Zinc Oxide (ZnO) is one of the most extensively studied semiconductors because of its unique properties, namely, its wide band gap (3.37 eV) and high excitation binding energy (60 meV). These properties make ZnO a promising material for uses in a broad range of applications including sensors, catalysis and optoelectronic devices. The presented research covers a broad spectrum of these interesting nanomaterials, from their synthesis and characterization to their use as photocatalyts. A new synthetic approach for producing morphology controlled ZnO nanostructures was developed using microwave irradiation (MWI). The rapid decomposition of zinc acetate in the presence of a mixture of oleic acid (OAC) and oleylamine (OAM) results in the formation of hexagonal ZnO nanopyramids and ZnO rods of varying aspect ratios. The factors that influence the morphology of these ZnO nanostructures were investigated. Using ligand exchange, the ZnO nanostructures can be dispersed in aqueous medium, thus allowing their use as photocatalysts for the degradation of malachite green dye in water. Photocatalytic activity is studied as a function of morphology; and, the ZnO nanorods show enhanced photocatalytic activity for the degradation of the dye compared to hexagonal ZnO nanopyramids. After demonstrating the catalytic activity of these ZnO nanostructures, various ways to enhance photocatalytic activity were studied by modification of this MWI method. Photocatalytic activity is enhanced through band gap modulation and the reduction of electron-hole recombination. Several approaches were studied, which included the incorporation of Au nanoparticles, N-doping of ZnO, supporting ZnO nanostructures on reduced graphene oxide (RGO), and supporting N-doped ZnO on N-doped RGO. ZnO-based nanostructures were studied systematically through the entire process from synthesis and characterization to their use as photocatalysis. This allows for a thorough understanding of the parameters that impact these processes and their unique photocatalytic properties.

This thesis presented the study of carbon-based materials for ultra-sensitive molecular sensing. Reduced Graphene Oxide (rGO), a 2-dimensional one-atomic layer thick carbon material, had the advantage of low-cost, aqueous and industrial-scalable production route. Using rGO as the transducer platform could potentially lower the cost of sensors down to a few dollars per chip. However, there were still limitations in rGO that prevented its widespread usage as a biosensor transducer or in electronics: its low electrical conductivity and large electrical deviations. This thesis was structured to understand and solve these problems for transducer application. The thesis could be broken down into 3 parts: The first part of the thesis presented the critical review of the background and limitations of graphene research, followed by the background and importance of biosensor developments for the detection of sweat sodium ions and circulatory Interleukin-6 proteins. The second part of the thesis tested the hypothesis that the rGO limitations could be eliminated to create a highly sensitive biosensor transducer via (A) improving rGO synthesis (B) pristine Carbon Nanotubes-rGO hybrid film and (C) growth of rGO. The mechanism of ultra-large graphene oxide synthesis and graphene oxide growth was also elucidated in this section. The third part of the thesis then presented the fabrication and test of the practical and homogenous carbon-based biosensor using the transducer synthesized earlier. The thesis showed that through proving the hypothesis correct, it enabled the synthesis of an all organic sodium ion sensor with integrated pump and an ultra-sensitive interleukin-6 bio-sensor. Both of these novel sensors were able to detect the respective molecules in their physiological ranges.

The Graphene term has become synonymous with layered carbon sheets having thicknesses ranging from the monolayer to stacks of about ten layers. For bulk volume production, graphite chemical exfoliation is the preferred solution. For this reason, much interest has congregated around different processes to oxidize and peel off graphite to obtain graphene oxide (GO) and its counterpart, reduced GO (rGO). The community at-large has quickly adopted those processes and has been intensively using the resulting (r)GO as active materials for a myriad of applications. Yet, partially given the absence of comparative studies in synthesis methodologies, a lack of understanding persists on how to best tailor these carbon materials for a given application. In this dissertation, the effect of using different chemical oxidation-reduction strategies for graphite, namely the impact on the structure and chemistry of GOs and rGOs is systematically discussed. Added to this, it is demonstrated that the drying step of the powdered materials cannot be neglected. Its influence is demonstrated in studies such as the optimization of capacitance of rGOs touted as electrochemical energy storage materials (Chapter 4). It is concluded that, in order to maximize the performance of GO and rGO materials for any particular application, there must be a judicious choice of their synthesis steps. Obvious as it may be for anyone working in Chemistry, this point has been surprisingly overlooked for too long by the vast majority of those working with these carbon materials.

In 1994 there was an earthquake occurred in Northridge, California which caused damage in structures built with Steel Moment Frames (SMF) due to the brittle fractures in the beam and column connections. It has led to the major modifications and improvements in the connection detailing prior to the earthquake occurred in the Northbridge. These changes came up with better materials for welding and introduced the use of cover plate and Reduced Beam Section (RBS). RBS connections are the most widely used connection today and it allows the SMF systems to yield extensively and deform plastically by avoiding brittle fracturing at connections. The most important factors that affect the response along with the design of Steel Moment Frames (SMF) and Reduced Beam Section (RBS) connections are connection strength, stiffness, connection type, use of deep columns and phenomena associated with its instability, the strength of ductility of the column panel zone-beam instability.

As florestas na Amazônia tem sido exploradas para a provisão de madeira. A exploração era feita sem planejamento das atividades (Exploração Convencional ou EC), resultando em grandes áreas de florestas degradadas. A partir da década de 90, foram estabelecidas técnicas para minimizar os danos da exploração à vegetação remanescente, visando ciclos sequenciais de corte, sem prejuízo à produção, através da Exploração de Impacto Reduzido (EIR). Embora muito tenha sido discutido sobre o quão mais eficiente a EIR seja em relação a EC, ainda existem lacunas, principalmente acerca da organização e manutenção da diversidade dessas áreas. A exploração é, de maneira muito resumida, o corte de algumas árvores de interesse comercial e a morte acidental de outras árvores que não as de interesse, pela queda e arraste das toras, construção das estradas e dos pátios de estocagem. As clareiras formadas, em geral, são maiores que as que ocorrem naturalmente na floresta. Essas clareiras são ocupadas por espécies de rápido crescimento, potencialmente mudando a organização da comunidade. Assim, são necessárias abordagens para detectar e então caracterizar quais os impactos que a exploração tem na diversidade de comunidades arbóreas. É importante ressaltar que muitas decisões sobre a sustentabilidade do manejo são tomadas considerando como essas comunidades respondem a distúrbios. Diante do apresentado, esta tese teve como objetivo analisar a dinâmica da diversidade de florestas submetidas à exploração florestal. A distribuição de abundância entre espécies (DAE) é uma abordagem paramétrica para caracterização de comunidades, baseada em um dos poucos padrões que se mantem em todas as comunidades: muitas espécies raras e poucas espécies abundantes, sendo também o reflexo de como as espécies partilham recursos. Distúrbios mudam a identidade das espécies dominantes, podendo ser refletido em alterações nos parâmetros e/ou curvas da DAE. Nós analisamos a DAE de áreas submetidas ao manejo florestal (EIR e EC) e uma área Controle, antes do manejo e ao longo de 16 anos em Paragominas, Pará, Brasil. Antes da exploração, em 1993, foram estabelecidas três parcelas permanentes, onde os indivíduos arbóreos com DAP &ge; 25 cm foram cadastrados. Indivíduos menores (DAP &ge; 10 cm) foram mensurados em sub-parcelas. Após essa primeira medição, foi conduzida exploração em duas parcelas (EIR e EC) e a terceira parcela foi mantida como Controle. As parcelas foram medidas novamente em 1994, 1998, 2000, 2006 e 2009. Para testar se a DAE muda devido ao manejo, usamos a distribuição Poisson Lognormal (PLN) para descrever cada ano e cada tratamento. Para detectar mudanças na similaridade, em termos de composição de espécies e abundância relativa de cada espécie, nós usamos o parâmetro de correlação da PLN bivariada para comparar a comunidade antes da exploração com os outros anos. Ao contrário do esperado, não foram encontradas mudanças estatisticamente relevantes nos parâmetros da DAE ao longo do tempo em nenhum dos três tratamentos. Entretanto o parâmetro de correlação diminui para a comunidade com o menor critério de inclusão de DAP, nas últimas medições das áreas exploradas. Nós também analisamos a DAE dessas mesmas áreas considerando como medida de abundância a área basal de cada espécie. Não foram encontradas mudanças relvantes na DAE, apenas diminuição do parâmetro de correlação. Embora o manejo tenha resultado na diminuição de até 22% dos indivíduos e 27% da área basal, ele não é imediatamente detectado na DAE pois as mortes acidentais são a maioria no manejo. Para cada árvore explorada, em média 19 árvores com DAP &ge; 10 cm são mortas acidentalmente. Essa morte acidental é de certa forma independente da espécie, assim todas as espécies tem suas abundâncias diminuídas. A distribuição PLN considera os efeitos da amostragem através do processo Poisson, então mesmo que a porcentagem de indivíduos mortos fosse maior, dificilmente seria detectável na DAE. No entanto, a diminuição do parâmetro de correlação ao longo do tempo nas áreas exploradas é devido ao aumento da abundância e da área basal de espécies de rápido crescimento como as do gênero Cecropia. A DAE da Ilha de Barro Colorado (BCI), Panamá, também foi analisada (28 anos de medições, DAP &ge; 1 cm). Nós dividimos o conjunto de dados em quatro critérios de inclusão de DAP (1, 10, 25 e 45 cm). Visto que a área não é submetida a grandes distúrbios e, como era esperado, não foram encontradas mudanças relevantes nem na DAE nem na identidade das espécies dominantes. Muitos indivíduos morreram durante esse período, devido a elevada mortalidade, comum para árvores pequenas (DAP < 10 cm), e outra grande parcela da comunidade não atingiu os critérios de DAP que geralmente são amostrados (10, 25 e 45 cm). Mesmo os indivíduos considerados ingressantes, de acordo com esses critérios, já estavam presentes na parcela na primeira medição, apenas eram menores que esses critérios. Diante do apresentado, um distúrbio pode demorar décadas para aparecer nas classes de DAP que geralmente são amostradas, por exemplo DAP &ge; 10 cm. Assim, reiteramos que efeito ou falta de efeito de distúrbios na diversidade de comunidades arbóreas deve ser interpretado com muita cautela. / Amazon tropical forests in Brazil have been exploited for the provisioning of timber, mainly using conventional logging (CL) practices. Little operational planning has been considered and, as a result, large forest areas in the Amazon have become highly degraded over time. Since the 1990\'s, reduced impact logging (RIL) has been adopted as a means of reducing the damage caused by timber exploitation and of establishing more sustainable practices, trying to make sequential logging cycles possible. Much has been discussed about the higher efficiency of RIL or CL, but there are still important knowledge gaps, mainly regarding tree diversity and forest functioning in logged areas. The logging of commercial species and the accidental death of non-targeted trees may alter environmental conditions, leading to higher abundance of some species and to the reduction of others, thus modifying forest structure and diversity. These changes promoted by exploitation have a signature in the structure of the remaining community and tracking them at the community level is still a great challenge, but important decisions are mainly taken considering tree diversity. The development of tools is crucial to quantify the effects of disturbance and to predict its consequence over communities. The main goal of this thesis was to analyze the temporal dynamics of tree diversity in the context of forest management. Species abundance distribution models (SAD) are a parametric approach, based on the most strong pattern in community ecology: few species have high abundance and rarity is the rule. It is also independent of sampling size and related to how species share resources. Species dominance change as a result of disturbances, and these changes may be detectable by changes on the parameters and/or curves of the SAD. We used inventory data from three permanent plots established in 1993 in Paragominas, Pará, Brazil. All the trees with Diameter at Breast Height (DBH) &ge; 25 cm were determined and measured and smaller individuals were measured within subplots (DBH &ge; 10 cm). After this first survey, we harvested two plots using different techniques (RIL and CL) and a third plot was kept as Control. The plots were surveyed again in 1994, 1998, 2000, 2006 and 2009. To test if it is possible to detect changes in the SAD due to logging we used the Poisson Lognormal distribution (PLN) to describe the data from each year. To detect changes in species similarity, we compared species composition and abundance over time, using the correlation parameter of the bivariate PLN. We compared the same plots in 1993 (before exploitation) and in the years that followed. We observed no relevant changes in SAD, but only small changes in the correlation parameter in the last surveys. We also analyzed species\' basal area distribution, and found no statistically relevant changes apart from small changes in the correlation parameter in harvested areas. After exploitation, we observed a reduction of as much as 22 % of the number of trees and 27% of the basal area, and mortality was mainly attributed to the accidental death of non-targeted trees. For each tree harvested, an average 19 trees died accidentally. Because of the dominant role of these random accidental deaths, the signature of management operations could not be detected immediately after logging, using SAD or the correlation parameter. Since SAD models consider sampling effects (Poisson process), any disturbance which causes the random death of trees may not be detected in the short run. However, the start of small changes could be noticed within a couple of decades. The relative abundance of some species has been altered in exploited forests, which was detected by changes in the correlation parameter. Pioneer species of the genus Cecropia have become the most abundant trees in the last survey, considering DBH &ge; 10 cm. We also evaluated species abundance distribution in the Barro Colorado Island, Panama (28 years, DBH &ge; 1 cm). We established four different inclusion criteria (DBH 1, 10, 25 and 45). The area was not subject to major disturbances and, as expected, we observed no relevant changes in the SAD during this period. A large number of individuals died during this period, due to the high mortality common to small trees (DBH &ge; 10 cm), and many others have not reached the used inclusion criteria (10, 25 and 45 cm). Using these inclusion criteria, we showed that the community recruited during this period was already present in the forest in the first survey, but those trees just did not reach the size to be measured. Therefore, a recent disturbance may take decades to be detected within the DBH classes usually sampled. We highlight the role of time scale in the interpretation of tree diversity dynamics.

O pluton Desemborque, de idade neoproterozóica, é parte do denominado Maciço Guaraú, aflorante na região sul do de estado de São Paulo e está inserido no contexto geológico da Província Graciosa. É composto por biotita sienogranito a álcali feldspato granito, metaluminosos a moderadamente peraluminosos, que apresentam assinaturas geoquímicas típicas de granitos de tipo-A, como conteúdos relativamente altos de álcalis, além de concentrações significativas de elementos LIL e HFS. Apresentam alteração hidrotermal em graus variáveis, claramente evidenciados tanto pelas texturas quanto pelas composições registradas em seus minerais essências e acessórios, destacando-se a albitização e a greisenização. Os feldspatos alcalinos são pertitas ou mesopertitas zonadas. Algumas composições químicas integradas exibem valores entre \'Or IND 53-58\'\'Ab4 IND 42-46\' (núcleos) e \'Or IND 68-71\'\'Ab4 IND 29-32\' (bordas). A maior parte das composições obtidas dos plagioclásios correspondem a albita, com poucos cristais classificados como oligoclásio sódico. Albita pura e pós magmática ocorre intersticialmente aos feldpastos ou como microvenulações. São encontradas duas fases micáceas estritamente magmáticas: biotitas castanhas (annita) e esverdeadas (protolitionita-siderofilita). Associadas ao processo de greisenização que substitui biotitas e feldspatos encontram-se micas verdes claras a incolores anteriormente definidas como zinnwaldita, que aqui são reclassificadas como fengita. Minerais acessórios foram examinados e estudados com imageamento BSE e análises quantitativas por EDS. Os mais comuns são: zircão, allanita, torita, cassiterita, galena, hematita, ilmenita, monazita, , columbita e fluoretos de terras raras. Entre eles, os primários (e.g zircão, allanita e cassiterita) exibem microestruturas ou transformações químicas relacionadas à processos tardios de alteração hidrotermal, enquanto outros foram desenvolvidos durante este processo, como torita, xenotímia e fluoretos de elementos terras raras e de ítrio. Os granitos típicos do Desemborque são bastante evoluídos e relativamente homogêneos com um estreito intervalo composicional, como \'SiO IND 2\' (76-77% em peso), álcalis (\'Na IND 2\'O até 4,1 % e \'K IND 2 O\' até 4,5 %), \'Al IND 2\'\'O IND 3\' (ca. 12%) e \'Fe IND 2\'\'O IND 3\' (~1%). Outros óxidos comuns contribuem com concentrações bem baixas como CaO e MgO. As rochas hidrotermais exibem relativo enriquecimento em\' Fe IND 2\'\'O IND 3\' (5,27 % em peso para o greisen) além de F, Rb, Sn e Li e empobrecimento em \'Na IND 2\'O (0,26%). As temperaturas de saturação em Zr fornecem valores entre 750-860º C, e que pode ser extrapolada como uma aproximação para a temperatura do líquido do sistema magmático. Dados geológicos, petrográficos e normativos indicam colocação em níveis rasos, com pressões não muito maiores que 1 kbar. Suas características remetem a cristalização em fugacidades de oxigênio relativamente baixas, uma exceção entre a associação aluminosa da Província Graciosa. As determinações de idades isotópicas U/Pb são problemáticas devido aos aspectos texturais dos cristais de zircão e componentes herdados. Após o tratamento dos dados chegou-se a uma idade estatisticamente mais confiável (590 ± 12 Ma) e em parte, coerente com a literatura. / The Neoproterozoic Desemborque Pluton is a part of the so-called Guaraú Granitic Massif, which crops out in the southern region of the state of São Paulo and is inserted in the geological context of Graciosa Province. It is made of metaluminous to moderately peraluminous biotite sienogranites and alkali-feldspar granites which present geochemichal signatures most typical of A-type granites, as for the relatively high total alkali, LILE and HFSE contents. It shows hydrothermal alteration imprinted to a variable grade, as clearly evidenced by textural as well as compositional features registered in its essential and accessory minerals, standing out albitization and greisenization. Alkali-fedspars are zoned perthite or meso-phertite. Some integrated chemical compositions gave values between \'Or IND 53-58\'\'Ab IND 42-46\' (crystal cores) and \'Or IND 68-71\'\'Ab4 IND 29-32\' (crystal rims). Most of the obtained plagioclase compositions correspond to albite, a minor number being classified as sodic oligoclase. Post-magmatic, almost pure albite, occurs intersticialy to feldspars or as minor veinlets. Two main types of magmatic micas were recognized: red-brown annitic biotite and a green protolitionite-siderofilite. Light green to colorless micas associated with the greisenization process that replaces biotite and feldspars previously called a zinwaldite-like mica were reclassified to fengite type. Accessory minerals were examined and studied with BSE imaging and EDS qualitative analysis. The most common are zircon, allanite, thorite, cassiterite, galena, hematite, ilmenite, monazite, xenotime, columbite, fluorite and REE fluorides. Among them, the primary ones (e.g., zircon, allanite, cassiterite) show micro-structural or chemical transformations related to the hydrothermal alteration, while others were developed during such process, as for thorite, xenotime, and the REE and Y fluorides. The main Desemborque granites are highly evolved and relatively homogenous, with a narrow chemical compositional range as for \'SiO IND 2\' (76-77% wt %), alkalis (\'Na IND 2O\' up to 4.1 % e \'K IND 2O\' up to 4.5 %), \'Al IND 2\'\'O IND 3\' (ca. 12%) e \'Fe IND 2\'\'O IND 3\' (~1%). Other common oxides contribute with very low concentrations like CaO and MgO. Hydrothermal rocks show relatively \'Fe IND 2\'\'O IND 3\'enrichment (up to 5.2 wt.% in the greisen sample) in addition F, Rb, Sn e Li and depletion in \'Na IND 2 O\' (down to 0.26 wt.%) Zircon saturation temperature gives values in the 750-800º C range, which approaches well the liquidus of such magmatic system. Geological, petrographic, and normative data indicate relative shallow emplacement levels, at pressures no greater than ca. 1 Kbar, and crystallization under a relatively low \'f IND O2\' , a exception in the aluminous association of the Graciosa Province. U/Pb isotopic age determinations are problematic due textural aspects of zircon cristals and inherited components. After the treatment of the data was reached a statistically more confiable age (590 ± 12 My) and, in part, coherent with the literature.

O presente experimento teve por objetivos comparar a adição de diferentes concentrações de glutationa reduzida (GSH) no diluidor para criopreservação do sêmen de cães, considerando-se as características morfofuncionais pós-descongelação; e verificar os índices de gestação e número de filhotes por ninhada obtidos a partir da inseminação artificial intra-uterina, por cateterização cervical endoscópica, com sêmen criopreservado contendo diferentes concentrações de glutationa. Na primeira fase do experimento, foram realizadas duas colheitas seminais de 11 reprodutores com intervalo mínimo de uma semana entre os procedimentos. Foram empregadas três concentrações diferentes de glutationa reduzida (0, 10 e 20 mM) ao meio de congelação tris-gema-citrato. O sêmen fresco, refrigerado, glicerolizado e descongelado foram avaliados por citometria de fluxo com uso de sondas específicas para determinar a integridade das membranas plasmática e acrossomal, potencial de membrana mitocondrial e fragmentação de DNA. Também foi realizada dosagem de substâncias reativas ao ácido tiobarbitúrico (TBARS) para avaliar os níveis de estresse oxidativo. Na segunda fase do experimento, foram inseminadas 6 fêmeas, alocadas em dois grupos: inseminação intra-uterina com sêmen congelado em diluidor contendo 10 mM (IA-GSH10, n=3) e sem a adição de glutationa (IA-GSH0, n=3). O acompanhamento do ciclo estral foi realizado por citologia vaginal, vaginoscopia, dosagem de progesterona e LH. Foram realizadas duas inseminações no 5o e 6o dias após pico de LH e a gestação diagnosticada aos 30 dias. A adição de 10 e 20 mM de GSH ao diluidor para criopreservação promoveu queda na motilidade espermática nas amostras descongeladas, sendo o maior prejuízo observado na concentração de 20 mM. Foi detectada maior porcentagem de acrossomos íntegros nos grupos tratados. A glicerolização e, principalmente, a exposição do espermatozóide ao nitrogênio líquido e posterior descongelação foram responsáveis pela diminuição da motilidade espermática, em consequência ao prejuízo da função mitocondrial promovida pela produção de radicais livres durante o processamento seminal. A gestação foi diagnosticada em duas fêmeas do grupo IA-GSH10 e duas do grupo IA-GSH0. Em conclusão, a adição de 10 e 20 mM de GSH ao diluidor para criopreservação seminal não promoveu os efeitos protetores esperados na espécie canina, sendo a concentração de 20 mM responsável por maiores prejuízos à amostra seminal. A adição de 10 mM de GSH ao diluidor para criopreservação seminal na espécie canina manteve o índice de fertilidade semelhante ao obtido com sêmen criopreservado sem a suplementação antioxidante. / The present experiment aimed to compare the addition of different concentrations of reduced glutathione (GSH) on frozen-thawed canine semen, considering the morphofunctional characteristics; and to verify the pregnancy rate and number of puppies per litter obtained from intrauterine insemination by endoscopic catheterization of the cervix, with frozen-thawed semen containing different concentrations of glutathione. During the first phase of the experiment, two seminal samples collected weekly from 11 mature dogs were used. Three different concentrations of reduced glutathione (0, 10 and 20 mM) were supplemented in a tris-citrate egg yolk extender. The fresh, chilled, glycerolized and post-thawed semen were assessed by flow cytometry using specific probes to determine plasma membrane and acrosomal integrity, mitochondrial membrane potential and DNA fragmentation. Thiobarbituric acid reactive substances (TBARS) assay was also performed to assess the occurrence of oxidative stress. In the second phase of the experiment, six canine females were allocated into two groups: intrauterine insemination with frozen-thawed semen containing 10 mM GSH (IA-GSH10, n = 3) and without the addition of glutathione (IA-GSH0, n = 3). Bitches were monitored by vaginal cytology, vaginoscopy, progesterone and LH assays. Two inseminations were performed on days 5 and 6 post LH peak. We verified that the addition of 10 and 20 mM of GSH to semen extender promoted a decrease in post-thaw sperm motility, as well as a higher damage degree at the 20 mM concentration. We also detected a higher percentage of acrossomal integrity in treated groups. At glycerolization and moreover, the sperm exposure to liquid nitrogen and further thawing, were responsible for the decrease in sperm motility, due to the loss of mitochondrial function through the free radicals production. Gestation was diagnosed in two female from IA-GSH10 group and two bitches of the IA-GSH0 group. In conclusion, we did not observe the expected protective effects of the addition of 10 and 20 mM GSH to semen extender. Furthermore, the concentration of 20 mM was responsible for the more extreme damage to semen sample. The supplementation of 10 mM GSH to semen extender for cryopreservation maintained the fertility rates similar to the ones observed for cryopreservation without antioxidant supplementation in dogs.

Anemia é a anormalidade hematológica mais comum em pacientes com câncer. Aproximadamente 30% dos cães com linfoma são anêmicos. A anemia pode ocorrer devido substituição da medula óssea por células tumorais, sangramentos ou hemólise, porém mais frequentemente é associada à doença crônica. Estudos realizados em seres humanos com neoplasias hematopoiéticas demonstraram que a diminuição das defesas antioxidantes eritrocitárias e aumento na concentração de marcadores de peroxidação lipídica no plasma são responsáveis pelo estresse oxidativo e ocorrência da anemia. Foram objetivos deste estudo determinar as concentrações eritrocitárias de glutationa reduzida e as atividades das enzimas antioxidantes eritrocitárias glutationa redutase, glutationa peroxidase, além de substâncias reativas ao ácido tiobarbitúrico e o estado antioxidante total em cães hígidos e com linfoma multicêntrico com e sem anemia, para avaliar a influência dos mecanismos oxidativos no desenvolvimento das anemias associadas a essa neoplasia. Foram observadas reduções significativas nas concentrações eritrocitárias de glutationa reduzida e glutationa peroxidase nos cães com linfoma multicêntrico e com anemia (p < 0,001 e p < 0,01, respectivamente). Não houve diferença significativa na avaliação das concentrações eritrocitárias de glutationa redutase e substâncias reativas ao ácido tiobarbitúrico, entretanto as concentrações plasmáticas de substâncias reativas ao ácido tiobarbitúrico eram maiores no grupo de cães com linfoma multicêntrico e com anemia (0,94 mol/L &plusmn; 0,72; média &plusmn; desvio padrão). Os valores do estado antioxidante total foram significativamente menores (p < 0,001) nos cães com linfoma multicêntrico e com anemia (0,60 mol/L &plusmn; 0,12) do que nos animais hígidos (0,87 mol/L &plusmn; 0,11). Os resultados obtidos indicam um aumento do estresse oxidativo principalmente nos cães com linfoma multicêntrico e com anemia pela diminuição das defesas antioxidantes, representadas pelo estado antioxidante total e glutationa reduzida intraeritrocitária e pela tendência a maior aumento das concentrações plasmáticas de substâncias reativas ao ácido tiobarbitúrico, podendo estas alterações contribuir para a ocorrência de anemia em cães com linfoma multicêntrico. / Anemia is the most common hematological abnormality in cancer patients. Approximately 30% of dogs with lymphoma are anemic. Anemia can occur due to bone marrow replacement by tumor cells, bleeding or hemolysis, but more often is associated with chronic disease. Researches in human hematopoietic malignancies demonstrated that reduction of erythrocyte antioxidant defenses and increased concentrations of markers of lipid peroxidation in the plasma are responsible for the occurrence of oxidative stress and anemia. This study was designed to measure the concentration of erythrocyte reduced glutathione and antioxidant enzyme activities of erythrocyte glutathione reductase, glutathione peroxidase, and thiobarbituric acid reactive substances and total antioxidant status in healthy dogs and with multicentric lymphoma with or without anemia, to evaluate the influence of oxidative mechanisms in the development of anemia associated with this neoplasia. Significant reductions were observed in erythrocyte concentrations of reduced glutathione and glutathione peroxidase in dogs with multicentric lymphoma and anemia (p < 0.001 and p < 0.01, respectively). There was no significant difference in the assessment of concentrations of erythrocyte glutathione reductase and thiobarbituric acid reactive substances, although concentrations of plasma thiobarbituric acid reactive substances were higher in dogs with multicentric lymphoma and anemia (0.94 mol/L &plusmn; 0.72, mean &plusmn; standard deviation). The values of total antioxidant status were significantly lower (p < 0.001) in dogs with multicentric lymphoma and anemia (0.60 mol/L &plusmn; 0.12) than in healthy animals (0.87 mmol/L &plusmn; 0.11). The results indicate an increased oxidative stress, especially in dogs with multicentric lymphoma with anemia and the decrease of antioxidant defenses, represented by the total antioxidant status and intraerythrocytic reduced glutathione and the trend to greater increase in plasma thiobarbituric acid reactive substances and may these changes contribute to the occurrence of anemia in dogs with multicentric lymphoma.

"The condensation of vapor onto a cooled surface is a phenomenon which can be difficult to quantify spatially and as a function of time; this thesis describes an ultrasonic system to measure this phenomenon. The theoretical basis for obtaining condensate film thickness measurements, which can be used to calculate growth rates and film surface features, from ultrasonic echoes will be discussed and the hardware and software will be described. The ultrasonic system utilizes a 5MHz planar piston transducer operated in pulse-echo mode to measure the thickness of a fluid film on a cooled copper block over the fluid thickness range of 50 microns to several centimeters; the signal processing algorithms and software developed to carry out this task are described in detail. The results of several experiments involving the measurement of both non-condensing and condensing films are given. In addition, numerical modeling of specific condensate film geometries was performed to support the experimental system; the results of modeling nonuniform fluid layers are discussed in the context of the effect of such layers on the measurement system."

Over the last decade, two dimensional (2D) materials have attracted considerable attention from both the scientific and engineering community due to their unique properties. One important advance of 2D materials is that they can be exfoliated into nanosheets suspended in a liquid phase and that this allows the formulation of 2D nanomaterials inks. Such inks can be deposited as functional components through low-cost inkjet printing techniques. Many 2D materials based inks have been produced over the years. This thesis investigates the use of inkjet printing to deposit 2D materials such as graphene oxide (GO) and black phosphorus (BP).GO, a derivative of graphene, has been widely used to produce graphene-based conductors via inkjet printing owing to its good stability in readily available solvents such as water. In this work, highly conductive reduced graphene oxide (rGO) films with bulk conductivity in excess of 2 × 10^4 Sm-1 have been prepared by inkjet printing a GO aqueous ink, with mean flake size 35.9 micro metre, through a 60 micro metre inkjet printing nozzle followed by a reduction step. Experimental results showed that individual GO flakes up to 200 micro metre diameter can be successfully printed with no instances of nozzle blocking or poor printing performance. The mechanism by which this occurs is believed to be GO sheet folding during drop formation followed by elastic unfolding during drop impact and spreading. In addition, the influence of GO flake size on rGO film conductivity has been investigated. It was found that the rGO film conductivity increased about 60% when the mean flake size of the GO flakes in the ink increases from 0.68 micro metre to 35.9 micro metre. The drying behaviour of printed GO droplets has been studied on eight GO aqueous inks in which the mean flake size of GO was varied over a range from 0.68 to 35.9 micro metre. It was found that the coffee ring effect (inhomogeneous drying of a droplet to leave a ring like deposit) of dried droplets of the GO ink weakened and disappeared when the flake size increasing. It was found that, with a printed deposit around 340 micro metre in diameter, the coffee ring effect (CRE) was suppressed with the mean flake size > 10.3 micro metre. The critical flake size for CRE suppression reduced to 5.97 and 3.68 micro metre when the substrate temperature was 40 and 50 °C, respectively. It was further found that the CRE weakened with decreasing printed drop size, with the critical flake size reducing to 1.58 micro metre with a printed drop diameter of 30 micro metre.The interaction between BP nanometre thickness flakes and humid atmospheres was investigated using an inkjet printed BP sensor. The BP sensor showed was very sensitive to changes in humidity with a response time of a few seconds and the effect is reproducible in minutes. However, long term exposure to humid air with a relative humidity (RH) > 11% leads to a significant chemical change in the BP films, with Fourier transform infra-red spectroscopy (FTIR) indicating partial hydrolysis of the BP to form phosphate and phosphonate ions. Low temperature heat treatment of BP films under dry conditions after exposure to elevated RH leads to a partial recovery of the impedance response and reversion to a chemical state similar to that before exposure to a humid environment. The recovery of BP properties is most complete after exposure to lower humidity environments (RH < 11%), although exact replication of the original impedance response and FTIR spectrum was not possible.