974 resultados para Ultrafine Particles, Laser Printer, Indoor Air Quality, Aerosol Formation


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Rakennustuotteena käytettävien teräskokoonpanojen lisääntyneet CE- merkintävaatimukset ovat aiheuttaneet runsaasti hämmennystä alan toimijoiden keskuudessa. Tämän tutkimuksen tavoitteena oli selvittää teräskokoonpanojen SFS-EN 1090-1 standardin soveltamisala suhteessa konedirektiiviin sekä kartoittaa mahdollisen muutoksen aiheuttamat toimenpiteet ilmansuojelulaitetoimituksissa. Työssä tutustuttiin asetusten teoreettiseen viitekehykseen, standardeihin sekä alan kirjallisuuteen. Teoriaa sovellettiin tulevaisuudentutkimuksen Delfoi- menetelmään, jossa asiantuntijahaastatteluiden perusteella arvioitiin asetuksen soveltamisalaa ja vaatimuksia. Tutkimuksen avaintuloksia ovat standardin SFS-EN 1090-1 vaatimuksenmukaisuuteen vaikuttavien tekijöiden tunnistaminen ja niiden perusteella laaditut ehdotukset yritystoiminnan kehittämiseksi.

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Ambient (03) ozone concentrations were compared to ozone damage on milkweed plants to determine if there was a correlation. Eight survey sites of at least 100 plants each were located within 5 kilometers of Air Quality Index (AQI) stations in southern Ontario. Sites were visited nine times from June-September (2007) and milkweed leaves from 75 plants were assessed using methods pioneered in the United States. Ambient 0 3 results were calculated into SUM65, seasonal cumulative 0 3, and total 03. The 0 3 exposure indices SUM65 and cumulative 0 3 were tested statistically to determine which index is biologically relevant to milkweed as an 0 3 damage indicator species. The milkweed damage indices were incidence of leaves damaged per plant, incidence of plants damaged per site, and total 0 3• The incidence of plants injured per site was the best damage parameter with an F(1,28)=17.37, p=0.0003 for SUM65 and F(1,28)=7.5, p=O.0106 for cumulative 03 .. Milkweed plants showed quantifiable ozone damage with minimal spatial differences in damage and thus have potential use as a biomonitor species in southern Ontario.

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Ce mémoire décrit et analyse différents types de systèmes d'échange de droits d'émission utilisés dans le cadre de politiques de gestion de la pollution atmosphérique. L'objectif premier est de répertorier des enjeux juridiques étant liés à l'efficacité de ces systèmes. Dans un premier temps, nous nous attardons à la structure et aux mécanismes internes des systèmes d'échange de droits d'émission. Tout d'abord, nous soulignons le fondement théorique de ce type de système. Nous évaluons par la suite la structure et certains litiges liés au système d'échange américain dans le cadre des émissions de dioxyde de soufre. Dans un deuxième temps, nous continuons la description de systèmes en nous attardant plus spécifiquement aux interactions entre les systèmes d'échange de droits d'émission et les autres politiques et règlementations environnementales (incluant d'autres systèmes d'échange d'émission) visant la même problématique environnementale.

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The hazards associated with major accident hazard (MAH) industries are fire, explosion and toxic gas releases. Of these, toxic gas release is the worst as it has the potential to cause extensive fatalities. Qualitative and quantitative hazard analyses are essential for the identitication and quantification of the hazards associated with chemical industries. This research work presents the results of a consequence analysis carried out to assess the damage potential of the hazardous material storages in an industrial area of central Kerala, India. A survey carried out in the major accident hazard (MAH) units in the industrial belt revealed that the major hazardous chemicals stored by the various industrial units are ammonia, chlorine, benzene, naphtha, cyclohexane, cyclohexanone and LPG. The damage potential of the above chemicals is assessed using consequence modelling. Modelling of pool fires for naphtha, cyclohexane, cyclohexanone, benzene and ammonia are carried out using TNO model. Vapor cloud explosion (VCE) modelling of LPG, cyclohexane and benzene are carried out using TNT equivalent model. Boiling liquid expanding vapor explosion (BLEVE) modelling of LPG is also carried out. Dispersion modelling of toxic chemicals like chlorine, ammonia and benzene is carried out using the ALOHA air quality model. Threat zones for different hazardous storages are estimated based on the consequence modelling. The distance covered by the threat zone was found to be maximum for chlorine release from a chlor-alkali industry located in the area. The results of consequence modelling are useful for the estimation of individual risk and societal risk in the above industrial area.Vulnerability assessment is carried out using probit functions for toxic, thermal and pressure loads. Individual and societal risks are also estimated at different locations. Mapping of threat zones due to different incident outcome cases from different MAH industries is done with the help of Are GIS.Fault Tree Analysis (FTA) is an established technique for hazard evaluation. This technique has the advantage of being both qualitative and quantitative, if the probabilities and frequencies of the basic events are known. However it is often difficult to estimate precisely the failure probability of the components due to insufficient data or vague characteristics of the basic event. It has been reported that availability of the failure probability data pertaining to local conditions is surprisingly limited in India. This thesis outlines the generation of failure probability values of the basic events that lead to the release of chlorine from the storage and filling facility of a major chlor-alkali industry located in the area using expert elicitation and proven fuzzy logic. Sensitivity analysis has been done to evaluate the percentage contribution of each basic event that could lead to chlorine release. Two dimensional fuzzy fault tree analysis (TDFFTA) has been proposed for balancing the hesitation factor invo1ved in expert elicitation .

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Bei Meßprojekten in denen Gebäude mit installierter Lüftungsanlage untersucht wurden, stellte man immer wieder ein breite Streuung der Meßwerte, als auch eine oftmals deutliche Abweichung vom vorher ermittelten Heizwärmebedarf der Gebäude fest. Es wird vermutet, daß diese Unterschiede systemspezifische Ursachen haben, ein Nachweis kann aufgrund der geringen Anzahl vorhandener Meßpunkte jedoch nicht geführt werden. Um die Sensitivität verschiedener Randbedingungen auf den Energieverbrauch zu ermitteln, wird im vorliegenden Forschungsprojekt ein Simulationsmodell erstellt. Das thermische Verhalten und die Durchströmung des Gebäudes werden durch ein gekoppeltes Modell abgebildet. Unterschiedliche Lüftungsanlagensysteme werden miteinander verglichen. Auf Basis vorhandener Meßdaten wird ein klimaabhängiges Modell zur Fensterlüftung entwickelt, welches in die Modellbildung der Gebäudedurchströmung mit einfließt. Feuchtegeregelte Abluftanlagen sind in der Lage den mittleren Luftwechsel auf ein hygienisch sinnvollen Wert zu begrenzen. Sie erweisen sich im Hinblick auf die Sensitivität verschiedener Randbedingungen als robuste Systeme. Trotz Einsatz von Lüftungsanlagen kann je nach Betriebszustand insbesondere bei Abluftanlagen keine ausreichende Luftqualität sichergestellt werden. Zukünftige Systeme dürfen das "Lüftungssystem" Fenster nicht vernachlässigen, sondern müssen es in das Gesamtkonzept mit einbeziehen.

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En el proceso de extracción de petróleo (crudo) deben realizarse tratamientos físicos y químicos en estaciones de recolección del hidrocarburo con el fin de garantizar su calidad antes de su entrega para el transporte y comercialización. Para la realización de esta actividad el personal operativo requerido (operadores) debe realizar diferentes actividades, tales como ronda operacional, verificación de sistemas de almacenamiento del crudo, agua residual del proceso e insumos químicos utilizados en su tratamiento y manipulación de facilidades en las estaciones de recolección, entre otras. Como resultados de las actividades rutinarias los operadores están expuestos a factores de riesgo químico asociados a gases y vapores orgánicos generados en los procesos de tratamiento del crudo. En el presente trabajo se realizaron mediciones de calidad de aire e higiene industrial en diferentes estaciones tratamiento de crudo, con el propósito de evaluar los niveles de exposición de los operadores a gases y vapores de hidrocarburos durante el proceso de tratamiento de crudo y dar respuesta a la siguiente pregunta: ¿existe relación entre la exposición ocupacional, las emisiones atmosféricas de gases (SO2, CO, H2S) y la percepción de afectación de la salud de los trabajadores que se encuentran expuestos durante la actividad laboral, en una empresa del sector de hidrocarburos? Se realizó un estudio de corte transversal, mediante la aplicación de cuestionarios sobre las condiciones de trabajo y de salud a 30 trabajadores que laboran en una estación de tratamiento de crudo de una compañía del sector de hidrocarburos. Los operadores objeto de estudio laboran en turnos rotativos, han estado vinculados con la compañía por más de dos años y tienen contrato directo, adicionalmente, se identificaron los factores de riesgos ambientales y ocupacionales para el grupo de trabajadores y se realizó una revisión de los informes de medición de higiene industrial y de calidad de aire de las estaciones donde labora el personal seleccionado con el fin de establecer si los resultados se relacionan. Los resultados obtenidos indican que el 100% de los trabajadores son de género masculino y se desempeñan en cargos de operadores, recorredores de pozos de crudo y supervisores. El 97% de los operadores tiene más de cuarenta años de edad y el 80% de los mismos ha laborado por más de 6 años en la compañía. Acerca de la percepción de los trabajadores sobre su estado de salud el 90% afirma que su salud es buena, el 97% respondió que no presenta problemas respiratorios, el 23% manifiesta que presenta trastornos dermatológicos y el 27% indican que presenta dolor de cabeza constante. De la revisión de los informes de calidad de aire disponibles se encontró que las mediciones de Dióxido de Azufre SO2, Monóxido de Carbono CO se encuentran dentro del rango definido como el de menor impacto para la salud humana. De los datos del informe se puede concluir que la calidad del aire es buena en el 100% de las áreas de influencia de las estaciones de tratamiento de crudo. Según los informes de higiene industrial el 34% de las instalaciones presenta concentraciones de Sulfuro de Hidrógeno (H2S) en el límite permisible para exposiciones crónicas en un promedio ponderado de tiempo (TLV-TWA) y el límite permisible para exposiciones agudas en un límite de exposición a corto plazo (TLV-STEL). Solo el 37% de los trabajadores objeto de este estudio percibe el riesgo por la exposición a factores de riesgo químicos y son claramente consientes que se encuentran expuestos a estos riesgos por la manipulación de productos químicos y exposición a sustancias químicas producto de sus actividades rutinarias, el 73% no percibe el riesgo de exposición por su actividad laboral. Se recomienda que la compañía fortalezca su esquema de vigilancia para generar alternativas que eleven los niveles de consciencia del riesgo del trabajador. Los factores de riesgo ambiental y ocupacional, de los gases y vapores generados se deben al proceso de tratamiento de crudo, están mutuamente relacionados dado que al generarse una emisión y/o escape no controlado como consecuencia se tiene una afectación directa al medio ambiente y a los trabajadores.

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Aviation and the environment: outline - Aircraft noise - Aircraft engine emissions Local air quality Greenhouse gases and climate change - Airline, airport and manufacturer impacts

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The North Atlantic Oscillation (NAO) is an important large-scale atmospheric circulation that influences the European countries climate. This study evaluated NAO impact in air quality in Porto Metropolitan Area (PMA), Portugal, for the period 2002-2006. NAO, air pollutants and meteorological data were statistically analyzed. All data were obtained from PMA Weather Station, PMA Air Quality Stations and NOAA analysis. Two statistical methods were applied in different time scale : principal component and correlation coefficient. Annual time scale, using multivariate analysis (PCA, principal component analysis), were applied in order to identified positive and significant association between air pollutants such as PM10, PM2.5, CO, NO and NO2, with NAO. On the other hand, the correlation coefficient using seasonal time scale were also applied to the same data. The results of PCA analysis present a general negative significant association between the total precipitation and NAO, in Factor 1 and 2 (explaining around 70% of the variance), presented in the years of 2002, 2004 and 2005. During the same years, some air pollutants (such as PM10, PM2.5, SO2, NOx and CO) present also a positive association with NAO. The O3 shows as well a positive association with NAP during 2002 and 2004, at 2nd Factor, explaining 30% of the variance. From the seasonal analysis using correlation coefficient, it was found significant correlation between PM10 (0.72., p<0.05, in 2002), PM2.5 (0 74, p<0.05, in 2004), and SO2 (0.78, p<0.01, in 2002) with NAO during March-December (no winter period) period. Significant associations between air pollutants and NAO were also verified in the winter period (December to April) mainly with ozone (2005, r=-0.55, p.<0.01). Once that human health and hospital morbidities may be affected by air pollution, the results suggest that NAO forecast can be an important tool to prevent them, in the Iberian Peninsula and specially Portugal.

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Ventilation of the boundary layer has an important effect on local and regional air quality and is a prerequisite for long-range pollution transport. Once in the free troposphere, pollutants can alter the chemical composition of the troposphere and impact on the Earth's radiative forcing. Idealised baroclinic life cycles, LC1 and LC2, have been simulated in a three-dimensional dry hemispheric model in the presence of boundary-layer turbulent fluxes. A passive tracer is added to the simulations to represent pollution emitted at, or near, the surface. A simple conveyor-belt diagnostic is developed to objectively identify regions of the boundary layer that can be ventilated by either warm or cold conveyor belts. Transport of pollutants within and above the boundary layer is examined on synoptic scales. Three different physical mechanisms are found to interact with each other to ventilate pollutants out of the boundary layer. These mechanisms are turbulent mixing within the boundary layer, horizontal advection due to Ekman convergence and divergence within the boundary layer, and advection by the warm conveyor belt. The mass of tracer ventilated by the two life cycles is remarkably similar given the differences in frontal structure, suggesting that the large-scale baroclinicity is an effective constraint on ventilation.

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Street-level mean flow and turbulence govern the dispersion of gases away from their sources in urban areas. A suitable reference measurement in the driving flow above the urban canopy is needed to both understand and model complex street-level flow for pollutant dispersion or emergency response purposes. In vegetation canopies, a reference at mean canopy height is often used, but it is unclear whether this is suitable for urban canopies. This paper presents an evaluation of the quality of reference measurements at both roof-top (height = H) and at height z = 9H = 190 m, and their ability to explain mean and turbulent variations of street-level flow. Fast response wind data were measured at street canyon and reference sites during the six-week long DAPPLE project field campaign in spring 2004, in central London, UK, and an averaging time of 10 min was used to distinguish recirculation-type mean flow patterns from turbulence. Flow distortion at each reference site was assessed by considering turbulence intensity and streamline deflection. Then each reference was used as the dependent variable in the model of Dobre et al. (2005) which decomposes street-level flow into channelling and recirculating components. The high reference explained more of the variability of the mean flow. Coupling of turbulent kinetic energy was also stronger between street-level and the high reference flow rather than the roof-top. This coupling was weaker when overnight flow was stratified, and turbulence was suppressed at the high reference site. However, such events were rare (<1% of data) over the six-week long period. The potential usefulness of a centralised, high reference site in London was thus demonstrated with application to emergency response and air quality modelling.

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During a 4-week run in October–November 2006, a pilot experiment was performed at the CERN Proton Synchrotron in preparation for the Cosmics Leaving OUtdoor Droplets (CLOUD) experiment, whose aim is to study the possible influence of cosmic rays on clouds. The purpose of the pilot experiment was firstly to carry out exploratory measurements of the effect of ionising particle radiation on aerosol formation from trace H2SO4 vapour and secondly to provide technical input for the CLOUD design. A total of 44 nucleation bursts were produced and recorded, with formation rates of particles above the 3 nm detection threshold of between 0.1 and 100 cm−3 s−1, and growth rates between 2 and 37 nm h−1. The corresponding H2SO4 concentrations were typically around 106 cm−3 or less. The experimentally-measured formation rates and H2SO4 concentrations are comparable to those found in the atmosphere, supporting the idea that sulphuric acid is involved in the nucleation of atmospheric aerosols. However, sulphuric acid alone is not able to explain the observed rapid growth rates, which suggests the presence of additional trace vapours in the aerosol chamber, whose identity is unknown. By analysing the charged fraction, a few of the aerosol bursts appear to have a contribution from ion-induced nucleation and ion-ion recombination to form neutral clusters. Some indications were also found for the accelerator beam timing and intensity to influence the aerosol particle formation rate at the highest experimental SO2 concentrations of 6 ppb, although none was found at lower concentrations. Overall, the exploratory measurements provide suggestive evidence for ion-induced nucleation or ion-ion recombination as sources of aerosol particles. However in order to quantify the conditions under which ion processes become significant, improvements are needed in controlling the experimental variables and in the reproducibility of the experiments. Finally, concerning technical aspects, the most important lessons for the CLOUD design include the stringent requirement of internal cleanliness of the aerosol chamber, as well as maintenance of extremely stable temperatures (variations below 0.1 _C).

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More than half the world's rainforest has been lost to agriculture since the Industrial Revolution. Among the most widespread tropical crops is oil palm (Elaeis guineensis): global production now exceeds 35 million tonnes per year. In Malaysia, for example, 13% of land area is now oil palm plantation, compared with 1% in 1974. There are enormous pressures to increase palm oil production for food, domestic products, and, especially, biofuels. Greater use of palm oil for biofuel production is predicated on the assumption that palm oil is an “environmentally friendly” fuel feedstock. Here we show, using measurements and models, that oil palm plantations in Malaysia directly emit more oxides of nitrogen and volatile organic compounds than rainforest. These compounds lead to the production of ground-level ozone (O3), an air pollutant that damages human health, plants, and materials, reduces crop productivity, and has effects on the Earth's climate. Our measurements show that, at present, O3 concentrations do not differ significantly over rainforest and adjacent oil palm plantation landscapes. However, our model calculations predict that if concentrations of oxides of nitrogen in Borneo are allowed to reach those currently seen over rural North America and Europe, ground-level O3 concentrations will reach 100 parts per billion (109) volume (ppbv) and exceed levels known to be harmful to human health. Our study provides an early warning of the urgent need to develop policies that manage nitrogen emissions if the detrimental effects of palm oil production on air quality and climate are to be avoided.

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More than half the world's rainforest has been lost to agriculture since the Industrial Revolution. Among the most widespread tropical crops is oil palm (Elaeis guineensis): global production now exceeds 35 million tonnes per year. In Malaysia, for example, 13% of land area is now oil palm plantation, compared with 1% in 1974. There are enormous pressures to increase palm oil production for food, domestic products, and, especially, biofuels. Greater use of palm oil for biofuel production is predicated on the assumption that palm oil is an "environmentally friendly'' fuel feedstock. Here we show, using measurements and models, that oil palm plantations in Malaysia directly emit more oxides of nitrogen and volatile organic compounds than rainforest. These compounds lead to the production of ground-level ozone (O-3), an air pollutant that damages human health, plants, and materials, reduces crop productivity, and has effects on the Earth's climate. Our measurements show that, at present, O-3 concentrations do not differ significantly over rainforest and adjacent oil palm plantation landscapes. However, our model calculations predict that if concentrations of oxides of nitrogen in Borneo are allowed to reach those currently seen over rural North America and Europe, ground-level O-3 concentrations will reach 100 parts per billion (10(9)) volume (ppbv) and exceed levels known to be harmful to human health. Our study provides an early warning of the urgent need to develop policies that manage nitrogen emissions if the detrimental effects of palm oil production on air quality and climate are to be avoided.