• Journal of Ocean Engineering and Technology
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• v.34 no.6
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• pp.436-441
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• 2020

Wave field changes resulting from artificial coastal structures constructed in coastal zones have emerged as a major cause of beach erosion, among other factors. The rates of erosion along the eastern coast of Korea have varied mainly owing to the construction of various ports and coastal structures; however, impact assessments of these structures on beach erosion have not been appropriately conducted. Thus, in this study, a methodology to assess the impact of erosion owing to the construction of artificial structures has been proposed, for which a parabolic bay shape equation is used in determining the shoreline angle deformation caused by the structures. Assuming that the conditions of sediment or waves have similar values in most coastal areas, a primary variable impacting coastal sediment transport is the deformation of an equilibrium shoreline relative to the existing beach. Therefore, the angle rotation deforming the equilibrium of a shoreline can be the criterion for evaluating beach erosion incurred through the construction of artificial structures. The evaluation criteria are classified into three levels: safety, caution, and danger. If the angle rotation of the equilibrium shoreline is 0.1° or less, the beach distance was considered to be safe in the present study; however, if this angle is 0.35° or higher, the beach distance is considered to be in a state of danger. Furthermore, in this study, the distance affected by beach erosion is calculated in areas of the eastern coast where artificial structures, mainly including ports and power plants, were constructed; thereafter, an impact assessment of the beach erosion around these areas was conducted. Using a proposed methodology, Gungchon Port was evaluated with caution, whereas Donghae Port, Sokcho Port, and Samcheok LNG were evaluated as being in a state of danger.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.443-451
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• 2021

Finger millet (Eleusine coracana) is widely cultivated in tropical regions worldwide owing to its high nutritional value. Finger millet is more tolerant against biotic and abiotic stresses such as pests, drought, and salt than other millet crops; therefore, it was proposed as a candidate crop to adapt to climate change in Korea. In 2019, we used expressed sequence tag simple sequence repeat (EST-SSR) markers to evaluate the genetic diversity and structure of 102 finger millet accessions from two geographical regions (Africa and South Asia) to identify appropriate accessions and enhance crop diversity in Korea. In total, 40 primers produced 116 alleles, ranging in size from 135 to 457 bp, with a mean polymorphism information content (PIC) of 0.18225. Polymorphism was detected among the 40 primers, and 13 primers were found to have PIC values > 0.3. Principal coordinate and phylogenetic analyses, based on the combined data of both markers, grouped the finger millet accessions according to their respective collection areas.Therefore, the 102 accessions were classified into two groups, one from Asia and the other from Africa. We have conducted an in-depth study on the finger millet landrace pedigree. By sorting out and using the molecular characteristics of each pedigree, it will be useful for the management and accession identification of the plant resource. The novel SSR markers developed in this study will aid in future genetic analyses of E. coracana.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.627-636
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• 2022

In nuclear power plants and other nuclear facilities the removal of cobalt from radioactive liquid waste is needed to reduce the radioactivity concentration in effluents. In liquid wastes containing strong organic complexing agents such as EDTA cobalt removal can be problematic due to the high stability of the Co-EDTA complex. In this study, the removal of cobalt from NaNO₃ solutions using antimony oxide (Sb₂O₃) synthesized from potassium hexahydroxoantimonate was investigated in the absence and presence of EDTA. The uptake studies on the ion exchange material were conducted both in the dark (absence of UV-light) and under UV-C irradiation. Ca²⁺ or Ni²⁺ were included in the experiments as competing cations to test the selectivity of the ion exchanger. Results show that UV-C irradiation noticeably enhances the cobalt sorption efficiency on the antimony oxide. It was shown that nickel decreased the sorption of cobalt to a higher extent than calcium. Finally, the sorption data collected for Co²⁺ on antimony oxide was modeled using six different isotherm models. The Sips model was found to be the most suitable model to describe the sorption process. The Dubinin-Radushkevich model was further used to calculate the adsorption energy, which was found to be 6.2 kJ mol^-1.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.69-72
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• 2022

This paper actually investigates the load on major large-scale buildings in the downtown area, examines the economic feasibility of installing PV and ESS in a microgrid target building, and evaluates whether an electric vehicle capable of V2G through two buildings is effective as an economical analysis program (HOMER) was analyzed using. It is economical to install a mixture of ESS rather than using the whole PV, and it is shown that if there is an electric vehicle using the V2G function of EV, there is an economic effect to replace the PV. So that Incentives and policies are needed to replace a large area of PV and utilize the existing parking lot to lead EV as a resource of the microgrid. Currently, P2X technology that stores power as ESS or converts it to other energy to control when surplus renewable energy occurs in large-capacity solar power plants and wind farms, etc. This is being applied, and efforts are being made to maintain the stability of the system through the management of surplus power, such as replacing thermal energy through a heat pump. Due to the increase in electric vehicles, which were recognized only as a means of transportation, technologies for using electric vehicles are developing. Accordingly, existing gas stations do not only supply traditional chemical fuels, but electricity, and super stations that also produce electricity have appeared. Super Station is a new concept power plant that can produce and store electricity using solar power, ESS, V2G, and P2G. To take advantage of this, research on an urban microgrid that forms an independent system by tying a large building and several buildings together and supplies power through a super station around the microgrid is in full swing.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.639-640
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• 2022

A Ypsolophid moth Saridoscelis sphenias Meyrick was recorded in 2020 first in Korea, and specimens were collected from Jindo and Wando in Jeonam province from 2016 to 2017. This moth uses host plants such as Pieris japonica (Thunb.) D. Don ex G. Don, Vaccinium bracteatum Thunb. and Leucothoe grayana Maxim. var oblongifolia (Miq.). This species was discovered once in a blueberry orchard in Jeju in August 2014, and since then it has been regarded as not an established species because of no further detection. However, S. sphenias was found again in blueberry orchards grown in vinyl houses in Jeju city and Seogwipo city in 2018 and 2019. Since 2020, this pest has also been found on field-grown blueberries. Hatched larvae first bored into new shoots and fed inside, and the mid-aged larvae escaped from the inside of shoots, attached several shoots with webs, and fed on the leaves in the group. It is considered that S. sphenias will become a severe pest on blueberries; thus, we report the basic life cycle here.

• Korean journal of applied entomology
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• v.62 no.2
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• pp.83-87
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• 2023

Nysius plebeius is a major lygaeid pest of various cereal crops and ornamental plants in East Asian countries, including Korea. The complete mitochondrial genome of N. plebeius was characterized and found to comprise a total of 17,367 bp, which included 13 protein-coding genes, NADH dehydrogenase components (complex I, ND), cytochrome oxidase subunits (complex VI, COX), cytochrome oxidase b (CYPB), two ATP synthases, two ribosomal RNA genes, and 22 transfer RNAs. The GC content of 23%. It showed high sequence similarity to other Lygaeidae species, such as N. cymoides (94.5%), N. fuscovittatus (91.7%), and an unknown Nysius species (94.1%). This new N. plebeius mitochondrial genome can be widely used for evolutionary studies of Lygaeidae and to improve pest management practices.

• Journal of Forest and Environmental Science
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• v.39 no.4
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• pp.246-253
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• 2023

Salix gracilistyla is widely distributed along riversides in Korea and very good for biomass production by SRC because of its excellent germination ability, but it is necessary to measure drying tolerance for cultivation. The drought tolerance of S. gracilistyla was tested using cuttings, and growth and physiological analysis were performed after irrigation was stopped. The growth inhibition of S. gracilistyla was observed from the day irrigation was stopped, and the soil moisture content decreased to less than 10% on the 25th day after irrigation was stopped. Over 50% of the seedlings turned brown 25 days after watering was stopped. The chlorophyll content of S. gracilistyla decreased dramatically after 25 days of stopping of irrigation. RWC values were unchanged until day 12 after irrigation was stopped but decreased rapidly until day 21, but there was a slightly decreasing trend after that. RWL levels increased slightly during irrigation stops. The proline content of plants subjected to drought stress was 0.91-2.63 mg/0.05 g, 2.75 times higher than that of the control treatment. The sugar content of the drought stress treatment group was 29.77 to 350.66 mg/0.05 g, which increased 12.24 times that of the control treatment. As a result of this study, S. gracilistyla was found to have a drought tolerance almost comparable to that of evergreen broad-leaved trees growing on the land. This study is expected to contribute to the resource utilization S. gracilistyla, a native willow tree of Korea, and the mass production of biomass by SRC.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.5
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• pp.253-259
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• 2023

Bioreactors are devices used by sewage treatment plants to process sewage and which produce active sludge, and sediments separated by solid-liquid are treated in anaerobic digestion tanks. In anaerobic digestion tanks, the volume of active sludge deposits is reduced and biogas is produced. After dehydrating the digestive sludge generated after anaerobic digestion, anaerobic digested wastewater, which features a high concentration of organic matters, is generated. In this study, the decomposition of organic carbon and nitrogen was studied by advanced oxidation process. Ozone-microbubble flotation process was used for oxidation pretreatment. During ozonation, the TOC decreased by 11.6%. After ozone treatment, the TOC decreased and the removal rate reached 80.4% as a result of the Ultra Violet-Advanced Oxidation Process (UV-AOP). The results with regard to organic substances before and after treatment differed depending on the organic carbon index, such as CODMn, CODCr, and TOC. Those indexes did not change significantly in ozone treatment, but decreased significantly after the UV-AOP process as the linkage treatment, and were removed by up to 39.1%, 15.2%, and 80.4%, respectively. It was confirmed that biodegradability was improved according to the ratio of CODMn to TOC. As for the nitrogen component, the ammonia nitrogen component showed a level of 3.2×10² mg/L or more, and the content was maintained at 80% even after treatment. Since most of the contaminants are removed from the treated water and its transparency is high, this water can be utilized as a resource that contains high concentrations of nitrogen.

• Korean Journal of Environment and Ecology
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• v.30 no.6
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• pp.939-961
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• 2016

For effective conservation of endangered wild plants, it is necessary to understand their interactions with environmental factors in each habitat together with life traits of target species. First, the characteristics of their distribution were investigated followed by their monitoring for 4 years focusing on the habitats in the lagoon. Also, their life traits were compared including production of hibernacles, fruits, and seeds by the soil fertilization and light intensities. Next, the information on the species was secured by germination experiment using the generated seeds from the cultivation experiment. The habitat of Glaux maritima var. obtusifolia Fernald in Korea was located in the rear edge of the worldwide distribution and its four habitats were isolated and distributed far away each other. Two of them were located in small salt-marsh and fine sand estuaries formed in the rocky area of the seashore, and the other two were inhabited with the sandy soil in the lagoon which was connected by river-mouth to the sea. Glaux maritima var. obtusifolia Fernald tends to be distributed in the sites where the establishment and growth of the competitor were inhibited by salinity, periodic flooding, and lower layer of the soil to extend a roots. It maintained its population by recruitments of hibernacles and seedling. The production of hibernacle was assumed to be affected by the particle consist of the sand together with organic matters in the soil. Seedling recruitment was observed only in the salt-marsh area located in the rear sites of sand ridge where was the shore of the lagoon. Glaux maritima var. obtusifolia Fernald was observed to have different threatening factors by each population. Its population in Pohang seemed the sedimentation of fine sand which affected the recruitment of hibernacles had been eroded due to the construction of the coastal road. The population in Ulsan appeared rapid expansion of competitor and reduction of its distribution area due to the interruption of eluted water supplied to the habitat. On the other hand, the habitat in the lagoon maintained the population relatively stable. Especially, the population in Songji-ho was determined to be the most stable one. To sustain the population of Glaux maritima var. obtusifolia Fernald distributed in the lagoon, it is suggested that the wide ranged scale of conservational activities is necessary to maintain the mechanisms including the entrance of seawater which belongs to the lagoon, and periodic flooding.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.1
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• pp.104-114
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• 2014

Nowadays, forests have been recognized as valuable resources for biological diversity and tourism/recreation. Temple forests occupy 1.3% of all the Korean forest and are under weak management although their ecological states are very good. Currently in the Buddhist society, the concern for the Buddhist arboretum has been raised as a good alternative for the practical use of temple forests to secure the sustainability of the temple forests as well as to actively meet the demand of the times for forests. This study aims to suggest establishment measures of Buddhist arboretum. This survey was performed on 105 temple forest managers and 130 laypersons. To summarize the results, the two groups differ in opinion. The temple forest managers more concerned for advertizing Buddhist culture and enhancing the image of the temple, while the laypersons had higher expectations for relaxation and education. However, they are similar in putting more emphasis on the conserving the heritage value of the temple and managing the temple forest. Above all, both groups evaluated the needs higher than the urgency and perceived managing temple forest as the most crucial function of a Buddhist arboretum. They also thought that a Buddhist arboretum should be planned to respond to the ecological characteristics of the temple area as well as to be non-exclusive to its users. Based on the important findings, five suggestions for a Buddhist arboretum were proposed. First, a Buddhist arboretum should be carried forward from a long-term point of view, developing a bond of sympathy between members of Buddhist society as well as conducting promotion and education to the general public. Second, the most significant function of a Buddhist arboretum should be preserving the temple forest, with the emphasis on relaxation and education. Third, in order to provide nonexclusive use, a Buddhist arboretum should provide mixed programs applicable to diverse user groups for high user satisfaction and educational effects. Fourth, the Buddhistic identification could be obtained through variety of plants closely associated with Buddhist culture. Lastly, in the process of collecting plants, it is also crucial to reflect the image of the temple and resource property so as to contribute itself in conservation and management of original temple forests. Thereby all Buddhist Arboretum can be classified into two types; preservation/collection and display/education/rest.