Abstract: An objective of the present invention is to quantitatively estimate the residual stress of an object. The present invention provides a method for estimating the residual stress of an object, the method comprising: irradiating an object with terahertz waves; measuring polarization intensity of the terahertz waves transmitted through or reflected by the object; and calculating tensile stress of the object based on the measured polarization intensity. In one embodiment, calculating the tensile stress includes calculating the tensile stress based on a relationship between polarization intensity and tensile stress derived from: a relationship between polarization intensity and tensile distance; and a relationship between tensile distance and tensile stress.

Abstract: An objective of the present invention is to provide a method, or the like, for estimating the convergence of dimensional changes in a molded article over time, by utilizing the polarization intensity of terahertz waves. The present invention provides a method for estimating the convergence of changes in the dimensions of a molded article over time, the method comprising: irradiating a molded article with terahertz waves at multiple positions thereon, wherein the molded article is irradiated with the terahertz waves at each position thereon in multiple orientations about the optical axis; measuring polarization intensities of the terahertz waves transmitted through or reflected from the molded article; and determining whether the polarization intensities at the multiple positions are in a given relationship with each other.

Abstract: This seal structure 1 is provided with an annular seal member 2, a shaft member 4 having a seal groove 5 where the inner peripheral side of said seal member 2 is arranged, and an inner peripheral wall member 6 which has an internal space surrounded by an inner peripheral wall 61, wherein the shaft member 4 is arranged in the internal space 62, and the annular seal member 2 is arranged in the seal groove 5 of the shaft member 4. The side of the outer periphery 21 of the annular seal member 2 is formed by overlapping, in the axial direction D1, a plurality of ring-shape parts 3 which are closed or unclosed when viewed in a radial direction D2; when viewed in the radial direction D2, on one side of a center axis C1 of the annular seal member 2, in a longitudinal cross-section of the plurality of ring-shape parts 3, one corner 32 of the two corners of the edge 31 facing the inner peripheral wall 61 of the inner peripheral wall member 6 contacts the inner peripheral wall 61 of the inner peripheral wall member 6.

Abstract: An annular seal member 2 is formed by overlapping, in the axial direction D1, a plurality of ring-shape parts 3 which are closed or unclosed when viewed in a radial direction D2 orthogonal to the axial direction D1 of the annular seal member 2. A seal groove 5 has a groove bottom 51 with an outer diameter R51 that increases along the axial direction D1. The inner periphery 22 of the annular seal member 2 contacts the groove bottom 51, and the inner diameter R22 of the inner periphery 22 increases as the outer diameter R51 of the groove bottom 51 increases. By this means, the outer diameter R21 of the outer periphery 21 increases, and the side of the outer periphery 21 of the annular seal member 2 that has a smaller outer diameter R21 does not contact the inner peripheral wall 61 of an inner peripheral wall member 6, and the side of the outer periphery 21 of the annular seal member 2 that has a greater outer diameter R21 does contact the inner peripheral wall 61 of the inner peripheral wall member 6.

Abstract: A planar broadband inverted F-type antenna has a pattern formed by etching a conductive foil laminated on the obverse side and the reverse side of the PET film 113. The antenna is applicable to the 5.0 GHz frequency band. The ground 107, the antenna element 101, and the connection element 105 are formed on the obverse side. The ground has the ground point connectable to the ground line of the feeding wire. The antenna element has a plurality of emission patterns adaptable to the 5.0 GHz frequency band. Each pattern has the length varying from each other. The connection element connects each emission pattern to the ground. The feeding pattern 183, which is formed on the reverse side, has the feeding terminal 181 connectable to the voltage line of the feeding wire. The feeding pattern is connected to the connection element. The feeding pattern includes a parallel wiring component to the emission patterns.