Abstract: A communication system includes a communication apparatus and a base station. The communication apparatus includes a Discrete Fourier Transform (DFT) transformer which transforms a time-domain signal into a frequency-domain signal with a DFT size that is a product of powers of a plurality of values; a mapper which maps the frequency-domain signal on a plurality of frequency bands, each frequency band being located at a position separate from position(s) of other(s) of the plurality of frequency bands; and a signal generator which generates a single carrier-frequency division multiple access (SC-FDMA) time-domain signal from the mapped signal. The base station includes a receiver which receives the SC-FDMA time-domain signal; a combiner which generates the frequency-domain signal from the SC-FDMA time-domain signal; and a transformer which transforms the frequency-domain signal into the time-domain signal with an inverse Discrete Fourier Transform (IDFT) having the DFT size.

Abstract: The present invention aims to provide an epoxy resin composition that is high in both fast curability and storage stability, a prepreg prepared by using the epoxy resin composition, and a fiber reinforced composite material prepared by curing the prepreg. The epoxy resin composition contains the following components [A], [B], [C], and [D] and meets the following requirements [a], [b], and [c]: [A]: epoxy resin, [B]: dicyandiamide, [C]: aromatic urea, [D]: borate ester, [a]: 0.014?(content of component [D]/content of component [C])?0.045, [b]: 0.9?(number of moles of active groups in component [A]/number of moles of active hydrogen in component [B])?1.2, and [c]: 14?(content of component [A]/content of component [C])?25.

Abstract: One purpose of the present invention is to provide an epoxy resin composition which is for obtaining a fiber-reinforced composite material that combines heat resistance with tensile strength on a high level. The other purpose is to provide: a fiber-reinforced composite material obtained using this epoxy resin composition; and a molded article and a pressure vessel both containing the fiber-reinforced composite material. The present invention has the following configuration in order to achieve the above purposes. Namely, the epoxy resin composition includes the constituent element [A]: An epoxy resin including an aromatic ring and having a functionality of 2 or higher and the following constituent element [B]: An acid anhydride-based hardener, and is characterized in that a cured object obtained by curing the epoxy resin composition has a rubber-state modulus of 10 MPa or less when evaluated for dynamic viscoelasticity and the cured object has a glass transition temperature of 95° C. or higher.

Abstract: One purpose of the present invention is to provide an epoxy resin composition which is for obtaining a fiber-reinforced composite material that combines heat resistance with tensile strength on a high level. Another purpose is to provide: a fiber-reinforced composite material obtained using this epoxy resin composition; and a molded article and a pressure vessel both containing the fiber-reinforced composite material. The present invention has the following configuration in order to achieve the above purposes. Namely, the epoxy resin composition includes the constituent element [A]: An epoxy resin including an aromatic ring and having a functionality of 2 or higher and the following constituent element [B]: An amine-based hardener, and is characterized in that a cured object obtained by curing the epoxy resin composition has a rubber-state modulus of 10 MPa or less when evaluated for dynamic viscoelasticity and the cured object has a glass transition temperature of 95° C. or higher.

Abstract: An epoxy resin composition comprises components [A] to [C]. The component [C] is a component [c1] or [c2] and the rubbery state elastic modulus of a cured article produced by curing the epoxy resin composition in a dynamic viscoelasticity evaluation is 10 MPa or less. Component[A] is a phenyl glycidyl ether substituted by a tert-butyl group, a sec-butyl group, an isopropyl group or a phenyl group. Component [B] is a bifunctional or higher aromatic epoxy resin. Component [C] is a curing agent selected from component [c1], which is an acid anhydride-type curing agent and component [c2], which is an aliphatic amine-type curing agent.

Abstract: One purpose of the present invention is to provide an epoxy resin composition which is for obtaining a fiber-reinforced composite material that combines heat resistance with tensile strength on a high level. Another purpose is to provide: a fiber-reinforced composite material obtained using this epoxy resin composition; and a molded article and a pressure vessel both containing the fiber-reinforced composite material. The present invention has the following configuration in order to achieve the above purposes. Namely, the epoxy resin composition includes the constituent element [A]: An epoxy resin including an aromatic ring and having a functionality of 2 or higher and the following constituent element [B]: An amine-based hardener, and is characterized in that a cured object obtained by curing the epoxy resin composition has a rubber-state modulus of 10 MPa or less when evaluated for dynamic viscoelasticity and the cured object has a glass transition temperature of 95° C. or higher.

Abstract: One purpose of the present invention is to provide an epoxy resin composition which is for obtaining a fiber-reinforced composite material that combines heat resistance with tensile strength on a high level. The other purpose is to provide: a fiber-reinforced composite material obtained using this epoxy resin composition; and a molded article and a pressure vessel both containing the fiber-reinforced composite material. The present invention has the following configuration in order to achieve the above purposes. Namely, the epoxy resin composition includes the constituent element [A]: An epoxy resin including an aromatic ring and having a functionality of 2 or higher and the following constituent element [B]: An acid anhydride-based hardener, and is characterized in that a cured object obtained by curing the epoxy resin composition has a rubber-state modulus of 10 MPa or less when evaluated for dynamic viscoelasticity and the cured object has a glass transition temperature of 95° C. or higher.

Abstract: One purpose of the present invention is to provide an epoxy resin composition which is for obtaining a fiber-reinforced composite material that combines heat resistance with tensile strength on a high level. The other purpose is to provide: a fiber-reinforced composite material obtained using this epoxy resin composition; and a molded article and a pressure vessel both containing the fiber-reinforced composite material. The present invention has the following configuration in order to achieve the above purposes. Namely, the epoxy resin composition includes the constituent element [A]: An epoxy resin including an aromatic ring and having a functionality of 2 or higher and the following constituent element [B]: An amine-based hardener or an acid anhydride-based hardener, and is characterized in that a cured object obtained by curing the epoxy resin composition has a rubber-state modulus of 10 MPa or less when evaluated for dynamic viscoelasticity and the cured object has a glass transition temperature of 95° C.

Abstract: The present invention aims to provide an epoxy resin composition that is high in both fast curability and storage stability, a prepreg prepared by using the epoxy resin composition, and a fiber reinforced composite material prepared by curing the prepreg. The epoxy resin composition contains the following components [A], [B], [C], and [D] and meets the following requirements [a], [b], and [c]: [A]: epoxy resin, [B]: dicyandiamide, [C]: aromatic urea, [D]: borate ester, [a]: 0.014?(content of component [D]/content of component [C])?0.045, [b]: 0.9?(number of moles of active groups in component [A]/number of moles of active hydrogen in component [B])?1.2, and [c]: 14?(content of component [A]/content of component [C])?25.

Abstract: Disclosed herein are an epoxy resin composition for fiber-reinforced composite materials which has low viscosity, high Tg, high elastic modulus, and excellent fracture toughness and a fiber-reinforced composite material using such an epoxy resin composition which has excellent thermal properties, compressive strength, impact resistance, fatigue resistance, and open-hole tensile strength and which is suitable for producing structural parts of aircraft and the like. The epoxy resin composition comprises at least a given bifunctional epoxy resin as a component (A), a liquid aromatic diamine curing agent as a component (B), and core-shell polymer particles as a component (C), wherein the core-shell polymer particles as the component (C) contain epoxy groups in their shell and have a volume-average particle size of 50 to 300 nm.

Abstract: An epoxy resin composition is provided including at least the following component [A], component [B], and component [C] or [D] wherein cured product obtained by curing the epoxy resin composition has a rubbery state modulus in dynamic viscoelasticity evaluation of 10 MPa or less, and the cured product has a glass transition temperature of at least 95° C.; [A] an aromatic epoxy resin having a functionality of at least 3, [B] an aromatic diamine having a substituent at ortho position of each amino group or a cycloalkyldiamine wherein the carbon atom adjacent to the carbon atom bonded to each amino group has a substituent, [C] an aliphatic polyamine having an alkylene glycol structure, [D] a straight chain or branched aliphatic polyamine containing 6 to 12 carbon atoms.

Abstract: One purpose of the present invention is to provide an epoxy resin composition which is for obtaining a fiber-reinforced composite material that combines heat resistance with tensile strength on a high level. The other purpose is to provide: a fiber-reinforced composite material obtained using this epoxy resin composition; and a molded article and a pressure vessel both containing the fiber-reinforced composite material. The present invention has the following configuration in order to achieve the above purposes. Namely, the epoxy resin composition includes the constituent element [A]: An epoxy resin including an aromatic ring and having a functionality of 2 or higher and the following constituent element [B]: An amine-based hardener or an acid anhydride-based hardener, and is characterized in that a cured object obtained by curing the epoxy resin composition has a rubber-state modulus of 10 MPa or less when evaluated for dynamic viscoelasticity and the cured object has a glass transition temperature of 95° C.

Abstract: An epoxy resin composition is provided including at least the following component [A], component [B], and component [C] or [D] wherein cured product obtained by curing the epoxy resin composition has a rubbery state modulus in dynamic viscoelasticity evaluation of 10 MPa or less, and the cured product has a glass transition temperature of at least 95° C.; [A] an aromatic epoxy resin having a functionality of at least 3, [B] an aromatic diamine having a substituent at ortho position of each amino group or a cycloalkyldiamine wherein the carbon atom adjacent to the carbon atom bonded to each amino group has a substituent, [C] an aliphatic polyamine having an alkylene glycol structure, [D] a straight chain or branched aliphatic polyamine containing 6 to 12 carbon atoms.

Abstract: Disclosed herein are an epoxy resin composition for fiber-reinforced composite materials which has low viscosity, high Tg, high elastic modulus, and excellent fracture toughness and a fiber-reinforced composite material using such an epoxy resin composition which has excellent thermal properties, compressive strength, impact resistance, fatigue resistance, and open-hole tensile strength and which is suitable for producing structural parts of aircraft and the like. The epoxy resin composition comprises at least a given bifunctional epoxy resin as a component (A), a liquid aromatic diamine curing agent as a component (B), and core-shell polymer particles as a component (C), wherein the core-shell polymer particles as the component (C) contain epoxy groups in their shell and have a volume-average particle size of 50 to 300 nm.

Abstract: A binder composition comprising [A] an amorphous polyamide with a glass transition temperature of 140° C. or higher having a dicyclohexylmethane skeleton in the molecule and [B] a sulfonamide compound is used to provide a binder composition, a reinforcing-fiber base material and a preform respectively most suitable for RTM, which respectively exhibit excellent impact resistance and physical properties remaining stable over the variations of molding conditions and can be used for producing a fiber-reinforced composite material most suitable for members such as primary structures of aircraft.

Abstract: A binder composition comprising [A] an amorphous polyamide with a glass transition temperature of 140° C. or higher having a dicyclohexylmethane skeleton in the molecule and [B] a sulfonamide compound is used to provide a binder composition, a reinforcing-fiber base material and a preform respectively most suitable for RTM, which respectively exhibit excellent impact resistance and physical properties remaining stable over the variations of molding conditions and can be used for producing a fiber-reinforced composite material most suitable for members such as primary structures of aircraft.

Abstract: Disclosed herein are an epoxy resin composition for fiber-reinforced composite materials which has low viscosity, high Tg, high elastic modulus, and excellent fracture toughness and a fiber-reinforced composite material using such an epoxy resin composition which has excellent thermal properties, compressive strength, impact resistance, fatigue resistance, and open-hole tensile strength and which is suitable for producing structural parts of aircraft and the like. The epoxy resin composition comprises at least a given bifunctional epoxy resin as a component (A), a liquid aromatic diamine curing agent as a component (B), and core-shell polymer particles as a component (C), wherein the core-shell polymer particles as the component (C) contain epoxy groups in their shell and have a volume-average particle size of 50 to 300 nm.

Abstract: A temperature compensating circuit includes a first circuit network 1 between an inverting input terminal of an operational amplifier 13 and an output terminal of the operational amplifier 13, and a second circuit network 2 between the inverting input terminal of the operational amplifier 13 and a reference potential. At least one of the first circuit network and the second circuit network is made of an arrangement containing a plurality of series-connected thermistor/resistor pairs in which the thermistors are connected parallel to the resistors, and the temperature compensating circuit compensates a temperature-dependent signal which is inputted into a positive phase input terminal of the operational amplifier 13, and outputs the temperature-compensated signal.

Abstract: A temperature compensating circuit includes a first circuit network 1 between an inverting input terminal of an operational amplifier 13 and an output terminal of the operational amplifier 13, and a second circuit network 2 between the inverting input terminal of the operational amplifier 13 and a reference potential. At least one of the first circuit network and the second circuit network is made of an arrangement containing a plurality of series-connected thermistor/resistor pairs in which the thermistors are connected parallel to the resistors, and the temperature compensating circuit compensates a temperature-dependent signal which is inputted into a positive phase input terminal of the operational amplifier 13, and outputs the temperature-compensated signal.

Abstract: A temperature compensating circuit includes a first circuit network 1 between an inverting input terminal of an operational amplifier 13 and an output terminal of the operational amplifier 13, and a second circuit network 2 between the inverting input terminal of the operational amplifier 13 and a reference potential. At least one of the first circuit network and the second circuit network is made of an arrangement containing a plurality of series-connected thermistor/resistor pairs in which the thermistors are connected parallel to the resistors, and the temperature compensating circuit compensates a temperature-dependent signal which is inputted into a positive phase input terminal of the operational amplifier 13, and outputs the temperature-compensated signal.