A técnica de confinamento de folhas de plantas em câmara de Teflon rígido (cuvette), com visor em vidro, submetida a um fluxo contínuo de ar foi adotada na avaliação da emissão de compostos carbonílicos voláteis por plantas. Os carbonílicos foram coletados sobre sílica impregnada com o reagente derivatizante 2,4-dinitrofenilhidrazina e analisados por cromatografia a líquido de alto desempenho e detecção por ultravioleta. Foram identificados e quantificados aldeídos alifáticos saturados (C1 a C6) e insaturados (acroleína, metacroleína, crotonaldeído), benzaldeído, acetona e 2-butanona. A temperatura ambiente e na superfície das folhas, a umidade relativa do ar, a intensidade da luz solar e os níveis de ozônio e de óxidos de nitrogênio no ar foram monitorados durante as coletas de amostras. Com o objetivo de avaliar os níveis de fundo de carbonílicos no sistema coletor empregado, 29 amostras de ar foram coletadas sem a introdução de folhas de planta no cuvette, em condições ambientais de laboratório e campo. Uma avaliação estatística dos resultados indicou que os níveis de fundo do cuvette vazio foram próximos a zero nas coletas feitas no laboratório e aumentaram de acordo com o aumento da intensidade da luz solar nas coletas em campo. Esses resultados mostraram que a exposição do cuvette à radiação solar conduz à formação de artefato positivo de amostragem. Foram feitas medidas da emissão de carbonílicos pela espécie Ficus benjamina, para a qual foram observadas taxas de emissão de acetaldeído altas em condições de temperatura na superfície das folhas superior a 40°C. Na ausência de luz solar incidente, não foi observada emissão de carbonílicos pelo exemplar avaliado dessa espécie. Foram feitas também medidas da emissão de carbonílicos pelas seguintes espécies de plantas ocorrentes na vegetação nativa da Região Metropolitana de São Paulo: Cecropia pachystachya, Casearia sylvestris, Croton floribundus, Solanum erianthum, Alchornea sidifolia, Syagrus rommanzoffiana e Ficus insipida, para as quais foram observadas taxas de emissão de carbonílicos que variaram entre 1,5 10-2 e 2,3 µgC g-1 h-1. / The leaf enclosure technique in air flow-through rigid Teflon chamber (cuvette) was employed to evaluate volatile carbonyl compound emission from plants. The gaseous carbonyl compounds were collected on silica gel coated with 2,4-dinitrophenylhydrazine and analyzed by high performance liquid chromatography with ultra-violet detection. The identified and quantified carbonyls were saturated (C1 - C6) and unsaturated (acrolein, methacrolein, crotonaldehyde) aliphatic aldehydes, benzaldehyde, acetone and 2-butanone. Ambient and leaf surface temperatures, relative humidity, light intensity, ozone and nitrogen oxides air levels were monitored during carbonyl emission sampling. With the aim of evaluate the collection system carbonyl background leveIs, 29 air samples were collected from the empty cuvette under laboratory and field conditions. Statistical analysis of the data indicated that the cuvette background leveIs were close to zero under laboratory conditions and increased with the increasing of the sunlight intensity under field conditions. These results showed that the cuvette exposition to the sunlight leaded to positive sampling artifact. Carbonyl compound emission from Ficus benjamina species was measured and high acetaldehyde emission rates were observed under leaf surface temperature higher than 40°C. In the absence of direct sunlight no carbonyl emission was measured from the evaluated individual of Ficus benjamina. Also carbonyI emissions from the following native species in the metropolitan region of São Paulo City were measured: Cecropia pachystachya, Casearia sylvestris, Croton floribundus, Solanum erianthum, Alchornea sidifolia, Syagrus rommanzoffzana e Ficus insípida. The observed rate emissions from these plants ranged between 1,5 10 -2 and 2,3 µgC g-1 h-1.

Made available in DSpace on 2014-08-20T13:42:05Z (GMT). No. of bitstreams: 1 Dissertacao_Renata_Schmidt_Filgueras.pdf: 703631 bytes, checksum: f31913527b1612d15991ff454beea7e8 (MD5) Previous issue date: 2007-06-16 / Samples of contra-filet (muscle Longissimus Dorsi) of 12 carcasses of Red Angus bovines and zebuines mixed breeds, knocked down with approximately 350 kg and 3 years of age, treated with or without electric stimulation of low voltage in the period post-mortem were vacuum-packed and stored under refrigeration ( 1,0±0,5ºC) for until 56 days. After 0, 7, 14, 35 and 56 days of maturation were made the determination of bioactive amines (putrescine, cadaverine, histamine, tiramine, serotonin, agmatine, tryptamine, feniletilamine, espermine and espermidine), standard count in plaque of aerobes microorganisms and total count of lactic bacteria. The count of microorganisms of the samples has correlated positively during the storage time (r>0,91 e p<0,001), achieving maximum scores of 6,67 and 7,6 LogUFC.g-1 for viable microorganisms aerobes and lactic bacteria, respectively, after 56 days. The breed variation of the animals and the electric stimulation of the carcass have not demonstrated to cause significant effects in the microbiotics and tenor of bioactive amines during the period observed, except as for the tenors of espermine, after 14 days, when a bigger concentration of such polyamine was detected in the mixed breed meat. Significant positive correlations (p<0,001), were also observed between the lactic bacteria count and the total of bioactive amines in the meat of carcass electrically stimulated, in both Red Angus and zebuines mixed breeds, which it did not occur in the meat of carcass without post-mortem electric stimulation. . / Aminas bioativas são bases orgânicas de baixo peso molecular encontradas em uma gama de alimentos de origem animal e vegetal e estão frequentemente envolvidas no desenvolvimento e potencialização de patologias humanas importantes, como desordens neurológicas, doenças gastrointestinais, hipo e hipertensão, respostas imunes anormais e câncer. O processo de maturação da carne bovina favorece o crescimento de bactérias anaeróbias facultativas, sobretudo bactérias láticas, as quais contribuem para a produção e aumento da concentração de aminas em alimentos. Amostras de contra-filé (músculo Longissimus Dorsi) de 12 carcaças de bovinos Red Angus e mestiços zebuínos, abatidos com aproximadamente 350kg e 3 anos de idade, com e sem estimulação elétrica da carcaça (estimulação de baixa voltagem), foram acondicionadas a vácuo e maturadas sob refrigeração por até 56 dias ( 1,0±0,5ºC). Aos 0, 7, 14, 35 e 56 dias de maturação foram efetuadas as determinações de aminas bioativas (putrescina, cadaverina, histamina, tiramina, serotonina, agmatina, triptamina, feniletilamina, espermina e espermidina), contagem total de bactérias láticas e contagem padrão em placa de microrganismos aeróbios. As contagens de bactérias láticas e microrganismos aeróbios correlacionaram-se positivamente com o tempo de maturação, atingindo ao final do período 6,67 e 7,6 LogUFC.g-1 para microrganismos aeróbios viáveis e bactérias láticas, respectivamente. Entre os diferentes tratamentos estudados, não foram observadas diferenças estatisticamente significativas nos teores de aminas bioativas e contagens de microrganismos (aeróbios e bactérias láticas), exceto aos 14 dias, quando os teores de espermina em amostras de carne de animais mestiços foram significativamente maiores (p<0,05) do que em carnes de Red Angus, com e sem estimulação elétrica. Em tratamentos iguais e ao longo do período de armazenamento houve aumento significativo tanto nas contagens de microrganismos aeróbios e bactérias lácticas quanto nos teores totais de aminas bioativas. Esse aumento é particularmente significativo a partir do 35º dia de maturação. Correlações positivas significativas (p<0,001) foram observadas entre contagem de bactérias láticas, total de aminas bioativas e tempo de maturação em amostras de carne de carcaças estimuladas eletricamente, tanto de animais Red Angus quanto mestiços zebuínos, o que não ocorreu nas carnes de carcaças que não sofreram estimulação elétrica post-mortem. .

The thesis presents observations on the CO2 concentration and carbon isotopes in air CO2 (δ13C) to constrain the inter-annual variability of carbon inventory over the Southern Ocean between the years 2011-2013. Based on the observation, the region of CO2 venting was identified over the Southern Ocean. Further, isotopic characterization allowed inferring about the possible sources of CO2 degassing and contribution from the dissolved inorganic carbon (DIC) that exsolved to generate CO2. It is concluded that the origin CO2 is mainly from the degassing of CO2 available from the dissociation of DIC or organic degradation. Live Foraminiferal samples of Globigerina bulloides from towing were captured, separated and analysed for δ18O and δ13C from various locations across the Southern Ocean between 10°N−60°S. A large similarities in the estimated values (deduced from simultaneous composition of ocean water 18O, δ13C in DIC and temperature i.e. SST under equilibrium condition) and measured δ18O and δ13C values were observed until 40°S from the equator, and hence it was concluded that the calcification depth of G. bulloides is confined to a depth of ~75-200m till 40°S latitude. However, further south (>40oS) disequilibrium from the estimates was detected. A number of possible reasons were cited for the observed disequilibrium such as (1) Deeper depth habitat (2) Partial dissolution (3) Non-equilibrium calcification (4) Oceanic Suess Effect and (5) Genetic Variability. A box model of isotopic mass balance was presented in this study to explain the pattern of enrichment in the 13C values of sea water DIC with latitude (up to about 43°S). The model shows that a steady state of the carbon isotope ratio of water is achieved in a relatively short time of ~5000 days. Rainwater isotope in the open marine condition across the latitudinal transects over Southern Ocean marking zone of precipitation and evaporation is another element of this thesis. A variation with excess lighter isotopes in rainwater was observed in high latitude rain in this study. Observed isotopic depletion is attributed to rainout process over the ocean. The average rainout fraction over the Southern Ocean in the region of zone of precipitation is ~44%, while it drops to ~25% in the zone of evaporation. Second part of the thesis presents a novel method of isotope thermometry which is called “clumped isotope (13C18O16O16O-2 in the calcite structure) thermometry”. A revision in the thermometry equation relating 47 vs T in synthetic carbonates precipitates and otoliths was proposed. The revised calibration was used on fish otoliths from the modern and past environment to estimate the temperatures. Together with the clumped isotope, conventional stable isotopes in the shell carbonates were measured to effectively reconstruct the seasonal fresh water fraction at seasonal time scales.

L'utilisation des isotopes du silicium (δ30Si) comme proxy paléocéanographique nécessite une bonne connaissance de la répartition et du devenir des isotopes du silicium à travers l'océan. Au cours des dernières années, des efforts considérables ont été faits pour cartographier la composition isotopique du silicium dissous (acide silicique, DSi) et de la silice biogénique (BSi) dans l'océan. Les diatomées utilisent le DSi pour construire leur frustule fait d’opale (BSi). Durant ce processus, les diatomées discriminent l'isotope lourd de silicium (30Si) en faveur de l'isotope léger (28Si). Ce fractionnement conduit à une BSi qui a un δ30Si inférieur de 1,1 ‰ à 1,5 ‰ par rapport au DSi source. Cela se traduit dans les eaux de surface par de faibles concentrations en DSi en raison de l'utilisation biologique et par des valeurs de δ30Si élevées en raison de la distillation de Rayleigh. Inversement, lorsque la BSi se dissout, il y a une discrimination contre l’isotope lourd et ainsi produit du silicium dissous avec un δ30Si inférieur de 0,55 ‰. Dans le même temps, la circulation océanique et le mélange vertical contribuent à modifier le δ30Si du pool de silicium dissous dans la couche de surface, ce qui complique l'utilisation du δ30Si des diatomées comme proxy pour l’utilisation du DSi durant la saison de croissance. Cette thèse vise à mieux comprendre les processus qui régissent le cycle du silicium et la signature en δ30Si des masses d'eau dans les différentes régions de l'océan. De nouvelles données de δ30Si de silicium dissous sont présentées et discutées. Ces données proviennent de 6 profiles CTD de la campagne ANTXXIII/9 (Atlantique et secteur indien de l'océan Austral), 7 profiles CTD de la campagne ANTXXIV/3 (secteur Atlantique de l'océan Austral), et 5 profiles CTD de la campagne MSM10/1 (région subtropical et tropical de l’océan Atlantique nord). Les échantillons ont été purifiés par chromatographie échangeuse d'ions après préconcentration par précipitation de Mg(OH)2, et le silicium est extrait en utilisant du triéthylamine molybdate. Les analyses isotopiques ont été réalisées sur Spectromètre de Masse Multi-Collection à source Plasma (MC-ICP-MS, Naptune) à moyenne résolution (Ifremer, Brest). / Use of silicon isotopes (δ30Si) as a paleoceanographic proxy requires sound knowledge of the distribution and behaviour of silicon isotopes throughout the ocean. Over the past few years considerable effort has been made to map the silicon isotope composition (δ30Si) of silicic acid (dissolved silicon, DSi) and biogenic silica (BSi) throughout the ocean. Diatoms uptake DSi to build up their opal frustules (BSi). During this process, diatoms discriminate against the heavier isotope of silicon (30Si) in favor of the light isotope (28Si). This fractionation leads to BSi that has a lower δ30Si than the DSi source by 1.1 ‰ to 1.5 ‰. In turn, this results in surface waters with low DSi concentrations due to biological removal, and high δ30Si values due to Rayleigh distillation. Conversely, when the BSi dissolves it is with discrimination against the heavier isotope producing dissolved silicon with a δ30Si lower by 0.55 ‰. At the same time, episodes of upwelling occurring throughout the growing season, ocean circulation and mixing, contribute to modify the δ30Si of the dissolved silicon pool in the surface mixed layer, which complicate the use of diatom δ30Si as a proxy for DSi removal during the growing season. This dissertation aims to better understand the processes driving the Si cycle and the δ30Si signature of water masses in different regions of the ocean. New data of δ30Si of dissolved Si are presented and discussed. These data come from 6 CTD profiles from ANTXXIII/9 campaign (Atlantic and Indian sector of the Southern Ocean), 7 CTD profiles from ANTXXIV/3 (Atlantic sector of the Southern Ocean), and 5 CTD profiles from the campaign MSM10/1 (north Subtropical and Tropical Atlantic Ocean). Samples were purified by ion-exchange chromatography following preconcentration via Mg(OH)2 precipitation and extraction of silicon using triethylamine molybdate. Isotopic analyses were carried on a Neptune MC-ICP-MS at medium resolution (Ifremer, Brest).

A técnica de confinamento de folhas de plantas em câmara de Teflon rígido (cuvette), com visor em vidro, submetida a um fluxo contínuo de ar foi adotada na avaliação da emissão de compostos carbonílicos voláteis por plantas. Os carbonílicos foram coletados sobre sílica impregnada com o reagente derivatizante 2,4-dinitrofenilhidrazina e analisados por cromatografia a líquido de alto desempenho e detecção por ultravioleta. Foram identificados e quantificados aldeídos alifáticos saturados (C1 a C6) e insaturados (acroleína, metacroleína, crotonaldeído), benzaldeído, acetona e 2-butanona. A temperatura ambiente e na superfície das folhas, a umidade relativa do ar, a intensidade da luz solar e os níveis de ozônio e de óxidos de nitrogênio no ar foram monitorados durante as coletas de amostras. Com o objetivo de avaliar os níveis de fundo de carbonílicos no sistema coletor empregado, 29 amostras de ar foram coletadas sem a introdução de folhas de planta no cuvette, em condições ambientais de laboratório e campo. Uma avaliação estatística dos resultados indicou que os níveis de fundo do cuvette vazio foram próximos a zero nas coletas feitas no laboratório e aumentaram de acordo com o aumento da intensidade da luz solar nas coletas em campo. Esses resultados mostraram que a exposição do cuvette à radiação solar conduz à formação de artefato positivo de amostragem. Foram feitas medidas da emissão de carbonílicos pela espécie Ficus benjamina, para a qual foram observadas taxas de emissão de acetaldeído altas em condições de temperatura na superfície das folhas superior a 40°C. Na ausência de luz solar incidente, não foi observada emissão de carbonílicos pelo exemplar avaliado dessa espécie. Foram feitas também medidas da emissão de carbonílicos pelas seguintes espécies de plantas ocorrentes na vegetação nativa da Região Metropolitana de São Paulo: Cecropia pachystachya, Casearia sylvestris, Croton floribundus, Solanum erianthum, Alchornea sidifolia, Syagrus rommanzoffiana e Ficus insipida, para as quais foram observadas taxas de emissão de carbonílicos que variaram entre 1,5 10-2 e 2,3 &#181;gC g-1 h-1. / The leaf enclosure technique in air flow-through rigid Teflon chamber (cuvette) was employed to evaluate volatile carbonyl compound emission from plants. The gaseous carbonyl compounds were collected on silica gel coated with 2,4-dinitrophenylhydrazine and analyzed by high performance liquid chromatography with ultra-violet detection. The identified and quantified carbonyls were saturated (C1 - C6) and unsaturated (acrolein, methacrolein, crotonaldehyde) aliphatic aldehydes, benzaldehyde, acetone and 2-butanone. Ambient and leaf surface temperatures, relative humidity, light intensity, ozone and nitrogen oxides air levels were monitored during carbonyl emission sampling. With the aim of evaluate the collection system carbonyl background leveIs, 29 air samples were collected from the empty cuvette under laboratory and field conditions. Statistical analysis of the data indicated that the cuvette background leveIs were close to zero under laboratory conditions and increased with the increasing of the sunlight intensity under field conditions. These results showed that the cuvette exposition to the sunlight leaded to positive sampling artifact. Carbonyl compound emission from Ficus benjamina species was measured and high acetaldehyde emission rates were observed under leaf surface temperature higher than 40°C. In the absence of direct sunlight no carbonyl emission was measured from the evaluated individual of Ficus benjamina. Also carbonyI emissions from the following native species in the metropolitan region of São Paulo City were measured: Cecropia pachystachya, Casearia sylvestris, Croton floribundus, Solanum erianthum, Alchornea sidifolia, Syagrus rommanzoffzana e Ficus insípida. The observed rate emissions from these plants ranged between 1,5 10 -2 and 2,3 &#181;gC g-1 h-1.

To survive, animals must adapt to a complex and challenging world in a way that is flexible and responsive, while maintaining internal homeostasis. Neuromodulators provide a means to systemically alter behavioral or physiological state based on intrinsic or extrinsic cues, however dysregulated neuroendocrine signaling has negative consequences for fitness and survival. Here I examine neuroendocrine function and dysfunction using the escape response in Caenorhabditis elegans. The RFamide neuropeptide FLP-18 is a co-transmitter with the monoamine tyramine and functions both synergistically and antagonistically to tyramine in coordinating escape behavior. Using behavioral analysis and calcium imaging, I show that FLP-18 functions primarily through the G-protein coupled receptor (GPCR) NPR-5 to increase calcium levels in muscle, enhancing locomotion rate, bending and reversal behavior during the escape response. Furthermore, I examine the relationship between persistent acute stress and resilience using repeated activation of the escape response as a model of neuroendocrine dysregulation. Repeated activation of the escape response shortens lifespan and renders animals more susceptible to thermal, oxidative, and nutritional stress. Tyramine release is necessary and sufficient for this effect and activity of the tyraminergic RIM neurons is differentially regulated by acute versus long-term stressors. Impaired stress resistance requires both the GPCR TYRA-3 in the intestine and intestinal neuropeptide release. Activation of the insulin receptor DAF-2 is downstream of TYRA-3 and inhibits the transcription factors DAF-16/FOXO, SKN-1/Nrf2 and HSF-1, linking monoamine signaling in acute stress to the insulin signaling pathway and impaired resilience to long-term stressors.

Diese Arbeit beschäftigt sich mit dem Einsatz biogener Ersatzbrennstoffe bei der motorischen Verbrennung. Zum einen wurden die laminaren Brenngeschwindigkeiten von Ethanol und iso-Butanol sowie Gemischen mit iso-Oktan bestimmt. Es konnten Messwerte für die Validierung von numerischen Mechanismen sowie Parameter für die Abbildung der Temperatur- und Druckabhängigkeit der Brenngeschwindigkeit bestimmt werden. Der Vergleich der Messverfahren zeigt eine gute Übereinstimmung. Zum anderen wurden die Auswirkungen der Beimischung von Wasserstoff auf die Abgaszusammensetzung und den Wirkungsgrad an einem Verbrennungsmotor ermittelt. Die Erhöhung des Wasserstoffanteils führt zur Erhöhung des Wirkungsgrades. Die Abgasbestanteile Kohlenstoffmonoxid, Formaldehyd und Methan werden reduziert, während Stickoxide zunehmen. Mit den begleitenden Simulationen kann gezeigt werden, dass höhere Wasserstoffanteile die Oxidation durch einen erhöhten Anteil an OH-Radikalen begünstigen. Der Grund für das verstärkte Auftreten von Stickstoffmonoxid liegt in der Verlängerung der Verweilzeit der verbrannten Gase in der Oxidationszone.

Foundry technology is an industrial sector, where progress is still the important aspect for reducing the environmental impact and increasing competitiveness. Master's thesis is focused on the possibilities of influencing residual strength of the core moulding mixtures with the biogenic binders, which forms a new group of binder systems.

No description available.

Dans cette thèse, nous présentons des travaux complémentaires conduits à ICARE-CNRS (Orléans), partie A et à l’Université de Fudan (Shanghai), partie B. Partie A : les 2-et 3-carène sont deux composés organiques volatils biogéniques importants présents dans l’atmosphère dont les voies de dégradation sont encore mal connues. Afin de déterminer les constantes de vitesse des réactions de ces espèces avec l’ozone, nous avons utilisé trois systèmes expérimentaux complémentaires : des chambres de simulation d’ICARE de 7300L et 80000L (HELIOS) et un réacteur à flux laminaire. Les rendements de certains produits de réactions, le radical hydroxyle (OH), le formaldéhyde (HCHO) et le monoxyde de carbone (CO) ont aussi été déterminés. D’autre part, pour avoir une meilleure compréhension d’intermédiaires de réaction formés lors de l’ozonolyse, appelés intermédiaires de Criegee, un réacteur à flux laminaire à deux étages a été mis en place pour mesurer leurs constantes de vitesse de réaction avec SO2, NO2 et O3. Partie B : les impacts du “black carbon (BC)” et du “brown carbon (BrC)” constituent une incertitude majeure dans les modèles climatiques actuels. Des rapports récents indiquent que la morphologie et l’évolution des BC et BrC dans l’atmosphère jouent un rôle important sur la capacité d’absorption de ces particules. Afin d’étudier leurs comportements, des mélanges de particules (BC-BrC) ont été exposés en chambre de simulation atmosphérique à l'acide sulfurique, au mélange ammoniac / triéthylamine, et à la vapeur d'eau de manière séquentielle. / In this thesis, we present a complementary work conducted at ICARE-CNRS (Orléans), Part A and at Fudan University (Shanghai), Part B. Part A: 2-and 3-carene are two important biogenic volatile organic compounds present in the atmosphere. The knowledge on their degradation pathways and the corresponding products are still poor. Using complementary reaction systems-ICARE 7300 L and HELIOS 80000 L simulation chambers, vertical laminar flow reactor, their kinetic rate constants for reaction with ozone were determined. Additionally, important product formation yields, hydroxyl radical (OH), formaldehyde (HCHO) and carbon monoxide (CO) have been determined with indication to their corresponding formation routes from the ozonolysis of carene. To have a better understanding on reactions of Criegee intermediates (CIs) generated through ozonolysis in the atmosphere, a horizontal 2-stage laminar flow reactor was set up to measure the rate constants of CIs with SO2, NO2 and O3. Part B: Radiative forcing of black carbon (BC) in the atmosphere, as well as that of brown carbon (BrC), remains to be a major uncertainty in current climate models. Recent reports indicate that the absorption enhancement of BC and BrC particles is determined by evolution of morphology and mixing state during the atmospheric processing. Laboratory-generated BC-BrC mixture particles (BC-BrC) were exposed to sulfuric acid, ammonia/triethylamine, and water vapor sequentially to investigate the alternation in light absorption, morphology and mixing state during simulated atmospheric processing.