Abstract: An ultrasonic imaging apparatus and method of forming an image of an acoustic image of an object employing the aperture synthesis technique, in which at least one partial aperture for accommodating a predetermined number of successive transducers is established and applied to a transducer array to select the predetermined number of successive transducers accommodated in the partial aperture so that the selected transducers serve to transmit ultrasonic acoustic signals to an object and receive signals reflected from the object, and the at least one partial aperture is specifically moved along the arrayed transducers for similar signal transmission to and/or signal reception from the object, whereby the apparatus and the method do not suffer substantial noise caused during changeover between transmitting and receiving operation modes and/or enjoy and enlarged aperture for signal transmission or enlarged aperture for signal reception with a suppressed decrease of the frame rate.

Abstract: A monolithic piezoelectric element comprising a sintered body comprising a plurality of ceramic layers which is provided with a first electrode group which includes a plurality of electrodes electrically connected with each other and located between alternate pairs of adjacent layers, and a second electrode group which includes a plurality of electrodes interposed between the electrodes of the first electrode group and electrically connected with each other. The two groups of electrodes are electrically isolated from each other. The respective electrodes of the first and second electrode groups are electrically connected with each other through through-holes formed in the sintered body.

Abstract: An ultrasonic probe used for ultrasonic diagnosis apparatus. A plurality of ultrasonic transducer elements are provided in a convexity at the tip of a probe so as to constitute a convex array ultrasonic probe. The curvature radius of the convexity is set at not greater than 12 mm and the pitch of adjacent transducer elements is set at not greater than 1/30 of the curvature radius and a ratio .DELTA./Y is set at not greater than 1/35, where Y represents the beam focal distance and .DELTA. represents the lateral resolution of the probe.

Abstract: A phase difference comparison type of ultrasonic velocity meter repeatingly transmitting acoustic waves in the form of pulses at alternate time intervals: T-T.sub.S and T+T.sub.S, receiving reflected waves generated by the transmission of these waves and reflected on an object, forming first and second mixed waves by mixing the reception signal obtained from the reflected waves with two reference waves having phases shifted 90 degrees from each other, detecting the phase difference between the present vectors representing the first and second mixed waves and similar vectors which have been obtained with respect to the preceding pulse transmission, detecting the phase difference Q between the phase difference caused in relation to the time interval T-T.sub.S and the phase difference caused in relation to the time interval T+T.sub.S with respect to a phase difference obtained each time a pulse is transmitted, and calculating the Droppler shift angle frequency .omega.d from .omega.d=Q/2T.sub.S.

Abstract: A piezoelectric sound generator which comprises a monolithic sintered body obtained by laminating a plurality of ceramic green sheets formed alternately with a plurality of electrodes and cofiring the same. Electrical connections between the electrodes in the sintered body are provided within through-holes formed at the vibrational node of the piezoelectric sound generator.

Abstract: A piezoelectric ceramic composition consists essentially of a main component consisting of lanthanum modified lead titanate and lead stanate antimonate, and an auxiliary component consisting of manganese oxide. The content of the main component is 98 to 99.0 mole % when expressed by the general formula:yPb(Sn.sub.1/2 Sb.sub.1/2)O.sub.3 -(1-y)(Pb.sub.1-3x/2 La.sub.x)TiO.sub.3(where 0.01.ltoreq.x.ltoreq.0.06 and 0.01.ltoreq.y.ltoreq.0.06), and the content of the manganese oxide is 0.1 to 2 mole % when converted into an amount of MnO.sub.2.

Abstract: A method of producing a long-life roll for a rolling mill manufacturing a rolled sheet having brightness. At least the surface of the roll barrel is made of steel containing carbide, the average grain size of which is not greater than 0.6 .mu.m, and the areal ratio of the carbide in the matrix is 6-30%. The roll is manufactured by canning steel powder produced by an RST process into a metal cylindrical container in a vacuum, sintering the powder in the cylindrical container by hot isostatic pressing, working the sintered body into the cnfiguration of a roll by machining and further giving it a heat treatment and finishing work. The roll and a rolling mill incorporating the roll are also disclosed.

Abstract: In an ultrasonic imaging apparatus, when a sampling time space determined corresponding to the respective phases of receiving signals from transducer elements adjacent to each other is shorter than the settling time of sample and hold circuits, these receiving signals are sampled at the same time. Noise is prevented from being mixed with the sample and hold values of these signals.

Abstract: An electronic scanning apparatus ultrasonic imaging adapted to converge or deflect an ultrasonic beam by controlling the amplitude and phase of the vibration of each transducer in a transducer array consisting of a plurality of regularly-arranged transducers, and adapted to move the ultrasonic beam by selecting from all of the transducers constituting the transducer array at least one transducer forming a transmitting and receiving aperture.

Abstract: Disclosed herein is a piezoelectric displacement element utilizing a sintered body obtained by stacking three or more ceramic layers (5a to 5h) through internal electrodes (6b to 6h) and co-firing the same. The sintered body has first, second and third regions when viewed in the direction of thickness. The first and third regions are so formed as to be displaced in reverse directions to each other. The second region consists of a plurality of piezoelectric ceramic layers (5d, 5e) in such a manner that an internal electrode (6e) interposed between the piezoelectric ceramic layers (5d, 5e) is connected with neither potentials in a driven state, whereby the second region is adapted not to be positively driven, to function as a buffer area.

Abstract: A pulsating sound wave beam is transmitted into an object using an array-type ultrasonic wave transducer which consists of a plurality of elements; the reflected sound waves are received using said transducer while electronically focusing the reflected sound waves depending upon an estimated speed of sound in the object, and the beam width of sound waves is measured repeatedly near a particular reflector while successively changing the estimated speed of sound. The estimated speed of sound of when the beam width is minimal is the mean speed of sound of the object in practice, and the beam width at that moment serves as an indication of acoustical homogeneity of the object.

Abstract: Piezoelectric ceramic compositions comprising a principal component, ##EQU1## and manganese contained therein as an additive in the amount of 0.1 to 2.0 wt % of MnO.sub.2 with respect to the weight of 1 mol of the principal component. The piezoelectric ceramic compositions are suitable for use for pyroelectric devices, piezoelectric vibrators, resonators, oscillators, ceramic filters, surface acoustic wave filters and so on.

Abstract: A piezoelectric ceramic for acoustic surface wave devices which consists essentially of a solid solution of the ternary system Pb(Sn.sub..alpha. Sb.sub.1-.alpha.)O.sub.3 -PbTiO.sub.3 -PbZrO.sub.3 having a composition showing a phase transition between a ferroelectric rhombohedral low temperature phase (F.sub.R(LT)) and a ferroelectric rohombohedral high temperature phase (F.sub.R(HT)) at a temperature within the range from -20.degree. C. to +80.degree. C. The solid solution consists essentially of a main component expressed by the formula:xPb(Sn.sub..alpha. Sb.sub.1-.alpha.)O.sub.3 -yPbTiO.sub.3 -zPbZrO.sub.3where in x+y+z=1.00, 1/4.ltoreq..alpha..ltoreq.3/4, and contains, as an additive, manganese in oxide form in an amount of 0.05 to 5.0 wt % when converted into MnO.sub.2 and, if necessary, further contains at least one element selected, from magnesium and chromium in oxide form in respective amounts of 0.05 to 5.0 wt % when respectively converted into MgO and Cr.sub.2 O.sub.3.

Abstract: An ultrasonic diagnosis system comprising a variable setting arrangement including an ultrasonic transducer array for transmitting a pulse-like ultrasonic wave to an object and detecting a reflection wave from the object, and assuming the acoustic velocity of the object; a control arrangement for determining the depth of electronic focusing in accordance with this assumed acoustic velocity; and a display for displaying the assumed acoustic velocity. The ultrasonic diagnosis system determines whether the reflection signal of the object at a predetermined position is in-focus or out-of-focus and knows the actual acoustic velocity of the object from the assumed acoustic velocity when the reflection signal is in-focus.

Abstract: A ceramic filter including a piezoelectric ceramic and input and output electrode groups disposed within the ceramic body. The input electrode group and the output electrode group extend toward each other from opposing sides of the piezoelectric ceramic. They do not meet, however, and a predetermined spacing, along the thickness dimension of the ceramic, separates the two electrode groups. The input and output electrode groups are each composed of a plurality of electrodes which overlap each other with ceramic layers interposed therebetween.

Abstract: A method of producing a composite material of and Nb or V used for a superconductive wire comprises vacuum - melting two kinds of raw materials, 70 wt % Cu and 30 wt % Nb or V to form a melt; scattering the melt by a rotating disc to form a plurality of fine droplets each of which includes Cu and Nb or V at substantially the same compounding rate as the raw materials; and cooling rapidly the fine droplets by spraying an inert gas onto the scattering droplets thereby providing particulate bodies each of which dendrites of Nb or V are precipitated in Cu. The fine particles are compression - molded to form a molded product. The molded product is sintered to form an ingot in which the dendrites of Nb or V are dispersed homogeneously in the Cu base. The ingot is used for producing a superconductive wire, namely, it is subjected to cold rolling to reduce its sectional area, coating with Su or Ga, and diffusion heat-treating the wire to form Nb.sub.3 Sn or V.sub.

Abstract: A piezoelectric ceramic composition comprises a major component, ##STR1## (where 0.01.ltoreq.X.ltoreq.0.40 and 0.ltoreq..alpha..ltoreq.1), and CuO contained therein as an additive in an amount of 0.05 to 2.5 wt % with respect to the weight of 1 mole of the major component. If required, this composition may contain 0.05 to 2.0 wt % of MnO.sub.2 with respect to the weight of 1 mole of the major component. The composition has excellent temperature characteristics in addition to excellent dielectric and piezoelectric characteristics suitable for use in various fields.

Abstract: A bulk wave piezoelectric device comprises a polarized ferroelectric ceramic plate, and electrodes formed on two main surfaces thereof, respectively, intersecting the polarization axis direction. The electrodes are connected to each other by means of an external resistance having a predetermined resistance value. The resistance value is selected to be smaller than the inherent resistance value of the ferroelectric ceramic plate between the two main surfaces. Positive and negative electric charges are stored on the two electrodes due to the pyroelectric effect responsive to a change of the temperature of the ferroelectric ceramic plate. The potential difference caused by the electric charges thus stored is rapidly decreased through the external resistance.

Abstract: Disclosed is a semiconductor device comprising: a semiconductor body having a first semiconductor layer of the N conductivity type, second and third semiconductor layers of the P conductivity type, and first and second regions of the N conductivity type formed in the second semiconductor layer; a cathode electrode having first and second portions formed on the first semiconductor region; a gate electrode provided in the second semiconductor layer in opposition to the cathode electrode with the second semiconductor region interposed therebetween; an anode electrode provided on the third semiconductor layer; an auxiliary electrode consisting of two first portions and one second portion connected at ends respectively to the first portions, said first portions being formed on said second region and having free ends spaced from each other, and said second portion formed on said second layer and extending along the periphery of the first portion of said cathode electrode; and the second portion of the cathode elect

Abstract: In discarding the used ion exchange resin by the demineralizer provided in the cooling system of an atomic reactor, the radioactivity-rich ion exchange resin and the radioactivity-rich crud can be treated separately by introducing 0.5% by weight of sodium hexamethaphosphate into a slurry of the ion exchange resin, irradiating supersonic of 20 to 60 kHz in frequency to the slurry of the ion exchange resin and removing the radioactive crud from the ion exchange resin.