A 3-D numerical model of comet nuclei is presented. An implicit numerical scheme was developed for the thermal evolution of a spherical nucleus composed of a mixture of ice and dust. The model was tested against analytical solutions, simplified numerical solutions, and 1-D thermal evolution codes. The 3-D code was applied to comet 67P/Churyumov-Gerasimenko; surface temperature maps and the inte...

Measurements of the circular polarization of Balmer-u radiation emitted by excited hydrogen atoms, following the transmission of (20—50)-keV protons through thin, tilted amorphous carbon foils, exhibit markedly unexpected behavior as a function of exposure of the foil to the proton beam. Specifically, the circular polarization changes from an initially well understood tilt-angle dependence to a...

Generalizations of the well-known Bassetti and Erskine formula to include tilt angle and non-Gaussian particle distributions, as well as centroid deflections, are derived.

The price of single point diamond tools with a sharp tip is very high due to complex machining process and highly expensive machining equipments. Yet, the performance is not quite satisfactory. In this paper, we have presented a very simple and cost effective machining process for the sharpening and polishing of diamond stylus using low energy reactive ion beam machining (RIBM). In our method, ...

We model the spontaneous elastic shear deformations of smectic elastomers as they make the thermal transition between the A and C phases. Tilt of the director is accompanied by shear. Unlike nematic elastomers where spontaneous elongation is associated with changes in the magnitude of order, spontaneous distortion in smectics is instead shear and is associated with rotation of the director of t...

MATERIAL AND METHODS We prospectively investigated 41 consecutive patients (mean age, 64 years; range, 22-81 years) who underwent corrective surgery for ASD from March 2011 to September 2012. The mean postoperative follow-up period was 26 (range, 15 33) months. Gait was analyzed before and 1 year after surgery, and the 4m walking status was recorded with a video camera. We measured the angle be...

Since scanning transmission electron microscopy can produce high signal-to-noise ratio bright-field images of thick (≥500 nm) specimens, this tool is emerging as the method of choice to study thick biological samples via tomographic approaches. However, in a convergent-beam configuration, the depth of field is limited because only a thin portion of the specimen (from a few nanometres to tens of...