Abstract: The invention provides a shut-off valve (10) for a hydrocarbon liquid or fuel intake. The valve includes a first float body (14) configured to float at the surface of hydrocarbon fuel (15), a fuel intake (16) located on the first float (14) and positioned such that the intake (16) is below the surface of the fuel (15), in use, and a second float body (18) configured to float on water (20) and sink in hydrocarbon fuel (15) such that the body (18) floats at an interface of hydrocarbon fuel (15) and water (20) phases, in use. A closing means (24) is located on the second float (18) for closing or restricting the fuel intake (16) when the first float (14) and second float (18) are in contact or in close proximity and further includes a guide arrangement (26) for guiding the first and second float (14, 18) towards each other as the surface of the hydrocarbon fuel (15) approaches the fuel water interface.

Abstract: A method for fabricating a sensor includes coating an end-polished sapphire fiber with aluminum to produce a sapphire fiber having an aluminum coating, anodizing the aluminum coating to produce an aluminum oxide coating, and removing the aluminum oxide coating from a distal end of the sapphire fiber.

Abstract: An power management unit receives AC power and, via an AC-DC-AC converter, provides an AC motor signal to a three-phase induction motor. Sensors in the power management unit provide data to a digital signal processor (“DSP”). The data includes a current of the AC motor signal. The DSP generates a PWM carrier signal to modulate a voltage amplitude of the AC motor signal, thereby improving the operating efficiency of the motor. The motor terminal voltage is reduced until limit conditions are reached, such as reaching a motor rated efficiency or when the motor current fluctuates.

Abstract: A method for fabricating a sensor includes coating an end-polished sapphire fiber with aluminum to produce a sapphire fiber having an aluminum coating, anodizing the aluminum coating to produce an aluminum oxide coating, and removing the aluminum oxide coating from a distal end of the sapphire fiber.

Abstract: A method for identifying a kidney condition of a patient includes receiving a urine sample from a patient. The patient provides the urine sample a predetermined amount of time after having been administered a dose of a sugar alcohol. The method also includes determining whether the sugar alcohol is present in the urine sample. The method also includes identifying a kidney condition of the patient, if the sugar alcohol is present in the urine sample.

Abstract: An inventive sensor is used in combination with spectroscopic techniques to detect, identify and quantify ultratrace (ppt to ppb) quantities of analytes in air or water samples. The sensor preferably comprises a photonic crystal fiber having an air hole cladding with functionalized air holes. Surface-enhanced Raman spectroscopy is a preferred spectroscopic technique. In such applications, the air holes of the fiber may be functionalized by adsorbing a self-assembled monolayer on their inner surfaces, and immobilizing metallic nanoparticles to the monolayer. The invention has chemical and biomedical applications, and utility in detecting chemical and biological agents used in warfare.

Abstract: Silica sol techniques are described for making thick silica or silica based films useful for planar optical waveguides. The process involves coating of a colloidal silica sol onto a substrate, drying the sol, and consolidating the dried sol to form the planar waveguide. Coating is performed in a simple operation, either by dipping, or preferably by spin coating. In a preferred embodiment the substrate is coated with a wetting agent prior to spin coating. It is found that the wetting agent substantially improves the thickness uniformity of the layer. Thick waveguide layers may be produced by repeating the coating process one or more times to produce a layer with the desired thickness. Buried waveguides are produced by forming a doped core layer, patterning the doped core layer and using the coating technique of the invention to form the cladding material.

Abstract: Silica sol techniques are described for making thick silica or silica based films useful for planar optical waveguides. The process involves coating of a colloidal silica sol onto a substrate, drying the sol, and consolidating the dried sol to form the planar waveguide. Coating is performed in a simple operation, either by dipping, or preferably by spin coating. In a preferred embodiment the substrate is coated with a wetting agent prior to spin coating. It is found that the wetting agent substantially improves the thickness uniformity of the layer.