783 research outputs found

    Can Fregeans have 'I'-thoughts?

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    We examine how Frege?s contrast between identity judgments of the forms ?a=a? vs. ?a=b? would fare in the special case where ?a? and ?b? are complex mental representations, and ?a? stands for an introspected ?I?-thought. We first argue that the Fregean treatment of I-thoughts entails that they are what we call ?one-shot thoughts?: they can only be thought once. This has the surprising consequence that no instance of the ?a=a? form of judgment in this specific case comes out true, let alone a priori true. This further reinforces Glezakos?s objections against the set-up of Frege?s puzzle, while also raising what we think is an acute problem for Fregeans, insofar as I-thought (and indexical thinking more generally), understood in their way, turns out to be incompatible with some basic features of rationality

    Modelling and performance of Nb SIS mixers in the 1.3 mm and 0.8 mm bands

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    We describe the modeling and subsequent improvements of SIS waveguide mixers for the 200-270 and 330-370 GHz bands (Blundell, Carter, and Gundlach 1988, Carter et al 1991). These mixers are constructed for use in receivers on IRAM radiotelescopes on Pico Veleta (Spain, Sierra Nevada) and Plateau de Bure (French Alps), and must meet specific requirements. The standard reduced height waveguide structure with suspended stripline is first analyzed and a model is validated through comparison with scale model and working scale measurements. In the first step, the intrinsic limitations of the standard mixer structure are identified, and the parameters are optimized bearing in mind the radioastronomical applications. In the second step, inductive tuning of the junctions is introduced and optimized for minimum noise and maximum bandwidth. In the 1.3 mm band, a DSB receiver temperature of less than 110 K (minimum 80 K) is measured from 180 through 260 GHz. In the 0.8 mm band, a DSB receiver temperature of less than 250 K (minimum 175 K) is obtained between 325 and 355 GHz. All these results are obtained with room-temperature optics and a 4 GHz IF chain having a 500 MHz bandwidth and a noise temperature of 14 K

    Determining Crack Aperture Distribution in Rocks Using the C-14-PMMA Autoradiographic Method : Experiments and Simulations

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    Because cracks control the global mechanical and transport properties of crystalline rocks, it is of a crucial importance to suitably determine their aperture distribution, which evolves through alteration processes and rock weathering. Due to the high variability of crack networks in rocks, a multiscale approach is needed. The C-14-PMMA (polymethylmethacrylate) method was developed to determine crack apertures using a set of artificial crack samples with different controlled apertures and tilt angles and also using Monte Carlo simulations. The experiments and simulations show the same result: the estimation of apparent aperture w(A) was successful regardless of tilt angle, even if the estimates are less accurate for low tilt angles (Peer reviewe

    Comparison of phosphor screen autoradiography and micro-pattern gas detector based autoradiography for the porosity of altered rocks

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    This study aims to further develop the C-14-PMMA porosity calculation method with a novel autoradiography technique, the Micro-pattern gas detector autoradiography (MPGDA). In this study, the MPGDA is compared with phosphor screen autoradiography (SPA). A set of rock samples from Martinique Island exhibiting a large range of connected porosities was used to validate the MPGDA method. Calculated porosities were found to be in agreement with ones from the SPA and the triple-weight method (TW). The filmless nature of MPGDA as well as straightforward determination of C-14 radioactivity from the source rock makes the porosity calculation less uncertain. The real-time visualization of radioactivity from C-14 beta emissions by MPGDA is a noticeable improvement in comparison to SPA.Peer reviewe

    Contrôle bactériologique et chimique des extraits de viande

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    Billon Jean, Cazaillet M., Chevallier R. Contrôle bactériologique et chimique des extraits de viande. In: Bulletin de l'Académie Vétérinaire de France tome 113 n°4, 1960. pp. 225-236

    Les potages déshydratés à base de viande : Etude bactériologique et chimique. Influence de la conservation

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    Billon Jean, Cazaillet M., Lafont Philippe. Les potages déshydratés à base de viande : Étude bactériologique et chimique, influence de la conservation. In: Bulletin de l'Académie Vétérinaire de France tome 115 n°9, 1962. pp. 383-391
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