Non-monotonic fluctuation spectra of membranes pinned or tethered discretely to a substrate

The thermal fluctuation spectrum of a fluid membrane coupled harmonically to a solid support by an array of tethers is calculated. For strong tethers, this spectrum exhibits non-monotonic, anisotropic behavior with a relative maximum at a wavelength about twice the tether distance. The root mean square displacement is evaluated to estimate typical membrane displacements. Possible applications cover pillar-supported or polymer-tethered membranes.Comment: 4 pages, 5 figure

Thesen zur Bundestagswahl 1976

Bei den Bundestagswahlen 1976 haben sich zwar diejenigen nicht durchsetzen können, die mit einer Klassenkampfparole gegen links (,,Freiheit oder Sozialismus") angetreten waren; dennoch ist das Wählerpotential der Unionsparteien heute nicht nur stärker denn je, sondern scheint auch - das ist von Bedeutung für die Landtagswahlen der nächsten Jahre - gefestigter denn je. In diesem Zusammenhang ist es wichtig, sich daran zu erinnern, daß bei den Bundestagswahlen 1969 die gültigen Stimmen von CDU/CSU und NPD zusammen über der 50 %-Marge lag und daß damals SPD und FDP ihre Mehrheit der Sitze im Bundestag nur der 5 %-Klausel verdankten. Die Bundestagswahl 1972 muß als Sondervotum für die Ostpolitik, die als Friedenspolitik verkauft wurde, und für Willy Brandt betrachtet werden. Doch selbst bei dieser Wahl konnten CDU und CSU mit 40,5 % der Wahlberechtigten das bei früheren Bundestagswahlen erzielte Ergebnis erreichen (1953: 37,5 %, 1957: 42,4 %, 1961: 38,2 %, 1965: 40,3 % und 1969: 39,3 % der Wahlberechtigten) (1). Erstmals in der Geschichte der Bundesrepbulik konnten sich CDU und CSU bei den Landtagswahlen 1974 bis 1976 (mit Ausnahme von Bayern und Baden-Württemberg) über das Ergebnis der Bundestagswahlen hinaus steigern: in der Summe der Landtagswahlen verbesserte sich die Union mit 1,2 Prozentpunkte

Thermodynamic Evaluation of the system Ta–O and Preliminary Assessment of the Systems Al–Nb–O and Al–Ta–O

The binary tantalum–oxygen system is assessed using the CALculation of PHase Diagrams (CALPHAD) method with experimental data from the literature. The oxygen solubility in the Ta solid-solution phase is discussed and modeled. The low- and high-temperature modifications of Ta₂O₅ are described as stoichiometric compounds. This dataset is extended into the ternary Al–Ta–O system by complementing it with binary datasets for Al–O and Al–Ta from the literature and adding mixed-oxide AlTaO₄. The dataset for the ternary system Al–Nb–O is created by combining the three corresponding binary datasets from the literature and by assessing the quasibinary section Al₂O₃–Nb₂O₅. The ternary aluminum niobates are described as stoichiometric compounds. Phase equilibria between refractory metals and alumina at high temperature are discussed

Modeling and Simulation the Thermal Runaway Behavior of Cylindrical Li-Ion Cells—Computing of Critical Parameter

The thermal behavior of Li-ion cells is an important safety issue and has to be known under varying thermal conditions. The main objectives of this work is to gain a better understanding of the temperature increase within the cell considering different heat sources under specified working conditions. With respect to the governing physical parameters, the major aim is to find out under which thermal conditions a so called Thermal Runaway occurs. Therefore, a mathematical electrochemical-thermal model based on the Newman model has been extended with a simple combustion model from reaction kinetics including various types of heat sources assumed to be based on an Arrhenius law. This model was realized in COMSOL Multiphysics modeling software. First simulations were performed for a cylindrical 1860 cell with a -cathode to calculate the temperature increase under two various simple electric load profiles and to compute critical system parameters. It has been found that the critical cell temperature [Math Processing Error] , above which a thermal runaway may occur is approximately [Math Processing Error] , which is near the starting temperature of the decomposition of the Solid-Electrolyte-Interface in the anode at [Math Processing Error] . Furthermore, it has been found that a thermal runaway can be described in three main stages

Laser-assisted post-processing of additive manufactured metallic parts

Laser-assisted additive manufacturing (AM) is the process of successively melting thin layers of material using a laser source to produce a three dimensional device or product. From the many technologies available, only a few can produce metallic parts that fulfil the requirements of industrial applications. Ultrafast laser machining is a new and promising technical approach for post-processing AM parts since laser ablation and surface modification processes could be applied with high accuracy for trimming shape and functionality, i.e., edge quality and wettability. The impact of different ultrafast laser parameters is evaluated for AM samples, which are examined for surface roughness before and after the laser-assisted post-processes. For all the parameters tested, the use of ultrafast laser resulted in a homogeneous material ablation of the samples’ surfaces. For the investigated parameter range, the AM building tracks were still maintained even after ultrafast laser post-processing. The achieved results showed the formation of self-organized porous structures at low laser scan velocities leading to an enhanced surface roughness. For higher scan velocities characteristic nano ripples might be induced having no significant impact on the measured surface roughness