Modeling the effect of anisotropic pressure on tokamak plasmas normal modes and continuum using fluid approaches

Extending the ideal MHD stability code MISHKA, a new code, MISHKA-A, is developed to study the impact of pressure anisotropy on plasma stability. Based on full anisotropic equilibrium and geometry, the code can provide normal mode analysis with three fluid closure models: the single adiabatic model (SA), the double adiabatic model (CGL) and the incompressible model. A study on the plasma continuous spectrum shows that in low beta, large aspect ratio plasma, the main impact of anisotropy lies in the modification of the BAE gap and the sound frequency, if the q profile is conserved. The SA model preserves the BAE gap structure as ideal MHD, while in CGL the lowest frequency branch does not touch zero frequency at the resonant flux surface where $m+nq=0$, inducing a gap at very low frequency. Also, the BAE gap frequency with bi-Maxwellian distribution in both model becomes higher if $p_\perp > p_\parallel$ with a q profile dependency. As a benchmark of the code, we study the m/n=1/1 internal kink mode. Numerical calculation of the marginal stability boundary with bi-Maxwellian distribution shows a good agreement with the generalized incompressible Bussac criterion [A. B. Mikhailovskii, Sov. J. Plasma Phys 9, 190 (1983)]: the mode is stabilized(destabilized) if $p_\parallel < p_\perp (p_\parallel > p_\perp)$

Analysing the impact of anisotropy pressure on tokamak equilibria

Neutral beam injection or ion cyclotron resonance heating induces pressure anisotropy. The axisymmetric plasma equilibrium code HELENA has been upgraded to include anisotropy and toroidal flow. With both analytical and numerical methods, we have studied the determinant factors in anisotropic equilibria and their impact on flux surfaces, magnetic axis shift, the displacement of pressures and density contours from flux surface. With $p_\parallel/p_\perp \approx 1.5$, $p_\perp$ can vary 20% on $s=0.5$ flux surface, in a MAST like equilibrium. We have also re-evaluated the widely applied approximation to anisotropy in which $p^*=(p_\parallel + p_\perp)/2$, the average of parallel and perpendicular pressure, is taken as the approximate isotropic pressure. We find the reconstructions of the same MAST discharge with $p_\parallel/p_\perp \approx 1.25$, using isotropic and anisotropic model respectively, to have a 3% difference in toroidal field but a 66% difference in poloidal current

Discovery of extreme asymmetry in the debris disk surrounding HD 15115

We report the first scattered light detection of a dusty debris disk surrounding the F2V star HD 15115 using the Hubble Space Telescope in the optical, and Keck adaptive optics in the near-infrared. The most remarkable property of the HD 15115 disk relative to other debris disks is its extreme length asymmetry. The east side of the disk is detected to ~315 AU radius, whereas the west side of the disk has radius >550 AU. We find a blue optical to near-infrared scattered light color relative to the star that indicates grain scattering properties similar to the AU Mic debris disk. The existence of a large debris disk surrounding HD 15115 adds further evidence for membership in the Beta Pic moving group, which was previously argued based on kinematics alone. Here we hypothesize that the extreme disk asymmetry is due to dynamical perturbations from HIP 12545, an M star 0.5 degrees (0.38 pc) east of HD 15115 that shares a common proper motion vector, heliocentric distance, galactic space velocity, and age.Comment: 4 pages, 3 figures, ApJ Letters, accepte

The Clinical Gestalts of Autism: Over 40 years of Clinical Experience with Autism

The clinical gestalts of autism are very broad and much more heterogeneous than people realise. DSM V [1] gives a more narrow and condensed description of what autism is in the twentieth century. DSM focuses on problems with socioemotional reciprocity, non-verbal communication and difficult interpersonal relationships, restricted, repetitive patterns of behaviour, early onset and functional impairment. First, I want to flesh out the autism spectrum disorder gestalts as it presents to experienced clinical practitioners. It is the opposite of the “tick box” approach to diagnosis so common today. It focuses on the phenomena as they would have been focused on in the late nineteenth and early twentieth century, an approach that has faded into the background in the late twentieth and early twenty-first century. It is critical at this point of the twenty-first century that we re-engage with phenomenology and with the clinical gestalt of psychiatric conditions which show a great deal of overlap with much mixed phenomenology. We will start by examining social relations in autism spectrum disorders. Clearly, this is central to autism

The Our Solar Siblings Pipeline: Tackling the data issues of the scaling problem for robotic telescope based astronomy education projects

In this paper, a pipeline designed to produce data products for education is described. The primary goal of the pipeline is to facilitate teacher usage of robotic telescopes in the classroom and to reduce administration time for project personnel. In so doing, it produces data products that are scientifically valid and robust using multiple different photometric measurement techniques to create catalogues of both instrumental measurements as well as calibrated measurements crossmatched to popular astronomical catalogues where standard stars are available. The main blocking factors that the pipeline addresses are outlined, an overview of the pipeline is provided and it’s future development is forecast

The Witness of the Monotheistic Religions

Archbishop Michael Fitzgerald is President of the Pontifical Council for Interreligious Dialogue. This talk was delivered on April 28, 2003, as the Annual Lecture hosted by the Center for Christian-Jewish Understanding of Sacred Heart University, on the eve of a conference sponsored by the CCJU titled ``Pathways to Peace in the Abrahamic Faiths.\u27\u2