• Elastomers and Composites
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• v.38 no.3
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• pp.243-250
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• 2003

Polyurethane waterproof (PW) coatings are increasingly demanded in Korea for repairing cracks on old building roofs and construction of many sporting facilities. Calcium carbonate, a common filler, is incorporated in PW compositions. In this study, PW coatings were prepared by substituting a part of calcium carbonate with fly ash. The maximum amounts of calcium carbonate which can be substituted by fly ash obtained in the cyclone and bag filter dust collectors were 20 and 10%, respectively. It was found that the curing rate of PWs ran be controlled by varying the amount of Pb-octoate catalyst. The elongations at break as well as tensile strength and tear strength of PW coatings containing fly ash could also be adjusted such that their values were comparable to those of a standard PW coating by varying relative amounts of some components. However, the amount of cadmium, mercury, and lead leached from PW coatings containing fly ash obtained from the bag filter collector exceeded the respective allowed upper limits, mainly due to the initial high contents of them in the fly ash. On the other hand, PW coatings containing fly ash obtained from the cyclone collector exhibited better mechanical properties and did not release any significant amounts of the heavy metals. Thus, it was concluded that PW coatings containing fly ash can be utilized for practical applications as long as an appropriate fly ash is used.

• Korean Journal of Plant Resources
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• v.27 no.2
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• pp.174-182
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• 2014

This study was carried out to investigated the effects of soil type and light condition on seedling quality of rare and endemic plants Orostachys iwarenge and Orostachys iwarenge for. magnus. The best seedling quality of O. iwarenge and O. iwarenge for. magnus seedling were shown in Klasmann soil at non-shading or LED (Red+Blue) condition, 50% shading or LED (Red+Blue) condition, respectively. Survival of O. iwarenge seedling was not influenced by the period of experiment but survival of O. iwarenge for. magnus seedling in sandy soil conditions decreased significantly. Results of correlation analysis of seedling quality and survival rate, indicated that O. iwarenge showed a correlation of 0.8 or more at plant height, leaf length and fresh weight. O. iwarenge for. magnus showed a correlation of 0.8 or more at plant height, leaf width and leaf length. Especially, seedling survival of O. iwarenge and O. iwarenge for. magnus showed a correlation of 0.8 or more at first seedling survival and second seedling survival. It was important to manage the early seedling stages of O. iwarenge and O. iwarenge for. magnus. Therefore, seedlings with plant height (over 2.5~4 cm) and root length (over 3~5 cm) were grown vigorously at 35 days after the seedling was transplanted in mid-April in Klasmann soil of 72 plug cell tray at LED (Red+Blue) conditions.

• Geophysics and Geophysical Exploration
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• v.8 no.3
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• pp.201-206
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• 2005

Interpretation of high-resolution seismic profiles from the southeastern continental shelf of Korea reveals that the sedimentary deposits consist of seven seismic units formed during the late Quaternary. These units comprise lowstand, transgressive, and highstand systems tracts. The lowstand systems tract consists of a lowstand prograding wedge (SU1) and a mass flow deposit (SU2) including slumps and slides. The transgressive systems tract contains four seismic units: an ancient beach/shoreface deposit (SU3), a channel-fill deposit (SU4), a transgressive sand layer (SU5), and a transgressive sand ridge (SU6). The highstand systems tract consists of an inner-shelf mud deposit (SU7) derived from the Nakdong and Seomjin rivers during the last 6 ka when sea level was close to the present level.

• Journal of Sericultural and Entomological Science
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• v.45 no.2
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• pp.90-95
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• 2003

This study was carried out to identify of C3G (cyanidin-3-glucoside) from mulberry fruits and quantify with different varieties. C3G of mulberry fruits was extracted with 1％ HCl-MeOH and purified with open column (5${\times}$90cm) which filled with Amberlite IRC-50 ion exchange resin. The $\lambda$max ranges of the purified C3G on UV/vis spectrum were 516nm and 280nm. Also, molecular weight of C3G from mulberry fruits by LC-Mass was determined as 449. From above results, we concluded that anthocyanin pigment of mulberry fruits was C3G only. The cyanidin-3-glucoside (C3G) was separated and quantified by High Performance Liquid Chromatography (HPLC) system using a Nova-Pack C$\_$18/ column. Mean content of the 35 tested accessions was 0.89％. Also fruity characteristics as well as C3G content to select the desirable mulberry varieties for the production of fruit were researched and analyzed. We selected three suitable varieties such as 'Susungppong', 'Kangsun', and 'Jeolgokchosaeng(Chungpuk)'.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.377-382
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• 2007

Porous mineral coating have been fabricated and applied for basic research on their slow release action to a fertilizer. Feldspar was selected as raw mineral for the coating and two different particle sizes of powder were prepared. Slow-release action was estimated by using a potassium sulfate fertilizer. Spherical pellets were prepared with a pan-type pelletizer and then screened into sizes ranging 1.4 to 2.35mm. While the fertilizer pellets were rotated in the pelletizer again, the feldspar powder and 0.5% polyvinyl alcohol solution were simultaneously sprayed on the pellets. The fertilizer pellets coated with feldspar powder were fabricated. The pellets were heated to increase their strength and screened to sort by coating thickness. Potassium releasing tests were conducted for 40 days and the performance for slow-release action was estimated as functions of the heating temperature, coating thickness and raw mineral powder size. The Burst effect caused high initial releasing rate. Releasing kinetics was proportional to concentration of potassium in pellets. The pellet that was fabricated with $27.4{\mu}m$-sized feldspar and heated at $1050^{\circ}C$ showed a releasing rate of 43% on the 40th day.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.60-67
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• 2021

In lately, it's been developed and used a system of using deck plates as formwork in order to solve various problems caused by conventional formwork system. This system is more economical and has higher constructability than the conventional system by permanently embedding most of deck plates into the members. However, for this kind of embedded deck plates formwork system, it's been reported that it is difficult to verify filling of concrete in members like beams with narrow width and complicated rebar arrangement. In addtion, there are several problems such as corrosion of deck plates in terms of constructability and maintenance. Therefore, in this study, it is attempted to develop a removal-deck plate formwork system for beams by removing deck plates after concrete curing. The system consists of a deck plate module that acts as form, a frame preventing deformation by concrete lateral pressure, stirrup frame, and connector that combines these. As a result of this research, it is verified that it has higher constructability, efficiently prevents deformation caused by concrete lateral pressure and could be easily removed in the developed formwork system.

• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.1-10
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• 2018

Although the soil nailing method is generally used as a gravity grouting, the development and application of pressurized grouting method has recently increased to address the problem of joint generation and filling due to grouting. Pressurized grouting of the soil nailing method is generally used in combination with ordinary portland cement and water. In the field, the cement is mixed with the rapid setting cement to reduce curing time because ordinary portland cement takes more than 10 days to satisfy the required strength. In this study, uniaxial compression tests and laboratory tests were carried out to confirm the efficiency of the grouting material according to the mixing ratio of rapid setting cement. The mixing ratio of 30% grouting satisfies the required strength within 7 days and satisfies the optimum gel time. As a result of the laboratory test with granite weathered soil, the reinforcing effect was confirmed to be 1.5 times as compared with the gravity type at an injection time of 10 seconds and a strain of 15%. The friction resistance increases linearly with the increase of the injection time, but it is confirmed that the friction resistance decreases due to the hydraulic fracturing effect at the injection time exceeding the limit injection pressure. Numerical analysis was performed to compare the stability of slopes not reinforced with slopes reinforced with gravity and pressurized soil nailing.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.582-594
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• 2018

In this study, the vertical and horizontal flow wetlands were combined in series to create conditions for flow in the exhalation and anaerobic state with the aim of monitoring the variability and reduction of dissolved organic matterin the bio-reactive artificial wetlands, and the performance assessment was conducted as acrylic reaction groups by designing artificial wetlands that filled the functionalresiduals. In case of artificial wetlands in vertical and horizontal planes, the concentration of dissolved oxygen (DO) in the reaction tank was measured as 2.7 mg/L in the vertical flow wetlands under exhalation, and N.D. in the horizontal flow artificial wetlands under anaerobic conditions. The test was carried out by changing the operation time to 140 min, 80 min, and 60 min. The test was conducted with the same natural operation time of 20 min depending on the operation time. All hours of operation were shown to be due to microbial activity. In 3D-EEM, it was found that the longer the driving time was taken, the more reduction the organic compounds in the areas of insoluble human resources, III and V. Further research on the mechanism analysis of future reduction effects is expected to be carried out, but the findings are expected to contribute to the development of technologies for reducing obfuscated substances using artificial wetlands in the future.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.85-85
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• 2019

가는잎향유[Elsholtzia angustifolia (Loes.) Kitag.]는 꽃이 원줄기와 가지 끝에 조밀하고 아름답게 달리며, 전초에 함유된 정유성분의 향이 우수하여 관상 및 약용으로 이용되고 있다. 이에 본 연구는 관상소재로 이용가능한 가는잎향유의 분화 재배기술을 확립하기 위해 2018년 7월 2일에 유묘(4월 3일~5월 31일 육묘)를 포트에 정식하여 10월 15일까지 수행하였다. 대조구는 플라스틱 화분 10호에 원예상토를 충진한 다음 200구 트레이에 셀당 4립 파종하여 생산된 유묘를 정식하여 이용하였다. 기비처리는 싱싱코트를 0, 10 및 20알로 처리하였고, 추비처리는 정식 후 4주 간격으로 hyponex (4-6-6)를 0, 1000 및 $2000mg{\cdot}L-1$로 3회 엽면시비 하였다. 차광정도 실험은 0, 55 및 75%로 광량을 달리하여 수행하였다. 왜화제는 diniconazole과 daminozide를 각 0, 1000 및 $2000mg{\cdot}L-1$로 정식 후 4주차에 처리하였다. 연구의 결과, 기비와 추비 처리는 무처리와 비교하여 생육에 큰 차이가 없었으나, 절간장은 처리량이 증가할수록 억제되었으며, 처리시 무처리에 비해 유의적으로 감소하였다. 측지수 및 엽수는 기비 처리에 따른 큰 차이가 없었으며, 추비는 측지수와 엽수가 많아지는 경향이었다. 한편, 기비와 추비 처리는 개화율을 비교적 감소시키는 결과를 보였다. 차광정도가 증가할수록 초장, 절간장, 경직경, 화서수, 화서장이 감소하는 경향이 나타났으며, 무차광과 차광처리 간 측지수와 엽수는 유의적인 차이가 나타나지 않았다. 왜화제 처리는 무처리와 비교하여 절간장을 감소시켰다. Daminozide 처리시 측지수와 엽수는 무처리에 비해 증가하였으나 유의적인 차이는 없었고, 지상부의 생체중은 엽수와 측지수에 비례하여 무거워지는 결과를 보였다. 또한, $2000mg{\cdot}L-1$ 농도 처리시 개화율이 100%에 도달하였다. Diniconazole 처리는 무처리와 비교하여 큰 차이가 없었다. 따라서, 가는잎향유를 분화재배를 하기 위해서는 기비와 추비는 처리하지 않고, 무차광 조건에서 재배하는 것이 좋다. 또한, 왜화제는 daminozide $2000mg{\cdot}L-1$로 처리하는 것이 측지수, 엽수 및 개화율이 우수한 결과를 보여 분화 재배에 적합할 것으로 판단된다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.86-86
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• 2019

현삼과(Scrophulariaceae)에 속하는 긴산꼬리풀(Veronica longifolia L.)은 벽자색의 긴 꽃이 총상화서로 달려 청량감을 자아내어 분화소재로 이용한다면 단조로운 실내의 분위기를 환기할 수 있다. 따라서, 조경 및 관상용 식재에 용이한 긴산꼬리풀의 재배는 2018년 5월 15일에 파종하여 생산된 유묘를 2018년 7월 16일에 정식하여 2018년 10월 15일까지 수행하였다. 기비실험은 코트비료(싱싱코트)를 포트당 0, 10 및 20알 처리하였다. 추비는 hyponex (N-P-K, 4-6-6)를 4주 간격으로 총 3회 각 0, 1000 및 $2000mg{\cdot}L-1$로 엽면시비 하였다. 광량 실험은 무차광, 55 및 75% 차광막을 설치하여 수행하였다. 왜화제 종류 및 농도 실험은 dinizonazole(빈나리)과 daminozide (B-9)를 각 0, 1000 및 $2000mg{\cdot}L-1$ 농도로 처리하였으며, 적심처리는 4주차에 1회 처리 유무를 달리하였다. 모든 실험의 공통사항은 플라스틱 10호 화분에 원예상토를 충진한 후 200구 트레이에 종자를 셀당 4립씩 파종하여 생산된 유묘를 정식하였다. 연구의 결과, 기비처리는 초장, 마디수, 엽수가 증가하고, 절간장 및 측지수를 감소시켰으나, 유의적인 차이는 나타나지 않았다. 추비 처리는 농도가 높을수록 엽수가 증가하는 경향을 보였으며, $2000mg{\cdot}L-1$에서 무처리에 비해 유의적으로 많았다. 차광정도에 따른 긴산꼬리풀의 생육은 무차광 조건에서 생육이 가장 양호하였다. 차광률이 증가할수록 전반적인 생육이 억제되고, 개화율도 크게 감소하는 결과를 보였다. 왜화제 처리별로는 종류에 관계없이 전반적인 생육이 억제 되었다. Diniconazole 및 daminozide의 농도가 높을수록 초장이 억제되는 경향을 보였으나, 측지수, 마디수, 엽수도 감소하여 관상적 이용에 적합하지 않다. 적심을 할 경우 전반적인 생육은 큰 차이가 나타나지 않았으며, 측지수가 감소하였다. 따라서, 긴산꼬리풀의 분화생산을 위한 재배기술은 기비는 처리하지 않고, 추비는 $2000mg{\cdot}L-1$로 시비하며, 광이 충분한 곳에서 재배하는 것이 효과적이다. 또한, 왜화제와 적심은 일반적으로 줄기신장을 억제하고 마디수와 엽수를 증가시켜 관상적 이용효과가 있는 것으로 알려져 있지만 본 연구에서는 반대의 결과를 보여 처리 하지 않는 것이 효과적인 것으로 판단된다.