Abstract: A piezoelectric element includes a stack including a plurality of internal electrodes and a plurality of piezoelectric layers stacked on one another, and a surface electrode located on a side surface of the stack and electrically connected to the plurality of internal electrodes. The stack includes the piezoelectric layers being stacked and the internal electrodes each between adjacent piezoelectric layers. The internal electrodes include a first electrode that applies a voltage to the piezoelectric layers to cause the stack to bend in a first direction (X-direction) orthogonal to a longitudinal direction (Z-direction) of the stack, and a second electrode that applies a voltage to the piezoelectric layers to cause the stack to bend in a second direction (Y-direction) orthogonal to the longitudinal direction and to the first direction. The stack includes a groove extending in the longitudinal direction on an upper surface of the stack.

Abstract: In preparing a solar cell, minute projections and recesses are uniformly formed in a surface of a single crystal silicon substrate or a polycrystal silicon substrate by dipping in an etching liquid composed of a mixed acid which is composed mainly of a hydrofluoride acid, a nitric acid and a phosphoric acid in addition to a surface active agent. A solar cell having a substrate in which spherical projections and recesses are formed in a surface of it to which light is incident; an apparatus for producing efficiently a solar cell by realizing the above-mentioned process, and a wet etching apparatus to effect stably the above-mentioned process to thereby maintaining a concentration of a nitric acid to be constant, are provided.

Abstract: In preparing a solar cell, minute projections and recesses are uniformly formed in a surface of a single crystal silicon substrate or a polycrystal silicon substrate by dipping the substrate in an etching liquid of a mixed acid including a hydrofluoride acid, a nitric acid and an adjusting agent containing at least a phosphoric acid or a water-soluble carboxylic acid having a higher molecular weight than acetic acid for adjusting the etching rate of the etching liquid. A solar cell having a substrate in which spherical projections and recesses are formed in a surface thereof to which light is incident; an apparatus for producing a solar cell, and a wet etching apparatus to maintain a constant concentration of a nitric acid, are provided.

Abstract: In preparing a solar cell, minute projections and recesses are uniformly formed in a surface of a single crystal silicon substrate or a polycrystal silicon substrate by dipping in an etching liquid composed of a mixed acid which is composed mainly of a hydrofluoride acid, a nitric acid and a phosphoric acid in addition to a surface active agent. A solar cell having a substrate in which spherical projections and recesses are formed in a surface of it to which light is incident; an apparatus for producing efficiently a solar cell by realizing the above-mentioned process, and a wet etching apparatus to effect stably the above-mentioned process to thereby maintaining a concentration of a nitric acid to be constant, are provided.

Abstract: A method for producing hydrogen peroxide by electrical discharge in a material gas in which oxygen concentration is not less than 0.5% and less than 13% is disclosed in the first aspect. In the second aspect, an apparatus for producing hydrogen peroxide having a plurality of electrical discharge chambers connected in series is disclosed. In the third aspect, an apparatus in which a material gas is recycled is disclosed. In the forth aspect, an apparatus having its electrodes covered with dielectric and an electrical discharge chamber which is cooled by a cooling member. In the fifth aspect, a method for producing hydrogen peroxide having a step of inactivating radical species produced by electrical discharges is disclosed. In the sixth aspect, an apparatus having a condensation tube coated with resin with low reactivity with hydrogen peroxide is disclosed.

Abstract: A microwave plasma apparatus comprises a discharge chamber for generating a plasma. A dielectric plate is placed on a surface of the discharge chamber. A microwave circuit surrounds the longitudinal side surface of the dielectric plate and the microwave circuit is adapted to couple the signal propagating therein to the dielectric plate, whereby a microwave electric field is formed within the discharge chamber to generate a plasma therein. The microwave circuit may comprise a rectangular waveguide, and a part of a wall surface of the rectangular waveguide is utilized as a terminal portion.

Abstract: The method of treating a surface of a substrate (12) comprises the steps of physically treating the surface by jetting hydrogen peroxide containing ice particles (28) onto the substrate surface, and chemically treating the substrate surface with hydrogen peroxide solution obtained by melting the hydrogen peroxide containing ice particles (28).

Abstract: A drinking water purifying apparatus for purifying water from a water service comprises an ozone generating means for producing ozonized gas, an ozone reaction means for reacting the ozonized gas from the ozone generating means with the water from a water service, and a treating means for treating the water obtained by reaction to the ozonized gas in the ozone reaction means, whereby drinking water being free from organic compounds and smelling substances and having good taste can be obtained.

Abstract: An apparatus for preventing biofouling caused by deposition and propagation of shellfish and algae in a cooling water system using sea water or river water for example, in a power plant, by periodically feeding ozone at high concentration to the system. An ozonizer is combined with an ozone-adsorbing and desorbing device so as to store ozone by adsorbing of an adsorbent and for a long time at lower temperature and desorbing ozone by periodically sucking at higher temperature if desired, by a water ejector.

Abstract: An ozonized oxygen fed from an ozonizer is passed to a reaction tower to treat an object material. In recovering non-reacted oxygen from the reaction tower to reuse in the ozonizer, zeolite is used as an adsorbent to remove impurities contained in the recovered oxygen, such as water, volatile organic materials and CO.sub.2 gas so that a raw material oxygen without containing any impurity is fed to the ozonizer to increase the ozonizing efficiency.

Abstract: An ozone-generating apparatus comprises an ozonizer; one or more moisture exchangers in which synthetic zeolite having fine pore diameter for inhibiting adsorption of ozone but easily adsorbing moisture, is filled as a moisture adsorbent; and switching means which switches the moisture exchangers at the inlets and the outlets thereof to alternatively repeat a moisture-adsorbing operation for drying air by passing a wet air through one of the moisture exchanger before feeding it to the ozonizer and a moisture adsorbent-recovering operation for drying the synthetic zeolite by passing the dry ozone-containing air generated from the ozonizer through the other moisture exchanger.

Abstract: A moisture exchanger type ozone-generating apparatus comprises one or more pairs of adsorption towers which alternatively repeat a step of adsorption and a step of desorption by passing a dry ozone-containing air, and at least one additional adsorption tower for imparting a step of partial desorption between the step of adsorption and the step of desorption, whereby the decrease of ozone concentration at the switching from the step of adsorption to the step of desorption is reduced.