National Repository of Grey Literature 17 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
In-situ compression test of artificial bone foams in controlled environment using X-Ray micro-computed tomography
Glinz, J. ; Kytýř, Daniel ; Fíla, Tomáš ; Šleichrt, Jan ; Schrempf, A. ; Fürst, D. ; Kastner, J. ; Senck, S.
X-RayMicro-computed tomography (XCT) has already become a standard method for investigations of bone and bone replacement materials in medical research. For an in-depth characterization of histomorphometric features, digital volume data acquired by XCT can be processed and visualized three dimensionally to determine parameters such as bone volume fraction, cortical thickness and porosity. In this study, we investigated specimens of artificial bone foams, developed by the research group for surgical simulators at the UAS Linz, which are used to mimic the haptic feedback of physiologic and pathologic bone for more realistic surgery training. Similar specimen of artificial bone foam in a dry state have already been characterized precisely in [1]. However, since physiological bone typically is in a wet state, the main purpose of this study was the investigation of the influence of environmental conditions on artificial bone foams of varying composition. Thus, specimens with two kinds of mineral filler material as well as different amounts of foaming agent were prepared and tested in an in-situ loading stage developed by the ITAM CAS. In this stage, specimens can be immersed in liquid and tested under temperature-controlled conditions. Consequently, a total amount of 12 specimens was subjected to compression loading; half of them immersed in water at 36.5◦C and half in dry condition. Results showed that there is no significant influence of liquid immersion to the compression outcome. However, foams with less amount of foaming agent appeared to have smaller pores resulting in higher compression strength. Different types of mineral filler material also showed no significant influence on compression strength. Furthermore, a time-lapse in-situ investigation with XCT scans in-between the load steps was performed for one specimen immersed in water to investigate behavior during load. Despite of the open porous morphology of the foam, water immersed only partially into the foam, leaving pores closer to the center unfilled. Concluding, the usage of the artificial bone foams investigated is despite their physiologically wet condition also valid in a dry state since environmental differences are nonessential for their mechanical properties.
Three-dimensional characterization of polymer foams using X-ray dark-field imaging
Senck, S. ; Plank, B. ; Gusenbauer, C. ; Salaberger, D. ; Vavřík, Daniel ; Santer, W. ; Kastner, J.
Due to the low cost, the ease of processing, and excellent material properties, polymer foams are used in various applications, e.g. packaging, building and construction, furnitures and bedding, and the automotive and aerospace sector. The mechanical response of polymer foams is primarily influenced by density and morphology. While foam density can be determined with high precision, cell morphology is more difficult to determine since the size distribution of foam cells differs in three dimensions. However, using conventional methods, e.g. optical light microscopy or scanning electron microscopy, it is very difficult to obtain three-dimensional information and to differentiate between the strut system and cell walls. An alternative for the three-dimensional characterization of foam morphology is micro-computed tomography (XCT). But even non-destructive techniques like XCT are not able to characterize anisotropic foams if the thickness of single struts and cell walls is below the physcial resolution of the respective XCT system. In this contribution we therefore investigate different polymeric foam samples using a Talbot-Lau grating interferometer XCT (TLGI-XCT) system. We show that the obtained darkfield contrast images show a high contrast and a strong signal at struts and cell walls, facilitating the segmentation of foam cells in various examples.
Effect of submitters to the form of outdoor management training courses
Kastner, Jan ; Frainšic, Michal (advisor) ; Turčová, Ivana (referee)
Summary Title of project: Effect of submitters to the design of outdoor management training courses. Aim of project: We compared the form of outdoor management training, which is described in the literature with images of HRs. We defined how much HRs affect form of outdoor management training courses. Methodology: We used a qualitative research method, specifically literature search in preparation for our project. We decided to incorporate the surfy as a quantitative methods of research. We created the questionnaire specifically for our purposes and we spread it among a random group of HRs. We used both of printed and electronic form. The results of the survey were compared with the facts found in the literature. Results: The results of the work serve to illustrate theories of courses of outdoor management training in the Czech republic. We found that the submitter's requirements of outdoor management training courses are not in accordance with the principles of this corporate training tool. We concluded that the influence of HRs is strong enough to alter the form of courses. Key words: outdoor management training, experiential education, experience, feedback, outdoor course
Evalution of information from Meteosat 8 and the CZRAD network of meteorological radars in selected significant convective situations
Hajáková, Jaroslava ; Kastner, Jiří (referee) ; Pešice, Petr (advisor)
KAPITOLA ABSTRACT Abstract Topic of Mc. S. Thesis: Evaluation of information from Meteosat 8 and the CZRAD network of meteorological radars in selected significant convective situations. Abstract: This paper focused on comparing the information from the satellite Meteosat 8 and the CZRAD network of meteorological radars in selected significant convective situations. The main goals of this study were to assess how satellite and radar data respond on development of convection and if the satellite data responds on intenzifying convection before the radar data. For this purpose, four significant convective situations and associated areas (72 x 72 km) were selected, and the satellite and radar data were preprocessed. Appropriate differences of spectral channels (i.e. satellite methods) and radar products were chosen. The preprocessing involved data synchronization in time and location. The parallax correction was used for satellite data. Seven satellite methods were used - spectral channel IR 10.8 (TIR10.8), difference of channels WV 0.6 and IR 10.8 (TWV6.2 - TIR10.8), IR 13.4 and IR10.8 (TIR13.4 - TIR10.8), IR 12.0 and IR 10.8 (TIR12.0 - TIR10.8), IR 8.7 and IR 10.8 (TIR8.7 - TIR10.8,), NIR 1.6 and VIS 0.6 (REFNIR1.6 - REFVIS0.6) and the trispectral method. The trispectral method resulted from measurements of...
Analysis and project plan of information services in climbing areas
Kastner, Jan ; Šafránek, Jiří (referee) ; Vomáčko, Ladislav (advisor)
Title: Analysis and design solutions to information services in the climbing areas. Objectives of work: To evaluate the current level and the penetration of information systems in climbing tourism. Designing the ideal information system for climbers, which would be applicable to any climbing area. Methodology: The investigation, we used quantitative and qualitative methods research, primarily survey. The questionnaire we created specifically for our purposes, and spread it among a random sample of climbers. For further information, were used guided interviews and written questions directed to the people, providing individual information sources. The investigation using case studies, we analyzed the two main Web site for climbers in the country. Results: The results of the work serves as a basis for a thesis, the to prepare the system for a particular rock area. Will also be used as basis for further increasing the level of information provided in the CR climbing tourism. Keywords: rock climbing, information services, tourism, websites, guides

National Repository of Grey Literature : 17 records found   1 - 10next  jump to record:
See also: similar author names
1 Kastner, Jakub
3 Kastner, Jan
Interested in being notified about new results for this query?
Subscribe to the RSS feed.