Abstract: A metallic mold-casting method excellent in the resistance to penetration is herein disclosed and the method comprises the steps of forming a coating layer by applying a mixture comprising at least one member selected from the group consisting of high melting metals, ceramic materials and graphite, and an aqueous surfactant solution or low boiling liquid oils and fats to at least part of the surface of a metallic mold on its cavity side, then applying heat to the coated portion to thus adhere the mixture to the inner surface of the mold, and thereafter repeatedly casting a magnesium alloy in the metallic mold provided with the coating layer. The metallic mold-casting method permits the metallic mold casting of magnesium alloys with good resistance to penetration and this accordingly leads to the production of a cheap and high quality cast magnesium alloy product.

Abstract: An implant screw assembly comprising; an inner screw provided with a thread on an outer periphery of one end, and with a base at the other end, wherein an angled socket for a wrench or a slot for a driver is provided at the base, an outer screw provided with a thread on at least part of an outer periphery, and coaxially disposed around the periphery of the base of the inner screw, wherein the thread of the inner screw and the thread of the outer screw are in the same rotation direction, and a meshing structure formed by an outer peripheral face of the inner screw and an inner peripheral face of the outer screw, to prevent relative rotation between the inner screw and the outer screw, whereby the outer screw and the inner screw are only able to slide axially.

Abstract: A sample is taken out of a molten magnesium alloy, the cooling curve of the sample during solidification is measured, the content of the aluminum component in the sample is determined by the use of the crystallization temperature of a phase appearing in the cooling curve, together with cooling curves, and if the results of bath analysis show the components to deviate from the standard values and target values, an aluminum-manganese master alloy, aluminum or magnesium is added to the molten magnesium alloy to adjust the components to an appropriate amount of aluminum or an appropriate iron/manganese ratio, whereby a magnesium alloy is produced.

Abstract: The present invention provides a method of manufacturing a zinc-titanium mother alloy and a manganese dry battery having an anode zinc can prepared from the zinc-titanium alloy. The method comprises: adding spongy titanium to molten zinc; and melting the spongy titanium to alloy with the zinc at 500.degree. to 750.degree. C. for 0.5 to 6 hours, thereby to obtain a zinc-titanium alloy which contains 0.001 to 5% by weight of titanium. The anode zinc can prepared from the zinc-titanium mother alloy is substantially free from metallic titanium and intermetallic compounds having the Zn--Ti atomic ratio of not less than 1/2.

Abstract: A manganese dry battery includes an anode zinc can made of a zinc alloy containing 0.001-0.5 wt. % of titanium and at least one element selected from the group consisting of 0.001-0.05 wt. % of indium and 0.001-0.05 wt. % of bismuth, or a zinc alloy further containing 0.01-0.4 wt. % of lead. Even without heavy metals such as Hg and Cd, the zinc alloy anode can has a corrosion-resistant property and mechanical strength equivalent to or greater than those of the conventional zinc anode can, thereby giving a low pollution zinc-carbon battery having a storage characteristic equivalent or superior to that of the conventional zinc anode can.

Abstract: A method for easily making an ice slab serving as the foundation of an artificial snow skiing field and artificial snow whose upper layer is powdery by flooding aqueous slurry made by adding water to granular wet water absorbent polymer on a slope of a natural skiing field or a slant or horizontal surface of a natural skiing field or indoor artificial snow skiing field equipped with a cooling system, obtaining the deposit layer of the granular wet water absorbent polymer in which water is separated from the slurry and freezing the deposit layer.

Abstract: A method for the preparation of a hydrocarbon conversion catalyst comprising a composite of a refractory support, or carrier, a Group VIII noble metal component, particularly platinum, a tin component, and a halogen component. Suitably, the catalyst composite can also contain a third metal component, or yet additional components. In the preparation of such catalyst, the tin is added from a solution of a soluble compound of tin comprised of an organo thionyl compound, or organic compound containing a thionyl group, whereby the tin component is uniformly dispersed from the surface into the inner part of a catalyst. Such catalyst is found useful in hydrocarbon conversion reactions, particularly reforming (hydroforming). A naphtha or straight run gasoline can be contacted with such catalyst at reforming conditions in the presence of hydrogen to improve the octane quality of a naphtha or gasoline.