• Title/Summary/Keyword: Separation principles

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CFD Simulation of Air-particle Flow for Predicting the Collection Efficiency of a Cyclone Separator in Mud Handling System (Mud handling system 내 cyclone separator의 집진효율 추정을 위한 공기-분체의 CFD 시뮬레이션)

  • Jeon, Gyu-Mok;Park, Jong-Chun
    • Journal of Ocean Engineering and Technology
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    • v.33 no.1
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    • pp.42-49
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    • 2019
  • Drilling mud was used once in the step of separating the gas and powder they were transported to a surge tank. At that time, the fine powder, such as dust that is not separated from the gas, is included in the gas that was separated from the mud. The fine particles of the powder are collected to increase the density of the powder and prevent air pollution. To remove particles from air or another gas, a cyclone-type separator generally can be used with the principles of vortex separation without using a filter system. In this study, we conducted numerical simulations of air-particle flow consisting of two components in a cyclone separator in a mud handling system to investigate the characteristics of turbulent vortical flow and to evaluate the collection efficiency using the commercial software, STAR-CCM+. First, the single-phase air flow was simulated and validated through the comparison with experiments (Boysan et al., 1983) and other CFD simulation results (Slack et al., 2000). Then, based on one-way coupling simulation for air and powder particles, the multi-phase flow was simulated, and the collection efficiency for various sizes of particles was compared with the experimental and theoretical results.

Amphetamine-type Stimulants in Drug Testing

  • Chung, Heesun;Choe, Sanggil
    • Mass Spectrometry Letters
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    • v.10 no.1
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    • pp.1-10
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    • 2019
  • Amphetamine-type stimulants (ATS) are a group of ${\beta}$-phenethylamine derivatives that produce central nervous system stimulants effects. The representative ATS are methamphetamine and 3, 4-methylenedioxymethamphetamine (MDMA), and abuse of ATS has become a global problem. Methamphetamine is abused in North America and Asia, while amphetamine and 3, 4-methyle nedioxym ethamphetamine (Ecstasy) are abused in Europe and Australia. Methamphetamine is also the most abused drug in Korea. In addition to the conventional ATS, new psychoactive substances (NPS) including phenethylamines and synthetic cathinones, which have similar effects and chemical structure to ATS, continue to spread to the global market since 2009, and more than 739 NPS have been identified. For the analysis of ATS, two tests that have different theoretical principles have to be conducted, and screening tests by immunoassay and confirmatory tests using GC/MS or LC/MS are the global standard methods. As most ATS have a chiral center, enantiomer separation is an important point in forensic analysis, and it can be conducted using chiral derivatization reagents or chiral columns. In order to respond to the growing drug crime, it is necessary to develop a fast and efficient analytical method.

Research on the Legal Composition and Institutional Systems of The Dao Constitution: Focusing on The Constitution of the Republic of Korea (『도헌』의 법률적 구성과 제도적 장치 연구 - 대한민국헌법을 중심으로 -)

  • Kim, Young-jin
    • Journal of the Daesoon Academy of Sciences
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    • v.40
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    • pp.77-114
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    • 2022
  • The purpose of this study is to analyze the ideological background, legal composition, and separation of powers contained within the institutional devices of The Dao Constitution based on the basic principles of the legal system, which would be embodied in The Constitution of the Republic of Korea. The ideological background of The Dao Constitution is that of the religion, Daesoon Jinrihoe. In Daesoon Jinrihoe, it is held that the Supreme God, Sangje, determined that Mutual Contention, the ruling pattern of the Former World, ran contrary to His divine will and this endangered the world as nature and humans had also fallen into Mutual Contention. As an act of divine intervention, Sangje established Mutual Beneficence so that nature and humanity could follow Mutual Beneficence as a paradigm shift culminating in a Great Opening of the universe. Sangje, the agent behind the paradigm shift, revealed His divine will that humans transform into mutually beneficent humans. Therefore, The Dao Constitution was written to be a set of fundamental norms based on the 'rights and obligations of the members of Daesoon Jinrihoe' to accept and implement the will of Sangje as it applies to each member's mission. The legal composition of The Dao Constitution consists of the body and supplementary provisions. The text consists of general rules, moral rights and obligations, origins, and institutional devices. Institutional devices include the Central Council, the Institute of Propagation and Edition, the Institute of Religious Services, Works, Financial Management, and the Institute of Audit and Inspection. The legal composition of The Dao Constitution is similar to that of the Constitution. The difference is that while the Constitution applies a 'principle of maximum rights and minimum obligations,' The Dao Constitution stipulates more obligations than rights in order to complete the mission of the members. The principle of separation of powers is applied to the institutional devices in The Dao Constitution. In The Dao Constitution, the organizational form of the central headquarters has been divided into a 'before and after' scheme surrounding the death of Dojeon. The organizational form of the central headquarters prior to Dojeon's death was similar to a Constitutional Monarchy. After the death of Dojeon, the central headquarters' organizational form became similar to a parliamentary cabinet system. The separation of powers at central headquarters is divided among a legislative power (the Central Council), an executive power (the Institute of Religious Services), and a judicial power (the Institute of Audit and Inspection). The separation of powers within the functions of the central government first occurs between the Central Council and its employees, then between the Central Council and the Institute of Auditing and Inspection, and also between the Legislative Government and the Institute of Religious Services. Furthermore, the principle of a vertical separation of powers exists between the central headquarters and the local organization.

Principles of Simulated Moving Bed Reactor(SMBR) (Simulated Moving Bed Reactor(SMBR)의 원리)

  • Song, Jae-Ryong;Kim, Jin-Il;Koo, Yoon-Mo
    • Korean Chemical Engineering Research
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    • v.49 no.2
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    • pp.129-136
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    • 2011
  • Simulated Moving Bed(SMB) process consists of multiple chromatographic columns, which are usually partitioned into four zones. Such a process characteristic allows a continuous binary separations those are impracticable in conventional batch chromatographic processes. Compared with batch chromatography, SMB has advantages of continuity, high purity and productivity. Various researches have been reported for the integration of reaction and recovery during process operation on the purpose of economics and effectiveness. Simulated Moving Bed Reactor(SMBR) is introduced to combine SMB as a continuous separation process and reactor. Several cases of SMBR have been reported for diverse reactions with catalytic, enzymatic and chemical reaction on ion exchange resin as main streams. With an early type of fixed bed using catalyst, SMBR has been developed as SMB using fluidized enzyme, SMB with immobilized enzyme and SMB with discrete reaction region. For simple modeling and optimization of SMBR, a method considering convection only is possible. A complex method considering axial dispersion and mass transfer resistance is needed to explain the real behavior of solutes in SMBR. By combining reaction and separation, SMBR has benefits of lower installation cost by minimizing equipment use, higher purity and yield by avoiding the equilibrium restriction in case of reversible reaction.

Smartphone Usage Experience of College students (대학생들의 스마트폰 사용 경험)

  • Kim, Jungae;Cho, Eui-young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.3
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    • pp.187-201
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    • 2016
  • The purpose of this study was to analyze the smart phone usage experience structure for college students. The phenomenology approach was used by conducting 4 times in-depth interviews with the 7 college students age between 20~23. Collected Data was analyzed by Giorgi's phenomenological method. There were 4 general structure descriptions and 28 themes. General structure descriptions were 'Dependence on smart phone', 'Phenomenon of smart phone usage', 'Results of smart phone usage' and 'Relationship between stress and smart phone'. Themes consisted of 'Ambivalence', 'Positive feelings for smart phones', 'Separation anxiety', 'Negative feelings for smart phones'. 'Dependent feelings for smart phones', 'A sense of unity with smart phones', 'Helpful for my life', 'Deeply involved with my life', 'Useful tool in my life', 'Study, communication, relaxation and health care', 'Maintain personal relationship', 'The most important thing in my life', 'Shallow relationship stress', 'Interference with personal relationship', 'Forming a negative relationship', 'Invasion of privacy', 'Forming a Incorrect relationship', 'Unwanted participation', 'No effort to improve relationship', 'Poor concentration', 'Interference with academic study', 'Study assistance', 'Limited help for study in depth', 'Shelter from the stress', 'Amplification of the stress', 'Obsessive focus', 'Feel separation for the reality' and 'Waste of time'. Smart phone usage make college students dependent on smart phones and had negative influence on both personal relationship and academic results. Usage of smart phone also amplified stress. Therefore we need fundamental principles on usage of smart phone and propose to build cultural etiquette that provides reasonable way to use smartphone.

$CO_2$ Separation in IGCC plant using Principles of Gas hydrate Formation (가스 하이드레이트 형성 원리를 이용한 IGCC 공정에서의 $CO_2$ 분리 연구)

  • Lee, Hyun Ju;Kim, Soo Min;Lee, Eun Kyung;Lee, Ju Dong;Kim, Yang Do
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.215.2-215.2
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    • 2010
  • 지구온난화의 주범으로 알려진 $CO_2$의 대기 중 농도는 산업혁명 이전 280ppm에서 산업 혁명 이후 375ppm으로 증가하였다. 정부 간 기후변화패널(IPCC)의 기후변화 시나리오에 의하면, 지금부터 다양한 감축노력을 한다 할지라도 $CO_2$ 증가추세는 계속되어 2100년경에는 대기 중 $CO_2$농도가 600~950ppm에 이를 것으로 예측하고 있다. 현재까지 화력발전부분은 온실가스($CO_2$)의 최대 배출 원으로 알려져 있으며 이 분야의 $CO_2$ 회수기술은 연소 후 포집(Post-combustion), 순산소 연소(Oxy-fuel combustion), 연소 전 탈탄소화(Pre-combustion) 3가지로 크게 구분된다. 이중 석탄가스화복합발전(IGCC)기술과 연계하여 $CO_2$를 회수할 수 있는 방법이 연소 전 탈탄소화 기술이다. 핵심기술은 $CO_2$ 분리공정으로 적용 될 수 있는 기술로서는 흡착 흡수법, 막분리법 그리고 가스 하이드레이트가 있으나 아직까지 우리나라의 가스 하이드레이트 기술은 전무한 형편이다. 본 연구에서는 가스 하이드레이트 형성원리를 이용하여 정온 정압 조건에서 $CO_2/H_2$ 하이드레이트를 제조하였으며 특히, 하이드레이트 형성 촉진제인 TBAB(Tetra-n-butyl ammonium bromide)를 첨가하여 TBAB 농도에 따른 상평형 및 속도론 실험을 수행 하였다. 또한 라만 분석을 통하여 $CO_2$ 회수 분리에 대한 연구도 병행하였다.

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A Study on Meanings of Funeral ceremony costumes in Chosun Dynasty (조선시대 상례행렬복식에 나타난 상징성에 관한 연구)

  • Hai-Yaul Choi;Soon-Won Lee
    • Journal of the Korean Society of Costume
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    • v.50
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    • pp.119-128
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    • 2000
  • this study was designed to discuss the pattern of Confucian funeral ceremony and its costumes in Chosun dynasty thereby exploring the ideas and symbolic meanings expressed on them. 1. Male's official mourning dresses were composed of Choieui symbolizing sadness Choisang(최상), Dukun Sangkwan Sujil Yojil Kyodai and mourning stick Female's official mourning dresses consisted of Daersoojangkon and Kaedoo which were of simple kinds as compared to those of males. Duration of wearing mourning dreses was the longest to the death of father husband and eldest son The forms of mouring dresses were one and the same irrespective of the noble and the mean which expressed the sameness of the sorrow full of losting blood relative. Symbol expressed on funeral ceremony costumes were something like "eldestson-oriented" "male-centered" "distinction of the sexes" and "principle of yin and yang" to reinforce vitality to the costumes. 2. In the other funeral ceremony costumes in a royal fami8ly were those Euijangsu in red and blue colors Yeosakon in purple and white colors. Bandsman in Danryung and Guards in Kukonbok Changeui and Hoeui with five colors while the generally of people woere white dress in the ceremony Hoeui with five colors symbolized the principle of Yin and Yang costumes of military uniforms the dignity of the royal family: white dresses grife symbolizing the dignity of a royal family and Confucian sorrow as well 3. Unlike the mouring dresses there were great differences relative to socio-ecpmpomic status in funeral goods for dercoration Soyeo and daeyeo Among the goods the instrument to drive out evil spirites symbolized shamanism the distinction of Soyeo and Daeyeo separation of body and soul; the sculpture of the Lord of Hades and messenger philosophy of buddhistic netherworld: the engraving of blue and yellow dragons in bier and Juksanma the principles of Yin and Yang : elaborate burial accesaries realistic viewpoint of the hereafter.

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TRIZ-based Creative Problem Solving Process (트리즈 기반의 창의적 문제해결 프로세스)

  • Kim, Eun-Gyung
    • The Journal of Korean Institute for Practical Engineering Education
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    • v.2 no.1
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    • pp.28-34
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    • 2010
  • Traditionally engineers' main roles are concentrated on solving any given problems and engineering education has emphasized problem solving ability. Therefore engineers intend to solve easily perceived problems with their knowledge and experience instead of trying to analyze the given problems thoroughly and to define real problems, and go through lots of trial and error. So, engineers require the ability to define real problems accurately before trying to solve the problems. This study proposes a real problem definition process using visualization of a core zone and TRIZ concepts such as contradictions and IFR(Ideal Final Result) in order to define real problems with minimum trial and error. TRIZ is the theory of inventive problem solving and was developed by a Soviet engineer and researcher Genrich Altshuller from 1946. Nowadays many industries use TRIZ and its effectiveness was already proved by lots of real problem solving in various areas. Therefore TRIZ might be very effective tool for developing students' inventive thinking ability in engineering education.

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Risk Governance Models Seen from the STS Perspectives: Risk Analysis Framework and the Precautionary Principles (STS 관점에서 본 위험 거버넌스 모델: 위험분석과 사전주의 원칙을 중심으로)

  • Hyun, Jaehwan;Hong, Sungook
    • Journal of Science and Technology Studies
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    • v.15 no.1
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    • pp.281-325
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    • 2015
  • In this paper, we continue our previous study on the differences, similarities and interfaces between the various models of scientific governance discussed in STS and those in risk governance developed by risk studies. In the previous paper we illuminated that theoretical differences among STS scholars on scientific governance and public participation goes back to the 1970s and 1980s, during which they first laid down the conceptual basis of STS. In this paper we investigate how these divergent positions among STS scholars influenced their evaluations of precautionary principle and the framework of risk analysis (especially the separation between risk assessment and risk management), which are the two main paradigms in the area of risk regulation. By doing that, this paper will show divergent positions of STS scholars on risk analysis and precautionary principle. Further, we will suggest some theoretical and practical interfaces between STS and risk governance models.

Basic principle of BSR (Buzz, Squeak, Rattle) noise according to the generation mechanism (BSR(Buzz, Squeak, Rattle)이음 발생 메커니즘 기본 원리와 시험평가 방법)

  • Choi, Sung uk;Ahn, Sungcheul;Ih, Kang Duck
    • The Journal of the Acoustical Society of Korea
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    • v.37 no.5
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    • pp.309-316
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    • 2018
  • Various studies have been conducted to improve the BSR (Buzz, Squeak, Rattle) noise generated irregularly while the vehicle is running. In vehicle, When an external force such as vibration or force flows into the contact surface, BSR noise is generated at the contact surfaces of nearby components. In this paper, BSR conceptually explain the kind of noise generation mechanisms and the basic principles of generation, which have been proven by observing and improving noise phenomena in automobiles over the last 10 years. Through this, it is expected that researchers who want to study BSR related improvement research not only in automobiles but also in other industries, It will be able to understand the BSR phenomenon and provide a framework for thinking out improvement ideas and to carry out further research.