• 한국염색가공학회지
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• 제9권6호
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• pp.33-41
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• 1997

This paper surveys the extraction condition of polygenetic natural dye, Sappan Wood and the effect of ash to the dyeability and fastness. The appropriate time for extracting Sappon Wood was 1hour. The pH was increased as the amount of ash increase. The pH was nearly invariable according to the time of ash solution, the extracting times and temperature. Absorbance of dyeing fabrics was about 480nm. From the result of K/S value determination of fabrics, 10g/$\ell$ quantity of ash was surfficient for treatment and the amount of Sappon Wood was in 100% o.w.f.. K/S value of fabrics pre-mordanted or post-mordanted were higher than that of fabrics simultaneous mordanted.K/S value was increased as pH of mordanting bath decrease and pre-mordanting and post-mordanting fabrics increased the amount of absorption (K/S value) compared with non-mordanted fabrics. It was found that pH of mordanting bath affected the amount of absorption and color change of dyed fabrics. Light fastness of fabric dyed was very poor and the fastness of fabric dyed was not influenced by the mordanting conditions and methods.

• Journal of Welding and Joining
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• 제19권1호
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• pp.75-81
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• 2001

The metallurgical study of microconstituents in transient liquid phase bonded joints of Ni-base single crystal superalloys, CMSX-2 and CMSX-4 was investigated employing MBF-80 insert metal. TLP bonding of specimens was carried out at 1,373~1,523K for 0~19.6ks in vacuum. Three types of microconstituents ; needle-like constituent, dot-like constituent and abnormal shape constituent were formed in the bonded interlayer during TLP bonding operation. All these microconstituents were identified as boride. Microconstituents contain a large percentage of Cr in the early stage of bonding. As increasing the holding time, the amount of Cr was decreased and the amount of W, Co and Re were increased. From the analysis results of electron diffraction pattern by TEM, composition of elements in microconstituents were into MBlongrightarrowM$_{5}$B$_3$longrightarrowM$_2$B type with the increased in holding time. It can be explained by the fact that the relative amount of boron in microconstituents was decreased when the holding time was increased.d.

• 한국세라믹학회지
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• 제35권4호
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• pp.413-419
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• 1998

${\beta}$-silicon carbides with yttrium aluminum garnet of 2,5,10 mol% were prepared by a liquid--phase sint-ering and the microstructural evolution and phase transformation were investigated during sintering as functions of liquid-phase amount and sintering time. The rate of grain growth decreases with the addition of the amount of yttrium aluminum garnet (YAG) in the SiC starting powder however the apparent density and the aspect ratio of grains in sintered body increase. The phase transformation from ${\beta}$-SiC to ${\alpha}$-SiC were dependent on the liquid-phase amount and sintering time.

• 상하수도학회지
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• 제14권1호
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• pp.76-83
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• 2000

This research is about wastewater containing non-biodegradable TDI(Toluene Diisocyanate) that is treated by the activated carbon adsorption method. In the case of the Fenton oxidation process being applied to the existing process, optimal pH, reaction time, chemical dosing amount, removal rate, and cost were investigated. A pilot plant test was applied after finding optimal conditions with lab experiments. The optimal conditions were pH 3~5(COD removal rate 84~88%) and reaction time 30min~1hr. In higher $H_2O_2$ dosing amount, COD removal rate was a little higher. But there was little difference in the removal rate according to $FeSO_4{\cdot}7H_2O$ dosing amount. Treatment cost was economical in the case of the Fenton oxidation process being operated earlier than activated carbon adsorption system. But chemical dosing point, chemical mixing effect, chemical dosing amount, removal rate, and the cost of facility and others must be considered in practical process.

• 한국표면공학회지
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• 제36권5호
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• pp.364-372
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• 2003

In continuous galvanizing process, dissolution of iron into molten zinc results in a fairly great amount of dross. In order to decrease dross, the amount of dissolved iron of strip in molten zinc was investigated in the range of 0∼0.22%Al content, 440∼$470^{\circ}C$ strip temperature and 3∼60 sec dipping time. Uniform Fe-Al-Zn inhibition layer was formed in the coating layer/strip interface not only in the grain boundary but also in the grain of substrate with the increase of Al content in the zinc pot, while the amount of iron dissolution was decreased. Inhibition layer was unstable as the dipping time and strip temperature increased and the amount of iron dissolution increased.

• 한국주조공학회지
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• 제7권3호
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• pp.199-206
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• 1987

This paper presents experimental data for the computerization of green sand control. The results can be summarized as follows: 1. To obtain the proper compactability at the mixer, the addtion of moisture is far more efficient than the control of mixing time or addtion of clay. 2. The log R(% clay/% moisture) vs. log compactability curve moves upward as the amount of clay increases and moves downward as the amount of seacoal, dead bentonite or coked seacoal increases. 3. The ratio of dead to initial clay amount or coked to initial seacoal amount is changed according to sand to metal ratio, mainly, and according to pouring temperature, partly, at a shake out time of 12hrs.

• 대한치과교정학회지
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• 제24권2호
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• pp.295-301
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• 1994

The movement of teeth during orthodontic treatment requires bone remodeling process in periodontal tissue. To find out the changes occuring in the cell itself, mechanical force was applied to the cultured periodontal ligament cells. Following results were obtained from measuring the changes in cyclic AMP and $PGE_2$, $^3H$-thymidine incorporation amount in time lapse after application of mechanical force. 1. When mechanical force was applied to cultured PDL cells, the amount of cAMP in cells were increased significantly after 15 min. of force application, but were decreased gradually as time lapsed. 2. When mechanical force was applied to cultured PDL cells, the amount of PGE2 were increased at 20,40,60 min. and was significantly increased at 20 min. 3. When mechanical force was applied to cultured PDL cells, the amount of $^3H$-thymidine incorporation was some increased, but was not statistically significant.

• 한국작물학회지
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• 제26권1호
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• pp.96-102
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• 1981

본 실험은 홍화에 대한 파종기 7수준(3월 17일부터 5월 16일까지 10일 간격)과 질소 비료 5개 수준(무배비, 0.5배비, 표준비, 1.5배비 및 2배비)으로 각각 파종하여 알맞는 파종 적기 및 시비량 수준에 따른 형질간의 변이를 구명하기 위하여 상지대학 농학과 실습 포장에서 실시하였다. 얻어진 결과를 요약하면 다음과 같다. 1. 발아율은 파종기가 늦어짐에 따라 감소되고 발아세는 파종기가 늦어질 수록 증가하였다. 발아 최감기는 위의 결과와 반대로 반종기가 늦어질수록 단축되였다. 발아 소요 기간도 파종기가 늦어갈 수록 단축되었다. 2.초장, 분지수, 치경에서도 파종기가 늦어질 수록 감소되는 경향을 보여주었다. 또한 질소 시비량이 증가할 수록 초장 및 분지수는 증가되는 경향을 보였다. 3. 꼬투리와 1,000입중도 파종기가 지연될수록 감소되었고 1,000입중은 파종기가 이를 수록 무거워지는 경향을 보였다. 또한 질소 시비량이 증가함에 따라 꼬뚜리수와 수량에서토 현저한 증가를 보여 주었다. 4. 파종기 차이에 따른 등황색 및 등홍색 꽃의 중량은 4월 상순 파종구가 가장 무거웠다. 그러나 질소 시비량의 증가는 개화에 영향을 주지 않는 것으로 나타나고 있었다. 5. 본 실험의 결과로서 파종 적기는 4월 상순이라고 믿어졌고 홍화 재배에서는 다비의 효과가 있는것으로 나타나고 있었다.

• 한국산업보건학회지
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• 제3권1호
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• pp.22-36
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• 1993

This study was conducted to evaluate the charcoal tube sampling method for carbon disulfide in the air. Breakthrough was investigated according to flow rate, sampling time and air volume. Also the storage stability by storage method and time was investigated. The results are summarized as follows. 1. The samples stored at room temperature($28.2^{\circ}C$), refrigerator($3.8^{\circ}C$) and freezer($-15.6^{\circ}C$) were analyzed every week to five weeks. At one week storage at room temperature, 3.5% of $CS_2$ in the front section of the charcoal tube migrated into the back section and 57.7% at five weeks. The amount of $CS_2$ in the back section of the charcoal increased continuously by storage time. Migration of $CS_2$ was slow at refrigerator, and stopped occur at freezer. Recovery rate $CS_2$ was 52-82% at room temperature and 92-101% at refrigerator, based on the amount at freezer as a reference value. Thus loss was observed at room temperature. 2. When 6-48 L of fresh air were passed through tubes with spiked amounts of 0.379 and 0.759mg sample, the amounts of $CS_2$ in the back section of charcoal were 5.7-132.4 and 0-92% of the amount in the front section, respectively. The total recovery rates of$CS_2$ from 0.379 and 0.759mg spiked sample were 35.7-101.0% and 9l.3-100.1%, respectively. $CS_2$ loss was observed in 0.379mg spiked sample, but not in 0.759mg spiked sample. In the spiked samples, the amount of $CS_2$ in the back section of charcoal was not affected by flow rate when the air volume was controlled. The amount of $CS_2$ in the back section of charcoal increased over sampling time. And the faster the flow rate, the more the migration amount when the sampling time was the same. 3. A known concentration, 10 ppm of $CS_2$, was produced in a 200 L Tedlar bag. When the air volume was 24, 36, 48 L, breakthrough was 5.8, 16.9, 47.4%, respectively. The sampling flow rate of 0.05, 0.1, 0.2 Lpm did not change the breakthrough rate. Breakthrough increased over sampling time. And the faster the flow rate, the more the breakthrough, when the sampling time was the same.

• International Journal of Human Ecology
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• 제14권1호
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• pp.29-39
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• 2013

The study examined how changes in time invested in private tutoring and academic achievement influenced each other through a multivariate latent growth model by using the data from the first to the third year presented in the KYPS. This study identifies not only how changes in the private tutoring experience exerted a direct influence on changes in academic achievement, but also measures what kind of changes in private tutoring and academic achievement had emerged over time. The detailed study results are as follows. First, the analysis of time invested in private tutoring showed that the higher the grades, the greater were the amount of time invested in private tutoring in the case of Korean language study. On the other hand, the results showed that in the case of English and mathematics, the higher the grades, the lesser was the amount of time invested in private tutoring. Second, private tutoring and academic achievement were all in a linear relationship. Third, it was shown that the time invested in private tutoring and academic achievement exerted a negative influence on each other according to the passage of time.