• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.1
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• pp.128-138
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• 2019

Effects of feeding type and food resource availability on community structure of mollusks inhabiting hard-bottom subtidal areas were investigated. By following guidance from several references, mollusks observed in this study were divided into 5 groups according to feeding type - 1) grazing, 2) filter feeding, 3) deposit feeding, 4) omnivorous and 5) predation. The results showed that both grazing and filter feeders were the most numerous, explaining grazing type in the East Sea accounting for 47.9%, 32.6% in the South Sea and 29.6% for filter feeding, and filter feeding as a dominant feeding type in Yellow Sea accounting for 42.3%. Results of this study showed distinctive difference in community structure depending on mechanism of feeding type and geographical areas where sampling took place. With the results, attempts were made to understand whether community structure could be affected by feeding type or feeding availability and found out that community structure depended heavily on food resource availability. In the East Sea where marine algal density was high, the algal community in the forms of thick-leathery and sheet often occurred in water column with high transparency which provides proper environment for growth. In the South Sea where grazing and filter feeding types were predominated similarly, the algal density was high, but had the relative highest phytoplankton density. Whereas in the Yellow Sea showing the lowest algal biomass compared to the one in the East and the South Sea, and phytoplankton density was similar to those. It might be a adequate environment for filter feeders than grazers. This study concluded that community structure of mollusks showing high abundance was present where food resource availability with types and quantity was high.

• Clean Technology
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• v.27 no.3
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• pp.232-239
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• 2021

In order to develop a novel system named "thermal medium and gas circulation type pyrolysis system," this study was conducted to obtain basic data for process simulation before performing the pyrolysis experiment. Polypropylene (PP) was chosen as model material in the basic pyrolysis experiment instead of waste plastic and fluidized sand (hereinafter referred to as "sand"), and it was used as a heat transfer material in the "thermal medium and gas circulation type pyrolysis system." Ni was impregnated as an active catalyst on the sand to promote catalytic pyrolysis. The basic physical properties of PP were analyzed using a thermogravimetric analyzer, and pyrolysis was performed at 600 ℃ in an N₂ atmosphere to produce liquid oil. The distribution of the carbon number of the liquid oil generated through the catalytic pyrolysis reaction was analyzed using GC/MS. We investigated the effects of varying the pyrolysis space velocity and catalyst amount on the yield of liquid oil and the carbon number distribution of the liquid oil. Using Ni/sand, the yield of liquid oil was increased except with the pyrolysis condition of 10 wt% Ni/sand at a space velocity of 30,000 h^-1, and the composition of C₆ ~ C₁₂ hydrocarbons increased. With increases in the space velocity, higher yields of liquid oil were obtained, but the composition of C₆ ~ C₁₂ hydrocarbons was reduced. With 1 wt% Ni/sand, the oil yield obtained was greater than that obtained with 10 wt% Ni/sand. In summary, when 1 wt% Ni/sand was used at a space velocity of 10,000 h^-1, the oil yield was 60.99 wt% and the composition of C₆ ~ C₁₂ hydrocarbons was highest at 42.06 area%.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.346-361
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• 2021

The range of D. spathulata identified in this survey was between N 35° 24' 58" ~ N 35° 26' 35", E 129° 05' 43" ~ E 129° 07' 04". It is located at an altitude of 98~592 m. The soil pH was strongly acidic in the range of 4.2~4.9, with a canopy openness of 18.56% and a chlorophyll index of 36.74 ± 2.80. As a result of the TWINSPAN analysis, 20 plots of 100 m² each were divided in 4 communities: Pinus densiflora community, Quercus monglica-Diabelia spathulata community, Quercus serrata-Diabelia spathulata community and Carpinus tschonoskii subassociation. The result of species diversity was 0.7615, and evenness and dominance were found to be 0.6077 and 0.3923, respectively. The height of D. spathulata is up to 3.4 m, and the average height is 1.1 m, with most of the species distributed as shrubbery and herbaceous. The average population density of the 20 plots was 1.635 individuals/m², the height range of flowering was 1.0 ~ 1.8 (aver. 1.39 m) and the rate of flowering was 27.37%. It's propagation pattern was mainly formed by extending the rhizome to the side, creating a colony of ground stems.

• Applied Chemistry for Engineering
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• v.31 no.6
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• pp.612-623
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• 2020

This study was initiated to quantitatively evaluate the inhibitory effects of five heavy metals (Cd, Cu, Zn, Pb, Ni) on bacterial growth and phosphorus removal in the binary culture of Alcaligenes sp. plus Pseudomonas sp. IC50 values of Alcaligenes sp. plus Pseudomonas sp. for Cd, Cu, Zn, Pb, and Ni were 0.75, 10.93, 7.08, 13.30, and 15.78 mg/L, respectively. For the binary treatments of heavy metals, IC50 was the lowest in the treatment of Cd + Cu, whereas, it was the highest in the Ni + Pb treatment. The EC50 values for Cd, Cu, Zn, Pb, and Ni were 0.54, 11.08, 6.14, 9.33, and 13.81 mg/L, respectively. For the binary treatments of heavy metals, EC50 was the lowest in the Cd + Zn, whereas, the highest in the Zn + Ni. Based on both IC50 and EC50 values for the binary culture of bacteria with the binary mixtures of heavy metals, the most interactive effect was found to be antagonistic, though the only synergistic effect was found in Cu + Ni treatment. Therefore, our results can provide basic data on the toxic effects of heavy metals on the bacterial growth and phosphorus removal in the wastewater treatment process.

• The Journal of the Korean Institute of Forest Recreation
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• v.22 no.4
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• pp.11-22
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• 2018

This study analyzes the economic feasibility on the transition of production structure to increase income for a local forest village in Laos PDR. The study area was the Nongboua village in Sangthong district where the primary product is rice from rice paddy. Possible strategies were considered to increase the villagers' revenue, and Noni (Morinda citrifolia) was production in the short-term. We assumed that the project period was for 20 years for the analysis, and a total of 1,100 Noni tree was planted in 1 ha by $3m{\times}3m$ spacing. This study classified basic scenario one, scenario two, scenario three by the survival rate and purchase pirce of Noni. Generally Noni grows well. However, the seedlings' average survival rate (= production volume) was set up conservatively in this study to consider potential risks such as no production experience of Noni and tree disease. The scenario one assumed that the survival rate of Noni seedlings was 50% for 0-1 years, 60% for 0-2 years, and 70% for 3-20 years; the scenario two, 10% less, i.e., 40%, 50%, and 60%; and the scenario three, 10% less, i.e., 40%, 50%, 60% and purchase price 10% less, i.e., $0.29 to $0.26, respectively. Our analysis showed that all 3 scenarios resulted in economically-feasible IRR (internal rate of return) of 24.81%, 19.02%, and 16.30% of with a discounting rate of 10%. The B/C (benefit/cost) ratio for a unit area (1ha) was also analyzed for the three scenarios with a discounting rate of 10%, resutling in the B/C ratio of 1.71, 1.47, and 1.31. The study results showed that the Nongboua village would have a good opportunity to improve its low-income structure through planting and managing alternative crops such as Noni. Also the results can be used as useful decision-making information at a preliminary analysis level for planning other government and public investment projects for the Nonboua village.

• The Journal of Korean Philosophical History
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• no.56
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• pp.81-117
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• 2018

The purpose of this study is to clarify the overall features and its meaning of the Gaebyok(開闢) through the intercomparison of the Gaebyok idea that is the core idea of a newly risen modern religion in Korea. Limitation of most studies so far is that they have stayed in the fragmentary study on the Gaebyok idea of each new religion. In order to overcome this problem, first of all, the Gaebyok idea was studied from a philosophical point encompassing the cosmological view of time in the book of changes. And based on this methodological foundation, with organizing the existing result of study, the process of development and characteristics in the Gaebyok idea of a posteriori Donghak(東學), Right I Ching (正易), Won Buddhism(圓佛敎), and Kangjeungsan(姜甑山) was investigated respectively. And through comparing and analyzing each Gaebyok idea, the similarities and differences between each other were organized. The founders of new religions thought that a great change in the universal and natural luck was made before and after the point of their living. The concept of the frequency of revolution theory is the concept to explain the aspect of transition according to the frequency of revolution(運度) of the cosmological nature that returns to the beginning, and in the idea of the posterior Gaebyok, this content and concepts is contained as it was. This study showed that the concept of the frequency of revolution theory in an apriority and a posterior like those becomes appeared in some preaches of Suun, Ilbu, Sotaesan and Jeungsan. An apriority in the Gaebyok idea of new religion is the world of crisis that represents the limited condition of human being, and a posterity means the religious ideal world realized through the power of the absolute being or a dramatic universal change from that limited circumstances. So the Gaebyok ida is a kind of an universal eschatology and religious view that expects the coming of ideal world in the future. In addition, since the universal eschatology is a kind of a view of time, it inevitably has an issue how long time apriority and a posterity included in it have. And especially, it becomes to premise the content how the social condition and human condition change in an apriority and a posterity. Accordingly, in this study, based on the understanding of the view of time in the cosmological level, the content of answers that each newly risen religion discloses was listed and analyzed with comparison. It can be considered that Suun took charge of a mission to deliver the message through being possessed of a god in heaven who is able to be called a transcendental existence, Ilbu disclosed the coming of the world of a posterity beyond an apriority through the Book of Changes(易學), Jeungsan proclaimed himself as the absolute being who could make such a posterity and bring it, and Sotaesan proposed the Gaebyok of mind in order to meet with the world of a posterity and to live in that era.

• Journal of Food Hygiene and Safety
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• v.36 no.3
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• pp.264-270
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• 2021

In this study we investigated the elution level of lead (Pb), cadmium (Cd), arsenic (As), zinc (Zn), nickel (Ni), antimony (Sb), germanium (Ge), aluminum (Al) and hexavalent chromium (Cr⁶⁺) from 69 home-cooking utensils into a food stimulants. The results of migration testing according to the Korea standards and specifications for utensils, containers and packages showed values the allowable migrantion limits. Al was detected in all 7 utensil materials with the average concentration ranging from 0.002-5.989 mg/L. According to the migration conditions for (180℃, 30 min), the average concentration of Al in paper was 7.2 times higher than 25℃, 10 min (P<0.05). The results of migration testing at 180℃, 30 min were also below the allowable migrantion limits. When comparing with the provisional tolerable weekly intake (PTWI) of Al, the estimated weekly intakes (EWI) accounted for 0.000-0.045% for Al.

• Journal of Environmental Impact Assessment
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• v.30 no.1
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• pp.13-23
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• 2021

In this study, we performed a Random Walker analysis to predict the Major Movement Paths of otters. The scope of the research was a simulation analysis with a radius of 7.5 km set as the final range centered on the Ansim-wetland in Daegu City, and a field survey was used to verify the model. The number of virtual otters was set to 1,000, the number of moving steps was set to 1,000 steps per grid, and simulations were performed on a total of 841 grids. As a result of the analysis, an average of 147.6 objects arrived at the boundary point under the condition of an interval of 50 m. As a result of the simulation verification, 8 points (13.1%) were found in the area where the movement probability was very high, and 9 points (14.8%) were found in the area where the movement probability was high. On the other hand, in areas with low movement paths probabilities, there were 8 points (13.1%) in low areas and 4 points (6.6%) in very low areas. Simulation verification results In areas with high otter values, the actual otter format probability was particularly high. In addition, as a result of investigating the correlation with the otter appearance point according to the unit area of the evaluation star of the movement probability, it seems that 6.8 traces were found per unit area in the area where the movement probability is the highest. In areas where the probability of movement is low, analysis was performed at 0.1 points. On the side where otters use the major movement paths of the river area, the normal level was exceeded, and as a result, in the area, 23 (63.9%), many form traces were found, along the major movement paths of the simulation. It turned out that the actual otter inhabits. The EN-Simulator analysis can predict how spatial properties affect the likelihood of major movement paths selection, and the analytical values are used to utilize additional habitats within the major movement paths. It is judged that it can be used as basic data such as to grasp the danger area of road kill in advance and prevent it.

• Korean Journal of Plant Resources
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• v.34 no.1
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• pp.23-30
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• 2021

Hemistepta lyrata Bunge (HL) has been used as a folk remedy to treat cancer, inflammation, bleeding, hemorrhoids and fever, and leaves and young shoots have been used as famine food. Nevertheless, the biological activities and underlying mechanisms of the anti-inflammatory effects remain unclear. In this study, it was undertaken to explore the functions of the aerial part of HL as a suppressor of inflammation by using RAW 264.7 cells. As immune response parameters, the productions of as nitric oxide (NO) and prostaglandin E2 (PGE2), cytokines such tumor necrotic factor (TNF)-α and interleukin (IL)-6 were evaluated. Although the release of TNF-α remained unchanged in HL-treated RAW 264.7 cells, the productions of NO, PGE2 and IL-6 were significantly increased at concentrations with no cytotoxicity. Furthermore, HL significantly attenuated the mitogen-activated protein kinases (MAPK) pathway including decreasing the phosphorylation of the extracellular signal-regulated kinase (ERK1/2) and p38 mitogen-activated protein kinases. Collectively, this study provides evidence that HL inhibits the production of major pro-inflammatory molecules in LPS-stimulated RAW 264.7 cells via suppression of ERK and P38 MAPK signaling pathways. These findings suggest that the beneficial therapeutic effects of HL may be attributed partly to its ability to modulate immune functions in macrophages.

• Korean Journal of Heritage: History & Science
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• v.55 no.2
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• pp.168-184
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• 2022

This paper examined the construction techniques of the earthen fortifications in the Hanseong Period of Baekje Kingdom, which has been researched most frequently among the Three Kingdoms. The construction processes of the Earthen Fortifications were reviewed and dividing into 'selection of location and construction of the base', 'construction of the wall', and 'finish, extension and repair'. The results show that various techniques were mobilized for building these earthen fortifications. Techniques which were adequate for the topography were utilized for reinforcing the base, and several other techniques were used for constructing the wall. In particular, techniques for wall construction may be clearly divided into those of the fill(盛土) and panchuk(版築) techniques. The fill method has been assumed since the 2000s to have been more efficient than the panchuk technique. This method never uses the structure of the panchuk technique and is characterized by a complex soil layer line, an alternate fill, use of 'earth mound(土堤)'/'clay clod(土塊)', and junctions of oval fill units. The fill method allows us to understand active technological sharing and application among the embankment structures in the period of the Three Kingdoms. The panchuk technique is used to construct a wall using a stamped earthen structure. This technique is divided into types B1 and B2 according to the height, scale, and extension method of the structure. Type B1 precedes B2, which was introduced in the late Hanseong Period. Staring with the Pungnap Earthen Fortification in Seoul, the panchuk technique seems to have spread throughout South Korea. The techniques of the fill and panchuk techniques coexisted at the time when they appeared, but panchuk earthen fortifications gradually dominated. Both techniques have completely different methods for the soil layers, and they have opposite orders of construction. Accordingly, it is assumed that both have different technical systems. The construction techniques of the earthen fortifications began from the Hanseong Period of Baekje Kingdom and were handed down and developed until the Woongjin-Sabi Periods. In the process, it seems that there existed active interactions with other nations. Recently, since studies of the earthen fortifications have been increasing mainly in the southern areas, it is expected that comparative analysis with neighboring countries will be done intensively.