Normal Nearby Galaxies

Following on from IRAS, ISO has provided a huge advancement in our knowledge of the phenomenology of the infrared (IR) emission of normal galaxies and the underlying physical processes. Highlights include: the discovery of an extended cold dust emission component, present in all types of gas-rich galaxies and carrying the bulk of the dust luminosity; the definitive characterisation of the spectral energy distribution in the IR, revealing the channels through which stars power the IR light; the derivation of realistic geometries for stars and dust from ISO imaging; the discovery of cold dust associated with HI extending beyond the optical body of galaxies; the remarkable similarity of the near-IR (NIR)/ mid-IR (MIR) SEDs for spiral galaxies, revealing the importance of the photo-dissociation regions in the energy budget for that wavelength range; the importance of the emission from the central regions in shaping up the intensity and the colour of the global MIR luminosity; the discovery of the ``hot'' NIR continuum emission component of interstellar dust; the predominance of the diffuse cold neutral medium as the origin for the main interstellar cooling line, [CII] 158 micron, in normal galaxies.Comment: 47 pages, 15 figures, to be published in the ISO Special Issue of Space Science Reviews: "ISO science legacy - a compact review of ISO major achievements", Springer 2005. See http://www.iso.vilspa.esa.es/science/SSR/ for a higher resolution version and for all papers in the volum

Stability of the pentaquark in a naive string model

The pentaquark is studied in a simple model of confinement where the quarks and the antiquark are linked by flux tubes of minimal cumulated length, and the Coulomb-like interaction, the spin-dependent terms and the antisymmetrization constraints are neglected.. The ground-state is found to be stable against spontaneous dissociation into a meson and a baryon, both in the case of five equal-mass constituents and for a static quark or antiquark surrounded by four equal masses.Comment: 8 pages, 2 figures, minor corrections, references added, to appear in Phys. Rev.

Positivity Constraints on Spin Observables in Exclusive Pseudoscalar Meson Photoproduction

Positivity constraints have proved to be important for spin observables of exclusive reactions involving polarized initial and final particles. Attention is focused in this note on the photoproduction of pseudoscalar mesons from spin 1/2 baryons, more specifically gamma+ N -> K+ Lambda, gamma+ N -> K Sigma, for which new experimental data are becoming available.Comment: 3 pages,RevTex, 1 figure, more details on the derivation, refs. added, to appear in Phys. Rev.

Chemical doping of individual semiconducting carbon-nanotube ropes

We report the effects of potassium doping on the conductance of individual semiconducting single-walled carbon nanotube ropes. We are able to control the level of doping by reversibly intercalating and de-intercalating potassium. Potassium doping changes the carriers in the ropes from holes to electrons. Typical values for the carrier density are found to be ∼100–1000 electrons/μm. The effective mobility for the electrons is μeff∼20–60 cm2 V-1 s-1, a value similar to that reported for the hole effective mobility in nanotubes [R. Martel et al., Appl. Phys. Lett. 73, 2447 (1998)]

Model-independent constraints on spin observables

We discuss model-independent constraints on spin observables in exclusive and inclusive reactions, with special attention to the case of photoproduction.Comment: 6 pages, 5 figures, Talk by J.-M. Richard at NSTAR 2009, IHEP, Beijing (China), April 19-22, 2009, Proc. to appear in "Chinese Physics C

3D Dynamical Model For Liquid Sloshing Simulation In A Partially Filled Elliptical Tank

Many of 2D mechanical models have been devel-oped to simulate liquid sloshing of a partially filled tank with different shapes. However, those models didn’t represent properly the complex liquid motion, especially in the case of portable tanks. Indeed, forces exerted on the liquid can be lat-eral, longitudinal and vertical. Then, liquid displacement and pressure forces applied to the tank walls are undervalued and may cause design flaws. In this case, 2D mechanical models are ineffective for liquid motion simulation. In previous studies, a 3D equivalent mechanical model has been developed. This dy-namical model is used to simulate different liquid motion in a partially filled tank that consider any sort of excitement forces and get more accurate results in terms of displacements and pressure forces. In this study, a brief description of the new dy-namical model is given, including the liquid discretization pro-cess, stiffness and damping coefficients computing method and equations of motion. Afterward, the model is applied to an el-liptical cross section tank to obtain displacement and pressure forces of the liquid. Finally, the results are compared to the lit-erature

Partizan Subtraction Games

Partizan subtraction games are combinatorial games where two players, say Left and Right, alternately remove a number n of tokens from a heap of tokens, with $n \in S_L$ (resp. $n \in S_R$) when it is Left's (resp. Right's) turn. The first player unable to move loses. These games were introduced by Fraenkel and Kotzig in 1987, where they introduced the notion of dominance, i.e. an asymptotic behavior of the outcome sequence where Left always wins if the heap is sufficiently large. In the current paper, we investigate the other kinds of behaviors for the outcome sequence. In addition to dominance, three other disjoint behaviors are defined, namely weak dominance, fairness and ultimate impartiality. We consider the problem of computing this behavior with respect to $S_L$ and $S_R$, which is connected to the well-known Frobenius coin problem. General results are given, together with arithmetic and geometric characterizations when the sets $S_L$ and $S_R$ have size at most 2

Catecholamine Training Effects from Exercise Programs: A Bridge to Exercise-Temperament Relationships

Three studies were conducted to test whether a catecholamine training effect results from a long-term aerobic exercise program. Study 1 showed significant increases in urinary adrenaline and noradrenaline following moderate mental stress/challenge for male aerobics subjects after a semester of training. Control groups of nonexercisers and continuously in-condition marathoners showed no comparable pre- to post semester catecholamine increases. Male and female Aerobics subjects were contrasted with nonexercisers across a semester in Study 2; the hypothesis was confirmed that postsemester increases in catecholamines occurred only following an episode of mental challenges/stress, and not following base-rate-rest conditions. Under conditions of more active challenge than in Studies 1 and 2, women subjects in Study 3 provided directional but nonsignificant support for the Study 2 findings. The results are discussed in the context of literature on the relationship of catecholamine availability during challenge/ stress to temperament and on the relationship of aerobic training to temperament. At a theoretical level, the question is discussed of increased catecholamine availability being a likely mediator in the exercise program to temperament relationship