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Methods for reduction of parachute systems opening shock
Zamazal, Jakub ; Daniel, Miloš (referee) ; Pejchar, Jan (advisor)
This bachelor‘s thesis deals with opening shock of the parachute rescue systems and summarizes the methods of its reduction. The beginning of thesis is about theoretical introduction into general problems of parachutes. Another part contains problems about opening shock including specifications for rescue systems. There is also mentioned some suitable measuring methods. Next is summary of using methods for reduction of opening shock. The end of thesis contains proposal suitable methods for reduction shock for aircraft with take-off weight of 450kg.
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Overview of launchers for manned flights
Šurkala, Martin ; Daniel, Miloš (referee) ; Daněk, Vladimír (advisor)
This Bachelor’s dissertation describes the development of rocket technology from its beginnings to space flight. The first section describes the basic principles of reactive propulsion and gives a brief description of the development of the first rockets. The following chapter describes the formation of modern astronautics as presented by leading scientists who were active in rocket technology during the early 20th century. The next part is focused on the German rocket program, which builds on the space programs of the USA and USSR (Russia). The last section describes rockets used by Europe, China and the private company SpaceX. This dissertation no only includes carriers used in the past but also carriers which are currently preparing for their first trip.
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Analysis of the labor market in the construction sector
Daniel, Martin ; Biolek, Vojtěch (referee) ; Hanák, Tomáš (advisor)
This bachelor thesis analyzes the labor market in construction. The theoretical part deals with the construction company, the labor market and work in construction. It describes the remuneration and specifics of the construction company, characterizes the labor market, state employment policy and the causes and effects of the situation on the labor market in construction and also deals with foreign workers. The practical part acquires a real overview of the situation in practice through a questionnaire survey, which is refined by interviews with specific companies. In general, the practical part deals with how construction companies evaluate the situation on the labor market and how this situation affects them.
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Friction and lubrication of articular cartilage
Hilšer, Pavel ; Daniel, Matej (referee) ; Vrbka, Martin (advisor)
The main goal of this diploma thesis is to determine the role of hyaluron acid and phospholipids on friction and lubrication of articular cartilage in regard to optimization of viscosupplements. This is carried out by measuring the coefficient of friction of the articular cartilage with several lubricants. Cartilage is lubricated particularly by a conventional viscosuplement, optimized viscosuplementation with phospholipids and model synovial fluid. In order to observe the function of those viscosuplements in the human body, both are mixed with the model synovial fluid, ubiquitous in human joints, in given ratio. Experiments revealed high friction when it comes to convectional viscosupplementation as opposed to low friction of the optimized viscosuplement with phospholipids. The same situation occurs when cartilage is lubricated with those viscosuplements mixed with model synovial fluid which might lead to development of a new, better, viscosupplementation based on hyaluron acid and phospholipids.
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Business Plan
Štěrba, Radek ; Daniel, Martin (referee) ; Němcová, Zuzana (advisor)
My master´s thesis will deal with the business plan for a new brewery. For it to be the ideal strategy to entail the enforcement of the consumer market. The thesis will focus primarily on how to achieve a successful and economically beneficial brewery. In particular the choice of an appropriate strategy is the cornerstone of predetermining the future success or failure of the project on the market. In my thesis will also report on the current state of problems brewing on the Czech market and abroad. The practical part will focus on the technical possibilities of building a brewery and the calculation will be made investments in technology and equipment brewery. There will also be calculated in the calculation of profits and expenses which affect the rate of return on investment in the brewery. Furthermore, I will support sales tools which will allow the successful startup company. It will also be designed optimal variant of websites including their calculations. It also made sociometric survey to obtain relevant information for designing optimal strategy for future production brewery.
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Analysis of Influence of Collagen Organization on Mechanical Properties of Arteries
Novák, Kamil ; Daniel, Matej (referee) ; Vimmr, Jan (referee) ; Burša, Jiří (advisor)
This dissertation thesis concerns with Analysis of Influence of Collagen Organization on Mechanical Properties of Arteries and it is divided into three main parts. Motivation for this dissertation thesis was in a study reviewing effect of material model upon resulting stresses in AAA. The effect was calculated in 70 patient-specific geometries of AAA, which exceeds the number of geometries in other scientific papers by one order. Within this study, two material models were used, i.e. real one and 100× stiffer, and obtained stresses were mutually compared. It was quantified that peak stress difference can be higher than 20 % in 10% of patients and therefore the real material model should be preferred over the artificial one although operation with this model is more demanding. The second part of this thesis deals with an identification of structural parameters (orientation and dispersion of collagen fibres) of porcine aortic tissue by using adjusted Fast Fourier Transform based algorithm. The extracted structural parameters were inserted into two-layer structure-motivated constitutive model Martufi-Gasser. This model was validated and its predictive capabilities were also tested with fine results. The most important information obtained from the digital image processing of ~9000 micrographs is existence of only one family of dispersed collagen fibres which breaks the current dogma present in many scientific papers about two families of collagen fibres. The third part concerns with a proposal of an automated phase-correlation based algorithm for obtaining collagen fibre direction from polarized light microscopy images. The proposed algorithm was verified and validated and it yields histograms of collagen fibre directions with overall number of measured points larger than it would be possible to get from any manual measurement. The limitation of the original proposed algorithm is in 90° period of polarized light intensity, thus the method results in angles in the range of 0°–90. Therefore the end of the thesis is dedicated resolving this problem and obtaining real angles in a span of 0°–180°. To this end, the microscope set-up was changed and the algorithm was adjusted accordingly. The original and the adjusted algorithms are collagen-specific, fast and an operator independent. Despite all the author´s effort put into collagen fibre waviness quantification directly from the histograms, the waviness has not been quantified yet in this way and it remains at the stage of research.
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The effect of synovial fluid composition on friction of joint cartilage
Furmann, Denis ; Daniel, Matej (referee) ; Nečas, David (advisor)
This thesis deals with the study of the effect of the constituents of the model synovial fluid on the frictional properties of articular cartilage. The influence of constituents, concentration, speed and load is observed. Experiments were performed on a commercial tribometer at configuration pin-on-plate. Several types of lubricants containing synovial fluid constituents have been selected for the experiments. Lubricants were prepared at two concentrations, the concentration of healthy individuals and at a concentration typical of for osteoarthritic patients. Speeds 5 and 10 mm/s and 5 and 10 N loads were used for all experiments. It is shown that when using only lubricant containing proteins, no difference in the coefficient of friction is observed and the effect of concentration is also not observed. The addition of hyaluronic acid has a synergistic effect with -globulin, however in the case of lubricants containing albumin, the effect is opposite. After the addition of phospholipids, no significant effect on friction is observed in -globulin containing lubricants. No significant effect of the composition and concentration of the lubricants is observed with the load change.
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Friction and lubrication of fascia
Chmelík, Jiří ; Daniel, Matej (referee) ; Vrbka, Martin (advisor)
The diploma thesis was part of the project "Regeneration and lubrication of fascia with hyaluronan" of the company Contipro a.s., whose main goal is the development of an injectable medicinal product. The number of patients suffering from so-called myofascial lower back pain is increasing. The cause of the pain is increased hyaluronic acid, which is produced between the layers of the fascia. If the viscosity is low, the fascia layers are not affected and the coefficient of friction is low. The purpose of the product is to improve the sliding movement of the fascia and relieve patients of pain. The main component of the medicine is hyaluronic acid. The project included rheological and tribological analysis of hyaluronic acid samples. A tribological model of fascia in a pin-on-plate configuration was created for the analysis of the coefficient of friction. Based on the fascia models used, the dependence between the coefficient of friction and viscosity of native hyaluronic acid solutions was found. For models and real fascias, the native solution (Bonharen) was found to have better friction properties than hyaluronic acid derivatives. These analyzes have contributed not only to the development of the drug, but also to the emergence of other studies that would like to address the biotribology of fascia.
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Effects of the crisis caused by Covid-19 on the operation of construction company
Daniel, Martin ; Biolek, Vojtěch (referee) ; Hanák, Tomáš (advisor)
The diploma thesis evaluates the impact of the crisis caused by covid-19 on construction companies, especially through a questionnaire survey and interviews with representatives of construction companies. The theoretical part of the work, which precedes the questionnaire survey and interviews, describes the construction company and also explains topics such as anti-epidemic restrictions, compensation programs or the state of emergency caused by the covid crisis.
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Biotribology of artificial tears for the treatment of dry eye syndrome
Černohlávek, Mikuláš ; Daniel, Matej (referee) ; Vrbka, Martin (advisor)
This master thesis is a part of the project TAČR TREND, which aim is the development of new ingredient for treatment of dry eye syndrome. Developed ingredient is derivative of hyaluronic acid, which is in this thesis compared with native hyaluronic acids and commercial eye drops. Aim of this thesis is to describe rheological and tribological properties of measured samples in terms of viscosity, mucoadhesivity and coefficient of friction. Coefficient of friction was measured on created tribological model of the eye in pin-on-plate configuration which represents physiologically relevant sliding speeds of blinking. Comparison with native hyaluronic acids and commercial products of eye drops showed, that derivative reaches higher values of viscosity, has mucoahesive properties and has low values of coefficient of friction. Those key parameters show that modification of hyaluronic acid is promising way for drug development for dry eye disease.
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