• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.826-833
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• 2022

A two-phase natural circulation test using SMART integral test loop (SMART-ITL) was conducted to explore thermo-hydraulic phenomena of two-phase natural circulation in the SMART reactor. Specifically, the test examined the natural circulation in the primary loop under a stepwise coolant inventory loss while keeping the core power constant at 5% of the scaled full power. Based on the test results, three flow regimes were observed: single-phase natural circulation (SPNC), two-phase natural circulation (TPNC), and boiler-condenser natural circulation (BCNC). The flow rate remained steady in the SPNC, slightly increased in the TPNC, and dropped abruptly and maintained in the BCNC. Using a natural circulation flow map, the natural circulation characteristic in the SMART-ITL was compared with those in pressurized water reactor simulators. In the SMART-ITL, a BCNC regime appeared instead of siphon condensation and reflux condensation regimes because of the use of once-through steam generators.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.3930-3943
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• 2021

To improve the capability of the SAS4A code, which simulates the initiating phase of core disruptive accidents for MOX-fueled Sodium-cooled Fast Reactors (SFRs), the authors have investigated in detail the physical phenomena under unprotected loss-of-flow (ULOF) conditions in a previous paper (Kawada and Suzuki, 2020) [1]. As the conclusion of the last article, fuel stub motion, in which the residual fuel pellets would move toward the core central region after fuel pin disruption, was identified as one of the key phenomena to be appropriately simulated for the initiating phase of ULOF. In the present paper, based on the analysis of the experimental data, the behaviors related to the stub motion were evaluated and quantified by the author from scratch. A simple model describing fuel stub motion, which was not modeled in the previous SAS4A code, was newly proposed. The applicability of the proposed model was validated through a series of analyses for the CABRI experiments, by which the stub motion would be represented with reasonable conservativeness for the reactivity evaluation of disrupted core.

• Journal of People, Plants, and Environment
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• v.23 no.2
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• pp.171-178
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• 2020

The present study was conducted to determine the effects of electron beam irradiation on the postharvest quality of cut flowers. Cut flowers were irradiated with electron beam at 100, 200, 400, 600, 800, 1,000, and 2,000 Gy with a 10 MeV linear electron beam accelerator to evaluate their irradiation tolerance. Postharvest quality was determined by monitoring fresh weight loss, flower longevity, flower diameter, flowering rate, visual quality of flowers and leaves, and chlorophyll content. Cut flowers showed a radiation-induced damage with increasing the irradiation dose. Flower longevity and fresh weight of cut flowers decreased when the irradiation dose was increased. Flower bud opening was also inhibited in a dose-dependent manner. The effective irradiation doses for 10% reduction of postharvest quality (ED₁₀) values were 144.4, 451.6, and 841.2 Gy in the 'Medusa' lily, 'Montezuma' carnation, and 'Rosina White' eustoma, respectively. Although tolerance of cut flowers to electron beam irradiation vary according to species, cultivars, or maturity stage conditions, it is conceivable that 'Montezuma' carnation and 'Rosina White' eustoma could be tolerated and maintained overall postharvest quality up to 400 Gy, the generic irradiation dose approved by the Animal and Plant Health Inspection Service (APHIS) and the International Plant Protection Convention (IPPC) for postharvest phytosanitary treatments.

• The Korean Journal of Food And Nutrition
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• v.35 no.4
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• pp.231-238
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• 2022

As cholesterol intake increases, the prevalence of hypercholesterolemia is also increasing. With increasing food selection considering health, consumption of functional foods that can help health is also expected to increase. Ginger is rich in minerals (such as potassium and magnesium) and antioxidants. Antioxidants have been shown to be effective in lowering blood cholesterol levels. Therefore, we would like to produce madeleines helpful for hypercholesterolemia by adding ginger syrup to madeleines recently consumed as desserts. In this study, the quality and characteristics were analyzed after making madeleine by adding ginger syrup at 0%, 5%, 10%, 15%, and 20%. Baking loss was significantly reduced as the addition amount increased (p<0.001). The pH value decreased as the addition amount increased except for the 5% added group (p<0.001). The b value of the chromaticity showed a significant increase from the 5% addition group (p<0.001). Regarding textures, hardness (p=0.006), gumminess (p=0.001), and chewiness (p=0.001) all decreased as the addition amount increased. Regarding antioxidant activity, polyphenol, DPPH, and ABTS values were significantly increased as addition amount increased (p<0.001). Consequently, Madeleine using ginger syrup rich in antioxidants is expected to help health.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.1
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• pp.1-6
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• 2022

Among the 13 species of otters in the world, only one Eurasian otter (Lutra lutra) is found in South Korea. In the Korean Peninsula, otter pelts were historically valuable and expensive commodities used for international trade, and otters have long been poached as hunting animals. Recent rapid economic development in South Korea has increased habitat fragmentation and loss, creating a continuing threat to the natural environment. Otters live only in the area of rivers and streams as a family group and are territorial (linear habitat). Due to these limited conditions of otter habitat, the population size of otter is lower than that of onshore mammals. According to recent research, DNA analyses using microsatellite markers have shown that only approximately 7-21 otter individuals inhabit river systems for a length of 50-230 km. Korea's urban streams are associated with many threats that hinder otters from inhabiting them. Many areas around the urban streams are surrounded by high concrete riverbanks, and the risk of roadkill is also high. Nevertheless, ecological restoration projects in the urban rivers will contribute greatly to the stable inhabitation of otters. Detailed otter conservation strategies, such as the elimination of threat factors, improvement of habitat environment, and restoration of food resources and shelter, will provide a positive restoration effect on otter and river ecosystems as well.

• Journal of Convergence Korean Medicine
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• v.5 no.1
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• pp.25-44
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• 2023

Objectives: Gaming disorder has been viewed as a disease in the DSM-5 and ICD-11. Its essential symptoms are loss of control over gaming, gaming becoming a markedly prioritized activity over other activities of daily living, and continued and excessive use of gaming despite negative problems occurring. Methods: Children and adolescents are especially vulnerable to gaming disorder because the striatal pathways related to reward develop earlier than the control regions of the prefrontal cortex. It is also associated with decreased dopamine D2 receptors. Addiction is related to 'want' and is explained by incentive-sensitization. In addition, allostasis, in which homeostasis is continuously achieved at a new target value, is also related to gaming disorder. In addition, personality causes, unchangeable factors, and external factors can influence on the onset of gaming disorder. Results: Prevention is the best solution for gaming disorder, and the role of parents is important. For gaming disorder, bupropion is used, cognitive-behavioral therapy and family-based therapy are also beneficial. Herbal medicine treatment such as Antler velvet and ginseng can be effective. Electroacupuncture and acupuncture using PC6, SP6, and LR3 has a correlation with relieving Internet craving. Ear-acupuncture was also effective in treating addiction. Conclusion: Psychologically, 'want' is an intense longing for reward and motivation, and is related to addiction. This 'want' may rather be related to avoidance, and game addiction in children and adolescents may be due to wanting to escape from academic stress or avoidance of comparison. Therefore, the importance of 'like', which gives pleasure in itself, increases. It can also be explained with Sasang Constitutional Medicine.

• Archives of Plastic Surgery
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• v.50 no.5
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• pp.523-528
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• 2023

The Gustilo IIIB tibiofibular fractures often result in long bone loss and extensive soft tissue defects. Reconstruction of these complex wounds is very challenging, especially when it includes long bone grafts, because the donor site is limited. We describe our experience using a set of chimeric ipsilateral vascularized fibula grafts with a thoracodorsal artery perforator free flap to reconstruct the traumatic tibia defects. A 66-year-old male suffered a severe comminuted tibia fracture and segmented fibula fracture with large soft tissue defects as a result of a traffic accident. He also had an open calcaneal fracture with soft tissue defects on the ipsilateral side. All the main vessels of the lower extremity were intact, and the cortical bone defect of the tibia was almost as large as the fractured fibula segment. We used an ipsilateral vascularized fibula graft to reconstruct the tibia and a thoracodorsal artery perforator flap to resurface the soft tissue, using the distal ends of peroneal vessels as named into sequential chimeric flaps. After 3 weeks, the calcaneal defect was reconstructed with second thoracodorsal artery perforator free flap. Reconstruction was successful and allowed rapid rehabilitation because of reduced donor site morbidity.

• Archives of Obesity and Metabolism
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• v.2 no.2
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• pp.45-53
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• 2023

Despite the emergence of obesity as a significant public health concern, artificial sweeteners have made their way into various food products due to the perception, that they serve as substitutes for sugar. Artificial sweeteners are used to supposedly achieve weight management and health improvement. However, their efficacy and safety remain debatable. Commonly used artificial sweeteners include aspartame, acesulfame potassium, saccharin, and sucralose. This article discusses the effects of artificial sweetener consumption on weight loss, appetite regulation, blood glucose control, and gut microbiota. Research findings, concerning the consumption of artificial sweeteners and their association with body weight, have shown inconsistencies between randomized controlled trials and cohort studies. Studies, comparing artificial sweeteners to sugar, have reported no significant differences in satiety. Although artificial sweeteners have no calories, they can affect blood sugar levels through the cephalic phase insulin response. A recent study suggested that artificial sweeteners influenced the occurrence of diabetes. Due to limitations in the study design, excluding diabetes-influencing factors was not feasible. The evidence showed that artificial sweeteners harbored potential health risks, necessitating further investigation. According to recent studies, the consumption of artificial sweeteners was associated with gut microbiota changes and individual blood sugar responses. It is important to note that artificial sweeteners cannot be considered safe alternatives to sugar, and further research is required.

• Journal of The Korean Astronomical Society
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• v.56 no.2
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• pp.149-157
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• 2023

The propagation speed of a circumstellar pattern revealed in the plane of the sky is often assumed to represent the expansion speed of the wind matter ejected from a post-main-sequence star at the center. We point out that the often-adopted isotropic wind assumption and the binary hypothesis as the underlying origin for the circumstellar pattern in the shape of multilayered shells are, however, mutually incompatible. We revisit the hydrodynamic models for spiral-shell patterns induced by the orbital motion of a hypothesized binary, of which one star is losing mass at a high rate. The distributions of transverse wind velocities as a function of position angle in the plane of the sky are explored along viewing directions. The variation of the transverse wind velocity is as large as half the average wind velocity over the entire three dimensional domain in the simulated models investigated in this work. The directional dependence of the wind velocity is indicative of the overall morphology of the circumstellar material, implying that kinematic information is an important ingredient in modeling the snapshot monitoring (often in the optical and near-infrared) or the spectral imaging observations for molecular line emissions.

• Clinical Endoscopy
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• v.56 no.6
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• pp.681-692
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• 2023

In general, gastroesophageal reflux disease (GERD) is diagnosed clinically based on typical symptoms and/or response to proton pump inhibitor treatment. Upper gastrointestinal endoscopy is reserved for patients presenting with alarm symptoms, such as dysphagia, odynophagia, significant weight loss, gastrointestinal bleeding, or anorexia; those who meet the criteria for Barrett's esophagus screening; those who report a lack or partial response to proton pump inhibitor treatment; and those with prior endoscopic or surgical anti-reflux interventions. Newer endoscopic techniques are primarily used to increase diagnostic yield and provide an alternative to medical or surgical treatment for GERD. The available endoscopic modalities for the diagnosis of GERD include conventional endoscopy with white-light imaging, high-resolution and high-magnification endoscopy, chromoendoscopy, image-enhanced endoscopy (narrow-band imaging, I- SCAN, flexible spectral imaging color enhancement, blue laser imaging, and linked color imaging), and confocal laser endomicroscopy. Endoscopic techniques for treating GERD include esophageal radiofrequency energy delivery/Stretta procedure, transoral incisionless fundoplication, and endoscopic full-thickness plication. Other novel techniques include anti-reflux mucosectomy, peroral endoscopic cardiac constriction, endoscopic submucosal dissection, and endoscopic band ligation. Currently, many of the new endoscopic techniques are not widely available, and their use is limited to centers of excellence.