Long range predictability of atmospheric flows

International audienceIn the light of recent advances in 2D turbulence, we investigate the long range predictability problem of atmospheric flows. Using 2D Euler equations, we show that the full nonlinearity acting on a large number of degrees of freedom can, paradoxically, improve the predictability of the large scale motion, giving a picture opposite to the one largely popularized by Lorenz: a small local perturbation of the atmosphere will progressively gain larger and larger scales by nonlinear interaction and will finally cause large scale change in the atmospheric flow

Hot Quark Matter with an Axial Chemical Potential

We analyze the phase diagram of hot quark matter in presence of an axial chemical potential, $\mu_5$. The latter is introduced to mimic the chirality transitions induced, in hot Quantum Chromodynamics, by the strong sphaleron configurations. In particular, we study the curvature of the critical line at small $\mu_5$, the effects of a finite quark mass and of a vector interaction. Moreover, we build the mixed phase at the first order phase transition line, and draw the phase diagram in the chiral density and temperature plane. We finally compute the full topological susceptibility in presence of a background of topological charge.Comment: 12 pages, 7 figures. Few references added, short discussion included. Final version appearing on Phys. Rev.

Reply to Comment on ‘‘Experimental test of the Anderson–Mott transition model for excitation transport’’

It is argued that the critical electronic energy transfer EET concentrations observed in naphthalene2,4 are not accounted for by the Klafler and Fortner1,3,5 models of an Anderson transition. (AIP)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70450/2/JCPSA6-73-2-1005-1.pd

Vibrational Exciton Density of States in Solid Benzene

Computer‐aided calculations, based on experimentally‐fitted pairwise interaction terms, give the complete exciton density‐of‐states profile for the entire Brillouin zone. The restricted Frenkel model, with short‐range interactions, is the key assumption. Results are given and discussed for the out‐of‐plane a2ua2u normal mode ν11ν11(C6H6 and C6D6), for ν12(b1u)ν12(b1u), and for ν15(b2u)ν15(b2u). The wide range of parameters used makes this investigation pertinent to other vibrational and electronic exciton bands of benzene and any other molecular crystal with the same interchange symmetry. Also, Van Hove singularities are found to be more important for symmetry‐based critical points than for “accidental” critical points. Present‐day experimental and theoretical intermolecular excitation exchange interaction terms are compared.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71006/2/JCPSA6-53-9-3674-1.pd

Experimental test of the Anderson–Mott transition model for excitation transporta)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69648/2/JCPSA6-70-6-3133-1.pd

Biodiversiteit onder glas : Voedsel voor luizenbestrijders

In het praktijknetwerk biodiversiteit onder glas is door glastuinders geëxperimenteerd met bloemen in en rond de kas . Al dan niet in combinatie met bankerplanten zoals granen. Deze brochure is gemaakt om kennis over bloemen en biologische bestrijders te geven en specifiek het nut van biodiversiteit . Biodiversiteit geeft ondersteuning aan meerdere natuurlijke bestrijders van bladluizen. Vooral in de paprikateelt vormen bladluizen soms een ware plaag. Het praktijknetwerk heeft kennis opgeleverd die helpt het agro-eco systeem te versterken

Chiral symmetry restoration in (2+1)-dimensional QEDQED with a Maxwell-Chern-Simons term at finite temperature

We study the role played by a Chern-Simons contribution to the action in the $QED_3$ formulation of a two-dimensional Heisenberg model of quantum spin systems with a strictly fixed site occupation at finite temperature. We show how this contribution affects the screening of the potential which acts between spinons and contributes to the restoration of chiral symmetry in the spinon sector. The constant which characterizes the Chern-Simons term can be related to the critical temperature $T_c$ above which the dynamical mass goes to zero.Comment: 8 pages, 4 figure

Ghost Condensate Busting

Applying the Thomas-Fermi approximation to renormalizable field theories, we construct ghost condensation models that are free of the instabilities associated with violations of the null-energy condition.Comment: 9 pages, minor corrections, a reference added, the discussion on consistency of the Thomas-Fermi approximation expanded, to appear in JCA

Body Integrity Identity Disorder

Introduction: Body Integrity Identity Disorder (BIID) is a rare, infrequently studied and highly secretive condition in which there is a mismatch between the mental body image and the physical body. Subjects suffering from BIID have an intense desire to amputate a major limb or severe the spinal cord in order to become paralyzed. Aim of the study is to broaden the knowledge of BIID amongst medical professionals, by describing all who deal with BIID. Methods: Somatic, psychiatric and BIID characteristic data were collected from 54 BIID individuals using a detaile

Slipping friction of an optically and magnetically manipulated microsphere rolling at a glass-water interface

The motion of submerged magnetic microspheres rolling at a glass-water interface has been studied using magnetic rotation and optical tweezers combined with bright-field microscopy particle tracking techniques. Individual microspheres of varying surface roughness were magnetically rotated both in and out of an optical trap to induce rolling, along either plain glass cover slides or glass cover slides functionalized with polyethylene glycol. It has been observed that the manipulated microspheres exhibited nonlinear dynamic rolling-while-slipping motion characterized by two motional regimes: At low rotational frequencies, the speed of microspheres free-rolling along the surface increased proportionately with magnetic rotation rate; however, a further increase in the rotation frequency beyond a certain threshold revealed a sharp transition to a motion in which the microspheres slipped with respect to the external magnetic field resulting in decreased rolling speeds. The effects of surface-microsphere interactions on the position of this threshold frequency are posed and investigated. Similar experiments with microspheres rolling while slipping in an optical trap showed congruent results.Comment: submitted to Journal of Applied Physics, 11 figure