• Restorative Dentistry and Endodontics
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• 제40권2호
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• pp.97-103
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• 2015

The first part of this study reviewed the characteristics of calcium hydroxide ($Ca(OH)_2$) and summarized the results of in vitro studies related to its antimicrobial effects. The second part of this review covers in vivo studies including human clinical studies and animal studies. The use of $Ca(OH)_2$ as an intracanal medicament represented better histological results in animal studies. However, human clinical studies showed limited antimicrobial effects that microorganisms were reduced but not eliminated through the treatment, and that some species had resistance to $Ca(OH)_2$. Most of clinical outcome studies supported that there is no improvement in healing of periapical lesions when $Ca(OH)_2$ was applied between appointments. Further studies are required for the antimicrobial effects of $Ca(OH)_2$, and search for the ideal material and technique to completely clean infected root canals should be continued.

• E2M - 전기 전자와 첨단 소재
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• 제10권6호
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• pp.555-561
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• 1997

The passivation of n-GaAs(100) surface has investigated by photoreflectance(PR). The surface of the sample was treated with the 0.001 N solution Se/NH$_4$OH. After the surface treatment, the samples were annealed between 400 to $700^{\circ}C$ in a $N_2$atmosphere for 10 min. The intensity of PR signal and period of Franz-Deldysh oscillation(FKO) gradually decreased as the annealing temperature increased. The surface electric field(E$_{s}$) of the sample annealed at $600^{\circ}C$ is obtained 1.34$\times$10$^{5}$ V/cm. This value is 1.97 times less than that of unannealed sample. It has found that the passivation of surface occurred when the surface of the sample had been treated with Se/NH$_4$OH solution and annealed from 500 to $600^{\circ}C$. This result could be due to activation of elemental Se on the surface. It has also found that the elemental Se of the surface diffused about 100 $\AA$ into the bulk GaAs when Se-treated sample was annealed at $600^{\circ}C$.>.

• 대한한방내과학회지
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• 제22권2호
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• pp.215-222
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• 2001

Against the mutagen MNNG and NOPD with SOS chromotest, the antigenotoxic activity of MeOH-soluble extract was much more effective than that of the water-soluble one. When the extract was added to the certain concentration, the antigenotoxic acivity was enhanced. Against the mutagen NOPD with Ames test, the antimutagenic activity of MeOH-soluble extract was better than that of the water-soluble one. The 60.4% of the inhibition ratio for the revertant colony-forming unit was shown at 5 mg of MeOH-soluble extract per plate. Antimutagenecity test with SOS chromotest and Ames test were performed using water-soluble and MeOH-soluble extracts from of Gleditsia sinensis. The antioxidant activity of MeOH-soluble extract with the NBT method was higher than that of the water-soluble one.

• 자원리싸이클링
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• 제25권6호
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• pp.58-64
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• 2016

제지산업은 다량의 산업부산물을 배출하고 있으며, 제지애쉬 발생량도 증가하고 있다. 본 연구에서는 제지애쉬를 시멘트 혼합재로 사용하기 위해서 수화수를 사용하여 전처리 하였다. 전처리 제지애쉬와 석고를 혼합하여 혼합재를 제조하였으며, 이후 시멘트를 대체하여 사용하였다. 제지애쉬 혼합시멘트는 제지애쉬 함량에 따라 물성이 변화하였으나, 10% 이하 사용시에는 기존 OPC와 동등 물성이 발현되었다. 이때 압축강도는 수화물 중 $Ca(OH)_2$의 생성량과도 일정 상관성을 나타내었으며, 3일 강도는 $Ca(OH)_2$ 함량이 증가할수록, 28일 강도는 감소할수록 압축강도가 증가하였다.

• Preventive Nutrition and Food Science
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• 제1권1호
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• pp.64-68
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• 1996

Chromosomal aberration tests in vitro using Chinese hamster lung(CHL) cells were carried out to evaluate the possible role of the MeOH extract of Ecklonia stolonifera in modulating the chromosomal damage induced by Mitomycin C(MMC) and Benzo(a)pyrene(B(a)P), respectively. The MeOH extract of Ecklonia stolonifera(260$\mu\textrm{g}$/ml) reduced significantly the incidence of chromosomal aberration induced by treatment with B(a)P by 80%. The suppressive effect was much stronger than that of $\beta$-carotene, which is well known antimu-tagen. However, there was no marked decrease in the chromosomal aberration induced by MMC. In the tests involving chromosomal aberration induced by the treatment of the MeOH extract of Exklonia stlolnifera alone, there was no significant increase in comparison with the negative control. The results would seem to indicate that. at least under the conditions examined, the MeOH extract of Ecklonis stolonifera decreased the chromosomal aberrations induced by B(a)P in the CHL cells, but had little effect on the chromosomal aberration induced by MMC.

• Korean Journal of Chemical Engineering
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• 제35권12호
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• pp.2413-2420
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• 2018

Sida acuta, a common type of weed in Thailand, contains relatively high cellulose (42.7%) content. We pretreated NaOH to improve glucose recovery from S. acuta. The effect of pretreatment temperature and NaOH concentration was fundamentally investigated based on hydrolysis efficiency with recovery of solid fraction. The pretreatment condition was determined to be 3% NaOH at $60^{\circ}C$ for 9 h, which showed the highest glucose recovery. The hydrolysates obtained by enzymatic hydrolysis of S. acuta were applied to the fermentation of Saccharomyces cerevisiae K35, and a theoretical yield of 97.6% was achieved at 18 h. This indicated that the hydrolysates medium without detoxification had no negative effects on the fermentation. The production of biomass into bioethanol was evaluated based on the material balance of 1,000 g basis. Following this estimation, approximately 28 g and 110 g bioethanol could be produced by untreated and pretreated S. acuta, respectively, and this production was improved about 3.9-fold by NaOH pretreatment. These results again show the importance of pretreatment in biorefinery process.

• 한국추진공학회지
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• 제22권1호
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• pp.72-79
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• 2018

초음파 진동자에 의해 미립화된 케로신 분무연소의 OH 라디칼과 CH 라디칼의 자발광 특성을 고찰하기 위한 실험이 수행되었다. ICCD 카메라를 이용하여 분무화염의 자발광 강도를 측정하였으며, 연소 시 소모된 연료량은 정밀유량측정법으로 계측하였다. 그 결과, 연료소모율은 수송기체인 공기 공급유량에 선형적으로 증가하였으며, 분무연소의 특징인 전형적인 그룹 연소가 관찰되었다. OH 라디칼과 CH 라디칼을 분석한 결과, 분사방향으로의 유량 증가에 따라 라디칼 방사강도의 최댓값은 감소하고 그 위치는 후류로 이동하여 반응대의 폭은 증가하였다.

• 한방비만학회지
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• 제18권1호
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• pp.19-26
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• 2018

Objectives: Alcoholic fatty liver is a potentially pathologic condition which can progress to steatohepatitis, fibrosis, and cirrhosis. The objective of this study is to investigate the effects of Scutellaria Radix (SR) extract on the alcoholic fatty liver induced by long-term EtOH administration. Results: Male Sprague Dawley rats were used in this study. All animals were randomly divided into Normal group, treated with saline (n=10); EtOH group, treated with ethanol (n=10); EtOH+SR group, treated with ethanol+Scutellaria Radix extract (n=10). For oral administration of ethanol in EtOH and EtOH+SR group, the ethanol was dissolved in distilled water in concentrations of 25% (v/v). Throughout the experiment of 8 week, the rats were allowed free access to water and standard chow. Sample group were administrated by Scutellaria Radix extract daily for 8 weeks. Results: The levels of hepatic marker such as aspartate aminotransferase and alanine aminotransferase were altered. Histopathological changes such as ballooning, fatty and hydropic degeneration were reduced and the expression of tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) was significantly attenuated by Scutellaria Radix extract. Conclusions: These data suggest that Scutellaria Radix extract attenuated the alcoholic simple fatty liver by improving hepatic lipid metabolism via suppression of $TNF-{\alpha}$ protein. Scutellaria Radix could be effective in protecting the liver from alcoholic fatty liver.

• Environmental Engineering Research
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• 제24권2호
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• pp.324-330
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• 2019

To recycle raw fly ash (RFA), a waste from thermal power plants, it was used to prepare solid catalysts which have many advantages compared with homogenous catalysts. When biodiesel was produced from soybean oil using RFA, only 1.2% of biodiesel conversion was obtained. A metal hydroxide, NaOH, KOH or $Ca(OH)_2$, was mixed with the acid-treated fly ash (ATFA), and the mixture was calcined at $700^{\circ}C$ for 3 h to prepare the solid catalyst. The solid catalyst prepared by mixing ATFA with NaOH, designated as SC-Na, showed a better performance than those prepared by mixing ATFA with KOH or $Ca(OH)_2$, respectively. The optimal mass ratio of ATFA with NaOH was 1:3, at which the proportion of $Na_2O$ increased to 60.2% in SC-Na, and 97.8% of biodiesel conversion was achieved under optimal reaction conditions (2 w% SC-Na relative to oil and 5 mL-methanol/g-oil at $50^{\circ}C$ for 4 h). Finally, a batch operation was repeatedly carried out to test the feasibility of reusing the solid catalyst, and more than 96% biodiesel conversion was stably achieved for the third round of operations. This study shows that RFA was successfully recycled to solid catalysts through a simple preparation method, and the solid catalyst was reused for the production of biodiesel with high conversion.

• 한국표면공학회지
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• 제54권3호
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• pp.152-157
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• 2021

The pseudocapacitor has a high energy density characteristic because it accumulates charges through a paradic redox reaction. However, due to its strong insulation properties, metal hydroxides should be designed as structural systems optimized for charge transfer to support fast electron transport. Also, Nickel material is weak to heat and is easily deformed when used as a cathode material, so stability must be secured. In this study, nickel hydroxide was produced by electrodeposition to secure the stability of nickel. Electrodeposition is a synthetic method suitable for growing optimized nickel hydroxide because it allows fine control. Nickel hydroxide (Ni(OH)₂) is a metal hydroxide used as a pseudocapacitor anode due to its high capacitance, electrical conductivity and resistance. Therefore, in order to determine how Ni(OH)₂ nanosheets are formed and what are the optimization conditions, various measurement methods were used to focus on structural growth of nanosheets produced by electrodeposition.