With the increased application of large eddy simulations and hybrid Reynolds-averaged Navier-Stokes techniques, the generation of realistic turbulence at inflow boundaries is crucial for the accuracy of numerical results. In this dissertation research, two novel turbulence inflow generation methods are derived and validated. The first method, the Triple Hill's Vortex Synthetic Eddy Method, is a new type of synthetic eddy method, where the fundamental eddy is constructed through a superposition of three orthogonal Hill's vortices. The amplitudes of the three vortices that form the fundamental eddy are calculated from known Reynolds stress profiles through a transformation from the physical reference frame to the principal-axis reference frame. In this way, divergenceree anisotropic turbulent velocity fields are obtained that can reproduce a given Reynolds stress tensor. The model was tested on isotropic turbulence decay, turbulent channel flow, and a spatially developing turbulent mixing layer. The Triple Hill's Vortex Synthetic Eddy Method exhibited a quicker recovery of the desired turbulent flow conditions when compared with other current synthetic turbulence methods. The second method is the Control Forced Concurrent Precursor Method which combines an existing concurrent precursor method and a mean flow forcing method with a new extension of the controlled forcing method. Turbulent inflow boundary conditions are imposed through a region of body forces added as source terms to the momentum equations of the main simulation which transfer flow variables from the precursor simulation. Controlled forcing planes imposed in the precursor simulation, allow for specific Reynolds stress tensors and mean velocities to be imposed. A unique feature of the approach is that the proposed fluctuating flow controlled forcing method can be applied to multiple fluctuating velocity components and couple their calculation to amplify the existing fluctuations present in the precursor flow field so that prescribed anisotropic Reynolds stress tensors can be reproduced. The new method was tested on high and low Reynolds number turbulent boundary layer flows, where the proposed fluctuating flow controlled forcing method greatly accelerated the development of the turbulent boundary layers when compared with cases without controlled forcing and with only the original controlled forcing.

Inläckage av grundvatten är ofrånkomligt i en bergtunnel, men måste vanligen begränsas för att inte medföra skador på både omgivning och den egna anläggningen. Denna begränsning uppnås genom tätning av tunneln och kontrolleras med mätningar av inläckaget. Vilka begränsningsvärden för inläckaget som är möjliga att uppnå, baseras på prediktioner av inläckaget och fastslås i tillståndet som ges för denna vattenverksamhet. Syftet med det här arbetet är att få förståelse för orsakerna till avvikelser mellan det faktiska inläckage som mätningarna visar (utfallet) och det predikterade inläckaget. För att göra detta kommer en fallstudie att genomföras på anläggningen av två ramptunnlar, Solhems- och Kälvestatunneln, i infrastrukturprojektet E4 Förbifart Stockholm. Baserat på fallstudien skapas en ny konceptuell modell av de två ramptunnlarna som inkluderar information om jord-, berg- och grundvattenförhållanden som framkommit till och med i byggskedet. Utifrån denna konceptuella modell görs nya prediktioner av inläckaget med en analytisk formel. Detta jämförs med den konceptuella modell i systemhandlingsskedet från vilken de ursprungliga prediktionerna gjordes. De nya beräkningarna predikterar genomgående ett högre inläckage än de ursprungliga och avviker mindre från utfallet på flertalet delsträckor. Orsakerna till avvikelserna utvärderas, framförallt med avseende på ansatt hydraulisk konduktivitet då detta visat sig ha stor effekt på prediktionerna. Utvärderingen visade att den hydrauliska konduktiviteten i berget generellt var för lågt ansatt, något som hade kunnat förutsägas med annorlunda datainsamling i ett tidigare skede. Mer specifikt orsakade en svaghetszon, som borttagits i tidigare skeden men som observerats i byggskedet, stora avvikelser mellan prediktion och utfall på åtminstone en delsträcka i Solhemstunneln. Om informationen om svaghetszoner tolkats annorlunda i ett tidigare skede hade även detta kunnat förutsägas. / Groundwater inflow to a rock tunnel is inevitable, but nonetheless important to limit. Otherwise both the surroundings and the tunnel itself risk becoming subject to damage. To prevent this, legal limitations are set for the inflow. Measurements are then made to ensure that the inflow does not exceed these limitations. When constructing a tunnel in hard rock, the limit objectives are hopefully met through the filling of rock fractures through grouting. Inflow predictions are made at an early stage of a tunnel project, both in order to establish the legal requirements but also as basis for grouting design. The aim of the work reported is to understand why these predictions in some cases deviate from the measured inflow. To accomplish this, a case study on two road tunnels in one of Sweden's most comprehensive infrastructure projects of all time, the construction of a motorway bypass around the capital Stockholm, is presented and assessed. Several causes of deviations between inflow predictions and observations in these two tunnels are suggested, most of them related to the hydraulic conductivity of the rock. Overall the rock quality seems to be worse than predicted. In one tunnel segment in particular, one cause of major deviations from inflow predictions is due to a fracture zone which has not been accounted for. These identified causes of increased inflow could have been foreseen in an early stage of the project, either through more extensive investigations or different interpretations of existing data. New inflow predictions have been made based on the suggested corrections. The result is consistently higher than the predictions made earlier and mostly less deviant from observations. This indicates that the real inflow is probably higher than initially predicted.

Devido às dificuldades encontradas na Medicina Veterinária com relação à circulação extracorpórea, despertou-se o interesse pela técnica de parada circulatória total (\"Inflow Occlusion\") para correção cirúrgica de algumas patologias cardíacas, principalmente estenose de valvas semi-lunares. O objetivo deste trabalho consistiu em comparar as possíveis alterações hemodinâmicas que podem ocorrer em cães submetidos à parada circulatória total através da técnica do \"Inflow Occlusion\" por diferentes períodos de tempo. Utilizou-se neste estudo, doze cães, subdivididos em dois grupos, sendo submetidos à parada circulatória total, por sete ou oito minutos. Realizou-se análise hemodinâmica durante quatro momentos do período transoperatório. Os parâmetros de oxigenação foram obtidos por meio da conjunção dos dados fornecidos pelo cateter de artéria pulmonar e pela análise hemogasométrica. Diferença estatisticamente significativa foi encontrada na comparação entre os grupos avaliados, cinco minutos após a restituição da circulação (momento M3), para a pressão arterial média (PAM) e para o índice de trabalho sistólico do ventrículo direito (ITSVD) e do ventrículo esquerdo (ITSVE). Ocorreram dois óbitos transoperatórios no grupo de animais submetidos à oito minutos de parada circulatória total, devido a fibrilação ventricular. Frente aos óbitos ocorridos, conclui-se que o \"Inflow Occlusion\" foi exequível em cães sadios por sete minutos, sendo contra-indicado para períodos de oito minutos. Entretanto, estudos clínicos envolvendo a técnica em questão, precisam ser realizados para que a referida técnica possa ser aplicada, seguramente, em animais portadores de disfunções cardiovasculares. / Because of difficulties related to extracorporeal circulation in Veterinary Medicine, more interest occurred about circulatory arrest trough \"Inflow Occlusion\" technique to correct surgically some cardiac pathologies, such as semilunar valves stenosis. The aim of this study was to compare possible hemodynamic alterations that can occur in dogs submitted to circulatory arrest using \"Inflow Occlusion\" technique for different periods of time. Twelve mongrel dogs were used in this study divided in two groups, each one submitted to seven or eight minutes of total circulatory arrest. Hemodynamic evaluation was realized during four moments on transoperatory period. Oxygenation parameters were obtained trough pulmonary artery catheter data and hemogasometric analysis. Statistical difference between groups were found on M3 moment, five minutes after circulatory arrest, for mean arterial pressure (MAP), right ventricular systolic stroke index (RVSSI) and left ventricular systolic stroke index (LVSSI). There were two transoperatory deaths on group B, because ventricular fibrillation. Because these deaths, we can say that \"Inflow Occlusion\" can be realized up to seven minutes on healthy dogs and is contra-indicated for periods of eight minutes. However, clinical studies should be performed in order to use this technique routinely with safe in dogs presenting cardiovascular abnormalities.

Devido às dificuldades encontradas na Medicina Veterinária com relação à circulação extracorpórea, despertou-se o interesse pela técnica de parada circulatória total (\"Inflow Occlusion\") para correção cirúrgica de algumas patologias cardíacas, principalmente estenose de valvas semi-lunares. O objetivo deste trabalho consistiu em comparar as possíveis alterações hemodinâmicas que podem ocorrer em cães submetidos à parada circulatória total através da técnica do \"Inflow Occlusion\" por diferentes períodos de tempo. Utilizou-se neste estudo, doze cães, subdivididos em dois grupos, sendo submetidos à parada circulatória total, por sete ou oito minutos. Realizou-se análise hemodinâmica durante quatro momentos do período transoperatório. Os parâmetros de oxigenação foram obtidos por meio da conjunção dos dados fornecidos pelo cateter de artéria pulmonar e pela análise hemogasométrica. Diferença estatisticamente significativa foi encontrada na comparação entre os grupos avaliados, cinco minutos após a restituição da circulação (momento M3), para a pressão arterial média (PAM) e para o índice de trabalho sistólico do ventrículo direito (ITSVD) e do ventrículo esquerdo (ITSVE). Ocorreram dois óbitos transoperatórios no grupo de animais submetidos à oito minutos de parada circulatória total, devido a fibrilação ventricular. Frente aos óbitos ocorridos, conclui-se que o \"Inflow Occlusion\" foi exequível em cães sadios por sete minutos, sendo contra-indicado para períodos de oito minutos. Entretanto, estudos clínicos envolvendo a técnica em questão, precisam ser realizados para que a referida técnica possa ser aplicada, seguramente, em animais portadores de disfunções cardiovasculares. / Because of difficulties related to extracorporeal circulation in Veterinary Medicine, more interest occurred about circulatory arrest trough \"Inflow Occlusion\" technique to correct surgically some cardiac pathologies, such as semilunar valves stenosis. The aim of this study was to compare possible hemodynamic alterations that can occur in dogs submitted to circulatory arrest using \"Inflow Occlusion\" technique for different periods of time. Twelve mongrel dogs were used in this study divided in two groups, each one submitted to seven or eight minutes of total circulatory arrest. Hemodynamic evaluation was realized during four moments on transoperatory period. Oxygenation parameters were obtained trough pulmonary artery catheter data and hemogasometric analysis. Statistical difference between groups were found on M3 moment, five minutes after circulatory arrest, for mean arterial pressure (MAP), right ventricular systolic stroke index (RVSSI) and left ventricular systolic stroke index (LVSSI). There were two transoperatory deaths on group B, because ventricular fibrillation. Because these deaths, we can say that \"Inflow Occlusion\" can be realized up to seven minutes on healthy dogs and is contra-indicated for periods of eight minutes. However, clinical studies should be performed in order to use this technique routinely with safe in dogs presenting cardiovascular abnormalities.

South Africa has become more dependent on portfolio inflow to finance investment and consumption due to the low rate of government and household savings. Therefore, it is important from South Africa‟s perspective to maintain a stable portfolio inflow in order to ensure that the current account deficit does not reach unsustainable levels. However, portfolio inflow is anything but stable in South Africa. The risk associated with this is that when foreigners‟ expectations of South Africa shift, due to any form of instability or risk within the country or even internationally, it leads to massive withdrawals or outflow of funds, which in turn causes the currency to depreciate. The portfolio balance theory on the other hand states that an increase in portfolio inflow leads to the appreciation of the nominal exchange rate, and that this is perceived to work against economic growth. The main objective of this research is to determine the nature of the relationship between exchange rate volatility and portfolio flows, and the extent to which volatility in the exchange rate affect South Africa‟s portfolio inflow. The research uses Vector Autoregressive (VAR) models and quarterly data, ranging from 1995 to 2012 to investigate this relationship. From the VAR models a Granger causality test, as well impulse response functions is used to shed light on the influence of a one-unit shock in both foreign portfolio inflow and exchange rate volatility on the other variables in the model. Exchange rate volatility is measured using both Autoregressive Conditional Heteroscedasticity (ARCH) family models and the conventional standard deviation, in order to control for possible biasness caused by the choice of instrument of volatility. The results showed the nature of the relationship between exchange rate volatility and foreign portfolio inflow to South Africa‟s capital markets can be described as country-dependent and time-varying. South Africa‟s portfolio inflow exhibits high volatility and low persistence that are characteristics normally associated with “hot money”, which is largely driven by foreign investors‟ appetite for short-term speculative gains. The study identified the consistent presence of bidirectional causality between the exchange rate volatility and foreign portfolio inflow to South Africa, irrespective of the measurement of exchange rate volatility. The results also revealed that net portfolio flows are associated with exchange rate appreciation and that foreign portfolio inflow react much stronger to changes in exchange rate volatility than vice versa. / MCom (Risk Management), North-West University, Potchefstroom Campus, 2015

South Africa has become more dependent on portfolio inflow to finance investment and consumption due to the low rate of government and household savings. Therefore, it is important from South Africa‟s perspective to maintain a stable portfolio inflow in order to ensure that the current account deficit does not reach unsustainable levels. However, portfolio inflow is anything but stable in South Africa. The risk associated with this is that when foreigners‟ expectations of South Africa shift, due to any form of instability or risk within the country or even internationally, it leads to massive withdrawals or outflow of funds, which in turn causes the currency to depreciate. The portfolio balance theory on the other hand states that an increase in portfolio inflow leads to the appreciation of the nominal exchange rate, and that this is perceived to work against economic growth. The main objective of this research is to determine the nature of the relationship between exchange rate volatility and portfolio flows, and the extent to which volatility in the exchange rate affect South Africa‟s portfolio inflow. The research uses Vector Autoregressive (VAR) models and quarterly data, ranging from 1995 to 2012 to investigate this relationship. From the VAR models a Granger causality test, as well impulse response functions is used to shed light on the influence of a one-unit shock in both foreign portfolio inflow and exchange rate volatility on the other variables in the model. Exchange rate volatility is measured using both Autoregressive Conditional Heteroscedasticity (ARCH) family models and the conventional standard deviation, in order to control for possible biasness caused by the choice of instrument of volatility. The results showed the nature of the relationship between exchange rate volatility and foreign portfolio inflow to South Africa‟s capital markets can be described as country-dependent and time-varying. South Africa‟s portfolio inflow exhibits high volatility and low persistence that are characteristics normally associated with “hot money”, which is largely driven by foreign investors‟ appetite for short-term speculative gains. The study identified the consistent presence of bidirectional causality between the exchange rate volatility and foreign portfolio inflow to South Africa, irrespective of the measurement of exchange rate volatility. The results also revealed that net portfolio flows are associated with exchange rate appreciation and that foreign portfolio inflow react much stronger to changes in exchange rate volatility than vice versa. / MCom (Risk Management), North-West University, Potchefstroom Campus, 2015

One of the most visible signs of the globalization of the world economy is the increase of Foreign Direct Investment (FDI) inflows across countries. This past decade the trend of FDI has shifted from developed countries to emerging economies, which is most notably in the BRICS countries. However, as BRICS reputation has been damaged these past years due to its weak growth outlook in the early 2010s, investors are shifting to the new economic grouping acronym, the MINT (Mexico, Indonesia, Nigeria and Turkey) countries for better future prospects of FDI destination. Since the MINT countries have emerged as a popular destination of FDI, it is necessary to investigate what are the key factors that make these four countries attractive as FDI destinations. Hence, this paper analyzes what are the determinants of inward FDI into the MINT countries during the time period from 1990 to 2014. To be able to answer the research question and demonstrate the effect of the seven independent variables (market size, economic instability, natural resources availability, infrastructure facilities, trade openness, institutional stability and political stability) on FDI as a dependent variable, the study uses a panel data analysis. The data is based on secondary data, which is collected from the World Bank dataset. The empirical finding from the study illustrates that market size, economic instability, infrastructure facilities, trade openness, institutional stability, and political stability are significant as determinants FDI inflows to the MINT countries, meanwhile, natural resources availability appears to be an insignificant determinant of FDI inflows to the MINT countries.

Este trabalho tem como objetivo analisar a estrutura do desemprego dos jovens no Brasil, procurando identificar os motivos da taxa de desemprego dos jovens ser muito superior à dos adultos. Apesar de sua importância, este tema tem recebido pouca atenção na literatura sobre o mercado de trabalho brasileiro. Na primeira análise deste estudo, decompõe-se a taxa de desemprego em dois determinantes, duração média e taxa de entrada no desemprego de jovens, adultos e idosos; percebe-se que a duração do desemprego é praticamente a mesma para as três categorias, enquanto a taxa de entrada dos jovens é maior que a das outras duas, sendo, portanto, o determinante que faz com que o desemprego juvenil seja mais elevado que o de trabalhadores mais velhos; assim, com uma nova decomposição da taxa de entrada de jovens, verifica-se que cerca de 80% dessa taxa é composta de jovens que já trabalharam. Outro método será o cálculo, para jovens e adultos, das matrizes de transição entre os estados do mercado de trabalho. Para avaliar a questão do desemprego dos jovens no Brasil, recalcula-se as taxas de desemprego de cada categoria, substituindo uma de cada vez nas matrizes, as probabilidades de transição da outra categoria; os resultados mostram a alta rotatividade dos jovens no mercado de trabalho. Com esses resultados, conclui-se que a causa do alto desemprego dos jovens não está na dificuldade em conseguir o primeiro emprego. / This work has the purpose to analyze the youth unemployment structure in Brazil, trying to identify the reasons for the youth unemployment rate being so superior relative to the unemployment of adults. Despite its importance, this subject has received less attention in the Brazilian labor market literature. In the first analysis of this work, the unemployment rate will be decomposed into two determinants, mean duration and inflow rate for young, adult and old people; it is noticed that the unemployment duration is practically the same for the three categories, but the youth inflow rate is relatively higher than the other two ones, being so, the determinant that makes youth unemployment be higher than unemployment of older workers; and, with a new decomposition of youth inflow rate, it is verified that about 80% of this rate is composed of young people that have already worked. Another method will be the calculus, for young and adult people, of the transition matrices between labor market states. To evaluate where is the problem of Brazilian youth unemployment, it is recalculated these rates for each one of the categories, substituting one at a time in the matrices, the transition probabilities of the other category; results show the high turnover of the category in labor market. With these results, it is concluded that the reason of the high youth unemployment is not the difficulty of finding the first job.

Rainfall derived inflow and infiltration (RDII) is a cause of sanitary sewer overflows and sewers exceeding capacity before the end of their design lives, but it is not well understood. Several methods exist to model RDII in existing sanitary sewers. These models are not applicable for design, which is frequently accomplished by applying constant unit rates. Two analytical probabilistic models are developed to estimate the contribution of RDII to peak flow and volume. The analytical models have been tested against computer simulations using long-term rainfall records and parameters calibrated using actual field data. One model relies on calibrated parameters from the RTK method; a commonly used method requiring a time-consuming calibration process. The second model relies on the R-value parameter of the RTK method, and a time of concentration parameter. By providing better information to designers, these analytical models aim to improve engineering decision-making in the design of sewer systems.

Rainfall derived inflow and infiltration (RDII) is a cause of sanitary sewer overflows and sewers exceeding capacity before the end of their design lives, but it is not well understood. Several methods exist to model RDII in existing sanitary sewers. These models are not applicable for design, which is frequently accomplished by applying constant unit rates. Two analytical probabilistic models are developed to estimate the contribution of RDII to peak flow and volume. The analytical models have been tested against computer simulations using long-term rainfall records and parameters calibrated using actual field data. One model relies on calibrated parameters from the RTK method; a commonly used method requiring a time-consuming calibration process. The second model relies on the R-value parameter of the RTK method, and a time of concentration parameter. By providing better information to designers, these analytical models aim to improve engineering decision-making in the design of sewer systems.