• Journal of Climate Change Research
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• v.6 no.4
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• pp.303-310
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• 2015

This study was conducted to estimate of carbon stock and greenhouse gas (GHGs) removals by tree species and forest type at Gangwon province. We used a point sampling data with permanent sample plots in national forest inventory and national emission factors. GHGs emissions was caclulated using the stock change method related to K-MRV and IPCC guidance. Total carbon stock and greenhouse gas removals were high in deciduous forest and species than in coniferous. The range of annual net greenhouse gas emissions in other deciduous species was from $-11,564.83Gg\;CO_2\;yr^{-1}$ to $-13,500.60Gg\;CO_2\;yr^{-1}$ during 3 years (2011~2013). On the other hand, coniferous forest was temporally converted to source due to reducing of growing stock in 2012. It was that growing stocks and forest area were likely to reduce by the deforestation and clear cutting. This study did not consider other carbon pools (soil and dead organic matter) due to the lack of data. This study needs to complement the activity data and emission factors, and then will find the way to calculate the greenhouse gas emissions and removals in the near future.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.2
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• pp.139-165
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• 2019

The current status and prospect of decommissioning technology development at KAERI are reviewed here. Specifically, this review focuses on four key technologies: decontamination, remote dismantling, decommissioning waste treatments, and site remediation. The decontamination technologies described are component decontamination and system decontamination. A cutting method and a remote handling method together with a decommissioning simulation are described as remote dismantling technologies. Although there are various types of radioactive waste generated by decommissioning activities, this review focuses on the major types of waste, such as metal waste, concrete waste, and soil waste together with certain special types, such as high-level and high-salt liquid waste, organic mixed waste, and uranium complex waste, which are known to be difficult to treat. Finally, in a site remediation technology review, a measurement and safety evaluation related to site reuse and a site remediation technique are described.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.327-332
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• 2019

Today's scientists try to remove heavy metals with many new technologies such as phytoremediation. One of the best cutting edge technologies is developing transgenic plants to remove certain heavy metal in soil. I constructed the transformation vector expressing T. goesingense Metal Transport Protein1 gene and TgMTP1: GFP genes. The transgenic plants were selected and confirmed the transformed genes into Arabidopsis thaliana genome. Expression was confirmed in several parts in Arabidopsis cells, tissues and organs. When TgMTP1 overexpressing Arabidopsis thaliana were subjected, transgenic plants showed higher heavy metal tolerance than non-transgenic. For further study I selected the transgenic plant lines with enhanced tolerance against four different heavy metals; Zn, Ni, Co, Cd. The accumulation of these metals in these plants was further analyzed. The TgMTP1 overexpressing Arabidopsis thaliana plant of selected lines are resistant against heavy metals. This plant is characterized by the expression of the MTP1 gene accumulating heavy metal in the vacuole and being simultaneously expressed on the plasma membrane. In conclusion, these plants may be used in plant purification applications, and as a plant with increased tolerance.

• Journal of Forest and Environmental Science
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• v.37 no.1
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• pp.1-13
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• 2021

The realities of Climate change and its untold implications on the livelihood of man are no longer new worldwide. In attempts to subdue the negative implications of Climate change scenario globally, several measures have being suggested and being put in place. One of such measures is urban reforestation especially in the developing nations where forest resources have extremely and uncontrollably exploited. Most of cities in developing nations are almost devoid of regularly maintained trees for whatever purpose. Thus, the enormous roles which urban tree performs are lacked in most cities. In order to subdue excessive heat in cities arising from exposure of urban land areas urban reforestation exercise needs to be embarked upon. The investigation was carried out through desk studies and review of relevant publications to examine what it entails to have a sustainable reforestation programme in cities. The study revealed that several factors need to be taken into consideration if sustainable urban reforestation will be achieved, especially in developing countries. These factors include urban soil nutrients status investigation, appropriate tree type study, public perception about the tree types, relevant legal instrument to achieve successful reforestation exercise in cities among others were found to be salient to this exercise. Urban reforestation has enormous potentials to subdue Climate change consequences, including urban renewal if adequate provision is made for its sustainability, especially in developing countries. To ensure this is realized it is recommended that relevant ministry/agency could be put in charge for the maintaining, cutting and replanting of urban tree and all that are involved in urban tree sustainability.

• Geomechanics and Engineering
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• v.28 no.3
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• pp.283-298
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• 2022

Landslides triggered by the combination of heavy precipitation and anthropological disturbance in hilly areas cause severe damage to human lives, properties, and infrastructure constructions. A comprehensive investigation of the influencing factors and failure mechanisms of landslides are significant for disaster mitigation and prevention. This paper utilized the combination of detailed geological investigation, physical experimental testing as well as numerical modelling to determine the failure mechanism, and proposed a countermeasures of the Lantian landslide occurred on 2, July 2017. The results reveal that the Lantian landslide is a catastrophic reactivated slide which occurred in an active tectonic region in Southwest China. Because of the unique geological settings, the fully to highly weathered basalts in the study area with well-developed fractures favored the rainwater infiltration, which is the beneficial to slide reactivation. Engineering excavation and heavy precipitation are the main triggering factors to activate the slide motion. Two failure stages have been identified in the landslide. The first phase involves a shallow mass collapse originated at the upper slopes, which extends from the road to platform at rear part, which is triggered by excavation in the landslide region. Subjected to the following prolonged rainfall from 19 June to 2 July, 2017, the pore water pressure of the slope continually increased, and the groundwater table successively rise, resulting in a significant decrease of soil strength which leads to successive large-scale deep slide. Thereinto, the shallow collapse played a significant role in the formation of the deep slide. Based on the formation mechanisms of the landslide, detailed engineering mitigation measures, involving slope cutting, anchor cable frame, shotcrete and anchorage, retaining wall and intercepting ditch were suggested to reduce the future failure risk of the landslide.

• Geomechanics and Engineering
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• v.34 no.1
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• pp.17-27
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• 2023

Taking a subway shield tunnel in a certain section of Zhengzhou Metro Line 5 as an example, the field tests of shield cutting cement-soil monopile composite foundation were carried out. The load and internal force of the tunnel lining under the action of composite foundation were tested on-site and the distribution characteristics and variation laws of earth pressure around the tunnel under the load holding state of the composite foundation were analyzed. Five different load combinations (i.e., overburden load theory + q₀, Terzaghi's theory + q₀, Bierbaumer's theory + q₀, Xie's theory + q₀, and the proposed method (the combination of compound weight method and Terzaghi's theory) + q₀) were used to calculate the internal force of the tunnel structure and the obtained results were compared with the measured internal force results. The action mode of earth pressure on the tunnel lining structure was evaluated. Research results show that the earth pressure obtained by the calculation method proposed in this paper was more consistent with the measured value and the deviation between the two was within 5%. The distribution of the calculated internal force of the tunnel structure was more in line with the distribution law of field test data and the deviation between the calculated and measured values was small. This effectively verified the rationality and applicability of the proposed calculation method. Research results provided references for the design and evaluation of shield tunnels under the action of composite foundations.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.44-44
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• 2020

본 연구는 최근 암세포 생장억제 효과가 입증되어 약용소재로서의 활용가치가 높은 상동나무 (Sageretia theezans)의 대량증식 연구의 기반을 마련하기 위해 삽수묘를 시기별로 채취하여 삽목실험을 실시하였다. 삽수묘는 제주 대정읍, 전남 완도 보길도, 청산도 인근에서 수집하였으며, 상동나무 삽목은 시기별로 2019년 3월 21일(춘계), 7월 22일(하계), 9월 2일(추계)에 실시하였다. 토양조건은 모래, 원예용 상토, 모래와 원예용 상토를 1 : 1 배율로 섞은 토양에 각각 치상하였다. 삽목 후 산림약용자원연구소 온 실에 약 100일간 보관하였으며 1일 2회 관수하여 관리하였다. 그 결과 춘계에 삽목한 삽수묘에서 66.4% 의 발근율로 나타났으며, 뿌리는 평균 17.5mm의 길이로 측정되었다. 하계는 27.4%의 발근율을 보였으 며, 뿌리는 평균 12.6mm의 발달을 보였다. 추계에는 29.6%의 발근율로 13.2mm의 뿌리 발달을 보였다. 상동나무는 춘삽이 추삽에 비해 발근율이 높고, 숙지삽이 상동나무 발근에 있어 유리한 것으로 사료된 다. 또한 토양은 모래에 삽목한 삽수묘가 60.3%로 가장 발근율이 높았으며, 그 다음으로 모래와 원예용 상토를 1 : 1 배율로 섞은 토양이 42.7%의 발근율을 보였다. 마지막으로 원예용 상토에서 25.4%의 발근 율을 보였다. 이는 상동나무 삽목시 배수가 양호한 상태가 뿌리 및 캘러스형성에 유리하게 작용하는 것 으로 사료된다.

• Journal of Ecology and Environment
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• v.47 no.3
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• pp.146-156
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• 2023

Background: Endemic species are important components in the flora of most world regions. Most of these species have become threatened and exposed to extinction within the last few years. The present study aims to evaluate the ecosystem services offered by the endemic plant taxa in Egypt and the threats that affect them. Twenty-five field visits were conducted during summer 2018 to spring 2022 to several locations all over Egypt. In each location, the main habitats, national distribution, abundance, goods and threats were recorded. Results: Egypt has 41 endemic taxa belonging to 36 genera and 20 families inhabiting 10 main habitats. Rocky surfaces and sandy formations have the highest number of endemic species. The relation between the number of endemic taxa and the abundance categories indicated that 2 taxa are rare (4.9% of the total taxa), while the remaining were very rare (95%). The most represented offered good was the medicinal uses (32 taxa = 78%), while fuel plants were only represented by 2 taxa (2 taxa = 4.9%). Besides, 14 taxa (34.1% of the total studied taxa) have at least 1 environmental service. Soil fertility (7 taxa = 50%) was the most represented, followed by sand accumulations (6 taxa out of 14 taxa = 43%), while shading plant was the least (1 taxon = 7.1%) (Rosa arabica). The most represented threat is over-cutting and over-collecting (38 taxa = 92.7%), while mining and quarrying is the least represented (4 taxa = 9.8%). Conclusions: The potential and actual goods, services and threats of the endemic taxa were assessed as follows; field observation, information collected from local inhabitants and herbalists, and a literature review. The present study recommended planning a strategy about the importance, threats and conservation of endemic taxa in Egypt that would help in the protection and rescue of these plants and increase awareness about the importance of these plants.

• Weed & Turfgrass Science
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• v.7 no.2
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• pp.140-147
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• 2018

In Korea, mowing the grass of a grave (Beolcho) is a very important event preceded by Chuseok (Korean thanks giving day) and Si-Hyang (annual ancestral feast). Because Beolcho usually takes place one or two weeks before Chuseok, the traffic accidents on roads are getting worse and safety accidents are getting more and more. Erroneous Beolcho methods can cause the soil to be exposed and cause the loss of soil or the low shoot density of graveyard grass or weed occurrence. Therefore, the dispersion of the Beolcho timing and the approprite method can be import issues. The present study assessed the effects of grass mowing timing and height before Chuseok on the growth of Zoysia japonica and Z. matrella. The mowing timing was evaluated at 1 week, 2 weeks, 3 weeks, and 4 weeks before Chuseok, and the mowing height differently according to the two type of grass. In Z. japonica, the faster mowing before Chuseok, the longer the plant height, and the coverage rate and shoot density were higher. In Z. matrella, the faster mowing, the longer the shoot length, but the coverage rate and shoot density did not show any difference or tendency. As compared to Z. japonica, the plant height of Z. matrella was kept short regardless of the time of mowing. In both grasses, the plant height was shortened when mowing was done at low cutting height, but the coverage rate and shoot density were decreased. In addition, it was shown that it is advantageous to maintain the shoot density of graveyard lawn by 40-50 mm or 30-40 mm cutting above the ground for Z. japonica or Z. matrella, respectively.

• Korean Journal of Agricultural Science
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• v.13 no.1
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• pp.103-112
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• 1986

This study was carried out to prevent the entwining of rice straw on rotary shaft and blade where rice straw was spreaded on paddy field as an organic source before rotary tilling. The rotary tillage was conducted in the paddy field having the soil moisture contents of 30%, 39%, 59% in dry basis and spreaded rice straw (450kg/10a) of 30cm, 45cm, 90cm length with the edged curve angles of rotary blade of $30^{\circ}$, $40^{\circ}$, $50^{\circ}$, $55^{\circ}$ at Yuseung area. And the test were performed on the plot which has width of 30cm and 5cm length and the quantity of entwined rice straw was analized. The test results were summarized as the followings. 1. Entwining phenomenon of rice straw was decreased as the blade edged curve angle increased. The edged curve angle of rotary blade must be determind by considering the characteristics of soil cutting resistance, tilling torque and entwining phenomenon of rice straw. But according to the entwining phenomenon of rice straw only, the edged curve angle of rotary blade should be bigger than $55^{\circ}$ for design. 2. Amount of entwining rice straw was minimized when soil moisture contents was 30 percent (d. b.). It would be better that rotary tillage is performed when soil moisture contents is lower than 30 percent in dry basis. 3. Amount of entwining rice straw was minimized when the length of rice straw was 30cm with $55^{\circ}$ edged curve angle. Therefore, it would be better to chop rice straw as 30cm. 4. Entwining phenomenon of rice straw was decreased as the forward speed decreased. To decrease the entwining rice straw, rotary tillage should be done with forward fist gear (0.35m/s).