Abstract: In the case of a gas in which several gases are mixed, a type and concentration of the gas may be incorrectly measured when measured using only an optical band-pass filter. The invention of the present application is directed to providing a technology in which a plurality of broadband band-pass filters having overlapping regions are provided to calculate a magnitude of absorption for each wavelength band for light passing through each broadband band-pass filter, thereby identifying the presence of a gas of interest and the presence of a gas other than the gas of interest.

Abstract: A method for preparing a molybdenum-bismuth-based composite metal oxide.

Abstract: The present invention relates to a bundle-type carbon nanotube which has a bulk density of 25 to 45 kg/m3, a ratio of the bulk density to a production yield of 1 to 3, and a ratio of a tap density to the bulk density of 1.3 to 2.0, and a method for preparing the same.

Abstract: The present invention relates to a bundle-type carbon nanotube which has a bulk density of 25 to 45 kg/m3, a ratio of the bulk density to a production yield of 1 to 3, and a ratio of a tap density to the bulk density of 1.3 to 2.0, and a method for preparing the same.

Abstract: The present invention relates to a catalyst for preparing acrolein and acrylic acid, and a preparation method thereof. The catalyst according to the present invention can be uniformly packed in a reactor and the collapse of the catalyst can be minimized because it has excellent mechanical properties, and it can be stably used for a long period of time.

Abstract: The present invention relates to a method for preparing a catalyst and a method for preparing unsaturated carboxylic acid using the catalyst prepared according to the preparation method. According to the method for preparing a catalyst, unsaturated carboxylic acid can be provided from an unsaturated aldehyde with a high conversion rate and selectivity.

Abstract: The present invention relates to a method for producing unsaturated aldehydes and unsaturated carboxylic acids. According to the present invention, a method for producing unsaturated aldehydes and unsaturated carboxylic acids which can impart activity and control temperature independently in fixed catalyst layer zones in a shell-and-tube reactor, thereby exhibiting improved yield and operation stability, is provided.

Abstract: The present invention relates to a method for producing unsaturated aldehydes and unsaturated carboxylic acids. According to the present invention, a method for producing unsaturated aldehydes and unsaturated carboxylic acids which can impart activity and control temperature independently in fixed catalyst layer zones in a shell-and-tube reactor, thereby exhibiting improved yield and operation stability, is provided.

Abstract: The present invention relates to a method for preparing a catalyst and a method for preparing unsaturated carboxylic acid using the catalyst prepared according to the preparation method. According to the method for preparing a catalyst, unsaturated carboxylic acid can be provided from an unsaturated aldehyde with a high conversion rate and selectivity.

Abstract: The present invention relates to a high-performance polyoxometalate catalyst and a method of preparing the same. More particularly, the present invention provides a high-performance polyoxometalate catalyst, the activity and selectivity of which may be improved by controlling the content of vanadium and the like and which has superior reproducibility and may unsaturated carboxylic acid from unsaturated aldehyde in a high yield for a long time, a method of preparing the same, and the like.

Abstract: Provided is a piezoelectric vibrating device including a case provided with a certain space therein, a piezoelectric vibrating member provided in the case and vibrating according to an applied voltage, a weight member provided in the case and connected to a part of the piezoelectric vibrating member in a vibration direction of the piezoelectric vibrating member, and a limitation member for limiting movement of the weight member.

Abstract: The present invention relates to a high-performance polyoxometalate catalyst and a method of preparing the same. More particularly, the present invention provides a high-performance polyoxometalate catalyst, the activity and selectivity of which may be improved by controlling the content of vanadium and the like and which has superior reproducibility and may unsaturated carboxylic acid from unsaturated aldehyde in a high yield for a long time, a method of preparing the same, and the like.

Abstract: Disclosed are a high-performance polyoxometalate catalyst and a method of preparing the same. More particularly, disclosed are a high-performance polyoxometalate catalyst which may enhance activity and selectivity by controlling the content of vanadium, etc. exhibits superior reproducibility, and may produce unsaturated carboxylic acid with high yield and long lifespan from unsaturated aldehyde, and a method of preparing the same.

Abstract: Disclosed are a high-performance polyoxometalate catalyst and a method of preparing the same. More particularly, disclosed are a high-performance polyoxometalate catalyst which may enhance activity and selectivity by controlling the content of vanadium, etc. exhibits superior reproducibility, and may produce unsaturated carboxylic acid with high yield and long lifespan from unsaturated aldehyde, and a method of preparing the same.

Abstract: The present invention relates to a catalyst for preparing acrolein and acrylic acid, and a preparation method thereof. The catalyst according to the present invention can be uniformly packed in a reactor and the collapse of the catalyst can be minimized because it has excellent mechanical properties, and it can be stably used for a long period of time.

Abstract: The present invention relates to a catalyst for preparing acrolein and acrylic acid, and use of the same. The catalyst according to the present invention can be uniformly packed in the reactor and collapse of the catalyst can be minimized because it has excellent mechanical properties, and it can lower initial pressure of the reaction by securing stable pore spaces and can be stably used for a long period of time. In addition, the preparation method of acrolein and acrylic acid according to the present invention can provide more improved production efficiency by using the catalyst.

Abstract: Provided is a piezoelectric vibrating device including a case provided with a certain space therein, a piezoelectric vibrating member provided in the case and vibrating according to an applied voltage, a weight member provided in the case and connected to a part of the piezoelectric vibrating member in a vibration direction of the piezoelectric vibrating member, and a limitation member for limiting movement of the weight member.

Abstract: The present invention provides a Mo—Bi—Nb based composite metal oxide (with the proviso that Te is not included); a method for producing (meth)acrylic acid from at least one reactant selected from the group consisting of propylene, propane, isobutylene, t-butyl alcohol and methyl-t-butyl ether, in which a Mo—Bi—Nb based composite metal oxide (with the proviso that Te is not included) is used as a catalyst; and a reactor used for producing (meth)acrylic acid from at least one reactant selected from the group consisting of propylene, propane, isobutylene, t-butyl alcohol and methyl-t-butyl ether, in which a Mo—Bi—Nb based composite metal oxide (with the proviso that Te is not included) is used as a catalyst. Further, the present invention provides a method for producing the (meth)acrylic acid without any additional process of converting (meth)acrolein into (meth)acrylic acid.

Abstract: The present invention provides a Mo—Bi—Nb based composite metal oxide (with the proviso that Te is not included); a method for producing (meth)acrylic acid from at least one reactant selected from the group consisting of propylene, propane, isobutylene, t-butyl alcohol and methyl-t-butyl ether, in which a Mo—Bi—Nb based composite metal oxide (with the proviso that Te is not included) is used as a catalyst; and a reactor used for producing (meth)acrylic acid from at least one reactant selected from the group consisting of propylene, propane, isobutylene, t-butyl alcohol and methyl-t-butyl ether, in which a Mo—Bi—Nb based composite metal oxide (with the proviso that Te is not included) is used as a catalyst. Further, the present invention provides a method for producing the (meth)acrylic acid without any additional process of converting (meth)acrolein into (meth)acrylic acid.

Abstract: The present invention relates to a method of preparing a heteropoly acid catalyst used for the production of methacrylic acid by gas phase oxidation of methacrolein, more precisely a method of preparing a heteropoly acid catalyst comprising the steps of preparing a slurry by adding metal precursors and ammonium salt to protonic acid Keggin-type heteropoly acid aqueous solution and stirring thereof; and drying, molding and firing the slurry to give a catalyst. The present invention provides a method of preparing a heteropoly acid catalyst exhibiting high methacrolein conversion rate and methacrylic acid selectivity without pre-firing process by using high purity protonic acid Keggin-type heteropoly acid and ammonium salt.