Abstract: A method for producing a polyelectrolyte membrane, including the step of immersing a basic polymer such as a polybenzimidazole in a strong acid having a concentration sufficient to impregnate the basic polymer with six or more strong acid molecules per polymer repeating unit of the basic polymer at a temperature of not less than 30° C. for a period of 5 h or less, as well as a fuel battery having the polyelectrolyte membrane. Hence, the times required to immerse the basic polymers in the strong acids can be shortened and the proton conductivity of the polyelectrolyte membranes can be improved.

Abstract: A method for producing a bridged polymer membrane includes the steps of: obtaining a liquid medium comprising a basic polymer having an amino group in a repeating unit, a bridging agent, and a solvent; shaping the liquid medium into a membrane configuration to obtain the shaped membrane; and bridging the basic polymer by the bridging agent in the shaped membrane. A fuel cell has the bridged polymer membrane. The mechanical strength of the polymer electrolyte membrane is improved.

Abstract: This invention relates to bipolar plates for electrochemical cells, particularly low-temperature fuel cells, with surface modification to enhance through-plate conductivity, processes for improving the surface properties of those bipolar plates, and fuel cell assemblies made with such plates. Graphite-polymer composite bipolar plates with high bulk conductivity are subjected to an abrasive surface treatment to improve the surface contact as well as the reactant transfer to the adjacent gas diffusion electrodes.

Abstract: This invention relates to bipolar plates for electrochemical cells, particularly low-temperature fuel cells, with surface modification to enhance through-plate conductivity, processes for improving the surface properties of those bipolar plates, and fuel cell assemblies made with such plates. Graphite-polymer composite bipolar plates with high bulk conductivity are subjected to an abrasive surface treatment to improve the surface contact as well as the reactant transfer to the adjacent gas diffusion electrodes.

Abstract: A method for producing a polymer electrolyte membrane is disclosed. A liquid medium is introduced into a cylinder having an inner surface having a cylindrical configuration. The liquid medium has at least one percent by weight of a polymer electrolyte and a solvent having a boiling point or an azeotropic point ranging from 60 to 220° C. Subsequently, the cylinder is rotated for evaporating the solvent by means of a centrifugal force created by such rotation so as to form a polymer electrolyte membrane having a cylindrical configuration with a substantially uniform thickness on the inner surface of the cylinder. Onto the inner surface of the polymer electrolyte membrane, a catalytic layer containing a catalytic particle may be formed.

Abstract: Acid-labile group protected hydroxystyrene polymers having recurrent pendant groups such as 1-(2-methanecarbonyl oxyethoxy)ethoxy group and 1-(2-N-methylcarbamatoethoxy) ethoxy group. A resist containing the polymer, a photo acid generator, a base, additives and a solvent is sensitive to UV, electron beam and X-ray. In the resist, acid is formed in the exposed area during irradiation, which deprotects acid-labile group catalytically during application of post-exposure baking. Positive patterns are formed after development using an alkaline solution.

Abstract: The present invention pertains to a film for detecting chemical substances comprising a homopolymer or a copolymer having recurring units represented by the following formula (I): ##STR1## wherein X is --H, --F, --Cl, --Br, --CH.sub.3, --CF.sub.3, --CN or --CH.sub.2 CH.sub.3 ; and R.sup.1 is --R.sup.2 or --Z--R.sup.2 ;wherein Z is --O--, --S--, --NH--, --NR.sup.2' --, --(C.dbd.Y)--, --(C.dbd.Y)--Y--, --Y--(C.dbd.Y)--, --(SO.sub.2)--, --Y'--(SO.sub.2)--, --(SO.sub.2)--Y'--, --Y'--(SO.sub.2)--Y'--, --NH--(C.dbd.O)--, --(C.dbd.O)--NH--, --(C.dbd.O)--NR.sup.2' --, --Y'--(C.dbd.Y)--Y'-- or --O--(C.dbd.O)--(CH.sub.2).sub.n --(C.dbd.O)--O--;wherein Y is independently O or S, and Y' is independently O or NH, and n is an integer of 0 to 20;and wherein R.sup.2 and R.sup.2' represent independently a hydrogen atom, a linear alkyl group, a branched alkyl group, a cycloalkyl group, an unsaturated hydrocarbon group, an aryl group, a saturated or unsaturated hetero ring or derivatives thereof, provided that R.sup.

Abstract: An optical sensor apparatus for detecting a vapor of an organic solvent is characterized by a simple structure which allows easy manufacture, high reliability, low cost, compactness in size, and portability. The optical sensor apparatus has a light source unit which emits light for irradiating a polymer thin film formed on a flat reflecting substrate of a sensing element. Light reflected by the sensing element is detected by a light detecting unit. The light source unit, the sensing element, and the light detecting unit are integrally supported by a housing. The polymer thin film which comes into contact with a vapor of an organic solvent causes a change in the thickness and a reflective index thereof. This change is utilized to detect the existence and/or concentration of a vapor of an organic solvent.

Abstract: The present invention pertains to a film for detecting chemical substances comprising a homopolymer or a copolymer having recurring units represented by the following formula (I): ##STR1## wherein X is --H, --F, --Cl, --Br, --CH.sub.3, --CF.sub.3, --CN or --CH.sub.2 CH.sub.3 ; and R.sup.1 is --R.sup.2 or --Z--R.sup.2 ;wherein Z is --O--, --S--, --NH--, --NR.sup.2' --, --(C.dbd.Y)--, --(C.dbd.Y)--Y--, --Y--(C.dbd.Y)--, --(SO.sub.2)--, --Y'--(SO.sub.2)--, --(SO.sub.2)--Y'--, --Y'--(SO.sub.2)--Y'--, --NH--(C.dbd.O)--, --(C.dbd.O)--NH--, --(C.dbd.O)--NR.sup.2' --, --Y'--(C.dbd.Y)--Y'-- or --O--(C.dbd.O)--(CH.sub.2).sub.n --(C.dbd.O)--O--;wherein Y is independently O or S, and Y' is independently O or NH, and n is an integer of 0 to 20;and wherein R.sup.2 and R.sup.2' represent independently a hydrogen atom, a linear alkyl group, a branched alkyl group, a cycloalkyl group, an unsaturated hydrocarbon group, an aryl group, a saturated or unsaturated hetero ring or derivatives thereof, provided that R.sup.

Abstract: A method for identifying a single fuel vapor in an atmosphere of interest that is selected from the group consisting of at least two fuels and that is the sole fuel component of the atmosphere, comprising the steps of: providing a plurality of measuring means that are at least equal in number to the types of fuels that compose the fuel group and which have different sensitivities to the respective fuel vapors; presetting the relationship between the magnitudes of the outputs from the respective measuring means at various fuel vapor concentrations in such a manner that it differs from one fuel vapor to another; placing said measuring means in the atmosphere of interest containing said single fuel vapor as the sole fuel component; measuring the concentration of that fuel vapor; determining the relationship between the magnitudes of outputs as obtained from the respective measuring means; and comparing the thus determined relationship with the preset relationships, thereby identifying the fuel vapor in the atmos

Abstract: Disclosed and claimed is an optical sensor for the detection of chemical species. The optical sensor includes an optical waveguide having a guiding thin film. The thickness of the refrative index of the guiding thin film changes due to adsorption or absorption of the chemical species or reaction of the chemical species with the guiding thin film. The thickness of the guiding thin film is above the cutoff thickness in the presence of gaseous or liquid chemical species to be detected. And, the thickness of the guiding thin film is below the cutoff thickness in the absence of such chemical species.

Abstract: An optical sensor for detecting gaseous or liquid chemical species including a sensing element having a flat light reflecting substrate and one or more transparent thin films which are organic or inorganic films or high-polymer films and are formed on the substrate. The detection of the gaseous or liquid chemical species is effected by measuring a change in the light reflection characteristic of the sensing element based on swelling of the thin film or a change in its thickness or refractive index or changes in both parameters.

Abstract: A method and apparatus for detecting the machining status of a laser beam machining device, having a multi-mirror resonator for generating a machining beam, which utilizes the secondary light generated by the machining operation and returned from the workpiece surface into the resonator for control of the machining operation. The oscillator and accompanying components, such as beam dividing mirrors and splitters, are operative to separate the secondary light from the laser beam within the resonator and direct the two beams separately to detectors located outside of the resonator. Alternatively, the secondary light and laser beam may be directed to the outside together where they are separated by an integrating sphere for detection.

Abstract: An assembly for supporting a magnetic head to float relative to a magnetic disk, comprises a load arm extending substantially tangentially of a magnetic disk and moved substantially radially of the magnetic disk, the load arm having a proximal end, and a distal end and including a spring portion at its proximal end, a gimbal secured to the distal end of the load arm and including a pivot, the load arm including a contact point at its distal end to contact with the pivot, and a magnetic head slider secured to the gimbal so as to pitch and roll about the pivot with movement of the magnetic disk. The magnetic head slider is adapted to support a magnetic head and is urged toward the magnetic disk under the influence of the spring portion of the load arm. The load arm has a shear center at the contact point.

Abstract: A positioning control apparatus comprises a feedback compensatory system and a feedforward compensatory system. The feedforward compensatory system comprises a detector for detecting a position of a controlled object whose position is to be controlled, and a compensator connected to the detector. The feedforward compensatory system comprises a first filter having a characteristics reverse to that of the feedback compensatory system, and a second filter having a characteristics reverse to that of the object. A desired drive signal generator supplies the feedforward compensatory system with a desired drive signal having a frequency spectrum having a minimum at the mechanical resonance frequency of the object.

Abstract: A retract mechanism for a magnetic head which can read from and/or write to a disk, the mechanism includes a spring arm which supports the head and urges the head toward the disk. The spring arm includes a cam follower which rides along the surface of the cam, which has two parallel horizontal surfaces and two incline surfaces. The spring arm is moved by an actuator in a radial direction along the disk. When the spring arm is moved radially away from the center of the disk, the cam urges the spring arm upwardly, thereby lifting the head up and away from the disk. As the spring arm continues to move radially away from the center of the disk, the cam guides the spring arm such that the head rests safely on a landing platform.

Abstract: A head positioning apparatus for a disc unit which moves a carriage having a movable portion by driving motors constituted by coils and magnets, wherein driving power distribution of the driving motors is variable, so that the acting points of the driving forces of the driving motors can be variably set at any position to position the acting points of driving forces of the driving motors on a centroidal axis of the movable portion.

Abstract: A carriage assembly has a carriage provided on both sides with voice coils, a magnet assembly surrounding the voice coils and adapted for causing the carriage to move in the radial direction of a disk, and guide rails for guiding the carriage in the radial direction of the disk. The carriage is provided on a lower portion thereof with first rollers for engagement with the guide rails and at its upper portion thereof with second rollers which co-operate with a biasing members in preventing the carriage from moving upward. Either the guide rails or the first rollers are provided with grooves which prevent the first rollers from moving in the tangential directions of the guide rails. Since the movement of the first rollers in the tangential directions of the guide rail is prevented, it is possible to locate the carriage with a high degree of precision with respect to the disk.

Abstract: A retract mechanism for a magnet head which can read from and/or write to a disk, the mechanism includes a spring arm which supports the head and urges the head toward the disk. The spring arm includes a cam follower which rides along the surface of the cam, which has two parallel horizontal surfaces and two incline surfaces. The spring arm is moved by an actuator in a radial direction along the disk. When the spring arm is moved radially away from the center of the disk, the cam urges the spring arm upwardly, thereby lifting the head up and away from the disk. As the spring arm continues to move radially away from the center of the disk, the cam guides the spring arm such that the head rests safely on a landing platform.

Abstract: A retract mechanism for a magnetic head which can read from and/or write to a disk, the mechanism includes a spring arm which supports the head and urges the head toward the disk. The spring arm includes a cam follower which rides along the surface of the cam, which has two parallel horizontal surfaces and two incline surfaces. The spring arm is moved by an actuator in a radial direction along the disk. When the spring arm is moved radially away from the center of the disk, the cam urges the spring arm upwardly, thereby lifting the head up and away from the disk. As the spring arm continues to move radially away from the center of the disk, the cam guides the spring arm such that the head rests safely on a landing platform.