Impact of point source pollution on nitrogen isotope signatures (delta N-15) of vegetation in SE Brazil

This study presents novel evidence that N-15 natural abundance can be used as a robust indicator to detect pollutant nitrogen in natural plant communities. Vegetation from the heavily polluted industrial area of Cubatao in Sao Paulo State, SE Brazil, was strongly N-15 depleted compared to plants at remote sites. Historic herbarium samples from Cubatao were significantly less N-15 depleted than extant plants, indicating that N-15 depletion of vegetation is associated with present-day nitrogen pollution in Cubatao. The heavy load of nitrogenous atmospheric pollutants in Cubatao provides a nitrogen source for plants, and strongly N-15 depleted air NH3 is likely to contribute to plant and soil N-15 depletion. Epiphytic plants from Cubatao were extremely N-15 depleted (average -10.9parts per thousand) contrasting with epiphytes at remote sites (averages -1.0parts per thousand and -3.0parts per thousand). Nitrogen isotope composition of vegetation provides a tool to determine input of pollutant nitrogen into plant communities. The strong isotopic change of epiphytes suggests that epiphytes are particularly sensitive biomonitors for atmospheric pollutant nitrogen.

Investigation of the flow field of a highly heated jet of air

Measurements of mean and fluctuating velocity and temperature and their self- and cross-products to the third-order are presented for a heated axisymmetric air jet. Froude numbers in the range of 3500 13,190, Reynolds numbers in the range of 3470-8500 and non-dimensional streamwise distances. X*, from 0.27 to 1.98 are covered by the data. It was found that turbulence intensity decreases for the heated jet in the region between the inertia dominated and the buoyancy dominated regions which is contrary to findings with helium jets mixing with ambient air to produce density fluctuations. The effects of heating on the turbulent kinetic energy budget and the temperature variance budget show small differences for the inertia dominated region and the intermediate region which help to explain the transition process to the far field plume region. Constants are evaluated for the isotropic eddy diffusivity and generalised gradient hypothesis models as well as the scalar variance model. No significant effect of heating on the dissipation time-scale ratio was found. A novel wire array with an inclined cold wire was used. Measurements obtained with this probe are found to lead to asymmetries in some of the higher-order products. Further investigation suggested that the asymmetries are attributable to an as yet unreported interference effect produced by the leading prong of the inclined temperature wire, The effect may also have implications for inclined velocity wires which contain a temperature component when used in heated flows. (C) 2002 Elsevier Science Inc. All rights reserved.

Air-water flows down stepped chutes: turbulence and flow structure observations

Interactions between turbulent waters and atmosphere may lead to strong air-water mixing. This experimental study is focused on the flow down a staircase channel characterised by very strong flow aeration and turbulence. Interfacial aeration is characterised by strong air-water mixing extending down to the invert. The size of entrained bubbles and droplets extends over several orders of magnitude, and a significant number of bubble/droplet clusters was observed. Velocity and turbulence intensity measurements suggest high levels of turbulence across the entire air-water flow. The increase in turbulence levels, compared to single-phase flow situations, is proportional to the number of entrained particles. (C) 2002 Elsevier Science Ltd. All rights reserved.

Beneficial effects of air inclusions on the performance of ethylene vinyl acetate (EVA) mouthguard material

Objective: To investigate the impact characteristics of an ethylene vinyl acetate (EVA) mouthguard material with regulated air inclusions, which included various air cell volumes and wall thickness between air cells. In particular, the aim was to identify the magnitude and direction of forces within the impacts. Method: EVA mouthguard material, A mm thick and with and without air inclusions, was impacted with a constant force impact pendulum with an energy of 4.4 J and a velocity of 3 m/s. Transmitted forces through the EVA material were measured using an accelerometer, which also allowed the determination of force direction and magnitude within the impacts. Results: Statistically significant reductions in the transmitted forces were observed with all the air inclusion materials when compared with EVA without air inclusions. Maximum transmitted force through one air inclusion material was reduced by 32%. Force rebound was eliminated in one material, and reduced second force impulses were observed in all the air inclusion materials. Conclusion: The regulated air inclusions improved the impact characteristics of the EVA mouthguard material, the material most commonly used in mouthguards world wide.

Exposure to automotive pollution increases plasma susceptibility to oxidation

Low-density lipoprotein oxidation is implicated in the development of atherosclerosis. Plasma susceptibility to oxidation may be used as a marker of low-density lipoprotein oxidation and thus predict atherosclerotic risk. In this study the authors investigated the relationship between plasma susceptibility to oxidation and exposure to automotive pollution in a group of automobile mechanics (n = 16) exposed to high levels of automotive pollution, vs. matched controls (n = 13). The authors induced plasma oxidation by a free radical initiator and they determined susceptibility to oxidation by (1) change in absorbance at 234 nm, (2) lag time to conjugated diene formation, and (3) linear slope of the oxidation curve. Mechanics had significantly higher values (mean standard error) for change in absorbance (1.60 +/- 0.05 vs. 1.36 +/- 0.05; p < .002), and slope (1.6 x 10(-3) +/- 0.1 x 10(-3) vs. 1.3 x 10(-3) +/- 0.1 x 10(-3); p < .001), compared with controls. These results indicate that regular exposure to automotive pollutants increases plasma susceptibility to oxidation and may, in the long term, increase the risk of developing atherosclerosis.

Experimental study of phase equilibria in the PbO-ZnO-"Fe2O3"-(CaO+SiO2) system in air for the lead and zinc blast furnace sinters (CaO/SiO2 weight ratio of 0.933 and PbO/(CaO+SiO2) ratios of 2.0 and 3.2)

Experimental studies on phase equilibria and liquidus in the multicomponent system PbO-ZnO-CaO-SiO2-FeO-Fe2O3 in air have been conducted over the temperature range between 1323 K (1050 degreesC) and 1623 K (1350 degreesC) to characterize the phase relations of the complex slag systems encountered in lead and zinc blast furnace sinters. The liquidus in two pseudoternary sections ZnO-Fe2O3-(PbO + CaO + SiO2) with the CaO/SiO2 weight ratio of 0.933 and PbO/(CaO + SiO2) weight ratios of 2.0 and 3.2 have been constructed.

Study of wet porous filtration

A growing demand for efficient air quality management calls for the development of technologies capable of meeting the stringent requirements now being applied in areas of chemical, biological and medical activities. Currently, filtration is the most effective process available for removal of fine particles from carrier gases. Purification of gaseous pollutants is associated with adsorption, absorption and incineration. In this paper we discuss a new technique for highly efficient simultaneous purification of gaseous and particulate pollutants from carrier gases, and investigate the utilization of Nuclear Magnetic Resonance (NMR) imaging for the study of the dynamic processes associated with gas-liquid flow in porous media. Our technique involves the passage of contaminated carrier gases through a porous medium submerged into a liquid, leading to the formation of narrow and tortuous pathways through the medium. The wet walls of these pathways result in outstanding purification of gaseous, liquid and solid alien additives. NMR imaging was successfully used to map the gas pathways inside the porous medium submerged into the liquid layer. (C) 2002 Elsevier Science B.V. All rights reserved.

Estudo do transporte atmosf��rico de Mp10 e SO2 com os Modelos WRF/CMAQ em regi��es costeiras urbanas

O objetivo principal deste trabalho foi o estudo do transporte atmosf��rico de PM10 e SO2 em regi��es costeiras urbanas usando modelos WRF/CMAQ. Duas regi��es foram contempladas neste estudo. Uma �� a Regi��o da Grande Vit��ria (RGV), no estado do Esp��rito Santo, Brasil; a outra �� a Regi��o da Grande Dunkerque (RGD), no Departamento Nord Pas-de-Calais, Fran��a. A RGV �� cercada por uma cadeia de montanhas paralela �� costa, resultando num topografia complexa e acidentada. J�� a RGD possui uma topografia muito mais suave. As entradas de dados para os modelos WRF/CMAQ englobaram o invent��rio de emiss��es de poluentes atmosf��ricos do IEMA-ES para a RGV, e o invent��rio de emiss��es no n��vel do solo de Nord Pas-de-Calais denominado ���Cadastre_totaux_3km_A2008 _M2010_V2_SNAPN2��� para a RGD. Ambos os invent��rios apresentaram restri����es, todavia. O invent��rio da RGV apresentou valores de ressuspens��o em vias de tr��fego elevados, em compara����o com diversos estudos, e teve esses dados modificados. Os dados no n��vel do solo e a grande ��rea de das c��lulas da grade (9 km2) do invent��rio da RGD n��o permitiram resultados satisfat��rios de modelagem. A valida����o dos modelos foi realizada por compara����o com resultados obtidos em duas campanhas experimentais: uma na cidade de Dunkerque, no norte da Fran��a, em setembro de 2009; a outra na cidade de Vit��ria, no sudeste do Brasil, em julho de 2012. Esses dados foram obtidos pelo uso de sistemas de Light Detection and Ranging (LIDAR) e Sonic Detection and Ranging (SODAR), bem como de Esta����es Meteorol��gicas de Superf��cie (EMS) e de monitoramento atmosf��rico. Os resultados deste trabalho mostraram que: a) existe uma necessidade de melhorias cont��nuas nos invent��rios regionais de emiss��es, adaptando-os para condi����es locais espec��ficas e focando na obten����o de par��metros necess��rios para modelagem fotoqu��mica; b) os valores de m��dulo e dire����o das velocidades obtidas na modelagem meteorol��gica influenciam fortemente os resultados da modelagem de concentra����o de poluentes; c) a qualidade do ar tanto na RGV quanto na RGD merece aten����o, sobretudo no que diz respeito ��s concentra����es de MP10. De acordo com os dados das esta����es de monitoramento, a situa����o parece mais cr��tica na RGD; d) a modelagem da RGV apresentou resultados mais satisfat��rios do que a da RGD, de acordo com os resultados das valida����es; e) a entrada da brisa do mar provocou altera����es significativas na concentra����o dos poluentes, o que p��de ser observado na an��lise da din��mica da dispers��o de MP10 e SO2. Esse fen��meno foi mais marcante na RGV, onde a entrada da brisa mar��tima provocou um movimento oscilat��rio na pluma de polui����o, levando-a para os bairros mais densamente povoados do conglomerado urbano. Na RGD, a entrada da brisa n��o foi cotidiana e, no dia em que ela aconteceu, houve uma altera����o de quase 180�� na dire����o do movimento da pluma de polui����o. Al��m do aumento da turbul��ncia vertical, o qual j�� foi estudado por diversos autores, este estudo focou tamb��m na influ��ncia brisa do mar na din��mica da pluma de dispers��o de poluentes atmosf��ricos em regi��es costeiras.

Fighting climate change in the air: lessons from the EU directive on global aviation

The European Union's (EU) decision to include aviation into the Emissions Trade Scheme was heatedly contested. Countries around the world, but mainly the Brazil, Russia, India, China and South Africa group (BRICS) and the US, denounced the EU's initiate as illegal and unilateral. Following a decade of frustrated negotiations at the International Civil Aviation Organization (ICAO), this paper interrogates why such measure, in principle climate-friendly, inspired so much global resentment. I argue that concerns with competitiveness and risks of legal inconsistency are important, but insufficient elements to explain the core of the conflict. The paper suggests that the EU was strongly criticized because third countries perceived this action as an imposed solution, which fostered an environment of distrust. Therefore, I claim that the problem has more to do with a normative divide than with a substantive divergence on what should be done regarding aviation emissions. My analysis is informed by the present literature on the links between trade and climate change, but gives particular weight to first-hand information through interviews with key stakeholders. The paper is divided in three parts. First, it presents the scope of the EU directive in historical perspective. Second, it explores the EU's measure through three different angles: legal, economical and political. The final part explores some possible solutions to overcome these divergences.

Sistema de apoio �� decis��o espacial para an��lise do impacte ambiental da dispers��o de poluentes atmosf��ricos

Neste artigo e�� apresentado um Sistema de Apoio a�� Decisa��o Espacial (SADE) onde os decisores podem facilmente definir diferentes tipos de problemas espaciais recorrendo a diferentes categorias de objetos, pre��-definidas ou a definir, associando- lhes caracteri��sticas com ou sem depende��ncia espacial, e indicando formas de interfere��ncia (impactos) entre essas caracte- ri��sticas/propriedades. A ana��lise espacial para determinac��a��o ou avaliac��a��o de configurac��o��es alternativas para a localizac��a��o de diferentes tipos de ocorre��ncias espaciais sera�� feita atrave��s da utilizac��a��o interativa do SADE de acordo com conjuntos de regras intri��nsecas aos va��rios elementos gra��ficos (objetos, categorias, caracteri��sticas, impactos) utilizados na definic��a��o dos problemas. O teste a�� generalidade representativa e anali��tica do SADE proposto e�� efectuado recorrendo a um problema concreto, suficientemente especi��fico e complexo, relativo a�� aplicac��a��o de modelos gaussianos para o estudo da dispersa��o atmosfe��rica de eventuais poluentes resultantes do tratamento de resi��duos so��lidos. A regia��o em estudo esta�� limitada, neste exemplo, ao munici��pio de Coimbra, Portugal. Para este munici��pio esta��o acessi��veis, e sa��o utilizados, os dados demogra��ficos ao ni��vel da secc��a��o de voto (censos oficiais) e, como tal, e�� possi��vel a realizac��a��o de um estudo reali��stico do impacto com populac��o��es humanas.