204,024 research outputs found

    Micropattern gas detector technologies and applications, the work of the RD51 collaboration

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    The RD51 collaboration was founded in April 2008 to coordinate and facilitate efforts for development of micropattern gaseous detectors (MPGDs). The 75 institutes from 25 countries bundle their effort, experience and resources to develop these emerging micropattern technologies. MPGDs are already employed in several nuclear and high-energy physics experiments, medical imaging instruments and photodetection applications; many more applications are foreseen. They outperform traditional wire chambers in terms of rate capability, time and position resolution, granularity, stability and radiation hardness. RD51 supports efforts to make MPGDs also suitable for large areas, increase cost-efficiency, develop portable detectors and improve ease-of-use. The collaboration is organized in working groups which develop detectors with new geometries, study and simulate their properties, and design optimized electronics. Among the common supported projects are creation of test infrastructure such as beam test and irradiation facilities, and the production workshop.Comment: Submitted to the IEEE Nuclear Science Symposium 2010 Conference Recor

    A general strong Nyman-Beurling Criterion for the Riemann Hypothesis

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    For each f:[0,\infty)\to\Com formally consider its co-Poisson or M\"{u}ntz transform g(x)=n1f(nx)1x0f(t)dtg(x)=\sum_{n\geq 1}f(nx)-\frac{1}{x}\int_0^\infty f(t)dt. For certain ff's with both f,gL2(0,)f, g \in L_2(0,\infty) it is true that the Riemann hypothesis holds if and only if ff is in the L2L_2 closure of the vector space generated by the dilations g(kx)g(kx), k\in\Nat. Such is the case for example when f=χ(0,1]f=\chi_{(0,1]} where the above statement reduces to the strong Nyman criterion already established by the author. In this note we show that the necessity implication holds for any continuously differentiable function ff vanishing at infinity and satisfying 0tf(t)dt<\int_0^\infty t|f'(t)|dt<\infty. If in addition ff is of compact support then the sufficiency implication also holds true. It would be convenient to remove this compactness condition.Comment: 10 page

    C. S. Peirce and the Square Root of Minus One: Quaternions and a Complex Approach to Classes of Signs and Categorical Degeneration

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    The beginning for C. S. Peirce was the reduction of the traditional categories in a list composed of a fundamental triad: quality, respect and representation. Thus, these three would be named as Firstness, Secondness and Thirdness, as well given the ability to degeneration. Here we show how this degeneration categorical is related to mathematical revolution which Peirce family, especially his father Benjamin Peirce, took part: the advent of quaternions by William Rowan Hamilton, a number system that extends the complex numbers, i.e. those numbers which consists of an imaginary unit built by the square root of minus one. This is a debate that can, and should, have contributions that take into account the role that mathematical analysis and linear algebra had in C. S. Peirce’s past
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