• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.538-538
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• 2008

금속계열의 박막을 평탄화하기위해서는 슬러리에 함유된 산화제에 의해 부동태층의 형성이 선행되어야 한다. 따라서 본 논문에서는 Copper 박막의 표면을 부동태층으로 형성시키고 CMP공정을 하기위해 산화제에 dipping을 시켰으며 삼화제의 종류는 $H_2O_2$, MSW2000B, $KIO_3$로 하고 dipping 시간은 30초, 60초, 90초, 3분, 10분으로 하여 시간과 산화제 종류에 따른 부동태층의 변화를 연구하였다. 부동태층의 관찰은 FESEM을 이용하여 표면과 단면을 관찰하였고 부동태층의 조성비율은 EDX를 이용하여 조사하였다. MSW 2000B의 경우는 부동태층이 덩어리 모양으로 형성되었으며 포화현상은 3분에 일어났다. 반면에 $H_2O_2$의 경우는 부동태층이 침상 모양으로 형성되었으며 포화현상은 90초에 일어났다. 산화제에 의해 부동태층을 형성시킨 후 POLI-450을 이용하여 평탄화공정을 진행하였으며 CMP공정조건은 부동태층의 연질상태임을 감안하여 헤드 스피드 20rpm, 플레이튼 스피드 10rpm, 슬러리 주입속도 90ml/min, 공정온도는 상온으로 하여 진행하였다. $H_2O_2$를 산화제로 사용하여 dipping을 하고 CMP를 하였을 경우에 균일한 박막을 확보 할 수 있었으며 CMP 공정 후 copper 박막의 균일성은 FESEM을 이용하여 관찰 하였다.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.846-855
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• 2002

Several soft white spring and winter wheat cultivars were evaluated by analyzing physicochemical properties such as Single Kernel Characterization System (SKCS), milling properties, Rapid Visco-Analyzer (RVA), mixograph pattern, and sugar-snap cookie-making potentialities. Results of SKCS revealed kernel hardness had a positive correlation coefficient with test weight $(r=0.497^{*})$ and near-infrared reflectance (NIR) hardness $(r=0.495^{*})$. SKCS kernel weight had a significantly high correlation of $r=0.942^{**}$ with SKCS kernel size. The test weight had significantly high correlations with straight-grade flour yield $(r=0.720^{**})$, break flour yield $(r=0.490^{*})$, flour ash content $(r=-0.781^{**})$, and milling score $(r=0.838^{**})$. The average RVA peak viscosity of the soft white winter wheat was higher (195.1 unit) than the soft white winter wheat varieties (135.7 unit). A correlation was found between RVA peak viscosity and swelling volume. Significant correlation coefficients were obtained among cookie properties, milling properties, protein content, and mixograph absorption. The cookie top grain score had a correlation coefficient of $r=0.447^{*}$ with swelling volume.

• Journal of Conservation Science
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• v.28 no.3
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• pp.193-204
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• 2012

This research aims to examination the material characteristics changes of the ancient clay depending to firing temperature and to verify the firing temperature of the Joseon potteries from the Yongam site in Ssangyongdong of Cheonan, Korea. To this study, we conducted a firing experiments using the ancient clay that was verified raw material of the Joseon potteries from the study area in the temperature range from 500 to $1,200^{\circ}C$. The yellowish tint, the reddish tint and the specific gravity of firing samples increase according to firing temperature rise. But the absorption ratio and the porosity decreased under same firing temperature range. The soft potteries from the Yongam site has similar material characteristics with the fired samples at 800 to $950^{\circ}C$. And the hard potteries from the Yongam site bears the same relation to the fired samples at about $1,100^{\circ}C$. This result is considerably signification for the interpretation of firing temperature. The geochemical characteristics of the original clay according to the firing experiments, on the other hand, is not affected of temperature in this study.

• Korean Journal of Dental Materials
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• v.45 no.4
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• pp.311-320
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• 2018

The purpose of this study is to evaluate the flow ability of the thermoplasticized Gutta Percha in different temperatures. Four Gutta Percha products were classified by its hardness (soft, medium, and hard) and were experimented by the Rheometer (Melt flow indexer MFI-10, DAVENPORT, England) measuring apparatus, in $(23{\pm}2)^{\circ}C$, and in a relative humidity of ($50{\pm}5$) %, following the guidelines of ISO 1133-1:2011. The heating temperature ranged from $108^{\circ}C$, $160^{\circ}C$ to $200^{\circ}C$, and the load at 2.16 kg and 3.8 kg. The Gutta Percha was cut in 5 mm to be suitable for the rheometer pressurization process. After the experiment was conducted with a preheating time of 5 minutes, a cutting time of 5-240 seconds, and a sample of 10 grams, the Gutta Percha did not show any changes in fluidity for $108^{\circ}C$, $160^{\circ}C$, but showed a change in its flow ability in $200^{\circ}C$. Also, the Gutta Percha did not show any changes in its fluidity when it was pressurized by 2.16 and 3.8 kilograms. Therefore, this experiment shows that the heating temperature and the cut-off time showed a significance while measuring the melt flow rate.

• Nuclear Engineering and Technology
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• v.3 no.3
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• pp.129-140
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• 1971

Two laboratory-melt heats of 3.25 silicon-iron were made and processed according to a normal commercial practice. Some of the important processing variables that were studied in relation to secondary recrystallization and texture development were contents of manganese and sulfur, heat-treatments after hot-rolling that were used to achieve different hot-rolled microstructures, and amounts of second cold-reduction. The main effort of the present study was directed toward elucidating the relationships among the amount of second cold-reduction, activation energies associated with secondary recrystallization and texture development. The specimens that had been cold-reduced 10% exhibited only grain growth by strain-induced grain boundary migration and did not exhibit secondary recrystallization. Secondary recrystallization did rot appear to completely occur in the 30% cold-reduced specimens, although the nucleation for secondary recrystallization was observed. The second cold-reduction in an amount of 50% was shown to be the optimun for secondary recrystallization and texture development by subsequent processing.

• Elastomers and Composites
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• v.15 no.1
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• pp.3-9
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• 1980

The oxygen permeability and it's proofness of te various commercial polymer films have been investigated at the constant pressure and temperature. Oxygen proofness, the reciprocals of the oxygen permeability for the various samples, were determined by means of a coulometric oxygen permeability tester. The testing of sample films was performed at constant temperature $(23{\pm}1^{\circ}C)$ under 1 atm. for 24 hours. The order of the relative proofness observed are as follows; oriented Nylon (O. Nylon)> oriented Polyester (O. PET)>nonoriented Nylon (N. Nylon)>nonoriented Polyester (N.PET)> rigid Polyvinyl chloride (Rigid PVC)>semirigid Polyvinyl chloride (Semirigid PVC)> oriented Polypropylene (O. PP)>plasticized Polyvinyl chloride (P. PVC)> casted Polypropylene (C. PP)> low density Polyethylene (LDPE)>high density Polyethylene (HDPE, Inflation)> high density-polyethylene (HDPE, T-die) The oxygen proofness of the films was increased with the polarity cf polymer, the film thickness and mechanical orientation and decreased with the addition of plasticizer in PVC. For the use of wrapping materials, one film with the polar property in the main chain of the polymer molecule and the others with nonpolar property in it are laminated for the protection from oxygen and moisture.

• Composites Research
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• v.34 no.1
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• pp.16-22
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• 2021

Polyurethane foam (PUF) can be manufactured in soft, semi-rigid, and hard forms, so it is used in various fields industrially. Among them, rigid PUF has excellent mechanical properties and low thermal conductivity, and is used as a thermal insulation material for buildings and as a cold insulation material in the natural gas transportation field. In this field, there is a steady demand on higher mechanical strength and lower thermal conductivity. In this study, a rigid PUF was manufactured, and the microstructure and physical properties were studied according to the impeller type (propeller, dispersed turbine) of the agitator. Through FE-SEM and Micro-CT analysis, it was confirmed that the average pore size of the foam manufactured with the dispersed turbine was 21.5% smaller than that of the pore made by the propeller. The compressive strength was improved by 15.4%, and the thermal conductivity decreased by 3.1% in the foam with small pores. This result can be utilized for fabricating PUF composites.

• Journal of Conservation Science
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• v.29 no.4
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• pp.395-406
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• 2013

The conservation of damaged object should be restored by the similar material with the original and they have to reversibility as possible as. The characteristics of Buddhist mural paintings composed of clay are with soft material. So far, there have been a number of researches done on filling material that reinforces cracks and exfoliation of mural painting. Based on the application of traditional materials, it was found that they are appropriate to various applications. However, only based on those research results, there are some constraints to the application in the field. In addition, there has been only a few researches done on physical characteristics of filling materials. A major issue is that there is not any standard established on various mixing ratio, which is required for treatment of mural painting. This study was carried out to understand the physical characteristics of filling materials on clay mural painting. The 1st test was conducted to analyze test specimen in twelve different conditions by varying soil mixing ratio and organic medium. The 2nd test was conducted to manufacture filling materials appropriate to the mural painting, based on the result of stable condition from the 1st test, and which was applied to treatment in field.

• Korean Journal of Materials Research
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• v.9 no.10
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• pp.962-969
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• 1999

Elastic and elasto-plastic stress analyses of AlN/Cu and AlN/W pints produced by active-metal brazing method using Ag-Cu-Ti insert-metal were performed with use of Finite-Element-Method(FEM). The results of stress analyses were compared with those from the pint strength tests and the observations of fracture behaviors. It was shown that a remarkably larger maximum principal stress is built in the AlN/Cu pint compared to the A1N/ W joint. Especially, the stress concentration with tensile component was confirmed at the free surface close to the bonded interface of AlN/Cu. The elasto-plastic analysis under consideration of stress relaxation effect of Ag-Cu-Ti insert possessing a so-called 'soft-metal effect' showed that the insert leads to a lowering of maximum principal stress in AlNiCu pint, even though an increase of the insert thickness above 100$\mu\textrm{m}$ could not bring its further decrease. The maximum pint strengths measured by shear test were 52 and 108 MPa for AlNiCu and AlN/W pints. respectively. Typical fractures of AlN/Cu pints occurred in a form of 'dome' which initiated from the free surface of AlN close to the bonded interface and proceeded towards the AlN inside forming a large angle. AlN/W pints were usually fractured at AlN side along the interface of AlN/insert-metal.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.3
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• pp.243-254
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• 2019

In this study, problems of the waterproofing methods in which water leakage occurs in the upper slab of the underground parking lot of apartment houses and the requirements considering the characteristics of the upper slab, and selected the appropriate performance(proposal) for the composite polyurea process are reviewed. As a result of the study, it is necessary to review performance such as responsiveness to upper slab of the multi-unit underground parking lot that is comprised of (1) crack and behavior responsiveness, (2) surface integrity, (3) vertical watertight stability, (4) pressure layer construction, (5) impact and pressure response and (6) vehicle moving load. As a result of evaluating 5 items corresponding to the requirements for the soft and hard complex polyurea, all of them were found to meet the conditions, and each materials were improved by compounding the materials that had problems when applying a single-ply method, thereby clarifying the advantages and disadvantages of the material property. However, in order to apply to the actual site, additional evaluation on site applicability such as mock-up evaluation should be conducted, and subsequent studies on the applicability of the market through review of economic feasibility and maintenance is required.