• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.1-8
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• 2019

Steel elevator pit was developed for the purpose of minimizing the excavation, simplifying the construction of the frame and economical efficiency by improving the problems that occurred in the existing reinforced concrete. It is common to apply conventional RC method through excavation to underground structures such as underground floor collector well and elevator pit. In recent years, the use of steel collector well and steel elevator pits to reduce construction costs by minimizing the materials of steel and concrete has been continuously increasing. The steel elevator pit is an underground structure and then the performance of the welding part and the structure system is important. Specimen with only steel plate and concrete without studs could support the load more than 3 times than the specimen with deck only. Therefore, even if there is no stud, the deck (steel plate) rib is formed and the effect of restraining the steel plate and the concrete during the bending action can be expected. However, since sudden fracture in the elevator pit may occur, stud bolt arrangement is necessary for the composite effect of steel plate and concrete. It is expected that the bending strength can be expected to increase by about 15% or more depending with and without stud bolts.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.392-399
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• 2007

This study was carried out to assess optimum conditions of peatmoss-based substrates for red pepper plug seedlings. Peatmoss-based substrates prepared by mixing of peatmoss with vermiculite, perlite, rice hull and zeolite at various mixing ratios were used for growing pepper plug seedlings. The physical and chemical properties of the peatmoss substrate were analyzed by the CEN(European committee for standardization) method. Fresh and dry weights (shoot, root), leaf area, root length and T/R ratio (dry shoot weight/dry root weight) were determined at 55 days after sowing. The results showed that the growing media PVSZ 6 (peatmoss:silver vermiculite: zeolite=6:3.9:0.1) and PVGZ 6 (peatmoss:gold vermiculite: zeolite=6:3.9:0.1) can successfully be used for red pepper plug seedlings judging from dry weight and T/R ratio of the plug seedlings. The optimal ranges of total pore space, water volume, air volume, easily available water content and water buffering capacity of the peatmoss based growing media for pepper plug seedlings were 87~93%, 52~71%, 20~41%, 10~37% and 0.6~10%, respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.2
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• pp.144-150
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• 2006

The purpose of this study is to predict outlet temperature and humidity through underground pit for the reduction of cooling load and heating load. Commonly, the underground temperature is lower than outdoor in summer but the reverse happens in winter. When the outdoor average air temperature is $25.7^{\circ}C$ during cooling periods, the average outlet air temperature through underground pit is $23.6^{\circ}C$ with 3 m-depth and 60m-length and is $22.2^{\circ}C$ with 3 m-depth and 150 m-length. When the outdoor average air temperature is $4.9^{\circ}C$ during heating periods, the average outlet air temperature through underground pit is $7.7^{\circ}C$ with 3m-depth and 60 m-length and is $10.8^{\circ}C$ with 3 m-depth and 150 m-length. The outlet air temperature is affected by more length than depth of underground pit. The diffusion ratio of outdoor humidity is $-7.7\times10^{-8}kg/s$ in cooling periods and $9.29\times10^{-7}kg/s$ in heating periods.

• Journal of the Speleological Society of Korea
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• no.53
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• pp.51-56
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• 1998

지금은 이미 지하수가 말라버리고 건조한 동굴이 되었지만 프린스 맘모스 동굴과 같이 큰 포화수대 기원의 터널이나 지하천이 사행하면서 거의 수평으로 발달한 장대한 동굴계는 미국의 대동굴 지대의 전형이라고 할 수 있다. 이 켄터키를 중심으로 북쪽은 펜실베니아, 남쪽은 알라바마까지의 애팔레치아 지방까지 펼쳐진다. 대조적으로 북조지아의 에리존즈동굴은 이 지방의 동굴과 달리 일직선으로 뻗어져 있다. 10이상의 길이로, 양단은 거대한 수직동굴로 되어 있으며 피지온산의 밑을 관통하고 있다. 입구의 수직동굴은 환타스틱 피트, 인크레져블 피트라 불리우며 양쪽모두 150M의 깊이이다. 미국동부의 동굴은 이차생성물은 일반적으로 그렇게 발달되어 있지 않은 것이 하나의 특징이다. 그러나 예외도 있는데 버지니아의 루뤠이 동굴에는 멋진 생성물을 볼 수 있고 관광동굴화 되어 있다.(중략)

• Journal of Bio-Environment Control
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• v.16 no.1
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• pp.40-46
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• 2007

This study was conducted to clarify the effects of the different substrates in terms of perlite (100%), peat moss (100%), granular rock wool (100%) and mixing perlite (50%) with peat moss (50%) on the growth responses and mineral contents of hydroponically grown Plantago asiatic in aggregate culture. Overall early plant growth such as plant height, stem diameter, number of leaves, root length, fresh and dry weight of shoot and root were increased in the order of that miked perlite and peat moss (50%:50%, v/v)>peat moss (100%)>granular rock wool (100%)>perlite (100%). Ca and Mg contents in plants became highest in the plants grown in the peat moss, however, Mg and Na in the granular rock wool. $P_2O_5$ content in plants were most increased in proportion to the plant growth increment in the peat moss (100%) and the mixing substrates of perlite and peat moss (50:50, v/v).

• Journal of Welding and Joining
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• v.13 no.3
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• pp.1-7
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• 1995

1992년 9월 현재 전 세계적으로 운전 중(건설포함)인 액화 및 인수기지의 LNG 저장탱크는 지상식-이중벽 금속 탱크, 지상식-맴브레인 PC 탱크, 지상식-자립식 내부탱크/PC 외부탱크, 피드식-RC(Reinforced Concrete) 보강둑 탱크, 피트식-이중벽 금속탱크, 피트식-자립식 내부탱크/PC 외부탱크 및 지하식 탱크의 7가지 유형으로 나 타낼 수 있다. 또한 액화천연가스를 저장하는 내부탱크 소재에 따라 9%Ni강 및 MEMBRANE(SUS304) 형식으로 대별할 수 있다. MEMBRANE 저장탱크 형식의 핵심기술인 MEMBRANE은 -162.deg.C의 LNG에 의한 열수축팽창에 견딜 수 있도록 스테인레스강판 (SUS304)을 사용하여 기하학적으로 특이한 주름진 형상을 갖도록 설계되었으며 주름 형상에 따라 프랑스의 테크니가즈(Technigaz), 일본의 가와사끼(Kawasaki). 미쓰비시 (Mitsubishi), 이시가와지마하리마(Ishikawajima-Harima)사의 멤브레인과 세계에서 3번째로 한국가스공사 연구개발원이 개발한 링디식 멤브레인으로 구별할 수 있다. 본 해설에서는 국내의 전국 천연가스 공급사업계획 및 건설현황을 검토하고 최근 전 세계적으로 널리 사용되고 있는 액화천연가스 저장탱크의 종류를 용량별, 년도별로 분석하여 전세계의 액화천연가스 저장탱크에 관해 소개 하겠다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.69-69
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• 2018

벼룩이울타리(Arenaria juncea M.Bieb.)는 청열, 양혈, 허로기열, 골증, 수심작열, 도한 등의 약효가 있으며, 백색의 꽃이 취산화서로 아름답게 개화하여 조경소재로 이용가치가 높다. 본 연구는 벼룩이울타리의 육묘기술 개발을 위하여 2017년 6월 2일부터 7월 31일까지 8주간 수행하였다. 실험의 대조구는 200구 트레이에 원예상토를 충진하고 종자를 셀 당 3립씩 파종하여 무차광 조건에서 육묘하였으며, hyponex $500mg{\cdot}L^{-1}$를 2회 추비하였다. 토양 실험은 원예상토[$300-200-200mg{\cdot}L^{-1}$(N-P-K)]와 피트모스:펄라이트(3:1), 코코피트:펄라이트(3:1) 혼용토를 이용하였으며, 원예상토를 제외한 모든 토양은 0-0-0, 300-200-200, $600-400-400mg{\cdot}L^{-1}$의 비료를 첨가하였다. 종자는 셀당 1, 3, 5립을 파종하였고, 추비는 hyponex (6.5-6-19)를 0, 500, $1000mg{\cdot}L^{-1}$로 4, 6주차에 총 2회 잎이 충분히 젖을 정도로 살포하였다. 차광은 0, 55, 75%로 설정되었다. 벼룩이울타리 육묘의 결과, 토양 종류별로는 원예상토에서 초장이 가장 길었으며, 다음으로 피트모스 혼용토의 순이었다. 피트모스 혼용토에서 육묘한 유묘의 초장은 비료를 첨가하지 않은 처리구에서 길어지는 경향을 보였다. 경직경과 근장은 원예상토 단용구와 코코피트 혼용토가 피트모스 혼용토에 비해 양호하였다. 엽수는 상토(26.1 ea)에서 가장 많았고 다음으로 비료 코코피트 혼용토 $600-400-400mg{\cdot}L^{-1}$(22.9 ea)의 순이었다. 셀 당 파종립수를 달리하여 육묘한 결과, 초장은 파종립수가 적을수록 길었으며, 경직경과 엽수는 처리에 따른 유의적인 차이를 확인할 수 없었다. 추비 처리별로 전반적인 생육은 큰 차이는 보이지 않았으나, 경직경은 처리농도가 낮을수록 두꺼워지는 경향이었다. 엽수는 hyponex 처리시 무처리구에 비해 증가하는 경향을 보였으며, $500mg{\cdot}L^{-1}$ 처리구에서 가장 많았다. 차광정도에 처리에 따른 생육은 차광률이 높을수록 생육이 억제되는 경향이었다. 초장, 엽수 및 근장은 무차광에서 차광처리구에 비해 우수하였다. 경직경은 무차광구와 50% 차광구가 70% 차광구에 비해 증가하였다. 지상부, 지하부의 생 건체중도 무차광에서 가장 무거웠으며, 차광률이 증가할수록 감소하였다.

• Horticultural Science & Technology
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• v.18 no.1
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• pp.33-38
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• 2000

This study was conducted in an effort to meet the need for domestic production of hydroponic media and for medium development using recycled hydroponic rockwool slabs. Two experiments were conducted to evaluate the growth of plug seedlings of petunia 'Romeo' in various mixtures including particles of used rockwool slabs (rockwool particles) and wood chips. In the first experiment, seedlings were grown in plugs filled with mixtures of steam- sterilized rockwool particles and chestnut wood chips, which had been weathered for six months and screened through either 2.8 mm or 5.6 mm sieve, at the mixing ratio of 100:0, 75:25, 50:50, 25:75, or 0:100 (v/v). In the second experiment, seedlings were grown in plugs filled with twenty different mixtures of steam-sterilized particles of used hydroponic rockwool slabs with 4 mm chestnut or pine wood chips, coir, peatmoss, or perlite. In the first experiment seedling growth was not affected by particle size of chestnut wood chips, was superior in the control (commercial plug medium) and in 100% rockwool particles, but was suppressed as mixing ratio of chestnut wood chips increased. In the second experiment, leaf length, and shoot fresh and dry weights were the greatest in rockwool particles+peatmoss+coir treatment, followed by rockwool particles+peatmoss treatment. Leaf length was suppressed as ratio of wood chips increased, especially of chestnut wood chips. Root development was the greatest in rockwool particles+peatmoss+perlite treatment, followed by the control, and rockwool particles+peatmoss+coir treatment. The growth was suppressed as the mixing ratio of rockwool particles, peatmoss, or coir decreased.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.228-232
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• 2007

We have also clarified the effects of the different substrates; (perlite, peatmoss and granular rock-wool) on the plant growth and the mineral contents of Campanula takesimana until 70 days after transplanting. Overall plant growth in terms of plant height, stem diameter, number of leaves, root length, fresh and dry weight of shoot and root were increased in the order of that mixed perlite and peat moss (50 : 50, v/v)>peat moss (100%)>perlite (100%)>granular rock wool (100%). Mineral contents in plants were much more in the order of potassium $(15.38-43.91cmol^+/kg)$, calcium $(5.48-7.78cmol^+/kg)$, magnesium $(4.38-6.55cmol^+/kg)$ and sodium $(1.25-1.69cmol^+/kg)$. The higher mineral contents of plants were also most made in the mixed substrates of perlite and peat moss (50 : 50, v/v).

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.239-243
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• 2006

This research compared growth and flowering of potted $Viola{\times}wittrockiana$ 'Majestic GT Scarlet Shadow' in various mixtures of recycled perlite and cellular glass foam (CGF). The crop was cultured in a mat subirrigation system. Numbers of leaves, opened flowers, flower buds, and branches, fresh and dry weights of shoot, leaf area, and total chlorophyll concentration were the greatest in plants grown in the medium of used perlite + granular rockwool+ peatmoss (25:50:25, v/v/v). Plant height and length of the longest root were the highest and longest, respectively, in plants grown in the medium of CGF+peatmoss (25:75, v/v). The medium of CGF+peatmoss (25:75, v/v) was better than the medium of used perlite+peatmoss (25:75, v/v) in plant growth. The medium of CGF + granular rockwool (25:75, v/v) was poorer than the medium of recycled perlite + granular rockwool (25:75, v/v).