Abstract: Provided are a silicon nitride film etching composition, a method of etching a silicon nitride film using the same, and a manufacturing method of a semiconductor device. Specifically, a silicon nitride film may be stably etched with a high selection ratio relative to a silicon oxide film, and when the composition is applied to an etching process at a high temperature and a semiconductor manufacturing process, not only no precipitate occurs but also anomalous growth in which the thickness of the silicon oxide film is rather increased does not occur, thereby minimizing defects and reliability reduction.

Abstract: Disclosed are novel compounds of Chemical Formula 1, optical isomers of the compounds, and pharmaceutically acceptable salts of the compounds or the optical isomers. The compounds, isomers, and salts exhibit excellent activity as GLP-1 receptor agonists. In particular, they, as GLP-1 receptor agonists, exhibit excellent glucose tolerance, thus having a great potential to be used as therapeutic agents for metabolic diseases. Moreover, they exhibit excellent pharmacological safety for cardiovascular systems.

Abstract: An encryption key management method includes: receiving a data registration request from a supplier terminal, determining a data identifier associated with the content data, encrypting a master key with a public key of the supplier terminal, and providing the supplier terminal with the master key encrypted with the public key of the supplier terminal, the data identifier, and a key update count value; receiving a subscription application related to the data identifier from a first subscriber terminal, encrypting the master key with a public key of the first subscriber terminal, and providing the first subscriber terminal with the master key encrypted with the public key of the first subscriber terminal and the key update count value; receiving encrypted content data encrypted with the symmetric key and a hash for the content data from the supplier terminal; and transmitting the encrypted content data and the hash to the first subscriber terminal.

Abstract: In a method for preparing lithium hydroxide, a first mixture of lithium sulfate (Li2SO4) and barium hydroxide (Ba(OH)2) is prepared, a second mixture that is converted into insoluble lithium sulfate (BaSO4) and soluble lithium hydroxide (LiOH) is prepared by roasting the first mixture, the second mixture is dissolved to precipitate the insoluble barium sulfate (BaSO4), the precipitated barium sulfate (BaSO4) is separated by solid-liquid separation, and the solution from which the barium sulfate (BaSO4) is separated is evaporated to obtain lithium hydroxide (LiOH).

Abstract: A method for producing high-purity trimanganese tetraoxide from dust containing manganese includes adding sulfuric acid (H2SO4) and a reductant to manganese dust and leaching manganese therefrom; eliminating primary impurities by adding calcium hydroxide (Ca(OH)2)) to the leached manganese solution acquired from the leaching step; eliminating secondary impurities by adding sulfides to the leached manganese solution from which primary impurities have been eliminated; precipitating manganese by using sodium hydroxide (NaOH) so as to control the pH in the leached manganese solution from which secondary impurities have been eliminated, and cleaning and drying the precipitated specimen; and acquiring high-purity trimanganese tetraoxide by injecting the dried specimen with air and heat-treating same under oxidizing conditions. Thus the present invention allows high-purity trimanganese tetraoxide to be produced from dust containing manganese, for use as material for a secondary battery.

Abstract: Disclosed is a method for manufacturing hydrated magnesium carbonate. Designed to produce high-purity hydrated magnesium carbonate from a solution where calcium ions and magnesium ions coexist, the method can add value to the resources. Compared to conventional techniques, the method can be conducted in a simpler procedure and allows for the production of high purity magnesium oxide (MgO), thus bringing about an economical benefit.

Abstract: A method for producing high-purity manganese sulfate monohydrate from a low-grade composition includes acquiring a primary leached manganese solution by adding sulfuric acid and a reductant to a low-grade manganese-containing composition and leaching manganese therefrom; acquiring a secondary leached manganese solution from which primary impurities have been eliminated by adding calcium hydroxide to the primary leached manganese solution; acquiring a tertiary leached manganese solution from which secondary impurities have been eliminated by adding sulfides to the secondary leached manganese solution; acquiring manganese oxide from precipitating manganese by using sodium hydroxide in the tertiary leached manganese solution so as to control the pH thereof; adding sulfuric acid to the manganese oxide and redissolving; and drying the redissolved manganese oxide and acquiring high-purity manganese sulfate monohydrate.

Abstract: A method for producing high-purity trimanganese tetraoxide from dust containing manganese includes adding sulfuric acid (H2SO4) and a reductant to manganese dust and leaching manganese therefrom; eliminating primary impurities by adding calcium hydroxide (Ca(OH)2)) to the leached manganese solution acquired from the leaching step; eliminating secondary impurities by adding sulfides to the leached manganese solution from which primary impurities have been eliminated; precipitating manganese by using sodium hydroxide (NaOH) so as to control the pH in the leached manganese solution from which secondary impurities have been eliminated, and cleaning and drying the precipitated specimen; and acquiring high-purity trimanganese tetraoxide by injecting the dried specimen with air and heat-treating same under oxidizing conditions. Thus the present invention allows high-purity trimanganese tetraoxide to be produced from dust containing manganese, for use as material for a secondary battery.

Abstract: A method for producing high-purity manganese sulfate monohydrate from a low-grade composition includes acquiring a primary leached manganese solution by adding sulfuric acid and a reductant to a low-grade manganese-containing composition and leaching manganese therefrom; acquiring a secondary leached manganese solution from which primary impurities have been eliminated by adding calcium hydroxide to the primary leached manganese solution; acquiring a tertiary leached manganese solution from which secondary impurities have been eliminated by adding sulfides to the secondary leached manganese solution; acquiring manganese oxide from precipitating manganese by using sodium hydroxide in the tertiary leached manganese solution so as to control the pH thereof; adding sulfuric acid to the manganese oxide and redissolving; and drying the redissolved manganese oxide and acquiring high-purity manganese sulfate monohydrate.