• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.1C
• /
• pp.1-6
• /
• 2012

In this study, field tests were performed to evaluate the stability of pre-insulated pipe during the compaction operation and to recommend an alternative backfill material. Three types of natural sand (fine-grained and medium-grained, coarse-grained sand), crushed sand and two types of gravel (10 mm, 20 mm) were used as backfill material in the field tests. Field tests were performed to determine the behavior (earth-pressure and deformation, installation damage) of the pre-insulated pipe due to variation of different types of backfill material. Based on the evaluation and comparison of field test results, it was determined that crushed sand is the most suitable back-fill material that can be used as an alternative for medium grained sand for pre-insulated pipes with respect to the engineering behavior and material supply.

• Applied Biological Chemistry
• /
• v.38 no.5
• /
• pp.422-424
• /
• 1995

In order to investigate the textural changes of cooked rice in a home electrical rice cooker during warm keeping period, rice was cooked and stored at $73^{\circ}C$ for 42 hours. The time course changes of hardness and adhesiveness of cooked rice were measured with the specimen prepared as a cylindrical rice block(H/D= 15 mm/20 mm). At the initial stage of warm keeping period the hardness was 1.61 kg and it was increased steadily to 1.95 kg up to 12 hours. And it was rapidly dropped to 1.57 kg within 3 hours, and thereafter gradually decreased to 1.44 kg. The adhesiveness was steadily declined with warm keeping period from 0.51 to 0.323kg set The cohesiveness and chewiness were also changed in the similar pattern to that of hardness while the springiness remained unchanged throughout the whole warm keeping period.

• Fashion & Textile Research Journal
• /
• v.1 no.3
• /
• pp.264-274
• /
• 1999

The thermal resistance of 60 men's suits for summer and winter was measured to determine their thermal characteristics and physical properties, including air permeability, weight, and thickness of the jackets and trousers consisted of the ensembles were measured to predict the thermal resistance of garments and ensembles. In this study, general physical properties of the men' suit ensembles were determined. In general, thickness and weight of winter ensembles were greater than those of summer ensembles. A factor which could distinguish the difference between summer and winter ensembles was the air permeability. The air permeability of summer ensembles was 3~6 times greater than those of winter ensembles. For the thermal characteristics, the thermal resistance of winter ensembles were higher than those of summer ensembles. When the wind was involved, the thermal resistance of both ensembles decreased up to 30%. In addition, the equations were developed to predict the thermal resistance of the garments and ensembles when there was no air velocity and the thermal resistance of the ensembles with air velocity of 1.2 m/sec. Looking at the equations, thickness, weight, and size of the garments were the definite factors that affect the thermal resistance of the samples.

• Journal of Bio-Environment Control
• /
• v.25 no.4
• /
• pp.288-293
• /
• 2016

The study was performed to evaluate thermal insulation covering materials (TICMs) to protect peach trunks against freezing temperatures in winter season by investigating thermo-physical properties and practical thermal insulation effect of the TICMs which was made of white non-woven fabrics, yellow paper sheets, and waterproof fabric pads. Among the three TICMs, Waterproof fabric pad (double layer) possessed the best performance about thermal insulation rate and thermal resistance among three kinds of TICMs. Day thermal insulation effects of waterproof fabric pad, which prevent from temperature rise on the bark tissues of trunks during the day time, were $14.09^{\circ}C$. Night thermal insulation effects of them, which prevent from temperature decline on the bark tissues of trunks at night time, were $7.23^{\circ}C$. Waterproof fabric pad showed the highest day and night thermal insulation effects. Thus our results suggest that development of TICMs using waterproof fabric pad might be helpful to protect the bark tissues of trunks from freezing injury.

• Journal of Bio-Environment Control
• /
• v.14 no.1
• /
• pp.22-28
• /
• 2005

The use of blankets to preserve heat in oriental melon cultivation is a common practise without artificial heating and warming systems. Efficiency of blanket decreased with annually usage. This experiment was conducted to investigate the effect of double layer nonwoven fabrics on heat conservation, plant growth, fruit quality and yield of oriental melon in greenhouse. The results were compared among the non-woven fabrics of 9+3, 6+6, 6+3 and 12 ounce from transplanting to April 20, 2001, 2002. Night temperature within tunnel was high at 9+3, 6+6, 6+3 and 12 ounce in order. In plant growth, stem length, leaf numbers and exudate, under double layer nonwoven fabrics were better than single layer blanket of 12 ounce especially, 9+3 double layer blanket was the best. Fruit weight, flesh thickness, soluble solid and marketable yield rate remained same in all treatments. Fermented fruit rate was the highest in 12 ounce as $32.9\%,\;19.6\%\;under\;9+3,\;17.1\%\;under\;6+6,\;16.6\%$ under 6+3 double layer nonwoven fabric, respectively. Compared to 2,260kg yield per 10a of 12 ounce single layer nonwoven fabrics, $7\%$ was increased under 9+3 but $3\%\;and\;13\%$ were decreased under 6+6 and 6+3 double layer nonwoven fabrics, respectively. Compared to income, 4,499-thousand-won per 10a, of 12 ounce single layer blanket, $13\%\;and\;3$ were increased under 9+3 and 6+6 double layer nonwoven fabrics, respectively. Whereas, $10\%$ decreased under 6+3 double layer nonwoven fabrics. From this results it is evident that 9+3 double layer nonwoven fabrics was the best for thermokeeping, fruit quality, and was most economic under non heating system.

• Product Safety
• /
• s.95
• /
• pp.42-43
• /
• 2001

전기보온밥솥의 전력소비비중은 11.5$\%$로 냉장고 17.3$\%$, 조명용 형광램프 14.8$\%$, 컬러TV 12.3$\%$에 이어 네 번째로 높은 비중을 차지하고 있어 에너지 소비를 줄일 수 있는 절전형 제품을 개발하는 것은 당연하다. 하지만 국내에는 아직 이에 대한 에너지 효율기준과 측정방법에 대한 기준이 마련되어 있지 않은 상태다.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.11a
• /
• pp.77-78
• /
• 2017

In this study, the effect of insulation curing for mass concrete wall according to thickness and curing period was evaluated by thermal analysis.

• Journal of Mushroom
• /
• v.18 no.3
• /
• pp.254-259
• /
• 2020

Grifola frondosa is a promising new kind of cultivated mushroom owing to its excellent taste and functionality. However, more research is required to determine its value. In this study, the effects of pretreating Grifola frondosa tea by drying, steaming, and warming, on quality characteristics and antioxidant activities were analyzed. There was no difference in sugar, soluble solid, and nitrogen content between dried and steamed tea. The color of the warm pretreated tea was the darkest, and the amino acid content was 462.9 mg/L, which was 1.8 times higher than that of the other pretreatments. Moreover, the warm pretreated tea had the highest total polyphenol and flavonoid content, 14.6 mg/g and 2.2 mg/g, respectively. DPPH and ABTS radical scavenging activities significantly increased with the increase of phenolic compounds. Warming pre-treatment slightly increased the taste preference to 7.0. In conclusion, warming Grifola frondosa before drying was confirmed to improve the extraction of nutrients, antioxidants, and taste preference.

• Journal of the Korea Institute of Building Construction
• /
• v.16 no.1
• /
• pp.67-76
• /
• 2016

Concrete exposed to severely low temperature below $-20^{\circ}C$ should be provided with proper heat supplying curing to protect the concrete from early frost damage at the time of pouring.meanwhile, so far, effective heat curingmethods of the concrete under severely low temperature are not well established in Korea. For this reason, the objective of this paper is to provide effective heat curingmethod of concrete exposed to severely low temperature to protect early frost damage by varying the combination of heat curingmaterial combinations. Temperature history,maturity development and core strength results are investigated. Fourmock-up specimens simulating slab, wall and column were prepared and heat insulation, heat supplying and both were applied. Test results indicate that the combination of quadruple layer bubble sheet(4BS) and embedding of heating cable has desirable performance for a slab, and heat supplying curing inside heat enclosure and heat generationmat also shows desirable performance for a wall, and for a column, use of EPS heat insulation has proper performance against early frost damage, which reaches $45^{\circ}D{\cdot}D$ and helps the concretemaintain above $0^{\circ}C$ within 3 days. Themethodsmentioned above are believed to be optimum protection from early frost damage of the concrete under $-20^{\circ}C$.

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 1999.04a
• /
• pp.87-91
• /
• 1999

봄철 하우스 수박 무가온 조숙재배에 알맞는 보온방법을 개발하고자 아취형 단동하우스에 PE필름터널, 유공필름＋축열물주머니, 유공필름터널＋부직포터널구를 처리하고, 삼복꿀수박을 '98년 3월 23일 정식하여 4월 27일까지 36일간 터널피복재의 보온성을 검토한 결과는 다음과 같다. (1) 보온재 피복 재배 기간중 터널내 최저온도는 PE터널구 10.9$^{\circ}C$에 비하여 유공필름터널에 축열물주머니구와 부직포터널구는 각각 0.9, 2.1$^{\circ}C$ 높았다. (2) 3월하순 활착기의 하우스내 일사량은 실외 175.2w/$m^2$ 비하여 124.2w/$m^2$로 51w/$m^2$ 낮았다. (3) 터널피복재 환기작업에 따른 소요 노동력은 PE터널구 25.2시간/10a/36일에 비하여 유공필름터널＋부직포터널구는 32.4시간으로 7.2시간/10a/36일 증가하였으나, 유공필름터널＋축열물주머니는 개폐작업으로 인한 투하 노동력이 없었다. (4) 터널재배 기간중 유공필름터널＋부직포터널구가 초기생육이 촉진되었으며, 생육후기에 발생한 흰가루병 이병엽율은 2.8%로 현저히 감소하였다. (5) 수박의 수확기는 PE필름터널구 6월 22일에 비하여 유공필름터널＋축열물주머니와 부직포터널구는 6월 12, 15일로 7, 10일 앞당겼으며, 수량은 PE터널구 2,385kg/10a에 비하여 20, 32% 각각 증수하였다.