Abstract: The present invention provides a desulfurizing agent that can desulfurize hydrocarbon oil in a stable and economical manner over a long period of time under specified conditions, and a method for producing the same. The desulfurizing agent of the present invention is such a desulfurizing agent that is used in a desulfurizing process for removing sulfur components from hydrocarbon oil and contains nickel, zinc and a sulfur component, wherein a sulfur content except metal sulfide in the desulfurizing agent is 0.2% by mass or more in the total mass of the desulfurizing agent, and a proportion of the metal sulfide in the sulfur component contained in the desulfurizing agent is 25% or less.

Abstract: A plant simulator which makes it possible to set factors which could invite a system accident and to simulate the process of occurrence of a system accident.

Abstract: Lamination molding resin-coated sand which can advantageously enhance accuracy for a formed article, is lamination molding resin-coated sand used for lamination molding for forming an article by laminating sand layers in thickness direction. Sand particles coated with resin are 20 to 100 &mgr;m in diameter and generally spherical. The resin has a mean molecular weight of about 2000 to 10000 and a fusion temperature of 100° C. or higher.

Abstract: A method for producing a laminated object repeats a depositing step and an irradiating step alternatively. The irriating step comprises the operations of: covering a deposited layer with a mask having a pattern configuration for penetrating the laser beam; and scanning the lader beam on the desposited layer covered with the mask in such a manner that the laser beam depicts an irradiated continous wave trace being wider than the pattern configuration of the mask, by moving the laser beam in the Y-direction with a Y-rotating mirror, while repeating oscillations of the laser beam in the X-direction with a X-rotating nirror, The laminated object may be a casting mold.

Abstract: The present invention mask 1 has a mask-portion 12. The mask-portion 12 comprises: a bed sheet layer 12c made of paper or resin; and an irradiation-resistant layer 12e made of metal and coated on the irradiation side of the bed sheet layer 12c. The irradiation-resistant layer 12e has durability with respect to the emitted energy such as laser beam than the bed sheet layer 12c.

Abstract: A method and apparatus for forming a laminated object using a laser-discharging means a laser beam, a material capable of forming a solid layer by receiving the laser beam, and a mask for interrupting the laser beam. The method includes the steps of: forming a layer of the material on a surface, covering the material with the mask, and discharging the laser beam onto the material covered with the mask to solidify the material and form the solid layer on the surface. The above cycle is repeated to produce a laminated object. The method and the apparatus are characterized in the adjusting at least one of a distance from the laser-discharging means to the mask and a distance from the mask to the material, so that the extent of the laser beam is adjusted and the dimension of the laminated object is adjusted.

Abstract: A depositing step and an irradiating step are repeated alternately so as to pile solid layers to produce a laminated mold for casting an alloy melt. In the depositing step there is formed a deposited layer of sand coated with a thermosetting resin capable of forming a solid layer upon being irradiated with a laser beam. In the irradiating step, the deposited layer is irradiated with a laser beam to form a hardened solid layer. The irradiating step includes the operations of: distinguishing an outer skin portion from an inner portion of the deposited layer, and emitting a thick laser beam having a large diameter to harden the inner portion of the deposited layer, and emitting a thin laser beam having a diameter smaller than the thick laser beam to harden the skin portion of the deposited layer.

Abstract: After sand of one layer is loaded into a sand layer elevator (20), a shading mask (38) is positioned above the sand, and a diffused laser beam is irradiated from a diffused laser irradiating source (16). Thereby, a predetermined range of sand under the shading mask (38) is exposed and this exposed portion is cured. This operation is repeated for a predetermined number of sand layers and cured portions are piled up to directly form a 3-D sand mould. Particularly, a diffused laser beam is used to cure a wide range of sand at a time, thereby making sand mould mass-production possible.

Abstract: A lower mold made of a metal mold is disposed on a stool and an upper mold consisting of a sand mold is guided and fitted to the lower mold in such a manner as to define a cavity for a product. Tubular members are disposed at several positions in such a manner as to penetrate through the upper and lower molds and the cavity. A cooling plate equipped with cooling nozzles fitting to the projecting ends of the tubular members from the upper mold is disposed in such a manner as to clamp the upper and lower molds between it and the stool. The cooling nozzles are communicated with a cooling medium tube disposed on the cooling plate so that a cooling medium supplied to the cooling medium tube is uniformly distributed to the cooling nozzles.

Abstract: A forced cooling casting apparatus has a loop track for guiding a stool having a lower mold fitted thereto and having a punch-out portion. A plurality of stations are sequentially disposed on the loop track for effecting the steps of cleaning the lower mold, arranging an upper mold, inserting tubular members for cooling, setting a cooling plate having a plurality of cooling nozzles for passing a cooling medium through the tubular members, pouring a molten metal, effecting cooling in several stages, removing the cooling plate and taking out the resulting casting. A cooling medium tube communicates with the cooling nozzles, having a coupler and disposed on the cooling plate. A cooling medium feeder is connected to the coupler and/or a cooling medium jet device for cooling the lower mold, and is disposed at each of the cooling stations.

Abstract: A sewage treatment apparatus having a rotary shaft and a plurality of rotary plates secured to the rotary shaft in an axially spaced-apart relationship, each of the rotary plates being adapted to be rotated while it is partly dipped in sewage within a treating tank,a plurality of holding members provided fixedly around the rotary shaft for rotation therewith, andthe rotary plates being secured such that at least one rotary plate is fixedly held at its central end portion between every two adjacent holding members.