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Additional file 4: Table 3. Serum calcium levels.

Additional file 3: Table 2. Wound areas.

Additional file 1: Fig. 1. Flow diagram for crossover study.

Additional file 2: Table 1. Information on patients.

Die Infiltration von porösen Kohlenstoffvorformen mit flüssigem Silicium ist eine der wirtschaftlichsten Technologien zur Herstellung von kohlenstofffaserverstärktem Siliciumcarbid. Trotz jahrzehntelanger Forschung sind die physikalischen Phänomene an der Infiltrationsfront noch nicht hinreichend verstanden worden. Die vorliegende Arbeit dient dazu, diese Forschungslücken zu schließen. Hierzu befasst sie sich zunächst mit den bisher bekannten Infiltrationsmodellen. Anschließend wird ein neuartiger Versuchsaufbau vorgestellt, der eine In-situ-Beobachtung einer Spaltkapillare aus Glaskohlenstoff während der Siliciuminfiltration ermöglicht. Die Versuche zeigten, dass sich die Infiltrationskinetik grundlegend von den Vorhersagen der bekannten Infiltrationsmodelle unterscheidet. Abschließend wird der Aufbau eines numerischen Modells erläutert, das erstmals die reaktive Infiltration der Kohlenstoffvorformen im Dreidimensionalen simuliert. Dabei führen eine neue Infiltrationsgleichung und ein zeitabhängiger Diffusionskoeffizient zu einer guten Übereinstimmung von Simulations- und Messergebnisse., The liquid phase infiltration of porous carbon preforms with silicon, commonly referred to as Liquid Silicon Infiltration (LSI), is one of the most economical technologies for the production of carbon fiber reinforced silicon carbide (C/SiC). Despite decades of research, the physical phenomena on the infiltration front have not yet been sufficiently understood. Consequently, up to now there is no mechanistic model of the reactive infiltration process that could help to optimize the production process of C/SiC components. The present work serves to close the research gaps and provide a validated simulation model for process optimization. The present study was divided into three parts, with the first part initially dealing with the manufacturing processes of C/SiC components. Subsequently, the basic chemical and physical processes of the reaction of silicon and carbon to silicon carbide are explained. Followed by the previous understanding of the infiltration of porous carbon fiber reinforced carbon preforms (C/C-Preforms) with liquid silicon, the state of the art will be dealt with using the existing infiltration and diffusion models. The second part deals with the investigation of the LSI process by a newly developed experimental setup. This enables in situ observation during the infiltration of a gap capillary of glassy carbon with silicon. Originally, the experimental setup was intended to validate the previously recognized infiltration models based on general capillary theory. However, the experiments showed that the infiltration kinetics fundamentally differ from the behavior predicted by the known infiltration models. Further investigations led to new findings, which enabled the development of a mesoscopic model for predicting the actual infiltration behavior. With the infiltration and investigation of porous C/C materials, the scope of the infiltration model is extended to commercial C/C materials. The third and last part deals with the structure of a numerical model for the simulation of the LSI process. The calculation model, based on the finite element method, includes both infiltration and reaction kinetics. For the first time, the reactive infiltration of porous C/C preforms was simulated in three dimensions and the model was validated with in situ measurements. A newly developed infiltration equation and the introduction of a time-dependent diffusion coefficient led to a good agreement between simulation and measurement results as well as to short computation times even for complex components on an industrial scale.

Air conditioning, space heating, and water heating makeup the largest proportion of building energy use in the U.S., making this segment an enormously rich opportunity for energy and cost savings. Devices like Vuilleumier Heat Pump (VHP), which can provide space heating, cooling and water heating at the same time, have very high efficiency compared to conventional air conditioners, space heaters and water heaters available in the market. The heat exchangers of a VHP play a significant role, and it affects the performance of a VHP significantly. Multi-Objectives such as reducing the pressure drop and dead volume of the working fluid in the heat exchangers should be considered while designing. The primary objective of this thesis is to develop an optimization tool using TeachingLearning based optimization (TLBO) algorithm, which considers minimizing dead volume and pressure drop as the objectives. A design process starts by assuming some random desired values for few unknowns and evaluating the rest of the parameters based on those assumptions. But, quite often, it is apparent that, as the design is refined, there might be a huge difference between initially assumed values and current design parameters. This process consumes time, effort and resources. As an alternative, implementation of optimization techniques such as TLBO over the design variables in a specified range, which can give a set of optimal solutions in very less time, is discussed in this thesis. This work shows the application of TLBO and the process of converging to an optimal solution. The results obtained by implementing TLBO for a VHP heat exchanger are then compared to the existing design. A tool like this can be used at the start of design process so that lot of time and resources can be saved in the development cycle. This process can also be used for optimizing the existing design as well.

Computer Algebra Systems (CAS) have been changing the mathematics instruction requirements for many years. Since the tendency of using CAS in mathematics instruction has been rising for decades and reports have often been positive, the implementation of notebook classes seems to be the consequent next step of mathematics instruction supported by computers. Experiences that have been made with the use of CAS in PC-rooms can be transformed directly into the classroom. Hence the use of CAS is no longer limited to certain rooms. The permanent availability of the notebook with installed CAS offers the chance to realize these concepts that have already been approved with the use of CAS so far. The following speech shall show what these concepts could look like and that the use of notebooks is not only the further development of teaching in PC-classes. Examples from personal experience in teaching will especially show meanders and thought-provoking impulses in order to support teachers finding their way into teaching mathematics instruction in notebook classes successfully. Please allow me to point out two things in the beginning: (1) Yes, I am a vehement supporter of the use of notebooks (and the use of CAS in particular) in mathematics instruction. (2) No, I do not believe that teachers who have chosen another path (or at least partly) are teaching badly.

Ill., graph. Darst.