A process (and a related system) for collecting samples of a polymerization catalyst or of a catalyst-containing polymer from an operation unit, having an upper end and a lower end, of a polymerization plant, including the steps of: a) extracting a prefixed amount of product from the lower end of the operation unit through a discharge valve; b) directing the product towards a filtering unit through an inlet valve; c) flushing an inert gas through the filtering unit; d) outgassing the filtering unit, through the outlet valve; and e) displacing the filtering unit, for collecting the sample.

A method and apparatus for preparing boron nitride nanotubes (BNNTs) according to an embodiment may ensure mass-production, may increase yield by reducing a production time, and may prepare BNNTs with high purity.

A process for the catalytic cracking of hydrocarbon oils includes the step of contacting a hydrocarbon oil feedstock with a catalytic cracking catalyst in a reactor having one or more fast fluidized reaction zones for reaction. At least one of the fast fluidized reaction zones of the reactor is a full dense-phase reaction zone, and the axial solid fraction ε of the catalyst is controlled within a range of about 0.1 to about 0.2 throughout the full dense-phase reaction zone. When used for catalytic cracking of hydrocarbon oils, particularly heavy feedstock oils, the process, reactor and system show a high contact efficiency between oil and catalyst, a selectivity of the catalytic reaction, an effectively reduced yield of dry gas and coke, and an improved yield of high value-added products such as ethylene and propylene.

A method and apparatus for preparing boron nitride nanotubes (BNNTs) according to an embodiment may ensure mass-production, may increase yield by reducing a production time, and may prepare BNNTs with high purity.

Embodiments comprise a system created through fabricating a lens array through which lasers are emitted. The lens array may be fabricated in the semiconductor substrate used for fabricating the lasers or may be a separate substrate of other transparent material that would be aligned to the lasers. In some embodiments, more lenses may be produced than will eventually be used by the lasers. The inner portion of the substrate may be formed with the lenses that will be used for emitting lasers, and the outer portion of the substrate may be formed with lenses that will not be used for emitting lasers—rather, through etching these additional lenses, the inner lenses may be created with a higher quality.

A process for polymerizing olefin monomer(s) in a gas-solids olefin polymerization reactor comprising a top zone; a middle zone, which comprises a top end in direct contact with said top zone and which is located below said top zone, the middle zone having a generally cylindrical shape; and a bottom zone, which is in direct contact with a bottom end of the middle zone and which is located below the middle zone; comprising the following steps: introducing a fluidization gas stream into the bottom zone; polymerizing olefin monomer(s) in the presence of a polymerization catalyst in a dense phase formed by particles of a polymer of the olefin monomer(s) suspended in an upwards flowing stream of the fluidization gas in the middle zone; introducing a jet gas stream through one or more jet gas feeding ports in a jet gas feeding area of the middle zone at the dense phase in the middle zone of the gas-solids olefin polymerization reactor; wherein the kinetic energy (E.sub.JG) input in the reactor by the jet stream is between 1.5 and 50 times higher than the kinetic energy (E.sub.FG) input in the reactor by the fluidization gas stream (FG).

Embodiments comprise a system created through fabricating a lens array through which lasers are emitted. The lens array may be fabricated in the semiconductor substrate used for fabricating the lasers or may be a separate substrate of other transparent material that would be aligned to the lasers. In some embodiments, more lenses may be produced than will eventually be used by the lasers. The inner portion of the substrate may be formed with the lenses that will be used for emitting lasers, and the outer portion of the substrate may be formed with lenses that will not be used for emitting lasers—rather, through etching these additional lenses, the inner lenses may be created with a higher quality.

A process and system for maintaining optimum polymerization production in a loop polymerization reactor by continuously and periodically obtaining polymerization results, such as melt index (MI), production rate and ash content of the polymer produced, determining whether each of the results is within desired ranges, storing and averaging recently obtained results in a database within a reaction rate controller program, and when one of the results is out of the desired range modifying at least one reaction parameter set-point such as monomer concentration, catalyst feed rate and reactor temperature to drive any out-of-range polymerization result(s) toward the desired range for that result.

Embodiments comprise a system created through fabricating a lens array through which lasers are emitted. The lens array may be fabricated in the semiconductor substrate used for fabricating the lasers or may be a separate substrate of other transparent material that would be aligned to the lasers. In some embodiments, more lenses may be produced than will eventually be used by the lasers. The inner portion of the substrate may be formed with the lenses that will be used for emitting lasers, and the outer portion of the substrate may be formed with lenses that will not be used for emitting lasers—rather, through etching these additional lenses, the inner lenses may be created with a higher quality.

A method for processing a chemical stream includes contacting a feed stream with a catalyst in a reactor portion of a reactor system causing a reaction which forms a product stream. The method includes separating the product stream from the catalyst, passing the catalyst to a catalyst processing portion of the reactor system, processing the catalyst in the catalyst processing portion, and passing a portion of the catalyst from the catalyst processing portion of the reactor system into a catalyst withdrawal system that includes a catalyst withdrawal vessel and a transfer line coupling the catalyst withdrawal vessel to the catalyst processing portion. Each of the catalyst withdrawal vessel and the transfer line include an outer metallic shell and an inner refractory lining. The method further includes cooling the catalyst in the catalyst withdrawal vessel from greater than or equal to 680° C. to less than or equal to 350° C.