We will review our mid-infrared and HST imaging surveys of the circumstellar dust shells of proto-planetary nebulae. While optical imaging indirectly probes the dust distribution via dust-scattered starlight, midIR imaging directly maps the distribution of warm dust grains. Both imaging surveys revealed preferencially axisymmetric nature of PPN dust shells, suggesting that axisymmetry in planet...

Viral shells are self-assembled protein nanocontainers with remarkable material properties. They combine simplicity of construction with toughness and complex functionality. These properties make them interesting for bionanotechnology. To date we know little about how virus structure determines assembly pathways and shell mechanics. We have here used atomic force microscopy to study structural ...

Hierarchical data structures have been widely used to design e cient algorithms for interference detection for robot motion planning and physically-based modeling applications. Most of the hierarchies involve use of bounding volumes which enclose the underlying geometry. These bounding volumes are used to test for interference or compute distance bounds between the underlying geometry. The e ci...

Spherical shells are proposed and presented to improve the gain of a class of wideband phased array systems. This kind of phased arrays is composed of compact elements, which allow for a small distance between elements that is much less than half wavelength at lower operating frequencies. This small distance, as a function of wavelength, results in a small gain. Therefore, shells confronting th...

The Digital Water Education Library collection (DWEL) is being generated by primary and secondary school teachers in the United States. This complex process involves both individual research and team design, and the use of a variety of online tools, such as an online cataloguing tool. Interactions amongst DWEL members are being ethnographically analysed in order to identify requirements for fur...

Gamma-ray bursts are believed to be produced when fast moving ejecta from some central source collides with slower moving, but relativistic, shells that were ejected at an earlier time. In this so called internal shock scenario we expect some fraction of the energy of the burst to be carried by slow moving shells that were ejected at late times. These slow shells collide with faster moving oute...