Abstract: An air-cleaning apparatus and air-cleaning method whereby air is cleaned with an air flow containing ions and ozone generated by corona discharge. The apparatus has a wind tunnel part including a trumpet-shaped member (3) having an opening at the bottom thereof and a cylindrical member (4) connected to the opening at the bottom of the trumpet-shaped member (3). The wind tunnel part has a titanium dioxide metal evaporated onto the surface thereof. A needle electrode (1) is placed in front of the trumpet-shaped member (3) of the wind tunnel part near an axis of the trumpet-shaped member (3). An annular electrode is formed on the inner surface of the wind tunnel part. A high-voltage generating unit applies a high voltage between the needle electrode (1) and the annular electrode (2). A housing (10) accommodates the needle electrode (1), the annular electrode (2) and the wind tunnel part and has an air inlet (11) on a side thereof closer to the needle electrode.

Abstract: A method for the removal of rust deposits from the interior walls of fluid conduits comprising the steps of preparing a shaped compound consisting of iron oxides and manganese oxides as primary elements, at least one oxide of Cu, Ni, Cr, Zn, Co, Mg, Ti, V, Sn, Ba, Y and Gd as secondary elements and at least one silica oxide, silicate salt, aluminum oxide and aluminum salt as a binding element. When chlorine containing water is contacted with the compounds, the water is activated to dissolve iron rust scales which have adhered to the interior of the pipe walls thereby facilitating removal while providing a protective coating onto the pipe walls.

Abstract: In an electrochromic display device having a plural number of indication electrodes displaying an information by repetition of coloring mode and discoloring mode, both modes of the indication electrodes being caused by an electrochemical oxidation-reduction reaction at the indication electrodes, and having an auxiliary electrode and counter-electrode to the indication electrodes and to the auxiliary electrode, the improvement is that an auxiliary electrode is further provided so as to act as the same acting mode as that of at least one of the indication electrodes, thereby removing an irregularity of color density of displaying at the acting indication electrodes.

Abstract: An electrochromic display device is disclosed including a cell container, a display electrode and a counter electrode both of a chemically stable conductor material. Also included in the container is an electrochromic aqueous solution composed of N,N'-di(p-cyanophenyl)-4,4'-bipyridinium dichloride, phosphoric acid and ammonium ferrous sulfate as a source of ferrous ions.