Abstract: A welding observation apparatus is provided to use partial darkening by a telecentric optical system and a photochromic filter (PCF) as an optical system for filtering light emission from arc discharge in order to verify the welding condition under the welding arc discharge, without forming an image on the PCF, so that light reducing performance can be secured even if a focus shifts from on the PCF, with satisfactory monitoring of welding condition. The welding observation apparatus comprises: an arc welding unit 8; an objective optical system (1, 2) for concentrating light from the arc welding unit 8; a telecentric optical system 3 for guiding the light concentrated by the objective optical system (1, 2); a PCF 4 for illuminating with the light guided by the telecentric optical system 3; and a solid state imaging device 9 for receiving the light passing through the PCF 4, wherein the light from the arc welding unit 8 is partial-darkened by the PCF 4.

Abstract: A welding observation apparatus is provided to use partial darkening by a telecentric optical system and a photochromic filter (PCF) as an optical system for filtering light emission from arc discharge in order to verify the welding condition under the welding arc discharge, without forming an image on the PCF, so that light reducing performance can be secured even if a focus shifts from on the PCF, with satisfactory monitoring of welding condition. The welding observation apparatus comprises: an arc welding unit 8; an objective optical system (1, 2) for concentrating light from the arc welding unit 8; a telecentric optical system 3 for guiding the light concentrated by the objective optical system (1, 2); a PCF 4 for illuminating with the light guided by the telecentric optical system 3; and a solid state imaging device 9 for receiving the light passing through the PCF 4, wherein the light from the arc welding unit 8 is partial-darkened by the PCF 4.

Abstract: A subject for the invention is to form a coating film which has high transparency and excellent adhesion to organic base materials and retains long-lasting excellent effects concerning hydrophilicity, antifogging properties, droplet repellency, and antifouling properties. The invention relates to an inorganic coating composition capable of forming a hydrophilic coating film on an organic base material, the organic coating composition comprising alumina particles having an aggregate diameter in a dispersion medium of 20-400 nm and either a silicic acid oligomer or a colloidal silica, a surfactant, a water-miscible organic solvent which is capable of swelling or dissolving the organic base material and has a boiling point of 120° C. or higher at an atmospheric pressure of 0.

Abstract: An activation method of decomposition enzyme contained in a food material, wherein the food material is brought into contact with electrolyzed water to activate the decomposition enzyme thereby to enhance taste of processed foodstuffs.