Abstract: There are disclosed a process for cleaning ammonia-containing exhaust gas which comprises bringing the exhaust gas into contact with an ammonia decomposition catalyst (e.g. nickel, ruthenium) under heating to decompose most of the ammonia into nitrogen and hydrogen, subsequently bringing the resultant mixed gas into contact with an ammonia adsorbent (e.g. synthetic zeolite) for adsorbing undecomposed ammonia, and then heating regenerating the adsorbent, while bringing reproduced exhaust gas containing the ammonia desorbed from the adsorbent into contact under heating, with the ammonia decomposition catalyst or another ammonia decomposition catalyst; and an apparatus for carrying out the process. It is made possible by the process and apparatus to efficiently and completely clean ammonia-containing exhaust gas exhausted from a semiconductor manufacturing process and the like without generating useless byproduct and dispensing with secondary treatment.

Abstract: A cleaning method for an exhaust gas containing ammonia, silanes, and organometallic compounds exhausted from a nitride film production step, etc., for producing compound semiconductors.After removing the silanes and the organometallic compounds from the exhaust gas by contacting the exhaust gas with a cleaning agent comprising soda lime having provided thereon a copper(II) salt, the exhaust gas is contacted with an ammonia decomposition catalyst to decompose ammonia into hydrogen and nitrogen, and undecomposed ammonia in the remaining exhaust gas is then removed by a cleaning agent comprising an inorganic carrier having provided thereon a copper(II) salt, or an active carbon having provided thereon copper sulfate.

Abstract: There is disclosed a process for cleaning a harmful gas which comprises bringing a harmful gaseous halogenide such as chlorine, hydrogen chloride, dichlorosilane, silicon tetrachloride, phosphorus trichloride, chlorine trifluoride, boron trichloride, boron trifluoride, tungsten hexafluoride, silicon tetrafluoride, fluorine, hydrogen fluoride and hydrogen bromide into contact with a cleaning agent comprising zinc oxide, aluminum oxide and an alkali compound to remove the above halogenide. The above process is extremely effective for promptly and efficiently removing the above gaseous halogenide that is contained in the gas discharged from semiconductor manufacturing process.

Abstract: There is disclosed a process for cleaning a harmful gas which comprises bringing a harmful gaseous halogenide such as chlorine, hydrogen chloride, dichlorosilane, silicon tetrachloride, phosphorus trichloride, chlorine trifluoride, boron trichloride, boron trifluoride, tungsten hexafluoride, silicon tetrafluoride, fluorine, hydrogen fluoride and hydrogen bromide into contact with a cleaning agent comprising zinc oxide, aluminum oxide and an alkali compound to remove the above halogenide. The above process is extremely effective for promptly and efficiently removing the above gaseous halogenide that is contained in the gas discharged from semiconductor manufacturing process or leaked suddenly from a gas bomb in an emergency.

Abstract: A marker dot detecting device for a color image recording apparatus such as a color copying machine, color facsimile, or color printer. The marker dot detecting device includes a marker dot detecting unit for detecting a marker dot by detecting a plane size of binary image data having a preset marker color. Further, the marker dot detecting unit includes a template mask unit having a first template mask in a predetermined first size and a second template mask in a predetermined second size larger than the first size, the second template mask including the first template mask. The template mask unit outputs a marker dot detecting signal when a detected size of the marker dot is larger than that of the first template mask and smaller than that of the second template mask.

Abstract: A method for cleaning an exhaust gas comprising a base gas and at least one toxic component selected from the group consisting of arsine, phosphine, diborane and hydrogen selenide is disclosed. The method comprises contacting the exhaust gas with a molded cleaning agent having a composition consisting essentially of (1) cupric oxide, (2) manganese dioxide, and (3) at least one metal oxide selected from the group consisting of silicon oxide, aluminum oxide and zinc oxide and having a density of from 0.6 to 1.5 g/ml, said composition having a metal atomic ratio M/(M+Cu+Mn) in the range of from 0.02 to 0.70 and a metal atomic ratio Cu/(Cu+Mn) in the range of from 0.1 to 0.9; wherein Cu represents a number of gram atom of copper; Mn represents a number of gram atom of manganese; and M represents a total number of gram atom of silicon, aluminum and/or zinc, to remove the toxic component from the exhaust gas. The method is effective even at low temperatures below 10.degree. C.

Abstract: A method for purifying a gaseous hydride, which comprises bringing a crude gaseous hydride into contact with at least one material from nickel arsenides, nickel phosphides, nickel silicides, nickel selenides, or nickel borides to remove oxygen contained in the crude gaseous hydride.

Abstract: A method for cleaning a gas containing at least one toxic component selected from the group consisting of arsine, phosphine, monosilane, diborane, and hydrogen selenide, which comprises contacting the gas with a cleaning agent containing a molded composition comprising (1) manganese dioxide and (2) cupric oxide, having deposited thereon (3) a silver compound, wherein the weight ratio of cupric oxide to manganese dioxide ranges from 0.2 to 1.2 and the amount of the deposited silver compound ranges from 0.01 to 10.5% by weight based on the cleaning agent. By the cleaning method, the toxic component can be removed from a gas, e.g., air, at high efficiency and at a high rate even in case of sudden leakage of the toxic component out of a bomb.