Accelerating transient dynamics: Targetet modal interaction

Vibrations occur in many areas ranging from heavy-duty industry over micro sensors to appliances in the private household. A key concept for limiting such vibrations is vibration control that avoids or at least minimize unintentional product behavior or negative effects on the health and safety of humans and animals. A concept for attacking vibrations in mechanical systems is outlined based on time-periodic modulation of a physical parameter in the system. This concept can be applied in parallel to existing controls and allows the artificial increase of damping transient dynamics

Vibration and Noise Identification of a Commercial Refrigerator

The vibration transmission to the cooled goods within a refrigerator is a usually neglected field of interest. Previous studies however show that biochemical properties can be affected by continuous exposure to vibration. Optimal storage conditions necessitate protection against UV light and vibration to prevent the cooled good's quality being degraded by outside factors. Using operational transfer path analysis, we investigate different excitation sources that affect a commercial refrigerator and quantify the spectral input-distributions for all potential sources. Environmental influences, operational conditions and human interactions with both the refrigerator directly as well as indirectly via the environment were considered. Based on previous works, we developed a robust algorithm for the estimation of the varying transmission paths within the refrigerator and the close environment. Utilizing the measured and calculated data we investigate optimizations in design. We identified and charactarized the impact of different vibration-sources and used deflection shapes of the system and the results from the TPA to identify areas of interest. Finally, we investigate measures to shift resonance frequencies into spectral ranges with less excitation and to introduce additional damping

Continuation for thin film hydrodynamics and related scalar problems

This chapter illustrates how to apply continuation techniques in the analysis of a particular class of nonlinear kinetic equations that describe the time evolution through transport equations for a single scalar field like a densities or interface profiles of various types. We first systematically introduce these equations as gradient dynamics combining mass-conserving and nonmass-conserving fluxes followed by a discussion of nonvariational amendmends and a brief introduction to their analysis by numerical continuation. The approach is first applied to a number of common examples of variational equations, namely, Allen-Cahn- and Cahn-Hilliard-type equations including certain thin-film equations for partially wetting liquids on homogeneous and heterogeneous substrates as well as Swift-Hohenberg and Phase-Field-Crystal equations. Second we consider nonvariational examples as the Kuramoto-Sivashinsky equation, convective Allen-Cahn and Cahn-Hilliard equations and thin-film equations describing stationary sliding drops and a transversal front instability in a dip-coating. Through the different examples we illustrate how to employ the numerical tools provided by the packages auto07p and pde2path to determine steady, stationary and time-periodic solutions in one and two dimensions and the resulting bifurcation diagrams. The incorporation of boundary conditions and integral side conditions is also discussed as well as problem-specific implementation issues

Molecular excitation in the Interstellar Medium: recent advances in collisional, radiative and chemical processes

We review the different excitation processes in the interstellar mediumComment: Accepted in Chem. Re

A comparison of the neuroprotective efficacy of newly developed oximes (K117, K127) and currently available oxime (obidoxime) in tabun-poisoned rats

The potency of newly developed bispyridinium compounds (K117, K127) to reduce tabun-induced acute neurotoxic signs and symptoms was compared with currently available oxime (obidoxime) using functional observational battery. The neuroprotective effects of atropine alone and atropine combined with one of three bispyridinium oximes (K117, K127, obidoxime) on rats poisoned with tabun at a sublethal dose (180 μg/kg i.m.; 80% of LD50 value) were studied. Tabun-induced neurotoxicity was monitored using a functional observational battery and automatic measurement of motor activity at 24 h following tabun challenge. The results indicated that all tested oximes combined with atropine enabled tabun-poisoned rats to survive 24 h following tabun challenge while one tabun-poisoned rats died within 24 h after tabun poisoning when the rats were treated with atropine alone. Newly developed oxime K127 combined with atropine was the most effective in decreasing tabun-induced neurotoxicity in the case of sublethal poisonings among all oximes tested. Nevertheless, the differences of neuroprotective efficacy between K127 and obidoxime are not sufficient to replace obidoxime by K127 for the treatment of acute tabun poisonings