The present invention provides a sensor head for use in an implantable device that measures the concentration of an analyte in a biological fluid which includes: a non-conductive body; a working electrode, a reference electrode and a counter electrode, wherein the electrodes pass through the non-conductive body forming an electrochemically reactive surface at one location on the body and forming an electronic connection at another location on the body, further wherein the electrochemically reactive surface of the counter electrode is greater than the surface area of the working electrode; and a multi-region membrane affixed to the nonconductive body and covering the working electrode, reference electrode and counter electrode. In addition, the present invention provides an implantable device including at least one of the sensor heads of the invention and methods of monitoring glucose levels in a host utilizing the implantable device of the invention.

Sensor head for use with implantable devices

A review on hydrogen industrial aerospace applications

A variable capacity rotary compressor includes a hermetic casing, a housing installed in the hermetic casing to define therein first and second compression chambers having different capacities, and a compressing unit placed in the first and second compression chambers and operated to execute a compression operation in either the first or second compression chamber according to a rotating direction of a rotating shaft which drives the compressing unit. The compressor further includes a suction path controller, a high-pressure pipe, and a high-pressure path controller. The suction path controller controls a refrigerant suction path so that a refrigerant is delivered into an inlet port of the first or second compression chamber where the compression operation is executed. The high-pressure pipe couples an outlet side of the compressor to the suction path controller. The high-pressure path controller is provided at a predetermined portion of the suction path controller, and controls a high-pressure path so that the high-pressure pipe communicates with the inlet port of the first or second compression chamber where an idle operation is executed, according to variance of temperature when the refrigerant suction path is controlled by the suction path controller.

Variable capacity rotary compressor

Apparatus and methods are provided for converting methane in a feed stream to acetylene. A hydrocarbon stream is introduced into a supersonic reactor and pyrolyzed to convert at least a portion of the methane to acetylene. The reactor effluent stream may be treated to convert acetylene to another hydrocarbon process.

Methane conversion apparatus and process using a supersonic flow reactor

The increasing demand for higher performance in rocketlaunchers promotes the development of nozzles with higherperformance, which basically is achieved by increasing theexpansion ratio. However, th ...

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Supersonic Flow Separation with Application to Rocket Engine Nozzles

A method of producing rocket combustors wherein in forming an outer cylin by a powder metallurgical method on the outer side of a cylinder provided on its outer periphery with a cooling wall of channel construction having a plurality of grooves, a low-melting alloy is used as a filler to be filled into the grooves. It is also possible to form the outer cylinder after forming a Cu plating shell on the periphery of the inner cylinder filled with the low-melting alloy.

Method of producing rocket combustors

The LE-X engine is under study for Japan’s next flagship expendable launcher (post H2A) to be operated in the next decade with enhanced reliability and reduced cost. The goal of LE-X development is to meet the requirements from the vehicle for higher reliability, lower production cost and appropriate performance. Technology development itself is also a purpose of this investigation and will be applied to other forthcoming engines to be developed in Japan. The early-stage feasibility study of the LE-X engine was completed in 2005 through primary studies on system design, engine component design, cost reduction, reliability prediction, subscale testing, and computational simulation. In 2006, engine system analysis and fundamental studies on LE-X components by means of element tests were successfully conducted. In 2007, we have optimized the engine baseline configuration from aspect of cost reduction activities. Significant cost reduction will be achieved by drastic simplification of the engine system, and the innovation of the manufacturing process. Technology development will be ongoingly conducted to mitigate development risks, such as precise life prediction analysis of combustion chamber, prediction of combustion instability, and high-fidelity simulation.

LE-X -Japanese Next Liquid Booster Engine-

Heat Transfer Simulations in Liquid Rocket Engine Subscale Thrust Chambers

The LE-X is a new cryogenic booster engine with high performance, high reliability and low cost, being designed for the next-generation Japanese launch vehicle. Following an early- stage feasibility study, detailed studies focusing on front-loading design approaches were conducted in 2006 and 2007. An optimum engine system was determined and potential risks were mitigated by various element tests. These activities will lead to the realization of the first booster engine in the world with expander cycle.

Next Booster Engine LE-X in Japan

To study the mechanism of the initiation of combustion instability as hydrogen injection temperature decreases, a hydrogen temperature ramping test was conducted with a single coaxial injection element with LOX/LH2 at a chamber pressure of 8.0 MPa. Two types of injectors were used in the tests. One employed a straight bore LOX post and the other employed a taper-reamed LOX post for better atomization of LOX. The combustion flame was visualized with a high-speed video camera at a rate of 6,000 frames per second. Results showed that unstable combustion was initiated when the hydrogen injection temperature decreased to less than a certain cryogenic temperature. By observing the movement of the prominent pattern of OH emission on the flame, the flame was found to propagate downstream at a constant speed with the flame angle remaining constant during stable combustion. On the other hand, injection pressure peaks appeared during unstable combustion. In this case, a block of flame with strong OH emission was occasionally observed. A block of flame caught up with an anterior block and coalesced into a large block with strong OH emission. This coalesced block of the flame is herein termed “flame burst”.

Akinaga Kumakawa

Papers

Method of producing rocket combustors

LE-X -Japanese Next Liquid Booster Engine-

Heat Transfer Simulations in Liquid Rocket Engine Subscale Thrust Chambers

Next Booster Engine LE-X in Japan

High-Frequency Flame Oscillation Observed at a Coaxial LOX/LH2 Injector Element