Reaction rates of catalytic cycles over supported metal catalysts are normalized by the exposed metal atoms on the catalyst surface, reported as site time yields which provide a rigorous standard to compare distinct metal surfaces. Defined as the fraction of exposed metal surface atoms to the total number of metal atoms, it is important to measure the dispersion of supported metal catalysts to report standardized rates for kinetic investigations. Multiple characterization techniques such as electron microscopy, spectroscopy and chemisorption are exploited for catalyst dispersion measurements. While effective, electron microscopy and spectroscopy are not readily accessible due to cost and maintenance requirements. Commercial instruments therefore typically rely on chemisorption measurements, but can be cost prohibitive nonetheless, hindering the ability of catalysis research to report rigorous measures of activity. Thus, a dispersion measurement technique based on gas chromatograph (GC) ubiquitous in catalysis research is proposed, based on the principle of dynamic carbon monoxide (CO) chemisorption, where number of exposed metal surface atoms are estimated based on the amount of adsorbed CO. In this technique, the supported metal catalyst is packed into a liner, and inserted in the temperature-controlled inlet of the GC. The catalyst is pre-treated, purged with inert gas, and pulses of known amount of CO are passed through it via an automated sequence. The CO chemically adsorbs on the supported metal catalyst and the unadsorbed CO is detected by the flame ionization detector/methanizer on the GC. The amount of CO adsorbed is estimated by the difference between the amount of CO pulsed and detected, translated to estimate the number of exposed metal surface atoms using a stoichiometry factor. Dispersion measurements for several group VIII metal catalysts were conducted using this technique to demonstrate its applicability across a range of weight loadings and support identities. An agreement between catalyst dispersion measured using this technique and commercially available instruments indicated the reliability of this technique. The amount of dispersed metal as low as 0.02 mg could be estimated by this technique.

O uso de óleos essenciais na indústria de fragrância tem crescido a cada ano. A indústria de cosméticos, em geral, tem buscado este tipo de ingrediente com o objetivo de agregar atributos únicos e melhores aos seus produtos e assim entregar, ao consumidor final, diferenciais que poderão valorizar suas formulações, além de simplesmente perfumar. O benefício de usar óleos naturais ou acordes de seus principais componentes em formulações de fragrâncias é que estes se tornam composições mais ricas, e em muitos casos, capazes de proporcionar perfumação prolongada ao produto, quando comparados àqueles sintetizados. A presença de compostos variados nos óleos, como terpenos e resinas, ajudam a promover singularidades à fragrância e até mesmo servem como inspiração às criações de produtos com descrições olfativas de produtos naturais. Croton tricolor (Euphorbiaceae), segundo avaliação inicial de um perfumista, apresentou excelentes características olfativas, o que facilitou seu uso nos estudos. A análise do óleo essencial de C. tricolor por cromatografia à gás com detector de ionização de chamas (CG/DIC) e cromatografia à gás acoplada à espectrometria de massas (CG/EM) permitiu quantificar e identificar seus principais marcadores, bem como utilizar estas informações para construção de acorde olfativo, reproduzindo o odor do produto natural. O óleo essencial de C. tricolor apresentou como principais componentes o biciclogermacreno (15,4%), espatulenol (10,5%) e o alfa-pineno (6,8%). A partir destes dados foi construído um acorde aromático que reproduziu o odor original, contendo alfa-pineno (7%), álcool fenetílico (5%), óleo de cedro (5%), óleo de laranja (0,5%), limoneno (1%), eucaliptol (0,5%) e nerolidol (0,3%). Os compostos majoritários, biciclogermacreno e espatulenol, não foram adicionados por não serem disponíveis comercialmente, por isso, usaram-se outras matérias-primas semelhantes em perfil olfativo e ofertadas no mercado, como foi o caso do uso de álcool fenetílico, óleo de cedro e óleo de laranja na criação do acorde. Os resultados evidenciaram que a criação de acordes é um método economicamente viável para a reprodução de odores naturais que podem ser utilizados em formulações de fragrâncias, além de ajudar a resolver problemas na produção e comercialização de óleos essenciais como, sazonalidade e reprodutibilidade. / The use of essential oils in the fragrance industry has grown every year. The cosmetics industry has generally sought this type of ingredient, with the aim of providing its products with differentiated benefits (unique and better attributes), and thus delivering to the final consumer a differential that can enhance their formulations, besides simply perfuming their products (theirs). The benefit of using natural oils or accords of their major components in fragrance formulations makes them richer, and in many cases capable of providing prolonged perfuming to the final product when compared to synthesized products. The presence of varied compounds in the oils, such as terpenes or (and) resins, helps to promote differentiated fragrance characteristics (singularities/peculiarities to the fragrance), or (and) even to serve as inspiration for product creations with olfactory descriptions of natural products. Croton tricolor (Euphorbiaceae), accordingly to an initial evaluation of a perfumer, presented excellent olfactory characteristics, which facilitated its use in the studies. The analysis of the C. tricolor essential oil by gas chromatography with flame ionization detector (GC/FID) and gas chromatography coupled to mass spectrometry (GC/MS) allowed to quantify and identify their main markers, as well as to use this information to construct an olfactory accord that reproduces the odor of natural products. The C. tricolor essential oil had as main components bicyclogermacrene (15.4%), spathulenol (10.5%) and alpha pinene (6.8%). From these data, an aromatic accord was created reproducing the original odor containing alpha pinene (7%), phenethyl alcohol (5%), cedar oil (5%), orange oil (0.5%), limonene (1%), eucalyptol (0.5%) and nerolidol (0.3%). Some of the major compounds, bicyclogermacrene and spatulenol, could not be added because they were not commercially available. In these cases (therefore), other products (raw materials) with similar olfactory characteristics (olfactory profile) and commercially viable (offered on the market) were used, such as the use of phenethyl alcohol, cedar oil and orange oil in the accord creation. The results showed that accord creation is an economically viable method for the reproduction of natural odors that can be used in fragrance formulations and may help to solve problems that exist in the production and commercialization of essential oils such as production seasonality and reproducibility.

No description available.

Submitted by (edna.saturno@ufrpe.br) on 2016-11-23T14:42:31Z No. of bitstreams: 1 Carolina Arruda Guedes.pdf: 366977 bytes, checksum: f52564e3d9d50d467b48ca37e9fee5cc (MD5) / Made available in DSpace on 2016-11-23T14:42:31Z (GMT). No. of bitstreams: 1 Carolina Arruda Guedes.pdf: 366977 bytes, checksum: f52564e3d9d50d467b48ca37e9fee5cc (MD5) Previous issue date: 2012-07-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The culture of tomato, Lycopersicon esculentum Mill., is of great socio-economic relevance to the world. Neoleucinodes elegantalis Guenée, known as tomato fruit borer (BPT), is key pest of the crop and can damage the reproductive parts of the plant, causing significant losses. The control is often ineffective because of the biological behavior of the pest, where the larvae are protected within the fruit. Therefore, alternatives to chemical control, to preserve the environment and health of workers and consumers can help reverse the current frame. The use of pheromone as behavioral tool for pest monitoring or control can help a reduction of pesticides utilization in crops. Thus, this study aimed to investigate the impact of deltamethrin on the emission, perception and composition of the pheromone, as well as the reproductive biology of N. elegantalis. The results showed that the trap Bio Neo in association with the synthetic sex pheromone are more effective in capturing males of BPT. Extracts of pheromone glands of N. elegantalis showed only the presence of compound (E)-11-hexadecenol (E11-16: OH), based on chromatographic analysis. This suggests a possible difference in the composition geographical pheromone compared the species from Venezuela, since the other components were not identified. The calling behavior of females treated with deltamethrin BPT did not differ from control. The periods of peak observed call from 6-8h after the start of scotophase for all treatments. However, control the peak obtained in the sixth hour, whereas for the treated females' s LD 20-40 showed a peak at the eighth hour. Thus it is concluded that sublethal doses of deltamethrin not interfere with the chemical composition of the sex pheromone of N. elegantalis but may have an influence in behavior by the change in peak calling hours observed. / A cultura do tomate, Lycopersicon esculentum Mill., é de grande relevância sócioeconômica para o mundo. Neoleucinodes elegantalis Guenée, conhecida como broca pequena do tomateiro (BPT), é praga-chave da cultura por danificar as partes reprodutivas da planta. O controle muitas vezes é ineficaz devido às larvas serem broqueadoras e não serem afetadas pelos inseticidas externos, por esse motivo táticas de controle incluem frequentes aplicações de inseticidas. O controle comportamental com o uso do feromônio sexual pode auxiliar na redução da utilização de inseticidas se usado para o monitoramento da praga ou no seu controle. Assim, o presente trabalho teve como objetivo investigar o impacto de deltametrina sobre o chamamento, composição e eficiência do feromônio sexual, bem como na biologia reprodutiva de N. elegantalis. Os resultados demonstraram que a armadilha Bio Neo em associação ao feromônio sexual sintético apresentam maior eficácia na captura de machos da BPT. Os extratos de glândulas de feromônio sexual de N. elegantalis tratados e não tratados revelaram apenas a presença do composto (E)-11-hexadecenol (E11-16:OH), de acordo com as análises cromatográficas. Esse resultado sugere uma possível diferença geográfica na composição de feromônio, quando comparado à espécie da Venezuela, já que os outros componentes não foram identificados. O comportamento de chamamento de fêmeas da BPT tratadas com deltametrina não diferiu da testemunha. Os períodos do pico de chamamento foram observados entre 6-8h, após o início da escotofase para todos os tratamentos. No entanto, a testemunha obteve o pico na sexta hora, enquanto que para as fêmeas tratadas com as DL`s 20 e 40 apresentaram o pico na oitava hora. Deste modo conclui-se que doses subletais de deltametrina não interferem na composição química do feromônio sexual de N. elegantalis, podendo no entanto ter uma influência na comunicação pela mudança do horário de pico de chamamento observado.

Volatile Organic Compounds (VOCs) are commonly used as indicators of an organism's health, among other factors. Traditionally, gas chromatographs (GC) are used to classify these but are prohibitively expensive and impractical for field use. This thesis outlines the motivations, design, construction, and characterization of a portable GC. This proof-of-concept uses off-the-shelf components to show that the production of a device is feasible. It was able to successfully generate carrier gas from the surrounding air via filtration by activated carbon fiber filters. It was also able to reliably produce distinguishable peaks for acetone and hexane at retention times that were reasonable for a prototype system. With some modifications, this system has the strong potential for long-term implementation in the field.