Search results for " composition"

2018

Abstract. As part of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) project, an airborne campaign was designed to measure a large range of atmospheric constituents, focusing on the effect of anthropogenic emissions on regional climate. The presented study details results of the French ATR42 research aircraft, which aimed to characterize gas-phase, aerosol and cloud properties in the region during the field campaign carried out in June/July 2016 in combination with the German Falcon 20 and the British Twin Otter aircraft. The aircraft flight paths covered large areas of Benin, Togo, Ghana and Côte d'Ivoire, focusing on emissions from large urban conurbations such …

Stress-induced cytological and chemical adaptations in Cupressus plants from an urban area of Palermo (Italy)

2004

We studied stress-induced cytological and chemical adaptations in Cupressus pollens and needles from the area of Palermo (Sicily, Italy), in polluted and control sites (unpolluted) of urban and suburban areas. Pollen and needle chemical composition were investigated to provide an indicator of contamination of the trees, which were also examined structurally throughout one year. The concentration of particulate with lead was found to be significantly higher in plants at the polluted traffic site. Lead is one of the worst particulate pollutants in cities, especially in the winter season. In trees from the polluted site, all structural analysis revealed displasies. Structural changes, observed…

Effects of air pollution on production of essential oil in Feijoa Sellowiana Berg. grown in the "Italian triangle of death"

2010

The composition of the essential oils of fruits from Feijoa sellowiana grown in the district of Acerra is compared with those collected from unpolluted sites. Essential oils from the fruits of F. sellowiana were analysed by GC/MS. Sixty compounds, representing 96.6% and 97.8% (unpolluted site and Acerra site, respectively) of the oils, were identified. The major constituents were β-caryophyllene (12.4% and 16.8%), ledene (9.6% and 11.1%), α-humulene (6.3% and 8.2%), β-elemene (4.9% and 5.3%) and δ-cadinene (4.7% and 5.2%) in the control site and Acerra site, respectively. The antioxidant components were increased in response to polluted condition. The acetonic extracts of F. sellowiana from…

First measurements of reactive α-dicarbonyl concentrations on PM2.5 aerosol over the Boreal forest in Finland during HUMPPA-COPEC 2010 – source…

2012

The first dataset for summertime boreal forest concentrations of two atmospherically relevant α-dicarbonyl compounds, glyoxal (Gly) and methylglyoxal (Mgly) on PM2.5 aerosol was obtained during the HUMPPA-COPEC-2010 field measurement intensive in Hyytiälä, Finland. Anthropogenic influences over the course of the campaign were identified using trace gas signatures and aerosol particle chemical composition analysis. The data evaluation allowed the identification of different events such as urban pollution plumes, biomass burning and sawmill emissions as sources of high Gly and Mgly concentrations. Mean aerosol concentrations during periods of biogenic influence were 0.81 ng m−3 for Gly and 0.…

The environmental impact of air pollution on the built heritage of historic Cairo (Egypt)

2020

In the last decades, many researchers investigated the relation between environmental pollution and the degradation phenomena on the built heritage, because of their rapid increase and growing harmfulness. Consequently, the identification of the main pollution sources has become essential to define mitigation actions against degradation and alteration phenomena of the stone materials. In this way, the present paper is focused on the study of the effect of air pollution on archaeological buildings in Historic Cairo. A multi-methodological approach was used to obtain information about the chemical composition of examined black crusts and to clarify their correlation with the air pollution, sp…

Microplastics in the Center of Mediterranean: Comparison of the Two Calabrian Coasts and Distribution from Coastal Areas to the Open Sea

2021

Plastic is everywhere—increasing evidence suggests that plastic pollution is ubiquitous and persistent in ecosystems worldwide. Microplastic pollution in marine environments is particularly insidious, as small fragmentation can increase interaction with biota and food chain access. Of particular concern is the Mediterranean Sea, which has become a large area of accumulation of plastic debris, including microplastics, whose polymeric composition is still largely unknown. In this study, we analyzed the polymeric composition, particle size distribution, shape, and color of small plastic particles (ranging from 50 to 5000 µm) collected from the sea surface in six stations at the center of the M…

Influence of the Residual Stresses Induced by Shot-Peening on the Oxidation of Zr Plates

2014

The present study evaluates the influence of the residual stress on the oxidation rate of Zr at 650°C. It is shown that the oxidation rate can be substantially decreased by shot-peening. A systematic instigation of the various factors (such as the residual stress, the surface pollution and the chemical composition of the oxidation atmosphere) is realized to separate their influence on the oxidation. The influence of an annealing made after the shot-peening is also considered. One show that the pollution of the surface during the shot-peening process is not responsible for the oxidation rate decrease.

Reduction of the Interfacial Tension between Poly(dimethylsiloxane) and Poly(ethylene oxide) by Block Copolymers:  Effects of Molecular Architecture …

1997

Interfacial tensions σ were measured by means of the sessile drop method for mixtures of poly(ethylene oxide) [PEO, Mw = 41 kg/mol] with five samples of poly(dimethylsiloxane)s [PDMS, Mw ranging fr...

Chemical Composition, In Vitro Bioaccessibility and Antioxidant Activity of Polyphenolic Compounds from Nutraceutical Fennel Waste Extract

2021

Fennel (Foeniculum vulgare Mill.) waste contains a broad range of bioactive molecules, including polyphenols, which have poor bioaccessibility during gastrointestinal digestion. This work aimed to investigate the bioaccessibility of total phenolic compounds and the antioxidant capacity during simulated gastrointestinal digestion using two nutraceutical formulations based on non-acid-resistant (NAR) and acid-resistant (AR) capsules containing aqueous-based extracts from fennel waste. Moreover, to obtain a comprehensive investigation of the polyphenolic constituents of the fennel waste extract, a high-resolution mass spectrometry (Q-Orbitrap) analysis was performed. Notably, chlorogenic acids…

Oblicze demograficzne Opola na początku XXI wieku

2019

Opole jako stolica regionu, który w przeszłości zmieniał przynależność państwową i zasięg terytorialny, co skutkowało wielokrotnymi przesunięciami granic wewnętrznych i zewnętrznych oraz ulegał przemianom kulturowo-cywilizacyjnym, współcześnie doświadcza gwałtownych przeobrażeń społecznych. Jednym z głównych jego problemów jest niekorzystny przebieg procesów demograficznych na przełomie XX i XXI w., m.in. depopulacja. Aktualny obraz demograficzny miasta ukształtowało wiele czynników występujących w przeszłości, a zwłaszcza po zakończeniu II wojny światowej, których skutki miasto nadal odczuwa. Celem artykułu było ukazanie depopulacji wraz z towarzyszącymi jej negatywnymi zjawiskami i proces…