Abstract: An exhaust gas containing a nitrogen oxides is passed at a temperature of 250.degree. to 550.degree. C. in the presence of a reducing agent through a catalyst bed filled with a molded denitration catalyst comprising at least the following three catalyst components(A) an oxide of at least one metallic element selected from the group consisting of Ti, Si and Zr,(B) an oxide of at least one metallic element selected from the group consisting of Mo and W, and(C) an oxide of Vsuch that the concentrations of the oxide (B) and/or the oxide (C) in the exhaust gas inlet site of the catalyst bed are higher than in the other site thereof.The molded denitration catalyst is also described.

Abstract: A catalyst for denitrizing nitrogen oxides contained in waste gas which contains a substantial amount of arsenic compounds therein, which comprises:(a) titanium, and(b) at least one element selected from the group consisting of arsenic and manganese. The catalyst is resistant to deactivation by arsenic compounds and retains high denitrizing activity over a long period of time. The catalyst may further contain at least one base metal selected from the group consisting of V, W, Mo, Cu, Fe, Cr, Co, Ni, Zn and Sn.

Abstract: A process for removing nitrogen oxides from an exhaust gas containing the nitrogen oxides and an arsenic compound, which comprises bringing said exhaust gas into contact with a reducing gas in the presence of a catalyst to reduce the nitrogen oxides in the exhaust gas and render them nontoxic. There are disclosed two types of catalysts: (1) a catalyst comprising (A) an oxide of titanium, (B) an oxide of at least one metal selected from tungsten and molybdenum, (C) an oxide of vanadium, and (D) an oxide and/or a sulfate of at least one metal selected from the group consisting of yttrium, lanthanum, cerium and neodymium, and (2) the above (A), (B), (C) components and (D)' at least one metal selected from the group consisting of yttrium, lanthanum, cerium, neodymium, copper, cobalt, manganese and iron, the component (D)' being deposited on zeolite.

Abstract: A catalyst for removing nitrogen oxides in an exhaust gas, said catalyst containing a first group of many pores having a diameter of 1.times.10.sup.2 .ANG. to less than 1.times.10.sup.3 .ANG. and a second group of many pores having a diameter of 1.times.10.sup.3 .ANG. to 1.2.times.10.sup.5 .ANG., the pore volume of the first group being at least 10% based on the total pore volume of the first group and the second group, and said catalyst comprising titanium and at least one metal selected from molybdenum, tungsten and vanadium as metal elements of catalytically active ingredients.

Abstract: Here is provided an adsorbent for adsorbing and removing an arsenic compound which becomes a catalyst poison in a selective contact reduction process for removing nitrogen oxides (NOx) from a combustion exhaust gas by the use of an ammonia as a reducing agent and a denitrating catalyst.The adsorbent of the present invention comprises a material in which the total volume of pores is 0.2 to 0.7 cc/g and the volume of the pores having a pore diameter of 300 .ANG. or more is 10% or more with respect to the total pore volume, and the material is a specific element, its oxide, an ion-exchanged zeolite or the like.In addition, the present invention is directed to a method for removing the arsenic compound from the combustion exhaust gas by injecting the adsorbent into the flow of the gas on the upstream side of the denitrating catalyst.

Abstract: A data transfer control unit comprises a first address register, a second address register and a control circuit. The first address register stores a first final address value of a memory area of a memory into which data is to be transferred. The second address register stores a second final address value of data which has already been transferred to the memory area of the memory. The control circuit compares the first final address value and a second final address value with an address value of data access by a CPU in order to generate a memory indication signal indicative of whether the address value of data accessed by the CPU belongs to the addresses of the data which has already been stored or has not yet been stored. The control circuit further prohibits a data transfer from the memory area to the CPU only when the address value of the data accessed by the CPU belongs to the addresses of the data which have not yet been stored in the memory.

Abstract: A process for removing nitrogen oxides from an exhaust gas containing the nitrogen oxides and an arsenic compound, which comprises bringing said exhaust gas into contact with a reducing gas in the presence of a catalyst to reduce the nitrogen oxides in the exhaust gas and render them nontoxic. There are disclosed two types of catalysts: (1) a catalyst comprising (A) an oxide of titanium, (B) an oxide of at least one metal selected from tungsten and molybdenum, (C) an oxide of vanadium, and (D) an oxide and/or a sulfate of at least one metal selected from the group consisting of yttrium, lanthanum, cerium and neodymium, and (2) the above (A), (B), (C) components and (D)' at least one metal selected from the group consisting of yttrium, lanthanum, cerium, neodymium, copper, cobalt, manganese and iron, the component (D)' being deposited on zeolite.

Abstract: A denitration catalyst comprising an oxide of titanium, an oxide of tungsten and an oxide of vanadium as catalytically active ingredients and having a specific surface area, measured by the BET method, of 80 to 200 m.sup.2 /g and a pore volume, measured by the mercury penetration method, of 0.1 to 0.5 cc/g.

Abstract: An extrusion die for forming a honeycomb stucture has a lattice molding groove formed in the outlet surface of the die body. In the inlet surface of the die body there are formed plural independent supply passages that are opposite to the intersecting portions of the molding groove and extend toward the outlet surface. A through hole is designed to communicate adjacent supply passages at a place that forms part of the partition wall between the supply passages and contacts with the molding groove. This through hole takes the combined shape of a trapezoid with the width of the molding groove as its top side and with the diameter of the supply passage as its maximum base side and a semicircle having said base side as its diameter.

Abstract: A direct memory access controller, such as for a disk, includes address registers containing beginning and end addresses defining a transfer area of a disk, a location counter which points to a specific location which is being accessed in the transfer area, updating circuitry to set the location counter to the initial address after the location corresponding to the end address has been accessed, and termination circuitry for disabling the location counter when all of the memory locations of the transfer area have been accessed. The address initially loaded into the location counter is for the location which can be accessed most quickly by the direct memory access controller.

Abstract: A catalyst which comprises titanium oxide reinforcing material and oxides of one or more metals selected from Group Ia, Group IIa, Group IIb and Group IVb of the periodic table, the weight of said oxides corresponding to at least 0.5 wt. % of the weight of a final catalyst exhibits an excellent activity in hydrolysis of carbonyl sulfide. Said catalytic activity has no possibility of deterioration even in the presence of hydrogen sulfide and/or carbon dioxide coexist with feed gas.