Nonlinear phononic crystals based on chains of disks alternating with toroidal structures

We study experimentally the acoustic response of a load-bearing, phononic crystal composed of alternating steel disks, and polytetrafluoroethylene o-rings under precompression. The crystal allows for axial, rocking, and shear-polarized wavemodes when excited by a broad-band signal applied off-axis. Finite element analysis is employed to determine the system’s wave modes. The nonlinear interaction between disks and o-rings supports a dynamic response that is tunable with variations in static precompression, leading to controllable frequency shifts in a large band gap. A modal analysis reveals that four of the six principal wave modes are susceptible to external precompression while two modes are not

A Groenewold-Van Hove Theorem for S^2

We prove that there does not exist a nontrivial quantization of the Poisson algebra of the symplectic manifold S^2 which is irreducible on the subalgebra generated by the components {S_1,S_2,S_3} of the spin vector. We also show that there does not exist such a quantization of the Poisson subalgebra P consisting of polynomials in {S_1,S_2,S_3}. Furthermore, we show that the maximal Poisson subalgebra of P containing {1,S_1,S_2,S_3} that can be so quantized is just that generated by {1,S_1,S_2,S_3}.Comment: 20 pages, AMSLaTe

Constrained Dynamics for Quantum Mechanics I. Restricting a Particle to a Surface

We analyze constrained quantum systems where the dynamics do not preserve the constraints. This is done in particular for the restriction of a quantum particle in Euclidean n-space to a curved submanifold, and we propose a method of constraining and dynamics adjustment which produces the right Hamiltonian on the submanifold when tested on known examples. This method we hope will become the germ of a full Dirac algorithm for quantum constraints. We take a first step in generalising it to the situation where the constraint is a general selfadjoint operator with some additional structures.Comment: 49 pages, TEX, input files amssym.def, amssym.te

The effects of moral disengagement mechanisms on doping likelihood are mediated by guilt and moderated by moral traits

Objectives We examined the effects of moral disengagement on doping likelihood and guilt, and determined whether the effects of moral disengagement on doping likelihood were mediated by guilt and moderated by moral traits. Design We used an experimental design to compare the effects of moral disengagement mechanisms on doping likelihood and guilt in hypothetical situations. Method Athletes indicated their doping likelihood and anticipated guilt in situations describing one of six moral disengagement mechanisms (moral justification, advantageous comparison, euphemistic labeling, distortion of consequences, displacement of responsibility, diffusion of responsibility) and in neutral (control) situations. They also completed measures of moral agency, identity, perfectionism, and values, to which we refer collectively as moral traits. Results Doping likelihood was higher in all six moral disengagement situations compared to neutral situations. Anticipated guilt was lower in five moral disengagement situations (except euphemistic labeling) compared to neutral situations. Doping likelihood and anticipated guilt differed among the moral disengagement mechanisms. The effect of five moral disengagement mechanisms (except euphemistic labeling) on doping likelihood was mediated by anticipated guilt. The effect of overall moral disengagement on doping likelihood was moderated by moral agency, moral perfectionism and moral values. Conclusions Moral disengagement increased the likelihood of doping and decreased affective self-sanction for doping as predicted by the theory of moral thought and action. The finding that the effects of moral disengagement on doping likelihood were moderated by moral agency, moral perfectionism and moral values highlights the role played by moral traits to restrain dishonest conduct in sport

Glueball Spin

The spin of a glueball is usually taken as coming from the spin (and possibly the orbital angular momentum) of its constituent gluons. In light of the difficulties in accounting for the spin of the proton from its constituent quarks, the spin of glueballs is reexamined. The starting point is the fundamental QCD field angular momentum operator written in terms of the chromoelectric and chromomagnetic fields. First, we look at the restrictions placed on the structure of glueballs from the requirement that the QCD field angular momentum operator should satisfy the standard commutation relationships. This can be compared to the electromagnetic charge/monopole system, where the quantization of the field angular momentum places restrictions (i.e. the Dirac condition) on the system. Second, we look at the expectation value of this operator under some simplifying assumptions.Comment: 11 pages, 0 figures; added references and some discussio

Female attraction to male muscle mass across the menstrual cycle.

The current project investigated female attraction to male muscle mass across the menstrual cycle. On four separate occasions in a five week period, female participants rated the attractiveness of images of male bodies. Images included four different levels of muscle mass: low muscle, medium muscle, high muscle, and extremely high muscle. It was hypothesized that females would rate the high and the extremely high muscle mass images higher in attractiveness when ovulating than when not ovulating. It was also hypothesized that females would rate the low muscle mass images low in attractiveness regardless of ovulatory status. Results revealed no significant interaction between ovulatory status and ratings of muscle mass. However, there was a significant main effect for muscle mass. Extremely high muscle images were rated significantly higher than both medium muscle images and low muscle images. High muscle images were rated significantly higher than both medium muscle images and low muscle images. Medium muscle images were rated significantly lower than both extremely high muscle images and high muscle images, but higher than low muscle images. Low muscle images were rated significantly lower than extremely high muscle images, high muscle images, and medium muscle images, each. It seems that muscle mass is not one of the indications of testosterone level that females use to evaluate mates. Additionally, females do not appear to be highly attracted to males with very low muscle mass, regardless of ovulatory status

The 6-vertex model of hydrogen-bonded crystals with bond defects

It is shown that the percolation model of hydrogen-bonded crystals, which is a 6-vertex model with bond defects, is completely equivalent with an 8-vertex model in an external electric field. Using this equivalence we solve exactly a particular 6-vertex model with bond defects. The general solution for the Bethe-like lattice is also analyzed.Comment: 13 pages, 6 figures; added references for section