• Proceedings of the Korean Magnestics Society Conference
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• 1992.03a
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• pp.68-69
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• 1992

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.11
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• pp.617-623
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• 2013

This study is to draw thermal property data during long-term aging, by testing the thermal conductivity of building insulation materials in Korea. The thermal resistance of extruded insulation within 3 days from manufacture performed well over the KS Standard. After 50 to 110 days, however, the thermal performance had deteriorated to the level of the KS standard. Eventually, after 4,000 days, the insulation performance had deteriorated to about 25.4~41.8% of the initial performance. Therefore, this research will be utilized as a reference for thermal properties during long-term aging, in order to improve standards and regulations related to building insulation materials.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.236-236
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• 2017

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.359-365
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• 2017

This study examined concrete characteristics depending on the replacement ratio of recycled fine aggregates, which suits the KS F 2573 concrete recycled aggregate standard. As physical properties, slump, air content, changes in the elapse of time and compressive strength were studied in order to provide basic data for activation of recycled fine aggregate recycling. As a result of experimenting recycled fine aggregate concrete, the increase in the replacement ratio of recycled aggregates led to the increase in slump and air content. Also, when the replacement ratio of recycled fine aggregates was 30%, it was judged that there was no problem with constructability. When the replacement ratio was 30%, recycled fine aggregate concrete had a similar tendency to natural aggregate concrete at a compressive strength of 24MPa. When the replacement ratio was 30%, at a target strength of 24MPa, recycled fine aggregate concrete had the same physical characteristics as natural aggregate concrete. This means that a replacement ratio of 30% is appropriate for replacement of recycled fine aggregates. In future, there will be a need to improve the quality of recycled fine aggregates for activating the use of recycled fine aggregates and further research will have to evaluate physical properties of recycled fine aggregate concrete using improved recycled fine aggregates.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.59-59
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• 1992

간헐적 혈액투석 또는 지속적 복막투석 요법을 받고 있는 만성 신부전 환자에서 carumonam의 약동학적 변화를 분석하여 이 환자들에서 적절한 투여용법을 고안하고, 이들 특수 질환군에서의 임상시험모형을 도굴하고자 하였다. 혈액투석환자는 carumonam 1g을 20분간 지속 정주 후 약물의 분포기 종료가 예상되는 시간에 혈액투석을 4-5시간 시행하였으며, 혈액, 투석액, 뇨를 경시적으로 채취하였다. 지속적 복막투석 환자군에 있어서는 1일 3회(6, 6, 12시간) 복막 투석을 시행하는 환자를 대상으로 carumonam 1g을 정주하고 24시간동안 혈액 및 투석액, 뇨를 경시적으로 채취하였다. 혈액, 투석액 및 뇨중 carumonam의 농도는 HPLC방법으로 측정하였으며, 경시적인 혈장 carumonam 농도변화 및 투석에 따른 약물의 제거를 혈액 투석환자는 2 compartmental model, 복막투석환자에서는 bidirectional 2 compartmental model에 의해 그 약동학적 성상을 분석하였다.

• Journal of the Korean Applied Science and Technology
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• v.35 no.2
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• pp.568-577
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• 2018

This study was conducted to evaluate the quality characteristics. Trehalose was used to manufacture rice bread in two ways: one was to substitute trehalose for sugar by (0, 25, 50, and 75%) trehalose in each sample and the other was to analyze the temporal changes in rice bread on Day 0, on Day 2, and on Day 4. The results concerning the characteristics of specific volumes, water content, water activity, variation in weight and height, physical property test, and sensory test and measurements of the temporal changes are as follows: First, as for variation in specific volumes, rice bread containing trehalose had the content and temporal changes decrease significantly (p<0.001). Second, as for texture, a higher trehalose content led to a slightly lower level of hardness. As for the temporal changes, addition of trehalose is generally effective in decreasing hardness of rice bread. the sample containing trehalose showed an almost similar value. The control group not containing trehalose showed the significantly lowest level of cohesiveness, springiness, Chewiness. Finally, the sensory evaluations revealed that the taste, Flavor, and Sweetness was at a significantly higher level in the group with trehalose substituted for sugar than in the control group. An increase in the trehalose content led to an increase in overall eating quality.

• Journal of the Korean Ceramic Society
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• v.26 no.4
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• pp.588-590
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• 1989

Charge sensitivity and its frequency response characteristics were measured in poled and aged lead zirconate titanate(PZT) ceramics prepared by sintering. Aged PZT has lower charge sensitivity and lower mounted resonance frequency than just poled PZT.

• Journal of Conservation Science
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• v.24
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• pp.67-74
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• 2008

The objective of this study was to investigate stability of traditional starch sizes according to time. The properties of wheat flour and fermented whole-wheat flour were studied. And comparison of stiffness, tensile strength, air permeability, whiteness, and surface observation of cotton fabrics sized with wheat flour and fermented whole-wheat flour before and after 12-years were examined. The amylograph data indicated that ISF-W(Isolated starch flour- white) have good pasting properties than NWF(Natural wheat flour) and ISF-B(Isolated starch flour- light brown). The cotton fabrics sized with ISF-W had higher tensile strength and whiteness, and lower stiffness and air permeability than those of NWF as the time takes 12 years. We identified the stability of traditional starch size using scanning electronic micrograph.

• Journal of the Korean Vacuum Society
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• v.22 no.4
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• pp.211-217
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• 2013

Two types of organic thin film solar cell devices with bulk hetero-junction (BHJ) structure were fabricated on plastic substrates using conjugated polymers of $PCDTBT:PC_{71}BM$ and $PTB7:PC_{71}BM$ blended as active channel layer. Time-variant characteristics of the organic thin film solar cell devices were investigated: short circuit current density ($J_{SC}$); open circuit voltage ($V_{OC}$); ; fill factor (FF); power conversion efficiency (PCE, ŋ). All the performance parameters were degraded by progress of the measurement time, while $V_{OC}$ showed the most drastic decrease with time. Possible factors to cause the time-variant alteration of performance parameters were discussed to be clarified.

• The Journal of the Korea Contents Association
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• v.22 no.4
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• pp.706-713
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• 2022

The study is to observe the time trend variation in the blood lead concentration of Korean teenage groups and to examine the changes in the daily lead intake from intake amount(g) by food groups as an influencing factor. A total of 1,540 subjects are participants in the Korea National Health and Nutrition Examination Survey (KNHANES) in 2011, 2012, 2014, 2016, and 2017. The blood lead concentrations were 1.25㎍/100ml in 2011 survey, 1.16㎍/100ml in 2012, 1.17㎍/100ml in 2013, 1.05㎍/100ml in 2016, and 0.84㎍/100ml in 2017. The time trend decrease in food intake amount appeared mainly in the plant food groups such as grains, potatoes and starch, pulses, mushrooms, vegetables, and fruits. And the milk and dairy products of the animal food group also showed a decreased trend. The decrease in the intake amount of these food groups can be an influencing factor in the decrease in lead concentration in the blood.