Null geodesics in conformal gravity

Abstract We present an analysis of the null geodesics of the static, spherically symmetric, vacuum solution to the equations of conformal (Weyl) gravity. We classify the full range of exotic spacetimes arising from the parameter space of the metric. The nature of various notable features of these spacetimes is investigated including light spheres, horizons and physical singularities.</jats:p

Vegetable Oil as an Emergency Fuel

The unstable world political situation combined with the fact that a large amount of the world\u27s oil reserves is located in the Middle East means we must continue to search for an alternate fuel source for our agricultural machinery. It is well-known that there is a limited amount of fossil fuels and even with no world political problems the demand will exceed supply in the not-too-distant future. The United States currently imports fossil fuels because we use more than we produce. Vegetable oils are a renewable resource. They offer a means of keeping our agricultural equipment operating in an oil emergency

Dielectric Coating Thermal Stabilization During GaAs-Based Laser Fabrication for Improved Device Yield

The quality and yield of GaAs-based ridge waveguide devices fabricated at MIT Lincoln Laboratory were negatively impacted by the random lot-to-lot appearance of blisters in the front-side contact metal. The blisters signaled compromised adhesion between the front-side contact metal, underlying SiO2 dielectric coating, and semiconductor surface. A thermal-anneal procedure developed for the fabrication of GaAs slab coupled optical waveguide (SCOW) ridge waveguide devices stabilizes the SiO2 dielectric coating by means of outgassing and stress reduction. This process eliminates a primary source of adhesion loss, as well as blister generation, and thereby significantly improves device yield. Stoney’s equation was used to analyze stress-induced bow in device wafers fabricated using this stabilization procedure. This analysis suggests that changes in wafer bow contribute to the incidence of metal blisters in SCOW devices.United States. Air Force (Air Force Contract No. FA8721-05-C- 0002

Texas Livestock Auction Markets - Methods and Facilities.

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