Uncovering the nature of dark matter is one of the most pressing problems in 21st century cosmology. Despite overwhelming evidence that dark matter exists and vigorous experimental efforts to detect it, dark matter has evaded detection and its fundamental nature remains shrouded in mystery. Indirect dark matter detection experiments search for Standard Model byproducts of dark matter annihilation or decay. At low energies, cosmic antideuterons provide an especially clean dark matter signature, since the production of low-energy antideuterons from conventional astrophysical processes is highly suppressed. The General Antiparticle Spectrometer (GAPS) is an Antarctic balloon experiment designed to search for low-energy cosmic antinuclei as signatures of dark matter. GAPS is optimized to detect low-energy antideuterons, as well as to provide unprecedented sensitivity to low-energy antiprotons and antihelium nuclei. GAPS uses a novel approach to detect antinuclei, based on the formation, decay, and annihilation of exotic atoms. At least three GAPS long-duration balloon (LDB) flights are planned, with the first launch date anticipated for December 2022. The core of the GAPS instrument is a particle tracker, comprised of >1000 lithium-drifted silicon (Si(Li)) detectors, that provides particle tracking and X-ray spectroscopy capabilities. In order to preserve the long-term performance of the tracker, the Si(Li) detectors require a surface passivation coating to protect against environmental contamination. In this thesis, I cover four main areas of my research: prototype Si(Li) detector fabrication and performance evaluation; development of a surface passivation technique to ensure the long-term stability of GAPS flight detectors; calculation of the GAPS antihelium sensitivity using particle tracking; and prediction of the antihelium exotic atom X-ray energies and yields for future identification studies. I discuss the prototype fabrication work that was carried out at Columbia, which led to the successful mass-production of large-area Si(Li) detectors for the GAPS LDB flights. I report the research and development of a surface passivation method to protect the GAPS flight detectors from environmental contamination. I then describe the calibration scheme for the GAPS Si(Li) detectors, and a simulation study that I conducted to disentangle the contribution of Compton scattering and intrinsic detector performance on the observed spectra. I then move on to discuss the simulation studies used to determine the performance capabilities of GAPS. I describe the benchmarking of the hadronic annihilation products in antinucleus-nucleus annihilations in Geant4. I review the exotic atom cascade model used to determine the X-rays produced by antiprotonic and antideuteronic exotic atoms, and discuss my work extending this model to describe the de-excitation of antihelium exotic atoms. Finally, I present the first GAPS antihelium nuclei sensitivity study, based on full instrument simulation, event reconstruction, and realistic atmospheric influence simulations.

Content: For sustainable developments the chemical industry is continuously looking for technical innovations with wide potential implications. The Design of Experiments (DOE) approach has been proven to be a powerful tool in determining the relationship between factors affecting certain output variables. This is done to establish a 'cause and effect' relationship and eventually realize output optimization. In order to evaluate whether DOE can be implemented for improving our products and processes, a case study, focusing on the synthesis and production of traditional phenolic syntans was carried out within our R&D department. Although we can influence properties by application, the effect a retanning agent has on leather originates to a large extent from the chemistry involved. To understand interactions and the possibilities of targeted improvements of the production process, a DOE factorial design approach was used to identify the control parameters and their interactions in our phenolic syntan recipes that influence the various properties and effects. Instead of trial-and-error or one-factor-at-a-time practices, DOE made it possible to limit the number of lab experiments to one third (1/3) of the amount needed for completing our study. As a result, a much deeper and more consistent understanding of the building blocks’ interactions and how these influence the chemical process of phenolic syntan synthesis has been gained. This includes the amount of different building blocks, their molar ratios as well as process conditions. Aiming at achieving optimal efficiency for various projects, right now we are looking at possibilities in implementing DOE within Smit & zoon. Take-Away: The Design of Experiments (DOE) approach is a powerful tool in realizing process and product improvements. DOE factorial design can be used to identify control parameters and their interactions in a wide reage of (industrial) applications. DOE has been proven to be efficient and effective in optimizing phenolic syntan recipes and production process.

The aim of this diploma thesis was to develop and validate a high performance liquid chromatography (HPLC) method for purity and stability evaluation of fesoterodine. The HPLC method development was carried out using design of experiments (DOE), which allows to find optimal separation conditions within small number of experimental analysis. Design was done by using L18 linear model. Chromatographic system of the developed method consisted of a C8 stationary phase (SF) XBridge BEH - C8 (100 x 4.6 mm, 2.5 µm), a binary mobile phase (MF) consisting of 10mM borate buffer pH 9.2 and MeOH in various ratios according to the gradient program. Flow rate was 0.7 ml/min, column temperature 35 řC and a diode-array detector (DAD) was applied for the detection at 227 nm. Analysis time was 22 min. The optimized method was validated and the forced degradation study was performed. Studied effects were: the effect of elevated temperature (60 řC), humidity (10 and 75% relative humidity), acidic and basic conditions, oxidation and light. Peak purity of fesoterodine was evaluated for all experiments of forced degradation study. Additionally, the sensitivity of the active substance to hydrolysis was determined within the pH range of 2-10.

Title: Experiments from geometrical optics for teaching at primary and secondary school Author: Ing. Filip Hložek Department: Department of Physics Education Supervisor: RNDr. Jitka Houfková, Ph.D., Department of Physics Education Abstract: This work is focused on experiments in geometric optics. There is a research of textbooks for primary and secondary schools, that deals with this topic of physics. Most of the work is dedicated to the proposed manuals for experiments for the excercise of geometric optics in Practical Course in School Experiments I. The manuals were tested with several groups of students at Practical Course. The test results are briefly summarized here, including several adjustments of the manuals that has risen from it. The work also deals with mirror telescopes, aberrations, and the production of models of two telescopes - Newtonian and Cassegrain printed on a 3D printer. The models are then used in two experiments for Practical Course. Keywords: experiments, geometrical optics, optical instruments

The search for physics beyond the Standard Model has been a main focus of the scientific community for several decades. Unknown physics in the form of new interactions violating the simultaneous reversal of charge and parity symmetries (CP) would, for example, provide a significant step towards understanding the baryon matter-antimatter asymmetry observed in the Universe. Such parameters are predicted to also manifest themselves in atomic and molecular systems in the form of both: permanent electric dipole moments and nuclear charge distribution asymmetries described by the nuclear Schiff moment. Both can be measured to a high degree of precision in modern experiments, allowing us to place stringent limits on parameters appearing in new fundamental theories. The Cold Molecule Nuclear Time Reversal Experiment (CeNTREX) is the latest approach to probing these effects. CeNTREX is a molecular beam experiment that uses thallium fluoride (²⁰⁵Tl⁹F) as its test species to measure energy shifts induced by the interaction of thallium's nuclear Schiff moment. It does so by performing nuclear magnetic resonance using a separate oscillatory fields technique. The precision of this measurement is dictated by the free precession time and the number of interrogated molecules, and is significantly enhanced by thallium fluoride's inherent properties. Employing novel methods, CeNTREX strives to achieve significant improvements to limits placed on the fundamental parameters. One such method is rotational cooling. It was thoroughly analyzed, simulated and experimentally confirmed - with the help of optical and microwave pumping, we collapsed the initial Boltzmann distribution of molecules amongst their rotational states into one chosen hyperfine state of the ground rotational state manifold. The efficiency of this process depends on multiple factors, the most crucial being the approach towards dark state destabilization and remixing. After careful investigation, we chose the most appropriate method and devised an efficient rotational cooling scheme. Experimental confirmation showed an enhancement factor of r𝑓23.70±1.13, very close to our theoretical predictions. This allows us to conclude that CeNTREX should provide a 2500-fold improvement over the current best measurements of the nuclear Schiff moment in thallium nucleus.

Considering the hypothetical core melt down scenario for a light water reactor (LWR) a possible failure mode of the reactor pressure vessel (RPV) and its failure time has to be investigated for a determination of the loadings on the containment. Numerous experiments have been performed accompanied with material properties evaluation, theoretical, and numerical work /REM 1993/, /THF 1997/, /CHU 1999/. For pre- and post-test calculations of Lower Head Failure experiments like OLHF or FOREVER it is necessary to model creep and plasticity processes. Therefore a Fi-nite Element Model is developed at the FZR using a numerical approach which avoids the use of a single creep law employing constants derived from the data for a limited stress and temperature range. Instead of this a numerical creep data base (CDB) is developed where the creep strain rate is evaluated in dependence on the current total strain, temperature and equivalent stress. A main task for this approach is the generation and validation of the CDB. Additionally the implementation of all relevant temperature dependent material properties has been performed. For an evaluation of the failure times a damage model according to an approach of Lemaitre is applied. The validation of the numerical model is performed by the simulation of and com-parison with experiments. This is done in 3 levels: starting with the simulation of sin-gle uniaxial creep tests, which is considered as a 1D-problem. In the next level so called "tube-failure-experiments" are modeled: the RUPTHER-14 and the "MPA-Meppen"-experiment. These experiments are considered as 2D-problems. Finally the numerical model is applied to scaled 3D-experiments, where the lower head of a PWR is represented in its hemispherical shape, like in the FOREVER-experiments. This report deals with the 1D- and 2D-simulations. An interesting question to be solved in this frame is the comparability of the French 16MND5 and the German 20MnMoNi55 RPV-steels, which are chemically nearly identical. Since these 2 steels show a similar behavior, it should be allowed on a lim-ited scale to transfer experimental and numerical data from one to the other.

The diploma thesis summarizes the topics from hydromechanics taught at Czech grammar schools (and other Czech secondary schools). Emphasis is placed on the careful derivation of all laws and equations according to the basic principles stated in the thesis (Pascal's law, Archimedes' law, Bernoulli's equation, Euler's laws of motion). The aim of the author was to make all derivations in the thesis to not exceed the complexity of secondary school mathematics and physics. A new approach of teaching hydromechanics based on Euler's laws of motion is outlined. Furthermore, each of the hydromechanics topics is accompanied by (sometimes more or less unconventional) examples and experiments. 1

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After the pilot phase of a simulation study, if the model contains many factors, then direct experimentation may need too much computer processing time, therefore the purpose of screening simulation experiments is to eliminate negligible or unimportant factors of a simulation model in order to concentrate the efforts upon a short list of important factors. For this matter the Sequential bifurcation procedure developed by Bettonvil and Kleijnen [3] is an efficient and effective screening method which can be used. In this study, the Sequential bifurcation screening method is used to determine the important factors of a simulation based decision support model designed by The Swedish Defense Research Agency (FOI) meant for testing operational plans. By using this simulation model, a decision maker is able to test a number of feasible plans against possible courses of events. The sequential bifurcation procedure was applied and sorted the most important factors involved in this simulation model based on their relative importance.

Monte Carlo-based radiation transport codes provide an opportunity to simulate situations with various levels of activation and different induced nuclides. However, to test their reliability, it is important to verify the simulation codes by comparing them with experimental data. In this study, validation of simulation models with experiments was performed with the purpose of determining the reliability of the simulation/experimental results. Concrete is the most generally used shield material as it is inexpensive and adjustable for any construction design. Radiation shielding properties of concrete may vary depending on the concrete composites. In this thesis, the fluences (i.e. the flux integrated over time) of neutrons impinging on the shielding nuclear material were studied using FLUKA Monte Carlo package. The rectangular blocks of shielding nuclear materials such as concrete ingredients: cement, sand and water were irradiated with a beam of 14 MeV neutrons and the shielding properties of these materials were investigated using FLUKA Monte Carlo simulation code. The simulation set-up replicates the experimental measurements performed within the nuclear laboratory in the Department of Physics at the University of Cape Town. The comparison of the effective removal cross-section shows a good agreement between experiments and FLUKA. The results from these two approaches show general agreement for sand and cement, but show some minor deviations for water and concrete. The source of these deviations is discussed, along with potential solutions. FLUKA has been well benchmarked and validated against other Monte Carlo codes. The discrepancies obtained on water and concrete may have occurred from the material properties in the input file. Comparisons of results are presented and the discrepancies and agreements between the two methods are discussed for these target materials. The effective removal cross section of a concrete mix was measured by simulation to be 0.1038 +/- 0.0005 cm-1 and by experiment to be 0.1230 +/- 0.0002 cm-1 of 14 MeV neutrons. This illustrates a broad agreement between experiment and simulation in the case of concrete ingredients. Validation and comparison of measured and simulated neutron irradiation on concrete ingredients shows good agreement, supporting the use of FLUKA for estimating the neutron transmission into the shielding material.