8,814 research outputs found

    The bearable lightness of being

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    How are philosophical questions about what kinds of things there are to be understood and how are they to be answered? This paper defends broadly Fregean answers to these questions. Ontological categories-such as object, property, and relation-are explained in terms of a prior logical categorization of expressions, as singular terms, predicates of varying degree and level, etc. Questions about what kinds of object, property, etc., there are are, on this approach, reduce to questions about truth and logical form: for example, the question whether there are numbers is the question whether there are true atomic statements in which expressions function as singular terms which, if they have reference at all, stand for numbers, and the question whether there are properties of a given type is a question about whether there are meaningful predicates of an appropriate degree and level. This approach is defended against the objection that it must be wrong because makes what there depend on us or our language. Some problems confronting the Fregean approach-including Frege's notorious paradox of the concept horse-are addressed. It is argued that the approach results in a modest and sober deflationary understanding of ontological commitments

    Evaluation of absorption cycle for space station environmental control system application Interim report

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    Zero-gravity absorption refrigeration system design and performance testing for space station environmental control applicatio

    A Variational Principle for Eigenvalue Problems of Hamiltonian Systems

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    We consider the bifurcation problem u+λu=N(u)u'' + \lambda u = N(u) with two point boundary conditions where N(u)N(u) is a general nonlinear term which may also depend on the eigenvalue λ\lambda. We give a variational characterization of the bifurcating branch λ\lambda as a function of the amplitude of the solution. As an application we show how it can be used to obtain simple approximate closed formulae for the period of large amplitude oscillations.Comment: 10 pages Revtex, 2 figures include

    Classification of decay resistance against white and brown rot fungi within the cultivated Calamus manan stems

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    The decay resistance classes of cultivated Calamus manan aged 10 and 13 years old were investigated. One stem of each age was divided into five different portions namely basal (1.5 metre), upper basal (5.5 metre), middle (13.5 metre), upper middle (17.5 metre) and top (22.5 metre) portions above the ground. Cross-wise, the stem was cut into periphery, intermediate and centre sections. The specimen of size 30 mm × 10 mm × thickness (l × w × t) was oven-dried at 103oC for 24 hours and exposed to agar contained Coriolus versicolor (white rot, FPRL 28A), Pycnoporus sanguineus (White rot) and Coniophora puteana (brown rot, FPRL 11E) for 12 weeks according to ASTM D2017-81 (1986). The results showed that the decay resistance of C. manan varies with fungus, but not obviously different with the age and portion. The periphery section has the best resistance class compared to intermediate and centre sections. C. manan has a better resistant class against brown rot than those of white rot fungi

    Stuttering Min oscillations within E. coli bacteria: A stochastic polymerization model

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    We have developed a 3D off-lattice stochastic polymerization model to study subcellular oscillation of Min proteins in the bacteria Escherichia coli, and used it to investigate the experimental phenomenon of Min oscillation stuttering. Stuttering was affected by the rate of immediate rebinding of MinE released from depolymerizing filament tips (processivity), protection of depolymerizing filament tips from MinD binding, and fragmentation of MinD filaments due to MinE. Each of processivity, protection, and fragmentation reduces stuttering, speeds oscillations, and reduces MinD filament lengths. Neither processivity or tip-protection were, on their own, sufficient to produce fast stutter-free oscillations. While filament fragmentation could, on its own, lead to fast oscillations with infrequent stuttering; high levels of fragmentation degraded oscillations. The infrequent stuttering observed in standard Min oscillations are consistent with short filaments of MinD, while we expect that mutants that exhibit higher stuttering frequencies will exhibit longer MinD filaments. Increased stuttering rate may be a useful diagnostic to find observable MinD polymerization in experimental conditions.Comment: 21 pages, 7 figures, missing unit for k_f inserte

    Measurements at low energies of the polarization-transfer coefficient Kyy' for the reaction 3H(p,n)3He at 0 degrees

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    Measurements of the transverse polarization coefficient Kyy' for the reaction 3H(p,n)3He are reported for outgoing neutron energies of 1.94, 5.21, and 5.81 MeV. This reaction is important both as a source of polarized neutrons for nuclear physics experiments, and as a test of theoretical descriptions of the nuclear four-body system. Comparison is made to previous measurements, confirming the 3H(p,n)3He reaction can be used as a polarized neutron source with the polarization known to an accuracy of approximately 5%. Comparison to R-matrix theory suggests that the sign of the 3F3 phase-shift parameter is incorrect. Changing the sign of this parameter dramatically improves the agreement between theory and experiment.Comment: 12 pages, RevTeX, 5 eps figures, submitted to Phys. Rev.

    A subsonic D-region probe-theory and instrumentation Scientific report no. 247

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    D-layer, subsonic, ion and electron probe operational mobility theory and instrumentation descriptio
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