• 제목/요약/키워드: compounding

검색결과 339건 처리시간 0.025초

고분자 나노복합재료의 가공조건 및 물성 최적화 (Optimization of Processing Conditions and Mechanical Properties in Polymer Nanocomposite)

  • 남병욱;홍채환;황태원
    • 한국자동차공학회논문집
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    • 제15권6호
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    • pp.73-80
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    • 2007
  • Nanocomposites are used as a new class of polymer system and many researchers have been interested in the clay nanocomposite because of its good mechanical properties, heat resistance, flame retardancy, and barrier property. Modified layered silicates as fillers are dispersed at a nanometer-level within a polymer matrix and then new extraordinary properties are observed. In this study, polypropylene/clay nanocomposites were prepared in a twin screw extruder by the melt compounding method. In order to increase the compatibility of PP with the clay, the MAPP was used as a compatibilizer. And organic modified clays were used as a nanometric filler during the melt extrusion. Through the analysis of SAXS, WAXS, the dispersion of clay was investigated. These nanocomposites compared with a neat polypropylene/talc composite have high modulus, low toughness, and reduced shrinkage at the stable dispersion.

NBR/Clay 나노복합체의 제조와 특성에 관한 연구 (Preparation and Mechanical Properties of NBR/Clay Nanocomposite)

  • 이돈;박세형;서길수
    • 폴리머
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    • 제34권3호
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    • pp.215-219
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    • 2010
  • 충전제로서 Cloisite$^{(R)}$ 10A와 carbon black을 사용하여 NBR 복합체를 제조하였다. 충전제로서 Cloisite$^{(R)}$ 10A를 사용했을 경우 복합재료의 기계적 물성, 내유성, 그리고 산소 투과성 등이 carbon black을 사용했을 경우 보다 우수하였다. 특히, 복합재료의 경화에 있어서 Cloisite$^{(R)}$ 10A를 사용하였을 경우 scorch 시간과 경화시간이 단축됨을 확인할 수 있었다. 이러한 결과로부터 Cloisite$^{(R)}$ 10A에 삽입되어 있는 알킬 암모늄 이온이 복합재료에 있어 가황 촉진제의 역할을 하고 있음을 알았다.

노인의 낙상과 연관된 위험요소와 균형 측정 방법 (Risk Factors and Methods in Balance Assessment Associated with Fall in Older Adults)

  • 이윤경;배성수
    • 대한물리의학회지
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    • 제2권1호
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    • pp.73-84
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    • 2007
  • Purpose : The purpose of this study was to determine risk factors and methods in balance assessment associated with fall in older adults. Methods : This article describes many of the tools that can be used to evaluate the physical parameters associated with fall risk in older adults. Results : Composite ratings of performance(Tinetti balance assessment, Guralnik test battery, Berg balance scale, modified-physical performance test) measures the score compounding the balance measure to determine fall risk. Static balance instruments are composed of FICSIT-4 that measures the ability of maintaining foot positions and CTSIB that measures postural stability. Dynamic balance instrument is composed of functional reach test. To measure walking velocity and mobility, 8-foot up-and-go test and walking around two cones are used. We can use 1-RM and to measure muscular strength, isokinetic dynamometery, and 30-second chair stand to measure lower extremity muscle strength. Conclusion : The described instruments are easy to use and widespread. To select and use these tool kits carefully is considered to be helpful in identifying those who are most likely to fall. The final part of the article includes a brief discussion of the potential role of exercise training interventions to improve these physical parameters and prevent falls.

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한의학과 불교의 관점에서 본 호흡에 대한 고찰 (A Study of Respiration Techniques Considered From An Oriental Medicine and Buddhistic Viewpoint)

  • 구병수
    • 동의신경정신과학회지
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    • 제16권2호
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    • pp.43-52
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    • 2005
  • Objectives : This study is an investigation the clinical development of oriental neuropsychiatry through the practical application of respiration techniques in oriental medicine and Buddhism. Methods : Oriental medicine and Buddhism both make much use of respiration techniques. According to a comparative study on these; A group for the clinical application of oriental medical respiration methods, and A study both the differences and common features of oriental medical and Buddhist respiration techniques, to deliver therapeutic and preventive medical assistance to patients. Results and Conclusion : 1. Oriental medical respiration techniques have as their object the prevention and treatment of disease through smooth circulation of Gi(氣) and Hyeol(血) according to the concentration of the mind on acupuncture points. 2. Buddhist respiration techniques make use of planned psychological rest and ascetic practical expedience according to the close observation of the five senses(五感) of the real world through exhalation(呼) and inhalation(吸) based on Buddhist philosophy. 3. Although the pursuit of oriental medicine and Buddhism can be different, I think a need to develop new respiration techniques can lead to psychological balance and medical treatment through compounding both sets of knowledge.

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Jean Dubuffet의 앗상블라주(Assemblage)를 응용한 네일아트 디자인 (Nail Art Design Applied Jean Dubuffet's Assemblage)

  • 정애란
    • 복식
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    • 제55권4호
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    • pp.29-37
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    • 2005
  • Beauty Art is an act which makes a face beautiful using various methods such as permanent, manicure and make-up. Recently, Beauty Art is recognized as the personal culture expressing the value of beauty and spirit. Therefore, there are growing interests in the comprehensive study of Beauty Art nor only from the beauty industries but also from academia, because Beauty Art is the high value-added field and Is recognized as a style of the dress. The purpose of this study is to open a new view to understand the Nail Art as a fold of experimental plastic art. The arctic expression is added to Beauty Art to develop it from the routine technique of the make-up and hairstyling to creative art. Assemblage is adopted to provide Beauty Art with fine harmonious expression which develop Nail Art into interesting and unique art area. Assemblage meaning compounding or collection is a technique through which three-dimension is added to two-dimension paintings, and which is an expression of an art work by recollection of miscellaneous articles or waste materials. Assemblage is a term which Jean Dubuffet coioned first in order to differentiate collage used by Picaso or Braque. Here, I present Nail Art Designs which applied Jean Dubuffet's works focusing on Automaticity and Happenstantial phenomena of materials, Materialization, and Directness. These features are characteristics of Assemblage which basic frameworks are fantastic collection, accumulation, constructive collection, and object collection.

TiO2, Carbonblack 및 POE로 보강된 열가소성 PETG 복합재료의 특성 (Characterization of PETG Thermoplastic Composites Enhanced TiO2, Carbon Black, and POE)

  • 유성훈;이종혁;심지현
    • 한국염색가공학회지
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    • 제31권4호
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    • pp.354-362
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    • 2019
  • In order to apply thermoplastic composites using PETG resin to various industrial fields such as bicycle frames and industrial parts, it is necessary to verify the impact resistance, durability and mechanical properties of the manufactured composite materials. To improve the mechanical properties, durability and impact resistance of PETG resin, an amorphous resin, in this study, compound and injection molding process were carried out using various additives such as TiO2, carbon black, polyolefin elastomer, and PETG amorphous resin. The thermal and mechanical properties of the thermoplastic composites, and the Charpy impact strength. The analysis was performed to evaluate the characteristics according to the types of additives. DSC and DMA analyzes were performed for thermal properties, and tensile strength, flexural strength, and tensile strength change rate were measured using a universal testing machine to evaluate mechanical properties. Charpy impact strength test was conducted to analyze the impact characteristics, and the fracture section was analyzed after the impact strength test. In the case of POE material-added thermoplastic composites, thermal and mechanical properties tend to decrease, but workability and impact resistance tend to be superior to those of PETG materials.

양방향 스위치를 이용한 고효율 H-Bridge 멀티레벨 인버터 시스템 (High Efficiency H-Bridge Multilevel Inverter System Using Bidirectional Switches)

  • 이화춘;황정구;김선필;최우석;이상혁;박성미;박성준
    • 조명전기설비학회논문지
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    • 제28권10호
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    • pp.16-26
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    • 2014
  • This paper proposes new 13-level inverter topology and DC/DC converter buck-boost structure topology for multilevel, compounding uni-directional and bi-directional switches, and proposes high-efficient multilevel inverter system in which the proposed two PCS(Power Conditioning System) was connected in series. In proposed multilevel inverter of forming a output 13-level phase voltage by using total 18 switching parts, Then bi-directional switch has a characteristic of reducing conduction loss and controlling the reactive power effectively by separating electrically from the neutral point. DC/DC converter for supplying in dependent 3 DC voltage to the proposed multi-level inverter generates 180-degree phase shifted PWM by the symmetrically combined structure of 2 buck-boost converter and twice switching frequency efficiency can be obtained, meanwhile, the converter can step up/down the output voltage and 20% output can be generated comparing the input voltage. This proposed system is verified with the simulation and laboratory test.

DDC의 패싯 구조에 대한 연구 -생명과학과 문학을 중심으로- (A Study on the Facet Structure of Life Science and Literature in DDC)

    • 한국도서관정보학회지
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    • 제30권3호
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    • pp.53-96
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    • 1999
  • This study intends to : 1) confirm the possibility to transform the enumerated scheme into the faceted scheme, 2) review general theories on facet structure employed in DDC of the enumerated scheme, 3) analyze the facet structure of life science and literature in DDC, and 4) comparison of the facet structure of life science and literature in DDC and CC. This study suggests following conclusions. 1) CC follows throughly the classification principles by Ranganathan, but all classification theories are not property applied to DDC yet. 2) Because DDC does not have any formula to classify the compound subject, but has to follow the compounding methods presented in each subject, its facet structure is too complicated. 3) DDC has transformed the entire system into the facet structure through its revision. Expecially the life science transformed into the facet structure employed the facet indicators and applies them to all the systems in life science. But the notations have sometimes twofold meanings, and no ability to differentiate the meanings in the same notation,. When DDC follows the classification method by facet, the number of items for classification so limited that it is difficult to array the subdivision and that length of notation becomes longer and longer.

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참조용어(Reference Terminology) 모델 확장을 위한 한의학용어 정형화(Normalization) 연구 (A study of Traditional Korean Medicine(TKM) term's Normalization for Enlarged Reference terminology model)

  • 전병욱;홍성천
    • 대한한의정보학회지
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    • 제15권2호
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    • pp.1-6
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    • 2009
  • The discipline of terminology is based on its own theoretical principles and consists primarily of the following aspects: analysing the concepts and concept structures used in a field or domain of activity, identifying the terms assigned to the concepts, in the case of bilingual or multilingual terminology, establishing correspondences between terms in the various languages, creating new terms, as required. The word properties has syntax, morphology and orthography. The syntax is that how words are put together. The morphology is consist of inflection, derivation, and compounding. The orthography is spelling. Otherwise, the terms of TKM(Traditional Korean Medicine) is two important element of visual character and phonetic notation. A visual character consist of spell, sort words, stop words, etc. For example, that is a case of sort words in which this '다한', '한다', '多汗', '汗多' as same. A phonetic notation consist of palatalization, initial law, etc. For example, that is a case of palatalization in which this '수족랭', '수족냉', '手足冷', '手足冷' as same. Therefore, to enlarged reference terminology is a method by term's normalization. For such a reason, TKM's terms of normalization is necessary.

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Heat-induced coarsening of layer-by-layer assembled mixed Au and Pd nanoparticles

  • Shon, Young-Seok;Shon, Dayeon Judy;Truong, Van;Gavia, Diego J.;Torrico, Raul;Abate, Yohannes
    • Advances in nano research
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    • 제2권1호
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    • pp.57-67
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    • 2014
  • This article shows the coarsening behavior of nanoparticle multilayers during heat treatments which produce larger metallic nanostructures with varying shapes and sizes on glass slides. Nanoparticle multilayer films are initially constructed via the layer-by-layer self-assembly of small and monodispersed gold and/or palladium nanoparticles with different compositions (gold only, palladium only, or both gold and palladium) and assembly orders (compounding layers of gold layers over palladium layers or vice versa). Upon heating the slides at $600^{\circ}C$, the surface nanoparticles undergo coalescence becoming larger nanostructured metallic films. UV-Vis results show a clear reliance of the layering sequence on the optical properties of these metal films, which demonstrates an importance of the outmost (top) layers in each nanoparticle multilayer films. Topographic surface features show that the heat treatments of nanoparticle multilayer films result in the nucleation of nanoparticles and the formation of metallic cluster structures. The results confirm that different composition and layering sequence of nanoparticle multilayer films clearly affect the coalescence behavior of nanoparticles during heat treatments.