Abstract: A scale inhibitor includes a granular material composed of a particle containing a plurality of polyphosphate salts, the granular material has an asymmetric particle diameter distribution, and a particle diameter with a maximum frequency is smaller than an average particle diameter of the granular material.

Abstract: A scale inhibitor includes a granular material composed of a particle containing a plurality of polyphosphate salts, the granular material has an asymmetric particle diameter distribution, and a particle diameter with a maximum frequency is smaller than an average particle diameter of the granular material.

Abstract: A piezoelectric element includes a piezoelectric composition pressure sensitive substance, a first electrode, a second electrode and a covering layer. The piezoelectric composition pressure sensitive substance includes a piezoelectric ceramic powder and a flexible organic polymer. The first and second electrodes are connected to the piezoelectric composition pressure sensitive substance and electrically insulated from each other. The covering layer is provided outside of the piezoelectric ceramic powder and suppresses absorption of the water by the piezoelectric ceramic powder.

Abstract: A method for manufacturing an acoustic matching member, the acoustic matching member being incorporated into an ultrasonic transducer for transmitting and receiving ultrasonic waves, and including: at least two layers including a first layer and a second layer that have different acoustic impedance values from each other. The method for manufacturing including the steps of: filling voids of a porous member with a fluid filling material, and solidifying both the fluid filling material inside the voids and the surplus fluid filling material at the same time. The acoustic matching member does not have independent intermediate layers between the layers, so that delamination hardly occurs and the difficulty in the designing associated with the presence of intermediate layers can be avoided.

Abstract: It is a principal object of the present invention to provide a dielectric having a high relative dielectric constant and dielectric loss minimized in high frequency bands. That is, the present invention relates to a composite dielectric comprising conductive particles dispersed in a porous body of inorganic oxide, wherein 1) the relative dielectric constant ¥r of the dielectric in high frequency bands of 1 GHz or more is 4 or more, and 2) the dielectric loss tan? of the dielectric in high frequency bands of 1 GHz or more is 2×10?4 or less, and to a manufacturing method therefor.

Abstract: A piezoelectric element includes a piezoelectric composition pressure sensitive substance, a first electrode, a second electrode and a covering layer. The piezoelectric composition pressure sensitive substance includes a piezoelectric ceramic powder and a flexible organic polymer. The first and second electrodes are connected to the piezoelectric composition pressure sensitive substance and electrically insulated from each other. The covering layer is provided outside of the piezoelectric ceramic powder and suppresses absorption of the water by the piezoelectric ceramic powder.

Abstract: It is an object of the present invention to provide an ultrasonic transducer, which is so configured as to reduce the variations in characteristics, thereby to enable the stabilization of the precision, as well as to enable the improvement of the durability, and the like, a method for manufacturing the ultrasonic transducer, and an ultrasonic flowmeter. In order to attain this object, in accordance with the present invention, the ultrasonic transducer is so configured as to include a piezoelectric element and an acoustic matching layer, wherein the acoustic matching layer is made of a dry gel of an inorganic oxide or an organic polymer, and a solid skeletal part of the dry gel has been rendered hydrophobic. With this configuration, it is possible to obtain the ultrasonic transducer having an acoustic matching layer 3 which is very lightweight and has a small acoustic impedance due to the solid skeletal part of the dry gel which has been rendered hydrophobic.

Abstract: An ultrasonic transducer according to the present invention includes: a piezoelectric body 4 to set up ultrasonic vibrations; an acoustic matching layer 3 made of a material with a density of 50 kg/m3 to 1,000 kg/m3 and an acoustic impedance of 2.5×103 kg/m2/s to 1.0×106 kg/m2/s; a lower acoustic matching layer 9 provided between the piezoelectric body 4 and the acoustic matching layer 3; and a structure supporting member 6 that supports the lower acoustic matching layer 9 and the piezoelectric body 4 thereon and shields the piezoelectric body 4 from a fluid that propagates the ultrasonic vibrations. The ultrasonic transducer includes a protective portion, which contacts with at least a portion of a side surface of the acoustic matching layer 4. This protective portion is defined by a portion of the lower acoustic matching layer 9 and forms an integral part of the lower acoustic matching layer 9.

Abstract: A nanoparticles-containing composite porous body according to the present invention includes a porous body having a solid skeleton and pores and nanoparticles of an inorganic substance. The nanoparticles are carried on the solid skeleton without coagulating together or being chemically bonded to the skeleton. The nanoparticles may be coated with organic aggregates and carried as composite particles on the solid skeleton. As the organic aggregates, spherical organic aggregates such as a spherical protein or a dendrimer are preferably used. Also, the organic aggregates may be decomposed and removed if necessary.

Abstract: An acoustic matching layer 1 according to the present invention includes a first acoustic matching layer 2, which has a low density and a low sonic velocity, and a second acoustic matching layer 3, which has a higher density and a higher sonic velocity. The first acoustic matching layer 2, of which the acoustic impedance is matched to that of a medium into an ultrasonic wave is radiated, is provided closer to the medium, while the second acoustic matching layer 3 is provided closer to a piezoelectric layer, thereby increasing the sensitivity of an ultrasonic transducer.

Abstract: It is a principal object of the present invention to provide a dielectric having a high relative dielectric constant and dielectric loss minimized in high frequency bands. That is, the present invention relates to a composite dielectric comprising conductive particles dispersed in a porous body of inorganic oxide, wherein 1) the relative dielectric constant ?r of the dielectric in high frequency bands of 1 GHz or more is 4 or more, and 2) the dielectric loss tans of the dielectric in high frequency bands of 1 GHz or more is 2×10?4 or less, and to a manufacturing method therefor.

Abstract: An acoustic matching layer according to the present invention includes a powder of a dry gel. The dry gel preferably has a density of 500 kg/m3 or less and an average pore diameter of 100 nm or less. By using the dry gel powder, a variation in the property of the acoustic matching layer can be reduced.

Abstract: An ultrasonic transducer according to the present invention includes a piezoelectric body 2 for transmitting and receiving an ultrasonic wave and acoustic matching layers 3a and 3b made of a dry gel. The acoustic matching layers 3a and 3b are multiple dry gel layers with mutually different acoustic impedances.

Abstract: A method of making a porous body, including a dry gel, includes the step of forming the dry gel. The step of forming the dry gel includes the steps of: preparing a first gel having a first skeleton and pores; and restructuring the first gel by decomposing at least a portion of the first skeleton and forming a second skeleton, which is thicker than the first skeleton.

Abstract: It is an object of the present invention to provide an ultrasonic transducer, which is so configured as to reduce the variations in characteristics, thereby to enable the stabilization of the precision, as well as to enable the improvement of the durability, and the like, a method for manufacturing the ultrasonic transducer, and an ultrasonic flowmeter. In order to attain this object, in accordance with the present invention, the ultrasonic transducer is so configured as to include a piezoelectric element and an acoustic matching layer, wherein the acoustic matching layer is made of a dry gel of an inorganic oxide or an organic polymer, and a solid skeletal part of the dry gel has been rendered hydrophobic. With this configuration, it is possible to obtain the ultrasonic transducer having an acoustic matching layer 3 which is very lightweight and has a small acoustic impedance due to the solid skeletal part of the dry gel which has been rendered hydrophobic.

Abstract: An acoustic matching member that is incorporated into an ultrasonic transducer for transmitting and receiving ultrasonic waves, includes: at least two layers including a first layer and a second layer that have different acoustic impedance values from each other. The first layer is made of a composite material of a porous member and a filing material supported by void portions of the porous member, the second layer is made of the filling material or the porous member, and the first layer and the second layer are present in this stated order. A piezoelectric member is disposed on a side of the first layer of the acoustic matching member to form an ultrasonic transducer or an ultrasonic flowmeter. The acoustic matching member does not have independent intermediate layers between the layers, so that delamination hardly occurs and the difficulty in the designing associated with the presence of intermediate layers can be avoided.

Abstract: It is an object of the present invention to provide an ultrasonic transducer, which is so configured as to reduce the variations in characteristics, thereby to enable the stabilization of the precision, as well as to enable the improvement of the durability, and the like, a method for manufacturing the ultrasonic transducer, and an ultrasonic flowmeter. In order to attain this object, in accordance with the present invention, the ultrasonic transducer is so configured as to include a piezoelectric element and an acoustic matching layer, wherein the acoustic matching layer is made of a dry gel of an inorganic oxide or an organic polymer, and a solid skeletal part of the dry gel has been rendered hydrophobic. With this configuration, it is possible to obtain the ultrasonic transducer having an acoustic matching layer 3 which is very lightweight and has a small acoustic impedance due to the solid skeletal part of the dry gel which has been rendered hydrophobic.

Abstract: An acoustic matching member that is incorporated into an ultrasonic transducer for transmitting and receiving ultrasonic waves, includes: at least two layers including a first layer and a second layer that have different acoustic impedance values from each other. The first layer is made of a composite material of a porous member and a filling material supported by void portions of the porous member, the second layer is made of the filling material or the porous member, and the first layer and the second layer are present in this stated order. A piezoelectric member is disposed on a side of the first layer of the acoustic matching member to form an ultrasonic transducer or an ultrasonic flowmeter. The acoustic matching member does not have independent intermediate layers between the layers, so that delamination hardly occurs and the difficulty in the designing associated with the presence of intermediate layers can be avoided.

Abstract: An acoustic matching layer 1 according to the present invention includes a first acoustic matching layer 2, which has a low density and a low sonic velocity, and a second acoustic matching layer 3, which has a higher density and a higher sonic velocity. The first acoustic matching layer 2, of which the acoustic impedance is matched to that of a medium into an ultrasonic wave is radiated, is provided closer to the medium, while the second acoustic matching layer 3 is provided closer to a piezoelectric layer, thereby increasing the sensitivity of an ultrasonic transducer.

Abstract: An ultrasonic transducer according to the present invention includes: a piezoelectric body 4 to set up ultrasonic vibrations; an acoustic matching layer 3 made of a material with a density of 50 kg/m3 to 1,000 kg/m3 and an acoustic impedance of 2.5×103 kg/m2/s to 1.0×106 kg/m2/s; a lower acoustic matching layer 9 provided between the piezoelectric body 4 and the acoustic matching layer 3; and a structure supporting member 6 that supports the lower acoustic matching layer 9 and the piezoelectric body 4 thereon and shields the piezoelectric body 4 from a fluid that propagates the ultrasonic vibrations. The ultrasonic transducer includes a protective portion, which contacts with at least a portion of a side surface of the acoustic matching layer 4. This protective portion is defined by a portion of the lower acoustic matching layer 9 and forms an integral part of the lower acoustic matching layer 9.