Abstract: The present disclosure relates to a method for carrying out dose delivery quality assurance for high-precision radiation treatment, in which parameters affecting a pass rate of dose delivery quality assurance can be derived through regression analysis, which is a known statistical analysis method, and a pass rate prediction model capable of predicting each parameter and the pass rate of dose delivery quality assurance can be derived, and accordingly, it can be predicted in advance whether dose delivery quality assurance will be passed according to the parameters through the above prediction model, without repeatedly carrying out dose delivery quality assurance according to a patient's treatment plan, and as a result, the efficiency of dose delivery quality assurance can be enhanced, and the time or capacity required for such quality assurance is reduced, such that radiation treatment for an actual patient can be quickly and precisely carried out.

Abstract: Provided is a surface modification method of calcite powder prepared from desulfurized gypsum and heat-treated at a high temperature. According to the surface modification method, hydrophilic calcite powder having polarity may be changed into hydrophobic non-polar calcite powder by safely adsorbing a surface modifier onto a surface of the calcite powder and coating the surface with non-polar fatty acid. Particularly, in the case in which calcite powder heat-treated at a high temperature is hydrophobized, a significantly excellent hydrophobic surface property may be implemented.

Abstract: Disclosed is a method of preparing calcium carbonate using a direct carbonation reaction. The method includes dissolving fuel gas desulfurization gypsum into an ammonia solution, performing a filtering process after making a carbonation reaction by feeding carbon dioxide into the ammonia solution in which the fuel gas desulfurization gypsum is dissolved, and performing a filtering process after precipitating the calcium carbonate by maintaining a filtered solution in a stationary state.

Abstract: Disclosed is a method of detoxifying asbestos of waste slate. The method includes concentrating the asbestos by introducing hydrochloric acid aqueous solution into waste slate powder to dissolve and remove a limestone component contained in the waste slate; and mixing the concentrated asbestos with oxalic acid and performing a low-temperature heat treatment. The waste slate is crushed and pulverized and powder of the crushed and pulverized waste slate is formed in a size in a range of 100 meshes to 300 meshes. The detoxified asbestos includes re-crystallized magnesium oxalate having a rhombohedral or amorphous shape.

Abstract: Disclosed is a method of detoxifying asbestos by using a room-temperature recrystallization scheme. The method includes heat-treating a rock or slate containing asbestos; and putting the heat-treated rock or slate in an aqueous solution, to which organic acid is added, to allow the heat-treated rock or slate to react with the aqueous solution having the organic acid.

Abstract: Provided is a method of recycling a high purity ammonium sulfate aqueous solution including: adding slurry obtained by mixing water, aqueous ammonia, and gypsum with each other and a predetermined amount of carbon dioxide to a reactor to performing a carbonation reaction, wherein an ammonium sulfate aqueous solution produced in the reactor is circulated in the reactor.

Abstract: Provided is a recycling method for producing calcite and ammonium sulfate having a high purity of at least 95% and generated by means of a carbonation reaction for fixing carbon dioxide inside the crystal structure of a mineral, and in which waste gypsum is reacted with carbon dioxide, which is a greenhouse gas, such that the carbon dioxide is fixed as a stable mineral, and high-purity calcite and ammonium sulfate are produced as resultant products.

Abstract: Disclosed is a method of removing asbestos from an asbestos-containing material by 99% through low temperature heat treatment. The method includes mixing an asbestos-containing material with an oxalic acid at a weight ratio in a range of 1:0.002 to 1:1 and performing heat treatment with respect to a mixture at a temperature of 90° C. to 110° C. to remove asbestos from the asbestos-containing material by 99% or more.

Abstract: Provided is a method of synthesizing high-purity calcite capable of controlling a grain size thereof, by reacting an aqueous calcium chloride solution with CO2 gas under strong alkaline condition, to crystallize into white and ultra-fine grain calcite. The method of synthesizing fine-grain calcite according to the present disclosure can decrease super-saturation by producing calcite under the strong alkaline conditions, thereby suppressing generation and growth of grain, resulting in controlling the grain size. Therefore, the above method is useful in producing high-purity ultra-fine grain calcite and can control the grain size of calcite from several hundreds of nanometers to several tens of nanometers by regulating the concentration of an aqueous caustic soda solution.

Abstract: Disclosed is a method of detoxifying asbestos by using a room-temperature recrystallization scheme. The method includes heat-treating a rock or slate containing asbestos; and putting the heat-treated rock or slate in an aqueous solution, to which organic acid is added, to allow the heat-treated rock or slate to react with the aqueous solution having the organic acid.

Abstract: Disclosed is a method of preparing calcium carbonate using a direct carbonation reaction. The method includes dissolving fuel gas desulfurization gypsum into an ammonia solution, performing a filtering process after making a carbonation reaction by feeding carbon dioxide into the ammonia solution in which the fuel gas desulfurization gypsum is dissolved, and performing a filtering process after precipitating the calcium carbonate by maintaining a filtered solution in a stationary state.

Abstract: Disclosed is a method of detoxifying asbestos of waste slate. The method includes concentrating the asbestos by introducing hydrochloric acid aqueous solution into waste slate powder to dissolve and remove a limestone component contained in the waste slate; and mixing the concentrated asbestos with oxalic acid and performing a low-temperature heat treatment. The waste slate is crushed and pulverized and powder of the crushed and pulverized waste slate is formed in a size in a range of 100 meshes to 300 meshes. The detoxified asbestos includes re-crystallized magnesium oxalate having a rhombohedral or amorphous shape.

Abstract: Disclosed is a method of removing asbestos from an asbestos-containing material by 99% through low temperature heat treatment. The method includes mixing an asbestos-containing material with an oxalic acid at a weight ratio in a range of 1:0.002 to 1:1 and performing heat treatment with respect to a mixture at a temperature of 90° C. to 110° C. to remove asbestos from the asbestos-containing material by 99% or more.

Abstract: Provided is a recycling method for producing calcite and ammonium sulfate having a high purity of at least 95% and generated by means of a carbonation reaction for fixing carbon dioxide inside the crystal structure of a mineral, and in which waste gypsum is reacted with carbon dioxide, which is a greenhouse gas, such that the carbon dioxide is fixed as a stable mineral, and high-purity calcite and ammonium sulfate are produced as resultant products.

Abstract: Provided is a method for fixing carbon dioxide, the method includding: pulverizing furnace slag; mixing water and the furnace slag such that the furnace slag is present in a concentration of 5˜15 parts by weight based on 100 parts by weight of water; adding NaOH to the mixture; and supplying carbon dioxide to the decomposed mixture, and then carrying out a hydrothermal reaction, so that carbon dioxide can be stably fixed; the treatment of the furnace slag can lead to ecofriendly effects; and the use of the furnace slag can lead to production of carbonate minerals as the final product.

Abstract: Disclosed herein is a method of producing carbonate, comprising the steps of: providing a water-containing solution including cations that are precipitated in the form of a salt after undergoing a precipitation reaction with carbonate ions; and generating carbon dioxide microbubbles having a diameter of 50 ?m or less in the water-containing solution to induce the precipitation reaction between the cations and the carbonate ions. The method is advantageous in that the carbonate produced using the microbubble system disclosed in the method can be practically used as high-priced building materials, filler for paper manufacturing, etc. and can also be used in foods, medicines and the like depending on the purity thereof, so that it can be recovered in a high yield. Further, the method is advantageous in that carbon dioxide is consumed, and cations can be effectively removed from waste water, so that it is environmentally useful.

Abstract: Provided is a method of analyzing a formation and a phase transition characteristic of amorphous calcium carbonate that may adjust a preferred orientation in crystalline calcium carbonate as well as an amorphous state of calcium carbonate using a water-soluble material containing an amino acid in an operation of forming calcium carbonate. It is possible to handle issues of a limit of a sampling and a standard pattern of an analysis scheme in in vitro calcium carbonate crystallization test by adjusting a holding time of amorphous calcium carbonate or a preferred orientation of a crystal calcium carbonate when forming calcium carbonate using a water-soluble material containing an amino acid. Further, it is possible to verify further characteristics of elements that adjust a formation of a biological material, which may be used for a synthesis of a new material in tissue engineering as well as for an biomineralizaton process.

Abstract: Provided is a method of synthesizing high-purity calcite capable of controlling a grain size thereof, by reacting an aqueous calcium chloride solution with CO2 gas under strong alkaline condition, to crystallize into white and ultra-fine grain calcite. The method of synthesizing fine-grain calcite according to the present disclosure can decrease super-saturation by producing calcite under the strong alkaline conditions, thereby suppressing generation and growth of grain, resulting in controlling the grain size. Therefore, the above method is useful in producing high-purity ultra-fine grain calcite and can control the grain size of calcite from several hundreds of nanometers to several tens of nanometers by regulating the concentration of an aqueous caustic soda solution.

Abstract: Provided is a fixation method of carbon dioxide. The method includes a) grinding waste gypsum to become 200˜300 mesh; b) performing reaction by supplying mixed gas while mixing the ground waste gypsum with aqueous ammonia, and c) separating solid from liquid in the manufactured slurry by centrifugation and drying separated solid and liquid portions with calcite and ammonium sulfate, wherein the mixed gas is formed of nitrogen and carbon dioxide, and the carbon dioxide provides carbon dioxide fixation method containing 5˜25 wt %. When carbon dioxide is fixed by using waste gypsum, reaction efficiency is remarkably high. The fixation method makes more than 95% of supplied carbon dioxide fixed. Also, provided is an economical method that disposes carbon dioxide as a disposal target without its separation, refinement and liquefaction processes, to thereby remarkably reduce the entire process and costs for processes.

Abstract: Disclosed herein is a method of producing carbonate, comprising the steps of: providing a water-containing solution including cations that are precipitated in the form of a salt after undergoing a precipitation reaction with carbonate ions; and generating carbon dioxide microbubbles having a diameter of 50 ?m or less in the water-containing solution to induce the precipitation reaction between the cations and the carbonate ions. The method is advantageous in that the carbonate produced using the microbubble system disclosed in the method can be practically used as high-priced building materials, filler for paper manufacturing, etc. and can also be used in foods, medicines and the like depending on the purity thereof, so that it can be recovered in a high yield. Further, the method is advantageous in that carbon dioxide is consumed, and cations can be effectively removed from waste water, so that it is environmentally useful.