Abstract: The invention provides an apparatus for polymer chromatography, comprising at least one column that comprises a first stationary phase comprising one of the following: A) a material comprising at least one non-carbon atom, excluding glass or a metal, selected from molybdenum sulfide MoS2, tungsten sulfide WS2, silicon carbide SiC, boron nitride BN, or combinations thereof, or B) glass, or a metal, or combinations thereof, and a material comprising at least one non-carbon atom selected from molybdenum sulfide MoS2, tungsten sulfide WS2, silicon carbide SiC, boron nitride BN, or combinations thereof. The invention also provides a method for polymer chromatography, comprising introducing a solution, comprising a polymer, into a liquid flowing through a first stationary phase, and wherein the first stationary phase comprises one of foregoing materials (A) or (B).

Abstract: The invention provides an apparatus for polymer chromatography, comprising at least one column that comprises a first stationary phase comprising one of the following: A) a material comprising at least one non-carbon atom, excluding glass or a metal, selected from molybdenum sulfide MoS2, tungsten sulfide WS2, silicon carbide SiC, boron nitride BN, or combinations thereof, or B) glass, or a metal, or combinations thereof, and a material comprising at least one non-carbon atom selected from molybdenum sulfide MoS2, tungsten sulfide WS2, silicon carbide SiC, boron nitride BN, or combinations thereof. The invention also provides a method for polymer chromatography, comprising introducing a solution, comprising a polymer, into a liquid flowing through a first stationary phase, and wherein the first stationary phase comprises one of foregoing materials (A) or (B).

Abstract: A perforating gun includes a multiplicity of shaped charges, the multiplicity of shaped charges including a plurality of planes of charges, each plane of charges including a plurality (N) of shaped charges and a detonating cord running down through the axial center of each of the plurality of planes of charges. The plurality (N) of shaped charges are equally spaced at an angle 360/N about the detonating cord. The plurality of planes of charges: (1) are rotated at an angle of 180/N relative to one another, and (2) are axially packed together along the longitudinal axis of the gun so that the charges in one plane are nearly touching the charges in the adjacent plane, yet they all share the same centered detonating cord. The proximity of one plane to another is close enough such that one plane of charges detonates within a few microseconds of its neighboring plane of charges.