• 제목/요약/키워드: property ($D_k$)

검색결과 1,618건 처리시간 0.032초

Study on the Evaluation of Stability of Gel Structured Cosmetics

  • Park, Chan-Ik;Kim, Ki-Sun;Lee, Sung-Jun;Yoon, Myeong-Suk;Kang, Seh-Hoon
    • 대한화장품학회지
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    • 제22권2호
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    • pp.167-173
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    • 1996
  • The stability of gel structured emulsion and the effect of polyols on it have been studied by rheological property and interfacial tension. In this paper, three types of gel structured emulsions were prepared by using three polyols respectively(glycerine for sample 1, 1.3 BG for sample 2, PG for sample 3). And both complex modulus($G^*$) and loss angle[$\delta$ = tan-1(G"/G')] of samples were investigated against oscillating shear stress and frequency($\omega$). The results show sample 1 is most highly consistent with oscillating shear stress. And the results were compared with those of accelerated tests concerning storage stability of gel structured emulsion. To correlate consistency of rheological property with storage stability, interfacial tension from which adsorption efficiency of surfactant(Octyldodecyl Ether) could be known was measured. Sample 1 showed the largest value of [$d{\gamma}/dIn_{Cconc. of surfactant}$] in Gibbs equation. In summary, the prediction of stability could be correctly made by the consistency of rheological property(G*,$\gamma$) of gel structured emulsion against oscillating shear stress and it could be supported by measuring interfacial tension. And polyol affected the value of [$d{\gamma}/dIn_{Cconc. of surfactant}$], consequently affected the stability.lity.

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Relationship between Field Emission Property and Composition of Carbon Nanotube Paste for Large Area Cold Cathode

  • Choi, Jong-Hyung;Kang, Sung-Kee;Han, Jae-Hee;Yoo, Ji-Beom;Park, Chong-Yun;Nam, Joong-Woo;Kim, J.M.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.852-854
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    • 2003
  • CNT paste was fabricated by mixture of multi-walled carbon nanotubes (MWNT) powder, organic vehicles and inorganic binder. Then firing process was performed at different temperature under air and $N_{2}$ atmosphere. It was found that emission property of CNT paste was changed by firing temperature and time due to interaction between remained resins and CNT powder. We obtained good emission property from CNT paste treated at $350^{\circ}C$ for 10 min.

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혼합가스의 이물 존재시 절연 특성 연구 (A study of dielectric strength and insulating property for particle contamination Under SF6/N2 Mixture)

  • 정동훈;우수열;서경보;김진호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.1262-1263
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    • 2011
  • Sulfur hexafluoride is the most commly used insulation gas in electrical systems. Gas insulated systems are widely used in the electric power industry for transmission and distribution of electrical energy. When $SF_6$ was first discovered, the potential application was only considered for insulation because of good dielectric properties. But the widespread use of $SF_6$ gas by electric power and other industries has led to increase concentrations of $SF_6$ gas in the atmosphere. This concern as to possible effects on global warming because $SF_6$ is a potent greenhouse gas. That's why firstly we studied uniform and nonuniform field property by mixing $SF_6$ and N2 gas. This paper presents the dielectric strength and insulating property for particle contamination under $SF_6/N_2$ mixtures. Two types of mixed gases(50% $SF_6$_50%$N_2$, 20% $SF_6$_80%$N_2$) were applied. We performed tests for the length and shape of particle. Test gas pressure is from 0.3 to 0.7 Mpa. The study was conducted to develop environment-friendly insulating material for GIS that can reduce $SF_6$ gas and make a design criteria for mixtures.

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고분자애자용(高分子碍子用) 실리콘고무 재료(材料)의 $Al(OH)_3$에 의한 Tracking성(性) 향상(向上) 연구(硏究) (Improvement of Tracking Property of Silicone Rubber Used for Out-door Polymer Insulator According to Aluminium Hydrate Filler)

  • 한기만;김동욱;오무원;권혁삼;김영성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 B
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    • pp.1239-1241
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    • 1993
  • This paper studies on the improvement of non-tracking property which is very important matter for developing polymer insulator. Non-Tracking property of silicon rubber used for polymer insulator was investigated by ASTM D 2303 according to Aluminium Hydrate filler. Furthermore other electrical and mechanical properties were estimated. The optimum amount of Aluminium Hydrate should be considered by following test results.

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CaO이 첨가된 AZ91D 마그네슘 합금의 발화저항특성 및 용탕보호특성 평가 (Melt Protection Property and Ignition Resistance Property of CaO added AZ91D Mg Alloy)

  • 이진규;하성호;김영직;조형호;김세광
    • 한국주조공학회지
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    • 제27권3호
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    • pp.131-134
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    • 2007
  • [ $SF_6$ ] gas that is used as a protective cover gas for Mg and Mg alloys during melting and casting has extremely high greenhouse effect. CaO added Mg alloys could maintain their original mechanical properties and original abilities such as fluidity and hot tearing susceptibility. The ignition temperature increased with increasing CaO addition under ambient atmosphere and nitrogen atmosphere. The minimum amount of $SF_6$ gas decreased by 0.13 wt%CaO added AZ91D Mg alloy in the sealed condition.

초자기변형소자(Terfenol-D)의 기초특성해석에 관한 연구 (A Study on the Fundamental Characteristics Analysis of Giant Magnetostrictive Materials)

  • 김동현;이춘만
    • 한국정밀공학회지
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    • 제28권4호
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    • pp.398-403
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    • 2011
  • Terfenol-D is one of several magnetostrictive materials with property of converting energy into mechanical motion, and vice versa. Magnetostriction is the property that causes certain ferromagnetic materials to change shape in a magnetic field. Terfenol-D is said to produce giant magnetostriction, strain greater than any other commercially available smart material. In this paper, fundamental characteristics analysis of giant magnetostrictive materials(Terfenol-D) has been investigated. The magnetic field analysis is carried out by using finite element method simulation ANSYS. The results show 223N in force and 9.5T in maximum magnetic flux density and 7.56 $10^6A/m$ in maximum magnetic field intensity 1A current. Through the analysis, basic data of Terfenol-D for the application of mechanical system are obtained.

$Ta_2O_5$의 유전 특성과 안정성에 관한 연구 (The study on dielectric and thermal property of $Ta_2O_5$ Thin-films)

  • 김인성;송재성;이동윤;김도한;김현식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 C
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    • pp.1487-1489
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    • 2001
  • The tantalum oxide($Ta_2O_5$) is an important material for present thin-film capacitor application owing to its high dielectric constant and thermal stability. We report dielectric property of Si(p type)/Pt/$Ta_2O_5$/Ag based MIM structure obtained by RF sputtering and annealed in vacuum environment. We have measured and researched the characteristics of C-F, C-V and EPMA. And we describe parameter dependence on sputtered condition and annealed temperature with dielectric property.

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특허권리성의 정량적 평가방법에 대한 연구 : AHP, 텍스트 마이닝, 회귀분석의 활용 (Quantifying the Process of Patent Right Quality Evaluation : Combined Application of AHP, Text Mining and Regression Analysis)

  • 윤장혁;송재국;류태규
    • 산업경영시스템학회지
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    • 제38권2호
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    • pp.17-30
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    • 2015
  • Technology-oriented national R&D programs produce intellectual property as their final result. Patents, as typical industrial intellectual property, are therefore considered an important factor when evaluating the outcome of R&D programs. Among the main components of patent evaluation, in particular, the patent right quality is a key component constituting patent value, together with marketability and usability. Current approaches for patent right quality evaluation rely mostly on intrinsic knowledge of patent attorneys, and the recent rapid increase of national R&D patents is making expert-based evaluation costly and time-consuming. Therefore, this study defines a hierarchy of patent right quality and then proposes how to quantify the evaluation process of patent right quality by combining text mining and regression analysis. This study will contribute to understanding of the systemic view of the patent right quality evaluation, as well as be an efficient aid for evaluating patents in R&D program assessment processes.

다항식 $z^{d}+(z+1)^{d}$에 의해 발생된 이상적인 자기상관을 갖는 주기 $2^{m}-1$의 이진 의사불규칙 시퀀스 (Binary pseudorandom sequences of period $2^{m}-1$ with ideal autocorrelation generated by the polynomial $z^{d}+(z+1)^{d}$)

  • 노종선;정하봉;윤민선
    • 한국통신학회논문지
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    • 제23권5호
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    • pp.1165-1172
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    • 1998
  • 본 논문에서는 다항식 $z^{d}+(z+1)^{d}$를 이용하여 이상적인 자기상관특성을 갖는 주기 $2^{m}-1$의 이진 의사불규칙시퀀스를 구성하는 것을 보였다. 다항식으로부터 얻어진 시퀀스는 어떤 d값에서는 m-시퀀스가된다. 또한 k가 양의 정수이고 m이 $3k{\pm}1$일 때 이상적인 자기상관특성을 갖는 새로운 이진 시퀀스를 산출하는 몇몇의 d값을 발견했다. 이들 새로운 시퀀스는 trace함수를 이용하여 표현하였으며 그 결과들을 표로 나타내었다.

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홍삼가수분해추출물(GS-E3D)의 항산화 및 양모 효과 (Anti-Oxidant and Hair-Growth-Promoting Effect of Pectin Lyase-Modified Red Ginseng Extract (GS-E3D))

  • 표미경;홍세철;정종태;조윤호;이기무
    • 생약학회지
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    • 제48권3호
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    • pp.195-201
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    • 2017
  • To develop new therapy for prevention and treatment of hair loss is very important according to increase of the number of hair loss people. The aim of this study was to investigate the hair growth promoting effects of pectin lyase-modified red ginseng extract (GS-E3D). We examined antioxidant and anti-inflammatory effects, human hair dermal papilla cells (HHDPC) proliferation, and testoterone-induced $5{\alpha}$-reductase inhibitory effects. GS-E3D show not only 1,1-diphenyl-2-picryhydrazyl (DPPH) radical scavenging activity and xanthine oxidase inhibitory effects as an anti-oxidant property, but also lip-oxygenase and hyaluronidase inhibitory effects as an anti-inflammatory property. Human hair dermal papilla cells proliferation by GS-E3D was higher than those of minoxidil or finasteride, using the positive controls. Moreover, GS-E3D exhibited $5{\alpha}$-reductase inhibitory activities after stimulating by testoterone. The present results indicate that GS-E3D has a potential to be as an hair growth promoting agent for cosmetic materials.