• Transactions on Electrical and Electronic Materials
• /
• 제11권3호
• /
• pp.134-137
• /
• 2010

We have proposed a transflective liquid crystal display (LCD) driven by the fringe field using a liquid crystal (LC) with a negative dielectric anisotropy. The device used different twist angles of the liquid crystals (LC) in the transmissive (T) and the reflective (R) regions when voltage is applied. With the optimization of the pixel electrode width and the distance between them, the LC directors in the R- and T-regions can be rotated by about $22.5^{\circ}$ and $45^{\circ}$ on an average, respectively. As a result, a high image quality transflective LCD with a single gap, a single gamma, and a wide viewing angle characteristics in both the R- and T- regions can be realized.

• Tribology and Lubricants
• /
• 제36권3호
• /
• pp.161-167
• /
• 2020

Petroleum is the most used energy source in Korea with a usage rate of 39.5% among the available 1st energy source. The price of liquid petroleum products in Korea includes a lot of tax such as transportation·environment·energy tax. Thus, illegal production and distribution of liquid petroleum is widespread because of its huge price difference, including its tax-free nature, from that of the normal product. Generally, illegal petroleum product is produced by illegally mixing liquid petroleum with other similar petroleum alternatives. In such case, it is easy to distinguish whether the product is illegal by analyzing its physical properties and typical components. However, if one the components of original petroleum product is added to illegal petroleum, distinguishing between the two petroleum products will be difficult. In this research, we inspect illegally produced gasoline, which is mixed with methyl tertiary butyl ether (MTBE) as an octane booster. This illegal gasoline shows a high octane number and oxygen content. Further, we analyze the different types of green dyes used in illegal gasoline through high performance liquid chromatography (HPLC). We conduct component analyses on the simulated sample obtained from premium gasoline and MTBE. Finally, the illegal gasoline is defined as premium gasoline with 10% MTBE. The findings of this study suggest that illegal petroleum can be identified through an analytic method of components and simulated samples.

• 한국산학기술학회논문지
• /
• 제8권3호
• /
• pp.632-638
• /
• 2007

HDPE와 LDPE에 대한 열분해실험을 반응기 크기가 40 $cm^3$인 스테인레스 스틸 반응기에서 수행하였으며 이때 반응온도는 $410{\sim}460^{\circ}C$이었다. 열분해생성물인 액상생성물과 기상생성물을 분리하여 채취하였고 각 생성물의 분자량분포는 HPLC-GPC와 GC분석을 통해 얻었다. 미분반응기에서 열분해온도와 시간이 증가할수록 액상생성물의 수율과 분자량 분포는 전체적으로 감소하는 경향을 보였다. 열분해반응에서 말단절단의 속도계수인 활성화에너지 값은 HDPE, 63.0kcal/mole, LDPE, 45.7kcal/mole 이었다.

• 대한화장품학회지
• /
• 제25권4호
• /
• pp.97-110
• /
• 1999

The new stick make-up product was studied by using a gel, which is a viscous complex formed with clay minerals, vitamins A and E and fluorinated liquid polymer with a 1500 molecular weight. The gel cannot be obtained with any random combination of clay minerals and the ingredients described above. It takes the sequential manufacturing method as follows to get this kind of gel. Firstly, clay minerals and liquid polymers have to be pre-mixed in order to saturate the liquid polymers with the clay minerals. Then the on-processed gel has to be finely crystallized. The clay minerals, which are the core elements for this gel, were used as a function of Binder & Buffer and liquid polymer was mixed together for the deterioration of the surface tension of each component and to form a functional film in the gel. This liquid polymer was combined with clay minerals because it is not miscible with most oils and solvents. Waxes have a function of keeping a solid status in the stick. We reduced the usage of waxes by putting clay minerals as buffer in the proportion of 0.5:1 with oil phase. Ceramide takes care of the skin when used regularly and maintains the skin's moisture. Vitamins A and E contribute to preventing skin aging by the activation of skin cells. We could get the stable viscous gel, which has about 80% oil phase using clay minerals and liquid polymer. The crystalline structures of gel were surface-chemically-analyzed using SEM and Image Analyzer and were thermodynamically analyzed using DSC. Surface tension test and softness were done by Rheometer. In the end, these characteristics were verified by consumer panel tests in Seoul, Daegeon and Pusan in Korea and Hokkaido, Osaka and Miyazaki in Japan with correlation to the climate.

• 대한화장품학회:학술대회논문집
• /
• 대한화장품학회 1999년도 IFSCC . ASCS 학술대회 발표 논문
• /
• pp.97-110
• /
• 1999

The new stick make-up product was studied by using a gel, which is a viscous complex formed with clay minerals, vitamins A and I and fluorinated liquid polymer with a 1500 molecular weight. The gel cannot be obtained with any random combination of clay minerals and the ingredients described above. It takes the sequential manufacturing method as follows to get this kind of gel. Firstly, clay minerals and liquid polymers have ·to be pre-mixed in order to saturate the liquid polymers with the clay minerals. Then tile on-processed gel has to be finely crystallized. The clay minerals, which are the core elements for this gel, were used as a function of Binder & Buffer and liquid polymer was mixed together for the deterioration of the surface tension of each component and to from a functional film in the gel. This liquid polymer was combined with clay minerals because it is not miscible with most oils and solvents. Waxes have a function of keeping a solid status in the stick. We reduced the usage of waxes by putting clay minerals as buffer in the proportion of 0.5 : 1 with oil phase. Ceramide takes care of the skin when used regularly and maintains the skin’s moisture. Vitamins A and I contribute to preventing skin’aging by the activation of skin cells. We could get the stable viscous gel, which has about 80% oil phase using clay minerals and liquid polymer, The crystal 1 me structures of gel were surface-chemical1y-analyzed using SEM and Image Analyzer and were thermodynamically analyzed using DSC, Surface tension test and softness were done by Rheometer. In the end, these characteristics were verified by consumer panel tests in Seoul, Baegeon and Pusan in Korea and Hokkaido, Oska and Miyazaki in Japan with correlation to the climate.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.50.3-50
• /
• 2001

Nonlinear feedback control scheme for reactive distillation column has been proposed. The proposed control scheme is derived in the framework of Nonlinear Internal Model Control. The product compositions and liquid and vapor flow rates in sections of the reactive distillation column are estimated from selected tray temperature measurements by an observer. The control scheme is applied to example reactive distillation column in which two products are produced in a single column and the reversible reaction A + B = C + D occurs. The relative volatilities are favorable for reactive distillation so that the reactants are intermediated boilers between the light product C and the heavy product D. Ideal physical properties, kinetics and ...

• International Journal of Aerospace System Engineering
• /
• 제5권2호
• /
• pp.16-22
• /
• 2018

An analysis has been made on the performance variation due to pressure drop change at propellant supply pipes of liquid rocket engine. The objective is to compare the effectiveness of control variables to tune the liquid rocket engine performance. The mode analysis program has been used to estimate the engine performance for different modes which is realized by controlling the flow rate of propellant. The oxidizer of combustion chamber, the fuel of combustion chamber, the oxidizer of gas generator and the fuel of gas generator are the independent variables to control engine thrust, engine mixture ratio and temperature of gas generator product gas. The analysis program is validated by comparing with the powerpack test results. The error range of compared variables is order of 4%. After comparison of tuning effectiveness it is turned out that the pressure drop at oxidizer pipe of gas generator and pressure drop at combustion chamber fuel pipe and the pressure drop at the fuel pipe of gas generator can effectively tune the thrust of engine, mixture ratio of engine and temperature of product gas from gas generator respectively.

• 한국환경농학회지
• /
• 제32권4호
• /
• pp.348-354
• /
• 2013

가축사체 액상부산물을 이용하여 액비의 최적조건(미생물, pH, 미생물 주입량)을 조사하였고, 이들 최적 조건하에서 112일간 부숙하여 액비의 품질을 평가하였다. 가축사체 액상부산물 액비 부숙시 최적 LP 미생물의 주입량은 0.5 mL/100 mL이었으며, pH는 7 조건에서 각각 50점으로 완숙판정을 받았다. 최적조건하에서 112일 동안 부숙시킨 액비의 부숙도는 부숙 후 28일에 50점을 받아 완숙판정을 받았으며, 부숙기간이 길어짐에 따라 부숙 56일에는 온도가 $60^{\circ}C$를 넘어 최고점인 55점을 받았고, 이후 온도가 조금씩 낮아져 부숙 후 112일에는 실온조건에 이르렀다. 완숙된 가축사체 액상부산물 액비의 품질을 평가해본 결과, 최적조건하에서 부숙시킨 액비의 경우에는 T-N, $P_2O_5$ 및 $K_2O$의 함량이 28일에 가장 높았으며, 시간이 경과함에 따라 약간 감소하는 경향이었다. 또한, 유해성분(As, Cd, Cu, Cr, Hg, Ni, Pb 및 Zn)의 함량은 28일, 56일 및 112일 부숙시킨 액비에서 모두 비료공정규격 기준치에 적합하였다. 이상의 결과를 미루어 볼 때 가축사체 액상부산물을 농업적 재활용을 위한 액비화 조건은 pH 7조건에서 LP 미생물을 0.5 mL/100 mL 주입한 경우이다. 하지만 본 연구에서 비교된 가축분뇨 발효액은 공시재료(가축사체)가 상이하여 향후 가축사체를 이용한 액비의 부숙도 기준이 개선되어야 할 것으로 판단된다.

• Archives of Plastic Surgery
• /
• 제48권5호
• /
• pp.549-552
• /
• 2021

Clinical applications of stromal cells obtained mechanically from adipose tissue are quite popular methods. However, generally accepted protocols still do not exist. In this study, three new delivery methods using different protocols are presented as innovative methods in accordance with an approach called "Indication-based protocols." In mechanical methods, before cutting the fat tissue with ultra-sharp blades, which we define as "Adinizing," mixing it with different liquids such as saline or plasma provides the stromal cells in liquid form with high number and viability as a final product. At the same time, since stromal cells and extracellular matrix are preserved by mechanical methods, it was deemed appropriate to use the term total stromal cells (TOST) instead of stromal vascular fraction for this final product, unlike the product obtained with the enzyme. TOST can be combined with plasma and used for dermal filling in "solid" form. In addition to this filling effect, it will also cause a change in the tissue regeneratively. Finally, the stromal cells obtained from liquid can be applied clinically in aerosol form with the help of nebulizer. We believe that three innovative delivery methods can be used successfully in the treatment of many clinical situations in the future.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
• /
• pp.1067-1070
• /
• 2005

A large size flat panel LCD-TV must fulfill different requirements than a desktop LCD-monitor: The contrast must be much larger, the viewing angle should be as wide as possible and the switching times must be shorter to allow moving pictures to be displayed naturally. The "Vertically Aligned" technology is most promising to realize such a product. LC-material development for this technology began at Merck about 10 years ago. New materials based on the 1,1,6,7-tetrafluoroindane skeleton were recently synthesized via ortho-metallation and intramolecular Heck cyclization followed by an oxidative fluorination procedure. The materials offer improved properties over liquid crystals currently employed in flat panel LCD-TVs.