3,372 research outputs found
On the concept of Bell's local causality in local classical and quantum theory
The aim of this paper is to give a sharp definition of Bell's notion of local
causality. To this end, first we unfold a framework, called local physical
theory, integrating probabilistic and spatiotemporal concepts. Formulating
local causality within this framework and classifying local physical theories
by whether they obey local primitive causality --- a property rendering the
dynamics of the theory causal, we then investigate what is needed for a local
physical theory, with or without local primitive causality, to be locally
causal. Finally, comparing Bell's local causality with the Common Cause
Principles and relating both to the Bell inequalities we find a nice
parallelism: Bell inequalities cannot be derived neither from local causality
nor from a common cause unless the local physical theory is classical or the
common cause is commuting, respectively.Comment: 24 pages, 5 figure
Point-contact spectroscopy of Al- and C-doped MgB2. Superconducting energy gaps and scattering studies
The two-band/two-gap superconductivity in aluminium and carbon doped MgB
has been addressed by the point-contact spectroscopy. Two gaps are preserved in
all samples with down to 22 K. The evolution of two gaps as a function
of the critical temperature in the doped systems suggest the dominance of the
band-filling effects but for the increased Al-doping the enhanced interband
scattering approaching two gaps must be considered. The magnetic field
dependences of the Andreev reflection excess currents as well as zero-energy
density of states determined from the experimental data are used to analyze the
intraband scattering. It is shown, that while the C-doping increases the
intraband scattering in the -band more rapidly then in the band,
the Al-doping does not change their relative weight.Comment: 8 pages, incl. 6 figure
A modulated RRd star observed by K2
We report the analysis of the double-mode RR Lyrae star EPIC 205209951, the
first modulated RRd star observed from space. The amplitude and phase
modulation are present in both modes.Comment: 2 pages, 3 figures, proceedings of the Joint
TASC2-KASC9-SPACEINN-HELAS8 Conference "Seismology of the Sun and the Distant
Stars 2016", to be published in EPJ Wo
Alienopterix santonicus sp. n., a metallic cockroach from the Late Cretaceous ajkaite amber (Bakony Mts, western Hungary) documents Alienopteridae within the Mesozoic Laurasia
Cockroaches (Blattaria s. str.) were documented from numerous amber localities around the world, representing both extinct and extant families. Alienopteridae is an extinct cockroach family known only from the Cretaceous of Gondwana (Brazil, Botswana, Myanmar amber) and the Cenozoic of North America. Alienopterix santonicus sp. n. from the Late Cretaceous amber of the Ajka Coal Formation (Bakony Mts, western Hungary) extends the rich geographical distribution of the family into Laurasia during the Mesozoic. As a member of the presumably pollinator cohort Alienopteridae, this species could have played an important role in the Ajka Coal ecosystem during the Santonian. The microrectangular structures of the forewing suggest that the new species likely possessed a metallic colouration already known from the group. Combined with the disruptive body pattern this could have served as an advanced camouflage. The microrectangular structures of the forewing were compared to integument microstructures of extant insects with metallic colouration. Various arthropod taxa are already known from ajkaite, and the new discovery further emphasizes the importance of this amber
BOOK REVIEW. Dario Bini and Victor Pan: Polynomial and Matrix Computations Volume I . Fundamental Algorithms
BOOK REVIEW . James S. Royer and John Case: Subrecursive Programming Systems Complexity & Succinctness
The key elements of conducting load-to-fracture mechanical testing on restoration-tooth units in restorative dentistry
Biomimetic restorative dentistry strives to replace lost tooth tissue by biomaterials with similar physical properties. In order to do so, mechanical testing of dental restorative materials on their own and later in dental cavities is highly important. During this process dentists and engineers are collaborating aiming to set the indications of certain restorative materials and application techniques. In vitro fracture resistance testing of a restored tooth is one of the most important tests to be carried out during the indication setting process. However, for this specific test and received results to be valid for clinicians, the group conducting the tests must pay attention to mimic intraoral conditions as much as possible. The article aims at identifying the key elements of fracture resistance tests in dentistry. Adequately conducting this test is a prerequisite for later testing in in vivo conditions the restorative techniques that produced the best results among the in vitro tests
Behavior of the structure of different materials under static force
The subject of rheology is the study of force-induced deformation and creep in materials, taking into account the effect of time too. The purpose of the measurements is to study time-dependent tension-deformation correlations, which include creep and tension-relaxation parameters, and viscosity. Due to the characteristic structure of biological materials, we try to introduce rheology through different materials. Our samples also include soft, semi-hard and hard materials from fish meat to human teeth. It is very clear from the obtained results that the internal structure of each material is influenced by many factors. These factors also interact with each other and they cannot be standardized in a single study
The key elements of conducting load-to-fracture mechanical testing on restoration-tooth units in restorative dentistry
Biomimetic restorative dentistry strives to replace lost tooth tissue by biomaterials with similar physical properties. In order to do so, mechanical testing of dental restorative materials on their own and later in dental cavities is highly important. During this process dentists and engineers are collaborating aiming to set the indications of certain restorative materials and application techniques. In vitro fracture resistance testing of a restored tooth is one of the most important tests to be carried out during the indication setting process. However, for this specific test and received results to be valid for clinicians, the group conducting the tests must pay attention to mimic intraoral conditions as much as possible. The article aims at identifying the key elements of fracture resistance tests in dentistry. Adequately conducting this test is a prerequisite for later testing in in vivo conditions the restorative techniques that produced the best results among the in vitro tests
Main-Belt Asteroids in the K2 Engineering Field of View
Unlike NASA's original Kepler Discovery Mission, the renewed K2 Mission will
stare at the plane of the Ecliptic, observing each field for approximately 75
days. This will bring new opportunities and challenges, in particular the
presence of a large number of main-belt asteroids that will contaminate the
photometry. The large pixel size makes K2 data susceptible to the effect of
apparent minor planet encounters. Here we investigate the effects of asteroid
encounters on photometric precision using a sub-sample of the K2 Engineering
data taken in February, 2014. We show examples of asteroid contamination to
facilitate their recognition and distinguish these events from other error
sources. We conclude that main-belt asteroids will have considerable effects on
K2 photometry of a large number of photometric targets during the Mission, that
will have to be taken into account. These results will be readily applicable
for future space photometric missions applying large-format CCDs, such as TESS
and PLATO.Comment: accepted for publication in AJ, 6 page
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