Abstract: Residual impurity reduction methods and apparatus are provided. A method comprises conducting a gaseous stream through an unlined portion of a pipe, wherein the gaseous stream comprises sodium and wherein the unlined portion of the pipe is at least about eighteen inches long, injecting a neutralizing agent into the gaseous stream at an injection point, wherein the injection point is located at a point where the sodium is in at least a partially condensed state. The gaseous stream is conducted through a heated portion of a pipe and a cooled portion of a pipe. In addition, methods and apparatus may include a trap system for use with a carbonization furnace.

Abstract: Residual impurity reduction methods and apparatus are provided. A method comprises conducting a gaseous stream through an unlined portion of a pipe, wherein the gaseous stream comprises sodium and wherein the unlined portion of the pipe is at least about eighteen inches long, injecting a neutralizing agent into the gaseous stream at an injection point, wherein the injection point is located at a point where the sodium is in at least a partially condensed state. The gaseous stream is conducted through a heated portion of a pipe and a cooled portion of a pipe. In addition, methods and apparatus may include a trap system for use with a carbonization furnace.

Abstract: Hydrogen cyanide removal during transformation of a carbon fiber precursor into carbon fiber is provided. The method may comprise heating a carbon fiber body precursor at a substantially atmospheric pressure to above about 1200° C. in a furnace in a first stage, expelling a stream of effluent gas outside the furnace, wherein the stream of effluent gas comprises a cyanide, thermally oxidizing the cyanide during the first stage, and heating the carbon fiber body precursor to a temperature of between about 1600° C. and about 2200° C. in a second stage.

Abstract: The invention provides a removable closure system comprising a tubular member having an internal surface with an internal profile therein, an entrance end and a plug end, the internal profile providing a collet shoulder and a plug stopping shoulder. A plug assembly is positioned within the tubular member. The plug assembly has a plug suitable for insertion through the tubular member at the entrance end and past the collet shoulder, a collet with a plurality of collet fingers. The collet fingers are moveable between a collapsed and a normally expanded condition, the collapsed condition suitable for insertion of the plug assembly through the tubular member past the collet shoulder and the expanded condition suitable for engaging the collet shoulder. When the plug assembly is placed in the tubular member against the plug stopping shoulder, and the collet fingers are in the expanded condition engaging the collet shoulder, the plug assembly is removably secured in the tubular member.

Abstract: The invention provides a removable closure system comprising a tubular member having an internal surface with an internal profile therein, an entrance end and a plug end, the internal profile providing a dog shoulder and a plug stopping shoulder. A plug assembly is positioned within the tubular member. The plug assembly has a plug suitable for insertion through the tubular member at the entrance end and past the dog shoulder, a plurality of dogs. The dogs are moveable between a collapsed and an expanded condition, the collapsed condition suitable for insertion of the plug assembly through the tubular member past the dog shoulder and the expanded condition suitable for engaging the dog shoulder. When the plug assembly is placed in the tubular member against the plug stopping shoulder, and the dogs are in the expanded condition engaging the dog shoulder, the plug assembly is removably secured in the tubular member.

Abstract: A recumbent cycling apparatus is provided that includes a frame structure, wheels rotatably attached to supporting the frame structure, and a central frame element configured to absorb and reduce the forces transmitted through the frame structure to a user. The frame structure has a front frame section and a back frame section that are substantially parallel to the ground. The central frame element is a curved elongated member composed of chromoly steel that is attached to the front frame section and the back frame section and extends therebetween. The central frame element is configured to allow the front frame section and the back frame section to move substantially independently in response forces exerted on the wheels. The central frame element is disposed in a substantially vertical plane above the back frame section and the front frame section and is substantially perpendicular thereto. A pair of recumbent seats are mounted on the back frame section in a side-by-side relationship.