Automatic selection of the arterial input function for DCE-MRI method

Tato práce je zaměřena na automatickou detekci arteriálních pixelů při metodě DCE-MRI. První část práce se zabývá literární rešerší dané problematiky. V druhé části jsou představeny 4 algoritmy pro detekci arteriálních pixelů.This thesis is aim to automatic detection of arterial pixels with use a method DCE-MRI. The first part of the essay occupy with literary search of theory. The second part of the essay introduce the four algorithms for detection of arterial pixels.

Effect of pigment concentration on mechanical properties of polycarbonate

This experimental study deals with the influence of pigments on the mechanical properties of polymeric polycarbonate material Lexan 923c, which is commonly used in industry and is being processed with injection technology. This material was stained with three different pigments from Lifokolor. It was also stained with 6 different concentrations of selected pigments. Emphasis was placed on measuring the tensile strength, impact strength and hardness of polyurethane mixtures. © The Authors, published by EDP Sciences, 2017.ERDF, European Regional Development Fun

Effect of pigment concentration on mechanical properties and on color stability of polycarbonate

This experimental study deals with the influence of pigments on the mechanical properties of polymeric polycarbonate material Lexan 923c, which is commonly used in industry and is being processed with injection technology. This material was stained with three different pigments from Lifokolor. It was also stained with 6 different concentrations of selected pigments. Emphasis was placed on measuring the tensile strength, impact strength and hardness of polymer mixtures. It also deals with the influence of pigment concentration on colorimetric properties and the concentration of pigment value at which the material needs to be colored. Colorimetric properties and reflective spectra of different concentrations were also measured. © 2017, World Scientific and Engineering Academy and Society. All rights reserved.IGA/FT/2017/010, MŠMT, Ministerstvo Školství, Mládeže a Tělovýchovy; MSMT-7778/2014, ERDF, European Regional Development Fun

The Influence of runner system on production of injection molds

This experimental study describes the influence of runner system on rheological properties during the injection molding process. Economic effects on the amount of production are discussed as well. Autodesk Moldflow Synergy 2016 (Moldflow) was used for the study of the injection process. Three suggestions of the runner system, cold runner system, hot runner system and the combination of cold hot runner system have been promoted. These three variants underwent the rheological and economic analysis. As a result, recommendations for the application of the runner system for the required amount of production have been suggested.Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089]; TBU in Zlin [IGA/FT/2016/010

Implementation of natural fillers in polyethylene and the resulting mechanical properties

In recent years, materials with natural fillers have begun to be used for manufacturing window frames and various linings. These compounds can replace natural materials such as wood and stone. The main reasons to use these fillers are price (which is lower than that of a polymer) and rigidity. The resulting product is strong, hard, light, possesses a long-term resistance to wind abrasion and takes on the appearance of wood and stone. The type of filler has a significant effect on the final properties of the material. In the past, however, insufficient attention was paid to the effect of natural fillers on the injection-molded product's mechanical properties. First, the test samples were measured by depth sensing indentation (DSI), which is a contemporary instrumented hardness test used to determine the micro-mechanical properties. A Micro Combi Tester made by the Anton Paar company was used for these tests. Then, the measurements were evaluated by the Oliver and Pharr method. The goal of this study was to prepare a low-density polyethylene (LDPE) filled with varying natural fillers, e.g., finely ground wood, coarsely ground wood and slate) and its subsequent granulation. The implementation of these fillers led to an increase of the mechanical properties, e.g., indentation hardness and modulus, by up to 100 % in comparison with the virgin material. The goal of this study was to evaluate the effect of natural fillers, such as wood and slate, on the mechanical properties of the tested materials.European Regional Development Fund under the project CEBIA-Tech Instrumentation [CZ.1.05/2.1.00/19.0376]; Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Program [LO1303 (MSMT-7778/2014)]; Internal Grant Agency of TBU in Zlin [IGA/FT/2020/003

Influence of electron beam irradiated on the surface properties of polyamide measured by micro-indentation test

Cross-linking is a process in which polymer chains are associated through chemical bonds. Radiation, which penetrated through specimens and reacted with the cross-linking agent, gradually formed cross-linking (3D net), first in the surface layer and then in the total volume, which resulted in considerable changes in specimen behaviour. This paper studies the effect of different doses of ionizing beta radiation on the micro-mechanical properties of commercially available polyamide. The measured results indicate, that electron beam irradiation is very effective tool for improvement of surface properties of PA6. The micro-mechanical properties after irradiated surface treatment was increased up to 24 % compared to non-irradiated surface. © The Authors, published by EDP Sciences, 2017

The Effect of Injection Molding on Physical Properties of EPDM Rubber

The paper a part of research aimed at the alternative of preparing test samples by injection molding. Such an alternative could bring more objective results in the field of testing samples produced in the same technology. The research is aimed at changing the preparation of rubber testing samples-replacing the standard method according to ISO 23529 by the injection method, especially with the use of rubber compounds for injection molding. This article compares and evaluates the selected physical properties (tensile strength and tear strength) of EPDM rubber injection molded samples with samples prepared by the standard method-cutting out of a compression molded plate. The results have shown that using the injection molded samples we will achieve more objective results mainly to determine the tear strength. In the case of tensile strength, the differences are not so significant. © 2018 The Authors, published by EDP Sciences.European Regional Development Fund under the project CEBIA-Tech Instrumentation [CZ.1.05/2.1.00/19.0376]; Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Program [L01303 (MSMT-7778/2014)]; Internal Grant Agency of TBU in Zlin [IGA/FT/2018/012

Influence of Mixing Recycled Polycarbonate to Charpy Impact Properties at Increased Temperature

This article deals with influence of amount of mixing recycled material with virgin polycarbonate to impact properties. The aim is to perform an experiment in which the products of the studied polymer will be grinded to recycled material and then reprocessed into new specimens. These are then subjected to Charpy impact properties at increased temperatures. Several mixtures differing in the content of recycled material in virgin polycarbonate were prepared. One mixture was from pure recycled polycarbonate. The most used technology made testing samples for production of plastic products, which is injection moulding. Testing was conducted at increased temperatures 60 °C. This temperature was choose because many products are used at this temperatures. The impact of added recycled material to virgin polypropylene not significant for all impact properties. © 2018 The Authors, published by EDP Sciences.European Regional Development Fund under the project CEBIA:fech Instrumentation [CZ.1.0512.1.00/19.0376]; Ministr\, of Education, Youth and Sports of the Czech Republic within the National Sustainability Program [1,01303 (MSMT-7778/2014)]; Internal Grant Agency of TBIJ in Zlin [IGA/FT/2018/012

Polymer fluidity influenced by type and amount of filler

Delivery of polymer melts into the mold cavity is the most important stage of the injection molding process. This paper shows the influence of cavity surface roughness and technological parameters on the flow length of polymers into mold cavity. Application of the measurement results may have significant influence on the production of shaping parts of the injection molds especially in changing the so far used processes and substituting them by less costly production processes which might increase the competitiveness of the tool producers and shorten the time between product plan and its implementation. This research focused into the influence of technological parameters on filling of the injection mold cavity and the flow length respectively.Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089]; TBU in Zlin [IGA/FT/2016/010

Influence of length of glass fibers in recycled polypropylene on tensile properties

The purpose of this article is to show the influence of grinded glass fibers in polymer material. Tested samples were processed by injection molding. Waste from this production was subsequently ground and a mixture was obtained with different size of crushed material. These particles contains glass fibers of similar length as the specific size of particle. Thus very small particles contain very short fibers. Investigation was carried out by testing tensile properties on material polypropylene with 30% glass fibers. Testing was conducted at ambient temperatures. The effect of reprocessing of material is mainly represented by fiber shortening. As a result, considerable reduction of tensile properties can be observed. The reduction is most evident in the modules of elasticity and ultimate tensile strength.TBU in Zlin [IGA/FT/2016/010]; Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089