National Repository of Grey Literature 32 records found  beginprevious23 - 32  jump to record: Search took 0.00 seconds. 
New directions for waterproofing of underground transport
Čech, Tomáš ; Vaněrek, Jan (referee) ; Šťastník, Stanislav (advisor)
This diploma thesis focuses on the implementation of waterproofing of underground constructions using an LLDPE membrane hinged on anchors. In the future, this method will replace the commonly used waterproofing system in Scandinavia with extruded polyethylene foam. This method of tunnel construction and waterproofing is compared with the NRTM method, often used in Central Europe. The thesis describes the installation of a waterproofing system, especially materials, accessories, welding devices and auxiliary installation equipment. The main focus of the thesis is to verify the reliability of the individual types of welds and to assess the waterproofing system in terms of implementation and environmental demands.
Functionalization of Polyethylene by Grafting
Hofmann, Jan ; Figalla, Silvestr (referee) ; Petrůj, Jaroslav (advisor)
The bachelor thesis deals with functionalization of polyethylene by grafting. The theoretical part summarizes informations about types of copolymers, free radical grafting techniques and the factors, that affect properties of modified polymers as well as their biodegradability. The experimental part deals with modification of polyethylene in kneader under various conditions. The blends are composed of polyethylene, polylactic acid and another aditives (initiator, stabilizers). The torque and the temperature were monitored during the kneading. Some mechanical properties of new materials were tested on Zwick Z010 apparatus. Rheological properties of samples were investigated with melt flow indexes.
Nano-structured multicomponent plasma polymers for controlled immobilization of biomolecules
Melnichuk, Iurii ; Shukurov, Andrey (advisor) ; Čech, Vladimír (referee) ; Pavlík, Jaroslav (referee)
Title: Nano-structured multicomponent plasma polymers for controlled immobilization of biomolecules Author: Iurii Melnichuk Department / Institute: Department of Macromolecular Physics/Charles University Supervisor of the doctoral thesis: Doc. Ing. Andrey Shukurov, Ph.D. Abstract: The aim of this thesis is to highlight the feasibility of tailored nano- structures in functionalizing surfaces for biointerfacial interactions. Development of new techniques for the production of nanoscaled biomaterials can be of use in a variety of medical and biological applications, e.g. biosensors, microarrays, drug sensors, implants, blood-contacting devices. This thesis first examines the early stages of nano-structured thin film growth fabricated by vapor phase deposition of poly(ethylene). We discuss island growth within a framework of rate equation theory, dynamic scaling theory and capture zone distribution. In a second stage, we test dielectric barrier discharge to activate PE nano-pattern for covalent immobilization of proteins. Finally, we assess cell behavior on surfaces in dependence on morphology and the presence of cell adhesive protein tropoelastin. We employ plasma polymerization to produce ultrathin hydrocarbon layer capable of protein anchoring. The thesis findings for the first time manifest the critical...
Properties of polyethylene blown-films dependent on their composition
Štaffová, Martina ; Poláček, Petr (referee) ; Tocháček, Jiří (advisor)
This work deals with the influence of quantity of recycled material on physical properties of blown-film. The task of this work is to prepare set of laboratory made films with amount of LLDPE granulate from 0 to 100 % with addition of LDPE recycled material and furthermore with addition of filler, calcite. The following methods were used for characterization of blown films: tensile test, differential scanning calorimetry, Fourier transform infrared spectroscopy, confocal laser scanning microscopy. The same measurements were performed also on industrial made blown-film.
Design and Development of Experimental Device for Testing the TEP Acetabula and Wear Identification using Optical Method
Houfek, Martin ; Kratochvíl, Ctirad (referee) ; Hortel, Milan (referee) ; Hlaváčková, Milada (referee) ; Florian, Zdeněk (advisor)
Today is the implantation of joint replacements, although a radical, but very functional restoration frequent way ill joint. The implants are placed high demands on their biocompatible and long-term function, which is directly related to wear of joint replacements in the human body. Therefore, analysis of the complex behavior of the implant in the human body is a fundamental problem of biomechanics of implants. This issue is dedicated, this dissertation thesis. Dissertation thesis deals with the solution design and development of experimental device for testing the TEP acetabula and wear identification using optical method. The proposed device allows the joint burden hole TEP physiological manner, but by working with the acetabulum burdened by Power resultant joint axis passes through the hole. The physiological loading of articular wells and evaluating the size of the loss of polyethylene is currently intensively addressed. The results of this study may in the near future, serving as information for assessing the conduct of wear prosthetic hip joint in vivo. The work is devoted to solving the problem of the size required to detect the loss of polyethylene for joint replacement arthroplasty: Design and development of experimental equipment for testing the acetabulum of the hip joint arthroplasty. Identify wear using optical methods. Design and development of experimental equipment was made in the system Inventor Professional 2010 at the level of 3D modeling. Great attention was paid to the design fit into the acetabulum TEP testing machines and gripping the acetabulum into an optical device. Management options were tested with combinations of experimental equipment engines. Suggestions were made and then tests for fixing the acetabulum into an optical device. Has the possibility of depth analysis and identification of wear joined with innovative solutions to evaluate the loss of polyethylene acetabulum arthroplasty. Identification of abrasion (loss of polyethylene) joint arthroplasty holes were carried out experimental measurements using an optical holographic interferometry. The comprehensive analysis of the results of experimental measurement of the loss of polyethylene shows that this method can identify both the size but also an area where there is even to small changes in the surface, which depend on the abrasion. One can also say that using this method we are able to affect the will or displacements that affect the size of the loss of polyethylene in joint arthroplasty hole. Despite the number of known and lessons learned arising from the results of solving the problem of design and development of experimental equipment for testing the acetabulum and hip arthroplasty wear identification using optical methods, this work is that the initial study to identify problematics wear of joint replacements. Complete resolution of this issue is beyond the scope of one doctoral thesis.
Optimization of production of thin films of metallic materials
Čejka, Marek ; Kadlec, Michal (referee) ; Šubarda, Jiří (advisor)
The present thesis deals with optimization of the formation of thin layers of metallic materials. In the theoretical part was elaborated overview of the implementation of the formation of thin- film structures, particularly using vacuum techniques. Chemical and physical vapor deposition. They were described methods of pretreatment of thin layers. The findings were discussed methods of controlling the pre-treated surface, quality control and mutual adhesion of coating layers. In the experimental part of the pre-treatment methods were selected and applied to selected substrates. Pretreatments were evaluated using a control surface by wetting angles and by atomic force microscopy. Then, the metal structure formed of copper on the pretreated substrates. Implementation by means of magnetron sputtering. Adhesion layers was checked by testing the surface lattice method. The quality was observed by scanning electron microscopy. The results were used to design the technological process of making metal layers.
Reactions of HDPE in the melt initiated by peroxides
Hampapa, Břetislav ; Kučera, František (referee) ; Petrůj, Jaroslav (advisor)
The thesis deals with HDPE modification by crosslinking. In the theoretical part, data available in the literature were reviewed. Modifications of the selected HDPE copolymer grade were carried out in a kneading device Brabender using 25 ml chamber size. After having optimized process conditions, there were performed a series of experiments in dependence on concentration of the initiator. Reological properties of polymer samples were investigated by melt flow indexes measured under different conditions. Changes in crystallinity and melting temperatures were evaluated from DSC heat flow measurements. The samples meeting characteristics supposed were selected for measuring complex viscosity on the Rheometer AR-G2 TA and for testing some mechanical properties on the device Zwick.
Polymeric biocompatible materials
Matlák, Jiří ; Stránský, Lubomír (referee) ; Molliková, Eva (advisor)
The aim of the bachelor’s thesis is polymeric biocompatible materials. In the first part the problematic of the biocompatible materials is discussed and the basic terms are explained. In the next part are described polymeric materials and their chemical composition, mechanical and chemical properties and examples of applications.
Voda a životní prostředí
Inkoteka, Praha ; Nesvadba, Jindřich
Publikace se skládá ze dvou samostatných částí. První tvoří abecední slovník pojmů a jevů týkajících se vody ve vztahu k životnímu prostředí. Druhou tvoří studie o posuzování vlivu na životního prostředí v oblasti odpadového hospodářství. V této části jsou popsány typy posuzovaní vlivu na životní prostředí a ekobilancování jako diagnostická metoda. Jsou definovány indikátory pro sestavení programového EIA pro odpadové hospodářství. Studie rozebírá metody posuzování vlivu pro řízené skládky TKO, pro spalování odpadu a pro znovu. Závěrečná kapitola rozebírá posuzování různých systémových variant v oblasti odpadového hospodářství.
Plasma modification of powder materials
ČERNÝ, Pavel
Thesis is focused on plasma modification of materials. The work has the character of a search of available literature, especially the papers presented in impacted journals. The aim is to provide a broader overview of the subject. The first section describes the most commonly modified powdered materials. The second part is focused on the plasma modification, the reasons for its use, capabilities and benefits respectively and disadvantages of these processes. The following sections are devoted to plasma discharges, plasma reactors, aspects of plasma modification and companies engaged in production, or modification of powders. Each chapter is intended to provide an overview of the modified powder materials, processes within the plasma discharges, construction and use of plasma reactors, plasma modification of aspects and the market situation in the context of powdered materials and companies dealing with the plasma modification.

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