• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.2
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• pp.140-146
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• 2008

Marine ecotoxicological standard method using fish larvae was established with the standard test species of Oryzias latipes(Japanese Medaka) and Paralichthys olivaceus(flounder) and with the 7 day $LC_{50}$ as endpoint. Test method referred to the USEPA(1994) with the replacement of test species found in the Korean water. Standard test species were selected in terms of the species supply and ecological importance in Korean waters. Japanese medaka can be reared with small tanks in the lab and has wide tolerance on salinity, and flounder eggs can be easily obtained from commercial fish hatcheries. General conditions for larval fish toxicity test are as follows. The possible salinity ranges for toxicity test were $0{\sim}35\;psu$ for medaka and >20 psu for flounder. Test type was designated as static non-renewal test if the dissolved oxygen in the test chamber does not fall below 4.0 mg/L. Ages of test species were selected as 7 days after hatched for medaka(about 5 mm TL) and 25 days for flounder(about 10 mm TL) because of the low natural mortality after these periods. Test can be accepted when the survival rates are over 80% in control. Also, species sensitivity on standard reference materials(copper, cadmium or zinc) must be provided with the toxicity test results.

• Journal of the Korean GEO-environmental Society
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• v.25 no.6
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• pp.19-24
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• 2024

Urban densification has necessitated the development of subterranean spaces such as subway networks and underground tunnels to facilitate the dispersal and movement of populations. Development of these underground spaces requires excavation from the ground surface, which can induce groundwater flow and potentially lead to ground subsidence and sinkholes, damaging structures. To mitigate these risks, it is essential to model groundwater flow prior to construction, analyze its characteristics, and predict potential groundwater discharge during excavation. In this study, we collected meteorological, topographical, and soil conditions data for the city of ○○, where tunnel construction was planned. Using the Visual MODFLOW program, we modeled the groundwater flow. Excavation sections were set as drainage points to monitor groundwater discharge during the excavation process, and the effectiveness of seepage control measures was assessed. The model was validated by comparing measured groundwater levels with those predicted by the model, yielding a coefficient of determination of 0.87. Our findings indicate that groundwater discharge is most significant at the beginning of the excavation. Additionally, the presence of seepage barriers was found to reduce groundwater discharge by approximately 59%.

• Ecology and Resilient Infrastructure
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• v.11 no.2
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• pp.43-54
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• 2024

Recently, most of the rivers in Korea are experiencing various problems in dimension and river environment, such as expansion of stable area where disturbance does not occur during flood, increase of excessive trees in river channel, fixation of river channel, reduction of sand bar. When the soil supplied by the flood is deposited in the river, the plant is settled in the formed terrain, and when another disturbance of the scale that does not erode there occurs after the plant is settled, the river gradually grows and the vegetation zone is formed there. In particular, in terms of river management, river forestation and river aggradation are objects that must be managed because they are disadvantageous in terms of flood control by lowering the flow rate and raising the water level. Therefore, in this study, the area of vegetation occupied by the year of sandbar was analyzed in the process of river aggradation in Jang-Hang wetland. In addition, the correlation between the growth of Jang-Hang wetland was analyzed through the analysis of the flow rate and the flooding frequency that directly affect the growth of Jang-Hang wetland. Through this, the management plan of Jang-Hang wetland, which is registered in Ramsar Wetland but has been river forestation and is undergoing river aggradation, was proposed.

• Korean Journal of Poultry Science
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• v.51 no.2
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• pp.47-56
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• 2024

This study investigated the quality characteristics of low-fat chicken breast sausage with cauliflower powder to replace the fat. Cauliflower was freeze-dried and then ground into powder form. Sausagebatter was prepared separately according to the amount of fat and cauliflower powder added. 1) Control, sausage with 20% of pork fat, 2) LF, sausage with 3% of pork fat, 3) C0.5, sausage with 3% of pork fat and 0.5% of cauliflower powder, 4) C1.0, sausage with 3% of pork fat and 1.0% cauliflower powder. The prepared sausage batter was heated to a final internal temperature of 75℃. The pH of sausage batter increased with the addition of cauliflower powder (P<0.05). Storage loss and cooking loss increased in low-fat samples but decreased as the amount of cauliflower powder added increased (P<0.05). The hardness measured on the 30th day of storage decreased in LF but increased with the content of cauliflower powder (P<0.05). The redness and yellowness of the sausage increased with the addition of cauliflower powder. The malondialdehyde content of chicken breast sausages decreased at C0.5 and C1.0 on the 30th day of storage. The sausages with cauliflower powder received lower scores in sensory evaluation (P<0.05). Therefore, the addition of cauliflower powder to low-fat chicken breast sausage reduced overall sensory acceptability but improved water-holding capacity and oxidative stability.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.24-31
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• 2024

Background: Honey from different geographical origins can have distinct characteristics due to variations in the floral sources available to stingless bees in different regions. The most abundant stingless bee for meliponiculture in Thailand is Tetragonula pagdeni. However, only a few studies about the properties of honey from a different origin were carried out. The objective of this study was focused on a comparative study to evaluate the melissopalynological, physicochemical, antioxidant activities, and total phenolic contents (TPCs) of stingless bee honey produced by T. pagdeni from different parts of Thailand. Results: Fifty honey samples were collected from five locations, and the physicochemical properties of T. pagdeni honey samples are acidic (pH 3.02-4.15) and have a high water content (18.42-25.06 %w/w), which is related to the regions of meliponary. Melisopalynological analysis reveals the predominant pollen from Melaleuca quinquenervia, Cocus nuciferca, Nephelium lappaceum, Salacca wallichiana, and multiflora honey. All honey samples were analyzed for their TPC and 2,2-diphenyl1-picrylhydrazyl radical scavenging activity. The results show that all samples had high TPC and antioxidant activities with a strong correlation (p < 0.05). Conclusions: The data from this study indicates the importance of geographical origin, which links physicochemical properties, phenolic compounds, and functional characteristics to their floral. Besides, the floral sources and harvesting location affected the properties of stingless bee honey. Our results identify Melaleuca honey as a promising source of phenolic content and antioxidant activity that can be used as a functional food, as well as multiflora and Cocus honey. However, further studies are required to characterize the phenolic compound and its biological potential, which could be a stingless bee honey biomarker and quality control, simultaneously with the physicochemical analysis.

• Journal of Food Hygiene and Safety
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• v.39 no.3
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• pp.273-280
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• 2024

In this study, the antibacterial activity and mechanisms of bitter orange extract, a natural antibacterial agent, were investigated, with a focus on its potential application in washing water for controlling Salmonella Typhimurium contamination of salad, a ready-to-eat food. The minimum inhibitory concentration (MIC) of bitter orange extract against S. Typhimurium was determined using the broth dilution method. Subsequently, S. Typhimurium was exposed to various concentrations of bitter orange extract (1/16 MIC-2 MIC) and growth curves were measured. Following treatment with bitter orange extract, we investigated its antibacterial mechanism by measuring intracellular reactive oxygen species (ROS) levels, alterations in membrane potential and integrity, and nucleic acid leakage in S. Typhimurium. Additionally, salads artificially contaminated with S. Typhimurium were treated with different concentrations of bitter orange extract using the dipping method for various durations to assess the reduction effect. The MIC of bitter orange extract against S. Typhimurium was 195.313 mg/L, and bacterial growth was completely inhibited at a concentration of 1 MIC. Furthermore, an increase in bitter orange extract concentration correlated with elevated intracellular ROS levels, membrane potential disruption, membrane damage, and nucleic acid release. Importantly, salads treated with bitter orange extract exhibited a significant reduction in S. Typhimurium counts compared to the control, and prolonged treatment times resulted in further reductions in bacterial counts. Bitter orange extract was more effective than sodium hypochlorite and can be used as a safer salad wash. These findings indicate the potential treatment of salads to prevent foodborne illnesses.

• Atmosphere
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• v.34 no.3
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• pp.305-317
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• 2024

The study examines the effects of parameters that define the characteristics of raindrops on the simulated precipitation during the summer season over Korea using the Weather Research and Forecasting (WRF) Double-Moment 6-class (WDM6) cloud microphysics scheme. Prescribed parameters, defining the characteristics of hydrometeors in the WDM6 scheme such as a_R, b_R, and f_R in the fall velocity (V_R) - diameter (D_R) relationship and shape parameter (𝜇_R) in the number concentration (N_R) - D_R relationship, presents different values compared to the observed data from Two-Dimensional Video Disdrometer (2DVD) at Boseong standard meteorological observatory during 2018~2019. Three experiments were designed for the heavy rainfall event on August 8, 2022 using WRF version 4.3. These include the control (CNTL) experiment with original parameters in the WDM6 scheme; the MUR experiment, adopting the 50th percentile observation value for 𝜇_R; and the MEDI experiment, which uses the same 𝜇_R as MUR, but also includes fitted values for a_R, b_R, and f_R from the 50th percentile of the observed V_R - D_R relationship. Both sensitivity experiments show improved precipitation simulation compared to the CNTL by reducing the bias and increasing the probability of detection and equitable threat scores. In these experiments, the raindrop mixing ratio increases and its number concentration decreases in the lower atmosphere. The microphysics budget analysis shows that the increase in the rain mixing ratio is due to enhanced source processes such as graupel melting, vapor condensation, and accretion between cloud water and rain. Our study also emphasizes that applying the solely observed 𝜇_R produces more positive impact in the precipitation simulation.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.4
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• pp.120-136
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• 2024

Yeong-dae(靈臺), Yeong-yu(靈囿), and Yeong-so(靈沼) - so-called 'Yeong-dae Garden' – appear in the poem 'Dae-ah(大雅)․Yeong-dae(靈臺)' in Shijing(詩經) which is considered the record of the earliest garden in East Asia, in the chapter 'Yanghyewang(梁惠王)' of Mencius(孟子). Focusing on those records, this research clarifies their characteristics and discusses the aspects related to garden practices in the Joseon Dynasty. The Yeong-dae Garden is the garden of King Wen of the Zhou Dynasty, who is considered a sage of Confucianism. It is considered to be the first imperial garden in China, and the basic form of all gardens consists of mountains and water. The characteristics of Yeong-dae Garden can be specified through the texts of Shijing and Mencius, the comments written by Zhu Xi and others, and later literature, such as Sambohwangdo. The characteristics of Yeong-dae Garden are as follows: In terms of form, the three spatial elements corresponding to raised ground, a wide area for raising animals, and a pond with fish form a simple arrangement; in terms of function, it combines observation and rest; and in terms of symbolism, it signifies the companionship of the public sentiment and the leader's sincerity. In literature from the Joseon Dynasty, Yeong-dae Garden mainly appear in historical materials related to the King, and its meaning shows an aspect of differentiation into two functions: an observatory for astronomical observation and a garden for rest and appreciation. For the intellectuals of Joseon who sought to restore an ancient ideal state like the Zhou Dynasty through Zhu Xi's Neo-Confucianism, the Yeong-dae Garden served as a control device to warn against royal garden's practices and a symbolic mechanism to expand its meaning of existence to good politics.

• Journal of Nutrition and Health
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• v.57 no.4
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• pp.389-402
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• 2024

Propose: This study examined the antioxidant and anti-gastritis properties of a mixture comprising Ipomoea batatas (IB) extract and Dioscorea japonica (DJ) extract. Methods: The mixture of IB and DJ extracts was analyzed for its total flavonoid content (TFC), total polyphenol content (TPC), and radical scavenging activities. Gastric lesions were induced by treating rats with 1 mL of a solution containing 60% ethanol and 150 mM HCl. The rats were then divided into 5 groups: CON (normal control), HEC (treated with 150 mM HCl-60% ethanol and distilled water), IBE (treated with 150 mM HCl-60% ethanol and IB extract at 350 mg/kg body weight [BW]), ID30 (treated with 150 mM HCl-60% ethanol and a mixture of IB and DJ extracts in a 7:3 ratio at 350 mg/kg BW), and DJE (treated with 150 mM HCl-60% ethanol and DJ extract at 350 mg/kg BW). Results: The ID30 group exhibited significantly higher TFC, TPC, and radical scavenging activities than the groups treated with single extracts. This group also showed a notable decrease in the formation of gastric lesions and preservation of gastric wall mucus. In addition, the serum levels of the inflammatory marker tumor necrosis factor (TNF)-α were significantly lower in the ID30 group than in the HEC group. Conclusion: The antioxidants present in the ID30 mixture effectively reduced oxidative stress and reactive oxygen species, mitigating gastric mucosal irritation induced by alcohol and acid. Furthermore, the mixture inhibited gastric acid secretion and inflammatory marker expression, such as TNF-α, preventing tissue damage. These findings suggest that the ID30 mixture is a potential preventative treatment for gastritis.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.149-153
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• 2008

The pollutant capacity occurred before and after the development of a watershed should be quantitatively estimated and controlled for the minimization of water contamination. The Ministry of Environment suggested a guideline for the legal management of nonpoint source from 2006. However, the rational method for the determination of treatment capacity from nonpoint source proposed in the guideline has the problem in the field application because it does not reflect the project based cases and overestimates the pollutant load to be reduced. So, we perform the standard rainfall analysis by analytical probabilistic method for the estimation of an additional pollutant load occurred by a project and suggest a methodology for the estimation of contaminant capacity instead of a simple rational method. The suggested methodology in this study could determine the reasonable capacity and efficiency of a treatment facility through the estimation of pollutant load from nonpoint source and from this we can manage the watershed appropriately. We applied a suggested methodology to the projects of housing land development and a dam construction in the watersheds. When we determine the treatment capacity by a rational method without consideration of the types of projects we should treat the 90% of pollutant capacity occurred by the development and to do so, about 30% of the total cost for the development should be invested for the treatment facility. This requires too big cost and is not realistic. If we use the suggested method the target pollutant capacity to be reduced will be 10 to 30% of the capacity occurred by the development and about 5 to 10% of the total cost can be used. The control of nonpoint source must be performed for the water resources management. However it is not possible to treat the 90% of pollutant load occurred by the development. The proper pollutant capacity from nonpoint source should be estimated and controlled based on various project types and in reality, this is very important for the watershed management. Therefore the results of this study might be more reasonable than the rational method proposed in the Ministry of Environment.