• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.573-582
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• 2021

In this study, a series of processes for evaluating the effective protection against barriers that should be equipped in institutions that perform reliability tests on high-risk ammunition, such as high-explosive ammunition, were introduced. The impact that high-explosive bombs can have on personnel includes damage to the eardrum and lungs caused by explosion overpressure and penetrating wounds that can be received by fragments generated simultaneously with the explosion. Therefore, a high-explosive with COMP B explosives as its contents were set up, and an explosion protection theory investigation to calculate the degree of damage, numerical calculations and simulations were performed to verify the protection power. A numerical calculation revealed the maximum explosion overpressure on the protective wall when the high-explosive exploded and the penetration force of the fragment against a 50 mm-thick protective wall to be 77.74 kPa and 41.34 mm, respectively. In the simulation verification using AUTODYN, the maximum explosion overpressures affecting the firewall and personnel were 56.68 kPa and 18.175 kPa, respectively, and the penetration of fragments was 35.56 mm. This figure is lower than the human damage limit, and it was judged that the protective power of the barrier would be effective.

• Korean Journal of Microbiology
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• v.51 no.3
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• pp.241-248
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• 2015

Although studies on probiotics have been performed mostly with viable microbes, the beneficial functions of dead or heat-killed form of probiotic strains have also been examined. In this study, live and heat-killed forms of Lactobacillus acidophilus CBT LA1 were investigated in vitro and in vivo to evaluate the properties necessary for gut barrier protection. Cell surface hydrophobicity (CSH), autoaggregation (AA), cell adhesion, and lipopolysaccharide (LPS)-binding properties were evaluated. In addition, the suppressive effect on LPS-induced interleukin (IL)-8 expression was investigated in HT-29 cells. To identify optimal conditions for CBT LA1 to adhere to HT-29 cells, CBT LA1 cells were heat-treated at 80, 85, 90, 95, 100, or $121^{\circ}C$ for 10 min; cells treated at $80^{\circ}C$ for 10 min showed the highest adhesion. Heat-killed bacteria at $80^{\circ}C$ showed higher levels of LPS-binding, CSH, AA, adhesion to HT-29, and suppression of IL-8 expression than did live CBT LA1. In vivo imaging was performed to evaluate the ability of live or heat-killed CBT LA1 to remove LPS from the intestine in a rat model of infection. At 16 h after infection, fluorescence from FITC-conjugated LPS had mostly disappeared from the intestine of the rats administered with live or heat-killed CBT LA1; the effect was greater with heat-killed CBT LA1 at $80^{\circ}C$. These results suggest that heat-killed CBT LA1 as well as its live form can be applied as a pharmabiotic for protection of the gut barrier.

• Journal of the Korean Geotechnical Society
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• v.35 no.11
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• pp.25-36
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• 2019

The safety barrier is installed on road embankment to prevent vehicles from falling into road side slope. Among the safety barrier, flexible guardrails are usually installed. The flexible guardrail generally consists of a protection cross-beam and supporting in-line piles. These guardrail piles are installed nearby slope edge of road embankment because the side area of the road is much narrow. The protection cross-beam absorbs impact energy caused by vehicle collision. The pile-soil interaction also absorbs the rest of the impact energy and then, finally, the flexible guardrail system resists the impact load. This paper aims to investigate the pile-soil interaction subjected to impact load using centrifuge model tests. In this study, a single pile was installed in compacted residual soil and loaded under lateral impact load. An impact loading system was designed and developed available on centrifuge tests. Using this loading system, a parametric study was performed and the parameters include types of loading and ground. Finally, the ultimate bearing capacity of supporting pile under impact load was analyzed using load-displacement curve and soil reaction pressure distributions at ultimate were evaluated and compared with previous studies.

• The Journal of Korean Medicine
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• v.32 no.2
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• pp.102-117
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• 2011

Objectives: This study was performed to investigate the protective and treating efficacy of Pyeongwi-san, Ijin-tang, and Pyeongjin-tang extracts to the mice with gastric mucosal lesions induced from indomethacin. Methods: In order to verify protective and treating efficacy of Pyeongwi-san, Ijin-tang, and Pyeongjin-tang extracts to the mice with gastric mucosal lesions induced from indomethacin, I administered the extracts of these prescriptions to three group, and induced gastric mucosal lesion by indomethacin, and then I observed the gastric mucosal morphology of stomach, changes from stress resulting from HSP70, changes of gastro-protection (mucous barrier, COX-1). After I observed the anti-oxidant effect, and anti-inflammation effect (IKK mRNA, iNOS mRNA, COX-2 mRNA) in vitro, I induced gastric mucosal lesion by indomethacin, and administered the extracts of each prescriptions to three group, and then I observed the gastric mucosal morphology, anti-inflammation effect to mucosa (NF-${\kappa}$B, iNOS, COX-2) in vivo. Results & Conclusions: 1. Hemorrhagic erosion and damaged mucus secreting cell, positive responses to HSP70 were decreased in all the before-gastric-mucosal-lesion-induced groups, compared to non-extract administered group. The effects were good in the order of Pyeongwi-san extracts administered group, Pyeongjin-tang extracts administered group and Ijin-tang extracts administered group. 2. In all the before-gastric-mucosal-lesion-induced groups, gastro- protection functions (mucous barrier, COX-1) were significant. The effects were good in the order of Pyeongwi-san extracts administered group, Pyeongjin-tang extracts administered group and Ijin-tang extracts administered group. 3. Anti-oxidant effect was significant in Pyeongwi-san extracts, Ijin-tang extracts and Pyeongjin-tang extracts. The effects were good in the order of Pyeongjin-tang extracts, Pyeongwi-san extracts and Ijin-tang extracts. 4. The anti-inflammation effects in vitro were good in Pyeongwi-san extracts, Ijin-tang extracts and Pyeongjin-tang extracts. Especially Pyeongjin-tang extracts showed the most prominent results. Damaged mucus secreting cells and the positive reactions of NF-${\kappa}$B, iNOS, COX-2 in vivo were decreased in after-gastric-mucosal-lesion-induced groups compared to non-extract administered group. The effects were good in the order of Pyeongjin-tang extracts administered group, Pyeongwi-san extracts administered group and Ijin-tang extracts administered group. These results show that Pyeongwi-san, Ijin-tang and Pyeongjin-tang are effective on both in protecting and treating the gastric mucosal membrane. Pyeongwi-san is more effective than other prescriptions, in protecting gastric mucosal membrane, and Pyeongjin-tang is more effective in treating gastric mucosal lesion.

• Journal of Microbiology and Biotechnology
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• v.25 no.1
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• pp.74-80
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• 2015

Skin is the soft outer covering of vertebrates that provides protection from pathogenic infection, physical damage, or UV irradiation, and controls body temperature and water content. In this study, we examined the effects of oral intake of kimchi-derived Lactobacillus plantarum K8 lysates on skin moisturizing. In an in vitro study, we observed that the hyaluronic acid content increased in HaCaT cells treated with L. plantarum K8 lysates. Oral administration of L. plantarum K8 lysates effectively attenuated the horny layer formation and decreased epidermal thickening in DNCB-treated SKH-1 hairless mice skin. The damage to barrier function was reduced after 8 weeks of oral administration of L. plantarum K8 lysates as compared with that in the atopic dermatitis mice. For the test with volunteers, we manufactured experimental candy containing 2.1% L. plantarum K8 lysates, while control candy did not contain bacterial lysate. A significant increase in hydration in the experimental candy-administered group as compared with the control candy-administered group was observed on the face after 4 and 8 weeks, and on the forearm after 4 weeks. Decreases in horny layer thickness and TEWL value were observed on the face and forearm of the experimental group. Together, the in vitro cell line and in vivo mouse studies revealed that L. plantarum K8 lysates have a moisturizing effect. A clinical research study with healthy volunteers also showed an improvement in barrier repair and function when volunteers took L. plantarum K8 lysates-containing candy. Thus, our results suggest that L. plantarum K8 lysates may help to improve skin barrier function.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.2
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• pp.113-120
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• 2023

This paper introduces a simulation method for the collision between roadblocks and vehicles using LS-DYNA. The need to evaluate the performance of anti-ram barriers to prepare for vehicle impact has increased since vehicle impact threats have been included as a design criterion for nuclear power plants. Anti-ram barriers are typically certified for their performance through collision experiments. However, because Koreas has no performance testing facilities for anti-ram barriers, their performance can only be verified through simulations. LS-DYNA is a specialized program for collision simulation. Various organizations, including NCAC, distributes numerical models that have been validated for their accuracy with collision tests. In this study, we constructed a finite element model of the most critical vehicle barrier module and simulated collision between roadblocks and vehicles. The calculated results were verified by applying the validation criteria for vehicle safety facility collision simulations of NCHRP 179.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.2
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• pp.177-181
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• 2015

The subfornical organ (SFO) is one of circumventricular organs characterized by the lack of a normal blood brain barrier. The SFO neurons are exposed to circulating glutamate ($60{\sim}100{\mu}M$), which may cause excitotoxicity in the central nervous system. However, it remains unclear how SFO neurons are protected from excitotoxicity caused by circulating glutamate. In this study, we compared the glutamate-induced whole cell currents in SFO neurons to those in hippocampal CA1 neurons using the patch clamp technique in brain slice. Glutamate ($100{\mu}M$) induced an inward current in both SFO and hippocampal CA1 neurons. The density of glutamate-induced current in SFO neurons was significantly smaller than that in hippocampal CA1 neurons (0.55 vs. 2.07 pA/pF, p<0.05). To further identify the subtype of the glutamate receptors involved, the whole cell currents induced by selective agonists were then compared. The current densities induced by AMPA (0.45 pA/pF) and kainate (0.83 pA/pF), non-NMDA glutamate receptor agonists in SFO neurons were also smaller than those in hippocampal CA1 neurons (2.44 pA/pF for AMPA, p<0.05; 2.34 pA/pF for kainate, p< 0.05). However, the current density by NMDA in SFO neurons was not significantly different from that of hippocampal CA1 neurons (1.58 vs. 1.47 pA/pF, p>0.05). These results demonstrate that glutamate-mediated action through non-NMDA glutamate receptors in SFO neurons is smaller than that of hippocampal CA1 neurons, suggesting a possible protection mechanism from excitotoxicity by circulating glutamate in SFO neurons.

• Journal of the Korea Society of Computer and Information
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• v.18 no.7
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• pp.93-100
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• 2013

The ensuing disaster brought by the massive earthquake and tsunami in the northeastern region of Japan in 2011 placed Japan, one of the three most advanced economic powers in the world, in a defenseless state. With the rising interest in disaster recovery, Korea is also making efforts to provide technological support for barrier-free system operation 24 hours a day, 365 days a year. To protect intelligence assets efficiently, this study draws a job performance plan to prepare for disasters, which systemizes methodical coping capabilities into business plans when disasters occur. Moreover, this study systemizes the job performance plan to allow members easy access to information that will help them proceed without confusion in emergencies. This plant is intended to protect intelligence assets of an organization clearly and promptly.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.9
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• pp.818-824
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• 2006

The effects of high-temperature process required to fabricate the SiC devices on the surface morphology and the electrical characteristics were investigated for 4H-SiC Schottky diodes. The 4H-SiC diodes without a graphite cap layer as a protection layer showed catastrophic increase in an excess current at a forward bias and a leakage current at a reverse bias after high-temperature annealing process. Moreover it seemed to deviate from the conventional Schottky characteristics and to operate as an ohmic contact at the low bias regime. However, the 4H-SiC diodes with the graphite cap still exhibited their good electrical characteristics in spite of a slight increase in the leakage current. Therefore, we found that the graphite cap layer serves well as the protection layer of silicon carbide surface during high-temperature annealing. Based on a closer analysis on electric characteristics, a conductive surface transfiguration layer was suspected to form on the surface of diodes without the graphite cap layer during high-temperature annealing. After removing the surface transfiguration layer using ICP-RIE, Schottky diode without the graphite cap layer and having poor electrical characteristics showed a dramatic improvement in its characteristics including the ideality factor[${\eta}$] of 1.23, the schottky barrier height[${\Phi}$] of 1.39 eV, and the leakage current of $7.75\{times}10^{-8}\;A/cm^{2}$ at the reverse bias of -10 V.

• Journal of Ocean Engineering and Technology
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• v.22 no.2
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• pp.28-33
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• 2008

From the 1997 to January, 2004, a groin 156m long was constructed at the mouth of the Heoya river-mouth as a protection and barrier. To understand the changes to Jinha beach from the blockade of the river mouth, several aerial photographs, etc., were compared, which showed that the changes were significant. Comparing these results to the state of the area before construction of the groin, the blockade of the river was relaxed, but the formation of the tombolo, in the middle groin area was accelerated and the total Jinha beach erosion and especially the erosion of the southern part of Jinha beach was developed. But according to statements by residents and some current documents, the blockade of the Heoya-river mouth is still underway at the surrounding areas of the groin and chronic dredged sand has been used for littoral nourishment at the northern part of the middle groin and on Jinha beach. The result of numerical simulation based on the present state shows that if this sort of dredging is stopped, the sand accumulation will progress near the river mouth groin and the existing tombolo at the middle groin will progress to the north and severe erosion will occur at the southern coastline near the middle groin and the farthest southern part of Jinha beach, and Jinha beach itself will experience a gradual erosion. The main reason for these erosions should be the typhoons that are happening during the summer season. To provide protection from these kinds of undesirable erosions, a total of 23 numerical simulations have been done. It has been shown that submerged breakwaters at the front area of the beach will be efficient to protect from main beach erosion, but there should be alternative proposals for the influence of the river mouth blockade.