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Lie algebra for rotational subsystems of a driven asymmetric top
(2022-05-11)
We present an analytical approach to construct the Lie algebra of finite-dimensional subsystems of the driven asymmetric top rotor. Each rotational level is degenerate due to the isotropy of space, and the degeneracy increases with rotational excitation. For a given rotational excitation, we determine the nested commutators between drift and drive Hamiltonians using a graph representation. We then generate the Lie algebra for subsystems with arbitrary rotational excitation using an inductive argument.
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The relevance of herders’ local ecological knowledge on coping with livestock losses during harsh winters in western Mongolia
(2018-01-29)
In many regions of the world, traditional and local ecological knowledge is still important today for coping with environmental challenges. This study explored the relevance of such knowledge for predicting and coping with harsh winter conditions (dzud) in a remote area of western Mongolia, where government support to disaster-affected herders is restricted by weak infrastructure. Structured face-to-face interviews were held in 50 households (HHs), addressing aspects of livestock possession and management as well as ...
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Genetic diversity and differentiation of Olea europaea subsp. cuspidata (Wall. & G.Don) Cif. in the Hajar Mountains of Oman
(2020-10-04)
Olea europaea subsp. cuspidata (Wall. & G. Don) Cif. is one of the six subspecies important for domestication of olive described as having valuable breeding traits. It is distributed from South Africa to the Middle East and the Mediterranean region to China mainly at mid to high altitudes with adequate precipitation. The currently rather fragmented Olea europaea subsp. cuspidata populations likely represent outposts of a formerly larger and more connected area and are hence vulnerable to additional stresses such as ...
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‘Nach und nach müssen wir alles ablehnen’: Hyperbolische Negativität bei Thomas Bernhard
(2021-02-02)
Thomas Bernhard's work abounds in rejections. The impulse of not wanting to participate, of refusing to be complicit, lies at the heart of Bernhard's oeuvre. If this refusal is frequently embedded in discursive or even programmatic strategies, it really seems to undermine its own foundations, the very arguments and justifications put forward to make the refusal possible. Before being directed at a specific object, the refusal appears to stem from a more general disposition to say no. Drawing on Der Keller (1976), the ...
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Numerical simulation of flow processes of wood‐polymer in extrusion dies
(2021-01-25)
The addition of wood to polymers results in wood‐polymer composites (WPC), whereby the wood content can be up to 80 %. This composite is mainly processed in extruded deckings. The extrusion die is an essential part of the process, which determines both process parameters and the final product. A characteristic of WPC extrusion dies is a partial solidification of the melt before leaving the die. This solidification is necessary to ensure a dimensionally stable extrusion. For the design of WPC extrusion dies numerical ...
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On A Hybrid Concept for Approximating Self‐Excited Periodic Oscillations of Large‐Scaled Dynamical Systems
(2021-01-25)
Concerning the approximation of self‐excited periodic oscillations in large‐scaled mechanical systems involving strong nonlinearities, this contribution suggests a concept for an efficient treatment. The presented Hybrid FD‐HB method takes the advantages of both schemes Harmonic Balance and Finite Difference to enhance the ratio of computational cost and accuracy for mechanical systems with many degrees of freedom. Within this contribution the residual equations, required when applying a NEWTON‐RAPHSON‐scheme, are ...
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The influence of magnetic field on nanoparticle transport in a micro channel
(2021-01-25)
The present study focuses on a new solver considering the effect of magnetic field on nanoparticles concentration in a micro size channel. To describe the multi component behavior of blood, the Euler‐Euler method is used. Particles are modeled by a concentration equation considering a magnetic drift. The influence of a realistic magnetic field on nanoparticles is investigated. A result for a test case is presented. It shows that the magnetic body force resulting from nanoparticles also influence the hematocrit ...
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Psychische Belastungen bei Müllwerkern – Konsequenzen für die Beratungstätigkeit
(2021-01-26)
Um die psychischen Belastungen von Müllwerkern zu erheben, wurde eine Bestandsaufnahme mit der Berufsgruppe vorgenommen, die Erkenntnisse für die spätere Beratungstätigkeit lieferte. Die Erhebung der Belastungen in Gruppendiskussionen wurde durch eine teilnehmende Beobachtung ergänzt, was einen psychodynamischen Blick auf die Besonderheiten der Organisation rund um den Müllwagen und die Charakteristika der Müllwerker erlaubte. Die Ergebnisse zeigen, dass ein Zusammenhang zwischen den Belastungen und dem beruflichen ...
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The J-integral for mixed-mode loaded cracks with cohesive zones
(2020-11-23)
The J-integral quantifies the loading of a crack tip, just as the crack tip opening displacement (CTOD) emanating from the cohesive zone model. Both quantities, being based on fundamentally different interpretations of cracks in fracture mechanics of brittle or ductile materials, have been proven to be equivalent in the late 60s of the previous century, however, just for the simple mode-I loading case. The relation of J and CTOD turned out to be uniquely determined by the constitutive law of the cohesive zone in front ...
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Numerical Simulation of Viscoelastic Fluid‐Structure Interaction Problems and Drug Therapy in the Eye
(2021-01-25)
The vitreous is a fluid‐like viscoelastic transparent medium located in the center of the human eye and is surrounded by hyperelastic structures like the sclera, lens and iris. This naturally gives rise to a fluid‐structure interaction (FSI) problem. While the healthy vitreous is viscoelastic and described by a viscoelastic Burgers‐type equation, the aging vitreous liquefies and is therefore modeled by the Navier‐Stokes equations. We derive a monolithic variational formulation employing the arbitrary Lagrangian ...