Abstract: Point source speaker systems are provided. The point source speaker system receives audio input from a device. The system comprises a mountable enclosure, which contains a speaker array. The array includes a substantially forward facing left speaker, a substantially forward facing center speaker, a substantially forward facing right speaker and a horizontally mounted woofer speaker. A woofer tunnel is located behind the left, center and right speakers. The woofer tunnel accelerates woofer sound waves and terminuses at a woofer baffle which leads to a woofer port. The left speaker, center speaker and right speaker may include more than one speaker. One or more of these left speakers and right speakers may be a tweeter. The left speakers receive a left minus right input, the center speakers receive a right plus left input, and the right speakers receive right minus left input.

Abstract: A damage evaluation method and apparatus of a metal material which is capable of determining whether a flaw in the metal sample is originated by the creep damage or in the manufacturing process, and also capable of estimating a remaining life of the metal component. The damage evaluation method of a metal material by the present invention is a method for evaluating a flaw in the metal sample comprising the steps of mounting onto a metal surface including an internal flaw and on both sides of the flaw a transmitting probe for transmitting an ultrasonic waves and a receiving probe for receiving the ultrasonic waves, transmitting the ultrasonic waves towards the internal flaw and receiving the diffracted wave from the flaw for determining whether or not a flaw is present in the metal, based on the analysis of the distribution of the diffracted waves and an analysis of the sample as to whether voids (creep voids) are present and, if present, the distribution of the voids.

Abstract: A damage evaluation method and apparatus of a metal material which is capable of determining whether a flaw in the metal sample is originated by the creep damage or in the manufacturing process, and also capable of estimating a remaining life of the metal component. The damage evaluation method of a metal material by the present invention is a method for evaluating a flaw in the metal sample comprising the steps of mounting onto a metal surface including an internal flaw and on both sides of the flaw a transmitting probe for transmitting an ultrasonic waves and a receiving probe for receiving the ultrasonic waves, transmitting the ultrasonic waves towards the internal flaw and receiving the diffracted wave from the flaw for determining whether or not a flaw is present in the metal, based on the analysis of the distribution of the diffracted waves and an analysis of the sample as to whether voids (creep voids) are present and, if present, the distribution of the voids.

Abstract: A damage evaluation method and apparatus of a metal material which is capable of determining whether a flaw in the metal sample is originated by the creep damage or in the manufacturing process, and also capable of estimating a remaining life of the metal component. The damage evaluation method of a metal material by the present invention is a method for evaluating a flaw in the metal sample comprising the steps of mounting onto a metal surface including an internal flaw and on both sides of the flaw a transmitting probe for transmitting an ultrasonic waves and a receiving probe for receiving the ultrasonic waves, transmitting the ultrasonic waves towards the internal flaw and receiving the diffracted wave from the flaw for determining whether or not a flaw is present in the metal, based on the analysis of the distribution of the diffracted waves and an analysis of the sample as to whether voids (creep voids) are present and, if present, the distribution of the voids.

Abstract: A sodium secondary battery which assures excellent sealing and can be manufactured in a simple manner is provided. The battery includes a negative electrode chamber defined by the inside of a bottom-closed, hollow cylindrical, solid electrolyte accommodated in an outer case and a positive electrode chamber formed outside the solid electrolyte and containing a porous electrode 4 impregnated with sulfur which serves as a positive electrode active substance. A cover, which closes the opening portion of the outer case, is fastened to the outer case by use of bolts and the interposition of an insulator.

Abstract: A tube flaw detecting method detects a flaw portion in a heat exchanger tube constituting a boiler furnace wall using two probes, enabling one to carry out appropriate inspection work with a high efficiency. A transmitter probe and a receiver probe are juxtaposed in a circumferential direction, and an ultrasonic wave is transmitted from the transmitter probe to propagate. Repeated reflections occur at a tube inner surface and tube outer surface, and the wave is reflected at a crack extending in the circumferential direction to return, propagating likewise to be received by the receiver probe so that existence of the crack is confirmed. Thus, inspection work for a crack can be done with certainty with a simple arrangement.

Abstract: A refrigerating unit comprising an adiabatic box provided with a door to its opening, a machine compartment in contact with said adiabatic box, and a refrigerating cycle wherein the machine compartment is covered with a damping plate and is attached to the adiabatic box with a jointing means so as to be sealed, and further said refrigerating unit comprises an oil cooler for cooling lubricating oil in a compressor in the refrigerating cycle is provided. By this, noise and vibration generated by a refrigerator itself such as noise generated by a flowing or boiling refrigerant in the compressor and an evaporator can be effectively removed, noise and vibration generated by resonance between vibration by a refrigerator and a wall or a cabinet can be attenuated and the effect of heat release can be enhanced.

Abstract: A hot water supply system having a plurality of electric heaters arranged at vertically displaced positions in the hot water tank, and a controller for controlling the temperature of the water based on the signal supplied by a plurality of water-temperature sensors, by controlling the electric currents through the heaters in three different modes in such a way that the upper and lower heaters are turned on individually in a first mode; only the upper heater is turned on in a second mode; and only the upper heater is turned on at a low preset temperature in a third mode to prevent the water from freezing, supplying necessary and sufficient amount of hot water from the upper portion of the tank and feeding water from the lower portion of the tank, the system providing efficient electric current control of the heater depending upon the demands and ambient temperature conditions, thereby allowing efficient utilization of energy and making the hot water supply system superb.

Abstract: An improved insert type supersonic crack hunting apparatus is capable of discovering cracks in a boiler steel tube from inside the tube. A crack hunting section provided with a probe, a slip ring for transmitting an ultrasonic signal issued from the probe, a rotary use motor for rotary the crack hunting section and an axial feed motor for moving the crack hunting section in an axial direction are connected in sequence. An axial feed nut for converting rotation of the axial feed motor into movement in the axial direction is disposed between the rotary use motor and the axial feed motor. In addition, there is provided a coupling section, in which a front end of a flexible shaft connected to the axial feed motor is coupled to a rear end of a shaft connected to the axial feed nut. An axial feed shaft thrust bearing for supporting the coupling section is disposed between the axial feed nut and the axial feed motor.

Abstract: An improved cleaning system for a horizontal type tube assembly which can achieve cleaning of the outer surfaces of the tubes in the tube assembly automatically by remote control without necessitating human labor of workers who are compelled to work in a narrow limited space, is disclosed.

Abstract: An automatic tube circumference scanning apparatus automatically performs inspections, repairs and other operation on a group of tubes arrayed in a narrow space and extending in horizontal directions. The apparatus includes an upper support/traverse section mounted on an upper tube in the group of tubes so as to be able to travel along a tube axis and to stop and grip the upper tube, a lower support/traverse section mounted on a lower tube so as to be able to travel, stop and grip the lower tube, a flexible rail extending vertically between the upper and lower support/traverse sections and fixed thereto, and a probe scanning section mounted on the flexible rail so as to be able to move up and down and which grips any arbitrary tube between the aforementioned upper and lower tubes for making a probe scan around such tube.

Abstract: An automated ultrasonic examination system for heat transfer tubes in a boiler makes it possible to perform ultrsonic examination from inside of the heat transfer tubes without necessitating the removal of scale from the outer surfaces of the boiler tubes by polishing and without necessitating access to places where manual measurements are difficult or impossible to make.

Abstract: A two-part type cable insert nozzle has spherical seats formed on a female die and a male die. An automatic restoring member restores the female die to coaxial alignment with the male die. The automatic restoring member may include a pressing element surrounding the male die between a nozzle holder for coupling together the female die and the male die and a flange portion fixedly secured to the outer circumference of a tubular portion of the male die and spaced from and opposed to the nozzle holder. Alternatively, the member may be a spring provided within cable insert holes extending through the male die and the female die.

Abstract: A cable insertion nozzle is provided of the type having a spherical seat formed by two female and male portions of a ball and socket joint, which is characterized in that in the inner peripheral surfaces of the female and male portions is formed a recess which has a rectangular shape in longitudinal cross section and a circular shape in transverse cross section when the axis of the female segment coincides with that of the male segment, and in the recess is floatably inserted a cylindrical member the end portions of which are provided with a collar section and whose inside diameter is substantially identical with the original inside diameter of the female and male segments, whereby no step is created in the inner face of the nozzle, thereby permitting smooth conveying of the cable and the like.