• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.6
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• pp.511-518
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• 2013

Steam Generator (SG) tube, as a barrier isolating the primary coolant system from the secondary side of nuclear power plants (NPP), must maintain the structural integrity for the public safety and their efficient power generation. So, SG tubes are subject to the periodic examination and the repairs if needed so that any defective tubes are not in service. Recently, corrosion related degradations were detected in the tubes of the domestic OPR-1000 NPP, as a form of axially oriented outer diameter stress corrosion cracking (ODSCC). According to the studies on the factors causing the heat fouling as well as developing corrosion cracking, densely scaled deposits on the secondary side of the SG tubes are mainly known to be problematic causing the adverse impacts against the soundness of the SG tubes [1]. Therefore, the processes of various cleaning methods efficiently to dissolve and remove the deposits have been applied as well as it is imperative to maintain the structural integrity of the tubes after exposing to the cleaning agent. So qualification test (QT) should be carried out to assess the perfection of the chemical cleaning and QT is to apply the processes and to do ECT. In this paper, the chemical cleaning processes to dissolve and remove the scaled deposits are introduced and results of ECT on the artificial crack specimens to determine the effectiveness of those processes are represented.

• Journal of Korean Neurosurgical Society
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• v.58 no.5
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• pp.494-498
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• 2015

Objective : To describe a novel spinous process-splitting hemilaminoplasty technique for the surgical treatment of intradural and posterior epidural lesions that promotes physiological restoration. Methods : The spinous process was split, the area of the facet lamina junction was drilled, and en bloc hemilaminectomy was then performed. After removing intradural and posterior epidural lesions, we fitted the previously en bloc-removed bone to the pre-surgery same shape, and held it in place with non-absorbable sutures. Surgery was performed on 16 laminas from a total of nine patients between 2011 and 2014. Bony union of the reconstructed lamina was assessed using computed tomography (CT) at 6 months after surgery. Results : Spinous process-slitting hemilaminoplasty was performed for intradural extramedullary tumors in eight patients and for ossification of the ligament flavum in one patient. Because we were able to visualize the margin of the ipsilateral and contralateral dura, we were able to secure space for removal of the lesion and closure of the dura. None of the cases showed spinal deformity or other complications. Bone fusion and maintenance of the spinal canal were found to be perfect on CT scans. Conclusion : The spinous process-splitting hemilaminoplasty technique presented here was successful in creating sufficient space to remove intradural and posterior epidural lesions and to close the dura. Furthermore, we were able to maintain the physiological barrier and integrity after surgery because the posterior musculature and bone structures were restored.

• BMB Reports
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• v.49 no.4
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• pp.214-219
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• 2016

A nucleosomal protein, high mobility group box 1 (HMGB1) is known to be a late mediator of sepsis. Dabrafenib is a B-Raf inhibitor and initially used for the treatment of metastatic melanoma therapy. Inhibition of HMGB1 and renewal of vascular integrity is appearing as an engaging therapeutic strategy in the administration of severe sepsis or septic shock. Here, we examined the effects of dabrafenib (DAB) on the modulation of HMGB1-mediated septic responses. DAB inhibited the release of HMGB1 and downregulated HMGB1-dependent inflammatory responses by enhancing the expressions of cell adhesion molecules (CAMs) in human endothelial cells. In addition, treatment with DAB inhibited the HMGB1 secretion by CLP and sepsis-related mortality and pulmonary injury. This study demonstrated that DAB could be alternative therapeutic options for sepsis or septic shock via the inhibition of the HMGB1 signaling pathway.

• Journal of Veterinary Clinics
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• v.30 no.4
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• pp.283-287
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• 2013

Canine skin is a highly dynamic organ that is constantly adapted to changes in its environment. It provides structural, sensory, immunologic, and physiologic functions and contributes an essential barrier function against potential environmental insults. We assessed the changes of canine skin hydration, pH, and protein contents by noninvasive method according to the frequency of application with canine commercial shampoo. Canine commercial shampoo was applied topically every other day, 5 days, and 8 days on different sites, respectively in 8 dogs. Saline-applied site was as a control. Skin hydration was increased and skin surface pH was decreased significantly in canine commercial shampoo-applied site every other day (p < 0.05). Also, skin protein concentration measured by D-squame$^{(R)}$ tape stripping method was increased significantly in canine commercial shampoo-applied site every other day (p < 0.05). There were alterations on every 5 days and 8 days, but not significantly. These results may be recognized that the frequent use of canine commercial shampoo cause abnormalities of the skin barrier function and alteration of stratum corneum integrity/cohesion. Consequently it was suggested that bathing the dog with canine commercial shampoo was appropriate every 5 or 8 days.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.3
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• pp.219-230
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• 2017

This study was conducted to predict and evaluate the uncertainty of safety after closure of the second phase surface disposal facility of the Gyeongju intermediate and low level repository in Korea. In this study, four scenarios are developed considering both intact and degraded states of multi-layered covers and disposal containers; also, the fluid flow by a rainfall into the disposal facility is simulated. The rainfall conditions are implemented based on the monthly average data of the past 30 years (1985~2014); the simulation period is 300 years, the management period regulated by institutional provisions. As a result of the evaluation of the basic scenario, in which the integrity of both of the containers and the covers is maintained, it was confirmed that penetration of rainfall does not completely saturate the inside of the disposal facility. It is revealed that the multiple cover layers and concrete containers effectively play the role of barrier against the permeation of rainfall.

• Journal of Microbiology and Biotechnology
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• v.29 no.6
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• pp.863-876
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• 2019

Farm animals such as piglets are often affected by environmental stress, which can disturb the gut ecosystem. Antibiotics were commonly used to prevent diarrhea in weaned piglets, but this was banned by the European Union due to the development of antibiotic resistance. However, the use of probiotics instead of antibiotics may reduce the risk posed by pathogenic microorganisms and reduce the incidence of gastrointestinal diseases. Therefore, this study was conducted to investigate the effects of Lactobacillus casei Zhang on the mechanical barrier and immune function of early-weaned piglets infected using Escherichia coli K88 based on histomorphology and immunology. Fourteen-day-old weaned piglets were divided into a control group and experimental groups that were fed L. casei Zhang and infected with E. coli K88 with or without prefeeding and/or postfeeding of L. casei Zhang. The L. casei Zhang dose used was $10^7CFU/g$ diet. Jejunum segments were obtained before histological, immunohistochemical, and western blot analyses were performed. In addition, the relative mRNA expression of toll receptors and cytokines was measured. Piglets fed L. casei Zhang showed significantly increased jejunum villus height, villus height-crypt depth ratio, muscle thickness, and expression of proliferating cell nuclear antigen and tight junction proteins ZO-1 and occludin. The use of L. casei Zhang effectively reduced intestinal inflammation after infection. We found that L. casei Zhang feeding prevented the jejunum damage induced by E. coli K88, suggesting that it may be a potential alternative to antibiotics for preventing diarrhea in early-weaned piglets.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.412-425
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• 2012

Concrete Soil Erosion Control Dam, which blocks flow of debris flow in torrential stream, are reported to lose expected functions due to structural failure and collapses, caused by poor construction, material deterioration and external impacts. In this paper, an integrity assessment technique for debris barriers was proposed, which allows preliminary detection of problems inherent in debris barriers. The proposed integrity assessment technique is a non-destructive method based on SASW method, one of surface-wave tests. In this paper, a practical procedure and analysis guidelines in applying the SASW technique to debris barrier was proposed and its validity was verified using five decrepit debris barriers older than 20-year old. As a result, the SASW method was validated for the reliable grade evaluation method for concrete soil erosion control dam, and the resulting grades turned out to agree with the results determined by Sabang Associations.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.535-542
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• 2015

A reactor containment acts as a final barrier to prevent leakage of radioactive material due to the possible reactor accidents into external environment. Because of the functional importance of the containment building, the SIT(Structural Integrity Test) for containments shall be performed to evaluate the structural acceptability and demonstrate the quality of construction. In this paper, numerical analyses are presented, which simulate the results obtained from the SIT for a prestressed concrete(PSC) structure. A sophisticate structural analysis model is developed to simulate the structural behavior during the SIT properly based on various preliminary analysis results considering contact condition among structural elements. From the comparison of the analysis and test results based on the acceptance criteria of ASME CC-6000, it can be concluded that the construction quality of the containment has been well maintained and the acceptable performance of new design features has been verified.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.523-533
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• 2015

A reactor containment acts as a final barrier to prevent leakage of radioactive material due to the possible reactor accidents into external environment. Because of the functional importance of the containment building, the SIT(Structural Integrity Test) for containments shall be performed to evaluate the structural acceptability and demonstrate the quality of construction. An initial numerical analysis was performed to simulate the results obtained from the SIT for a prestressed concrete(PSC) structure. But the analysis results by the initial model expected smaller displacements than the measured ones by 30% at some locations. Accordingly, the research and development to improve the initial model to corelate the measured results of the SIT more properly have been performed. In this paper, the effects of the loss of concrete due to duct for tendons and the contact of duct and tendons in un-bonded tendon system are mainly evaluated based on the preliminary analysis results. In addition, the importances of the proper definition of mesh connectivity among structural elements of concrete, liner plates, rebars and tendons are discussed.

• Tunnel and Underground Space
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• v.24 no.6
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• pp.405-417
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• 2014

In a high-level waste repository, the gap fill of the engineered barrier is an important component that influences the performance of the buffer and backfill. This paper reviewed the overseas status of R&D on the gap fill used engineered barriers, through which the concept of the gap fill, manufacturing techniques, pellet-molding characteristics, and emplacement techniques were summarized. The concept of a gap fill differs for each country depending on its disposal type and concept. Bentonite has been considered a major material of a gap fill, and clay as an inert filler. Gap fill was used in the form of pellets, granules, or a pellet-granule blend. Pellets are manufactured through one of the following techniques: static compaction, roller compression, or extrusion-cutting. Among these techniques, countries have focused on developing advanced technologies of roller compression and extrusion-cutting techniques for industrial pellet production. The dry density and integrity of the pellet are sensitive to water content, constituent material, manufacturing technique, and pellet size, and are less sensitive to the pressure applied during the manufacturing. For the emplacement of the gap fill, pouring, pouring and tamping, and pouring with vibration techniques were used in the buffer gap of the vertical deposition hole; blowing through the use of shotcrete technology and auger placement and compaction techniques have been used in the gap of horizontal deposition hole and tunnel. However, these emplacement techniques are still technically at the beginning stage, and thus additional research and development are expected to be needed.