Abstract: A translucent cover (9) is so provided as to cover a high pressure sodium lamp (11) adapted to radiate at least visible light and rays of light in the wavelength range of 300 nm to 400 nm. A photocatalytic film (13) which is capable of preventing generation of interference between visible light is formed on either one of or both the inner side and outer side of the translucent cover (9). The photocatalytic film (13) contains as the principal component titania (TiO2) of which the peak wavelength for visible light transmittance is nearly the same as the peak wavelength for visible light radiated from the high pressure sodium lamp (11). Ultraviolet light radiated from the high pressure sodium lamp (11) enhances oxidation and decomposition of substances performed by the photocatalytic film (13), thereby preventing grime and contaminants from adhering to the translucent cover (9).

Abstract: A noise barrier wall is provided which has a main wall body standing generally vertically and provided atop thereof with a first sound absorbing unit, and on a side thereof opposite to a noise source with an overhang extending away from the noise source and of which the free end is directed upward and provided at an end thereof with a second sound absorbing unit. Each of the first and second sound absorbing units comprises two branch walls extending obliquely upward to the left and right, respectively. Each of the two branch walls is provided with an additional branch wall. These additional branch walls extend obliquely upward towards each other. An opening is defined between free ends of the additional branch walls.

Abstract: A noise barrier includes upright-standing support columns spaced a predetermine distance from each other and each made of an H section, and a plurality of wall panels provided between two neighboring ones of the support columns by inserting each wall panel at opposite lateral edges thereof from above into U-shaped recesses, opposite to each other, of the support columns, the plurality of wall panels being thus stacked one on another to form a main soundproof wall, and a noise control module to be installed on the topmost wall panel, the noise control module comprising side frame members to be inserted at lower ends thereof from above into the upper portions of the U-shaped recesses, opposite to each other, of the support columns; a lower frame member connecting the side frame members to each other by securing them at lower ends thereof to the lower frame member; first and second additional screens installed at lower ends thereof pivotably to the lower frame member and having a horizontal length smaller than t