Abstract: A nitrogen adsorbent comprising a crystalline X zeolite having a faujasite structure with an SiO2/Al2O3 ratio of less than 3.0, wherein the crystal contains at least one trivalent element of the group consisting of Fe, B and Ga and (AlO4)5− tetrahedral units thereof associated with cations. Although the adsorbent contains a designated trivalent element in the zeolite, it maintains the number of cation sites contributing to adsorption, has an excellent separation performance of nitrogen and oxygen, and exhibits excellent heat resistance. Further, when the nitrogen adsorbent of the present invention is used in such a particular manner that it adsorbs nitrogen after being heated under a vacuum, adsorption performance is improved.

Abstract: A pulse tube refrigerator which enables holding a cooling temperature without the use of a heater and the like. The pulse tube refrigerator employs a working gas which has a liquefying temperature within the range of an operating temperature of the pulse tube refrigerator.

Abstract: A method and an apparatus for cutting a wafer from a crystalline ingot, by directing a stream or streams of etching gas at the crystalline ingot in a vacuum. Waste in cutting can be greatly minimized and the work environment can also be kept clean. Further, excellent surface smoothness can be realized on the cut wafers.

Abstract: Gas sensor materials composed of carbon mixture or metal-containing carbon mixture obtained as evaporated matter by arc discharge which occurs by passing an alternating current or a direct current with electric current density of 0.8 to 3.5 A/mm.sup.2 on discharge surfaces of carbon electrodes or metal-containing carbon electrodes in an inert gas under a pressure of 0.1 to 600 torr.

Abstract: There are included a fractionating tower for liquefying and separating the compressed air cooled by heat exchangers to an ultralow temperature, a liquid oxygen takeout path for guiding the liquid oxygen in the above-mentioned fractionating tower to the above-mentioned heat exchangers to gasify so as to become a gasified oxygen, and a product oxygen gas takeout path which extends from the front end of the above-mentioned liquid oxygen takeout path and increases the temperature of the above-mentioned gasified oxygen so as to obtain a product oxygen gas, the above-mentioned liquid oxygen takeout path being provided with an oxygen gas pressurizing pump, and the above-mentioned product oxygen gas takeout path on the side upstream the above-mentioned heat exchangers being provided with an expansion turbine.

Abstract: A method and an apparatus for producing a wafer from a crystalline ingot, wherein the method supplies an etching gas, having a high etching property for at least one constituent of the crystalline ingot, in a state of a molecular beam stream on a predetermined part of the crystalline ingot to be processed, volatilizing the predetermined part gradually from the ingot, and then removing the predetermined part entirely so as to cut the wafer from the ingot. According to the method, waste in cutting can be greatly minimized and the work environment can also be kept clean. Further, excellent surface smoothness can be realized on the cut wafers.

Abstract: A method for processing semiconductor materials such as a crystalline ingot or a wafer and an apparatus employed therein. An etching gas is supplied on the surface of a semiconductor material, while laser irradiation or light quantum irradiation is applied on a predetermined part of the semiconductor material surface, whereby a component of the etching gas is excited, reacted with a component of the semiconductor material and evaporated for elimination. Thereby, semiconductor materials can be processed hygienically, easily and with high precision.

Abstract: A method of carburizing austenitic stainless steel comprising the steps of holding austenitic stainless steel in a fluorine- or fluoride-containing gas atmosphere with heating prior to carburizing and carburizing the austenitic stainless steel at a temperature not more than 680.degree. C. wherein said austenitic stainless steel is stable austenitic stainless steel having 1 to 6 weight % molybdenum or 13 to 25 weight % chromium, wherein a carburized hard layer having corrosion resistance superior to base material forms and austenitic stainless steel products obtained thereby.

Abstract: There is provided a skin substitute that can suitably be used for covering the surface of a damaged skin area which is typically a wound produced by a traumatic local loss of the skin of the human body as a result of a burn or some other cause of damage. It is a skin substitute of a laminate comprising a squid chitin sheet and a fish skin collagen coat layer, which may be a salmon skin collagen coat layer. Such a skin substitute effectively exploits the suppleness and the effect of proving an environment for encouraging the production of lysozyme and defending the wound of squid chitin and, at the same time, compensate the disadvantage of poor adhesion of fibroblast cells that operate for curing the wound.

Abstract: A method of nitriding steel which comprises reacting the steel surface with nitrogen so as to form a hard nitrided layer, and, prior to nitriding, holding steel under a gas atmosphere containing fluorine compound gas or fluorine gas and also containing air of 0.5 to 20 volume % of the total or oxygen gas of 0.1 to 4 volume % of the total with heating, whereby occurrence of uneven nitriding is prevented and at the same time savings in consumption of expensive fluorine- or fluoride-containing gas can be realized.

Abstract: An improved cryogenic liquefied gas container, or a so-called cold evaporator (CE) for containing a plurality of different liquefied gases such as oxygen and nitrogen gases can be installed on a site with a limited surface area and can store the gases at a substantially equal and constant temperature level to ensure a stable gas supply to consumers that may include medical facilities and manufacturing plants. A plurality of inner tanks 4 are vertically arranged and surrounded by an insulation layer 3 in an outer shell 2 in order to economically utilize the site. The temperature of the high boiling point liquefied gas LG1 contained in the upper inner tank 4a and hence the internal pressure of the upper inner tank are stabilized by means of a heat exchanger section 11 to which the low boiling point liquefied gas LG.sub.

Abstract: A method of carburizing austenitic metal comprising the steps of holding austenitic metal in a fluoride-containing gas atmosphere with heating prior to carburizing and carburizing the austenitic metal at a temperature not more than 680.degree. C. and austenitic metal products obtained thereby.

Abstract: A method for carburizing austenitic metal comprising fluorinating the austenitic metal and consecutive carburizing at a low temperature not more than 680.degree. C. A carburizing temperature can be lowered by such a fluorination. As a result, carbide of chrome component in the austenitic metal can be prevented from depositing. That is, much chrome component remains in the austenitic metal. Therefore, the austenitic metal surface can be hardened and also superior anti-corrosion property can be maintained.

Abstract: A high pressure valve and low pressure valve are positioned at a hot end of the pulse tube and two direction valves are positioned respectively between the high pressure reservoir, the low pressure reservoir and the pulse tube. In the pulse tube refrigerator wherein the cold is produced by time-phase displacement with orifice, an irreversible loss is caused when the gas passes through the orifice. However, the refrigeration in this invention comprising high and low pressure reservoirs, and open and close valves, all the energy can be converted without loss in adiabatic expansion of the gas in the pulse tube, theoretical efficiency is 100%.

Abstract: A loom guide bar blade for automatic weaving machinery such as an air or water jet loom wherein the surface of the blade which contacts yarn is nitrided to form a nitrided hardened layer. When this blade is used in automatic high-speed weaving machinery, wearing and the like at contacting points of the blade with the yarn are prevented. As a result yarn fluffing from its being abraded by a roughened blade surface is minimized.