Abstract: An apparatus for measuring displacement by light wave interference, wherein means are provided to determine true displacement in spite of atmospheric flicker in the light path. Two coherent light beams of different wavelengths are transmitted over a common path and reflected from a light reflector means, the displacement of which is to be measured. The reflected beams are separated and compared with reference beams to measure a phase difference for each reflected beam, and signal processing means is provided for calculating atmospheric flicker error from the phase differences, and for determining true displacement by taking the measured error into consideration.

Abstract: An input signal passes by way of a variable gain amplifier to an output terminal. In addition the input signal is applied to a peak detector and then a control signal is derived by applying a smoothing function taking into account a predetermined number of peak values. A selected gain function is applied to the control signal. The control signal is preferably also multiplied by a compression control signal which acts on individual half cycles to bring all peak values in the output signal to the same value.

Abstract: A dry etching method for Al.sub.x Ga.sub.1-x N(0.ltoreq.x.ltoreq.1) semiconductor is disclosed. The method includes a first method using plasma of carbon tetrachloride (CCl.sub.4) gas, and a second method using plasma of dichlorodifluoromethane (CCl.sub.2 F.sub.2) gas. The etching speed of the former method was 430 .ANG./min. and the etching speed of the latter method was 625 .ANG./min. Also, no crystal defect was produced in the above-mentioned semiconductor by the above-mentioned etching.

Abstract: In transparent tone-in-band communication systems a notch in the frequency band is usually formed and then the resulting spectrum is translated in frequency to an intermediate frequency range as part of the transmission process. In a transmitter of the present invention a more simple arrangement is used in which the notch is formed directly in an intermediate frequency range by using mirror filters to divide an input signal into two portions and supply respective mixers, each having one output sideband in the intermediate frequency range. The mixers receive different reference frequencies and the mixer outputs are supplied to a summing circuit whose output is passed to a band pass filter to remove the unwanted sidebands. The original frequency spectrum is restored at the receiver by mixer processes of shifting the two selected sidebands similar to, but the inverse of, those used in the transmitter.

Abstract: Simultaneous time-variable and position-variable control of the polarization properties from any position along the length of an optical fibre, is effected by launching an acoustic disturbance into the fibre, thereby locally modifying the birefringence of the fibre. A current measurement device incorporating a monomode optical fiber 1 may be made insensitive to vibration by launching an acoustic wave from one end of the fiber. This wave 7 consists of two linearly polarized shear waves orthogonal in direction, and in phase quadrature is of such an amplitude and frequency as to provide a circular birefringence very much greater than the vibrationally-induced linear birefringence.

Abstract: The present invention relates to a method for preparing magnetic powder comprising homogeneous and fine particles using an alkali-producing enzyme. The object of the present invention is to provide a method suitable for preparing magnetic powder comprising relatively small particles, for instance, fine particles having a particle size ranging from 50 to 500 nm. The present invention relates to a method for preparing at least one member selected from the group consisting of iron oxides, iron hydroxides and iron oxyhydroxides which comprises the step of alkalizing a solution containing iron ions utilizing an alkali-producing enzyme and a substrate of the enzyme.According to the present invention, there can be produced magnetite (Fe.sub.3 O.sub.4) and maghemite (gamma-Fe.sub.2 O.sub.3) useful as magnetic powder as well as goethite (alpha-FeO(OH)), hematite (alpha-Fe.sub.2 O.sub.3) and lepidocrocite (gamma-FeO(OH)) useful as the starting materials thereof.

Abstract: An electrostatic dust collector for removing particles, such as smoke particles, pollen and the like from a gas stream passed therethrough. The dust collector includes a filter element formed of narrow strips of pliable, porous dielectric material superimposed, face to face, with electrodes therebetween and so that no air gap is formed between the face to face strips. The superimposed strip is coiled or randomly packed into a non-conductive bag, such as of nylon net, and positioned in a gas stream from which particles are to be removed and the pores of the dielectric material are charged to attract in such gas stream to the walls of the charged pores by applying a voltage to the electrodes.

Abstract: Prostaglandin analogues exhibiting activity at thromboxane receptor sites have been prepared.

Abstract: A position-sensitive radiation detector has a multi-layer scintillator assembly coupled to a position-sensitive photo-detector. Individual scintillator blocks of rectangular solid form in each scintillator layer are optically isolated by a reflecting agent such as BaSO.sub.4, and the adjacent layers are optically coupled by a coupling agent such as silicon grease. In the case of the scintillator assembly of n layers, the scintillator blocks in one layer are staggered with those in the adjacent layer by one nth of the width of each block. In addition to information on a horizontal position, information on the depth of radiation absorption can be obtained by calculating the centroid or variance of a spatial distribution of light outputted from the scintillator assembly.

Abstract: A ball-like article includes a flexible outer skin of a size and shape adapted to be readily grasped within the palm of one hand. The skin has a plush outer surface and defines an interior approximately fifty percent (50%) of which is occupied by a quantity of plastic pellets or other granular material to be movable in a generally fluidic fashion within the interior. The article has a characteristic kneadable quality adapted for therapeutic manual manipulation, light manual tossing and catching, and other non-impactive recreational activities.

Abstract: A synthetic vascular prosthesis comprises a hollow tubular base member having a multitude of continuous pores and formed of an elastomer material, and a hydrogel layer formed on the inner surface of the base member. The hydrogel layer is partly embedded in the inner portion of the base member at the pores, thereby permitting anchoring adhesion between the hydrogel layer and the base member. A method for manufacturing the synthetic vascular prosthesis is also disclosed, in which the formation of pores in the base member is effected by two separate steps and the hydrogel layer is formed after formation of an inner porous portion of the base member.

Abstract: A method for treating porous polytetrafluoroethylene and other types of synthetic materials having low surface tension to render the material suitable for use in bonding to living tissue. The synthetic material is enveloped with a liquid of sufficiently low surface tension to permit the liquid to enter the pores of the material. The liquid has a sufficiently low gas content to enable the liquid to absorb or displace essentially all gas nuclei held in the pores of the material as the liquid fills essentially all pores. After the low surface tension liquid has permeated all pores of the porous material, such liquid is replaced with a solution compatible with the body fluid and in which proteins have a low solubility to render the material suitable for implant. When such material is placed in contact with exposed tissue, an immediate bond is formed which permits implanting the material without the need of sutures to hold the material in place.

Abstract: This invention relates to several novel intermediates useful in the manufacture of thromboxane A.sub.2 inhibiting 7-[3-.alpha.-[1-[[(phenylamino)-thioxomethyl]hydrazono]ethyl]-bicyclo[2.2. 1]-heptenoic acids.

Abstract: An intelligent scan image sensor including a two-dimensional solid-state array of addressable imaging cells arranged for exposure to an image, where each cell includes a photosensitive diode and a sample and hold unit. The diode accumulates an electrical quantity having a value in relation to the image light intensity falling thereupon during successive integration periods and the sample and hold unit repeatedly samples and stores the accumulated quantities as analog video data values at the end of each of the successive integration periods.

Abstract: A liquid column (2) is placed between two high-frequency ultrasound sources (6) in the field of a standing wave produced by the sources. Each source produces a convergent beam that compensates for a substantial part of the attenuation of the ultrasound energy that occurs at higher frequencies. It is thereby possible to increase considerably the axial distance along the standing wave over which streaming effects due to acoustic pressure are absent or negligible. It is also possible to increase the angle of convergence to compensate for divergence of the outputs from the sources.

Abstract: A membrane for use in an X-ray mask composed of a compound comprising at least three kinds of elements of boron (B), silicon (Si) and nitrogen (N) in which the content of silicon in the compound is at least 15 atomic percent, but less than 100 atomic percent, and the atomic ratio of Si/(B+Si) in the compound is at least 0.2, but less than one. The membrane is synthesized from source gases including at least the foregoing three kinds of elements by chemical reaction under such conditions that the ratio of nitrogen to boron plus silicon is at least one in the source gases and thereby depositing a film of the compound onto a substrate. Since the membrane thus prepared has a high transmittance in the visible region and X-ray and their residual stress can be readily controlled by adjusting the conditions for the formation of the membrane, it is suitable for the preparation of X-ray masks.

Abstract: A process for the deformation of a workpiece of an orientable, thermoplastic polymer by passage in the solid phase through a die having both an entry side and an exit side, which process includes providing the workpiece of the orientable, thermoplastic polymer which is initially present, at least in part, in an extended chain crystalline morphology at the entry side of the die; causing the workpiece to deform in the solid phase through the die; and collecting the deformed workpiece from the exit side of the die.

Abstract: Dental cements and abrasives are provided which are polymerizable with visible light. Such adhesives may be applied in thinner films than heretofore possible and demonstrate superior physical properties. Processes employing such materials are disclosed wherein the polymerization of the adhesive is accomplished by transmitting visible light through tooth or other structures to effect the adhesion.

Abstract: An ultrafine grain fluorescent body comprises an ultrafine grain luminescent material containing an activator and having a surface carrying thereon a layer which is formed from a different material from the luminescent material, or which has different properties from those of the luminescent material. The layer forms a heterojunction or p-n junction defining a luminescent mechanism in an interface between the luminescent material and the layer. The heterojunction is formed if the layer is a film of oxide, nitride or any other different substance formed on the surface of the luminescent material, e.g. ZnS, having a grain size of several hundred to several thousand angstroms. Alternatively, the p-n junction is formed if the luminescent material is a p-type (or n-type) semiconductor, and if the layer is a film of an n-type (or p-type) a semiconductor formed on the surface thereof.