We have studied the interplay between the layered crystal structure and the 5f magnetism in uranium-based tetragonal compounds UnTIn3n+2. Sin- gle crystals of U2RhIn8, URhIn5 and UIn3 were prepared by In self-flux method. The novel U2RhIn8 compound adopts the Ho2CoGa8-type struc- ture with lattice parameters a = 4.6056(6) ˚A and c = 11.9911(15) ˚A. The behavior of U2RhIn8 strongly resembles that of related URhIn5 and UIn3 with respect to magnetization, specific heat and electrical resistivity except for magnetocrystalline anisotropy developing on stacking composition in the series UIn3 vs. U2RhIn8 and URhIn5. U2RhIn8 orders antiferromagnetically below TN = 117 K and exhibits slightly enhanced Sommerfeld coefficient γ = 47 mJ·mol−1 ·K−2 . TN increases with increasing c/a ratio in contrast to the behavior of their CenTIn3n+2 counterparts. Magnetic field leaves the value of the Néel temperature of URhIn5 and U2RhIn8 unaffected up to 9 T. On the other hand, TN increases with applied hydrostatic pressure up to 3.2 GPa with the ∂TN/∂p coefficient resembling URhIn5 and UIn3. Ther- mal expansion of U2RhIn8 reveals a hysteretic behavior of the antiferromag- netic transition pointing to its 1st -order character. The magnetic structure of URhIn5 obtained from neutron diffraction propagates with k = (1 /2, 1 /2, 1 /2) and the...

Title: Application of Molecular Simulations in Complex Structural Analysis of Layered Materials Author: RNDr. Marek Veteška Department: Department of Chemical Physics and Optics Supervisor: RNDr. Miroslav Pospíšil, Ph.D., Dept. of Chemical Physics and Optics Abstract: Techniques of molecular simulations were used together with experimental measurements (X-ray diffraction, thermogravimetry, infrared spectroscopy, elemental analysis and others) to clarify the structure properties of various types of layered materials. The structure of Zn-Al-layered double hydroxide intercalated by pyrenetetra- sulfonate acid was solved. Depending on the relative humidity, the samples showed different arrangements with three planes of water molecules and with either one or two planes of pyrenetetrasulfonate anions. At the same time considerable variability of anions arrangement was demonstrated. The adsorption behavior of natural montmorillonite and montmorillonite modified by tetramethylammonium cations in relation to aniline and phe- nol was explored. Adsorption features differed according to both the type of adsorbed molecules and the type of adsorbents. An important role was played by the plane of water molecules right above the surface which medi- ated adsorption of anilines. The water plane area was reduced by...

This work deals with the structural analysis of layered zirconium sulfophenylphosphonates and their intercalates with the use of the classical molecular simulation methods. The inner composition of both fully and partially sulfonated layers was determined in agreement with available experimental data, especially chemical analysis, thermogravimetric measurements and X-ray diffraction. The calculations revealed the positions of the water molecules in the planes of sulfo groups which strongly affect the resultant diffraction pattern. Within the zirconium sulfophenylphosphonate layered structure, the arrangements of intercalated species based on optically active dipyridylamine molecules and cations of sodium, copper and iron were solved with the respect to the agreement with experimental results and values of potential energy. In case of the dipyridylamine molecules and its derivatives, the resultant disordered partially row arrangements of the organic molecules in the interlayer were showed to influence the dipole moment of the intercalate. From this point of view, nitro-derivative has been picked out as the most suitable for potential applications. Regarding the intercalated cations, sodium cations take up the space of water molecules next to the sulfo groups while copper and iron cations are distributed in a...

The training of movement procedures to increase the skills of athletes is a fundamental part of competitive sports. A realistic training, supported by technical equipment provides athletes a better success of training and is requested by trainers and training centers all over the world. Especially in winter sports, like luge or bob, a realistic training simulation is not always possible and demands adaptations of specific training procedures. As a part of this article, a new multilayer slide-foil will be presented, which allows athletes an even more realistic training. For this purpose the structure and production process of the foil composite will be shown, as well as results of the tribological behaviour of the foil. / Das Training von Bewegungsabläufen, zur Steigerung von Fähigkeiten, ist ein fundamentaler Bestandteil im Leistungssport. Ein realistisches Training, unterstützt durch technische Systeme, ermöglicht es Athleten optimale Trainingserfolge zu erzielen und wird dementsprechend von Trainern und Leistungszentren überall auf der Welt gewünscht. Insbesondere in Wintersportarten, wie z. B. Rennrodeln oder Bobfahren, kann dies allerdings nur bedingt realisiert werden und erfordert oftmals Abstriche bei der Trainingsgestaltung. Im Rahmen dieses Beitrags wird daher eine mehrschichtige Verbundfolie vorgestellt, welche den Athleten ein realistischeres Training ermöglichen soll. Hierzu werden zum einen der Aufbau und die Herstellung des Folienverbundes erläutert sowie tribologische Untersuchungsergebnisse präsentiert.

Liquefaction is a major challenge in geotechnical engineering in which soil strength and stiffness are compromised due to earthquake activity. Understanding and predicting the behaviour and liquefaction susceptibility of soils under cyclic loading is a critical issue in civil engineering, mining and protective engineering. Numerous earthquake-induced ground failure events (e.g., substantial ground deformation, reduced bearing capacity) or liquefaction in natural fine-grained soils or manmade fine-grained soils (i.e., fine tailings) produced by mining activities have been observed and reported in the literature. Tailings are manmade soils that remain following the extraction of metals and minerals from mined ore in a mine processing plant. Traditionally, such tailings are stored in surface tailings impoundments at the mine’s surface. However, geotechnical and environmental risks and consequences related to conventional tailings impoundments have attracted the attention of the engineering community to develop novel methods of tailings disposal and management to minimize geotechnical and environmental risks. Thus, engineers have introduced and implemented innovative tailings technologies—thickened tailings and paste tailings—as cost-effective means for tailings management in mining operations. As both thickened tailings and paste tailings have lower water content and higher solid content than tailings in conventional impoundments, these tailings may be more resistant to liquefaction. However, it should be noted that the seismic or cyclic behaviour of these thickened and paste tailings, with and without heavy rainfall effects, are not fully understood. There is little technical information or data about the behaviour and liquefaction of thickened and paste tailings under seismic or cyclic loading conditions. The objective of the present PhD research is to investigate the response of layered thickened and paste tailings deposits, with and without heavy rainfall effects, to cyclic loads by conducting shaking table tests. To simulate the field deposition of thickened and paste tailings, tailings were deposited in three thin layers in a flexible laminar shear box (FLSB) attached to the shaking table equipment. A sinusoidal seismic loading at a frequency of 1 Hz and peak horizontal acceleration of 0.13g was applied at the bottom of the layered tailings deposits. Acceleration, displacement and pore water pressure responses to the cyclic loading were monitored at the middle depth of each layer of the tailings deposits. Regarding the acceleration response of these thickened and paste tailings deposits (without the effect of heavy rainfall), there was no difference between the middle of the bottom and middle layers or at the base of the shaking table. However, the acceleration at the middle of the top layer differed from the acceleration at the base of the shaking table. Throughout shaking, the layered tailings deposits (with and without the effect of heavy rainfall) exhibited contraction and dilation responses. The excess pore water pressure ratios of the layered thickened tailings deposit that was not exposed to heavy rainfall prior to shaking were found to exceed 1.0 during shaking. However, for the layered paste tailings deposit that was not exposed to the effect of heavy rainfall prior to shaking, the excess pore water pressure ratios were found to be lower than 0.85 during shaking. This reveals that without the effect of heavy rainfall, the layered thickened tailings deposit was susceptible to liquefaction, whereas the layered paste tailings deposit was resistant to liquefaction during shaking. The excess pore water ratios of the layered thickened and the paste tailings deposits that were exposed to heavy rainfall prior to shaking were found to be lower than 0.8 during shaking. This reveals that with the effect of heavy rainfall, the layered thickened and paste tailings deposits were resistant to liquefaction during shaking. The results and findings of this PhD research thus provide valuable information for the implementation of tailings in earthquake-prone areas.

The enrichment of heavy hydrogen isotopes (deuterium, tritium) is required to fulfill their increasing application demands, e.g., in isotope related tracing, cancer therapy and nuclear reaction plants. However, their exceedingly low natural abundance and the close resemblance of physiochemical properties to protium render them extremely difficult to be separated. In this thesis, we investigate hydrogen isotope transport and separation via layered and two-dimensional materials. Three different theoretical challenges are undertaken in this work: (1) identification of the transported hydrogen species (proton H+ or protium H atom) inside interstitial space of layered materials (hexagonal boron nitride, molybdenum disulfide and graphite) and elucidation of their transport mechanism; (2) separation of hydron (proton H+, deuteron D+, and triton T+) isotopes through vacancy-free graphene and hexagonal boron nitride monolayers; (3) capture of the extremely rare light helium isotope (3He) with atomically thin two-dimensional materials. In the case of hydrogen transport, the essential challenges are investigation of its mechanism as well as the identification of transported particles. Regarding the case of hydron isotope separation, the essential questions are whether or not pristine graphene is permeable to the isotopes, and how quantum tunneling and topological Stone-Wales 55-77 defects affect their permeation and separation through graphene. In the last case, to capture the light helium isotope, quantum tunneling, which favors the lighter particles, is utilized to harvest 3He using graphdiyne monolayer. Our results provide novel theoretical insights into hydrogen particle transport inside the interstitial space of van der Waals materials; they uncover the mechanism of hydron isotope separation through 2D graphene and hexagonal boron nitride monolayers; and they predict the influence of pure quantum tunneling on the enrichment of 3He through graphdiyne membrane.

Modified-release oral drug delivery dosage forms are widely used in the pharmaceutical field to overcome all the potential issues imposed by the physiological variabilities of the gastrointestinal tract as well as to maintain drug concentrations within the therapeutic window. In the market, they are available only as solid dosage forms such as capsules or tablets. The development of a liquid oral dosage form with modified-release properties has been keenly awaited. This form could increase the compliance of patients with a swallowing impairment (i.e. paediatric, older or critically ill patients) and, consequently, the efficacy of the therapeutic treatment. In this study, a new technology has been developed that consists of multi-layered particles suspended extemporaneously in a syrup. Omeprazole and budesonide have been employed as model drugs. The coating procedure was optimized to obtain a yield of minimum 90% w/w and a median diameter below 500 µm. Once the final suspension is prepared extemporaneously, it presents sufficient stability to guarantee the administration of multiple doses filled into a syrup bottle and kept for a limited storage time at room temperature (e.g. up to 10 doses to be administered within 10 days). / Doctorat en Sciences biomédicales et pharmaceutiques (Pharmacie) / info:eu-repo/semantics/nonPublished

For the analysis of the wet pressing process, which was presented in the first part of this paper, a theoretical approach was chosen. This enabled the pre-definition of three quality-related priorities which now will be considered in detail in the second part. For further analysis, real process data, recorded in an early phase of the process implementation, are used. The challenge is that in this process status, the availability of data is limited or the data sets are incomplete. Supported by the theoretical approach, an easier interpretation of the process data, and in case of ambiguous issues, an accelerated decision making is expected. The objective is to show that this combination is suitable for the process analysis in an early production phase.

The wet pressing process represents a new production method for carbon fibre-reinforced plastics components. Due to the low cycle times, it is suitable for use in the automotive industry. Therefore, a sufficient degree of industrialisation needs to be achieved, which is characterised by a stable process. The knowledge about relevant process parameters, their interactions, and influence on the part quality builds the basis of an economic process. This is a major challenge, since in the early stage of process development the available amount of recorded process data is small and the data sets are not complete. As the implementation of time-, material-, and cost-intensive experiments represents no acceptable alternative, a theoretical approach is chosen. This article describes a theoretical procedure to define the critical factors of the wet pressing process with significantly less resource input.

The presented thesis focuses on static analysis of plastic structures, taking into account nonlinear behaviour of the material depending on the stress. The static analysis is performed using the finite element method. The difference between material linear and material nonlinear approach is illustratively described in the introduction. A shell finite element, which is enhanced by the possibility of further delamination into layers and integration points along its thickness, is suitable to be used for a numerical analysis of a plastic structures. Separate chapters are devoted to the integration of the resulting values over the height of the cross-section. The integration of the material stiffness matrix correctly reflects the emergence of eccentricity. A part of the attention is devoted to the numerical quadrature rules. Next chapter is devoted to material nonlinear models. Two approaches are described: a simpler one, using the isotropic nonlinear elastic model, and more general one, using the orthotropic plastic model. The theoretical description is complemented by the graphic interpretation of the criteria according to the individual authors. A significant portion of this work is devoted to the algorithmization of calculation procedures described in the theoretical chapters. The algorithmization itself is implemented in Fortran language into a dynamic-link library which is part of the software program RFEM 5 which is widely used in engineering practice. A part of the work is a study comparing the performance of the different technologies applicable for the algorithmization of the described issues. The agreement of the theoretical analysis of the material models and subsequent implementation within the RFEM 5 is demonstrated on the example of the bent cantilever. The thermoplastic aboveground tank structure is subject of detailed material linear, and nonlinear analysis respectively. The various approaches are compared on the results of stress, deformation an