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Selective surface - Wikipedia, the free encyclopedia (186 words) |
 | In solar thermal collectors, a selective surface is chosen based on the ratio of radiation-absorption (alpha) to radiation-emission (epsilon), with a higher ratio meaning better performance. |
| One of the first selective surfaces investigated was simply copper with a layer of fl cupric oxide. |
| Black chromium ("fl chrome") nickel-plated copper is another selective surface that is very durable, highly resistant to humidity or oxidizing atmospheres and extreme temperatures while being able to retain its selective properties - but expensive. |
| Selective surface, endosseous dental implants - United States Patent 5,885,079 (0 words) |
| Externally-threaded implants usually have an unthreaded portion at the proximal end of the implant that is commonly referred to as the neck portion, with the remainder of the external surface substantially threaded to or near to the distal end of the implant. |
| Regardless of the smoothness of the HA surface, it is unsuitable material for coating the neck portion of an implant that may become exposed to oral mucosa when crestal bone recession occurs around the top of the implant. |
| The neck surface may be machined, as in the Branemark/Nobel-pharma dental implant, or machined and acid etched to remove loose titanium particles from the surface, as in Core-Vent Corporation's Screw-Vent implant, or the neck may be polished or made of a ceramic. |
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