Chatter is a concern in boring process, due to the low dynamic stiffness of long cantilever boring bars. Chatter suppression in machining permits higher productivity and better surface finishes. The MR fluid, which changes stiffness and undergoes a phase transformation when subjected to an external magnetic field, is applied to adjust the stiffness of the boring bar and suppress chatter. The st...

Bioerosion by boring sponges is an important mechanism shaping the structure of coral reefs all around the world. To determine the excavation rate by boring sponges, we developed a system in which chemical and mechanical boring rates [calcium carbonate (CaCO(3)) dissolution and chip production, respectively] were measured simultaneously in experimental tanks containing reefal rock inhabited by ...

For rotating-tool machining, such as milling, line boring, and cylinder boring, the tool rotation causes the machining force on each tooth to rotate repetitively relative to the inertial coordinate frame. This is quite different than stationary-tool machining, such as turning or boring with a stationary boring bar, in which the force directions are fixed relative to the inertial frame. Although...

Inter-specific interactions are important drivers and maintainers of biodiversity. Compared to trophic and competitive interactions, the role of non-trophic facilitation among species has received less attention. Cavity-nesting bees nest in old beetle borings in dead wood, with restricted diameters corresponding to the body size of the bee species. The aim of this study was to test the hypothes...

A classical example of chatter prone machining is the boring operation. Turning under conditions with high vibrations in the cutting tool deteriorates the surface finish and may cause tool breakage. Severe noise is also a consequence of the high vibration levels in the boring bar. Active control is one possible solution to the noise and vibration problem in boring operations. In boring operatio...

and an increased chlorophyll b to chlorophyll a ratio for better light capture in low light. Furthermore, an Ostreobium strain living in a coral skeleton, where nearly all of the red light has been captured by the zooxanthellae in the coral tissue, has been shown to have modified chlorophyll with a spectrum shifted towards far-red wavelengths. As zooxanthellae cannot use far-red light, more of ...