• Title/Summary/Keyword: 표면 이질성

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UV Treatment Technique for High Electrical Conductivity and Adhesion Strength of 3D Printed Circuit (3D 프린터로 제작된 회로의 전기전도성 및 접착강도 향상을 위한 UV 소결 기술)

  • Lee, Se-Hun;Gwon, O-Chang;Lee, Yu-Mi;Lee, Heon-Ju;Mun, Myeong-Un
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.11a
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    • pp.340-340
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    • 2015
  • 상지 절단 장애인들을 위한 미관형 의수는 95% 이상의 시장 보급률을 보인다. 하지만 외부 형상 향상에만 연구 초점이 맞추어져 있어 많은 장애인들이 의수를 착용할 때 차가운 표면으로 인해 이질감을 느낀다. 이로 인해 의수 제작 업체 및 절단 장애인들은 착용 시 이질감이 적은 의수의 보급을 희망하고 있다. 그러므로 본 연구에서는 인체와 유사한 온도를 발생시켜 이질감을 감소시키는 의수를 개발하기 위해 유연 기판인 TPU (Temperature Polyurethane)와 PET (Polyethylene terephthalate) 위에 상용 silver nano paste를 3D 프린터로 인쇄하였으며, UV 표면처리를 사용하여 단시간 내에 낮은 저항과, 높은 회로 접착강도를 갖는 회로를 개발 하였다.

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Adsorption Calculation of Oxygen, Nitrogen and Argon in Carbon-Based Adsorbent with Randomly Etched Graphite Pores (무작위 에칭 흑연 기공을 가지는 탄소기반 흡착제에 의한 산소, 질소 및 아르곤의 흡착 계산)

  • Seo, Yang Gon
    • Clean Technology
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    • v.24 no.4
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    • pp.348-356
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    • 2018
  • The adsorption equilibria of oxygen, nitrogen and argon on carbonaceous adsorbent with slit-shaped and randomly etched graphite (REG) pores were calculated by molecular simulation method. Reliable models of adsorbents and adsorbates for adsorption equilibria are important for the correct design of industrial adsorptive separation processes. At the smallest physical pore of $5.6{\AA}$, only oxygen molecules were accommodated at the center of the slit-shaped pore, and from $5.9{\AA}$ nitrogen and argon molecules could be accommodated in the pores. Slit pores showed higher adsorption capacity compared with REG pores with same averaged reenterance pore size due to dead volume and inaccessible volume in defected pores. And it was shown the adsorption capacities of oxygen and argon was same in larger pore size. From calculated adsorption isotherms at 298 K it showed that the adsorption capacity ratio of oxygen to nitrogen is increased as pressure is increased.

Heterogeneity of hard skin layer in wrinkled PDMS surface fabricated by Ar ion beam irradiation (아르곤 이온빔 조사로 형성된 주름진 PDMS 표면 경화층의 이질성)

  • Lee, Seunghun;Byeon, Eunyeon;Kim, Do-Geun;Jung, Sunghoon
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2018.06a
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    • pp.43.1-43.1
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    • 2018
  • Spatial distribution of binding state in depth direction is investigated in a hard skin layer on soft polydimethylsiloxane (PDMS) fabricated by Ar ion beam irradiations. The hard skin layer known as a silica-like homogenous layer was composed of two layers. Impinging Ar ions transfer energy to PDMS as a function of collisional energy transfer rate, which is the maximum at surface and decreases gradually as an ion penetrates. This formed the heterogeneous hard skin layer that consists of a top-most layer and an intermediate layer. XPS depth profiling showed the existence of the top-most layer and intermediate layer. In the top-most layer, scission and cross-linking were occurred simultaneously and Si-O bond showed dissociated status, SiOx (x = 1.25 - 1.5). Under the top-most layer, there was the intermediate layer in which cross-linking is mainly occurred and Si-O bond showed silica-like binding status, SiOx (x = 1.75 - 2). And theoretical analysis which calculates the collisional energy transfer and a displacement per atom explained the thickness variation of top-most layer according to Ar ion energy from 360 eV to 840 eV.

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The Effect on Pulmonary Indices of Surfactant Therapy for Meconium Aspiration Syndrome: Systematic Review and Meta-analysis (태변흡인증후군에서 폐표면활성제 사용이 호흡기지표에 미치는 영향에 대한 체계적 문헌고찰과 메타분석)

  • Choi, Hyun-Jin;Hahn, Seo-Kyung;Lee, Soon-Min;Kim, Han-Suk;Bae, Chong-Woo
    • Neonatal Medicine
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    • v.18 no.2
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    • pp.189-196
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    • 2011
  • Purpose: Surfactants have been used to improve oxygenation for infants with meconium aspiration syndrome (MAS). We evaluated the change of pulmonary indices after surfactant therapy for MAS through a systematic meta-analysis. Methods: Relevant randomized controlled studies (RCTs) were identified by database searches in MEDLINE, EMBASE, and CENTRAL, up to June 2011, and by additional hand searches. Data were extracted regarding pulmonary indices, such as the oxygen index and arterial alveolar oxygen gradient. Meta-analyses were separately conducted for the studies of surfactant lavage therapy and surfactant bolus therapy. The risk of bias was assessed, and clinical as well as statistical heterogeneities were also investigated. Results: Two RCTs for bolus surfactant therapy and two RCTs for surfactant lavage therapy were identified. The oxygenation index results were heterogeneous between the two studies in which bolus surfactant therapy was given, while a/A $PO_2$ showed significantly better results in the treatment group over time after use of surfactant (12 hours: WMD 0.08, 95% CI 0.04-0.12; 24 hours: WMD 0.17, 95% CI 0.06-0.28). For surfactant lavage therapy, both studies consistently suggested an interventional benefit in terms of the pulmonary indices although it did not reach statistical significance. Conclusion: Surfactant therapy appeared to improve oxygenation of infants with MAS. Since a limited number of RCTs are available in the current literature and those studies were also clinically heterogeneous in terms of illness severity and the method of surfactant use, further research is needed to gather evidence to support surfactant therapy in MAS.

Numerical Analysis of NDT Using Elastic Stress Waves in Concrete Lining (터널 라이닝내부에서 전파되는 탄성응력파를 이용한 수치해석적 비파괴검사)

  • 김문겸;이재영
    • Computational Structural Engineering
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    • v.11 no.3
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    • pp.187-198
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    • 1998
  • 지하구조물의 건전성을 평가하기 위한 비파괴시험으로써 탄성응력파를 이용한 충격반향탐사법을 수치해석적인 방법을 통하여 수행하였다. 즉, 일면만으로 접근 가능한 터널 면에서의 충격가진과 동적응답의 측정으로 이질면을 포함한 내부의 상태를 예측할 수 있다. 연구의 수행은 탄성거동을 하는 매질 내부에서 전파되는 탄성응력파의 특성을 이해하고, 이를 동적 유한요소해석으로 모형화하여 충격반향탐사법을 수치해석적으로 수행한다. 이질재료가 2개의 층을 이루고 있는 경우 표면층의 두께를 쉽게 측정할 수 있었으며, 구조물의 병진운동, 휨운동과 구조물 내에서 다중반사되는 탄성응력파에 의한 복합적인 영향을 받는 터널과 같은 원통형 구조물에서 동적응답의 주파수 특성으로부터 터널라이닝 내부에 형성된 공동의 위치와 크기의 예측이 가능하였다. 수치해석적인 방법과 병행하여 다양한 형태의 경계조건을 가지는 구조물에 대한 충격반향탐사법의 실험을 수행할 경우 실제적인 문제에 적용, 건전성 평가의 지표를 마련할 수 있을 것으로 사료된다.

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Dyeability and Antibacterial Activity against Food Poisoning Bacteria Dyed with Geranium nepalense Extracts (이질풀 추출물로 염색한 면직물의 염색성과 항식중독균성)

  • Park, Yun-Jum;Kim, Hyun-Ju;Park, Yong-Seo;Cho, Ja-Yong;Jang, Hong-Gi;Heo, Buk-Gu
    • Korean Journal of Medicinal Crop Science
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    • v.14 no.3
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    • pp.139-142
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    • 2006
  • This study was conducted to develop antibacterial hand towel and dishcloth against food poisoning bacteria, and to examine the dyeability and the antibacterial activity of cotton fabrics against food poisoning bacteria, which was dyed with 1 % extracts of Geranium nepalense at $50\;to\;60^{\circ}C$ minutes. Surface colors of cotton fabrics treated nothing, alum $[AIK(SO_4)_2{\cdot}nH_2O]$, and calcium hydroxide $[Ca(OH)_2]$ with mordants showed grayed-yellow group, that treated copper sulfate $(CUSO_4)$ with mordant was grey-brown group, and that treated sulfate of iron $(FeSO_4{\cdot}7H_2O)$ made grayed-green group. Hue value of cotton fabrics dyed with the extracts of Geranium nepalense and dried until twenty times was an order of descent Y, that dried thirty to forty an order of descent YR. Cotton fabrics dyed with the extracts of Geranium nepalense had the antibacterial activity against food poisoning bacteria such as Staphylococcus aureus, Escherichia coil and Salmonella typhimurium by over 99.99%. And that dried over thirty times showed the antibacterial activities against food poisoning bacteria by 52.91%.

Oleophilic Nanocomposites for Oil Spill Adsorbent (유류흡착용 친유성 나노복합체 신소재 제조)

  • ;;;;N.N. Mofa;T.A. Keteguenov;Z.A. Mansurov
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.05a
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    • pp.769-771
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    • 2003
  • 고분산성을 이루는 물질들이 석영(quartz)을 바탕물질로 하여 기계-화학적 반응 기술을 이용하여 제작하였다. 반응의 처리 조건과 이후의 응용에 따라서 기계-화학적 반응을 이용하여 제작한 물질은 자기 특성, 유전체 특성, 전기적 특성을 동시에 나타냈다. 부착성 복합물질의 특징을 고려하여 세그네토 마그네틱스(Segneto-magnetics)로 분류 제작된 자기-전기적 분말은 유전체재료 특성을 나타냈다. 특히, 석영 표면에 하나 또는 그 이상의 이질 화합물 층이 10∼50nm 두께로 합성되어, 자기ㆍ전기적 특성을 나타냈다.

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IE-SASW Method for Nondestructive Testing of Geotechnical Concrete Structure : I. Numerical Studies (콘크리트 지반구조물의 비파괴검사를 위한 충격반향-표면파병행기법 : I. 수치해석적 연구)

  • 김동수;서원석;이광명
    • Journal of the Korean Geotechnical Society
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    • v.18 no.4
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    • pp.257-270
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    • 2002
  • The Impact-Echo(IE) method has been used to evaluate the integrity of concrete structures. In this method, the P-wave velocity of concrete is a crucial parameter in determining the thickness of concrete lining, the location of cracks or other defects. In many field applications of the IE method, the P-wave velocity is obtained by testing the core or the portion of a structure where the exact thickness is known. Occasionally, however, the core can not be obtained in specific structures and the P-wave velocity determined from core testing may not be a representative value of the structure. This study introduces an IE-SASW method that may determine the P-wave velocity on a surface of each testing area using the Spectral Analysis of Surface Wave (SASW) method. Results obtained from numerical studies are presented in this paper (Part I), and results obtained from experimental studies are presented in the companion paper (Part II). In this paper, numerical analyses using ABAQUS were carried out to investigate the effectiveness and the limitations of the IE-SASW method.

Study on the Educational Plan to Enhance Intercultural Abilities Using the Oral Folktales of Immigrants who Mov ed to Korea (이주민 구술 설화를 활용한 상호문화능력 신장의 교육 방안연구)

  • Kim, Jeong-Eun
    • Journal of Korean Classical Literature and Education
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    • no.38
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    • pp.201-238
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    • 2018
  • As a way of enhancing the intercultural ability needed for diverse cultural eras, this study focuses on the "narration" of the Italian education scholar Maddalena De Carlo in order to determine the "diverse values" created by the "symbolic representation" based on the folktales narrated by immigrants living in Korea. Through this, it specifically presents educational elements and contents that can raise relative sensitivity. The authors of this paper have connected, empathized, and communicated with people of various cultures in order to go beyond Carlo's discussion. The paper discusses the expansion of cultural sensitivity as an element of education through narrative topics using the folktales of immigrant narrators in Korea. It also recognizes the limitations of a desire for a homogeneous union within an intercultural society and thus formulates educational contents for creating a relationship with heterogeneous ideas through the elimination of communication barriers through heterogeneity and a consideration of the surface and the back. This is systemized in six steps. Step 1: Listening to oral folktales of immigrants, Step 2: Finding heterogeneous motifs imprinted in the immigrants' memories, Step 3: Understanding the meaning of the opposing qualities symbolized by heterogeneous motifs, Step 4: Creating narrative topics containing the key motifs, Step 5: Generating the value of symbolic representation as a narrative topic, and Step 6: Expanding the value of life into a cultural symbol. In Chapter 3, this study focuses on educational contents using immigrants' folktales by applying these six steps. The class contents include the recognition of the limitations of desire for a homogeneous union within an intercultural society and the consideration of how to create a relationship with heterogeneous ideas through the elimination of communication barriers through heterogeneity and consideration of the surface and the back. This paper then compares the Indonesian folktale, The Inverted Ship Mountain and the Mom's Mountain, with the world-famous Oedipus myth, to determine what the symbolic representation of these heterogeneous motifs is. In Step 6, when the symbolic system is culturally extended, the incestuous desire that appears in the "inverted ship" is interpreted as a fixation that was created when the character sought to unite with homogenous idea. The Cambodian folktale, The Girl and the Tiger, is a story that is reminiscent of the Korean folktale, The Old Man with a Lump. Through the motif in "Tiger," this paper generates a narrative topic that will enhance the students' intercultural abilities by culturally expanding their skills in how to relate with a heterogeneous being that is usually represented as an animal. The Vietnamese folktale, The Coconut Bowl, similar to the Korean folktale, GureongDeongDeong SinSeonBi, is a story that draws a variety of considerations about the surface and theback, and it shows readers how to build a relationship with a heterogeneous idea and how to develop and grow with such a relationship. Thus, if a narrative topic is generated and readers are able to empathize using an opposing feature formed by the core motif of the folktale, it becomes possible, through immigrant folklore, to construct a possibility of a new life through the formation of a relationship with an unfamiliar and heterogeneous culture.

A Study on Rainfall-induced Erosion of Land Surface on Reinforced Slope Using Soil Improvement Material (지반 개량재에 의한 보강사면의 강우시 표면침식에 관한 연구)

  • Kim, You-Seong;Kim, Jae-Hong;Bhang, In-Hwang;Seo, Se-Gwan
    • Journal of the Korean Geotechnical Society
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    • v.29 no.1
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    • pp.49-59
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    • 2013
  • Heavy rainfall intensity may cause shallow slope failures and debris flow by rill erosion and scour on land surface. The paper represents the difference between native soil (weathered soil) and reinforced soil, which is mixed by hardening agent with flyash as main material, for investigating experimental findings of rill erosion and erosion. Results obtained from artificial rainfall simulator show that erosion rate of reinforced soil mixed with hardening agent is reduced by 20% because an amount of eroded soil on slope surface is inversely proportional to the increase of soil strength. For example, rainfall of 45mm (at the elapsed time of 25mins in rainfall intensity of 110mm/hr) triggers rill erosion on native soil surface, but the rill erosion on reinforced soil surface does not even occur at 330mm rainfall (at the elapsed time of 3hrs in rainfall intensity of 110mm/hr). As a result of slope stability analysis, it was found that the construction method for reinforced soil surface would be more economical, easy and fast construction technology than conventional reinforcement method.