• 대한화학회지
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• 제4권1호
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• pp.67-69
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• 1957

The synthetic method of tetramethyl-4,4'-diaminobenzophenone accomplished by W. Michler is to pass gaseous carbonyl chloride in dimethylaniline until theoretical value of weight increases at room temperature and synthesize the ketone by heating it at above 120$^{\circ}C. In the result of the experiment to synthesize the ketone by Michler's method, it was observed that if gaseous phosgen was to be used at room temperature according to the method, the gas inhaling tube would be closed up by reaction products (gruel-like crystals) before the theoretical amount of gases passed in and causing difficulty for gas to be produce or inhaled With a view to remove the difficulty, the author examined an article published by W. Michler entitled. "The synthesis of organic acid with phosgen" and guessing that the use of liquid phosgen could overcome the difficulty, succeeded in synthesizing the substance in good yield easily by reacting dimethylaniline with phosgen that was condensed into liquid state.

• 한국연초학회지
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• 제21권1호
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• pp.102-108
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• 1999

This study was conducted to evaluate the ventilation to remove gases, vapor and particles of environmental tobacco smoke(ETS) in a closed room. The ventilation rate choosed were 0.445 ㎥/min, 0.528 ㎥/min, and 0.625 ㎥/min. ETS components measured were total suspended particle(TSP), ultraviolet particulate matter(UVPM), fluorescent particulate matter(FPM), solanesol, carbon dioxide($CO_2$), carbon monoxide(CO), nicotine, and 3-ethenylpyri-dine(3-EP). The concentration of ETS components measured rapidly decreased as increasing ventilation rate, but the removal efficiency by ventilation was different from each ETS compounds. The $CO_2$, and CO, gaseous components of ETS, were dominant components to be removed from the room by ventilation. The ventilation with 0.528 ㎥/min for 1 hr was enough to remove over 99% of those gaseous components. Nicotine and 3-EP needed the ventilation for 2 hrs to reduce over 95 % of those components. As the same ventilation rate, 99 % of TSP and solanesol concentration were removed from the room within 2 hrs, UVPM and FPM concentration decreased 90 %.

• 연구논문집
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• 통권29호
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• pp.91-99
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• 1999

Fatigue crack growth behaviors of Cr-Mo steels developed recently for thick-wall pressure vessel were investigated. Experiments in accordance with ASTM E647 standard were performed for 1/2 inch CT specimens of $2^(1/4)$Cr-1Mo and 3Cr-IMo steels in gaseous environments, hydrogen gas of 10 atm, 1 atm and argon gas of 1 atm. Fatigue crack growth rates were observed and effects of gaseous hydrogen and argon on the crack growth behavior were discussed.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1199-1202
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• 2005

Inside of working PDP, there exist highly reactive conditions in the gap between two glass panels. MgO film and phosphor have been investigated as a function of discharge, also phosphor and sealing frits have been investigated as a function of temperature. Changes of impurity generation of MgO, phosphor and sealing fits were measured by using x-ray photoelectron spectroscopy (XPS) and quadropole mass spectroscopy (XPS) and quadropole mass spectrometer (QMS). Impurities such as CO, $CO_2$, OH and $H_2O$ were increased during discharge and heating treatment. Gaseous impurities such as carbon compounds and water deteriorated the characteristics of PDP operation during of lifetime. So metal is used to remove the impurities of phosphor and sealing frits during hearting, the result that the quantity of the impurities such as carbon monoxide and water was reduced.

• 천문학논총
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• 제7권1호
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• pp.63-69
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• 1992

We have systematically investigated the X-ray spectra of normal galaxies, by using the Imaging Proportional Counter (IPC) data in the Einstein data base. We employed the X-ray color-color plot as well as the standard model fitting method which requires higher signal to noise ratio. We discuss X-ray emission mechanisms in terms of their spectral properties and the signature of cooling flows which are most likely present in X-ray bright early type galaxies. On the average, fits to absorbed thermal spectra show that the X-ray emission temperature of spirals is higher than that of ellipticals. This is consistent with our understanding that accreting binaries are a major X-ray source in spirals, while extended gaseous halos are present in ellipticals. The emission temperature becomes lower with increasing X-ray to optical luminosity ratio in E and S0 galaxies. This result is what we would expect if the emission of X-ray faint early type galaxies consists of a large evolved stellar component, while the gaseous emission becomes dominant in X-ray brighter galaxies. We also find a cool, self-absorbed core in some early type galaxies, which directly indicates the presence of cooling flows in such galaxies.

• 천문학회보
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• 제42권1호
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• pp.31.2-31.2
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• 2017

The central regions of barred-spiral galaxies contain interesting gaseous structures such as dust lanes and nuclear rings with intense star formation. While our previous studies were useful in understanding the formation of these structures star formation history, they were limited to 2D isothermal galaxies in which the stellar disk and halo are modeled by fixed gravitational potentials. To study the effects of bar growth as well as the vertical dimension, we use the mesh-free hydrodynamic code named GIZMO and run 3D simulations by treating the stellar disk and halo as being live. We find that the new 3D models form the gaseous features similarly to the previous 2D models, although the detailed formation processes are quite different. For example, a ring has a large radius when it first forms and shrinks over time in the previous 2D models. In the 3D live-potential models, however, a ring forms small and grows in size with time. We present the results of the new simulations and discuss them in comparison with the previous 2D results.

• 한국응용과학기술학회지
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• 제14권2호
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• pp.35-40
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• 1997

The organization of phospholipid monolayers and their monolayers mixed with fatty acid containing azobenzene on the water surface was investigated by means of the displacement current measurement method. The phase transition from the gaseous phase to the gaseous-fluid phase which accompanies the polar ordering of phospholipid molecules was detected in the range of immeasurably low surface pressure. The molecular area which gives the onset of the transition was determined for phospholipid monolayers. The Maxwell displacement current(MDC) pulses were generated across mixed monolayers due to the photoisomerization of fatty acid containing azobenzene by alternating irradiation of ultraviolet and visible light, because the condensation of pure azobenzene monolayers was loosened by the introduction of phospholipids into the monolayers. The displacement currents generated during light irradiation were also investgated in connection with monolayer compression cycles. It was found that the maximum of MDC appeared at the molecular area just before the initial rise of surface pressure in compression cycles.

• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.145-152
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• 2003

The objective of the present study is to develop methodology for the assesment of combustion stability of liquid rocket injectors. To simulate actual combustion occurring inside of a thrust chamber, a full-scale injector has been employed in the study, which burns gaseous oxygen and mixture of methane and propane. The main idea of the experiment is that the mixing mechanism is considered as a dominant factor significantly affecting combustion instability in a full-scale thrust chamber. Single & multi split triplet injectors have been used with an open-end cylindrical combustion chamber. The characteristics revealed by excited dynamic pressures in gaseous combustion show degrees of relative acoustic damping depending on operating conditions. Upon test results, the direct comparison between various types of injectors can be realized for the selection of the best design among prospective injectors.

• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.139-143
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• 2003

Study on the ignition characteristics of combustor and gas generator for LOx-kerosene liquid rocket engine was performed experimentally through a series of combustion tests of sub-scale engine combustor and gas generator. Characteristic of gas-torch ignitor based on gaseous methane and gaseous oxygen was compared with hypergolic ignition using propellant tri-ethyl-aluminium. Gas-torch ignitor showed good performance on igniting sub-scale liquid rocket engine combustor and gas generator. It was observed that the ignition delay is also affected by the extent of nitrogen in the combustion chamber.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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• pp.21-24
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• 2012

In the iron ore sinter process, temperature distribution pattern in sintering bed is related with productivity and quality of sintered ore. Evenly heat distribution make the uniform quality of sintered ore but in normal operating condition, upper part of bed has lack of heat and scarce quality of sintered ore, thus yeild rate is decreased and productivity is diminished. Therefore, using the additional fuel in the upper part of bed is considered and effect of fuel is discussed. (max. 80 words).