Abstract: A laser-sinterable powder product has been prepared having unique properties which allow the powder to be sintered in a selective laser sintering machine to form a sintered part which is near-fully dense. For most purposes, the sintered part is indistinguishable from another part having the same dimensions made by isotropically molding the powder. In addition to being freely flowable at a temperature near its softening temperature, a useful powder is disclosed that has a two-tier distribution in which substantially no primary particles have an average diameter greater than 180 .mu.m, provided further that the number average ratio of particles smaller than 53 .mu.m is greater than 80%, the remaining larger particles being in the size range from 53 .mu.m to 180 .mu.m. A powder with slow recrystallization rates, as evidenced by non-overlapping or slightly overlapping endothermic and exothermic peaks in their differential scanning calorimetry characteristics for scan rates of on the order of 10.degree. C. to 20.

Abstract: A laser-sinterable powder product has been prepared having unique properties which allow the powder to be sintered in a selective laser sintering machine to form a sintered part which is near-fully dense. For most purposes, the sintered part is indistinguishable from another part having the same dimensions made by isotropically molding the powder. In addition to being freely flowable at a temperature near its softening temperature, a useful powder is disclosed that has a two-tier distribution in which substantially no primary particles have an average diameter greater than 180 .mu.m, provided further that the number average ratio of particles smaller than 53 .mu.m is greater than 80%, the remaining larger particles being in the size range from 53 .mu.m to 180 .mu.m. A powder with slow recrystallization rates, as evidenced by non-overlapping endothermic and exothermic peaks in their differential scanning calorimetry characteristics for scan rates of on the order of 10.degree. C. to 20.degree. C.

Abstract: A laser-sinterable powder product has been prepared having unique properties which allow the powder to be sintered in a selective laser sintering machine to form a sintered part which is near-fully dense. For most purposes, the sintered part is indistinguishable from another part having the same dimensions made by isotropically molding the powder. In addition to being freely flowable at a temperature near its softening temperature, a useful powder is disclosed that has a two-tier distribution in which substantially no primary particles have an average diameter greater than 180 .mu.m, provided further that the number average ratio of particles smaller than 53 .mu.m is greater than 80%, the remaining larger particles being in the size range from 53 .mu.m to 180 .mu.m. A powder with slow recrystallization rates, as evidenced by non-overlapping or slightly overlapping endothermic and exothermic peaks in their differential scanning calorimetry characteristics for scan rates of on the order of 10.degree. C. to 20.

Abstract: Ethane is reacted with oxygen and a chlorine source in the presence of a solid solution catalyst containing iron cations stabilized with lanthanum and/or lanthanides to yield ethylene, vinyl chloride, and other valuable by-products. Conversion of ethane to products approaches 100 percent, ethylene is prepared in up to 90 mole percent yield, and the combined yield of ethylene, vinyl chloride, and ethyl chloride is up to 95 mole percent.

Abstract: Ethane is reacted with oxygen and a chlorine source in the presence of a solid solution catalyst containing iron cations which is stabilized with lanthanum and/or lanthanides and modified with selected metal cations, to yield ethylene, vinyl chloride, and other valuable by-products. Conversion of ethane to products approaches 100 percent, ethylene is prepared in up to 90 mole percent yield, and the combined yield of ethylene, vinyl chloride and ethyl chloride is over 90 mole percent.

Abstract: Ethylene and vinyl chloride are prepared in excellent yields by the reaction of ethane with a chlorine source in the presence of oxygen and a solid solution catalyst containing iron cations. The present invention comprises an improvement in the above process wherein the solid solution catalyst after exhibiting a loss in activity is regenerated in situ by the addition of an iron source such as Fe(NO.sub.3).sub.3 to the ongoing process. After addition of the iron source, ethane conversion to products and yields of ethylene and vinyl chloride similar to that originally obtained using freshly prepared solid solution catalyst are achieved. Furthermore, the invention allows for extended operation of the process without loss of time and productivity due to possible interruptions caused by regeneration of the catalyst using known techniques.

Abstract: A laser-sinterable powder product has been prepared having unique properties which allow the powder to be sintered in a selective laser sintering machine to form a sintered part which is near-fully dense. For most purposes, the sintered part is indistinguishable from another part having the same dimensions made by isotropically molding the powder. In addition to being freely flowable at a temperature near its softening temperature, a useful powder is disclosed that has a two-tier distribution in which substantially no primary particles have an average diameter greater than 180 ?m, provided further that the number average ratio of particles smaller than 53 ?m is greater than 80%, the remaining larger particles being in the size range from 53 ?m to 180 ?m. A powder with slow recrystallization rates, as evidenced by non-overlapping or slightly overlapping endothermic and exothermic peaks in their differential scanning calorimetry characteristics for scan rates of on the order of 10° C. to 20° C.