• Title/Summary/Keyword: efficiency property

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Thermal Property of Geopolymer Ceramics Based on Fly Ash-Blast Furnace Slag (플라이애시-고로슬래그 기반 지오폴리머 세라믹스의 열적특성)

  • Kim, Jin-Ho;Nam, In-Tak;Park, Hyun;Kim, Kyung-Nam
    • Korean Journal of Materials Research
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    • v.26 no.10
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    • pp.521-527
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    • 2016
  • Geopolymers have many advantages over Portland cement, including energy efficiency, reduced greenhouse gas emissions, high strength at early age and improved thermal resistance. Alkali activated geopolymers made from waste materials such as fly ash or blast furnace slag are particularly advantageous because of their environmental sustainability and low cost. However, their durability and functionality remain subjects for further study. Geopolymer materials can be used in various applications such as fire and heat resistant fiber composites, sealants, concretes, ceramics, etc., depending on the chemical composition of the source materials and the activators. In this study, we investigated the thermal properties and microstructure of fly ash and blast furnace slag based geopolymers in order to develop eco-friendly construction materials with excellent energy efficiency, sound insulation properties and good heat resistance. With different curing times, specimens of various compositions were investigated in terms of compressive strength, X-ray diffraction, thermal property and microstructure. In addition, we investigated changes in X-ray diffraction and microstructure for geopolymers exposed to $1,000^{\circ}C$ heat.

Comparison of the Functional Minimalism in Fashion and Architecture (패션과 건축에 표현된 기능주의적 미니멀리즘 비교)

  • Park, Seon-Ji;Yim, Eun-Hyuk
    • Journal of the Korean Society of Clothing and Textiles
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    • v.37 no.3
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    • pp.247-259
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    • 2013
  • This study conceptually approaches and clearly compares the similarities and differences of fashion and architecture through a focus on their correlations. This study identifies the conceptual definitions of functional minimalism by an examination of function that represents the largest similarity between architecture and fashion. This study classifies the nature of functional minimalism and studies cases for each architectural classification in the areas of: the simplicity of a structure, unitarity pursuit of economic value, repeatability in an efficiency unit, reducibility stressing property, and multi-functional spatiality. The characteristics of functional minimalism fashion are distinguish as: simplicity in a structure that highlight structural lines in non-decorated design, unitarity pursuit of economic value represented in united process and pattern for its economic effect, repeatability in an efficiency unit represented through the repeated decoration of a functional unit, reducibility stressing a property that emphasizes property with a dominant design element through a highlight of the characteristics of materials and multi-functional spatiality that represents variability in clothes through an expansion of limited spatial function. This study approaches each discipline with a clear understanding of the differences between the two and suggests standards for a comparative study of architecture and fashion.

Enhancing photoluminescence of Au - TiO2 nanoparticles using Drude model

  • Dang, Diem Thi-Xuan;Vu, Thi Hanh Thu
    • Journal of IKEEE
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    • v.21 no.3
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    • pp.288-296
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    • 2017
  • The enhancement of photoluminescence of Au-$TiO_2$ nanoparticles by surface plasmon resonance has been studied extensively by experiment in recent years. For the purpose of optimizing the photoluminescence property of Au-$TiO_2$ nanoparticles, the manufacturing parameters related to the Au nanoparticles and $TiO_2$ nanoparticles need to be considered. In this paper, Drude model and Maier's effective volume method are used to analyze the variation of the metal nanoparticle radius, separation between metal nanoparticle and dielectric molecule, and total absorption cross-section with original radiative efficiency on the photoluminescence property of Au-$TiO_2$ nanoparticles. The results show that to obtain the optimized enhancement factor for photoluminescence process, the size of Au nanoparticle is about 13 - 20 nm, the separation between Au nanoparticle and $TiO_2$ molecule is about 5 -15 nm, the total absorption cross-section of $TiO_2$ molecules is about $1-100nm^2$ and the original radiative efficiency of $TiO_2$ molecule is weak about 0.001- 0.1. With these fabrication parameters, the photoluminescence property of Au-$TiO_2$ nanoparticles can be enhanced several thousand times compared to traditional $TiO_2$ nanoparticles.

$Cr^{6+}$ leaching property of cement using high performance lignin (고성능 혼화제를 이용한 시멘트의 $Cr^{6+}$ 용출특성)

  • Park, Hyun;Kim, Kyung-Nam
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.19 no.3
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    • pp.135-143
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    • 2009
  • To study possibility of $Cr^{6+}$ solid solution and efficiency of admixture, leaching property of Portland cement mortar was investigated by using KSLT (Korea Standard Leaching Test), TCLP (Toxicity Characteristic Leaching Procedure), Soacking procedure, as adding excess $Cr^{6+}$. As a result, admixture of lignin type showed high compressive strength of mortar but no changing leaching property.

Fast Matching Pursuit Method Using Property of Symmetry and Classification for Scalable Video Coding

  • Oh, Soekbyeung;Jeon, Byeungwoo
    • Proceedings of the IEEK Conference
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    • 2000.07a
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    • pp.278-281
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    • 2000
  • Matching pursuit algorithm is a signal expansion technique whose efficiency for motion compensated residual image has already been demonstrated in the MPEG-4 framework. However, one of the practical concerns related to applying matching pursuit algorithm to real-time scalable video coding is its massive computation required for finding dictionary elements. In this respective, this paper proposes a fast algorithm, which is composed of three sub-methods. The first method utilizes the property of symmetry in 1-D dictionary element and the second uses mathematical elimination of inner product calculation in advance, and the last one uses frequency property of 2-D dictionary. Experimental results show that our algorithm needs about 30% computational load compared to the conventional fast algorithm using separable property of 2-D gabor dictionary with negligible quality degradation.

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A Study on the Improvement Plans of Green Insurance Industry (녹색보험산업의 발전방안에 관한 연구)

  • Han, Nak Hyun;Cho, Sung Woo;Kim, Eun Joo
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.57
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    • pp.305-331
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    • 2013
  • The purpose of this study aims to the improvement prospect of green insurance industry in Korea. Green insurance includes all classes of general insurance business including unoccupied property insurance and empty building insurance, business insurance, personal insurance, etc. Green policies often cover expensive systems that are not covered under most property policies. The same is true for some underground property, which is also exempted from many property policies. At least insurers already offer products designed to fund rebuilding damaged properties to meet certain environmental and building standards. While the products are in their infancy, insurers and brokers say the huge interest in environmental issues will increase demand. Green buildings that improve energy efficiency and air quality and reduce waste are designed to reduce their effects on the environment and the health of building occupants. Buildings account for 39% of U.S. carbon dioxide emissions, according to the Department of Energy. Insurers say that, as sustainable buildings become more common, green insurance will become more popular and some of its features might become a standard part of property policies.

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A Study on the Comparison of Test Methods of Fabric Drapaability (직물의 드레이프성 실험방법에 관한 비교 평가 연구)

  • Choi, In-Ryu;Bang, Hey-Kyong
    • Journal of the Korea Fashion and Costume Design Association
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    • v.16 no.2
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    • pp.189-194
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    • 2014
  • Drape property, one of the dynamic properties, is significant element of appearance and silhouette of garment. There are two methods of measuring drape property: objective method and subjective method. The purpose of this study is to search convenient method of measuring drape property which affects the appearance of garment. The method of this study was as below: First, the drape properties of ten various fabrics were measured within both of professional paper ring and visual handy measuring instrument. Second, Pearson's correlation coefficient was analyzed in order to analyze the correlation of two results of the experiments. This study used professional paper ring and visual handy measuring instrument on ten samples. Both of the results from the paper ring and visual handy measuring instrument were very similar in terms of drape property. Significant correlation between results of the professional paper ring and visual handy method indicates the efficiency of the visual handy measuring at school or work environment etc.

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Surface Chemical Studies on Flotation Processes -Importance of the Hydrophobic Property of Solid Particles in Flotation Efficiency- (부유부상 공정에 대한 표면화학적 연구 -부유부상 효율과 고형입자의 소수화도-)

  • 이학래;이진희;허용성;조중연;한신호
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.33 no.1
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    • pp.1-7
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    • 2001
  • The immediate purposes of this study is to establish the surface chemical principles associated with the flotation process of waste papers and to verify them by practical flotation experiments. To achieve this AKD sized hydrophobic microcrystallince cellulose (MCC) with different levels of hydrophobicity, and hydrophilic MCC dyed with black were prepared as model substances. The effects of surface characteristics on flotation efficiency were evaluated by measuing the brightness of the flotation rejects obtained after the flotation experiments carried out using MCC mixtures prepared with different ratios of hydrophobic and hydrophilic MCCs. Results showed that more than 90% of the flotation rejects consisted of hydrophobic MCC indicating the critical importance of the hydrophobicity of the materials in the flotation process. The proportions of hydrophobic materials in the reject remained constant when highly sized MCC was used as a model of hydrophobic substance.

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Single-prodect dynamic lot-sizing : review and extension (단일품목 동적 롯트량결정에 대한 이론적 고찰과 적용)

  • 김형욱;김상천;현재호
    • Korean Management Science Review
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    • v.5 no.1
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    • pp.56-70
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    • 1988
  • In this study, We reviewed the solution methods (for the heuristic and optimization method) for the single-item dynamic lot-sizing problem, and improved the efficiency (speed and optimality) of the conventional heuristic method by utilizing the inventory decomposition property. The iventory decomposition property decomposes the given original problem into several independent subproblems without violating the optimality conditions. Then we solve each decomposed subproblems by using the conventional heuristics such as LTC, LUC, Silver-Meal etc. For testing the efficiency of the proposed decomposition method, we adopted the data sets given in Kaimann, Berry and Silver-Meal. The computational results show that the suggested problem solving framework results in some promising effects on the computation time and the degree of optimality.

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Stabilization of the luminance efficiency in the blue organic light-emitting devices utilizing CBP and DPVBi emitting layers

  • Bang, H.S.;Choo, D.C.;Park, J.H.;Seo, J.H.;Kim, Y.K.;Kim, T.W.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1454-1456
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    • 2007
  • The electrical and the optical properties of blue organic light-emitting devices (OLEDs) with a multiple emitting layer (EML) acting as electron and hole trapping layers were investigated. While the luminance efficiency of the OLEDs with a multiple EML was very stable, regardless of variations in the applied voltage.

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