565 resultados para Paint, Antifouling.


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O desporto automóvel, e particularmente os ralis, tem milhares de seguidores em Portugal. Apesar de existirem algumas obras que relatam com rigor a história do automobilismo desportivo em Portugal, nenhuma consagrou por inteiro o seu espaço às provas de estrada que, há mais de 100 anos, fascinam multidões. O projeto para a edição de uma obra consagrada aos ralis sustenta a sua viabilidade no interesse que a mesma possa despertar tanto em adeptos, como em parceiros de diferente natureza que possam vislumbrar mais-valias numa possível parceria com o editor da obra. Editar uma obra que faz a história dos ralis em Portugal implica a consciencialização de que o mercado-alvo é de natureza restrita e que, por essa razão, os meios de divulgação e comercialização devem ser focalizados com um cuidado redobrado. O relatório apresenta as diferentes tarefas da edição da obra. Algumas são comuns a tudo o que é editável, como a conceção gráfica. Outras são do mundo da edição impressa, como a escolha do papel ou das tintas. Algumas, ainda, são específicas das edições que procuram fazer a história de um desporto em que o movimento, a cor, o imprevisto, os pormenores, são parte importante da sua história, como a escolha de fotografias ou a inserção de caixas de texto com a mais variada informação.

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Catalogue and invitation card for Exhibition at Eagle Gallery, London. 16 June – 16 July 2016 “My paintings are like ghost schema, assemblages of images and surfaces that generate spectral encounters.” James Fisher’s paintings are carefully calibrated. They explore dualities and employ complex visual palimpsests to construct images that are rich with association. Abstract and figurative motifs are laid on different layers of their surfaces, covered over, and re-discovered through sanding back the paint. As a former British School at Rome Scholar, Fisher’s early work was influenced by the study of fresco painting and he retains an approach that allows for time and chance to enter the process of painting. Fabrication – in the sense both of making things and making things up – produces enigmatic and mysterious results. Many of Fisher’s recent paintings are titled after notable, now forgotten women, or after characters from folklore and comic books. The range of subject matter allows him to conflate biography with fiction, and to borrow from a wide range of visual sources for patterned elements that formally hold in place the more fugitive suggestions of the images. Fisher’s fourth solo exhibition at the Eagle Gallery coincides with the selection of two works in this year’s Royal Academy Summer Exhibition, and his inclusion in Towards Night – a forthcoming exhibition at the Towner, Eastbourne.

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This work presents a tool to support authentication studies of paintings attributed to the modernist Portuguese artist Amadeo de Souza-Cardoso (1887-1918). The strategy adopted was to quantify and combine the information extracted from the analysis of the brushstroke with information on the pigments present in the paintings. The brushstroke analysis was performed combining Gabor filter and Scale Invariant Feature Transform. Hyperspectral imaging and elemental analysis were used to compare the materials in the painting with those present in a database of oil paint tubes used by the artist. The outputs of the tool are a quantitative indicator for authenticity, and a mapping image that indicates the areas where materials not coherent with Amadeo's palette were detected, if any. This output is a simple and effective way of assessing the results of the system. The method was tested in twelve paintings obtaining promising results.

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As poeiras urbanas, vulgarmente designadas na literatura por street dusts ou road dusts, são misturas heterogêneas de partículas minerais do solo e partículas resultantes do tráfego, formando um material com características únicas e específicas de cada local. Estas partículas, geralmente enriquecidas com elementos potencialmente tóxicos, quando inaladas ou ingeridas poderão ser um risco para a saúde das populações. Neste trabalho foram recolhidas 21 amostras de poeiras urbanas na cidade de Estarreja assim como amostras representativas de partículas relacionados com o tráfego (poeiras resultante do desgaste dos travões e das marcações dos pavimentos e estradas) com o objetivo de investigar a contribuição relativa destas partículas no comportamento geoquímico dessas amostras e o risco associado para as populações locais. Para a concretização do objetivo proposto caracterizou-se química e mineralogicamente as amostras de poeiras urbanas e as partículas relacionadas com o tráfego e avaliou-se a disponibilidade e bioacessibilidade para três elementos considerados potencialmente tóxicos (Cu, Pb e Zn) usando uma combinação de ensaios: (a) digestão ácida; (b) extração sequencial para identificar o fracionamento do Cu, Pb e Zn nas diferentes fases-suporte dos metais, e (c) bioaccessibilidade oral in vitro. Os resultados da análise química mostram que as poeiras dos travões apresentam concentrações elevadas em Fe, Cu, Zn, Mn, Ba, Sb, Cr e Ni sendo de referir diferenças composicionais significativas entre as amostras estudadas. A amostra de tinta contém teores elevados de Ba, Ca, Ti e Pb e também pode conter outros elementos tais como Co, Cr, Cu, Mn. Mineralogicamente constata-se que as amostras de poeiras dos travões tem uma composição mineralógica semelhante mostrando que são constituídas por uma elevada percentagem de material de baixa cristalinidade, grafite e óxidos/hidróxidos de Fe amorfos. A amostra de tinta de marcação dos pavimentos das estradas é composta por material mais cristalino do que a poeira dos travões e é essencialmente constituída por carbonatos (maioritariamente dolomite) e também por barite (em menor quantidade). Os resultados obtidos nas amostras de poeiras urbanas indicam a existência de associações de elementos que definem claramente a componente geogénica e/ou antropogénica e apontam para diferenças entre essas associações nas duas frações estudadas (250 m e 63 m). A heterogeneidade das poeiras é revelada pela existência de partículas com origem geogénica (por exemplo quartzo e aluminossilicatos), de partículas com características marcadamente antropogénicas (partículas enriquecidas em Fe, Pb, Zn e Cu) ou ainda de partículas com origem mista (óxidos de Fe e Ti). Os resultados da extração química seletiva sequencial permitiu concluir que, nas amostras em estudo, as fases de troca e ácido-solúveis são as fases suporte mais importantes para o Cu, Pb e Zn Os resultados dos ensaios de bioacessibilidade mostraram também que uma percentagem significativa de Cu, Pb e Zn total está disponível para absorção gástrica. Este estudo destaca também a necessidade de se caracterizar em detalhe as propriedades intrínsecas das partículas antrópicas presentes nas poeiras urbanas, de forma a compreender as variações da fração bioacessível nos diferentes elementos estudados assim como nas diferentes frações.

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Most commercially available reverse osmosis (RO) and nanofiltration (NF) membranes are based on the thin film composite (TFC) aromatic polyamide membranes. However, they have several disadvantages including low resistance to fouling, low chemical and thermal stabilities and limited chlorine tolerance. To address these problems, advanced RO/NF membranes are being developed from polyimides for water and wastewater treatments. The following three projects have resulted from my research. (1) Positively charged and solvent resistant NF membranes. The use of solvent resistant membranes to facilitate small molecule separations has been a long standing industry goal of the chemical and pharmaceutical industries. We developed a solvent resistant membrane by chemically cross-linking of polyimide membrane using polyethylenimine. This membrane showed excellent stability in almost all organic solvents. In addition, this membrane was positively charged due to the amine groups remaining on the surface. As a result, high efficiency (> 95%) and selectivity for multivalent heavy metal removal was achieved. (2) Fouling resistant NF membranes. Antifouling membranes are highly desired for “all” applications because fouling will lead to higher energy demand, increase of cleaning and corresponding down time and reduced life-time of the membrane elements. For fouling prevention, we designed a new membrane system using a coating technique to modify membrane surface properties to avoid adsorption of foulants like humic acid. A layer of water-soluble polymer such as polyvinyl alcohol (PVA), polyacrylic acid (PAA), polyvinyl sulfate (PVS) or sulfonated poly(ether ether ketone) (SPEEK), was adsorbed onto the surface of a positively charged membrane. The resultant membranes have a smooth and almost neutrally charged surface which showed better fouling resistance than both the positively charged NF membranes and commercially available negatively charged NTR-7450 membrane. In addition, these membranes showed high efficiency for removal of multivalent ions (> 95% for both cations and anions). Therefore, these antifouling surfaces can be potentially used for water softening, water desalination and wastewater treatment in a membrane bioreactor (MBR) process. (3) Thermally stable RO membranes. Commercial RO membranes cannot be used at temperature higher than 45°C due to the use of polysulfone substrate, which often limits their applications in industries. We successfully developed polyimides as the membrane substrate for thermally stable RO membranes due to their high thermal resistance. The polyimide-based composite polyamide membranes showed desalination performance comparable to the commercial TFC membrane. However, the key advantage of the polyimide-based membrane is its high thermal stability. As the feed temperature increased from 25oC to 95oC, the water flux increased 5 - 6 times while the salt rejection almost kept constant. This membrane appears to provide a unique solution for hot water desalination and also a feasible way to improve the water productivity by increasing the operating temperature without any drop in salt rejection.

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This article analyzes how the selection process for the executive affects the risk of rebellion and insurgencies in sub-Saharan Africa between 1971 and 1995. Four executive recruitment processes are distinguished, which are characteristic for the African context: (1) a process without elections, (2) single candidate elections, (3) single party, multiple candidate elections, and (4) multiparty executive elections. The results suggest that single candidate elections and multiparty elections substantially reduce the risk of insurgencies compared to systems without any kind of executive elections. They further show that during times of political instability the risk of large-scale violent dissent increases substantially. The article supports findings of the civil war literature that higher levels of income are associated with a lower risk of intrastate violence, while oil-exporting countries are at a higher risk of rebellion. In short, this article further strengthens the need to use more specific measures of elements of political regimes, which also take into account regional particularities, in order to paint a more informative picture of how political structures influence the risk of internal violence.

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Uno de los principales inconvenientes que tiene la pintura al óleo es su lento secado. Dicho esto, cabe preguntarse si existe algún tipo de pintura que tenga las cualidades de los óleos pero que sequen más rápido que estos. La respuesta, afirmativa, la encontramos en los óleos alquídicos, que en nuestro país únicamente se comercializan bajo la marca Griffin de Winsor & Newton. Se trata de unas pinturas relativamente recientes, poco conocidas por los pintores y muy poco estudiadas. Con el objetivo de paliar estas carencias, el presente artículo contiene las principales conclusiones de un trabajo en el que se ha estudiado la composición de las pinturas Griffin, sus principales características (viscosidad, brillo, flexibilidad, textura, opacidad, secado que es lo que más nos interesa, estabilidad etc.), su aplicación práctica mediante el arte pictórico (soportes, disolventes, reglas para pintar, correcciones, veladuras, barnizado, etc.) y su mezcla con otro tipo de procedimientos pictóricos como el óleo, el acrílico, la cera encáustica y diversos temples (huevo, cola y caseína).

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Relatório de Estágio apresentado para a obtenção do grau de Mestre em Desporto com especialização em Treino Desportivo

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Over the last decade, rapid development of additive manufacturing techniques has allowed the fabrication of innovative and complex designs. One field that can benefit from such technology is heat exchanger fabrication, as heat exchanger design has become more and more complex due to the demand for higher performance particularly on the air side of the heat exchanger. By employing the additive manufacturing, a heat exchanger design was successfully realized, which otherwise would have been very difficult to fabricate using conventional fabrication technologies. In this dissertation, additive manufacturing technique was implemented to fabricate an advanced design which focused on a combination of heat transfer surface and fluid distribution system. Although the application selected in this dissertation is focused on power plant dry cooling applications, the results of this study can directly and indirectly benefit other sectors as well, as the air-side is often the limiting side for in liquid or single phase cooling applications. Two heat exchanger designs were studied. One was an advanced metallic heat exchanger based on manifold-microchannel technology and the other was a polymer heat exchanger based on utilization of prime surface technology. Polymer heat exchangers offer several advantages over metals such as antifouling, anticorrosion, lightweight and often less expensive than comparable metallic heat exchangers. A numerical modeling and optimization were performed to calculate a design that yield an optimum performance. The optimization results show that significant performance enhancement is noted compared to the conventional heat exchangers like wavy fins and plain plate fins. Thereafter, both heat exchangers were scaled down and fabricated using additive manufacturing and experimentally tested. The manifold-micro channel design demonstrated that despite some fabrication inaccuracies, compared to a conventional wavy-fin surface, 15% - 50% increase in heat transfer coefficient was possible for the same pressure drop value. In addition, if the fabrication inaccuracy can be eliminated, an even larger performance enhancement is predicted. Since metal based additive manufacturing is still in the developmental stage, it is anticipated that with further refinement of the manufacturing process in future designs, the fabrication accuracy can be improved. For the polymer heat exchanger, by fabricating a very thin wall heat exchanger (150μm), the wall thermal resistance, which usually becomes the limiting side for polymer heat exchanger, was calculated to account for only up to 3% of the total thermal resistance. A comparison of air-side heat transfer coefficient of the polymer heat exchanger with some of the commercially available plain plate fin surface heat exchangers show that polymer heat exchanger performance is equal or superior to plain plate fin surfaces. This shows the promising potential for polymer heat exchangers to compete with conventional metallic heat exchangers when an additive manufacturing-enabled fabrication is utilized. Major contributions of this study are as follows: (1) For the first time demonstrated the potential of additive manufacturing in metal printing of heat exchangers that benefit from a sophisticated design to yield a performance substantially above the respective conventional systems. Such heat exchangers cannot be fabricated with the conventional fabrication techniques. (2) For the first time demonstrated the potential of additive manufacturing to produce polymer heat exchangers that by design minimize the role of thermal conductivity and deliver a thermal performance equal or better that their respective metallic heat exchangers. In addition of other advantages of polymer over metal like antifouling, anticorrosion, and lightweight. Details of the work are documented in respective chapters of this thesis.

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O imposex em gastrópodes (Acanthina monodon, Oliva peruviana e Xanthochroid Cassidyformis) e os níveis de butilestânicos (BTs) em sedimentos superficiais e tecidos foram avaliados em três áreas sob a influência das atividades marítimas ao longo da costa central do Chile. As concentrações mais elevadas de TBT foram observadas na baia de São Vicente (Concepción), atingindo 122,3 ng Sn g-1 em sedimentos superficiais e 59,7 ng Sn g-1 em tecidos de gastrópodes, enquanto em Valparaiso variou de 7,4 a 15,8 ng Sn g-1 em biota. As menores concentrações de TBT em sedimentos foram detectadas em Coquimbo (<2 ng Sn g- 1 ), que pode ser atribuída a um menor tráfego de embarcações (provavelmente usando produtos livres de TBT) associado à dinâmica local. Apesar de DBT e MBT serem os analitos predominantes, aportes recentes de TBT foram evidentes em algumas áreas. Na verdade, os barcos de pesca pode ser uma fonte relevante, uma vez que estes predominaram nos locais mais contaminados. Além disso, a ausência de diferenças significativas entre os níveis BTs de ambos os sexos de A. monodon sugere que os tecidos de sexos distintos podem ser indistintamente utilizados para estudos futuros de contaminação. A incidência de Imposex foi detectada em 11 dos 15 locais amostrados, indicando que os níveis ambientais de TBT tem sido suficiente para induzir efeitos deletérios sobre os organismos expostos. Assim, os impactos causados pelo TBT nas zonas costeiras do Chile foram detectáveis e consistentes com outros estudos realizados na América do Sul. Este problema ambiental pode ser, provavelmente, devido a falta de regulamentação proibindo o uso de tintas antiincrustantes a base de TBT, indicando que esta pode ser a realidade das demais áreas do Chile sob influência de atividades marítimas.

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The purpose of this thesis is to provide research, supporting paperwork, production photographs and other materials that document the scenic design process for James and the Giant Peach at Adventure Theatre MTC. This thesis contains the following: concept statement, scenic research images collected to express location, and the emotional/ intellectual/ psychological landscapes for the production, preliminary sketches, photographs of the ¼” scale model, drafting plates and supporting paint elevations to communicate the design, prop list and accompanying research, archival production photographs to document the completed design, and finally periodical reviews of the show.

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The purpose of this thesis is to provide research, supporting paperwork, production photographs, and other materials that document the scenic design process for the production of William Shakespeare’s Troilus & Cressida by the University of Maryland – College Park, School of Theater, Dance, and Performance Studies. This thesis contains the following: scenic research images collected to express period, location, and emotional/intellectual landscapes to the production team; preliminary sketches; photographs of the ¼” scale model; a full set of drafting plates and paint elevations used to communicate the design to the technical director and paint charge; a unit list naming each scenic element; a props list and research book to detail each hand prop, furniture piece and consumable to the prop master; and, lastly, archival production photographs to document the completed design.

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A spectral aging test was developed to estimate the photochemical damage of oil, acrylic and gouache paints exposed to permanent lighting. The paints were irradiated at seven different wavelengths in the optical range to control and evaluate their spectral behaviour. To reach this objective, boxes with isolated aging cells were made. In each of box, one LED of a different wavelength and one photodiode were installed. Inside the boxes, the temperature of an exhibit area was recreated through a thermocouple sensor that controlled the temperature using a fan. The heat produced by the LED was dissipated by a thermal radiator. Moreover, to evaluate the exposure time dependence of the irradiation level, the test was performed using two different irradiation levels in ten exposure series. After each series, the spectral reflectance was measured, and the data collected for each paint and wavelength were used to develop a model of damage produced by the interaction between the spectral radiant exposure and the paint.

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An outbreak of Tunga Penetrans (Jigger Flea) infestation affecting a number of villages near to a Central Hospital in Malawi is described. Due to the large number of affected individuals, high parasitic load, and extended duration of infection an alternative to the recommended approach of surgical removal of the flea was required. Benzyl benzoate paint and liquid paraffin had been used in local Primary Healthcare settings previously and topical treatment with antiparasitic agents has been advocated in the literature, particularly for severe infestation. Benzyl benzoate and liquid paraffin were applied topically to four adults with numerous jigger flea burrows, and their progress assessed regularly. After completion of 7 days of treatment patients noted that fleas were dislodging spontaneously, and that embedded parasites had not increased in size to the same extent that untreated fleas had in previous infestations. Following confirmation of the viability of its implementation in a resource-poor setting, this treatment regimen has subsequently been adopted by the local branch of the District Health Office for distribution to infected communities.

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This thesis presents an investigation on endoscopic optical coherence tomography (OCT). As a noninvasive imaging modality, OCT emerges as an increasingly important diagnostic tool for many clinical applications. Despite of many of its merits, such as high resolution and depth resolvability, a major limitation is the relatively shallow penetration depth in tissue (about 2∼3 mm). This is mainly due to tissue scattering and absorption. To overcome this limitation, people have been developing many different endoscopic OCT systems. By utilizing a minimally invasive endoscope, the OCT probing beam can be brought to the close vicinity of the tissue of interest and bypass the scattering of intervening tissues so that it can collect the reflected light signal from desired depth and provide a clear image representing the physiological structure of the region, which can not be disclosed by traditional OCT. In this thesis, three endoscope designs have been studied. While they rely on vastly different principles, they all converge to solve this long-standing problem.

A hand-held endoscope with manual scanning is first explored. When a user is holding a hand- held endoscope to examine samples, the movement of the device provides a natural scanning. We proposed and implemented an optical tracking system to estimate and record the trajectory of the device. By registering the OCT axial scan with the spatial information obtained from the tracking system, one can use this system to simply ‘paint’ a desired volume and get any arbitrary scanning pattern by manually waving the endoscope over the region of interest. The accuracy of the tracking system was measured to be about 10 microns, which is comparable to the lateral resolution of most OCT system. Targeted phantom sample and biological samples were manually scanned and the reconstructed images verified the method.

Next, we investigated a mechanical way to steer the beam in an OCT endoscope, which is termed as Paired-angle-rotation scanning (PARS). This concept was proposed by my colleague and we further developed this technology by enhancing the longevity of the device, reducing the diameter of the probe, and shrinking down the form factor of the hand-piece. Several families of probes have been designed and fabricated with various optical performances. They have been applied to different applications, including the collector channel examination for glaucoma stent implantation, and vitreous remnant detection during live animal vitrectomy.

Lastly a novel non-moving scanning method has been devised. This approach is based on the EO effect of a KTN crystal. With Ohmic contact of the electrodes, the KTN crystal can exhibit a special mode of EO effect, termed as space-charge-controlled electro-optic effect, where the carrier electron will be injected into the material via the Ohmic contact. By applying a high voltage across the material, a linear phase profile can be built under this mode, which in turn deflects the light beam passing through. We constructed a relay telescope to adapt the KTN deflector into a bench top OCT scanning system. One of major technical challenges for this system is the strong chromatic dispersion of KTN crystal within the wavelength band of OCT system. We investigated its impact on the acquired OCT images and proposed a new approach to estimate and compensate the actual dispersion. Comparing with traditional methods, the new method is more computational efficient and accurate. Some biological samples were scanned by this KTN based system. The acquired images justified the feasibility of the usage of this system into a endoscopy setting. My research above all aims to provide solutions to implement an OCT endoscope. As technology evolves from manual, to mechanical, and to electrical approaches, different solutions are presented. Since all have their own advantages and disadvantages, one has to determine the actual requirements and select the best fit for a specific application.