On Failure of Determinism in Classical Mechanics

Newtonian mechanics is generally considered to be deterministic: Once the initial conditions are known, all the future behaviour of a system can be predicted by solving the equations of motion. (That is the idea of Laplace’s demon.) But a simple example will reveal that the solution of the initial value problem need not be unique. A prediction thus becomes impossible. An effect can happen without a cause, so that causality is annulled

Classical Mechanics recast with Mach’s Principle

Newton introduced the absolute space as a basis of his mechanics. Inertia causes the resistance of masses against an acceleration with respect to this space. Mach raised the objection that this space is unphysical since it is not tangible. He proposed to describe inertial forces in a similar manner like gravitational ones, namely as produced by all masses of the universe. The paper at hand gives the mathematical exploitation of Mach’s concept. Only relative motions of masses enter the resulting equations. Their solutions, however, do not differ from   those of Newton’s approach

Efficient Integration in the Plasticity of Crystals with Pencil Glide and Deck Glide

A stress update algorithm is proposed based on an approximate additive decomposition of the elastic predictor strain. It yields acceptable results even if the strain increments are an order of magnitude larger than the elastic strains. Moreover, it is shown that, in the context of the models of pencil glide and deck glide, at most four nonlinear equations for the computation of the unknown increments of plastic shear are needed in the case of b.c.c. and f.c.c. crystals

The Statics of Fluid Films with Bending Stiffness

Based on the principles of rational mechanics, a general formulation for the bending of a fluid monolayer is given. The internal forces of the surface turn out to be by far more copious than for the classical theory of capillarity, in which case the energy density is independent of the local curvature. There are two striking consequences of the investigation: the membrane forces are not isotropic and hence cannot be characterized by one single surface tension and the tangential component of the surface force must vanish if no torque density acts on the surface. The results should be noted in the study of amphiphiles

Parallel versus Conventional Elastoplasticity

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Texture-Based Modeling of Sheet Metal Forming and Springback

In this paper the application of a crystal plasticity model for body-centered cubic crystals in the simulation of a sheet metal forming process is discussed. The material model parameters are identified by a combination of a texture approximation procedure and a conventional parameter identification scheme. In the application of a cup drawing process the model shows an improvement of the strain and earing prediction as well as the qualitative springback results in comparison with a conventional phenomenological model

Biological maturation and β-adrenergic effectors: development of β-adrenergic receptors in rabbit heart

The β-adrenergic receptor, transduction processes and catalytic activity of the adenylate cyclase enzyme complex have been investigated in rabbit heart at different stages of biological maturation. The binding of [ 3 H]-dihydroalprenolol to a washed membrane preparation isolated from rabbit ventricular muscle was used to characterize β-adrenergic receptors. Significant age-related differences were noted in β-receptor affinity (K d ) and density (RD) of neonatal and adult animals; the adult K d was 3.7-fold greater and the RD 2-fold higher than the neonates. No significant differences in these parameters were detected among the 27-day old fetus and the 1- and 7-day old neonates. Age-dependent differences in agonist isoproterenol affinity for the receptor were not observed in contrast to the significant changes in antagonist (DHA) affinity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45349/1/11010_2004_Article_BF00240617.pd

Comprehensive study of the CuF<inf>2</inf> conversion reaction mechanism in a lithium ion battery

Conversion materials for lithium ion batteries have recently attracted considerable attention due to their exceptional specific capacities. Some metal fluorides, such as CuF2, are promising candidates for cathode materials owing to their high operating potential, which stems from the high electronegativity of fluorine. However, the high ionicity of the metal–fluorine bond leads to a large band gap that renders these materials poor electronic conductors. Nanosizing the active material and embedding it within a conductive matrix such as carbon can greatly improve its electrochemical performance. In contrast to other fluorides, such as FeF2 and NiF2, good capacity retention has not, however, been achieved for CuF2. The reaction mechanisms that occur in the first and subsequent cycles and the reasons for the poor charge performance of CuF2 are studied in this paper via a variety of characterization methods. In situ pair distribution function analysis clearly shows CuF2 conversion in the first discharge. However, few structural changes are seen in the following charge and subsequent cycles. Cyclic voltammetry results, in combination with in situ X-ray absorption near edge structure and ex situ nuclear magnetic resonance spectroscopy, indicate that Cu dissolution is associated with the consumption of the LiF phase, which occurs during the first charge via the formation of a Cu1+ intermediate. The dissolution process consequently prevents Cu and LiF from transforming back to CuF2. Such side reactions result in negligible capacity in subsequent cycles and make this material challenging to use in a rechargeable battery.We acknowledge the funding from the U.S. DOE BES via funding to the EFRC NECCES, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001294 (support for Rosa Robert and Lin-Shu Du) and EPSRC via the “nanoionics” programme grant (support for Xiao Hua). Use of the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory (BNL), was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-98CH10886. Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357.This is the final published version of the article. It first appeared at http://pubs.acs.org/doi/abs/10.1021/jp503902z and is posted here under the terms of ACS's Editors' Choice scheme (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html)

Symmetriebrechung bei biegeelastischen Schichten

Es lässt sich beobachten, dass in bestimmten Situationen isotrope Schichten anisotrop gekrümmte Konfigurationen einnehmen (austrocknende Brotscheibe, Tensidfilm). Im vorliegenden Aufsatz wird gezeigt, dass diese Symmetriebrechung sich aus dem Vorhandensein eines Eigenspannungszustandes in der Schicht erklären lässt. Dieser führt insbesondere im Falle verschwindender mittlerer Krümmung dazu, dass eine gekrümmte Konfiguration der Schicht (deren Mittelfläche dann also eine Minimalfläche darstellt) eine geringere Formänderungsenergie besitzt als die ungekrümmte Konfiguration und deshalb bevorzugt wird