Abstract: A glass panel unit manufacturing method includes a bonding step, a pressure reducing step, and a sealing step. The bonding step includes bonding together a first substrate and a second substrate with a first sealant to create an inner space. The pressure reducing step includes producing a reduced pressure in the inner space through an exhaust port that the first substrate has. The sealing step includes melting and expanding a second sealant, inserted into the exhaust port, by heating the second sealant and thereby sealing the exhaust port up with the second sealant expanded to the point of coming into contact with a dam arranged in the inner space.

Abstract: A welding nut comprising a main cylindrical body having a bearing surface end and an axial screw hole, a flange set around an outer perimeter of the body at the bearing surface end, and axially extending protrusions formed by partially pressed the flange in a direction towards the bearing surface. The protrusions extend axially beyond the bearing surface for resistance welding. At least one groove can be formed in the bearing surface between the screw hole and the protrusions. A guide tube having an external diameter smaller than an external diameter of the body can extend axially from the bearing surface. Screw threads can be bored continuously through the screw hole of the cylindrical body and an inner perimeter of the guide tube. A large number of serrated protrusions can be formed on an outer perimeter of the cylindrical body. Each of the protrusions can have an inner surface slanting radially outwardly and axially away from the bearing surface towards an outer edge of the flange.

Abstract: A process for producing a partially hydrolyzed polyacrylamide which has a high molecular weight and high water solubility and can be suitably used as a flocculant for water treatment and a size for paper manufacture comprising polymerizing an aqueous solution of an acrylamide monomer in the presence of an alkali metal hydroxide such as sodium hydroxide and boric acid, whereby a partial hydrolysis of the polymer formed is also conducted substantially simultaneously with the polymerization. In an additional embodiment, a maturing of the polyacrylamide produced can be conducted by continuing to heat the polymer solution to increase the hydrolysis percentage.