Abstract: A tube-cutting apparatus and method for separating centrifuged materials are shown in which a resilient axial compressive force is exerted on the tube during cutting by spaced tube-holding members; and the cutting knife has flat upper and lower sides against which the severed portions of the tube are held in sealing engagement by the axial force. Independent adjustment is provided for (a) the relative positions of the tube and the cutting knife, and (b) the relative positions of the spaced tube-holding members.

Abstract: A device suitable for dispensing a radioactive gas from a sealed radioactive gas-containing vial having a pierceable septum wherein the dispenser contains two needles which pierce the septum, one of the needles conducting the radioactive gas from the vial into the dispenser and the other for the introduction of a displacement gas to the vial. The improvement being a means in the dispenser whereby the septum is automatically released from the needles without handling the vial so that the vial may be removed from the dispenser.

Abstract: An apparatus for removing liquid contaminants from the oil sump of a vacuum pump. A liquid separator mounted on the housing of the pump connects the interior of the pump housing to the atmosphere through a liquid trap. An inlet passage through the separator connects a source of purging air to the interior of the pump housing, causing the air therein to flow through the liquid trap to the atmosphere. Because outflowing purged air is cooled by inflowing purging air, oil is selectively retained within the pump housing.

Abstract: A thermoelectric temperature control assembly for transferring heat to or from a heat sink. A nonconducting substrate is provided with a plurality of mounting openings for receiving the mounting features of a plurality of respective thermoelectric devices. Each mounting openings is internally partitioned so as to form a pair of flexible tongues by which the thermoelectric devices may be clamped to a heat sink to assure a good thermal contact therewith.

Abstract: A thick walled centrifuge tube with a generally constant internal diameter and having at least one circumferential groove within the exterior surface of the tube. The groove is designed to have a depth slightly less than the wall thickness of the tube. The circumferential groove is designed to assist in slicing of the tube subsequent to centrifugation in order to isolate different separated particles of a fluid sample which have formed fraction bands at certain levels in the tube. The groove reduces the cutting force required to partition the tube. The groove provides a guide for a slicing blade. The groove is formed in such a manner that a fluid tight seal is formed between the slicing blade and the tube as the blade proceeds through the tube. The centrifuge tube wall at the base of the groove, after slicing, is resilient enough to allow the tube sections to be rejoined under force and create a fluid tight seal.