Basic creep and autogenous shrinkage of Limestone Calcined Clay Cement (LC3)

The use of supplementary cementitious materials (SCM) to lower the clinker factor of cements is now commonplace, for it benefits performance, economics and ecology. This thesis focuses on ternary blends of limestone and calcined kaolinitic clays, two very promising SCM thanks to their worldwide availability. In particular, this research aims to get an insight on the delayed strains in sealed condition of such binders, christened LC3 for Limestone - Calcined Clay Cement. Delayed strains refer to time-dependent deformations undergone by the material during its lifetime, such as shrinkage and creep. This work evaluates the impact of the calcined kaolinite content of the clay - which can vary in accordance with the origin of the clay - on the autogenous shrinkage and basic creep properties of LC3. Compressive creep tests on mature paste samples indicated that the presence of limestone and calcined clay dramatically reduced creep compliance. This reduction is significant even with lower grade clays and does not depend on the clay purity if it has at least 40% of calcined kaolinite. A two-dimensional finite elements model was used to simulate the creep response of the tested microstructures in order to try to determine whether the compliance reduction originated from a different phase assemblage or a higher viscosity of the C-S-H. The outputs pointed towards a different rheology of C-S-H gel. Autogenous shrinkage measurements on LC3 binders showed that these ternary blends had a lower or comparable shrinkage to plain cement reference during the two first months of hydration. Shrinkage rate and amplitude was found to be close for LC3 mixes usingmedium to high grade clays of natural origin. A study of the evolution of microstructure with shrinkage demonstrated that if the calcined clay contained enoughmetakaolin to consume most of the available portlandite, the porosity and desaturation of the microstructure were very similar regardless of the clay. As these features play a large role on the origin of shrinkage force, the macroscopic response is comparable among these specific mixes

Measurements of three-dimensional glenoid erosion when planning the prosthetic replacement of osteoarthritic shoulders.

The three-dimensional (3D) correction of glenoid erosion is critical to the long-term success of total shoulder replacement (TSR). In order to characterise the 3D morphology of eroded glenoid surfaces, we looked for a set of morphological parameters useful for TSR planning. We defined a scapular coordinates system based on non-eroded bony landmarks. The maximum glenoid version was measured and specified in 3D by its orientation angle. Medialisation was considered relative to the spino-glenoid notch. We analysed regular CT scans of 19 normal (N) and 86 osteoarthritic (OA) scapulae. When the maximum version of OA shoulders was higher than 10°, the orientation was not only posterior, but extended in postero-superior (35%), postero-inferior (6%) and anterior sectors (4%). The medialisation of the glenoid was higher in OA than normal shoulders. The orientation angle of maximum version appeared as a critical parameter to specify the glenoid shape in 3D. It will be very useful in planning the best position for the glenoid in TSR

A semi-automated quantitative CT method for measuring rotator cuff muscle degeneration in shoulders with primary osteoarthritis

Background: Rotator cuff muscle degeneration is an important parameter to consider when planning shoulder arthroplasty. Hypothesis: We hypothesized that rotator cuff muscle degeneration is correlated with scapulohumeral subluxation in patients planned for anatomical total shoulder arthroplasty (TSA). Materials and methods: We developed a semi-automated quantitative CT method to measure rotator cuff muscle degeneration, and retrospectively analyzed 107 preoperative shoulder CT scans of patients with primary osteoarthritis. On a standardized sagittal-oblique CT slice perpendicular to the scapular axis, two observers measured the cross-sectional areas of residual rotator cuff muscle tissues, normalized by the estimated area of healthy muscles. Muscle degeneration was quantified in a semi-automated manner, and divided into atrophy and fatty infiltration. Scapulohumeral subluxation was determined in 3D as the distance between the humeral head center and the glenoid surface center, projected on the same CT slice, and normalized by the humeral head radius. We tested all potential correlations between muscle degeneration and scapulohumeral subluxation. Results: Muscle degeneration, primarily due to atrophy, predominated in the supraspinatus; it varied from 0.8% to 88.8%. Scapulohumeral subluxation varied from 2.5% to 72.9%, and was mainly in a posterior and postero-superior orientation. There was a significant but weak correlation between the amount of sublux- ation and both supraspinatus (R = 0.207, P = 0.032) and infraspinatus (R = 0.225, P = 0.020) degeneration. Inter- and intra-observer reproducibility of muscle degeneration measurements were both excellent (ICCs range = 0.955–0.987 and 0.971–0.988, respectively). Conclusion: This new semi-automated CT method allows to quantitatively and reproducibly measure rotator cuff muscle degeneration in shoulders with primary osteoarthritis. Muscle degeneration is weakly correlated with scapulohumeral subluxation in patients planned for anatomical TSA

Zpracování modelu technicko-ekonomického hodnocení alternativního paliva při výrobě v tepelných elektrárnách, cementárnách a na aglomeraci železných rud

Import 07/02/2011Při těžbě a následné úpravě černého uhlí ve Slezsku vznikalo zejména v minulosti velké množství černouhelných kalů, které byly v minulosti deponovány na skládky. Dnes jsou tyto kaly zpětně těženy a zpracovávány s cílem energetického využití. Cílem této disertační práce je popsat jejich možné použití v energetice a částečně také v procesu výroby cementu a to nejen jako paliva, ale také jako aditivačního činidla. V teoretické části disertační práce je popsán současný stav řešené problematiky a vysvětleny možnosti jeho uplatnění v oblastech energetiky a výroby cementu. V praktické části disertační práce je popsán proces přípravy navrhovaného alternativního paliva a následná analýza jednotlivých vlastností, které jsou podstatné pro jeho použití v uvedených oblastech. Poznatky získané v předchozích částech disertační práce jsou využity při sestavení technicko – ekonomického modelu efektivnosti výroby alternativního paliva. V závěrečné části disertační práce je popsáno možné rozšíření základní podoby alternativního paliva, které zvýší potenciál jeho možného použití.Coal mining and processing in Silesia (Slezsko) has produced a huge amount of coal-water slurry as its by-product; it was, as a rule, deposited at disposal sites. The coal-water slurry is now being re-extracted and re-processed for fuel. This thesis gives account of it being used to produce electricity and, to an extent, in cement production, both as fuel and an additive agent. The theoretical section describes ways of dealing with coal-water slurry used so far and outlines its power supply and cement production potential. The practical section gives a detailed account of the proposed alternative fuel production, including an analysis of its relevant properties. This yielded information which was then used to draft a technical-economic model to explore the alternative fuel production efficiency. The final section seeks to cover potential ways of enhancing the properties of the fuel to extend the application range.Prezenční634 - Katedra ekonomiky a managementu v metalurgiivyhově

North American Indians matter and its incorporation in the lessons of drama education

Abstract The thesis gives several examples of literature published in Czech /Slovak that either focus on the matter of the Indians of the US Great Plains, or are original pieces of Indian literature. The selected fiction and non-fiction work is a starting point for discussing the topic of North American Indians, our relation to it as well as potential analogies with the topics of the current society, and designing related drama education projects. The thesis consists of three chapters, each devoted to stories and issues of a single tribe. The first two chapters contain North American Indian mythology, the third one explores the relationships and conflicts of Indians and settlers (especially throughout the 19th century). The resulting projects of each chapter aim at different target groups (pre-school age, primary school age, secondary school age)

Optimization of experimental conditions for measurements of perfluorinated organic acids by GC

Commercial software Pro ezGC was used for calculation of optimal temperature program for analysis of isobutylesters of perfluorinated organic acids (C6 - C12) by gas chromatography with flame ionization detector. Optimization was done with respect to the complete resolution of all peaks of analytes. The calculated temperature program was also applied to the analysis of substances of interest on GC-MS. The calculated and measured values have been compared. The measured resolutions were higher than the calculated ones in all cases. Keywords: perfluorinated organic acids, isobutylesters, peak resolution Subject words: gas chromatography, numerical optimizatio

Vyhodnocení projektu realizace investičních akcí v podniku stavebního průmyslu

Import 20/04/2006Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Ekonomická fakulta. Katedra (152) podnikohospodářsk

Development and optimization of a robust pressure modulator for multidimensional gas chromatography

Comprehensive gas chromatography (GC×GC) is a modern and advanced analytical method designed to separate very complex samples, when the separation efficiency of classical gas chromatography is not sufficient. GC×GC allows complete simultaneous analysis of a sample on two different columns, interconnected by special interface called the modulator. Three types of control units were set up and a robust pulse flow modulator (PFM) was developed in this work. PFM working parameters have been always optimized to allow combinations of columns with different sizes. Optimized PFM allows application of columns with 10-60 m length and 0.15-0.25 mm internal diameters for the first dimensions and with 1-10 m length and 0.25-0.32 mm internal diameters for the second dimension. For demonstration reasons, analyses of complex real samples, such as essential oils, oil derivatives and biological samples, were performed. PFM was compared with the commercial cryofocusation modulator Zoex for the selected column set and one sample (a mixture of volatile solvents) on a gas chromatograph equipped with both modulators. The average repeatability of retention times, expressed as a relative standard deviation, was approximately 2.0 % for PFM (cryofocusation about 0.5 %) and of the peak areas was approximately 3.5 %..