• Title/Summary/Keyword: Internal properties

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AC Dielectric Breakdown Properties and Mechanical Properties of Interpenetrating Polymer Network Epoxy Resin (상호침입망목 에폭시수지의 교류 절연파괴특성 및 기계적 특성)

  • 이덕진;김명호;김경환;심종탁;손인환;김재환
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.11a
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    • pp.320-323
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    • 1995
  • In this paper, in order to improve withstand voltage properties of epoxy resin, IPN(interpenetrating polymer network) method was introduced and the influence was investigated. The sing1e network structure specimen(E series), simultaneous interpenetrating polymer network specimen(EMF series) and pseudo interpenetrating polymer network(EMP series) specimen were manufactured. In order to understand the internal structure properties, scanning electron microscopy method was utilized, rind glass transition temperature was measured. Also, AC voltage dielectric strength, tensile strength and impact strength were measured to investigate influence upon electrical and mechanical properties. As a result, it was confirmed that simultaneous interpenetrating polymer network specimen was the most execellent.

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Constructional Constraints in English Free Relative Constructions

  • Kim, Jong-Bok
    • Language and Information
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    • v.5 no.1
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    • pp.35-53
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    • 2001
  • As a subtype of English relative clause constructions, free relative constructions like what John ate in I ate what John ate exhibit complicated syntactic and semantic properties. In particular, the constructions have mixed properties of nominal and verbal: they have the internal syntax of sentence and the external syntax of noun phrase. This paper provides a constraint-based approach to these mixed constructions, and shows that simple constructional constraints are enough to capture their complexities. The paper begins by surveying the properties of the constructions. In discusses two types(Specific and nonspecific) of free relatives, their ,lexical restrictions nominal properties and behavior with respect to extraposition, piped piping and stacking Following these it sketches the basic framework of the HPSG(Head-driven Phrase Structure Grammar) which is of relevance in this paper. As the main part, the paper presents a constraint- based analysis in which tight interactions between grammatical constructions and a rich network of inheritance relations play important roles in accounting for the basic as well as complex properties of the constructions is question.

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A Study on the Dielectric Characteristics in Epoxy Resins due to Variation of Network Structures (망목 구조 변화에 따른 에폭시 수지의 유전 특성에 관한 연구)

  • 김재환;손인환;심종탁;김경환;김명호;최병옥
    • Electrical & Electronic Materials
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    • v.10 no.7
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    • pp.651-658
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    • 1997
  • In this paper, effect of interpenetrating polymer network(IPN) introduction on the dielectric properties, heat proof properties, internal structure and defects of the Epoxy/SiO$_2$composite materials, were investigated. we reported a relation between network structures and electrical properties, especially dielectric characteristics with variation of network structures for epoxy composite materials. According to experimental results, the specimens which have single network structures have lower dielectric constant than interpenetrating polymer network(IPN) specimens, but have relatively larger dependency to variation of temperature and frequency. It was confirmed that change of structures is attained by introducing of IPN to insulating materials. Therefore it is counted that introduction of multiple structure including IPN is necessary to improve heat proof and electrical properties.

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Effect of heat treatment of core fabricated by Ni-Cr alloy on marginal and internal fit (열처리가 Ni-Cr 합금으로 제작된 하부구조물의 변연 및 내면 간격에 미치는 영향)

  • Kim, Jae-Hong;Kim, Ki-Baek;Jung, Jae-Kwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.9
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    • pp.244-250
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    • 2017
  • The most important aspect determining the completeness of aprosthesis is itsmarginal and internal fit. Alloysare processed using a softening/hardening heat treatment methodin order to improve their mechanical, physical properties and polishing properties. To examinehow the heat treatment method affects the marginal and internal fit of the Ni-Cr alloy core,thirty dental stone models of the abutment of the mandibular left molar were manufactured.The Ni-Cr alloy coreswere manufactured by the dipping method for the experiment and dividedinto three groups; A for no heat treatment, B for softening heat treatment and C for hardening heat treatment. The marginal and internal fitsof all of the groups were measured by the silicone replica technique. A statistical analysis was performed using one-way ANOVA(${\alpha}=0.05$) in order to examine whether there is a significant difference in the average values of the marginal and internal fits among the three groups and it was found that themarginal fits (1, 6) were significantly different (p<0.05), but the internal fits (2, 3, 4, 5) were not significantly different (p>0.05). These results show that Ni-Cr alloys should not be processed bythe heat treatmentmethod.However, they need to be confirmed in further clinical application studies.

Comparisons of internal self-field magnetic flux densities between recent Nb3Sn fusion magnet CICC cable designs

  • Kwon, S.P.
    • Progress in Superconductivity and Cryogenics
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    • v.18 no.3
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    • pp.10-20
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    • 2016
  • The Cable-In-Conduit-Conductor (CICC) for the ITER tokamak Central Solenoid (CS) has undergone design change since the first prototype conductor sample was tested in 2010. After tests showed that the performance of initial conductor samples degraded rapidly without stabilization, an alternate design with shorter sub-cable twist pitches was tested and discovered to satisfy performance requirements, namely that the minimum current sharing temperature ($T_{cs}$) remained above a given limit under DC bias. With consistent successful performance of ITER CS conductor CICC samples using the alternate design, an attempt is made here to revisit the internal electromagnetic properties of the CICC cable design to identify any correlation with conductor performance. Results of this study suggest that there may be a simple link between the $Nb_3Sn$ CICC internal self-field and its $T_{cs}$ performance. The study also suggests that an optimization process should exist that can further improve the performance of $Nb_3Sn$ based CICC.

Change in A Compoent Properties of Beef Tenderloin Steak by Oven Roasting (쇠고기 안심스테이크의 가열 조리중 일반성분의 변화)

  • Lee Jong Ho;Kim Jong Uk
    • Journal of Applied Tourism Food and Beverage Management and Research
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    • v.15 no.1
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    • pp.127-136
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    • 2004
  • This study was conducted to investigate the changes in physico-chemical characteristics of beef tenderloin steak by oven roasting at different internal temperatures. 1. Cooking time required for the internal temperatures of 60, 70 and $80^{\circ}$ of steaks were 15min, 23min and 28min, respectively, and standing time of cooked beef steaks were 10.5min at $60^{\circ}$, 9.4min at $70^{\circ}$ and 8.5min at $80^{\circ}$, respectively. 2. Total losses and evaporation losses were larges in cooked steaks at $60^{\circ}$ and $70^{\circ}$ than that of $80^{\circ}$ cooking. Total losses were 14.5% by cooking at $60^{\circ}$, 23.3% at $0^{\circ}$ and 26.6% at $80^{\circ}$ respectively. As internal temperature of meat was increased, moisture and fats content was decreased and protein content of meat was not changed.

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Interface shear between different oil-contaminated sand and construction materials

  • Mohammadi, Amirhossein;Ebadi, Taghi;Boroomand, Mohammad Reza
    • Geomechanics and Engineering
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    • v.20 no.4
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    • pp.299-312
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    • 2020
  • The aim of this paper was to investigating the effects of soil relative density, construction materials roughness, oil type (gasoil, crude oil, and used motor oil), and oil content on the internal and interface shear behavior of sand with different construction materials by means of a modified large direct shear test apparatus. Tests conducted on the soil-soil (S-S), soil-rough concrete (S-RC), soil-smooth concrete (S-SC), and soil-steel (S-ST) interfaces and results showed that the shear strength of S-S interface is always higher than the soil-material interfaces. Internal and interface friction angles of sand beds increased by increase in relative density and decreased by increasing oil content. The oil properties (especially viscosity) played a major role in interface friction behavior. Despite the friction angles of contaminated sands with viscous fluids drastically decreased, it compensated by the apparent cohesion and adhesion developed between the soil grains and construction materials.

Development of the injection mold structure for internal gears (내측기어 성형용 사출성형 금형구조의 개발)

  • Kwon, Y.S.;Jeong, Y.D.
    • Journal of Power System Engineering
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    • v.12 no.6
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    • pp.78-82
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    • 2008
  • Plastic gears are more and more widely used in many industrial machine elements. Plastic gear has higher properties such as light weight, wear resistance, and vibration absorbing ability than metallic gears. But, in case of using an inaccurate plastic gear, its tooth breakage happen and fatigue life is shortened due to increase of applying load and temperature rising on the tooth flank. Inaccuracy of plastic gears such as pitch circle roundness and tooth profile generates vibration and noise. In this study, an internal plastic gears which is molded by a new injection mold structure are developed. The new mold structure is called the HR3P(hot runner type 3plate mold) that has an improved runner system in order to have good filling balance. As a result from this study, an internal gear with very accurate roundness was developed by using design of experiment.

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A Study of Plastic Deformation Mechanisms in $Fe_3$Al Intermetallics Alloys by Inelastic Deformation Theory (비탄성 변형이론을 이용한 $Fe_3$Al 금속간화합물의 소성변형 기구 고찰)

  • 정호철
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.03b
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    • pp.180-183
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    • 1999
  • It is well known that Fe3Al intermetallic compound shows an anomalous peak of the yield strength at about 50$0^{\circ}C$ and then decrease at higher temperatures The dislocation structure was examined by transmission electron microscopy and high temperatures. The dislocation structure was examined by transmission electron microscopy and high temperature mechanical properties were examined by tensile and load relaxation tests. The flow stress curves obtained from load relaxation tests were then analyzed in terms of internal variable deformation theory. it was found that the flow curves consisted of three micro-deformation mechanisms -i. e inelastic deformation mode plastic deformation mode and dislocation creep deformation mode depending on both dislocation structure and deformation temperature. The flow curves could be well described by the constitutive equations of these three micro-deformation mechanisms based on the internal variable deformation theory.

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Effect of Electrical Properties in the insulating Varnish due to Internal Voids (내부 보이드가 절연 바니시의 전기적 특성에 미치는 영향)

  • Park, Hyoung-Jun;Heo, Youn;Kim, Weon-Jong;Yoon, Hun-Ju;Shin, Jong-Yeal;Hong, Jin-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.472-475
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    • 2003
  • In this paper, insulating varnish has been used for field magnet and armature impregnated insulating material of electric locomotive and traction motor. When it was duplicated coating, it could be accuse internal void, and which could change electrical characteristics. We used to boundary elemental method of simulation tool, and improved optimal insulating design of insulating varnish according to measuring electric distribution in void of specimen.

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