Magister Commercii - MCom / A possible effect of quantitative easing (QE) undertaken by the United States of America (USA) Federal Reserve Bank (Fed) may have been an increase in capital flowing into emerging market economies (EMEs). The 2008 global financial crisis created an environment in which traditional monetary policies – cutting policy rates – became ineffective in stimulating growth. Faced with this policy environment, several high-income countries including the USA resorted to unconventional monetary policies notably QE, to grow their economies. While QE was effective in lowering interest rates in high-income countries, some argued that investors switched to higher yielding assets, mostly EME assets. Therefore, QE is perceived to have increased capital flows into EMEs. Using a dynamic panel data model with fixed effects this mini-thesis investigates empirically whether QE worked through unobservable channels to increase gross private capital inflows to Brazil, Russia, India, China and South Africa (BRICS) in the period 2000-2015. The study finds evidence in support of the view that QE increased capital inflows to EMEs. The results reveal that gross private capital inflows to the BRICS increased during the QE intervention period and that the increase was higher in the first period of QE than in subsequent QE periods. The empirical results also reveal differences in the way types of capital flows responded to QE; portfolio flows, and in particular equity flows were the most responsive to QE.

Wind energy has been the fastest emerging renewable energy source over the last decade. The overriding provisos to minimise greenhouse emissions and increasing concerns regarding energy security have been the major inducements for many countries to make a resolute transition to new and non-conventional power sources. Direct-drive systems for wind turbines are potentially a more reliable alternative to gearbox driven systems. Gearboxes are liable to significant accumulated fatigue torque loading with relatively high maintenance costs. It is with this in mind that the primary focus of this research is on direct-drive wind turbines. Generators in direct-drive wind turbines tend to be of large diameter and heavier due to the support structure required to maintain as small air-gap as possible between the stationary and rotating parts of the generator. Permanent magnet generators (PMGs) are the most common type to be used within direct-drive wind turbines nowadays. Generators and other drive-train components in wind turbines experience significant varying loads, which may lead to a bearing failure. These varying loads can lead to misalignment within the drivetrain producing eccentricity between the generator rotor and stator. Rotor eccentricity generates a magnetic force referred to as Unbalanced Magnetic Pull (UMP). The induced UMP for the same rotor eccentricity is much higher in PMGs than induction generators because of the higher permanent magnet magnetic field. UMP is an important issue requiring further research. A part of this study provides a more detailed treatment of UMP under varying rotor eccentricity regimes for various permanent magnet machine topologies. The effect of UMP in direct-drive PMGs on the lifetime of the main bearing is a topic that requires more research aimed at proposing design improvements and solutions. The hope being that the availability of such solutions can be applied to practical reductions in operating costs. In brief, identification of the root causes of failure and impacts on component lifetime remain a subject of research. Establishing analytical tools for studying the impact of UMP on component lifetime in direct drive wind turbines and identifying the prospects for air gap winding machines using single bearing configuration are the two key areas for further research. Firstly, this research aims to establish the relationship between bearing forces and different types of eccentricities and UMP in direct drive machines. It is intended to use such models for predicting bearing wear and fatigue. Secondly, this research aims to establish the analytical tools for studying static, dynamic and tilting eccentricity in air-gap winding direct drive generators. Such tools are used to increase the understanding of the dynamics of direct drive PM generators. The final step of this study is using a multi-body simulation software (SIMPACK) to initiate investigations and comparison by providing assessments of electromagnetic interaction and internal drive-train loading for four possible designs for a proposed 5MW direct-drive wind turbine in response to the loads normally seen by a wind turbine. The four designs include: (a) iron-cored PM direct-drive generator supported by two main bearings, (b) airgap winding PM direct-drive generator supported by two main bearings, (c) iron-cored PM direct-drive generator supported by a single main bearing, (d) airgap winding PM direct-drive generator supported by a single main bearing. An aero-elastic simulation code (HAWC2) is used to extract the hub loads for different wind speeds corresponding to the normal operation of the wind turbine. The dynamic eccentricity and its influence on the electromagnetic interaction and consequential effects on bearing loading for all four designs is examined to determine the most optimal support structural configuration for a direct-drive system. In summary, the main aim of this thesis is studying the effect of different types of rotor eccentricities in different types of direct drive PMGs on the main bearing arrangements. The results show that static rotor eccentricity has the maximum impact compared to the other types of eccentricities. The main result of an eccentricity is the induced UMP which applies directly as an extra force on the bearings. The influence of UMP on bearing wear is studied. This influence is found to be significant in PM machines and should be considered when designing the bearing stiffness. A 20% static rotor eccentricity in a PM machine is found to induce an UMP that roughly equals third the total weight of the machine. A single bearing design for a direct-drive wind turbine is proposed and compared with a conventional two-bearing design. The results show that the Iron-cored PM direct-drive generator supported by two main bearings design and airgap winding PM direct-drive generator supported by a single main bearing design have advantages over the other two designs in this study.

Concrete is a strong material as to its compressive strength. However, it is a material with a low tensile and shear strength, and brittleness at failure. Concrete has to be reinforced with appropriate materials. Steel fibre is one of the most common materials currently being used to develop reinforced concrete, which may replace partially or completely conventional steel reinforcement. Successful reinforcement of concrete composite is closely related to the bond characteristics between the reinforcing fibre and matrix. The effective utilisation of steel fibre reinforced concrete (SFRC) requires in-depth and detailed understanding of bonding mechanisms governing the tensile behaviour. In response to this demand, this study embraced two main areas: understanding the reinforcing mechanisms of fibres in SFRC and material's post-cracking behaviour. Comprehensive experimental and theoretical programmes have therefore been developed: the experimental work is subdivided into three parts. The first part was to investigate the effect of various physical parameters, such as fibre characteristics (i.e. geometry, inclination angle, embedded length, diameter and tensile strength) and matrix strength which controls the pull-out behaviour of steel fibres. The second part is concerned with the assessment of the bond mechanisms of straight and hooked end fibres after exposure to elevated temperatures and varying matrix strength. The third part is devoted to gain further insight on the bond mechanisms governing the post-cracking behaviour through uniaxial and bending tests. It was found that the varying hook geometry and matrix strength each had a major influence on the pull-out response of hooked end fibres. As the number of the hook's bends increased, the mechanical anchorage provided by fibre resulted in significant improvement of mechanical properties of SFRC. The reduction in bond strength at elevated temperatures is found to be strongly related to the degradation in properties of the constituent materials, i.e. the fibre and concrete. The most effective combination of matrix strength and fibre geometry was found to be as follows: 3DH (single bend) fibre with normal-medium strength matrix, 4DH (double bend) fibre with high strength matrix and 5DH (triple bend) fibre with ultra-high performance matrix. Two analytical models to predict the pull-out behaviour of hooked end fibres were developed. Both models were able to predict the pull-out response of SFRC made from a variety of fibre and matrix characteristics at ambient temperature. This work has established a comprehensive database to illustrate the bonding mechanisms of SFRC and anchorage strengthening of various hooked end fibres, and this should contribute towards an increasing interest and growing number of structural applications of SFRC in construction.

A utilização de placas bloqueadas e suas vantagens biomecânicas na redução de fraturas cominutivas de ossos longos em cães já foram descritas por diversos autores. O presente trabalho teve como objetivo avaliar diferentes configurações de placa bloqueadas submetidas a dois diferentes testes biomecânicos, um de flexão em quatro pontos para avaliar a influencia do preenchimento dos orifícios centrais na resistência a flexão da placa bloqueada com função de placa de apoio. O outro teste avaliou a força máxima ao arrancamento de dois diferentes tipos de placas, um com todos os orifícios perpendiculares e outro com os orifícios angulados alternadamente lateral e medialmente em relação ao eixo longitudinal da placa. Para cada teste formou-se dois grupos com dez corpos de prova cada. Não houve diferença estatística no resultado obtido no teste de flexão, a resistência a flexão do grupo com preenchimentos dos orifícios centrais foi maior em relação ao grupo sem preenchimento, porem sem significância. Já no teste de arrancamento o grupo de placas com orifícios angulados obteve um valor de forma máxima de arrancamento significantemente superior em relação ao grupo com orifícios perpendiculares em relação ao eixo longitudinal da placa. Concluiu-se que não há influencia na resistência da placa de apoio com o preenchimento dos orifícios centrais da placa bloqueada e que a configuração de placa com os orifícios angulados se mostrou mais resistente ao arrancamento. / The feasibility of locking plates and their biomechanical advantages in comminuted fractures are well known. The objective of this study was to evaluate different locking plate´s configurations submitted to a four point´s flexion test and pull out test. The flexion test evaluated the influence of screws in center position in bridging plate, the pull out test compared relative to pull out strength locking plates using parallel locking screws or angulated locking screws. For each biomechanical assay two groups of ten test materials were formed. The results found no statistical differences relative to flexion resistance in the groups with and without central screws. Relative to pull out test the group with angulated screws showed higher values of maximum pull out strength when compared with the perpendicular screws, the data were statistically significant. We concluded that there was no improvement in the resistance of bridging plate with the use of central screws, but the use of angulated screws showed a greater resistance to pull out when compared to parallel screws.

Introdução: Com o aumento da idade, estudos demonstram que a população experimenta um declínio de sistemas fisiológicos participantes no controle da estabilidade postural. Dentre os métodos de avaliação descritos na literatura, encontra-se o Pull Test (PT), que é amplamente utilizado em escala mundial para avaliação do equilíbrio em indivíduos com doença de Parkinson. O teste examina a resposta do corpo a um deslocamento corporal posterior, oferecendo um identificador útil da estabilidade postural do indivíduo. O padrão de ativação muscular durante a realização do PT não foi ainda estudado. Objetivo: analisar o padrão da atividade eletromiográfica durante a realização do PT, em indivíduos hígidos acima de 40 anos de idade. Métodos: Vinte e três indivíduos hígidos realizaram o estudo eletromiográfico (EMG) de superfície dos músculos tibial anterior, gastrocnêmio medial e bíceps femoral durante a realização do PT. O PT e registros eletromiográficos foram realizados sucessivamente por 10 vezes em cada indivíduo. Os indivíduos foram também avaliados pelo Montreal Cognitive Assessment (MoCA). Resultados: O registro EMG mostrou que a atividade muscular inicia pelo tibial anterior, sendo seguida sucessivamente pelo gastrocnêmio medial e bíceps femoral. A frequência do número de passos para a manutenção da estabilidade postural foi de 93,9% para 1 ou 2 passos e 6,1% para 3 passos ou mais. A latência para ativação muscular foi relacionada com o desempenho cognitivo no MoCA. Pacientes com escores no MoCA inferior a 26 apresentavam maior latência do tibial anterior (p=0,03) e do bíceps femoral (p=0,02). Além disso, a amplitude do gastrocnêmio medial relacionou-se inversamente com o índice de massa corporal (IMC) (p=0,01). Conclusão: Constatou-se que o declínio da função executiva e o sobrepeso estão relacionados com mudanças nas respostas 12 neurofisiológicas durante a realização do PT. Os mesmos podem contribuir para prejuízos da estabilidade postural nestes indivíduos. / Background: Physiologic systems that participate of the postural stability control are impaired with aging. Pull Test (PT) is an assessment method widely worldwide utilized for evaluating the balance in individuals with Parkinson’s disease. The test examines the body’s response to a posterior bodily displacement, offering a useful identifier of the individual’s postural stability. The pattern of muscle activation during the PT has not yet been studied. Objective: the objective of this study was to analyze the pattern of electromyographic activity during the PT, in healthy individuals, over 40 years of age. Methods: Twenty three healthy individuals have carried out an electromyographic (EMG) study of the tibialis anterior, gastrocnemius medialis and biceps femoris muscles during the PT. The PT and the electromyographic recordings have been taken successively for 10 times in each individual. The individuals cognition have been assessed by the Montreal Cognitive Assessment (MoCA). Results: The EMG recording has showed that the muscle activity begins by the tibialis anterior, being successively followed by the gastrocnemius medialis and by the biceps femoris. The rate of the number of steps for keeping the postural stability was 93.9% for 1 or 2 steps, and 6.1% for 3 or more steps. The latency for muscle activation was related to the cognitive performance in the MoCA. Patients with MoCA scores lower than 26 have presented a larger latency in the tibialis anterior (p=0.03), and in the biceps femoris (p=0.02). Furthermore, the amplitude of the gastrocnemius medialis has been inversely related to the body mass index (BMI) (p=0.01). Conclusion: It has been found out that the decline in the executive function and overweight related to changes in the neurophysiologic 14 response during the taking of the PT. These may contribute for the losses of postural stability in such individuals.

A utilização de placas bloqueadas e suas vantagens biomecânicas na redução de fraturas cominutivas de ossos longos em cães já foram descritas por diversos autores. O presente trabalho teve como objetivo avaliar diferentes configurações de placa bloqueadas submetidas a dois diferentes testes biomecânicos, um de flexão em quatro pontos para avaliar a influencia do preenchimento dos orifícios centrais na resistência a flexão da placa bloqueada com função de placa de apoio. O outro teste avaliou a força máxima ao arrancamento de dois diferentes tipos de placas, um com todos os orifícios perpendiculares e outro com os orifícios angulados alternadamente lateral e medialmente em relação ao eixo longitudinal da placa. Para cada teste formou-se dois grupos com dez corpos de prova cada. Não houve diferença estatística no resultado obtido no teste de flexão, a resistência a flexão do grupo com preenchimentos dos orifícios centrais foi maior em relação ao grupo sem preenchimento, porem sem significância. Já no teste de arrancamento o grupo de placas com orifícios angulados obteve um valor de forma máxima de arrancamento significantemente superior em relação ao grupo com orifícios perpendiculares em relação ao eixo longitudinal da placa. Concluiu-se que não há influencia na resistência da placa de apoio com o preenchimento dos orifícios centrais da placa bloqueada e que a configuração de placa com os orifícios angulados se mostrou mais resistente ao arrancamento. / The feasibility of locking plates and their biomechanical advantages in comminuted fractures are well known. The objective of this study was to evaluate different locking plate´s configurations submitted to a four point´s flexion test and pull out test. The flexion test evaluated the influence of screws in center position in bridging plate, the pull out test compared relative to pull out strength locking plates using parallel locking screws or angulated locking screws. For each biomechanical assay two groups of ten test materials were formed. The results found no statistical differences relative to flexion resistance in the groups with and without central screws. Relative to pull out test the group with angulated screws showed higher values of maximum pull out strength when compared with the perpendicular screws, the data were statistically significant. We concluded that there was no improvement in the resistance of bridging plate with the use of central screws, but the use of angulated screws showed a greater resistance to pull out when compared to parallel screws.

The purpose of this study was to compare the achievement scores in reading/language arts and math of fourth and fifth grade special education learning-disabled students who received academic instruction in an inclusion classroom or a pull-out classroom. Student achievement scores from the 2012-2013 Tennessee Comprehensive Assessment Program (TCAP) and the Discovery Education Assessment (DEA) improvement scores were compared with regard to service location and analyzed for significant differences between the locations: inclusion and pull-out classrooms. A quantitative study was used to find the differences in reading/language arts and math achievement scores for fourth and fifth grade special education learning-disabled students in an East Tennessee school district. Eleven research questions guided the study. The results of the analyses indicated significant differences in reading/language arts and math scores between the groups in all but 2 analyses. The inclusion students scored higher than the pull-out students. The fourth grade inclusion students scored significantly higher than the fourth grade pull-out students in TCAP reading/language arts, TCAP math, and DEA math but scored with similar results in DEA reading/language arts. The fifth grade inclusion students scored significantly higher than the fifth grade pull-out students in TCAP reading/language arts, TCAP math, and DEA reading/language arts but scored with similar results in DEA math. This study supported the idea that learning-disabled students receiving academic instruction in an inclusion classroom score significantly higher on achievement tests than the students who received their instruction in the pull-out classroom.

Abstract available through Orthapaedic & Sport Physical Therapy.

Estágio realizado na Bi-silque, e orientado pelo Eng. Abel Maia / Tese de Mestrado Integrado. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 2012

Estágio realizado na LeanKed Academy, e orientado pelo Eng. Nuno Fontes / Tese de mestrado integrado. Engenharia Industrial e Gestão. Universidade do Porto. Faculdade de Engenharia. 2010