Textured Walls Research Articles

Nitride-Based LEDs With Textured Side Walls

Nitride-based light-emitting diodes (LEDs) with textured side walls were fabricated. By using plasma-enhanced chemical vapor deposition SiO/sub 2/ layer as the etching mask, we successfully etched the nitride epitaxial layers to achieve wavelike side walls. It was found that such wavelike side walls could mainly enhance the light output at the horizontal directions. With a 20-mA current injection, it was found that the output powers of the LED with textured side walls and normal LED were 9.3 and 8.4 mW, respectively. Furthermore, it was found that such textured side walls will not result in a higher operation voltage.

Odor localization requires visual feedback during free flight in Drosophila melanogaster.

Adult fruit flies follow attractive odors associated with food and oviposition sites through widely varied visual landscapes. To examine the interaction between olfactory and visual cues during search behavior, we recorded three-dimensional flight trajectories as individuals explored controlled sensory landscapes. When presented with the source of an attractive odor invisibly embedded in the floor of a 1 m arena, flies spend most of their time hovering back and forth over the source when flying within a randomly textured visual background but fail to localize the source when searching within a uniform white surround. To test whether flies are associating unique features of the visual background with the strength of odor cues, we flew them within arenas containing evenly spaced vertical stripes. Flies readily localized the odor when flying within visual landscapes lacking azimuthal landmarks provided that vertical edges were present. Flies failed to localize odor when flying within a background pattern consisting of horizontal stripes. These results suggest that, whereas flies do not require spatially unique visual patterns to localize an odor source, they do require visual feedback generated by vertical edges. Quantitative shifts in several components of flight behavior accompanied successful odor localization. Flies decrease flight altitude, turn more often and approach visually textured walls of the arena near an odor source. A simple model based on the statistics of flight behavior supports the hypothesis that a subtle influence on these behaviors is sufficient to lead a fly to its food.

Engineering the surface texture and shape of channels in ceramic substrates

Ceramic/ceramic joining can transform surface channels on a ceramic subcomponent into an interior channel. Interior channels have a number of potential uses in advanced ceramic applications, including application as conduits of a variety of fluids, such as fuel, medicine, or cooling fluids. For cooling fluids in particular, the surface texture and shape of the channel can greatly affect its heat transfer and fluid flow characteristics. This paper explores means of “engineering” the surface textures and shapes of such channels, including the fabrication of channels with circular and non-circular cross-sections as well as channels with smooth or textured walls (and channels with a combination of smooth and textured regions). The microstructure of the channels is analyzed using laser scanning confocal microscopy (LSCM). Although LSCM has been used extensively in biological studies, this study is one of the first studies to apply LSCM as a tool to characterize three-dimensional shapes and textures in ceramic materials.

Parts of British Buildings as Sculpture by Architects

While studying 20th-century publicly sited sculpture in Britain in 1970 [1], I came upon many contemporary functional parts of buildings such as chimneys, cooling towers and textured walls that might be compared to the works of sculptors but were designed by architects. Considerable thought is devoted by some architects to the aesthetic impact of such features, unrelated to their functionalism and unguided by the idea that 'form follows function'. My interview with about 40 architects and 70 sculptors revealed various reasons why sculptors were not called upon by architects for such projects. One common reason given by architects was that their limited budgets did not permit sculptors' fees. Others were that they enjoyed acting as sculptors as a distraction from their routine work, that they were capable of designing total environments and that they knew of few sculptors interested in architecturally related work.