The case has an opening and a wall section with a hole provided on the wall section and the wall section forms an inner space. The case also has a recessed area surrounding the hole. The piezoelectric diaphragm is supported around its periphery on top of the case so that an enclosure, including the hole, is formed within the inner space. An acoustic resistance sheet is bonded on to the wall section with the adhesive that is filled into the recessed area to close off the hole. With this structure...

A process for preparing a supported silver catalyst for the production of alkylene oxide by the vapor phase oxidation of alkylene with an oxygen-containing gas is disclosed and comprises contacting a silver-contacting support with a solution comprising a metal-containing promoter other than alkali metals or alkaline earth metals. The solution is chosen so that the metal-containing promoter has an increased affinity to the silver-containing carrier relative to its affinity to the carrier without ...

A method of magnetotelluric exploration is described, wherein measures of the earth's electric and magnetic fields are obtained at a plurality of sensing locations comprising an areal array of sensing locations. Specifically, first and second components of the earth's electric field are measured at a plurality of sensing locations within an areal array of sensing locations whereby each of the components of the earth's electric field are spatially continuous. Additionally, first and second compon...

A piezoelectric electro-acoustic transducer eliminates a negative influence caused by metal terminals upon the sound pressure and resonant frequency characteristics even when size and thickness reduction of the transducer are made. The transducer includes a piezoelectric diaphragm which includes a piezoelectric ceramic plate and a metal plate stored in a casing. The transducer also includes metal terminals in contact with the piezoelectric diaphragm and extending to the outside of the casing. Th...

In a piezoelectric vibrator capable of vibrating under an expansion mode of vibration, which has a piezoelectric vibrating element including a generally rectangular vibrateable substrate, made of a metallic material having a constant modulus of elasticity. The substrate is supported by a retaining member through a pair of connecting elements which extend outwardly from an arbitrarily chosen pair of side edges, respectively, so as to terminate in rigid connection with the retaining member. The wi...

The invention relates to a method for the correction of video signals which are produced by pixel-by-pixel reading of picture cells from an optoelectronic sensor via two or more channels which have different transmission characteristics. In this case, the video signal is supplied to a processing circuit and is converted to digital pixel values. Estimated values for pixel values of another transmission channel are calculated from the digital pixel values of one transmission channel, and the estim...

A process for the production of silicon comprising reacting a gaseous silicon compound of the formula SiH.sub.n X.sub.4-n, wherein X is halogen and n is 0 to 3, with aluminum in solid state. The resulting silicon can be highly pure and will have the particle size of the aluminum feed, making it especially useful for production of solar cells.

An inking pad assembly includes a support spindle on which a cylindrical inking pad is mounted. The inking pad is mounted on a sleeve which is a free rotating fit on the spindle apart from a central location where the clearance is relatively small. This central location enables limited pivotal movement of the ink pad about axes transverse to the axes of the rotation of the pad. The ink pad assembly has a knob by which it can be locked into a wall of apparatus in which the pad is incorporated.

An electromagnetic survey method for geophysical exploration, in which the variations in the earth's magnetic field are measured in two, non-parallel directions at one point in the survey area. Simultaneously, the variations in the earth's electrical field parallel to the survey line are measured at a number of points along the survey line. These measured variations are transformed to the frequency domain, and then the horizontal component of the magnetic field orthogonal to the direction of the...

Geological formation resistivity is determined. Circuitry is located within the borehole casing that is adjacent to the geological formation. The circuitry can measure one or more voltages across two or more voltage measurement electrodes associated with the borehole casing. The measured voltages are used by a processor to determine the resistivity of the geological formation. A common mode signal can also be reduced using the circuitry.