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1.
J Environ Sci (China) ; 40: 92-104, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26969549

RESUMO

Molecular speciation of atmospheric organic matter was investigated during a short summer field campaign performed in a citrus fruit field in northern Corsica (June 2011). Aimed at assessing the performance on the field of newly developed analytical protocols, this work focuses on the molecular composition of both gas and particulate phases and provides an insight into partitioning behavior of the semi-volatile oxygenated fraction. Limonene ozonolysis tracers were specifically searched for, according to gas chromatography-mass spectrometry (GC-MS) data previously recorded for smog chamber experiments. A screening of other oxygenated species present in the field atmosphere was also performed. About sixty polar molecules were positively or tentatively identified in gas and/or particle phases. These molecules comprise a wide range of branched and linear, mono and di-carbonyls (C3-C7), mono and di-carboxylic acids (C3-C18), and compounds bearing up to three functionalities. Among these compounds, some can be specifically attributed to limonene oxidation and others can be related to α- or ß-pinene oxidation. This provides an original snapshot of the organic matter composition at a Mediterranean site in summer. Furthermore, for compounds identified and quantified in both gaseous and particulate phases, an experimental gas/particle partitioning coefficient was determined. Several volatile products, which are not expected in the particulate phase assuming thermodynamic equilibrium, were nonetheless present in significant concentrations. Hypotheses are proposed to explain these observations, such as the possible aerosol viscosity that could hinder the theoretical equilibrium to be rapidly reached.


Assuntos
Aerossóis/análise , Aerossóis/química , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Monoterpenos Bicíclicos , Compostos Bicíclicos com Pontes/análise , Cicloexenos/análise , Monitoramento Ambiental/métodos , França , Cromatografia Gasosa-Espectrometria de Massas , Gases/análise , Gases/química , Limoneno , Região do Mediterrâneo , Monoterpenos/análise , Oxirredução , Smog/análise , Terpenos/análise , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química , Tempo (Meteorologia)
2.
Soins Gerontol ; (89): 37-8, 2011.
Artigo em Francês | MEDLINE | ID: mdl-21698966

RESUMO

A person's diet can be revealed through an examination of the contents of his/her refrigerator and a simple questionnaire. To present the risk of malnutrition and dehydration in the elderly, Reliage, a community information and coordination centre in Lagny-sur-Marne, carried out a survey into volunteer elderly peoples' diets.


Assuntos
Desidratação/enfermagem , Desidratação/prevenção & controle , Preferências Alimentares , Conservação de Alimentos , Serviços de Assistência Domiciliar , Avaliação em Enfermagem , Equipe de Enfermagem , Desnutrição Proteico-Calórica/enfermagem , Idoso , Idoso de 80 Anos ou mais , França , Humanos , Desnutrição Proteico-Calórica/prevenção & controle , Medição de Risco , Inquéritos e Questionários
3.
Chemphyschem ; 11(18): 3962-70, 2010 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-21110376

RESUMO

The primary oxidation steps of (γ-terpinene+OH) and (d-limonene+OH) reactions are investigated using two techniques: an excimer laser photolysis set-up coupled with UV absorption spectrometry performed at atmospheric pressure and a fast-flow reactor coupled to time of flight mass spectrometry at low pressure. OH radicals are generated either by photolysis of H(2)O(2) or via the reaction of H atoms with NO(2). The primary reaction of monoterpenes with hydroxyl radicals can proceed by two reaction pathways: OH-addition and H-abstraction. The branching ratios for these channels are measured at various pressures for (γ-terpinene+OH) and (d-limonene+OH) reactions and a discussion on the H-abstraction importance for reactions of monoterpenes with hydroxyl radicals is proposed. H-abstraction may contribute to (31±9)% and (34±8)% respectively, for γ-terpinene and d-limonene reactions with OH at atmospheric pressure and respectively to (28±6)% and (28±8)% at low pressure (between 0.5 and 2.8 torr). As already pointed out by the Leuven group of Peeters, H-abstraction may be a significant reaction pathway for the reactions of monoterpenes with hydroxyl radicals. Therefore, oxidation products resulting from the H-abstraction should not be neglected in the mechanisms describing the formation of secondary organic aerosols (SOA) from gas-phase reactions of monoterpenes+OH.


Assuntos
Aerossóis/análise , Aerossóis/química , Gases/análise , Gases/química , Radical Hidroxila , Espectrometria de Massas/métodos , Monoterpenos , Atmosfera , Pressão Atmosférica , Radical Hidroxila/análise , Radical Hidroxila/química , Cinética , Monoterpenos/análise , Monoterpenos/química , Oxirredução , Fotólise
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