• Journal of the Korean Wood Science and Technology
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• 제10권1호
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• pp.5-37
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• 1982

건축물(建築物)의 내장(內裝)에 많이 사용(使用)하고 있는 합판(合板)은 가열성(可燃性) 물질(物質)로서 각종(各種) 대형화재(大型火災)로 수발(受發)하여 많은 인명(人命)과 재산(財産)의 손실(損失)을 초래(招來)하고 있다. 따라서 이로 인(因)한 피해(被害)를 최대한(最大限)으로 줄이기 위(爲)하여, 내화합판제조(耐火合板製造)의 필요성(必要性)이 절실(絶實)히 요구(要求)되며 또한 내화합판제조(耐火合板製造)에서 우선적(優先的)으로 해결(解決)해야 될 합판(合板)의 재건조(再乾燥)에 관(關)해서 연구(硏究)할 필요(必要)가 있다고 생각한다. 본(本) 연구(硏究)에서는 3.5mm 얇은 5.0mm 두꺼운 합판(合板)에 Ammonium sulfate, Mono -ammonium phosphate, Di - ammonium phosphate, Borax - boric acid, Minalith 및 Water를 1, 3, 6 및 9 시간(時間)으로 처리하고 90, 120 및 $150^{\circ}C$ 등(等)으로 열판건조(熱板乾燥)를 실시한 후(後), 건조곡선(乾燥曲線), 건조율(乾燥率), 내화제(耐火劑)의 흡수율(吸收率), 비중(比重)(용적중(容積重)) 및 내화도(耐火度) 등(等)을 연구검토(硏究檢討)한 결과(結果)를 요약(要約)하면 다음과 같다. (1) Borax-boric acid와 Minalith 처리시간(處理時間)이 증가(增價)함에 따라 양액(藥液) 흡수량(吸收量)율(率)이 증가(增加)하는 경향(傾向)이 뚜렷이 하였으나 수분처리(水分處理) 흡수량(吸收量)율(率)에는 미치지 못 하였다. (2) 합판(合板)의 단위용적당(單位容積當) 약액(藥液) 흡수량(吸收量)은 일정시간(一定時間)의 처리(處理)에 있어서 두께 3.5mm의 얇은 합판(合板)이 두께 5.0mm의 두꺼운 합판(合板)보다 높았으며 가장 높은 흡수량(吸收量)은 두께 3.5mm의 얇은 합판(合板)에서 9시간(時間)을 처리(處理)하였을 때 Ammonium sulfate에서 1.353kg/$(30cm)^3$의 치(値)를 나타내었고 두께 5.0mm의 두꺼운 합판(合板)에서는 역시(亦是) 9시간(時間)의 처리(處理)에서 Ammonium sulfate의 1.356kg/$(30cm)^3$의 치(値)를 얻었다. (3) 약액처리(藥液處理) 후(後)의 합판(合板)의 용적중(容積重)은 처리(處理) 전(前)보다 뚜렷하게 상승(上昇)하였으나 열판건조(熱板乾燥) 후(後)에는 다시 용적중(容積重)의 치(値)가 하락(下落)하였는데 약액처리(藥液處理) 전(前)보다는 약간 높은 경향(傾向)을 나타내었다. (4) 약액처리합판(藥液處理合板)의 두께팽창율(膨脹率)은 두께 3.5mm의 얇은 합판(合板)과 두께 5.0mm의 두꺼운 합판(合板)에서 모두 1시간(1時間)과 3시간(時間) 처리(處理)에서 팽창율(膨脹率)의 증가(增加)가 수분처리(水分處理)와 비슷한 경향(傾向)을 보였으나 처리시간(處理時間)이 6시간(時間) 이상(以上)으로 연장(延長)되면서 약액처리합판(藥液處理合板)보다 수분처리합판(水分處理合板)의 두께 팽창율(膨脹率)이 급상승(急上昇)하여 뚜렷하게 높은 치(値)를 나타내었는데 두께 5.0mm의 두꺼운 합판(合板)에서 더욱 큰 치(値)를 보였다. (5) 열판건조(熱板乾燥) 후(後)의 두께 수축율(收縮率)도 팽창율(膨脹率)과 똑같은 경향(傾向)을 나타내었으며 두께 5.0mm의 합판(合板)에서는 약액처리시간(藥液處理時間)이 증가(增加)함에 따란 수축율(收縮率)이 뚜렷하게 상승(上昇)하는 경향(傾向)을 모든 처리약액(處理藥液)과 수분처리(水分處理)에서 나타내었다. (6) 건조곡선(乾燥曲線)은 1시간(時間)과 3시간(時間)의 처리(處理)를 제외(除外)하고 두께에 관계(關係)없이 6시간(時間) 이상(以上)의 처리(處理)에서 모두 수분처리합판(水分處理合板)의 건조곡선(乾燥曲線)이 약액처리합판(藥液處理合板)의 곡선(曲線)보다 상위(上位에 위치(位置)하였다. (7) 처리합판(處理合板)의 두께에 따른 건조율(乾燥率)은 두께 3.5mm의 얇은 합판(合板)의 경우(境遇), 두께 5.0mm의 두꺼운 합판(合板)에서 얻은 건조율(乾燥率)보다 거의 두 배(倍) 이상(以上)의 치(値)를 나타내어 얇은 합판(合板)이 두꺼운 합판(合板)보다 건조효과(乾燥效果)가 뚜렷하게 높았다. (8) 건조온도(乾燥溫度)에 따른 건조율(乾燥率)은 열판온도(熱板溫度)가 상승(上昇)함에 따라 뚜렷하게 상승(上昇)하였으며 두께 3.5mm의 얇은 합판(合板)의 경우(境遇) 열판온도(熱板溫度) 90, 120 및 $150^{\circ}C$에서 각각(各各) 1.226%/min., 6.540%/min., 25.752%/min, 였고 두께 5.0mm의 두꺼운 합판(合板)에서는 각각(各各) 0.550%/min, 2.490%/min., 8.187%/min.를 나타내었다. (9) 약액별(藥液別) 건조율(乾燥率)은 열판온도(熱板溫度) $120^{\circ}C$로 건조(乾燥)하였을 때 두께 3.5mm의 얇은 합판(合板)에서 Mono-ammonium phosphate가 가장 높은 경향(傾向)을 나타내었고 두께 5.0mm의 두꺼운 합판(合板)에서는 Di-ammonium phosphate가 가장 높은 경향(傾向)을 나타내었으나 처리시간(處理時間) 6기간(時間) 이후(以後)에는 수분처리합판(水分處理合板)의 건조율(乾燥率)이 더 높았다. (10) 약액처리합판(藥液處理合板)의 내화도(耐火度)는 측정(測定)된 중량감소율(重量減少率), 착염시간(着炎時間), 잔염시간(殘炎時間), 이면(裏面)의 탄화율(炭火率)을 통(痛)하여 수분처리합판(水分處理合板)이나 미처리합판(未處理合板)보다 뚜렷하게 높았다. (11) 내화약제간(耐火藥劑間) 내화효과(耐火效果)는 Di-ammonium phosphate가 가장 우수(優秀)하였고 다음은 Mono-ammonium phosphate와 Ammonium sulfate이며 Borax-boric acid와 Minalith는 가장 불량(不良)하였다.

• 대한치과보철학회지
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• 제38권1호
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• pp.108-115
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• 2000

This study was designed to compare the effect of polishing on surface roughness of composite resin. We used Z100(3M) composite resin and placed the composite resin in the hole (4mm thick and 4mm in diameter) of vinyl plate and polymerized it under manufacturer's instructions. Samples were divided into 5 groups by polishing methods. Group 1 was control: resin was polymerized under glass plate, Group 2: resin was polymerized without any polishing procedure, Group 3: resin was polymerized with a polishing procedure of abrasive disc, Group 4: bonding agent was applyed in thin layer and polymerized on the polished polymerized resin surface. Group 5: resin was polymerized under transparent celluloid strip. The surface roughness of each specimen was measured with Sufacoder SEF-30D (Kosaka lab. Ltd) under 0.08mm cut off, 0.05mm/s stylus speed, ${\times}40$ horizontal magnification, ${\times}5000$ vertical magnification. The results were as follows : 1. Group 1 showed the most smooth surface in this study. 2. Group 3 showed more rough surface than Group 2. Considering the surface roughness, it would be better to make the shape completely before polymerize the resin. To finish and polish after the polymerization of resin makes less smooth surface. 3. When we use the transparent celluloid strip, minimum finishing procedures are recommended. Any polishing procedure could not recover the smooth resin surface of celluloid strip. 4. Application and polymerization of the thin layer of bonding agent on the polished surface showed the minimum surface smoothing effect.

• 대한치과보철학회지
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• 제23권1호
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• pp.145-154
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• 1985

To study the effect of the vent and dense surface of the phophate-bonded investment on the castability of a non-precious alloy used in PFM restoration, one-ended polypropylene straw patterns of 0.15mm thick, 5mm radius. 10mm-high were cast with Vera Bond. The following results were obtained. 1. Thin patterns could be cast completely with a non-precious alloy. 2. No difference in the castability was found among the patterns with vent, chill vent and with out vent. 3. Dense surface of the phosphate-bonded investment had no effect on the cast ability of a nonprecious alloy.

• E2M - 전기 전자와 첨단 소재
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• 제7권2호
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• pp.100-106
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• 1994

A bilayer film consisting of a layer of a-Se$_{75}$ Ge$_{25}$ with a surface layer of silver -100[.angs.] thick and a monolayer film of a-Se$_{75}$ Ge$_{25}$ are irradiated with 9[keV] Ga$^{+}$ ion beam. The Ga$^{+}$ ion (10$^{16}$ [ions/cm$^{2}$] exposed a-Se$_{75}$ Ge$_{25}$ and Ag/a-Se$_{75}$ Ge$_{25}$ thin films show an increase in optical absorption, and the absorption edge on irradiation with shifts toward longer wavelength. The shift toward longer wavelength called a "darkening effect" is observed also in film exposure to optical radiation(4.5*10$^{20}$ [photons/cm$^{2}$]). The 0.3[eV] edge shift for ion irradiation films is about twice to that obtained on irradiation with photons. These large changes are primarily due to structural changes, which lead to high etch selectivity and high sensitivity.

• 한국초전도ㆍ저온공학회논문지
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• 제19권3호
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• pp.13-17
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• 2017

We investigated the effect of self-assembled BSO nano-defects as pinning centers in BSO-added GdBCO films when the thicknesses of films were varied. 3.5 vol. % BSO-added GdBCO films with varying thicknesses from 200 nm to 1000 nm were deposited on $SrTiO_3$ (STO) substrate by using pulsed laser deposition (PLD) process. For the films with thicknesses of 400 nm and 600 nm, 'anomaly shoulders' in $J_c-H$ characteristic curves were observed near the matching field. The anomaly shoulders appeared in the field dependence of $J_c$ may be attributed to the existence of double pinning mechanisms in thin films. The fit to the pinning force density as a function of reduced field h ($H/H_{irr}$) using the Dew-Hughes' scaling law shows that both the 400 nm- and the 600 nm-thick films have double pinning mechanisms while the other films have a single pinning mechanism. These results indicate that the self-assembled property of BSO result in different role as pinning centers with different thickness.

• 한국표면공학회지
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• 제29권6호
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• pp.862-868
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• 1996

Cadmium sulfide is commonly used as the window material for thin film solar cells, and can be prepared by several techniques such as sputtering, spray pyrolysis, close spaced sublimation (CSS), thermal evaporation, solution growth methods, etc. In this study, CdS films were deposited by thermal evaporation, close spaced sublimation, and solution growth methods, respectively, and the effects of the methods on physical properties of polycrystalline CdS deposited on ITO/glass were investigated. Also, the effects of variously prepared CdS thin films on the physical properties of CdTe deposited on the CdS were investigated. The thickness of polycrystalline CdS films was maintained at $0.3\mu\textrm{m}$ except for the solution grown CdS when $0.2\mu\textrm{m}$ thick CdS was deposited. After the deposition, all the samples were annealed at $400^{\circ}C$ or $500^{\circ}C$ in H2 atmosphere. To investigate physical properties of the deposited and annealed CdS thin films, UV-VIS spectro-photometry, X-ray diffractometry (XRD), and Auger electron spectroscopy (AES), and cross sectional transmission electron microscopy(XTEM) were used to analyze grain size, crystal structure, preferred orientation, optical properties, etc. The annealed CdS showed the bandedge transition at 510nm and the optical transmittance high than 80% for all of the variously deposited films. XRD results showed that CdS thin films variously deposited and annealed had the same hexagonal structures, however, showed different preferred orientations. CSS grown CdS had [103] preferred orientation, thermally evaporated CdS had [002], and CdS grown by the solution growth had no preferred orientation. The largest grain size was obtained for the CSS grown CdS while the least grain size was obtained for the solution grown CdS. Some of the physical properties of CdTe deposited on the CdS thin film such as grain size at the junction and grain orientation were affected by the physical properties of CdS thin films.

• 한국기계가공학회지
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• 제14권5호
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• pp.88-95
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• 2015

The thickness of adsorbed molecular layers is the most critical factor in studying thin-film lubrication, and it is the most essential parameter that distinguishes thin-film from thick-film lubrication analysis. The thin film between the shaft and bearing surface within a very narrow gap was considered. The general Reynolds equation has been derived for calculating thin-film lubrication parameters affecting the performance of the circular journal bearing. Investigation of the load-carrying capacity and pressure distribution for the journal bearing considering the adsorbed layer thickness has been carried out. A Reynolds equation appropriate for the journal bearing is used in this paper for the analysis, and it is discussed using the finite difference method of the central difference scheme. The parameters, such as eccentricity and attitude angle, are used for discussing the load-carrying capacity of the journal bearing. The results reported in this paper should be applied to analysis of the journal bearing with different lubrication factors. The steady-state analysis of the journal bearing is conducted using the Reynolds model under thin-film lubrication conditions. For a journal bearing, several parameters, such as a pressure, load capacity, and pressure components of the bearing can be obtained, and these results can be stored in a sequential data file for later analysis. Finally, their distribution can be displayed and analyzed easily by using the MATLAB GUI technique. The load-carrying capability of the journal bearing is observed for the specified operating conditions. This work could be helpful for the understanding and research of the mechanism of thin-film lubrication.

• 한국진공학회지
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• 제10권4호
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• pp.396-402
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• 2001

전자빔 증착기를 이용하여 1000 $\AA$의 두께를 가진 MgO박막을 구리 기판위에 상온에서 증착하였다. 스퍼터링수율 측정시 MgO 층에 충전현상을 없애주기 위해서 1000 $\AA$ 두께의 Al을 증착하였다. 갈륨 액체금속을 집속이온빔 이온원으로 사용하였다. 두 개의 정전렌즈를 사용하여 이온빔을 집속하였고, MgO에 이온빔을 주사하기 위해 편향기를 사용하였다. 가속전압의 변화에 따라 시료대 전류와 이차입자 전류를 측정하였고, 이 전류값은 소스에 인가하는 가속전압에 따라 변화되었다 MgO 박막의 스퍼터링 수율은 분석된 시료대 전류, 이차입자 전류 및 순수빔 전류의 값을 사용하여 결정하였다. 집속이온빔 장치의 가속전압이 15 kV일 때 MgO 박막의 스퍼터링 수율은 0.30으로 나왔고 가속전압의 값이 증가할 때 스퍼터링 수율이 선형적으로 증가하였다. 이러한 결과를 볼 때 집속이온빔 장치를 이용하면 MgO 박막의 스퍼터링 수율을 측정할 패 매우 효과적임을 알 수 있다.

• 한국재료학회지
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• 제24권9호
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• pp.443-450
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• 2014

Amorphous (a-Si) films were epitaxially crystallized on a very thin large-grained poly-Si seed layer by a silicide-enhanced rapid thermal annealing (SERTA) process. The poly-Si seed layer contained a small amount of nickel silicide which can enhance crystallization of the upper layer of the a-Si film at lower temperature. A 5-nm thick poly-Si seed layer was then prepared by the crystallization of an a-Si film using the vapor-induced crystallization process in a $NiCl_2$ environment. After removing surface oxide on the seed layer, a 45-nm thick a-Si film was deposited on the poly-Si seed layer by hot-wire chemical vapor deposition at $200^{\circ}C$. The epitaxial crystallization of the top a-Si layer was performed by the rapid thermal annealing (RTA) process at $730^{\circ}C$ for 5 min in Ar as an ambient atmosphere. Considering the needle-like grains as well as the crystallization temperature of the top layer as produced by the SERTA process, it was thought that the top a-Si layer was epitaxially crystallized with the help of $NiSi_2$ precipitates that originated from the poly-Si seed layer. The crystallinity of the SERTA processed poly-Si thin films was better than the other crystallization process, due to the high-temperature RTA process. The Ni concentration in the poly-Si film fabricated by the SERTA process was reduced to $1{\times}10^{18}cm^{-3}$. The maximum field-effect mobility and substrate swing of the p-channel poly-Si thin-film transistors (TFTs) using the poly-Si film prepared by the SERTA process were $85cm^2/V{\cdot}s$ and 1.23 V/decade at $V_{ds}=-3V$, respectively. The off current was little increased under reverse bias from $1.0{\times}10^{-11}$ A. Our results showed that the SERTA process is a promising technology for high quality poly-Si film, which enables the fabrication of high mobility TFTs. In addition, it is expected that poly-Si TFTs with low leakage current can be fabricated with more precise experiments.

• 대한가정학회지
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• 제20권1호
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• pp.65-77
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• 1982

The intent of this study was to focus attention on the relationship between curtain fabrics and consumer perceptions towards curtains and draperies. This study consisted of the laboratory test for thermal transmittance of selected fabrics and the exploratory survey for consumer perceptions towards curtains and draperies. The objectives of the laboratory test were to measure fabric's thermal transmittance, thickness, and count which affect to the effect in heat controlling. Selected 23 fabrics were tested at Korean Yarn and Fabrics Testing Inspection Institute. The objectives of the exploratory survey were to determine sociodemographic factors; the stage of family life cycle, the economics status, and homemaker's level of education, and physical factors; the type of houses, the direction of windows, and the type of windows, affect consumer perceptions toward curtains and draperies. Questionaires were administered to 489 homemakers selected by a stratified propotional sampling plan, in Seoul in October, 1981. Data from responses were analyzed by T-test(Analysis of Varience) and Partial Correlation. The major findings are as follows; 1. The results of the laboratory test 1) The fabrics used for draperies had higher effect in heat controlling than the fabrics used for glass curtains. 2) It did not show much differences among the fibers in heat controlling. The thicker fibers, however, had the higher effect in heat controlling among same fibers. 3) The fabrics which had high level of effect I heat controlling were corduroy, flax, rayon, nylon, acetate, thick polyester, and thick polyacrylic. The fabrics which had midium level of affect in heat controlling were velveteen, velvet, and thin polyester. The fabrics which had low level of effect in heat controlling were cotton, silk, and thin polyarcylic. 4) The draperies with lining showed 2∼5 times more effective in heat controlling than the draperies without lining. 2. The results of the exploratory survey Consumer perceptions towards curtains and draperies consisted of functional, financial, and aesthetic perception. 1) Factor affecting functional perception towards curtains and draperies was the stage of family life cycle. Families in the contracting stage considered function of curtains and draperies significantly better than those in others stages. 2) Factors affecting financial perception towards curtains and draperies were the economic status, homemaker's level of education, the direction of windows, and the type of windows. However the correlation between the factors and financial perception was too low to explain the significance of tendency. 3) There was not any factors affecting aesthetic perception towards curtains and draperies.