Ceramic-coated boat is chemically inert, provides good heat transfer

Refractory metal foil sprayed with ceramic coating serves as evaporating boat for inorganic materials. The high thermal conductivity of this boat makes it useful with ohmic heaters

Thin-film gage measures low heat-transfer rates

Low heat-transfer gage facilitates determination of the transition between laminar and turbulent conditions, in the boundary layer surrounding slender and moderately slender cones under test in a hypersonic blowdown helium tunnel. The gage consists of a thin layer of vacuum-evaporated platinum on a heat resistant glass substrate contoured to fit model surfaces

Exposure interlock for oscilloscope cameras

An exposure interlock has been developed for oscilloscope cameras which cuts off ambient light from the oscilloscope screen before the shutter of the camera is tripped. A flap is provided which may be selectively positioned to an open position which enables viewing of the oscilloscope screen and a closed position which cuts off the oscilloscope screen from view and simultaneously cuts off ambient light from the oscilloscope screen. A mechanical interlock is provided between the flap to be activated to its closed position before the camera shutter is tripped, thereby preventing overexposure of the film

Hyperbola-generator for location of aperiodic events

Plotting device, when used in conjunction with three or more detectors and local receiver and recorder, can quickly pinpoint location of any aperiodic event. Operation requires minimal training and is readily adapted to the field. Mechanical error in device prototype is less than or equal to 3 percent

Simulator model specification for the augmentor wing jet STOL research aircraft

The configuration and simulation studies of a C-8A (De Havilland Buffalo) aircraft are described. The modifications to STOL configuration consisted of augmentor-wing jet flaps, blown and drooped ailerons, and leading edge slats. The total simulator model includes a number of component parts for producing realistic visual, aural, tactile, vestibular, and kinesthetic cues for the pilot to assess the predicted behavior of the real airplane

Mechanism for neurotransmitter-receptor matching.

Synaptic communication requires the expression of functional postsynaptic receptors that match the presynaptically released neurotransmitter. The ability of neurons to switch the transmitter they release is increasingly well documented, and these switches require changes in the postsynaptic receptor population. Although the activity-dependent molecular mechanism of neurotransmitter switching is increasingly well understood, the basis of specification of postsynaptic neurotransmitter receptors matching the newly expressed transmitter is unknown. Using a functional assay, we show that sustained application of glutamate to embryonic vertebrate skeletal muscle cells cultured before innervation is necessary and sufficient to up-regulate ionotropic glutamate receptors from a pool of different receptors expressed at low levels. Up-regulation of these ionotropic receptors is independent of signaling by metabotropic glutamate receptors. Both imaging of glutamate-induced calcium elevations and Western blots reveal ionotropic glutamate receptor expression prior to immunocytochemical detection. Sustained application of glutamate to skeletal myotomes in vivo is necessary and sufficient for up-regulation of membrane expression of the GluN1 NMDA receptor subunit. Pharmacological antagonists and morpholinos implicate p38 and Jun kinases and MEF2C in the signal cascade leading to ionotropic glutamate receptor expression. The results suggest a mechanism by which neuronal release of transmitter up-regulates postsynaptic expression of appropriate transmitter receptors following neurotransmitter switching and may contribute to the proper expression of receptors at the time of initial innervation

Evolution of the Dark Matter Distribution at the Galactic Center

Annihilation radiation from neutralino dark matter at the Galactic center (GC) would be greatly enhanced if the dark matter were strongly clustered around the supermassive black hole (SBH). The existence of a dark-matter "spike" is made plausible by the observed, steeply-rising stellar density near the GC SBH. Here the time-dependent equations describing gravitational interaction of the dark matter particles with the stars are solved. Scattering of dark matter particles by stars would substantially lower the dark matter density near the GC SBH over 10^10 yr, due both to kinetic heating, and to capture of dark matter particles by the SBH. This result suggests that enhancements in the dark matter density around a SBH would be modest whether or not the host galaxy had experienced the scouring effects of a binary SBH.Comment: 5 pages, 3 figures. Submitted to Physical Review Letter

Issues of alcohol safety in the Vologda oblast

The article presents the destructive social processes and threats to alcohol safety. The estimation of the basic indicators of production and consumption of alcoholic beverages in the region. The study of the international experience of regulate alcohol consumption, the necessity of toughening of state regulation of turnover of alcoholic products

Boundary conditions and defect lines in the Abelian sandpile model

We add a defect line of dissipation, or crack, to the Abelian sandpile model. We find that the defect line renormalizes to separate the two-dimensional plane into two half planes with open boundary conditions. We also show that varying the amount of dissipation at a boundary of the Abelian sandpile model does not affect the universality class of the boundary condition. We demonstrate that a universal coefficient associated with height probabilities near the defect can be used to classify boundary conditions.Comment: 8 pages, 1 figure; suggestions from referees incorporated; to be published in Phys. Rev.