• Resources Recycling
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• v.19 no.5
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• pp.44-49
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• 2010

SiC powders have been recovered from silicon-containing waste slurry by carbothermal reduction method with carbon black. Large amount of silicon-containing waste slurry is generated from Solar Cell industry. In an environmental and economic point of view, retrieve of the valuable natural resource from the silicon waste is important. In this study, SiC powder recovered by the reaction ball-milled silicon powder from waste and carbon black at $1350^{\circ}C$ for 3h under vacuum condition. Physical properties of samples have been characterized using SEM, XRD, Particle size analyzer and FT-IR spectroscopy.

• Journal of Korean Medicine Rehabilitation
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• v.32 no.1
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• pp.1-19
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• 2022

Objectives This study aims to evaluate the wound healing effects of oral administered hot water extracts of Korean black ginseng (KBG). Methods 40 C57BL/6 mice were divided into five groups; normal, control, vitamin E 200 mg/kg, KBG 100 mg/kg, KBG 200 mg/kg, each n=8. Skin wounds were made in the back of all mice except normal group using biopsy punches. Wounds were observed on days 7 and 14 after injury. The anti-oxidant and inflammatory protein levels were evaluated using western blotting. Skin tissue was analyzed by hematoxylin & eosin and Masson's trichrome staining method. Results KBG significantly accelerated reducing wound area. KBG significantly decreased myeloperoxidase activity. KBG significantly decreased oxidative stress factors such as NADPH oxidase-4 and p22^phox and increased antioxidant enzymes including nuclear factor erythroid 2-related factor2, kelch-like ECH-associated protein-1, heme oxygenase-1, superoxide dismutase, catalase and glutathione peroxidase-1/2. Moreover, KBG significantly decreased inflammation factors including nuclear factor-κB, phosphorylated inhibitor of κBα, cyclooxygenase-2, inducible nitric oxide synthase, tumor necrosis factor-α and interleukin (IL)-6 and increased anti-inflammation cytokine such as IL-4 and IL-10. In addition, KBG significantly increased tight junction proteins including claudin-1, claudin-3, claudin-4. In histopathologic, KBG made the epithelium thin and uniform, and accelerated the remodeling of collagen. Conclusions The results suggest that KBG has healing effects on skin wound in mice by anti-inflammatory and antioxidant activity.

• The Plant Pathology Journal
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• v.39 no.3
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• pp.265-274
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• 2023

Citrus black rot is a serious disease of citrus plants caused by Alternaria citri. The current study aimed to synthesize zinc oxide nanoparticles (ZnO-NPs) by chemically or green method and investigate their antifungal activity against A. citri. The sizes of synthesized as measured by transmission electron microscope of ZnO-NPs were 88 and 65 nm for chemical and green methods, respectively. The studied prepared ZnO-NPs were applied, in vitro and in situ, at different concentrations (500, 1,000, and 2,000 ㎍/ml) in post-harvest treatment on navel orange fruits to verify the possible control effect against A. citri. Results of in vitro assay demonstrated that, at concentration 2,000 ㎍/ml, the green ZnO-NPs was able to inhibit about 61% of the fungal growth followed by 52% of chemical ZnO-NPs. In addition, scanning electron microscopy of A. citri treated in vitro with green ZnO-NPs showed swelling and deformation of conidia. Results showed also that, using a chemically and green ZnO-NPs at 2,000 ㎍/ml in situ in post-harvest treatment of orange, artificially-infected with A. citri, has reduced the disease severity to 6.92% and 9.23%, respectively, compared to 23.84% of positive control (non-treated fruits) after 20 days of storage. The out findings of this study may contribute to the development of a natural, effective, and eco-friendly strategy for eradicating harmful phytopathogenic fungi.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3A
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• pp.547-553
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• 2006

To know the effect of pigments on the material properties of color concrete, mortar and concrete tests were carried out by the using 5 kinds of pigment. The major component of red, yellow and black pigments was iron oxide and coloring component of blue and green pigments was copper phthalocyanine. Properties of mortar and concrete were some of difference according to adding ratio and kind of pigments. In case of using red, yellow and black pigments, setting time of concrete speeded a little and compressive strength was tendency to increase and slump or air content of concrete was same or decreased. On the other hand, in case of using green and blue pigments, compressive strength of concrete decreased largely because of the excessive air entrainment of surfactant and sump or air content of concrete increased highly. When the antifoaming agent was added to the color concrete mixed with green and blue pigments, compressive strength of concrete was improved and similar to that of concrete without pigment.

• Korean Journal of Materials Research
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• v.8 no.6
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• pp.513-519
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• 1998

Zr-Si binary alloys containing 0.01 to O.lwt.%Si were prepared to investigate the effect of Si on the corrosion behavior of Zr. Corrosion test was performed in pure water at 36$0^{\circ}C$ under a pressure of 2660psi for 100days. The alloys containing 0.01 wt. % and 0.05wt. %Si had the black and uniform oxide film and didn't show the transition of corrosion rate. However. the alloys containing O.lwt.%Si had white oxide film and showed the trasition of corrosion rate at 70 days corrosion test. The weight gain increased with the increasing Si content from 0.01 to 0.1 wt.%. The variation of Si contents had no effect on changing the oxide structure but had significant effect on the electrical resistivity of oxide. The electrical resistivity decreased with increasing Si content. The fraction of precipitates in the Zr-Si binary alloys. identified as tetragonal $Zr_{3}$Si increased with increasing Si content. The increase of the volume fraction of precipitates is thought to be responsible for the increase of weight gain due to short circuit effect of precipitate.

• Analytical Science and Technology
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• v.29 no.1
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• pp.35-42
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• 2016

A new nano-composite carbon ink for the development of disposable dopamine (DA) biosensors based on screen-printed carbon electrodes (SPCEs) is introduced. The method developed uses SPCEs coupled with a tyrosinase modified nano-composite carbon ink. The ink was prepared by an “in-house” procedure with reduced graphene oxide (rGO), Pt nanoparticles (PtNP), and carbon materials such as carbon black and graphite. The rGO-PtNP carbon composite ink was used to print the working electrodes of the SPCEs and the reference counter electrodes were printed by using a commercial Ag/AgCl ink. After the construction of nano-composite SPCEs, tyrosinase was immobilized onto the working electrodes by using a biocompatible matrix, chitosan. The composite of nano-materials was characterized by X-ray photoelectron spectroscopy (XPS) and the performance characteristics of the sensors were evaluated by using voltammetric and amperometric techniques. The cyclic voltammetry results indicated that the sensors prepared with the rGO-PtNP-carbon composite ink revealed a significant improvement in electro-catalytic activity to DA compared with the results obtained from bare or only PtNP embedded carbon inks. Optimum experimental parameters such as pH and operating potential were evaluated and calibration curves for dopamine were constructed with the results obtained from a series of amperometric detections at −0.1 V vs. Ag/AgCl. The limit of detection was found to be 14 nM in a linear range of 10 nM to 100 µM of DA, and the sensor’s sensitivity was calculated to be 0.4 µAµM⁻¹cm⁻².

• The Journal of Korean Medicine
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• v.29 no.1
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• pp.106-116
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• 2008

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 and atherosclerosis. The aim of this study was to investigate the $ONOO^-$, NO, and $({\cdot}O_2^-)$ scavenging and anti-inflammatory activities of Mori Fructus 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 received the standard chow. The experimental groups were fed a diet of chow supplemented with 7.5, 15 and 30 mg Mori Fructus 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 and anti-iNOS respectively. Results : Mori Fructus inhibited the generation of $ONOO^-$, NO and $({\cdot}O_2^-)$ in the lipopolysaccharide (LPS)-treated mouse kidney postmitochondria in vitro. The generation of $ONOO^-$, NO and $({\cdot}O2^-)$ were inhibited in the Mori Fructus-administered ob/ob mice groups. The GSH/GSSG ratio decreased in the ob/ob mice, whereas they improved in the Mori Fructus-administered groups. Mori Fructus inhibited the expression of phospho $I{\kappa}B-\alpha$, IKK-$\alpha$, COX-2, iNOS genes, and thereby the activation of NF-$I{\kappa}B$. Conclusions : These results suggest that Mori Fructus is an effective $ONOO^-$, $({\cdot}O_2^-)$ and NO scavenger, and therefore it might be a potential therapeutic drug against the inflammation process and inflammation-related diseases.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.40-48
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• 2010

Reflected-Ultraviolet photography is applied to the evidence of crime, Archaeology, and Dermatology. In the past, Ultraviolet photography was done with standard black-and-white film. Because emulsion of film is more sensitive to near UV light than CCD(Charge Coupled Device) or CMOS(Complementary Metal-Oxide-Semiconductor)of digital camera. In this research, we purpose to improve qulity of ultraviolet photographs and to find out the best alternative digital camera by utilizing a cunsumer digital camera. To achieve theses, we removed IR cutoff filter from digital camera. And by using modified UV pass filter, we verified the increase of image resolution of digital ultraviolet photographs. Also, we analyze reproducibility of digital ultraviolet photographs according to type, size, pixel of image sensor. Furthermore, this research resulted in the development of an practical digital camera system by utilizing a cunsumer digital camera. Eventually, it will contribute to practical use in the various field of digital ultraviolet photographs

• Journal of the Korean Professional Engineers Association
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• v.5 no.19
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• pp.3-16
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• 1972

1. Purposes and importances of the study. In gaining heating resources by combustion of briquette, which is the necessaries of every day's life, victims occur from poisonous affection of combustion gas (carbon mono-oxide) in every year and this gas attributable to increase death rate proportion to the high demand of briquette usage. It arise great problem ill point of national sanitation. Therefore, the study has a big aim to accomplish depressing CO gas or stimulating comlete combustion by both the methods of physical improvement of present combustion devices and chemical improvement by using V$_2$O$\sub$5/ catalyst to depress CO gas or fasten complete combustion Progress. Sucessful result of this study will not only to decrease the death rate but also to contribute fearless handling of briquette combustion so as to perform improving public Welfare. 2. Contents and scope of study. A. comparison of present and improved fuel hole device. B. Examination of effectness of improved elements. C. Effectness of miffed usage of catalyst. D. Comparison of Catalyst effectness. E. Examination of effectness of black slate containing V$_2$O$\sub$5/. 3. Results and recommendations of the study A. Absolute necessity of supplying secondary air by improved combustion device. B. Oxide Vanadium (V$_2$O$\sub$5/) has the greatest effectness to eliminate CO gas. C. Most effective catalyst of V$_2$O$\sub$5/ containing slate comes from "Samgoe" coal mine. D. By plastering catalyst on the cover plate of fire hole, it stimulate chemical reaction of re-combustion and preserving heat. E. Recommend to continute further precise study to practice with low-cost and handy devices to be applied the study results.

• Journal of Conservation Science
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• v.34 no.5
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• pp.421-431
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• 2018

Analyses of the three-storied stone pagoda at the Bulguksa temple in Gyeongju were carried out in order to identify the cause for material characteristics of inorganic contaminants and conservation treatment materials. Results indicated that foreign soil or weathering soil caused yellow discoloration of the pagoda, reddish-brown contaminants were formed by goethite (FeOOH), an iron oxide mineral, and black pollutants were formed by manganese (Mn) oxide, leading to discoloration of the rock. Among the restoration materials used in the past, cement mortar could cause whitening by reacting with the external environment. The results were used as basic standards to evaluate the material characteristics of the surface contaminants and identify a set of effective conservation treatments. Nevertheless, continuous monitoring is required, as there is a high possibility of regeneration of pollutants in the future because of the continuous exposure of the pagoda to the external environment.