Abstract:
The present invention relates to a zinc ferrite catalyst, a method of producing the same, and a method of preparing 1,3-butadiene using the same. Specifically, the present invention relates to a zinc ferrite catalyst which is produced in a pH-adjusted solution using a coprecipitation method, a method of producing the same, and a method of preparing 1,3-butadiene using the same, in which the 1,3-butadiene can be prepared directly using a C4 mixture including n-butene and n-butane through an oxidative dehydrogenation reaction. The present invention is advantageous in that 1,3-butadiene can be obtained at a high yield directly using a C4 fraction without performing an additional process for separating n-butene, as a reactant, from a C4 fraction containing impurities.
Abstract:
A process and apparatus for separating an olefin from mixed gases containing light olefins is provided. The process includes adsorbing the olefin of an olefin-containing mixed gas in an adsorption column packed with an adsorbent selectively adsorbing the olefin; discharging gases other than the olefin through the outlet of the adsorption column; desorbing the adsorbed olefin by displacement using a desorbent, and separating the olefin from the desorbent, thereby producing a high-purity olefin. The apparatus includes adsorption columns packed with an adsorbent selectively adsorbing an olefin, and at least two distillation columns for separating an olefin/desorbent mixture and an olefin poor stream/desorbent into their components. If the olefin concentration of the off-gas from an olefin rinse step is higher than that of a raw material gas, recovering the olefin from the off-gas is carried out before or after the adsorption step.
Abstract:
A method of producing 1,3-butadiene by the oxidative dehydrogenation of n-butene using a continuous-flow dual-bed reactor designed such that two kinds of catalysts charged in a fixed-bed reactor are not physically mixed. More particularly, a method of producing 1,3-butadiene by the oxidative dehydrogenation of n-butene using a C4 mixture including n-butene and n-butane as reactants and using a continuous-flow dual-bed reactor in which a multi-component bismuth molybdate catalyst and a zinc ferrite catalyst having different reaction activity in the oxidative dehydrogenation reaction of n-butene isomers (1-butene, trans-2-butene, cis-2-butene).
Abstract:
A display substrate includes an insulating substrate, a first gate line, a first lower electrode, a second lower electrode, a first upper electrode, and a second upper electrode. The insulating substrate includes a first pixel region and a second pixel region located at a first direction from the first pixel region. The first gate line extends in a second direction crossing the first direction on the insulating substrate. The first and the second lower electrodes are in the first and the second pixel regions, respectively. The first upper electrode overlaps the first lower electrode in the first pixel region and includes a first slit pattern extending in a third direction different from the first and the second directions. The second upper electrode overlaps the second lower electrode in the second pixel region and includes a second slit pattern extending in a fourth direction different from the first to third directions.
Abstract:
A liquid crystal display (LCD) apparatus and a method of manufacturing the same include a seal line having two protrusions, one of the protrusions having a liquid crystal (LC) injection hole. Moreover, the LCD apparatus having the seal line constitutes a closed loop. The display apparatus and the manufacturing method thereof increase production yields because the number of apparatus substrates for the display apparatus obtained from a mother substrate is increased by minimizing a distance between two adjacent apparatus substrates on the mother substrate. The method of manufacturing an exemplary LCD apparatus includes a one drop filling method or a vacuum injection method.
Abstract:
A semiconductor device for providing a reliable data valid window includes a drive control unit configured to output a driving power control signal in response to an internal clock and a command signal; a sub-drive voltage supply unit configured to supply sub-drive voltages; a main drive unit configured to generate a delay-locked loop (DLL) clock by driving the internal clock with a main drive voltage; a sub-drive unit configured to drive the internal clock with the sub-drive voltage in response to the driving power control signal; and a data output driver configured to drive and output a data signal in sync with the DLL clock, wherein the main drive unit and the sub-drive unit share their output terminal.
Abstract:
The present invention relates to a zinc ferrite catalyst, a method of producing the same, and a method of preparing 1,3-butadiene using the same. Specifically, the present invention relates to a zinc ferrite catalyst which is produced in a pH-adjusted solution using a coprecipitation method, a method of producing the same, and a method of preparing 1,3-butadiene using the same, in which the 1,3-butadiene can be prepared directly using a C4 mixture including n-butene and n-butane through an oxidative dehydrogenation reaction. The present invention is advantageous in that 1,3-butadiene can be obtained at a high yield directly using a C4 fraction without performing an additional process for separating n-butene, as a reactant, from a C4 fraction containing impurities.
Abstract:
A clock synchronization circuit and a clock synchronization method which generate an internal clock synchronized to an external clock is presented. The circuit and method include a clock enable control circuit generating a clock enable control signal controlled by a power supply voltage and a power-down signal. The circuit and method also include a clock generating circuit receiving an input clock which selectively generates an internal clock synchronized to an external clock using the input clock using the clock enable control signal. Whereupon, a locking failure can be prevented by performing a phase update operation selectively in accordance with whether the power supply voltage is varied or not in the power-down mode. Furthermore, current consumption can be reduced by controlling phase update time in accordance with a variable magnitude of the power supply voltage.
Abstract:
A frequency multiplier increases the frequency of an external clock and outputs a high-frequency external clock. A period determinator determines whether or not a predetermined period of the external clock elapses and outputs a period determination signal. A frequency selector selectively transmits the external clock or the high-frequency external clock to a clock input buffer under the control of a power-up signal and the period determination signal.
Abstract:
An internal voltage generator includes an oscillator, a cycle control unit and a voltage generator. The oscillator periodically generates a pulse-shaped oscillation signal. The cycle control unit bypasses the oscillation signal to an output node, or selectively controls the cycle of the oscillation signal and output a controlled oscillation signal to the output node. The voltage generator generates an internal voltage in response to the oscillation signal or the controlled oscillation signal received through the output node. The cycle of the controlled oscillation signal is shorter than that of the oscillation signal. The operating speed of the voltage generator when receiving the controlled oscillation signal is faster than that of the voltage generator when receiving the oscillation signal.