For years, researchers have studied the movement of cells and mathematicians have attempted to model the movement of the cell using various methods. This work is an extension of the work done by Zheltukhin and Lui (2011), Mathematical Biosciences 229:30-40, who simulated the stress and displacement of a one-dimensional cell using a model based on viscoelastic theory. The report is divided into three main parts. The first part considers viscoelastic models with a first-order constitutive equation and uses the standard linear model as an example. The second part extends the results of the first to models with second-order constitutive equations. In this part, the two examples studied are Burger model and a Kelvin-Voigt element connected with a dashpot in series. In the third part, the effects of substrate with variable stiffness are explored. Here, the effective adhesion coefficient is changed from a constant to a spatially-dependent function. Numerical results are generated using two different functions for the adhesion coefficient. Results of this thesis show that stress on the cell varies greatly across each part of the cell depending on the constitute equation we use, while the position and velocity of the cell remain essentially unchanged from a large-scale point of view.

Friction modifiers are a new effective way to control adhesion in wheel and rail contact. The aim of this diploma thesis is experimental study of the influence of the constituents of water based friction modifier on adhesion. Measurement of the adhesion behavior for different friction modifier compositions is carried out on a ball–on–disc laboratory device creating point contact. The introductory part of the experiments describes the effect of individual components on adhesion. Subsequently, combinations of different friction modifier compositions are tested. In conclusion, selected compositions are used for wear tests. The results obtained show that the performance of friction modifiers is greatly influenced by evaporation of base medium.

Presented master’s thesis describes the design and the implementation of an experimental device used for the study of tribological aspects of wheel-rail contact. In this work, the reader will first learn the fundamentals such as adhesion, slip, traction curve, etc. Subsequently, the work is describing devices that are used for the study of wheel-rail contact around the world. This section is followed by the author proposed solution. The result is a twin disc device in the scale of 1:3. The device allows determining traction characteristics for different environmental conditions (presence of water, sand and oil in contact for different temperatures) and various operating parameters (contact pressure and speed). A part of this work are also the validation experiments and complete design documentation.

The adhesion in the wheel-rail contact can be effectively controlled by using the friction modifier. Adhesion control can reduce excessive wear of the contact bodies or noise. The essence of this diploma thesis is to determine the optimal amount of friction modifier in wheel-rail contact depending on the climatic and operating conditions. For experimental study of the behavior of the friction modifier, the twin-disc device is used. Twin-disc simulates and controls the most important operating parameters such as speed, slip, attack angle or contact pressure. On the basis of these findings, the off-board top-of-rail lubricator system was designed. This system controls the amount of friction modifier according to current climatic and operating conditions.

The thesis deals on the theory of partial wetting of a wall, whereby a relation between the velocity of a droplet moving along an inclined plane and time is derived. There are explained basic definitions coherent to the theory of partial wetting. According to divergence of a normal vector of the droplet surface, there is developed a technique for mathematical evaluation of the component of dynamic adhesive force. Within the scope of diploma paper, there was an experimental measurement performed, whereat a velocities of droplets of various volumes and at different inclination angles on four analyzed surfaces were determined. By using non-linear regression, unknown parameters such as the adhesion coefficient, the component of a dynamic adhesive force, initial and terminal velocity of a droplet were evaluated from the experiment results. Within the thesis there was performed a simulation of droplet motion on an inclined plane in ANSYS Fluent. Conclusion includes an assessment and a comparison of results obtained, and new procedures that may be helpful at further research of descending droplet.

This diploma thesis focuses on effects of active vehicle safety on the prevention of traffic accidents. In the introductory section, the term of active safety is defined and divided into four categories. In next four chapters, the particular elements of active safety are described in more detail and some selected elements are described in depth. Chapter seven includes a questionnaire; it enquires opinions of people about some of the elements of active safety. Practical road tests were conducted as part of this work. Theirs description and evaluation are in the last chapters.

n this work is processed a summary of selected driving parameters of vehicles, methods of measuring and use in the automotive industry or related branch especially. This work is focused on driving tests of vehicles and measurement driving parameters of vehicles. As part of this work was done measurements parameters of vehicles driving in various driving regimes and subsequent analyse of obtained data. The result of this work is determination methodology division driving regimes and evaluation the impact of driving regimes on to ride a car in a directional curve.