• Microbiology and Biotechnology Letters
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• 제50권3호
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• pp.375-386
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• 2022

In the present study, four distinctly colored bacterial isolates that show intense pigmentation upon brief ultraviolet (UV) light exposure are chosen. The strains are identified as Micrococcus luteus (Milky yellow), Cryseobacterium pallidum (Yellow), Cryseobacterium spp. (Golden yellow), and Kocuria turfanensis (Pink) based on their morphological and 16S rDNA analysis. Moderate salinity (1.25%), 25-37℃ temperature, and pH of 7.2 are found to be the most favorable conditions of growth and pigment production for all the selected isolates. The pigments are extracted using methanol: chloroform (1:1) and the purity of the pigments are confirmed by high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). Further, Fourier transform infrared (FTIR) and UV-Visible spectroscopy indicate their resemblance with carotenoids and flexirubin family. The antioxidant activities of the pigments are estimated, and, all the pigments have shown significant antioxidant efficacy in 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picryl-hydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. The UV protective property of the pigments is determined by cling-film assay, wherein, at least 25% of UV sensitive Escherichia coli survive with bio-pigments even after 90 seconds of UV exposure compared to control. The pigments also hold a good sun protective factor (SPF) value (1.5-4.9) which is calculated with the Mansur equation. Based on these results, it can be predicted that these bacterial pigments can be further developed into a promising antioxidant and UV-protectant for several biomedical applications.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 한국화재소방학회 2013년도 춘계학술대회 초록집
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• pp.78-79
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• 2013

소방보호복은 화재진압현장에서 소방관들을 화상 위험으로부터 보호하기 위해 가장 많이 착용하는 장비이다. 소방보호복의 열보호 특성을 정확히 파악하고 있어야 소방관들의 화재진압작업시 위험요소를 적절히 판단하여 화상 사고 등을 예방할 수 있다. 따라서 본 연구는 복사열 노출에 따른 소방보호복의 열보호 성능을 정확히 측정 및 분석하기 위해 실험 장비를 제작하고 실험을 수행하였다. 소방 보호복의 구성 재료 각각에 대해 복사열 노출을 시켜 시간에 따른 피복 전후면의 온도차와 통과 열유속을 측정하여 소방 보호복의 열보호 성능 특성을 살펴보았다.

• Journal of Advanced Marine Engineering and Technology
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• 제17권3호
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• pp.42-49
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• 1993

Recently, because the lubricating oil showed a tendency to be emulsified and oxidized by high speed, high output and the extension of maintenance & conservation of marine engine, the cavitation erosion-corrosion at such an environment became a big problem on effective performance of engine. Therefore, there was a need to study the behavior and protection of erosion-corrosion damage, and then applied inhibitor to a protective method of cavitation erosion- corrosion damage. At this time, test environments were marine lubricating oil & various emulsified oil that mixed distilled water and sea water etc., and also used 20KHz, 24.mu.m piezoelectric vibrator as an experimental apparatus of cavitation erosion. With this apparatus, we investigated an influence of the emulsified oil on characteristics of erosion-corrosion and protection for erosion-corrosion by inhibitor at slide bearing metals.

• Journal of Chest Surgery
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• 제27권10호
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• pp.815-823
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• 1994

This study was undertaken to hemodynamically determine the differences of myocardial protective effect between crystalloid and blood cardioplegic solution. Twenty nine children undergoing cardiac operations due to cyanotic congenital heart diseases were randomized into two groups receiving crystalloid or blood cardioplegia. Cardiac indices and other hemodynamic datum were examined postoperatively. Although there was no statistical differences between groups, postoperative stroke volume indices and left ventricular stroke work indices were slightly better with blood cardioplegia. We also found that postoperative left atrial pressures[p=0.0003], central venous pressures[p=0.004], and heart rates[p=0.014] were significantly lower with blood cardioplegia. The fact that relatively lower ventricular preloads [left atrial pressure and central venous pressure] were required to provide adequate cardiac output in blood cardioplegia group suggested superior myocardial protective effect of blood cardioplegic solution.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.1822-1831
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• 2014

Micro-grid is connected to the main power grid through a static switch. One of the critical issues in micro-grids is protection which must disconnect the micro-grid from the network in short-circuit contingencies. Protective methods of micro-grid mainly follow the model of distribution system protection. This protection scheme suffers from improper operation due to the presence of single-phase loads, imbalance of three-phase loads and occurrence of power swings in micro-grid. In this paper, a new method which prevents from improper performance of static micro-grid protection is proposed. This method works based on artificial neural network (ANN) and able to differentiate short circuit from power swings by measuring impedance and the rate of impedance variations in PCC bus. This new technique provides a protective system with higher reliability.

• The Korean Journal of Physiology and Pharmacology
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• 제10권4호
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• pp.181-186
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• 2006

This study was undertaken to evaluate whether peroxisome proliferator-activated-receptor-gamma $(PPAR-{\gamma})$ agonist-rosiglitazone (ROSI) induces postischemic functional recovery in Langendorf heart model. Hearts isolated from normal rats were subjected to 20 min of normoxia or 25 min zero-flow ischemia followed by 50 min reperfusion. In this acute protocol, ROSI $(20\;{\mu}g/ml)$ administered 10 min before ischemia had no effect on hemodynamic cardiac function, but had protective effect on lipid peroxidation in in vitro experiments. In chronic protocol in which ROSI was given by daily gavage (4 mg/kg) for three consecutive days, ROSI could not prevent the hemodynamic alteration on cardiac performance, but has protective effect on the activity of superoxide dismutase (SOD). There was no significant difference in the contents of reduced glutathione (GSH) and catalase activity between ischemia-reperfusion (IR) and ROSI treated IR hearts. Although ROSI had no effect on hemodynamic factor, it had effect on antioxidant activity. Our results indicate that ROSI provides partial beneficial effects by inhibiting lipid peroxidation and/or recovering normal level of SOD activity in the ischemic reperfused heart.

• International Journal of Human Ecology
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• 제3권1호
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• pp.55-72
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• 2002

The purpose of this study was to evaluate the thermal resistance of pesticideprotective clothing and to investigate its subjective wear performance. Three different nonwoven fabrics, which provide barrier properties against water and pesticide, were used to manufacture the experimental clothing: spunbonded nonwoven (SB), spunbonded/meltblown/spunbonded nonwoven (SM), and spunlaced nonwoven (SL). The thermal insulation values of the experimental clothing were measured with a thermal manikin, and other wear trials were performed on human subjects in a climate chamber at $28^{\circ}C$, with 70% R.H. and air movement at less than 0.15m/s. Our results found that the thermal resistance was lower in the SB experimental clothing than in the others; that the mean skin temperature of subjects who wore the experimental clothing made with SL was significantly lower than that of subjects who wore the SB and SM clothing; and that the microclimate temperature and humidity with SB were significantly higher than that of the others. Overall, the experimental clothing made with SL was more comfortable than the others in terms of subjective wear sensations.

• Korean Journal of Child Studies
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• 제25권5호
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• pp.29-40
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• 2004

Three groups of maltreated Korean children (Grades 1 through 3) drawn from Child Protective Services (CPS) agencies were compared to a control group of nonmaltreated children on academic achievement as measured by standardized tests of reading, spelling, arithmetic, and writing. Findings were that maltreated children performed significantly below their nonmaltreated children on the standardized tests, in particular in arithmetic. In first grade, maltreated children did not perform below nonmaltreated children on writing and reading, but maltreated children gradually declined in academic performance in these skills. The older, grade 3, children showed more serious academic problems than the younger children (Grades 1 and 2) on four academic skills. This suggests that early experience of child abuse have a strong affect on children's academic achievement.

• Proceedings of the KIEE Conference
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1876-1878
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• 1996

This paper describes the combination surge generator for applying performance tests of surge protective devices. The $8/20{\mu}s$ waveform applies to low impedance circuits and components and is commonly used to determine the characteristics of surge protective devices. And the $1.2/50{\mu}s$ waveform applies to high impedance circuits and components and is used for testing dielectric behavior. Therefore, the combination surge generator, which generates $1.2/50{\mu}s$ voltage waveform under open-circuit conditions and $8/20{\mu}s$ current waveform under short-circuit condition, was proposed. Also this generator can produce $10/1000{\mu}s$ as well as $0.5{\mu}s/100kHz$ ring waveform.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권4호
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• pp.117-122
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• 2003

The AC power lines and signal lines of info-communication networks are routed on overhead poles and are highly exposed to lightning strikes. Due to the potential difference between grounding points of AC power lines and signal lines, the electronic equipments connected to the signal lines can easily be damaged by lightning surges. In this work, in order to develop reliable methods of protecting information and communication facilities from lightning surges, the reliability and performance of SPDs (surge protective devices) were experimentally investigated in an actual-sized test circuit. The behaviors of SPDs against lightning surges from AC power lines and signal lines and the coordinated effects of SPD installation methods were evaluated. As a consequence, it was confirmed that the bypass arrester methods and common grounding system are both highly effective.