the environment and the public from radioactive and chemical hazards has always been a top priority for all companies operating in the nuclear domain. In this scope, SGN provides all the services the nuclear industry needs in environmental studies especially in relation to the impact assessment in normal operating conditions and risk assessment in off-normal conditions. In order to quantify dose impact on members of the public due to atmospheric releases, COGEMA and SGN developed MISTRAL V1.1.1 code. Dose impact depends strongly on dispersion of radionuclides in atmosphere. The main parameters involved in dispersion characterization are wind velocity and direction, rain, diffusion conditions, coordinates of the point of observation and stack elevation. MISTRAL code implements DOURY and PASQUILL Gaussian plume models which are widely used in the scientific community. These models, applicable for distances of transfer ranging from 100 m up to 30 km, are used to calculate atmospheric concentration and deposit at different distances from the point of release. MISTRAL allows the use of different dose regulations or dose coefficient databases such as: - ICRP30 and ICPR71 for internal doses (inhalation, ingestion) - Despres/Kocher database or US-EPA Federal Guidance no.12 (ICPR72 for noble gases) for external exposure (from plume or ground). The initial instant of the release can be considered as the origin of time or a date format can be specified (could be useful in a crisis context). While the context is specified, the user define the meteorological conditions of the release. In normal operating mode (routine releases), the user gives the annual meteorological scheme. The data can be recorded in the MISTRAL meteorological database. In off-normal conditions mode, MISTRAL V1.1 allows the use of successive release stages for which the user gives the duration, the meteorological conditions, that is to say stability class, wind speed and direction and rainfall

  18. Sulfur X-ray absorption fine structure in porous Li–S cathode films measured under argon atmospheric conditions

    International Nuclear Information System (INIS)

    Müller, Matthias; Choudhury, Soumyadip; Gruber, Katharina; Cruz, Valene B.; Fuchsbichler, Bernd; Jacob, Timo; Koller, Stefan; Stamm, Manfred; Ionov, Leonid; Beckhoff, Burkhard

    2014-01-01

    In this paper we present the first results for the characterization of highly porous cathode materials with pore sizes below 1 μm for Lithium Sulfur (Li–S) batteries by Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy. A novel cathode material of porous carbon films fabricated with colloidal array templates has been investigated. In addition, an electrochemical characterization has been performed aiming on an improved correlation of physical and chemical parameters with the electrochemical performance. The performed NEXAFS measurements of cathode materials allowed for a chemical speciation of the sulfur content inside the cathode material. The aim of the presented investigation was to evaluate the potential of the NEXAFS technique to characterize sulfur in novel battery material. The long term goal for the characterization of the battery materials is the sensitive identification of undesired side reactions, such as the polysulfide shuttle, which takes place during charging and discharging of the battery. The main drawback associated with the investigation of these materials is the fact that NEXAFS measurements can usually only be performed ex situ due to the limited in situ instrumentation being available. For Li–S batteries this problem is more pronounced because of the low photon energies needed to study the sulfur K absorption edge at 2472 eV. We employed 1 μm thick Si 3 N 4 windows to construct sealed argon cells for NEXAFS measurements under ultra high vacuum (UHV) conditions as a first step towards in situ measurements. The cells keep the sample under argon atmosphere at any time and the X-ray beam passes mainly through vacuum which enables the detection of the low energy X-ray emission of sulfur. Using these argon cells we found indications for the presence of lithium polysulfides in the cathode films whereas the correlations to the offline electrochemical results remain somewhat ambiguous. As a consequence of these findings one may

  19. Farmers prevailing perception profiles regarding GM crops: A classification proposal.

    Science.gov (United States)

    Almeida, Carla; Massarani, Luisa

    2018-04-01

    Genetically modified organisms have been at the centre of a major public controversy, involving different interests and actors. While much attention has been devoted to consumer views on genetically modified food, there have been few attempts to understand the perceptions of genetically modified technology among farmers. By investigating perceptions of genetically modified organisms among Brazilian farmers, we intend to contribute towards filling this gap and thereby add the views of this stakeholder group to the genetically modified debate. A comparative analysis of our data and data from other studies indicate there is a complex variety of views on genetically modified organisms among farmers. Despite this diversity, we found variations in such views occur within limited parameters, concerned principally with expectations or concrete experiences regarding the advantages of genetically modified crops, perceptions of risks associated with them, and ethical questions they raise. We then propose a classification of prevailing profiles to represent the spectrum of perceptions of genetically modified organisms among farmers.

  20. To a scientific substantiation of a practical method of inspection of radiating conditions on territories, polluted with atmospheric fallout

    International Nuclear Information System (INIS)

    Burmistrov, V.R; Makarenko, N.G.; Karimova, L.M.

    2001-01-01

    Full text: In the report a question on necessity of practical development of a method of inspection of radiating fields, adapted to a nature of pollution is put. 50-year study of radionuclides pollution, dropping out from atmosphere after nuclear tests or failures, have shown non-perspective of traditional techniques of inspection of a radiating conditions on large territories. The detailed measurements covering surface without gaps are very expensive, and use of a unloaded grid requires interpolation irregular mosaic structure. Detection Fractal structure at the analysis Chernobyl losses and pollution of fragments of Semipalatinsk test nuclear site specify necessity of the account of self-similar properties of pollution in philosophy of measurement. For realization of potential opportunities Fractal field the special circuit of measurements, distinguished from, is required standard. Fractal approach requires shooting with system of crossed vicinities on chosen detailed platforms, making a rather small part of surveyed territory. These data will allow to reveal scale laws, which are universal in a significant range of scales. Using scaling of small platforms, it is possible to receive correct estimation of structure of pollution of large territories. The stated above reasons are based on our experiments on fractal approach to the analysis of continuous shooting (aero-scale shooting of scale 1:5000) in a zone of Semipalatinsk test site on three platforms by the sizes on 1000x400 m 2 . Our results specify necessity revision almost of all conclusions, received earlier on the basis of traditional techniques

  1. Mapping land water and energy balance relations through conditional sampling of remote sensing estimates of atmospheric forcing and surface states

    Science.gov (United States)

    Farhadi, Leila; Entekhabi, Dara; Salvucci, Guido

    2016-04-01

    In this study, we develop and apply a mapping estimation capability for key unknown parameters that link the surface water and energy balance equations. The method is applied to the Gourma region in West Africa. The accuracy of the estimation method at point scale was previously examined using flux tower data. In this study, the capability is scaled to be applicable with remotely sensed data products and hence allow mapping. Parameters of the system are estimated through a process that links atmospheric forcing (precipitation and incident radiation), surface states, and unknown parameters. Based on conditional averaging of land surface temperature and moisture states, respectively, a single objective function is posed that measures moisture and temperature-dependent errors solely in terms of observed forcings and surface states. This objective function is minimized with respect to parameters to identify evapotranspiration and drainage models and estimate water and energy balance flux components. The uncertainty of the estimated parameters (and associated statistical confidence limits) is obtained through the inverse of Hessian of the objective function, which is an approximation of the covariance matrix. This calibration-free method is applied to the mesoscale region of Gourma in West Africa using multiplatform remote sensing data. The retrievals are verified against tower-flux field site data and physiographic characteristics of the region. The focus is to find the functional form of the evaporative fraction dependence on soil moisture, a key closure function for surface and subsurface heat and moisture dynamics, using remote sensing data.

  2. Increasing Juniperus virginiana L. pollen in the Tulsa atmosphere: long-term trends, variability, and influence of meteorological conditions

    Science.gov (United States)

    Flonard, Michaela; Lo, Esther; Levetin, Estelle

    2018-02-01

    In the Tulsa area, the Cupressaceae is largely represented by eastern red cedar ( Juniperus virginiana L.). The encroachment of this species into the grasslands of Oklahoma has been well documented, and it is believed this trend will continue. The pollen is known to be allergenic and is a major component of the Tulsa atmosphere in February and March. This study examined airborne Cupressaceae pollen data from 1987 to 2016 to determine long-term trends, pollen seasonal variability, and influence of meteorological variables on airborne pollen concentrations. Pollen was collected through means of a Burkard sampler and analyzed with microscopy. Daily pollen concentrations and yearly pollen metrics showed a high degree of variability. In addition, there were significant increases over time in the seasonal pollen index and in peak concentrations. These increases parallel the increasing population of J. virginiana in the region. Pollen data were split into pre- and post-peak categories for statistical analyses, which revealed significant differences in correlations of the two datasets when analyzed with meteorological conditions. While temperature and dew point, among others were significant in both datasets, other factors, like relative humidity, were significant only in one dataset. Analyses using wind direction showed that southerly and southwestern winds contributed to increased pollen concentrations. This study confirms that J. virginiana pollen has become an increasing risk for individuals sensitive to this pollen and emphasizes the need for long-term aerobiological monitoring in other areas.

  3. A Narrow-Linewidth Atomic Line Filter for Free Space Quantum Key Distribution under Daytime Atmospheric Conditions

    Science.gov (United States)

    Brown, Justin; Woolf, David; Hensley, Joel

    2016-05-01

    Quantum key distribution can provide secure optical data links using the established BB84 protocol, though solar backgrounds severely limit the performance through free space. Several approaches to reduce the solar background include time-gating the photon signal, limiting the field of view through geometrical design of the optical system, and spectral rejection using interference filters. Despite optimization of these parameters, the solar background continues to dominate under daytime atmospheric conditions. We demonstrate an improved spectral filter by replacing the interference filter (Δν ~ 50 GHz) with an atomic line filter (Δν ~ 1 GHz) based on optical rotation of linearly polarized light through a warm Rb vapor. By controlling the magnetic field and the optical depth of the vapor, a spectrally narrow region can be transmitted between crossed polarizers. We find that the transmission is more complex than a single peak and evaluate peak transmission as well as a ratio of peak transmission to average transmission of the local spectrum. We compare filters containing a natural abundance of Rb with those containing isotopically pure 87 Rb and 85 Rb. A filter providing > 95 % transmission and Δν ~ 1.1 GHz is achieved.

  4. 78 FR 29657 - Prevailing Rate Systems; Definition of Vanderburgh County, Indiana, to a Nonappropriated Fund...

    Science.gov (United States)

    2013-05-21

    ...-AM82 Prevailing Rate Systems; Definition of Vanderburgh County, Indiana, to a Nonappropriated Fund... County, IN; and Jefferson and Pulaski Counties, MO. The Federal Prevailing Rate Advisory Committee, the... as follows: [[Page 29658

  5. Linking atmospheric synoptic transport, cloud phase, surface energy fluxes, and sea-ice growth: observations of midwinter SHEBA conditions

    Science.gov (United States)

    Persson, P. Ola G.; Shupe, Matthew D.; Perovich, Don; Solomon, Amy

    2017-08-01

    Observations from the Surface Heat Budget of the Arctic Ocean (SHEBA) project are used to describe a sequence of events linking midwinter long-range advection of atmospheric heat and moisture into the Arctic Basin, formation of supercooled liquid water clouds, enhancement of net surface energy fluxes through increased downwelling longwave radiation, and reduction in near-surface conductive heat flux loss due to a warming of the surface, thereby leading to a reduction in sea-ice bottom growth. The analyses provide details of two events during Jan. 1-12, 1998, one entering the Arctic through Fram Strait and the other from northeast Siberia; winter statistics extend the results. Both deep, precipitating frontal clouds and post-frontal stratocumulus clouds impact the surface radiation and energy budget. Cloud liquid water, occurring preferentially in stratocumulus clouds extending into the base of the inversion, provides the strongest impact on surface radiation and hence modulates the surface forcing, as found previously. The observations suggest a minimum water vapor threshold, likely case dependent, for producing liquid water clouds. Through responses to the radiative forcing and surface warming, this cloud liquid water also modulates the turbulent and conductive heat fluxes, and produces a thermal wave penetrating into the sea ice. About 20-33 % of the observed variations of bottom ice growth can be directly linked to variations in surface conductive heat flux, with retarded ice growth occurring several days after these moisture plumes reduce the surface conductive heat flux. This sequence of events modulate pack-ice wintertime environmental conditions and total ice growth, and has implications for the annual sea-ice evolution, especially for the current conditions of extensive thinner ice.

  6. 76 FR 9694 - Prevailing Rate Systems; Redefinition of the Northeastern Arizona and Colorado Appropriated Fund...

    Science.gov (United States)

    2011-02-22

    ... 3206-AM33 Prevailing Rate Systems; Redefinition of the Northeastern Arizona and Colorado Appropriated... changes are based on recent consensus recommendations of the Federal Prevailing Rate Advisory Committee to... Northeastern Arizona wage area. The Federal Prevailing Rate Advisory Committee (FPRAC), the national labor...

  7. 76 FR 70321 - Prevailing Rate Systems; Redefinition of the Northern Mississippi and Memphis, TN, Appropriated...

    Science.gov (United States)

    2011-11-14

    ... OFFICE OF PERSONNEL MANAGEMENT 5 CFR Part 532 RIN 3206-AM37 Prevailing Rate Systems; Redefinition... on a consensus recommendation of the Federal Prevailing Rate Advisory Committee (FPRAC) to best match... which OPM received no comments. The Federal Prevailing Rate Advisory Committee (FPRAC), the national...

  8. 78 FR 60182 - Prevailing Rate Systems; Definition of Broward County, Florida, to a Nonappropriated Fund Federal...

    Science.gov (United States)

    2013-10-01

    ... OFFICE OF PERSONNEL MANAGEMENT 5 CFR Part 532 RIN 3206-AM83 Prevailing Rate Systems; Definition of... wage area. The Federal Prevailing Rate Advisory Committee, the national labor-management committee... follows: PART 532--PREVAILING RATE SYSTEMS 0 1. The authority citation for part 532 continues to read as...

  9. 78 FR 18252 - Prevailing Rate Systems; North American Industry Classification System Based Federal Wage System...

    Science.gov (United States)

    2013-03-26

    ...-AM78 Prevailing Rate Systems; North American Industry Classification System Based Federal Wage System... applicable sections. The Federal Prevailing Rate Advisory Committee, the national labor- management committee... proposing to amend 5 CFR part 532 as follows: PART 532--PREVAILING RATE SYSTEMS 0 1. The authority citation...

  10. 76 FR 12769 - Federal Prevailing Rate Advisory Committee; Cancellation of Upcoming Meeting

    Science.gov (United States)

    2011-03-08

    ... OFFICE OF PERSONNEL MANAGEMENT Federal Prevailing Rate Advisory Committee; Cancellation of... Prevailing Rate Advisory Committee is issuing this notice to cancel the March 17, 2011, public meeting..., Chairman, Federal Prevailing Rate Advisory Committee. [FR Doc. 2011-5266 Filed 3-7-11; 8:45 am] BILLING...

  11. 76 FR 9640 - Prevailing Rate Systems: Santa Clara, CA, Tulsa County, OK, and Angelina County, TX

    Science.gov (United States)

    2011-02-22

    ... OFFICE OF PERSONNEL MANAGEMENT 5 CFR Part 532 RIN 3206-AM22 Prevailing Rate Systems: Santa Clara... County, Texas, as an area of application to the Dallas, TX, NAF FWS wage area. The Federal Prevailing.... Accordingly, the U.S. Office of Personnel Management amends 5 CFR part 532 as follows: PART 532--PREVAILING...

  12. 48 CFR 22.1002-2 - Wage determinations based on prevailing rates.

    Science.gov (United States)

    2010-10-01

    ... on prevailing rates. 22.1002-2 Section 22.1002-2 Federal Acquisition Regulations System FEDERAL... Contract Act of 1965, as Amended 22.1002-2 Wage determinations based on prevailing rates. Contractors... Department of Labor to prevail in the locality or, in the absence of a wage determination, the minimum wage...

  13. 78 FR 41962 - Federal Prevailing Rate Advisory Committee; Cancellation of Upcoming Meeting

    Science.gov (United States)

    2013-07-12

    ... OFFICE OF PERSONNEL MANAGEMENT Federal Prevailing Rate Advisory Committee; Cancellation of... Prevailing Rate Advisory Committee is issuing this notice to cancel the July 18, 2013, public meeting... Prevailing Rate Advisory Committee. [FR Doc. 2013-16763 Filed 7-11-13; 8:45 am] BILLING CODE 6325-49-P ...

  14. 78 FR 20359 - Federal Prevailing Rate Advisory Committee; Cancellation of Upcoming Meeting

    Science.gov (United States)

    2013-04-04

    ... OFFICE OF PERSONNEL MANAGEMENT Federal Prevailing Rate Advisory Committee; Cancellation of... Prevailing Rate Advisory Committee is issuing this notice to cancel the April 18, 2013, public meeting... Officer, Federal Prevailing Rate Advisory Committee. [FR Doc. 2013-07875 Filed 4-3-13; 8:45 am] BILLING...

  15. 75 FR 58339 - Prevailing Rate Systems; Redefinition of the Shreveport, LA; Texarkana, TX; Milwaukee, WI; and...

    Science.gov (United States)

    2010-09-24

    ... 3206-AM28 Prevailing Rate Systems; Redefinition of the Shreveport, LA; Texarkana, TX; Milwaukee, WI... area. These changes are based on recent consensus recommendations of the Federal Prevailing Rate... below. The Federal Prevailing Rate Advisory Committee (FPRAC), the national labor-management committee...

  16. 77 FR 28640 - Federal Prevailing Rate Advisory Committee; Cancellation of Upcoming Meeting

    Science.gov (United States)

    2012-05-15

    ... OFFICE OF PERSONNEL MANAGEMENT Federal Prevailing Rate Advisory Committee; Cancellation of... Prevailing Rate Advisory Committee is issuing this notice to cancel the May 24, 2012, public meeting..., Federal Prevailing Rate Advisory Committee. [FR Doc. 2012-11728 Filed 5-14-12; 8:45 am] BILLING CODE 6325...

  17. 76 FR 31885 - Prevailing Rate Systems; Redefinition of the Northern Mississippi and Memphis, TN, Appropriated...

    Science.gov (United States)

    2011-06-02

    ... OFFICE OF PERSONNEL MANAGEMENT 5 CFR Part 532 RIN 3206-AM37 Prevailing Rate Systems; Redefinition... Prevailing Rate Advisory Committee (FPRAC) to best match the county proposed for redefinition to a nearby FWS... Memphis wage area. The Federal Prevailing Rate Advisory Committee (FPRAC), the national labor-management...

  18. 29 CFR 2704.202 - Contents of application-where the applicant has prevailed.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Contents of application-where the applicant has prevailed... Information Required From Applicants § 2704.202 Contents of application—where the applicant has prevailed. (a) An application for an award under § 2704.105(a) shall show that the applicant has prevailed in a...

  19. 78 FR 29658 - Prevailing Rate Systems; Definition of Broward County, Florida, to a Nonappropriated Fund Federal...

    Science.gov (United States)

    2013-05-21

    ... OFFICE OF PERSONNEL MANAGEMENT 5 CFR Part 532 RIN 3206-AM83 Prevailing Rate Systems; Definition of... and Palm Beach Counties, FL. The Federal Prevailing Rate Advisory Committee, the national labor... 532--PREVAILING RATE SYSTEMS 0 1. The authority citation for part 532 continues to read as follows...

  20. 75 FR 34182 - Federal Prevailing Rate Advisory Committee; Cancellation of Upcoming Meeting

    Science.gov (United States)

    2010-06-16

    ... OFFICE OF PERSONNEL MANAGEMENT Federal Prevailing Rate Advisory Committee; Cancellation of... Prevailing Rate Advisory Committee is issuing this notice to cancel the June 17, 2010, public [email protected] ; or FAX: (202) 606-4264. Sheldon Friedman, Chairman, Federal Prevailing Rate...

  1. 76 FR 70512 - Federal Prevailing Rate Advisory Committee; Cancellation of Upcoming Meeting

    Science.gov (United States)

    2011-11-14

    ... OFFICE OF PERSONNEL MANAGEMENT Federal Prevailing Rate Advisory Committee; Cancellation of... Prevailing Rate Advisory Committee is issuing this notice to cancel the November 17, 2011, public meeting..., Chairman, Federal Prevailing Rate Advisory Committee. [FR Doc. 2011-29274 Filed 11-10-11; 8:45 am] BILLING...

  2. Microwave propagation and remote sensing atmospheric influences with models and applications

    CERN Document Server

    Karmakar, Pranab Kumar

    2011-01-01

    Because prevailing atmospheric/troposcopic conditions greatly influence radio wave propagation above 10 GHz, the unguided propagation of microwaves in the neutral atmosphere can directly impact many vital applications in science and engineering. These include transmission of intelligence, and radar and radiometric applications used to probe the atmosphere, among others. Where most books address either one or the other, Microwave Propagation and Remote Sensing: Atmospheric Influences with Models and Applications melds coverage of these two subjects to help readers develop solutions to the problems they present. This reference offers a brief, elementary account of microwave propagation through the atmosphere and discusses radiometric applications in the microwave band used to characterize and model atmospheric constituents, which is also known as remote sensing. Summarizing the latest research results in the field, as well as radiometric models and measurement methods, this book covers topics including: Free sp...

  3. Global empirical wind model for the upper mesosphere/lower thermosphere. I. Prevailing wind

    Directory of Open Access Journals (Sweden)

    Y. I. Portnyagin

    Full Text Available An updated empirical climatic zonally averaged prevailing wind model for the upper mesosphere/lower thermosphere (70-110 km, extending from 80°N to 80°S is presented. The model is constructed from the fitting of monthly mean winds from meteor radar and MF radar measurements at more than 40 stations, well distributed over the globe. The height-latitude contour plots of monthly mean zonal and meridional winds for all months of the year, and of annual mean wind, amplitudes and phases of annual and semiannual harmonics of wind variations are analyzed to reveal the main features of the seasonal variation of the global wind structures in the Northern and Southern Hemispheres. Some results of comparison between the ground-based wind models and the space-based models are presented. It is shown that, with the exception of annual mean systematic bias between the zonal winds provided by the ground-based and space-based models, a good agreement between the models is observed. The possible origin of this bias is discussed.

    Key words: Meteorology and Atmospheric dynamics (general circulation; middle atmosphere dynamics; thermospheric dynamics

  4. Assessment of capabilities of lidar systems in day-and night-time under different atmospheric and internal-noise conditions

    Science.gov (United States)

    Agishev, Ravil; Comerón, Adolfo

    2018-04-01

    As an application of the dimensionless parameterization concept proposed earlier for the characterization of lidar systems, the universal assessment of lidar capabilities in day and night conditions is considered. The dimensionless parameters encapsulate the atmospheric conditions, the lidar optical and optoelectronic characteristics, including the photodetector internal noise, and the sky background radiation. Approaches to ensure immunity of the lidar system to external background radiation are discussed.

  5. Does undernutrition still prevail among nursing home residents?

    Science.gov (United States)

    Törmä, Johanna; Winblad, Ulrika; Cederholm, Tommy; Saletti, Anja

    2013-08-01

    During recent years public awareness about malnutrition has increased and collective initiatives have been undertaken. Simultaneously, the number of older adults is increasing, and the elderly care has been placed under pressure. The aim was to assess the nutritional situation and one-year mortality among nursing home (NH) residents, and compare with historical data. Mini Nutritional Assessment-Short Form (MNA-SF), ADL Barthel Index (BI), Short Portable Mental Status Questionnaire (SPMSQ), EQ-5D, Charlson Comorbidity Index (CCI), and blood samples were collected from 172 NH residents (86.3 ± 8 years, 70% women). Mortality data was taken from NH records. Nutritional data from 166 NH residents (83.8 ± 8 years, 61% women) examined in 1996 was retrieved for historical comparison. The prevalence of malnutrition was 30%, as compared to 71% in the historical data set, corresponding to a present average body mass index of 23.7 ± 5.1 compared with 22.3 ± 4.2 kg/m(2) (p prevails and is associated with deteriorated cognition, function and increased mortality. A possible improvement in nutritional status in NH residents over time was observed. Copyright © 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  6. Genetics of Schizophrenia: Historical Insights and Prevailing Evidence.

    Science.gov (United States)

    van de Leemput, J; Hess, J L; Glatt, S J; Tsuang, M T

    2016-01-01

    Schizophrenia's (SZ's) heritability and familial transmission have been known for several decades; however, despite the clear evidence for a genetic component, it has been very difficult to pinpoint specific causative genes. Even so genetic studies have taught us a lot, even in the pregenomic era, about the molecular underpinnings and disease-relevant pathways. Recurring themes emerged revealing the involvement of neurodevelopmental processes, glutamate regulation, and immune system differential activation in SZ etiology. The recent emergence of epigenetic studies aimed at shedding light on the biological mechanisms underlying SZ has provided another layer of information in the investigation of gene and environment interactions. However, this epigenetic insight also brings forth another layer of complexity to the (epi)genomic landscape such as interactions between genetic variants, epigenetic marks-including cross-talk between DNA methylation and histone modification processes-, gene expression regulation, and environmental influences. In this review, we seek to synthesize perspectives, including limitations and obstacles yet to overcome, from genetic and epigenetic literature on SZ through a qualitative review of risk factors and prevailing hypotheses. Encouraged by the findings of both genetic and epigenetic studies to date, as well as the continued development of new technologies to collect and interpret large-scale studies, we are left with a positive outlook for the future of elucidating the molecular genetic mechanisms underlying SZ and other complex neuropsychiatric disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Measurements of Atmospheric CO2 Column in Cloudy Weather Conditions using An IM-CW Lidar at 1.57 Micron

    Science.gov (United States)

    Lin, Bing; Obland, Michael; Harrison, F. Wallace; Nehrir, Amin; Browell, Edward; Campbell, Joel; Dobler, Jeremy; Meadows, Bryon; Fan, Tai-Fang; Kooi, Susan; hide

    2015-01-01

    This study evaluates the capability of atmospheric CO2 column measurements under cloudy conditions using an airborne intensity-modulated continuous-wave integrated-path-differential-absorption lidar operating in the 1.57-m CO2 absorption band. The atmospheric CO2 column amounts from the aircraft to the tops of optically thick cumulus clouds and to the surface in the presence of optically thin clouds are retrieved from lidar data obtained during the summer 2011 and spring 2013 flight campaigns, respectively.

  8. Spring soil moisture-precipitation feedback in the Southern Great Plains: How is it related to large-scale atmospheric conditions?

    KAUST Repository

    Su, Hua

    2014-02-22

    The Southern Great Plains (SGP) has been shown as a region of significant soil moisture-precipitation (S-P) coupling. However, how strong evapotranspiration (ET) can affect regional precipitation remains largely unclear, impeding a full grasp of the S-P feedback in that area. The current study seeks to unravel, in a spring month (April), the potential role played by large-scale atmospheric conditions in shaping S (ET)-P feedback. Our regional climate modeling experiments demonstrate that the presence of anomalous low (high) pressure and cyclonic (anticyclonic) flows at the upper/middle troposphere over the relevant areas is associated with strongest (minimum) positive S-P feedback in the SGP. Their impacts are interpreted in terms of large-scale atmospheric dynamical disturbance, including the intensity and location of synoptic eddies. Further analyses of the vertical velocity fields corroborate these interpretations. In addition, the relationship between lower tropospheric moisture conditions (including winds) and feedback composites is evaluated. Key Points The S-P feedback strength in SGP in April varies inter-annually The atmospheric dynamic features affect significantly the feedback strength composite moisture conditions are related to atmospheric circulation structure ©2014. American Geophysical Union. All Rights Reserved.

  9. Spring soil moisture-precipitation feedback in the Southern Great Plains: How is it related to large-scale atmospheric conditions?

    KAUST Repository

    Su, Hua; Yang, Zong-Liang; Dickinson, Robert E.; Wei, Jiangfeng

    2014-01-01

    The Southern Great Plains (SGP) has been shown as a region of significant soil moisture-precipitation (S-P) coupling. However, how strong evapotranspiration (ET) can affect regional precipitation remains largely unclear, impeding a full grasp of the S-P feedback in that area. The current study seeks to unravel, in a spring month (April), the potential role played by large-scale atmospheric conditions in shaping S (ET)-P feedback. Our regional climate modeling experiments demonstrate that the presence of anomalous low (high) pressure and cyclonic (anticyclonic) flows at the upper/middle troposphere over the relevant areas is associated with strongest (minimum) positive S-P feedback in the SGP. Their impacts are interpreted in terms of large-scale atmospheric dynamical disturbance, including the intensity and location of synoptic eddies. Further analyses of the vertical velocity fields corroborate these interpretations. In addition, the relationship between lower tropospheric moisture conditions (including winds) and feedback composites is evaluated. Key Points The S-P feedback strength in SGP in April varies inter-annually The atmospheric dynamic features affect significantly the feedback strength composite moisture conditions are related to atmospheric circulation structure ©2014. American Geophysical Union. All Rights Reserved.

  10. Methodical development of a modular planning and decision-making model for local energy supply concepts with regard to the special conditions which prevail in the new Lands of unified Germany. Methodische Entwicklung eines strukturierten Planungs- und Entscheidungsmodells fuer die Gestaltung integrierter oertlicher Energieversorgungskonzepte unter Beruecksichtigung der besonderen Rahmenbedingungen in den neuen Bundeslaendern

    Energy Technology Data Exchange (ETDEWEB)

    Puestow, H.D.

    1992-05-27

    An action-oriented planning and decision-making model considering individual local conditions and general aspects of energy economy is presented for the development of feasible municipal energy supply concepts. The decision-making model was given a modular structure for future knowledge-based energy-economy planning by use of personal computers. The formalized methodology and a corresponding expert system development environment help to implement the developed phase model and give better and more rapid access to the expert knowledge which is relevant to energy economy. (orig.).

  11. Experimental and numerical study of atmospheric turbulence and dispersion in stable conditions and in near field at a complex site

    International Nuclear Information System (INIS)

    Wei, Xiao

    2016-01-01

    - ε closure adapted for atmospheric flows and a canopy model for the forest. These simulations are shown to reproduce correctly the characteristics of the mean flow on the measurements site, especially the impact of the forest for different wind directions, in both neutral and stable conditions. Simulation results also show the directional wind shear and the turbulent kinetic energy increase induced by the forest. A sensitivity study has been made for various values of forest density and shows that the typical features of canopy flow become more pronounced as canopy density increases. Pollutant dispersion study is made for several IOPs. Concentration data analysis shows a consistency with previous measurements made in a near-source region where the plume scale is smaller than the large-scale turbulence eddies. Concentration fluctuations are characterized through concentration time series, histogram and statistical analysis. The inertial sub-range can be observed in the concentration spectra. Next, pollutant dispersion is modelled by transport equations for concentration and its variance. The mean concentrations show a good agreement with measurements in values for all the IOPs studied, except that the position of the concentration peak depends on the accuracy of simulated wind rotation below the forest height. The concentration fluctuations obtained from simulations seem to be affected significantly by the condition at the source and the modelling of the dissipation term. A sensitivity study to the parameterization is then presented. (author) [fr

  12. Atmosphere self-cleaning under humidity conditions and influence of the snowflakes and artificial light interaction for water dissociation simulated by the means of COMSOL

    Science.gov (United States)

    Cocean, A.; Cocean, I.; Cazacu, M. M.; Bulai, G.; Iacomi, F.; Gurlui, S.

    2018-06-01

    The self-cleaning of the atmosphere under humidity conditions is observed due to the change in emission intensity when chemical traces are investigated with DARLIOES - the advanced LIDAR based on space- and time-resolved RAMAN and breakdown spectroscopy in conditions of consistent humidity of atmosphere. The determination was performed during the night, in the wintertime under conditions of high humidity and snowfall, in urban area of Iasi. The change in chemical composition of the atmosphere detected was assumed to different chemical reactions involving presence of the water. Water dissociation that was registered during spectral measurements is explained by a simulation of the interaction between artificial light and snowflakes - virtually designed in a spherical geometry - in a wet air environment, using COMSOL Multiphysics software. The aim of the study is to explain the decrease or elimination of some of the toxic trace chemical compounds in the process of self-cleaning in other conditions than the sun light interaction for further finding application for air cleaning under artificial conditions.

  13. Improvement of a mesoscale atmospheric dynamic model PHYSIC. Utilization of output from synoptic numerical prediction model for initial and boundary condition

    International Nuclear Information System (INIS)

    Nagai, Haruyasu; Yamazawa, Hiromi

    1995-03-01

    This report describes the improvement of the mesoscale atmospheric dynamic model which is a part of the atmospheric dispersion calculation model PHYSIC. To introduce large-scale meteorological changes into the mesoscale atmospheric dynamic model, it is necessary to make the initial and boundary conditions of the model by using GPV (Grid Point Value) which is the output of the numerical weather prediction model of JMA (Japan Meteorological Agency). Therefore, the program which preprocesses the GPV data to make a input file to PHYSIC was developed and the input process and the methods of spatial and temporal interpolation were improved to correspond to the file. Moreover, the methods of calculating the cloud amount and ground surface moisture from GPV data were developed and added to the model code. As the example of calculation by the improved model, the wind field simulations of a north-west monsoon in winter and a sea breeze in summer in the Tokai area were also presented. (author)

  14. Experimental and numerical study of atmospheric turbulence and dispersion in stable conditions and in near field at a complex site

    International Nuclear Information System (INIS)

    Wei, Xiao

    2016-01-01

    -ε closure adapted for atmospheric flows and a canopy model for the forest. These simulations are shown to reproduce correctly the characteristics of the mean flow on the measurements site, especially the impact of the forest for different wind directions, in both neutral and stable stratification. Simulations results also show the directional wind shear and the turbulent kinetic energy increase induced by the forest. A sensitivity study has been made for various values of forest density and shows that the typical features of canopy flow become more pronounced as canopy density increases. Pollutants dispersion study are made for several IOPs. Concentration data analysis shows a consistency with previous measurements made in a near-source region where the plume scale is smaller than the large-scale turbulence eddies. Concentration fluctuations are characterized through concentration time series, histogram and statistical analysis. The internal sub-range can be observed in the concentration spectra. Next, pollutants dispersion are modelled by transport equations for concentration and its variance. The mean concentrations show a good agreement with measurements in values for all the IOPs studied, except that the position of the concentration peak depends on the accuracy of simulated wind rotation below the forest height. The concentration fluctuations obtained from simulations seem to be affected significantly by the initial condition and the modelling of the dissipation term. A sensitivity study to the parameterization is then presented. (author)

  15. Changes in flavonoids of sliced and fried yellow onions (allium cepa L. var. zittauer) during storage at different atmospheric, temperature and light conditions

    DEFF Research Database (Denmark)

    Islek, Merve; Nilufer-Erdil, Dilara; Knuthsen, Pia

    2015-01-01

    Flavonoid changes in sliced and fried onions which were packed and stored at different atmospheric conditions (air, nitrogen and vacuum), temperatures (ambient, +5 and -18C) and light (dark or light) were investigated. Flavonoids were extracted using accelerated solvent extraction and analyzed us......, or -18C, vacuum or nitrogen atmosphere, under dark, preserved flavonoids for 21 days, whereas for fried onions, 7 days of storage at +5C, vacuum atmosphere under dark resulted in highest flavonoid content. © 2014 Wiley Periodicals, Inc.......Flavonoid changes in sliced and fried onions which were packed and stored at different atmospheric conditions (air, nitrogen and vacuum), temperatures (ambient, +5 and -18C) and light (dark or light) were investigated. Flavonoids were extracted using accelerated solvent extraction and analyzed...... using ultra performance liquid chromatography coupled with photodiode array detector. Total flavonoid content, quercetin-3,4'-O-diglucoside and quercetin-4'-O-monoglucoside contents in sliced reference onion samples were found as 1,570±176, 926±105 and 564±64μg q.e./g d.w., respectively. Frying did...

  16. Dynamic Regression Model for Evaluating the Association Between Atmospheric Conditions and Deaths due to Respiratory Diseases in São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Ana Carla dos Santos Gomes

    Full Text Available Abstract The article reports the modeling of mortality due to respiratory diseases emanating from atmospheric conditions, capturing significant associations and verifying the ability of stochastic modeling to predict deaths arising from the relationship between weather conditions and air pollution. The statistical methods used in the analysis were cross-correlation and pre-whitening, in addition to dynamic regression modeling combining the dynamics of time series and the effect of explanatory variables. The results show there are significant associations between mortality and sulfur dioxide, air temperature, atmospheric pressure, relative humidity, and autoregressive structure. The cross-correlations captured significant lags between atmospheric variables and deaths, of two months for SO2 and relative humidity, eleven months for PM10, seven months for O3, and eight months for air temperature and the cross-correlation without lag with NO2. With CO variables, precipitation and atmospheric pressure, cross-correlations were not detected. Stochastic modeling showed that deaths due to respiratory diseases can be predicted from the combination of meteorological and air pollution variables, especially considering the existing trend and seasonality.

  17. In the ideal condition an experimental study on migration of radon and its daughters in the atmosphere

    International Nuclear Information System (INIS)

    Zeng Bing; Zhang Jinzhao; Wang Qing

    2010-01-01

    According to the relevant theory of thermodynamics, this presentation which based on the radon migration of the cluster theory has deduced ordinarily the ideal velocity period and displacement. The purpose was to establish the theoretical model of migration of radon and its daughters in the atmosphere in the ideal case, which would provide a underlying theoretical basis for the further research. (authors)

  18. A climatological analysis of high-precipitation events in Dronning Maud Land, Antarctica, and associated large-scale atmospheric conditions

    NARCIS (Netherlands)

    Welker, Christoph; Martius, Olivia; Froidevaux, Paul; Reijmer, Carleen H.; Fischer, Hubertus

    2014-01-01

    The link between high precipitation in Dronning Maud Land (DML), Antarctica, and the large-scale atmospheric circulation is investigated using ERA-Interim data for 1979-2009. High-precipitation events are analyzed at Halvfarryggen situated in the coastal region of DML and at Kohnen Station located

  19. Ascorbic acid and tissue browning in pears (Pyrus communis L. cvs Rocha and Conference) under controlled atmosphere conditions

    NARCIS (Netherlands)

    Veltman, R.H.; Kho, R.M.; Schaik, van A.C.R.; Sanders, M.G.; Oosterhaven, J.

    2000-01-01

    The relationships between storage gas composition and ascorbic acid (AA) levels, and between AA levels and the development of internal browning, were studied in 'Conference' and 'Rocha' pears (Pyrus communis L.). In both cultivars, AA levels declined under (browning-inducing) controlled atmosphere

  20. Vertical variations in the turbulent structure of the surface boundary layer over vineyards under unstable atmospheric conditions

    Science.gov (United States)

    Due to their highly-structured canopy, turbulent characteristics within and above vineyards, may not conform to those typically exhibited by other agricultural and natural ecosystems. Using data collected as a part of the Grape Remote sensing and Atmospheric Profiling and Evapotranspiration Experime...

  1. Fire weather conditions and fire-atmosphere interactions observed during low-intensity prescribed fires - RxCADRE 2012

    Science.gov (United States)

    Craig B. Clements; Neil P. Lareau; Daisuke Seto; Jonathan Contezac; Braniff Davis; Casey Teske; Thomas J. Zajkowski; Andrew T. Hudak; Benjamin C. Bright; Matthew B. Dickinson; Bret W. Butler; Daniel Jimenez; J. Kevin. Hiers

    2016-01-01

    The role of fire-atmosphere coupling on fire behaviour is not well established, and to date few field observations have been made to investigate the interactions between fire spread and fire-induced winds. Therefore, comprehensive field observations are needed to better understand micrometeorological aspects of fire spread. To address this need, meteorological...

  2. Cooldown to residual heat removal entry conditions using atmospheric dump valves and auxiliary pressurizer spray following a loss-of-offsite power at Calvert Cliffs, Unit 1

    International Nuclear Information System (INIS)

    Jenks, R.P.

    1984-01-01

    An investigation of cooldown using atmospheric dump valves (ADVs) and auxiliary pressurizer spray (APS) following loss-of-offsite power at Calvert Cliffs-1 showed residual heat removal entry conditions could not be reached with the plant ADVs alone. Use of APS with the plant ADVs enhanced depressurization, but still provided insufficient cooldown. Effective cooldown and depressurization was shown to occur when rated steady state flow through the ADVs was increased by a factor of four. 6 refs., 30 figs., 2 tabs

  3. A whiff of nebular gas in Titan's atmosphere - Potential implications for the conditions and timing of Titan's formation

    Science.gov (United States)

    Glein, Christopher R.

    2017-09-01

    In situ data from the GCMS instrument on the Huygens probe indicate that Titan's atmosphere contains small amounts of the primordial noble gases 36Ar and 22Ne (tentative detection), but it is unknown how they were obtained by the satellite. Based on the apparent similarity in the 22Ne/36Ar (atom) ratio between Titan's atmosphere and the solar composition, a previously neglected hypothesis for the origin of primordial noble gases in Titan's atmosphere is suggested - these species may have been acquired near the end of Titan's formation, when the moon could have gravitationally captured some nebular gas that would have been present in its formation environment (the Saturnian subnebula). These noble gases may be remnants of a primary atmosphere. This could be considered the simplest hypothesis to explain the 22Ne/36Ar ratio observed at Titan. However, the 22Ne/36Ar ratio may not be exactly solar if these species can be fractionated by external photoevaporation in the solar nebula, atmospheric escape from Titan, or sequestration on the surface of Titan. While the GCMS data are consistent with a 22Ne/36Ar ratio of 0.05 to 2.5 times solar (1σ range), simple estimates that attempt to account for some of the effects of these evolutionary processes suggest a sub-solar ratio, which may be depleted by approximately one order of magnitude. Models based on capture of nebular gas can explain why the GCMS did not detect any other primordial noble gas isotopes, as their predicted abundances are below the detection limits (especially for 84Kr and 132Xe). It is also predicted that atmospheric Xe on Titan should be dominated by radiogenic 129Xe if the source of primordial Xe is nebular gas. Of order 10-2-10-1 bar of primordial H2 may have been captured along with the noble gases from a gas-starved disk, but this H2 would have quickly escaped from the initial atmosphere. To have the opportunity to capture nebular gas, Titan should have formed within ∼10 Myr of the formation of the

  4. The influence of seeding conditions and shielding gas atmosphere on the synthesis of silver nanowires through the polyol process

    Science.gov (United States)

    Chen, Chang; Wang, Li; Jiang, Guohua; Yang, Qiang; Wang, Jianjun; Yu, Haojie; Chen, Tao; Wang, Chiliang; Chen, Xu

    2006-01-01

    The polyol process including the introduction of preformed seeds and the inducement of poly(vinyl pyrrolidone) (PVP) has been developed as a powerful approach for synthesizing silver nanowires. Here, silver nanowires without other metal elements as impurities were synthesized through a silver seeding polyol process in a shielding gas atmosphere. It is demonstrated that the first seeding step is critical in obtaining silver nanowires as the principal product, and we also observe that the shielding gas atmosphere not only improves the repeatability of experiments but also affects the morphology of the final product. We obtained nanocubes with hydrogen gas shielding in a short reaction time; these would scarcely appear with argon or air shielding. Our work supplies new evidence to explain the actual growth mechanism of silver nanowires.

  5. Microstructure and texture evolution in a non-oriented electrical steel during γ→α transformation under various atmosphere conditions

    International Nuclear Information System (INIS)

    Xie, Li; Yang, Ping; Xia, Dongsheng; Mao, Weimin

    2015-01-01

    The microstructure and texture evolution of Fe–0.50%Mn non-oriented electrical steel during austenite (γ) to ferrite (α) transformation was studied following various processing conditions. The experimental results demonstrate that the γ→α transformation interface moves from the surface of sheets towards the inner part along the normal direction (ND) under a high temperature gradient in pure hydrogen atmosphere, hereafter calling the process as “directional” phase transformation. Driven by the anisotropic strain energy, the strong {100} textured columnar grains are obtained during the “directional” phase transformation in pure hydrogen atmosphere with a high flow rate. However, driven by the anisotropies of both strain energy and surface energy, the fine {100} and {110} textured columnar grains are developed in pure hydrogen atmosphere with a relatively low flow rate. By contrast, the transformation process is “global” when specimens are annealed in pure nitrogen atmosphere. As a consequence, a {111} texture with equiaxed grains is obtained. In addition, the effect of manganese (Mn) upon the surface oxidation behavior is investigated. - Highlights: • The various atmosphere conditions lead to the microstructure and texture evolution. • The γ→α transformation is “directional” in hydrogen and “global” in nitrogen. • {100} textured columnar grains are obtained at the high flow rate of hydrogen. • {100} and {110} textured columnar grains are obtained at a low flow rate of hydrogen. • A γ-fiber texture with equiaxed grains is obtained in “global” γ→α transformation

  6. Modeling of methane bubbles released from large sea-floor area: Condition required for methane emission to the atmosphere

    OpenAIRE

    Yamamoto, A.; Yamanaka, Y.; Tajika, E.

    2009-01-01

    Massive methane release from sea-floor sediments due to decomposition of methane hydrate, and thermal decomposition of organic matter by volcanic outgassing, is a potential contributor to global warming. However, the degree of global warming has not been estimated due to uncertainty over the proportion of methane flux from the sea-floor to reach the atmosphere. Massive methane release from a large sea-floor area would result in methane-saturated seawater, thus some methane would reach the atm...

  7. Atmospheric Effects on Signal Propagation in Adverse Environmental Conditions: A Validation of the Advanced Refractive Effects Prediction System

    Science.gov (United States)

    2008-09-01

    65 Figure 30. Chiang Mai , Thailand March Climatology AREPS M-unit graphic. ..............66 Figure 31. Standard Atmosphere AREPS M-unit...experiment as a precursor to the annual capstone field experiment (May and June) at the Mae Ngat Dam north of Chiang Mai , Thailand. COASTS R&D...Motorola 802.16 network components as discussed in Chapter II. Testing occurred approximately 40 km north of Chiang Mai , Thailand, at the Mae Ngat Dam

  8. Oceanic and atmospheric conditions associated with the pentad rainfall over the southeastern peninsular India during the North-East Indian Monsoon season

    Science.gov (United States)

    Shanmugasundaram, Jothiganesh; Lee, Eungul

    2018-03-01

    The association of North-East Indian Monsoon rainfall (NEIMR) over the southeastern peninsular India with the oceanic and atmospheric conditions over the adjacent ocean regions at pentad time step (five days period) was investigated during the months of October to December for the period 1985-2014. The non-parametric correlation and composite analyses were carried out for the simultaneous and lagged time steps (up to four lags) of oceanic and atmospheric variables with pentad NEIMR. The results indicated that NEIMR was significantly correlated: 1) positively with both sea surface temperature (SST) led by 1-4 pentads (lag 1-4 time steps) and latent heat flux (LHF) during the simultaneous, lag 1 and 2 time steps over the equatorial western Indian Ocean, 2) positively with SST but negatively with LHF (less heat flux from ocean to atmosphere) during the same and all the lagged time steps over the Bay of Bengal. Consistently, during the wet NEIMR pentads over the southeastern peninsular India, SST significantly increased over the Bay of Bengal during all the time steps and the equatorial western Indian Ocean during the lag 2-4 time steps, while the LHF decreased over the Bay of Bengal (all time steps) and increased over the Indian Ocean (same, lag 1 and 2). The investigation on ocean-atmospheric interaction revealed that the enhanced LHF over the equatorial western Indian Ocean was related to increased atmospheric moisture demand and increased wind speed, whereas the reduced LHF over the Bay of Bengal was associated with decreased atmospheric moisture demand and decreased wind speed. The vertically integrated moisture flux and moisture transport vectors from 1000 to 850 hPa exhibited that the moisture was carried away from the equatorial western Indian Ocean to the strong moisture convergence regions of the Bay of Bengal during the same and lag 1 time steps of wet NEIMR pentads. Further, the moisture over the Bay of Bengal was transported to the southeastern peninsular

  9. Neoseismotectonics and glacial isostatic uplift. Deformations and changes of prevailing conditions in the Swedish bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Moerner, N.A. [Stockholm Univ. (Sweden)

    1997-04-01

    The conclusions from this contribution are that no bedrock repository can be considered to be safely placed in the bedrock at the event of new glaciations, which are to be expected over Sweden in 5, 23, and 60 thousand years AP (following the astronomical, natural or long-term variability). Instead, there are all reasons to expect that such a repository would be seriously damaged, and constitute a threat to the biosphere on Earth. These conclusions are based on an extensive observational network of records on the multiple glacial dynamics and the interaction of different variables. 24 refs.

  10. Radiolysis of cesium iodide solutions in conditions prevailing in a pressurized water reactor severe accident

    International Nuclear Information System (INIS)

    Lucas, M.

    1988-01-01

    Measurements were made of I/sub 2/ formed when aqueous cesium iodide (CsI) solutions were exposed to two temperatures, 43 and 95 0 C, with irradiation. Iodine partition coefficients were obtained from the experiments. The parameters varied were dose, CsI concentration, and Cs/sub 2/CO/sub 3/ concentration, in the presence of air-carbon dioxide and air-carbon dioxide-hydrogen mixtures, to provide information to calculate the form in which iodine released from fuel as CsI in a reactor accident might reach the environment. In a series of experiments, a two-compartment cell was used to trap the gaseous iodine produced. In this case, it was found that the quantity of gaseous iodine produced increased approximately linearly with the dose (at the dose rate used)

  11. Geostatistical analysis of prevailing groundwater conditions and potential solute migration at Elstow, Bedfordshire

    International Nuclear Information System (INIS)

    MacKay, R.; Cooper, T.A.; Porter, J.D.; O'Connell, P.E.; Metcalfe, A.V.

    1988-06-01

    A geostatistical approach is applied in a study of the potential migration of contaminants from a hypothetical waste disposal facility near Elstow, Bedfordshire. A deterministic numerical model of groundwater flow in the Kellaways Sands formation and adjacent layers is coupled with geostatistical simulation of the heterogeneous transmissivity field of this principal formation. A particle tracking technique is used to predict the migration pathways for alternative realisations of flow. Alternative statistical descriptions of the spatial structure of the transmissivity field are implemented and the temporal and spatial distributions of escape of contaminants to the biosphere are investigated. (author)

  12. Neoseismotectonics and glacial isostatic uplift. Deformations and changes of prevailing conditions in the Swedish bedrock

    International Nuclear Information System (INIS)

    Moerner, N.A.

    1997-01-01

    The conclusions from this contribution are that no bedrock repository can be considered to be safely placed in the bedrock at the event of new glaciations, which are to be expected over Sweden in 5, 23, and 60 thousand years AP (following the astronomical, natural or long-term variability). Instead, there are all reasons to expect that such a repository would be seriously damaged, and constitute a threat to the biosphere on Earth. These conclusions are based on an extensive observational network of records on the multiple glacial dynamics and the interaction of different variables. 24 refs

  13. 5 CFR 532.205 - The use of Federal, State, and local minimum wage requirements in determining prevailing rates.

    Science.gov (United States)

    2010-01-01

    ... minimum wage requirements in determining prevailing rates. 532.205 Section 532.205 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PREVAILING RATE SYSTEMS Prevailing Rate Determinations § 532.205 The use of Federal, State, and local minimum wage requirements in determining prevailing...

  14. Temperature dependence of carbon kinetic isotope effect for the oxidation reaction of ethane by OH radicals under atmospherically relevant conditions

    Science.gov (United States)

    Piansawan, Tammarat; Saccon, Marina; Laumer, Werner; Gensch, Iulia; Kiendler-Scharr, Astrid

    2015-04-01

    Modeling of the global distribution of atmospheric ethane sources and sinks by using the 13C isotopic composition requires accurate knowledge of the carbon kinetic isotope effect (KIE) of its atmospheric removal reactions. The quantum mechanical prediction implies the necessity to elucidate the temperature dependence of KIE within atmospherically relevant temperature range by experiment. In this study, the KIE and its temperature dependence for ethane oxidation by OH radicals was investigated at ambient pressure in a temperature range of 243 K to 303 K. The chemical reactions were carried out in a 15 L PFE reaction chamber, suspended in a thermally controlled oven. The isotope ratios of the gas phase components during the course of the reactions were measured by Thermal Desorption -- Gas Chromatography -- Isotope Ratio Mass Spectrometry (TD-GC-IRMS). For each temperature, the KIE was derived from the temporal evolution of the concentration and stable carbon isotope ratio (δ13C) of ethane using a method adapted from the relative reaction rate concept. The room temperature KIE of the ethane reaction with OH radicals was found to be 6.85 ± 0.32 ‰. This value is in agreement with the previously reported value of 8.57 ± 1.95 ‰ [Anderson et al. 2004] but has a substantially lower uncertainty. The experimental results will be discussed with the KIE temperature dependence predicted by quantum mechanical calculations. Reference: Rebecca S. Anderson, Lin Huang, Richard Iannone, Alexandra E. Thompson, and Jochen Rudolph (2004), Carbon Kinetic Isotope Effects in the Gas Phase Reactions of Light Alkanes and Ethene with the OH Radical at 296 ± 4 K, J. Phys. Chem. A, 108, 11537--11544

  15. 7 CFR 27.35 - Lower class of two samples to prevail.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Lower class of two samples to prevail. 27.35 Section 27.35 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE... Micronaire Determinations § 27.35 Lower class of two samples to prevail. In case a sample drawn from one...

  16. 78 FR 60181 - Prevailing Rate Systems; Redefinition of the Clayton-Cobb-Fulton, Georgia, Nonappropriated Fund...

    Science.gov (United States)

    2013-10-01

    ... OFFICE OF PERSONNEL MANAGEMENT 5 CFR Part 532 RIN 3206-AM84 Prevailing Rate Systems; Redefinition of the Clayton-Cobb-Fulton, Georgia, Nonappropriated Fund Federal Wage System Wage Area AGENCY: U.S... Counties). The Federal Prevailing Rate Advisory Committee, the national labor-management committee...

  17. 75 FR 18552 - Federal Prevailing Rate Advisory Committee; Open Committee Meetings

    Science.gov (United States)

    2010-04-12

    ... of Personnel Management Building, 1900 E Street, NW., Washington, DC. The Federal Prevailing Rate... business. Therefore, these caucuses will be closed to the public because of a determination made by the..., Federal Prevailing Rate Advisory Committee, Room 5H27, 1900 E Street, NW., Washington, DC 20415, (202) 606...

  18. The Prevailing Catalytic Role of Meteorites in Formamide Prebiotic Processes.

    Science.gov (United States)

    Saladino, Raffaele; Botta, Lorenzo; Di Mauro, Ernesto

    2018-02-22

    Meteorites are consensually considered to be involved in the origin of life on this Planet for several functions and at different levels: (i) as providers of impact energy during their passage through the atmosphere; (ii) as agents of geodynamics, intended both as starters of the Earth's tectonics and as activators of local hydrothermal systems upon their fall; (iii) as sources of organic materials, at varying levels of limited complexity; and (iv) as catalysts. The consensus about the relevance of these functions differs. We focus on the catalytic activities of the various types of meteorites in reactions relevant for prebiotic chemistry. Formamide was selected as the chemical precursor and various sources of energy were analyzed. The results show that all the meteorites and all the different energy sources tested actively afford complex mixtures of biologically-relevant compounds, indicating the robustness of the formamide-based prebiotic chemistry involved. Although in some cases the yields of products are quite small, the diversity of the detected compounds of biochemical significance underlines the prebiotic importance of meteorite-catalyzed condensation of formamide.

  19. The Prevailing Catalytic Role of Meteorites in Formamide Prebiotic Processes

    Directory of Open Access Journals (Sweden)

    Raffaele Saladino

    2018-02-01

    Full Text Available Meteorites are consensually considered to be involved in the origin of life on this Planet for several functions and at different levels: (i as providers of impact energy during their passage through the atmosphere; (ii as agents of geodynamics, intended both as starters of the Earth’s tectonics and as activators of local hydrothermal systems upon their fall; (iii as sources of organic materials, at varying levels of limited complexity; and (iv as catalysts. The consensus about the relevance of these functions differs. We focus on the catalytic activities of the various types of meteorites in reactions relevant for prebiotic chemistry. Formamide was selected as the chemical precursor and various sources of energy were analyzed. The results show that all the meteorites and all the different energy sources tested actively afford complex mixtures of biologically-relevant compounds, indicating the robustness of the formamide-based prebiotic chemistry involved. Although in some cases the yields of products are quite small, the diversity of the detected compounds of biochemical significance underlines the prebiotic importance of meteorite-catalyzed condensation of formamide.

  20. Effect of cadmium pollution of atmospheric origin on field-grown maize in two consecutive years with diverse weather conditions.

    Science.gov (United States)

    Anda, Angéla; Illés, Bernadett; Soós, G

    2013-12-01

    The aim of the study was to analyse the effect of atmospheric cadmium (Cd) pollution of atmospheric origin in maize compared to a control without Cd pollution. The plant parameters investigated were the timing of phenological phases, leaf area index (LAI) and yield, while radiation and water regime parameters were represented by albedo (reflection grade) and evapotranspiration, respectively. In treatments with and without irrigation, Cd caused a significant reduction in LAI, accompanied by lower evapotranspiration. The mean annual albedo in the Cd-polluted treatment only rose to a moderate extent in 2011 (in 2010 there was hardly any change), but changes within the year were more pronounced in certain phases of development. Cd led to greater reflection of radiation by plants during the vegetative phase, so the radiation absorption of the canopy was reduced leading to a lower level of evapotranspiration. In the dry, hot year of 2011 maize plants in the non-irrigated treatments showed a substantial reduction in grain dry matter, but maize yield losses could be reduced by irrigation in areas exposed to Cd pollution.

  1. Visible spectroscopy as a tool for the assessment of storage conditions of fresh pork packaged in modified atmosphere

    DEFF Research Database (Denmark)

    Spanos, Dimitrios; Christensen, Mette; Ann Tørngren, Mari

    2016-01-01

    The storage conditions of fresh meat are known to impact its colour and microbial shelf life. In the present study, visible spectroscopy was evaluated as a method to assess meat storage conditions and its optimisation. Fresh pork steaks (longissimus thoracis et lumborum and semimembranosus) were...

  2. Assessment of the dispersion of fission products in the atmosphere following a reactor accident under meteorological conditions of low wind speed

    International Nuclear Information System (INIS)

    Crabol, B.

    1984-11-01

    The aim of the study is the assessment of the dispersion in a low speed situation and the validation of the computer code ICAIR3 by means of SF6 tracing experiments carried out on the CADARACHE site under different stability conditions. The results show clearly some characteristic features of the dispersion. In particular, high concentrations are found in the experimental field several hours after the end of the release. Large differences of the plume width are observed depending on the atmospheric stability. The flow seems well organized under stable conditions, probably in relation with a topographic effect (CADARACHE is situated in a valley), while there is a much larger spread out of the plume in neutral or unstable conditions. A reasonable agreement with the values predicted by the calculation code is found for the maximum concentration

  3. Near-field krypton-85 measurements in stable meteorological conditions around the AREVA NC La Hague reprocessing plant: estimation of atmospheric transfer coefficients.

    Science.gov (United States)

    Connan, O; Solier, L; Hébert, D; Maro, D; Lamotte, M; Voiseux, C; Laguionie, P; Cazimajou, O; Le Cavelier, S; Godinot, C; Morillon, M; Thomas, L; Percot, S

    2014-11-01

    The aim of this work was to study the near-field dispersion of (85)Kr around the nuclear fuel reprocessing plant at La Hague (AREVA NC La Hague - France) under stable meteorological conditions. Twenty-two (85)Kr night-time experimental campaigns were carried out at distances of up to 4 km from the release source. Although the operational Gaussian models predict for these meteorological conditions a distance to plume touchdown of several kilometers, we almost systematically observed a marked ground signal at distances of 0.5-4 km. The calculated atmospheric transfer coefficients (ATC) show values (1) higher than those observed under neutral conditions, (2) much higher than those proposed by the operational models, and (3) higher than those used in the impact assessments. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Long term corrosion of iron in concrete and in atmospheric conditions: a contribution of archaeological analogues to mechanism comprehension

    International Nuclear Information System (INIS)

    Burger, E.; Demoulin, A.; Dillman, Ph.; Neff, D.; Berge, P.; Burger, E.; Perrin, St.; L'hostis, V.; Dillman, Ph.; Millard, A.

    2009-01-01

    Full text of publication follows: The prediction of iron (or low alloy steel) corrosion on very long term period is necessary in two different purposes: (i) the preservation and conservation of cultural heritage and (ii) the French storage and repository concept for the radioactive wastes. In order to determine the evolution of corrosion processes for very long period, mechanistic models have been developed. In these models that are based on a phenomenological approach to evaluate the average corrosion rates, two different environments are considered: concrete (steel reinforcements) and atmospheric. The study of archaeological analogues is a very pertinent tool for the validation of these models. First, physico-chemical analysis on old corrosion layers lead to a precise localisation and identification of the phases present in the corrosion system. Moreover, experimental reinduced corrosions of ancient samples under controlled parameters (temperature, relative humidity) bring new insight on the mechanisms involved. In particular, one crucial question related to the wet-dry cycle is the localisation of oxygen reduction sites in the rust layer. For this purpose, specific experiments have been set up to re-corrode the ancient samples in marked medium (using 18 O 2 ). Samples were exposed to cycling between high and low relative humidity, produced by saline saturated solutions. Then cross-sections of samples obtained were investigated by nuclear reaction analysis (NRA) 18 O(p,α) 15 N on the Pierre Sue Laboratory nuclear microprobe. In this presentation the 18 O distribution profiles are discussed and interpreted in order to bring new insight on corrosion mechanisms. A comparative interpretation is made for each medium (concrete and atmosphere)

  5. Understanding Natural Gas Methane Leakage from Buried Pipelines as Affected by Soil and Atmospheric Conditions - Field Scale Experimental and Modeling Study

    Science.gov (United States)

    Smits, K. M.; Mitton, M.; Moradi, A.; Chamindu, D. K.

    2017-12-01

    Reducing the amount of leaked natural gas (NG) from pipelines from production to use has become a high priority in efforts to cut anthropogenic emissions of methane. In addition to environmental impacts, NG leakage can cause significant economic losses and safety failures such as fires and explosions. However, tracking and evaluating NG pipeline leaks requires a better understanding of the leak from the source to the detector as well as more robust quantification methods. Although recent measurement-based approaches continue to make progress towards this end, efforts are hampered due to the complexity of leakage scenarios. Sub- surface transport of leaked NG from pipelines occurs through complex transport pathways due to soil heterogeneities and changes in soil moisture. Furthermore, it is affected by variable atmospheric conditions such as winds, frontal passages and rain. To better understand fugitive emissions from NG pipelines, we developed a field scale testbed that simulates low pressure gas leaks from pipe buried in soil. The system is equipped with subsurface and surface sensors to continuously monitor changes in soil and atmospheric conditions (e.g. moisture, pressure, temperature) and methane concentrations. Using this testbed, we are currently conducting a series of gas leakage experiments to study of the impact of subsurface (e.g. soil moisture, heterogeneity) and atmospheric conditions (near-surface wind and temperature) on the detected gas signals and establish the relative importance of the many pathways for methane migration between the source and the sensor location. Accompanying numerical modeling of the system using the multiphase transport simulator TOUGH2-EOS7CA demonstrates the influence of leak location and direction on gas migration. These findings will better inform leak detectors of the leak severity before excavation, aiding with safety precautions and work order categorization for improved efficiency.

  6. Survival of lactic acid and chlorine dioxide treated Campylobacter jejuni under suboptimal conditions of pH, temperature and modified atmosphere

    DEFF Research Database (Denmark)

    Smigic, Nada; Rajkovic, Andreja; Nielsen, Dennis Sandris

    2010-01-01

    As mild decontamination treatments are gaining more and more interest due to increased consumer demands for fresh foods, it is of great importance to establish the influence of decontamination treatments on the subsequent bacterial behaviour under suboptimal storage conditions. For this purpose...... Campylobacter jejuni cells treated with lactic acid (LA, 3% lactic acid, pH 4.0, 2 min) or chlorine dioxide (ClO(2), 20 ppm, 2 min) were inoculated in Bolton broth (pH 6.0) and incubated under 80% O(2)/20% N(2), 80% CO(2)/20% N(2), air or micro-aerophilic (10% CO(2)/85% N(2)/5% O(2)) atmosphere, at 4 degrees C...... on their pH(i) values. The pH(i) response was independent on the surrounding atmosphere since similar distribution of the subpopulations was observed for all tested atmospheres. However, the pH(i) response was dependent on the initial decontamination treatment. The investigation of intracellular parameters...

  7. Transmitter Spatial Diversity for FSO Uplink in Presence of Atmospheric Turbulence and Weather Conditions for Different IM Schemes

    Science.gov (United States)

    Viswanath, Anjitha; Kumar Jain, Virander; Kar, Subrat

    2017-12-01

    We investigate the error performance of an earth-to-satellite free space optical uplink using transmitter spatial diversity in presence of turbulence and weather conditions, using gamma-gamma distribution and Beer-Lambert law, respectively, for on-off keying (OOK), M-ary pulse position modulation (M-PPM) and M-ary differential PPM (M-DPPM) schemes. Weather conditions such as moderate, light and thin fog cause additional degradation, while dense or thick fog and clouds may lead to link failure. The bit error rate reduces with increase in the number of transmitters for all the schemes. However, beyond a certain number of transmitters, the reduction becomes marginal. Diversity gain remains almost constant for various weather conditions but increases with increase in ground-level turbulence or zenith angle. Further, the number of transmitters required to improve the performance to a desired level is less for M-PPM scheme than M-DPPM and OOK schemes.

  8. Prevailing public perceptions of the ethics of gene therapy.

    Science.gov (United States)

    Robillard, Julie M; Roskams-Edris, Dylan; Kuzeljevic, Boris; Illes, Judy

    2014-08-01

    Gene therapy research is advancing rapidly, and hopes of treating a large number of brain disorders exist alongside ethical concerns. Most surveys of public attitudes toward these ethical issues are already dated and the content of these surveys has been researcher-driven. To examine current public perceptions, we developed an online instrument that is responsive and relevant to the latest research about ethics, gene therapy, and the brain. The 16-question survey was launched with the platform Amazon Mechanical Turk and was made available to residents of Canada and the United States. The survey was divided into six themes: (1) demographic information, (2) general opinions about gene therapy, (3) medical applications of gene therapy, (4) identity and moral/belief systems, (5) enhancement, and (6) risks. We received and analyzed responses from a total of 467 participants. Our results show that a majority of respondents (>90%) accept gene therapy as a treatment for severe illnesses such as Alzheimer disease, but this receptivity decreases for conditions perceived as less severe such as attention deficit hyperactivity disorder (79%), and for nontherapeutic applications (47%). The greatest area of concern for the application of gene therapy to brain conditions is the fear of not receiving sufficient information before undergoing the treatment. The main ethical concerns with enhancement were the potential for disparities in resource allocation, access to the procedure, and discrimination. When comparing these data with those from the 1990s, our findings suggest that the acceptability of gene therapy is increasing and that this trend is occurring despite lingering concerns over ethical issues. Providing the public and patients with up-to-date information and opportunities to engage in the discourse about areas of research in gene therapy is a priority.

  9. Sea-ice, clouds and atmospheric conditions in the arctic and their interactions as derived from a merged C3M data product

    Science.gov (United States)

    Nag, Bappaditya

    The polar regions of the world constitute an important sector in the global energy balance. Among other effects responsible for the change in the sea-ice cover like ocean circulation and ice-albedo feedback, the cloud-radiation feedback also plays a vital role in modulation of the Arctic environment. However the annual cycle of the clouds is very poorly represented in current global circulation models. This study aimed to explore the atmospheric conditions in the Arctic on an unprecedented spatial coverage spanning 70°N to 80°N through the use of a merged data product, C3MData (derived from NASA's A-Train Series). The following three topics provide outline on how this dataset can be used to accomplish a detailed analysis of the Arctic environment and provide the modelling community with first information to update their models aimed at better forecasts. (1)The three properties of the Arctic climate system to be studied using the C3MData are sea-ice, clouds, and the atmospheric conditions. The first topic is to document the present states of the three properties and also their time evolutions or their seasonal cycles. (2)The second topic is aimed at the interactions or the feedbacks processes among the three properties. For example, the immediate alteration in the fluxes and the feedbacks arising from the change in the sea-ice cover is investigated. Seasonal and regional variations are also studied. (3)The third topics is aimed at the processes in native spatial resolution that drive or accompany with sea ice melting and sea ice growth. Using a composite approach based on a classification due to surface type, it is found that limitation of the water vapour influx from the surface due to change in phase at the surface featuring open oceans or marginal sea-ice cover to complete sea-ice cover is a major determinant in the modulation of the atmospheric moisture. The impact of the cloud-radiative effects in the Arctic is found to vary with sea-ice cover and seasonally

  10. Projected changes in prevailing winds for transatlantic migratory birds under global warming.

    Science.gov (United States)

    La Sorte, Frank A; Fink, Daniel

    2017-03-01

    A number of terrestrial bird species that breed in North America cross the Atlantic Ocean during autumn migration when travelling to their non-breeding grounds in the Caribbean or South America. When conducting oceanic crossings, migratory birds tend to associate with mild or supportive winds, whose speed and direction may change under global warming. The implications of these changes for transoceanic migratory bird populations have not been addressed. We used occurrence information from eBird (1950-2015) to estimate the geographical location of population centres at a daily temporal resolution across the annual cycle for 10 transatlantic migratory bird species. We used this information to estimate the location and timing of autumn migration within the transatlantic flyway. We estimated how prevailing winds are projected to change within the transatlantic flyway during this time using daily wind speed anomalies (1996-2005 and 2091-2100) from 29 Atmosphere-Ocean General Circulation Models implemented under CMIP5. Autumn transatlantic migrants have the potential to encounter strong westerly crosswinds early in their transatlantic journey at intermediate and especially high migration altitudes, strong headwinds at low and intermediate migration altitudes within the Caribbean that increase in strength as the season progresses, and weak tailwinds at intermediate and high migration altitudes east of the Caribbean. The CMIP5 simulations suggest that, during this century, the likelihood of autumn transatlantic migrants encountering strong westerly crosswinds will diminish. As global warming progresses, the need for species to compensate or drift under the influence of strong westerly crosswinds during the initial phase of their autumn transatlantic journey may be diminished. Existing strategies that promote headwind avoidance and tailwind assistance will likely remain valid. Thus, climate change may reduce time and energy requirements and the chance of mortality or

  11. Effect of irradiation and modified atmosphere packaging on the microbiological safety of minced pork stored under temperature abuse conditions

    International Nuclear Information System (INIS)

    Grant, I.R.; Patterson, M.F.

    1991-01-01

    The safety of irradiated pork packed in 25% CO 2 :75% N 2 and stored at abuse temperature (10 or 15°C) was assessed by inoculation studies involving Salmonella typhimurium, Listeria monocytogenes, Escherichia coli, Yersinia enterocolitica and Clostridium perfringens. Irradiation to a dose of 1.75 kGy reduced pathogen numbers to below the detection limit of 10 2 cells g -1 . When higher inoculum levels were used (10 6 cells g -1 ) irradiation at 1.75 kGy reduced pathogen numbers by 1 –>5 log 10 cycles depending on strain. Clostridium perfringens was the most resistant, and Y. enterocolitica the most sensitive of the pathogens studied. In all cases when high numbers (10 6 to 10 7 g -1 ) of spoilage and/or pathogenic bacteria were present initially on the pork the meat appeared spoiled, and although irradiation reduced the number of microorganisms, the meat was still unacceptable from a sensory viewpoint after treatment. It was concluded that the microbiological safety of irradiated, modified atmosphere packaged (MAP) pork is better than that of unirradiated MAP pork

  12. Novel N4 Bacteriophages Prevail in the Cold Biosphere.

    Science.gov (United States)

    Zhan, Yuanchao; Buchan, Alison; Chen, Feng

    2015-08-01

    Coliphage N4 is a lytic bacteriophage discovered nearly half a century ago, and it was considered to be a "genetic orphan" until very recently, when several additional N4-like phages were discovered to infect nonenteric bacterial hosts. Interest in this genus of phages is stimulated by their unique genetic features and propagation strategies. To better understand the ecology of N4-like phages, we investigated the diversity and geographic patterns of N4-like phages by examining 56 Chesapeake Bay viral communities, using a PCR-clone library approach targeting a diagnostic N4-like DNA polymerase gene. Many new lineages of N4-like phages were found in the bay, and their genotypes shift from the lower to the upper bay. Interestingly, signature sequences of N4-like phages were recovered only from winter month samples, when water temperatures were below 4°C. An analysis of existing metagenomic libraries from various aquatic environments supports the hypothesis that N4-like phages are most prolific in colder waters. In particular, a high number of N4-like phages were detected in Organic Lake, Antarctica, a cold and hypersaline system. The prevalence of N4-like phages in the cold biosphere suggests these viruses possess yet-to-be-determined mechanisms that facilitate lytic infections under cold conditions. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  13. Variation of crack intensity factor in three compacted clay liners exposed to annual cycle of atmospheric conditions with and without geotextile cover.

    Science.gov (United States)

    Safari, E; Jalili Ghazizade, M; Abduli, M A; Gatmiri, B

    2014-08-01

    Performance of compacted clay liners commonly used as landfill barrier systems can be subject to decline in terms of hydraulic conductivity if left exposed to atmospheric conditions for an extended period of time prior to placement of overlaying layers. The resulting desiccation cracking can lead to increased hydraulic conductivity. Desiccation crack intensity was studied for three clayey soils commonly used for construction of landfill barrier system in a relatively large scale test setup exposed to real time atmospheric conditions over a complete annual cycle. A white separator geotextile cover was presumed to be capable of reducing the intensity of desiccation cracking through absorbing and maintaining higher amounts of moisture and reducing the temperature of the soil surface in comparison to a directly exposed soil surface. Desiccation cracking was monitored using a digital imaging technique for three compacted clay liners in two sets, one open to air and the second covered with the white geotextile. Crack intensity factor approached a relatively stable phase after certain cycles corresponding to atmospheric dry wet cycles. The results indicated that the white separator geotextile was capable of reducing the crack intensity factor by 37.4-45.9% throughout the experiment including the cyclic phase of desiccation cracking. During the stable phase, the maximum reduction in crack intensity factor of 90.4% as a result of applying geotextile cover was observed for the soil with the lowest plastic index and clay content and therefore the lowest magnitude of crack intensity factor. The other two soils with similar clay content but different plastic index showed 23.6% and 52.2% reductions in crack intensity factor after cyclic phase when covered with geotextile. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Extraction of compositional and hydration information of sulfates from laser-induced plasma spectra recorded under Mars atmospheric conditions - Implications for ChemCam investigations on Curiosity rover

    Energy Technology Data Exchange (ETDEWEB)

    Sobron, Pablo, E-mail: pablo.sobron@asc-csa.gc.ca [Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130 (United States); Wang, Alian [Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130 (United States); Sobron, Francisco [Unidad Asociada UVa-CSIC a traves del Centro de Astrobiologia, Parque Tecnologico de Boecillo, Parcela 203, Boecillo (Valladolid), 47151 (Spain)

    2012-02-15

    Given the volume of spectral data required for providing accurate compositional information and thereby insight in mineralogy and petrology from laser-induced breakdown spectroscopy (LIBS) measurements, fast data processing tools are a must. This is particularly true during the tactical operations of rover-based planetary exploration missions such as the Mars Science Laboratory rover, Curiosity, which will carry a remote LIBS spectrometer in its science payload. We have developed: an automated fast pre-processing sequence of algorithms for converting a series of LIBS spectra (typically 125) recorded from a single target into a reliable SNR-enhanced spectrum; a dedicated routine to quantify its spectral features; and a set of calibration curves using standard hydrous and multi-cation sulfates. These calibration curves allow deriving the elemental compositions and the degrees of hydration of various hydrous sulfates, one of the two major types of secondary minerals found on Mars. Our quantitative tools are built upon calibration-curve modeling, through the correlation of the elemental concentrations and the peak areas of the atomic emission lines observed in the LIBS spectra of standard samples. At present, we can derive the elemental concentrations of K, Na, Ca, Mg, Fe, Al, S, O, and H in sulfates, as well as the hydration degrees of Ca- and Mg-sulfates, from LIBS spectra obtained in both Earth atmosphere and Mars atmospheric conditions in a Planetary Environment and Analysis Chamber (PEACh). In addition, structural information can be potentially obtained for various Fe-sulfates. - Highlights: Black-Right-Pointing-Pointer Routines for LIBS spectral data fast automated processing. Black-Right-Pointing-Pointer Identification of elements and determination of the elemental composition. Black-Right-Pointing-Pointer Calibration curves for sulfate samples in Earth and Mars atmospheric conditions. Black-Right-Pointing-Pointer Fe curves probably related to the crystalline

  15. Analysis and experimental study on formation conditions of large-scale barrier-free diffuse atmospheric pressure air plasmas in repetitive pulse mode

    Science.gov (United States)

    Li, Lee; Liu, Lun; Liu, Yun-Long; Bin, Yu; Ge, Ya-Feng; Lin, Fo-Chang

    2014-01-01

    Atmospheric air diffuse plasmas have enormous application potential in various fields of science and technology. Without dielectric barrier, generating large-scale air diffuse plasmas is always a challenging issue. This paper discusses and analyses the formation mechanism of cold homogenous plasma. It is proposed that generating stable diffuse atmospheric plasmas in open air should meet the three conditions: high transient power with low average power, excitation in low average E-field with locally high E-field region, and multiple overlapping electron avalanches. Accordingly, an experimental configuration of generating large-scale barrier-free diffuse air plasmas is designed. Based on runaway electron theory, a low duty-ratio, high voltage repetitive nanosecond pulse generator is chosen as a discharge excitation source. Using the wire-electrodes with small curvature radius, the gaps with highly non-uniform E-field are structured. Experimental results show that the volume-scaleable, barrier-free, homogeneous air non-thermal plasmas have been obtained between the gap spacing with the copper-wire electrodes. The area of air cold plasmas has been up to hundreds of square centimeters. The proposed formation conditions of large-scale barrier-free diffuse air plasmas are proved to be reasonable and feasible.

  16. Measurement of pool boiling CHF for SUS 304 and SA 508 flat plate under downward-facing and atmospheric conditions

    International Nuclear Information System (INIS)

    Kam, Dong Hoon; Park, Hae Min; Choi, Young Jae; Jeong, Yong Hoon

    2015-01-01

    Heat transfer performance of downward-facing conditions are important especially in severe accident mitigation strategy (IVR-ERVC and Core-catcher). Heat transfer limit, in other word, critical heat flux (CHF) is important value in this basis to guarantee the integrity of the system. For the application point of view in nuclear power plant, carbon steel surface should also be considered since reactor pressure vessel (RPV) in IVR-ERVC strategy consists of carbon steel, and core-catcher in EU-APR1400 is also composed of carbon steel. In this perspective, carbon steel surface was used in previous studies. In this study, CHF of both stainless steel and carbon steel material were measured under pool boiling condition with various inclination angles and dimensions. There was a width effect as angle increases, but it disappeared as approached to horizontally downward condition. Besides, there was almost no length effect for both of the width since the size of coalesced bubble was far smaller than the length of short test section (100 mm). SA 508 showed enhanced results at high angles for 40 mm-width case even though no oxidation occurred on the surface during the experiments

  17. Measurement of pool boiling CHF for SUS 304 and SA 508 flat plate under downward-facing and atmospheric conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kam, Dong Hoon; Park, Hae Min; Choi, Young Jae; Jeong, Yong Hoon [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    Heat transfer performance of downward-facing conditions are important especially in severe accident mitigation strategy (IVR-ERVC and Core-catcher). Heat transfer limit, in other word, critical heat flux (CHF) is important value in this basis to guarantee the integrity of the system. For the application point of view in nuclear power plant, carbon steel surface should also be considered since reactor pressure vessel (RPV) in IVR-ERVC strategy consists of carbon steel, and core-catcher in EU-APR1400 is also composed of carbon steel. In this perspective, carbon steel surface was used in previous studies. In this study, CHF of both stainless steel and carbon steel material were measured under pool boiling condition with various inclination angles and dimensions. There was a width effect as angle increases, but it disappeared as approached to horizontally downward condition. Besides, there was almost no length effect for both of the width since the size of coalesced bubble was far smaller than the length of short test section (100 mm). SA 508 showed enhanced results at high angles for 40 mm-width case even though no oxidation occurred on the surface during the experiments.

  18. High transpiration efficiency increases pod yield under intermittent drought in dry and hot atmospheric conditions but less so under wetter and cooler conditions in groundnut (Arachis hypogaea (L.)).

    Science.gov (United States)

    Vadez, Vincent; Ratnakumar, Pasala

    2016-07-01

    Water limitation is a major yield limiting factor in groundnut and transpiration efficiency (TE) is considered the main target for improvement, but TE being difficult to measure it has mostly been screened with surrogates. The paper re-explore the contribution of TE to grain yield in peanut by using a novel experimental approach in which TE is measured gravimetrically throughout the crop life cycle, in addition to measurement of TE surrogates. Experimentation was carried out with the groundnut reference collection (n = 288), across seasons varying for the evaporative demand (vapor pressure deficit, VPD) and across both fully irrigated and intermittent water stress conditions. There was large genotypic variation for TE under water stress in both low and high VPD season but the range was larger (5-fold) in the high- than in the low-VPD season (2-fold). Under water stress in both seasons, yield was closely related to the harvest index (HI) while TE related directly to yield only in the high VPD season. After discounting the direct HI effect on yield, TE explained a large portion of the remaining yield variations in both seasons, although marginally in the low VPD season. By contrast, the total water extracted from the soil profile, which varied between genotypes, did not relate directly to pod yield and neither to the yield residuals unexplained by HI. Surrogates for TE (specific leaf area, SLA, and SPAD chlorophyll meter readings, SCMR) never showed any significant correlation to TE measurements. Therefore, TE is an important factor explaining yield differences in groundnut under high VPD environments, suggesting that stomatal regulation under high VPD, rather than high photosynthetic rate as proposed earlier, may have a key role to play in the large TE differences found, which open new opportunities to breed improved groundnut for high VPD.

  19. Site-Specific Atmospheric Dispersion Characteristics of Korean Nuclear Power Plant Sites

    International Nuclear Information System (INIS)

    Han, M. H.; Kim, E. H.; Suh, K. S.; Hwang, W. T.; Choi, Y. G.

    2001-01-01

    Site-specific atmospheric dispersion characteristics have been analyzed. The northwest and the southwest wind prevail on nuclear sites of Korea. The annual isobaric surface averaged for twenty years around Korean peninsula shows that west wind prevails. The prevailing west wind is profitable in the viewpoint of radiation protection because three of four nuclear sites are located in the east side. Large scale field tracer experiments over nuclear sites have been conducted for the purpose of analyzing the atmospheric dispersion characteristics and validating a real-time atmospheric dispersion and dose assessment system FADAS. To analyze the site-specific atmospheric dispersion characteristics is essential for making effective countermeasures against a nuclear emergency

  20. Modeling char conversion under suspension fired conditions in O2/N2 and O2/CO2 atmospheres

    DEFF Research Database (Denmark)

    Brix, Jacob; Jensen, Peter Arendt; Jensen, Anker Degn

    2011-01-01

    The aim of this investigation has been to model combustion under suspension fired conditions in O2/N2 and O2/CO2 mixtures. Experiments used for model validation have been carried out in an electrically heated Entrained Flow Reactor (EFR) at temperatures between 1173 K and 1673 K with inlet O2...... concentrations between 5 and 28 vol.%. The COal COmbustion MOdel, COCOMO, includes the three char morphologies: cenospheric char, network char and dense char each divided between six discrete particle sizes. Both combustion and gasification with CO2 are accounted for and reaction rates include thermal char...

  1. Action of a clay suspension on an Fe(0) surface under anoxic conditions: Characterization of neoformed minerals at the Fe(0)/solution and Fe(0)/atmosphere interfaces

    International Nuclear Information System (INIS)

    Le Pape, Pierre; Rivard, Camille; Pelletier, Manuel; Bihannic, Isabelle; Gley, Renaud; Mathieu, Sandrine; Salsi, Lise; Migot, Sylvie; Barres, Odile; Villiéras, Frédéric; Michau, Nicolas

    2015-01-01

    Highlights: • Immersion of an Fe(0) foil in a clay suspension at 90 °C and in anoxic conditions. • Magnetite was observed on the atmospheric part. • Iron-rich 7 Å serpentines were observed on the clay suspension part. • A gradient in serpentine cristallochemistry was observed. • A pure Fe–Si phyllosilicate was identified at the Fe(0)/clay suspension contact. - Abstract: To better understand the reaction mechanisms involved at the Fe(0)/clay minerals interface, we investigate in the present study the reaction between an Fe(0) surface and a clay suspension extracted from the Callovo-Oxfordian claystone (COx). Batch experiments were carried out under anoxic conditions in sealed autoclave, at 90 °C to mimic predicted radioactive waste disposal conditions. An Fe(0) foil was introduced into the autoclave so that the lower part of the foil was immersed in the clay suspension while the upper part was contacted with the atmosphere of the experimental setup. After two months, the mineralogical deposits that precipitated at the surface of the Fe(0) foil were analyzed using multiple techniques, namely X-ray diffraction (XRD), scanning/transmission electron microscopy associated to microanalysis (SEM/TEM–EDXS), and micro-spectroscopic measurements (μ-FTIR and μ-Raman). Both parts of the Fe(0) foil were then shown to react: magnetite was the main resulting mineral formed at the Fe(0) surface in the atmospheric conditions whereas serpentine 1:1 phyllosilicates were the main end-products in the clay suspension. The analyses performed on the immersed part of the foil revealed a spatial heterogeneity in both serpentine cristallochemistry and morphology, with a gradient from the Fe(0) contact point toward the clay suspension. A pure Fe–Si phyllosilicate ring was observed at the direct contact point with the Fe(0) foil and a progressive incorporation of Al instead of Fe into the clay phases was identified as deposit thickness increased from the Fe(0) surface to

  2. Atmospheric Photochemistry

    Science.gov (United States)

    Massey, Harrie; Potter, A. E.

    1961-01-01

    The upper atmosphere offers a vast photochemical laboratory free from solid surfaces, so all reactions take place in the gaseous phase. At 30 km altitude the pressure has fallen to about one-hundredth of that at ground level, and we shall, rather arbitrarily, regard the upper atmosphere as beginning at that height. By a little less than 100 km the pressure has fallen to 10(exp -3) mm Hg and is decreasing by a power of ten for every 15 km increase in altitude. Essentially we are concerned then with the photochemistry of a nitrogen-oxygen mixture under low-pressure conditions in which photo-ionization, as well as photodissociation, plays an important part. Account must also be taken of the presence of rare constituents, such as water vapour and its decomposition products, including particularly hydroxyl, oxides of carbon, methane and, strangely enough, sodium, lithium and calcium. Many curious and unfamiliar reactions occur in the upper atmosphere. Some of them are luminescent, causing the atmosphere to emit a dim light called the airglow. Others, between gaseous ions and neutral molecules, are almost a complete mystery at this time. Similar interesting phenomena must occur in other planetary atmospheres, and they might be predicted if sufficient chemical information were available.

  3. Analysis of changes in tornadogenesis conditions over Northern Eurasia based on a simple index of atmospheric convective instability

    Science.gov (United States)

    Chernokulsky, A. V.; Kurgansky, M. V.; Mokhov, I. I.

    2017-12-01

    A simple index of convective instability (3D-index) is used for analysis of weather and climate processes that favor to the occurrence of severe convective events including tornadoes. The index is based on information on the surface air temperature and humidity. The prognostic ability of the index to reproduce severe convective events (thunderstorms, showers, tornadoes) is analyzed. It is shown that most tornadoes in North Eurasia are characterized by high values of the 3D-index; furthermore, the 3D-index is significantly correlated with the available convective potential energy. Reanalysis data (for recent decades) and global climate model simulations (for the 21st century) show an increase in the frequency of occurrence of favorable for tornado formation meteorological conditions in the regions of Northern Eurasia. The most significant increase is found on the Black Sea coast and in the south of the Far East.

  4. Surface-rain interactions: differences in copper runoff for copper sheet of different inclination, orientation, and atmospheric exposure conditions.

    Science.gov (United States)

    Hedberg, Yolanda S; Goidanich, Sara; Herting, Gunilla; Wallinder, Inger Odnevall

    2015-01-01

    Predictions of the diffuse dispersion of metals from outdoor constructions such as roofs and facades are necessary for environmental risk assessment and management. An existing predictive model has been compared with measured data of copper runoff from copper sheets exposed at four different inclinations facing four orientations at two different urban sites (Stockholm, Sweden, and Milan, Italy) during a 4-year period. Its applicability has also been investigated for copper sheet exposed at two marine sites(Cadiz, Spain, for 5 years, and Brest, France, for 9 years). Generally the model can be used for all given conditions. However, vertical surfaces should be considered as surfaces inclined 60-80 due to wind driven effects. The most important parameters that influence copper runoff, and not already included in the model, are the wind and rain characteristics that influence the actual rainfall volume impinging the surface of interest.

  5. Effect of irradiation, active and modified atmosphere packaging, container oxygen barrier and storage conditions on the physicochemical and sensory properties of raw unpeeled almond kernels (Prunus dulcis).

    Science.gov (United States)

    Mexis, Stamatios F; Riganakos, Kyriakos A; Kontominas, Michael G

    2011-03-15

    The present study investigated the effect of irradiation, active and modified atmosphere packaging, and storage conditions on quality retention of raw, whole, unpeeled almonds. Almond kernels were packaged in barrier and high-barrier pouches, under N(2) or with an O(2) absorber and stored either under fluorescent lighting or in the dark at 20 °C for 12 months. Quality parameters monitored were peroxide value, hexanal content, colour, fatty acid composition and volatile compounds. Of the sensory attributes colour, texture, odour and taste were evaluated. Peroxide value and hexanal increased with dose of irradiation and storage time. Irradiation resulted in a decrease of polyunsaturated and monounsaturated fatty acids during storage with a parallel increase of saturated fatty acids. Volatile compounds were not affected by irradiation but increased with storage time indicating enhanced lipid oxidation. Colour parameters of samples remained unaffected immediately after irradiation. For samples packaged under a N(2) , atmosphere L and b values decreased during storage with a parallel increase of value a resulting to gradual product darkening especially in irradiated samples. Non-irradiated almonds retained acceptable quality for ca. 12 months stored at 20 °C with the O(2) absorber irrespective of lighting conditions and packaging material oxygen barrier. The respective shelf life for samples irradiated at 1.0 kGy was 12 months packaged in PET-SiOx//LDPE irrespective of lighting conditions and 12 months for samples irradiated at 3 kGy packaged in PET-SiOx//LDPE stored in the dark. Copyright © 2010 Society of Chemical Industry.

  6. Influence and importance of daily weather conditions in the supply of chloride, sulfate, and other ions to fresh waters from atmospheric precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Gorham, E

    1958-01-01

    From the data presented here it seems clear that local weather conditions play a very large part in determining the atmospheric supply of ions to natural waters in the lake district. It is likewise evident that atmospheric precipitation is of the utmost importance as a source of many of the major dissolved ions, especially to bogs, to upland tarns on hard volcanic rocks, and to heavily leached soils and more humus layers. The dissolved ions in rain must therefore have considerable ecological significance, though little is known of this at present. On the one hand, appreciable amounts of plant nutrients, for example nitrogen, potassium, calcium, and sulphur (and perhaps certain heavy metals), are supplied to habitats deficient in these elements; but on the other hand sulphuric acid, and probably also some of the organic compounds in smoke, may be toxic to many plants. In addition, the large amounts of sulphuric acid provided by pollution of the atmosphere will presumably hasten deterioration of the already heavily leached lake district soils. Whether the effects of the industrial age upon air chemistry have as yet seriously influenced the ecology of the lake district is difficult to say, but such influence might best be sought in the high tarns, since they are the most dependent upon rain for nutrients, and other factors such as local sewage pollution, agriculture, forestry operations, etc., could be discounted. Bog and moorland peat profiles might also repay investigation. But while there are regretably few undisturbed peat deposits in the lake district nowadays, there are fortunately a great many tarns in the central hills where mud cores might easily be taken with the aid of light instruments developed in recent years, and it is hoped that these matters will receive some attention in the future.

  7. Conditions for the formation and atmospheric dispersion of a toxic, heavy gas layer during thermal metamorphism of coal and evaporite deposits by sill intrusion

    Science.gov (United States)

    Storey, Michael; Hankin, Robin K. S.

    2010-05-01

    There is compelling evidence for massive discharge of volatiles, including toxic species, into the atmosphere at the end of the Permian. It has been argued that most of the gases were produced during thermal metamorphism of coal and evaporite deposits in the East Siberia Tunguska basin following sill intrusion (Retallack and Jahren, 2008; Svensen et al., 2009). The release of the volatiles has been proposed as a major cause of environmental and extinction events at the end of the Permian, with venting of carbon gases and halocarbons to the atmosphere leading to global warming and atmospheric ozone depletion (Svensen et al., 2009) Here we consider the conditions required for the formation and dispersion of toxic, heavier than air, gas plumes, made up of a mixture of CO2, CH4, H2S and SO2 and formed during the thermal metamorphism of C- and S- rich sediments. Dispersion models and density considerations within a range of CO2/CH4 ratios and volatile fluxes and temperatures, for gas discharge by both seepage and from vents, allow the possibility that following sill emplacement much of the vast East Siberia Tunguska basin was - at least intermittently - covered by a heavy, toxic gas layer that was unfavorable for life. Dispersion scenarios for a heavy gas layer beyond the Siberian region during end-Permian times will be presented. REFERENCES G. J. Retallack and A. H. Jahren, Methane release from igneous intrusion of coal during Late Permian extinction events, Journal of Geology, volume 116, 1-20, 2008 H. Svensen et al., Siberian gas venting and the end-Permian environmental crisis, Earth and Planetary Science Letters, volume 277, 490-500, 2009

  8. Heavy Rainfall Episodes in the Eastern Northeast Brazil Linked to Large-Scale Ocean-Atmosphere Conditions in the Tropical Atlantic

    Directory of Open Access Journals (Sweden)

    Yves K. Kouadio

    2012-01-01

    Full Text Available Relationships between simultaneous occurrences of distinctive atmospheric easterly wave (EW signatures that cross the south-equatorial Atlantic, intense mesoscale convective systems (lifespan > 2 hour that propagate westward over the western south-equatorial Atlantic, and subsequent strong rainfall episodes (anomaly > 10 mm·day−1 that occur in eastern Northeast Brazil (ENEB are investigated. Using a simple diagnostic analysis, twelve cases with EW lifespan ranging between 3 and 8 days and a mean velocity of 8 m·s−1 were selected and documented during each rainy season of 2004, 2005, and 2006. These cases, which represent 50% of the total number of strong rainfall episodes and 60% of the rainfall amount over the ENEB, were concomitant with an acceleration of the trade winds over the south-equatorial Atlantic, an excess of moisture transported westward from Africa to America, and a strengthening of the convective activity in the oceanic region close to Brazil. Most of these episodes occurred during positive sea surface temperature anomaly patterns over the entire south-equatorial Atlantic and low-frequency warm conditions within the oceanic mixing layer. A real-time monitoring and the simulation of this ocean-atmosphere relationship could help in forecasting such dramatic rainfall events.

  9. 76 FR 70365 - Prevailing Rate Systems; Redefinition of the Austin, TX and Waco, TX, Appropriated Fund Federal...

    Science.gov (United States)

    2011-11-14

    ... 3206-AM50 Prevailing Rate Systems; Redefinition of the Austin, TX and Waco, TX, Appropriated Fund... the Federal Prevailing Rate Advisory Committee to best match the counties proposed for redefinition to... Prevailing Rate Advisory Committee (FPRAC), the national labor-management committee responsible for advising...

  10. 77 FR 68073 - Prevailing Rate Systems; Redefinition of the St. Louis, MO; Southern Missouri; Cleveland, OH; and...

    Science.gov (United States)

    2012-11-15

    ... 3206-AM70 Prevailing Rate Systems; Redefinition of the St. Louis, MO; Southern Missouri; Cleveland, OH... Cleveland wage area. These changes are based on recent consensus recommendations of the Federal Prevailing... proposing the changes described below. The Federal Prevailing Rate Advisory Committee (FPRAC), the national...

  11. 75 FR 39460 - Prevailing Rate Systems; Redefinition of the Chicago, IL; Fort Wayne-Marion, IN; Indianapolis, IN...

    Science.gov (United States)

    2010-07-09

    ...-AM21 Prevailing Rate Systems; Redefinition of the Chicago, IL; Fort Wayne-Marion, IN; Indianapolis, IN... wage area. These changes are based on recent consensus recommendations of the Federal Prevailing Rate... below. The Federal Prevailing Rate Advisory Committee (FPRAC), the national labor-management committee...

  12. 76 FR 14679 - Prevailing Wage Rates for Construction Occupations on Guam for Purposes of the H-2B Temporary...

    Science.gov (United States)

    2011-03-17

    ...)(v)(E) and (F). If the prevailing wage rate is too low, available U.S. workers may be dissuaded from... Docket No. USCIS-2010-0006] RIN 1615-ZA98 Prevailing Wage Rates for Construction Occupations on Guam for... the public on the system that the Governor of Guam is using to determine prevailing wage rates for...

  13. A standalone decay heat removal device for the Gas-cooled Fast Reactor for intermediate to atmospheric pressure conditions

    Energy Technology Data Exchange (ETDEWEB)

    Epiney, A., E-mail: aaron@epiney.ch [Paul Scherrer Institute PSI, Villigen (Switzerland); Ecole Polytechnique Federale EPFL, Lausanne (Switzerland); Alpy, N., E-mail: nicolas.alpy@cea.fr [CEA, DEN, Service d' Etudes des Systemes Innovants, F-13108 Saint Paul Lez Durance (France); Mikityuk, K., E-mail: konstantin.mikityuk@psi.ch [Paul Scherrer Institute PSI, Villigen (Switzerland); Chawla, R., E-mail: rakesh.chawla@psi.ch [Paul Scherrer Institute PSI, Villigen (Switzerland); Ecole Polytechnique Federale EPFL, Lausanne (Switzerland)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer An analytical model predicting Brayton cycle off-design steady states, is developed. Black-Right-Pointing-Pointer The model is used to design an autonomous decay heat removal system for the GFR. Black-Right-Pointing-Pointer Predictions of the analytical model are verified using CATHARE. Black-Right-Pointing-Pointer CATHARE code is used to simulate a set of GFR safety depressurization transients using this device. Black-Right-Pointing-Pointer Convenient turbo-machine designs exist for the targeted autonomous decay heat removal for a wide pressure range. - Abstract: This paper reports a design study for a Brayton cycle machine, which would constitute a dedicated, standalone decay heat removal (DHR) device for the Generation IV Gas-cooled Fast Reactor (GFR). In comparison to the DHR reference strategy developed by the French Commissariat a l'Energie Atomique during the GFR pre-conceptual design phase (which was completed at the end of 2007), the salient feature of this alternative device would be to combine the energetic autonomy of the natural convection process - which is foreseen for operation at high and medium pressures - with the efficiency of the forced convection process which is foreseen for operation down to very low pressures. An analytical model, the so-called 'Brayton scoping model', is described first. This is based on simplified thermodynamic and aerodynamic equations, and was developed to highlight design choices. Two different machine designs are analyzed: a Brayton loop turbo-machine working with helium, and a second one working with nitrogen, since nitrogen is the heavy gas foreseen to be injected into the primary system to enhance the natural convection under loss-of-coolant-accident (LOCA) conditions. Simulations of the steady-state and transient behavior of the proposed device have then been carried out using the CATHARE code. These serve to confirm the insights obtained from usage of the

  14. Modeling soil evaporation efficiency in a range of soil and atmospheric conditions using a meta-analysis approach

    Science.gov (United States)

    Merlin, O.; Stefan, V. G.; Amazirh, A.; Chanzy, A.; Ceschia, E.; Er-Raki, S.; Gentine, P.; Tallec, T.; Ezzahar, J.; Bircher, S.; Beringer, J.; Khabba, S.

    2016-05-01

    A meta-analysis data-driven approach is developed to represent the soil evaporative efficiency (SEE) defined as the ratio of actual to potential soil evaporation. The new model is tested across a bare soil database composed of more than 30 sites around the world, a clay fraction range of 0.02-0.56, a sand fraction range of 0.05-0.92, and about 30,000 acquisition times. SEE is modeled using a soil resistance (rss) formulation based on surface soil moisture (θ) and two resistance parameters rss,ref and θefolding. The data-driven approach aims to express both parameters as a function of observable data including meteorological forcing, cut-off soil moisture value θ1/2 at which SEE=0.5, and first derivative of SEE at θ1/2, named Δθ1/2-1. An analytical relationship between >(rss,ref;θefolding) and >(θ1/2;Δθ1/2-1>) is first built by running a soil energy balance model for two extreme conditions with rss = 0 and rss˜∞ using meteorological forcing solely, and by approaching the middle point from the two (wet and dry) reference points. Two different methods are then investigated to estimate the pair >(θ1/2;Δθ1/2-1>) either from the time series of SEE and θ observations for a given site, or using the soil texture information for all sites. The first method is based on an algorithm specifically designed to accomodate for strongly nonlinear SEE>(θ>) relationships and potentially large random deviations of observed SEE from the mean observed SEE>(θ>). The second method parameterizes θ1/2 as a multi-linear regression of clay and sand percentages, and sets Δθ1/2-1 to a constant mean value for all sites. The new model significantly outperformed the evaporation modules of ISBA (Interaction Sol-Biosphère-Atmosphère), H-TESSEL (Hydrology-Tiled ECMWF Scheme for Surface Exchange over Land), and CLM (Community Land Model). It has potential for integration in various land-surface schemes, and real calibration capabilities using combined thermal and microwave

  15. Gaussian Plume Model Parameters for Ground-Level and Elevated Sources Derived from the Atmospheric Diffusion Equation in the Neutral and Stable Conditions

    International Nuclear Information System (INIS)

    Essa, K.S.M.

    2009-01-01

    The analytical solution of the atmospheric diffusion equation for a point source gives the ground-level concentration profiles. It depends on the wind speed ua nd vertical dispersion coefficient σ z expressed by Pasquill power laws. Both σ z and u are functions of downwind distance, stability and source elevation, while for the ground-level emission u is constant. In the neutral and stable conditions, the Gaussian plume model and finite difference numerical methods with wind speed in power law and the vertical dispersion coefficient in exponential law are estimated. This work shows that the estimated ground-level concentrations of the Gaussian model for high-level source and numerical finite difference method are very match fit to the observed ground-level concentrations of the Gaussian model

  16. Role of process conditions on the microstructure, stoichiometry and functional performance of atmospheric plasma sprayed La(Sr)MnO3 coatings

    Science.gov (United States)

    Han, Su Jung; Chen, Yikai; Sampath, Sanjay

    2014-08-01

    Strontium doped lanthanum manganite (LSM) perovskite coatings were produced via atmospheric plasma spray technique to examine their applicability as electrically conductive coatings to protect chromium-poisoning of cathode side metallic interconnects in solid oxide fuel cells. Various plasma spray process conditions were manipulated including plasma power, total gas flow and content of H2 in the plasma gas in order to understand their effects on coating properties as well as efficacy as a protectant against Cr-poisoning. In-flight temperatures and velocities of spray particles were monitored for the various plasma spray conditions enabling assessment of thermal and kinetic energies of LSM particles. As anticipated, coating density improves with increasing thermal and/or kinetic energies of the LSM particles. However, the LSM particles also experienced significant phase decomposition at higher thermal exposure and longer residence time conditions. Due to preferential loss of oxygen and manganese, La2O3 phase is also formed under certain processing regimes. The resultant mixed-phase coating is ineffective both from electrical transport and as a protective coating for the metallic interconnect. Concomitantly, coatings with limited decomposition show excellent conductivity and protection characteristics demonstrating the need for mechanism driven process optimization for these functional oxide coatings.

  17. Response of northern hemisphere environmental and atmospheric conditions to climate changes using Greenland aerosol records from the Eemian to the Holocene

    Science.gov (United States)

    Fischer, H.

    2017-12-01

    The Northern Hemisphere experienced dramatic climate changes over the last glacial cycle, including vast ice sheet expansion and frequent abrupt climate events. Moreover, high northern latitudes during the last interglacial (Eemian) were warmer than today and may provide guidance for future climate change scenarios. However, little evidence exists regarding the environmental alterations connected to these climate changes. Using aerosol concentration records in decadal resolution from the North Greenland Eemian Ice Drilling (NEEM) over the last 128,000 years we extract quantitative information on environmental changes, including the first comparison of northern hemisphere environmental conditions between the warmer than present Eemian and the early Holocene. Separating source changes from transport effects, we find that changes in the ice concentration greatly overestimate the changes in atmospheric concentrations in the aerosol source region, the latter mirroring changes in aerosol emissions. Glacial times were characterized by a strong reduction in terrestrial biogenic emissions (only 10-20% of the early Holocene value) reflecting the net loss of vegetated area in mid to high latitudes, while rapid climate changes during the glacial had essentially no effect on terrestrial biogenic aerosol emissions. An increase in terrestrial dust emissions of approximately a factor of eight during peak glacial and cold stadial intervals indicates higher aridity and dust storm activity in Asian deserts. Glacial sea salt aerosol emissions increased only moderately (by approximately 50%), likely due to sea ice expansion, while marked stadial/interstadial variations in sea salt concentrations in the ice reflect mainly changes in wet deposition en route. Eemian ice contains lower aerosol concentrations than ice from the early Holocene, due to shortened atmospheric residence time during the warmer Eemian, suggesting that generally 2°C warmer climate in high northern latitudes did not

  18. Staging atmospheres

    DEFF Research Database (Denmark)

    Bille, Mikkel; Bjerregaard, Peter; Sørensen, Tim Flohr

    2015-01-01

    The article introduces the special issue on staging atmospheres by surveying the philosophical, political and anthropological literature on atmosphere, and explores the relationship between atmosphere, material culture, subjectivity and affect. Atmosphere seems to occupy one of the classic...

  19. Lichens and atmospheric pollution

    Energy Technology Data Exchange (ETDEWEB)

    Tallis, J H

    1964-09-01

    The extreme sensitivity of lichens, particularly the larger ones, to industrialization has been recognized for many years. Most people attribute the absence of lichens from urban areas to the atmospheric pollution prevailing, and a few attribute it to climatic dryness, resulting from efficient drainage systems in towns. The two main components of air pollution are solid matter, or soot, and gaseous sulfur dioxide. The main effects of pollution appear to be: a direct reduction of light intensity by smoke haze, a deposit of soot on the plant surface, an acidification of the soil, and direct damage to plants. A body of evidence indicates that SO/sub 2/ may be the main harmful component for lichens. The distribution of lichens thus might be used to determine the limits within which atmospheric pollution is operating. 5 references.

  20. Prevailing trends of climatic extremes across Indus-Delta of Sindh-Pakistan

    Science.gov (United States)

    Abbas, Farhat; Rehman, Iqra; Adrees, Muhammad; Ibrahim, Muhammad; Saleem, Farhan; Ali, Shafaqat; Rizwan, Muhammad; Salik, Muhammad Raza

    2018-02-01

    This study examines the variability and change in the patterns of climatic extremes experienced in Indus-Delta of Sindh province of Pakistan, comprising regions of Karachi, Badin, Mohenjodaro, and Rohri. The homogenized daily minimum and maximum temperature and precipitation data for a 36-year period were used to calculate 13 and 11 indices of temperature and precipitation extremes with the help of RClimDex, a program written in the statistical software package R. A non-parametric Mann-Kendall test and Sen's slope estimates were used to determine the statistical significance and magnitude of the calculated trend. Temperatures of summer days and tropical nights increased in the region with overall significant warming trends for monthly maximum temperature as well as for warm days and nights reflecting dry conditions in the study area. The warm extremes and nighttime temperature indices showed greater trends than cold extremes and daytime indices depicting an overall warming trends in the Delta. Historic decrease in the acreage of major crops and over 33% decrease in agriculture credit for Sindh are the indicators of adverse impacts of warmer and drier weather on Sindh agriculture. Trends reported for Karachi and Badin are expected to decrease rice cultivation, hatching of fisheries, and mangroves forest surrounding these cities. Increase in the prevailing temperature trends will lead to increasingly hotter and drier summers resulting to constraints on cotton, wheat, and rice yield in Rohri and Mohenjodaro areas due to increased crop water requirements that may be met with additional groundwater pumping; nonetheless, the depleted groundwater resources would have a direct impact on the region's economy.

  1. Atmospheric Concentrations of Organochlorine Pesticides in the ...

    African Journals Online (AJOL)

    Organochlorine pesticides may still be in use in the Eastern African region for agricultural purposes and for the control of mosquitoes. Atmospheric concentrations of organochlorine pesticides are expected to be higher in the tropics compared to temperate regions due to prevailing high temperatures. However, no study has ...

  2. Kinetics and dynamics of nanosecond streamer discharge in atmospheric-pressure gas bubble suspended in distilled water under saturated vapor pressure conditions

    KAUST Repository

    Sharma, Ashish

    2016-09-08

    We perform computational studies of nanosecond streamer discharges generated in helium bubbles immersed in distilled water under atmospheric pressure conditions. The model takes into account the presence of water vapor in the gas bubble for an accurate description of the discharge kinetics. We find that the dynamic characteristics of the streamer discharge are different at low and high positive trigger voltages with the axial streamer evolution dominant for low voltages and a surface hugging mode favored for high voltages. We also find a substantial difference in initiation, transition and evolution stages of discharge for positive and negative trigger voltages with the volumetric distribution of species in the streamer channel much more uniform for negative trigger voltages on account of the presence of multiple streamers. We observe that the presence of water vapor does not affect the breakdown voltage even for oversaturated conditions but significantly influences the composition of dominant species in the trail of the streamer as well as the flux of the dominant species on the bubble surface. © 2016 IOP Publishing Ltd.

  3. Atmospheric Corrections and Multi-Conditional Algorithm for Multi-Sensor Remote Sensing of Suspended Particulate Matter in Low-to-High Turbidity Levels Coastal Waters

    Directory of Open Access Journals (Sweden)

    Stéfani Novoa

    2017-01-01

    Full Text Available The accurate measurement of suspended particulate matter (SPM concentrations in coastal waters is of crucial importance for ecosystem studies, sediment transport monitoring, and assessment of anthropogenic impacts in the coastal ocean. Ocean color remote sensing is an efficient tool to monitor SPM spatio-temporal variability in coastal waters. However, near-shore satellite images are complex to correct for atmospheric effects due to the proximity of land and to the high level of reflectance caused by high SPM concentrations in the visible and near-infrared spectral regions. The water reflectance signal (ρw tends to saturate at short visible wavelengths when the SPM concentration increases. Using a comprehensive dataset of high-resolution satellite imagery and in situ SPM and water reflectance data, this study presents (i an assessment of existing atmospheric correction (AC algorithms developed for turbid coastal waters; and (ii a switching method that automatically selects the most sensitive SPM vs. ρw relationship, to avoid saturation effects when computing the SPM concentration. The approach is applied to satellite data acquired by three medium-high spatial resolution sensors (Landsat-8/Operational Land Imager, National Polar-Orbiting Partnership/Visible Infrared Imaging Radiometer Suite and Aqua/Moderate Resolution Imaging Spectrometer to map the SPM concentration in some of the most turbid areas of the European coastal ocean, namely the Gironde and Loire estuaries as well as Bourgneuf Bay on the French Atlantic coast. For all three sensors, AC methods based on the use of short-wave infrared (SWIR spectral bands were tested, and the consistency of the retrieved water reflectance was examined along transects from low- to high-turbidity waters. For OLI data, we also compared a SWIR-based AC (ACOLITE with a method based on multi-temporal analyses of atmospheric constituents (MACCS. For the selected scenes, the ACOLITE-MACCS difference was

  4. 76 FR 21036 - Application of the Prevailing Wage Methodology in the H-2B Program

    Science.gov (United States)

    2011-04-14

    ... Department to ``promulgate new rules concerning the calculation of the prevailing wage rate in the H-2B... wage methodology set forth in this Rule applies only to wages paid for work performed on or after...: Notice. SUMMARY: On January 19, 2011, the Department of Labor (Department) published a final rule, Wage...

  5. 75 FR 75706 - Federal Prevailing Rate Advisory Committee; Open Committee Meetings

    Science.gov (United States)

    2010-12-06

    ... Building, 1900 E Street, NW., Washington, DC. The Federal Prevailing Rate Advisory Committee is composed of... considered and would disrupt substantially the disposition of its business. Therefore, these caucuses will be... 5H27, 1900 E Street, NW., Washington, DC 20415, (202) 606-9400. U.S. Office of Personnel Management...

  6. 78 FR 70599 - Federal Prevailing Rate Advisory Committee; Open Committee Meetings

    Science.gov (United States)

    2013-11-26

    ... of Personnel Management Building, 1900 E Street NW., Washington, DC. The Federal Prevailing Rate... the matters being considered and would disrupt substantially the disposition of its business... Advisory Committee, Room 5H27, 1900 E Street NW., Washington, DC 20415, (202) 606-9400. U.S. Office of...

  7. 76 FR 75567 - Federal Prevailing Rate Advisory Committee; Open Committee Meetings

    Science.gov (United States)

    2011-12-02

    ..., 1900 E Street, NW., Washington, DC. The Federal Prevailing Rate Advisory Committee is composed of a... disrupt substantially the disposition of its business. Therefore, these caucuses will be closed to the... 5H27, 1900 E Street, NW., Washington, DC 20415, (202) 606-9400. U.S. Office of Personnel Management...

  8. 77 FR 8926 - Federal Prevailing Rate Advisory Committee; Open Committee Meetings

    Science.gov (United States)

    2012-02-15

    ... Personnel Management Building, 1900 E Street NW., Washington, DC. The Federal Prevailing Rate Advisory... considered and would disrupt substantially the disposition of its business. Therefore, these caucuses will be... 5H27, 1900 E Street NW., Washington, DC 20415, (202) 606-9400. U.S. Office of Personnel Management...

  9. 77 FR 76304 - Federal Prevailing Rate Advisory Committee; Open Committee Meetings

    Science.gov (United States)

    2012-12-27

    ... 5A06A, U.S. Office of Personnel Management Building, 1900 E Street NW., Washington, DC. The Federal... the matters being considered and would disrupt substantially the disposition of its business... Management, Federal Prevailing Rate Advisory Committee, Room 5H27, 1900 E Street NW., Washington, DC 20415...

  10. Prevailing Wage Regulations and School Construction Costs: Evidence from British Columbia.

    Science.gov (United States)

    Bilginsoy, Cihan; Philips, Peter

    2000-01-01

    Examines effects of prevailing wage laws on school construction costs, using final cost data from six British Columbia school districts. When controlling for factors such as construction business cycle, number of competitors, and school type, there was no significant unit cost change following the Skill Development and Fair Wage Policy Act.…

  11. Jovian atmospheres

    International Nuclear Information System (INIS)

    Allison, M.; Travis, L.D.

    1986-10-01

    A conference on the atmosphere of Jupiter produced papers in the areas of thermal and ortho-para hydrogen structure, clouds and chemistry, atmospheric structure, global dynamics, synoptic features and processes, atmospheric dynamics, and future spaceflight opportunities. A session on the atmospheres of Uranus and Neptune was included, and the atmosphere of Saturn was discussed in several papers

  12. Study of atmospheric condition during the heavy rain event in Bojonegoro using weather research and forecasting (WRF) model: case study 9 February 2017

    Science.gov (United States)

    Saragih, I. J. A.; Meygatama, A. G.; Sugihartati, F. M.; Sidauruk, M.; Mulsandi, A.

    2018-03-01

    During 2016, there are frequent heavy rains in the Bojonegoro region, one of which is rain on 9 February 2016. The occurrence of heavy rainfall can cause the floods that inundate the settlements, rice fields, roads, and public facilities. This makes it important to analyze the atmospheric conditions during the heavy rainfall events in Bojonegoro. One of the analytical methods that can be used is using WRF-Advanced Research WRF (WRF-ARW) model. This study was conducted by comparing the rain analysis from WRF-ARW model with the Himawari-8 satellite imagery. The data used are Final Analysis (FNL) data for the WRF-ARW model and infrared (IR) channel for Himawari-8 satellite imagery. The data are processed into the time-series images and then analyzed descriptively. The meteorological parameters selected to be analyzed are relative humidity, vortices, divergences, air stability index, and precipitation. These parameters are expected to indicate the existence of a convective activity in Bojonegoro during the heavy rainfall event. The Himawari-8 satellite imagery shows that there is a cluster of convective clouds in Bojonegoro during the heavy rainfall event. The lowest value of the cloud top temperature indicates that the cluster of convective clouds is a cluster of Cumulonimbus cloud (CB).

  13. IR-thermography-based investigation of critical heat flux in subcooled flow boiling of water at atmospheric and high pressure conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bucci, Matteo [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Seong, Jee H. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Buongiorno, Jdacopo [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Richenderfer, Andrew [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Kossolapov, A. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2017-11-01

    Here we report on MIT’s THM work in Q4 2016 and Q1 2017. The goal of this project is to design, construct and execute tests of flow boiling critical heat flux (CHF) at high-pressure using high-resolution and high-speed video and infrared (IR) thermometry, to generate unique data to inform the development of and validate mechanistic boiling heat transfer and CHF models. In FY2016, a new test section was designed and fabricated. Data was collected at atmospheric conditions at 10, 25 and 50 K subcoolings, and three mass fluxes, i.e. 500, 750 and 1000 kg/m2/s. Starting in Q4 2016 and continuing forward, new post-processing techniques have been developed to analyze the data collected. These new algorithms analyze the time-dependent temperature and heat flux distributions to calculate nucleation site density, nucleation frequency, growth and wait time, dry area fraction, and the complete heat flux partitioning. In Q1 2017 a new flow boiling loop was designed and constructed to support flow boiling tests up 10 bar pressure and 180 °C. Initial shakedown and testing has been completed. The flow loop and test section are now ready to begin high-pressure flow boiling testing.

  14. Alpha spectroscopy by the Φ25 mm×0.1 mm YAlO{sub 3}:Ce scintillation detector under atmospheric conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kvasnicka, Jiri [Radiation Detection Systems, Unit 10, 186 Pulteney Street, Adelaide SA 5000 (Australia); Urban, Tomas, E-mail: tomas.urban@fjfi.cvut.cz [Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Brehova 78/7, 115 19 Prague, Czech Republic (Czech Republic); Tous, Jan; Smejkal, Jan; Blazek, Karel [Crytur Ltd, Palackeho 175, 511 01 Turnov (Czech Republic); Nikl, Martin [Institute of Physics AS CR, Cukrovarnicka 10, 162 53 Prague (Czech Republic)

    2017-06-01

    The YAlO{sub 3}:Ce scintillation crystal has excellent mechanical properties and is not affected if used in chemically aggressive environments. The detector with the diameter of Φ25.4 mm and thickness of 0.1 mm was coupled with the PMT, associated electronics and the MCA in order to study its alpha spectroscopy properties. The measured alpha spectra of the surface calibration sources of {sup 241}Am and {sup 230}Th were compared with results of a Monte Carlo simulation. The experiment and the simulation were carried out for three distances between the detector and the surface alpha source in order to assess the effect of the distance on the detected energy of alpha radiation. Finally, the detector was used for the monitoring of radon ({sup 222}Rn) decay products (radon daughters) in the air. It was concluded that the detector is suitable for the in-situ alpha spectroscopy monitoring under ambient atmospheric conditions. Nevertheless, in order to identify radionuclides and their activity from the measured alpha spectra a computer code would need to be developed. - Highlights: • Thin YAP: Ce scintillator crystal is proposed to be used for alpha spectrometry. • Experimental alpha spectra were compared with Monte Carlo simulated spectra. • The proposed detector assembly is suitable for the monitoring of radon decay products in air. • The results give a good potential for a quantitative analysis of the spectrum.

  15. Experimental study of the injection conditions influence over n-dodecane and diesel sprays with two ECN single-hole nozzles. Part I: Inert atmosphere

    International Nuclear Information System (INIS)

    Gimeno, Jaime; Bracho, Gabriela; Martí-Aldaraví, Pedro; Peraza, Jesús E.

    2016-01-01

    In this research, two Engine Combustion Network (ECN) mono-orifice nozzles, referred to as Spray C and Spray D respectively, were analyzed by performing visualization tests through Schlieren and Diffused Backlight Illumination (DBI) techniques under a wide range of ambient conditions in a non-reactive atmosphere. Spray C presents a straight nozzle designed with a sharp fillet in opposition to Spray D that has similar hydraulic properties, but with a convergent nozzle construction and a smoother corner. The experiments were carried out injecting two distinct fuels at different injection pressure ranges, from 50 MPa to 150 MPa with n-dodecane and to 200 MPa for diesel. The images were processed with Matlab home-built routines to calculate parameters as spray penetration, spreading angle, quasi-steady liquid length, as well as the spray penetration derivative respect to the square root of time, presented in this document as R-parameter. The results showed a clear influence of nozzle geometry in all measured parameters, due mainly to the nature of Spray C to cavitation, which increase the spreading angle and consequently a reduction in vapor penetration. On the other hand, fuel properties also affected spray penetration due to its dependency on viscous forces expressed in terms of the Reynolds number and its volatility in case of liquid length. This last parameter was calculated employing two processing methodologies, finding a good general agreement between them.

  16. Nonlinear dynamics of global atmospheric and Earth-system processes

    Science.gov (United States)

    Saltzman, Barry; Ebisuzaki, Wesley; Maasch, Kirk A.; Oglesby, Robert; Pandolfo, Lionel

    1991-01-01

    General Circulation Model (GCM) studies of the atmospheric response to change boundary conditions are discussed. Results are reported on an extensive series of numerical studies based on the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM) general circulation model. In these studies the authors determined the response to systematic changes in atmospheric CO2 ranging from 100 to 1000 ppm; to changes in the prescribed sea surface temperature (SST) in the Gulf of Mexico, such as occurred during the deglaciation phase of the last ice age; to changes in soil moisture over North America; and to changes in sea ice extent in the Southern Hemisphere. Study results show that the response of surface temperature and other variables is nearly logarithmic, with lower levels of CO2 implying greater sensitivity of the atmospheric state to changes in CO2. It was found that the surface temperature of the Gulf of Mexico exerts considerable control over the storm track and behavior of storm systems over the North Atlantic through its influence on evaporation and the source of latent heat. It was found that reductions in soil moisture can play a significant role in amplifying and maintaining North American drought, particularly when a negative soil moisture anomaly prevails late in the spring.

  17. Evaluating the atmospheric dispersion characteristics of Suez Canal area

    International Nuclear Information System (INIS)

    Aly, A.I.M.; Sabek, G.; Abd El-Aal, M.; El-Ghamry, M.

    1988-01-01

    The atmospheric dispersion characteristics of Suez Canal area were determined for subsequent estimation of the environmental impacts of transporting radioactive or hazardous material through the Suez Canal and for the study of environmental pollution resulting from fossil power plants. The atmospheric stability classes were determined at three stations: Port Said, Ismailia and Port Tawfiek (Suez). For achieving this purpose, a computer program was developed through which the atmospheric stability classes A - F and insolation were determined by combining the measured meteorological parameters and the sun elevation which was calculated by another developed computer program with the help of astronomical tables. The results show that the most frequent stability class at Port-Said and Suez is stability class D (neutral condition), whereas at Ismailia area the moderately stable class F, which is the inversion condition with unfavourable dispersion characteristics, is prevailing. The determination of the frequency of stability classes will make it possible to calculate the concentration of a pollutant at a given distance from the source and therefore will be used in dose assessment

  18. Review on the prevailing methods for the prediction of potential rock burst / rock spalling in tunnels

    OpenAIRE

    Panthi, Krishna Kanta

    2017-01-01

    Rock burst / rock spalling is among the prevailing stability challenges, which can be met while tunneling through hard rock mass. Especially, this is very relevant for the mountainous country like Norway where hard rock is dominating and many road, railway and hydropower tunnels have to be aligned deep into the mountain with steep valley slope topography. Tunnels passing beneath deep rock cover (overburden), in general, are subjected to high in-situ stresses. If the rock mass is relatively un...

  19. Nuclear energy is not the prevailing energy in the French energetic mix

    International Nuclear Information System (INIS)

    Destais, G.

    2011-01-01

    The author first shows that the share of nuclear energy in the French electricity production is in fact of 76% (and not 80% as usually said), and that the share of this energy in the final electricity consumption was 69% in 2009. She also outlines that nuclear electricity is only 16,5% of the total final energy consumption in France in 2009, whereas oil still prevails with 42%

  20. Effects of Hydrated Potato Starch on the Quality of Low-fat Ttoekgalbi (Korean Traditional Patty Packaged in Modified Atmosphere Conditions during Storage

    Directory of Open Access Journals (Sweden)

    S. M. Kang Muhlisin

    2012-05-01

    Full Text Available This study was carried out to investigate the effects of hydrated potato starch on the quality of low-fat ttoekgalbi (Korean traditional patty packaged in modified atmosphere conditions during storage. The ttoekgalbi was prepared from 53.2% lean beef, 13.9% lean pork, 9.3% pork fat, and 23.6% other ingredients. Two low-fat ttoekgalbi treatments were prepared by substituting pork fat with hydrated potato starch; either by 50% fat replacement (50% FR or 100% fat replacement (100% FR. Both 50% and 100% FR increased the moisture, crude protein, and decreased fat content, cooking loss, and hardness. For MAP studies, 200 g of ttoekgalbi were placed on the tray and filled with gas composed of 70% O2: 30% CO2 (70% O2-MAP and 30% CO2: 70% N2 (70% N2-MAP, and were stored at 5°C for 12 d. During the storage time, both 50% and 100% FR showed higher protein deterioration, while no differences were found in CIE a*, CIE L*, lipid oxidation, and bacterial counts in comparison to control. The ttoekgalbi with 70% O2-MAP was more red, lighter in color, and showed higher TBARS values compared with 70% N2-MAP. The meat with 70% N2-MAP showed lower aerobic bacterial counts in control than those with 70% O2-MAP. The lower anaerobic bacterial counts were observed only in 50% FR and 100% FR packed with 70% N2-MAP in comparison with 70% O2-MAP. In conclusion, the fat replacement with hydrated potato starch showed no negative effects on the quality of low fat ttoekgalbi during storage and 70% N2-MAP was better than 70% O2-MAP for low-fat ttoekgalbi packaging.

  1. Atmospheric contamination

    International Nuclear Information System (INIS)

    Gruetter, Juerg

    1997-01-01

    It is about the levels of contamination in center America, the population's perception on the problem, effects of the atmospheric contamination, effects in the environment, causes of the atmospheric contamination, possibilities to reduce the atmospheric contamination and list of Roeco Swisscontac in atmospheric contamination

  2. Urban atmospheric contamination

    International Nuclear Information System (INIS)

    Baldasano Jose, M.

    1997-01-01

    The problems of contamination are not only limited to this century, pale pathology evidences of the effects of the contamination of the air exist in interiors in the health of the old ones; the article mention the elements that configure the problem of the atmospheric contamination, atmospheric pollutants and emission sources, orography condition and effects induced by the urbanization process

  3. Dissolution rates of unirradiated UO{sub 2}, UO{sub 2} doped with {sup 233}U, and spent fuel under normal atmospheric conditions and under reducing conditions using an isotope dilution method

    Energy Technology Data Exchange (ETDEWEB)

    Ollila, Kaija [VTT Processes, Helsinki (Finland); Albinsson, Yngve [Chalmers Univ. of Technology, Goeteborg (Sweden); Oversby, Virginia [VMO Konsult, Stockholm (Sweden); Cowper, Mark [AEA Technology, Harwell (United Kingdom)

    2003-10-01

    The experimental results given in this report allow us to draw the following conclusions. 1) Tests using unirradiated fuel pellet materials from two different manufacturers gave very different dissolution rates under air atmosphere testing. Tests for fragments of pellets from different pellets made by the same manufacturer gave good agreement. This indicates that details of the manufacturing process have a large effect on the behavior of unirradiated UO{sub 2} in dissolution experiments. Care must be taken in interpreting differences in results obtained in different laboratories because the results may be affected by manufacturing effects. 2) Long-term tests under air atmosphere have begun to show the effects of precipitation. Further testing will be needed before the samples reach steady state. 3) Testing of unirradiated UO{sub 2} in systems containing an iron strip to produce reducing conditions gave [U] less than detection limits (<0.02 ppb) after a few days to a few weeks of testing. Uranium recovered from the rinsing of reaction vessels and from acid stripping of vessels was shown to be from dissolution of grains of solid dislodged when the samples were handled after the tests were terminated. 4) Batch tests conducted under reducing conditions showed evidence of colloidal material in the early solution samples. 5) In the batch tests, measurements taken at day 3 and day 5 show that precipitation occurs from day 3 to day 5 without any further dissolution of the solid. 6) At termination of the batch tests, all but one sample had [U] in solution less than detection limits (< 0.02 ppb). Materials recovered in test termination samples showed evidence for recovery of small amounts - amounts corresponding to that expected from a few grains of 5 to 10 {mu}m size - in the acidified solution samples. These are interpreted to have been dislodged during sample handling operations. 7) Batch test data show that increasing test duration beyond 2 weeks does not provide

  4. Novel sampling methods for atmospheric semi-volatile organic compounds (SOCs) in a high altitude alpine environment.

    Science.gov (United States)

    Offenthaler, I; Jakobi, G; Kaiser, A; Kirchner, M; Kräuchi, N; Niedermoser, B; Schramm, K-W; Sedivy, I; Staudinger, M; Thanner, G; Weiss, P; Moche, W

    2009-12-01

    High- and low-volume active air samplers as well as bulk deposition samplers were developed to sample atmospheric SOCs under the adverse conditions of a mountain environment. Active sampling employed separate filters for different European source regions. Filters were switched depending on daily trajectory forecasts, whose accuracy was evaluated post hoc. The sampling continued on three alpine summits over five periods of four months. The prevailing trajectories varied stronger between sampling periods than between stations. The sampling equipment (active and bulk deposition) proved dependable for operation in a mountain environment, with idle times being mainly due to non-routine manipulations and connectivity.

  5. Polycyclic aromatic hydrocarbons in the urban atmospheric particulate matter in the city of Naples (Italy)

    Science.gov (United States)

    Caricchia, Anna Maria; Chiavarini, Salvatore; Pezza, Massimo

    An investigation on PAH in the atmospheric particulate matter of the city of Naples has been carried out. Urban atmospheric particulate matter was sampled in three sampling sites (West, East and central areas of the city), whose characteristics were representative of the prevailing conditions. In each site, 24 h samplings for 7 consecutive days were performed during three sampling campaigns, in 1996-1997. The results were comparable with those reported in literature for similar investigations. Total PAH were in the range 2-130 ng m -3, with a seasonal variation (autumn/winter vs. summer) in the range 1.5-4.5. The relative contribution of diesel engines vs. gasoline fuelled engines was evidenced.

  6. Atmospheric circulation changes and neoglacial conditions in the Southern Hemisphere mid-latitudes: insights from PMIP2 simulations at 6 kyr

    Science.gov (United States)

    Rojas, Maisa; Moreno, Patricio I.

    2011-07-01

    Glacial geologic studies in the Southern Hemisphere (SH) mid-latitudes (40-54°S) indicate renewed glacial activity in southern South America (Patagonia) and New Zealand's (NZ) South Island starting at ˜7 kyr, the so-called neoglaciation. Available data indicate that neoglacial advances in these regions occurred during a rising trend in atmospheric CO2 and CH4 concentrations, lower-than-present but increasing summer insolation and seasonality contrasts. In this paper we examine the climatological context in which neoglaciations occurred through analysis of the complete Paleoclimate Modelling Inter-comparison Project (PMIP2) database of simulations at 6 kyr for the SH. We observe that the amplitude of the annual insolation cycle in the SH did not change significantly at 6 kyr compared to the pre-industrial values, the largest difference occurring in autumn (MAM, negative anomalies) and spring (SON, positive anomalies). The simulated changes in temperatures over the SH respond to the insolation changes, with a 1-2 month delay over the oceans. This results in a reduced amplitude of the annual cycle of temperature and precipitation over most continental regions, except over Patagonia and NZ, that show a slight increase. In contrast, large-scale circulation features, such as the low and upper level winds and the subtropical anticyclones show an amplified annual cycle, as a direct response to the increased/decreased insolation during the transitional seasons SON/MAM. In the annual mean, there is a small but consistent equatorward shift of the latitude of maximum wind speed of 1-3° over the entire SH, which results in a small increase of wind speed over the South Pacific and Atlantic Oceans north of ˜50°S and a widespread decline south of 50°S. PMIP2 simulations for 6 kyr, indicate that in the annual mean, the SH mid-latitudes were colder, wetter and with stronger winds north of about 50°S. These conditions are consistent with the observed neoglacial advances in the

  7. Atmospheric circulation changes and neoglacial conditions in the Southern Hemisphere mid-latitudes: insights from PMIP2 simulations at 6 kyr

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, Maisa [University of Chile, Department of Geophysics, Santiago (Chile); Moreno, Patricio I. [University of Chile, Department of Ecology, Santiago (Chile)

    2011-07-15

    Glacial geologic studies in the Southern Hemisphere (SH) mid-latitudes (40-54 S) indicate renewed glacial activity in southern South America (Patagonia) and New Zealand's (NZ) South Island starting at {proportional_to}7 kyr, the so-called neoglaciation. Available data indicate that neoglacial advances in these regions occurred during a rising trend in atmospheric CO{sub 2} and CH{sub 4} concentrations, lower-than-present but increasing summer insolation and seasonality contrasts. In this paper we examine the climatological context in which neoglaciations occurred through analysis of the complete Paleoclimate Modelling Inter-comparison Project (PMIP2) database of simulations at 6 kyr for the SH. We observe that the amplitude of the annual insolation cycle in the SH did not change significantly at 6 kyr compared to the pre-industrial values, the largest difference occurring in autumn (MAM, negative anomalies) and spring (SON, positive anomalies). The simulated changes in temperatures over the SH respond to the insolation changes, with a 1-2 month delay over the oceans. This results in a reduced amplitude of the annual cycle of temperature and precipitation over most continental regions, except over Patagonia and NZ, that show a slight increase. In contrast, large-scale circulation features, such as the low and upper level winds and the subtropical anticyclones show an amplified annual cycle, as a direct response to the increased/decreased insolation during the transitional seasons SON/MAM. In the annual mean, there is a small but consistent equatorward shift of the latitude of maximum wind speed of 1-3 over the entire SH, which results in a small increase of wind speed over the South Pacific and Atlantic Oceans north of {proportional_to}50 S and a widespread decline south of 50 S. PMIP2 simulations for 6 kyr, indicate that in the annual mean, the SH mid-latitudes were colder, wetter and with stronger winds north of about 50 S. These conditions are consistent

  8. Investigation of time-resolved atmospheric conditions and indoor/outdoor particulate matter concentrations in homes with gas and biomass cook stoves in Nogales, Sonora, Mexico.

    Science.gov (United States)

    Holmes, Heather A; Pardyjak, Eric R

    2014-07-01

    This paper reports findings from a case study designed to investigate indoor and outdoor air quality in homes near the United States-Mexico border During the field study, size-resolved continuous particulate matter (PM) concentrations were measured in six homes, while outdoor PM was simultaneously monitored at the same location in Nogales, Sonora, Mexico, during March 14-30, 2009. The purpose of the experiment was to compare PM in homes using different fuels for cooking, gas versus biomass, and to obtain a spatial distribution of outdoor PM in a region where local sources vary significantly (e.g., highway, border crossing, unpaved roads, industry). Continuous PM data were collected every 6 seconds using a valve switching system to sample indoor and outdoor air at each home location. This paper presents the indoor PM data from each home, including the relationship between indoor and outdoor PM. The meteorological conditions associated with elevated ambient PM events in the region are also discussed. Results indicate that indoor air pollution has a strong dependence on cooking fuel, with gas stoves having hourly averaged median PM3 concentrations in the range of 134 to 157 microg m(-3) and biomass stoves 163 to 504 microg m(-1). Outdoor PM also indicates a large spatial heterogeneity due to the presence of microscale sources and meteorological influences (median PM3: 130 to 770 microg m(-3)). The former is evident in the median and range of daytime PM values (median PM3: 250 microg m(-3), maximum: 9411 microg m(-3)), while the meteorological influences appear to be dominant during nighttime periods (median PM3: 251 microg m(-3), maximum: 10,846 microg m(-3)). The atmospheric stability is quantified for three nighttime temperature inversion episodes, which were associated with an order of magnitude increase in PM10 at the regulatory monitor in Nogales, AZ (maximum increase: 12 to 474 microg m(-3)). Implications: Regulatory air quality standards are based on outdoor

  9. Atmosphere-vegetation-soil interactions in a climate change context; Impact of changing conditions on engineered transport infrastructure slopes in Europe

    NARCIS (Netherlands)

    Tang, A.M.; Hughes, P.N.; Dijkstra, T.A.; Askarinejad, A.; Brenčič, M.; Cui, Y.J.; Diez, J.J.; Firgi, T.; Gajewska, B.; Gentile, F.; Grossi, G.; Jommi, C.; Kehagia, F.; Koda, E.; Maat, Ter H.W.; Lenart, S.; Lourenco, S.; Oliveira, M.; Osinski, P.; Springman, S.M.; Stirling, R.; Toll, D.G.; Beek, Van V.

    2018-01-01

    In assessing the impact of climate change on infrastructure, it is essential to consider the interactions between the atmosphere, vegetation and the near-surface soil. This paper presents an overview of these processes, focusing on recent advances from the literature and those made by members of

  10. 5-Year Outcomes After Left Atrial Appendage Closure: From the PREVAIL and PROTECT AF Trials.

    Science.gov (United States)

    Reddy, Vivek Y; Doshi, Shephal K; Kar, Saibal; Gibson, Douglas N; Price, Matthew J; Huber, Kenneth; Horton, Rodney P; Buchbinder, Maurice; Neuzil, Petr; Gordon, Nicole T; Holmes, David R

    2017-12-19

    The PROTECT AF (WATCHMAN Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) trial demonstrated that left atrial appendage closure (LAAC) with the Watchman device (Boston Scientific, St. Paul, Minnesota) was equivalent to warfarin for preventing stroke in atrial fibrillation, but had a high rate of complications. In a second randomized trial, PREVAIL (Evaluation of the WATCHMAN LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy), the complication rate was low. The warfarin cohort experienced an unexpectedly low ischemic stroke rate, rendering the efficacy endpoints inconclusive. However, these outcomes were based on relatively few patients followed for a relatively short time. The final results of the PREVAIL trial, both alone and as part of a patient-level meta-analysis with the PROTECT AF trial, are reported with patients in both trials followed for 5 years. PREVAIL and PROTECT AF are prospective randomized clinical trials with patients randomized 2:1 to LAAC or warfarin; together, they enrolled 1,114 patients for 4,343 patient-years. Analyses are by intention-to-treat, and rates are events per 100 patient-years. For the PREVAIL trial, the first composite coprimary endpoint of stroke, systemic embolism (SE), or cardiovascular/unexplained death did not achieve noninferiority (posterior probability for noninferiority = 88.4%), whereas the second coprimary endpoint of post-procedure ischemic stroke/SE did achieve noninferiority (posterior probability for noninferiority = 97.5%); the warfarin arm maintained an unusually low ischemic stroke rate (0.73%). In the meta-analysis, the composite endpoint was similar between groups (hazard ratio [HR]: 0.820; p = 0.27), as were all-stroke/SE (HR: 0.961; p = 0.87). The ischemic stroke/SE rate was numerically higher with LAAC, but this difference did not reach statistical significance (HR: 1.71; p = 0.080). However, differences in

  11. Atmospheric Icing on Sea Structures,

    Science.gov (United States)

    1984-04-01

    results. ESTIMATION OF ICING INTENSITY Freezing process When supercooled water drops fall or move with wind, hit a structure, and freeze, the...a collision with another drop- let, with the ground, or with a structure. When a supercooled droplet hits a solid obstacle, it spreads and turns to...accretion is likely. The meteorological conditions that prevail during ship icing have been studied widely (Shektman 1968, Tabata 1968, Borisenkov and

  12. Will the New Gnosticism prevail? Remarks on Synthetic Biology, Nanotechnologies and Genetic Manipulation facing the Century of the Big Challenge

    Directory of Open Access Journals (Sweden)

    Jorge Riechmann

    2016-12-01

    Full Text Available Technological utopianism seduces many people, from the very origins of Western modernity –remember Francis Bacon’s island of Bensalem in his New Atlantis–, with the temptation of complete mastery over nature (which includes human immortality. Today, the prevailing mentality in the West, which tends to become a universal worldview, has much in common with the beliefs of the ancient Gnostics. According to this mindset, science and technology can allow the human mind to escape the limitations that characterize its natural state, releasing the anchor to biological stuff and escaping the human condition. In short, we would become gods –gods thought of as Immortal Super-Engineers. We must resist these destructive illusions and delusions, which means: technical rationality has to make his own critique of utopian reason (in the sense of Franz Hinkelammert. Without this self-criticism, a judicious use of techniques and technologies will be out of reach –and they do have an enormous potential for improving the human condition–, while avoiding –if it were still possible– the exterminist, nihilistic and suicidal drift of industrial civilization.

  13. CONSTRUCTION TECHNOLOGY DIFFUSION IN DEVELOPING COUNTRIES: LIMITATIONS OF PREVAILING INNOVATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Emilia van Egmond-deWilde de Ligny

    2008-12-01

    Full Text Available The diffusion of innovative technologies in the market is usually a complex and difficult process with a varying degree of success and the effects of the diffused innovative technologies are very un-balanced. The objective of our research is to gain insight into the reasons why the diffusion of innovative technology fails, even though they promise a superior performance compared to incumbent technologies. Drawing on innovation systems theories, we have identified and used the concepts of technological regime, actor network and technology sets to analyze technology diffusion in a case study in the dwelling construction industry in Costa Rica. The results showed bottlenecks in the prevailing innovation system that curtailed the diffusion of an innovative construction technology.

  14. Economic impact of enoxaparin after acute ischemic stroke based on PREVAIL.

    Science.gov (United States)

    Pineo, Graham; Lin, Jay; Stern, Lee; Subrahmanian, Tarun; Annemans, Lieven

    2011-04-01

    The efficacy and safety of low-molecular-weight heparins (LMWHs) versus unfractionated heparin (UFH) has been demonstrated for the prevention of venous thromboembolism (VTE) after acute ischemic stroke. Few data exist regarding the economic impact of LMWHs versus UFH in this population. A decision-analytic model was constructed using clinical information from the Prevention of VTE after Acute Ischemic stroke with LMWH Enoxaparin (PREVAIL) study, and drug costs and mean Centers for Medicare & Medicaid Services event costs. When considering the total cost of events and drugs, enoxaparin was associated with cost-savings of $895 per patient compared with UFH ($2018 vs $2913). Findings were retained within the univariate and multivariate analyses. From a payer perspective, enoxaparin was cost-effective compared with UFH in patients with acute ischemic stroke. The difference was driven by the lower clinical event rates with enoxaparin. Use of enoxaparin may help to reduce the clinical and economic burden of VTE.

  15. Energy balance at the soil atmosphere interface

    NARCIS (Netherlands)

    Sedighi, M; Hepburn, B.D.P.; Thomas, HR; Vardon, P.J.

    2016-01-01

    Soil atmospheric interactions play an important role within the thermal energy balance and seasonal temperature variations of the ground. This paper presents a formulation for the surface boundary conditions related to interactions between soil and atmosphere. The boundary condition formulated

  16. Pluto's atmosphere

    International Nuclear Information System (INIS)

    Elliot, J.L.; Dunham, E.W.; Bosh, A.S.; Slivan, S.M.; Young, L.A.

    1989-01-01

    Airborne CCD photometer observations of Pluto's June 9, 1988 stellar occultation have yielded an occultation lightcurve, probing two regions on the sunrise limb 2000 km apart, which reveals an upper atmosphere overlying an extinction layer with an abrupt upper boundary. The extinction layer may surround the entire planet. Attention is given to a model atmosphere whose occultation lightcurve closely duplicates observations; fits of the model to the immersion and emersion lightcurves exhibit no significant derived atmosphere-structure differences. Assuming a pure methane atmosphere, surface pressures of the order of 3 microbars are consistent with the occultation data. 43 references

  17. Atmospheric electricity

    CERN Document Server

    Chalmers, J Alan

    1957-01-01

    Atmospheric Electricity brings together numerous studies on various aspects of atmospheric electricity. This book is composed of 13 chapters that cover the main problems in the field, including the maintenance of the negative charge on the earth and the origin of the charges in thunderstorms. After a brief overview of the historical developments of atmospheric electricity, this book goes on dealing with the general principles, results, methods, and the MKS system of the field. The succeeding chapters are devoted to some aspects of electricity in the atmosphere, such as the occurrence and d

  18. El suicidio: Una conducta antisocial que prevalece/Suicide: An antisocial behavior that prevails

    Directory of Open Access Journals (Sweden)

    Omar Alejandro De León Palomo

    2012-01-01

    Full Text Available The suicide has existed throughout history and has prevailed as a behavior that was contrary to the rules of the society in terms of preservation of life itself; the objective of this research was to make emphasis on the nature of antisocial behavior of this behavior and show its prevalence in the years 2006 to 2010 in Mexico and Tamaulipas, as well as from 1999 to 2008 in Reynosa, Tamaulipas. For which the data were obtained from the National Institute of Statistics and Geography to the country and the State and the books of the register of deaths by cause violent of the Regional Unit of Expert Services of the Attorney General of Justice, which has its headquarters in Reynosa; developed a theoretical framework on the impact of the conduct in society and the means to prevent it, The data obtained we revealed the continued presence of this conduct year-on-year, 23.554 cases appearing in Mexico and 819 in Tamaulipas in the period from 2006 to 2010; in Reynosa, Tamaulipas were presented 278 suicides in the period 1999 to 2008. The results show us a conduct stable in numbers, but without excessive overflows that prevails year-on-year, suicide, and the attempt of the same should be viewed as a social problem and not detract from the importance that it deserves a conduct of these dimensions, that is no more than a reflection of the situation in which are the means of social control toward the preservation of life itself.

  19. Population Causes and Consequences of Leading Chronic Diseases: A Comparative Analysis of Prevailing Explanations

    Science.gov (United States)

    Stuckler, David

    2008-01-01

    Context The mortality numbers and rates of chronic disease are rising faster in developing than in developed countries. This article compares prevailing explanations of population chronic disease trends with theoretical and empirical models of population chronic disease epidemiology and assesses some economic consequences of the growth of chronic diseases in developing countries based on the experiences of developed countries. Methods Four decades of male mortality rates of cardiovascular and chronic noncommunicable diseases were regressed on changes in and levels of country income per capita, market integration, foreign direct investment, urbanization rates, and population aging in fifty-six countries for which comparative data were available. Neoclassical economic growth models were used to estimate the effect of the mortality rates of chronic noncommunicable diseases on economic growth in high-income OECD countries. Findings Processes of economic growth, market integration, foreign direct investment, and urbanization were significant determinants of long-term changes in mortality rates of heart disease and chronic noncommunicable disease, and the observed relationships with these social and economic factors were roughly three times stronger than the relationships with the population's aging. In low-income countries, higher levels of country income per capita, population urbanization, foreign direct investment, and market integration were associated with greater mortality rates of heart disease and chronic noncommunicable disease, less increased or sometimes reduced rates in middle-income countries, and decreased rates in high-income countries. Each 10 percent increase in the working-age mortality rates of chronic noncommunicable disease decreased economic growth rates by close to a half percent. Conclusions Macrosocial and macroeconomic forces are major determinants of population rises in chronic disease mortality, and some prevailing demographic explanations

  20. Population causes and consequences of leading chronic diseases: a comparative analysis of prevailing explanations.

    Science.gov (United States)

    Stuckler, David

    2008-06-01

    The mortality numbers and rates of chronic disease are rising faster in developing than in developed countries. This article compares prevailing explanations of population chronic disease trends with theoretical and empirical models of population chronic disease epidemiology and assesses some economic consequences of the growth of chronic diseases in developing countries based on the experiences of developed countries. Four decades of male mortality rates of cardiovascular and chronic noncommunicable diseases were regressed on changes in and levels of country income per capita, market integration, foreign direct investment, urbanization rates, and population aging in fifty-six countries for which comparative data were available. Neoclassical economic growth models were used to estimate the effect of the mortality rates of chronic noncommunicable diseases on economic growth in high-income OECD countries. Processes of economic growth, market integration, foreign direct investment, and urbanization were significant determinants of long-term changes in mortality rates of heart disease and chronic noncommunicable disease, and the observed relationships with these social and economic factors were roughly three times stronger than the relationships with the population's aging. In low-income countries, higher levels of country income per capita, population urbanization, foreign direct investment, and market integration were associated with greater mortality rates of heart disease and chronic noncommunicable disease, less increased or sometimes reduced rates in middle-income countries, and decreased rates in high-income countries. Each 10 percent increase in the working-age mortality rates of chronic noncommunicable disease decreased economic growth rates by close to a half percent. Macrosocial and macroeconomic forces are major determinants of population rises in chronic disease mortality, and some prevailing demographic explanations, such as population aging, are

  1. Effect of flue gas composition on deposit induced high temperature corrosion under laboratory conditions mimicking biomass firing. Part I: Exposures in oxidizing and chlorinating atmospheres

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Kiamehr, Saeed; Montgomery, Melanie

    2017-01-01

    on hightemperature corrosion of an austenitic superheater material under laboratoryconditions mimicking biomass firing is investigated in this work. Exposuresinvolving deposit (KCl)-coated and deposit-free austenitic stainless steel (TP347H FG) samples were conducted isothermally at 560 8C for 72 h, under...... only in an oxidizing-chlorinating atmosphere, otherwise corrosionresults in formation of a duplex oxide. Corrosion attack on deposit-coatedsamples was higher than on deposit-free samples irrespective of the gaseousatmosphere. Specifically, severe volatilization of alloying elements occurred ondeposit-coated...

  2. Adding complex terrain and stable atmospheric condition capability to the OpenFOAM-based flow solver of the simulator for on/offshore wind farm applications (SOWFA

    Directory of Open Access Journals (Sweden)

    Churchfield Matthew J.

    2014-01-01

    Full Text Available The National Renewable Energy Laboratory's Simulator for On/Offshore Wind Farm Applications contains an OpenFOAM-based flow solver for performing large-eddy simulation of flow through wind plants. The solver computes the atmospheric boundary layer flow and models turbines with actuator lines. Until recently, the solver was limited to flows over flat terrain and could only use the standard Smagorinsky subgrid-scale model. In this work, we present our improvements to the flow solver that enable us to 1 use any OpenFOAM-standard subgrid-scale model and 2 simulate flow over complex terrain. We used the flow solver to compute a stably stratified atmospheric boundary layer using both the standard and the Lagrangian-averaged scale-independent dynamic Smagorinsky models. Surprisingly, the results using the standard Smagorinsky model compare well to other researchers' results of the same case, although it is often said that the standard Smagorinsky model is too dissipative for accurate stable stratification calculations. The scale-independent dynamic subgrid-scale model produced poor results, probably due to the spikes in model constant with values as high as 4.6. We applied a simple bounding of the model constant to remove these spikes, which caused the model to produce results much more in line with other researchers' results. We also computed flow over a simple hilly terrain and performed some basic qualitative analysis to verify the proper operation of the terrain-local surface stress model we employed.

  3. Articulating Atmospheres

    DEFF Research Database (Denmark)

    Kinch, Sofie

    2011-01-01

    This paper presents an architectural approach to designing computational interfaces by articulating the notion of atmosphere in the field of interaction design. It draws upon the concept of kinesthetic interaction and a philosophical notion on atmosphere emphasizing the importance of bodily...

  4. Atmospheric electrodynamics

    International Nuclear Information System (INIS)

    Volland, H.

    1984-01-01

    The book Atmospheric Electrodynamics, by Hans Voland is reviewed. The book describes a wide variety of electrical phenomena occurring in the upper and lower atmosphere and develops the mathematical models which simulate these processes. The reviewer finds that the book is of interest to researchers with a background in electromagnetic theory but is of only limited use as a reference work

  5. The Effect of Thermal Convection on Earth-Atmosphere CO2 Gas Exchange in Aggregated Soil

    Science.gov (United States)

    Ganot, Y.; Weisbrod, N.; Dragila, M. I.

    2011-12-01

    Gas transport in soils and surface-atmosphere gas exchange are important processes that affect different aspects of soil science such as soil aeration, nutrient bio-availability, sorption kinetics, soil and groundwater pollution and soil remediation. Diffusion and convection are the two main mechanisms that affect gas transport, fate and emissions in the soils and in the upper vadose zone. In this work we studied CO2 soil-atmosphere gas exchange under both day-time and night-time conditions, focusing on the impact of thermal convection (TCV) during the night. Experiments were performed in a climate-controlled laboratory. One meter long columns were packed with matrix of different grain size (sand, gravel and soil aggregates). Air with 2000 ppm CO2 was injected into the bottom of the columns and CO2 concentration within the columns was continuously monitored by an Infra Red Gas Analyzer. Two scenarios were compared for each soil: (1) isothermal conditions, representing day time conditions; and (2) thermal gradient conditions, i.e., atmosphere colder than the soil, representing night time conditions. Our results show that under isothermal conditions, diffusion is the major mechanism for surface-atmosphere gas exchange for all grain sizes; while under night time conditions the prevailing mechanism is dependent on the air permeability of the matrix: for sand and gravel it is diffusion, and for soil aggregates it is TCV. Calculated CO2 flux for the soil aggregates column shows that the TCV flux was three orders of magnitude higher than the diffusive flux.

  6. Weather forecasting by insects: modified sexual behaviour in response to atmospheric pressure changes.

    Science.gov (United States)

    Pellegrino, Ana Cristina; Peñaflor, Maria Fernanda Gomes Villalba; Nardi, Cristiane; Bezner-Kerr, Wayne; Guglielmo, Christopher G; Bento, José Maurício Simões; McNeil, Jeremy N

    2013-01-01

    Prevailing abiotic conditions may positively or negatively impact insects at both the individual and population levels. For example while moderate rainfall and wind velocity may provide conditions that favour development, as well as movement within and between habitats, high winds and heavy rains can significantly decrease life expectancy. There is some evidence that insects adjust their behaviours associated with flight, mating and foraging in response to changes in barometric pressure. We studied changes in different mating behaviours of three taxonomically unrelated insects, the curcurbit beetle, Diabrotica speciosa (Coleoptera), the true armyworm moth, Pseudaletia unipuncta (Lepidoptera) and the potato aphid, Macrosiphum euphorbiae (Hemiptera), when subjected to natural or experimentally manipulated changes in atmospheric pressure. In response to decreasing barometric pressure, male beetles exhibited decreased locomotory activity in a Y-tube olfactometer with female pheromone extracts. However, when placed in close proximity to females, they exhibited reduced courtship sequences and the precopulatory period. Under the same situations, females of the true armyworm and the potato aphid exhibited significantly reduced calling behaviour. Neither the movement of male beetles nor the calling of armyworm females differed between stable and increasing atmospheric pressure conditions. However, in the case of the armyworm there was a significant decrease in the incidence of mating under rising atmospheric conditions, suggesting an effect on male behaviour. When atmospheric pressure rose, very few M. euphorbiae oviparae called. This was similar to the situation observed under decreasing conditions, and consequently very little mating was observed in this species except under stable conditions. All species exhibited behavioural modifications, but there were interspecific differences related to size-related flight ability and the diel periodicity of mating activity. We

  7. Urban atmospheres.

    Science.gov (United States)

    Gandy, Matthew

    2017-07-01

    What is an urban atmosphere? How can we differentiate an 'atmosphere' from other facets of urban consciousness and experience? This essay explores some of the wider cultural, political, and philosophical connotations of atmospheres as a focal point for critical reflections on space and subjectivity. The idea of an 'affective atmosphere' as a distinctive kind of mood or shared corporeal phenomenon is considered in relation to recent developments in phenomenology, extended conceptions of agency, and new understandings of materialism. The essay draws in particular on the changing characteristics of air and light to reflect on different forms of sensory experience and their wider cultural and political connotations. The argument highlights some of the tensions and anomalies that permeate contemporary understandings of urban atmospheres.

  8. Surface conditioning of a cold-rolled dual-phase steel by annealing in nitriding atmospheres prior to hot-dip galvanizing

    Energy Technology Data Exchange (ETDEWEB)

    Luther, F.; Beste, D.; Bleck, W. [Institute for Ferrous Metallurgy (IEHK), RWTH Aachen (Germany); Dimyati, A.; Mayer, J. [Central Facility for Electron Microscopy (GFE), RWTH Aachen (Germany)

    2007-04-15

    The development of steel grades for automotive applications in the recent years has been driven on by two trends: lightweight and improved crash safety. By using steels like DP (dual phase) the goals of passenger safety, fuel efficiency and environmental friendliness can be met at reasonable price. The favorite corrosion protection method for sheet steels in the car industry is the hot-dip galvanizing process. Here, an approach was made to reduce the surface enrichment of critical alloying elements of a dual phase steel grade by reactive annealing in ammonia containing atmospheres. The effects of this treatment on mechanical properties and hot-dip coating behavior are reported. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  9. Measurement-based J(NO2) sensitivity in a cloudless atmosphere under low aerosol loading and high solar zenith angle conditions

    International Nuclear Information System (INIS)

    Frueh, B.; Trautmann, T.

    2000-01-01

    The comparison between measured and simulated photodissociation frequencies of NO 2 , J(NO 2 ), in a cloudless atmosphere in a recent paper by Frueh et al., 2000 (Journal of Geophysical Research 105, 9843-9857) revealed an overestimation of J(NO 2 ) near ground level by model calculations compared with measurements and an underestimation in the upper part of the aerosol layer. A possible reason for the disagreement is the changing sun position during the vertical ascent. To resolve this problem we carried out a sensitivity study varying the solar zenith angle of 74 o by 1.4 o (which corresponds to the change of sun position during the vertical flight patterns). This results in a considerable deviation of J(NO 2 ) of about 10%. Further sensitivity studies on J(NO 2 ) have been done. These include realistic variations in ground albedo, humidity and aerosol properties. A variation in ground albedo from the measured value of A G = 0.023 (292-420 nm wavelength) to A G = 0 and A G = 0.05, respectively, resulted in an average J(NO 2 ) reduction and enhancement of only 2% near ground level with a slight decrease with increasing altitude. Furthermore, we compared simulations based on different relative humidity profiles with results from a dry atmosphere. Compared to the dry case the deviations of J(NO 2 ) were considerable (5-16%) although the measured aerosol concentration was very low. Moreover, we doubled the aerosol particle concentration. The maximum J(NO 2 ) deviations were in the same order of magnitude as for the relative humidity (5-16%). These changes are in the range of measurement uncertainty of J(NO 2 ) (author)

  10. Atmospheric Electricity

    Science.gov (United States)

    Aplin, Karen; Fischer, Georg

    2018-02-01

    Electricity occurs in atmospheres across the Solar System planets and beyond, spanning spectacular lightning displays in clouds of water or dust, to more subtle effects of charge and electric fields. On Earth, lightning is likely to have existed for a long time, based on evidence from fossilized lightning strikes in ancient rocks, but observations of planetary lightning are necessarily much more recent. The generation and observations of lightning and other atmospheric electrical processes, both from within-atmosphere measurements, and spacecraft remote sensing, can be readily studied using a comparative planetology approach, with Earth as a model. All atmospheres contain charged molecules, electrons, and/or molecular clusters created by ionization from cosmic rays and other processes, which may affect an atmosphere's energy balance both through aerosol and cloud formation, and direct absorption of radiation. Several planets are anticipated to host a "global electric circuit" by analogy with the circuit occurring on Earth, where thunderstorms drive current of ions or electrons through weakly conductive parts of the atmosphere. This current flow may further modulate an atmosphere's radiative properties through cloud and aerosol effects. Lightning could potentially have implications for life through its effects on atmospheric chemistry and particle transport. It has been observed on many of the Solar System planets (Earth, Jupiter, Saturn, Uranus, and Neptune) and it may also be present on Venus and Mars. On Earth, Jupiter, and Saturn, lightning is thought to be generated in deep water and ice clouds, but discharges can be generated in dust, as for terrestrial volcanic lightning, and on Mars. Other, less well-understood mechanisms causing discharges in non-water clouds also seem likely. The discovery of thousands of exoplanets has recently led to a range of further exotic possibilities for atmospheric electricity, though lightning detection beyond our Solar System

  11. A steady-state continuous flow chamber for the study of daytime and nighttime chemistry under atmospherically relevant NO levels

    Science.gov (United States)

    Zhang, Xuan; Ortega, John; Huang, Yuanlong; Shertz, Stephen; Tyndall, Geoffrey S.; Orlando, John J.

    2018-05-01

    Experiments performed in laboratory chambers have contributed significantly to the understanding of the fundamental kinetics and mechanisms of the chemical reactions occurring in the atmosphere. Two chemical regimes, classified as high-NO vs. zero-NO conditions, have been extensively studied in previous chamber experiments. Results derived from these two chemical scenarios are widely parameterized in chemical transport models to represent key atmospheric processes in urban and pristine environments. As the anthropogenic NOx emissions in the United States have decreased remarkably in the past few decades, the classic high-NO and zero-NO conditions are no longer applicable to many regions that are constantly impacted by both polluted and background air masses. We present here the development and characterization of the NCAR Atmospheric Simulation Chamber, which is operated in steady-state continuous flow mode for the study of atmospheric chemistry under intermediate NO conditions. This particular chemical regime is characterized by constant sub-ppb levels of NO and can be created in the chamber by precise control of the inflow NO concentration and the ratio of chamber mixing to residence timescales. Over the range of conditions achievable in the chamber, the lifetime of peroxy radicals (RO2), a key intermediate from the atmospheric degradation of volatile organic compounds (VOCs), can be extended to several minutes, and a diverse array of reaction pathways, including unimolecular pathways and bimolecular reactions with NO and HO2, can thus be explored. Characterization experiments under photolytic and dark conditions were performed and, in conjunction with model predictions, provide a basis for interpretation of prevailing atmospheric processes in environments with intertwined biogenic and anthropogenic activities. We demonstrate the proof of concept of the steady-state continuous flow chamber operation through measurements of major first-generation products

  12. A steady-state continuous flow chamber for the study of daytime and nighttime chemistry under atmospherically relevant NO levels

    Directory of Open Access Journals (Sweden)

    X. Zhang

    2018-05-01

    Full Text Available Experiments performed in laboratory chambers have contributed significantly to the understanding of the fundamental kinetics and mechanisms of the chemical reactions occurring in the atmosphere. Two chemical regimes, classified as high-NO vs. zero-NO conditions, have been extensively studied in previous chamber experiments. Results derived from these two chemical scenarios are widely parameterized in chemical transport models to represent key atmospheric processes in urban and pristine environments. As the anthropogenic NOx emissions in the United States have decreased remarkably in the past few decades, the classic high-NO and zero-NO conditions are no longer applicable to many regions that are constantly impacted by both polluted and background air masses. We present here the development and characterization of the NCAR Atmospheric Simulation Chamber, which is operated in steady-state continuous flow mode for the study of atmospheric chemistry under intermediate NO conditions. This particular chemical regime is characterized by constant sub-ppb levels of NO and can be created in the chamber by precise control of the inflow NO concentration and the ratio of chamber mixing to residence timescales. Over the range of conditions achievable in the chamber, the lifetime of peroxy radicals (RO2, a key intermediate from the atmospheric degradation of volatile organic compounds (VOCs, can be extended to several minutes, and a diverse array of reaction pathways, including unimolecular pathways and bimolecular reactions with NO and HO2, can thus be explored. Characterization experiments under photolytic and dark conditions were performed and, in conjunction with model predictions, provide a basis for interpretation of prevailing atmospheric processes in environments with intertwined biogenic and anthropogenic activities. We demonstrate the proof of concept of the steady-state continuous flow chamber operation through measurements of major first

  13. Hygroscopic properties of atmospheric aerosol particles over the Eastern Mediterranean: implications for regional direct radiative forcing under clean and polluted conditions

    Directory of Open Access Journals (Sweden)

    M. Stock

    2011-05-01

    Full Text Available This work examines the effect of direct radiative forcing of aerosols in the eastern Mediterranean troposphere as a function of air mass composition, particle size distribution and hygroscopicity, and relative humidity (RH. During intensive field measurements on the island of Crete, Greece, the hygroscopic properties of atmospheric particles were determined using a Hygroscopicity Tandem Differential Mobility Analyzer (H-TDMA and a Hygroscopicity Differential Mobility Analyzer-Aerodynamic Particle Sizer (H-DMA-APS. Similar to former studies, the H-TDMA identified three hygroscopic sub-fractions of particles in the sub-μm range: a more hygroscopic group, a less hygroscopic group and a nearly hydrophobic particle group. The average hygroscopic particle growth factors at 90 % RH were a significant function of particle mobility diameter (Dp: 1.42 (± 0.05 at 30 nm compared to 1.63 (± 0.07 at 250 nm. The H-DMA-APS identified up to three hygroscopic sub-fractions at mobility diameters of 1.0 and 1.2 μm. The data recorded between 12 August and 20 October 2005 were classified into four distinct synoptic-scale air mass types distinguishing between different regions of origin (western Mediterranean vs. the Aegean Sea as well as the degree of continental pollution (marine vs. continentally influenced. The hygroscopic properties of particles with diameter Dp≥150 nm showed the most pronounced dependency on air mass origin, with growth factors in marine air masses exceeding those in continentally influenced air masses. Particle size distributions and hygroscopic growth factors were used to calculate aerosol light scattering coefficients at ambient RH using a Mie model. A main result was the pronounced enhancement of particle scattering over the eastern Mediterranean due to hygroscopic growth, both in the marine and continentally influenced air masses. When RH reached its summer daytime values around 70

  14. Environmental factors prevail over dispersal constraints in determining the distribution and assembly of Trichoptera species in mountain lakes.

    Science.gov (United States)

    de Mendoza, Guillermo; Ventura, Marc; Catalan, Jordi

    2015-07-01

    Aiming to elucidate whether large-scale dispersal factors or environmental species sorting prevail in determining patterns of Trichoptera species composition in mountain lakes, we analyzed the distribution and assembly of the most common Trichoptera (Plectrocnemia laetabilis, Polycentropus flavomaculatus, Drusus rectus, Annitella pyrenaea, and Mystacides azurea) in the mountain lakes of the Pyrenees (Spain, France, Andorra) based on a survey of 82 lakes covering the geographical and environmental extremes of the lake district. Spatial autocorrelation in species composition was determined using Moran's eigenvector maps (MEM). Redundancy analysis (RDA) was applied to explore the influence of MEM variables and in-lake, and catchment environmental variables on Trichoptera assemblages. Variance partitioning analysis (partial RDA) revealed the fraction of species composition variation that could be attributed uniquely to either environmental variability or MEM variables. Finally, the distribution of individual species was analyzed in relation to specific environmental factors using binomial generalized linear models (GLM). Trichoptera assemblages showed spatial structure. However, the most relevant environmental variables in the RDA (i.e., temperature and woody vegetation in-lake catchments) were also related with spatial variables (i.e., altitude and longitude). Partial RDA revealed that the fraction of variation in species composition that was uniquely explained by environmental variability was larger than that uniquely explained by MEM variables. GLM results showed that the distribution of species with longitudinal bias is related to specific environmental factors with geographical trend. The environmental dependence found agrees with the particular traits of each species. We conclude that Trichoptera species distribution and composition in the lakes of the Pyrenees are governed predominantly by local environmental factors, rather than by dispersal constraints. For

  15. On the prevailing construction waste recycling practices: a South East Queensland study.

    Science.gov (United States)

    Tam, Vivian W Y; Kotrayothar, Duangthidar; Loo, Yew-Chaye

    2009-03-01

    Waste generated from construction and building demolition work constitutes about 68% of all solid waste generated each year in South East Queensland. Consequently, it has created a serious waste management problem. The State Governments of Victoria and New South Wales have been encouraging the use of recycled materials from construction and related waste; they have also promulgated specifications for their use. In Queensland, however, similar regulations are not anticipated in the near future, which explains the lack of funded research conducted in this important arena. This paper presents an evaluation of the prevailing waste recycling practices in Queensland. Nine sites were visited, including two construction sites, three demolition sites, three recycling plants and one landfill in South East Queensland. The difficulties encountered by the recycling programme operators and their associates at these sites are described and the benefits of recycling construction materials are presented. One of the major barriers is that the local councils disallow the use of recycled materials in new construction work. To help rectify these impediments to recycling, recommendations are given to increase the use of recycled construction waste in South East Queensland.

  16. Appreciation of the nature of light demands enhancement over the prevailing scientific epistemology

    Science.gov (United States)

    Roychoudhuri, Chandrasekhar

    2011-09-01

    Based on attempts to resolve the problem of various self contradictory assumptions behind the prevailing belief on single photon interference, we have analyzed the process steps behind our experimental measurements and named the process as the Interaction Process Mapping Epistemology (IPM-E). This has helped us recognize that the quantum mechanical Measurement Problem has a much universal and deeper root in nature. Our scientific theorization process suffers from a Perpetual Information Challenge (PIC), which cannot be overcome by elegant and/or sophisticated mathematical theories alone. Iterative imaginative application of IPM-E needs to be used as a metaphorical analytical continuation to fill up the missing information gaps. IPM-E has also guided us to recognize the generic NIW-principle (Non-Interaction of Waves) in the linear domain, not explicitly recognized in current books and literature. Superposition effects become manifest through light-matter interactions. Detecting dipoles gets stimulated by multiple superposed beams; it sums the simultaneous multiple stimulations into a single resultant undulation, which then guides the resultant energy exchange. The consequent transformation in the detector corresponds to observed fringes. They neither represent interference of light; nor represent selective arrival or non-arrival of photons on the detector. Photons do not possess any force of mutual interaction to generate their redistribution. Implementation of IPM-E requires us to recognize our subjective interpretation propensity with which we are burdened due to our evolutionary successes.

  17. Why nature prevails over nurture in the making of the elite athlete.

    Science.gov (United States)

    Georgiades, Evelina; Klissouras, Vassilis; Baulch, Jamie; Wang, Guan; Pitsiladis, Yannis

    2017-11-14

    While the influence of nature (genes) and nurture (environment) on elite sporting performance remains difficult to precisely determine, the dismissal of either as a contributing factor to performance is unwarranted. It is accepted that a complex interaction of a combination of innumerable factors may mold a talented athlete into a champion. The prevailing view today is that understanding elite human performance will require the deciphering of two major sources of individual differences, genes and the environment. It is widely accepted that superior performers are endowed with a high genetic potential actualised through hard and prodigious effort. Heritability studies using the twin model have provided the basis to disentangle genetic and environmental factors that contribute to complex human traits and have paved the way to the detection of specific genes for elite sport performance. Yet, the heritability for most phenotypes essential to elite human performance is above 50% but below 100%, meaning that the environment is also important. Furthermore, individual differences can potentially also be explained not only by the impact of DNA sequence variation on biology and behaviour, but also by the effects of epigenetic changes which affect phenotype by modifying gene expression. Despite this complexity, the overwhelming and accumulating evidence, amounted through experimental research spanning almost two centuries, tips the balance in favour of nature in the "nature" and "nurture" debate. In other words, truly elite-level athletes are built - but only from those born with innate ability.

  18. Phylogenomics resolves a spider backbone phylogeny and rejects a prevailing paradigm for orb web evolution.

    Science.gov (United States)

    Bond, Jason E; Garrison, Nicole L; Hamilton, Chris A; Godwin, Rebecca L; Hedin, Marshal; Agnarsson, Ingi

    2014-08-04

    Spiders represent an ancient predatory lineage known for their extraordinary biomaterials, including venoms and silks. These adaptations make spiders key arthropod predators in most terrestrial ecosystems. Despite ecological, biomedical, and biomaterial importance, relationships among major spider lineages remain unresolved or poorly supported. Current working hypotheses for a spider "backbone" phylogeny are largely based on morphological evidence, as most molecular markers currently employed are generally inadequate for resolving deeper-level relationships. We present here a phylogenomic analysis of spiders including taxa representing all major spider lineages. Our robust phylogenetic hypothesis recovers some fundamental and uncontroversial spider clades, but rejects the prevailing paradigm of a monophyletic Orbiculariae, the most diverse lineage, containing orb-weaving spiders. Based on our results, the orb web either evolved much earlier than previously hypothesized and is ancestral for a majority of spiders or else it has multiple independent origins, as hypothesized by precladistic authors. Cribellate deinopoid orb weavers that use mechanically adhesive silk are more closely related to a diverse clade of mostly webless spiders than to the araneoid orb-weaving spiders that use adhesive droplet silks. The fundamental shift in our understanding of spider phylogeny proposed here has broad implications for interpreting the evolution of spiders, their remarkable biomaterials, and a key extended phenotype--the spider web. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Mars: Atmosphere

    Science.gov (United States)

    Moroz, V.; Murdin, P.

    2001-07-01

    The atmosphere of MARS is much thinner than the terrestrial one. However, even the simplest visual telescopic observations show a set of atmospheric events such as seasonal exchange of material between polar caps, temporal appearance of clouds and changes of visibility of dark regions on the disk of the planet. In 1947 the prominent CO2 bands in the near-infrared part of the Martian spectrum were...

  20. Atmospheric boundary layer response to sea surface temperatures during the SEMAPHORE experiment

    Science.gov (United States)

    Giordani, Hervé; Planton, Serge; Benech, Bruno; Kwon, Byung-Hyuk

    1998-10-01

    The sensitivity of the marine atmospheric boundary layer (MABL) subjected to sea surface temperatures (SST) during the Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiment in 1993 has been studied. Atmospheric analyses produced by the Action de Recherche, Petite Echelle, Grande Echelle (ARPEGE) operational model at the French meteorological weather service assimilated data sets collected between October 7 and November 17, 1993, merged with the Global Telecommunication System (GTS) data. Analyses were validated against independent data from aircraft instruments collected along a section crossing the Azores oceanic front, not assimilated into the model. The responses of the mean MABL in the aircraft cross section to changes in SST gradients of about 1°C/100 km were the presence of an atmospheric front with horizontal gradients of 1°C/100 km and an increase of the wind intensity from the cold to the warm side during an anticyclonic synoptic situation. The study of the spatiotemporal characteristics of the MABL shows that during 3 days of an anticyclonic synoptic situation the SST is remarkably stationary because it is principally controlled by the Azores ocean current, which has a timescale of about 10 days. However, the temperature and the wind in the MABL are influenced by the prevailing atmospheric conditions. The ocean does not appear to react to the surface atmospheric forcing on the timescale of 3 days, whereas the atmospheric structures are modified by local and synoptic-scale advection. The MABL response appears to be much quicker than that of the SSTs. The correlation between the wind and the thermal structure in the MABL is dominated by the ageostrophic and not by the geostrophic component. In particular, the enhancement of the wind on either side of the SST front is mainly due to the ageostrophic component. Although the surface heat fluxes are not the only cause of ageostrophy, the

  1. The effect of sage, sodium erythorbate and a mixture of sage and sodium erythorbate on the quality of turkey meatballs stored under vacuum and modified atmosphere conditions.

    Science.gov (United States)

    Karpińska-Tymoszczyk, M

    2010-12-01

    1. The combined effect of sage (S), sodium erythorbate (SE), a mixture of sage and sodium erythorbate (MIX) and vacuum packaging (VP) and modified atmosphere packaging (MAP) on the quality of cooked turkey meatballs stored at 4°C was investigated. The physicochemical properties (colour, MDA, AV, pH, water activity), microbiological quality characteristics (counts of mesophilic and psychrotrophic bacteria, fungi, coliforms and Clostridium sp.) and flavour attributes of meatballs were determined. 2. The values of the colour parameters L*, a* and b* were affected by the additives and packaging method. The colour of meatballs was better protected by sodium erythorbate than by sage or a mixture of sage and sodium erythorbate. The additives effectively stabilised lipids against oxidation and slowed down hydrolytic changes in turkey meatballs. Sage and a mixture of sage and sodium erythorbate showed stronger antioxidant properties than sodium erythorbate added alone. Products with additives were characterised by better sensory quality than control samples. Sage and MIX prevented the growth of mesophilic and psychrotrophic bacteria. All additives inhibited the growth of coliforms. 3. MAP was more effective than VP in maintaining the microbial and sensory quality stability of cooked turkey meatballs. However, VP appears to be a better method as regards the maintaining of lipid stability in turkey meatballs.

  2. Ventilation conditions and atmospheric characteristics of a laboratory uranium mine. Application to the distribution of radioactive particles in the respiratory tract

    International Nuclear Information System (INIS)

    Duport, Philippe.

    1978-09-01

    The CEA laboratory uranium mine and the characteristics of its ventilation are described. A method of measuring air flows based on the determination of a tracer gas was developed. Variations of radon concentrations and of its daughter products concentrations and radioactive equilibrium were observed as a function of the various ventilation rates. Particle size distribution of radioactive aerosols was studied in the laboratory mine when unoperated. Several methods of evaluation of the free fraction were compared, and the application of the laws of aerosol physics to the production of radioactive aerosols in a mine was investigated. A study of radioactive ions showed that the usual equations of atmospheric electricity could be applied to charged radioactive aerosols in a mine. Finally an experimental method was developed in order to directly examine the deposit of an aerosol labelled by radon daughter products in the respiratory tract of animals. The experimental results obtained with aerosols in the particle size range 5.10 -8 - 5.10 -6 were compared to the theoretical data derived from models published in the literature [fr

  3. Thermochemical Properties of the 1-Ethyl-3-Methylimidazolium Bis(trifluoromethylsulfonyl)imide Ionic Liquid under Conditions of Equilibrium with Atmospheric Moisture

    Science.gov (United States)

    Ramenskaya, L. M.; Grishina, E. P.; Kudryakova, N. O.

    2018-01-01

    Thermochemical properties of the 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ionic liquid [EMim]NTf2 containing moisture absorbed from the atmosphere (0.242 wt %) are investigated. The phase behavior and thermal stability relative to salt dried in vacuum are studied by means of thermogravimetry and differential scanning calorimetry at different heating and cooling rates. The glass transition, crystallization, and melting temperatures, the enthalpies of phase transitions, and the changes in heat capacity during the formation of glass are determined. It is established that the absorbed water crystallizes at a temperature of around -40.6°C and has virtually no effect on the thermal stability and phase behavior of the salt. Rapid cooling results in the ionic liquid transitioning into the glass state at -91.7 °C and the formation of three mesophases with different melting temperatures; one crystalline modification that melts at a temperature of -19.3°C forms upon slow cooling.

  4. Tracer Studies to Characterize the Effects of Roadside Noise Barriers on Near-Road Pollutant Dispersion under Varying Atmospheric Stability Conditions

    Science.gov (United States)

    A roadway toxics dispersion study was conducted by the Field Research Division (FRD) of NOAA at the Idaho National Laboratory (INL) near Idaho Falls, ID to document the effects on concentrations of roadway emissions behind a roadside sound barrier in various conditions of atmosph...

  5. Speciation of radiocesium in atmospheric aerosol after the Chernobyl accident

    International Nuclear Information System (INIS)

    Tomasek, M.; Rybacek, K.; Wilhemova, L.

    1995-01-01

    The aim of this analysis was to verify the hypothesis that physico-chemical forms of radiocesium in the fallout after the accident could depend on the transport conditions, including the distance of a sampling location from Chernobyl. From the results it is obvious that the prevailing form in all samples taken in the period of direct contamination was water-soluble radiocesium. It can be concluded from the presented results that physico-chemical forms of radiocesium in atmospheric aerosol and fallout after the nuclear power plant accident at Chernobyl as well as particulate size distribution can depend on the distance or the conditions of transport from a contamination source to a sampling location. The influence of the conditions of radiocesium transport could result in observed differences in the 137 Cs penetration into soil profile in different locations and also in the found dependence on the resuspension factor for 137 Cs on the level of its fallout in the period of NPP accident for different locations in Europe. (J.K.) 1 tab

  6. Speciation of radiocesium in atmospheric aerosol after the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Tomasek, M; Rybacek, K; Wilhemova, L [Academy Science of the Czech Republic, 18086 Prague (Czech Republic). Nuclear Physics Inst., Dept. of Radiation Dosimetry

    1996-12-31

    The aim of this analysis was to verify the hypothesis that physico-chemical forms of radiocesium in the fallout after the accident could depend on the transport conditions, including the distance of a sampling location from Chernobyl. From the results it is obvious that the prevailing form in all samples taken in the period of direct contamination was water-soluble radiocesium. It can be concluded from the presented results that physico-chemical forms of radiocesium in atmospheric aerosol and fallout after the nuclear power plant accident at Chernobyl as well as particulate size distribution can depend on the distance or the conditions of transport from a contamination source to a sampling location. The influence of the conditions of radiocesium transport could result in observed differences in the {sup 137}Cs penetration into soil profile in different locations and also in the found dependence on the resuspension factor for {sup 137}Cs on the level of its fallout in the period of NPP accident for different locations in Europe. (J.K.) 1 tab.

  7. The Formation of Fe/Mg Smectite Under Mildly Acidic Conditions on Early Mars

    Science.gov (United States)

    Sutter, B.; Golden, D. C.; Ming, Douglas W.; Niles, P. B.

    2011-01-01

    The detection of Fe/Mg smectites and carbonate in Noachian and early Hesperian terrain of Mars suggests that neutral to mildly alkaline conditions prevailed during the early history of Mars. If early Mars surface geochemical conditions were neutral to moderately alkaline with a denser CO2 atmosphere than today, then large carbonates deposits should be more widely detected in Noachian terrain. Why have so few carbonate deposits been detected compared to Fe/Mg smectites? Fe/Mg smectites on early Mars formed under mildly acidic conditions, which would preclude the extensive formation of carbonate deposits. The goal of the proposed work is to evaluate the formation of Fe/Mg smectites under mildly acidic conditions.

  8. Condições de atmosfera controlada para o armazenamento de maçãs 'Royal Gala' de diferentes tamanhos Controlled atmosphere-storage conditions for 'Royal Gala' apples of different sizes

    Directory of Open Access Journals (Sweden)

    Auri Brackmann

    2005-10-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de condições de atmosfera controlada sobre a conservação da qualidade de maçãs 'Royal Gala' de tamanho pequeno (5-6cm de diâmetro e grande (8-9cm de diâmetro. Os frutos foram armazenados durante oito meses em atmosfera controlada, seguido de sete dias a 20°C. De acordo com os resultados obtidos, verificou-se que a condição de atmosfera controlada com 1,5kPa de O2 + 3,0kPa de CO2 permitiu melhor conservação dos frutos pequenos, por permitir menor ocorrência de degenerescência interna e elevados valores de acidez titulável. Em relação aos frutos grandes, a condição de atmosfera controlada com 1,0kPa de O2 + 3,0kPa de CO2 foi a mais adequada, pois permitiu uma maior firmeza de polpa e elevados valores de acidez titulável. Os frutos pequenos mantiveram a cor de fundo da epiderme mais verde e apresentaram menores incidências de podridões em relação aos frutos grandes.The objective of this work was to evaluate the effect of controlled atmosphere conditions on the quality of 'Royal Gala' apples of small-size (5-6cm of diameter and large-size (8-9cm of diameter. Fruit were kept during 8 months in controlled atmosphere, followed by 7 days of shelf-life at 20°C. According to the results, controlled atmosphere with 1.5kPa O2 + 3.0kPa CO2 decreased internal breakdown and maintained the highest level of tritable acidity on small size fruit. Large size fruit stored on controlled atmosphere condition with 1.0kPa O2 + 3.0kPa CO2 had higher flesh firmness and elevated tritable acidity, showing therefore better quality than fruits stored on the other evaluated conditions. Small size fruit maintained greener skin background colour and lower rot incidence than large size fruit.

  9. Extraction of compositional and hydration information of sulfates from laser-induced plasma spectra recorded under Mars atmospheric conditions — Implications for ChemCam investigations on Curiosity rover

    International Nuclear Information System (INIS)

    Sobron, Pablo; Wang, Alian; Sobron, Francisco

    2012-01-01

    Given the volume of spectral data required for providing accurate compositional information and thereby insight in mineralogy and petrology from laser-induced breakdown spectroscopy (LIBS) measurements, fast data processing tools are a must. This is particularly true during the tactical operations of rover-based planetary exploration missions such as the Mars Science Laboratory rover, Curiosity, which will carry a remote LIBS spectrometer in its science payload. We have developed: an automated fast pre-processing sequence of algorithms for converting a series of LIBS spectra (typically 125) recorded from a single target into a reliable SNR-enhanced spectrum; a dedicated routine to quantify its spectral features; and a set of calibration curves using standard hydrous and multi-cation sulfates. These calibration curves allow deriving the elemental compositions and the degrees of hydration of various hydrous sulfates, one of the two major types of secondary minerals found on Mars. Our quantitative tools are built upon calibration-curve modeling, through the correlation of the elemental concentrations and the peak areas of the atomic emission lines observed in the LIBS spectra of standard samples. At present, we can derive the elemental concentrations of K, Na, Ca, Mg, Fe, Al, S, O, and H in sulfates, as well as the hydration degrees of Ca- and Mg-sulfates, from LIBS spectra obtained in both Earth atmosphere and Mars atmospheric conditions in a Planetary Environment and Analysis Chamber (PEACh). In addition, structural information can be potentially obtained for various Fe-sulfates. - Highlights: ► Routines for LIBS spectral data fast automated processing. ► Identification of elements and determination of the elemental composition. ► Calibration curves for sulfate samples in Earth and Mars atmospheric conditions. ► Fe curves probably related to the crystalline structure of Fe-sulfates. ► Extraction of degree of hydration in hydrous Mg-, Ca-, and Fe-sulfates.

  10. The networked minority: How a small group prevailed in a local windfarm conflict

    International Nuclear Information System (INIS)

    Anderson, Carmel

    2013-01-01

    This paper aims to explain through a qualitative case study how a small protest group prevailed during a local windfarm conflict in south-eastern Australia. A social capital analytical framework was developed to analyse the data. The analysis found that two communities inhabited the area for which the windfarm development was proposed. The public participation process failed to address the concerns of both communities and led to the emergence of a social network of resistance. The network had high stocks of bridging social capital, which enabled an effective protest that led to the abandonment of the development. Their effectiveness was inadvertently aided by the windfarm supporters who were unable to act collectively to defend their interests because socio-economic changes in the community among other factors had led to a depletion of their social capital. In this context, different democratic participatory processes were needed to address the concerns of the two communities. Guidance and tools for researching and developing the types of participatory processes needed for vulnerable communities with low social capital and those similar to the social network with high social capital are provided. These will inform community-appropriate public participation processes and participatory planning policy. - Highlights: ► A case study of a local social network's resistance to a windfarm is undertaken. ► The link between high social capital and resistance is confirmed. ► Successful protest groups can be aided by passive windfarm supporters. ► Protesters are likely to participate in well-designed participatory processes. ► Guidance for developing community-specific participatory processes is provided

  11. Additive effects prevail: The response of biota to multiple stressors in an intensively monitored watershed.

    Science.gov (United States)

    Gieswein, Alexander; Hering, Daniel; Feld, Christian K

    2017-09-01

    Freshwater ecosystems are impacted by a range of stressors arising from diverse human-caused land and water uses. Identifying the relative importance of single stressors and understanding how multiple stressors interact and jointly affect biology is crucial for River Basin Management. This study addressed multiple human-induced stressors and their effects on the aquatic flora and fauna based on data from standard WFD monitoring schemes. For altogether 1095 sites within a mountainous catchment, we used 12 stressor variables covering three different stressor groups: riparian land use, physical habitat quality and nutrient enrichment. Twenty-one biological metrics calculated from taxa lists of three organism groups (fish, benthic invertebrates and aquatic macrophytes) served as response variables. Stressor and response variables were subjected to Boosted Regression Tree (BRT) analysis to identify stressor hierarchy and stressor interactions and subsequently to Generalised Linear Regression Modelling (GLM) to quantify the stressors standardised effect size. Our results show that riverine habitat degradation was the dominant stressor group for the river fauna, notably the bed physical habitat structure. Overall, the explained variation in benthic invertebrate metrics was higher than it was in fish and macrophyte metrics. In particular, general integrative (aggregate) metrics such as % Ephemeroptera, Plecoptera and Trichoptera (EPT) taxa performed better than ecological traits (e.g. % feeding types). Overall, additive stressor effects dominated, while significant and meaningful stressor interactions were generally rare and weak. We concluded that given the type of stressor and ecological response variables addressed in this study, river basin managers do not need to bother much about complex stressor interactions, but can focus on the prevailing stressors according to the hierarchy identified. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Prevailing theories of consciousness are challenged by novel cross-modal associations acquired between subliminal stimuli.

    Science.gov (United States)

    Scott, Ryan B; Samaha, Jason; Chrisley, Ron; Dienes, Zoltan

    2018-06-01

    While theories of consciousness differ substantially, the 'conscious access hypothesis', which aligns consciousness with the global accessibility of information across cortical regions, is present in many of the prevailing frameworks. This account holds that consciousness is necessary to integrate information arising from independent functions such as the specialist processing required by different senses. We directly tested this account by evaluating the potential for associative learning between novel pairs of subliminal stimuli presented in different sensory modalities. First, pairs of subliminal stimuli were presented and then their association assessed by examining the ability of the first stimulus to prime classification of the second. In Experiments 1-4 the stimuli were word-pairs consisting of a male name preceding either a creative or uncreative profession. Participants were subliminally exposed to two name-profession pairs where one name was paired with a creative profession and the other an uncreative profession. A supraliminal task followed requiring the timed classification of one of those two professions. The target profession was preceded by either the name with which it had been subliminally paired (concordant) or the alternate name (discordant). Experiment 1 presented stimuli auditorily, Experiment 2 visually, and Experiment 3 presented names auditorily and professions visually. All three experiments revealed the same inverse priming effect with concordant test pairs associated with significantly slower classification judgements. Experiment 4 sought to establish if learning would be more efficient with supraliminal stimuli and found evidence that a different strategy is adopted when stimuli are consciously perceived. Finally, Experiment 5 replicated the unconscious cross-modal association achieved in Experiment 3 utilising non-linguistic stimuli. The results demonstrate the acquisition of novel cross-modal associations between stimuli which are not

  13. Prevailing negative soil biota effect and no evidence for local adaptation in a widespread Eurasian grass.

    Directory of Open Access Journals (Sweden)

    Viktoria Wagner

    2011-03-01

    Full Text Available Soil biota effects are increasingly accepted as an important driver of the abundance and distribution of plants. While biogeographical studies on alien invasive plant species have indicated coevolution with soil biota in their native distribution range, it is unknown whether adaptation to soil biota varies among populations within the native distribution range. The question of local adaptation between plants and their soil biota has important implications for conservation of biodiversity and may justify the use of seed material from local provenances in restoration campaigns.We studied soil biota effects in ten populations of the steppe grass Stipa capillata from two distinct regions, Europe and Asia. We tested for local adaptation at two different scales, both within (ca. 10-80 km and between (ca. 3300 km regions, using a reciprocal inoculation experiment in the greenhouse for nine months. Generally, negative soil biota effects were consistent. However, we did not find evidence for local adaptation: both within and between regions, growth of plants in their 'home soil' was not significantly larger relative to that in soil from other, more distant, populations.Our study suggests that negative soil biota effects can prevail in different parts of a plant species' range. Absence of local adaptation points to the possibility of similar rhizosphere biota composition across populations and regions, sufficient gene flow to prevent coevolution, selection in favor of plasticity, or functional redundancy among different soil biota. From the point of view of plant--soil biota interactions, our findings indicate that the current practice of using seeds exclusively from local provenances in ecosystem restoration campaigns may not be justified.

  14. Seasonal atmospheric extinction

    International Nuclear Information System (INIS)

    Mikhail, J.S.

    1979-01-01

    Mean monochromatic extinction coefficients at various wavelengths at the Kottamia Observatory site have shown the existence of a seasonal variation of atmospheric extinction. The extinction of aerosol compontnts with wavelengths at winter represent exceedingly good conditions. Spring gives the highest extinction due to aerosol. (orig.)

  15. Atmospheric thermodynamics

    CERN Document Server

    Iribarne, J V

    1973-01-01

    The thermodynamics of the atmosphere is the subject of several chapters in most textbooks on dynamic meteorology, but there is no work in English to give the subject a specific and more extensive treatment. In writing the present textbook, we have tried to fill this rather remarkable gap in the literature related to atmospheric sciences. Our aim has been to provide students of meteorology with a book that can playa role similar to the textbooks on chemical thermodynamics for the chemists. This implies a previous knowledge of general thermodynamics, such as students acquire in general physics courses; therefore, although the basic principles are reviewed (in the first four chapters), they are only briefly discussed, and emphasis is laid on those topics that will be useful in later chapters, through their application to atmospheric problems. No attempt has been made to introduce the thermodynamics of irreversible processes; on the other hand, consideration of heterogeneous and open homogeneous systems permits a...

  16. Atmospheric pollution

    International Nuclear Information System (INIS)

    Lambrozo, J.; Guillossou, G.

    2008-01-01

    The atmosphere is the reservoir of numerous pollutants (nitrogen oxides, sulfur oxides, carbon oxides, particulates, volatile organic compounds, polycyclic aromatic hydrocarbons) from natural origin or anthropogenic origin ( industry, transport, agriculture, district heating). With epidemiologic studies the atmospheric pollution is associated with an increase of respiratory and cardiovascular diseases. At the european level, the technological progress, the legislation have allowed a reduction of pollutant emissions, however these efforts have to be continued because the sanitary impact of atmospheric pollution must not be underestimated, even if the risks appear less important that these ones in relation with tobacco, inside pollution or others factors of cardiovascular risks. Indeed, on these last factors an individual action is possible for the exposure to air pollution people have no control. (N.C.)

  17. Interannual variability in the extent and intensity of tropical dry forest deciduousness in the Mexican Yucatan (2000-2016): Drivers and Links to Regional Atmospheric Conditions

    Science.gov (United States)

    Cuba, Nicholas Joseph

    The dry topical forests of the southern Yucatan Peninsula experience multiple natural and anthropogenic disturbances, as well as substantial interannual climate variability that can result in stark interannual differences in vegetation phenology. Dry season deciduousness is a typical response to limit tree water loss during prolonged periods of hot and dry conditions, and this behavior has both direct implications for ecosystem functioning, and the potential to indicate climate conditions when observed using remotely-sensed data. The first research paper of this dissertation advances methods to assess the accuracy of remotely-sensed measurements of canopy conditions using in-situ observations. Linear regression models show the highest correlation (R2 = 0.751) between in-situ canopy gap fraction and Landsat NDWISWIR2. MODIS time series NDWISWIR2 are created for the period March 2000-February 2011, and exhibit stronger correlation with time series of TRMM precipitation data than do MODIS EVI time series (R2= 0.48 vs. R2 = 0.43 in deciduous forest areas). The second paper examines differences between the deciduous phenology of young forest stands and older forest stands. Land-cover maps are overlaid to determine whether forested areas are greater than or less than 22 years old in 2010, and metrics related to deciduous phenology are derived from MODIS EVI2 time series in three years, 2008 to 2011. Statistical tests that compare matched pairs of young (12-22 years) and older (>22 years) forest stand age class samples are used to detect significant differences in metrics related to the intensity and timing of deciduousness. In all three years, younger forests exhibit significantly more intense deciduousness, measured as total seasonal change of EVI2 normalized by annual maximum EVI2 (pmediating environmental factors that drive the spatial and temporal variability in the intensity of deciduousness, and point toward analyzing deciduousness to reveal information about other

  18. Modelling in the experimental study of the hydrogen mixing with inner atmosphere of the safety containers of nuclear power plants in post LOCA conditions

    International Nuclear Information System (INIS)

    Fineschi, F.; Lanza, S.

    1979-01-01

    In light water nuclear power plants hydrogen releases from the pressure containment system may take place following a loss-of-coolant accident. In view of preparing technical safeguards aiming at the control of the flame propagation probability and of explosions, it is important to know the space-time distribytion of hydrogen concentrations in the safety containers. It is shown that an experimental study on a scale model is praticable only in the case when full turbulence conditions occur in the container and in the model. Then general aspects of a methodology capable to verify with a reasonable confiance degree the validity of the assumptions is illustrated

  19. Experimental study of the injection conditions influence over n-dodecane and diesel sprays with two ECN single-hole nozzles. Part II: Reactive atmosphere

    International Nuclear Information System (INIS)

    Payri, Raul; Salvador, F.J.; Gimeno, Jaime; Peraza, Jesús E.

    2016-01-01

    The second part of this experimental analysis, presented in this paper, seeks to go deep on the characterization of the Spray C and Spray D nozzles from the Engine Combustion Network, investigating the penetration of fuel spray at reacting conditions alongside characteristic parameters of combustion such as ignition delay and lift-off length. Both ECN mono-orifice injectors have similar nozzle flow capacity but different conicity degrees and corner sharpness, being Spray C more susceptible to cavitate. Schlieren imaging technique was employed to quantitatively measure reactive penetration and ignition delay, while lift-off length was identified through OH ∗ chemiluminescence. As in the inert part of this research, n-dodecane and commercial diesel were selected for the tests, thereby the effect of the fuel properties in the measured parameters was analyzed. Also, once again the concept of R-parameter, defined as the penetration derivative respect to the square root of time was calculated to delve into the penetration behavior. The experiments were performed in a constant pressure-flow facility able to reproduce engine-like thermodynamic conditions. Results revealed that R-parameter evolution can be divided in four stages: an inert zone, a ‘bump’, a ‘valley’ part and a quasi-steady one that overlaps the previous inert part. Those stages are highly governed by ambient temperature and oxygen concentration. Nozzle geometry and fuel properties demonstrated to have a noteworthy influence on all measured parameters.

  20. Blood lactate changes in men during graded workloads at normal atmospheric pressure (100 kPa) and under simulated caisson conditions (400 kPa).

    Science.gov (United States)

    Neubauer, B; Tetzlaff, K; Buslaps, C; Schwarzkopf, J; Bettinghausen, E; Rieckert, H

    1999-05-01

    A hyperbaric environment may influence lactate metabolism due to hyperoxia affecting biochemical pathways. The purpose of our study was to determine the blood lactate levels occurring at high workloads in a sample of professional divers under simulated caisson conditions. The ambient air pressure was equivalent to a diving depth of 30 m of seawater (400 kPa). A total of 23 healthy male subjects performed graded bicycle exercise in a dry hyperbaric chamber up to a maximum of 3.5 W kg(-1) body weight at normal (100 kPa) and elevated ambient air pressure (400 kPa). The blood lactate level and the heart rate were measured. In comparison with control conditions, the heart rate and the peripheral blood lactate level were significantly lower at depth for all workloads. The differences between the normobaric and hyperbaric lactate values may be explained by an overall improvement in lactate metabolism at elevated ambient pressure, especially in the working muscles and the organs responsible for the lactate reduction, i.e., the liver. The reduced heart rate may be an effect of the improved tissue oxygen supply at depth.

  1. Corrosion resistance of ceramic materials in pyrochemical reprocessing atmosphere by using molten salt for spent nuclear oxide fuel. Corrosion research under chlorine gas condition

    International Nuclear Information System (INIS)

    Takeuchi, Masayuki; Hanada, Keiji; Koizumi, Tsutomu; Aose, Shinichi; Kato, Toshihiro

    2002-12-01

    Pyrochemical reprocessing using molten salts (RIAR process) has been recently developed for spent nuclear oxide fuel and discussed in feasibility study. It is required to improve the corrosion resistance of equipments such as electrolyzer because the process is operated in severe corrosion environment. In this study, the corrosion resistance of ceramic materials was discussed through the thermodynamic calculation and corrosion test. The corrosion test was basically carried out in alkali molten salt under chlorine gas condition. And further consideration about the effects of oxygen, carbon and main fission product's chlorides were evaluated in molten salt. The result of thermodynamic calculation shows most of ceramic oxides have good chemical stability on chlorine, oxygen and uranyl chloride, however the standard Gibb's free energies with carbon have negative value. On the other hand, eleven kinds of ceramic materials were examined by corrosion test, then silicon nitride, mullite and cordierite have a good corrosion resistance less than 0.1 mm/y. Cracks were not observed on the materials and flexural strength did not reduce remarkably after 480 hours test in molten salt with Cl 2 -O 2 bubbling. In conclusion, these three ceramic materials are most applicable materials for the pyrochemical reprocessing process with chlorine gas condition. (author)

  2. An atmospheric dispersion model for linear sources in calm wind, stable conditions; Un modello di dispersione atmosferica per sorgenti lineari in condizioni di vento debole

    Energy Technology Data Exchange (ETDEWEB)

    Cirillo, M. C. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente; Buratti, D. [Rome Univ. La Sapienza, Rome (Italy). Facolta' di Scienze Statistiche; Metallo, M. C.; Poli, A.A. [ESA s.a.s., Bracciano, RM (Italy)

    1999-07-01

    In this report a dispersion model is proposed that provides an estimate of concentration of gaseous pollutants emitted by an highway, or in general by a line source, in presence of low wind speed. This aim was pursued because available models have not a satisfactory behaviour in such conditions, which is critical for dispersion of gaseous pollutants. This lack is due to difficulty of simulating dispersion turbulent component which is determined by fluctuation of wind speed and wind direction, and in presence of calm conditions it assumes values comparable with transport component. The proposed model overcomes this difficulty, as it is shown by sensitivity analysis and comparison with experimental data. The capability of simulating dispersion eve in critical conditions, like the presence of low level inversion, and the absence of source geometrical approximations make the model a tool that, properly used, may contribute to the efficient planning and management of environmental resources. [Italian] In questo rapporto viene proposto un modello per la stima delle concentrazioni di inquinanti aeriformi emessi da un'arteria stradale, o in generale da una sorgente lineare, in presenza di vento debole. Questo scopo e' stato perseguito in quanto in questa condizione, nonostante la dispersione degli inquinanti risulti fortemente problematica, i modelli disponibili in letteratura non hanno un comportamento soddisfacente. Questa mancanca e' attribuibile alla difficolta' di simulare la componente turbolenta della dispersione, dovuta alla fluttuazione della direzione e della velocita' del vento che, in presenza di vento debole, assume valori confrontabili alla componente di trasporto. Il modello qui di seguito proposto supera questa difficolta', come dimostrano l'analisi di sensibilita' e il confronto con un caso reale; la capacita' di simulare la dispersione anche in condizioni fisicamente critiche quali la presenza di inversione a

  3. Effect of flue gas composition on deposit induced high temperature corrosion under laboratory conditions mimicking biomass firing. Part II: Exposures in SO2 containing atmospheres

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Kiamehr, Saeed; Montgomery, Melanie

    2017-01-01

    SO2. Scanning electron microscopy (SEM), energy dispersive X-rayspectroscopy (EDS) and X-ray diffraction (XRD) techniques werecomplimentarily applied to characterize the resulting corrosion products. Apartially molten K2SO4-layer formed on KCl coated specimens, and corrosionresulted in localized......In biomass fired power plants, the fast corrosion of superheaters is facilitatedby the presence of corrosive flue gas species, for example, SO2, which arereleased during combustion. To understand the role of the gas species on thecorrosion process, comparative laboratory exposures of deposit (KCl......)-coatedand deposit-free austenitic stainless steel (TP 347H FG) samples to gas mixturescontaining SO2 was carried out, under conditions relevant to biomass-firing.Exposures were conducted isothermally at 560 8C for 72 h, in oxidizingsulphidizing,and oxidizing-sulphidizing-chlorinating gas mixtures containing60 ppmv...

  4. Alarming atmospheres

    DEFF Research Database (Denmark)

    Højlund, Marie; Kinch, Sofie

    2014-01-01

    Nurses working in the Neuro-Intensive Care Unit at Aarhus University Hospital lack the tools to prepare children for the alarming atmosphere they will enter when visiting a hospitalised relative. The complex soundscape dominated by alarms and sounds from equipment is mentioned as the main stressor...

  5. Meteorological controls on atmospheric particulate pollution during hazard reduction burns

    Science.gov (United States)

    Di Virgilio, Giovanni; Hart, Melissa Anne; Jiang, Ningbo

    2018-05-01

    Internationally, severe wildfires are an escalating problem likely to worsen given projected changes to climate. Hazard reduction burns (HRBs) are used to suppress wildfire occurrences, but they generate considerable emissions of atmospheric fine particulate matter, which depend upon prevailing atmospheric conditions, and can degrade air quality. Our objectives are to improve understanding of the relationships between meteorological conditions and air quality during HRBs in Sydney, Australia. We identify the primary meteorological covariates linked to high PM2.5 pollution (particulates pollution, the PBLH between 00:00 and 07:00 LT (local time) was 100-200 m higher than days with high pollution. The PBLH was similar during 10:00-17:00 LT for both low and high pollution days, but higher after 18:00 LT for HRB days with low pollution. Cloud cover, temperature and wind speed reflected the above pattern, e.g. mean temperatures and wind speeds were 2 °C cooler and 0.5 m s-1 lower during mornings and evenings of HRB days when air quality was poor. These cooler, more stable morning and evening conditions coincide with nocturnal westerly cold air drainage flows in Sydney, which are associated with reduced mixing height and vertical dispersion, leading to the build-up of PM2.5. These findings indicate that air pollution impacts may be reduced by altering the timing of HRBs by conducting them later in the morning (by a matter of hours). Our findings support location-specific forecasts of the air quality impacts of HRBs in Sydney and similar regions elsewhere.

  6. Prevailing climatic trends and runoff response from Hindukush-Karakoram-Himalaya, upper Indus Basin

    Science.gov (United States)

    Hasson, Shabeh ul; Böhner, Jürgen; Lucarini, Valerio

    2017-05-01

    Largely depending on the meltwater from the Hindukush-Karakoram-Himalaya, withdrawals from the upper Indus Basin (UIB) contribute half of the surface water availability in Pakistan, indispensable for agricultural production systems, industrial and domestic use, and hydropower generation. Despite such importance, a comprehensive assessment of prevailing state of relevant climatic variables determining the water availability is largely missing. Against this background, this study assesses the trends in maximum, minimum and mean temperatures, diurnal temperature range and precipitation from 18 stations (1250-4500 m a.s.l.) for their overlapping period of record (1995-2012) and, separately, from six stations of their long-term record (1961-2012). For this, a Mann-Kendall test on serially independent time series is applied to detect the existence of a trend, while its true slope is estimated using the Sen's slope method. Further, locally identified climatic trends are statistically assessed for their spatial-scale significance within 10 identified subregions of the UIB, and the spatially (field-) significant climatic trends are then qualitatively compared with the trends in discharge out of corresponding subregions. Over the recent period (1995-2012), we find warming and drying of spring (field-significant in March) and increasing early melt season discharge from most of the subregions, likely due to a rapid snowmelt. In stark contrast, most of the subregions feature a field-significant cooling within the monsoon period (particularly in July and September), which coincides well with the main glacier melt season. Hence, a decreasing or weakly increasing discharge is observed from the corresponding subregions during mid- to late melt season (particularly in July). Such tendencies, being largely consistent with the long-term trends (1961-2012), most likely indicate dominance of the nival but suppression of the glacial melt regime, altering overall hydrology of the UIB in

  7. Prevailing climatic trends and runoff response from Hindukush–Karakoram–Himalaya, upper Indus Basin

    Directory of Open Access Journals (Sweden)

    S. U. Hasson

    2017-05-01

    Full Text Available Largely depending on the meltwater from the Hindukush–Karakoram–Himalaya, withdrawals from the upper Indus Basin (UIB contribute half of the surface water availability in Pakistan, indispensable for agricultural production systems, industrial and domestic use, and hydropower generation. Despite such importance, a comprehensive assessment of prevailing state of relevant climatic variables determining the water availability is largely missing. Against this background, this study assesses the trends in maximum, minimum and mean temperatures, diurnal temperature range and precipitation from 18 stations (1250–4500 m a.s.l. for their overlapping period of record (1995–2012 and, separately, from six stations of their long-term record (1961–2012. For this, a Mann–Kendall test on serially independent time series is applied to detect the existence of a trend, while its true slope is estimated using the Sen's slope method. Further, locally identified climatic trends are statistically assessed for their spatial-scale significance within 10 identified subregions of the UIB, and the spatially (field- significant climatic trends are then qualitatively compared with the trends in discharge out of corresponding subregions. Over the recent period (1995–2012, we find warming and drying of spring (field-significant in March and increasing early melt season discharge from most of the subregions, likely due to a rapid snowmelt. In stark contrast, most of the subregions feature a field-significant cooling within the monsoon period (particularly in July and September, which coincides well with the main glacier melt season. Hence, a decreasing or weakly increasing discharge is observed from the corresponding subregions during mid- to late melt season (particularly in July. Such tendencies, being largely consistent with the long-term trends (1961–2012, most likely indicate dominance of the nival but suppression of the glacial melt regime

  8. Artificial Neural Network model for the determination of GSM Rxlevel from atmospheric parameters

    Directory of Open Access Journals (Sweden)

    Julia Ofure Eichie

    2017-04-01

    Full Text Available Accurate received signal level (Rxlevel values are useful for mobile telecommunication network planning. Rxlevel is affected by the dynamics of the atmosphere through which it propagates. Adequate knowledge of the prevailing atmospheric conditions in an environment is essential for proper network planning. However most of the existing GSM received signal determination model are function of distance between point of signal reception and transmitting site thus necessitating the development of a model that involve the use of atmospheric parameters in the determination of received GSM signal level. In this paper, a three stage approach was used in the development of the model using some atmospheric parameters such as atmospheric temperature, relative humidity and dew point. The selected and easily measurable atmospheric parameters were used as input parameters in developing two new models for computing the Rxlevel of GSM signal using a three-step approach. Data acquisition and pre-processing serves as the first stage and formulation of ANN design and the development of parametric model for the Rxlevel using ANN synaptic weights form the second stage of the proposed approach. The third stage involves the use of ANN weight and bias values, and network architecture in the development of the model equation. In evaluating the performance of the proposed models, network parameters were varied and the results obtained using mean squared error (MSE as performance measure showed the developed model with 33 neurons in the hidden layer and tansig activation, function in both the hidden and output layers as the optimal model with least MSE value of 0.056. Thus showing that the developed model has an acceptable accuracy value as demonstrated from comparison of results with actual measured values.

  9. Fault of the correction factor for pressure and temperature kPT in the atmospheric conditions of Dosimetric Calibration Lab. - LSCD of ININ - Mexico

    International Nuclear Information System (INIS)

    Alvarez R, Jose T.; Jesus Cejudo, A.; La Cruz H., Daniel de; Tovar M, Victor M.

    2013-01-01

    The realization of the operational quantities H*, Hp y/0 H'(0.07) for estimating the effective dose E, usually is done by measuring the air kerma Ka air within the field of ionizing radiation of interest and was subsequently applied appropriate conversion factors for both the quality of radiation and the operational quantity of interest. However, the SSDL in performing the Ka to environmental conditions of ININ (3000 m above sea level, P ∼ 710 hPa) with ionization chambers has found that the pressure correction factor and kPT temperature is not sufficient to correct the change in air density. Indeed, in the case of 60 Co the discrepancy between the measurement of a primary standard graphite walls Ka (BEV CC01 be 131) and a side of the plastic walls (Exradin A12) is on the order of 0.4% for the case of the RX BIPM qualities to 100,135, 180 and 250 kV. It was found that for a camera model 30001 PTW (PMMA graphite wall) is needed an additional correction factor k PT ranging from 0.4% to 1.5%, correction factor calculated by MC simulation. For Sk of 125 I brachytherapy sources was given an additional correction lower in 11% compared to conventional k PT value measured with a well chamber Standard Imaging HDR 1000 plus. Finally, it is in the process of studying the behavior of this additional correction factor to the case of 137 Cs

  10. Experimental determination of the atmospheric dispersion at the Karlsruhe Nuclear Research Center for 160 m and 195 m emission heights. Pt. 1

    International Nuclear Information System (INIS)

    Thomas, P.; Huebschmann, W.; Schuettelkopf, H.; Vogt, S.

    1983-03-01

    Diffusion experiments have been carried out at the Karlsruhe Nuclear Research Center in order to investigate the atmospheric diffusion of pollutants and to determine specifically the influence on atmospheric diffusion of topographic conditions specific to the site. For this purpose, halogenated hydrocarbons are emitted at 160 m and 195 m height, their local concentration distribution is measured at ground level downwind of the source. Part 1 of the report describes the diffusion experiments performed and presents the detailed data of measurements. These include the coordinates of the sampling positions, the measured concentrations and the relevant meteorological data recorded during the experiments. The stability classes prevailing during the experiments are derived from these data and are indicated. (orig.) [de

  11. Experimental determination of the atmospheric dispersion parameters at the Karlsruhe Nuclear Research Center for 60 m and 100 m emission heights. Pt. 1

    International Nuclear Information System (INIS)

    Thomas, P.; Dilger, H.; Huebschmann, W.; Schuettelkopf, H.; Vogt, S.; Kernforschungszentrum Karlsruhe G.m.b.H.

    1981-09-01

    Experiments have been carried out at the Karlsruhe Nuclear Research Center in order to investigate the atmospheric diffusion of pollutants. The influence on atmospheric diffusion of topographic conditions specific to the site is to be determined. For this purpose, halogenated hydrocarbons are emitted at 60 m and 100 m height; their local concentration distribution is measured at ground level downwind of the source. Part 1 of the report describes the diffusion experiments performed and presents the measured data in a detailed manner. The data include the coordinates of the sampling positions, the measured concentrations and the relevant meteorological data recorded during the experiments. The stability classes prevailing during the experiments are derived from these data and are indicated. (orig./HP) [de

  12. Further analysis of PREVAIL: enzalutamide use in chemotherapy-naïve men with metastatic castration-resistant prostate cancer.

    Science.gov (United States)

    Aragon-Ching, Jeanny B

    2014-01-01

    PREVAIL was a phase III multinational, double-blind, placebo-controlled trial that enrolled chemotherapy-naïve men with metastatic castration-resistant prostate cancer (mCRPC), which showed remarkable improvement in co-primary endpoints with an overall 81% reduction in the risk of radiographic progression, as well as 29% reduction in the risk of death in favor of the enzalutamide arm over placebo. All secondary endpoints including time to subsequent chemotherapy initiation and prostate specific antigen (PSA) progression were in favor of the enzalutamide arm. The results of PREVAIL shows the utility of enzalutamide that would likely soon expand the indication to asymptomatic or minimally symptomatic men with mCRPC not previously treated with chemotherapy.

  13. False-positive findings in mammography screening induces short-term distress - breast cancer-specific concern prevails longer

    DEFF Research Database (Denmark)

    Aro, A R; Pilvikki Absetz, S; van Elderen, T M

    2000-01-01

    -ups at 2 and 12 months postscreening. At 2 months, there was a moderate multivariate effect of group on distress; and intrusive thinking and worry about breast cancer, in particular, were most frequent amongst the false positives. Intrusive thinking still prevailed at 12 months, in addition to a higher...... findings (n=1407), false-positive findings (n=492) and referents from outside the screening programme (n=1718, age 48-49 years). Distress was measured as illness worry, anxiety, depression, cancer beliefs and early detection behaviour. Measurements were one month before screening invitation with follow...... perceived breast cancer risk and susceptibility. Distress related to screening and false-positive findings seems to be moderate, but prevailing cancer-specific concerns call for improvements in screening programmes....

  14. Radiative and temperature effects of aerosol simulated by the COSMO-Ru model for different atmospheric conditions and their testing against ground-based measurements and accurate RT simulations

    Science.gov (United States)

    Chubarova, Nataly; Poliukhov, Alexei; Shatunova, Marina; Rivin, Gdali; Becker, Ralf; Muskatel, Harel; Blahak, Ulrich; Kinne, Stefan; Tarasova, Tatiana

    2017-04-01

    We use the operational Russian COSMO-Ru weather forecast model (Ritter and and Geleyn, 1991) with different aerosol input data for the evaluation of radiative and temperature effects of aerosol in different atmospheric conditions. Various aerosol datasets were utilized including Tegen climatology (Tegen et al., 1997), updated Macv2 climatology (Kinne et al., 2013), Tanre climatology (Tanre et al., 1984) as well as the MACC data (Morcrette et al., 2009). For clear sky conditions we compare the radiative effects from the COSMO-Ru model over Moscow (55.7N, 37.5E) and Lindenberg/Falkenberg sites (52.2N, 14.1E) with the results obtained using long-term aerosol measurements. Additional tests of the COSMO RT code were performed against (FC05)-SW model (Tarasova T.A. and Fomin B.A., 2007). The overestimation of about 5-8% of COSMO RT code was obtained. The study of aerosol effect on temperature at 2 meters has revealed the sensitivity of about 0.7-1.1 degree C per 100 W/m2 change in shortwave net radiation due to aerosol variations. We also discuss the radiative impact of urban aerosol properties according to the long-term AERONET measurements in Moscow and Moscow suburb as well as long-term aerosol trends over Moscow from the measurements and Macv2 dataset. References: Kinne, S., O'Donnel D., Stier P., et al., J. Adv. Model. Earth Syst., 5, 704-740, 2013. Morcrette J.-J.,O. Boucher, L. Jones, eet al, J.GEOPHYS. RES.,VOL. 114, D06206, doi:10.1029/2008JD011235, 2009. Ritter, B. and Geleyn, J., Monthly Weather Review, 120, 303-325, 1992. Tanre, D., Geleyn, J., and Slingo, J., A. Deepak Publ., Hampton, Virginia, 133-177, 1984. Tarasova, T., and Fomin, B., Journal of Atmospheric and Oceanic Technology, 24, 1157-1162, 2007. Tegen, I., Hollrig, P., Chin, M., et al., Journal of Geophysical Research- Atmospheres, 102, 23895-23915, 1997.

  15. Comparison of the local-scale atmospheric dispersion model Cedrat with 85KR measurements

    International Nuclear Information System (INIS)

    Rennesson, M.; Devin, P.; Maro, D.; Fitamant, M.L.; Bouland, P.

    2004-01-01

    An accurate model of atmospheric dispersion of radionuclides over the complex terrain of the La Hague reprocessing plant (North Cotentin, France) has been developed by COGEMA, in partnership with Paris VI University. This model, called CEDRAT 1.0.1 (operational since October 2002), takes into account areas typically outside the validity limits of Gaussian models: relief and building influence, short-distance (beyond 500 m from the release point) and stable atmospheric conditions. The modelling tool is based on an original method: a 2D-meshed model for flow resolution at permanent rate in the prevailing wind direction, and a 3D description of the dispersion phenomena, taking into account wet and dry deposits, at permanent or transitory rate. This leads to an effective compromise between rapidity (45 min on a 6000 nodes grid, with a standard PC), robustness and accuracy, coupled with a user-friendly interface. Primarily the validation process consisted of a comparison with the 3D complex dispersion reference model MERCURE, developed by EDF. Then, MERCURE and CEDRAT results were compared on real release scenario basis, for which actual meteorological conditions and tracer data collected at monitoring stations around the site were known. To enlarge this validation process, a second level of comparison was made in collaboration with a IRSN Cherbourg team, through different field experiments, which provided both ground and elevated level measurements (collected with a captive balloon), for different stability classes of the atmosphere. The plume tracer is krypton 85, an inert gas released from a height of 100 m. Thus, the aim of this paper is to present the original method to describe short distance dispersion over complex terrain and its validation enrichment for stability conditions and areas not yet observed, through wind and cross-wind Atmospheric Transfer Coefficients comparisons, at both ground and elevated levels. (author)

  16. False-positive findings in mammography screening induces short-term distress - breast cancer-specific concern prevails longer

    DEFF Research Database (Denmark)

    Aro, A R; Pilvikki Absetz, S; van Elderen, T M

    2000-01-01

    The aim of this study was to examine psychological distress in a mammography screening process as a consequence of screening after adjusting for background, personality and prescreening distress. Subjects, aged 50 years, were invitees at their first screening. There were three groups; normal find...... perceived breast cancer risk and susceptibility. Distress related to screening and false-positive findings seems to be moderate, but prevailing cancer-specific concerns call for improvements in screening programmes....

  17. The surface oxidation kinetics of zirconium-niobium alloys and aα-Fe with prevailing cubical texture

    International Nuclear Information System (INIS)

    Mukhambetov, D.G.; Kargin, D.B.; Chalaya, O. V.; Berber, N.N.

    2002-01-01

    It is known, that the kinetics of oxidation of zirconium at formed heating is characterized by two consecutive stages. At the initial stage the thin protecting film will be derived. The relation of its depth from time h (t) is described predominantly by parabolic law. Some time later there can be a transition to the linear law of oxidation. The time moment divided these areas on the kinetic relation is called as a point of break. The film is formed at the second stage, has a developed grid of pores or cracks, can be flake away and be crumbled by losing its protective properties. At the oxidation of the surface shells of the heat generating elements and the technological channels of atomic boilers both stages are proceeded simultaneously. This phenomenon is called modular corrosion. Its consequences can be dangerous for the equipment. Its mechanism is not clear till now. Similar dependencies h(t), with the break point, beginning from which the thin film is transformed into the thick one were found by us at the oxidation α-Fe with prevailing cubical texture. The task of the work was to study the oxide film growth laws in order to clarify the mechanisms of transition of the thin film into the oxide layer on the α-Fe surface and Zr-Nb alloy modular corrosion emergence. Low-carbonate steel with contents 99.43 % of α-Fe was used as a model object of our research. In the texture of the steel surface planar direction [100] was prevalent. Its part accounted for about 40 %. The isothermal air oxidation was carried out in the interval of 450-500 deg. C . Phase composition of the film was determined with X-ray diffraction. The mathematical treatment of the dependencies h(t) obtained by experiment showed that the kinetics of the film growth can be conditionally divided into 4-stages. The initial stage is described by function logarithmic function, the other stages - by the power mode h n =A n ·t, namely, the second stage - is described by function close to cubical (n≅3

  18. Atmospheric Forcing of the Winter Air–Sea Heat Fluxes over the Northern Red Sea

    KAUST Repository

    Papadopoulos, Vassilis P.; Abualnaja, Yasser; Josey, Simon A.; Bower, Amy; Raitsos, Dionysios E.; Kontoyiannis, Harilaos; Hoteit, Ibrahim

    2013-01-01

    The influence of the atmospheric circulation on the winter air–sea heat fluxes over the northern Red Sea is investigated during the period 1985–2011. The analysis based on daily heat flux values reveals that most of the net surface heat exchange variability depends on the behavior of the turbulent components of the surface flux (the sum of the latent and sensible heat). The large-scale composite sea level pressure (SLP) maps corresponding to turbulent flux minima and maxima show distinct atmospheric circulation patterns associated with each case. In general, extreme heat loss (with turbulent flux lower than −400 W m−2) over the northern Red Sea is observed when anticyclonic conditions prevail over an area extending from the Mediterranean Sea to eastern Asia along with a recession of the equatorial African lows system. Subcenters of high pressure associated with this pattern generate the required steep SLP gradient that enhances the wind magnitude and transfers cold and dry air masses from higher latitudes. Conversely, turbulent flux maxima (heat loss minimization with values from −100 to −50 W m−2) are associated with prevailing low pressures over the eastern Mediterranean and an extended equatorial African low that reaches the southern part of the Red Sea. In this case, a smooth SLP field over the northern Red Sea results in weak winds over the area that in turn reduce the surface heat loss. At the same time, southerlies blowing along the main axis of the Red Sea transfer warm and humid air northward, favoring heat flux maxima.

  19. Atmospheric Forcing of the Winter Air–Sea Heat Fluxes over the Northern Red Sea

    KAUST Repository

    Papadopoulos, Vassilis P.

    2013-03-01

    The influence of the atmospheric circulation on the winter air–sea heat fluxes over the northern Red Sea is investigated during the period 1985–2011. The analysis based on daily heat flux values reveals that most of the net surface heat exchange variability depends on the behavior of the turbulent components of the surface flux (the sum of the latent and sensible heat). The large-scale composite sea level pressure (SLP) maps corresponding to turbulent flux minima and maxima show distinct atmospheric circulation patterns associated with each case. In general, extreme heat loss (with turbulent flux lower than −400 W m−2) over the northern Red Sea is observed when anticyclonic conditions prevail over an area extending from the Mediterranean Sea to eastern Asia along with a recession of the equatorial African lows system. Subcenters of high pressure associated with this pattern generate the required steep SLP gradient that enhances the wind magnitude and transfers cold and dry air masses from higher latitudes. Conversely, turbulent flux maxima (heat loss minimization with values from −100 to −50 W m−2) are associated with prevailing low pressures over the eastern Mediterranean and an extended equatorial African low that reaches the southern part of the Red Sea. In this case, a smooth SLP field over the northern Red Sea results in weak winds over the area that in turn reduce the surface heat loss. At the same time, southerlies blowing along the main axis of the Red Sea transfer warm and humid air northward, favoring heat flux maxima.

  20. Patterns of Precipitation and Streamflow Responses to Moisture Fluxes during Atmospheric Rivers

    Science.gov (United States)

    Henn, B. M.; Wilson, A. M.; Asgari Lamjiri, M.; Ralph, M.

    2017-12-01

    Precipitation from landfalling atmospheric rivers (ARs) have been shown to dominate the hydroclimate of many parts of the world. ARs are associated with saturated, neutrally-stable profiles in the lower atmosphere, in which forced ascent by topography induces precipitation. Understanding the spatial and temporal variability of precipitation over complex terrain during AR-driven precipitation is critical for accurate forcing of distributed hydrologic models and streamflow forecasts. Past studies using radar wind profilers and radiosondes have demonstrated predictability of precipitation rates based on upslope water vapor flux over coastal terrain, with certain levels of moisture flux exhibiting the greatest influence on precipitation. Additionally, these relationships have been extended to show that streamflow in turn responds predictably to upslope vapor flux. However, past studies have focused on individual pairs of profilers and precipitation gauges; the question of how orographic precipitation in ARs is distributed spatially over complex terrain, at different topographic scales, is less well known. Here, we examine profiles of atmospheric moisture transport from radiosondes and wind profilers, against a relatively dense network of precipitation gauges, as well as stream gauges, to assess relationships between upslope moisture flux and the spatial response of precipitation and streamflow. We focus on California's Russian River watershed in the 2016-2017 cool season, when regular radiosonde launches were made at two locations during an active sequence of landfalling ARs. We examine how atmospheric water vapor flux results in precipitation patterns across gauges with different topographic relationships to the prevailing moisture-bearing winds, and conduct a similar comparison of runoff volume response from several unimpaired watersheds in the upper Russian watershed, taking into account antecedent soil moisture conditions that influence runoff generation. Finally

  1. Reconstructing the prevailing meteorological and optical environment during the time of the Titanic disaster

    Science.gov (United States)

    Basu, Sukanta; Nunalee, Christopher G.; He, Ping; Fiorino, Steven T.; Vorontsov, Mikhail A.

    2014-10-01

    In this paper, we reconstruct the meteorological and optical environment during the time of Titanic's disaster utilizing a state-of-the-art meteorological model, a ray-tracing code, and a unique public-domain dataset called the Twentieth Century Global Reanalysis. With high fidelity, our simulation captured the occurrence of an unusually high Arctic pressure system over the disaster site with calm wind. It also reproduced the movement of a polar cold front through the region bringing a rapid drop in air temperature. The simulated results also suggest that unusual meteorological conditions persisted several hours prior to the Titanic disaster which contributed to super-refraction and intermittent optical turbulence. However, according to the simulations, such anomalous conditions were not present at the time of the collision of Titanic with an iceberg.

  2. Influência da época de colheita e do armazenamento em atmosfera controlada na qualidade da maçã 'Braeburn' Influence of harvest maturity and controlled atmosphere conditions on the quality of 'Braeburn' apple

    Directory of Open Access Journals (Sweden)

    Auri Brackmann

    2002-03-01

    Full Text Available Foi avaliado o efeito da época de colheita e das condições de armazenamento em atmosfera controlada sobre a firmeza da polpa, acidez titulável, ºBrix e, principalmente, sobre a ocorrência de degenerescência da polpa em maçãs (Malus domestica cv. Braeburn. Os tratamentos consistiram na combinação da data de colheita (27/3/1997 e 9/4/1997 com condição de armazenamento (temperatura de 0,5°C com: 1 kPa de O2/4,0 kPa de CO2; 1 kPa de O2/3,0 kPa de CO2; 1 kPa de O2/2,0 kPa de CO2; 21 kPa de O2/0,0 kPa de CO2, e temperatura de -0,5°C com: 1kPa de O2/3,0 kPa de CO2; 1 kPa de O2/2,0 kPa de CO2. Após oito meses de armazenamento, não foi observada suscetibilidade da maçã cv. Braeburn à baixa temperatura de armazenamento (-0,5ºC e os frutos armazenados em ambiente refrigerado apresentaram baixa qualidade para o consumo. As condições de atmosfera controlada de 1 kPa de O2 associadas com 2 e 3 kPa de CO2 e a -0,5ºC apresentaram menor incidência de podridões, rachaduras e degenerescência senescente. Os frutos colhidos tardiamente, em 9/4/1997, apresentaram maior incidência de podridões, polpa farinhenta, degenerescência com cortiça e rachaduras. Nos parâmetros firmeza da polpa, acidez titulável e teor de sólidos solúveis totais não se observaram diferenças entre as condições de atmosfera controlada, após sete dias de exposição à temperatura de 25ºC.This work was carried out to evaluate the effect of harvest maturity and controlled atmosphere on the quality and internal breakdown incidence in apples (Malus domestica cv. Braeburn. The treatments consisted in the combination of harvest maturity (March 27, 1997 and April 9, 1997 with storage conditions (0.5°C with: 1 kPa O2/4 kPa CO2; 1 kPa O2/3 kPa CO2; 1 kPa O2/2 kPa CO2; 21 kPa O2/0 kPa CO2-cold storage and; -0.5°C with: 1 kPa O2/3 kPa CO2; 1 kPa O2/2 kPa CO2. After eight months of storage, there was no low temperature injury on fruits stored at -0.5ºC, and the

  3. Novel sampling methods for atmospheric semi-volatile organic compounds (SOCs) in a high altitude alpine environment

    Energy Technology Data Exchange (ETDEWEB)

    Offenthaler, I. [Umweltbundesamt GmbH (Austria); Jakobi, G. [Helmholtz Zentrum Muenchen (German Research Centre for Environmental Health) (Germany); Kaiser, A. [ZAMG-Zentralanstalt fuer Meteorologie und Geo-dynamik (Austria); Kirchner, M. [Helmholtz Zentrum Muenchen (German Research Centre for Environmental Health) (Germany); Kraeuchi, N. [WSL-Swiss Federal Institute for Forest, Snow and Landscape Research (Switzerland); Niedermoser, B. [ZAMG-Zentralanstalt fuer Meteorologie und Geo-dynamik (Austria); Schramm, K.-W. [Helmholtz Zentrum Muenchen (German Research Centre for Environmental Health) (Germany); Sedivy, I. [WSL-Swiss Federal Institute for Forest, Snow and Landscape Research (Switzerland); Staudinger, M. [ZAMG-Zentralanstalt fuer Meteorologie und Geo-dynamik (Austria); Thanner, G.; Weiss, P. [Umweltbundesamt GmbH (Austria); Moche, W., E-mail: wolfgang.moche@umweltbundesamt.a [Umweltbundesamt GmbH (Austria)

    2009-12-15

    High- and low-volume active air samplers as well as bulk deposition samplers were developed to sample atmospheric SOCs under the adverse conditions of a mountain environment. Active sampling employed separate filters for different European source regions. Filters were switched depending on daily trajectory forecasts, whose accuracy was evaluated post hoc. The sampling continued on three alpine summits over five periods of four months. The prevailing trajectories varied stronger between sampling periods than between stations. The sampling equipment (active and bulk deposition) proved dependable for operation in a mountain environment, with idle times being mainly due to non-routine manipulations and connectivity. - Equipment for direction-specific air sampling and bulk deposition sampling in mountains was developed and tested.

  4. Assorted interactions of amino acids prevailing in aqueous vitamin C solutions probed by physicochemical and ab-initio contrivances

    Science.gov (United States)

    Das, Koyeli; Roy, Milan Chandra; Rajbanshi, Biplab; Roy, Mahendra Nath

    2017-11-01

    Qualitative and quantitative analysis of molecular interaction prevailing in tyrosine and tryptophan in aqueous solution of vitamin C have been probed by thermophysical properties. The apparent molar volume (ϕV), viscosity B-coefficient, molal refraction (RM) of tyrosine and tryptophan have been studied in aqueous vitamin C solutions at diverse temperatures via Masson equation which deduced solute-solvent and solute-solute interactions, respectively. Spectroscopic study along with physicochemical and computational techniques provides lots of interesting and highly significant insights of the model biological systems. The overall results established strong solute-solvent interactions between studied amino acids and vitamin C mixture in the ternary solutions.

  5. Types of analysis of trompenaar's (1994 organizational culture prevailing in the area of controllership in family businesses in textile industry

    Directory of Open Access Journals (Sweden)

    Vanderlei dos Santos

    2010-01-01

    Full Text Available The study aims to identify the types of analysis of Trompenaar's (1994 organizational culture prevailing in the area of controllership in family businesses in textile industry. Descriptive research was performed, with quantitative and qualitative approach, using a multiple case study. Data were collected through interviews with the controller of the companies. In the four basic culture types suggested by Trompenaars (1994, it is concluded that there isn´t a pure kind, but there is a strong presence of family culture among the companies surveyed in dimensions relationship between employees, attitude in relation to the ways of change, forms of motivation and reward

  6. Atmospheres in a Test Tube

    Science.gov (United States)

    Claudi, R.; Erculiani, M. S.; Giro, E.; D'Alessandro, M.; Galletta, G.

    2013-09-01

    The "Atmosphere in a Test Tube" project is a laboratory experiment that will be able to reproduce condition of extreme environments by means of a simulator. These conditions span from those existing inside some parts of the human body to combinations of temperatures, pressures, irradiation and atmospheric gases present on other planets. In this latter case the experiments to be performed will be useful as preliminary tests for both simulation of atmosphere of exoplanets and Solar System planets and Astrobiology experiments that should be performed by planetary landers or by instruments to be launched in the next years. In particular at INAF Astronomical Observatory of Padova Laboratory we are approaching the characterization of extrasolar planet atmospheres taking advantage by innovative laboratory experiments with a particular focus on low mass Neptunes and Super earths and low mass M dwarfs primaries.

  7. Effect of growth conditions on the Al composition and optical properties of Al x Ga 1−x N layers grown by atmospheric-pressure metal organic vapor phase epitaxy

    KAUST Repository

    Soltani, S.

    2017-02-17

    The effect of growth conditions on the Al composition and optical properties of AlxGa1-xN layers grown by atmospheric-pressure metal organic vapor phase epitaxy is investigated. The Al content of the samples is varied between 3.0% and 9.3% by changing the gas flow rate of either trimethylaluminum (TMA) or trimethylgallium (TMG) while other growth parameters are kept constant. The optical properties of the AlxGa1-xN layers are studied by photoreflectance and time-resolved photoluminescence (TR-PL) spectroscopies. A degeneration in the material quality of the samples is revealed when the Al content is increased by increasing the TMA flow rate. When the TMG flow rate is decreased with a fixed TMA flow rate, the Al content of the AlxGa1-xN layers is increased and, furthermore, an improvement in the optical properties corresponding with an increase in the PL decay time is observed. (C) 2017 Elsevier B.V. All rights reserved.

  8. Effect of growth conditions on the Al composition and optical properties of Al x Ga 1−x N layers grown by atmospheric-pressure metal organic vapor phase epitaxy

    KAUST Repository

    Soltani, S.; Bouzidi, M.; Chine, Z.; Toure, A.; Halidou, I.; El Jani, B.; Shakfa, M. K.

    2017-01-01

    The effect of growth conditions on the Al composition and optical properties of AlxGa1-xN layers grown by atmospheric-pressure metal organic vapor phase epitaxy is investigated. The Al content of the samples is varied between 3.0% and 9.3% by changing the gas flow rate of either trimethylaluminum (TMA) or trimethylgallium (TMG) while other growth parameters are kept constant. The optical properties of the AlxGa1-xN layers are studied by photoreflectance and time-resolved photoluminescence (TR-PL) spectroscopies. A degeneration in the material quality of the samples is revealed when the Al content is increased by increasing the TMA flow rate. When the TMG flow rate is decreased with a fixed TMA flow rate, the Al content of the AlxGa1-xN layers is increased and, furthermore, an improvement in the optical properties corresponding with an increase in the PL decay time is observed. (C) 2017 Elsevier B.V. All rights reserved.

  9. The contributions of the cerebellum in sensorimotor control: what are the prevailing opinions which will guide forthcoming studies?

    Science.gov (United States)

    Manto, Mario; Oulad Ben Taib, Nordeyn

    2013-06-01

    Although considerable progress has been made in developing models of cerebellar function in sensorimotor control, the exact nature of the basic operations performed by the cerebellum remain elusive. Several major theories have emerged these last decades. According to the hypothesis of Marr and Albus, the climbing fiber input carries an error signal weakening the strength of a subset of parallel fibers/Purkinje neurons synapses in the cerebellar cortex. Cerebellar circuits would gain the control of movement through trial and error. The hypothesis of internal models emulating movements is currently highly cited. There is a general agreement that (1) the central nervous system has to cope with an intrinsic time delay of sensory feedback related to motor activities and (2) estimations of future motor states are essential to perform fast and accurate movements. According to this second theory, cerebellar dysmetria, one of the cardinal cerebellar deficits, would result from a distorted predictive control. A third popular theory relates to the inverse models that would be stored in the cerebellum. Acquisition of a motor act would require forward models, and the acquisition process itself would generate an inverse model to allow an unconscious coordinated movement. Recently, an international panel of experts from various disciplines discussed the prevailing opinions in a consensus statement and tried to extract their clinical relevance in terms of pathogenesis of the clinical symptoms. Although a consensus is still not reached, the prevailing opinions provide a sound framework to conduct novel studies and try to discover the secrets of cerebellar circuits.

  10. Atmospheric chemistry and climate

    OpenAIRE

    Satheesh, SK

    2012-01-01

    Atmospheric chemistry is a branch of atmospheric science where major focus is the composition of the Earth's atmosphere. Knowledge of atmospheric composition is essential due to its interaction with (solar and terrestrial) radiation and interactions of atmospheric species (gaseous and particulate matter) with living organisms. Since atmospheric chemistry covers a vast range of topics, in this article the focus is on the chemistry of atmospheric aerosols with special emphasis on the Indian reg...

  11. Functional diagnostics for thyrotropin hormone receptor autoantibodies: bioassays prevail over binding assays.

    Science.gov (United States)

    Lytton, Simon David; Schluter, Anke; Banga, Paul J

    2018-06-01

    Autoantibodies to the thyrotropin hormone receptor (TSH-R) are directly responsible for the hyperthyroidism in Graves' disease and mediate orbital manifestations in Graves' orbitopathy (otherwise known as thyroid eye disease). These autoantibodies are heterogeneous in their function and collectively referred to as TRAbs. Measurement of TRAbs is clinically important for diagnosis of a variety of conditions and different commercial assays with high sensitivity and specificity are available for diagnostic purposes. This review provides overwhelming evidence that the TRAbs detected in binding assays by mainly the automated electrochemical luminescence immunoassays (ECLIA) do not distinguish TRAbs that stimulate the TSH-R (called TSIs or TSAbs) and TRAbs that just inhibit the binding of TSH without stimulating the TSH-R (called TBAbs). However, TSAbs and TBAbs have divergent pathogenic roles, and depending which fraction predominates cause different clinical symptoms and engender different therapeutic regimen. Therefore, diagnostic distinction of TSAbs and TBAbs is of paramount clinical importance. To date, only bioassays such as the Mc4 TSH-R bioassay (Thyretain TM , Quidel) and the Bridge assay (Immulite 2000, Siemens) can measure TSAbs, with only the former being able to distinguish between TSAbs and TBAbs. On this note, it is strongly recommended to only use the term TSI or TSAb when reporting the results of bioassays, whereas the results of automated TRAb binding assays should be reported as TRAbs (of undetermined functional significance). This review aims to present a technical and analytical account of leading commercial diagnostic methods of anti-TSH-R antibodies, a metaanalysis of their clinical performance and a perspective for the use of cell based TSH-R bioassays in the clinical diagnostics of Graves' disease.

  12. Desulfofrigus sp. prevails in sulfate-reducing dilution cultures from sediments of the Benguela upwelling area.

    Science.gov (United States)

    Kraft, Beate; Engelen, Bert; Goldhammer, Tobias; Lin, Yu-Shih; Cypionka, Heribert; Könneke, Martin

    2013-04-01

    Sediments of coastal upwelling areas are generally characterized by a high content of organic carbon that is mainly degraded via anaerobic microbial processes including sulfate reduction as a major terminal oxidation step. Despite the high importance of sulfate reduction in these sediments, the identity of sulfate-reducing bacteria (SRB) has remained almost unknown. Here, we applied a cultivation-based approach using selective enrichment conditions to study the diversity and distribution of active SRB in sediments along a transect perpendicular to the continental slope off the coast of Namibia (Meteor-cruise M76/1). To promote growth of the most abundant SRB, dilution series were prepared and amended with hydrogen, acetate, or a mixture of monomers representing typical substrates for SRB. Growth of SRB could be detected in the presence of all electron donors and from sediment down to 4 m depth. 16S rRNA gene-based DGGE analysis and sequencing revealed the predominance of SRB related to psychrophiles in particular to the genus Desulfofrigus, which made up 1 % of the total microbial community, accounting for an absolute abundance of up to 4.8 × 10(7)  cells mL(-1) . In general, the abundance of cultured SRB changed with depth and between the different sampling sites and correlated with the content of organic carbon as previously reported. Growth of chemolithotrophic SRB in relatively high dilution steps and the enrichment of methanogens as well as acetogens from deeper sediment point to a competition between hydrogen-utilizing microbial processes and their biogeochemical significance in deep sediment layers of the Benguela upwelling area. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  13. Flowering and fruit set of six cultivars of highbush blueberry (Vaccinium corymbosum L. in the conditions of the Lublin Region

    Directory of Open Access Journals (Sweden)

    Małgorzata Bożek

    2012-12-01

    Full Text Available The results presented in this paper relate to the time and duration of flowering of highbush blueberry as well as fruit set in the conditions of flower isolation and free visitation by pollinating insects. Observations were carried out in the years 2001- 2004 at a plantation located in Niemce near the city of Lublin. Six cultivars: 'Bluecrop', 'Bluejay', 'Croatan', 'Darrow', 'Northland' and 'Spartan', were covered by the study. The flowering period of the studied highbush blueberry cultivars was in May in three years of study, whereas in 2004 in May and June. Depending on the year, it lasted from 14 up to 21 days, on the average. Significant differences were found in the life span of a single flower which, depending on the cultivar and conditions prevailing during flowering, bloomed from 5 up to 10 days (the average for all the years for all the cultivars. With free access of pollinating insects, highbush blueberry set an average of 92 false-berries per 100 flowers, whereas only 40 during spontaneous self-pollination under the isolating cover. In each year of study, irrespective of atmospheric conditions prevailing during flowering as well as the time and duration of flowering, fruit set of the investigated cultivars in flowers freely accessible to pollinating insects should be considered to be good or very good.

  14. Nature, distribution, and effects upon vegetation of atmospheric impurities in and near an industrial town

    Energy Technology Data Exchange (ETDEWEB)

    Crowther, C; Ruston, A G

    1911-01-01

    The investigtions recorded constitute a rough survey of the influence of atmospheric impurities upon the growth of plants. They do show clearly that this influence, even outside the towns, may under certain conditions have appreciable bearing upon farm economy. The atmosphere in and around a large industrial city such as Leeds is relatively highly charged with impurities, many of which exert a marked deleterious effect upon plant growth. The impurities are most abundant in the industrial quarters of the city, but are disseminated over very large areas, especially in the direction of the prevailing winds. The rain falling through such a polluted atmosphere becomes notably rich in suspended matters, chlorides, sulphates (often also other sulphur compounds, such as SO/sub 2/), nitrogenous compounds (notably ammonia) and free acid. The suspended matters in the air impede the growth of plants not only by their deposition upon the leaves and consequent hindrance to the free passage of gases into and out of the leaves, but also by reducing the intensity of illumination of the leaves, such reduction amounting in the worst case investigated to fully 40 per cent of the maximum light available. The presence of free acid in the atmosphere exercises a detrimental influence upon plant growth: (a) by direct action upon the leaves indirectly by reducing the activity not only of the necessary ammoniacal fermentation of the soil humus, but even more of the beneficial nitrifying and nitrogen-fixing organisms in the soil. The experiment with the perennial meadow grass, timothy, indicates that with the continued application to the soil of acid rain the produce becomes distinctly poorer in protein and richer in crude fiber, and consequently less nutritious.

  15. Rectenna related atmospheric effects

    Science.gov (United States)

    Lee, J.

    1980-01-01

    Possible meteorological effects arising from the existence and operations of a solar power satellite (SPS) system rectenna are examined. Analysis and model simulations in some chosen site situations and meteorological conditions indicate that the meteorological effects of the construction and operation of a rectenna are small, particularly outside the boundary of the structure. From weather and climate points of view, installation of an SPS rectenna seems likely to have effects comparable with those due to other nonindustrial land use changes covering the same area. The absorption and scattering of microwave radiation in the troposphere would have negligible atmospheric effects.

  16. Atmospheric radiation monitor

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, M.A. Leigui de; Peixoto, C.J. Todero; Leao, M.S.A.B.; Luzio, V.P. [Universidade Federal do ABC (UFABC), SP (Brazil); Barbosa, A.F.; Lima Junior, H.P.; Vilar, A.B.; Gama, R.G.; Ferraz, V.A. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Full text: The Atmospheric Radiation Monitor (MonRAt) is a compact telescope designed to detect fluorescence photons generated in the atmosphere by ultra-high energy cosmic rays showers with energies in the interval between 10{sup 17} eV and 10{sup 18} eV. It is composite by a 64 pixels MultiAnodic PhotoMultiplier Tube (MAPMT) placed at the focus of a parabolic mirror mounted in a Newtonian telescope setup and the data acquisition system. In front of the MAPMT photocathode, filters will be positioned to select light with wavelength in the near ultraviolet region (300 nm < {lambda} < 450 nm) where the nitrogen fluorescent emissions occurs. The data acquisition system consists of a set of pre-amplifiers and FPGA-based boards able to record trigger times and waveforms from each channel and send the data to a computer by USB ports. MonRAt will be used to detect fluorescence photons under different atmospheric conditions (pressure, temperature, humidity, local geomagnetic field, etc) and will contribute with a detailed study of the fluorescence radiation yield. The assembly of the telescope is under way and we present in this work the status of the experiment and its first measurements in the laboratory. (author)

  17. Atmospheric radiation monitor

    International Nuclear Information System (INIS)

    Oliveira, M.A. Leigui de; Peixoto, C.J. Todero; Leao, M.S.A.B.; Luzio, V.P.; Barbosa, A.F.; Lima Junior, H.P.; Vilar, A.B.; Gama, R.G.; Ferraz, V.A.

    2011-01-01

    Full text: The Atmospheric Radiation Monitor (MonRAt) is a compact telescope designed to detect fluorescence photons generated in the atmosphere by ultra-high energy cosmic rays showers with energies in the interval between 10 17 eV and 10 18 eV. It is composite by a 64 pixels MultiAnodic PhotoMultiplier Tube (MAPMT) placed at the focus of a parabolic mirror mounted in a Newtonian telescope setup and the data acquisition system. In front of the MAPMT photocathode, filters will be positioned to select light with wavelength in the near ultraviolet region (300 nm < λ < 450 nm) where the nitrogen fluorescent emissions occurs. The data acquisition system consists of a set of pre-amplifiers and FPGA-based boards able to record trigger times and waveforms from each channel and send the data to a computer by USB ports. MonRAt will be used to detect fluorescence photons under different atmospheric conditions (pressure, temperature, humidity, local geomagnetic field, etc) and will contribute with a detailed study of the fluorescence radiation yield. The assembly of the telescope is under way and we present in this work the status of the experiment and its first measurements in the laboratory. (author)

  18. The Atmospheric Boundary Layer

    Science.gov (United States)

    Garratt, J. R.

    1994-05-01

    A comprehensive and lucid account of the physics and dynamics of the lowest one to two kilometers of the Earth's atmosphere in direct contact with the Earth's surface, known as the atmospheric boundary layer (ABL). Dr. Garratt emphasizes the application of the ABL problems to numerical modeling of the climate, which makes this book unique among recent texts on the subject. He begins with a brief introduction to the ABL before leading to the development of mean and turbulence equations and the many scaling laws and theories that are the cornerstone of any serious ABL treatment. Modeling of the ABL is crucially dependent for its realism on the surface boundary conditions, so chapters four and five deal with aerodynamic and energy considerations, with attention given to both dry and wet land surfaces and the sea. The author next treats the structure of the clear-sky, thermally stratified ABL, including the convective and stable cases over homogeneous land, the marine ABL, and the internal boundary layer at the coastline. Chapter seven then extends this discussion to the cloudy ABL. This is particularly relevant to current research because the extensive stratocumulus regions over the subtropical oceans and stratus regions over the Arctic have been identified as key players in the climate system. In the final chapters, Dr. Garratt summarizes the book's material by discussing appropriate ABL and surface parameterization schemes in general circulation models of the atmosphere that are being used for climate stimulation.

  19. Radiographic progression with nonrising PSA in metastatic castration-resistant prostate cancer: post hoc analysis of PREVAIL.

    Science.gov (United States)

    Bryce, A H; Alumkal, J J; Armstrong, A; Higano, C S; Iversen, P; Sternberg, C N; Rathkopf, D; Loriot, Y; de Bono, J; Tombal, B; Abhyankar, S; Lin, P; Krivoshik, A; Phung, D; Beer, T M

    2017-06-01

    Advanced prostate cancer is a phenotypically diverse disease that evolves through multiple clinical courses. PSA level is the most widely used parameter for disease monitoring, but it has well-recognized limitations. Unlike in clinical trials, in practice, clinicians may rely on PSA monitoring alone to determine disease status on therapy. This approach has not been adequately tested. Chemotherapy-naive asymptomatic or mildly symptomatic men (n=872) with metastatic castration-resistant prostate cancer (mCRPC) who were treated with the androgen receptor inhibitor enzalutamide in the PREVAIL study were analyzed post hoc for rising versus nonrising PSA (empirically defined as >1.05 vs ⩽1.05 times the PSA level from 3 months earlier) at the time of radiographic progression. Clinical characteristics and disease outcomes were compared between the rising and nonrising PSA groups. Of 265 PREVAIL patients with radiographic progression and evaluable PSA levels on the enzalutamide arm, nearly one-quarter had a nonrising PSA. Median progression-free survival in this cohort was 8.3 months versus 11.1 months in the rising PSA cohort (hazard ratio 1.68; 95% confidence interval 1.26-2.23); overall survival was similar between the two groups, although less than half of patients in either group were still at risk at 24 months. Baseline clinical characteristics of the two groups were similar. Non-rising PSA at radiographic progression is a common phenomenon in mCRPC patients treated with enzalutamide. As restaging in advanced prostate cancer patients is often guided by increases in PSA levels, our results demonstrate that disease progression on enzalutamide can occur without rising PSA levels. Therefore, a disease monitoring strategy that includes imaging not entirely reliant on serial serum PSA measurement may more accurately identify disease progression.

  20. Immediate occlusal loading of NanoTite PREVAIL implants: a prospective 1-year clinical and radiographic study.

    Science.gov (United States)

    Ostman, Pär-Olov; Wennerberg, Ann; Albrektsson, Tomas

    2010-03-01

    Recently, a new implant surface texture, featuring application of nanometer-scale calcium phosphate has been shown to enhance early bone fixation and formation in preclinical studies and in human histomorphometric studies, which may be beneficial in immediate loading situations. The purpose of the present prospective clinical study was to, during 1 year, clinically and radiographically evaluate a nanometer scale surface modified implant placed for immediate loading of fixed prostheses in both maxillary and mandibular regions. Thirty-five out of 38 patients who needed implant treatment and met inclusion criteria agreed to participate in the study and were consecutively enrolled. Surgical implant placement requirements consisted of a final torque of a least 25 Ncm prior to final seating and an implant stability quotient above 55. A total of 102 NanoTite PREVAIL (NTP) implants (BIOMET 3i, Palm Beach Gardens, FL, USA) (66 maxillary and 36 mandibular) were placed by one investigator, and the majority of these were placed in posterior regions (65%) and in soft bone (69%). A total of 44 prosthetic constructions were evaluated consisting of 14 single-tooth restorations, 26 fixed partial dentures, and four complete fixed restorations. All provisional constructions were delivered within 1 hour, and the final constructions placed after 4 months. Implants were monitored for clinical and radiographic outcomes at follow-up examinations scheduled for 3, 6, and 12 months. Of the 102 study implants, one implant failed. The simple cumulative survival rate value at 1 year was 99.2%. The average marginal bone resorption was 0.37 mm (SD 0.39) during the first year in function. According to the success criteria of Albrektsson and Zarb, success grade 1 was found with 93% of the implants. Although limited to the short follow-up, immediate loading of NanoTite Prevail implants seems to be a viable option in implant rehabilitation, at least when a good initial fixation is achieved.

  1. One-year multicentre outcomes of transapical aortic valve implantation using the SAPIEN XT™ valve: the PREVAIL transapical study.

    Science.gov (United States)

    Walther, Thomas; Thielmann, Matthias; Kempfert, Joerg; Schroefel, Holger; Wimmer-Greinecker, Gerhard; Treede, Hendrik; Wahlers, Thorsten; Wendler, Olaf

    2013-05-01

    The study aimed to evaluate 1-year outcomes of the multicentre PREVAIL transapical (TA) study of TA-aortic valve implantation (AVI) in high-risk patients. From September 2009 to August 2010, a total of 150 patients, aged 81.6 ± 5.8 years, 40.7% female, were included at 12 European TA-AVI experienced sites. Patients received 23 (n = 36), 26 (n = 57) and 29 mm (n = 57) second-generation SAPIEN XT™ (Edwards Lifesciences, Irvine, CA, USA) valves. The mean logistic EuroSCORE was 24.3 ± 7.0, and mean Society Thoracic Surgeons score was 7.5 ± 4.4%. Survival was 91.3% at 30 days and 77.9% at 1 year. Subgroup analysis revealed survivals of 91.7/88.9, 86.0/70.2, 96.55/91.2% for patients receiving 23-, 26- and 29-mm valves at 30 days and at 1 year, respectively. Transthoracic echocardiography revealed preserved left ventricular ejection fraction and low gradients. Aortic incompetence was none in 41/48, trace 30/36, mild 22/12 and moderate in 7/4% at discharge and 1 year. Walking distance increased from 221 (postimplant) to 284 m (at 1 year, P = 0.0004). Three patients required reoperation due to increasing aortic incompetence during follow-up. Causes of mortality at 1 year were cardiac (n = 7), stroke (n = 1) and others (n = 5). The European PREVAIL multicentre trial demonstrates good functionality and good outcomes for TA-AVI using the second-generation SAPIEN XT prosthesis and the ASCENDRA-II delivery system. The 29-mm SAPIEN XT valve was successfully introduced and showed excellent results.

  2. Deciduous birch canopy as unexpected contributor to stand level atmospheric reactivity in boreal forests

    Science.gov (United States)

    Bäck, Jaana; Taipale, Ditte; Aalto, Juho

    2017-04-01

    senescence in addition to prevailing temperature and light conditions. With these improvements and inputs to the 1D biosphere-atmosphere model SOSAA (model to Simulate Organic vapours, Sulphuric Acid and Aerosols), we showed that the contribution of Silver birch to stand scale atmospheric reactivity may exceed the ones from conifers, and therefore specific land use and species distribution patterns should be accounted for in biosphere-atmosphere models describing the surface-atmosphere exchange of reactive gases.

  3. When politics prevails

    DEFF Research Database (Denmark)

    Jensen, Mads Dagnis; Snaith, Holly

    2016-01-01

    This article analyses Britain’s quest to negotiate its future membership of the European Union (EU) through the lens of Liberal intergovernmentalism. The article demonstrates that despite the significant economic consequences of a potential Brexit, party political factors have hitherto proven more...

  4. OECOSYS prevailing exercise applications

    International Nuclear Information System (INIS)

    Mueck, K.; Suda, M.

    1999-10-01

    In the Research Center Seibersdorf the computer simulation code OECOSYS was installed in 1989 which represents a version of the model ECOSYS-87 developed by GSF in Neuherberg, and adapted to the Austrian situation. The model available since then simulates from input parameters such as the integral of the activity concentration in air and the ground deposition of each radionuclide as well as the precipitation values via the interception on plants and deposition on soil and the transfer of radionuclides into the various ecosystems and fodder-food chains into the various foodstuffs and calculates in this way the course of the activity concentration in these foodstuffs. Via the consumption rates of each foodstuff the contribution of the ingestion of each foodstuff and by that the total ingestion dose may be evaluated. Further, the simulation model permits the calculation of the various exposure pathways as inhalation and external irradiation from the plume and ground and enable the user to obtain a fast comparison of the various exposure pathways. In order to ensure the availability of the code and the accompanying infrastructure, by order of the federal chancellery sect. VI the computer code is run in certain intervals and test calculations are performed with it. Each exercise run was based on scenarios which could result in case of severe accidents in neighboring nuclear power plants. Generally, extremely unrealistic scenarios were assumed which do not correspond to the safety standard of the respective nuclear power plant in order to obtain calculation examples which may serve the emergency units in their planning for emergency situations. Furthermore, by these exercise runs a demonstration of the contribution of the various exposure pathways for the persons responsible for emergency management in case of a crisis shall be given to enable them to appropriately design the respective planning features. In the present report the calculations performed up to now are compiled and comparatively displayed. (author)

  5. Can Cooler Heads Prevail?

    Science.gov (United States)

    Rice, A. R.

    2015-12-01

    The significant correlation between dropping temperatures throughout the Pliocene and the concomitant explosive expansion of the Hominid brain has led a number of workers to postulate climate change drove human evolution. Our brain (that of Homo sapiens), comprises 1-2 percent of our body weight but consumes 20 -25 percent of the body's caloric intake. We are "hotheads". Brains are extremely sensitive to overheating but we are endowed with unparalleled thermal regulation, much of it given over to protecting the Central Nervous System (CNS). Will there be reversed trends with global warming? The human brain has been shrinking since the end of the Ice Ages, losing about 150cc over the past 10,000 years. Polar bear skulls have been downsizing as well. Almost all mass extinctions or evolutionary upheavals are attributed to global warming: e.g. the Permian/Triassic (P/T) event, i.e., "The Great Dying", 250 million years ago (~90% of all life forms wiped out); the Paleocene/ Eocene Thermal Maximum (PETM) 55 million years ago. They may be analogs for what might await us. Large creatures, whose body size inhibits cooling, melted away during the PETM. Horses, initially the size of dogs then, reduced to the size of cats. An unanticipated hazard for humans that may attend extreme global warming is dumbing down or needing to retreat to the Poles as did those creatures that survived the P/T event (some references: http://johnhawks.net/research/hawks-2011-brain-size-selection-holocene; Kandel, E. et al Principles of Neural Science 4th ed. New York (US): McGraw-Hill, 2000; Selective Brain Cooling in Early Hominids:phylogenetic and evolutionary implications, Reeser, H., reeser@flmnh.ufl.edu; How the body controls brain temperature; the temperature shielding effect of cerebral blood flow, Mingming Z. et al. J Appl Physiol. 2006 November; 101(5): 1481-1488; news.nationalgeographic.com/ news/2014/03/140327-climate-change-shrinks-salamanders-global-warming-science/; Heat illness and heat stroke, www.ozemedicine.com/wiki/doku.php?id=heat illness 7/3/2010)

  6. Where the signs prevail

    Directory of Open Access Journals (Sweden)

    Dardo Scavino

    2016-03-01

    Full Text Available We propose to show in our paper that through his semiotic theory, Barthes developed a theory of subjectivity and society continued with the anti-utilitarian tradition of the Collège de Sociologie where George Bataille, Carl Einstein or Michel Leiris had favored the mythical and ritual dimension of collective life.

  7. Reducing strength prevailing at root surface of plants promotes reduction of Ag+ and generation of Ag(0/Ag2O nanoparticles exogenously in aqueous phase.

    Directory of Open Access Journals (Sweden)

    Peddisetty Pardha-Saradhi

    Full Text Available Potential of root system of plants from wide range of families to effectively reduce membrane impermeable ferricyanide to ferrocyanide and blue coloured 2,6-dichlorophenol indophenol (DCPIP to colourless DCPIPH2 both under non-sterile and sterile conditions, revealed prevalence of immense reducing strength at root surface. As generation of silver nanoparticles (NPs from Ag+ involves reduction, present investigations were carried to evaluate if reducing strength prevailing at surface of root system can be exploited for reduction of Ag+ and exogenous generation of silver-NPs. Root system of intact plants of 16 species from 11 diverse families of angiosperms turned clear colorless AgNO3 solutions, turbid brown. Absorption spectra of these turbid brown solutions showed silver-NPs specific surface plasmon resonance peak. Transmission electron microscope coupled with energy dispersive X-ray confirmed the presence of distinct NPs in the range of 5-50 nm containing Ag. Selected area electron diffraction and powder X-ray diffraction patterns of the silver NPs showed Bragg reflections, characteristic of crystalline face-centered cubic structure of Ag(0 and cubic structure of Ag2O. Root system of intact plants raised under sterile conditions also generated Ag(0/Ag2O-NPs under strict sterile conditions in a manner similar to that recorded under non-sterile conditions. This revealed the inbuilt potential of root system to generate Ag(0/Ag2O-NPs independent of any microorganism. Roots of intact plants reduced triphenyltetrazolium to triphenylformazon and impermeable ferricyanide to ferrocyanide, suggesting involvement of plasma membrane bound dehydrogenases in reduction of Ag+ and formation of Ag(0/Ag2O-NPs. Root enzyme extract reduced triphenyltetrazolium to triphenylformazon and Ag+ to Ag(0 in presence of NADH, clearly establishing potential of dehydrogenases to reduce Ag+ to Ag(0, which generate Ag(0/Ag2O-NPs. Findings presented in this manuscript put

  8. Objective Method for Selecting Outdoor Reporting Conditions for Photovoltaic Performance

    International Nuclear Information System (INIS)

    Maish, A.

    1999-01-01

    Outdoor performance of photovoltaic modules and systems depends on prevailing conditions at the time of measurement. Outdoor test conditions must be relevant to device performance and readily attainable. Flat-plate, nonconcentrator PV device performance is reported with respect to fixed conditions referred to as Standard Reporting Conditions (SRC) of 1 kW/m plane of array total irradiance, 25 C device temperature, and a reference spectral distribution at air mass 1.5 under certain atmospheric conditions. We report a method of analyzing historical meteorological and irradiance data to determine the range of outdoor environmental parameters and solar irradiance components that affect solar collector performance when the SRC 1 kW/m total irradiance value occurs outdoors. We used data from the 30 year U.S. National Solar Radiation Data Base (NSRDB) , restricting irradiance conditions to within +/- 25 W/m of 1 kW/m on a solar tracking flat-plate collector. The distributions of environmental parameter values under these conditions are non-Gaussian and site dependent. Therefore the median, as opposed to the mean, of the observed distributions is chosen to represent appropriate outdoor reporting conditions. We found the average medians for the direct beam component (834 W/m), ambient temperature (24.4 C), total column water vapor (1.4 cm), and air mass (1.43) are near commonly used SRC values. Average median wind speed (4.4 m/s) and broadband aerosol optical depth (0.08) were significantly different from commonly used values

  9. Shift of large-scale atmospheric systems over Europe during late MIS 3 and implications for Modern Human dispersal.

    Science.gov (United States)

    Obreht, Igor; Hambach, Ulrich; Veres, Daniel; Zeeden, Christian; Bösken, Janina; Stevens, Thomas; Marković, Slobodan B; Klasen, Nicole; Brill, Dominik; Burow, Christoph; Lehmkuhl, Frank

    2017-07-19

    Understanding the past dynamics of large-scale atmospheric systems is crucial for our knowledge of the palaeoclimate conditions in Europe. Southeastern Europe currently lies at the border between Atlantic, Mediterranean, and continental climate zones. Past changes in the relative influence of associated atmospheric systems must have been recorded in the region's palaeoarchives. By comparing high-resolution grain-size, environmental magnetic and geochemical data from two loess-palaeosol sequences in the Lower Danube Basin with other Eurasian palaeorecords, we reconstructed past climatic patterns over Southeastern Europe and the related interaction of the prevailing large-scale circulation modes over Europe, especially during late Marine Isotope Stage 3 (40,000-27,000 years ago). We demonstrate that during this time interval, the intensification of the Siberian High had a crucial influence on European climate causing the more continental conditions over major parts of Europe, and a southwards shift of the Westerlies. Such a climatic and environmental change, combined with the Campanian Ignimbrite/Y-5 volcanic eruption, may have driven the Anatomically Modern Human dispersal towards Central and Western Europe, pointing to a corridor over the Eastern European Plain as an important pathway in their dispersal.

  10. The ACCENT-VOCBAS field campaign on biosphere-atmosphere interactions in a Mediterranean ecosystem of Castelporziano (Rome: site characteristics, climatic and meteorological conditions, and eco-physiology of vegetation

    Directory of Open Access Journals (Sweden)

    S. Fares

    2009-06-01

    Full Text Available Biosphere-atmosphere interactions were investigated on a sandy dune Mediterranean ecosystem in a field campaign held in 2007 within the frame of the European Projects ACCENT and VOCBAS. The campaign was carried out in the Presidential estate of Castelporziano, a peri-urban park close to Rome. Former campaigns (e.g. BEMA performed in Castelporziano investigated the emission of biogenic volatile organic compounds (BVOC. These campaigns focused on pseudosteppe and evergreen oak groves whereas the contribution of the largely biodiverse dune vegetation, a prominent component of the Mediterranean ecosystem, was overlooked. While specific aspects of the campaign will be discussed in companion papers, the general climatic and physiological aspects are presented here, together with information regarding BVOC emission from the most common plant species of the dune ecosystem. During the campaign regular air movements were observed, dominated by moderate nocturnal land breeze and diurnal sea breeze. A regular daily increase of ozone concentration in the air was also observed, but daily peaks of ozone were lower than those measured in summer on the same site. The site was ideal as a natural photochemical reactor to observe reaction, transport and deposition processes occurring in the Mediterranean basin, since the sea-land breeze circulation allowed a strong mixing between biogenic and anthropogenic emissions and secondary pollutants. Measurements were run in May, when plant physiological conditions were optimal, in absence of severe drought and heat stress. Foliar rates of photosynthesis and transpiration were as high as generally recorded in unstressed Mediterranean sclerophyllous plants. Most of the plant species emitted high level of monoterpenes, despite measurements being made in a period in which emissions of volatile isoprenoids could be restrained by developmental and environmental factors, such as leaf age and relatively low air temperature

  11. a Study of the Origin of Atmospheric Organic Aerosols

    Science.gov (United States)

    Hildemann, Lynn Mary

    1990-01-01

    The sources of ambient organic particulate matter in urban areas are investigated through a program of emission source measurements, atmospheric measurements, and mathematical modeling of source/receptor relationships. A dilution sampler intended to collect fine organic aerosol from combustion sources is designed to simulate atmospheric cooling and dilution processes, so that organic vapors which condense under ambient conditions will be collected as particulate matter. This system is used to measure the emissions from a boiler burning distillate oil, a home fireplace, catalyst and noncatalyst automobiles, heavy-duty diesel trucks, natural gas home appliances, and meat cooking operations. Alternate techniques are used to sample the particulate matter emitted from cigarette smoking, a roofing tar pot, paved road dust, brake lining wear, tire wear, and vegetative detritus. The bulk chemical characteristics of the fine aerosol fraction are presented for each source. Over half of the fine aerosol mass emitted from automobiles, wood burning, meat cooking, home appliances, cigarettes, and tar pots is shown to consist of organic compounds. The organic material collected from these sources is analyzed using high-resolution gas chromatography. Using a simple analytical protocol, a quantitative, 50-parameter characterization of the elutable fine organic aerosol emitted from each source type is obtained, which proves to be a unique fingerprint that can be used to distinguish most sources from each other. A mathematical model is used to predict the characteristics of fine ambient organic aerosol in the Los Angeles area that would prevail if the primary organic emissions are transported without chemical reaction. The model is found to track the seasonal variations observed in the ambient aerosol at the three sites studied. Emissions from vehicles and fireplaces are identified as significant sources of solvent-extractable organic aerosol. Differences between the model

  12. Skeletal-related events significantly impact health-related quality of life in metastatic castration-resistant prostate cancer: data from PREVAIL and AFFIRM trials.

    Science.gov (United States)

    Saad, F; Ivanescu, C; Phung, D; Loriot, Y; Abhyankar, S; Beer, T M; Tombal, B; Holmstrom, S

    2017-03-01

    We investigated the impact of skeletal-related events (SREs) on health-related quality of life (HRQoL) in patients with metastatic castration-resistant prostate cancer (mCRPC) in phase III trials of enzalutamide versus placebo. Patients with mCRPC experiencing at least one SRE during AFFIRM and PREVAIL were assessed for trajectory-adjusted mean change in HRQoL by first SRE using Functional Assessment of Cancer Therapy-Prostate (FACT-P; AFFIRM, three domains, and PREVAIL, nine domains) and EQ-5D (PREVAIL) instruments. First SREs caused HRQoL deterioration in both trials. Spinal cord compression had the largest impact, with clinically meaningful reductions in seven of nine FACT-P domains in PREVAIL and all three in AFFIRM (mean (95% confidence interval (CI)) change in FACT-P total score -16.95 (-26.47, -7.44) and -9.69 (-16.10, -3.27), respectively). In PREVAIL, first SREs caused clinically meaningful declines in EQ-5D utility index, irrespective of category; spinal cord compression had the largest impact (mean (95% CI) change -0.24 (-0.39, -0.08)). In AFFIRM, FACT-P and FACT-General total scores showed clinically meaningful declines after radiation/surgery to bone. SREs were associated with clinically meaningful functional declines in the daily lives of patients with mCRPC. Spinal cord compression had the largest impact on HRQoL.

  13. Atmosphere in a Test Tube

    Science.gov (United States)

    Claudi, R.; Pace, E.; Ciaravella, A.; Micela, G.; Piccioni, G.; Billi, D.; Cestelli Guidi, M.; Coccola, L.; Erculiani, M. S.; Fedel, M.; Galletta, G.; Giro, E.; La Rocca, N.; Morosinotto, T.; Poletto, L.; Schierano, D.; Stefani, S.

    The ancestor philosophers' dream of thousand of new world is finally realised: more than 1800 extrasolar planets have been discovered in the neighborhood of our Sun. Most of them are very different from those we used to know in our Solar System. Others orbit the Habitable Zone (HZ) of their parent stars. Space missions, as JWST and the very recently proposed ARIEL, or ground based instruments, like SPHERE@VLT, GPI@GEMINI and EPICS@ELT, have been proposed and built to measure the atmospheric transmission, reflection and emission spectra over a wide wavelength range of these new worlds. In order to interpret the spectra coming out by this new instrumentation, it is important to know in detail the optical characteristics of gases in the typical physical conditions of the planetary atmospheres and how those characteristics could be affected by radiation driven photochemical and bio-chemical reaction. Insights in this direction can be achieved from laboratory studies of simulated planetary atmosphere of different pressure and temperature conditions under the effects of radiation sources, used as proxies of different bands of the stellar emission. ''Atmosphere in a Test Tube'' is a collaboration among several Italian astronomical, biological and engineering institutes in order to share their experiencece in performing laboratory experiments on several items concerning extrasolar planet atmospheres.

  14. Swell impact on wind stress and atmospheric mixing in a regional coupled atmosphere-wave model

    DEFF Research Database (Denmark)

    Wu, Lichuan; Rutgersson, Anna; Sahlée, Erik

    2016-01-01

    Over the ocean, the atmospheric turbulence can be significantly affected by swell waves. Change in the atmospheric turbulence affects the wind stress and atmospheric mixing over swell waves. In this study, the influence of swell on atmospheric mixing and wind stress is introduced into an atmosphere-wave-coupled...... regional climate model, separately and combined. The swell influence on atmospheric mixing is introduced into the atmospheric mixing length formula by adding a swell-induced contribution to the mixing. The swell influence on the wind stress under wind-following swell, moderate-range wind, and near......-neutral and unstable stratification conditions is introduced by changing the roughness length. Five year simulation results indicate that adding the swell influence on atmospheric mixing has limited influence, only slightly increasing the near-surface wind speed; in contrast, adding the swell influence on wind stress...

  15. Atmospheric sciences annual progress report, 1974

    International Nuclear Information System (INIS)

    Tucker, W.D.

    1975-11-01

    Activities in atmospheric sciences in the Department of Applied Science at Brookhaven National Laboratory carried out during 1974 are described. Included are contributions from the Meteorology, Atmospheric Diagnostics, Atmospheric Chemistry Research, and Atmospheric Instrumentation Groups. Programs in Meteorology reported on include diffusion from an off-shore source, plume dynamics studies, modeling of coastal effects on wind and temperature fields and pollutant distributions, effects of indoor shelter on inhalation of airborne radionuclides, chemical-dynamical interactions, techniques for determining acid-rain impact upon the ecology of the eastern U.S., and climatology. Work under Atmospheric Chemistry Research was concentrated on atmospheric aerosol studies, including formation by free radical and neutral association reactions, identification of reactive systems leading to aerosol formation, growth of sodium aerosols under atmospheric conditions and clustering reactions. Atmospheric Diagnostics presents work on field sampling and analytical technology for atmospheric pollutants, airborne sampling systems, atmospheric sulfate particulates methodology, and on a pyroturbidometric method for particulate sulfate discrimination and determination. Methodology for the use of sulfur hexafluoride in field tracer studies is discussed under Atmospheric Instrumentation. A list of publications is included

  16. Atmospheric transport, diffusion, and deposition of radioactivity

    International Nuclear Information System (INIS)

    Crawford, T.V.

    1969-01-01

    From a meteorological standpoint there are two types of initial sources for atmospheric diffusion from Plowshare applications. One is the continuous point-source plume - a slow, small leak from an underground engineering application. The other is the large cloud produced almost instantaneously from a cratering application. For the purposes of this paper the effluent from neither type has significant fall speed. Both are carried by the prevailing wind, but the statistics of diffusion for each type are different. The use of constant altitude, isobaric and isentropic techniques for predicting the mean path of the effluent is briefly discussed. Limited data are used to assess the accuracy of current trajectory forecast techniques. Diffusion of continuous point-source plumes has been widely studied; only a brief review is given of the technique used and the variability of their results with wind speed and atmospheric stability. A numerical model is presented for computing the diffusion of the 'instantaneously-produced' large clouds. This model accounts for vertical and diurnal changes in atmospheric turbulence, wet and dry deposition, and radioactivity decay. Airborne concentrations, cloud size, and deposition on the ground are calculated. Pre- and post-shot calculations of cloud center, ground level concentration of gross radioactivity, and dry and wet deposition of iodine-131 are compared with measurements on Cabriolet and Buggy. (author)

  17. Atmospheric transport, diffusion, and deposition of radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, T V [Lawrence Radiation Laboratory, Livermore, CA (United States)

    1969-07-01

    From a meteorological standpoint there are two types of initial sources for atmospheric diffusion from Plowshare applications. One is the continuous point-source plume - a slow, small leak from an underground engineering application. The other is the large cloud produced almost instantaneously from a cratering application. For the purposes of this paper the effluent from neither type has significant fall speed. Both are carried by the prevailing wind, but the statistics of diffusion for each type are different. The use of constant altitude, isobaric and isentropic techniques for predicting the mean path of the effluent is briefly discussed. Limited data are used to assess the accuracy of current trajectory forecast techniques. Diffusion of continuous point-source plumes has been widely studied; only a brief review is given of the technique used and the variability of their results with wind speed and atmospheric stability. A numerical model is presented for computing the diffusion of the 'instantaneously-produced' large clouds. This model accounts for vertical and diurnal changes in atmospheric turbulence, wet and dry deposition, and radioactivity decay. Airborne concentrations, cloud size, and deposition on the ground are calculated. Pre- and post-shot calculations of cloud center, ground level concentration of gross radioactivity, and dry and wet deposition of iodine-131 are compared with measurements on Cabriolet and Buggy. (author)

  18. Atmospheric nitrogen compounds: Occurrence, composition and deposition

    DEFF Research Database (Denmark)

    Nielsen, T.; Pilegaard, K.; Egeløv, A.H.

    1996-01-01

    Traffic in cities and on highways is an important contributor to NOy atmospheric pollution in open areas. In this situation both the concentration and composition of NOy compounds show a wide variation and are dependent on meteorological and atmospheric chemical conditions. The proportion of NOz ...

  19. Clinical efficacy of transcatheter aortic valve replacement for severe aortic stenosis in high-risk patients: the PREVAIL JAPAN trial.

    Science.gov (United States)

    Sawa, Yoshiki; Takayama, Morimasa; Mitsudo, Kazuaki; Nanto, Shinsuke; Takanashi, Shuichiro; Komiya, Tatsuhiko; Kuratani, Toru; Tobaru, Tetsuya; Goto, Tsuyoshi

    2015-01-01

    Transcatheter aortic valve replacement (TAVR) is suggested to be less invasive and/or equally effective in comparison to conventional aortic valve replacement for high-risk symptomatic aortic stenosis patients. We herein report the initial results of a pivotal clinical trial of TAVR in Japan (the PREVAIL JAPAN). Sixty-four aortic stenosis patients (mean age 84.3 ± 6.1 years) not suitable for surgery were enrolled at three centers in Japan, with a primary composite endpoint of the 6-month post-procedure improvements in the aortic valve area and New York Heart Association (NYHA) functional classification. A transfemoral approach was used in 37 patients and a transapical approach was used in 27. The device success rate was 91.9 %. After 30 days and 6 months, the rates of mortality from any cause were 8.1 and 11.3 %, respectively. At 6 months, symptomatic stroke was found in 3.1 % of the patients, and silent infarction in 7.8 %. The aortic valve area and mean pressure gradient were significantly improved over time with both approaches (p < 0.001). At 6 months, the NYHA functional classification based on a conventional physician's assessment was improved in 87.9 % of the patients. We found results that were equivalent to those in other major TAVR trials, such as an acceptable 30-day survival (91.9 %), suggesting that balloon-expandable TAVR is effective for small Japanese AS patients classified as high-risk or inoperable.

  20. Activating KIR molecules and their cognate ligands prevail in children with a diagnosis of ASD and in their mothers.

    Science.gov (United States)

    Guerini, Franca R; Bolognesi, Elisabetta; Chiappedi, Matteo; Manca, Salvatorica; Ghezzo, Alessandro; Agliardi, Cristina; Zanette, Michela; Littera, Roberto; Carcassi, Carlo; Sotgiu, Stefano; Clerici, Mario

    2014-02-01

    The activity of natural killer (NK) cells is modulated by the interaction between killer-cell immune globulin-like receptor (KIR) proteins and their cognate HLA ligands; activated NK cells produce inflammatory cytokines and mediate innate immune responses. Activating KIR/HLA complexes (aKIR/HLA) were recently suggested to prevail in children with autism spectrum disorders (ASD), a neurodevelopmental syndrome characterized by brain and behavioral abnormalities and associated with a degree of inflammation. We verified whether such findings could be confirmed by analyzing two sample cohorts of Sardinian and continental Italian ASD children and their mothers. Results showed that aKIR/HLA are increased whereas inhibitory KIR/HLA complexes are reduced in ASD children; notably this skewing was even more significant in their mothers. KIR and HLA molecules are expressed by placental cells and by the trophoblast and their interactions result in immune activation and influence fetal, as well as central nervous system development and plasticity. Data herein suggest that in utero KIR/HLA immune interactions favor immune activation in ASD; this may play a role in the pathogenesis of the disease. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Thermal Band Atmospheric Correction Using Atmospheric Profiles Derived from Global Positioning System Radio Occultation and the Atmospheric Infrared Sounder

    Science.gov (United States)

    Pagnutti, Mary; Holekamp, Kara; Stewart, Randy; Vaughan, Ronald D.

    2006-01-01

    TRANsmittance) radiative transport software to separate out the atmospheric component of measured top of atmosphere radiance. Simulated water bodies across a variety of MODTRAN model atmospheres including desert, mid-latitude, tropical and sub-artic conditions provide test bed conditions. Atmospherically corrected radiance and surface temperature results were compared to those obtained using traditional radiosonde balloon data and models. In general, differences between the different techniques were less than 2 percent indicating the potential value satellite derived atmospheric profiles have to atmospherically correct thermal imagery.

  2. The role of ion-induced aerosol formation in the lower atmosphere

    International Nuclear Information System (INIS)

    Raes, Frank; Janssens, Augustin; Dingenen, Rita van

    1986-01-01

    The rate of ion-induced aerosol formation in a H 2 0-H 2 S0 4 mixture depends on the relative humidity, the relative acidity and the number of ions (clusters) available for nucleation. Figure 1 shows the rates of homogeneous and ion-induced aerosol formation as a function of the H 2 S0 4 sup((gas)) concentration, for conditions prevailing in the lower atmosphere. The rate of ion-induced aerosol formation is plotted for different concentrations of pre-existing aerosol. It can be seen that ion-induced aerosol formation will only play a role in the formation of new particles when (1) the H 2 S0 4 sup((gas)) concentration is confined within the critical values for ion-induced and homogeneous aerosol formation (about 5 x 10 7 and 4 x 10 8 cm -3 respectively), and (2) the concentration of pre-existing aerosol is lower than about 5 x 10 3 cm -3 (Dp = 0.1 μm). It will be shown by numerical calculations that such conditions may be expected above the oceans. (author)

  3. A Long-lived Cyclone In Saturn's Atmosphere: Observations And Models

    Science.gov (United States)

    Del Rio Gaztelurrutia, Teresa; Legarreta, J.; Hueso, R.; Pérez-Hoyos, S.; Sánchez-Lavega, A.

    2009-09-01

    The atmospheres of the Giant Planets Jupiter and Saturn possess large numbers of atmospheric vortices. On Jupiter, anticyclones are generally long-lived structures while cyclones survive a much shorter time. A long term survey of images of Saturn atmosphere obtained by the Cassini ISS camera has revealed the presence of a long-lived cyclone in Saturn's southern hemisphere during at least four years, making this vortex the longest lived cyclone on either Jupiter or Saturn. We find that the vortex drifts following the wind profile, with changes in velocity following changes of latitude. During the four years of our survey its size remained essentially constant, and there was no other structure of comparable size at its latitude. Internal circulation is cyclonic, with a maximum velocity of 20±5 m/s and an average vorticity of 4·10-5 s-1, an order of magnitude lower than planetary vorticity, but only slightly higher than the ambient vorticity. Photometric analysis shows that the vortex is located at a slightly lower altitude than its surroundings, at an average of 10-20 mbar below adjacent clouds. Finally, EPIC simulations of the vortex that reproduce its behavior imply a Rossby deformation radius of 2000 km in the weather layer (1 - 10 bar), consistent with the size of the cyclone. The long-lifetime of this cyclonic spot is surprising in view of its low tangential velocity and it suggests that low dissipation conditions prevail at mid-latitudes in Saturn's upper troposphere. Acknowledgements This work has been funded by Spanish MEC AYA2006-07735 with FEDER support and Grupos Gobierno Vasco IT-464-07. RH acknowledges a "Ramón y Cajal” contract from MEC.

  4. Features of atmospheric phenomena’s dynamics in Kharkiv region

    Directory of Open Access Journals (Sweden)

    Світлана Решетченко

    2017-09-01

    Full Text Available The article presents the results of rainfall, hail, precipitation and fogs’ frequency study in Kharkiv region during the period 2001-2014 by means of statistical analysis. The calculations were carried out on the basis of monthly rainfall data at the meteorological stations of the region (Lozova, Kharkiv, Zolochiv, Kupyansk, Izyum, Krasnograd, Bogodukhiv, Velykyi Burluk, Slobozhanske, Kolomak for the period 1961-2014, the number and duration of fogs. The conditions of their formation, distribution and development on the territory of Kharkiv region characterizing the annual and seasonal changes have been determined. All types of atmospheric precipitation are observed on the investigated area, namely long-term deposits prevailing throughout the year (liquid (103% and solid (68%, amongst streams - liquid (121%. Long-term precipites are characteristic of the autumn period, when atmospheric phenomena are formed. Fogs, mist, storms, thunderstorms and lightnings are observed in the spring and summer (30% and 74% respectively. In the winter, it is possible to observe the same probability that liquid and snow, ice cover (24% and 20% respectively mix , frosts (46%. Most often, (35% of showers happen within one day, 30% of cases occur for 2 and 3-5 days. Sometimes they are observed for several days. There is a great variety of heavy rains on the territory of Kharkiv region, where you can expect 3-5 days with showers for a year. As a rule, the rains can be accompanied by hail and thunderstorms. The hail is a more rare phenomenon than a thunderstorm, it falls predominantly during the warmer years of the powerful cumulonimbus clouds with a strong upright movement. Hail is formed in the conditions of a large variety of synoptic processes. In 53% of cases, hail is associated with cold fronts, and 47% - correspond to the internal processes of the mass. Hailstones with a diameter of 20 mm and more cause significant damage to the economy, It has been established

  5. Armazenamento sob condições ambiente e aceitabilidade do melão 'F1 Jangada' produzido em sistema hidropônico Storage under atmosphere conditions and acceptability of the melon 'F1 Jangada' croped in hydroponic system

    Directory of Open Access Journals (Sweden)

    Maria M. Rinaldi

    2006-12-01

    Full Text Available O objetivo deste trabalho foi determinar o período de armazenamento pós-colheita e a aceitabilidade pelo consumidor de melão híbrido 'F1 Jangada' (Cucumis melo L., produzido em sistema hidropônico, mantido em condições ambiente (22 ± 2 ºC e umidade relativa de 40 ± 5%. O experimento compreendeu o período de 21-6-2005 a 2-8-2005. Foi utilizado o esquema fatorial 5 x 2, em delineamento experimental inteiramente casualizado, com cinco períodos de armazenamento (0; 7; 21; 28 e 42 dias e dois tipos de substrato (areia e fibra de coco, com três repetições, em que cada repetição consistiu em cinco frutos de meloeiro. Foram avaliados o pH, a acidez titulável, os sólidos solúveis, a perda de massa fresca, a análise sensorial e a decisão de compra dos melões. Foram verificados efeitos do tipo de substrato e tempo de armazenamento sobre os valores de pH dos melões. A acidez titulável dos melões diminuiu significativamente nos primeiros sete dias de armazenamento, em ambos os substratos. Não foram verificados efeitos do tipo de substrato e tempo de armazenamento nos sólidos solúveis dos melões durante o armazenamento. Não houve diferença de perda de massa fresca dos frutos produzidos nos dois substratos, sendo de 7,1 ± 0,2%, durante os 42 dias de armazenamento. O tipo de substrato não interferiu na aparência geral, cor, textura e sabor dos melões. Aos 42 dias de armazenamento, os melões produzidos nos dois tipos de substrato apresentaram-se aceitáveis pelo consumidor. No entanto, os produzidos no substrato com areia apresentaram melhor aceitabilidade e decisão de compra ao longo do armazenamento.The objective of this work was to evaluate the storage period postharvest and acceptability by consumer of hybrid melon 'F1 Jangada' (Cucumis melo L., produced in hydroponic system, stored in atmosphere conditions (22 ± 2 ºC and 40 ± 5% relative humidity. The research was carried from June 21st to August 2nd, 2005. It was

  6. Efeito das condições de atmosfera controlada sobre a ocorrência de degenerescência em maçã 'Fuji' Effect of controlled atmosphere conditions on the breakdown of 'Fuji' apples

    Directory of Open Access Journals (Sweden)

    A. Brackmann

    1995-08-01

    Full Text Available O trabalho foi conduzido durante o ano de 1993, com objetivo avaliar o efeito das temperaturas e concentrações de oxigênio nas câmaras de atmosfera controlada (AC, sobre a manifestação da degenerescência e conservação da qualidade dos frutos da maçã 'Fuji', durante o armazenamento. Os frutos utilizados já haviam sido armazenados em câmaras de atmosfera normal (AN durante 72 dias, quando então já apresentavam 17% de degenerescência interna. Foram então armazenados em duas temperaturas (1 °C e 2 °C, UR de 97% e diferentes condições de AC: AC>0%CO2/ 1%O2, 0%CO2/1,5%O2 e 0%C2/2%O2. Após 6 meses de armazenamento, a temperatura de 1 °C e concentrações de oxigênio mais baixas (0%CO2/1%O2 e 0%CO2/1,5%O2 proporcionaram os menores percentuais de degenerescência interna e externa, mantendo a firmeza da polpa mais elevada. No entanto, a acidez titulável manteve-se mais elevada na temperatura de 2 °C. Os teores de sólidos solúveis totais foram mais elevados na temperatura de 2 °C na presença de 1,5 e 2,0% de O2.The main aim of this research was to evaluate the effect of temperatures and oxygen concentrations in controlled atmosphere (CA storage on the quality, conservation and breakdown of 'Fuji' apples, during storage. Fruits used had already been stored in cold storage during 72 days, and exhibited 17% of internal breakdown. Afterwards they were stored at two different temperatures (1 °C and 2 °C and in different CA conditions: 0%CO2/1%O2, 0%CO2/ 1.5%O2 and 0%CO2/2%O2. After a six months storage, fruits at 1 °C and at lower oxygen concentrations (0%CO2/ 1%O2 and 0%CO2/1.5%O2 showed less internal and external breakdown and had higher firmness than fruits that had been stored at 2°C or at higher oxygen concentrations (0%CO/2%O2. Tritatable acidity, however, was higher at 2 °C. Soluble solids were higher at 2°C with 1.5 and 2.0% of oxygen.

  7. Thermal Conductivity of the Multicomponent Neutral Atmosphere

    Science.gov (United States)

    Pavlov, A. V.

    2017-12-01

    Approximate expressions for the thermal conductivity coefficient of the multicomponent neutral atmosphere consisting of N2, O2, O, He, and H are analyzed and evaluated for the atmospheric conditions by comparing them with that given by the rigorous hydrodynamic theory. The new approximations of the thermal conductivity coefficients of simple gases N2, O2, O, He, and H are derived and used. It is proved that the modified Mason and Saxena approximation of the atmospheric thermal conductivity coefficient is more accurate in reproducing the atmospheric values of the rigorous hydrodynamic thermal conductivity coefficient in comparison with those that are generally accepted in atmospheric studies. This approximation of the thermal conductivity coefficient is recommended to use in calculations of the neutral temperature of the atmosphere.

  8. Atmospheric oxidation of selected alcohols and esters

    Energy Technology Data Exchange (ETDEWEB)

    Becker, K H; Cavalli, F

    2001-03-01

    The decision whether it is appropriate and beneficial for the environment to deploy specific oxygenated organic compounds as replacements for traditional solvent types requires a quantitative assessment of their potential atmospheric impacts including tropospheric ozone and other photooxidant formation. This involves developing chemical mechanisms for the gasphase atmospheric oxidation of the compounds which can be reliably used in models to predict their atmospheric reactivity under a variety of environmental conditions. Until this study, there was very little information available concerning the atmospheric fate of alcohols and esters. The objectives of this study were to measure the atmospheric reaction rates and to define atmospheric reaction mechanisms for the following selected oxygenated volatile organic compounds: the alcohols, 1-butanol and 1-pentanol, and the esters, methyl propionate and dimethyl succinate. The study has successfully addressed these objectives. (orig.)

  9. Evaluative conditioning of food technologies

    DEFF Research Database (Denmark)

    Loebnitz, Natascha; Grunert, Klaus G

    2015-01-01

    Consumer attitudes play an important role in the acceptance of new technologies. The success of food innovations depends on understanding how consumers form and change attitudes toward food technologies. Earlier post hoc explanations suggest that evaluative conditioning can change consumer...... attitudes toward food technologies. The present study tests how evaluative conditioning can affect consumer acceptance of new food technologies. Furthermore, authors investigate whether evaluative conditioning is resistant to extinction after a two-month period and whether the evaluative conditioning effect...... prevails in a product-related context. Within an evaluative conditioning paradigm including between-subjects control groups in addition to standard within-subjects control conditions, participants were presented with three food technologies (conventional, enzyme, and genetic technology) paired...

  10. Our shared atmosphere

    Science.gov (United States)

    Our atmosphere is a precious and fascinating resource, providing air to breath, shielding us from harmful ultraviolet radiation (UV), and maintaining a comfortable climate. Since the industrial revolution, people have significantly altered the composition of the atmosphere throu...

  11. Carbon-Water-Nitrogen relationships between lichens and the atmosphere: Tools to understand metabolism and ecosystem change

    Directory of Open Access Journals (Sweden)

    Cristina Máguas

    2013-04-01

    Full Text Available Due to the close linking between the biosphere and atmosphere, there are clear impacts of changes in climate, atmospheric deposition of nutrients/pollutants and land use (Global Changes on the terrestrial biosphere. Lichens, with a direct dependence on atmospheric conditions, are much more affected by their immediate microclimate than by the ecosystem’s prevailing macroclimate. In contrast to higher plants, poikilohydric organisms have different mechanisms of water and CO2 exchange. The application of stable isotopes to the understanding of the mechanisms that are fundamental to lichen gas exchange and water uptake is a promising tool for the evaluation of lichen response to environmental changes. Indeed, lichens have been shown to be influenced by a large number of natural and anthropogenic environmental factors, serving as ecological indicators. Thus, we may use these organisms to model the impact of key global change drivers, such as nitrogen deposition and biodiversity changes, at local scale. Particularly useful is the application of the Lichen Diversity Value (LDV in order to evaluate the impact of global drivers. Moreover, it has been shown that these indices, associated with main photobiont types, green-algae (LDVch or cyanobacteria (LDVcyh, and/or nitrophilous versus oligotrophic species, were good candidates as ecological indicators. Besides mapping with high spatial resolution the effects of climate alterations, lichen functional groups could also be used as an early-warning system in order to detect the first effects of climate change in ecosystems before sudden shifts occur on other components that may be less sensitive. Clearly, lichens possess the adequate traits to be used as powerful indicators of complex interactions between atmosphere and biosphere, and thus can generate potentially interesting models for global change drivers.

  12. Enzalutamide in Men with Chemotherapy-naive Metastatic Castration-resistant Prostate Cancer: Extended Analysis of the Phase 3 PREVAIL Study

    NARCIS (Netherlands)

    Beer, T.M.; Armstrong, A.J.; Rathkopf, D.; Loriot, Y.; Sternberg, C.N.; Higano, C.S.; Iversen, P.; Evans, C.P.; Kim, C.S.; Kimura, G.; Miller, K.; Saad, F.; Bjartell, A.S.; Borre, M.; Mulders, P.; Tammela, T.L.; Parli, T.; Sari, S.; Os, S. van; Theeuwes, A.; Tombal, B.

    2017-01-01

    Enzalutamide significantly improved radiographic progression-free survival (rPFS) and overall survival (OS) among men with chemotherapy-naive metastatic castration-resistant prostate cancer at the prespecified interim analysis of PREVAIL, a phase 3, double-blind, randomized study. We evaluated the

  13. Prevailing of sensitive blood driving to AIDS/HIV. Provincial Blood Bank of Sancti Spíritus. 2007-2008.

    Directory of Open Access Journals (Sweden)

    Martha Quesada Concepción

    2011-09-01

    Full Text Available Because of blood transfusions are one of the ways of transmitting the immune deficiency syndrome (AIDS/HIV; it constitutes warriness from the epidemiological point of view. A descriptive research was done with the objective of determining the prevailing of sensitive blood driving AIDS/HIV in the Provincial Blood Bank from Sancti Spíritus from January 1 st , 2007 to December 31 st, 2008. The sample was conformed by 312 donants with positive diagnosis to AIDS/HIV. Some variables were used such as prevailing, age, sex, race, home town. The scores of higher prevailing to AIDS/HIV were shown by the male sex (4,42, the 26-33 year old group (1,55; it prevailing volunteer blood driving (81,0 % , and Sancti Spíritus municipality gave more cases (27,5% .Just because sensibility to tests based on antibody, that is why it is important the constant checking of all processes that guarantee blood driving to be sired.

  14. Influence of prevailing disturbances on soil biology and biochemistry of montane habitats at Nanda Devi Biosphere Reserve, India during wet and dry seasons

    DEFF Research Database (Denmark)

    Singh, S.K.; Singh, Anoop; Rai, J.P.N.

    2011-01-01

    The impact of prevailing disturbances in montane habitats of Nanda Devi Biosphere Reserve (NDBR) was studied on soil microbial population, biomass, soil respiration and enzyme activities during wet and dry seasons. The physico-chemical characteristics of soils exhibited conspicuous variation in t...

  15. Condições de temperatura, umidade relativa e atmosfera controlada para o armazenamento de cebolas da cultivar 'Crioula' Temperature, relative humidity and controlled atmosphere conditions to storage 'Crioula' onions

    Directory of Open Access Journals (Sweden)

    Auri Brackmann

    2010-08-01

    Full Text Available O objetivo deste trabalho foi de avaliar condições de armazenamento para ampliar o período de pós-colheita de cebola da cultivar 'Crioula'. Para tanto, foram executados três experimentos para avaliar o efeito da temperatura, umidade relativa (UR e atmosfera controlada (AC: experimento 1 (diferentes temperaturas: [1] -0,5°C, [2] 0,5°C, [3] 2°C, [4] 4°C, [5] 6°C e [6] 10°C; experimento 2 (níveis de UR: [1] 70%, [2] 80% e [3] 90%; e experimento 3 (condições de AC: [1] 21kPa O2+0,03kPa CO2, [2] 0,5kPa O2+0kPa CO2, [3] 1,0kPa O2+0kPa CO2, [4] 2,0kPa O2+0kPa CO2, [5] 1,0kPa O2+2,0kPa CO2 e [6]1,0kPa O2+4,0kPa CO2. O delineamento experimental utilizado foi o inteiramente casualizado. Após seis meses de armazenamento, foram realizadas as análises no momento da saída dos bulbos das câmaras e após 15 dias de exposição a 20°C. A brotação e a podridão foram inibidas na temperatura de 0,5°C, diferentemente das temperaturas iguais e superiores a 4°C, em que mais de 90% dos bulbos brotaram. As UR de 70 e 80% foram melhores, pois ocorreu menor brotação. O baixo oxigênio controlou a brotação dos bulbos, proporcionando maior número de bulbos comerciáveis após seis meses em AC e também após 15 dias de exposição a 20°C.The aim of this research was to evaluate conditions to maintain postharvest quality of 'Crioula' onions. Three experiments were done, evaluating the effect of temperature, relative humidity (RH and controlled atmosphere (CA: different temperatures: [1] -0.5°C, [2] 0.5°C, [3] 2°C, [4] 4°C, [5] 6°C and [6] 10°C. Levels of RH: [1] 70%, [2] 80% and [3] 90%; and different CA conditions: [1] 21kPa O2+0.03kPa CO2, [2] 0.5kPa O2+0kPa CO2, [3] 1.0kPa O2+0kPa CO2, [4] 2.0kPa O2+0kPa CO2, [5] 1.0kPa O2+2.0kPa CO2 and [6] O2 1.0kPa+4.0kPa CO2. The experimental design was completely randomized. Ripening and quality evaluations were carried out after six months of storage more fifteen days at 20°C. The sprout and rot

  16. Atmospheric refraction : a history

    NARCIS (Netherlands)

    Lehn, WH; van der Werf, S

    2005-01-01

    We trace the history of atmospheric refraction from the ancient Greeks up to the time of Kepler. The concept that the atmosphere could refract light entered Western science in the second century B.C. Ptolemy, 300 years later, produced the first clearly defined atmospheric model, containing air of

  17. Atmospheric Chemistry Over Southern Africa

    Science.gov (United States)

    Gatebe, Charles K.; Levy, Robert C.; Thompson, Anne M.

    2011-01-01

    During the southern African dry season, regional haze from mixed industrial pollution, biomass burning aerosol and gases from domestic and grassland fires, and biogenic sources from plants and soils is worsened by a semi-permanent atmosphere gyre over the subcontinent. These factors were a driver of several major international field campaigns in the 1990s and early 2000s, and attracted many scientists to the region. Some researchers were interested in understanding fundamental processes governing chemistry of the atmosphere and interaction with climate change. Others found favorable conditions for evaluating satellite-derived measurements of atmospheric properties and a changing land surface. With that background in mind a workshop on atmospheric chemistry was held in South Africa. Sponsored by the International Commission for Atmospheric Chemistry and Global Pollution (ICACGP; http://www.icacgp.org/), the workshop received generous support from the South African power utility, Eskom, and the Climatology Research Group of the University of the Witwatersrand, Johannesburg, South Africa. The purpose of the workshop was to review some earlier findings as well as more recent findings on southern African climate vulnerability, chemical changes due to urbanization, land-use modification, and how these factors interact. Originally proposed by John Burrows, president of ICACGP, the workshop was the first ICACGP regional workshop to study the interaction of air pollution with global chemical and climate change. Organized locally by the University of the Witwatersrand, the workshop attracted more than 60 delegates from South Africa, Mozambique, Botswana, Zimbabwe, France, Germany, Canada, and the United States. More than 30 presentations were given, exploring both retrospective and prospective aspects of the science. In several talks, attention was focused on southern African chemistry, atmospheric pollution monitoring, and climate processes as they were studied in the field

  18. Atmospheric Habitable Zones in Y Dwarf Atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Yates, Jack S.; Palmer, Paul I. [School of GeoSciences, University of Edinburgh (United Kingdom); Biller, Beth; Cockell, Charles S., E-mail: j.s.yates@ed.ac.uk [Centre for Exoplanet Science, University of Edinburgh (United Kingdom)

    2017-02-20

    We use a simple organism lifecycle model to explore the viability of an atmospheric habitable zone (AHZ), with temperatures that could support Earth-centric life, which sits above an environment that does not support life. To illustrate our model, we use a cool Y dwarf atmosphere, such as WISE J085510.83–0714442.5, whose 4.5–5.2 μ m spectrum shows absorption features consistent with water vapor and clouds. We allow organisms to adapt to their atmospheric environment (described by temperature, convection, and gravity) by adopting different growth strategies that maximize their chance of survival and proliferation. We assume a constant upward vertical velocity through the AHZ. We found that the organism growth strategy is most sensitive to the magnitude of the atmospheric convection. Stronger convection supports the evolution of more massive organisms. For a purely radiative environment, we find that evolved organisms have a mass that is an order of magnitude smaller than terrestrial microbes, thereby defining a dynamical constraint on the dimensions of life that an AHZ can support. Based on a previously defined statistical approach, we infer that there are of the order of 10{sup 9} cool Y brown dwarfs in the Milky Way, and likely a few tens of these objects are within 10 pc from Earth. Our work also has implications for exploring life in the atmospheres of temperate gas giants. Consideration of the habitable volumes in planetary atmospheres significantly increases the volume of habitable space in the galaxy.

  19. Prevailing of ischemia cardiopathy, demonstrated by gammagraphy in less than 40 years old persons and its association with risk factors

    International Nuclear Information System (INIS)

    Cano G, M.A.; Castillo M, L.; Orea T, A.

    2005-01-01

    The Coronary Arterial Illness (EAC) is the first cause of death of those Mexicans. Among their numerous risk factors it highlights the age with more bias starting from the 45 years. The objective of this investigation was to determine the prevailing of ischemic cardiopathy (Cl) and heart attack to the myocardium (IAM) in fellows smaller than 40 years and to identify risk factors. The study of myocardial perfusion (EPM) it is a non invasive study and of great sensibility and specificity that it allows to detect obstructive coronary lesions. The used method was retrospective-traverse Study in 125 patients smaller than 40 years. Files of patients to who EPM had been practiced with Technetium 99m-SESTAMlBI, protocol of one day, were revised, where its were analyzed the short and long axis (vertical and horizontal). General data, somatometry, emotional profile analysis, lipids and glucose profiles were gathered. Results. The population conformed it 53% women and 47% men with average of 31.9 year-old age of corporal mass index (IMC) 25.1 kg/cm 2 . 46% of abnormal studies was obtained, of which 35% was compatible with ischemic cardiopathy (Cl) and 11% with heart attack to the myocardium (IAM). The characteristics of these were: age 31.6±6 Vs 32.6±5.9 years; IMC 25.4±7.0 Vs 24.4±3.34 kg/cm 2 ; stature 161.6±9.8 Vs 165.5±9.7cm; TAS 139.1±29.2 Vs. 115±13.4 mm Hg, TAD 84.5±17.4 Vs. 75±9.4 mm Hg; civil state married 65.5% (p=0.005) Vs single 57%; bigger depression 32% Vs anxiety 28%, in the group of patients with Cl and IAM, respectively. In the IAM population it was found an additional IRC 21% (p=0.030), HAS 21% (p=0.025) and drug addiction 21% (p=0.002). The rest of the results didn't show significant differences. Conclusion: Only 6.5% of the patients that went to EPM- 99m Tc-SESTAMIBl in a 6 year-old lapse, were smaller than 40 years. 71% of them was referred by prechordal pain in who almost the half it was evidenced Cl or IAM. In this investigation besides the

  20. Solar Wind Interaction and Impact on the Venus Atmosphere

    Science.gov (United States)

    Futaana, Yoshifumi; Stenberg Wieser, Gabriella; Barabash, Stas; Luhmann, Janet G.

    2017-11-01

    Venus has intrigued planetary scientists for decades because of its huge contrasts to Earth, in spite of its nickname of "Earth's Twin". Its invisible upper atmosphere and space environment are also part of the larger story of Venus and its evolution. In 60s to 70s, several missions (Venera and Mariner series) explored Venus-solar wind interaction regions. They identified the basic structure of the near-Venus space environment, for example, existence of the bow shock, magnetotail, ionosphere, as well as the lack of the intrinsic magnetic field. A huge leap in knowledge about the solar wind interaction with Venus was made possible by the 14-year long mission, Pioneer Venus Orbiter (PVO), launched in 1978. More recently, ESA's probe, Venus Express (VEX), was inserted into orbit in 2006, operated for 8 years. Owing to its different orbit from that of PVO, VEX made unique measurements in the polar and terminator regions, and probed the near-Venus tail for the first time. The near-tail hosts dynamic processes that lead to plasma energization. These processes in turn lead to the loss of ionospheric ions to space, slowly eroding the Venusian atmosphere. VEX carried an ion spectrometer with a moderate mass-separation capability and the observed ratio of the escaping hydrogen and oxygen ions in the wake indicates the stoichiometric loss of water from Venus. The structure and dynamics of the induced magnetosphere depends on the prevailing solar wind conditions. VEX studied the response of the magnetospheric system on different time scales. A plethora of waves was identified by the magnetometer on VEX; some of them were not previously observed by PVO. Proton cyclotron waves were seen far upstream of the bow shock, mirror mode waves were observed in magnetosheath and whistler mode waves, possibly generated by lightning discharges were frequently seen. VEX also encouraged renewed numerical modeling efforts, including fluid-type of models and particle-fluid hybrid type of models

  1. Atmospheric Prebiotic Chemistry and Organic Hazes

    Science.gov (United States)

    Trainer, Melissa G.

    2012-01-01

    Earth's atmospheric composition at the time of the origin of life is not known, but it has often been suggested that chemical transformation of reactive species in the atmosphere was a significant source of pre biotic organic molecules. Experimental and theoretical studies over the past half century have shown that atmospheric synthesis can yield molecules such as amino acids and nucleobases, but these processes are very sensitive to gas composition and energy source. Abiotic synthesis of organic molecules is more productive in reduced atmospheres, yet the primitive Earth may not have been as reducing as earlier workers assumed, and recent research has reflected this shift in thinking. This work provides a survey of the range of chemical products that can be produced given a set of atmospheric conditions, with a particular focus on recent reports. Intertwined with the discussion of atmospheric synthesis is the consideration of an organic haze layer, which has been suggested as a possible ultraviolet shield on the anoxic early Earth. Since such a haze layer - if formed - would serve as a reservoir for organic molecules, the chemical composition of the aerosol should be closely examined. The results highlighted here show that a variety of products can be formed in mildly reducing or even neutral atmospheres, demonstrating that contributions of atmospheric synthesis to the organic inventory on early Earth should not be discounted. This review intends to bridge current knowledge of the range of possible atmospheric conditions in the prebiotic environment and pathways for synthesis under such conditions by examining the possible products of organic chemistry in the early atmosphere.

  2. Atmospheric Propagation Modeling Indicates Homing Pigeons use Loft-Specific Infrasonic 'Map' Cues

    Science.gov (United States)

    Hagstrum, J. T.; Baker, L. M.; Spritzer, J. M.; McKenna, M. H.

    2011-12-01

    Pigeons (Columba livia) released at distant sites commonly depart in directions significantly off the actual homeward bearing. Such site-dependent deviations, or biases, for birds from a given loft are generally stable over time, but can also change from hour to hour, day to day, and year to year. At some release sites, birds consistently vanish in random directions and have longer flight times and lower return rates. Release sites characterized by frequent disorientation are not uncommon for pigeon lofts in both Europe and the USA. One such site is the Jersey Hill fire tower in upstate New York located ~120 km W of the Cornell loft in Ithaca. Cornell birds released at Jersey Hill between 1968 and 1987 almost always vanished randomly, although birds from other lofts had little difficulty orienting there. The results for one day, however, stand out: on August 13, 1969, Cornell birds released at Jersey Hill vanished consistently to the NE (r = 0.921; n=7) and returned home after normal flight times. Cornell pigeons released the next day again showed 'normal' behavior for the site and departed randomly. If, in fact, the birds are using acoustic cues to navigate, the long-term acoustic 'dead' zone we propose for Jersey Hill, due to prevailing atmospheric conditions, indicates that the cues are coming from a single, relatively restricted area, most likely surrounding the home loft. We have modeled the transmission of infrasonic waves, presumably coupled to the atmosphere from ocean-generated microseisms (0.14 Hz), between the Cornell loft and a number of release sites using HARPA (Hamiltonian Acoustic Ray-tracing Program for the Atmosphere) and rawinsonde data collected near Albany and Buffalo, NY. The HARPA modeling shows that acoustic signals from the Cornell loft reached Jersey Hill only on a few release days with unusual atmospheric conditions, including August 13, and were launched at angles less than ~2° above horizontal, most likely from steep-sided terrain in

  3. Functional activity of plasmid DNA after entry into the atmosphere of earth investigated by a new biomarker stability assay for ballistic spaceflight experiments.

    Directory of Open Access Journals (Sweden)

    Cora S Thiel

    Full Text Available Sounding rockets represent an excellent platform for testing the influence of space conditions during the passage of Earth's atmosphere and re-entry on biological, physical and chemical experiments for astrobiological purposes. We designed a robust functionality biomarker assay to analyze the biological effects of suborbital spaceflights prevailing during ballistic rocket flights. During the TEXUS-49 rocket mission in March 2011, artificial plasmid DNA carrying a fluorescent marker (enhanced green fluorescent protein: EGFP and an antibiotic resistance cassette (kanamycin/neomycin was attached on different positions of rocket exterior; (i circular every 90 degree on the outer surface concentrical of the payload, (ii in the grooves of screw heads located in between the surface application sites, and (iii on the surface of the bottom side of the payload. Temperature measurements showed two major peaks at 118 and 130 °C during the 780 seconds lasting flight on the inside of the recovery module, while outer gas temperatures of more than 1000 °C were estimated on the sample application locations. Directly after retrieval and return transport of the payload, the plasmid DNA samples were recovered. Subsequent analyses showed that DNA could be recovered from all application sites with a maximum of 53% in the grooves of the screw heads. We could further show that up to 35% of DNA retained its full biological function, i.e., mediating antibiotic resistance in bacteria and fluorescent marker expression in eukaryotic cells. These experiments show that our plasmid DNA biomarker assay is suitable to characterize the environmental conditions affecting DNA during an atmospheric transit and the re-entry and constitute the first report of the stability of DNA during hypervelocity atmospheric transit indicating that sounding rocket flights can be used to model the high-speed atmospheric entry of organics-laden artificial meteorites.

  4. Airborne Atmospheric Aerosol Measurement System

    Science.gov (United States)

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

    2015-12-01

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

  5. Fair weather atmospheric electricity

    International Nuclear Information System (INIS)

    Harrison, R G

    2011-01-01

    Not long after Franklin's iconic studies, an atmospheric electric field was discovered in 'fair weather' regions, well away from thunderstorms. The origin of the fair weather field was sought by Lord Kelvin, through development of electrostatic instrumentation and early data logging techniques, but was ultimately explained through the global circuit model of C.T.R. Wilson. In Wilson's model, charge exchanged by disturbed weather electrifies the ionosphere, and returns via a small vertical current density in fair weather regions. New insights into the relevance of fair weather atmospheric electricity to terrestrial and planetary atmospheres are now emerging. For example, there is a possible role of the global circuit current density in atmospheric processes, such as cloud formation. Beyond natural atmospheric processes, a novel practical application is the use of early atmospheric electrostatic investigations to provide quantitative information on past urban air pollution.

  6. Atmosphere physics and chemistry

    International Nuclear Information System (INIS)

    Delmas, R.; Megie, G.; Peuch, V.H.

    2005-10-01

    Since the 1970's, the awareness about the atmospheric pollution threat has led to a spectacular development of the researches on the complex interactions between the chemical composition of the atmosphere and the climate. This book makes a synthesis of the state-of-the-art in this very active domain of research. Content: introduction, atmosphere dynamics and transport, matter-radiation interaction and radiant transfer, physico-chemical processes, atmospheric aerosol and heterogenous chemistry, anthropic and natural emissions and deposition, stratospheric chemical system, tropospheric chemical system, polluted boundary layer, paleo-environments and ice archives, role of atmospheric chemistry in global changes, measurement principles and instruments, numerical modeling, experimental strategy, regulation and management of the atmospheric environment, index. (J.S.)

  7. Void growth suppression by dislocation impurity atmospheres

    International Nuclear Information System (INIS)

    Weertman, J.; Green, W.V.

    1976-01-01

    A detailed calculation is given of the effect of an impurity atmosphere on void growth under irradiation damage conditions. Norris has proposed that such an atmosphere can suppress void growth. The hydrostatic stress field of a dislocation that is surrounded by an impurity atmosphere was found and used to calculate the change in the effective radius of a dislocation line as a sink for interstitials and vacancies. The calculation of the impurity concentration in a Cottrell cloud takes into account the change in hydrostatic pressure produced by the presence of the cloud itself. It is found that void growth is eliminated whenever dislocations are surrounded by a condensed atmosphere of either oversized substitutional impurity atoms or interstitial impurity atoms. A condensed atmosphere will form whenever the average impurity concentration is larger than a critical concentration

  8. Phytoremediation of Atmospheric Methane

    Science.gov (United States)

    2013-04-15

    REPORT Phytoremediation of Atmospheric Methane 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: We have transformed a plant, Arabidopsis thaliana, with the...298 (Rev 8/98) Prescribed by ANSI Std. Z39.18 - 31-Mar-2012 Phytoremediation of Atmospheric Methane Report Title ABSTRACT We have transformed a...DD882) Scientific Progress See attachment Technology Transfer 1    Final Report for DARPA project W911NF1010027  Phytoremediation  of Atmospheric

  9. Oscillations in stellar atmospheres

    International Nuclear Information System (INIS)

    Costa, A.; Ringuelet, A.E.; Fontenla, J.M.

    1989-01-01

    Atmospheric excitation and propagation of oscillations are analyzed for typical pulsating stars. The linear, plane-parallel approach for the pulsating atmosphere gives a local description of the phenomenon. From the local analysis of oscillations, the minimum frequencies are obtained for radially propagating waves. The comparison of the minimum frequencies obtained for a variety of stellar types is in good agreement with the observed periods of the oscillations. The role of the atmosphere in the globar stellar pulsations is thus emphasized. 7 refs

  10. Cost-Effectiveness of Percutaneous Closure of the Left Atrial Appendage in Atrial Fibrillation Based on Results From PROTECT AF Versus PREVAIL.

    Science.gov (United States)

    Freeman, James V; Hutton, David W; Barnes, Geoffrey D; Zhu, Ruo P; Owens, Douglas K; Garber, Alan M; Go, Alan S; Hlatky, Mark A; Heidenreich, Paul A; Wang, Paul J; Al-Ahmad, Amin; Turakhia, Mintu P

    2016-06-01

    Randomized trials of left atrial appendage (LAA) closure with the Watchman device have shown varying results, and its cost effectiveness compared with anticoagulation has not been evaluated using all available contemporary trial data. We used a Markov decision model to estimate lifetime quality-adjusted survival, costs, and cost effectiveness of LAA closure with Watchman, compared directly with warfarin and indirectly with dabigatran, using data from the long-term (mean 3.8 year) follow-up of Percutaneous Closure of the Left Atrial Appendage Versus Warfarin Therapy for Prevention of Stroke in Patients With Atrial Fibrillation (PROTECT AF) and Prospective Randomized Evaluation of the Watchman LAA Closure Device in Patients With Atrial Fibrillation (PREVAIL) randomized trials. Using data from PROTECT AF, the incremental cost-effectiveness ratios compared with warfarin and dabigatran were $20 486 and $23 422 per quality-adjusted life year, respectively. Using data from PREVAIL, LAA closure was dominated by warfarin and dabigatran, meaning that it was less effective (8.44, 8.54, and 8.59 quality-adjusted life years, respectively) and more costly. At a willingness-to-pay threshold of $50 000 per quality-adjusted life year, LAA closure was cost effective 90% and 9% of the time under PROTECT AF and PREVAIL assumptions, respectively. These results were sensitive to the rates of ischemic stroke and intracranial hemorrhage for LAA closure and medical anticoagulation. Using data from the PROTECT AF trial, LAA closure with the Watchman device was cost effective; using PREVAIL trial data, Watchman was more costly and less effective than warfarin and dabigatran. PROTECT AF enrolled more patients and has substantially longer follow-up time, allowing greater statistical certainty with the cost-effectiveness results. However, longer-term trial results and postmarketing surveillance of major adverse events will be vital to determining the value of the Watchman in clinical

  11. First direct comparison of clinical outcomes between European and Asian cohorts in transcatheter aortic valve implantation: the Massy study group vs. the PREVAIL JAPAN trial.

    Science.gov (United States)

    Watanabe, Yusuke; Hayashida, Kentaro; Takayama, Morimasa; Mitsudo, Kazuaki; Nanto, Shinsuke; Takanashi, Shuichiro; Komiya, Tatsuhiko; Kuratani, Toru; Tobaru, Tetsuya; Goto, Tsuyoshi; Lefèvre, Thierry; Sawa, Yoshiki; Morice, Marie-Claude

    2015-02-01

    The efficacy and safety of transcatheter aortic valve implantation (TAVI) in Asian populations were unknown. The purpose of this study was to compare directly the clinical outcomes of the first Japanese trial and a European single-center experience after TAVI. Between April 2010 and October 2011, 64 patients were included in the PREVAIL JAPAN multicenter trial which was set up to evaluate the safety and efficacy of the Edwards SAPIEN XT™ (Edwards Lifesciences, Irvine, CA, USA) in high-risk Japanese patients with severe aortic stenosis. Between March 2010 and January 2012, 237 consecutive patients treated with TAVI using the Edwards SAPIEN XT™ prosthesis at Institut Cardiovasculaire Paris Sud were prospectively included in the Massy cohort. We compared the clinical outcomes of these two cohorts. Patients were of similar age (83.4±6.6 years vs. 84.5±6.1 years, p=0.25), but logistic EuroSCORE was higher in the Massy cohort (20.2±11.7% vs. 15.6±8.0%, pPREVAIL JAPAN cohort (1.41±0.14m(2) vs. 1.72±0.18m(2); pPREVAIL JAPAN cohort (12.7±11.4mmHg vs. 10.1±3.6mmHg, p=0.01), but satisfactory improvement in 6-month functional status was obtained in both cohorts (76.5% vs. 77.2%, p=0.91). Clinical outcomes after TAVI in the patients included in the PREVAIL JAPAN trial were acceptable and as safe as that of a single-center European cohort. Copyright © 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  12. Cost-Effectiveness of Percutaneous Closure of the Left Atrial Appendage in Atrial Fibrillation Based on Results from PROTECT AF vs. PREVAIL

    Science.gov (United States)

    Freeman, James V.; Hutton, David W.; Barnes, Geoffrey D.; Zhu, Ruo P.; Owens, Douglas K.; Garber, Alan M.; Go, Alan S.; Hlatky, Mark A.; Heidenreich, Paul A.; Wang, Paul J.; Al-Ahmad, Amin; Turakhia, Mintu P.

    2016-01-01

    Background Randomized trials of left atrial appendage (LAA) closure with the Watchman device have shown varying results, and its cost-effectiveness compared to anticoagulation has not been evaluated using all available contemporary trial data. Methods and Results We used a Markov decision model to estimate lifetime quality-adjusted survival, costs, and cost-effectiveness of LAA closure with Watchman, compared directly with warfarin and indirectly with dabigatran, using data from the long-term (mean 3.8 year) follow-up of PROTECT AF and PREVAIL randomized trials. Using data from PROTECT AF, the incremental cost-effectiveness ratios (ICER) compared to warfarin and dabigatran were $20,486 and $23,422 per quality adjusted life year (QALY), respectively. Using data from PREVAIL, LAA closure was dominated by warfarin and dabigatran, meaning that it was less effective (8.44, 8.54, and 8.59 QALYs, respectively) and more costly. At a willingness-to-pay-threshold of $50,000 per QALY, LAA closure was cost-effective 90% and 9% of the time under PROTECT AF and PREVAIL assumptions, respectively. These results were sensitive to the rates of ischemic stroke and intracranial hemorrhage for LAA closure and medical anticoagulation. Conclusions Using data from the PROTECT AF trial, LAA closure with the Watchman device was cost-effective; using PREVAIL trial data, Watchman was more costly and less effective than warfarin and dabigatran. PROTECT AF enrolled more patients and has substantially longer follow-up time, allowing greater statistical certainty with the cost-effectiveness results. However, longer term trial results and post-marketing surveillance of major adverse events will be vital to determining the value of the Watchman in clinical practice. PMID:27307517

  13. Nucleation in the atmosphere

    International Nuclear Information System (INIS)

    Hegg, D A; Baker, M B

    2009-01-01

    Small particles play major roles in modulating radiative and hydrological fluxes in the atmosphere and thus they impact both climate (IPCC 2007) and weather. Most atmospheric particles outside clouds are created in situ through nucleation from gas phase precursors and most ice particles within clouds are formed by nucleation, usually from the liquid. Thus, the nucleation process is of great significance in the Earth's atmosphere. The theoretical examination of nucleation in the atmosphere has been based mostly on classical nucleation theory. While diagnostically very useful, the prognostic skill demonstrated by this approach has been marginal. Microscopic approaches such as molecular dynamics and density functional theory have also proven useful in elucidating various aspects of the process but are not yet sufficiently refined to offer a significant prognostic advantage to the classical approach, due primarily to the heteromolecular nature of atmospheric nucleation. An important aspect of the nucleation process in the atmosphere is that the degree of metastability of the parent phase for the nucleation is modulated by a number of atmospheric processes such as condensation onto pre-existing particles, updraft velocities that are the main driving force for supersaturation of water (a major factor in all atmospheric nucleation), and photochemical production rates of nucleation precursors. Hence, atmospheric nucleation is both temporally and spatially inhomogeneous

  14. Atmospheric Measurements Laboratory (AML)

    Data.gov (United States)

    Federal Laboratory Consortium — The Atmospheric Measurements Laboratory (AML) is one of the nation's leading research facilities for understanding aerosols, clouds, and their interactions. The AML...

  15. Who's afraid of atmospheres (and of their authority?

    Directory of Open Access Journals (Sweden)

    Tonino Griffero

    2014-07-01

    Full Text Available An atmosphere possesses and exercises authority over the perceiver and his felt-body. This authority (a ‘numinous’ one exists in the proper sense only when it prevails over our resistance and we cannot access a further critical level. This is because an atmosphere that I feel externally, as poured out into the surrounding space, is mine not because I possess it, but because it concerns me.Its normativity, moreover, is not so much discreet but rather loosely diffused into a situation and yet it is able to inhibit any critical distance in those who come across it, especially if unexpectedly. This atmospherological approach implies of course a reflection about the ethical consequences of our ‘necessary’ felt-bodily feelings. Even if the manipulative appearance is implicit in every practice that generates an atmosphere, it’s true thatonly by acquiring a better atmospheric ‘competence’ (both as thinkers and as perceivers we can really learn how not to be grossly manipulated. An atmosphere is maybe less manipulative when it allowsaquick alternation between an uncritical-pathicimmersion and a critical-rational emersion, namely, between an emotional mood and a more analytical one.

  16. Soil-vegetation-atmosphere transfer modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ikonen, J.P.; Sucksdorff, Y. [Finnish Environment Agency, Helsinki (Finland)

    1996-12-31

    In this study the soil/vegetation/atmosphere-model based on the formulation of Deardorff was refined to hour basis and applied to a field in Vihti. The effect of model parameters on model results (energy fluxes, temperatures) was also studied as well as the effect of atmospheric conditions. The estimation of atmospheric conditions on the soil-vegetation system as well as an estimation of the effect of vegetation parameters on the atmospheric climate was estimated. Areal surface fluxes, temperatures and moistures were also modelled for some river basins in southern Finland. Land-use and soil parameterisation was developed to include properties and yearly variation of all vegetation and soil types. One classification was selected to describe the hydrothermal properties of the soils. Evapotranspiration was verified against the water balance method

  17. Soil-vegetation-atmosphere transfer modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ikonen, J P; Sucksdorff, Y [Finnish Environment Agency, Helsinki (Finland)

    1997-12-31

    In this study the soil/vegetation/atmosphere-model based on the formulation of Deardorff was refined to hour basis and applied to a field in Vihti. The effect of model parameters on model results (energy fluxes, temperatures) was also studied as well as the effect of atmospheric conditions. The estimation of atmospheric conditions on the soil-vegetation system as well as an estimation of the effect of vegetation parameters on the atmospheric climate was estimated. Areal surface fluxes, temperatures and moistures were also modelled for some river basins in southern Finland. Land-use and soil parameterisation was developed to include properties and yearly variation of all vegetation and soil types. One classification was selected to describe the hydrothermal properties of the soils. Evapotranspiration was verified against the water balance method

  18. Enzalutamide in Men with Chemotherapy-naïve Metastatic Castration-resistant Prostate Cancer: Extended Analysis of the Phase 3 PREVAIL Study.

    Science.gov (United States)

    Beer, Tomasz M; Armstrong, Andrew J; Rathkopf, Dana; Loriot, Yohann; Sternberg, Cora N; Higano, Celestia S; Iversen, Peter; Evans, Christopher P; Kim, Choung-Soo; Kimura, Go; Miller, Kurt; Saad, Fred; Bjartell, Anders S; Borre, Michael; Mulders, Peter; Tammela, Teuvo L; Parli, Teresa; Sari, Suha; van Os, Steve; Theeuwes, Ad; Tombal, Bertrand

    2017-02-01

    Enzalutamide significantly improved radiographic progression-free survival (rPFS) and overall survival (OS) among men with chemotherapy-naïve metastatic castration-resistant prostate cancer at the prespecified interim analysis of PREVAIL, a phase 3, double-blind, randomized study. We evaluated the longer-term efficacy and safety of enzalutamide up to the prespecified number of deaths in the final analysis, which included an additional 20 mo of follow-up for investigator-assessed rPFS, 9 mo of follow-up for OS, and 4 mo of follow-up for safety. Enzalutamide reduced the risk of radiographic progression or death by 68% (hazard ratio [HR] 0.32, 95% confidence interval [CI] 0.28-0.37; pPREVAIL provides more complete assessment of the clinical benefit of enzalutamide. PREVAIL is registered on ClinicalTrials.gov as NCT01212991. According to data from longer follow-up, enzalutamide continued to provide benefit over placebo in patients with metastatic castration-resistant prostate cancer. Copyright © 2016 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  19. Improved Orbit Determination and Forecasts with an Assimilative Tool for Atmospheric Density and Satellite Drag Specification

    Science.gov (United States)

    Crowley, G.; Pilinski, M.; Sutton, E. K.; Codrescu, M.; Fuller-Rowell, T. J.; Matsuo, T.; Fedrizzi, M.; Solomon, S. C.; Qian, L.; Thayer, J. P.

    2016-12-01

    Much as aircraft are affected by the prevailing winds and weather conditions in which they fly, satellites are affected by the variability in density and motion of the near earth space environment. Drastic changes in the neutral density of the thermosphere, caused by geomagnetic storms or other phenomena, result in perturbations of LEO satellite motions through drag on the satellite surfaces. This can lead to difficulties in locating important satellites, temporarily losing track of satellites, and errors when predicting collisions in space. We describe ongoing work to build a comprehensive nowcast and forecast system for specifying the neutral atmospheric state related to orbital drag conditions. The system outputs include neutral density, winds, temperature, composition, and the satellite drag derived from these parameters. This modeling tool is based on several state-of-the-art coupled models of the thermosphere-ionosphere as well as several empirical models running in real-time and uses assimilative techniques to produce a thermospheric nowcast. This software will also produce 72 hour predictions of the global thermosphere-ionosphere system using the nowcast as the initial condition and using near real-time and predicted space weather data and indices as the inputs. Features of this technique include: • Satellite drag specifications with errors lower than current models • Altitude coverage up to 1000km • Background state representation using both first principles and empirical models • Assimilation of satellite drag and other datatypes • Real time capability • Ability to produce 72-hour forecasts of the atmospheric state In this paper, we will summarize the model design and assimilative architecture, and present preliminary validation results. Validation results will be presented in the context of satellite orbit errors and compared with several leading atmospheric models including the High Accuracy Satellite Drag Model, which is currently used

  20. Radiological impact of atmospheric releases from a coal-fired power station

    International Nuclear Information System (INIS)

    Aigueperse, J.; Chalabreysse, J.; Coulon, R.; Grauby, A.; Uzzan, G.

    1982-01-01

    As the first stage of a study carried out under contract with the Commission of the European Communities for the comparative assessment of the risks to which the individuals of a regional population are exposed, the paper seeks to evaluate atmospheric releases from a coal-fired thermal power station. The station is of traditional design with an installed capacity of 415MW(e) and uses only li