• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.06a
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• pp.220-224
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• 1999

Sliding wear test was employed to determine the effect of whisker content and orientation on the firiction and wear behavior of SiC whisker reinforced alumina. Composites containing unidirectionally oriented whiskers were prepared by a modified tape casting followed by lamination, binder removal and hot pressing in order to align the whiskers in the tape casting direction. Wear coefficients on three directions were measured; parallel and normal to the tape casting direction on the tape casting surface and normal to lamination direction on surfnce normal to the tape casting direction. In the effect of whisker orientation, the highest wear rate was obtained in the direction parallel tape casting direction and the lowest in the direction normal to lamination direction at all temperatures. Silicon oxide layer amoothing the surface was detected by energy dispersive X-ray analysis on the worn surface.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.06a
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• pp.166-172
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• 2000

Friction characteristics of phenolic resin-based friction composites containing threedifferent relative amounts of graphite and zirconium silicate were investigated by using a pad-on-disk type friction tester. Constant temperature test and constant interval test at three different initial temperatures(100. 200, 300$^{\circ}C$) were performed to examine the effects of friction heat on friction characteristics at elevated temperature. The friction composite(FMO.7) with higher content of ZrSiO$_4$showed unstable friction force at higher temperature and resulted in larger fluctuations of vibration during friction test. The abrasive action of ZrSiO$_4$in friction composite impeded stable transfer film and induced higher friction heat at friction interface. Friction oscillations according to the temperature were associated with the formation of transfer film(i'd body layer) on the friction composite and the counter part.

• Korean Journal of Materials Research
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• v.6 no.1
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• pp.84-89
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• 1996

분자선 증착법(Molecular Beam Epitaxy)에 의하여 성장시킨 고농도 InGaAs layer에서 성장중지법이 계면 거칠기에 미치는 영향이 연구되었다. 계면을 평활화하기 위하여 단원자층의 GaAs 또는 AIAs를 InGaAs alyer 양쪽 계면에 증착한 뒤 뒤이어 성장중지를 실시하였다. Photoluminescence(PL) 측정에 의하면, 단원자 GaAs층 증착을 통한 평활화법보다 상당히 향상된 계면조건을 보여졌다. 고 분해능 단면 전자현미경법(Cross-section high resolution transmission electron microscopy, XHRTEM)에 의해 관찰되어진바, 계면 평활화법에 의해 계면의 평활성, 연속성 및 결정결함 밀도등에서 현저한 향상이 얻어졌다.

• Korean journal of food and cookery science
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• v.1 no.1
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• pp.57-64
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• 1985

This study was conducted to investigate the effect of fat on structure and texture of soybean curds by partial or whole replacement of soybean with defatted soy flour, The textural properties of soybean curd were examined by Instron universal testing machine, and the microscopic structure of soybean curds was examined by Scanning electron microscope(SEM). The results obtained were as follows ; 1. Textural parameters determined by Instron universal testing machine showed that hardness and gumminess of soybean curs were significantly increased as the fat contents of the samples decreased. On the while, springiness of the samples were significantly lowered as the fat content decreased. 2. Microscopic structure of soybean curds examined by SME demonstrated that samples with high fat had more fat globules and thinner network layer which were assumed to surround moisture with.

• Membrane and Water Treatment
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• v.1 no.1
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• pp.1-12
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• 2010

Membrane distillation process was used for purification of pre-treated natural water (tap water). The rejection of inorganic and organic compounds in this process was investigated. The obtained rejection of inorganic solutes was closed to 100%, but the volatile organic compounds (VOCs) diffused through the membrane together with water vapour. The content of trihalomethanes (THMs) in the obtained distillate was two-three fold higher than that in the feed, therefore, the rejection of the total organic compounds present in the tap water was reduced to a level of 98%. The intensive membranes scaling was observed during the water separation. The morphology and composition of the fouling layer was studied using scanning electron microscopy coupled with energy dispersion spectrometry. The influence of thermal water pre-treatment performed in a heat exchanger followed by filtration on the MD process effectiveness was evaluated. This procedure caused that significantly smaller amounts of $CaCO_3$ crystallites were deposited on the membrane surface, and a high permeate flux was maintained over a period of 160 h.

• Journal of Biosystems Engineering
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• v.15 no.1
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• pp.44-51
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• 1990

Four models in current use for cereal grain drying, equilibrium model, Morey model, partial differential equation model and simplified partial differential equation model, were modified to be suitable for natural air drying of barley. The predicted by the four models and experimental results were compared. Three models except equilibrium model predicted moisture comtent and grain temperature very well. But equilibrium model overpredicted moisture content and grain temperature of bottom layer. The degree of prediction of the four models for relative humidities of exhaust air didn't differ much from one another and equally the four models predicted relative humidity statisfatorily. Morey model took much shorter computing time than any other models. Therefore, considering the degree of prediction and computing time Morey model was the most suitable for natural air drying of barley.

• The Korean Journal of Ecology
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• v.19 no.1
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• pp.47-53
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• 1996

Effects of group breeding of herons on pine community were studied at Pomaeri, in Yangyang, Kangwon Province, Korea. This site has been protected as a Natural Monument (No. 229) since 1970. Herons have used this habitat as a breeding site from] anuary to October every year. In 1995, more than 500 herons were observed in this habitat. Many big pine trees are dying or already dead due to group inhabitation of herons, and no pine saplings were found at forest floor in this habitat. Nutrient contents of soil in this habitat were much higher than those in control plot. This must be due to the addition of feces from herons and of thin twigs and other organic materials from the canopy and bird nests. Species composition of herb layer in this habitat was quite different from that in control plot. Breeding site was dominated by Humulus japonicus. Persiearia perJohata, Persicaria thunbergii. and Commelina communis. which are indicator species of soil eutrophication.

• Applied Biological Chemistry
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• v.15 no.1
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• pp.1-6
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• 1972

The naturally occurring indole derivatives in mung bean (Phaseolus vidissinus) sprouts were investigated by means of paper and thin layer chromatographic techniques. The results can be summerized as follows: 1. The mung bean sprouts are richer in free tryptophan than other plant species. 2. Indole ethanol and indole lactic acid were identified. 3. The content of indole ethanol was more than that of indole acetic acid. This result appeared to support the idea that indole ethanol is the storage product of indole acetic acid.

• Journal of Surface Science and Engineering
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• v.35 no.3
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• pp.141-148
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• 2002

Fe-C alloy layers were produced by pulse plating and the properties were compared with those produced by D.C. plating. When the pulse on time ($T_{on}$ ) was the same, both the duty cycle and peak current density($I_{p}$ ) had little influence on the carbon content and the hardness of the layer. The structure and hardness of the direct current plating were similar to those of the pulse current plating. However, the ductility was enhanced when the pulse current was applied due to the release of residual stress during the pulse off time($T_{off}$).).

• Journal of Korean Society of Forest Science
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• v.15 no.1
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• pp.39-41
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• 1972

Yew heartwood from different species was analysed by thin-layer chromatography for its phenolic content. A separation could be made between the species examined on the basis of the occurrence of heartwood phenols.