Aqui apresentamos um modelo teórico para superfícies super-hidrofóbicas que são formadas por superfícies contendo padrões periódicos na forma de microcavidades. Com este modelo obtivemos a relação ideal entre profundidade e diâmetro das cavidades para que a superfície manifeste seu caráter super-hidrofóbico. Assim, fabricamos superfícies em PDMS (popular silicone) capazes de produzir ângulos de contato elevados. Produzimos amostras contendo microcavidades específicas (paralelepípedas, hexagonais e cilíndricas) as quais foram microfabricadas por litografia de feixes de elétrons e caracterizadas por Microscopia Eletrônica de Varredura (MEV), Microscopia de Força Atômica (AFM), e medidas de ângulo de contato. Os padrões das microcavidades das superfícies produzidas seguiram as considerações da teoria e as medidas dos ângulos de contato de avanço e recesso mostram boa concordância com as previsões do modelo. Portanto, podemos afirmar que a teoria aqui descrita permite projetar superfícies altamente hidrofóbicas. / Here we present a theoretical model for super-hydrophobic surfaces formed by surfaces containing periodic patterns in the form of microcavities. With this model we obtained the ideal relationship between depth and diameter of the cavities so that the surface expresses a super-hydrophobic character. Thus manufacture of PDMS surfaces (with known silicone) is capable of producing high contact angles. We produced samples containing specific microcavities (parallelepipeds, hexagonal and cylindrical) which have been microfabricated by electron beam lithography and characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle measurements. The patterns of the surfaces of the cavities produced following the considerations of theory and measurements of advancing and recending contact angles show good agreement with the model predictions. Therefore, we can attest that the theory described here allows the design of highly hydrophobic surfaces.

Made available in DSpace on 2014-06-12T18:28:06Z (GMT). No. of bitstreams: 2 arquivo4026_1.pdf: 467015 bytes, checksum: 246134b0be27231e215728b62fadf75f (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nesta dissertação, estudamos a existência de soluções de um problema elíptico com não linearidade côncava-convexa num domínio regular e limitado. Uma solução é obtida usando o método das sub e super soluções. Usamos também o método variacional, especi ficamente o teorema do passo da montanha, para obter uma segunda solução

In this master thesis, we design and implemented a super mode for multiple streaming signal processing applications, and got the timing budget based on Senior DSP processor. This work presented great opportunity to study the real-time system and firmware design knowledge on embedded system.

En mängd slutprodukter kan fås med hjälp av olika ihopsättningar av olika komponenter, vilket görs för att tillfredställa kunders unika behov. Det är väldigt riskabelt och kostsamt för företagen att lagerföra alla dessa olika varianter av produkter i ett färdigvarulager eftersom det kanske inte blir någon större efterfrågan på alla dessa olika varianter. Det är därför många företag väljer att montera mot kundorder. I detta examensarbete sammanställs vad litteraturen tar upp om montering mot kundorder och utifrån detta presenteras de riktlinjer företag kan använda sig av när de vill montera mot kundorder. Utifrån litteraturstudierna, som har används som en referensmodell, har en undersökning gjorts på företaget Forbo Forshaga för att se hur de ligger till utifrån modellen. I nuläget tillverkar företaget mot lager men funderar på att börja montera mot kundorder i stället vilket de verkar ligga bra till för att kunna göra inom den närmsta framtiden.

Bildgruppen på enheten för dokument och informationsteknik hos SKL har ett behov av att kunna förbättra bilder med extremt låg upplösning. Detta bildmaterial kan komma från diverse övervakningskameror där det intressanta objektet endast utgör en väldigt liten del, i detta fall registreringsskyltar på förbipasserande bilar. Att skapa en högupplöst bild av en registreringsskylt utav ett fåtal lågupplösta bilder är ett välkänt problem med ett flertal förslag på metoder och lösningar. I denna rapport kommer vi att undersöka vilka metoder som passar bäst vid bildförbättring av registreringsskyltar. Vi kommer även att skapa ett användargränssnitt där man kan läsa in en bild och välja mellan att automatiskt hitta registreringsskylten i bilden eller att manuellt klippa ut den. Efter att man erhållit en bild innehållandes endast registreringsskylten ska de olika implementerade bildförbättringsmetoderna kunna användas. Slutligen diskuteras vilka för- och nackdelar de respektive metoderna har. Förslag på eventuella förbättringar och hur man kan utveckla dessa metoder vidare presenteras därtill.

It is well known that a translating mask can optically encode low-resolution measurements from which higher resolution images can be computationally reconstructed. We experimentally demonstrate that this principle can be used to achieve substantial increase in image resolution compared to the size of the focal plane array (FPA). Specifically, we describe a scalable architecture with a translating mask (also referred to as a coded aperture) that achieves eightfold resolution improvement (or 64: 1 increase in the number of pixels compared to the number of focal plane detector elements). The imaging architecture is described in terms of general design parameters (such as field of view and angular resolution, dimensions of the mask, and the detector and FPA sizes), and some of the underlying design trades are discussed. Experiments conducted with different mask patterns and reconstruction algorithms illustrate how these parameters affect the resolution of the reconstructed image. Initial experimental results also demonstrate that the architecture can directly support task-specific information sensing for detection and tracking, and that moving objects can be reconstructed separately from the stationary background using motion priors. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)

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Sport plays a significant role in societies worldwide and this has lead to an increase in the interest in sports fans’ behaviour. South Africans regard rugby as an important role player in their country, national culture - and also as a symbol of hope. This study aimed to enhance the knowledge of fans’ loyalty; and it also addressed the issue of a distinguished scale that can measure fans’ loyalty in the South African rugby context. Furthermore, this study aimed to increase the understanding regarding the determinants of rugby fans’ loyalty in South Africa. This replication study (a repeat of a previous study) investigated the application and relevance of Funk’s (2001:2) Sport Interest Inventory (SII) scale in the South African Super 14 rugby context. The Sport Interest Inventory (SII) scale measures twelve determinants of fan loyalty, namely: bonding with family, bonding with friends, drama, entertainment value, escape, excitement, player interest, role model, socialisation, team interest, vicarious achievement and sports interest. Identifying the determinants of fan loyalty can result in guidelines that can be used by sports marketers to improve their marketing campaigns. This will assist them in identifying related sports products that are essential to rugby fans. This will result in a more profitable sports’ team. The first step in this study was to synthesise a conceptual framework of the relationships between fan loyalty and the identified determinants of fan loyalty from the relevant literature. This was followed by a survey conducted at the Loftus Versveld Stadium, where Super 14 rugby fans of local Super 14 rugby teams were asked to participate in the study. The resulting data were analysed by using multiple regression analysis. The results of the multiple regression analysis identified sport interest, family bonding, escape and team interest as significant determinants of fan loyalty. The first implication for managers is to focus on sport interest as a significant determinant of fan loyalty. Sport interest indicates an interest in rugby as a sport in general. Therefore, management is advised to focus on developing programmes focused on increasing the knowledge and interest of fans in the Super 14 rugby tournament. Secondly, managers should start identifying and creating methods of focusing the attention of their marketing mix on the escape, family bonding and team interest determinants which may increase the attendance levels of Super 14 rugby games. / Dissertation (MCom)--University of Pretoria, 2011. / Marketing Management / MCom / Unrestricted

The ~ 73 ka ‘super-eruption’ of the Toba caldera in Sumatra is the largest known eruption of the Quaternary. The products of this eruption, the Youngest Toba Tuff (YTT), have been implicated in global and regional climate deterioration with widespread ecological effects. In this thesis I study the YTT co-ignimbrite ashfall, in particular the mechanisms of transport, sedimentation and preservation of ash deposits. I use distal marine and terrestrial ash sediments: a) to estimate the volume of YTT ash fallout; b) to quantify variability in the geochemistry of YTT ash; c) to assess the reliability of YTT ash as a chronostratigraphic marker; and d) to determine local influences on the reworking of YTT ash deposits. Following the introductory chapters, I address topics a) and b) through detailed investigations of published physical and chemical evidence. Chapter three shows that particle size and sediment thickness do not decline exponentially with distance from the eruption vent, highlighting the limitations of current methods of volume estimation for co-ignimbrite super-eruptions. Chapter four analyses geochemical variation in 72 YTT samples, and reveals the signatures of magma chamber zonation and post-depositional alteration. I address topics c) and d) through fieldwork in six locations, and detailed analysis of ash samples from a wide variety of local depositional environments. Chapter five uses high-resolution stratigraphic analysis of the YTT layer in the Son Valley, India, to show that variable deposition and sediment reworking may compromise the reliability of the ash layer as an isochronous marker for interpreting archaeological sequences. Chapter six combines a new understanding of the mechanisms of reworking, using new data on microscopic characteristics of reworked ash at four sites in Malaysia to demonstrate the necessity of accounting for reworking in palaeoenvironmental reconstructions. I conclude that accurate analyses of distal ash deposits can reliably determine the chemical properties of the YTT eruption, and that a detailed understanding of deposition and reworking processes is essential to inference of the environmental impacts of super-eruptions.

The objective of this research is to develop suitable models to simulate and analyse Electrical Vehicle (EV) power-trains to identify and improve some of the deficiencies of EVs and investigate new system architectures. Although some electro-chemical batteries improvements have lately been achieved in specific-energy, the power density is still low. Therefore, an efficient, cost-effective and high power density support unit could facilitate EV competitiveness compared to conventional internal combustion engine powered vehicles in the near future. The Na-Ni-Cl2, or ZEBRA battery as it is most commonly known, has good energy and power densities; it is very promising electro-chemical battery candidate for EV's. The thesis presents a detail simulation model for the ZEBRA technology and investigates its application in an EV power-train with regard to state-of-charge and voltage transients. Unlike other battery systems, the ZEBRA technology can sustain about 5-10% of failed cells. While this is advantageous in single series string or single battery operation it is problematic when higher numbers of batteries are connected in parallel. The simulation model is used to investigate faulted operation of parallel battery configurations. A non-linear capacitance versus voltage function is implemented for the supercapacitor model which yields good energy and terminal voltage predictions when the supercapacitor is cycled over dynamic regimes common to EV applications. A thermal model is also included. Multiple energy source systems are modelled and studied in the form of an energy dense ZEBRA battery connected in parallel with a power dense supercapacitor system. The combination is shown to increase available power, reduce the maximum power demanded from the battery and decrease battery internal power loss. Consequently, battery life would be increased and more energy would be recovered from regenerative braking, enhancing the energy conversion efficiency of the power-train.A combination of ICE and ZEBRA battery is implemented as a range extender for London taxi driving from Manchester to London. The hybridisation ratio of the system is discussed and applied to fulfil the requirement with minimum emissions. This study offers a suitable model for different energy sources, and then optimises the vehicle energy storage combination to realize its full potential. The developed model is used to assess different energy source combinations in order to achieve an energy efficient combination that provides an improved vehicle performance, and, importantly, to understand the energy source interconnection issues in terms of energy flow and circuit transients.