• 제목/요약/키워드: various

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페놀수지의 마찰특성에 미치는 HEXA의 함량 및 경화도의 영향 (The effect of hexamethylenetetramine contents and cure properties on friction characteristics of phenolic resin)

  • 김대균;장호;윤호규
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1999년도 제30회 추계학술대회
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    • pp.49-56
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    • 1999
  • A material was formulated with Phenol novolac and HEXA only. The cure kinetics and thermal characteristics of phenol novolac with various HEXA contents were peformed by differential scanning calorimetry and thermal gravimetric analysis. All kinetic parameters of the curing reaction including the reaction order, activation energy, and rate constant were calculated and reported. The results indicate that the curing reaction goes through an autocatalytic kinetic mechanism. The friction and wear characteristics of this material were determined using friction material testing machine. The friction coefficient of phenol novolac with various HEXA contents was determined using the PV(pressure & velocity) factor. The most stable and highest friction coefficient with a various pressure and velocity condition was found at HEXA 10 wt.% material. The specific wear rate per unit sliding distance with a various HEXA contents was reported.

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SKD 11 금형 표면처리에 따른 AZ31 판재 마찰 특성 연구 (Study on the Friction Characteristics for AZ31 Sheet as Various Surface Treatment of SKD11)

  • 장성호;신광호;김흥규;전용준;허영무
    • 소성∙가공
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    • 제19권7호
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    • pp.429-434
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    • 2010
  • The material used is a commercial magnesium based alloy AZ31(Mg-3Al-1Zn) sheet with a thickness of 0.8 mm. Friction tests at various temperatures(R.T. to $200^{\circ}C$) and at various holding forces in the 4 type molds were carried out to investigate the coefficient of friction. A warm drawing process with a local heating and cooling technique was developed in the Mg alloy sheet forming to improve formability because it is very difficult for Mg alloy to deform at room temperature by the conventional method. So, the coefficient of friction at various mold surface treatment conditions in this study was needed to develop the Mg alloy sheet forming technology.

Photoinduced Electron- and Energy-Transfer Processes in Supramolecules using Imide Compounds

  • Fujitsuka, Mamoru;Majima, Tetsuro
    • Rapid Communication in Photoscience
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    • 제3권1호
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    • pp.1-15
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    • 2014
  • We summarize recent studies on photoinduced electron- and energy-transfer processes of various supramolecules including imide group(s) as a component. Recently, imides have been employed in various functional molecular systems, because of their excellent photophysical and electron accepting properties. Our research group also employed imides in various supramolecular systems such as donor-acceptor dyads, quantum dots, DNA, and so on. First, we summarize fundamental properties of imides such as photophysical and electrochemical properties. Then, photoinduced processes of imides in the supramolecular systems are described to show their applicability in the various fields.

한정사 '도'의 의미-화용론 (Semantic and pragmatic aspects of the delimiter to)

  • 김용범
    • 한국언어정보학회지:언어와정보
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    • 제3권2호
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    • pp.85-96
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    • 1999
  • This paper deals with questions involving the polysemous meanings of Korean delimiter to, which include existence of a sister item, polar values, emphasis, reciprocality, and concession among others. In this paper it is argued that the basic meaning of to is the implication of a sister proposition and that various other meanings can be pragmatically derived from the basic meaning. The pragmatic notion of emphasis is defined formally and it is shown that various meanings of to can be accounted for by investigating how the speaker exploits the background knowledge which the speaker and the listener share in a speech context. According to what type of the context is made use of by the speaker, the various polysemous meanings are analyzed as involving either a simple implicature or a series of implicatures, i.e., scalar implicatures, so the various meanings of the delimiter can be attributable to the different attunement of the speaker to different kinds of context.

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대나무를 이용한 각종 화학펄프 제조에 관한 연구 (Studies on the production of Various Chemical Pulps from Bamboo)

  • 강진하;박성종
    • 펄프종이기술
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    • 제32권3호
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    • pp.57-64
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    • 2000
  • This study was carried out to acquire basic data necessary for the use of non-wood pulp. It investigated various chemical pulping methods using bamboo to achieve higher yield lower kappa no. and then the physical properties of various pulps were tested. The results of this study were as follows. When various chemical pulps(Soda, Soda-AQ, Soda-AQ-H2O2, Soda-urea, AS, AS-AQ, Kraft) were produced with bamboo. the pulps with the higher yield and lower kappa no. were AS-AQ and Kraft. In the case of the breaking length Soda pulps(5.77∼6.46 km) showed the greatest and Soda-urea pulps(3.81∼4.522km) showed the lower value. Similarly for the burst index Soda pulps (3.28∼3.50 kPa$.$m2/g) were the best and Soda-urea pulps(2.29∼2.39 kPa$.$m2/g) were worst. On the other hand the tearing indexes of AS-AQ pulps(73.6∼89.7mN$.$m2/g) showed the tendency which was higher then those of other pulps.

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유체장 변화에 따른 사각형 탱크의 진동에 관한 연구 (Case Study on Hydroelastic Vibration of Plate for Various Bounded Fluid Field)

  • 최수현;조현동;김극수
    • 한국소음진동공학회논문집
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    • 제17권1호
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    • pp.3-9
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    • 2007
  • In this paper, a numerical case study is carried out on the hydroelastic vibration of rectangular plate with various fluid field. It is assumed that the tank wall is clamped along the plate edges. The VMM(virtual mass method) of Nastran is used for the simulation of fluid domain and calculating natural frequency of fluid-coupled structure. In this paper, natural frequencies are calculated and compared for rectangular plates with various fluid field such as infinite fluid and finite fluid, length change of finite fluid field and various fluid contacting conditions.

White Light Emission with Quantum Dots: A Review

  • Kim, Nam Hun;Jeong, Jaehak;Chae, Heeyeop
    • Applied Science and Convergence Technology
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    • 제25권1호
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    • pp.1-6
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    • 2016
  • Quantum dots (QDs) are considered as excellent color conversion and self-emitting materials for display and lighting applications. In this article, various technologies which can be used to realize white light emission with QDs are discussed. QDs have good color purity with a narrow emission spectrum and tunable optical properties with size control capabilities. For white light emission with a color-conversion approach, QDs are combined with blue-emitting inorganic and organic light-emitting diodes (LED) to generate white emission with high energy conversion efficiency and a high color rendering index for various display and lighting applications. Various device structures for self-emitting white QD light-emitting diodes (QD-LED) are also reviewed. Various stacking and patterning technologies are discussed in relation to QD-LED devices.

Electrocatalytic Reduction of Dioxygen at Schiff base Co(II) Complexes supported Glassy Carbon Electrode in various pH Solution

  • Park, Kyoung-Hee;Rim, Chae-Pyeong;Chjo, Ki-Hyung;Jeon, Seungwon;Choi, Yong-Kook
    • 분석과학
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    • 제8권4호
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    • pp.617-622
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    • 1995
  • Electrocatalytic reduction of dioxygen has been investigated by cyclic voltammetry at glassy carbon electrode modified with new Co(II)-Schiff base complexes in aqueous solutions of various pH. The reduction potentials of dioxygen at chemically adsorbed electrodes show the dependence of pH between pH 4 and 14. The catalytic effect is large and the reaction occurs via two or four electron transfer in various pH solution.

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Grid Management System and Information System for Semantic Grid Middleware

  • Kim, Hyung-Lae;Han, Byong-John;Jeong, In-Yong;Jeong, Chang-Sung
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제4권6호
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    • pp.1080-1097
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    • 2010
  • Well organized and easy usable Grid management system is very important for executing various Grid applications and managing Grid computing environment. Moreover, information system which can support Grid management system by providing various Grid environment related information is also one of the most interesting issue in the Grid middleware system area. Effective cooperation between Grid management system and information system can make a novel Grid middleware system. Especially, service oriented architecture based Grid management system is flexible and extensible for providing various type of Grid services. Also, information system based on data mining process which comprises various different kinds of domains such as users, resources and applications can make Grid management system more precise and efficient. In this paper, we propose semantic Grid middleware system which is a combination of Grid management system and semantic information system.

다양한 Laser를 이용한 Peri-Implantitis의 치료 (The treatment of peri-implantitis using various types of lasers)

  • 유재식;김수관;안종모
    • 대한치과의사협회지
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    • 제53권12호
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    • pp.906-909
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    • 2015
  • Peri-implantitis is the inflammatory process, such as edema, bleeding, pus, of the mucosa surrounding dental implants. As the symptoms become severe, the surrounding bone is absorbed causing the implant surface to be exposed. Clinicians treat periimplantitis in various ways since a gold standard for the treatment of peri-implantitis has not been established. Various treatment methods include mechanical, chemical surface treatment and surgical excision, and recently decontamination of the implant surface using various types of lasers has been proposed. Thus, this study reviews the types of lasers and its effects that can be used for the treatment of peri-implantitis.