Abstract: A ceramic metal halide lamp is provided wherein the ceramic discharge vessel is comprised of dysprosium oxide. The lamp has a warm-up time that is less than about 50%, and preferably less than about one-third, of the warm-up time of a similarly constructed and operated lamp having a ceramic discharge vessel made of polycrystalline aluminum oxide.

Abstract: The present invention uses a post-sinter-HIP anneal to increase the total transmittance of ceramic discharge vessels comprised of a submicron-grained alumina doped with MgO. After the anneal, the submicron-grained alumina discharge vessels have high values of both total and in-line transmittance, and are thus suitable for use in focused-beam, short-arc lamps. In particular, the total transmittance of the discharge vessel is increased to greater than 92% in the wavelength range from about 400 nm to about 700 nm.

Abstract: The present invention is a ceramic discharge vessel for use in high-intensity-discharge (HID) lamps. The discharge vessel has a ceramic body and at least one seal region comprised of an aluminum oxynitride material. The seal region further has a surface layer for contacting a frit material wherein the surface layer is less reactive than the aluminum oxynitride material with respect to the molten frit during sealing. Preferably, the surface layer has a lower nitrogen content than the aluminum oxynitride material. The less reactive surface acts to minimize the formation of bubbles in the sealing frit during the sealing operation.

Abstract: A ceramic discharge vessel is provided wherein the discharge vessel has a ceramic body and at least one expanded reaction-bonded aluminum oxide member hermetically sealed to the ceramic body. The method of making the discharge vessel includes (a) forming a ceramic body; (b) forming a reaction-bonded aluminum oxide member in a green state by compacting a mixture of aluminum metal and aluminum oxide powders; (c) assembling the ceramic body and the reaction-bonded aluminum oxide member in the green state to form an assembly; and (d) reaction sintering the assembly to cause the reaction-bonded aluminum oxide member to expand and form a hermetic seal with the ceramic body.

Abstract: Aluminum nitride arc discharge vessels having a high total transmittance may be made by annealing the as-sintered AlN vessel in a nitrogen atmosphere, preferably at a temperature of at least about 1850° C. and for a time of at least about 50 hours. The annealing increases the total transmittance of the vessel to greater than 92% in the wavelength region from about 400 nm to about 700 nm. The annealed AlN discharge vessels are useful for lamp applications, such as metal halide lamps, and offer an improved durability and life over polycrystalline alumina (PCA).

Abstract: A ceramic discharge vessel is provided wherein the vessel comprises a hollow body for enclosing a discharge and the hollow body is made of a polycrystalline dysprosium oxide containing a luminescent dopant that emits one or more visible light wavelengths when stimulated by radiation generated by the discharge. Preferably, the polycrystalline dysprosium oxide has been doped with one or more of europium, cerium, or terbium in an amount from about 0.1 to about 10 percent by weight on an oxide basis.

Abstract: A translucent polycrystalline material suitable for use in ceramic discharge vessels for metal halide lamps is produced by sintering an alumina powder doped with a MgO sintering aid in a nitrogen atmosphere containing a partial pressure of a vapor phase carbon-containing species. The sintered polycrystalline alumina has a grain boundary phase containing aluminum, oxygen and nitrogen. The formation of the AL—O—N grain boundary phase is believed to facilitate the transport of nitrogen from entrapped pores during sintering. Preferably, the PCA is sintered in a carbon-element furnace under flowing ultra-high-purity nitrogen.

Abstract: An optically translucent polycrystalline alumina sintered body consists essentially of alumina, magnesia, terbia and, optionally, yttria. The magnesia is present in an amount of about 0.020 wgt. percent and the terbia is present in an amount of from about 0.005 to 0.060 wgt. percent. The yttria is present in an amount up to about 0.035 wgt. percent.

Abstract: An optically transparent polycrystalline alumina sintered body consists essentially of alumina, magnesia, yttria and zirconia. The magnesia is present in an amount of about 0.020 wgt. percent, the yttria is present in an amount of about 0.035 wgt. percent, and the zirconia is present in an amount of about 0.018 wgt. percent. An arc tube for a high pressure sodium lamp made from this composition has greatly increased resistance to sodium loss and concomitant outer jacket darkening, whereby the effective amount of lumen output is increased.

Abstract: A resource allocation manager and technique for servers within a computer system. Resources are initially allocated to servers and in order to enhance system performance, resources are reallocated based on a minimization of the maximum performance index. In one example, the server with the largest performance index is allocated additional resources and the server with the smallest performance index loses some of its resources.

Abstract: An optically translucent polycrystalline alumina sintered body consists essentially of alumina, magnesia, terbia and, optionally, yttria. The magnesia is present in an amount of about 0.020 wgt. percent and the terbia is present in an amount of from about 0.005 to 0.060 wgt. percent. The yttria is present in an amount up to about 0.035 wgt. percent.

Abstract: Grit is removed from liquid sewage by flowing such sewage into a settling chamber and causing the sewage to flow in a toroidal pattern around the periphery of the chamber. Grit falls to the floor of the settling chamber and passes radially to and then through a central opening into a grit collection chamber therebeneath. Organic solids are kept in motion in the toroidal flow pattern, or lifted from the settling chamber floor into such flow pattern, and are discharged through an outlet adjacent the upper surface of the liquid in the settling chamber. Toroidal flow is created and maintained by obstructing the tangential flow path of incoming sewage with a baffle which blocks the tangential inlet and has an edge extending above the upper surface of the liquid. A propeller rotating about a vertical axis in the center of the chamber is adjustable so as to keep the contents of the chamber impinging against the baffle as they flow around the tank in the toroidal pattern.