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"Die Bachelorarbeit “Music of the Spheres” soll wissenschaftliche und künstlerische Elemente zum Thema “Klang der Planeten” in Form einer populärwissenschaftlichen Publikation versammeln. Seit Beginn der Menschheit fasziniert uns der Blick in den nächtlichen Sternenhimmel. Einher geht die Sehnsucht des Unbekannten, die unsere Fantasie beflügelt. Als auf die Erde gebundenen Lebewesens treibt uns der Drang, mehr über das Universum da draußen herauszufinden. Dieses Spannungsfeld zwischen Wissensdrang und Fantasie ist eine interessante Grundlage für die geplante Bachelorarbeit.
In der Bachelorarbeit sollen unsere Emotionen mit wissenschaftlichen Erkenntnissen verbunden werden. Für das menschliche Ohr ist die Klangwelt des Weltalls, verursacht durch die sich bewegenden Planeten, ohne Hilfsmittel nicht hörbar. Nach unseren bekannten physikalischen Erkenntnissen ist es im Weltraum komplett still, aufgrund des im All vorherrschenden Vakuums. Der Schall kann sich nicht wie auf der Erde über Schallwellen ausbreiten. In der Publikation soll der Klang der Planeten beschrieben bzw. dargestellt werden. Die wissenschaftshistorische Dimension soll aufgezeigt werden. So hat man sich zum Beispiel in der Antike musikalische und lyrische Bilder davon gemacht, wie sich der Klang des Weltalls und der Planeten anhören könnte. Weiterhin faszinierte diese Frage Künstler unterschiedlicher Epochen und Stilrichtungen, und ist bis heute ein Thema das Anlaß zu künstlerischem Schaffen gibt.
In Form einer Printpublikation soll die Bachelorarbeit historische Thesen und aktuelle wissenschaftliche Texte, Forschungsberichte und Klangdokumente zusammenbringen, literarische und musikalische Umsetzungen zum Thema aufzeigen, und mit wissenschaftlichem und künstlerisch-interpretativem Bildmaterial vereinen.
Um das Thema visuell zu veranschaulichen, sollen die Texte durch Bilder und Siebdrucke ergänzt werden. Selbst erstellte Siebdruck Experimente könnten mit- und ineinander verknüpft werden. Die Publikation weißt ein durchgehendes Gestaltungskonzept auf, welches Texte, Illustrationen und Bildmaterial als Einheit verknüpfen und wiedererkennbar machen. Ebenfalls ist die Auswahl der verwendeten Materialien und Verarbeitungstechniken, wie Druck, Bindung und Papier zu beachten. Neben dem Text- und Bildmaterial werden Klang-Beispiele eingebunden durch QR Codes. So kann der Leser den QR Code der Siebdrucke scannen, um den von der US-Weltraumorganisation NASA erstellten Klang des Planeten anzuhören. Oder ausgehend von wissenschaftlichem Bildmaterial kann der Leser per Scan eine musikalische Partition zum entsprechenden Planeten anhören.
Die angestrebte Zielgruppe besteht aus Wissenschafts- und Designaffinen Personen, die sich insbesondere für den Weltraum interessieren. Entsprechend soll die Gestaltung informativ und gleichzeitig zeitgenössisch sein, um Aufmerksamkeit zu erregen. Mit dem Inhalt der Publikation soll dem Leser gleichzeitig auch der Klang der Planeten hörbar zugänglich gemacht werden.
Vitamin D plays an essential role in calcium and inorganic phosphate (Pi) homeostasis, maintaining their optimal levels to assure adequate bone mineralization. Vitamin D, as calcitriol (1,25(OH)2D), not only increases intestinal calcium and phosphate absorption but also facilitates their renal reabsorption, leading to elevated serum calcium and phosphate levels. The interaction of 1,25(OH)2D with its receptor (VDR) increases the efficiency of intestinal absorption of calcium to 30–40% and phosphate to nearly 80%. Serum phosphate levels can also influence 1,25 (OH)2D and fibroblast growth factor 23 (FGF23) levels, i.e., higher phosphate concentrations suppress vitamin D activation and stimulate parathyroid hormone (PTH) release, while a high FGF23 serum level leads to reduced vitamin D synthesis. In the vitamin D-deficient state, the intestinal calcium absorption decreases and the secretion of PTH increases, which in turn causes the stimulation of 1,25(OH)2D production, resulting in excessive urinary phosphate loss. Maintenance of phosphate homeostasis is essential as hyperphosphatemia is a risk factor of cardiovascular calcification, chronic kidney diseases (CKD), and premature aging, while hypophosphatemia is usually associated with rickets and osteomalacia. This chapter elaborates on the possible interactions between vitamin D and phosphate in health and disease.
Unsteady shallow meandering flows in rectangular reservoirs: a modal analysis of URANS modelling
(2022)
Shallow flows are common in natural and human-made environments. Even for simple rectangular shallow reservoirs, recent laboratory experiments show that the developing flow fields are particularly complex, involving large-scale turbulent structures. For specific combinations of reservoir size and hydraulic conditions, a meandering jet can be observed. While some aspects of this pseudo-2D flow pattern can be reproduced using a 2D numerical model, new 3D simulations, based on the unsteady Reynolds-Averaged Navier-Stokes equations, show consistent advantages as presented herein. A Proper Orthogonal Decomposition was used to characterize the four most energetic modes of the meandering jet at the free surface level, allowing comparison against experimental data and 2D (depth-averaged) numerical results. Three different isotropic eddy viscosity models (RNG k-ε, k-ε, k-ω) were tested. The 3D models accurately predicted the frequency of the modes, whereas the amplitudes of the modes and associated energy were damped for the friction-dominant cases and augmented for non-frictional ones. The performance of the three turbulence models remained essentially similar, with slightly better predictions by RNG k-ε model in the case with the highest Reynolds number. Finally, the Q-criterion was used to identify vortices and study their dynamics, assisting on the identification of the differences between: i) the three-dimensional phenomenon (here reproduced), ii) its two-dimensional footprint in the free surface (experimental observations) and iii) the depth-averaged case (represented by 2D models).
Virgin passive colon biomechanics and a literature review of active contraction constitutive models
(2022)
The objective of this paper is to present our findings on the biomechanical aspects of the virgin passive anisotropic hyperelasticity of the porcine colon based on equibiaxial tensile experiments. Firstly, the characterization of the intestine tissues is discussed for a nearly incompressible hyperelastic fiber-reinforced Holzapfel–Gasser–Ogden constitutive model in virgin passive loading conditions. The stability of the evaluated material parameters is checked for the polyconvexity of the adopted strain energy function using positive eigenvalue constraints of the Hessian matrix with MATLAB. The constitutive material description of the intestine with two collagen fibers in the submucosal and muscular layer each has been implemented in the FORTRAN platform of the commercial finite element software LS-DYNA, and two equibiaxial tensile simulations are presented to validate the results with the optical strain images obtained from the experiments. Furthermore, this paper also reviews the existing models of the active smooth muscle cells, but these models have not been computationally studied here. The review part shows that the constitutive models originally developed for the active contraction of skeletal muscle based on Hill’s three-element model, Murphy’s four-state cross-bridge chemical kinetic model and Huxley’s sliding-filament hypothesis, which are mainly used for arteries, are appropriate for numerical contraction numerical analysis of the large intestine.
Solar thermal concentrated power is an emerging technology that provides clean electricity for the growing energy market. To the solar thermal concentrated power plant systems belong the parabolic trough, the Fresnel collector, the solar dish, and the central receiver system.
For high-concentration solar collector systems, optical and thermal analysis is essential. There exist a number of measurement techniques and systems for the optical and thermal characterization of the efficiency of solar thermal concentrated systems.
For each system, structure, components, and specific characteristics types are described. The chapter presents additionally an outline for the calculation of system performance and operation and maintenance topics. One main focus is set to the models of components and their construction details as well as different types on the market. In the later part of this article, different criteria for the choice of technology are analyzed in detail.
Concentrating solar power
(2022)
The focus of this chapter is the production of power and the use of the heat produced from concentrated solar thermal power (CSP) systems.
The chapter starts with the general theoretical principles of concentrating systems including the description of the concentration ratio, the energy and mass balance. The power conversion systems is the main part where solar-only operation and the increase in operational hours.
Solar-only operation include the use of steam turbines, gas turbines, organic Rankine cycles and solar dishes. The operational hours can be increased with hybridization and with storage.
Another important topic is the cogeneration where solar cooling, desalination and of heat usage is described.
Many examples of commercial CSP power plants as well as research facilities from the past as well as current installed and in operation are described in detail.
The chapter closes with economic and environmental aspects and with the future potential of the development of CSP around the world.
A Gamified Information System (GIS) implements game concepts and elements, such as affordances and game design principles to motivate people. Based on the idea to develop a GIS to increase the motivation of software developers to perform software quality tasks, the research work at hand aims at investigating relevant requirements from that target group. Therefore, 14 interviews with software development experts are conducted and analyzed. According to the results, software developers prefer the affordances points, narrative storytelling in a multiplayer and a round-based setting. Furthermore, six design principles for the development of a GIS are derived.
Das Werk kommentiert leicht verständlich, aktuell und praxisnah die DSGVO sowie das BDSG und - neu - auch das TTDSG (Telekommunikation-Telemedien-Datenschutzgesetz). Verantwortliche erhalten damit eine umfassende Darstellung mit Handlungsempfehlungen zum gesamten neuen Datenschutzrecht. Betriebliche Datenschutzbeauftragte können sich an den fundierten Kommentierungen orientieren, in denen Literatur und Rechtsprechung aktuell berücksichtigt wurden.
Wearable EEG has gained popularity in recent years driven by promising uses outside of clinics and research. The ubiquitous application of continuous EEG requires unobtrusive form-factors that are easily acceptable by the end-users. In this progression, wearable EEG systems have been moving from full scalp to forehead and recently to the ear. The aim of this study is to demonstrate that emerging ear-EEG provides similar impedance and signal properties as established forehead EEG. EEG data using eyes-open and closed alpha paradigm were acquired from ten healthy subjects using generic earpieces fitted with three custom-made electrodes and a forehead electrode (at Fpx) after impedance analysis. Inter-subject variability in in-ear electrode impedance ranged from 20 kΩ to 25 kΩ at 10 Hz. Signal quality was comparable with an SNR of 6 for in-ear and 8 for forehead electrodes. Alpha attenuation was significant during the eyes-open condition in all in-ear electrodes, and it followed the structure of power spectral density plots of forehead electrodes, with the Pearson correlation coefficient of 0.92 between in-ear locations ELE (Left Ear Superior) and ERE (Right Ear Superior) and forehead locations, Fp1 and Fp2, respectively. The results indicate that in-ear EEG is an unobtrusive alternative in terms of impedance, signal properties and information content to established forehead EEG.