• Title/Summary/Keyword: KJ3

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

  • Lee, Jae-Yeong;Choe, Hyeong-Gi;Sim, Mi-Ja;Kim, Sang-Uk
    • Korean Journal of Materials Research
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    • v.7 no.3
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    • pp.229-233
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    • 1997
  • Estimation of thermal stability for diglycidy1 ether of bisphenol A(DGEMA)/4, 4'-methylene dianiline (MDA)/pheny1 glycidy1 ether(PGE)-acetamide(AcAm)/carboxy1-terminated acrylonitrile butadiene copolymer (CTBN) system was studied by thermogravimetry(TG) analysis. To get activation energy for thermal degradation, Freeman & Carroll, Kissinger, and Flynn & Wall expressions were used. The activation energy of Freeman & Wall expression was 112.9kj/mol, that of Kissinger expression was 151.5 kj/mol and that of Flynn & Wall was 168.3kj/mol.

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

  • Kye-Ho Nho;Sun-Pil Choi;Byong-Whi Lee
    • Nuclear Engineering and Technology
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    • v.21 no.2
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    • pp.111-122
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    • 1989
  • With the Zircaloy-4 tube oxidized in high temperature (1323 K) steam for 5, 10, 30 and 60 minutes, the expanding copper mandrel test was carried out over a temperature range of 673-l173k at $\varepsilon\;=\;3.0\times10^5S\;^1$. The oxidation parameters $(K_i)$ in the present study were linearly proportional to square root of time $(Ki= \delta_{kit})$ and their rate constants ($\delta_{ki}$) are 0.281, 2.82, and 2.313 for weight gain and thickness of Zr02 and $\alpha$(0) layer, respectively. Activation energy for high temperature (873-1073k) plastic deformation of Zircaloy-4 increases from 251 KJ/mol to 323 KJ/mol with increase in oxidation time from 5 minutes to 60 minutes due to the high strengthened Zr02. With the oxide layer thickness [K ; expressed in "Equivalent Cladding Reacted" (ECR,%)] and the yield stress obtained from the mandrel test, an empirical relation was derived as ($\sigma/C)^n=K^mexp$ (Q/RT) with n=6.9, m=5.7, C=0.155, 0.138, 0.051, and 0.046 MPa for Q=251, 258, 316, 323 KJ/mol, respectively.

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

  • 정의덕;김호성;박경원;백우현
    • Journal of Environmental Science International
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    • v.8 no.4
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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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The Effects of Deposition Conditions on Deposition Rate and Crystallinity of ZnO Thin Films Deposited by PECVD (PECVD를 이용한 ZnO박막 증착시 증착 변수가 증착속도 및 결정 구조에 미치는 영향)

  • Kim, Yeong-Jin;Kim, Hyeong-Jun
    • Korean Journal of Materials Research
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    • v.4 no.1
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    • pp.90-96
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    • 1994
  • ZnO thin films were deposited using Diethylzinc and $N_{2}O$ gas by plasma enhanced CVD (PECVD) at low substrate temperatures below $300^{\circ}C$. The effect of deposition parameters on the growth rate and the structural properties was determined at various deposition conditions. Crystallized ZnO thin films were successfully deposited even at $150^{\circ}C$ of substrate temperature. Above $200^{\circ}C$ c-axis oriented ZnO thin films, of which a standard deviation of X-ray rocking curve was less than $6^{\circ}$. were deposited on glass substrates. The variation of deposition rate showed different trends depending on substrate temperature and rf-input power. According to the deposition rate behavior as a function of substrate temperature, the transition points were observed resulting from crystallization of ZnO thin films. The activation energies for the deposition of ZnO thin films were 3.1KJ/mol and 1.9KJ/mol for the rf powers of 200W and 250W, respectively.

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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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    • v.13 no.2
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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.

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

  • Lee, A-Leum;Park, Hae-Ryoung;Kim, Mi-So;Cho, Sangbuem;Choi, Nag-Jin
    • Korean Journal of Organic Agriculture
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    • v.22 no.4
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    • pp.801-813
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    • 2014
  • A study was conducted to improve the biological activity of two medicinal plants, Eucommia ulmoides Oliv. and Glycyrrhiza uralensis, by fermentation. The biological activity was assessed by determining antibacterial, antioxidant and antimethanogenic properties. Fermentation was achieved by adding the plant materials in MRS broth at 10% (w/v) and different starter cultures at 1% (v/v). Condition for fermentation were incubation temperature of $30^{\circ}C$ and agitation at 150 rpm for 48 h. Six starter cultures, Weissella confusa NJ28 (Genbank accession number KJ914897), Weissella cibaria NJ33 (Genbank accession number KJ914898), Lactobacillus curvatus NJ40 (Genbank accession number KJ914899), Lactobacillus brevis NJ42 (Genbank accession number KJ914900), Lactobacillus plantarum NJ45 (Genbank accession number KJ914901) and Lactobacillus sakei NJ48 (Genbank accession number KJ914902) were used. Antibacterial activity was observed in L. curvatus NJ40 and L. plantarum NJ45 only as opposed to other treatments, including the non-fermented groups, which showed no antibacterial activity. Both plants showed antioxidant activity, although E. ulmoides Oliv. had lower activity than G. uralensis. However, fermentation by all strains significantly improved (p<0.05), antioxidant activity in both plants compared to non-fermented treatment. Six treatments were based on antibacterial activity results, selected for in vitro rumen fermentation; 1) non-fermented E. ulmoides, 2) fermented E. ulmoides NJ40, 3) fermented E. ulmoides NJ45, 4) non-fermented G. uralensis, 5) fermented G. uralensis NJ40, 6) fermented G. uralensis NJ45. A negative control was also added, making a total of 7 treatments for the in vitro experiment. Medicinal plant-based treatments significantly improved (p<0.05) total volatile fatty acid (VFA) concentration. Significant methane reduction per mol of VFA were observed in G. uralensis (p<0.05). Based on the present study, fermentation improves the biological activity of E. ulmoides Oliv. and G. uralensis. Fermented G. uralensis could also be applied as an enteric methane mitigating agent in ruminant animals.

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

  • Rho, Jae-Young;Park, Sang-Don
    • Korean Journal of Microbiology
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    • v.49 no.2
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    • pp.191-194
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    • 2013
  • The fresh fruit bodies of Pleurotus eryngii var. ferulae was irradiated with ultraviolet (UV)-B (280-320 nm) in order to increase vitamin $D_2$ contents, which was assayed using HPLC (Waters 1525, USA). The vitamin $D_2$ contents were $3.5{\mu}g/g$ after 3 min UV-B irradiation ($21.6KJ/m^2$) and $6.02{\mu}g/g$ after 5 min UV-B irradiation ($36KJ/m^2$), respectively, which showed the significant increase considering the vitamin $D_2$ content ($0.01{\mu}g/g$) before UV-B irradiation. This increasing effect was confirmed also for other edible mushrooms; Pleurotus eryngii, from $0.09{\mu}g/g$ to $2.75{\mu}g/g$ (3 min) and $5.21{\mu}g/g$ (5 min); Lentinus edodes, from $0.021{\mu}g/g$ to $3.02{\mu}g/g$ (3 min) and $3.78{\mu}g/g$ (5 min); Pleurotus ostreatus, from $0.19{\mu}g/g$ to $9.63{\mu}g/g$ (3 min) and $11.6{\mu}g/g$ (5 min). Although the original content of vitamin $D_2$ was the highest in P. ostreatus, the extent of increase by UV irradiation was remarkably high in P. eryngii var. ferulae.

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

  • Lee, Ki-Tae;Baek, In-Hum
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.1
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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
    • CELLMED
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    • v.10 no.3
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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.