• 제목/요약/키워드: External mixture

검색결과 173건 처리시간 0.024초

Electro-Optic Devices Based on Ferroelectric Liquid Crystal/Polymer Composite Films

  • Park, Jae-Hong;Kim, Sung-Jin;Lee, Won-Je;Kim, Jae-Hoon;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.910-913
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    • 2002
  • We have achieved an improved stability of an analog electro-optic effect in FLC/polymer composite films. The optimization of device depends on both the composition of the FLC/polymer mixture and the energy of UV irradiation. This device exhibits continuous gray scales and the mechanical stability against external forces.

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상업공간에서의 자연요소 표현방법 및 특성에 관한 연구 (A Study on the Expression Method and Characteristics of Ecology Design in Commercial Space)

  • 이진영;서지은
    • 한국실내디자인학회논문집
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    • 제22권2호
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    • pp.186-193
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    • 2013
  • In the commercial space, the modern consumers want to consume not only product but also culture. Thus, the modern commercial space tries to induce the customer's concern and purchase to the differentiated design. The introduction of this 'the natural element' delivers the pleasure and stability to the consumer buying process and availability is enlarged. Therefore, the purpose of study is gain that expression and characteristic method of the natural element in the commercial space. The detailed study method are as follows. First, the study looks into the natural element expression tendency in the modern space. Second, the expression type of the natural element was classified as 'Reappearance', 'Transformation', and 'Fuse' based on the preceding research. And according to the content of the expression type, subdivided method of 'Inclusion' and 'Replication' of 'Reappearance' and method of 'Imitation' and 'Association' of 'Transformation' and method of 'Juxtaposition' and 'Combine' of 'Fuse'. Third, the result of analyze the characteristic of expression of the natural element of the besides the commercial space case 20 place is as follows. First, 'Inclusion' of 'Reappearance' introduced the external scenery or planned garden as the inside through the opening. 'Replication' is used for decorative purposes or functional purposes as the natural element. 'Imitation' of 'Transformation' imitated the form, pattern, and color of the natural element and was mainly expressed in the wall and objet. The method of 'Association' expressed the concept of the natural element for the whole of the space and a portion of the wall and objet repetitively. As for 'Juxtaposition', mixture of 'Reappearance' had a good visual effect, because it can be obtained the external-internal nature. As for 'Combine', mixture of 'Replication' and 'Imitation' was the most common method. Thus, the study results are expected to be utilized as base date in designing the commercial with development of the natural element application method.

열전달 촉진관에서 HFC32/HFC152a 혼합냉매의 외부 응축열전달계수 (External Condensation Heat Transfer Coefficients of HFC32/HFC152a Mixtures on Enhanced Tubes)

  • 이요한;강동규;김현주;이호생;정동수
    • 설비공학논문집
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    • 제26권7호
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    • pp.315-321
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    • 2014
  • In this study, external condensation heat transfer coefficients (HTCs) of two non-azeotropic refrigerant mixtures of HFC32/HFC152a at various compositions were measured on both 26 fpi low-fin and Turbo-C enhanced tubes, of 19.0 mm outside diameter. All data were taken at the vapor temperature of $39^{\circ}C$, with a wall subcooling of 3~8 K. Test results showed that the HTCs of the tested mixtures on the enhanced tubes were much lower than the ideal values calculated by mass fraction weighting of the pure component HTCs. Also, the reduction of HTCs due to the diffusion vapor film was much larger than that of a plain tube. Unlike HTCs of pure fluids, HTCs of the mixtures measured on enhanced tubes increased, as the wall subcooling increased, which was due to the sudden break-up of the vapor diffusion film with an increase in wall subcooling. Finally, the heat transfer enhancement ratios for mixtures were found to be much lower, than those of pure fluids.

페놀 폼의 연소특성에 관한 연구 (A Study on the Combustion Characteristics of Phenol Foam)

  • 박형주
    • 한국화재소방학회논문지
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    • 제24권1호
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    • pp.122-127
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    • 2010
  • 외부복사 열원(20, 25, 35, 50, $70kW/m^2$)과 산소/질소의 혼합가스의 농도 변화에 따른 페놀폼의 연소 특성을 분석하였다. 산소지수는 KS M ISO 4589-2를 만족하는 산소지수시험기를 사용하였으며, 점화시간, 임계열속, 그리고 질량감소속도는 ISO 5660-1를 만족하는 mass loss calorimeter를 사용하여 측정하였다. 연구결과, 외부 복사열원에서 임계열유속은 $28.99kW/m^2$, 평균질량감소속도는 $0.56{\sim}1.77g/m^2s$로 측정되었으며, 한계산소지수는 45.1%를 나타내었다. 모든 연구결과를 종합한 결과 페놀 폼이 다른 발포 물질에 비해 아주 우수한 화재안정성을 나타낸다는 것을 알 수 있었다.

Triboelectrostatic Separation System for Separation of PVC and PS Materials Using Fluidized Bed Tribocharger

  • Lee, Jae-Keun;Shin, Jin-Hyouk;Hwang, Yoo-Jin
    • Journal of Mechanical Science and Technology
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    • 제16권10호
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    • pp.1336-1345
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    • 2002
  • A triboelectrostatic separation system using a fluidized bed tribocharger for the removal of PVC material in the mixture of PVC/PS plastics is designed and evaluated as a function of electric field strength, air flow rate, and the mixing ratio of two-component mixed plastics. It consists of a fluidized-bed tribocharger, a separation chamber, a collection chamber and a controller. PVC and PS particles can be imparted negative and positive surface charges, respectively, due to the difference in the work function values of plastics suspended in the fluidized-bed tribocharger, and can be separated by passing them through an external electric field. Experimental results show that separation efficiency is strongly dependent on the electric Deld strength and particle mixing ratio. In the optimum conditions of 150 Ipm air flow rate and 2.6 kV/cm electric field strength a highly concentrated PVC (99.1%) can be recovered with a yield of more than 99.2% from the mixture of PVC and PS materials for a single stage of processing.

INFRARED EMISSION FROM SPHERICAL DUST CLOUDS

  • Lee, Hyung-Mok;Hong, Seung-Soo;Yun, Hong-Sik;Lee, Sang-Gak
    • 천문학회지
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    • 제25권2호
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    • pp.111-128
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    • 1992
  • Infrared emissions from spherical dust, clouds are calculated using quasi-diffusion method. We have employed graphite-silicate mixture with power-law size distribution for the dust model. The grains are assumed to be heated and cooled by radiative processes only. The primary heating source is diffuse interstellar radiation field. hut the cases with an embedded source are also considered. Since graphite grains have higher temperature than silicate grains, the observed IR emission is mainly due to graphite grains, unless the fraction of graphite grains is negligibly small. The color temperature of Bok globules obtained from IRAS 60 and $100{\mu}m$ data are found to be consistent with the dust cloud with graphite-silicate mixture exposed to average interstellar radiation field. The color temperature is sensitive to the external radiation field, but rather insensitive to the size distribution of the grains. We found that the density distribution can be recovered outside the beam size using the inversion technique that assumes negligible optical depth. However, the information within the beam size is lost for if beam convolved intensity distributions are used in deriving density profile.

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세기말에 나타난 역사주의(Historicism) 의상에 관한 연구 (A Study on the Historicism Fashion of Century-end)

  • Yoon-Jeong Park;Sook-Hi Yang
    • 복식문화연구
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    • 제8권1호
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    • pp.87-101
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    • 2000
  • The purpose of study is explaining the Historicism as a result of compromise, historical eclecticism, between historical things and current cultural background instead of regarding it as an imitation from the past. It means that external factors in history help internal esthetic value surface out as costume. Fashion s history is more than the classified thing according to the appearance with the changes of the times. Intrinsic cultural elements should be added in creating new fashion. One of the different features between Modernism and Post-modernism. When coming to the period of Post-modernism, it connected with the historical factors to make something new by fragmenting, magnifying, or minimizing them. This is calles 'Historicism'in the world of art. It revived the past, not the past itself, in new ways : quotation, reuse, metaphor, and mixture. To represent the image, parody, pastiche, or bricolage was usually used. In post-modernism fashion, parody is a technique for imitating the past or the preceding forms with artists'own critical points of view. This technique gives us shock or surprise by using satirical, ironical or paradoxical expressions. pastiche shares the same part with parody in imitating particular or unique style, and it can be renamed empty parody, because it doesn't have any hidden motivation or satirical impulse. bricolage is a mixture of quotations from other works. It contains fragments that deepen the image. Like the techniques uttered above, the revival of history through parody, pastiche or bricolage is historical eclecticism and it is included in Historicism.

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열전달 촉진관에서 2원 혼합냉매의 외부 응축열전달계수 (Condensation Heat Transfer Coefficients of Binary Refrigerant Mixtures on Enhanced Tubes)

  • 김경기;서강태;채순남;정동수
    • 설비공학논문집
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    • 제14권2호
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    • pp.161-167
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    • 2002
  • In this study, external condensation heat transfer coefficients (HTCs) of two non-azeotropic refrigerant mixtures of HFC32/HFC134a and HF0134a/HCF0123 at various compositions were measured on both low fin and Turbo-C enhanced tubes of 19.0 mm outside diameter All data were taken at the vapor temperature of 39$^{\circ}C$ with a wall subcooling of 3- 8 K. Test results showed that HTCs of the tested mixtures on the enhanced tubes were much lower than the ideal values calculated by the mass fraction weighting of the pure compo- nents'HTCs. Also the reduction of HTCs due to the diffusion vapor film was much larger than that of a plain tube. Unlike HTCs of pure fluids, HTCs of the mixtures measured on enhanced tubes increased as the wall subcooling increased, which was due to the sudden break up of the vapor diffusion film with an increase in wall subcooling. Finally, heat transfer enhancement ratios for mixtures were found to be much lower than those of pure fluids.

창덕궁 내전 일곽 공사로 보는 일제강점기 궁궐 별전 (The Examination of the Palace Byeoljeon, the King's non-ceremonial space, during Japanese Occupation Period to look into inner palace construction of Changdeokgung Palace)

  • 김지현
    • 건축역사연구
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    • 제29권2호
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    • pp.63-74
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    • 2020
  • The palace byeoljeon(別殿), the King's non-ceremonial space, were created as a space for the king to comfortably use and for the king to do what he wanted to do. The byeoljeon housed various types of spaces and were flexible in that they could be repurposed to meet the demands of the times. Nevertheless, their characteristic as palatial building created for the King's convenience has remained unchanged. In this study, we examine the process by which such royal spaces were created by focusing on the reconstruction of the Changdeokgung Huijeongdang during Japanese occupation period, with a view to continuity and the transformation process. The reconstruction of Huijeongdang at the time may be considered along internal and external characteristics. Internally, Huijeongdang connected the symbolism of the king's space as the palace byeoljeon. Externally, Huijeongdang is characterized by its mixture of traditional and western style, where western style structures were housed within traditional buildings. The plans for the block of Huijeongdang also included the coexistence of traditional building, western style building, and mixture of traditional and western style building. This reflects the characteristic continuity of the byeoljeon as well as the architectural techniques of the time, manifested together within a specific spatial block.

변색 실활치에 대한 carbamide peroxide gel의 표백효과 (BLEACHING EFFECT OF CARBAMIDE PEROXIDE GEL ON DISCOLORED NONVITAL TEETH)

  • 박선아;김선호;황윤찬;오병주;윤창;박영준;정선와;황인남;오원만
    • Restorative Dentistry and Endodontics
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    • 제27권4호
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    • pp.441-447
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    • 2002
  • The bleaching of discolored nonvital teeth is conservative treatment that satisfy the cosmetic desire. The most common method for this treatment, walking bleaching, is using 30% hydrogen peroxide and sodium perborate. Many alternatives are suggested for preventing the external cervical root resorption that is the common complication of the nonvital teeth bleaching with 30% hydrogen peroxide The same extent of oxidation reactions as that resulted by the bleaching with the application of 30% hydrogen peroxide and sodium perborate can also be acquired more safely by materials that contain 10% carbamide peroxide, used primarily for the bleaching of vital teeth. Therefore, this study was performed to evaluate the efficacy of 10% and 15% carbamide peroxide bleaching gel in nonvatal teeth bleaching. The internal bleaching of intentionally discolored teeth was performed in vitro with 10% carbamide peroxide (Group 1), 15% carbamide peroxide (Group 2), mixture of distilled water and sodium perborate (Group 3), and mixture of 30% hydrogen peroxide and sodium perborate (Group 4). The bleaching materials were refreshed following 3, 6, 9 and 12 days. To evaluate the bleaching effect, the color change of the crowns was measured at 1, 2, 3, 4, 7 and 15 days of bleaching using the colorimeter. The results were as follows:1. L$^*$ and $\Delta$E$^*$ values were increased with time in all bleaching agents (p<0.01). 2. There was no significant difference in L$^*$ and $\Delta$E$^*$ value among bleaching agents. 3. $\Delta$E$^*$ value higher than 3 was shown after 3 days of bleaching with 10% carbamide peroxide gel, 1 day with 15% carbamide poroxide gel, 4 days with mixture sodium perborate and distilled water and 4 days with mixture sodium perborate and 30% hydrogen peroride, respectively. These results revealed that the use of 10% and 15% carbamide peroxide bleaching gel in non-vital teeth bleaching is as effective as mixture of distilled water and sodium perborate and mixture of 30% hydrogen peroxide and sodium perborate. Accordingly, carbamide peroxide could be used clinically to bleach discolored non-vital teeth.