• Journal of Soil and Groundwater Environment
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• v.27 no.2
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• pp.61-75
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• 2022

This study evaluated the potential threat of agricultural and human activities to groundwater in the Noseong stream watershed, a typical agricultural area, through hydrogeochemical characteristics and microbial community analyses. The groundwater in the study area was Ca-SO₄ and Ca-HCO₃ types alluvial aquifer mainly used for agricultural and living purposes, and contained high levels of NO₃^- and Cl^- ions generated from anthropogenic sources such as fertilizer, livestock wastewater, and domestic sewage. Proteobacteria was most abundant in all samples with an average of 46.1% while Actinobacteria, Bacteroidetes, and Cyanobacteria were dominant on an occasional basis. The prevalence of aerobic bacteria such as the genus Mycobacterium, Flavobacterium, and Sphingomonas suggests that groundwater was well connected with the surface layer. The potential pathogen Mycobacterium was detected in most samples, and other pathogenic bacteria were also widely distributed, indicating the vulnerability to contamination. Therefore, an integrated management system is required to secure the sustainable use of groundwater in agricultural areas with high groundwater dependence.

• Journal of the FoodService Safety
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• v.3 no.1
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• pp.8-18
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• 2022

Dry-aging is one of the traditional aging processes, especially for beef. This aging process is being popular, because it produces unique brown/roasted flavor and texture that consumers prefer. However, as it is exposed to outside without packaging food safety concerns have been raised. The objective of this study was to investigate the presence of total aerobic bacteria (TAB) and pathogenic bacteria in manufacturing environment and suggest the safety management plan for the production of dry-aged meat. Surface samples from 66 environmental and 6 beef carcass samples were collected. According to the monitoring results, the contamination levels of TAB were in the order of shelves (5.4±1.1 Log CFU/cm²), cotton gloves (2.9±0.2 Log CFU/cm²), and door knobs (2.8±0.4 Log CFU/cm²) in the dry-aging room. In the door knobs, the level of mold was higher than that of yeast. These results indicate that the mold spores may be cross-contaminated with environmental factors inside the aging room. The risk factors that may occur during the manufacturing process were presented and possibility of risk was determined. From the aspect of microbiology, aging and trimming steps were determined as the critical control points. The temperature of the aging room should be maintained below 10℃ and the humidity below 75-85%. Based on the monitoring and the risk assessment of the dry-aging process, we prepared the safety management plan for the production of dry-aged meat, and it should be useful in improving the food safety of dry-aged meat.

• Journal of Practical Agriculture & Fisheries Research
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• v.7 no.1
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• pp.81-89
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• 2005

The experiment was conducted to evaluate the effect of fruit skin spray of the lime fertilizer in 'Campbell Early' grapes. The T-N, P, K, Ca and Mg of fruit skin and cluster weight, berry weight, cluster length showed no difference between control and lime fertilizer. But soluble solids in fruit was reduced by fruit skin spray of liquid calcium fertilizer extracted from oyster shell after bagging(LCaB). The anthocyanin content of fruit skin was decreased by air-slaked lime(HCa) and LCaB treatment. Also, occurrence of fruit skin bloom was significantly reduced by HCa and oyster shell powder(OS-CaP) treatment. The berry firmness was significantly increased through liquid calcium fertilizer extracted from oyster shell(LCa) and HCa treatment. Conspicuously, berry elasticity was rather decreased by OS-CaP treatment. However, there was no difference of weight loss of fruit among treatments during room temperature storage.

• Journal of Animal Science and Technology
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• v.65 no.1
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• pp.258-270
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• 2023

Climate change has worsened droughts and floods, and created conditions more likely to lead to pathogen contamination of surface water and groundwater. Thus, there is a growing need to disinfect livestock water. Ultraviolet (UV) irradiation is widely accepted as an appropriate method for disinfecting livestock water, as it does not produce hazardous chemical compounds and kills pathogens. However, UV-based disinfection inevitably consumes electricity, so it is necessary to improve UV disinfection effectiveness. Aluminum-based reflective nanolens arrays that enhanced the effectiveness of a continuous-flow UV water disinfection system were developed using electrochemical and chemical processes, including electropolishing and two-step anodization. A continuous UV disinfection system was custom designed and the parts were produced using a three-dimensional printer. Electropolished aluminum was anodized at 40 and 80 V in 0.3 M oxalic acid, at 120 and 160 V in 1.0 M phosphoric acid, and at 200 and 240 V in 1.5 M citric acid. The average nanolens diameters (D) of the aluminum-based reflective nanolens arrays prepared using 40, 80, 120, 160, 200, and 240 V anodization were 95.44, 160.98, 226.64, 309.90, 296.32, and 339.68 nm, respectively. Simple UV reflection behind irradiated water disinfected Escherichia coli O157:H7 in water more than did the non-reflective control. UV reflection and focusing behind irradiated water using an aluminum-based reflective nanolens array disinfected E. coli O157:H7 more than did simple UV reflection. Such enhancement of the UV disinfection effectiveness was significantly effective when a nanolens array with D 226.64 nm, close to the wavelength of the irradiated UV (254 nm), was used.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2158-2165
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• 2023

Marine radioactivity monitoring is critical for taking immediate action in case of unexpected nuclear accidents at nuclear facilities located near coastal areas. Especially when the level of contamination is not predictable, mobile monitoring systems will be useful for wide-area ocean radiation survey and for determination of the level of radioactivity. Here, we used a silicon photomultiplier and a high-efficiency GAGG crystal to fabricate a compact, battery-powered gamma spectroscopy that can be used in an ocean environment. The developed spectroscopy has compact dimensions of 6.5 × 6.5× 8 cm³ and weighs 560 g. We used LoRa, a low-power wireless protocol for communication. Successful data transmission was achieved within 1.4 m water depth. The developed gamma spectroscopy was able to detect radioactivity from a ¹³⁷Cs point source (3.7 kBq) at a distance of 20 cm in water. Moreover, we demonstrated an unmanned radioactivity monitoring system in a real sea by combining unmanned surface vehicle with the developed gamma spectroscopy. A hidden ¹³⁷Cs source (3.07 MBq) was detected by the unmanned system at a distance of 3 m. After successfully testing the developed mobile spectroscopy in an ocean environment, we believe that our proposed system will be an effective solution for mobile real-time marine radioactivity monitoring.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.152-152
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• 2021

The importance of groundwater has long been recognized, but the ground water potential to become contaminated as a result of human activities has only been recognized in recently. Before 1980 it was thought that soils served as filters, preventing harmful substances deposited at the surface from migrating into groundwater. Today it is known that soils have a finite capacity to protect groundwater. It can be contaminated from divers sources. Therefore, Assessment of aquifer vulnerability to pollution is essential for the protection and management of groundwater and land use planning. In this study, we used DRASTIC and AVI for groundwater vulnerability to contamination assessment. the different methods were applied to the southern coastal sedimentary basin of Benin and DRASTIC method was modified in two different steps. First, we modified DRASTIC by adding land use parameter to include the actual pollution sources (DRASTIC_LcLu) and second, classic DRASTIC weights was modified using Shannon's entropy (Entropy weight DRASTIC). The reliability of the applied approaches was verified using nitrate (NO3^-) concentration and by comparing the overall vulnerability maps to the previous researches in the study area and in the world. The results from validation showed that the addition of landcover/land use parameter to the classic DRASTIC helps to improve the method for better definition of the vulnerable areas in the basin and also, the weight modification using entropy improved better the method because Entropy weight DRASTIC_LcLu showed the highest correlation with nitrate concentration in the study basin. In summary the weight modification using entropy approach reduced the uncertainty of the human subjectivity in assigning weights and ratings in the standard DRASTIC.

• Journal of Soil and Groundwater Environment
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• v.28 no.6
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• pp.58-70
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• 2023

The improper management of radioactive waste or accidents caused by natural disasters can result in the release of radioactive materials into the surrounding environment, potentially leading to soil and groundwater contamination by radionuclides. In this study, adsorption-desorption behaviors of the radionuclides (cobalt and strontium) in natural soil, montmorillonite, Mn-PILC, Fe-PILC, and fishbone were investigated. Several models were used to predict adsorption isotherms of radionuclides on various absorbents. Adsorption isotherms of cobalt and strontium in several adsorbents were examined at pH 5.5. The amount of sorbed cobalt and strontium were represented fishbone > natural soil > Mn-PILC > Fe-PILC > montmorillonite and natural soil > Mn-PILC > fishbone > Fe-PILC > montmorillonite, respectively. Adsorption datas were fitted with several models such as Freundlich, Langmuir, Sips, Redlich-Peterson, Khan, and Generalized model. The results of curve fitting showed R²> 0.98 in all of adsorption models, except Sr²⁺ adsorption onto montmorillonite. For modified clays (Mn-PILC, Fe-PILC), it is suggested that, unlike natural soils and fish bones, there are not only single adsorption mechanisms but also adsorption mechanisms based on chemical adsorption and surface charge. In the case of fish bones, due to the relatively higher adsorption capacity than modified clays and its characteristic of significant desorption, it is expected more suitable for the removal of radionuclides in aquatic environments than for the immobilization of radionuclides in soil.

• Journal of Environmental Science International
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• v.33 no.4
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• pp.269-277
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• 2024

Scientific forensic techniques are used to verify environmental impact of groundwater pollution, surface water pollution, air pollution, noise, and vibration according to residents' complaints in connection with construction and civil engineering works. In this study, we investigated the contamination of groundwater and the lowering of the groundwater level in an area surrounding a tunnel excavation site for the Andong-Yeongdeok national road, using a forensic hydrogeological technique. We reviewed the groundwater level and water quality of well GW1 in the area surrounding the tunnel excavation site as well as tunnel construction information and then we analyzed the correlations among the obtained data. Before tunnel excavation, the water level of well GW1 was lower than the tunnel elevation. Considering the relationship between the precipitation, tunnel discharge, tunnel depth, and groundwater level of well GW1, the groundwater flowed from the tunnel to well GW1. Moreover, the tunnel discharge and groundwater levels were not related to each other. The pH of well GW1 was 8.4 before tunnel excavation. During excavation, the pH declined to 8.1-8.2 at the beginning, and increased to 8.8 at the end of the excavation. The fluorine concentration in well GW1 was 2.49 mg/L, 1.91-3.22 mg/L, and 1.7-2.67 mg/L, respectively, before, during, and after the excavation. The sulfate ion concentration was very high, over 2,000 mg/L, before and during the excavation; after the excavation, it was between 200 and 323 mg/L. Turbidity was 1.47, 10.5, and 4.51 NTU before, during, and after tunnel excavation, respectively. Therefore, the excavation of this tunnel is not related to the groundwater quality of well GW1.

• Safety and Health at Work
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• v.15 no.1
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• pp.33-41
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• 2024

Background: Dust generated during the processing of building materials enterprises can pose a serious health risk. The study aimed to compare and analyze the results of ART and the Monte Carlo model for the dust exposure assessment in building materials enterprises, to derive the application scope of the two models. Methods: First, ART and the Monte Carlo model were used to assess the exposure to dust in each of the 15 building materials enterprises. Then, a comparative analysis of the exposure assessment results was conducted. Finally, the model factors were analyzed using correlation analysis and the scope of application of the models was determined. Results: The results show that ART is mainly influenced by four factors, namely, localized controls, segregation, dispersion, surface contamination, and fugitive emissions, and applies to scenarios where the workplace information of the building materials enterprises is specific and the average dust concentration is greater than or equal to 1.5 mg/m³. The Monte Carlo model is mainly influenced by the dust concentration in the workplace of building materials enterprises and is suitable for scenarios where the dust concentration in the workplace of the building materials enterprises is relatively uniform and the average dust concentration is less than or equal to 6mg/m³. Conclusion: ART is most accurate when workplace information is specific and average dust concentration is > 1.5 mg/m³; whereas, The Monte Carlo model is the best when dust concentration is homogeneous and average dust concentration is < 6 mg/m³.

• Journal of Soil and Groundwater Environment
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• v.29 no.3
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• pp.1-13
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• 2024

This study investigated the hydrogeochemical and microbiological characteristics of freshwater on Ulleung Island, a volcanic island in the Ulleung Basin on the East Coast of Korea. The shallow groundwater (CSW, NRGW) and the surface water (SISW) samples are classified as Na-HCO₃ type, reflecting an alkaline rock type and an oxidizing environment due to the influence of a highly permeable pyroclastic rock layer. In contrast, the deep groundwater sample (DMW) is classified as Ca-HCO₃ type, suggesting the influence of deep-sourced carbon dioxide and reducing conditions. Microbial communities in the water samples are generally dominated by Proteobacteria, with the relative abundance of major genera varying depending on water quality and environmental conditions. Network analysis reveals the ecological characteristics of microbial communities adapted to specific environments. The presence of pathogenic genera in the shallow groundwater suggests potential groundwater contamination, necessitating appropriate management to ensure its use as drinking water or domestic water. The findings of this study provide valuable insights into the ecological characteristics of Ulleung Island's groundwater resources and can inform future groundwater management strategies.