Abstract: A membrane-electrode assembly for a fuel cell of the present invention includes an anode and a cathode facing each other, and a polymer electrolyte membrane interposed therebetween. At least one of the anode and the cathode includes a catalyst layer and an electrode substrate. The catalyst layer includes a catalyst and a porous ionomer. The polymer electrolyte membrane contacts one side of the catalyst layer and the electrode substrate contacts the other side of the catalyst layer.

Abstract: A membrane-electrode assembly includes a polymer electrolyte membrane with an anode and a cathode on opposite sides. Each of the anode and the cathode includes an electrode substrate, and a catalyst layer is formed on at least one of the electrode substrates and includes at least one proton conductive crosslinked polymer. The membrane-electrode assembly may include catalyst layers that are positioned on opposite sides of a polymer electrolyte membrane, either of which includes at least one crosslinked proton conductive polymer.

Abstract: A tamper detection method and a data storage device using the same are provided. The tamper detection method includes sensing a value of pressure applied to a data storage device using a pressure sensor, comparing the sensed pressure value with an initial pressure value sensed at an initial operation time of the data storage device, and detecting malicious tamper by comparing a threshold pressure value varying with the number of loads applied to the data storage device when the sensed pressure value is smaller than the initial pressure value.

Abstract: The present invention relates to a membrane-electrode assembly and a fuel cell system including an anode and a cathode facing each other, the polymer electrolyte membrane being interposed between the anode and the cathode, and the membrane-electrode assembly including an amphiphilic block copolymer including a hydrophobic block and a hydrophilic block of the polymer electrolyte membrane.

Abstract: A polymer electrolyte membrane for a fuel cell, a method of preparing the same, and a fuel cell system comprising the same. The polymer electrolyte membrane includes a metal-bound inorganic ion-conductive salt and an ion-conductive cation exchange resin.

Abstract: A polymer electrolyte membrane for a fuel cell, a method of preparing the same, and a fuel cell system comprising the same. The polymer electrolyte membrane includes a metal-bound inorganic ion-conductive salt and an ion-conductive cation exchange resin.

Abstract: The membrane-electrode assembly of the present invention includes an anode and a cathode facing each other, and a polymer electrolyte membrane interposed therebetween. At least one of the anode and the cathode includes an electrode substrate and a metal catalyst layer disposed thereon. The metal catalyst layer includes a metal catalyst and a liquid crystal material.

Abstract: The polymer electrolyte membrane of the present invention includes polymers having a fluoroalkyl group and a proton conductive group. The present invention also provides a membrane-electrode assembly, a fuel cell system including the polymer electrolyte membrane, and a method of making the polymer electrolyte membrane by a chemical grafting method. The amount of the proton conductive groups in the polymer electrolyte membrane can be controlled, the membrane thickness can be easily controlled, adherence between a polymer electrolyte membrane and an electrode is improved due to the fluoroalkyl of the polymer, and long-term stability of a membrane-electrode assembly is improved.

Abstract: A polymer electrolyte membrane for a fuel cell, a method of preparing the same, and a fuel cell system comprising the same. The polymer electrolyte membrane includes a metal-bound inorganic ion-conductive salt and an ion-conductive cation exchange resin.

Abstract: The present invention relates to a membrane-electrode assembly and a fuel cell system including an anode and a cathode facing each other, the polymer electrolyte membrane being interposed between the anode and the cathode, and the membrane-electrode assembly including an amphiphilic block copolymer including a hydrophobic block and a hydrophilic block of the polymer electrolyte membrane.

Abstract: The polymer electrolyte membrane according to the present invention includes a proton-conducting polymer including metal ions bound to polyalkylene oxide. The polymer electrolyte membrane can save manufacturing cost of a fuel cell and improve proton conductivity and mechanical strength.

Abstract: The electrode for a fuel cell of the present invention includes a catalyst layer and an electrode substrate supporting the catalyst layer, where the electrode substrate includes a hydrophilic region and a hydrophobic region separated from each other. The hydrophilic region and the hydrophobic region that are separated from each other can easily release water produced at the cathode, and thereby prevent clogging of pores of the membrane by water, and smoothly diffuse the reactants resulting in obtaining a high current density.

Abstract: A membrane-electrode assembly for a fuel cell of the present invention includes an anode and a cathode facing each other, and a polymer electrolyte membrane interposed therebetween. At least one of the anode and the cathode includes a catalyst layer and an electrode substrate. The catalyst layer includes a catalyst and a porous ionomer. The polymer electrolyte membrane contacts one side of the catalyst layer and the electrode substrate contacts the other side of the catalyst layer.

Abstract: The present invention relates to a process for preparing optically pure (S)-3-hydroxy-&ggr;-butyrolactone expressed by the following Formula 1 and more particularly, to a process that enables preparing optically pure (S)-3-hydroxy-&ggr;-butyrolactone economically in large quantities, by: (a) Preparing &agr;-(1,4) linked oligosaccharide with adequate sugar distribution by reacting starch which is easily available from natural product with enzyme under a specific condition; and (b) Performing oxidation and cyclization sequentially under a specific condition.

Abstract: The present invention relates to a process for preparing optically pure (S)-3-hydroxy-&ggr;-butyrolactone expressed by the following Formula 1 and more particularly, to a process that enables preparing optically pure (S)-3-hydroxy-&ggr;-butyrolactone economically in large quantities, by:

Abstract: The present invention relates to a continuous process for preparing optically pure (S)-3,4-dihydroxybutyric acid derivatives expressed by the following Formula 1 and more particularly, to the continuous process which enables preparing optically pure (S)-3,4-dihydroxybutyric acid derivatives economically in large quantities, by: (a) Preparing &agr;-(1,4) linked oligosaccharide having adequate sugar distribution by reacting amylopectin which is easily available from natural product with enzyme under a specific condition; and (b) Performing oxidatioin by running basic anion exchange resin with an oxidant to give (S)-3,4-dihydroxybutyric acid-anion exchange resin complex, dissociating the (S)-3,4-dihydroxybutyric acid from anion exchange resin complex and esterification sequentially under a specific condition.  wherein Represents linear or branched alkyl group with 1˜5 carbon atoms.

Abstract: This invention relates to a process for manufacturing an optically active (S)-3,4-epoxybutyric acid salt and more particularly, to a method for manufacturing (S)-3,4-epoxybutyric acid salt expressed by the following formula 1, wherein an optically active (S)-3-hydroxybutyrolactone is employed to undergo an economical ring-opening reaction and epoxvdation so that its chiral center is maintained in an original form, Wherein, R1 represents alkali metal atom, alkaline earth metal atom, alkylamine group or quarternary amine group.

Abstract: The present invention relates to a continuous process for preparing optically pure (S)-3-hydroxy-&ggr;-butyrolactone expressed by the following Formula 1 and more particularly, to a process which enables preparing optically pure (S)-3-hydroxy-&ggr;-butyrolactone economically in large quantities, by: (a) Preparing &agr;-(1,4) linked oligosaccharide with adequate sugar distribution by reacting amylopectin which is easily available from natural product with enzyme under a specific condition; and (b) Performing oxidation, esterification and cyclization sequentially under a specific condition.

Abstract: The present invention relates to a process for preparing optically pure (S)-3,4-dihydroxybutyric acid derivatives expressed by the following Formula 1 and more particularly, to a process that enables preparing optically pure (S)-3,4-dihydroxybutyric acid derivatives economically in large quantities, by: (a) Preparing &agr;-(1,4)-linked oligosaccharide with adequate sugar distribution by reacting amylopectin which is easily available from natural product with enzyme under a specific condition; and (b) Performing oxidation and esterification sequentially under a specific condition. wherein, R represents linear or branched alkyl group with 1˜5 carbon atoms.

Abstract: The present invention relates to a process for preparing optically pure (S)-3-hydroxy-.gamma.-butyrolactone expressed by the following Formula 1 and more particularly, to a process that enables preparing optically pure (S)-3-hydroxy-.gamma.-butyrolactone economically in large quantities, by:(a) Preparing .alpha.-(1,4) linked oligosaccharide with adequate sugar distribution by reacting amylopectin which is easily available from natural product with enzyme under a specific condition; and(b) Performing oxidation, esterification and cyclization sequentially under a specific condition.