• 제목/요약/키워드: KJ3

검색결과 197건 처리시간 0.027초

열중량 분석에 의한 DGEBA/MDA/PGE-AcAm/CTBN계의 열적 안정성 평가 (Estimation of Thermal Stability for DGEBA/MDA/PGE-AcAm/CTBN System by TG Analysis)

  • 이재영;최형기;심미자;김상욱
    • 한국재료학회지
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    • 제7권3호
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    • pp.229-233
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    • 1997
  • Diglycidyl ether of bisphenol A(DGEBA)/4,4'-methylene dianiline(MDA)/phenyl glycidyl ether(PGE)-acetamide(AcAm)/carboxyl-terminated acrylonitrile butadiene copolymer(CTBN) 계의 열적 안정성을 평가하기 위해 열중량 분석법(TG)을 사용하였다. 활성화 에너지를 구하기 위해 Freeman & Carrol, kissinger, Flynn & Wall 식을 사용하였다. Freeman & Wall 식을 이용하여 구한 활성화 에너지는 112.9 kJ/mol, Kissinger 식에 의한 값은 151.5kJ/mol 이었으며, Flynn & Wall식에 의해 구한 값은 168.3 kJ/mol 이었다.

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가압경수형 핵연료 피복관 지르칼로이-4의 항복현상에 대한 고온 수증기 산화의 영향 -구리 맨드렐 팽창시험법- (Effect of High Temperature Steam Oxidation on Yielding of Zircaloy-4 PWR Fuel Cladding -Expanding Copper Mandrel Test-)

  • Kye-Ho Nho;Sun-Pil Choi;Byong-Whi Lee
    • Nuclear Engineering and Technology
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    • 제21권2호
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    • pp.111-122
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    • 1989
  • 고온 수증기(1323 K)분위기에서 산화시킨 지르칼로이-4 피복관으로, 구리 맨드렐 팽창실험(Copper Mandrel Expension Test)을 변형률(Strain Rate)이 $3.0\times10^{-5}$/sec일때 673-1173 K 온도 범위에서 수행하였다. 본 연구에서, 산화매개변수(Ki)는 시간(t)의 제곱근에 비례하고 $(Ki=\delta_{kit}\frac{1}{2}$), 비례상수($\delta_{ki}$)는 무게증가(Weight Gain), Zr02의 두께, $\alpha$(0) 층에 대하여 각각 0.281, 2.82, 2.313을 사용하였다. 지르칼로이-4의 고온(873-1073 K) 소성변형에 의한 활성화 에너지는 Zr02가 높은 강도를 갖기 때문에 산화 시간이 5분에서 60분으로 증가함에 따라 251 KJ/mol에서 323KJ/mo1로 증가하였다. 산화막 두께, K와 항복 응력의 관계는 ($\sigma/C)^n=K^m$exp (Q/RT)인 관계식을 얻었다. 여기서 n은 6.9, m은 5.7, 그리고 Q가 251, 258, 316, 323 KJ/mo1에 대해 C는 0.155, 0.138, 0.051, 0.046MPa이다.

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황토의 물리적 특성 및 수용액중의 중금속 이온의 흡착 특성에 관한 연구 (A Study on Physical Properties and Adsorption Characteristics of Heavy Metal Ions of Loess)

  • 정의덕;김호성;박경원;백우현
    • 한국환경과학회지
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    • 제8권4호
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    • pp.491-496
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    • 1999
  • Removal of Cu(II), Cr(III) and Pb(II) ions from aqueous solutions using the adsorption process on the loesses has been investigated. Variations of contact time, pH, adsorption isotherms and selectivity of coexisting ions were experimental parameters. pH of KJ and YIK samples diluted to 1% solution, was rearly the same with each value of pH 5.58 and 5.49, and both samples showed weak acidic properties. From chemical analysis, both samples contain remarkably different amounts of ${SiO}_{2}$, ${Al}_{2}O_{3}$ and ${Fe}_{2}O_{3}$. From XRD measurement, quartz was mainly observed in both samples. Kaolinite was also observed, also in both samples, but Feldspar was only observed in KJ sample. Adsorption of metal ions on the loesses were reached at equilibrium by shaking for about 30min. The adsorption of Cr(III) ion was higher than that of Cu(II) oand Pb(II) ions. The order of amount adsorbed among the investigated ions was Cr(III)>Pb(II)>Cu(II). In acidic solution, the adsorptivity of loesses was increased as pH increased. The adsorption of Cr(III) ion on the loesses were fitted to the Freundlich isotherms. Freundlich constants(1/n) of KJ and YIK loesses were 0.54 and 0.55, respectively.

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PECVD를 이용한 ZnO박막 증착시 증착 변수가 증착속도 및 결정 구조에 미치는 영향 (The Effects of Deposition Conditions on Deposition Rate and Crystallinity of ZnO Thin Films Deposited by PECVD)

  • 김영진;김형준
    • 한국재료학회지
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    • 제4권1호
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    • pp.90-96
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    • 1994
  • 플라즈마 CVD(PECVFD)장치로 금속유기물인 Diethylzinc와 $N_{2}O$를 합성하여 $300^{\circ}C$이하의 낮은 기판 온도에서 ZnO 박막을 증착하여, 증착변수가 박막의 증착속도 및 결정구조에 미치는 영향을 알아 보았다. 기판 온도 $150^{\circ}C$에서부터 이미 결정화된 ZnO 박막의 증착이 가능했으며, $200^{\circ}C$이상에서 X-ray rocking curve분석결과, 표준편차값($\delta$)이 6˚ 미만의 c축 배향성이 뛰어난 ZnO박막이 유리 기판위에 증착되었다. 기판온도오 인가된 rf전력에 의한 증착속도의 변화 양상은 매우 다양하였으며, 특히 결정화에 따른 증착속도 변화의 전이점이 관찰되었다. 200 W와 250W의 rf 전력에서 증착된 박막의 경우 활성화 에너지는 각각 3.1 KJ/mol과 1.9 KJ/mol이었다.

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Isolation and Identification of a Lactic Acid Bacterial Strain KJ-108 and Its Capability for Deodorizing Malodorous Gases Under Anaerobic Culture Conditions

  • KIM, JEONG-DONG;JUNG-HOON YOON;YONG-HA PARK;DAE-WEON LEE;KYOU-SEUNG LEE;CHANG-HYUN CHOI;WON-YEOP PARK;KOOK-HEE KANG
    • Journal of Microbiology and Biotechnology
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    • 제13권2호
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    • pp.207-216
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    • 2003
  • A number of different sources, such as composts, leachates, and pig feces samples, were collected from different pig farms in Korea, and several microorganisms were screened for their ability to deodorize the malodorous gases. Consequently, a novel malodorous gases-deodorizing bacterial strain, KJ-108. was isolated, because it was highly abundant in nitrate-supplemented minimal medium ($MM-NO_3^-$) under anaerobic culture conditions. Airtight crimp-sealed serum bottles containing $MM-NO_3^-$ , medium were inoculated with KJ-108. Nitrate concentration was decreased rapidly after 20 h of incubation, and incubation was carried out until nitrite production reached almost zero. Taxonomic identification, including 16S rDNA base sequencing and phylogenetic analysis, indicated that the isolate had $100\%$ homology in its 165 rDNA base sequence with Lactobacillus pentosus. Among the volatile fatty acids, acetic acid contained in large amounts in fresh piggery slurry was decreased by about $40\%$ after 50 h incubation with strain KJ-108. n-Butyric acid, n-valeric acid, and isovaleric acid were gradually decreased, and isobutyric acid and capronic acid were dramatically eliminated at theinitial period with the treatment. Moreover, NH, removal efficiency reached a maximum of $98.5\%$ after 50 h of incubation, but the concentration of $H_2S$ was not changed.

천연 약용식물의 미생물 발효를 통한 장내 메탄 생성 억제 효과 비교 연구 (A Comparative Study between Microbial Fermentation and Non-Fermentation on Biological Activities of Medicinal Plants, with Emphasis on Enteric Methane Reduction)

  • 이아름;박해령;김미소;조상범;최낙진
    • 한국유기농업학회지
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    • 제22권4호
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    • pp.801-813
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    • 2014
  • 본 연구는 반추위 메탄저감용 약용식물 첨가제 개발을 위해 유산균을 이용하여 발효한 두충 및 감초 추출물의 항균활성, 항산화활성 및 in vitro 반추위 발효시험을 실시하였다. 발효 약용식물 추출물 제조를 위해 접종된 종균의 성장효율을 조사하기 위해 실시한 생균수 측정 결과 L. curvatus NJ40, L. brevis NJ42 및 L. plantarum NJ45가 두충과 감초 모두에서 유의적으로 높은 균주 성장을 나타냈다(p<0.05). 항균활성측정 결과는 두충과 감초 추출물에서 공통적으로 L. curvatus NJ40 및 L. plantarum NJ45 로 발효한 추출물이 일부 병원균에 대한 항균효과를 나타내는 것으로 조사되었다. In vitro 반추위 발효시험에서 두충 및 감초발효 추출물을 적용한 결과, 감초 추출물에서 메탄 저감효과가 나타났다. 특히 반추위내 미생물 발효 특성을 대표할 수 있는 휘발성지방산 생성효율을 향상 시키면서, 전반적 반추위 발효에 부정적 영향이 없는 것으로 나타났다.

자외선(UV)-B 조사에 의한 아위느타리버섯(Pleurotus eryngii var. ferulae) 자실체의 비타민 D2 함량 증가 (Ultraviolet (UV)-B Irradiation Increased Vitamin D2 Contents in the Fruit Bodies of Pleurotus eryngii var. ferulae)

  • 노재영;박상돈
    • 미생물학회지
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    • 제49권2호
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    • pp.191-194
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    • 2013
  • 아위느타리버섯(P. eryngii var. ferulae)의 비타민 $D_2$ (ergocalciferol) 함량 증강을 위하여 아위느타리버섯 자실체에 자외선(UV)-B파장(280-320 nm)을 조사하였다. 비타민 $D_2$ (ergocalciferol)의 증가된 함유량은 HPLC (Waters 1525, USA) 분석으로 확인하였다. 비타민 $D_2$ 함량은 3분($21.6KJ/m^2$) 처리시 $3.5{\mu}g/g$, 5분($36KJ/m^2$) 처리시 $6.02{\mu}g/g$으로 자외선을 조사하지 않은 대조군 $0.01{\mu}g/g$에 비교하여 높은 증가를 나타내었다. 이와 함께 큰느타리버섯(P. eryngii)은 대조군 $0.09{\mu}g/g$, 3분 처리시 $2.75{\mu}g/g$, 5분 처리시 $5.21{\mu}g/g$으로 나타났다. 표고버섯(L. edodes)은 대조군 $0.02{\mu}g/g$, 3분 처리시 $3.02{\mu}g/g$, 5분 처리시 $3.78{\mu}g/g$으로 나타났다. 느타리버섯(P. ostreatus)은 대조군 $0.19{\mu}g/g$, 3분 처리시 $9.63{\mu}g/g$, 5분 처리시 $11.60{\mu}g/g$으로 나타났다. 느타리버섯(P. ostreatus)의 비타민 $D_2$ 함량이 아위느타리버섯, 큰느타리버섯과 표고버섯 보다 높았으나 비타민 $D_2$ 함량 증가율은 아위느타리버섯이 월등히 높았다.

컨테이너 항만경쟁력 결정요인 분석 (The Analysis on the Determinations Factors of Container Port Competitiveness)

  • 이기태;백인흠
    • 수산해양교육연구
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    • 제27권1호
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    • pp.262-272
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    • 2015
  • The aim of this study is to analysis factors that determine the competitiveness of container ports using the KJ and AHP methods. For this, 54 detailed attributing factors were identified both by previous studies and port users. 24 attributing factors were identified by a group of port experts. also, These were grouped 18 detailed attributing factors into 6 attributing factors by a group of port experts using the KJ method. These were made into a model of hierarchical structure with 3 levels, taking 1 goal factor, 6 evaluation factors and 18 detailed evaluation factors. The collected date of questionnaires were analyzed by a group of port experts using the AHP method. The analysis result of the evaluation factors in container port shows that port cargo volume is the most important factor, followed by port location, port cost, port service, port facility and port management. The analysis results of detailed evaluation factors in container port shows that import and export cargo volume is the most important factor, followed by transshipment cargo volume, distance from main trunk, cargo handling cost, distance from the point of importing and exporting, speediness of cargo handling, stability of cargo handling, vessel/cargo cost in port entry and leaving, punctuality in port entry and leaving, number and length of berth, collateral service cost, terminal area, hinterland accessibility, ability of terminal operation company, front depth of berth, etc.

Kushta Jast, a conventional herbo-mineral immunity booster tonic: potential use in COVID-19

  • Ahmad, Tasleem;Zakir, Mohammad;Fatma, Syeda Hajra;Kazmi, Munawwar Husain;Javed, Ghazala;Ali, Shakir
    • 셀메드
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    • 제10권3호
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    • pp.24.1-24.6
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    • 2020
  • Kushta Jast (KJ) is a unique herbo-mineral preparation of the Unani System of Medicine (USM) which is prepared by taklis (calcination) and prescribed by the practitioners of USM for the treatment of various ailments, including the respiratory ailments. It is used as muqawwi (tonic) to boost the immunity (Muqawwi-i-badan), and can increase the phagocyte activity of the immune cells, thereby, promoting the growth and spread of lymphocytes and increasing circulating antibodies to neutralize a harmful pathogen and reduce humma or body fever (Dafi'-i-humma). Incidentally, the principal mineral component of KJ, zinc, has been widely acknowledged for its beneficial influence on the immune function, and decrease the risk of developing serious respiratory illnesses. In this manuscript, we provide a glimpse of the literature on KJ and postulate its potential beneficial effects in respiratory infections, including COVID-19.