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      • SCOPUSKCI등재

        과열증기처리 반탄화 추출물의 항산화 효과 검증에 관한 연구

        오근혜(Geun Hye Oh),남정빈(Jeong Bin Nam),양승민(Seung Min Yang),정원희(Won Hee Joung),정진산(Jin San Jeong),신종민(Jong Min Shin),강석구(Seog Goo Kang) 한국펄프·종이공학회 2018 펄프.종이기술 Vol.50 No.2

        The antioxidant properties of the extracts from torrefied wood subjected to superheated steam treatment were investigated. Total polyphenolics, total flavonoids, DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity, reducing power, and FRAP (Ferric reducing antioxidant power) were determined to evaluate antioxidant activity. The total polyphenol content was 879.67±40.41 ㎎/mL at a concentration of 25 g/mL when the extract was subjected to a temperature of 300℃ for 10 min, and 759.67±25.17 ㎎/mL at a concentration of 25 g/mL at 350℃ for 10 min. The value of at 300℃ was 15.79% higher than that obtained at 350℃. Total flavonoid content was 111.18±3.55 ㎎/mL at a concentration of 25 g/mL at 300℃ for 10 min, and 80.58±2.58 ㎎/mL at a concentration of 25 g/mL at 350℃ for 10 min. The value at 300℃ was 37.97% higher than that obtained at 350℃. For the DPPH free radical scavenging activity, the highest scavenging activity was observed at a concentration of 6 g/mL. DPPH free radical scavenging activity at a concentration of 6 g/mL at 300℃ for 10 min was 89.83±0.03%, whereas at 350℃ for 10 min at the same concentration, it was found to be 87.99±0.1%. The value at 300℃ was 2.09% higher than that obtained at 350℃. Reducing power was determined to be 3.59±0.04 at a concentration of 25 g/mL at 300℃ for 10 min, and 2.92±0.1 at a concentration of 25 g/mL at 350℃ for 10 min. The value at 300℃ was 22.94% higher than that obtained at 350℃. FRAP was 1742±37 μM at a concentration of 25 g/mL at 300℃ for 10 min, and 1106±8 μM at a at 350℃ for 10 min. At 300℃, the FRAP value was 57.50% higher than that obtained at 350℃. Based on these results, we suggest that torrefied wood treated with superheated steam can be used in various applications because of its effective antioxidant properties.

      • SCOPUSKCI등재

        인간포배기 배아의 효과적인 유리화 동결법의 개발을 위한 연구

        이상민,이주희,이상원,이승민,윤산현,임진호,박흠대,이성구,Lee, Sang-Min,Lee, Ju-Hee,Lee, Sang-Won,Lee, Seoung-Min,Yoon, San-Hyun,Lim, Jin-Ho,Park, Huem-Dai,Lee, Seong-Goo 대한생식의학회 2003 Clinical and Experimental Reproductive Medicine Vol.30 No.3

        Objective: The purpose of this study was to evaluate the survival rate of vitrified blastocyst according to the freezing vessels, equilibration time in cryoprotectant and artificial dehydration method. Methods: Human blastocysts were vitrified after loading onto the plastic straw, open-pulled straw (OPS), electron microscopy grid (EM grid) for 1.5 min or 3 min. They also were directly plunged into LN2 within 30sec. For artificial shrinkage of blastocysts, 36 gauge fine needle was pushed at the cellular junction of the trophectoderm into the blstocoele cavity until it shrank without damage of inner cell mass. Results: The survival rate of vitrified blastocysts on plastic straw, OPS, EM grid as freezing vessels were 26.7, 13.0 and 60.5%, respectively. The survival rate of EM grid was significantly higher than that of plastic straw and OPS (p<0.05). For 1.5 min equilibrium, the survival rates of early blastocyst (EB), middle blastocyst (MB) and late blastocyst (LB) were 64.4, 81.0, and 20.0% respectively. For 3 min equilibrium, the survival rates of EB, MB, and LB were 69.9, 50.0 and 57.5% respectively. The survival rates of EB and MB were significantly higher than that of LB in 1.5 min equilibrium group (p<0.05), however, the significance was not observed in 3 min equilibrium groups. In cytoplasmic shrinkage before vitrification, the survival rates of EB, MB and LB were 92.9, 100 and 75.9% respectively. The survival rate of MB was significantly higher than that of LB (p<0.05). The survival rates of vitrified blastocysts by artificial dehydration and slow-frozen blastocysts were not significantly different as 88.9 and 66.7%, respectively. Conclusion: This study showed that the vitrification of human blastocysts using EM grid and artificial dehydration is an effective method. Therefore, these methods would be an useful techniques for blastocyst cryopreservation.

      • SCIESCOPUSKCI등재
      • KCI등재후보

        DEMS(Diethoxymethylsilane) precursor를 이용한 PECVD 저유전물질 박막증착연구

        강민구,김대희,김영철,서화일,Kang, Min-Goo,Kim, Dae-Hee,Kim, Yeong-Cheol,Seo, Hwa-Il 한국반도체디스플레이기술학회 2008 반도체디스플레이기술학회지 Vol.7 No.4

        We studied deposition of low-k SiOCH dielectric film by PECVD. DEMS(diethoxymethlysilane) precursor, which has two ethoxy groups along with one methyl group attached to the silicon atoms, was used as precursor. The SiOCH film was deposited as a function of oxygen flow rates ranging from 0 to 100sccm. The deposition rate($\AA$/min) of SiOCH film was increased due to the increase of oxygen radical as a function of $O_2$ flow rates. The dielectric constant was decreased from 3.0 to 2.77, as the film was annealed at $450^{\circ}C$ for 30 min. So, it could account that the dielectric constant changes sensitively with $O_2$ flow rates. Also, the leakage current of the annealed film exhibited stable curve than that of asdeposited. These results were caused by the increase of Si-O-Si group and decrease of Si-CH group and OH group within the film by annealing.

      • 유화처리 바이오디젤이 도포된 콘크리트의 침투깊이 판정

        백철 ( Baek Cheol ),김태우 ( Kim Tae-woo ),이재진 ( Lee Jae-jin ),이동윤 ( Lee Dong-yun ),한민철 ( Han Min-cheol ),한천구 ( Han Cheon-goo ) 한국건축시공학회 2017 한국건축시공학회 학술발표대회 논문집 Vol.17 No.2

        This study is to provide a evaluation method for the penetration depth of emulsified refined bio diesel(ERBD)applied to a surface of the concrete by using water absorption capability of the concrete. The concrete applied with ERBD was immersed at water for 1 min., 5min., and 10 min. and then was checked the brightness with elapse of time. Test results indicated that there was clear difference between ERBD part and non ERBD part in concrete specimen after measuring the brightness until 120min.

      • KCI등재

        잔디종자의 물리적 전처리가 캘러스 형성과 식물체 재분화에 미치는 효과

        안나영,김용구,라하만 아티쿨,배은지,최수민,이광수,이병현,Ahn, Na-Young,Kim, Yong-Goo,Rahman, Md. Atikur,Bae, Eun Ji,Choi, Su Min,Lee, Kwang Soo,Lee, Byung-Hyun 한국초지조사료학회 2015 한국초지조사료학회지 Vol.35 No.4

        잔디에 있어서 낮은 형질전환 효율의 직접적인 원인 중에 하나인 낮은 캘러스 유도율과 식물체 재분화율을 개선시키기 위하여 잔디 완숙종자의 전처리의 효과를 비교해 보았다. 살균한 잔디종자에 swelling 처리를 10분간 실시한 후, sea sand를 이용 하여 sea sand와 종자의 비율을 1:1로 한 다음, shaking 처리는 vortex speed 6 (1,000 rpm)에서 처리시간은 10분간 전처리를 실시하였을 때 무처리구에 비해 2배 이상의 배양 효율을 나타내었다. 또한 sea sand로 전처리한 잔디종자로부터 형성된 캘러스를 식물체 재분화 유도배지에 치상했을 그 효율이 훨씬 더 증가하는 것을 확인할 수 있었다. 이러한 결과는 연중 아무 때나 이용할 수 있는 장점을 지닌 잔디 완숙종자로부터 유도시킨 캘러스 세포를 이용하여 Agrobacterium으로 형질전환하는데 있어서 그 효율을 향상 시키는데 큰 기여를 할 것으로 추측된다. In order to improve the transformation efficiency of zoysiagrass by increasing the frequency of callus formation from mature seeds and plant regeneration, the effect of pre-treatment with sea sand was examined. Mature zoysiagrass seeds were given 10 min of swelling time before sea sand treatment using a sea sand and seed ratio of 1 : 1 and a vortex shaking speed of 6 (1,000 rpm) for 10 min. The seeds showed increased callus formation that was more than 2 times the rate in the control. In addition, plant regeneration efficiency was also increased when embryogenic callus induced from sea sand-treated mature seeds was cultured in regeneration medium. These results will be very helpful for improving the genetic transformation frequency of zoysiagrass, a recalcitrant monocot grass.

      • SCOPUSKCI등재

        C -11 및 F - 18 표지 콜린의 합성과 체내동태에 관한 연구

        전권수,유국현,김상욱,임상무,홍성운,서용섭,양승대,안순혁,허민구 대한핵의학회 2001 핵의학 분자영상 Vol.35 No.3

        Objectives: Recently, [methyl-(11)^C]-(β-Hydroxyethyl)trimethylammonium ([(11)^C]choline) has been discovered to be a very effective tracer in imaging various human tumors using positron emission tomography. Because of the short half-life of C-11, it is very difficult to use in a routine imaging procedure and needs a frequent synthesis of [(11)^]choline. This can be supplemented by the substitution of [(11)^Ccholine with [methyS-18]fluorocholine. Here, we would like to report cell uptake and biodistribution of [(11)^Ccholine and [(18)^F]fluorocholine as a basic study. Methods [(11)^C]Choline was prepared by the treatment of [(11)^C]CHzI with N,N-dimethylaminoethanol and [18F]fluorocholine was synthesized from reaction of CHzBr[18F]F with N,N-dimethylaminoethanol. The radiochemical purity was checked by high performance liquid chromatography (HPLC). The biodistribution of [(11)^C]choline and [(18)^F]fluorocholine was determined in balb/c mouse at 5 min, 20 min, 40 min and 80 min. The cell uptake wa measured using glioma (9L) and colon adeocarcinoma (SW620). Results: The radiochemical purity was more than 98% after purification. In the liver, uptake did not change over time the uptake was 20/ID/g for [C]choline and 13%ID/g for [(18)^F]fluorocholine. In the kidney, radioactivity decreased over tirne the uptake was 15%1D/g for [(11)^Ccholine and 20%ID/g for [(18)^F]fluorocholine, 80 min post-injection. The cell uptake of [(11)^Ccholine was 4.93% for glioma (9L) and 18.69F for colon adenocarcinoma (SW620). For [(18)^F]fluorocholine, 1.77% for glioma (9L) and 2.77% for colon adenocarcinoma (SW620). Conclusion: [(11)^CCholine and [(18)^F]fluorocholine showed a different cell uptake tendency, depending on cancer cell line. (Korean J Nucl Med 200135:185-191)

      • 수축저감제 혼입률 변화에 따른 콘크리트의 공학적 특성에 관한 연구

        한민철,金光華,정규문,정평유,윤성노,한천구 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

        In this paper, tests are carried out using concrete incorporating shrinkage reducing agent(SR) in order to investigate the engineering properties of concrete. The contents of SR and W/C are varied. According to test results, as for fresh concrete, as SR content increases, slump and air content shows decline tendency, and setting time is accelerated with increase of SR content and decrease of W/C. As for compressive strength, as SR contents increases compressive strength shows to be decreased. As for the effect of SR on drying shrinkage, it shows to be reduced with increase of SR content. This is due to the reduced surface tensile strength of water and tensile strength of capillary pore in concrete.

      • 조강성 혼화제 종류에 따른 콘크리트의 물리적 특성

        한천구,한민철,노상균 청주대학교 산업과학연구소 2009 産業科學硏究 Vol.26 No.2

        The purpose of this study is to compare and analyze the physical properties of concrete in connection with the recent trends to reduce construction periods, in order to increase early-strength of the concrete where the various kinds of liquified early strength concrete agent are used. As for the experiment plan in two levels such as the W/C 30, 50 %, which the standard air entraining water reducing agent(The following P) was intermixed as the plain, the early-strength agent of MAS serial(The following A), the AE reducing agent of early-strength type of the polycarbonic acid serial(The following B) and the naphthalene+lignin serial(The following C) were selected to change them into 4 levels, so that total 8 levels might be included in the experiment. According to the results, the setting time accelerated as the B was fastest and followed by A and C. And as for the compressive strength, the strength development of A recorded 115 %, B recorded 95% and C recorded 80 % of the plain mixture respectively when they were compared with the plain mixture at one day of age, but in the case of 3 days of age, a recorded 103 %, B recorded 104 % and C recorded 110 % of the plain mixture respectively. On the other hand, when A was added the air content increased by 2 %, so it is judged that the compressive strength of A would more than by 10% in consideration of the fact that the compressive strength fell off by 4~6 % when the air content increased by 1 %.

      • 개인휴대통신의 기술발전

        강민구,조형래,강성철 호남대학교 정보통신연구소 1994 정보통신연구 Vol.3 No.-

        이동통신 서비스의 증가와 무선통신 기술의 발전으로 개인휴대통신 서비스의 도입이 각국에서 활발히 추진되고 있다. 본 논문은 국내 개인휴대통신 서비스의 보급과 확대를 위해 고려해야 할 여러 시장 동향과 표준화 동향에 대해 조사하고, 개인휴대통신 구축을 위한 기반기술인 지능형 교환기와 부호다중화 접속기술 및 개인휴대통신 서비스의 직면한 과제의 해결책에 논한다. In this thesis, the technical trend of personal communication service (PCS) is showned for the implementation of PCS in Korea. The comparision betweem technical schemes of many countries is represented for the Korean standards and the core technique of PCS. EspEcially, the code division multiple access (CDMA) and the intelegent switching systems are explained for the Korean PCS standards.

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