Voltage regulator with plural parallel power source sections Patent

Dissipative voltage regulator system for minimizing heat dissipatio

Voltage regulator with multiple parallel power source sections

Voltage regulator provides improved voltage-regulating system in which power dissipation and consequent heat generation are minimized. Each power source section is controlled sequentially so that only one operates in a linear range at a time

Gas chromatograph sample-transfer valve

Slide-type gate valve incorporates sampling volume and transfer passageway for guiding a metered quantity of gas from pressurized test cell to gas chromatograph. Gate is moved by pneumatic bellows-type actuator

Miniature high pressure regulator

Metal bellows, capable of suppling required spring rate and operational stability, replaced diaphragms, sliding seals, and springs in design of small gas regulator

Two-stage coaxial gas compressor

Compressor raises pressure of gases from low ambient supply during space experiments by a system of low weight, size, and power input. Dc rotary-torque motor and ball-screw drive shaft activate first and second stage of compressor, utilizing inertia forces to operate check valves

The voluntary principle in education: the contribution to English education made by the Clapham sect and its allies and the continuance of evangelical endeavour by Lord Shaftesbury

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A prospective clinical comparison of two intravenous polyurethane cannulae

Publisher's copy made available with the permission of the publisher © 1997 Australian Society of Anaesthetists "Because of a printer's error in the December 1996 issue of Anaesthesia and Intensive Care (Vol. 24, No. 6, p. 708, Figure 4) this paper is reprinted here in its entirety and in its correct form"--cf. p.42Tissue irritation, as evidenced by phlebitis, associated with Optiva™ (Johnson & Johnson Medical) and Insyte™ (Becton Dickinson) polyurethane cannulae was studied. The integrity of the cannulae on removal, the incidence of infection at the cannula site and the factors which influence phlebitis were also examined. One thousand and eight patients had a polyurethane cannula placed for induction of anaesthesia for cardiac surgery. After surgery, the cannula was examined every 24 hours. If evidence of phlebitis occurred, the cannula was removed and sent for culture. All remaining cannulae were removed at 72 hours and the site examined daily for a further three days. There were 503 Optiva™ and 505 Insyte™ cannulae studied. The distributions between the two cannulae with respect to patient characteristics, gauge of cannula, number of attempts and difficulty of insertion, cannula site and anaesthetist inserting were similar. The early removal rate for both groups was 47%. Overall phlebitis rate with Optiva™ was 31% and Insyte™ 33%. This difference is not statistically significant. The cumulative phlebitis rate increased with time but did not differ between the two types of cannulae. Minor tip distortion or shaft kinking of the cannulae occurred in 16.2% of Optiva™ and 23.5% of Insyte™. This difference is statistically significant and may relate to the slightly more acute taper at the Optiva™ cannula tip. Both cannulae were similar in clinical performance.W.J. Russell, S. Micik, S. Gourd, H. Mackay, S. Wrigh