• Analytical Science and Technology
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• v.5 no.1
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• pp.143-152
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• 1992

Corrosion resistances in various acids and high temperature oxidation properties have been investigated for the Ni-base superalloy KM 1557. Corrosion tests were performed in $H_2SO_4$, HCl, $HNO_3$, $H_3PO_4$ and $CH_3COOH$. Oxidation tests were carried out in air for 20 and 110hrs at $900^{\circ}C$, $950^{\circ}C$ and $1050^{\circ}C$. Hot corrosion tests were done in salt bath of 75% $Na_2SO_4-25%$ NaCl at $900^{\circ}C$ for 20hrs. After the tests, the samples were observed by optical microscopy and analysed by EPMA and X-ray mapping in order to investigate the distribution of composition. It was shown that corrosion resistances in various acids and hot salt bath were proven to be excellent. It was suggested that the amounts of oxides were determined mainly by the depth of internal and intergranular $Al_2O_3$ oxide layers.

• Geophysics and Geophysical Exploration
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• v.14 no.2
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• pp.127-132
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• 2011

We acquired and interpreted more than 650 km of high-resolution seismic reflection profiles in the Hupo Basin, offshore east coast of Korea at $37^{\circ}N$ in the East Sea (Japan Sea) to image shallow and basement deformation. The seismic profiles reveal that the main depocenter of the Hupo Basin in the study area is bounded by the large offset Hupo Fault on the east and an antithetic fault on the west; however, the antithetic fault is much smaller both in horizontal extension and in vertical displacement than the Hupo Fault. Sediment infill in the Hupo Basin consists of syn-rift (late Oligocene. early Miocene) and post-rift (middle Miocene.Holocene) units. The Hupo Fault and other faults newly defined in the Hupo Basin strike dominantly north and show a sense of normal displacement. Considering that the East Sea has been subjected to compression since the middle Miocene, we interpret that these normal faults were created during continental rifting in late Oligocene to early Miocene times. We suggest that the current ENE direction of maximum principal compressive stress observed in and around the Korean peninsula associated with the motion of the Amurian Plate induces the faults in the Hupo Basin to have reverse and right-lateral, strike-slip motion, when reactivated. A recent earthquake positioned on the Hupo Fault indicates that in the study area and possibly further in the eastern Korean margin, earthquakes would occur on the faults created during continental rifting in the Tertiary.

• Journal of the Korean earth science society
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• v.31 no.4
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• pp.354-369
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• 2010

The synoptic and kinematic characteristics of a heavy rainfall that occurred in Gangneung region on 22 to 24 October 2006 were investigated using weather maps, infrared images, AWS observation data and NCEP global final analyses data. The total amount of rainfall observed in the region for the period was 316.5 mm, and the instanteneous maximum wind speed was $63.7m\;s^{-1}$. According to the analysis of weather maps, before the starting of the heavy rainfall, an extratropical low pressure system was developed in the middle region of the Korean Peninsula, and an inverted trough was formed in the northern region of the peninsula. In addition, a jet stream on the upper charts of 300 hPa was located over the Yellow Sea and the southern boundary of the peninsula. A cutoff low in the cyclonic shear side of the upper jet streak, which was linked to an anomaly of isentropic potential vorticity, was developed over the northwestern part of the peninsula. And there are analyzed potential vorticity and wind, time-height cross section of potential vorticity, vertical air motion, maximums of the divergence and convergence and vertical distribution of potential temperature in Gangneung region. The analyzed results of the synoptic conditions and kinematic processes strongly suggest that the tropopause folding made a significant role of initializing the heavy rainfall.

• Journal of Mushroom
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• v.15 no.3
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• pp.150-154
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• 2017

A self-propelled turner was developed to produce mushroom compost at low costs and high efficiency, and the uniformity of compost produced by an excavator, compost mixer, and self-propelled turner was compared. The material of the compost was mixed with rice straw and chicken manure at a dry weight ratio of 3:1. After the final turning, internal temperature distribution, water content of the compost pile, ash ratio, and uniformity of the compost pile were examined. After the compost was completed, the water content was $69.9{\pm}0.54%$, $72.1{\pm}0.15%$, and $74.5{\pm}0.82%$, respectively. The length of rice straw was $47.5{\pm}15.4cm$, $24.9{\pm}10.1cm$, and $31.0{\pm}10.6cm$, respectively. The ash content in the dry weight of each compost was $25.0{\pm}6.2%$, $33.6{\pm}4.2%$, and $28.2{\pm}1.1%$, respectively. The deviation in the length of rice straw was affected by the linear velocity of the spinner in the compost mixer and the self-propelled turner, which were 21.5 m/sec and 9 m/sec, respectively. As a result, the most uniform mushroom compost was produced by the self-propelled turner.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.355-361
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• 2018

Mining is important as a national key industry that supplies energy and raw materials that are the basis for industrial development. On the other hand, mine development is necessarily accompanied by mineralization, for example, ground subsidence, heavy metal pollution, and water pollution. The mine hazard has a large range of damage, and it takes much time and cost to recover. In addition, there is a need for systematic mining management in order to prevent damages from occurring continuously. In this study, the present status of domestic mining industry and geospatial information construction technology for mining management were investigated. 95% of the mines surveyed were nonmetallic, and limestone mines accounted for 67%, and the constructed mine spatial information is not constructed with 3D geospatial information due to 2D current status, section, and geological map. Considering the results of the survey and analysis of 3D laser scanner and characteristics of Korean mine, handheld scanner is considered to be the most suitable method for constructing mine geospatial information. In addition, the data acquired through the 3D laser scanner can effectively visualize the object, and it can contribute to the systematic management of mining because it can be used for various purposes such as generation of drawings and calculation of volume.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.127-131
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• 2012

In this study we examined the changes in expression of pigments in black rice during kernel development, which were sampled at 2~3-day intervals to the 40th day after flowering. The first expression of pigment on kernels was observed on the seed coat about 5 days after flowering. At that times, the ratio of pigment expression was 0.08% of total area. The order in expression of pigments in black rice during kernel development was top first, followed by bottom, dorsal side, then ventral side. Maximum percentage of the total colored area in kernel was about 25 days after flowering. After that, the color has changed to dark purple from pale purple during kernel development after flowering. After harvesting, the non-uniform color kernels were observed. As a result, the ventral side in a kernel was a position of the non-uniform color such as a mixture of pale purple and dark purple. Also, we could be concluded that patten of pigment expression was similar in kernel development.

• Applied Chemistry for Engineering
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• v.17 no.1
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• pp.28-32
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• 2006

This study investigated the variation of flow rates in microchannels that consisted of polydimethyl siloxane (PDMS) and glass using various external voltages. Three different microchannel widths and two different depths. PDMS and negative photoresist (SU-8) were used to make the microchannels by the soft lithographic method. For each depth of microchannel ($50{\mu}m$ and $100{\mu}m$), three different widths ($100{\mu}m$, $200{\mu}m$ and $300{\mu}m$) were made. In each case, several different external voltages were applied (0.3 kV, 0.35 kV, 0.4 kV and 0.45 kV) to examine the flow rates. Our results indicated that flow rate increased with an increase of the external voltage at the same microchannel width. This was because the electrical field was increased as the external voltage increased. For the same external voltage, the flow rate increased as the microchannel's width increased. These results showed that the resistance in the microchannel decreased as the microchannel's width increased. Also, to investigate the effect of microchannel's depth and width, the cross-sectional area of the microchannel was increased to the double in area. As a result, the effect of the microchannel's depth was higher at a low external voltage, and the effect of the microchannel's width was higher at a high external voltage.

• Journal of Bio-Environment Control
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• v.25 no.3
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• pp.168-172
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• 2016

The effect of different exposed length of M.9 rootstock on growth and yield was tested in the new apple cultivars. The 'Seohong', 'Summer Dream', and 'Hongguem' grafted on M.9 rootstock were planted in March 2010. The trees were planted in such a way that the exposed length of the rootstock to be 10, 20 and 30 cm. The result showed that as decreasing exposure length, TCA of 'Seohong', 'Summer Dream', and 'Hongguem' was increased between $3^{rd}$ and $6^{th}$ year after planting. The TCA of 20 cm and 30 cm exposure length showed respectively 70% and 60% in 'Seohong', 88% and 66% in 'Summer Dream', and 55% and 41% in 'Hongguem' of the TCA with 10 cm exposure length on 6-year-old trees. Tree height, canopy width, shoot length and terminal shoot length were also increased according to decreased exposure length in 6-year-old trees. The cumulative yield of three cultivars was higher in the tree with a lower exposure length between $4^{th}$ and $6^{th}$ year after planting. The cumulative yield of 20 cm and 30 cm exposure length showed respectively 77% and 63% in 'Seohong', 85% and 76% in 'Summer Dream', and 73% and 58% in 'Hongguem' of the cumulative yield with 10 cm exposure length in 6-year-old trees. Considering tree growth and yield, the optimum exposure length of M.9 was 10 cm for 'Seohong', 'Summer Dream' and 'Hongguem'.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.638-644
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• 2010

This study was carried out to establish the informations on the optimum container for production of Larix leptolepsis container seedlings. Height growth of 1-year-old container seedling was highest in 250 mL of container (19.3 cm), and of 2-year-old seedling was in 500 mL (56.9 cm). On the other hand, the highest growth of root-collar diameter was observed in the both 1-year-old and 2-year-old seedlings grown in 500 mL. Dry mass production in both a whole seedling and each organs of 2-year-old seedling was significantly high in the container with larger volume and lower seedling density. According to the analysis using by WinRhizo program, the larger container in volume showed better root morphological traits such as total root length, root projected area, root surface area, root volume and average root diameter. Among the elements for analysis of root morphological traits, the root volume was the highest one affected by container volume. And it was observed that the root volume was 79.5% and 46.8% in 320 mL and 250 mL, respectively, compared to 500 mL.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.74-74
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• 2022

본 연구는 붉나무의 기능성 성분의 산업화 활용을 위한 고품질의 붉나무 1년생 용기묘 대량생산을 위해 실시되었다. 붉나무 1년생 용기묘의 묘목품질의 향상을 위해 다양한 농도의 시비처리하여 우량묘 생산에 적합한 시비수준을 구명하고자 하였다. 시비실험은 무시비구 포함하여 수용성 복합비료 (N:P:K=20:20:20, v/v)를 1,000mg·L^-1, 2,000mg·L^-1, 3,000mg·L^-1 수준으로 실시하였다. 시비처리는 붉나무 용기묘의 간장과 근원경 생장은 1,000mg·L^-1 시비처리구에서 생장이 가장 좋게 나타났으며 시비수준이 증가할수록 감소하는 경향을 보였다. 뿌리형태 특성분석에서도 전체뿌리길이, 투영단면적, 표면적 및 뿌리부피가 간장과 근원경 생장과 동일한 경향을 보이는 것으로 조사되었다. 건물 생산량은 부위별 잎, 줄기, 뿌리 및 전체가 모두 1,000mg·L^-1 시비처리구에서 가장 높았으며, 그 이상의 시비수준에서는 점점 감소하는 경향을 보였다. H/D(Hight/Root collar diameter)율은 전체가 3.82(무시비구) ~ 4.90, T/R(Top/Root)율은 전체가 0.56(1,000mg·L^-1 시비처리구) ~ 0.82로 조사되었다. 시비처리 에 의한 붉나무의 LWR(Leaf dry weight ratio)은 무시비구, SWR(Shoot dry weight ratio)은 3,000mg·L^-1 시비처리구, 그리고 RWR(Root dry weight ratio)은 1,000mg·L^-1 시비처리구에서 유의적 차이를 보이며 높게 나타났다. 묘목품질지수(QI)의 경우 1,000mg·L^-1 시비처리구에서 12.13으로 다른 시비수준들보다 월등히 높았다. 본 실험의 결과를 종합하면, 뿌리발달이 좋은 우량한 붉나무 생산에 적절한 시비수준은 1,000mg·L^-1 정도인 것으로 판단된다.