Abstract: Embodiments of a lighting apparatus comprise a barrier coating with multiple layers. Each layer comprises metal oxide particles such as gamma alumina particles and alpha alumina particles. In one embodiment, the barrier coating comprises a first layer that reduces mercury depletion and a second layer that improves opacity.

Abstract: A mercury vapor discharge fluorescent lamp having a barrier layer and a phosphor layer. The barrier layer comprises yttria-coated alumina particles. The barrier layer is preferably at least 11 weight percent yttria. Preferably the yttrium-coated alumina particles are provided in an aqueous suspension and are then substantially separated from the dissolved salts therein before being combined into a coating suspension for coating the lamp.

Abstract: A germicidal UV reactor for use in fluid purifiers is provided, in which the UV reactor comprises an UV lamp with an UV transparent primary envelope and also an UV transparent secondary envelope around the primary envelope. The outer surface of the secondary envelope is in contact with a flowing fluid to be purified. There is an isolating space between the outer surface of the primary envelope and the inner surface of the secondary envelope. At least one of the outer surface of the primary envelope and the inner surface of the secondary envelope is provided with electrical means for heating and thus enhancing UV emitting efficiency of the UV lamp.

Abstract: A germicidal UV reactor for use in fluid purifiers is provided, in which the UV reactor comprises an UV lamp with an UV transparent primary envelope and also an UV transparent secondary envelope around the primary envelope. The outer surface of the secondary envelope is in contact with a flowing fluid to be purified. There is an isolating space between the outer surface of the primary envelope and the inner surface of the secondary envelope. At least one of the outer surface of the primary envelope and the inner surface of the secondary envelope is provided with electrical means for heating and thus enhancing UV emitting efficiency of the UV lamp.

Abstract: A mercury vapor discharge fluorescent lamp having a barrier layer and a phosphor layer. The barrier layer comprises yttria-coated alumina particles. The barrier layer is preferably at least 11 weight percent yttria. Preferably the yttrium-coated alumina particles are provided in an aqueous suspension and are then substantially separated from the dissolved salts therein before being combined into a coating suspension for coating the lamp.

Abstract: An emission mix slurry for coating fluorescent lamp electrodes is provided having a suspension medium of polyethylene glycol 200, and a mixture of calcium-, strontium-, and barium carbonate powder as suspended solids. In another embodiment, the suspension medium is primarily water. The slurry is formulated such that upon activation, the carbonates are oxidized to their corresponding oxides to form the emission mix oxide coating while the polyethylene glycol suspension medium is cleanly oxidized evolving substantially only CO2 and H2O vapor. A method for preparing the emission mix slurry is also provided.

Abstract: An electrodeless low-pressure discharge lamp which comprises a discharge vessel, a means for exciting discharge, an UV-to-visible-converting layer and an UV reflecting layer. The discharge vessel encloses a gas-tight discharge cavity containing an ionizable fill. The discharge vessel has a light-transmitting bulb portion and a reentrant tube protruding into the discharge cavity, and the bulb portion and the reentrant tube each exhibit a surface facing to the discharge cavity. The means for exciting discharge is arranged at least partially in the reentrant tube. The UV-to-visible-converting layer is applied only to the surface of the bulb portion, while the UV reflecting layer is applied to the surface of the reentrant tube.

Abstract: An emission mix slurry for coating fluorescent lamp electrodes is provided having a suspension medium of polyethylene glycol 200, and a mixture of calcium-, strontium-, and barium carbonate powder as suspended solids. In another embodiment, the suspension medium is primarily water. The slurry is formulated such that upon activation, the carbonates are oxidized to their corresponding oxides to form the emission mix oxide coating while the polyethylene glycol suspension medium is cleanly oxidized evolving substantially only CO2 and H2O vapor. A method for preparing the emission mix slurry is also provided.

Abstract: A low pressure mercury vapor discharge lamp is provided, said discharge lamp (10) comprising an envelope (12) formed from light-transmitting material and containing an ionizable gas fill (22), mercury, and electrodes (18) sealed in the envelope. The envelope (12) is provided with a single layer coating (14) on the internal surface thereof next to the discharge space. The coating (14) contains halo-phosphate phosphor and 5-30 mass % aluminum oxide relative to the halo-phosphate phosphor, and the primary particle size of the aluminum oxide is smaller than 30 nanometers, the floc size of the aluminum oxide is smaller than 1 micrometer, and the void fraction of the total floc volume is at least 50%.

Abstract: An electrodeless fluorescent reflector lamp includes a housing arrangement having a threaded screw base for receiving line power and a lamp envelope mounted on the housing arrangement. A ballast circuit is disposed within the housing arrangement and is effective for converting line power into an RF signal which excites a fill contained within the lamp envelope to a discharge state thereby resulting in the production of visible light. The lamp envelope is constructed having an upper curved face portion and a lower tapered portion which extends partly within the housing. A reflective coating is applied to the lower tapered portion of the lamp envelope. A phosphor coating distribution is applied to the interior surface of the lamp envelope in a manner so as to maximize the light output from the reflector lamp.

Abstract: In a luminescent material which comprises a first component for luminescing red light under influence of incident optical radiation and a second component for luminescing in the spectral range from 520 to 560 nm, the second component includes a first phase of garnet crystallization system consisted of yttrium aluminate activated by trivalent cerium and determined by the general structural formula Y.sub.3-a Ce.sub.a Al.sub.5 O.sub.12, wherein 0.0003<a<0.1, and a second phase of hexagonal crystallization system of general structural formula La.sub.b Ce.sub.1-b Al.sub.11 O.sub.18, wherein O<b<1, and the second phase is present in an amount ranging from the amounts detectable by means of X-ray diffractometry to the double amount of the first phase.