• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.6
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• pp.226-231
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• 2020

Polyvinyl pyrrolidone nanofibers including nickel, zinc, and iron precursors were fabricated via the electrospinning method. To convert as-spun nanofibers to Ni0.5Zn0.5Fe2O4 oxide nanof ibers which is capable of shielding an electromagnetic wave, heat treatment conditions were optimized. To obtain the heat treatment condition that can exclude amorphous carbon black and secondary crystal phase, samples were taken at each temperature while the calcination process and analyzed. According to the X-ray diffraction (XRD) analysis, the Ni0.5Zn0.5Fe2O4 crystal phase started to appear from 300℃, but it was confirmed through energy dispersive spectroscopy (EDS) analysis that heat treatment of 500℃ or more was required to remove most of the carbon black. When the calcination temperature exceeds 650℃, crystal nuclei starts to grow and the fiber surface condition becomes rough, so it was confirmed that the heat treatment conditions should be selectively determined according to the application field.

• Conservation Science in Museum
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• v.27
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• pp.67-90
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• 2022

A C-46 transport aircraft, which can be thought of as a large cultural heritage item from the modern period, was subjected to paint analysis and conservation treatment in preparation for its exhibition. The C-46 is the first aircraft ever dispatched to overseas combat zones by the Korean Air Force and carried out missions during the Vietnam War. The aircraft is mainly made of aluminum and shows signs of corrosion on its surface, including pitting and etching, as well as gray and white powdery attachments. In the analysis of the paint, diatomite(SiO₂·nH₂O) was confirmed in the red paint, titanium dioxide(TiO₂) was identified in the white paint, black iron oxide(Fe₃O₄) was detected in the black paint, and colcothar(Fe₃O₄) mixed with putty was confirmed in the blue paint. Infrared spectroscopy revealed the use of alkyd resin in the paint on the main body and nitrocellulose in the Taegeuk pattern. During the conservation treatment, mechanical cleaning, such as sanding, was conducted to remove paint and varnish from the surface. Corrosion was removed by sanding and cleaning with chemical solvents, and new paints and varnishes were applied. Through the paint analysis and conservation treatment, the aircraft was made available for exhibition in a stable condition.

• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.442-448
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• 2023

This study aimed to prepare kombucha, a fermented tea beverage, containing Dendropanax morbiferus (DM) leaves and roots, and analyze its antioxidant and intracellular activities. We compared the pH change, total acidity, radical scavenging activity, and oxygen radical absorbance capacity (ORAC) of kombucha fermented with black tea alone and that with added DM leaves or roots during fermentation. Using RAW 264.7, we evaluated the effects of kombucha containing different DM parts on nitric oxide (NO) production and inflammation-related cytokine content in cells. Kombucha containing ethanol extracts of DM leaves (BTK-E-DML) and roots (BTK-E-DMR) showed higher radical scavenging activity and ORAC 3 d after fermentation than that prepared from black tea alone (BTK-Ori). In an in vitro experiment using RAW 264.7, samples were treated with 8 mg/mL kombucha considering cytotoxicity; the lipopolysaccharide (LPS)-induced NO content significantly reduced after BTK-E-DML and BTK-EDMR treatments compared with that after BTK-Ori treatment. Additionally, the levels of interleukin-6 and tumor necrosis factor-alpha, which were LPS-stimulated inflammatory cytokines, significantly decreased in cells treated with BTK-E-DML and BTK-E-DMR 15 d after fermentation compared with those treated with BTK-Ori. In conclusion, these results demonstrate that kombucha fermented with the leaves and roots of DM increases antioxidant activity and can significantly regulate inflammatory responses at the cellular level.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.8
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• pp.677-685
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• 2014

A direct carbon fuel cell (DCFC) generates electricity directly by converting the chemical energy in coal. In particular, a DCFC system with a solid oxide electrolyte and molten carbonate anode media has been proposed by SRI. In this system, however, there are conflicting effects of temperature, which enhances the ion conductivity of the solid electrolyte and reactivity at the electrodes while causing a stability problem for the anode media. In this study, the effect of temperature on the stability of a carbon-carbonate mixture was investigated experimentally. TGA analysis was conducted under either nitrogen or carbon dioxide ambient for $Li_2CO_3$, $K_2CO_3$, and their mixtures with carbon black. The composition of the exit gas was also monitored during temperature elevation. A simplified reaction model was suggested by considering the decomposition of carbonates and the catalyzed Boudouard reactions. The suggested model could well explain both the measured weight loss of the mixture and the gas formation from it.

• Microbiology and Biotechnology Letters
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• v.34 no.4
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• pp.299-305
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• 2006

In this study, we have isolated and identified a proteolytic bacterium from conventional Cheongkukjang. We also characterized several bioactivity of Cheongkukjang, which was fermented by an isolated strain. One strain out of about $10^4$ strains obtained from Cheongkukjang showed relatively high proteolytic activity was selected and named as a Bacillus subtilis LSH805 strain. White soy-bean Cheongkukjang possessed less odor and more viscous substance than black soy-bean Cheongkukjang. Cheongkukjang showed fibrinolytic activity, and about 1,500 mg fibrin was degraded after 20 h incubation. Although nitric oxide (NO) assays of soy-bean and Cheongkukjang were almost the same, their activities were significantly higher than that of no treatment. Activity of water fraction of Cheongkukjang was somewhat higher than that of soy-bean. Fibrinolytic and NO assays of Cheongkukjang suggest that Cheongkukjang, which was fermented by an isolated strain may be a useful candidate for natural fibrinolytic and macrophage-stimulating agents.

• The Journal of Korean Medicine
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• v.30 no.1
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• pp.51-63
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• 2009

Objectives: Peroxynitrite ($ONOO^-$), superoxide anion radical (${\cdot}{O_2}^-$ and nitric oxide (NO) are cytotoxic because they can oxidize several cellular components such as proteins, lipids and DNA. They have been implicated in the aging processes, and age-related diseases such as Alzheimer's disease, rheumatoid arthritis, cancer, diabetes, obesity and atherosclerosis. The aim of this study was to investigate the $ONOO^-$, NO, ${\cdot}{O_2}^-$ scavenging and NF-${\kappa}B$ related anti-inflammatory activities of Sotosaja-hwan in ob/ob mice. Methods: Mice were grouped and treated for 5 weeks as follows. Both the normal lean (C57/BL6J black mice) and control obese (ob/ob mice) groups have received standard chow. The experimental groups were fed with a diet of chow supplemented with 30 and 90 mg Sotosaja-hwan per 1 kg of body weight for 14 days. For this study, the fluorescent probes, namely 2',7'-dichlorodihydrofluorescein diacetate (DCFDA), 4,5-diaminofluorescein (DAF-2) and dihydrorhodamine 123 (DHR 123) were used. Western blotting was performed using anti-phospho-$I{\kappa}B$-${\alpha}$, anti-IKK-${\alpha}$, anti-NF-${\kappa}B$ (p50, p65), anti-COX-2, anti-iNOS, anti-YCAM-1 and anti-MMP-9 antibodies, respectively. Results: Sotosaja-hwan inhibited the generation of $ONOO^-$, NO and ${\cdot}{O_2}^-$ in the lipopolysaccharide (LPS)-treated mouse kidney postmitochondrial fraction in vitro. The generation of $ONOO^-$, NO, ${\cdot}{O_2}^-$ and PGE2 were inhibited in the Sotosaja-hwan-administered ob/ob mice groups. The GSH/GSSG ratio was decreased in the ob/ob mice, whereas the ratio was improved in the Sotosaja-hwan-administered groups. Sotosaja-hwan inhibited the protein expression levels of phospho-$I{\kappa}B$-${\alpha}$, IKK-${\alpha}$, NF-${\kappa}B$ (p50, p65), COX-2, iNOS, YCAM-1 and MMP-9 genes. Conclusions: These results suggest that Sotosaja-hwan is an effective $ONOO^-$, ${\cdot}{O_2}^-$ and NO scavenger and has NF-kB related anti-inflammatory activity in ob/ob mice. Therefore, Sotosaja-hwan might be a potential therapeutic drug against the inflammation process and inflammation-related diseases.

• Conservation Science in Museum
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• v.4
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• pp.1-16
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• 2003

For the conservation treatment of the Central Asia mural painting which is to be exhibited in the new museum in Yongsan, we analyzed the pigments used in this mural painting and examined to identify the species of the straw in the wall. We also analyzed the species of the wood of the wooden protective frame and the material of the paper in it, in order to review the material and technique of the conservation treatment performed before the mural painting had been brought to the National Museum of Korea in 1916. The results were as follows: the black pigments of Bon4075 and Bon4078 is carbon(C); the white pigment on the background is gypsum[Ca(SO)₄(H₂O)₂]; the red pigment is lead oxide(Pb₃O₄) and hematite(Fe₂O₃) etc. The straw, which had been mixed into the wall to prevent the wall from cracking, was proved to be either wheat straw or oats straw. The wooden protective frame, which protects the mural painting now, was proved to be made of Salix, Populus, Cryptomeria japonica and pine. The paper discovered in the frame was proved to be made of the bark of a mulberry.

• 보존과학연구
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• s.26
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• pp.165-188
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• 2005

From the ancient to these days, there have been used many kinds of pigment which have two types that are inorganic pigment and organic pigment. At the ancient times, natural pigment had been used but the artificially mixed pigment has been used in modern times. By the way, searching for studies has been studied recently, it would be said the ancient pigments such as Danchung, Wall painting and Mural painting are the mainthema. However, studies about the pigments used in modern pictured relics have rarely can be found. Therefore, this analysis of Ilweolokdo would be important at the point of the pigments used in pictures of royal family in modern times and the results can be briefly summarized as below; Firstly, the results of qualitative analysis of the pigments that base or all pigments of picture was detected components of Ca, Fe and As, this results meaning that picture was used filler and basic paint. Secondly, a result of the analysis on the composition elements of the pigments shows that the main components in their composition are ;White - Lead Cyanamide($2PbCO_3$.$Pb(OH)_2$) or Titanium Oxide($TiO_2$)Blue - Ultramarine($2(Na_2O$.$Al_2O_3$ .$2Si_O2$).$Na_2S_2$)Green - Emerald green($C_2H_3A_s3Cu_2O_8$)Gold - Gold(Au), Red-Red Lead($Pb_3O_4$) or Cinnabar(HgS)Black - Carbon(C)Thirdly, X-ray diffraction analysis of crystalline structure for the blue and green pigment peeling off in picture shows that the components of blue pigment is Ultramarine($2(Na_2O$.$Al_2O_3$ .$2Si_O2$).$Na_2S_2$) and green pigment is Emerald green($C_2H_3A_s3Cu_2O_8$). Especially, microcrystalline structure of the green pigment was the shape like a cross section of wood. Consequently, we knew through the analysis of qualitative and microcrystallinestructures seen on the cross section of analyzed pigments layer that the all pigments used in the Ilweoloakdo is possible to use synthetic pigments in modern.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.60.2-60.2
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• 2011

본 연구에서는 Indium-free 및 gallium-free 기반의 산화물 TFT를 제작하기 위해 n-type $TiO_2$ 반도체 기반의 thin film transistor ($Mo/TiO_{2-x}/SiO_2/p+\;+Si$)를 oxygen deficient black $TiO_{2-x}$ 타겟을 이용하여 DC magnetron sputtering 공법으로 제작하고 그 특성을 분석하였다. DC magnetron sputtering 공법으로 성막된 $TiO_{2-x}$ semiconductor의 전기적, 광학적, 화학적 결합 에너지 및 구조적 특성 분석을 위해 semiconductor parameter analyzer (Aglient 4156-C), UV/Vis spectrometer, X-ray Photoelectron Spectroscopy, Transmission Electron Microscopy를 각각 이용하여 분석하였으며 이를 RTA 전/후 특성 비교를 통하여 관찰하였다. $TiO_{2-x}$ TFT의 소자 특성은 RTA 열처리 전/후 전형적인 insulator 특성에서 semiconductor 특성으로 변화되는 것을 관찰할 수 있었으며, 최적화된 열처리 공정에서 filed effect mobility 0.69 $cm^2$/Vs, on to off current ratio $2.04{\times}10^7$, sub-threshold swing 2.45 V/decade와 Vth 10.45 V를 확보할 수 있었다. 또한 RTA 열처리 후 밴드갭이 3.25에서 3.41로 확장되는 특성을 나타내었다. 특히 RTA 열처리 후 stoichiometric $TiO_2$ 상태와는 다른 $Ti^{2+}$, $Ti^{3+}$, $Ti^{4+}$ 등의 다양한 oxidation states가 관찰되었으며 이러한 oxidation states를 $TiO_{2-x}$ 박막에서의 oxygen deficient 상태와 연관시킴으로써 oxygen vacancy의 n-type dopant로의 거동을 확인하였다. $TiO_2$ 채널 기반의 TFT 특성을 통하여서 indium free 또는 gallium free 산화물 채널로써의 가능성을 확인하였다.

• Plant Resources
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• v.4 no.3
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• pp.161-170
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• 2001

A major portion of drugs used in Ayurvedic system of medicine which has been practiced since the early human civilization in Indian subcontinent were of plant origin. It should be noted that 70% of the population in this region depends on Ayurveda for their medical treatment and 60% of the drug resources are obtained from the Himalayan region. Therefore, Nepal becomes a potential source of plant drug resource since it occupies a major portion of the Himalaya. In the present paper, in general a current status of medicinal plant resources of Himalayan region especially Nepal will be discussed. In addition to this, a typical example of antidiabetic activity of Shilajit will be taken for the discussion. Shilajit is one of the crucial elements in several formulations including those of Rasayana, a therapy in Ayurveda, which has been practiced in the prevention of ageing and mental disorder. Although, Shilajit is widely used for the treatment of diabetes, no satisfactory scientific reports are available up to now. The crude Shilajit in the market is a dark brown or black rock-like substance collected from the Himalayan region with a strong smell of cow's stale urine. In our studies, Shilajit (collected in the central Himalayan region) prevented the diabetes in nonobese diabetic (NOD) mice model. Shilajit also prevented the diabetes in the rats against the action of multiple low-dose (10 mg/kg, i.v., 5 times) of streptozotocin. On the other hand, Shilajit did not show antioxidative activity. The preventive action of Shilajit on diabetes is mainly focused on the Thl and Th2 cell activities, since Th2 cells activity was found to be significantly upregulated. Shilajit, however, showed a mild action in controlling the blood sugar level in young, old, and mild diabetic rats, but not in the severe diabetic rats. It also stimulated the nitric oxide production in macrophages. Based on these evidences, the antidiabetic activities of Shilajit appear to be immunomodulative probably by protecting or strengthening insulin-producing b-cells in the pancreas. Further systematic research on constituents of Shilajit and its quality evaluation is necessary to enable the use of natural medicines in the treatment of diabetes.