This thesis addresses various concerns of maritime and rail transport of goods between East Asia and the Czech Republic. Its conceptual part outlines the present situation of sea freight transportation with the emphasis on the container use. Furthermore, the thesis describes the rail infrastructure between East Asia and Europe. In the how-to part, the author describes working procedures of an actual freight forwarding company carrying out an import shipment from China into the Czech Republic, utilising ocean and rail carriers. The last part of the thesis contains a summary of the main differences when employing various types of transport, and of their comparison based on the time of the shipment and on its cost.

The dissertation has focused its attention on rail freight transport in the EU where it tried to identify trends that have accompanied that transport in the last decades. The identified trends are: intermodality, interoperability, creation of railway corridors and harmonization of legal norms for transport of goods. Each trend has been judged from the perspective of the so-called "common transport policy". The complexity of the analyzed environment as well as the interest in the depiction of the situation in the Czech Republic have led to the setting of three goals and three scientific questions. The result of the author's scientific investigation is a completely original work that should contribute to better understanding of changes of structural-systemic nature that happen in the rail cargo transport in the territory of the EU. Such a work is also an evaluating mirror for the reform of the railway sector undertaken by the same institution.

This Master Thesis focuses on rail transport in Japan. It describes the evolution of Japanese railroads from the beginning until present day, when is Japan the leading country in personal rail transportation. Further, there are described major railway operators and high-speed railway network Shinkansen. Later it explains modern system Maglev, which is momentarily built in Japan. The analysis focuses on financial indicators and specific traits of Japanese railroads. In the end the author compares Shinkansen against other means of transport on two major routes of different length. He asks question how introduction of new forms of rail transportation can change the Japan.

In order to reform the monopoly structure of the railway sector in the Czech Republic the railway operation was separated from railway infrastructure. Despite the mentioned organization reform current intensity of rivalry of the competition in the passenger rail transport segment stays considerably limited and high subsidy demands are made to ensure the public rail transport operation. This thesis analyses funding of the passenger rail transport and tries to discover the causes of high subsidy demands. It also tries to quantify potential savings of the public funds that are provided to operate long-distance passenger rail transport.

Un siècle aura suffi à révolutionner les habitudes de transport des voyageurs grâce à la popularisation du rail puis de l’aviation civile. Cette révolution s’est accompagnée progressivement de nouvelles règles de protection des passagers notamment sur les aspects « sécuritaires ». L’objectif de ces travaux de recherche est de parvenir ainsi, à partir de l'étude juridique de la notion de la sûreté de l’aviation civile et de la notion de sûreté ferroviaire et des particularités inhérentes à ces deux modes de transport, à dresser une définition générale de la « sûreté des transports ». / It will have taken only one century to revolutionize the transport habits of travelers through the popularization of rail and then civil aviation. This revolution has gradually been accompanied by new passenger protection rules, particularly on "security" aspects. The goal of this research work is to draw up a general definition of "transport security" from the legal study of civil aviation security and of railway security concepts and the particularities of these two means of transport.

One of the main aspects in the development of modern diesel engines has been the direct injection systems, due to its influence in the atomization and evaporation processes. The study of all physical and chemical phenomena involved in the scarce milliseconds that the diesel injection last allows a better understanding of the injection. Therefore, it allows a better control of the combustion process (i.e. a higher energy efficiency and lower pollutant emissions). Despite its relevance, there are however many uncertainties regarding the internal flow and the air-fuel mixing process, caused by the small size of the injector ducts, the high injection pressures (i.e. high velocities in the ducts) and the transient nature of the diesel injection influenced by the needle lift. Hence, the use of numerical simulations provides invaluable data to improve the knowledge of the process. Therefore, CFD (computational fluid dynamics) simulations are each day commoner. In order to achieve the purpose of the present thesis, a comparative study of the injection process of three different diesel nozzles through a new CFD code, which simplifies the mesh creation and endows the simulation with the possibility of a dynamic mesh through the use of an AMR (adaptive mesh refinement) algorithm that refines the mesh where high gradients of the physical fields (velocity, concentration, etc.) exist, has been performed. This study has allowed to study the internal flow and diesel spray (in evaporative and non-evaporative conditions) and enlightened the relation between the nozzle geometry and the calibration parameters of the different sub-models used in the simulations (atomization, coalescence, evaporation, etc.). The computational study shows a good agreement between the experimental data and the computational results, in particular for the transient internal flow study, where the AMR algorithm has allowed a run-time mesh generation and thus the study of the needle lift without a negative influence in the mesh quality. Furthermore, the computational study of the diesel spray through an eulerian-lagrangian approach with three different nozzle geometries arose the existing relation between the spray sub-models and the nozzle geometry, so that the spray calibration was generalized for every injection system (injector). / Los sistemas de inyección directa han sido uno de los aspectos principales en el desarrollo de los motores diésel actuales, debido a su influencia en los procesos de atomización y evaporación del combustible. El estudio de todos los fenómenos físicos y químicos que ocurren durante los pocos milisegundos que dura el proceso de inyección diésel contribuye a una mejor comprensión del mismo, y por tanto, un mejor control del proceso de combustión (i.e. mejora de la eficiencia energética y reducción de las emisiones contaminantes). A pesar de su importancia, existen aún muchas incertidumbres respecto al flujo interno y al proceso de formación de la mezcla aire-combustible debido principalmente a la complejidad de su medida experimental, a causa de las pequeñas dimensiones de los orificios de los inyectores diésel, las altas presiones de inyección utilizadas (i.e. altas velocidades del combustible) y el comportamiento transitorio debido al movimiento de la aguja. Por ello, se recurre con cada vez más frecuencia al estudio computacional mediante simulaciones de CFD (computational fluid dynamics). El objetivo de la tesis es el estudio comparativo del proceso de inyección de tres geometrías de toberas de inyector diferentes mediante un novedoso código de cálculo CFD con malla adaptativa utilizado para el estudio del flujo interno y del chorro diésel, en condiciones no evaporativas y evaporativas, y arrojar luz en la relación entre la geometría de las toberas y las constantes de calibración de los diferentes sub-modelos utilizados (atomización, coalescencia, evaporación, etc.) en la simulación. La particularidad de este código CFD y el motivo por el cuál se ha elegido para la presente tesis es la generación automática de la malla mediante el algoritmo de AMR (adaptive mesh refinement) presente en el propio código, refinando el mallado en aquellas zonas donde, debido a la presencia de importantes gradientes de velocidad, concentración, etc., se requiera mayor precisión. Los resultados computacionales muestran un buen ajuste con los datos experimentales, especialmente en el caso del estudio transitorio del flujo interno, donde el algoritmo AMR ha permitido la generación dinámica de la malla y con ello el movimiento de la aguja del inyector sin afectar a la calidad de la misma. Además, el estudio computacional del chorro diésel mediante una aproximación euleriana-lagrangiana con tres geometría de toberas diferentes ha permitido generalizar la calibración de los modelos de chorros para cualquier sistema de inyección (inyector) al relacionar la variación de los parámetros de los modelos con las condiciones de inyección. / Els sistemes d'injecció directa han sigut un dels principals aspectes en el desenvolupament dels motors dièsel actuals, a causa de la seua influència en els processos d'atomització i evaporació del combustible. L'estudi de tots els fenòmens físics i químics que ocorren durant els pocs mil·lisegons que dura el procés d'injecció dièsel contribueix a un millor enteniment del mateix, i per tant, a un millor control del procés de combustió, una millora de la eficiència energètica i una reducció de les emissions contaminants. Malgrat la seua importància, hi ha encara moltes incerteses respecte al flux intern i el procés de formació de la mescla aire-combustible degut principalment a la complexitat de la mesura experimental, a causa del les menudes dimensions dels orificis dels injectors dièsel, les altes pressions d'injecció empleades (i.e. altes velocitats del combustible) y el comportament transitori degut al moviment de l'agulla. Per això, es cada volta mes freqüent d'utilització de ferramentes computacionals com les simulacions CFD (computational fluid dynamics). L'objectiu d'aquesta Tesi és l'estudi comparatiu del procés d'injecció de tres geometries de toveres d'injectors diferents mitjançant un innovador codi de càlcul CFD amb malla adaptativa utilitzat per al estudi del flux intern i de l'esprai dièsel, en condicions no evaporatives i evaporatives, i aclarir la relació entre la geometria de les toveres i les constants de calibratge dels diferents sub-models utilitzats (atomització, coalescència, evaporació, etc.) en la simulació. La particularitat d'aquest codi CFD i el motiu pel qual s'ha elegit per a la present Tesi es la generació automàtica de la malla mitjançant un algoritme AMR (\adaptive mesh refinement) present en el propi codi, el qual permet el refinat de la malla en aquelles regions que degut a la presencia d'importants gradients de velocitat, concentració, etc., es requereix major precisió. Els resultats computacionals mostren un bon ajustament amb les dades experimentals, especialment per al cas del estudi transitori del flux intern, on el algoritme AMR ha permès la generació dinàmica de la malla i en conseqüència el moviment de l'agulla del injector sense afectar negativament la qualitat d'aquesta. A més, l'estudi computacional de l'esprai mitjançant una aproximació euleriana-lagrangiana amb tres geometries de toveres diferents ha permès generalitzar el calibratge dels models d'esprai per a qualsevol sistema d'injecció (injector) al relacionar la variació dels paràmetres dels models amb les condicions d'injecció. / Jaramillo Císcar, D. (2017). Estudio experimental y computacional del proceso de inyección diésel mediante un código CFD con malla adaptativa [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/92183 / TESIS

Presented master’s thesis is focused on the experimental research of influence of climate conditions on wheel-rail adhesion, where climate conditions are meant two parameters: ambient air temperature and air humidity. These parameters always affect wheel-raid contact and their values change significantly during the year. For presented experimental research was used tribometer Mini Traction Machine (MTM) in configuration „ball on disc“. For determination of influence climate conditions was first found out the influence of air humidity on adhesion at certain temperatures, which varied between (1 to 50) °C. These experiments were performed for two types of discs, where one disc was exposed to leaf extract contamination. After that was assembled influence of both parameters (air humidity and ambient air temperature) on adhesion in the form of a 3D map, where were distinctioned states, when condensation has occured and when didn‘t. Obtained results in this thesis will be used for optimalization of rail vehicle control systems.

The paper evaluates technological, economic and construction aspects of the component production and the design of the tool serving for large-scale production of the S355MC steel rack component. Use of a progressive tool combining cutting and bending operations in four steps has been decided as the most appropriate according to literature study. Based on the need of production of two plane-symmetrical pieces at a time, the tool will produce both pieces simultaneously, which is economically advantageous. The tool is designed for use on the Arisa 630t mechanical press. Material will be winded off the roll, flattened and pushed into the tool by a precision feeder. The total cost of production of the component was set at 18.80 CZK.

Combustion-engine control is one of the most important parts of engine application and has a direct impact on its characteristics. Diploma thesis shows the preparation of a test engine and its installation to test cell. It describes measurement and data post processing necessary for common-rail diesel engine control and their application in the creation of a mathematic model in GT-SUITE.

The aim of this work is to assess the possibilities of using numerical simulation tools in the process of laser welding of the guide rail of a car seat. In the diploma thesis, a description of the components and the problem, which consists in the deformation of the groove of the guide rail, was made. A description was made of the manufacturing operations that the components go through. The positives of selected welding methods were evaluated and the choice of those used in production was justified. A description of the issues of laser welding, deformation and the use of simulation tools was made. The influence of individual production operations was evaluated in terms of the size and nature of deformations. Using the Visual – Mesh, Visual – Weld and Visual – Assembly simulation tools, which are products of the French company ESI Group, the same state of the simulated and real process was achieved. Subsequently, a proposal for the elimination of deformations and its verification using a simulation tool could be approached. The use of a spacer wedge, which acts on the most deformed places of the groove, was proposed. By its application, the resulting deformations were eliminated or significantly reduced. In the last part of the work, a technical and economic evaluation was made, taking into account the current global crisis and the important role of the automotive industry.