Abstract: A method for recovering high-purity magnesium sulfate includes: a pre-precipitation step of mixing an alkali precipitant and seawater; a concentration step of reacting a precipitate formed in the pre-precipitation step with sulfuric acid, followed by filtering to obtain a first eluate; a first precipitation step of adding ethanol to the first eluate, and then removing a first precipitated solid to obtain a second eluate; and a second precipitation step of precipitating magnesium sulfate solid by further adding ethanol to the second eluate from which the first precipitated solid has been removed.

Abstract: There is provided a solar power generator having a variable shape which can secure a maximum solar power generation area by being unfolded horizontally and upward in the case of performing solar power generation and can be transformed to have a minimum volume by being transformed into a box shape in the case of not performing solar power generation. The solar power generator includes a base frame, four solar panel members for forming a box which are respectively coupled to four sides of the base frame, a rotation drive source for rotating each of the four solar panel members, a tube member, a lower surface of which is fixed to a center portion of an upper surface of the base frame, an air injection and discharge part, a top plate for the tube member, and a plurality of solar panel assemblies for tube member sidewalls.

Abstract: There is provided a method for producing calcium carbonate by utilizing seawater and calcinated shells, and calcium carbonate and a calcium agent produced thereby. The method for producing calcium carbonate includes: eluting calcium by mixing calcinated shells, seawater, and sugar; and generating calcium carbonate by injecting carbon dioxide into the calcium eluate generated in the eluting calcium. The calcium agent includes vaterite-type calcium carbonate.

Abstract: There is provided a solar power generator having a variable shape which can secure a maximum solar power generation area by being unfolded horizontally and upward in the case of performing solar power generation and can be transformed to have a minimum volume by being transformed into a box shape in the case of not performing solar power generation. The solar power generator includes a base frame, four solar panel members for forming a box which are respectively coupled to four sides of the base frame, a rotation drive source for rotating each of the four solar panel members, a tube member, a lower surface of which is fixed to a center portion of an upper surface of the base frame, an air injection and discharge part, a top plate for the tube member, and a plurality of solar panel assemblies for tube member sidewalls.

Abstract: A load area tracking type ship battery management system is proposed. The ship battery management system includes a calculation unit for generating SFOC curve data periodically by calculating specific fuel oil consumption (SFOC) versus ship load factors, a LF setting unit for specifying a ship load factor point as a light load factor (LF) point in the SFOC curve data, a HF setting unit for specifying a ship load factor point as a heavy load factor (HF) point, a Emax setting unit configured to obtain a highest point (Emax) of generator efficiency, a Rmin setting unit for calculating battery charging efficiency in the LF to obtain a smallest load factor point (Rmin) bearing a generator load by battery charging, and a Rmax setting unit for calculating battery charging efficiency in the HF to obtain a highest load factor point (Rmax) bearing the generator load by battery discharging.

Abstract: Disclosed herein are an apparatus and method for decoding a bootstrap signal. The apparatus for decoding a bootstrap signal according to an embodiment of the present invention includes an operation unit for calculating the relative cyclic shift and the channel gain estimate of a received bootstrap signal and correcting the channel gain estimate using the relative cyclic shift, and a decoding unit for decoding the bootstrap signal using the corrected channel gain estimate.

Abstract: A buoy system according to one embodiment of the present invention includes a buoy body configured to provide buoyance; a fixing belt configured to fasten the buoy body to a ship structure; an auto-release unit configured to release the buoy body to be buoyed by releasing the fixing belt when a predetermined water pressure is reached; and an auto-reel chain box fixed to the ship structure, being opened in conjunction with releasing of the fixing belt, and including a chain which is reeled out when the buoy body is buoyed, wherein the auto-reel chain box comprises: a weight provided in the auto-reel chain box and being movable upward and downward according to a water pressure and buoyance; a pulley provided in the auto-reel chain box, having the chain wounded thereon and a plurality of teeth on an outer circumferential surface thereof; and a shaft having one end connected to the weight and the other end engaging with the teeth to fix the pulley and provided to be rotatable around a portion fixed in the auto-re

Abstract: Disclosed herein are an apparatus and method for decoding a bootstrap signal. The apparatus for decoding a bootstrap signal according to an embodiment of the present invention includes an operation unit for calculating the relative cyclic shift and the channel gain estimate of a received bootstrap signal and correcting the channel gain estimate using the relative cyclic shift, and a decoding unit for decoding the bootstrap signal using the corrected channel gain estimate.

Abstract: Disclosed is an apparatus for decreasing a thrust of a radial flow turbine. The apparatus includes a rotary shaft having an axial through-hole in the interior thereof, a rotor assembled in the rotary shaft and having a rotor hub and rotor blades formed on an outer peripheral surface thereof, a casing configured to isolate the rotary shaft and the rotor from the outside, and a shaft seal configured to maintain a seal between the rotary shaft and the casing.

Abstract: Disclosed is an apparatus for decreasing a thrust of a radial flow turbine. The apparatus includes a rotary shaft having an axial through-hole in the interior thereof, a rotor assembled in the rotary shaft and having a rotor hub and rotor blades formed on an outer peripheral surface thereof, a casing configured to isolate the rotary shaft and the rotor from the outside, and a shaft seal configured to maintain a seal between the rotary shaft and the casing.

Abstract: A terahertz band filter for filtering, in a frequency band, a terahertz wave propagating between a pair of metal plates with an upper parallel surface facing a lower parallel surface includes a sheet parallel to the upper and lower parallel surfaces, which is disposed between the metal plates and is spaced apart therefrom, and at least one slit located in the sheet to face the upper and lower parallel surfaces, wherein the sheet comprises a single slit to function as a notch filter for blocking in a specific frequency band.

Abstract: A terahertz band filter for filtering, in a frequency band, a terahertz wave propagating between a pair of metal plates with an upper parallel surface facing a lower parallel surface includes a sheet parallel to the upper and lower parallel surfaces, which is disposed between the metal plates and is spaced apart therefrom, and at least one slit located in the sheet to face the upper and lower parallel surfaces, wherein the sheet comprises a single slit to function as a notch filter for blocking in a specific frequency band.