Abstract: A piezoelectric device comprises a ferroelectric ceramic plate as polarized, 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. The 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: A method for producing piezoelectric ceramics of a Pb(Sn.sub..alpha. Sb.sub.1-.alpha.)O.sub.3 -PbTiO.sub.3 -PbZrO.sub.3 system is disclosed which comprises providing a piezoelectric ceramic composition expressed by the general formula:xPb(Sn.sub..alpha. Sb.sub.1-.alpha.)O.sub.3 -yPbTiO.sub.3 - zPbZrO.sub.3wherein subscripts .alpha., x and y are mole fractions of the respective components and have the following values, x+y+z= 1.00, 1/4.ltoreq..alpha..ltoreq.3/4, said composition falling within a polygonal area defined by points A, B, C, D and E in FIG. 3, forming powder of the composition into forming bodies, and firing the forming bodies in an oxygen atmosphere containing not less than 80 vol % of oxygen. The firing in the oxygen atmosphere is effected at a temperature not less than 1000.degree. C. A part of lead in the composition may be replaced with not more than 20 atomic percent of at least one metal selected from the group consisting of Ba, Ca, Sr and Cd.

Abstract: An apparatus and process for tubular membrane separation, such as reverse osmosis or ultrafiltration, with an arrangement for removing undesirable deposits from the semipermeable membrane surfaces. For the removal of the deposits, elastic elements are passed, together with the feed solution being treated, through the tubular modules lined with semipermeable membranes, separated from the solution, and are recycled with a fresh supply of the solution from a tank, so that the semipermeable membranes are continuously cleaned while separating a part of the solution by permeation therethrough.

Abstract: A method for producing piezoelectric ceramics of a Pb(Sn.sub..alpha. Sb.sub.1-.alpha.)O.sub.3 -PbTiO.sub.3 system is disclosed which comprises providing a piezoelectric ceramic composition expressed by the general formula:xPb(Sn.sub..alpha. Sb.sub.1-.alpha.)O.sub.3 -PbTiO.sub.3wherein subscripts .alpha., x and y are mole fractions of the respective components and have the following values, x+y=1.00, 1/4.ltoreq..alpha..ltoreq.3/4, 0.01.ltoreq.x.ltoreq.0.40, and 0.60.ltoreq.y.ltoreq.0.99, forming powder of the composition into forming bodies, and firing the forming bodies in an oxygen atmosphere containing not less than 80 vol % of oxygen. The firing in the oxygen atmosphere is effected at a temperature not less than 1000.degree. C. A part of lead in the composition may be replaced with not more than 20 atomic percent of at least one metal selected from the group consisting of Ba, Ca, Sr and Cd. The composition may contain a small amount of Mn, Mg and/or Cr.

Abstract: Piezoelectric crystalline film on a substrate, which is a crystalline zinc oxide film with a hexagonal crystal structure and a c-axis substantially perpendicular to the substrate surface, the crystalline zinc oxide film containing, as an additive element, uranium. The piezoelectric crystalline films have high resistivity and a smooth surface, and make it possible to produce piezoelectric transducers with good conversion efficiency. Such films are made by sputtering zinc oxide and uranium onto a substrate from a film material source consisting essentially of a ceramic of zinc oxide containing uranium.

Abstract: Piezoelectric crystalline film on a substrate, which is a crystalline zinc oxide film with a c-axis substantially perpendicular to the substrate surface, the crystalline zinc oxide film containing, as an additive or additives, at least one element selected from the group of sulphur, selenium and tellurium. The piezoelectric crystalline films have high resistivity and a smooth surface, and make it possible to produce piezoelectric transducers with goal conversion efficiency. The piezoelectric crystalline films are made by sputtering zinc oxide and an additive onto a substrate from a film material source consisting essentially of a ceramic of zinc oxide containing at least one element of the group consisting of sulphur, selenium and tellurium.

Abstract: Piezoelectric crystalline film on a substrate, which is a crystalline zinc oxide film with a c-axis substantially perpendicular to the substrate surface, the crystalline zinc oxide film containing, as an additive element, phosphorus. The piezoelectric crystalline films have high resistivity and a smooth surface, and make it possible to produce piezoelectric transducers with good conversion efficiency. Such films are made by sputtering zinc oxide and phosphorus onto a substrate from a film material source consisting essentially of a ceramic of zinc oxide containing phosphorus.

Abstract: A tubular membrane separation apparatus and process, for reverse osmosis or ultrafiltration, with an arrangement for removing undesirable deposit from semipermeable membrane surfaces. The apparatus is of the multiple-stage type wherein the number of tubular modules per stage gradually decreases in a pattern like a Christmas tree laid on its side. Elastic elements are forced through the tubular modules lined with the semipermeable membrane, the number of the elements being gradually decreased stage by stage, so that the deposit is mechanically rubbed off from the membrane surfaces with an optimum number of elastic elements for each stage.

Abstract: Piezoelectric crystallime film on a substrate, which is a crystalline zinc oxide film with a c-axis perpendicular to the substrate surface, the crystalline zinc oxide film containing one copper compound selected from the group consisting of copper sulphide, copper telluride, copper selenide, copper selenate, copper phosphide and copper phosphate. The copper is present in the crystalline zinc oxide film in the form of its sulphide, telluride, selenide, selenate, phosphide or phosphate and in the concentration of 0.01 to 20.0 atomic percent. The piezoelectric crystalline film have high resistivity and a smooth surface so that they can be used in a wide range of low to high frequencies.

Abstract: Piezoelectric crystalline film of zinc oxide with a hexagonal crystal structure and a c-axis substantially perpendicular to the film surface, the crystalline film containing, as additive elements, vanadium and manganese together with or without copper. The piezoelectric crystalline films have high resistivity and a smooth surface, and make it possible to produce piezoelectric transducers with good conversion efficiency which can be used in a wide range of low to high frequencies. Such films can be made by a method comprising sputtering source materials, i.e., zinc oxide, vanadium and manganese together with or without copper onto a surface of a substrate to form a crystalline zinc oxide film, the sputtering being effected by using a film material source consisting essentially of a ceramic of zinc oxide containing vanadium, and manganese together with or without copper.

Abstract: Piezoelectric crystalline film on a substrate, which is a crystalline zinc oxide film with a c-axis perpendicular to the substrate surface, the crystalline zinc oxide film containing as additive elements, vanadium, manganese and at least one element selected from the group consisting of chromium, iron, cobalt and nickel. The piezoelectric crystalline films are homogeneous and have high resistivity and a smooth surface so that they can be used as a transducer with good conversion efficiency in a wide range of low to high frequencies.

Abstract: Piezoelectric crystalline films which consist essentially of a crystalline zinc oxide film with a c-axis perpendicular to a substrate surface, containing 0.01 to 20.0 atomic percent of vanadium. These films are prepared by radio-frequency sputtering.

Abstract: Piezoelectric crystalline films on substrate, which consist essentially of a crystalline zinc oxide film with a c-axis perpendicular to a substrate surface, containing 0.01 to 20.0 atomic percent of at least one element selected from the group consisting of iron, chromium, cobalt and nickel.

Abstract: Piezoelectric crystalline films which consist essentially of a crystalline zinc oxide film with a c-axis perpendicular to a substrate surface containing 0.01 to 20.0 atomic percent of manganese with or without 0.01 to 20.0 atomic percent of copper.

Abstract: Piezoelectric crystalline films which consist essentially of a crystalline zinc oxide film with a c-axis perpendicular to a substrate surface, containing 0.01 to 20.0 atomic percent of bismuth. These films are prepared by radio-frequency sputtering.

Abstract: There is disclosed an ultrasonic tomography apparatus of electronic scanning type in which an array of ultrasonic transducer elements are excited with desired time delays allotted for the transducer elements thereby to transmit and receive ultrasonic beams at a deflection angle corresponding to the desired time delays, and the received echo signal of the ultrasonic beams is displayed on a CRT display device in a form of a tomograph of a sample to which the ultrasonic beams are directed. The apparatus comprises a memory in which both of first signals representative of the time delays given to the transducer elements in dependence on given deflection angles and signals designating display position in the X- and Y-directions of the CRT are previously stored and read out for producing delays allotted for the transducer elements and displaying the received echo signal on the CRT.

Abstract: In a method for controlling ultrasonic waves wherein a plurality of elements constituting a phased array ultrasonic transducer are driven with desired delay times, the improvement therein comprising the fact that when values obtained by quantizing the delay times by a predetermined time are different between the adjacent elements, the ultrasonic waves are radiated with a delay of time corresponding to the difference.

Abstract: A system is provided for separating waste water or solution into a permea solution and a concentrated solution by feeding the waste water or solution to a reverse osmosis apparatus using a membrane.A chemical pretreating apparatus is provided to prevent hard scales contained in the waste water or solution from precipitation during the concentration in the reverse osmosis apparatus using the membrane. An apparatus for charging sponge balls is further provided to mechanically remove suspended solids and other suspended matters, that is, soft scales when deposited on the surface of membrane. The sponge balls are desirably recyclically used.

Abstract: A redundancy system for data communications upon two duplicate communication channels, each having transmission and reception circuits, characterized by a switching circuit for selecting one of said two communication channels, a single error detection circuit for detecting an error in the signal transmitted, and a control circuit for the switching circuit arranged to cause said two communication channels to alternately transmit signals when both the channels are in normal operation, and to cause one of said two channels to be selected when the other fails. The two channels share the error detection circuit and the control circuit and can therefore be built at a reduced cost and operated efficiently. Since the two channels are regularly checked for errors, they are operated with increased reliability.

Abstract: A ferroelectric ceramic composition of a ternary system solid solution represented by the general formula:xPb(Sn.sub..alpha.Sb.sub.1.sub.-.sub..alpha.)O.sub.3 -- yPbTiO.sub.3 -- zPbZrO.sub.3wherein x, y and z are the respective mol fractions of the components, x + y + z = 1.00 and 1/4 .ltoreq. .alpha. .ltoreq. 3/4.