• Journal of Dairy Science and Biotechnology
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• v.40 no.3
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• pp.103-109
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• 2022

Lactic acid bacteria with antibacterial activity can be effectively used as probiotics to inhibit the growth of harmful bacteria that cause food spoilage or food poisoning. In this study, Pediococcus pentosaceus M132-2, isolated from soybean paste, was analyzed for its effects on three major contaminating fungi. M132-2 was confirmed to exert antifungal activity by inhibiting the growth of all three fungi tested. In addition, M132-2 displayed excellent salt resistance and low temperature tolerance. Thus M132-2 can survive at the salinity level in cheese and at the low temperatures used in the aging process. Finally, when supernatant from an M132-2 culture was applied to Gouda cheese, the growth of contaminating fungi was significantly inhibited. Consequently, M132-2 may be useful for the prevention of spoilage of various foods, including cheese.

• The Plant Pathology Journal
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• v.37 no.3
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• pp.215-231
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• 2021

Brown leaf spot disease caused by Nigrospora guilinensis on Phellodendron chinense occurs in a large area in Dayi County, Chengdu City, Sichuan Province, China each year. This outbreak has severely reduced the production of Chinese medicinal plants P. chinense and caused substantial economic losses. The bacterial isolate JKB05 was isolated from the healthy leaves of P. chinense, exhibited antagonistic effects against N. guilinensis and was identified as Bacillus megaterium. The following fermentation medium and conditions improved the inhibitory effect of B. megaterium JKB05 on N. guilinensis: 2% glucose, 0.1% soybean powder, 0.1% KCl, and 0.05% MgSO₄; initial concentration 6 × 10⁶ cfu/ml, and a 42-h optimal fermentation time. A composite of 0.1% nano-SiO₂ JKB05 improved the thermal stability, acid-base stability and ultraviolet resistance by 16%, 12%, and 38.9%, respectively, and nano-SiO₂ was added to the fermentation process. The best formula for the wettable powder was 35% kaolin, 4% polyethylene glycol, 8% Tween, and 2% humic acid. The following quality test results for the wettable powder were obtained: wetting time 87.0 s, suspension rate 80.33%, frequency of microbial contamination 0.08%, pH 7.2, fineness 95.8%, drying loss 1.47%, and storage stability ≥83.5%. A pot experiment revealed that the ability of JKB05 to prevent fungal infections on P. chinense increased considerably and achieved levels of control as high as 94%. The use of nanomaterials significantly improved the ability of biocontrol bacteria to control this disease.

• Analytical Science and Technology
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• v.35 no.1
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• pp.15-23
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• 2022

Food delivery is gaining popularity due to changes in lifestyle and dietary patterns. However, packages used to delivery food may contain contaminants including heavy metals, or additives added during manufacturing process which may migrate into food during processing and transportation. In this study, a total of 58 food packages for delivery were collected and tested for migration of heavy metals (lead, cadmium and arsenic), bisphenol A and phenol into food simulants. The method was validated by evaluating linearity of calibration curve, limit of detection, limit of quantification, recovery and precision. Result of heavy metal migration showed that lead was the most frequently migrated metal and the highest concentration was detected in a polypropylene sample. Although there are no specific migration limits for bisphenol A and phenol in packaging materials tested in this study, migrations of bisphenol A and phenol were detected in some packages. This may due to contamination or additives added during manufacture of packages. Risk (%) was calculated to analyze the risk associated with the migration of heavy metals, bisphenol A and phenol, and was always below 1 %. These results showed that food packages for delivery are safe in terms of heavy metals, bisphenol A and phenol migration.

• Journal of the Korean Society of Radiology
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• v.16 no.2
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• pp.185-194
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• 2022

The decommission of nuclear legacy sites, which have been contaminated by previous activities such as uranium mining & milling as well as nuclear tests, has started to gain global attention. Within the Korean peninsula, Republic of Korea(ROK)has had experience in dismantling research reactors. For the Democratic People's Republic of Korea(DPRK), the possibility of nuclear activities being implemented and operations records being managed without consideration of the latest nuclear safety regulations are high. Hence, the chances of DPRK's sites remaining as nuclear legacy is also high. This study investigates approaches and considerations that needs to be taken in account in the event of a nuclear legacy site occurrence, reviewing its international cases for the solution of the legacy sites. The regulation, process of optimization, and stakeholder engagement for a nuclear legacy site should be considered in such an event. Developing legacy site response plans can be used to prevent future legacy site occurrences.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.3
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• pp.601-607
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• 2024

The discharge of oily wastewater into water bodies and soil poses a serious hazard to the environment and public health. Various conventional techniques have been employed to treat oil-water mixtures and emulsions; Unfortunately, these approaches are frequently expensive, time-consuming, and unsatisfactory outcomes. Porous materials and adsorbents are commonly used for purification, but their use is limited by low separation efficiencies and the risk of secondary contamination. Recent advancements in nanotechnology have driven the development of innovative materials and technologies for oil-contaminated wastewater treatment. Nanomaterials can offer enhanced oil-water separation properties due to their high surface area and tunable surface chemistry. The fabrication of nanofiber membranes with precise pore sizes and surface properties can further improve separation efficiency. Notably, novel technologies have emerged utilizing nanomaterials with special surface wetting properties, such as superhydrophobicity, to selectively separate oil from oil-water mixtures or emulsions. These special wetting surfaces are promising for high-efficiency oil separation in emulsions and allow the use of materials with relatively large pores, enhancing throughput and separation efficiency. In this study, we introduce a facile and scalable method for fabrication of superhydrophobic-superoleophilic felt fabrics for oil/water mixture and emulsion separation. AlN nanopowders are hydrolyzed to create the desired microstructures, which firmly adhere to the fabric surface without the need for a binder resin, enabling specialized wetting properties. This approach is applicable regardless of the material's size and shape, enabling efficient separation of oil and water from oil-water mixtures and emulsions. The oil-water separation materials proposed in this study exhibit low cost, high scalability, and efficiency, demonstrating their potential for broad industrial applications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.1
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• pp.46-63
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• 2024

One of the biggest dangers in the globe is water contamination. Water is a necessity for human survival. In most cities, the digging of borewells is restricted. In some cities, the borewell is allowed for only drinking water. Hence, the scarcity of drinking water is a vital issue for industries and villas. Most of the water sources in and around the cities are also polluted, and it will cause significant health issues. Real-time quality observation is necessary to guarantee a secure supply of drinking water. We offer a model of a low-cost system of monitoring real-time water quality using IoT to address this issue. The potential for supporting the real world has expanded with the introduction of IoT and other sensors. Multiple sensors make up the suggested system, which is utilized to identify the physical and chemical features of the water. Various sensors can measure the parameters such as temperature, pH, and turbidity. The core controller can process the values measured by sensors. An Arduino model is implemented in the core controller. The sensor data is forwarded to the cloud database using a WI-FI setup. The observed data will be transferred and stored in a cloud-based database for further processing. It wasn't easy to analyze the water quality every time. Hence, an Optimized Neural Network-based automation system identifies water quality from remote locations. The performance of the feed-forward neural network classifier is further enhanced with a hybrid GA- PSO algorithm. The optimized neural network outperforms water quality prediction applications and yields 91% accuracy. The accuracy of the developed model is increased by 20% because of optimizing network parameters compared to the traditional feed-forward neural network. Significant improvement in precision and recall is also evidenced in the proposed work.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.19 no.2
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• pp.102-108
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• 2023

A Chloride-induced stress corrosion cracking (CISCC) of austenite stainless steel in dry cask storage system (DCSS) can occur with extending service time than originally designed. Cold spray coating (CSC) not only form a very dense microstructure that can protect from corrosive environments, but also can generate compressive stress on the surface. This characteristic of CSC process is very helpful to increase the resistance for CISCC. CSC with several powders, such as 304L, 316L and Ni can be optimized to form very dense coating layer. In addition, the impact energy generated as the CSC powder collides with the surface of base metal at a speed of Mach 2 or more can remove the residual tensile stress of welding area and serve the compress stress. CSC layers include no oxidation and no contamination with under 0.2% porosity, which is enough to protect from the penetration of corrosive chloride. Therefore, the CSC coating layer can be accompanied by a function that can be disconnected from the corrosive environment and an effect of improving the residual stress that causes CISCC, so the canister's CISCC resistance can be increased.

• Journal of Radiation Industry
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• v.17 no.4
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• pp.457-469
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• 2023

The clearance level by nuclide is announced by the Nuclear Safety and Security Commission. However, the clearance level of uranium existing in nature has not been announced, and research is needed. Therefore, the purpose of this study was to evaluate the clearance level of uranium nuclides appropriate to domestic conditions preliminary. For this purpose, this study selected major processes for recycling metal wastes and analyzed the exposure scenarios and major input factors by investigating the characteristics of each process. Then, the radiation dose to the general public and workers was evaluated according to the selected scenarios. Finally, the results of the radiation dose per unit radioactivity for each scenario were analyzed to derive the clearance level of uranium in metal waste. The results of the radiation dose assessment for both the general public and workers per unit radioactivity of uranium isotopes were shown to meet the allowable dose (individual dose of 10 µSv y^-1 and collective dose of 1 Man-Sv y^-1) regulated by the Nuclear Safety and Security Commission. The most conservative scenarios for volumetric and surface contamination were evaluated for the handling of the slag generated after the melting of the metal waste and the direct reuse of the contaminated metal waste into the building without further disposal. For each of these scenarios, the radioactivity concentration by uranium isotope was calculated, and the clearance level of uranium in metal waste was calculated through the radioactivity ratio by enrichment. The results of this study can be used as a basic data for defining the clearance level of uranium-contaminated radioactive waste.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.197-202
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• 2010

Purpose: Recently, many hospitals have been tried to increase the satisfaction of the outpatients through blood-gathering, exam, result notice and process in a day. Each laboratory has been used the automatic equipment for the rapid requests of the result notice and the increase of the reliability and efficiency. Current automatic equipments that have been limited short TAT(Turn-Around Time)because of the restricted batch lists and 1 tip-5 detectors. The Gamma Pro which is made in Korea to improve the shortcomings of existing automation equipment, complemented with capacity to perform a wide range of domestic automation equipment. In this study, we evaluated the usefulness and reliability of short TAT by comparing Gamma Pro with current automatic equipment. Materials and Methods: We studied the correlation between Gamma Pro and RIA-mat 280 using the respective 100 specimens of low or high density to the patients who were requested the thyroid hormone test (Total T3, TSH and Free T4) in Samsung Medical Center Sep. 2009. To evaluate the split-level Gamma Pro, First, we measured accuracy and carry over on the tips. Second, the condition of optimal incubation was measured by the RPM (Revolution Per Minute) and revolution axis diameter on the incubator. For the analysis for the speed of the specimen-processing, TAT was investigated with the results in a certain time. Result: The correlation coefficients (R2) between the Gamma Pro and RIA-mat 280 showed a good correlation as T3 (0.98), TSH (0.99), FT4 (0.92). The coefficient of variation (C.V) and accuracy was 0.38 % and 98.3 % at tip 1 and 0.39 % and 98.6 % at tip 2. Carry over showed 0.80 % and 1.04% at tip 1 and tip 2, respectively. These results indicate that tips had no effect on carry over contamination. At the incubator condition, we found that the optimal condition was 1.0mm of diameter at 600RPM in 1.0mm and 1.5mm of at 500RPM or 1.0mm and 1.5 mm of diameter at 600 RPM. the Gamma Pro showed that the number of exam times were increased as maximum 20 times/day comparing to 6 times/day by current automatic equipment. These results also led to the short TAT from 4.20 hour to 2.19 hours in whole processing. Conclusion: The correlation of between the Gamma Pro and RIA-mat 280 was good and has not carry over contamination in tips. The domestic automation equipment (Gamma Pro) decreases the TAT in whole test comparing to RIA-280. These results demonstrate that Gamma Pro has a good efficiency, reliability and practical usefulness, which may contribute to the excellent skill to process the large scale specimens.

• Journal of the East Asian Society of Dietary Life
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• v.13 no.1
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• pp.25-38
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• 2003

This study was conducted to establish the microbiological quality standards applying the HACCP system on sushi items of Japanese restaurant in Korea. The study evaluated hygienic conditions of kitchen and workers, pH time-temperature relationship, and microbial assessments during whole process of sushi making in 2001. Overall hygienic conditions were normal for both kitchen and for workers by 3 point scale, but hygienic controls against the cross-contamination were still needed. Each process of sushi making was performed under the risk of microbial contamination, since pH value of most of ingredients was over pH 4.6 and also production time(3.5~6 hrs) were long enough to cause problems. Microorganisms were high enough to cause foodborne illness ranged 8.0$\times$10$^2$~3.3$\times$10$^{6}$ CFU/g of TPC and 1.0$\times$10$^1$~1.6$\times$10$^3$CFU/g of coliforms, although TPC, coliforms and Staphylcoccus aureus were within the standard limits (TPC 10$^2$~10$^{6}$ CFU/g, coliforms 10$^3$CFU/g). However, Salmonella and Vibrio parahaemolyticus were not detected. High populations TPC and coliforms were also found in the cooks' hands and cooking utensils(TPC 10$^2$~10$^{6}$ CFU/100cm$^2$and Coliforms 10$^1$~10$^3$CFU/100cm$^2$). Based on the CCP decision tree analysis, the CCPs were the holding steps far six sushi production line except the tuna and the thawing step for tuna sushi. In conclusion, overall state of sushi production was fairly good but much improvement was still needed.