Abstract: A compound of formula (I) (wherein R1 is a hydrogen atom, a hydrocarbon group which may be substituted, a non-aromatic heterocyclic group which may be substituted, R2 is a hydrocarbon group which may be substituted, a non-aromatic heterocyclic group which may be substituted, or R1 and R2 may combine to each other together with A to form a heterocyclic group which may be substituted; A is N or N+—R5.

Abstract: A kaleidoscope includes a kaleidoscope body assembled in the shape of a sleeve so as to locate surfaces of mirrors therein and a support body, having two concave parts, attached to an end portion of the kaleidoscope body and supporting an image material assembly at the end portion. A retaining member is attached to one of the support body, the end portion of the kaleidoscope body and a part adjacent the support body and kaleidoscope body, to prevent the image material assembly from falling from an opening end of the concave parts. The image material assembly is supported rotatably and detachably by the support body so that it can change from the image material assembly attached in the kaleidoscope body to a different image material assembly.

Abstract: A kaleidoscope includes a kaleidoscope body assembled in the shape of a sleeve so as to locate the surfaces of mirrors thereinto; a support body, having two concave parts, attached to an end portion of the kaleidoscope body, supporting an image software at the end portion, holding at least two points of the outer circumferential portion of the container; a prevention member attached to one of the support body, the end portion of the kaleidoscope body and a part adjacent the support body and kaleidoscope body, preventing for coming out the image software from an opening end of the concave parts; and the image software having an image software member thereinto, being supported rotatably and detachably by the support body so that it can change from the image software attached in the kaleidoscope body to the different image software easily and can enjoy many images.

Abstract: A compound of formula (I) (wherein R1 is a hydrogen atom, a hydrocarbon group which may be substituted, a non-aromatic heterocyclic group which may be substituted, R2 is a hydrocarbon group which may be substituted, a non-aromatic heterocyclic group which may be substituted, or R1 and R2 may combine to each other together with A to form a heterocyclic group which may be substituted; A is N or N+—R5.

Abstract: A compound of formula (I) (wherein R1 is a hydrogen atom, a hydrocarbon group which may be substituted, a non-aromatic heterocyclic group which may be substituted, R2 is a hydrocarbon group which may be substituted, a non-aromatic heterocyclic group which may be substituted, or R1 and R2 may combine to each other together with A to form a heterocyclic group which may be substituted; A is N or N+—R5.

Abstract: A process to avoid or limit corrosion at the junction of two piping comprising devices welded together, said piping comprising devices being adapted to flow corrosive gases through them, said process comprising the steps of:a) providing a first piping comprising device and connecting it to an inert gas source;b) purging it with an inert gas comprising substantially not more than 10 ppb of an oxidizing gas selected from the group consisting of oxygen, carbon dioxide, water vapor or mixtures thereof, said inert gas flowing from a first opening to a second opening of said piping comprising device;c) providing a second pipe comprising device in flow communication with the first one, while continuing to purge the first piping comprising device;d) welding the two piping comprising devices, said welding being carried out under an inert gas atmosphere; ande) repeating steps c and d if necessary.