• Title/Summary/Keyword: Material change

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An experimental study on thermal performance evaluation of PCM mixed coating material constructed in and out of the wall (벽체 내·외부에 시공한 PCM혼입 도료의 열적성능 평가에 관한 실험적 연구)

  • Ju, Dong-Uk;Shin, Sang-Heon;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.216-217
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    • 2014
  • Optimum finishing position, thickness and phase change temperature of winter and summer season were selected and suitability of finishing materials was evaluated based on temperature measurement of specimens applying the coating material mixed phase change materials(PCM). As a result, when finishing position was interior and finishing thickness of coating material mixed n-Octadecane(28℃ PCM) was 4mm, thermal performance was effective. n-Octadecane in summer season and n-Hexadecane(18℃ PCM) in winter season are indicated effective on energy savings, respectively.

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Electrolyte Mechanizm Study of Amorphous Ge-Se Materials for Memory Application (Ge-Se의 스위칭 특성 향상을 위한 Sb-doping에 관한 연구)

  • Nam, Ki-Hyun;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.69-69
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    • 2009
  • In other to progress better crystallization transition and long phase-transformation data of phase-change memory (PRAM), we investigated about the effect of Sb doping and Ag ions percolating into Ge-Se-Te phase-change material. Doped Sb concentrations was determined each of 10 wt%, 20 wt% and 30 wt%. As the Sb-doping concentration was increased, the resistivity decreased and the crystallization temperature increased. Ionization of Ag was progressed by DPSS laser (532 nm) for 1 hour. The resistivity was more decreased and the crystallization temperature was more increased in case of adding Ag layer under Sh-(Ge-Se-Te) thin film. At the every condition of thin films included Ag layer more stable states were indicated compare with just Sh-doped Ge-Se-Te thin films.

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Profiling Female College Students' Apparel Buying Decision-Making Styles (여대생들의 의류구매 의사결정 스타일 특성에 관한 연구)

  • 정혜영
    • The Research Journal of the Costume Culture
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    • v.12 no.3
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    • pp.468-484
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    • 2004
  • The purposes of this study were (1) to segment female college students' apparel shoppers into unique apparel buying decision-making style groups; and (2) to profile for each segment in terms of personal characteristics (material values, change seeking tendency and prestige sensitivity) and fashion information sources. Data were collected through questionnaires from convenient sample of 290 female college students. As a result of cluster analysis and univariate analysis of variance, distinctive consumer decision-making style groups of consumers were identified; Value-maximizing Recreational Shoppers, Brand-Maximizing Emotional Shoppers, and Apathetic Shoppers. These three groups were compared as to the effect of personal characteristics variables and fashion information sources through univariate analysis of variance and chi-square statistics. The result showed that personal characteristics (material values, change seeking tendency and prestige sensitivity) and fashion-information sources do influence the consumer decision-making styles and that these three groups were unique in their decision-making characteristics showing that consumer decision-making styles can be a good segmentation base for apparel market.

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The Fabrication and Characteristics of White Emission using CCM on Flexible Substrate (플렉시블 무기EL 색변환 백색 발광 소자 제작 및 특성평가)

  • Kim, Gi-Ryoung;Ahn, Sung-Il;Kum, Jeong-Hun;Lee, Heung-Ryeol;Yim, Tae-Hong;Lee, Seong-Eui
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.10
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    • pp.911-915
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    • 2008
  • EL (electro-luminescent) device as a light source has an advantage in embodying large area with great flexibility. On nickel foil as an electrode and backplane, we demonstrated a white EL flexible light source with blue phosphor layer combined with color change layer. A correlation between color change layer and color coordination was analyzed by Gaussian method, and then the color coordinate was controlled near to (0.33, 0.33) of pure white light.

A Study on Heat Transfer Phenomena during Solidification in a Circular Tube Containing Phase Change Material (Effect of Inclination) (원통형 용기내의 상변화물질에서의 응고 열전달에 관한 연구 (경사각 변화의 영향))

  • Song, H.J.;Kim, Y.J.;Ohu, S.C.;Yim, C.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.6 no.3
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    • pp.182-192
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    • 1994
  • This paper focuses on the investigation of the heat transfer phenomena that occur inside the cylindrical tube. The inclination of the tube is adopted as a principal parameter varying from vertical to horizontal. The phase change material employed in this experiment is 99 percent pure n-docosane paraffin($C_{22}$ $H_{46}$). It is found that the amount of solidified mass during a prescribed solidifying period is not sensitive to the inclination of the tube but to the local layer thickness. It is studied that the latent energy is the largest contributor to the total extracted energy. The sensible energy($E_{s1}$, $E_{s2}$, $E_{s3}$) may not be negligible at the large wall-subcooling and initial-liquid-superheating, also at the first step of solidifying.

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A Study on Bending, Compressive Strength of Mortar According to Temperature and Heating Time Change using Oyster Shell as Aggregate (굴 패각을 골재로 사용한 모르타르의 온도별 가열 시간에 따른 휨·압축 강도에 관한 연구)

  • You, Nam-Gyu;Jung, Ui-In;Kim, Bong-Joo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.131-132
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    • 2017
  • As the building is becomes bigger and larger, it can lead to big damage in case of fire. Also, tunnel, machine room and underground joint are spaces that can cause high temperature fire above 1,350℃ in case of fire. Therefore, a refractory material is need that can be withstand in high temperatures for long time. One side, the composition of oyster shell is CaCO3 of 90% or more. It is expected that it will be possible to use it as a high calcium natural material which is the material of the refractory board. According to, Study on bending, compressive strength of mortar according to temperature and heating time change using oyster shell as aggregate the most commonly occurring particle sizes form 2.5mm to 5mm.

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PRAM Switching Device By Using Current Pulse Modulation

  • Lee, Seong-Hyun;Gil, Gyu-Hyun;Lee, Jung-Min;Song, Yun-Heup
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.384-384
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    • 2012
  • PRAM switching device by using current pulse modulation was investigated to verify its possibility for 3D architecture. In this work, two phase change materials connected in series having a different crystallization temperature are used. Its structural for different phase change material was evaluated by electrical resistance. We confirmed that Germanium-Antimony-Tellurium (GST) alloy and Germanium- Copper-Tellurium (GCT) alloy material were selected according to crystallization temperature, ${\sim}180^{\circ}C$ for switching and ${\sim}240^{\circ}C$ for memory devices, respectively. From this research, it is expected that phase change switching device could have advantages of process in terms of material similarity and structural simplification.

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The Indoor Environmental Quality Improving and Energy Saving Potential of Phase-Change Material Integrated Facades for High-Rise Office Buildings in Shanghai

  • Jin, Qian
    • International Journal of High-Rise Buildings
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    • v.6 no.2
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    • pp.197-205
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    • 2017
  • The conflict between indoor environmental quality and energy consumption has become an unneglectable problem for highrise office buildings, where occupants' productivity is highly affected by their working environment. An effective Façade, therefore, should play the role of an active building skin by adapting to the ever-changing external environment and internal requirements. This paper explores the energy-saving and indoor environment-improving potential of a phase-change material (PCM) integrated Façade. Building performance simulations, combined with parametric study and sensitivity analysis, are adopted in this research. The result quantifies the potential of a PCM-integrated Façade with different configurations and PCM properties, taking as an example a south-oriented typical office room in Shanghai. It is found that a melting temperature of around $22^{\circ}C$ for the PCM layer is optimal. Compared to a conventional Façade, a PCM-integrated Façade effectively reduces total energy use, peak heating/cooling load, and operative temperature fluctuation during the periods of May-July and November-December.

A study on bending, Compressive Strength of Mortar According to Temperature and Heating Time Change using Classified Oyster shell as Aggregate (분급한 굴 패각을 골재로 사용한 모르타르의 가열 시간에 따른 휨·압축 강도에 관한 연구)

  • You, Nam-Gyu;Hong, Sang-Hun;Jung, Ui-In;Kim, Bong-Joo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.122-123
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    • 2017
  • As the building is becomes bigger and larger, it can lead to big damage in case of fire. Also, tunnel, machine room and underground joint are spaces that can cause high temperature fire above 1,350℃ in case of fire. Therefore, a refractory material is need that can be withstand in high temperatures for long time. One side, the composition of oyster shell is CaCO3 of 90% or more. It is expected that it will be possible to use it as a high calcium natural material which is the material of the refractory board. According to, Study on bending, compressive strength of mortar according to temperature and heating time change using classified oyster shell as aggregate.

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A study on heat transfer during solidification of phase change material on a finned vertical cooling tube (휜붙이 수직냉각관 주위의 상변화물질에서 응고열전달에 관한 연구)

  • 정석주;송하진
    • Journal of the Korean Society of Safety
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    • v.11 no.2
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    • pp.33-41
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    • 1996
  • Experiments were performed to study solidification of phase change material on a finned vertical tube when either conduction In the solid or natural convection in a liquid controls the heat transfer. The liquid was housed in a cylindrical containment vessel whose surface was maintained at a uniform, time-invariment temperature during a data run, and the solidification occurred at a finned and unfinned vertical tube positioned along the axis of the vassel. The phase change material(PCM) employed in this experiment is 99 percent pure n-Octacosan paraffin($C -{28}H_{58}/$). For conduction-controlled and convection-controlled solidification, the enhancement of the solidified mass rate due to finning is great when the solidified layer is thin and decreases as the layer grows thicker. It is studied that the latent energy($E_{\lambda}$) is the largest contributor to the total extracted energy($E_{\lambda} + E_{sl}+E_{s2}$) and the total extracted energy rate at a finned vertical tube is greater than that at a unfinned vertical tube.

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