Abstract: An apparatus for mixing a vaporized precursor with a gas for producing silica particles is provided. The apparatus includes a mixer housing, a precursor delivery chamber having an output in communication with the mixer housing for delivering a vaporized precursor in the mixer housing, and an oxidizing gas delivery chamber having an output in communication with the mixer housing for delivering an oxidizing gas to be mixed with the vaporized precursor. The apparatus further includes a flashback member disposed within the mixer housing and between the output of the precursor delivery chamber and the output of the oxidizing gas delivery chamber. The flashback member is located at a minimum distance from the output of the oxidizing gas delivery chamber defined by Lminimum (cm)=0.453U (Re)?0.5567, wherein U is the flow rate in cm/sec of precursor and Re is the flow Reynolds number. The flashback member may include a tapered surface on at least one side to reduce recirculation of vaporized gas.

Abstract: An apparatus for mixing a vaporized precursor with a gas for producing silica particles is provided. The apparatus includes a mixer housing, a precursor delivery chamber having an output in communication with the mixer housing for delivering a vaporized precursor in the mixer housing, and an oxidizing gas delivery chamber having an output in communication with the mixer housing for delivering an oxidizing gas to be mixed with the vaporized precursor. The apparatus further includes a flashback member disposed within the mixer housing and between the output of the precursor delivery chamber and the output of the oxidizing gas delivery chamber. The flashback member is located at a minimum distance from the output of the oxidizing gas delivery chamber defined by Lminimum (cm)=0.453U (Re)?0.5567, wherein U is the flow rate in cm/sec of precursor and Re is the flow Reynolds number. The flashback member may include a tapered surface on at least one side to reduce recirculation of vaporized gas.

Abstract: An apparatus for mixing a vaporized precursor with a gas for producing silica particles is provided. The apparatus includes a mixer housing, a precursor delivery chamber having an output in communication with the mixer housing for delivering a vaporized precursor in the mixer housing, and an oxidizing gas delivery chamber having an output in communication with the mixer housing for delivering an oxidizing gas to be mixed with the vaporized precursor. The apparatus further includes a flashback member disposed within the mixer housing and between the output of the precursor delivery chamber and the output of the oxidizing gas delivery chamber. The flashback member is located at a minimum distance from the output of the oxidizing gas delivery chamber defined by Lminimum (cm)=0.453 U (Re)?0.5567, wherein U is the flow rate in cm/sec of precursor and Re is the flow Reynolds number. The flashback member may include a tapered surface on at least one side to reduce recirculation of vaporized gas.

Abstract: An apparatus for mixing a vaporized precursor with a gas for producing silica particles is provided. The apparatus includes a mixer housing, a precursor delivery chamber having an output in communication with the mixer housing for delivering a vaporized precursor in the mixer housing, and an oxidizing gas delivery chamber having an output in communication with the mixer housing for delivering an oxidizing gas to be mixed with the vaporized precursor. The apparatus further includes a flashback member disposed within the mixer housing and between the output of the precursor delivery chamber and the output of the oxidizing gas delivery chamber. The flashback member is located at a minimum distance from the output of the oxidizing gas delivery chamber defined by Lminimum (cm)=0.453 U (Re)?0.5567, wherein U is the flow rate in cm/sec of precursor and Re is the flow Reynolds number. The flashback member may include a tapered surface on at least one side to reduce recirculation of vaporized gas.

Abstract: Methods and apparatus, including computer program products, for fitness assessment. A method includes, in a server system, receiving base data from a user, generating a fitness score in each of a plurality of categories, the categories selected from the group consisting of: flexibility, cardiovascular endurance, muscle strength, body composition, and overall fitness, and generating a report in conjunction with the fitness score in each of the plurality of categories.