Abstract:
A wing-in-ground (WIG) craft having a streamlined WIG craft body, a main wing mounted on opposite sides of the WIG craft body, a pylon mounted on the WIG craft body or the main wing, and a combined thruster having a primary thruster unit mounted on the pylon, and an auxiliary thruster unit serving as a booster used when the WIG craft takes off from a water surface.
Abstract:
The wing structure of a WIG vehicle comprising left and right main wings, left and right downward wings, and a rudder unit. The left and right main wings protrude out from the central portions of left and right sides of the WIG vehicle. The panel of the main wing is flat and tapers successively toward the lateral edge, whereof the cross-section is airfoil-shaped and has the shape of a tadpole. The panel shaped left and right downward wings are connected with both ends of the left and right main wings without a joint and are formed heading downward to suppress vortex and guidance drag generated in both ends of the main wings. The rudder units are mounted on the rear surface of the left and right downward panels with a slight gap in order to compensate asymmetry between left and right lateral ends caused by movement under control of the fuselage driving unit of the WIG vehicle and to turn the fuselage left or right. Therefore, the wing structure of the WIG vehicle is capable of minimizing vortex and guidance drag generated in both ends of the left and right main wings by maximizing ground effect. Additionally, the wing structure has advantages for absorbing impact from the fuselage when taking off and landing and stabilizing horizontal disturbance of the fuselage because the left and right downward wings occupy much more volume than a winglet.
Abstract:
A body having a fuselage, a wing unit including a main wing, and a propulsion unit including an engine. The wing unit includes a main wing protruding out from the lateral center of the WIG vehicle fuselage, a downward wing which is vertically and downwardly installed on the outer tip of the main wing, and a canard which protrudes out horizontally from the front end of the fuselage, which is in the moving direction of the WIG vehicle from the main wing. The canard includes a horizontal stabilization plate which has a stationary horizontal panel structure, and a variable flap which is installed to face the rear surface of the horizontal stabilization plate. In the lateral cross section shape, the front surface portion including the leading edge is round at a proper thickness to prevent clearance generated by turning of the canard, the trailing edge is sharp and straight, and the thickness of a portion between the thickest portion and rear portion narrows. The lateral cross section of the entire horizontal stabilizer is airfoil-shaped. Accordingly, the invention is able to resolve the design problem of the horizontal stabilizer caused by a ground effect because the WIG vehicle comprises a canard for stabilizing vertical disturbance instead of a horizontal stabilizer.
Abstract:
The present invention relates to a novel protein having O-acetylhomoserine sulfhydrylase activity, a mutant protein thereof, a polynucleotide encoding the same, a recombinant vector comprising the polynucleotide, a microorganism transformed with the recombinant vector, and a method for producing methionine or acetic acid using the protein. The production method of the present invention has the advantage of producing L-methionine and acetic acid cost-effectively through having higher conversion rate and reduced reaction time compared to the existing methods, and it can minimize the amount of enzyme homogenate added when using the mutant protein, thereby easily producing L-methionine and acetic acid at high yield.
Abstract:
The present invention relates to a microorganism producing L-methionine precursor, O-acetylhomoserine, and a method of producing L-methionine precursor using the microorganism.
Abstract:
The present invention relates to a polypeptide that is modified to have homoserine O-acetyltransferase activity, and in particular, the present invention provides a modified polypeptide having homoserine O-acetyltransferase activity, in which the amino acid at position 111 of a polypeptide having homoserine succinyltransferase activity is substituted with other amino acid.
Abstract:
The present invention relates to a novel protein having O-acetylhomoserine sulfhydrylase activity, a mutant protein thereof, a polynucleotide encoding the same, a recombinant vector comprising the polynucleotide, a microorganism transformed with the recombinant vector, and a method for producing methionine or acetic acid using the protein. The production method of the present invention has the advantage of producing L-methionine and acetic acid cost-effectively through having higher conversion rate and reduced reaction time compared to the existing methods, and it can minimize the amount of enzyme homogenate added when using the mutant protein, thereby easily producing L-methionine and acetic acid at high yield.
Abstract:
The present invention relates to a polypeptide that is modified to have homoserine O-acetyltransferase activity, and in particular, the present invention provides a modified polypeptide having homoserine O-acetyltransferase activity, in which the amino acid at position 111 of a polypeptide having homoserine succinyltransferase activity is substituted with other amino acid.
Abstract:
The present invention relates to a method for increasing L-methionine productivity and organic acid productivity. More particularly, the present invention relates to a method which involves adding a mixture containing methyl mercaptan and dimethyl sulfide at a appropriate ratio to O-acetyl homoserine or O-succinyl homoserine and to an enzyme having an activity of converting methionine precursor into L-methionine, so as to perform an enzyme reaction, to thereby improve the conversion rate of L-methionine and organic acid from the L-methionine precursor, and thus increasing L-methionine yield as compared to conventional method.
Abstract:
The present invention relates to a microorganism producing L-methionine precursor, O-acetylhomoserine, and a method of producing L-methionine precursor using the microorganism.