Novos tipos de sílicas mesoporosas esféricas (SMEs) com tamanho de partícula entre 3 e 10 µm foram sintetizadas utilizando os copolímeros tribloco EO17PO60EO17 (P103) ou EO26PO39EO26 (P85) como direcionadores de estrutura. As SMEs foram preparadas via um processo de síntese com duas etapas de tratamento hidrotérmico (TH) em forno convencional, utilizando o ortosilicato de tetraetila como fonte de sílica, os surfatantes P103 ou P85 como moldes em combinação com o co-surfatante brometo de cetiltrimetilamônio (CTAB) e o co-solvente etanol, sob condições ácidas. As SMEs obtidas foram caracterizadas por microscopia eletrônica de varredura (MEV) e medidas de adsorção/dessorção de N2. O volume e o tamanho do poro das SMEs podem ser aumentados com o aumento da temperatura do TH. O volume e o tamanho do poro (0,41 cm3g-1; 2,84 nm) da amostra sintetizada com P103 aumentaram (1,20 cm3g-1; 4,32 nm) quando a temperatura do TH aumentou de 80°C para 120°C na segunda etapa do TH. O aumento do volume e do tamanho de poro também pode ser obtido utilizando um único tratamento hidrotérmico, porém empregando 1,3,5-trimetilbenzeno (TMB) como agente dilatador de poros. O volume e o tamanho do poro (0,34 cm3g-1; 2,02 nm) da amostra sintetizada com P85 sem TMB aumentaram (0,37 cm3g-1; 2,51 nm) na amostra preparada com P85 e TMB. As características texturais e de superfície dos materiais obtidos com P103 e P85 foram comparadas com um material sintetizado em paralelo, nas mesmas condições experimentais, utilizando o copolímero EO20PO70EO20 (P123) como direcionador de estrutura e CTAB como co-surfatante. A SME sintetizada com P103 foi usada como adsorvente de compostos orgânicos voláteis (COVs) oriundos de misturas padrões. Os componentes da mistura padrão foram então removidos do adsorvente (sílica) por dessorção térmica e introduzidos em uma coluna cromatográfica para separação por cromatografia a gás (CG) e identificação por espectrometria de massa (EM). Esta SME foi também testada como adsorvente de uma amostra de ar coletada em uma rua com significativo fluxo de veículos. O ar foi coletado paralelamente na SME e num adsorvente comercial (Tenax TA/Carbotrap). Os compostos n-hexano, benzeno, tolueno e o-xileno, oriundos de emissões veiculares, foram encontrados em ambos adsorventes (sílica e Tenax TA/Carbotrap). O fármaco Rifampicina foi encapsulado numa SME sintetizada com P123/CTAB e na sílica SBA-15 (poros ordenados hexagonalmente). A encapsulação do fármaco (cerca de 30%) em ambas as sílicas foi confirmada pelos resultados de adsorção/dessorção de N2. / New types of mesoporous silica spheres with particle diameter of 3 - 10 µm were synthesized by using a triblock copolymer EO17PO60EO17 (P103) or EO26PO39EO26 (P85) as templates. The microspheres were prepared via a two-step hydrothermal treatment (HT) in an oven by using tetraethoxysilane as silica source, the surfactants P103 or P85 as templates in combination with a cosurfactant cetyltrimethylammonium bromide (CTAB) and a cosolvent ethanol, under acidic conditions. The obtained silica spheres in both procedures were characterized by scanning electron microscopy (SEM) and N2 sorption technique. The volume and the pore size of the silica spheres can become greater by increasing the temperature of the HT. The volume and the pore size (0.41 cm3g-1; 2.84 nm) of the sample prepared with P103 became greater (1.20 cm3g-1; 4.32 nm) when the temperature of HT increased by 80°C to 120°C in the second step of the HT. The volume and the pore size can also be increased using 1,3,5-trimethylbenzene (TMB) as a swelling agent, instead of raising the temperature of the HT. The volume and the pore size (0.34 cm3g-1; 2.02 nm) of the sample prepared with P85 without TMB became greater (0.37 cm3g-1; 2.51 nm) in the sample prepared with P85 and TMB. The characteristics of textures and surfaces of the materials synthesized by using P103 or P85 were compared with a material prepared with the copolymer EO20PO70EO20 (P123) as template using the same experimental conditions. The silica microspheres synthesized with P103 were used as adsorbents for volatile organic compounds (VOCs) from standard mixtures. The compounds of the standard mixture were then removed from the adsorbent (silica) by thermal desorption and introduced into a chromatographic column for separation by gas chromatography (GC) and identification by mass spectrometry (MS). This material was also used as adsorbent of an air sample collected on a street with a significant flow of motor vehicles. The air was collected on the silica and on a commercial adsorbent (Tenax TA/Carbotrap) one by one. The compounds n-hexane, benzene, toluene and o-xylene, resulted from the emissions from vehicles, were found in both adsorbents (silica and Tenax TA/Carbotrap). The drug Rifampicin was encapsulated in the mesoporous spherical silica, prepared with P123/CTAB and in the silica SBA-15 (hexagonally ordered pores). The encapsulation of the drug (about 30%) in both the silica was confirmed by measurements of adsorption/desorption of N2

A qualidade do ar dos grandes centros urbanos é impactada diretamente pela emissão de poluentes dos veículos automotores. São dois os principais indicadores da deterioração da qualidade do ar: a concentração de material particulado e de ozônio. A concentração desses poluentes frequentemente atinge valores preocupantes, em especial na Região Metropolitana de São Paulo. O ozônio é um poluente secundário formado a partir de reações fotoquímicas em ambiente com a presença de compostos orgânicos voláteis e óxidos de nitrogênio, dentre os principais compostos precursores emitidos pela combustão dos motores dos veículos. A metodologia desenvolvida busca caracterizar o impacto da circulação dos veículos utilizando um índice, baseado na especiação, quantificação e reatividade dos precursores de ozônio emitidos. Esse índice pode identificar o impacto de um modelo de veículo e atender a demanda por rotulagem ambiental ou o impacto de um conjunto de veículos e subsidiar políticas públicas de redução das emissões / Air quality in large urban centers is directly impacted by the emission of pollutants from motor vehicles. There are two main indicators of the deterioration of air quality: the concentration of particulate matter and ozone. The concentration of these pollutants often reaches alarming values, particularly in São Paulo Metropolitan Area. Ozone is a secondary pollutant formed by photochemical reactions in atmosphere with the presence of volatile organic compounds and nitrogen oxides, precursors compounds emitted by combustion in vehicle engines. The methodology developed seeks to characterize the impact of the movement of vehicles using an index based on speciation, quantification and reactivity of emitted ozone precursors. This index can identify the impact of a vehicle and meet the demand for environmental labeling or the impact of a set of vehicles and support public policies to reduce emissions

O presente estudo justifica-se pelo crescente aumento da economia e conseqüentemente dos diferentes tipos de transportes para viabilizar esta economia, a exemplo do transporte aéreo que vem crescendo significativamente. Este estudo objetivou verificar um possível efeito mutagênico causado pelo combustível de aeronaves em bioindicadores vegetais As áreas selecionadas para esta pesquisa foram o Aeroporto Internacional de São Paulo (pontos: torre, pátio, pista L e pista R), um bairro adjacente que é rota de aeronaves e o Parque Estadual da Cantareira que dista 16km do aeroporto. O aeroporto situa-se a 749m de altitude com ventos médios de 129 graus e velocidade média de cinco nós, temperatura média de 19 graus centígrados e umidade relativa do ar média de 80 por cento. Um bioindicador vegetal proposto foi a Tradescantia pallida, com 15 floreiras em cada ponto mencionado, analisando o potencial mutagênico através dos números de micronúcleos (Trad-MCN) e metais pesados impregnados nas folhas da planta, sendo coletadas as inflorescências e folhas mensalmente durante um ano e meio. Para caracterizar a área de estudo foi analisado o material particulado presente nos diversos pontos, utilizou-se amostradores mini-vol, com exposição por 24 horas em sete coletas durante um ano. Para verificar os compostos orgânicos voláteis (COVs), foram feitas três coletas através de canisters. As maiores concentrações de gases provenientes da queima do querosene foram encontradas nos pontos: pátio, pista L e bairro. Os resultados indicaram uma correlação positiva (p=0,034) entre COVs e MCN, no local de maior concentração (pátio, indicando que os compostos orgânicos voláteis provenientes de combustível de aeronaves (QAV) apresentaram componentes capazes de causar mutagenicidade em nosso estudo. / The worthiness of this study lies on the fact that, within the scenario of the multiplication of various kinds of transportation means resulting from the economical development, the growing use of air transportation means has been quite significant. The aim of this study was to verify a mutagenic potential effects caused by aircraft fuel on a vegetable indicator. The locations selected to carry out this research are the São Paulo International Airport Guarulhos (points: tower, apron, runway L and runway R), an adjoining district which lies within the route of the aircrafts, and Parque Estadual da Cantareira (a public park), 16 km away from the airport and apparently not impacted by the aircraft traffic (reference point). The airport lies at an altitude of 749 meters, with average winds of 129 degrees and average speed of five knots, average temperature of 19 degrees centigrade and air relative humidity of 80 per cent. The vegetal bioindicator propos, the Tradescantia pallida, with 15 flowerbeds placed in each of the locations mentioned above, which were used for the observation of the mutagenic potential through the analysis of the amounts of micronuclei (Trad-MCN) and heavy metals accumulated on the leaves. The inflorescences and leaves were collected on monthly basis within a period of eighteen months. For to characterize the study area was analyzed the particulate material in the various locations, using mini-vol sample collectors, with 24 hour exposure through a one year period. For the analysis of the volatile organic compounds (VOCs), three collections were made with the use of canisters. The greatest concentrations of gases resulting from the burning of kerosene were found on the locations: apron, runway L and district. The result showed a positive correlation (p=0,034) between the VOCs and micronuclei in the location with greatest concentration (apron) indicating that the organic compounds from aircraft fuel (AVK) have mutagenic able components.

The influence of crude oil-contaminated and remediated sites on agrifood production is not clearly understood. To address this knowledge gap, the research was divided into two stages involving: (1) assessment of the efficiency of two bioremediation strategies to support hydrocarbons degradation as well as agrifood production with the initial analysis of the experimental materials, and (2) evaluation of the effect of different crude oil remediation intervention values (CRIV) on selected vegetables (Brassica juncea, Brassica oleracea, Lactuca sativa and two different cultivars of Solanum lycopersicum). Results from the first stage showed that the crude oil used had a pristane/phytane ratio of 0.98 (within the 0.8 – 3.0 range of most crude oils), higher concentrations of C10 – C14, C15 – C20 and C21 – C27 alkanes than the C28 – C36 alkanes including higher concentrations of two of the US EPA priority pollutant polycyclic aromatic hydrocarbons (PAHs) - phenanthrene and anthracene. Four treatments were prepared in which weekly tillage enhanced the degradation of C15 – C20 and C21 - C27 alkanes in the Remediation by Enhanced Natural Attenuation (RENA) treatment. The two bioremediation strategies (RENA and bioaugmentation) enhanced PAHs degradation compared with the remediation-study control treatment while only RENA application among the two approaches supported the growth of B. juncea. Although there was no statistical significant difference (p > 0.05) between the major dietary mineral contents of samples from the various treatments compared with the control treatment samples, RENA application affected the Cr, Zn and Pb contents. Meanwhile, the Ca/P (> 1.0) and Na/K (< 0.60) ratios of all the harvested samples imply that they provide a good source of these minerals for bone formation and would not contribute to high blood pressure. The crude oil used also deterred the attack of juvenile caterpillars of cabbage white butterfly. Findings from the second stage revealed that the yield of the green leafy vegetables including one of the selected tomato cultivars (Micro-Tom), was in most cases impaired at CRIV ≥ 3,000 mg/kg total petroleum hydrocarbon (TPH). Compared with the control treatment samples’ composition, crude oil stress at 10,000 mg/kg TPH enhanced the concentration of K, Mn and crude protein of B. oleracea and L. sativa as well as the sucrose, total sugars, total phenolics and total flavonoids contents of the latter vegetable. Sucrose was also only detected in M82 tomato cultivar samples from the crude oil-containing treatments. The Cd content of B. oleracea, Pb contents of: L. sativa and M82 tomato harvested samples were all below the FAO/WHO Codex Alimentarius Commission 2015 recommended maximum levels. However, tartaric acid was only detected in B. oleracea and L. sativa samples from the 10,000 mg/kg TPH treatment as well as in M82 tomato cultivar samples from the treatment involving CRIV of 5,000 mg/kg TPH. Generally, the yield of these crops in response to crude oil contamination varied in which B. juncea had the least tolerance to crude oil stress among the green leafy vegetables tested. Most of the quality parameters in the two tomato cultivars were not affected by CRIV between 750 - 5,000 mg/kg TPH with p-xylene having the greatest toxic potential among the VOCs emitted from the 5,000 mg/kg TPH treatment. The research findings, under the experimental conditions, indicated the effectiveness of RENA for the degradation of low molecular weight PAHs and its agricultural benefits. They also suggest that crude oil-contaminated sites at ≤ 3,000 mg/kg TPH present a similar growing environment to a clean site for agrifood production and the possibility that crude oil stress at 10,000 mg/kg TPH could enhance crop quality. Nonetheless, the contribution of bio- accumulated PAHs in these crops to the food chain demands further investigation.

Quality control is essential in food industry and efficient quality assurance is becoming increasingly important. The assessment of food quality still centers on its sensory properties (appearance, aroma and texture). Bread is one of the most consumed food item all over the world. Bakery product manufacturers expect that the bread should retain all of its attributes during storage and consumers expect their bread to be ‘fresh’. Unfortunately, it remains truly ‘fresh’ for only a few hours after it leaves the oven because the ingredients of the bread undergo series of physical and chemical changes that eventually lead to deterioration, referred as “staling”, of bread quality. Bread staling is classified in two categories: crust (outer portion of bread) staling and crumb (center portion of bread) staling. Crust staling is associated to the moisture migration from crumb to crust during storage. This moisture migration leads to a phenomenon called glass transition at crust. This phenomenon changes the mechanical and dielectric properties of bread crust. Crumb staling is mainly associated to the physicochemical changes in starch. During storage, amorphous starch regains its crystallinity, which increases the firmnesss and dryness of bread crumb. Thus, the knowledge of moisture content, starch recrystallization and the glass transition helps in understanding the bread staling mechanism. There are some volatiles produced from the bread during storage, which forms the characteristic flavor or aroma of the bread. The loss of this characteristic flavor during storage also gives the information about the loss of freshness and staling. Thus, there is a need for detection and monitoring the loss of these volatiles to determine the characteristic flavor during storage. Hence, the present investigations are focused on these issues and developed a measurement facility to monitor the above physicochemical changes in bread during storage. As a part of experimental investigations, two separate test facilities have been developed. A multichannel ring electrodes with suitable instrumentation based on impedance spectroscopy technique is developed for simultaneous measurement of electrical properties of bread at crust and crumb during storage in the frequency range from 50 Hz to 100 kHz. The detailed investigations have been conducted on wheat bread. The variation in capacitance showed that the glass transition phenomenon, at room temperature, in bread crust occurs after 96 h of storage with 18% of moisture in it. The resistance changes at bread crumb showed the starch recrystallization during staling. The electrical property results are justified with the results obtained from the conventional differential scanning calorimmetery (DSC) studies. The impedance measurement at crust and crumb estimates the moisture content at the respective zones of bread. Thus the test facility is used for the simultaneous measurement of moisture content, starch recrystallization and glass transition at crumb and crust respectively without destructing the bread loaf. A few experiments are conducted on maida bread and the obtained results are compared with the wheat bread results. Another test facility has been developed for the detection of volatiles produced from the wheat bread during storage. The gas chromatography and mass spectroscopy (GC-MS) experimentations are conducted to identify the volatiles produced from the bread during storage. The major volatiles produced from wheat bread are found to be 1-Heptanol, 1-Pentanol, 1-Octanol, Furan and Hydroperoxyde. A conducting polymer based gas sensor is designed and developed to sense these volatiles and the changes in its electrical property is monitored with a suitable instrumentation based on impedance spectroscopy technique in the frequency range from 10 Hz to 2MHz. Experimental investigations are carried out in an in-house air tight closed test chamber. The bread sample and the designed sensor are kept inside the test chamber and closed tightly so that only bread volatile can interact with the sensor. The sensor response is monitored by measuring the changes in its capacitance upon exposure to organic volatiles produced from bread during storage. It is observed that the capacitance of the sensor changes with the quantitative changes of the above volatiles. Thus, the test facility is found quite suitable for the detection and monitoring the bread volatiles produced during storage, which finally affects the aroma property. Thus, the developed experimental test facilities with suitable sensors and instrumentation based on impedance spectroscopy technique are found quite suitable to monitor the changes in physicochemical properties and aroma of bread during storage. The correlation between the measured electrical properties and the changes in the textural and flavor properties of bread during storage has been established. The results obtained with the developed test facilities are in good agreement with the results obtained from the standard traditional techniques like DSC and GC-MS.

Poluentes atmosféricos como nanopartículas (N), black carbon (BC) e compostos orgânicos voláteis (COVs) são de importante compreensão para a saúde infantil devido às suas propriedades cancerígenas (N, COVs e BC), bem como podem ser causados ou intensificados sintomas irritativos (COVs e BC), cefaleia, asma, doenças pulmonares e cardíacas (BC). As partículas muito pequenas (N) ainda podem atingir os sistemas cardiovascular e cerebrovascular, e até mesmo prejudicar o desempenho escolar e cognitivo das crianças. Neste contexto, o objetivo deste trabalho foi estudar a qualidade do ar indoor (sala de aula) e outdoor (portão de acesso) em escolas, onde as crianças permanecem expostas aos poluentes por um longo período, e comparar os níveis entre os ambientes. Para isso, selecionamos duas escolas da Região Metropolitana de Porto Alegre – RMPA: uma em área urbana (Canoas); e outra em área rural (Nova Santa Rita); nas quais foram realizadas 11 campanhas quinzenais de amostragem dos poluentes atmosféricos estudados entre julho e dezembro de 2016. Em complemento, foram medidos NOx, NO2, NO e O3 e variáveis meteorológicas (temperatura, umidade relativa, radiação solar e velocidade do vento) coletados na RMPA. Foram aplicadas técnicas de sensoriamento remoto para a obtenção de imagens dos filtros de BC através de MEV. Os resultados apontam que no ambiente externo - outdoor da escola urbana os níveis máximos de BC e N ocorreram nas horas de rush, devido aos altos níveis das emissões veiculares. Na escola de Nova Santa Rita os níveis de BC e N foram ligeiramente mais baixos, possivelmente por ser um ambiente com pouca influência de fontes de emissão veicular. Por outro lado, os COVs apresentaram maiores concentrações no ambiente interior - indoor das duas escolas, as fontes de emissão destes se encontram dentro das salas de aula e não estão relacionadas com as fontes externas, ou seja, a geração dos COVs é independente de ter fontes de poluição urbana ou rural. Os níveis de BC em área urbana são regidos por fontes de emissões veiculares (outdoor), as quais são facilmente transferidas para o ar indoor, para onde podem carregar consigo outras partículas (contendo, por ex., Fe); além disso, sua dispersão é dificultada em dias frios e com menor velocidade do vento. Enquanto isso, as concentrações de COVs e N são determinadas por uma influência combinada de fontes de emissão, processos secundários de formação e meteorologia, refletindo em maior sensibilidade sob diferentes condições atmosféricas tanto outdoor quanto indoor nas áreas urbana e rural. Importa ressaltar que os dirigentes de escolas rurais devem estar atentos quanto aos níveis de COVs nas salas de aula; enquanto as escolas de centros urbanos devem triplicar a atenção, pois além de COVs há concentrações expressivas de N e BC decorrentes de emissões veiculares, principalmente nas horas de rush que coincidem com o início e fim das aulas, quando as crianças permanecem no outdoor diretamente expostas à poluição veicular. / Air pollutants as nanoparticles (N), black carbon (BC) and volatile organic compounds (VOCs) may have short and long-term adverse health effects, especially when it comes to children’s health. These pollutants are known to cause cancer and other health effects may include also eye, nose and throat irritation (VOCs and BC), headaches, asthma, pulmonary and cardiovascular diseases (BC). Air-pollution-sized nanoparticles (N) can also affect cerebrovascular system. It can negatively affect students’ learning and children’s cognition. The aim of this study was to verify and compare the indoor (classrooms) and outdoor (access gates) air quality in different schools, where the children remain exposed to air pollutants for long hours per day. Two schools in different areas of Porto Alegre Metropolitan Region (RMPA) were chosen: the first one in an urban area (Canoas) and the second one in a rural area (Nova Santa Rita). Eleven fortnightly samplings were conducted to evaluate N, BC and VOCs levels between July 2016 and December 2016. We also used data of gaseous pollutants (O3, NOx, NO2, and NO) and meteorological data (temperature, relative humidity, solar radiation and wind speed) collected in the same area. Remote sensing techniques and a scanning electron microscope (SEM) were used to obtain images of the black carbon filters. In the outdoor site of the urban school, the maximum levels of BC and N were registered in the rush hours due to a high level of vehicular carbon emissions. The lower levels of BC and N in Nova Santa Rita were attributed to the fact the school is located in a rural area, which assumes a less impacted environment. Nevertheless, this study indicates that these compounds are generated during the classroom activities, since the VOCs levels were higher in the two schools indoor sites. The black carbon particles in the urban area come from vehicle emissions (outdoor) and are easily transferred to the school indoor areas. These emissions can also carry other particles (e.g., Fe) and its dispersion can be hampered in cold days with low wind speed. VOCs and N concentrations are site-independent compounds influenced by several emission sources, reactions of primary pollutants and meteorology. It causes them to reflect with a high sensibility in different atmospheric conditions both in urban and rural areas (indoor and outdoor). We would like to emphasize that both rural and urban schools managers should be aware of the risks involving air pollutants in the classroom (especially VOCs). Urban schools boards should also remain vigilant on the expressive concentrations of N and BC near their access gates, arising from vehicle carbon emissions, which represents a risk for the children’s health.

This thesis is focused on the possibility of analysis of volatile organic compounds produced by monocytes during sepsis. Method of comprehensive two-dimensional gas chromatography with mass spectrometric detection was chosen for this purpose. Content of the first part was the optimization of the method of two-dimensional gas chromatography for the determination of volatile organic compounds. In this part were gradually adjusted parameters of the gas chromatography method to achieve the maximum efficiency. Further were adjusted conditions of samples preparation. Content of the second part was the usage of already optimized method for the analysis of the samples set of monocytes. Samples were subjected to the action of different inhibitors of the immune system and stimulators simulating bacterial or yeast infection. Based on this analysis were identified some compounds, which are produced by monocytes under condition simulating the infection.

Polypyrol (PPy) je heterocyklický vodivý polymer s chemickou strukturou založenou na existenci systému konjugovaných elektronů mezi střídajícími se jednoduchými a dvojnými vazbami. Díky svým vynikajícím vlastnostem jako je dobrá elektrická vodivost, relativně vysoká stabilita prostředí a zároveň i jednoduchost a variabilita metod jeho přípravy, přilákal tento polymer pozornost mnoha vědců z různých vědních disciplín. Cílem výzkumu v této dizertační práci byla studie senzorického chování PPy. Za tímto účelem byla ověřena účinnost nanostruktur PPy při detekci vybraných „vysoce důležitých molekul plynů“ včetně acetonu, amoniaku, etanolu, etylenu a toluenu. V této práci byl připraven PPy ve formě nanotyčinek (NRs) pomocí elektrochemické syntézy a také ve formě nanočástic (NPs) chemickou cestou. Dále byly připraveny modifikované PPy struktury, a to funkcionalizací PPy NPs katalytickými částicemi zlata (Au), stříbra (Ag) a teluridu kademnatého (CdTe). Pro charakterizaci morfologie, složení a struktury připravených materiálů bylo použito několik komplementárních analytických (mikroskopických i spektroskopických) technik. Navíc byly využity techniky jako Ramanova a rentgenová fotoelektronová spektroskopie (XPS) pro in-situ test detekce plynů, které potvrdily potenciál připraveného materiálu, tedy PPy NRs i PPy NPs, pro využití v senzorech plynů. Za účelem výroby senzoru plynů byl připravený PPy materiál integrován do dvou typů převodníkových platforem: chemorezistivní a na bázi povrchové akustické vlny v tzv. Love módu (L-SAW). Test detekce plynů pro chemorezistivní senzory s PPy NRs ukázal pouze zanedbatelnou odpověď těchto senzorů pro oxid dusičitý a amoniak z důvodu jejich komplikované architektury. Změření odzevy tvou typú chemorezistivních senzorů-nemodifikovaného i modifikovaného PPy NPs nebylo možné z dúvodu extrémně vysoké odporu v řádu G. Nicméně multivodivé L-SAW senzory založené na holých PPy NPs či PPy NPs modifikovaných Au či Ag NPs a nebo CdTe kvantovými tečkami (QDs) vykazovaly odezvu pro nízké koncentrace všech testovaných velmi důležitých molekul plynů při pokojové teplotě (RT). Obecně měly L-SAW senzory s modifikovanou citlivou vrstvou vyšší citlivost než senzory s nemodifikovanou PPy citlivou vrstvou. Účinnost L-SAW senzoru primárně závisí na pracovní frekvenci a na výběru citlivé vrstvy v aktivní oblasti senzoru. Z otestovaných typů vrstev senzoru vuči jednotlivým plynům, modifikovaná PPy NPs s Ag NPs i Au NPs se javí jako nejlepší varianta pro detekci acetonu. Připravené L-SAW senzory na bázi PPy jsou jednoduchá a cenově přijatelná zařízení s vylepšenými detekčními vlastnostmi jako je vysoká senzitivita a nízký limit detekce (LOD), což je řadí mezi potenciální kandidáty v budoucích systémech pro kontrolu kvality vzduchu, potravin a rovněž pro diagnostiku nemocí z dechu.

La réactivité totale OH est la perte totale du radical hydroxyle (le principal oxydant de l'atmosphère) avec les gaz réactifs dans l'air ambiant. Elle représente la mesure de la quantité totale des réactifs dans un environnement donné.Nous présentons ici un travail expérimental se concentrant sur les améliorations techniques d'une méthode appelée "Comparative Reactivity Method" pour mesurer la réactivité OH su le terrain ainsi que sur des résultats obtenus sur deux sites ciblés dans le bassin méditerranéen.La réactivité OH mesurée était élevée dans les deux sites. Sur le site récepteur en Corse (France) au cours de l'été 2013, nous avons observé que la réactivité OH était en moyenne de 5,5 s-1 (avec un maximum de 17 s-1). Ces mesures ont été comparées avec les observations de composés en phase gazeuse réalisées pendant la campagne. Il a été noté que pendant une période de la campagne, seulement 50% de la réactvité était expliqué par les mesures complémentaires.Lors de mesures dans une forêt de chênes pubescents, émetteurs isoprène, dans le sud de la France, nous avons observé que la réactivité OH maximale était très élevée (69 s-1), en accord avec la réactivité calculée à partir des mesures des gaz réactifs.Ce travail de thèse met en évidence que: (i) le bassin méditerranéen est un fort émetteur de gaz réactifs, (ii) la réactivité mesurée dans ces deux sites de la Méditerranée a été fortement impactée par les émissions biogéniques, (iii) il reste encore beaucoup de composés inconnus associés aux émissions biogéniques primaires et secondaires. A l'avenir, plusieurs approches pourraient etre utilisées pour identifier ces composés inconnus: en couplant la mesure de la réactivité OH avec des mesures de plantes dans des enceintes fermées (composés primaires), études en chambre de vieillissement (composés primaires et secondaires), ainsi que des approches de modélisation. / The total OH reactivity is the total loss rate of the hydroxyl radical with the reactive gases in ambient air. It represents the measure of the total loading of reactants in a given environment.Here we present an experimental work focusing on the technical improvements of the Comparative Reactivity Method to measure the OH reactivity on the field and field measurements of OH reactivity at two targeted sites in the Mediterranean basin.The measured OH reactivity was high at both sites. At a receptor site in Corsica (France) during summer 2013, we observed that the OH reactivity was maximum 17 s-1, on average 5.5 s-1 and during one week only 50% was explained by the complementary measurements in the gas phase.At a forest of downy oak trees, high isoprene emitters, in the south of France, we observed that the OH reactivity was maximum 69 s-1, in agreement with the reactivity calculated from the measurements of reactive gases only during daytime.This thesis work highlights that: (i) the Mediterranean basin is a strong emitter of reactive gases, (ii) the reactivity measured in these two sites in the Mediterranean was strongly impacted by the biogenic emissions, (iii) there are still many unknowns associated to measures of biogenic volatiles primary emitted and secondary produced. Such unknowns might be reduced in the future by coupling the measurement of the OH reactivity with plants enclosures and chambers studies as well as modelling approaches.

Please read the abstract in the section, 00front of this document / Dissertation (MEng (Environmental Engineering))--University of Pretoria, 2008. / Chemical Engineering / MEng / Unrestricted