Abstract: A heat flux probe uses a thermoelectric module to heat a relatively large sensing surface while cooling a substantially smaller one that is connected to the thermoelectric module by an elongated thermal conductor. A temperature difference between either the two sensing surfaces or the heated sensing surface and the cooled end plate of the thermoelectric module is controlled to have a selected value. Then the temperature change along the elongated thermal conductor is used as a measure of heat flux. This approach reduces inaccuracies arising from the thermal characteristics of the thermoelectric module and allows for in situ compensation for drift errors.

Abstract: A leaded piezoelectric transducer element is attached to the inside of the end surface of a closed-end cylindrical container such as a plastic cup. The outside end surface of the cup is intended for exposure to a fluid. The required components to isolate and/or resonate with the piezoelectric element are added, after which a rigid encapsulant is formed in the cup to make a single solid assembly strong enough to be clamped. The end of the cup is then thinned to yield a thin, compliant, and environmentally protecting acoustic window.

Abstract: The specific heat of a working fluid flowing along a channel is measured without having to provide an explicit flow rate correction. A specific heat sensing probe is configured with a stagnation enclosure surrounding a thermal transfer sensor. The stagnation enclosure is designed to provide a stagnation chamber in throttled communication with an outside of the enclosure so that the working fluid can flow into and out of the stagnation chamber at a seepage rate substantially less than the fluid flow rate. The thermal transfer sensor is operable to exchange heat with adjacent fluid and to provide a signal representative of the quantity of heat exchanged.

Abstract: Tangential forces present at the mating area between a clamp-on transducer and a pipe can be made very small in order to provide a higher quality, more stable acoustic coupling. In some cases this is accomplished by providing a low friction bearing on a surface of a transducer housing. This bearing may be a slippery surface portion, or may involve a rotary bearing mounted on the housing. In other cases, where a steel pipe is used, pairs of permanent magnets coupled by a yoke can provide the desired clamping force directed solely along a radius of the pipe.

Abstract: Thermal transfer measurements are useful for measuring either a mass flow rate or the specific heat of a fluid. Thermoelectric devices are desirable for this because of their ability to simultaneously heat one portion of the sensor while cooling another. However, the internal thermal resistance of thermoelectric devices has limited the accuracy of thermoelectric thermal transfer sensors. This problem is solved by using separate temperature sensors to measure selected temperature differences established by the thermoelectric portion of a thermal transfer sensor.

Abstract: An asymmetric heat flux sensor has two sensing surfaces separately thermally coupled to the end plates of a thermoelectric module so that one is heated and the other cooled. The heated sensing surface is constrained to have a wettable area much larger than the area of the cooled sensing surface. This allows the heated sensing surface to be nearly the same temperature as the fluid ambient while providing a relatively large temperature differential. Because bubbles, which degrade a heat flux measurement, form preferentially on a heated surface, the asymmetric design avoids bubble formation and hence provides enhanced accuracy.

Abstract: The accuracy of instruments used to measure the specific heat of heat transfer fluids is limited by the accumulation of bubbles, debris or loose surface films on an active measurement surface. Accumulated bubbles, debris or loose film may be reduced or eliminated by using an agitator to cause relative motion between a working fluid and an active surface of a specific heat sensor. The accumulation of bubbles, debris or loose film may also be reduced or eliminated by electrolytically cleaning an electrically conductive heat transfer surface.

Abstract: Power at a selected frequency in the high frequency region of the spectrum is supplied by a power converter having a wide range of input voltages. The power converter uses a source oscillator and a NOR gate. The source oscillator generates a rectangular wave at the selected frequency and supplies that signal to one of the NOR gate inputs. The rectangular wave is differentiated and the differentiated signal is supplied to the second NOR input along with a feedback signal from an amplifier controlled by the NOR gate's output.

Abstract: A sanitary single-use container for both food (e.g., an individual portion of bread) and drink (e.g., an individual portion of wine or grape juice) is designed to be placed over the mouth of a chalice, as may used in a communion service. The container is compatible with any chalice having a diameter and a wall thickness lying within conventional ranges of values. The container has a skirt portion that, in use, extends far enough down over a side wall of the chalice that someone drinking from the container does not touch the chalice with his or her lip. A sealed, but easily opened, food packet is attached to the skirt.

Abstract: Ultrasonic transit time flow meters using transducers mounted on insertion probes spaced apart along a pipe axis provide an economical way to measure fluid flow. The accuracy of these flow meters can be improved by providing additional transducers to measure the current speed of sound of a working fluid; the actual spacing of the probes; and the diameter of the pipe through which the fluid is flowing.

Abstract: Beverage containers can be sealed against various sorts of contamination by a sealing member having, on its underside, generally circular channels arranged to hold a drinking straw. When the liquid is to be dispensed, the flexible sealing member is pulled off the rim of the container, the straw is retrieved from the channels on the sealing member, a conventional pop-top is used to open the container, and the straw is inserted into the container so that the consumer can drink the liquid.

Abstract: An ultrasonic transit time approach is used for measuring both a speed of sound of a fluid and a diameter of a pipe through which the fluid flows. A reflecting structure is provided to split an acoustic beam generated by a transducer into two portions. One of these portions traverses an acoustic path of known length in order to determine the speed of sound in the fluid. The second portion of the beam may be directed along a path that includes reflections from an inner surface of the pipe. In this case the second portion of the beam can be used to measure the diameter of the pipe. Alternately, the second portion of the beam may extend to a second transducer that is spaced apart along the pipe from the transducer generating the split beam.

Abstract: A time-of-flight ultrasonic flow meter uses transducers placed on streamlined heads of probes that are spaced out along a pipe. The placement of the transducers and probes is selected so that an acoustic signal can propagate between the transducers on the two probes along a path that involves at least one reflection from an internal surface of the pipe.

Abstract: A capacitive discharge stun-gun uses a flyback output circuit in which a semiconductor switch operates under control of a controller or suitable logic circuitry. The flyback circuit can deliver 50-65 kV pulses to a pair of electrodes in order to ionize air adjacent a target in order to initiate good electrical contact. When the electrodes are in good contact with the target, the flyback circuit delivers current at a lower voltage. In one mode of operation the stun-gun is controlled to initially deliver wider pulses optimized for causing air breakdown and to then deliver a series of shorter pulses in pulse groups optimized for causing involuntary muscle cramping.

Abstract: The specific heat of working fluids used in commercial heating systems commonly change with temperature and composition. Conventional heat metering systems assume a fixed value of the specific heat at a nominal temperature. This source of inaccuracy is removed by measuring the specific heat of a working fluid as a heating system operates and using the currently measured value in calculating the heat transferred. The real time specific heat measurement may be made by using a specific heat sensor having either a resistive heating element or a thermoelectric module.

Abstract: A clamp-on acoustic flow meter for measuring the rate of flow of a fluid in a pipe uses a transducer stack mounted in a housing that includes a rigid polymeric foam body in which the stack is embedded. This transducer configuration is used in combination with a clamping mechanism operable to supply a clamping force directed substantially entirely along a radius of the pipe for clamping the exposed portion of a transducer stack end piece to the pipe.

Abstract: A method of preparing an electrochromic device involves forming multiple layers of selected materials on a substrate in a vacuum processing chamber. A first of these layers is an electrode layer deposited directly on the substrate and used for making contact to a subsequently deposited precursor film, preferably tungsten oxide, from which an electrochromic layer is formed by lithium loading in the presence of ionized nitrogen. This not only forms the electrochromic layer by diffusion of the lithium into the tungsten oxide, but also forms a thin lithium nitride ion transfer layer on the then exposed surface. Subsequently, a lithium fluoro-nitride electrolyte layer is formed on the ion transfer layer by evaporation from a lithium fluoride source in the presence of ionized nitrogen. An ion storage layer, which may be a vanadium oxide and a transparent second electrode layer are subsequently vacuum deposited.