Abstract: Provided is a flux that includes at least one polybutadiene (meth)acrylate compound selected from polybutadiene (meth)acrylate compounds and polybutadiene (meth)acrylate compounds, and a hydrogenated dimer acid.

Abstract: Provided is a flux that includes at least one polybutadiene (meth)acrylate compound selected from polybutadiene (meth)acrylate compounds and polybutadiene (meth)acrylate compounds, and a hydrogenated dimer acid.

Abstract: A communication system to enable a communication between different places including: a transmitting section which transmits information from a first place in order to detect whether a communication partner is present at a second place; a detection section which receives the information and detects whether the communication partner is present; and a judgment section which, in cases where the communication partner is detected to be present, determines whether the communication partner is possible of communication.

Abstract: One end of a seal ring retained in a seal ring groove is formed in such a manner that it is offset radially inwardly from the other end, so that oil is permitted to leak by opening an abutment joint formed by the two ends in a condition in which no hydraulic pressure is applied. If a hydraulic pressure is supplied to bring a hydraulic actuator into an engaged state, the one end of the seal ring is deformed radially outwardly by the hydraulic pressure to come into close contact with a sealing surface and to close the abutment joint, thereby preventing the oil from-leaking past the oil ring. Consequently, upon engagement of the hydraulic actuator, a sealing property or salability of the oil can be assured, and upon releasing of the engagement of the hydraulic actuator, an oil leaking property of the seal ring can be provided, leaking property of the oil can be provided, thereby enhancing the responsiveness of the hydraulic actuator.

Abstract: In a sealing device, a crank-shaped oil channel is defined in an abutment of a sealing ring for sealing between a shaft member and a housing which surrounds the shaft member and is rotatable relative the shaft member. The crank-shaped oil channel is comprised of a first oil channel portion and a second oil channel portion which extend axially, and a third oil channel portion which connects the first and second oil channel portions to each other. If the sealing ring is thermally expanded circumferentially due to a change in temperature, the sectional area of the flow path in each of the first and second oil channel portions is varied, but the sectional area of the flow path in the third oil channel portion is not substantially varied. Therefore, it is possible to leak a given amount of an oil from one side of the sealing ring through the crank-shaped oil channel to the other side, thereby preventing the wearing of the shaft member caused by foreign matter, such as an iron powder, contained in the oil.