Abstract: Provided are a system of highly clean rooms capable of continuously maintaining high cleanliness of air of class 1 or above and supplying enough oxygen inside the room for several persons to live in and a wall adapted to the structure of such a system. The system of highly clean rooms 10 is provided with a living space 6 and a space 5 between the roof and the ceiling as subspaces of an enclosed space formed by a room 1a. One of the lateral walls of the room 1a is constituted of a wall 9 with an internal space 7, which is a hollow wall. The internal space 7 and the living space 6 are in contact via an inner wall 9a of the wall 9, and a gas exchange membrane 26 is stretched in the inner wall 9a.

Abstract: A room 100 in a building has a living etc. space 101 of volume V that is an enclosed space. Ventilation of an air flow F is performed from the outside to the living etc. space 101. Entering/exiting of air as an air current between the inside of the living etc. space 101 and the outside is eliminated, and at least a part of the boundary between the living etc. space 101 and the outside is configured from a gas exchange membrane 310 having a diffusion constant D, a thickness L, and an area A for gas molecules of interest. When air inside the living etc. space 101 is sufficiently agitated and the concentration of gas molecules constituting the air is made spatially uniform, ?(t) is controlled so as to vary according to ? ? ( t ) = ? o - BL AD ? ( 1 - exp ? ( - [ AD ? / ? L ] ? t ? / ? V ) ) ( 9 ) B(m3/s) is the gas consumption amount inside the living etc. space 101, ?1 (t) is the gas concentration inside the living etc.

Abstract: Provided are a system of highly clean rooms capable of continuously maintaining high cleanliness of air of class 1 or above and supplying enough oxygen inside the room for several persons to live in and a wall adapted to the structure of such a system. The system of highly clean rooms 10 is provided with a living space 6 and a space 5 between the roof and the ceiling as subspaces of an enclosed space formed by a room 1a. One of the lateral walls of the room 1a is constituted of a wall 9 with an internal space 7, which is a hollow wall. The internal space 7 and the living space 6 are in contact via an inner wall 9a of the wall 9, and a gas exchange membrane 26 is stretched in the inner wall 9a.

Abstract: Provided is a failure detection sensor which, when attached to structural members of various structures such as buildings can easily detect the risk of the failure of the structural members, and thus the structure, before such failure occurs and has a simple structure, which leads to realization at a low price. The failure detection sensor comprises: the first member 10 and the second member 20 provided in parallel with the first member 10 such that one end of the second member 20 is fixed to or restricted by the first member 10 and the other end of the second member 20 is not fixed to or restricted by the first member 10, having fracturing characteristics such that the second member 20 fractures during elastic deformation or plastic deformation of the first member 10. The failure detection sensor may have a compression coil spring 40 which applies a tensile force to the other end of the second member 20 on the opposite side of the one end.