Tese de Mestrado Integrado. Engenharia Civil. Faculdade de Engenharia. Universidade do Porto. 2011

In this research, a set of integrated I/O interconnection and packaging technologies are investigated. MEMS-based sea-of-leads (SoL) compliant interconnects are demonstrated to be promising to eliminate the need for underfill between a Si chip and organic packaging substrate. Wafer-level packaging with the compliant interconnects can largely reduce the impact on the fragile low-k interlevel dielectric (ILD) films. The technology feasibility of the SoL MEMS I/O interconnects is demonstrated by process integration, assembly, and reliability assessment. To achieve the high power dissipation with compact form factor, integrated thermal-fluidic I/O interconnects and CMOS compatible microchannels are developed to enable a prototype on-chip microfluidic heat sink. In addition, highly integrated electrical and optical interconnects based on dual-mode polymer pillars are fabricated, assembled and tested as a potential solution to the I/O bandwidth bottleneck. The resulting integrated I/O interconnection and packaging technologies are compatible with back-end-of-the-line (BEOL) wafer processing and conventional flip-chip assembly.

Tese de mestrado integrado. Engenharia Civil ( Especialização em Geotecnia). Faculdade de Engenharia. Universidade do Porto. 2009

Diploma Thesis focuses on adult wild boar females and analysis of their reproductive potential based on data obtained on drives during main reproduction period (August to January) at 30 areas of interest throughout the Czech Republic in years 2014–2017. Average value detection of Gonadosomatic Index (GSI) out of gravid female wild boars 0,0097 and out of all samples 0,0071. Rut period based on the age of fetuses is from October to January and expected dates of birth are determined by shifting the length of pregnancy towards the rut period with a peak in March. The litter size has just low correlation with the weight and very low with the age, average litter size in adult wild boar females is 6,1 youngsters for hoggets and 6,3 youngsters for wild sows. Average embryonic mortality reaches 13 %. The total sex ratio of piglets is 1:1,08 (M:F), the sex ratio of piglets for hoggets is 1:1,13 and for wild sows 1:1. The resulting finding of this analysis is, that there is no significant difference between the average litter size of hoggets and wild sows, so it is recommended to regulate the number of adult wild boar females year-round irrespective of age of the individuals.

It is evident from several studies that ultimate bearing capacities calculated by traditional methods are conservative and subjective. For large civil structures founded on spread footings, cost-effective and safer foundation could be achieved by adopting optimum ultimate bearing capacity values that are based on an objective and pragmatic analysis. There is a pressing need to modify the existing methods for accurate estimation of the bearing capacities of rocks for spread footings. In practice, foundation bearing capacities of rock masses are often estimated using the presumptive values from Building Officials Code Administrators, National Building Code, and methods adopted by the American Association of State Highway and Transportation Officials. However, the estimated values are often not realistic, and site-specific analyses are essential. In this study, geotechnical reports and drill-log data from successful geotechnical design projects founded on a wide range of granites in eastern Tennessee were consulted. Different published methods were used to calculate ultimate bearing capacity of rock mass. These methods included Peck, Hansen and Thornburn, Hoek and Brown, Army Corps of Engineers, Naval Facilities Engineering Command, and Terzaghi's general bearing capacity equations. Wide variation was observed in the calculated ultimate bearing capacity values, which ranged over about two orders of magnitude. Only two of the methods provided realistic results when validated with plate-load test data from similar rocks.

No description available.

Land degradation, a phenomenon referring to (drought) in arid, semi-arid and dry sub-humid regions as a result of climatic variations and anthropogenic activities most especially in the semi-arid lands of Sudan, where vast majority of the rural population depend solely on agriculture and pasture for their daily livelihood, the ecological pattern had been greatly influenced thereby leading to loss of vegetation cover coupled with climatic variability and replacement of the natural tree composition with invasive mesquite species. The principal aim of this study is to quantitatively examine the vigour of vegetation in Sudan through different vegetation indices. The assessment was done based on indicators such as soil adjusted vegetation index (SAVI). Cloud free multi-spectral remotely sensed data from LANDSAT imagery for the dry season periods of 1984 and 2009 were used in this study. Results of this study shows conversion of vegetation to other land use type. In general, an increase in area covered by vegetation was observed from the NDVI results of 2009 which is a contrast of that of 1984. The results of the vegetation indices for NDVI in 1984 (vegetated area) showed that about 21% was covered by vegetation while 49% of the area were covered with vegetation in 2009. Similar increase in vegetated area were observed from the result of SAVI. The decrease in vegetation observed in 1984 is as a result of extensive drought period which affects vegetation productivity thereby accelerating expansion of bare surfaces and sand accumulation. Although, increase in vegetated area were observed from the result of this study, this increase has a negative impact as the natural vegetation are degraded due to human induced activities which gradually led to the replacement of the natural vegetation with invasive tree species. The results of the study shows that NDVI perform better than by SAVI.

Theory predicts that in species with a greater risk of sperm competition, males will invest more in ejaculate traits. In species with alternative mating tactics (AMTs), males of different phenotypes will be under different sperm competition risk. Because minors sneak inside other males\' territories to mate they should always face sperm competition. Major males, on the other hand, defend territories and have more chance of mating exclusively with females. For majors, the risk of sperm competition is theoretically lower. The main prediction from game theory models for species with AMTs is that majors invest less in ejaculate traits than minors. However, when the proportion of minors in the population increases, majors should invest more in ejaculate traits, reaching a similar level of ejaculate expenditure to minors. In this study, we tested these predictions with a meta-regression analysis of 29 fish species with AMTs. As a proxy for the risk of sperm competition, we ranked each species according to a sperm competition rank with five levels, from 1 (low risk of sperm competition) to 5 (high risk of sperm competition). Overall, we found that minors invest more in ejaculate traits than majors. We also categorized the ejaculate expenditure of males, according to the original variables quantified in the studies that were included in our analysis and found that minors invest more energy in the production of gonads than majors. Additionally, minors and majors have a similar investment in sperm number and sperm quality, but majors allocate more sperm to females. Overall, the sperm competition rank did not influence the magnitude of the difference in investment of majors and minors. The differential investment in gonad mass between majors and minors should represent an increase in sperm numbers, but our data showed that majors and minors are not producing different amount of sperm. Therefore, the higher investment in gonad mass can be related to minors mating more frequently than majors. minors are not able to produce sperm in greater quantities than majors, but they probably can replenish sperm faster than majors. Against theoretical predictions, sperm quality does not respond to differences of sperm competition, probably because sperm quality is not under such strong selection as gonad mass. Our findings suggest that, in fishes with alternative mating tactics, both majors and minors are under strong selection from sperm competition, even when the risk of polyandry is low / A teoria prevê que em espécies sob maior risco de competição espermática, os machos irão investir mais em características do ejaculado. Em espécies com táticas alternativas de acasalamento (AMTs), machos de fenótipos diferentes estão sob diferentes riscos de competição espermática. Uma vez que machos minors (i.e., machos furtivos) se esgueiram para dentro do território de outros machos para acasalar, eles provavelmente sempre enfrentam competição espermática. Machos major, por outro lado, defendem territórios e possuem uma chance maior de acasalar exclusivamente com fêmeas. Para os majors, o risco de competição espermática é teoricamente menor. A principal previsão de modelos de teoria dos jogos para espécies com AMTs é que majors investem menos em características de ejaculado do que minors. Entretanto, quando a proporção de minors em uma população aumenta, os majors devem investir mais em características do ejaculado, alcançando um nível similar de investimento em ejaculado que os minors. Neste estudo, nós testamos essas previsões com uma meta-regressão de 29 espécies de peixes com AMTs. Como proxy para o risco de competição espermática, nós classificamos cada espécie de acordo com um ranking de competição espermática. Esse ranking utiliza características de história de vida e demografia de cada espécie, e possui cinco níveis, de 1 (baixo risco de competição espermática) até 5 (alto risco de competição espermática). De maneira geral, nós encontramos que minors investem mais em características de ejaculado do que majors. Nós também categorizamos o investimento em ejaculado dos machos de acordo com as variáveis originais quantificadas nos estudos que foram incluídos na nossa análise e encontramos o resultado de que minors investem mais na produção de gônadas para seu próprio tamanho do que majors. Além disso, minors e majors apresentam investimento similar em número de espermatozoides e qualidade espermática, mas majors alocam mais esperma para as fêmeas. Em geral, o ranking de competição espermática não influenciou a magnitude da diferença de investimento entre majors e minors. O investimento diferencial em massa gonadal entre majors e minors deveria representar um aumento no número de espermatozoides, porém nossos dados mostraram que majors e minors não estão produzindo quantidades diferentes de esperma. Assim, um investimento maior em massa gonadal pode estar relacionado aos minors acasalarem mais frequentemente que os majors. minors não conseguem produzir esperma em maiores quantidades que os majors, mas eles provavelmente conseguem repor seu estoque de esperma mais rápido que os majors. Contrário às previsões teóricas, a qualidade espermática não responde às variações de competição espermática, provavelmente porque a qualidade espermática não está sob forte seleção como a massa gonadal. Nossos resultados sugerem que, em peixes com táticas alternativas de acasalamento, tanto os majors como os minors estão sob forte seleção da competição espermática, mesmo quando o risco de poliandria é baixo

SOFIA (Studies On FIssion with Aladin - Études de fission avec ALADIN) est un projet expérimental qui se propose de mesurer systématiquement les rendements isotopiques de fission, ainsi que l'énergie cinétique totale des fragments, pour une large gamme de noyaux fissionnants. Le travail de thèse présenté ici prend part au projet SOFIA, et a pour objet l'étude de la fission de noyaux dans la région des actinides : ²³⁴U, ²³⁵U, ²³⁷Np et ²³⁸Np.L'expérience SOFIA est menée au GSI, un accélérateur d'ions lourds situé à Darmstadt en Allemagne. Cette installation fournit un faisceau relativiste et intense d'uranium-238. Par une réaction de fragmentation de ce faisceau primaire, il est créé un faisceau secondaire contenant une large variété d'ions, dont, pour certains, la fission va être étudiée. Les ions de ce faisceau secondaire sont triés et identifiés dans le séparateur de fragments FRS, un spectromètre de recul de haute résolution qui est réglé pour sélectionner les ions d'intérêt.Ensuite, les ions fissiles sélectionnés continuent leur vol jusqu'à la Cave-C, une aire expérimentale où l'expérience de fission elle-même a lieu. À l'entrée de la cave, l'ion du faisceau secondaire est excité par interaction Coulombienne alors qu'il traverse une cible; les voies de dé-excitation possibles incluent la fission de basse énergie. Lors d'une fission, les deux fragments sont émis dans un cône étroit dans le référentiel du laboratoire, dû à l'impulsion relativiste qui leur est transmise par le système fissionnant. Un spectromètre de recul complet a été développé par la collaboration SOFIA autour du dipôle existant ALADIN. L'identification des fragments est réalisée par des mesures de perte d'énergie, de temps de vol et de déviation dans l'aimant. Les deux fragments de fission sont identifiés simultanément et complètement (en masse et en charge). Ce document présente l'analyse menée pour (1) l'identification du système fissionnant, (2) l'identification des deux fragments de fission - évènements par évènements -, et (3) l'extraction des observables de fission : rendements, énergie cinétique totale, multiplicité total en neutrons prompts. Ces résultats concernant les actinides sont discutés, et l'ensemble des données extraites est fourni. / SOFIA (Studies On FIssion with Aladin) is an experimental project which aims at systematically measuring the fission fragments' isotopic yields as well as their total kinetic energy, for a wide variety of fissioning nuclei. The PhD work presented in this dissertation takes part in the SOFIA project, and covers the fission of nuclei in the region of the actinides : ²³⁴U, ²³⁵U, ²³⁷Np and ²³⁸Np.The experiment is led at the heavy-ion accelerator GSI in Darmstadt, Germany. This facility provides intense relativistic primary beam of 238U. A fragmentation reaction of the primary beam permits to create a secondary beam of radioactive ions, some of which the fission is studied. The ions of the secondary beam are sorted and identified through the FR-S (FRagment Separator), a high resolution recoil spectrometer which is tuned to select the ions of interest.The selected - fissile - ions then fly further to Cave-C, an experimental area where the fission experiment itself takes place. At the entrance of the cave, the secondary beam is excited by Coulomb interaction when flying through an target; the de-excitation process involves low-energy fission. Both fission fragments fly forward in the laboratory frame, due to the relativistic boost inferred from the fissioning nucleus.A complete recoil spectrometer has been designed and built by the SOFIA collaboration in the path of the fission fragments, around the existing ALADIN magnet. The identification of the fragments is performed by means of energy loss, time of flight and deviation in the magnet measurements. Both fission fragments are fully (in mass and charge) and simultaneously identified.This document reports on the analysis performed for (1) the identification of the fissioning system, (2) the identification of both fission fragments, on an event-by-event basis, and (3) the extraction of fission observables: yields, TKE, total prompt neutron multiplicity. These results, concerning the actinides, are discussed, and the set of data extracted is provided.

Συγκριτική θεώρηση των συστημάτων ταξινόμησης βραχομάζας rmr gsi και rmi σε υδροηλ/κες σήραγγες στη θέση Παλιούρης Ν. Ιωαννίνων / The comparison of rockmass classification systems, rmr, gsi, rmi in hydrological tunnels at Paliouris Ioanninon