11,806 research outputs found

    Recent Results Addressing the KARMEN Timing Anomaly

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    Recent resuls from experiments at Fermilab and the Paul Scherrer Institute have constrained the parameter space available for a hypothetical particle Q0Q^0 produced in the decay Ļ€+ā†’Ī¼+Q0\pi^+ \to \mu^+ Q^0. This decay has been invoked to explain a peculiar feature of an event arrival time distribution observed in the KARMEN neutrino experiment.Comment: 5 pages, 1 figure. Presented at the Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2000), Quebec City, May 200

    Updated Search for Electron Antineutrino Appearance at MiniBooNE

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    The MiniBooNE experiment at Fermilab has updated its search for \nu_\mu-bar -> \nu_e-bar oscillations with data collected through May 2011. This represents a statistics increase of 52% over the result published in 2010. The data favor LSND-like oscillations over a background-only hypothesis at the 91.1% confidence level. While the new result remains equally consistent with LSND, the compatibility with the background-only hypothesis is improved. An excess of 38.6 +- 18.5 \nu_e-like events below 475 MeV is observed, consistent with the observation of such an excess in neutrino mode.Comment: 3 pages, 1 figure. Proceedings of the PANIC 11 conference, Cambridge, Mass., July 2011 Corrected typographical error in Table

    A cryocooler for applications requiring low magnetic and mechanical interference

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    A very low-power, low-interference Stirling cryocooler is being developed based on principles and techniques described in several previous publications over the last four years. It differs in several important details from those built previously. It uses a tapered displacer based upon an analytical optimization procedure. The displacer is driven by an auxiliary piston and cylinder (rather than by mechanical linkage) using some of the working fluid itself to provide the driving force. This provides smooth, vibration-free motion, and, more importantly, allows complete mechanical and spatial separation of the cryostat from the pressure-wave generator. Either of two different pressure-wave generators can be used. One is a non-contaminating, unlubricated ceramic piston and cylinder. The other is a compressed-air-operated rubber diaphragm with motor-driven valves to cycle the pressure between appropriate limits

    A Single-armed Manta-board as a New Diver-controlled Planing Board and Its Use for Underwater Surveys

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    Due to inadequacies of previous underwater towing techniques and the special needs of a recent underwater survey, a modified mania-board technique was developed. With this new technique, the diver holds on to the manta-board with one arm; consequently, the board is referred to as a single-armed manta-board (sam-board). The sam-board proved inexpensive and highly maneuverable, allowing the divers to freely collect samples or record information. Through some experimenting with the board and changing some of the variables, such as rope lengths, towing speeds, etc., a highly efficient towing method can be achieved. Preplanning and strict diving safety procedures must, however, be implemented to assure efficiency. This paper presents the materials, guidelines for board construction, equipment, and preplanning and diving safety procedures necessary for the sam-board towing operation

    An approach to optimization of low-power Stirling cryocoolers

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    A method for optimizing the design (shape of the displacer) of low power Stirling cryocoolers relative to the power required to operate the systems is described. A variational calculation which includes static conduction, shuttle and radiation losses, as well as regenerator inefficiency, was completed for coolers operating in the 300 K to 10 K range. While the calculations apply to tapered displacer machines, comparison of the results with stepped displacer cryocoolers indicates reasonable agreement

    From an axiological standpoint

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    I maintain that intrinsic value is the fundamental concept of axiology. Many contemporary philosophers disagree; they say the proper object of value theory is final value. I examine three accounts of the nature of final value: the first claims that final value is nonā€instrumental value; the second claims that final value is the value a thing has as an end; the third claims that final value is ultimate or nonā€derivative value. In each case, I argue that the concept of final value described is either identical with the classical notion of intrinsic value or is not a plausible candidate for the primary concept of axiology

    A method of calibrating a photo optical system for determining spatial relationships

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    A technique is described for the calibration of a photo-optical system. This technique yields a response surface. Measurements of image density and image width taken from a microdensitometer trace can be related through this response surface to object dimensions
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