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Comparison of optical methods for characterization of glass mosaic weathering
Kocour, Vladimír ; Petráňová, Veronika ; Valach, Jaroslav
The work presented in this paper is a part of research project supported by Ministry of Culture and devoted to conservation of precious mosaic of 'Last Judgement' on St. Vitus Cathedral in Prague. The aim of the project is to enhance external protective polymeric coating on glass tesserae of mosaic and also to develop optical method for assessment of coating’s surface conditions. The paper concentrates on comparison of various methods for surface evaluation assesses their advantages and disadvantages and also discusses their suitability for long term monitoring of coating state, namely reflectometry, scanning probe microscopy, nanoindentation, white-light interferometry, and scanning electron microscopy. It is found that white-light interferometry and reflectometry methods are the most suitable ones for monitoring purposes.
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Mechanics of laser cut stent grafts
Major, Štěpán ; Kocour, Vladimír ; Hubálovský, Š.
This article is dedicated to a finite element analysis of tubular, laser cut stent grafts with peak-to peak bridge geometry under representative cyclic loading conditions for abdominal aortic aneurysm repair. Cardiovascular diseases are the principal cause of death in the developed world. For computational analysis, ANSYS software was employed to study the mechanical behavior of stents. Contrary to conventional engineering materials, nitinol stent fracture is not stress based but strain based. The effects of crimpling and cyclic pressure loading on stent–graft fatigue life were simulated and analyzed.
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Fatigue testing and calculation of a conical pedicle screws for spine fusion
Major, Štěpán ; Kocour, Vladimír ; Hubálovský, Š.
The main goal of spinal surgery is to stop the pain caused by joints that have worn out over time or degenerated due to disease. Spinal fusion joins together the vertebrae on either side of a joint in spine. Fixation with pedicle screws is one method which is used by surgeons for fusing the vertebrae in spine. Implants are subjected to many loading cycles during their life. Any damage to the implant leads to significant complications in the treatment and causes considerable pain. For this reason, it is necessary to pay close attention to testing and fatigue prediction of implants.
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The influence of deformation of the frame of testing device on the accuracy of Brazilian test and indirect assessment of Young modulus
Major, Štěpán ; Vavřík, Daniel ; Kocour, Vladimír ; Bryscejn, Jan
This article deals with determination of mechanical properties based on indirect measurements of brittle building materials like stones using portable device. Due to the fact, that the material samples may change their properties during transportation, it is preferred to test samples on site. For these reasons, portable testing device was developed. The testing machine operates on the split test principle. The device also shall to serve for estimation of other mechanical characteristics of the tested material, such as Young's modulus, compressive strength or flexural strength, etc. This paper concentrates on the effect of deformation of frame on the accuracy of indirect determination of mechanical properties.
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Semiautomatic Surface Reflectance Measurement for Monitoring of Material Weathering
Kocour, Vladimír ; Valach, Jaroslav
We present a device for measurement of surface reflectance in dependence on incidence angle and reflectance angle. This measurement enables us to quantitatively determine how much the surface is glossy or matt. The device is programmable, which enables us to choose non-equidistant steps of angles, and study special situations more in detail. It can be used for monitoring of material weathering or other types of degradation as weathering usually causes that the surface becomes more matt.
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Investigation of Optical Properties of Protective Layer for Glass Medieval Mosaic of Last Judgement from St. Vitus Cathedral in Prague
Valach, Jaroslav ; Kocour, Vladimír ; Černý, Miloš
The Mosaic of Last Judgement from St. Vitus Cathedral in Prague is a medieval masterpiece created in late 14th century by Venetian craftsmen. If very dramatic history and various problems encountered are taken into consideration, the current state of preservation is acceptable, perhaps mainly due to systematic effort to protect the valuable item of cultural heritage. The research project, part of which is presented here, also aims on developing effective means for preservation of the precious object. It concentrates on finding formula for creation of protective layer that eliminates influence of chemicals present in air and in water, while being stable itself. The main goal of the investigation is to help in finding the best formula for protective layer that is most stable itself, i.e. which does not represent a future obstacle in viewing the mosaic, e.g. because of losing its transparency.
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New trends in internet marketing.
Vaľková, Alexandra ; Štědroň, Bohumír (vedoucí práce) ; Kocour, Vladimír (oponent)
Tato diplomová práce popisuje vývoj Internetu, jeho význam v oblasti marketingu a rovněž nové trendy a nástroje používané v internetovém marketingu. Zároveň řeší otázku možného kolapsu Internetu v budoucnosti, popisuje varianty, jak by k němu mohlo dojít a předkládá návrhy řešení tohoto problému. Diplomová práce dále obsahuje předpovědi vývoje Internetu do roku 2030 a předpovědi významných světových agentur týkající se vývoje informačních technologií a technologických novinek, které můžou významně ovlivnit sféru podnikání mnohých firem na celém světe.
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Vybrané aspekty marketingu ve stavebnictví
Trsková, Adéla ; Štědroň, Bohumír (vedoucí práce) ; Kocour, Vladimír (oponent)
Tématem této práce jsou vybrané aspekty marketingu ve stavebnictví. Cílem práce je popsat některé vybrané aspekty marketingu ve stavebnictví a jeho specifika na rozdíl od marketingu obecného. Práce se zabývá stavebním trhem, jeho segmentací, analýzou a jednotlivými subjekty na něm působícím, dále také marketingovýma transpozičním mixem a využitím marketingových informačních systémů u stavebních podniků. V praktické části práce popisuje pět největších stavebních podniků na českém trhu, jejich ekonomickou a marketingovou situaci a jejich největší zakázky. V poslední části se práce zabývá průběhem a popisem konkrétní státní zakázky -- architektonické soutěže o výstavbu nové budovy národní knihovny. Na té se práce snaží poukázat na fungování zadávání státních stavebních zakázek a aspekty, které jej ovlivňují.
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