• Clean Technology
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• v.27 no.2
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• pp.198-204
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• 2021

This study focused on a two-step process using heterogeneous catalysts to produce biodiesel using Nepalese jatropha oil as a raw material. As a first step, the effect of the repetitive regeneration number of Amberlyst-15 on the esterification reaction of FFA in jatropha oil was investigated. Second, the possibility of a transesterification reaction scale-up using a dolomite bead catalyst was tested. Using 120 kg of jatropha seeds from Nepal, 30 L (27 kg) of jatropha oil was obtained, and the jatropha oil yield from the seeds was about 25.0 wt%. The acid value and FFA content of jatropha oil were measured to be 11.3 mgKOH g^-1 and 5.65%, respectively. As a result of the esterification reaction of jatropha oil using the Amberlyst-15 catalyst in the form of beads, the acid value of the reaction product could be lowered to 0.26 mgKOH g^-1 when the fresh Amberlyst-15 catalyst was used. As the regeneration of the Amberlyst-15 catalyst is repeated, the catalyst has been deactivated, and the esterification reaction performance has deteriorated. The cause of the deactivation seems to be due to the catalyst being broken and impurities being deposited. It was confirmed that the Amberlyst-15 catalyst could be reused up to 5 times for the esterification reaction of jatropha oil. In the second step, the transesterification reaction, a dolomite catalyst, was mass-produced and used in the form of beads. By transesterifying the pretreated jatropha oil in a spinning catalyst basket reactor equipped with 90 g of dolomite bead catalyst, 89.1 wt% of biodiesel yield was obtained in 2 hours after the start of the reaction, which was similar to the transesterification of soybean oil under the same conditions.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.9-10
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• 2019

순천만은 순천시의 남쪽에 위치하여 여수반도와 고흥반도의 사이에 있는 만 지형 형태로 만 전체를 순천만이라고도 하나, 보통 고흥군반도와 여수반도 사이의 만을 여자만이라 하고 만내부에 위치한 여자도라는 섬의 위쪽으로 순천시의 해안하구에 형성된 지역을 순천만이라 일컫는다. 순천만은 순천시에서 유입되는 동천과 이사천 및 해룡천의 하류에 형성되어 있어서 육지부에서 유입되는 퇴적물과 유기물로 인하여 갯벌과 갈대등이 잘 형성된 습지로서 2003년 12월 31일 해양수산부 갯벌 습지보존지역으로 지정되어 관리되고 있으며, 2004년에는 동북아 두루미 보호 국제네트워크에 가입하였고, 2006년 1월 국내 연안습지로는 최초로 람사르협약에 "Suncheon Bay"로 등록되었으며, 2016년 6월에는 람사르습지로 지정된 국내외적으로 중요한 습지이다. 순천만습지에 형성되어 있는 갯벌($28.0km^2$)은 세계 5대 연안습지 중 하나로서, 넓은 사니질 갯벌과 갈대군락이 잘 발달되어 있는 생태계의 보고(寶庫)이자 소중한 생태자원으로서, 순천시에서는 순천만을 자연생태공원으로 지정하여 보호 관리하고 있으며, 각종 자연학습자료들과 영상물들을 갖춘 생태전시관과 갈대숲 탐방로, 용산전망대, 야생화 정원, 담수습지, 갈대정자, 갯벌관찰대 등 사계절 생태체험을 위한 각종 시설들을 잘 갖춰놓고 많은 관광객의 이용할 수 있도록 하고 있다. 갯벌은 바닷가의 넓은 벌판이란 뜻으로서 삼면이 바다인 우리나라는 갯벌의 전체 면적이 약 $2,500km^2$에 달하는데 여기에는 많은 종류의 다양한 생물들이 살아가고 있으며 어민들의 생계에 지대한 영향을 주고있다. 이러한 갯벌은 퇴적된 입자의 구성에 따라 펄갯벌, 모래갯벌, 혼합갯벌 등으로 구별되는데 이에 따라 갯벌 생태계를 구성하고 있는 생물들의 종류도 바뀌게 된다. 순천만갯벌과 여기에 조성되어 있는 습지환경에 따라 확인되고 있는 수산자원으로는 새꼬막, 꼬막, 눈알고둥, 갯고둥, 비툴이고둥, 돌조개, 접시조개, 새알조개, 가무락조개, 바지락, 우럭, 가재붙이, 방게, 칠게, 농게 등의 저서 생물들과 짱뚱어, 문절망둑 등의 어류가 있으며, 해조류로 우뭇가사리 등이 있고, 인근의 어민들의 어업형태는 꼬막 등 패류의 채취나 종패를 뿌려 일정기간 양성하여 수확하는 양식업, 육상부에서 폐염전 등을 활용한 전어나 새우 등을 양식하는 양식업, 수산물을 직접 손이나 간단한 도구를 이용하여 잡는 맨손 어업 형태가 주를 이루고 있는 것으로 나타나고 있다. 이와 같이 국내외적으로 중요할 뿐만 아니라 인근의 어민들의 생계에도 지대한 영향을 미치고 있는 순천만의 습지는 뻘층이 깊고, 분해성 미생물이 다양하게 서식하여 유기물 분해능력이 뛰어나며, 유기영양분이 풍부하여 우리나라에서 가장 질이 좋은 습지로 평가되고 있으나, 순천시 등 순천만 인근에 거주하고 있는 인간의 활동에 따른 간섭에 많은 영향을 받고 있으며, 이에 따라 끊임없는 생태환경이 변화하고 있어서 순천만의 효율적인 보전 및 지속가능한 이용을 위해서는 생태계에서 가장 기본적인 요소인 수 저질 환경의 지속적이고 체계적인 조사 및 관리가 필요하다. 한편, 오염물질의 70% 이상은 하천이나 강을 통해서 해역으로 유입된다고 알려져 있기 때문에 생태계의 보고(寶庫)라고 알려진 순천만의 지속적인 보존 및 관리를 위해서는 유입수계 하천의 수질현황 및 오염물질의 주요 배출원을 파악하고, 이에 대한 저감대책을 수립할 필요가 있다. 따라서 본 연구는 순천만의 수저질 특성과 여기에 유입되는 하천의 수질환경 현황 및 오염원을 파악함으로써 순천만의 보전을 위한 효율적 관리방안을 제시하는 것을 목적으로 수행되었다. 연구의 결과에 따르면, 순천만의 수질평가지수에 의한 등급(WQI)은 III등급으로 나타나고 있으며, 득량만, 광양만 등에 비해 비교적 높은 유기물 및 T-N, T-P의 농도 분포를 보이고 있는 것으로 조사되었다. 이는 순천만에 유입되는 하수종말처리장의 방류수와 도시하수가 유입되어 그대로 방류되고 있는 해룡천 및 연안에 위치한 어촌으로부터 직접 방류되고 있는 일부 정화조 유출수 등, 다양한 원인에 의한 것으로 판단되며 이들의 관리가 부실할 경우 순천만의 갯벌과 습지의 지속가능한 생태환경유지는 쉽지 않다. 따라서 이를 효율적으로 관리하기 위해서는 순천만 연안의 오염물질 방류를 총량관리로 전환하여 철저히 관리하는 것이 필요할 것으로 판단된다.

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.153-160
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• 2018

Purpose : We retrospectively analyzed doses of each radiation therapy technique used in the treatment for left breast cancer patients after partial mastectomy through dose results for normalorgans and tumor volume to use this as a clinical reference for radiation therapy of domestic left breast cancer patients. Materials and Methods : 40 patients who underwent partial mastectomy on left breast cancer were classified in 3 treatment methods. The treatment plan was evaluated by HI(homogeneity index), $D_{95%}$, and CI(conformity index), and the $V_{hot}$ for gross tumor volume and clinical target volume of each treatment method. In Cyberknife treatment, tumor volume was the same as high dose volume in the other techniques, so no consideration was given to clinical target volume. Treatment plan evaluation for normal organs were evaluated by mean dose on ipsilateral lung, heart, left anterior descending artery, opposite breast and lung, and non-target tissue. Result : Treatment with volumetric arc radiotherapy(VMAT) showed $95.84{\pm}0.75%$ of $D_{95%}$ on the clinical target volume, significantly higher than that of 3D-CRT. The $D_{95%}$ value of the total tumor volume was slightly higher than the other treatments. In Cyberknife treatment, the dose to the normal organs was significantly lower than other treatments. Overall, the maximum dose and mean dose to the heart were $26.2{\pm}6.12Gy$ and $1.88{\pm}0.2Gy$ in VMAT treatment and $20.25{\pm}9.35Gy$ and $1.04{\pm}0.19Gy$ in 3D-CRT therapy, respectively. Conclusion : In comparison on 3D-CRT and VMAT, most of the dosimetric parameters for the evaluation of the treatment plan showed similar values, so that there is no significant difference in treatment plan evaluation. It is possible to select the treatment method according to the patient's anatomical structure or possibility of breath control. Cyberknife treatment is very useful treatment for normal organs because of its accurate dose exposure to the tumor volume However, it has restrictions to treat the local area, to have relatively long treatment time and to involve invasive procedure.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.175-183
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• 2021

Gongjae Yoon DuSeo(1668~1715), from Haenam in the late Joseon Dynasty, is a scholar-born painter who was active during King Sukjong. He is the person who created the foundation as a pioneer of realist paintings in the late Joseon period during the transition from the middle to the latter period. He was born in Namin's prestigious family, but he ended his career as part of a partisan fight and immersed himself in painting and learning. 18C, the beginning of the late Joseon Dynasty, was a period when Silhak emerged and the Jinkyung era opened with awareness of nationalism. At this time, by incorporating the Silhak thought into the art world, the real reformed aesthetic consciousness was demonstrated to pioneer common people's customs, the application of Western painting methods, the pursuit of realist techniques, and the introduction of Namjongmuninhwa. His view of painting, who thoroughly learned the old things and pursued change, must have both the form and spirit that he can achieve 'HwaDo' only when it has the science of 'learning and knowledge' and the technical elements of 'practice and quality' emphasized. He has worked in a variety of reconciliations. In particular, portrait paintings are characterized by ihyeongsasin's realistic expressions of aesthetics. His masterpiece, 「Self-portrait」, excels in extreme-realistic depiction and innovation in composition, and stands out with an unconventional experimentation spirit that expresses his mind and thoughts in a painting with a sense of resentment. His landscape paintings combine to express the form as it is and mental notions, and beautifully embodied Do as a form, thus achieving ihyeongmido, which reached the level of'joyfulness forgotten even the heart of joy'. On the other hand, the generalization of the common people using various common people's lives as the subject of an open-mindedness aimed at gaining the facts of ihyeongsajin, a passive protest against corrupt power and an expression of a spirit of love. Since then, his painting style has been passed down from generation to generation to his eldest son Yoon Deok-hee and his grandson Yoon Yong, leading the change and revival of calligraphy art in the late Joseon Dynasty.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.4
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• pp.67-83
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• 2022

Biochar is a carbon material produced through the pyrolysis of agricultural biomass with limited oxygen condition. It has been suggested to enhance the carbon sequestration and mineralization of soil carbon. Objective of this study was to investigate soil potential carbon mineralization and carbon dioxide(CO₂) emissions in different soils cooperated with barely straw and livestock manure biochars in the closed chamber. The incubation was conducted during 49 days using a closed chamber. The treatments consisted of 2 different biochars that were originated from barley straw and livestock manure, and application amounts were 0, 5, 10 and 20 ton ha^-1 with different soils as upland, protected cultivation, converted and reclaimed. The results indicated that the TC increased significantly in all soils after biochar application. Mineralization of soil carbon was well fitted for Kinetic first-order exponential rate model equation (P<0.001). Potential mineralization rate ranged from 8.7 to 15.5% and 8.2 to 16.5% in the barely straw biochar and livestock manure biochar treatments, respectively. The highest CO₂ emission was 81.94 mg kg^-1 in the upland soil, and it was more emitted CO₂ for barely straw biochar application than its livestock biochar regardless of their application rates. Soil amendment of biochar is suitable for barely straw biochar regardless of application rates for mitigation of CO₂ emission in the cropland.

• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.515-529
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• 2020

Constructed wetlands undergo biological and physical changes such as an increase in the proportion of arid plants due to the natural succession process after formation. It can adversely affect not only the purification function but also the habitat of species. As such, this study aims to identify environmental factors affecting biodiversity and propose management plans based on the monitoring results of physical environmental changes and the emergence of species in seven constructed wetlands selected based on the water depth and surrounding conditions among the lands purchased by the Nakdong River basin. We examined the environmental conditions and emergence of the Odonata, which is a wetland-dependent species, to predict the trend of changes in biodiversity and abundance. The results showed that the open water area decreased as the emergent plants spread to the deep water in 2015 compared to 2012 when they were initially restored to a depth of 0.2 to 1 m. While a total of 54 dragonfly species were observed, the habitat diversity, such as vegetation, water surface, and grassland, remained similar to the initial formation of the wetlands despite the expansion of the emergent plants. On the other hand, the number of Agrionidae species, which prefer areas with fewer aquatic plants, decreased between 2012 and 2015 due to the diminished water surface. The p-values of the differences in the number of species and population between wetlands by year were 2.568e-09 and 1.162e-08, respectively, indicating the statistically significant differences. The decrease in open water surface was found to have the greatest effect on the biodiversity and habitat density of dragonflies. The time-series survey of constructed wetlands confirmed that the spread of Phragmites communis, P. japonica, Typha orientalis, etc., caused a decrease in species diversity. It suggests that environmental management to maintain the open water surface area is necessary.

• MISULJARYO - National Museum of Korea Art Journal
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• v.98
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• pp.54-77
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• 2020

Produced during the Goryeo period (718-1392), the statue of the monk Huirang Daesa at Haeinsa Temple in Hapcheon is almost life-size, with a height of 82.4 cm, a width of 66.6 cm at the knees, and a maximum width of 44 cm at the torso (front and back). Notably, it is the only known example of an East Asian Buddhist sculpture made from wood and dry lacquer that was formed by joining the front and back halves. However, a similar technique was used on a dry lacquer statue of the Medicine Buddha at Cheongnyangsa Temple in Bonghwa, which is estimated to date from the late Goryeo or early Joseon period. As such, this technique is thought to represent this particular time period. In an eighteenth-century travelogue about a trip to Mt. Gayasan, the author describes a sculpture that is believed to be the statue of Huirang Daesa at Haeinsa Temple, based on various unique features that closely correspond to the sculpture's current appearance. For example, the sculpture is said to have a hole in the chest and rough, knobby tendons and bones, two features that can still be seen today. Another sculpture of a Buddhist monk who was active in the western regions during the third and fourth century also has a hole in the chest, which is said to be a symbol of spiritual strength. The travelogue also states that the statue was lacquered black at the time, which means that it must have been painted with its present colors some time in the nineteenth century. Over time, the sculpture has been enshrined in various halls of Haeinsa Temple, including Haehaengdang, Jinsangjeon, and later Josajeon (Hall of the Patriarchs), and Bojangjeon. Records show that images of Buddhist monks, or "seungsang," were produced in Korea as early as the Three Kingdoms period (18 BCE-660 CE), but few of these works have survived. At present, only four such sculptures are extant, including the images of Huirang Daesa from the Goryeo period, and those of Monk Naong and Uisang Daesa from the Joseon period. Of these, the sculpture of Huirang Daesa has special significance for its early production date (i.e., CE. tenth century), outstanding production techniques, and superb artistic quality, realistically capturing both the external appearance and internal character of the subject. The tradition of producing, sanctifying, and worshipping statues of monks was prevalent not only in Korea, but also in China and Japan. However, each country developed its own preferred materials and techniques for producing these unique images. For example, while China has a large number of mummified Buddhist images (yuksinbul), Japan produced diverse images with various materials (e.g., dry lacquer, wood, clay) according to period. But despite the differences in materials and techniques, the three nations shared the same fundamental purpose of expressing and honoring the inherent spirituality of the monks.

• MISULJARYO - National Museum of Korea Art Journal
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• v.98
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• pp.130-153
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• 2020

Using stylistic analysis and historical documents, this paper examines the production details of images enshrined in Myeongbujeon (Hall of the Underworld) at Magoksa Temple in Gongju, focusing on the wooden seated Ksitigarbha Bodhisattva and the stone Ten Kings of Hell. Inside Myeongbujeon, the wooden seated Ksitigarbha Bodhisattva is placed at the center, flanked by standing images of Mudokgwiwang and Domyeong-jonja, with images of the Ten Kings and their attendants along the walls. All of these images were transferred to Magoksa Temple in the latter half of the 1930s. The wooden seated Ksitigarbha Bodhisattva came from Jeonghyesa Temple in Cheongyang, the other sculptures came from Sinheungsa Temple in Imsil, and a painting of the Ten Kings came from Jeongtosa Temple in Nonsan. The wooden seated Ksitigarbha Bodhisattva is known to have been produced in 1677, around the same time as the stone sculptures of the Ten Kings. A close analysis of the details of the bodhisattva sculpture-including the facial features, body proportions, and drapery characteristics-strongly suggests that it was produced in the 1620s or 1630s by the monk sculptor Suyeon (who was active in the early half of the seventeenth century) or his disciples. In particular, the rendering of the drapery on the lower half of the body closely resembles Buddhist sculptures produced by Suyeon that are now enshrined at Bongseosa Temple in Seocheon (produced in 1619) and at Sungnimsa Temple in Iksan (produced at Bocheonsa Temple in Okgu in 1634). According to the votive inscription, the stone sculptures of the Ten Kings and their attendants were produced in 1677 under the supervision of the monk sculptor Seongil. However, these are the only known Buddhist images produced under Seongil, and no details about other monks involved in the production have ever been found, making it difficult to speculate about their lineage. Historical records do suggest that Seongil worked on other projects to produce or repair sculptures with disciples of the monk sculptors Hyehi or Unhye, indicating amicable relations between the two groups. Unlike most such images in the Honam or Yeongseo regions, the Ten Kings at Magoksa Temple are made from stone, rather than wood or clay. Also, the overall form and the drapery conform to statues of the Ten Kings that were popularly produced in the Yeongnam region. Thus, the images are believed to be the work of monks who were primarily active in Yeongnam, rather than Honam. In the future, a systematic investigation of wooden seated Ksitigarbha Bodhisattva images and stone Ten Kings of Hell images produced in the Chungnam region could illuminate more details about the production of the images at Magoksa Temple, and perhaps shed light on the conditions that led to the production of stone Buddhist sculptures in the Honam area during the late seventeenth century.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.531-542
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• 2021

Open-pit mines require constant monitoring as they can cause surface changes and environmental disturbances. In open-pit mines, there is little vegetation at the mining site and can be monitored using InSAR (Interferometric Synthetic Aperture Radar) coherence imageries. In this study, activities occurring in mine were analyzed by applying the recently developed InSAR coherence-based NDAI (Normalized Difference Activity Index). The March 5 Youth Mine is a North Korean mine whose development has been expanded since 2008. NDAI analysis was performed with InSAR coherence imageries obtained using Sentinel-1 SAR images taken at 12-day intervals in the March 5 Youth Mine. First, the area where the elevation decreased by about 75.24 m and increased by about 9.85 m over the 14 years from 2000 was defined as the mining site and the tailings piles. Then, the NDAI images were used for time series analysis at various time intervals. Over the entire period (2017-2019), average mining activity was relatively active at the center of the mining area. In order to find out more detailed changes in the surface activity of the mine, the time interval was reduced and the activity was observed over a 1-year period. In 2017, we analyzed changes in mining operations before and after artificial earthquakes based on seismic data and NDAI images. After the large-scale blasting that occurred on 30 April 2017, activity was detected west of the mining area. It is estimated that the size of the mining area was enlarged by two blasts on 30 September 2017. The time-averaged NDAI images used to perform detailed time-series analysis were generated over a period of 1 year and 4 months, and then composited into RGB images. Annual analysis of activity confirmed an active region in the northeast of the mining area in 2018 and found the characteristic activity of the expansion of tailings piles in 2019. Time series analysis using NDAI was able to detect random surface changes in open-pit mines that are difficult to identify with optical images. Especially in areas where in situ data is not available, remote sensing can effectively perform mining activity analysis.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.4
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• pp.170-181
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• 2011

This Research will explore the meaning indicated in the landscape meaning and feature of literary group culture, focusing in Gurujeong(九老亭: pavilion for nine elders) and Samgaeseokmun(三溪石門: stone gate in three valleys) located in Dundeok-myun, Imshil-gun, and will seek to understand the implications by studying the cultural landscape spread out in the area. The place where Gurojeong and Samgaeseokmun is located is the meeting point of the three valleys, Dunnam stream, Osu stream, and Yul stream, which is the main location to view the beautiful scenery, which has the nickname as the dwelling place of a celestial being. Especially, based on the description of old maps, "Samgae(three valleys)" and "Samgaeseokmun" possesses significance as a landmark and shows a characteristic feature of landscape structures of low hills. Dangugurohwe(丹丘九老會: nine elders gathering on the dwelling of a celestial being) originated from Hyangsangurohwe(香山九老會: gathering of nine elders on a fragrant mountain), where Baekgeoi(白居易) of China was one of the main people. This group was organized by nine elders over the age of 60 desiring to view the scenery of Doyeonmyeong. The group enhanced the literary spirit on the low hill, erecting a tower, and enjoying the beautiful scenery changing every season with scholars from the same region. This phenomenon seems to have been formed upon the positive response to gatherings of elders, which were prevalent in the Joseon Dynasty. If the internal idea pursued by the group was "longevity," the external idea pursued can be summarized as "the spirit the respect for the elders." Naming the groups as 'Dangudae(place where the celestial being lives), Guseondong(valley of seeking a celestial life), Bangjangsan(mountain of a high priest), and Daecheondae(place of communicating with God) was likely a device to introspect oneself and symbolize one's life process. Furthermore, the reason Samgaeseokmun, which is an imitation of Choi, Chiwon's work, was built near Soyocheo, was probably to yearn the celestial land and based on the desire to follow Choi, Chiwon, who was the most self-fulfilling being presumed to have become a celestial being by practicing the pursuit of freedom, escaping from the reality. After tracing the symbolizing meaning of the four letters carved in the left side of the stone wall of Dangudae, the conclusion that this place was not only a place for literary gatherings of the nine elders of Saseong(four families), but was a place where the celestial being dwelled could be inferred. Corresponding with Dangudae and Gurojeong, which are places where the order of human and nature is harmonized and where its meaning associated with the location intensifies, arouses strong bond, can be said to be the symbol of the traces of celestial beings where the spirits of attachment to a certain place is embedded. The acts performed in Dangugurohwe were those of traditional leisure including strolling, viewing the scenery, drinking, composing poems, and playing instruments, and sometimes listening to stories, tea ceremony, prayers, and fishing were added, which indicates that the gathering had a strong tendency towards pastoral and hermit life.