• Title/Summary/Keyword: Performance Surface

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A Study on Painting Layer Fixative Processing of Mural Paintings of Buddhist Temples in Korea (한국 사찰벽화 채색층 고착처리제 적용 연구)

  • Lee, Haw-Soo;Han, Kyeong-Soon;Lee, Sang-Jin
    • Journal of Conservation Science
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    • v.29 no.1
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    • pp.81-92
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    • 2013
  • In the past, European material and method were applied to conservation of Buddhist mural paintings in Korea. At that time, there were inadequate to selection of materials in consideration of porosity and hydrophilicity, therefore insufficiency to assessing their suitability for materials. The treatment result of mural painting are dissatisfied with consolidation of painting layer using synthetic resin. Therefore, it has experimented on applying fixative for reinforcement of painting layer on Buddhist mural painting in order to establish the effects of conservation. In relationship of binder's viscosity, adhesion and penetrating depth, adhesion increased in high-viscosity specimen whereas it decreased in low-viscosity specimen. While the binder's penetrating depths show similar patterns, the surface's response and combination adjacent to painting layer have differences. Animal glue and methyl cellulose (MC) shows excellent performance in their reaction with soil and painting layer. It is estimated that the fixative penetrates deep into soil to produce a stable fixing effect. The viscosity of polyvinyl acetate resin (PVAc) and acrylic resins are low, and thus penetrates well into soil, but they adhere poorly to soil.

Preparation and Current-Voltage Characteristics of Well-Aligned NPD (4,4' bis[N-(1-napthyl)-N-phenyl-amino] biphenyl) Thin Films (분자배열된 4,4' bis[N-(1-napthyl)-N-phenyl-amino] biphenyl 증착박막 제조와 전기적 특성)

  • Oh, Sung;Kang, Do-Soon;Choe, Youngson
    • Applied Chemistry for Engineering
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    • v.17 no.6
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    • pp.591-596
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    • 2006
  • Topology and molecular ordering of NPD(4,4'-bis-[N-(1-naphthyl)-N-phenyl-amino]biphenyl) thin films deposited under magnetic field with post-deposition annealing were investigated. NPD was deposited onto ITO glass substrates via thermal evaporation process in vacuum. It is of great importance for highly oriented organic/metal films to have improved device performances such as higher current density and luminance efficiency. AFM (Atomic Force Microscope) and XRD (X-Ray Diffraction) analyses were used to characterize the topology and structure of oriented NPD films. The multi-source meter was used to observe the current-voltage characteristics of the ITO (Indium-Tin Oxide) / NPD (4,4'bis[N-(1-napthyl)-N-phenyl-amino]-biphenyl) / Al (Aluminum) device. While NPD thin films deposited under magnetic field were not molecularly well aligned according to the XRD results, the films after post-deposition annealing at $130^{\circ}C$ were well-oriented. AFM images show that NPD thin films deposited under magnetic field had a smoother surface than those deposited without magnetic field. The current-voltage performance of NPD thin films was improved due to the enhanced electron mobility in the well-aligned NPD films.

Synthesis of MnO2 Nanowires by Hydrothermal Method and their Electrochemical Characteristics (수열합성법을 이용한 망간 나노와이어 제조 및 이의 전기화학적 특성 연구)

  • Hong, Seok Bok;Kang, On Yu;Hwang, Sung Yeon;Heo, Young Min;Kim, Jung Won;Choi, Bong Gill
    • Applied Chemistry for Engineering
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    • v.27 no.6
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    • pp.653-658
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    • 2016
  • In this work, we developed a synthetic method for preparing one-dimensional $MnO_2$ nanowires through a hydrothermal method using a mixture of $KMnO_4$ and $MnSO_4$ precursors. As-prepared $MnO_2$ nanowires had a high surface area and porous structure, which are beneficial to the fast electron and ion transfer during electrochemical reaction. The microstructure and chemical structure of $MnO_2$ nanowires were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and Brunauer-Emmett-Teller measurements. The electrochemical properties of $MnO_2$ nanowire electrodes were also investigated using cyclic voltammetry and galvanostatic charge-discharge with a three-electrode system. $MnO_2$ nanowire electrodes showed a high specific capacitance of 129 F/g, a high rate capability of 61% retention, and an excellent cycle life of 100% during 1000 cycles.

Determination of Ethylenethiourea in Fruits (과실류에 잔류하는 Ethylenethiourea 분석)

  • Kim, Eun-Hee;Jang, Mi-Ra;Kim, Jin-A;Kim, Tae-Rang;Yook, Dong-Hyun;Hwang, In-Sook;Kim, Jung-Hun
    • Korean Journal of Food Science and Technology
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    • v.43 no.3
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    • pp.277-281
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    • 2011
  • A rapid and very sensitive high-performance liquid chromatography/atmospheric-pressure chemical-ionization mass spectrometry method to detect ethylenethiourea (ETU) fungicide residues in fruits was developed. Methylene chloride was used as the surface extraction solvent for the target component. Recovery rates improved when cysteine hydrochloride and sodium carbonate were added to product prior to fortification. The limits of detection and quantification were approximately 0.006 and 0.02 mg/kg, respectively, from mandarin oranges. Recoveries from mandarin oranges, oranges, bananas, and pears, spiked in the range of 0.05-0.5 mg/kg, averaged 80-100%. The proposed method was used to monitor the presence of ETU in commercial fruits purchased from different markets in Seoul, Korea. ETU was found in four orange peels and in three mandarin orange peel samples. The highest ETU residue levels were $73.6{\mu}g/kg$ and $29.8{\mu}g/kg$.

Fire Resistance Performance of High Strength Concrete with 4 Deformation Factors (4변형 인자에 의한 고강도콘크리트의 내화성능 평가)

  • Lee, Tae Gyu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.5
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    • pp.112-120
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    • 2012
  • A numerical model considering the internal vaporization and the creep effect, in the form of a analytical program, for tracing the behavior of high strength concrete(HSC) members exposed to fire is presented. The two stages, i.e., spalling procedure and fire resistance time, associated with the thermal, moisture flow, creep and structural analysis, for the prediction of fire resistance behavior are explained. The use of the analytical program for tracing the response of HSC member from the initial pre-loading stage to collapse, due to fire, is demonstrated. Moisture evaporates, when concrete is exposed to fire, not only at concrete surface but also at inside the concrete to adjust the equilibrium and transfer properties of moisture. Finite element method is employed to facilitate the moisture diffusion analysis for any position of member, so that the prediction method of the moisture distribution inside the concrete members at fire is developed. The validity of the numerical model used in this program is established by comparing the predictions from this program with results from others fire resistance tests. The analytical program can be used to predict the fire resistance of HSC members for any value of the significant parameters, such as load, sectional dimensions, member length, and concrete strength.

An Experimental Study of Bond Stress between Concrete and Various Kinds of FRP Plank used as a Permanent Formwork (영구거푸집으로 활용한 FRP 판의 종류에 따른 콘크리트와의 부착응력에 관한 실험적 연구)

  • Park, Chan-Young;Yoo, Seung-Woon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.3
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    • pp.92-103
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    • 2015
  • Development of new concrete bridge deck system with FRP plank using as a permanent formwork and the main tensile reinforcement recently has been actively conducted. Concurrent use as a reinforcing material and a permanent formwork, it is possible to reduce the construction time and construction costs than the usual concrete slab. In this study, an experiment was carried out for the bond stress between cast-in-place concrete and the type of FRP plank using as a permanent formwork. The interfacial fracture energy that can be one of the most important parameters were evaluated for adhesion performance and bond stress to know the characteristics of the failure mechanism of the adhesion surface. Interfacial fracture energy of normal concrete is 0.24kN/m of GF11 case, in the case of GF21, 0.43kN/m appears, in the case of CF11 and GF31, 0.44kN/m and 0.46kN/m respectively it appeared. In case of RFCON, 0.52kN/m appears from GF12, the CF12 and GF22, 0.51kN/m and 0.36kN/m appeared each case.

Improvement of Durability in Concrete Structures Using CRM (내화학성 적층보강공법(CRM)을 활용한 콘크리트 구조물의 내구성능 향상)

  • Kim, Chun-Ho;Kim, Sang-Doh;Kim, Nam-Wook
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.6
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    • pp.145-152
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    • 2013
  • As a typical construction material, concrete has been used in building all kinds of structures since the late $19^{th}$ century. Although it was recognized to secure durability as long as the regulations on design and construction have been reasonably complied, the trends of life-shortening and deterioration have frequently occurred due to all kinds of the external effects that have been experienced during the procedures of using the structures. To make matters even worse, deterioration of the concrete structures according to deterioration can not be controlled any more. Finally, the reality is that repair and maintenance are necessary in the maintenance aspect of the concrete structure. In this study, CRM(Chemical Resistance of Laminating Reinforcement Method), which had been developed to reinforce the surface of concrete and specially improve chemical resistance performance, has been applied to enhance the existing repairing and maintenance method. Therefore, the result has been drawn with comparison and analysis of the specimens applied with the general repairing and maintenance method and CRM through a variety of durability test in this study. With the result of the test, durability of the specimen applied with CRM has been more improved than the existing repairing and maintenance method, which is judged as because of the laminating effect due to reinforcement of epoxy impregnated of alkali-resistance fiber and double layered fiber reinforced seat.

Experimental Study on the Characteristics of Asphalt Seal Waterproofing Material for Underground External Walls According to Temperature (온조도건에 따른 외벽방수용 아스팔트 씰계 재료의 흘러내림 특성에 관한 실험)

  • Um, Tae-Ho;Kim, Young-Sam;Shin, Hong-Chul;Cho, Jae-Woo;Kim, Young-Geun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.1
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    • pp.1-5
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    • 2018
  • The present study investigated the characteristics of vertical sagging down of high temperature in chamber and characteristics of vertical sagging down in the outdoor asphalt sheet and asphalt seal under korea ltimate condition using asphalt seal products of solvent based type, solventless type, water dispersion type, and heat melting type, which are currently applied in Korea. Prior to the investigation of outdoor vertical sagging down characteristics, the assessment of sagging down performance of single use of sealing products at $20^{\circ}C$, $40^{\circ}C$, $60^{\circ}C$ was conducted and the result showed that sagging down did not occur at $20^{\circ}C$ but some solventless type, water dispersion type specimens at $40^{\circ}C$ had sagging down up to 10 mm. In addition, some solventless type, water dispersion type specimens had sagging down up to 55 mm at $60^{\circ}C$. For specimens to which asphalt seal and renovated asphalt sheet were layered over the outdoor concrete vertical surface, sheet sagging and sagging down occurred up to 50 mm in water dispersion specimens after three month later since the construction in summer.

Characteristic Evaluation of SCR catalyst using Aluminum dross (알루미늄 폐드로스를 활용한 SCR 탈질촉매 제조 및 특성평가)

  • Bae, Min A;Kim, Hong Dae;Lee, Man Sig
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.10
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    • pp.4672-4678
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    • 2013
  • Aluminum dross is formation at the surface of the molten metal as the latter reacts with the furnace atmosphere and it was an unavoidable by-product of the aluminum production process. However aluminum dross was usually landfilled or disposed without treatment, causing much environmental damage. The purpose of this study is to investigate the possibility of ceramic catalyst support using recycled Al dross. The recycled Al dross was made into SCR catalyst by mixing with $WO_3$, $V_2O_5$ and $TiO_2$. The $V_2O_5-WO_3/TiO_2-Al_2O_3$ SCR catalyst was observed with XRF, XRD and BET. $V_2O_5-WO_3/TiO_2-Al_2O_3$ SCR strength was measured by Universal Testing Machine(UTM). As the added $Al_2O_3$, streagth is increased. And the NOx removal activity was observed by MR(Micro-Reactor). The temperatures ranging from $350^{\circ}C$ and $400^{\circ}C$, $V_2O_5-WO_3/TiO_2-Al_2O_3$ SCR catalyst De-NOx performance result of showed excellent activity over 90% at application condition.

A Study on the Performance of Flat-plate Solar Air Collector and its Application to Grain Drying (평면식 태양열집열기를 이용한 곡물 건조개선에 관한 연구)

  • 민영봉;최규홍
    • Journal of Biosystems Engineering
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    • v.3 no.2
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    • pp.114-125
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    • 1978
  • The use of petroleum fuels in grain drying causes problems of high cost and management. To solve these problems, it is required to study on soLar energy as an alternative to petroleum fuels for grain drying. The purposes of this study were to find out the optimum received area and air flow rate of a flat-plate solar air collector for grain drying and to assess its effects on grain drying with a small grain bin. The results of this study are summarized as follows ; 1. The calculated optimum tilt angles of the collector in the summer and autumn drying seasons were 20 and 50 degress, respectively, in suwon area. 2. The outlet temperature of the collector was $36^\circ C$ on the daily average with the maximum of $36^\circ C$ at 12:00 o clock. Solar radiation on the collector surface was 1.04 ly( 1 langley = 1 cal/$cm^2$) per minute on the daily average and 1.30 ly per minute on the maximum at 11:00am. The thermal efficiency of the collector was 62.4 percent on the daily average, and the air flow-rate per unit receiving are was 1.03 $m^3$/min/$m^2$.4. The calculated optimum receiving area and the air flow-rate per unit cubic volume for paddy in autumn drying season was 2 $m^2$ and 2$m^3$/min , respectively. 5. not significantly difference in the collector efficiency was appeared between the rotating and fixed type of solar collector. 6. For drying of wheat with 0.6 meter of the depth in the bin, approximately 9 hours were required to reduce the moisture content from 21.6% to 13% with air follow rate of 5 $m^3$/min an initial moisture per cubic meter of wheat and with air temperature of $52^\circ C$. 7. In the drying test of rough rice with a turning operation in a grain bin approximately 21 hours were required to reduced the moisture from 21% to 14.5% with airflow rate of 2 $m^3$/min per cubic meter of rice and the air temperature of $43.5^\circ C$. 8. Over-drying at the bottom and less -drying at the top of the grain mass was resulted from the high -temperature of drying air which was obtained from the flat-plate solar collector in this test. An appropriate operation should be prepared for the uniform moisture of the grain in the bin.

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