RESUMO
When deformed beyond their elastic limits, crystalline solids flow plastically via particle rearrangements localized around structural defects. Disordered solids also flow, but without obvious structural defects. We link structure to plasticity in disordered solids via a microscopic structural quantity, "softness," designed by machine learning to be maximally predictive of rearrangements. Experimental results and computations enabled us to measure the spatial correlations and strain response of softness, as well as two measures of plasticity: the size of rearrangements and the yield strain. All four quantities maintained remarkable commonality in their values for disordered packings of objects ranging from atoms to grains, spanning seven orders of magnitude in diameter and 13 orders of magnitude in elastic modulus. These commonalities link the spatial correlations and strain response of softness to rearrangement size and yield strain, respectively.
RESUMO
A general model is presented for the production of images of thermospheric dayglow emissions. Ultraviolet images are generated that are relevant to remote sensing of the principal constituents of the thermosphere (O and N(2)) and the ionosphere (O(+)). The emission features considered here are 1356-Å (O), Lyman-Birge-Hopfield bands of N(2) between 1650 and 1715 Å, and 834 Å (O(+)). The MSIS-86 and International Reference Ionosphere models were used as climatological representations of the distributions of neutrals and ions, respectively. We describe the generation of the images beginning with the production of volume-emission-rate profiles. A detailed description of the generalized image-generation technique is given. This technique permits us to change the observer's altitude and viewing geometry without incurring a large computational burden. The images produced by this technique demonstrate the potential of airglow imaging systems for remote sensing of global variability in thermospheric composition.
RESUMO
In 1870, Ansil L. Robinson was charged with the murder of his mistress, Mary Lunsford, in Mansfield, Ohio, U.S.A. Evidence against Robinson included an attempt to match his teeth to bite marks on the victim's arm. Robinson was acquitted after a 3-week trial despite the evidence linking his teeth to the wounds. This trial represents an early and perhaps the first attempt to admit bite-mark evidence in a court of law in the United States. The acquittal resulted in the obscurity that prevented this case from coming to the awareness of the forensic dental and legal communities sooner.
