Fabric anisotropy & DEM informed two-surface hyperplasticity : constitutive formulation, asymptotic states & experimental validation.

In geotechnical analysis continuum idealisations of the bulk material still provide the most appropriate approach for engineers designing large-scale structures. In this area, the most successful framework for describing the behaviour of soils is Critical State (CS) soil mechanics. However, the findings from discrete element method (DEM) analysis, such as the uniqueness of the CS, can provide invaluable information in the development such models. This paper details the key concepts behind a two-surface hyperplasticity model (?) whose development was informed by recent DEM findings on the uniqueness of the CS. Asymptotic states of the model will be confirmed and the DEM-continuum-experimental loop will be closed through comparison of the developed model with experimental data on coarse-grained particulate media. This will demonstrate, that providing the previous stress history is accounted for, the proposed model is suitable for a variety of particulate media

Observations of Plasma Upflow in a Warm Loop with Hinode/EIS

A complete understanding of Doppler shift in active region loops can help probe the basic physical mechanism involved into the heating of those loops. Here we present observations of upflows in coronal loops detected in a range of temperature temperatures (log T=5.8 - 6.2). The loop was not discernible above these temperatures. The speed of upflow was strongest at the footpoint and decreased with height. The upflow speed at the footpoint was about 20 km/s in Fe VIII which decreased with temperature being about 13 km/s in Fe X, about 8 km/s in Fe XII and about 4 km/s in FeXIII. To the best of our knowledge this is the first observation providing evidence of upflow of plasma in coronal loop structures at these temperatures. We interpret these observations as evidence of chromospheric evaporation in quasi-static coronal loops.Comment: 14 pages, 5 figures, Accepted for Publication in The Astrophysical Journal Letter

Observations on the linguistic epigraphic choice in late antique inscriptions from Malta

The aim of this paper is to reconsider the Maltese epigraphic material from a linguistic point of view, with an attempt to point out what the specific linguistic choice means within the epigraphic context. Analysing the epigraphic data, it is possible to suppose that in late antiquity the Greek-speaking community in Malta was linked to a Jewish community maybe coming from abroad. Furthermore, a parallel can be established with the south-eastern area in Sicily, where there is evidence for the presence of Jewish burial places in Christian necropoleis, with the preponderance of Greek used as epigraphic language. The choice of Greek for the funerary inscriptions from Malta does not tend to be arbitrary, and might indicate the persistent use of the original language of an immigrant community.peer-reviewe

Observations

Observations on qualia, death, free will, why there is something rather than nothing, and the Star Trek vs. the Star Wars debate

Jicamarca mesospheric observations

In explaining the scattering of VHF radar signals from the mesosphere there are two observational facts that must be accounted for. These are; (1) the aspect sensitivity of the scattered signal and that this aspect sensitivity is largest in the lower part of the mesosphere, and (2) the correlating between the scattered power and the signal correlation time. This behavior is similar to that of the scattering from the troposphere/stratosphere region, and it is suggested that the scattering mechanisms are similar in these three regions. Several different experiments are performed. They all show strong indications of aspect sensitivity and changing correlation between scattered power and correlation time. There is no indication of stratified reflecting layers unless these layers are modulated in space and time to a degree that they cannot be distinguished from turbulence in any other way than that they cause somewhat aspect sensitive scattering

Optimal Microlensing Observations

One of the major limitations of microlensing observations toward the Large Magellanic Cloud (LMC) is the low rate of event detection. What can be done to improve this rate? Is it better to invest telescope time in more frequent observations of the inner high surface-brightness fields, or in covering new, less populated outer fields? How would a factor 2 improvement in CCD sensitivity affect the detection efficiency? Would a series of major (factor 2--4) upgrades in telescope aperture, seeing, sky brightness, camera size, and detector efficiency increase the event rate by a huge factor, or only marginally? I develop a simplified framework to address these questions. With observational resources fixed at the level of the MACHO and EROS experiments, the biggest improvement (factor ~2) would come by reducing the time spent on the inner ~25 deg^2 and applying it to the outer ~100 deg^2. By combining this change with the characteristics of a good medium-size telescope (2.5 m mirror, 1" point spread function, thinned CCD chips, 1 deg^2 camera, and dark sky), it should be possible to increase the detection of LMC events to more than 100 per year (assuming current estimates of the optical depth apply to the entire LMC).Comment: Submitted to ApJ, 13 pages plus 3 figure

Observations of Doppler Boosting in Kepler Lightcurves

Among the initial results from Kepler were two striking lightcurves, for KOI 74 and KOI 81, in which the relative depths of the primary and secondary eclipses showed that the more compact, less luminous object was hotter than its stellar host. That result became particularly intriguing because a substellar mass had been derived for the secondary in KOI 74, which would make the high temperature challenging to explain; in KOI 81, the mass range for the companion was also reported to be consistent with a substellar object. We re-analyze the Kepler data and demonstrate that both companions are likely to be white dwarfs. We also find that the photometric data for KOI 74 show a modulation in brightness as the more luminous star orbits, due to Doppler boosting. The magnitude of the effect is sufficiently large that we can use it to infer a radial velocity amplitude accurate to 1 km/s. As far as we are aware, this is the first time a radial-velocity curve has been measured photometrically. Combining our velocity amplitude with the inclination and primary mass derived from the eclipses and primary spectral type, we infer a secondary mass of 0.22+/-0.03 Msun. We use our estimates to consider the likely evolutionary paths and mass-transfer episodes of these binary systems.Comment: 8 pages, 4 figures, ApJ 715, 51 (v4 is updated to match the published version, including a note added in proof with measured projected rotational velocities)

Observations on the aurora,

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