• 제목/요약/키워드: internal materials

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당뇨병성 말초 신경병증에 대한 천연제제의 효과 연구 고찰 (Review of Natural Materials in Diabetic Peripheral Neuropathy)

  • 김진미;정호영;박상우;윤성식;조충식;김철중
    • 동의생리병리학회지
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    • 제25권6호
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    • pp.1056-1060
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    • 2011
  • To summarize and make a reference number of natural materials used to treat diabetic peripheral neuropathy. We surveyed all papers of diabetic peripheral neuropathy studies using natural materials in PubMed as "diabetic peripheral neuropathy AND plant", "diabetic peripheral neuropathy AND herbal", "diabetic peripheral neuropathy AND herb", etc. The number of papers, the formation of experiments, frequency of natural materials studies, and main studies were analyzed. Total 48 studies were finally selected. Of the papers, experiments with rats were the most common. Most studies were about fatty acids or herbal medicines. Rehmannia glutinosa, Cinnamomi Ramulus, Astragali Radix and so on were relatively studied much. This study produced an overview of worldwide natural materials used for diabetic peripheral neuropathy. This result may provide a valuable information of development of Korean herbal medicine used to treat diabetic peripheral neuropathy.

INFLUENCE OF INCLUSION ON INTERNAL DEFECT IN MULTI-STAGE EXTRUSION

  • Yoshida Y.;Fukaya Y.;Yukawa N.;Ishikawa T.;Ito K.
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2003년도 The 8th Asian Symposium on Precision Forging ASPF
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    • pp.51-54
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    • 2003
  • Internal defects such as chevron crack occasionally occur in the process of cold extrusion or cold drawing. It is known that the existence and property of inclusion greatly influences the generation of the internal crack. However, in the plastic working field, research about the effect of the inclusion on the fracture is not theoretically analyzed. This paper describes effects of the physical property of inclusion on the internal fracture generation in the process. Prediction of fracture was evaluated by critical damage value calculated by the equation of Cockcroft & Latham and its change by the inclusion physical property such as size and stiffness was investigated.

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건축물의 화재안전설계를 위한 각국의 내·외장재 기준 비교 연구 (Comparative Study on the Standards of Internal and External Materials of Each Country for Fire Safety of Buildings)

  • 허예림;김윤성;이병흔;권영진
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2021년도 봄 학술논문 발표대회
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    • pp.170-171
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    • 2021
  • In Korea, the concentration of cities has led to the high-rise and deep-rise of buildings. In the case of such high-rise buildings, there is a high risk of fire, and the number of internal fires expanding to the outside continues to increase. The Korean Building Act continues to change the ban on combustible exterior materials, and combustible exterior materials are currently not available for buildings with three stories or more than 9 meters, and detailed test standards for finishing materials are also strengthened after the Ulsan residential and commercial fires in 2020. However, the path of fire in the actual building is through a series of processes in which the fire in the compartment grows internally and expands through openings supplied with ventilation factors. Therefore, other than just external materials, design criteria for embedded materials also need to be established. The purpose of this study is to compare standards for internal and external materials at home and abroad and to secure basic data for fire safety design of buildings based on them.

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내첨 형광증백제의 형광현상에 영향하는 인자에 대한 연구 (Study on the Factors Influencing the Fluorescence Index of Internal Fluorescent Whitening Agent)

  • 임기백;이지영;김철환;김선영;박종혜
    • 펄프종이기술
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    • 제46권1호
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    • pp.11-17
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    • 2014
  • This study analyzed the effects of specific factors on the fluorescence index of the fluorescent whitening agent (FWA) that is used for internal addition. The specific factors were identified by the literature review, and a statistical survey was carried out to analyze the effects of those factors on the fluorescence index. Bulk, grammage, fillers and internal sizing agents were selected as the specific factors. The paper samples were prepared with internal FWA in a laboratory. The fluorescence indices of the model papers were measured, and p-values of the specific factors on the fluorescence index were calculated by the SPSS program. Most of p-values were greater than 0.05, so the specific factors do not have a significant impact on the internal FWA fluorescence index.

A micro-computed tomography evaluation of voids using calcium silicate-based materials in teeth with simulated internal root resorption

  • Tek, Vildan;Turker, Sevinc Aktemur
    • Restorative Dentistry and Endodontics
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    • 제45권1호
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    • pp.5.1-5.8
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    • 2020
  • Objectives: The obturation quality of MTA, Biodentine, Total Fill BC root canal sealer (RCS), and warm gutta-percha (WGP) in teeth with simulated internal root resorption (IRR) was evaluated by using micro-computed tomography. Materials and Methods: Standardized IRR cavities were created using 40 extracted maxillary central incisor teeth and randomly assigned into 4 groups (n = 10). IRR cavities were filled with MTA, Biodentine, Total Fill BC RCS (bulk-fill form) and WGP + Total Fill BC RCS. Percentage of voids between resorptive cavity walls and obturation material (external void), and inside the filling materials (internal voids) were measured. Results: Total Fill BC sealer in the bulk-fill form presented significantly highest values of external and internal void percentages (p < 0.05). Biodentine showed a significantly lowest external void percentage (p < 0.05). WGP + Total Fill BC RCS presented significantly lower values of internal void percentages than all groups (p < 0.05), except Biodentine (p > 0.05). Conclusion: None of the filling materials were created void-free obturation in resorption cavities. Biodentine may favor its application in teeth with IRR over Angelus MTA and bulkfill form of Total Fill BC.

트럭용 커넥팅 로드 소재의 내부 품질에 따른 기계적 특성 연구 (A study on the Mechanical Characteristics by the Internal Quality of Connecting Rod Materials for Trucks)

  • 김동현
    • 한국생산제조학회지
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    • 제7권1호
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    • pp.75-81
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    • 1998
  • We have studied internal quality including chemical compositions, microscopic structure and nonmetallic inclusion of test materials. We have analyzed tensile strength value, hardness value, impact value etc. In analyzing internal quality, all of the test materials showed typical ferrite+pearlite structure. But nonmetallic inclusion showed oxide and sulfide inclusions in medium carbon steels, and sulfide inclusion is S-free cutting steels. In ca+ S-free cutting steels, the calcium aluminate and sulfide complex inclusion had low-melting points as deformation of sulfide and oxide inclusion is existed. It was found that tensile strength and hardness give maximum value in medium carbon steels, where as minimum in Ca + -free cutting steels. But values of elongation, reduction of area impact are reverse. Fracture surface of impact specimen is ductile in free cutting steels but brittle in medium cabon steels.

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트럭용 커낵팅 로드 소재의 내부 품질에 따른 절삭 특성 연구 (A Study on the Machining Characteristics by the Internal Quality of Conecting Rod's Meterials for Trucks)

  • 김동현
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 춘계학술대회 논문집
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    • pp.97-101
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    • 1996
  • In this paper, We have studied internal quality incluiding chemical compositions, microscopic structrue and nonmetalic inclusion of test materials. We have analyzed dynamic characteristics of cutting resistence including tensile strength value, hardeness value, impact value etcs. We have compared chip treatments of test materials. In analyzing internal quality, all of test materials have typical ferrite+pearlite structure. But, nonmetallic inclusion have oxide and sulfide inclusion in medium carbon steels, mainly sulfide inclusion is existed in S-free cutting steels. In Ca+S-free cutting steels, calcium aluminate and sulfide complex inclusion, had low-melting points, as deformation of sulfide and oxide inclusion is existed. machining characteristics, cutting resistence is maximum in Ca+S-free cutting steels, minimum in medium carbon steels. Chip treatements are excellent in S-free cutting steels, similar to the Ca+S free cutting steels and medium carbon steels.

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Internal modification in transparent materials using plasma formation induced by a femtosecond laser

  • Park, Jung-Kyu;Yoon, Ji-Wook;Cho, Sung-Hak
    • 한국레이저가공학회지
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    • 제15권1호
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    • pp.15-19
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    • 2012
  • The fabrication of internal diffraction gratings with photoinduced refractive index modification in transparent materials was demonstrated using low-density plasma formation excited by a femtosecond (130 fs) Ti: sapphire laser (${\lambda}_p$=800 nm). The refractive index modifications with diameters ranging from $1{\mu}m$ to $3{\mu}m$ were photoinduced after plasma formation occurred upon irradiation with peak intensities of more than $2.0{\times}10^{13}W/cm^2$. The graded refractive index profile was fabricated to be a symmetric around from the center of the point at which low-density plasma occurred.

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응고조직 및 성분편석에 미치는 내부냉금의 효과 (The Effect of Internal Chills on the Solidified Structure and Chemical Segregation)

  • 김명한;조현남;김정겸;조형호
    • 한국재료학회지
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    • 제9권9호
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    • pp.883-889
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    • 1999
  • 직경이 각각 4,6,8,12 및 15mm인 순Al 또는 Al-(1,2,3wt%) Cu합금 내부냉금이 95mm ø$\times$200mm H 크기의 흑연주형 중심부에 설치되었다. 이 내부냉금과 같은 조성의 용융금속이 $750^{\circ}C$의 주입온도에서 주형에 주입되었고, 냉각속도, 응고조직 및 성분편석이 분석되었다. 주괴직경/내부냉금직경의 비가 8까지 증가될수록 결정립도, 2차수지상간격 및 성분편석이 현저하게 감소됨이 확인되었다. 그러나 이 비가 8이상이 되면, 미용해 내부냉금이 발생되고, 내부냉금의 효과는 급속히 감소되었다. 순Al 및 Al-(1,2,3wt%)Cu 합금에서 최대 내부냉금 효과를 얻을 수 있는 적정 주괴직경/내부냉금직경의 비는 $750^{\circ}C$주입온도에서는 8이었다.

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