• Bulletin of the Korean Chemical Society
• /
• 제16권5호
• /
• pp.432-436
• /
• 1995

The solubility of caffeine in compressed carbon dioxide has been measured to determine its fugacity coefficient between 330 and 410 K up to 500 bar. The result allows the calculation of the thermodynamic excess functions such as the molar excess enthalpy, the molar excess free energy, and the molar excess entropy. The pressure variations of the molar excess functions of caffeine in the caffeine-CO2 mixture were discussed and also compared them with those in the caffeine-NH3 mixture.

• Bulletin of the Korean Chemical Society
• /
• 제18권10호
• /
• pp.1071-1075
• /
• 1997

Detonation characteristics of acetylene were studied behind reflected shock waves in the temperature range 800-1350 K by monitoring OH emission and pressure profiles. For a comprehensive measurement of ignition delay time, the mixture composition was varied in a wide range of Ar mole % was varied from 0.625 to 2.5 in stoichiometric ratio of C2H2-O2-Ar. A computer simulation study was also performed to elucidate the important elementary steps determining ignition behavior. The 33-reaction mechanism provides a good agreement in delay time between the observed and the calculated ones.

• 한국군사과학기술학회지
• /
• 제17권3호
• /
• pp.289-295
• /
• 2014

The composition of bright flash device is a pyrotechnic mixture consisting of metal powder, oxidizer and additives. A pyrotechnic mixture of bright flash device generates a bright flash through burning after being ignited by initiator. The function of bright flash is to distract or incapacitate electro optical sensor systems and enemy eyes temporally. This study is to develop composition of pyrotechnic mixture of bright flash and to analyze the test results by considering intensity and efficiency of light.

• 한국응용과학기술학회지
• /
• 제27권4호
• /
• pp.437-444
• /
• 2010

Dry Process(natural drying, hot-air drying, oil fry drying), optimized mixture ratio and the condition of carbonization was carried out in order to improve the product durability develop eco-friendly solid fuel mixing food waste and paper sludge. As a result of the experiment, oil fry drying process was the fastest method for drying food waste and paper sludge mixture that contains 80% water inside, and the optimized mixture ratio to minimize the generating concentration of chlorine gas against caloric value of mixture ratio was 7:3. Additionally proper temperature of product carbonization was about $200^{\circ}C$ and shown increasing product durability through the carbonization. Therefore, the pelletized solid fuel be shaped diameter around 0.5cm, length 2cm under which was pulverized and molded using 7:3 mixture of food waste, and paper sludge was the eco-friendly solid fuel possible to be industrialized which is consist of chlorine concentration of below 2.0wt% and the lowest caloric value of over 5,000kcal/kg. In conclusion, this developing manufacturing process of the solid fuel can be interpreted to contribute alternative energy development in accordance with low carbon and green growth era.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
• /
• pp.943-946
• /
• 2004

We have investigated to observe the photoisomerization using the mixture solutions in chloroform and LB monolayers mixed with DPPA and BASH containing azobenzene group which has reversible to cis-trans by light irradiation.. Spreading solutions for the LB films were Prepared in chloroform($5.0{\times}10^{-5}mol/L$). We investigated the photoisomerization and property of the organic ultra thin film of fatty acid containing azobenzene was Prepared on the glass plate by LB method. As a result, the absorption spectra of 8A5H and DPPA mixture of LB films was induced to photoisomerization by alternating irradiation of ultraviolet and visible light, because the condensation of pure azobenzene monolayers was loosened by the introduction of phospholipid into the monolayers, and the molecular high aggregation in pure azobenzene monolayers is also weakened by the introduction of phospholipid. We found that it was reversibly induced to cis-trans photoisomerization in a various mixture molar ratio.

• 한국식품영양학회지
• /
• 제3권2호
• /
• pp.169-176
• /
• 1990

Effects of metal chelating agents and metal ions on the volatile substance of cooked oil with chicken and pork mixture meat were examined by chemical analysis and sensory test. The addition of Na-tripolyphosphate(Na-TPP) to chicken and pork mixture meat increased the amount of H2S among volatiles evolved during cooking but decreased that of volatile carbonyl compounds(VCC) This treatment enhanced meat flavor in cooked oil with chicken and pork mixture. It was recognized that the increase in Ha5 evolution was caused by the rise of pH value. On the contrary cupric ion produced a negative effect on the production of chicken and pork mixture meat flavor and this addition increased VCC and TBA value. Other metal chelating agents such as citric acid, phytic acid and EDTA, provided the same results as Na-TPP. It was supposed that these phenomena were attributable to the chelating action to metal prooxidant in mixture meat at could be concluded that a proper evolution of H2S and protection against lipid oxidation during cooking were important to produce an excellent chicken and pork mixture meat flavor.

• Korean Chemical Engineering Research
• /
• 제52권3호
• /
• pp.307-313
• /
• 2014

본 연구에서는 Isobutyl Acetate와 Isobutyl Alcohol의 공비혼합물을 압력변환증류공정(PSD; Pressure Swing Distillation Process)을 이용하여 99.9 mol% 이상의 Isobutyl Acetate를 분리하는 공정모사를 수행하였다. 압력변환증류공정은 공비혼합물의 상대휘발도와 공비조성이 압력의 변화에 따라 차이가 나는 특성을 이용한 공정이다. 액상에서는 Non-Random Two Liquid (NRTL) model을 그리고 기상에서는 Peng-Robinson equation을 이용하였다. 최적화 방법으로 환류비와 주입단 위치를 변수로 두고 총 재비기 소요 열량을 최소화시키는 목적으로 최적화를 수행하였다. 압력변환 증류공정은 두 개의 증류탑을 필요로 함에 따라 고압 증류탑과 저압 증류탑의 배열에 따른 최적화 조건 또한 비교를 수행하였다.

• 한국막학회:학술대회논문집
• /
• 한국막학회 2005년도 추계 총회 및 학술발표회
• /
• pp.133-147
• /
• 2005

In order to investigate applicability for 2,2,2-trifluoroethyl methacrylate (TFEMA) produced by esterification of 2,2,2-trifluoroethanol(TFEA) and methacrylic acid(MA) using pervaporation membrane, poly(vinyl alcohol) (PVA) composite membranes were prepared with glutaraldehyde(GA) onto porous polyethersulfone(PES) support. The degree of crosslinking and thickness of PVA coating layer were analyzed by swelling test and SEM(scanning electron microscopy), respectively. Pervaporation test was done with two feed mixures; TFEA/water, MA/water. The pervaporation data were obtained as a function of content of crosslinking agent, feed composition, and operating temperature, respectively. In case of TFEA-water(90/10 wt%) feed mixture at $80^{\circ}C$, the optimized membrane showed the high permeation flux of 1.5 $kg/m^2hr$ and separation factor of 320. In case of MA-water(90/10 wt%) feed mixture, the membranealso showed high permeation flux of 2.3 $kg/m^2hr$ and separation factor of 740 in same conditions.

• Korean Chemical Engineering Research
• /
• 제47권2호
• /
• pp.174-178
• /
• 2009

이성분 혼합물의 응고중에 수지상 결정으로 이루어진 mush 층이 형성될 수 있다. 본 연구진이 개발한 전파이론으로 mush 층에서 성분적 대류의 발생을 해석하였다. Emms와 Fowler의 모델로부터 유도한 자기유사 안정성 방정식을 사용하여 대류 발생에 대한 임계 Rayleigh 수를 수치방법으로 계산하였다. 과열량이 아주 크거나 mush 층의 성장률이 아주 작은 극한의 경우에 본 연구 결과는 준정적 안정성 해석 결과와 같아진다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.1508-1510
• /
• 2009

In this work, we have compared OLED devices made of blended MEH-PPV/Ruburene mixture and MEH-PPV/Rubrene bi-layer structure devices. The emission layers were made with two different ways - one with gravure printed single layer of blended mixture of MEH-PPV and rubrene, the other with gravure printed bilayers of MEH-PPV and rubrene. Both brightness and efficiency with gravure printed bi-layer devices were higher than blended devices. In this work, we demonstrated that organic bi-layers can be formed with gravure printing technology and higher efficiency can be achieved with bi-layer structure than with blended single layer structure.