• Structural Engineering and Mechanics
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• v.76 no.3
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• pp.421-433
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• 2020

Masonry infills are normally considered as non-structural elements in design practice, therefore, the interaction between the bounding frame and the strength contribution of masonry infills is commonly ignored in the seismic analysis work of the RC frames. However, a number of typical RC frames with irregular distributed masonry infills have suffered from undesirable weak-story failure in major earthquakes, which indicates that ignoring the influence of masonry infills may cause great seismic collapse risk of RC frames. This paper presented the investigation on the risk of seismic collapse of RC frames with irregularly distributed masonry infills through a large number of nonlinear time history analyses (NTHAs). Based on the results of NTHAs, seismic fragility curves were developed for RC frames with various distribution patterns of masonry infills. It was found that the existence of masonry infills generally reduces the collapse risk of the RC frames under both frequent happened and very strong earthquakes, however, the severe irregular distribution of masonry infills, such as open ground story scenario, results in great risk of forming a weak story failure. The strong-column weak-beam (SCWB) ratio has been widely adopted in major seismic design codes to control the potential of weak story failures, where a SCWB ratio value about 1.2 is generally accepted as the lower limit. In this study, the effect of SCWB ratio on inter-story drift distribution was also parametrically investigated. It showed that improving the SCWB ratio of the RC frames with irregularly distributed masonry infills can reduce inter-story drift concentration index under earthquakes, therefore, prevent weak story failures. To achieve the same drift concentration index limit of the bare RC frame with SCWB ratio of about 1.2, which is specified in ACI318-14, the SCWB ratio of masonry-infilled RC frames should be no less than 1.5. For the open ground story scenario, this value can be as high as 1.8.

• Korean Journal of Metals and Materials
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• v.50 no.3
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• pp.201-205
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• 2012

The effects of various manganese precursors for the low-temperature selective catalytic reduction (SCR) of $NO_x$ were investigated in terms of structural, morphological, and physico-chemical analyses. $MnO_x/TiO_2$ catalysts were prepared from three different precursors, manganese nitrate, manganese acetate(II), and manganese acetate(III), by the sol-gel method. The manganese acetate(III)-$MnO_x/TiO_2$ catalyst tended to suppress the phase transition from the anatase structure to the rutile or the brookite after calcination at $500^{\circ}C$ for 2 h. It also had a high specific surface area, which was caused by a smaller particle size and more uniform distribution than the others. The change of catalytic acid sites was confirmed by Raman and FT-IR spectroscopy and the manganese acetate(III)-$MnO_x/TiO_2$ had the strongest Lewis acid sites among them. The highest de-NOx efficiency and structural stability were achieved by using the manganese cetate(III) as a precursor, because of its high specific surface area, a large amount of anatase $TiO_2$, and the strong catalytic acidity.

• Journal of Magnetics
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• v.18 no.3
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• pp.342-347
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• 2013

Local wall thinning in pipelines affects the structural integrity of industries, such as nuclear power plants (NPPs). In the present study, a development of pulsed eddy current (PEC) technology that detects the wall thinning of pipelines covered with insulation is reviewed. The methods and experimental results, which have two kinds of probe with a single and double core, were compared. For this purpose, the single and double core probes having one and two excitation coils have been devised, and the differential probe with two Hall sensors has been fabricated to measure the wall thinning in insulated pipelines. The test sample is a stainless steel having different thickness, laminated by plastic insulation to simulate the pipelines in NPPs. The excitation coils in the probe is driven by a rectangular current pulse, the difference of two Hall sensors has been measured as a resultant PEC signal. The peak value of the detected signal is used to describe the wall thinning. The double core probe has better performance to detect the wall thinning covered with insulation; the single core probe can detect the wall thinning up to an insulation thickness of 18 mm, whereas the double probe can detect up to 25 mm. The results show that the double core PEC probe has the potential to detect the wall thinning in an insulated pipeline of the NPPs.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.28 no.3
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• pp.14-29
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• 2015

Objectives : The extract of Sagunja-tang has been traditionally used for restorative treatment of constitutional weakness, vascular and immune disorder, and nervous disease in Oriental country. This study investigated the regulatory effects of Sagunja-tang on the expression, production, and activity of immune mediators.Methods : In this study, the extract of Sagunja-tang was prepared by extracting with distilled water at 100$^{\circ}C$ for 2.5h. The extract was freeze-dried following filtration through 0.45${{\mu}m}$ filter. The extract was dissolved in Hank's balanced salt solution (HBSS) and filtered again through 0.45${{\mu}m}$ filter before use. The level of nitrite, an oxidative product of nitric oxide(NO) was measured in the culture medium by the Griess reaction. The levels of prostaglandin E₂(PGE₂), Th1 cytokines (IFN-${\gamma}$, IL-2) and Th2 cytokines(IL-4, IL-5, IL-13) were measured by enzyme-linked immunosorbent assay and the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression were determined by Western blot analysis. Also examined the effects of the extract on T-cell proliferation and cytotoxic activity of natural killer cells.Results : In this investigation, Production levels of Th2 cytokines (IL-4, IL-5, IL-13) was inhibited in a dose dependent manner by treatment with the extract. I also found that the extract increased T-cell proliferation and cytotoxic activity of natural killer cells in a dose-dependent manner.Conculsions : These results suggest that the water extract of Sagunja-tang may be useful for a therapeutic drug against a sickly constitution and immune diseases, probably by regulating the production of immune mediators.

• Archives of Pharmacal Research
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• v.20 no.6
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• pp.533-538
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• 1997

Biflavonoid is one of unique classes of naturally-occurring bioflavonoid. Previously, certain biflavonoids were found to possess the inhibitory effects on phospholipase $A_2$ activity and lymphocytes $ proliferation^1$ suggesting their anti-inflammatory/immunoregulatory potential. In this study, effects of several biflavonoids on arachidonic acid release from rat peritoneal macrophages were investigated, because arachidonic acid released from the activated macrophages is one of the indices of inflammatory conditions. When resident peritoneal macrophages labeled with $[^{3}H]$arachidonic acid were activated by phorbol 12-myristate 13-acetate(PMA) or calcium ionophore, A23187, radioactivity released in the medium was increased approximately 4.1-7.3 fold after 120 min incubation compared to the spontaneous release in the control incubation. In this condition, biflavonoids (10 uM) such as ochnaflavone, ginkgetin and isoginkgetin, showed inhibition of arachidonate release from macrophages activated by PMA (32.5-40.0% inhibition) or A23187 (21.7-41.7% inhibition). Amentoflavone showed protection only against PMA-induced arachidonate release, while apigenin, a monomer of these biflavonoids, did not show the significant inhibition up to 10 uM. Staurosporin (1 uM), a protein kinase C inhibitor, showed an inhibitory effect only against PMA-induced arachidonate release (96.8% inhibition). Inhibition of arachidonate release from the activated macrophages may contribute to an anti-inflammatory potential of biflavonoids in vivo.

• Membrane and Water Treatment
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• v.8 no.2
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• pp.113-123
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• 2017

This study investigated effects of physical and chemical cleaning methods on the initial flux recovery of fouled membrane in membrane distillation process. A laboratory scale direct contact membrane distillation (DCMD) experiment was performed to treat digested livestock wastewater with 3.89 mg/L suspended solids, 874.7 mg/L COD, 543.7 mg/L nitrogen, 15.6 mg/L total phosphorus, and pH of 8.6. A hydrophobic PVDF membrane with an average pore size of $0.22{\mu}m$ and a porosity of 75 % was installed inside a direct contact type membrane distillation module. The temperature difference between feed and permeate side was maintained at $40^{\circ}C$ with the feed and permeate stream velocity of 0.18 m/s. The results showed that the permeate flux decreased from $22.1L{\cdot}m^{-2}{\cdot}hr^{-1}$ to $19.0L{\cdot}m^{-2}{\cdot}hr^{-1}$ after 75 hours of distillation. The fouled membrane was cleaned first by physical flushing and consecutively by chemicals with NaOCl and citric acid. After the physical cleaning the flux was recovered to 92 % as compared with the initial clean water flux of the virgin membrane. Then 94 % of the flux was recovered after cleaning by 2,000 ppm NaOCl for 90 minutes and finally 97 % of flux recovered after 3 % citric acid for 90 minutes. SEM-EDS and FT-IR analysis results presented that the foulants on the membrane surface were removed effectively after each cleaning step. The contact angle measurement showed that the hydrophobicity of the membrane surface was also restored gradually after each cleaning step to reach nearly the same hydrophobicity level as the virgin membrane.

• Journal of Digital Convergence
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• v.17 no.2
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• pp.265-273
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• 2019

The Purpose of this study was to investigate the attitude and confidence of patient safety in undergraduate healthcare professions students. The subjects consisted of 145 grade 3,4 students who have had clinical practice in nursing and emergency medical technician schools in a J province from June 1st to 30th in 2016. Data were analyzed with SPSS 21.0 using descriptive statistics. The results of the study showed that the attitude of nursing students were more positive, but there was no difference in patient safety self-confidence and patient safety education experience, and the students who had experienced medical errors saw positive attitude and self-confidence. Based on the results of this study, I propose case-based multidisciplinary contents development to nurture emergency healthcare professions

• Journal of Ginseng Research
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• v.43 no.1
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• pp.135-142
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• 2019

Background: Panax ginseng Meyer, known as Korean Red Ginseng (KRG), is one of the important age-old traditional herbs used in boosting libido and improving male fertility. In this study, the effects of Rg3-enriched KRG extract (KGC04P) on heat stress-induced testicular damage in experimental rats was evaluated. Methods: Male rats (Sprague-Dawley) were divided into four groups (n = 10): normal control (NC), heat-stressed control (HC), heat-stressed plus KGC04P-100 mg/kg (HK100), and heat-stressed plus KGC04P-200 mg/kg (HK200) groups. Starting 1 week prior to heat stress, animals were administered orally with KGC04P (100 and 200 mg/kg) mixed with a regular pellet diet and continued for 25 weeks. Heat stress was induced to HC, HK100, and HK200 groups by intermittently exposing the animals to high temperatures ($32{\pm}1^{\circ}C$, 2 h/day). After 6 months, animals were euthanized under general anesthesia with carbon dioxide and evaluated for various parameters in serum and testicular tissue by using Western blotting, biochemical kits, and reverse transcription-polymerase chain reaction. Results: Significant (p < 0.05) alterations in several parameters, such as body/organ weight, sperm kinematics, and lipid metabolism marker levels, in the serum and testis of rats were observed. Further, the expression of testicular antioxidant enzymes, inflammatory cytokines, sex hormonal receptors, and spermatogenesis-related genes were also affected significantly (p < 0.05) in the heat-stressed group. However, KGC04P prevented the heat stress-induced changes in rats significantly (p < 0.05) at both concentrations. Conclusion: KGC04P attenuated heat stress-induced testicular damage by a multifunctional approach and can be developed as an excellent therapeutic agent for hyperthermia-mediated male infertility.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.3
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• pp.113-120
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• 2018

The one-way gas valve developed in this study was designed to prevent the breakage of packages from increased internal pressure, which is a problem in packaged Kimchi, and simultaneously reduce the outflow of the offodor release. The effect of the one-way gas valve on the headspace atmospheric compositions was investigated in the packaging system. The changes of atmospheric compositions and quality factors of Kimchi, such as $CO_2$ accumulation, pH, titratable acidity, and salinity, were measured during a 4-week storage period at $4^{\circ}C$. The Kimchi package with the one-way gas valve dramatically reduced pressure build-up in the pouch by allowing the controlled flow of gas to the atmosphere. In addition, the package design allows the possibility of controlling the gas generated from Kimchi by adjusting the viscosity of the open pressure control oil. The one-way gas valve did not affect the sensory characteristics of Kimchi products during the storage period. Furthermore, the deodorizing capability of the activated carbon contained in the one-way gas valve effectively reduced the off-odor of Kimchi products released along with carbon dioxide. The novel one-way gas valve is considered to be an active packaging system that can solve major problems of expansion and off-odor leakage in the packaging of Kimchi.

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.239-246
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• 2019

In this study, an evaluation of the anti-inflammatory effect of ferulic acid isolated from Tetragonia tetragonioides in lipopolysaccharide (LPS) simulated RAW 264.7 cells was made. The chemical structure of the active compound was elucidated by $^1H$-NMR, $^{13}C$-NMR, and FAB-MS, and was confirmed to be ferulic acid. Ferulic acid was purified via open column chromatography with Sephadex LH-20 and MCI gel CHP-20. To test the anti-inflammatory effect of ferulic acid, LPS-stimulated RAW 264.7 cells were treated in subsequent experiments with different concentrations of ferulic acid (5, 10, and $25{\mu}g/mL$) and the levels of inflammatory cytokines and enzymes were also measured by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. Cell viability was above 95% at acid concentrations ranging from $5-25{\mu}g/mL$. The results showed that 30% of the production of nitric oxide and 66% of prostaglandin $E_2$ were inhibited by $25{\mu}g/mL$ of ferulic acid, it also inhibited the protein expression of both inducible nitric oxide synthase and cyclooxygenase-2 by 70%. Additionally, it inhibited the production of the pro-inflammatory cytokines, tumor necrosis factor-${\alpha}$, interleukin-6, and interleukin-$1{\beta}$ by 40, 75, and 77%, respectively. According to these results, the anti-inflammatory activity of ferulic acid was demonstrated via his implication in the inhibition of the expression and secretion of inflammatory substances in LPS-stimulated RAW 264.7 cells. Therefore, we concluded that ferulic acid can be used as a functional additive having anti-inflammatory activity.