ABSTRACT Ago, E.K. EU Common Commercial Policy’s Perception by Ghana- Based Businesses. Diploma thesis; Brno: Mendel University, Brno , 2019 This diploma thesis covers extensive investigations into the existing EU-Ghana bilateral trade, and provides recommendations instructive for top managerial decision making regarding how best trade ties between the two organizations will be tightened and ensure effective trade relations. The thesis provides deep insights information that is vital for Ghanaian companies on the EU common commercial policies and the 2016 stepping stone Economic Partnership Agreement. Analyses were based on qualitative and quantitative approaches on general perception by Ghanaian companies about the European Union Economic Partnership Agreement and commercial policy. The questionnaire data has shown that most companies in Ghana are willing to transact business with the EU within a favourable framework of trade. Keywords: CCP, Economic Partnership Agreement, EU, Ghana - Based Companies, Stepping Stone

In this master thesis an implementation of an Organic Rankine Cycle (ORC) on a stepping furnace in a steel mill is modeled and proposed. The study is a case study at the company Štore&STEEL d.o.o. with intentions of realization. In a steel mill a stepping furnace is used to preheat the steel billets for later forging. The stepping furnace is gas fired and already has recuperation of the inlet air implemented. Still there is high temperature of the stack after recuperation, which makes application of an ORC worth of researching and modeling.First the flue gas over one year of furnace operation is analyzed in terms of temperature and volumetric flow. Mass flow and heat capacity are calculated. A layout of an ORC is proposed and modeled in IPSEpro for different temperatures of the flue gas resulting in different output powers and efficiencies. For each temperature an economic viability calculation with the method of reference cost of electric energy is done.The results are presented and the best design and conditions are proposed. The results of the thesis proved that further detailed measurements and calculation are worthwhile , as the flue gas from the stepping furnace has satisfactory conditions to make an application of an Organic Rankine cycle viable. Also the least ammount of state support to fulfill the companies conditions on return of investment is calculated and presented. Finally there are additional measurements and calculations suggested.

In this paper the rocking response of slender/rigid structures stepping on a viscoelastic foundation is revisited. The study examines in depth the motion of the system with a non-linear analysis that complements the linear analysis presented in the past by other investigators. The non-linear formulation combines the fully non-linear equations of motion together with the impulse-momentum equations during impacts. The study shows that the response of the rocking block depends on the size, shape and slenderness of the block, the stiffness and damping of the foundation and the energy loss during impact. The effect of the stiffness and damping of the foundation system along with the influence of the coefficient of restitution during impact is presented in rocking spectra in which the peak values of the response are compared with those of the rigid block rocking on a monolithic base. Various trends of the response are identified. For instance, less slender and smaller blocks have a tendency to separate easier, whereas the smaller the angle of slenderness, the less sensitive the response to the flexibility, damping and coefficient of restitution of the foundation.

This study seeks to reduce the cost of numerically solving non-linear partial differential equations by reducing the number of computations without compromising accuracy. This was done by using accurate local time stepping. This algorithm uses local time stepping but compensates for the inconsistencies in the temporal dimension by interpolations and/or extrapolations. Reduction in computations are obtained by time-stepping only a particular region with small time steps. A shock tube problem and a detonation wave were the two test cases considered. The performance of the solution using this algorithm was compared with an algorithm that does not use accurate local time stepping.

Many fields in science and engineering require large-scale numerical simulations of complex systems described by differential equations. These systems are typically multi-physics (they are driven by multiple interacting physical processes) and multiscale (the dynamics takes place on vastly different spatial and temporal scales). Numerical solution of such systems is highly challenging due to the dimension of the resulting discrete problem, and to the complexity that comes from incorporating multiple interacting components with different characteristics. The main contributions of this dissertation are the creation of new families of time integration methods for multiscale and multiphysics simulations, and the development of industrial-strengh tools for sensitivity analysis. This work develops novel implicit-explicit (IMEX) general linear time integration methods for multiphysics and multiscale simulations typically involving both stiff and non-stiff components. In an IMEX approach, one uses an implicit scheme for the stiff components and an explicit scheme for the non-stiff components such that the combined method has the desired stability and accuracy properties. Practical schemes with favorable properties, such as maximized stability, high efficiency, and no order reduction, are constructed and applied in extensive numerical experiments to validate the theoretical findings and to demonstrate their advantages. Approximate matrix factorization (AMF) technique exploits the structure of the Jacobian of the implicit parts, which may lead to further efficiency improvement of IMEX schemes. We have explored the application of AMF within some high order IMEX Runge-Kutta schemes in order to achieve high efficiency. Sensitivity analysis gives quantitative information about the changes in a dynamical model outputs caused by caused by small changes in the model inputs. This information is crucial for data assimilation, model-constrained optimization, inverse problems, and uncertainty quantification. We develop a high performance software package for sensitivity analysis in the context of stiff and nonstiff ordinary differential equations. Efficiency is demonstrated by direct comparisons against existing state-of-art software on a variety of test problems. / Ph. D.

The ability to successfully negotiate stairs and steps is an important factor for functional independence. While work has been undertaken to understand the biomechanics of gait in lower-limb amputees, little is known about how amputees negotiate stairs and steps. This study aimed to determine the mechanics of landing in unilateral lower-limb amputees when stepping down to a new level. A secondary aim was to assess the effects of using a shank-mounted shock-absorbing device (Tele-Torsion Pylon) on the mechanics of landing. Methods Ten unilateral amputees (five transfemoral and five transtibial) and eight able-bodied controls performed single steps down to a new level (73 and 219 mm). Trials were repeated in amputees with the Tele-Torsion Pylon active and inactive. The mechanics of landing were evaluated by analysing peak limb longitudinal force, maximal limb shortening, lower extremity stiffness, and knee joint angular displacement during the initial contact period, and limb and ankle angle at the instant of ground-contact. Data were collected using a Vicon 3D motion analysis system and two force platforms. Findings Amputees landed on a straightened and near vertical limb. This limb position was maintained in transfemoral amputees, whereas in transtibial amputees knee flexion occurred. As a result lower extremity stiffness was significantly greater in transfemoral amputees compared to transtibial amputees and able-bodied controls (P < 0.001). The Tele-Torsion Pylon had little effect on the mechanics of landing in transtibial amputees, but brought about a reduction in lower extremity stiffness in transfemoral amputees (P < 0.05). Interpretation Amputees used a stepping strategy that ensured the direction of the ground reaction force vector was kept anterior of the knee joint centre. Using a Tele-Torsion Pylon may improve the mechanics of landing during downward stepping in transfemoral amputees.

No description available.

Call number: LD2668 .T4 1985 S565 / Master of Science

La perte d'équilibre chez l'humain est un phénomène courant de la vie quotidienne. Plusieurs causes peuvent être identifiées, dont notamment des perturbations extérieures. Le scénario qui nous intéresse particulièrement est celui des passagers debout dans les transports en commun. La combinaison de plusieurs études accidentologiques fait ressortir un risque de blessure important pour ce type de situations, surtout pour des passagers debout et/ou âgées. Ces incidents en gendrent des blessures qui coûtent très cher au niveau du budget de la santé. La sécurité de ces passagers est donc à l’origine de ce travail. La perte et/ou le rattrapage d’équilibre est une question complexe qui met en jeu un ensemble de phénomènes tels que la perception de la perturbation, le traitement de l’information, la prise de décision et la mise en œuvre d’actions correctrices. Bien que les connaissances théoriques sur chacun de ces phénomènes soient avancées, il n’existe pas, à l’heure actuelle, de modèle global permettant de représenter la réaction des personnes dans des situations aussi concrètes et complexes que celle des passagers debout de transport en commun.Dans ce contexte, l’objectif principal de ce travail était de développer un outil de simulation pour évaluer les risques associés à la perte d’équilibre des passagers de transport en commun. / Loss of balance is a common phenomenon in our society resulting in injuries and even deaths each year. Among other common sources of destabilization such as slips or trips from an obstacle, the public transportation vehicles are a major source of balance-related injuries to its passengers. Accidental data suggest that the passenger casualties in these vehicles are common, especially to the standing and the elderly passengers, mainly due to the sudden acceleration/deceleration changes of the vehicle. These injuries as well as associated discomfort may discourage people from using these means of transport resulting in adverse economic and societal effects. In this context, the security of the standing passengers in these vehicles constitutes the main motivation of this work.Recovering balance from an external disturbance is a complex process which involves a set of phenomenon such as the perception of the disturbance, information processing, decision making and its implementation. Even though experimental research in the fields of biomechanics and neurosciences provide us with a fair understanding of these phenomena separately, we are unaware of a global model which represents the reaction of people in response to the external disturbances to their equilibrium. In this context, the objective of this work is to develop such a numerical tool which can be used for the assessment of risks associated with the loss of balance of the standing passengers. The essential feature of this tool is the prediction of the post-disturbance kinematics of the subjects depending upon the disturbance characteristics (magnitude, duration etc.) as well as the active recovery response. Another key feature is the representation of the reaction of different populations, especially the elderly, by integrating age effects in the model. For the development of the tool, mathematical modeling (e.g. simplified body representations) and control ideas are borrowed from the field of biped robotics which explicitly deals with the balance issues of bipeds. Further development is done in view of human balance recovery (BR) characteristics. The resulting BR tool shows reasonable predictive capacity of a human balance recovery response confirmed by the comparison of model predictions with experimental balance recovery data.

A simulação de escoamentos com superfícies livres vem ganhando importância ao longo dos últimos anos devido às várias aplicações práticas em que esse tipo de escoamento está envolvido. Dentre os métodos numéricos existentes para a simulação de escoamentos, temos o GENSMAC, que é uma técnica numérica para simular escoamentos newtonianos com superfícies livres. A implementação de métodos semi-implícitos para a discretização temporal das equações de Navier-Stokes permitiu uma relaxação significativa na restrição no passo temporal, reduzindo consideravelmente o custo computacional na simulação de escoamentos com Re 1. Mas, mesmo no caso dos métodos semi-implícitos, o passo temporal não pode aumentar além de certos limites, bem aquém daquele da restrição CFL, sem provocar sérios problemas de precisão nos resultados numéricos e consequente aparecimento de resultados não físicos. Portanto, mesmo na formulação semi-implícita, uma restrição no passo temporal é aplicada. Neste trabalho, analisamos e implementamos no sistema FREEFLOW2D uma estratégia de adaptação do passo temporal de maneira a garantir a estabilidade e a precisão utilizando o maior passo temporal possível. A eficiência e robustez da técnica incorporada à formulação implícita do GENSMAC são demonstradas na solução de problemas bidimensionais complexos com superfícies livres e baixo número de Reynolds, incluindo os problemas do inchamento do extrudado e jet flow / The simulation of free surfaces flows has gained importance in the recent years due to the many practical applications of this type of flow. Among the many numerical methods available for the simulation of fluid flows, there is GENSMAC, which is a numerical technique to simulate Newtonian flows with free surfaces. The implementation of semi-implicitmethods for the temporal discretization of the Navier-Stokes equations allowed a significant loosening in the time step restriction, reducing considerably the computational cost of the simulation of flows with Re 1. But, even with the semi-implicit methods, the time step cannot increase beyond certain limits, well below the CFL restriction, without causing serious accuracy problems in the numerical results and the consequent appearance of non-physical results. Therefore, even in the semi-implicit formulation, a time step restriction is applied. In this work, we analyse and implement in the FREEFLOW2D system a strategy for adaptive time-stepping in order to ensure stability and precision while using the largest possible time step. The efficiency and robustness of the technique incorporated to the implicit formulation of GENSMAC are demonstrated in the solution of two-dimensional complex problems with free surfaces and low Reynolds numbers, including the swelling of the extrudate and jet flow problems