• Journal of the Korean Institute of Gas
• /
• v.20 no.6
• /
• pp.31-36
• /
• 2016

The flash point is one of the most important indicators of the flammability of liquid solutions. The flash point is the lowest temperature at which there is enough concentration of flammable vapor to form an ignitable mixture with air. In this study the flash points of ternary liquid solutions, n-nonane+n-decane+n-dodecane system, were measured using Seta flash closed cup tester. The measured values were compared with the calculated values using Raoult's law and empirical equation. The calculated data by empirical equation described the measured values more effectively than those calculated by Raoult's law.

• The Korean Journal of Applied Statistics
• /
• v.28 no.5
• /
• pp.1025-1034
• /
• 2015

Traditional Shewhart control charts assume that the observations are independent over time. Current progress in measurement and data collection technology lead to the presence of autocorrelated process data that may affect poor performance in statistical process control. One of the most popular charts for autocorrelated data is to model a correlative structure with an appropriate time series model and apply control chart to the sequence of residuals. Model parameters are estimated by an in-control Phase I reference sample since they are usually unknown in practice. This paper deals with the effects of parameter estimation on Phase II control limits to monitor autocorrelated data.

• The Journal of the Convergence on Culture Technology
• /
• v.5 no.3
• /
• pp.305-310
• /
• 2019

This paper proposes the method of exactly identifying both viscous and friction damping from free vibration response to SDOF structure. Both displacement and acceleration free vibration responses to SDOF system, in which both viscous and friction damping are considered as its damping mechanism, are discussed to verify the proposed method. The relationship for identifying both viscous and friction damping is derived from two consecutive amplitudes of displacement or acceleration peak response. The proposed method is verified through the numerical simulation for an assumed SDOF system consisting of mass, both viscous and friction damping and spring components.

• Journal of the Korean Magnetics Society
• /
• v.15 no.4
• /
• pp.231-235
• /
• 2005

We studied the microstructural evolution of ZrTM-Al (TM=Nb and Ti) alloy films, MR and electrical properties of the MTJ with $ZrTM-AlO_x$ barrier as a function of Zr/TM ratio. We observed that the ternary-oxide barrier reduced the TMR ratio due mainly to the structural defects such as the surface roughness. The change in TMR ratio and $V_h$ with Zr/TM ratio exactly corresponds to the systematic changes in the microstructural variation. Although the MTJ with ternary oxide reduced the TMR and the electrical stabilities, the junction resistances decreased as the Ti and Nb concentration increased due to the band-gap reduction caused by the formation of extra bands

• Conservation Science in Museum
• /
• v.26
• /
• pp.25-34
• /
• 2021

3D printing technology has been actively applied for the restoration of cultural properties. However, its application to the restoration of glass cultural properties has not yet been reported and thus requires further study. In this study, 3D printing technology was used to restore a defective part of a glass sarira bottle that forms an element of a series of sarira reliquaries commissioned by Yi Seonggye (known as King Taejo after founding the Joseon Dynasty) that was excavated from Geumgangsan Mountain (designated as Treasure No. 1925) and is currently housed at the National Museum of Korea. The defective area was reproduced using 3D printing and the printed reproduction was reproduced again using an epoxy resin. This latter piece was used as the restoration component rather than the 3D printed element. After the completion of the conservation treatment, the materials used for the 3D printing were compared with transparent materials used to restore ceramics to evaluate their usability and stability. A total of five specimens were produced, including from photocurable resin made by a stereo lithography apparatus (SLA), epoxy resin, acrylic resin, and more. They were exposed to UV for 96 hours to test for yellowing. Of the two specimens made of photocurable resins and exposed to UV, one was sprayed with a UV blocking agent but the other was exposed as-is. The UV exposure test showed that the specimen made by the SLA and sprayed with a UV blocking agent and the specimen made of epoxy resin were stable in terms of yellowing with a change in the b-value was less than 1. They are thus considered to be suitable materials for the restoration of glass cultural properties. Such glass cultural properties are often diverse in shape and their restoration can be difficult as they generally consist of a range of complex parts that hamper restoration. In this regard, diverse materials should be considered when selecting materials for the restoration of glass cultural properties.

• Korean Chemical Engineering Research
• /
• v.57 no.2
• /
• pp.198-204
• /
• 2019

For the removal of carbon dioxide from the chemical process, a chemical absorption method is typically used industrially. Development of new processes for the removal of carbon dioxide by the chemical absorption method has been developing new absorbents by using various absorbents. Thermodynamic data of the sorbent mixture in the new process design using hybrid absorbent is essential to reduce the equipment cost and operating costs of the process. In this study, densities of water+diisopropanolamine (DIPA), DIPA+MDEA(Methyldiethanolamine) binary systems and Water+DIPA+MDEA ternary system were measured over the full range of composition at temperatures from 303.15 K to 333.15 K by using an Anton Paar digital vibrating tube densimeter (DMA4500). The experimental excess volumes have been obtained from the experimental density results and have been fitted using the Redlich-Kister-Muggianu expression. The parameters obtained from the binary excess volume data were used for the correlation of ternary system with one additional ternary parameter for each isotherm. All investigated binary and ternary systems are completely miscible, because the values of excess volume are negative under the examined conditions.

• The Journal of Korean Philosophical History
• /
• no.35
• /
• pp.165-188
• /
• 2012

The purpose of this study is to examine the historical consciousness and view of the three religions (Buddhism, Taoism, and Confucianism) of Won Cheon Seok who lived a period of historical transition from the end of the Goryeo Dynasty to the early Joseon Dynasty. Actively speaking for the public in his time and having the same attitude as the Neo-Confucian scholars in the end of Goryeo Dynasty, he kept criticizing the abuse of the power by powerful families who made the people fall into a state of distress and misery. He believed the dispatch of troops to conquer the Yodong region as a great opportunity to boost the valiant spirit of his country; however, the reality was quite opposite to his expectation as Lee Seong Gye had withdrawn the army troops at the Wihwado causing a great risk to his country. He took a very hard line stance against what Lee Seong Gye did. Although he was a Confucian scholar, he did not ignore Buddhism and Taoism and understood that after all the three religions were based on the same principle. His deep understanding of Buddhism and Taoism as well as Confucianism helped him to make sense of Confucianism even further. He was able to sublimate the worldly anguish coming from the Confucian thinking system by indulging himself deeply into the world view of Buddhism and Taoism. In the end, his view on the three religions was based on the idea that they taught the same principle. His view of the three religions with transactional features has a huge implication for the contemporary society in which various values and multiple cultures coexist and have more common grounds.

• Applied Chemistry for Engineering
• /
• v.16 no.5
• /
• pp.689-692
• /
• 2005

In order to improve the electrochemical performances of Li-ion batteries when spinel $LiMn_2O_4$ is employed as a cathode active material, binary conductive agents were prepared using two different particle-sized carbons like Super P Black and $Vulcan^{(R)}$ XC-72R. The electrochemical performances of the $LiMn_2O_4$ cell system using binary conductive agents were evaluated in terms of specific charge and discharge capacities and cycle life. The cell with binary conductive agent in the 3:7 weight ratios of Super P Black and $Vulcan^{(R)}$ XC-72R showed better electrochemical performances due to the proper combination of ionic diffusion rate and electric contact.

• The Korean Publising Journal, Monthly
• /
• s.154
• /
• pp.8-9
• /
• 1994

글쓰기과외가 성행하면서 글쓰기에 대한 관심이 출판계에도 영향을 미치고 있다. 어린이용 글쓰기지침서가 벌써 30여 종이나 출판된 것을 비롯해서 고교생이나 성인용 글쓰기지침서도 심심찮게 찾아볼 수 있는 실정이다. 글쓰기에 대한 관심은 대학입시 정책의 변화에 기인하는 것이라는 부정적 측면 이외에도 창조적인 사고를 할 수 있다는 점에서 긍정적으로 평가하는 이들도 많다. 하지만 많은 글쓰기지침서 중에서 정작 필요한 책을 고르기는 쉽지 않다. 책 선별의 첫째 조건은 "어느것이 올바른 글쓰기인가"라는 물음에서 비롯되어야 한다고 관계자들은 말한다. 이와 함께 "글이란 것은 만들어지는 것이 아니라 올바른 삶을 살아가면서 느끼는 감동을 자연스럽게 표현하는 것"이라는 관점에서 글쓰기를 본다면, 글쓰기지침서가 자칫 고정관념을 만들어낼 수도 있다는 지적도 있다.

• Proceedings of the Korean Fiber Society Conference
• /
• 2002.04a
• /
• pp.25-28
• /
• 2002

비공역형 단량체인 비닐아세테이트(VAc)는 공역형 비닐계 단량체와 달리 라디칼의 활성이 너무 커서 중합 도중 빈번한 연쇄이동반응과 정지반응에 의해 분지구조의 고분자가 얻어지며 고분자량의 폴리비닐아세테이트를 얻기가 어려운 것으로 알려져 있다. 폴리비닐알코올(PVA)은 비닐알코을 단량체의 호변이성질화 때문에 단량체의 직적중합에 의해서는 얻을 수 없고 일반적으로 비닐아세테이트(VAc)를 라디칼 중합하여 얻어진 폴리비닐아세테이트(PVAc)를 비누화하여 합성한다. (중략)