• Title/Summary/Keyword: 분산 방법

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Preparation of Charged Composite Particles for Electrophoretic Display (전기영동 디스플레이용 대전 복합입자의 제조)

  • Na, Hae-Jin;Baek, Jeong-Ju;Kim, Ji-Suk;Kim, Sung-Soo
    • Polymer(Korea)
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    • v.33 no.4
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    • pp.347-352
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    • 2009
  • Charged organic-inorganic composite particles were prepared for the application to electrophoretic display technology such as electronic paper. $TiO_2$ and $Co_3O_4$ particles were used for core particles and were coated with poly(methyl methacrylate) by dispersion polymerization. Composite particles were endowed with charge moiety for electrophoresis; positive charge for $TiO_2$ and negative charge for $Co_3O_4$ composite particles. Scanning electron microscopic results revealed that the charged composite particles have spherical shape. Densities of the composite particles were controlled to be that of medium of electrophoresis. Density of $TiO_2$ particle changed from 4.02 to 1.44 g/$cm^3$ after the polymer coating, and that of $Co_3O_4$ particles changed from 6.11 to 1.49 g/$cm^3$. Urea, melamine, and formaldehyde were used as wall materials for capsule, and microcapsule containing black or white particles inside were prepared by in-situ polymerization. Microcapsule showed the inspection by a video microscope demonstrated the formation of uniform transparent capsules.

Sibutramine Release Behavior from Microspheres Prepared by Spray-Dry Method (분무건조 방법으로 제조된 미립구에서 Sibutramine의 방출거동)

  • Park, Jung-Soo;Oh, Jung-Soo;Oh, Jae-Min;Kim, Yun-Tae;Lee, Jun-Hee;Mo, Jong-Hyun;Lee, Hai-Bang;Khang, Gil-Son
    • Polymer(Korea)
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    • v.32 no.3
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    • pp.193-198
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    • 2008
  • Sibutramine is a highly crystalline and poorly water soluble drug as the appetite depressant for obesity treatment. In order to increase water solubility of sibutramine, microspheres including sibutramine were prepared by solid dispersion method using a spray dryer. The crystallinity and morphology of the prepared microspheres were confirmed by SEM and XRD. The morphology of micro spheres has gradually changed into spherical shape as increasing evaporation rate of solvent. According to XRD analysis, crystallinity of sibutramine in micro spheres was decreased by below 10%. Release behavior of microspheres was investiaged at pH 1.2, pH 6.8, and solubility of the sibutramine was significantly different depending on pH. The hard capsule showed fast release of sibutramine comparing with the tablet. These results demonstrated that the pharmaceutical preparation is able to control the release behaviors.

Household Patterns in Early 18th - Century Korea -A Study Based on the Triinnial Household Register Data of Danseong-Hyon, Kyongsang Province, 1720- (1720년도 단성현 호적대장자료를 통한 이조중기 가구형태 분석)

  • 이흥탁
    • Korea journal of population studies
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    • v.13 no.2
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    • pp.19-47
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    • 1990
  • 1720년 경상도 단성진 진내면 소재의 390가구를 대상으로 1970년대 초 케임브리지 대학의 역사인구학 연구소에서 개발한 Laslett-Hammel가구 형태 분석법을 적용하여 본 결과 표9에서 제시된바와 같이 전체가구의 48.9%가 핵가족의 형태이며, 42.1 퍼센트가 대가족으로 밝혀지고 있다. 물론 도표3에서 지적되고 있듯이 5세이하의 인구에 대한 자료가 미비한 상태라 호적 자료만으로 당시의 가구 형태에 대한 정확한 분석이 어렵다고 하드라도 이제까지 일반적으로 믿어져 왔던 대가족 형태의 이조 중기의 종가제도나 일반 서민들의 가구 형태 및 유아가구에 대한 보다 구체적인 연구가 호적 자료에 대한 면밀한 분석으로 가능해질것으로 믿어진다. 역촌, 즉 하류계층의 사람들이 주로 많이 주거하였던 단성진 진내면의 전체 조사 대상 가구의 절반이 핵가족의 형태로 보이고 있는것은 당연한 것으로 받아질수 있겠으나 표6에서 나타내고 있듯이 상류계층에 속하는 양소계층의 경우도 평균 가구 규격 16명중에서 약 13명이 율거유아로 실제 가구의 크기는 가족 구성원수 4명을 넘지않는 핵가족의 형태였을 가능성이 짙음을 알수 있다. 한가지 특이할만한 사항은 상류,중류,그리고 하류 계층 다같이 평균 가족 구성원수가 4명을 넘지 않는다는 점이다. 단성진이 독촌들로 구성되어 있는 만큼 앞으로 상류계층이 밀집되어 있었던 경북 월성군의 양동 지역 향방 자료나 호적 초안자료를 단성진의 자료와 비교 분석함으로써 이조 중기의 가구 형태에 대한 보다 신뢰성 있는 결과를 도출해 낼수 이ㅛ는것이다. 단성진의 자료는 이조 중기의 유아 인구와 유아 가구 형태에 대한 연구에는 귀중한 자료로 앞으로 역사인구학의 방법론 개발에 큰 기여를 할것으로 기대된다.의 핑거를 식별, 추적할 수 있었다.는 경도방향의 해구수가 많았으며, 특히 8월은 1년중 경도방향의 분산이 가장 컸고, 어장중심은 5월에는 3888해구, 6월에는 3884해구, 7월에는 4078해구, 8월에는 4154해구, 9월에는 4146해구, 10월에는 4044해구였다. 3. 어획수온과 어획적수온은 5월에는 $14.0~18.5^{\circ}C,$ $15.0~16.0^{\circ}C,$ 6월에는 $13.5~18.5^{\circ}C,$ $14.5~16.0^{\circ}C,$ 7월에는 $14.0~20.0^{\circ}C,$ $14.5^{\circ}C,$ $19.0^{\circ}C,$ 8월에는 $16.0~21.5^{\circ}C,$ $18.0~20.0^{\circ}C,$ 9월에는 $14.5~22.0^{\circ}C,$ $17.0~18.5^{\circ}C,$ 10월 $14.0~18.0^{\circ}C,$ $16.0~17.0^{\circ}C였다.$ 4. 평균CPUE는 5월에는 3.2kg/sheet, 6월에는 4.5kg/sheet, 7월에는 4.3kg/sheet, 8월에는 5.1kg/sheet, 9월에는 6.4kg/sheet, 10월에는 5.8kg/sheet였다. 5. 한국정부의 1990년 북태평양 오징어 어업감시계획과 실제의 어장형성범위를 비교하면 5월에는 어장이 형성된 21개 해구 가운데 12개, 6월에는 24개 가운데 7개, 7월에는 25개 가운데 4개 해구에서

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Design and Properties of Laminating Waterborne PSA for Eco-friendly Flexible Food Packaging (식품연포장용 라미네이트 수성 감압점착제의 친환경적 적용에 대한 연구)

  • Lee, Jin-Kyoung;Shim, Myoung-Sik;Chin, In-Joo
    • Journal of Adhesion and Interface
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    • v.17 no.2
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    • pp.49-55
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    • 2016
  • In this study, we designed an environment friendly, water-based adhesive using the acrylic emulsion method as a replacement for solvent-based adhesives, which are most commonly used in layered laminates for flexible food packaging. We designed adhesives with different combinations of anionic, non-ionic, and phosphoric ester surfactants, and with different concentrations of chain transfer agent (CTA). We also examined the effect of the degree of cross-linking by synthesizing and comparing 8 test group adhesives with different types of functional monomers. Additionally, we synthesized 2 other test group pressure-sensitive adhesives (PSA) using styrene/alpha-methyl styrene/acrylic acid (SAA) semipolymer dispersing agents (with molecular weights of 13,000 g/mol and 8,600 g/mol, respectively) to replace the conventional surfactants. We evaluated whether the 10 test group pressure-sensitive adhesives met the basic physical property criteria required for flexible food packaging by carrying out a physical analysis of their glass transition temperature (Tg), particle size, adhesion, and molecular weight. In our test, 2 test group adhesives manufactured with the combination of anionic and non-ionic surfactants, CTA concentration of 0.2%, and functional monomers of hydroxyethyl acrylate (HEA) and glycidyl methacrylate (GMA) demonstrated molecular weight and flexibility suitable for flexible packaging, with low adhesiveness and small particle size.

Preparation and characterization of Poly(2-methacryloyloxyethyl phosphorylcholine/fluorescein O-methacrylate)-coated iron oxide nanoparticles (Poly(2-methacryloyloxyethyl phosphorylcholine/fluorescein O-methacrylate)가 도입된 산화철 나노 입자의 제조 및 발열 특성 연구)

  • Ryu, Sunggon;Cheong, In Woo
    • Journal of Adhesion and Interface
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    • v.19 no.3
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    • pp.106-112
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    • 2018
  • Recently, the hyperthermia treatment of malignant tissues has gained great attention as a biocompatible and benign method that facilitates successful cancer therapy compared to radiation and chemotherapy. In this study, superparamagnetic ($Fe_3O_4$) iron oxide nanoparticles (IONP) coated with biocompatible polymer (IONP@P(MPC/FOM)) for the purpose of hyperthermia treatment were prepared and related characterization were performed. IONPs with having 15 nm diameter were first prepared by coprecipitation and followed by surface modification with 4-cyanopentanoic acid dithiobenzoate (CTP) for reversible addition-fragmentation chain transfer (RAFT) copolymerization by using 2-methacryloyloxyethyl phosphorylcholine (MPC) and fluorescein O-methacrylate (FOM) to form corona layer of P(MPC/FOM) on the surface of the IONP. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) confirmed the morphology and hydrodynamic size of the IONP@P(MPC/FOM) and thermogravimetric analysis (TGA) confirmed the formation of P(MPC/FOM) corona layer, respectively. Exposing IONP dispersion to alternating magnetic field suggests that the IONP@P(MPC/FOM) aqueous dispersion with 0.2 wt.% can be used for hyperthermia treatment.

Integration Process of Federation Object Model for Interoperation of Federations (페더레이션 연동을 위한 객체 모델 통합 프로세스)

  • Kwon, Se Jung;Yu, Minwook;Kim, Tag Gon
    • Journal of the Korea Society for Simulation
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    • v.26 no.2
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    • pp.1-8
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    • 2017
  • High Level Architecture(HLA) is a specification for interoperation among heterogeneous simulators which are executed in a distributed environment. HLA originally allows many federates to join in a federation using a single RTI(Run-Time Infrastructure). As the target systems become more complex, the need for the interoperation of federations, performed in a RTI-RTI interoperation environment, has been growing. It can be performed by the confederation interface with the agents, which subrogate the API calls and callbacks of each federation. The existing studies have assumed that the object models of each federation are based on same HLA standard and their object descriptions are equal. Because the existing federations are usually not under this assumption, this paper proposes the integration process of object models for the federation interoperation environment. To integrate the object models for the interoperation of federations, this process resolves the differences of HLA standards, provides conversion process between objects with different descriptions and excludes the security objects. We expect that this process enhances the reusability and effectiveness of interoperation of federations in various domains.

Antioxidant capacity and nutritive components from biji sub-micron suspension by ultra-high pressure homogenization process (초고압균질 가공에 의해 제조된 초미세 비지 현탁액의 영양성분 및 항산화성)

  • Lee, Seon-Ho
    • Food Science and Preservation
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    • v.22 no.5
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    • pp.714-720
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    • 2015
  • Biji is a tofu by-product made by squeezing the liquid out of the dregs left over from making tofu. The objectives of this research were to break the biji into sub-micron-scale particles and to prepare a biji sub-micron suspension having increased quality characteristics such as antioxidant capacity, polyphenol, dietary fiber, and soluble protein contents, in comparison with untreated biji. Disruption of biji by an ultra-high-pressure homogenization (UHPH) process was used to prepare the sub-micron suspension of biji. UHPH can be used to prepare emulsions or suspensions with extremely small particle sizes. The effect of the UHPH process on biji was studied at 1,000, 1,500, and 2,000 bar. The extraction yield increased up to 1.64 times by breaking the biji to form a sub-micron suspension. The soluble dietary fiber, protein, and free amino acid contents were increased by the UHPH process (p<0.05), in comparison with those of untreated biji. Furthermore, the total sugar, free sugar, and total polyphenol contents of biji were augmented by the UHPH process. Antioxidant activity (ABTS) after exposure to UHPH (1,000-2,000 bar) was well retained (p<0.05). The extraction efficiencies and nutritive components were enhanced by increasing the pressure in the UHPH process.

An Analysis of Differences in Motivation, Self-regulation Strategy use, Learning Style Preference among High, Medium, Low Achievers in an Online Gifted Program (온라인 영재교육 프로그램 성취 수준에 따른 학생의 동기, 자기조절전략, 학습양식 차이 분석)

  • Chae, Yoojung;Lee, Sunghye
    • Journal of Gifted/Talented Education
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    • v.25 no.6
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    • pp.905-926
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    • 2015
  • This study examined differences among high, medium, and low achievers' motivation, self-regulation strategy, and learning style in an online gifted program. The sample included 788 middle and high school students who participated in the 3-months online gifted program. Participants volunteerly completed 60 questions on their motivation, self-regulation strategy use, and learning style. Multivariate analysis of variance(MANOVA) was conducted for data analysis using SPSS 19.0. The results of this study showed that (1) as levels of students' achievement increased, levels of intrinsic motivation increased as well; (2) statistically significant differences also existed on the levels of elaboration strategy, effort management, and time management strategy use among three levels of achievement and (3) no significant differences in students' learning style preference were found between competitive or cooperative learning style. To sum up, high achieving students' levels of intrinsic motivation, elaboration strategy, effort management strategy, and time management strategy use were the highest compared to medium and low achieving students.

Comparison of Carbon Budget between Rice-barley Double Cropping and Rice Mono Cropping Field in Gimje, South Korea (국내 벼-보리 이모작지와 벼 단작지의 탄소수지 비교)

  • Shim, Kyo-Moon;Min, Sung-Hyun;Kim, Yong-Seok;Jung, Myung-Pyo;Choi, In-Tae;Kang, Kee-Kyung
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.4
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    • pp.337-347
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    • 2016
  • Carbon dioxide ($CO_2$) and methane ($CH_4$) were measured in a rice-barley double cropping and rice mono cropping paddy fields, which are located in the southwestern coast of Korea, over a one-year period. Net ecosystems $CO_2$ exchange (NEE) and ecosystem respiration (Re) were estimated by the eddy covariance (EC) method, and an automatic open/close chamber (AOCC) method was used to measure $CH_4$ fluxes. Environmental factors (solar radiation, air temperature, precipitation etc.) were also measured along with fluxes. After the quality control and gap-filling, the observed fluxes were analyzed. As a result, NEE was -603.0 and $-471.5g\;C\;m^{-2}\;yr^{-1}$ in rice-barley double cropping and rice mono cropping paddy field, respectively. $CH_4$ emissions increased during the course of flooded days and were similar in two cropping paddy field. Accoding to rough results considering only fluxes of $CO_2$ and $CH_4$, it was estimated that the carbon absorbation in rice-barley double cropping paddy field was higher than that in rice mono cropping paddy field by $128.9g\;C\;m^{-2}\;yr^{-1}$.

Satisfaction Survey of Occupational Therapy Service at Specialized Child-care Centers for Disabled in Gyeongbuk (경북지역 장애아전문어린이집의 작업치료서비스에 대한 만족도 조사)

  • Kang, Suk-Gu;Lee, Chun-Yeop
    • The Journal of Korean society of community based occupational therapy
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    • v.5 no.1
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    • pp.55-62
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    • 2015
  • Objective : The purpose of this study was to investigate the satisfaction of occupational therapy service for parents of children with disabilities using specialized child-care centers for disabled in Gyeongbuk. Methods : The subjects of this study were 104 parents who have experience in occupational therapy at 14 specialized child-care centers for disabled in Gyeongbuk. A questionnaire was conducted from July, 2014 to March, 2015. Descriptive statistics of frequency, mean, standard deviation, and One-Way ANOVA study were used to analyze data. Results : Disabled children got occupational therapy at first when they were 3.25 years, on average. Duration of occupational therapy use were 31.84 month, on average. The subjects determined to got occupational therapy mostly through consultation nurseries(40.4%). Most of them got speech therapy(78.0%) other than receiving occupational therapy service, responded very necessary to occupational therapy(69.3%). Satisfaction of occupational therapy service were 4.49 point at attitude of occupational therapists, 4.36 point at occupational therapy program, and 4.26 point at environment of occupational therapy room. Attitude of occupational therapists were the highest satisfied. Conclusion : This study would contribute to effective and meaningful occupational therapy through objective view

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