Snoqualmia, a new polydesmid milliped genus from the northwestern United States, with a description of two new species (Diplopoda, Polydesmida, Polydesmidae)

Snoqualmia, new genus, is described for two species of polydesmid millipeds from the northwestern United States: Snoqualmia snoqualmie, new species, from Washington State, and S. idaho, new species, from Idaho. Males of S. idaho possess unusually complex gonopods, perhaps the most complex to be found in the Order Polydesmida. Snoqualmia is placed in context with other polydesmid genera known from North America. The polydesmid fauna of North America is discussed, as well as characters of the gonopods of the family

Tunnel diode circuit used as nanosecond-range time marker

Simple tunnel diode time marker circuit determines the time at which an event occurs in a scintillation crystal. It is capable of triggering at voltages as low as the noise level of a 10-stage PM tube

Experimental observation of shear thickening oscillation

We report experimental observation of the shear thickening oscillation, i.e. the spontaneous macroscopic oscillation in the shear flow of severe shear thickening fluid. The shear thickening oscillation is caused by the interplay between the fluid dynamics and the shear thickening, and has been predicted theoretically by the present authors using a phenomenological fluid dynamics model for the dilatant fluid, but never been reported experimentally. Using a density-matched starch-water mixture, in the cylindrical shear flow of a few centimeters flow width, we observed strong vibrations of the frequency around 20 Hz, which is consistent with our theoretical prediction.Comment: 4pages, 5 figure

Eastern Approaches to Altered States of Consciousness

Eastern civilizations have traditionally placed much greater emphasis on altered states of consciousness than the civilizations of the West. Altered, higher states are crucial to the major Eastern religions. They play an important role in the practice and content of cultural activities from poetry, painting, and dance to traditional martial arts throughout much of Asia. And their existence is taken for granted, and often emphasized, in popular mythology. So it is only natural that Eastern civilizations over the centuries have paid a great deal of attention to analyzing the nature of these states and developing techniques to produce them as effectively as possible. A wide variety of approaches to altering states of consciousness have been developed and used. These include purely mental meditation procedures, ancillary physical procedures, and behavioral procedures combining mental and physical components.[1] The story of Eastern approaches to altering consciousness is much too vast and complex to be covered in a single chapter. Nevertheless if we confine ourselves to the major traditions such as Yoga, Vedanta and East-Asian Buddhism, important common understandings of altered, higher states of consciousness readily emerge. For despite their different imagery and often conflicting metaphysical interpretations, they all emphasize meditation, recognize comparable levels of mind, and describe the same basic higher states of consciousness. This chapter describes important experiences, states of consciousness, levels of consciousness, and real-world effects emphasized by these traditions, relate them to features of meditation procedures, and offer reflections from the perspective of ongoing scientific research. [1] The use of pharmaceutical approaches is also mentioned favorably in some very ancient texts. In recent millennia, however, it has generally been downplayed and portrayed negatively, and major traditions often discourage it as damaging to aspects of the nervous system responsible for the growth of higher states of consciousness

Shear Flows and Shear Viscosity in a Two-Dimensional Yukawa System (Dusty Plasma)

The shear viscosity of a two-dimensional liquid-state dusty plasma was measured experimentally. A monolayer of highly charged polymer microspheres, with a Yukawa interaction, was suspended in a plasma sheath. Two counter-propagating Ar laser beams pushed the particles, causing shear-induced melting of the monolayer and a shear flow in a planar Couette configuration. By fitting the particle velocity profiles in the shear flow to a Navier-Stokes model, the kinematic viscosity was calculated; it was of order 1 mm^2/s, depending on the monolayer's parameters and shear stress applied.Comment: all 3 figures are combined in a separate pdf fil

Generation of coherent magnetic fields in sheared inhomogeneous turbulence: No need for rotation?

Coherent magnetic fields are often believed to be generated by the combination of stretching by differential rotation and turbulent amplification of magnetic field, via the so-called alpha effect. The latter is known to exist in helical turbulence, which is envisioned to arise due to both rotation and convection in solar-type stars. In this contribution, a turbulent flow driven by a nonhelical inhomogeneous forcing and its kinematic dynamo action are studied for a uniform magnetic field in the background of a linear shear flow. By using a quasilinear analysis and a nonperturbative method utilizing a time-dependent wave number, turbulence property and electromotive force are computed for arbitrary shear strength. Due to the large-scale shear flow, the turbulence is highly anisotropic, as a consequence, so is the electromotive force. The latter is found to exist even without rotation due to the combined effect of shear flow and inhomogeneous forcing, containing not only the alpha effect but also magnetic pumping (the gamma effect representing a transport of magnetic flux by turbulence). Specifically, without shear, only the magnetic pumping exists, aligned with the direction of inhomogeneity. For a weak but nonzero shear, the combined effects of shear and inhomogeneous forcing modify the structure of the magnetic pumping when the inhomogeneity is in the plane of the shear flow, the magnetic pumping becoming bidimensional in that plane. It also induces an alpha tensor which has nondiagonal components. When the inhomogeneity is perpendicular to the plane of the shear flow, the alpha effect has three nonzero diagonal components and one off-diagonal component. However, for a sufficiently strong shear, the gamma and alpha effects are suppressed due to shear stabilization which damps turbulence. A simplified dynamo model is then proposed where a large-scale dynamo arises due to the combined effect of shear flow and inhomogeneous forcing. In particular, the growth of a large-scale axisymmetric magnetic field is demonstrated in case of an inhomogeneity which is perpendicular to the plane of the shear flow. Interesting implications of these results for the structure of magnetic fields in star with slow rotation are discussed. (C) 2011 American Institute of Physics. [doi:10.1063/1.3551700