Abstract: According to an embodiment, a solar cell string 8 including solar cell modules 1 connected in series and each configured to generate DC power by being irradiated with light; and a junction box 2 configured to receive the DC power from the solar cell string are included. The junction box includes: a DC detector 10 configured to detect a current flowing through the solar cell string; a measurement device 11 configured to measure a current value of the current detected by the DC detector; and a data transmitter 12 configured to send the current value measured by the measurement device.

Abstract: An airflow generation device of an embodiment has a main body and a voltage application unit. The main body has a base formed of an insulating material and provided with a first electrode and a second electrode. The voltage application unit generates an airflow by applying voltage between the first electrode and the second electrode. Here, the main body is formed to include a portion which gradually decreases in thickness from a center portion to an end portion.

Abstract: In one embodiment, an air current generating apparatus includes: a dielectric substrate exposed to gas: a first electrode disposed inside the dielectric substrate; a second electrode disposed near a surface of the dielectric so as to correspond the first electrode and having a sharp shape; and a power source applying a voltage between the first and second electrodes and plasmatizing part of the gas to generate an air current.

Abstract: In one embodiment, a wind-power generating system 10 includes: a lightning protecting device including a receptor 70 provided on a blade surface and a lightning conductor 73 grounding the receptor 70; an airflow generating device 60 provided on the blade surface and including first and second electrodes 61, 62 separated via a dielectric 63; a discharge power source 65 including switches 90, 91 able to connect the first and second electrodes 61, 62 to output terminals 84, 85 respectively and a switch 92 able to connect the first or second electrode 61, 62 to a grounding conductor 100; and a thundercloud detecting device detecting information regarding thundercloud approach. When the information regarding the thundercloud approach is detected, the second electrode 62 is connected to the grounding conductor 100 and the first and second electrodes 61, 62 are disconnected from the output terminals 84, 85.

Abstract: In one embodiment, an air current generating apparatus includes: a dielectric substrate exposed to gas: a first electrode disposed inside the dielectric substrate; a second electrode disposed near a surface of the dielectric so as to correspond the first electrode and having a sharp shape; and a power source applying a voltage between the first and second electrodes and plasmatizing part of the gas to generate an air current.

Abstract: An airflow control device 10 in an embodiment includes: a vortex shedding structure portion 20 discharging an airflow flowing on a surface in a flow direction as a vortex flow; and a first electrode 40 and a second electrode 41 disposed on a downstream side of the vortex shedding structure portion 20 via a dielectric. By applying a voltage between the first electrode 40 and the second electrode 41, flow of the airflow on the downstream side of the vortex shedding structure portion 20 is controlled.

Abstract: In one embodiment, a wind-power generating system 10 includes: a lightning protecting device including a receptor 70 provided on a blade surface and a lightning conductor 73 grounding the receptor 70; an airflow generating device 60 provided on the blade surface and including first and second electrodes 61, 62 separated via a dielectric 63; a discharge power source 65 including switches 90, 91 able to connect the first and second electrodes 61, 62 to output terminals 84, 85 respectively and a switch 92 able to connect the first or second electrode 61, 62 to a grounding conductor 100; and a thundercloud detecting device detecting information regarding thundercloud approach. When the information regarding the thundercloud approach is detected, the second electrode 62 is connected to the grounding conductor 100 and the first and second electrodes 61, 62 are disconnected from the output terminals 84, 85.

Abstract: According to an embodiment, a solar cell string 8 including solar cell modules 1 connected in series and each configured to generate DC power by being irradiated with light; and a junction box 2 configured to receive the DC power from the solar cell string are included. The junction box includes: a DC detector 10 configured to detect a current flowing through the solar cell string; a measurement device 11 configured to measure a current value of the current detected by the DC detector; and a data transmitter 12 configured to send the current value measured by the measurement device.

Abstract: In one embodiment, an air current generating apparatus includes: a dielectric substrate exposed to gas: a first electrode disposed inside the dielectric substrate; a second electrode disposed near a surface of the dielectric so as to correspond the first electrode and having a sharp shape; and a power source applying a voltage between the first and second electrodes and plasmatizing part of the gas to generate an air current.

Abstract: According to a ceramic fiber reinforced ceramic matrix composite material of the present invention, a ceramic fiber reinforced ceramic matrix composite material 1 comprises a composite ceramic matrix, and a preform 5 resulting from a fiber bundle 3 obtained by bundling a plurality of ceramic fibers 2 and disposed therein, and is characterized in that a first ceramic matrix M1 is formed in an inner space of the fiber bundle 3 and at a region adjacent to an outer periphery thereof, and a second ceramic matrix M2 is formed in an inner space of the preform 5 and at an outer peripheral region thereof, the space and region of the preform being defined except for those of the fiber bundle. Also characteristically, ceramic fibers are compositely disposed in a fiber volume fraction (Vf) of greater than 10% in a reaction-sintered ceramic matrix.

Abstract: In fiber composite ceramic containing reaction sintered SiC as a matrix and having BN-coated SiC continuous fibers as composite fibers, the thickness of the BN coating need not be especially made large, and a sliding effect during growing of cracks can be improved, i.e., breakdown energy can be increased. A method of manufacturing fiber composite ceramic in which large number of BN-coated SiC fibers covered with a BN coating are gathered to form yarns, or yarns are woven to form a two-dimensional or three-dimensional fabric, and a preform is formed by the yarns or the fabric, C powder is arranged in a gap portion between fibers of the preform to form a compact, a molten Si is impregnated into the compact to form an SiC matrix between fibers. A region having a high B concentration is formed around the SiC fibers before the preform is impregnated with the molten Si, and B in the region is solid-solved in Si during reaction sintering to suppress B in the BN-coated SiC fibers from being solid-solved in Si.

Abstract: A ceramic matrix composite material comprising a matrix containing silicon carbide as the primary component and silicon nitride as the secondary component is disclosed. The silicon nitride includes not more than 1% by weight of iron and reinforcements mixed and dispersed. The ceramic matrix composite material is manufactured, for example, by forming a matrix containing reaction sintered silicon carbide as the primary component and nitriding the free metal silicon produced in the sintering process so that the free metal silicon will be converted to fine silicon nitride particles. Said metal silicon used for reaction sintering already contains iron. These processes enable the containing of a comparatively large amount of reinforcements, as well as the improvement of heat resistance of the sintered compact and the suppression of the deterioration of reinforcements.

Abstract: A ceramic matrix composite material comprising a matrix containing silicon carbide as the primary component and silicon nitride as the secondary component is disclosed. The silicon nitride includes not more than 1% by weight of iron and reinforcements mixed and dispersed. The ceramic matrix composite material is manufactured, for example, by forming a matrix containing reaction sintered silicon carbide as the primary component and nitriding the free metal silicon produced in the sintering process so that the free metal silicon will be converted to fine silicon nitride particles. Said metal silicon used for reaction sintering already contains iron. These processes enable the containing of a comparatively large amount of reinforcements, as well as the improvement of heat resistance of the sintered compact and the suppression of the deterioration of reinforcements.

Abstract: Sintered bodies with the primary phase of .beta. and/or .alpha. prime sialon. In the sialon phase which is the primary phase, hafnium oxide and silicon carbide are dispersedly contained as dispersion phases. 1 to 60 parts by weight of hafnium oxide are contained in 100 parts by weight of the primary phase. 5 to 30 parts by weight of silicon carbide are contained in 100 parts by weight of the primary phase. Hafnium oxide suppresses decrease of sintering characteristic which is caused by silicon carbide. Thus, a large amount of silicon carbide can be added, thereby improving the fracture toughness value.

Abstract: A ceramic sinter whose mother phase substantially satisfies a sialon composition. This sialon containing ceramic sinter contains at least one kind of compound selected from the group of oxides, carbides, nitrides, and silicides of hafnium, niobium, or titanium in the range of from 0.2 to 40 weight %. The compound of hafnium, niobium, or titanium is present independently in the mother phase in particle-dispersive form. The dispersed particles contribute to improving the mechanical strength, fracture toughness, and heat impact resistance because the sinter body is reinforced by dispersion. The sialon containing ceramic sinter is so excellent in high-temperature properties that it is suitable for use in high-temperature structural materials. Further, a .beta.