Die „Würde der Kreatur” und die Frage nach dem moralischen Status von Pflanzen und Tieren bei gentechnischen Eingriffen

During the last decade the Swiss constitutional formula “dignity of creatures” made a remarkable career, although some authors regularly rejected the term since it introduces a specifically human moral entitlement into the realm of plants and animals. But the term proofed to be useful: using the phrase “dignity” bioethicists could give a more precise version of the moral status of non-human living beings, focussing on their intrinsic, non-instrumental values on one hand and demanding adequate human behaviour on the other. Though originally coined to judge the ethical implications of gene technology, the relevance “dignity” and related concepts such as integrity became clearer in a whole set of questions arising from “using” animals and plants for human purposes.     

Verhalten von Gasturbinenschaufelwerkstoffen bei mechanischer Langzeitbeanspruchung unter Heißgaskorrosion. Teil 2: Metallkundliche Nachuntersuchungen

Behaviour of gas turbine blade materials under mechanical long term loading and hot gas corrosion. Part 2: Metallographical and microanalytical investigations Results of metallographical and microanalytical investigations on selected specimens after mechanical long term creep and LCF-loading under hot gas corrosion conditions will be presented. Uncoated and MCrAlY or Al-diffusion coated specimens of the polycristalline materials IN-738 LC and IN-939 and the single crystal alloys M 002 mod., CM-SX-6 and B 1914 were investigated. The corrosion attack increases with increasing impurities of the hot gas. Internal nitridation and sulphidation of base material or coating is observed after deterioration of the protective scales rich in Cr₂O₃ and/or Al₂O₃.     

The exact moment for the plastic torsion of a cylindrical bar of elliptical cross section

Summary An exact expression for the limiting moment of the torsion of an isotropic, perfectly plastic elliptical bar has not been previously derived. In this note, the solution of this classical problem is reduced in form to a single quadrature. It is shown by comparison that an approximation due to Sokolovsky is inaccurate for large aspect ratios of semiaxes. Through a transformation of coordinates, the exact solution is also applicable to the plastic torsion of an orthotropic circular cylinder with generators perpendicular to a principal axis. It follows that for highly orthotropic materials an approximate solution derived by Hill may also prove inaccurate.With 1 Figure     

Effects of symmetry-breaking perturbations on the onset of the “Smale-horseshoe” chaos

Summary We shall consider in detail, by means of Melnikov method, the appearance of transverse homoclinic points in 1-dimensional problems whose potential term is given by an even function perturbed by some parity-breaking term. After having described the two possible and essentially different situations one can find, we shall introduce two methods in order to carefully analyze in each case the effects of the symmetry perturbing term on the appearance of homoclinic points (and therefore on the onset of the typical “Smale horseshoe” chaotic motion). As examples for the various cases, we shall consider a perturbed Duffing equation the equation for the Josephson junction, and finally an equation for which we can provide the explicit solution, and which becomes in this way a good test for the results. With 3 Figures     

Upper and lower solution estimates in unilateral viscoelastodynamics

Summary The variational and bounding method of hypercircle for linear, elliptic, boundary-value problems of mathematical physics, see e.g. [1], [2], is extended in this paper to inequality, evolution problems of time-dependent structural mechanics. So a procedure is presented, which provides two-sided estimates for solution quantities, either global or local, of the initial mixed boundary-value problem in piece-wise linearized unilateral viscoelastodynamics.     

Influence of initial imperfections on nonlinear free vibration of elastic bars

Summary Nonlinear free vibration of elastic bars possessing initial imperfections is studied. This generalizes the problem of a perfect bar studied previously by Woinowsky-Krieger and Burgreen. For the vibration frequency the differential equation is solved exactly in terms of complete elliptic integrals. Numerical results demonstrate that the initial imperfections usually reduce the frequency of nonlinear free vibration of elastic bars subjected to moderate compression, but there are exceptions with the opposite effect. Such an effect of incerease in frequency was observed previously in unstiffened and cylindrical shells by Singer et al. The exact solution is contrasted with timewise single-term and two-term Galerkin approximations. It turns out that while the single-term treatment fails to show the increase, the two-term treatment brings it out with attendant close agreement with the exact solution.With 3 Figures