Membrane Distillation (MD) is an emerging sustainable desalination technique. While MD has many advantages and can be powered by solar thermal energy, its main drawback is the low water production rate. However, the MD process has not been fully optimized in terms of its manipulated and controlled variables. This is largely due to the lack of adequate dynamic models to study and simulate the process. In addition, MD is prone to membrane fouling, which is a fault that degrades the performance of the MD process. This work has three contributions to address these challenges. First, we derive a mathematical model of Direct Contact Membrane Distillation (DCMD), which is the building block for the next parts. Then, the proposed model is extended to account for membrane fouling and an observer-based fouling detection method is developed. Finally, various control strategies are implemented to optimize the performance of the DCMD solar-powered process. In part one, a reduced-order dynamic model of DCMD is developed based on lumped capacitance method and electrical analogy to thermal systems. The result is an electrical equivalent thermal network to the DCMD process, which is modeled by a system of nonlinear differential algebraic equations (DAEs). This model predicts the water-vapor flux and the temperature distribution along the module length. Experimental data is collected to validate the steady-state and dynamic responses of the proposed model, with great agreement demonstrated in both. The second part proposes an extension of the model to account for membrane fouling. An adaptive observer for DAE systems is developed and convergence proof is presented. A method for membrane fouling detection is then proposed based on adaptive observers. Simulation results demonstrate the performance of the membrane fouling detection method. Finally, an optimization problem is formulated to maximize the process efficiency of a solar-powered DCMD. The adapted method is known as Extremum Seeking (ES). A Newton-based ES is designed and the proposed model is used to accurately forecast the distilled water flux. Although good results are obtained with this method, a practical modification to the ES scheme is proposed to enhance the practical stability.

The final thesis Centrum volnočasových aktivit is elaborated in a form of bulding plan containing all units by valid regulations. The designed object is placed on the plots number 1970 and 1980/1 in the cadastral area Zábřeh. The main bulding is conceived as the four floor building wiht the partial besement. The building is a brick of a comprehensive system based on the underlying belts. The roof is designed flat. This building is suitable for leisure activities, there are classrooms and space to relax in the café. On the top floor there are two separate apartments for the owners of the building. Built up area is 561 m2., Area 7896 m2 plots.

Master thesis is about increasing of protection the crew in race car with changes in its roll-over protective structure according to current safety rules. For examination was used the Finite Element Method. The products of this thesis are different variation of roll cages, which are tasked to increasing the safety of existent race car.

This master thesis describes the design and optimization of connecting rod motor racing car. At the beginning of the whole work is a 3D-model of rods, from which then the whole work is based. Then it analyzes the current model of stress and on the basis of the results are made structural changes to the solution of rods. Newly adapted connecting rod is again analyzed using FEM and newly obtained results are compared with results of the original model of connecting rods. The conclusion deals with sensitivity analysis of selected parameters of rods and their potential effect on the resulting changes in strength connecting rod .Then is an assessment of all results.

Area navigation RNAV and reducing vertical separation minimum RVSM methods are both considerable phase of high air traffic density issue solution. By implementation of these methods the optimization of airspace is achieved. In present the RNAV and RVSM procedures are implemented in European airspace and the procedures of these metods are valid. Thesis sumarizes the substance of these methods, its implementation and especially procedures they are connected with. The purpose of this thesis is to form qualified analysis of RNAV and RVSM methods and to desctibe its feasibility and its trends in European airspace. The thesis is intended as an educational aid for pilots and aerospace engineering students self-study.

Multifunctional building is designed as a 4 storey building with one floor underground and three above-ground floors. The building is situated in the administrative area Vajnory Bratislava. Basement includes cellars and 15 parking spaces. The first floor covers commercial premises suitable for civic amenities. In second and third floor are located apartments. Recent third floor is intentionally reduced to achieve a lower index for compliance with a built-up area.

Direct Reduced Iron (DRI) is used as an alternative feedstock in electric arc furnaces, making up 50% or more of the total iron charge. DRI produced with coal based reductants (for example in rotary kilns) make up roughly 25% of DRI produced in the world. It was found that SL/RN DRI samples from a kiln cooler had high nitrogen contents (50-250ppm, depending on particle size), higher than DRI from gas-based reduction. The higher nitrogen content of SL/RN DRI would increase the levels of nitrogen of liquid steel produced in the EAFs. The problem is exacerbated by the fact that the SL/RN DRI contains virtually no carbon (which would aid in preventing nitrogen pickup). The proposed mechanism of nitrogen pick-up by the SL/RN DRI is one where nitrogen present within the atmosphere of the rotary cooler (where hot DRI, discharged at 1000°C from the rotary kiln, is cooled to approximately 100 °C in ca. two hours) penetrates the solids bed and nitrides DRI particles. Possible rate-determining steps for nitriding in the cooler have been evaluated. Nitriding of DRI particles is predicted to be rapid: the most plausible location for rapid nitrogen pickup is the first 5 meters of the rotary cooler, where the high temperature, nitrogen-rich gas atmosphere and rapid solids bed mixing are conducive to nitriding; solid-state and pore diffusion of nitrogen into DRI particles are predicted to be rapid too. The most plausible rate determining step for nitriding of DRI particles is that of nitrogen dissociation on the DRI surface, which can be further retarded by the presence of sulphur. A strong correlation was found between the amount of “melt-in” carbon in the liquid steel and the final tap nitrogen content, with 0.3% C resulting in nitrogen levels as low as 50 ppm (80 ppm or less is desired on the plant in question) at tap, even with DRI material that is high in nitrogen and contains virtually no carbon. Proposals to increase the melt-in carbon are included. / Dissertation (MEng)--University of Pretoria, 2013. / gm2014 / Materials Science and Metallurgical Engineering / unrestricted

Thermal energy storage (TES) modules are specifically designed to respond to transient thermal loading. Their dynamic response depends on the overall structure of the module, including module geometry and dimensions, the internal spatial distribution of phase change material (PCM) and conductive heat-spreading elements, and the thermophysical properties of the different materials composing the module. However, due to the complexity of analyzing a system’s dynamic thermal response to transient input signals, optimal design of a TES module for a particular application is challenging. Conventional design approaches are limited by (1) the computational cost associated with high fidelity simulation of heat transfer in nonlinear systems undergoing a phase transition and (2) the lack of model integration with robust optimization tools. To overcome these challenges, I derive reduced-order dynamic models of two different metal-PCM composite TES modules and validate them against a high fidelity CFD model. Through simulation and validation of both turbulent and laminar flow cases, I demonstrate the accuracy of the reduced-order models in predicting, both spatially and temporally, the evolution of the dynamic model states and other system variables of interest, such as PCM melt fraction. The validated models are used to conduct univariate and bivariate parametric studies to understand the effects of various design parameters on different performance metrics. Finally, a case study is presented in which the models are used to conduct detailed design optimization for the two HX geometries.

Untersuchung des Einflusses von Komorbiditäten auf Patienten mit allogener Stammzelltransplantation nach reduzierter Konditionierung, Überprüfung der Validität des HCT-CI an Leipziger Patienten

Zur Bestimmung singulärer Punkte eines bestimmten Typs muss eine zugehörige reduzierte Funktion und deren Ableitungen bestimmte Bedingungen erfüllen. Dabei ist diese reduzierte Funktion implizit durch ein nichtlineares Gleichungssystem definiert. Man erhält letztendlich ein minimal erweitertes System, das auch Ableitungen der reduzierten Funktion enthält,und den singulären Punkt als reguläre Lösung besitzt. In der vorliegenden Arbeit wird die Technik des automatischen Differenzierens für die Vorwärtsmethode dargestellt, insbesondere wird die Differentiation iterativer Verfahren untersucht. Es wird ein Überblick über die Theorie von singulären Punkten gegeben und das Erkennungsproblem definiert. Ein zweistufiges Verfahren zur Bestimmung singulärer Punkte wird auf Basis der Vorwärtsmethode und des Newton-Verfahrens beschrieben und wurde an verschiedenen Typen von singulären Punkten getestet.