This diploma thesis deals with a new concept of maintenance and operation of production technologies, where spare parts are manufactured using rapid prototyping methods. The options are compared with currently used methods. Furthermore, methodological recommendations are written on how to proceed with the application. The aim of the work is to evaluate the concept and confirm the theoretical assumptions on a case study.

This thesis solves actual engineering tasks from the field of motorcycle industry. The first part describes the design of several plastic parts for Czech motorcycle Blata125. The design of injection moulds for selected parts is described in second part of the thesis.

This diploma thesis is deal with problems of supporting applications for technologic process creation of shaft parts. Thesis contains a description of the problem of technological processes, shaft parts and supporting applications for technological pro-cesses creation of technologic process. It is also described their proposed applications, and its possible cooperation with existing systems.

PETR SMUTNÝ: Production single parts from sheet metal. Diploma assert of daily magisterial`s studies, study programme INDUSTRY. The branch manufacturing technology, level 2, 2nd form, academical year 2010/2011, study group 60. FME of Brno University of Technology, department of forming and plastics, May 2011, 65 pages, 9 tables, 3supplements. The theme of this diploma assert is suggestion technology of production drawn part with plange by plat forming. The component is made from the steel sheet 17240 width 1,5 mm. Drawn part is made from sheet about proportion 2000 x 1000 mm, by set of production 50 000 ps/year. For production is designed two variants of deep drawing. The komponent will be made on press CTH250 in two steps. The aim of this diploma assert is designing of suitable technology progression of production including technical documetation.

This thesis deals with the experimental study of the formation of the lubricating film used for sintered metal parts impregnated with oil. The thickness of the lubricating film in a line contact is measured by the method of optical interferometry of thin lubricating films. In this thesis, the effects of various operating parameters on the formation of the lubricating film are described. The usage of impregnated lubricant leads to insufficient supply of lubricant to the contact. Individual results are significantly influenced by the degree of flooding of the contact area.

Syftet med studien är att undersöka hur förskollärare resonerar kring den fysiska lärandemiljön inomhus och hur delaktiga barnen är i utformningen av den. Studien utgår från en kvalitativ ansats och bygger på semistrukturerade intervjuer. Vi har genomfört intervjuer med fem förskollärare på tre olika förskolor. Det insamlade materialet har analyserats utifrån teorierna om loose parts och affordances. Resultatet i undersökningen visar att förskollärarna anser att den fysiska lärandemiljön är viktig och att den diskuteras ofta i arbetslaget. Förskollärarna säger vidare att de ofta ändrar om i miljön men hur mycket barnen görs delaktiga i processen varierar. Hur tillgängligt materialet kan vara för barnen lyfts men delar också förskollärarnas svar åt. Men alla ser problematiken i att ha en fysisk lärandemiljö där precis allt är tillgängligt för alla. En slutsats som vi kunnat dra utifrån resultatet är att förskollärarna förstår att den fysiska lärandemiljön är viktig för barns utveckling och lärande men att de ser olika hinder för att kunna skapa den fysiska lärandemiljö som de önskar.

Context. Underwater human detection has been an important problem in computer vision areas. Body part-based models could gain good performance in on-land human detection with occlusion existing scenarios. This thesis explores the feasibility of human body parts detection in underwater environment. Objectives. This thesis aims to build a DNN-based underwater human body part detector for human body part detection task. Three body part detectors implemented with different DNN-based models (Faster R-CNN, SSD and YOLO) are built and compared over underwater human body part detection task. Methods. In this thesis, experiments are used as research methods. Three DNN-based models which are regarded as the independent variables in the experiment is trained, tested and evaluated. And the detection results of detector based on the three different models are dependent variables. Finally the detection performance calculated on the result for each detector is compared. Results. Underwater Body part detector based on Faster R-CNN provides the best detection performance on the body part detection task in terms of mAP, and YOLOv2 achieves the fastest detection speed but it has the smallest mAP value. In addition, SSD model has both decent detection performance and also detection speed. Conclusions. Underwater Body part detector based on Faster R-CNN, SSD, and YOLO could gain good performance over underwater human body part detection task. Building an underwater body part detector via deep learning method is feasible.

This thesis studies the problem of modeling life-limited spare units in a steady-state scenario. This means that units that have a predefined lifespan are to be modeled in a scenario where all conditions are kept constant and all transients have faded out. OPUS10 is a spare parts optimization software developed by Systecon AB. There is no way to explicitly model the life-limited units in OPUS10, although there are different approximate models that are built on adjustments of the failure rate and repair fraction or the definition of preventive maintenance. The objective of this thesis is to analyze the usage of life-limited items in real life and to investigate what approximated models different OPUS10 users will utilize in their modeling of life-limited units. Furthermore, the objective is to analyze the consequences of the approximated models and to investigate the possibility of an improved model. The results show that the main interest when choosing which approximated model to use is the type of life limit. There are three different types of operating time life limits investigated. Either the unit is discarded immediately after the life limit is reached, or it is instead discarded at the next failure. There is also the possibility of resetting of the life limit timer at each maintenance. In all three cases, it is shown that if choosing the most fitting approximate model, the results are very accurate. If the life limit is instead measured in calendar time, even the best approximation will give an under-estimation of the expected number of backorders. It is also shown that most of the OPUS10 users model life-limited units as preventive maintenance with discard, which is not the best approximation in any of the types of life limits.

We consider diagonal-norm classical summation-by-parts (SBP) operators us-ing the simultaneous approximation term (SAT) method of imposing boundaryconditions. We derive a formula for the inverse of these SBP-SAT discretizationmatrices. This formula is then used to show that it is possible to construct a secondorder accurate SBP-SAT operator using only seven grid points.

Thesis (M. Sc. ( Physics)) -- University of Limpopo, 2020 / In this work, we present first-principles calculation on the structural, thermodynamic, mechanical and electronic stabilities of Fe-Al and FeAl-X (X: Pt, Pd, Ru and Ag) alloys at lower and high temperatures. These systems have recently attracted a lot of attention for both scientific and possible technological application in turbines, Steel-It coating, energy sector, boilers, pipes and automotive parts as a potential replacement of steel due to their excellent resistance to oxidation at high temperatures. However, they suffer limited room temperature ductility and a sharp drop in strength above 873 K. We determined the lattice parameters, heats of formation, elastic constants, bulk to shear moduli, density of states, phonon dispersion curve and X-ray diffraction pattern for binary and ternary system at various concentrations between 0 ≤ x ≤ 10. Furthermore, the lattice expansion, elastic constants, Gibbs free energy, X-ray diffraction pattern and radial distribution function were done on the most stable systems to determine the melting point of FeAl-X ternary systems. A systematic investigation was performed on the stability of the Fe-Al alloys at zero K. We employed CASTEP code to evaluate the thermodynamic, elastic and electronic stability. Virtual crystal approximation was used to determine various atomic concentrations (0 ≤ x ≤ 5) of both Pt and Ru; this allowed more precise predictions on the materials’ behaviour. Further analysis was done on the density of states to describe the behaviour of each phase near the Fermi level; these phases were observed at different percentage compositions. A supercell approach, DMol3 was also used to evaluate these systems at a larger scale (0 ≤ x ≤ 50). VASP and LAMMPS codes were used to determine the stability of these FeAl-X ternary systems at concentrations (0 ≤ x ≤ 10). It was found that the equilibrium lattice parameters of the binary systems are in good agreement to within 2% with the available experimental data. The heats of formation showed that β2 FeAl phase was the most energetically stable system since it displayed the lowest value compared to all other binary systems. This observation accord well with the experimental phase diagram. It was also confirmed from the corresponding electronic DOS behaviour near the Fermi level. Furthermore, the shear modulus (C’) of these Fe-Al binary systems, i.e. FeAl, Fe2Al5, Fe4Al13, Fe5Al8, Fe2Al and FeAl3 were found to be positive fulfilling the condition of stability. The Fe2Al5 system was found to be the second most stable phase, followed by the monoclinic structure Fe4Al13. This observation was confirmed from the total DOS (where the Fermi level falls in the pseudogap, condition of stability). We further employed virtual crystal approximation and supercell approaches to model various atomic compositions at 0 ≤ x ≤1 and 0 ≤ x ≤ 50 for Ag, Pt, Pd and Ru. The heats of formation, density of states and elastic constants were determined to describe the structural, thermodynamic and mechanical stability of these systems. It was found that the addition of Ag, Pt, Pd and Ru enhances the stability at lower atomic percentage composition below 0.5%. Interestingly, the addition of Pt and Ru was found to significantly improve the ductility of the ternary FeAl-X compound for 0.2 and 0.5 at. % compositions. These systems showed that the Fe-sublattice was the preferred doping site with promising improvement in strength on the properties. It was further deduced that Ag and Pd stabilize the FeAl-X system at atomic percentage compositions of 0.5 and 0.7 respectively. Furthermore, a molecular dynamics-based LAMMPS-EAM was employed to model Fe50-XXXAl doped systems with either Ag, Pt or Pd. The lattice site preferences of the dopant were deduced from their energy landscape. More importantly, Ag and Pd doped systems gave comparable transition temperatures to experimental findings of 1273 K and 1073 K, respectively. Their thermodynamic and mechanical stability trends showed promising properties for industrial applications, displaying stability at a high temperature below 1300 K. This was evident for Ag, Pt (0.5 at %) and Pd (0.7 at %) doping as was the most stable systems with respect to Cij, ΔG, and RDF’s which indicated to influence the elastic instability above 1200 K as well as the ductility of these systems. The XRD confirmed that the doped systems preserved the structural symmetry as expected.