摘要:
Disclosed is a method for selective dealkylation of alkyl-substituted C9+ aromatic compounds using a bimodal porous dealkylation catalyst at a low temperature. The catalyst has a bimodal porous structure including both mesopores and micropores. The catalyst includes a crystalline aluminosilicate and a metal. The catalyst is highly active at a low temperature. According to the method, C9+ aromatic compounds substituted with at least one C2+ alkyl group as by-products formed by xylene production can be selectively dealkylated and converted to BTX, etc. on a large scale within a short time. In addition, the method is an environmentally friendly process entailing reduced waste treatment cost when compared to conventional mesitylene production methods. Therefore, high value-added mesitylene can be separated from low value-added C9+ aromatic compounds at lower cost compared to conventional methods. Furthermore, the supported metal catalyst is easy to recover after dealkylation and is recyclable, thereby contributing to reduced cost.
摘要:
Disclosed is a method for selective dealkylation of alkyl-substituted C9+ aromatic compounds using a bimodal porous dealkylation catalyst at a low temperature. The catalyst has a bimodal porous structure including both mesopores and micropores. The catalyst includes a crystalline aluminosilicate and a metal. The catalyst is highly active at a low temperature. According to the method, C9+ aromatic compounds substituted with at least one C2+ alkyl group as by-products formed by xylene production can be selectively dealkylated and converted to BTX, etc. on a large scale within a short time. In addition, the method is an environmentally friendly process entailing reduced waste treatment cost when compared to conventional mesitylene production methods. Therefore, high value-added mesitylene can be separated from low value-added C9+ aromatic compounds at lower cost compared to conventional methods. Furthermore, the supported metal catalyst is easy to recover after dealkylation and is recyclable, thereby contributing to reduced cost.
摘要:
Provided is a method of controlling voltage levels of overall outputs in a combinational mode, in an ultrasonic diagnosis apparatus that may operate in the combinational mode. A judging unit of the ultrasonic diagnosis apparatus may judge whether at least a part of individual modes included in the combinational mode exceeds a threshold determined by safety standards, in accordance with an inputted overall output voltage level control command. When it is judged that at least the part of the individual modes exceeds the threshold determined by the safety standards, an output control unit may maintain an individual output with respect to the at least the part, among the voltage levels that may be outputted from a transducer, to be below the threshold, so that the individual output may be below the standards in accordance with the overall output control command.
摘要:
A hinge apparatus includes a substantially cylindrical holder having at least one guide hole with a predetermined degree slope that extends in a longitudinal direction. A hinge shaft includes a substantially cylindrical surface configured to linearly move in the longitudinal direction of the holder. A guide pin has an end located inside the guide hole and is configured to extend through the cylindrical surface of the hinge shaft. Therefore, when the hinge shaft moves linearly in the holder, the guide pin moves along the guide hole so that the hinge shaft rotates in the holder.
摘要:
A memory device for adjusting a write recovery time includes a synchronous write recovery time controlling block which receives a control signal for performing an auto-precharge operation and delays out the control signal as long as a certain clock section of the operational clock corresponding to the write recovery time, an asynchronous write recovery time controlling block for delaying out the control signal coupled thereto as long as a fixed delay time corresponding to the write recovery time, a selecting block for choosing the synchronous write recovery time controlling block or the asynchronous write recovery time controlling block, and an auto-precharge controlling block which outputs as an auto-precharge execution signal used in performing the auto-precharge operation a signal outputted from the synchronous write recovery time controlling block or the asynchronous write recovery time controlling block in response to a write command.
摘要:
An integrated circuit memory device includes first and second input buffers, and first and second input bus lines corresponding to the first and second input buffers. The first input buffer is connected to the first input bus line while a transfer gate is provided between the second input buffer and the second input bus line. The transfer gate connects the second input buffer with the second input bus line during a data input-output operation and disconnects the second input buffer from the second input bus line during a memory test operation. A coupling circuit couples the first and second input bus lines during the memory test operation so that a data value from the first input bus line is inverted and applied to the second input bus line responsive to a first value of an address buffer output during the memory test operation. The data value from the first input line is applied to the second input bus line without inversion responsive to a second value of the address buffer output during the memory test operation. Furthermore, a coupling circuit isolates the first and second input bus lines during the data input-output operation.
摘要:
Provided is a method of controlling voltage levels of overall outputs in a combinational mode, in an ultrasonic diagnosis apparatus that may operate in the combinational mode. A judging unit of the ultrasonic diagnosis apparatus may judge whether at least a part of individual modes included in the combinational mode exceeds a threshold determined by safety standards, in accordance with an inputted overall output voltage level control command. When it is judged that at least the part of the individual modes exceeds the threshold determined by the safety standards, an output control unit may maintain an individual output with respect to the at least the part, among the voltage levels that may be outputted from a transducer, to be below the threshold, so that the individual output may be below the standards in accordance with the overall output control command.
摘要:
A pulse control device is maintained with a constant pulse width corresponding to a change of process or temperature. The pulse control device comprises a fuse set for selectively outputting a delay increase signal and a delay decrease signal that have a different state based on a cutting or non-cutting state of a fuse on which information on a change of process is programmed, and a pulse generator provided with a plurality of delay cells with predetermined time delay for selectively increasing or decreasing the number of the plurality of delay cells depending on the delay increase signal and the delay decrease signal to generate an internal clock with a pulse width corresponding to the number of the increased or decreased delay cells.
摘要:
A portable communication device including a first housing and second housing, wherein the second housing is connected to the first housing so that it is rotatable around a first hinge axis while facing a top surface of the first housing to allow movement toward or away from the first housing. The device also includes a third housing connected to the second housing so that it is rotatable around the first hinge axis while facing the top surface of the first housing to allow movement toward or away from the first housing, and rotatable around a third hinge axis to allow rotational movement of a display. A battery pack, serving as a grip, is connected to the first housing so that it is rotatable around a third hinge axis while facing a bottom surface of the first housing to allow movement toward or away from the first housing. A sensing unit is provided to sense whether the battery pack is rotated.