• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.73-74
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• 2022

The corrosion inhibitive effect of a new hydrazone-based heterocyclic compound for steel in simulated concrete pore solution with 3.5 wt.% sodium chloride was investigated by experimental and computational techniques. Electrochemical studies, up to 30 days of immersion, and surface analysis (X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscope (SEM)) were performed to assess the corrosion protection abilities of investigated compound for steel rebar. Results showed that adding the organic compound to the chloride contaminated concrete pore solution decreased the corrosion rate of the steel rebar thanks to the effective adsorption of inhibitor molecules. After 30 days of immersion of steel rebar in inhibited chloride contaminated synthetic concrete pore solution, the inhibition efficiency exceeded 80% at low concentration of 1 mmol/L. Computational studies by Density Functional based Tight Binding (DFTB) method revealed the formation of covalent bonds between the hydrazone molecule and the iron surface.

• 정보보호학회논문지
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• 제25권6호
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• pp.1485-1494
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• 2015

기존 데이터 은닉은 대용량 멀티미디어 파일에 데이터를 삽입하는 방식으로 이루어졌다. 하지만 최근 Microsoft Office 2003 이하 버전 제품의 문서파일은 구조가 파일시스템과 유사하여 데이터 은닉이 비교적 용이해 커버데이터(Cover data)로 사용되고 있다. 데이터가 은닉된 문서파일을 MS Office 프로그램으로 실행할 경우 은닉 사실을 모르는 사용자는 은닉 데이터를 눈으로 쉽게 확인할 수 없다. 이에 본 논문에서는 Microsoft Office 2003 이하 버전과 한컴오피스 문서파일에서 사용되는 복합문서 파일 이진형식(Compound File Binary Format) 파일 포맷 구조를 분석하여 데이터 삽입이 가능한 공간을 살펴보고 이를 탐지하기 위한 방안을 제시하고자 한다.

• Advances in Traditional Medicine
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• 제10권1호
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• pp.21-28
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• 2010

The objective of the present investigation is to evaluate the antimicrobial potency of the terpenoid fractions isolated from Luffa cylindrica seeds against various pathogenic microbes. The seeds were powdered and extracted with methanol in soxhlet appratus based on phytochemical screening. Three terpenoid components were isolated by column chromatography and identified by thin layer chromatography and chemical analysis which were designated as ${LCSF_4}^*$, ${LCSF_6}^*$ & ${LCSF_8}^*$ respectively. Disc diffusion method was employed to determine the antimicrobial effectiveness of test compounds I, II and III $({LCSF_4}^*,\;{LCSF_6}^*\;&\;{LCSF_8}^*)$ against 6 microbial species viz., Staphylococcus (S.) aureus, Bacillus (B.) subtilis, Escherichia (E.) coli, Pseudomonas (P.) aeruginosa, Candida (C.) albicans and Aspergillus niger. The disc was saturated with $100{\mu}l$ of each compound, allowed to dry and introduced on the upper layer of seeded agar plate. The plates were incubated overnight at $37^{\circ}C$. Microbial growth was determined by measuring the zonal inhibition diameters. Compound I showed maximum potency against gram positive S. aureus (21 mm) in comparison with standard ciprofloxacin (38 mm), whereas the same compound was completely devoid of activity against both the fungi tested. Compound II was found to be highly sensitive against both the gram negative E. coli (20 mm) and P. aeruginosa (22 mm). Compound II was found to exhibit maximum potency against the fungi C. albicans (15 mm) and A. niger (20 mm). Compound III was found to be very effective against both the gram positive S. aureus (20 mm) and B. subtilis (15 mm) respectively.

• 열처리공학회지
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• 제5권4호
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• pp.215-223
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• 1992

This study has been performed to investigate into some effects of temperature, gas mixing ratio and time on the optical microstructure, hardness and wear characteristics of medium carbon alloy steel treated by plasma nitriding. The results obtained from the experiment are summarized as follows: (1) Optical micrographs of AISI 4140 steel plasma-nitrided by the double stage technique have revealed that the nitrided layer is composed of the compound layer and the diffusion layer. The variation in temperature at the first stage gives effects, on the formation of compound layer and the growth rate is shown to be relatively fast at $460^{\circ}C$. (2) The thickness of compound layer has been found to increase with increasing nitrogen percentage in the gas mixture and the holding time. It is therefore recommended that a shorter holding time and a lower nitrogen percentage are more effective to produce a tougher compound layer and a diffusion layer only. (3) X-ray diffraction analysis for AISI 4140 steel has shown that the compound layer consist of ${\gamma}^{\prime}-Fe_4N$ and ${\alpha}-Fe$ and that tough compound layer diffustion layer only can be obtained by the double stage plasmanitriding process. (4) There is also a tendency that the total hardened layer depth increases with increasing temperature, time and nitrogen percentage in the first stage during the double stage plasma nitriding. (5) The wear resistance of plasma nitrided specimens has been found thobe considerably increased compared to the untreated specimens and the amount of increment has appeared to increase further with increasing nitriding temperature, holding time and notrogen percentage of gas mixture in the first stage treatment.

• 대한약침학회지
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• 제19권3호
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• pp.246-252
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• 2016

Objectives: The purpose of this study was to obtain a natural antibiotic from Phenol-rich compounds; for the dressing and the treatment of chronic wounds. Methods: The Phenol-rich compound sweet gel was prepared by blending four natural herbal extracts, Acacia catechu (L.F.), Momia (Shilajit), Castanea sativa, and Ephedra sinica stapf, with combination of a sweet gel medium, including honey, maple saps, Phoenix dactylifera L. (date), pomegranate extract and Azadirachta indica gum as a stabilizer. The combinations were screened by using a well-diffusion assay with cloxacillin as a control. Pseudomonas spp. was tested with our novel antimicrobial compound. The zones of inhibition in agar culture were measured for each individual component and for the compound, and the results were compared with those of the control group which had been treated with cloxacillin. Data were expressed as means ${\pm}$ standard deviations. Quantitative analyses were performed using the paired t-test. Results: The antibiotic effect of the Phenol-rich compound sweet gel was statistically shown to be more significant than that of cloxacillin against Pseudomonas aeruginosa (P < 0.05). Conclusion: Our novel approach to fighting the antibiotic resistance of Pseudomonas proved to be successful. The Phenol-rich compound sweet gel was found to be suitable for use as an alternative medicine and bioactive dressing material, for the treatment of patients with various types of wounds, including burns, venous leg ulcers, ulcers of various etiologies, leg ulcers on the feet of diabetic, unhealed graft sampling sites, abscesses, boils, surgical wounds, necrotic process, post-operative and neonatal wound infection, and should be considered as an alternative to the usual methods of cure.

• 한국미생물·생명공학회지
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• 제49권2호
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• pp.174-180
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• 2021

Chalcones exhibit multiple biological activities. Various studies have attempted to modify the structure of chalcones with a special focus on the addition of substituents to the benzene rings. However, these chemical modifications did not improve the water solubility and bioavailability of chalcones. Glycosylation can markedly affect the physical and chemical properties of hydrophobic compounds. Here, we evaluated the ability of a highly promiscuous glycosyltransferase (GT) BsGT1 from Bacillus subtilis ATCC 6633 to biosynthesize chalcone glucosides. Purified BsGT1 catalyzed the conversion of 4'-hydroxychalcone (compound 1), 4'-hydroxy-4-methylchalcone (compound 2), and 4-hydroxy-4'-methoxychalcone (compound 3), into chalcone 4'-O-β-D-glucoside (compound 1a), 4-methylchalcone 4'-O-β-D-glucoside (compound 2a), and 4'-methoxychalcone 4-O-β-D-glucoside (compound 3a), respectively. To avoid the addition of expensive uridine diphosphate glucose (UDP-Glc), a whole-cell biotransformation system was employed to provide a natural intracellular environment for in situ co-factor regeneration. The yields of compounds 1a, 2a, and 3a were as high as 90.38%, 100% and 74.79%, respectively. The successful co-expression of BsGT1 with phosphoglucomutase (PGM) and UDP-Glc pyrophosphorylase (GalU), which are involved in the biosynthetic pathway of UDP-Glc, further improved the conversion rates of chalcones (the yields of compounds 1a and 3a increased by approximately 10%). In conclusion, we demonstrated an effective whole-cell biocatalytic system for the enzymatic biosynthesis of chalcone β-D-glucoside derivatives.

• 전기의세계
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• 제22권6호
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• pp.33-51
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• 1973

To lower the earth resistance shall be one of the most effective method for the prevention of lightening damage on power transmission line. In this report, in order to investigate various characteristic necessary to lowering the earth resistance, the following experiments have been made at 154KV U1San-PoHang T/L, 154KV YoSu-SoonChun T/L and so on. 1. Measurement of Earth specific resistance, 2. Efficiency of Earthing of concrete foundation for steel structure., 3. Efficiency of Earthing with counter poise., 4. Compound impulse test with foundation of steel structure and counter poise. With the above investigate a guidance have been prepared for the effective work-performance of steel structure.

• Applied Microscopy
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• 제40권4호
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• pp.201-209
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• 2010

한방에서 사용되는 약재 중 가자와 지모, 단삼은 면역조절 및 항암효과, 항염증효과가 있다고 알려졌다. 그러나 비만세포와 관련된 아나필락스를 이해할 수 있는 세포학적 기전에 대한 가자와 지모, 단삼의 효과에 대해서는 알려진 바 없다. 본 연구에서는 가자와 지모, 단삼의 메탄올 추출물이 아나필락시스 반응에 대해 어떠한 영향을 끼치는지를 조사하였다. 시험관내 실험과 생체 실험을 통하여, 가자와 지모, 단삼의 메탄올 추출물이 compound 48/80에 의한 아나필락시스와 비만세포 활성화 및 IgE에 의한 피부반응을 관찰하였다. 실험결과는 다음과 같다. 1) 가자와 지모, 단삼의 메탄올 추출물은 compound 48/80에 의한 전신성 아나필락시스와 귀부종 반응, IgE에 의한 피부반응을 억제하였다. 2) Compound 48/80에 의한 비만세포 탈과립과 흰쥐 복강 비만세포로부터 히스타민 유리가 가자와 지모, 단삼의 메탄올 추출물 전처리에 의해 억제되었다. 3) Compound 48/80에 의한 흰쥐 복강 비만세포내로의 칼슘 유입이 가자와 지모, 단삼의 메탄올 추출물 전처리에 의해 현저하게 억제되었다. 이상의 결과로 가자와 지모, 단삼의 메탄올 추출물은 비만세포 탈과립과 비만세포로부터 히스타민 유리, 비만세포내로 칼슘유입을 억제함으로써 compound 48/80에 의한 아나필락시스와 IgE에 의한 피부반응을 억제한다는 것을 알 수 있었다. 이로써 가자와 지모, 단삼은 알레르기 질환에 대한 효과적인 치료제로 이용될 수 있을 것으로 생각된다.

• 한국토양비료학회지
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• 제11권1호
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• pp.37-42
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• 1978

수도추비용시제복합비료(水稻追肥用試製複合肥料) (조선비료공업주식회사(朝鮮肥料工業株式會社) 제품(製品)) 17-0-17과 17-0-14의 비효를 밝히기 위(爲)하여 수도(水稻)아끼바레를 표식작물(標識作物)로 포장시험(圃場試驗)을 한 결과(結果)는 다음과 같다. 1. 정조(正租)의 수량(收量)과 질소(窒素) 및 가리(加里)의 흡수량(吸收量)으로 보아 시제복합비료(試製複合肥料)의 비효는 단비요소(單肥尿素) 염화가리(鹽和加里)에 뒤떨어지지 않는다. 2. 복합비료(複合肥料) 17-0-17 입제(粒製)는 비효가 완만하여 수비용(穗肥用)보다는 유효분벽기비용으로 가(可)할 것 같다. 3. N K 복비(複肥)의 추비(追肥)는 수량(收量)과 양분(養分)의 흡수량(吸收量)을 증가(增加)하고 시험후(試驗後) 토양(土壤)의 치환성가중함량(置煥性加里含量)을 증가(增加)한다는 점(點)으로 보아 시제복비(試製複肥)와 같은 비료(肥料)의 개발(開發)에 관(關)하여 적극적(積極的)인 고려(考慮)가 필요(必要)한 것으로 생각된다.

• 한국토양비료학회지
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• 제12권3호
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• pp.133-139
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• 1979

수도추비용(水稻追肥用)으로 시제(試製)된 NK 복비(複肥) 17-0-17 (입상(粒狀) 및 분말상(粉末狀))과 17-0-14의 효과를 단비(單肥)(요소(尿素) 및 염화가리(鹽化加里))와 비교(比較)하기 위하여 신품종 수도(水稻)(밀량 23호)를 써서 포장시험(圃場試驗)을 실시(實施)했든바 그결과(結果)를 요약(要約)하면 다음과 같다. 1. 수량면(收量面)에서 볼때 복비수비(複肥穗肥)는 단비수비(單肥穗肥)보다 더 효과적인 경향(傾向)이 였다. 2. 입상(粒狀) 17-0-17 수비구(穗肥區)에서 K 및 N의 흡수(吸收)가 타구(他區)에 비(比)해 많았으며 K/(Ca+Mg)값도 높았다. 3. 복비구(複肥區)에서 가리(加里)와 질소흡수량(窒素吸收量)이 많았든 원인(原因)에 대(對)해서는 본시험(本試驗)성적만으로 설명(說明)이 어려웠다. 4. N-K복비(複肥)는 수비(穗肥)로 뿐만아니라 수도(水稻)에 대(對)한 즉(卽) 기비(基肥) 유효분벽기(有效分蘗期)나 최고분벽기(最高分蘗期)에 추비(追肥) 하여도 그 효과(效果)를 검토(檢討)해볼 만 할것 같다.