• Title/Summary/Keyword: Heat stable

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Involvement of Heat-stable and Proteinaceous Materials in the Culture of Pseudomonas putida JB-1 for the Inhibition of Tobacco mosaic virus Infection

  • Jeon, Yong-Ho;Kim, Jae-Hyun;Kim, Young-Ho
    • The Plant Pathology Journal
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    • v.24 no.3
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    • pp.328-336
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    • 2008
  • Out of various fungi and bacteria tested for inhibition of Tobacco mosaic virus(TMV) infection using Nicotiana tabacum cv. Xanthi-nc, a bacterial isolate JB-l, identified as Pseudomonas putida had a strong direct inhibitory activity against the TMV infection. Its systemic or indirect activity was also noted at more than a half level of the direct control efficacy. Disease severity was reduced significantly in the susceptible tobacco N. tabacum cv. NC 82 by the treatment of the bacterial culture filtrate, somewhat more by the pretreatment than by simultaneous treatment, probably by inhibiting the TMV transmission and translocation in the plants, showing negative serological, which responses in the viral detection by DAS-ELISA. TMV-inhibitory substances from P. putida JB-1 were water-soluble, stable to high temperature(even boiling), and to a wide range of pH. As proteinase K nullified their antiviral activity, the TMV inhibition activity of P. putida may be derived from proteinaceous materials. In electron microscopy, TMV particles treated with the JB-1 culture were shown to be shrunken with granule-like particles attached on them. All of these aspects suggest that P. putida JB-1 may be developed as a potential agent for the control of TMV.

Studies on Heat Sensitivity of Egg Albumen II. Effects of pH and/or the Addition of Metal ions on Heat Sensitivity of Egg Albumen (난백의 숙감수성에 관한 연구 II. 금속염의 첨가와 pH가 난백의 열감수성에 미치는 영향)

  • 유익종;이성기;김영붕
    • Korean Journal of Poultry Science
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    • v.16 no.1
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    • pp.17-22
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    • 1989
  • In order to dull heat sensitivity of egg albumen, metal ions (aluminium, ferric, ferrous, copper) were added and functional properties or egg albumen were determined before and after heat treatment at $60^{\circ}C$ for 5 minutes. Effect of pH on heat sensitivity of aluminium salt added egg albumen was also determined. Addition of metal ions increased turbidity of egg albumen before and after the heat treatment. Changes of the turbidity were minimized by addition of aluminium salt. The foaming power was markedly increased by addition of ferric salt before the heat treatment and increased by addition of aluminium, ferric and copper salt after the heat treatment. Before the heat treatment the foam was stable by addition of ferric and ferrous salt but after the heat treatment it was stable by addition of aluminium and ferric salt. The turbidity and foaming property of the egg albumen with aluminium salt were not largely changed after the heat treatment at pH range 7 to 8.5. Over pH 9 the turbidity and foaming power were not decreased, but the foam stability was increased before and after the heat treatment. Salmonella typhimurium ATCC 14028 (10$^{6}$ cells/$m\ell$) inoculated in egg albumen at pH range 7 to 8.5 was destructed by the heat treatment.

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Enterotoxin Production and Plasmid Detection of Citrate Utilizing Escherichia coli Isolated from Cattle (우(牛) 유래(由來) Citrate이용(利用) 대장균(大腸菌)의 장독소(腸毒素) 산생능(産生能) 및 Plasmid DNA)

  • Chae, Tae-chul;Choi, Won-pil
    • Korean Journal of Veterinary Research
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    • v.28 no.1
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    • pp.59-65
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    • 1988
  • This paper deals with the 0 groups of citrate utilizing variants of Escherichia coli ($Cit^+$ E. coli) isolated from cattle, the production of colicin, hemolysin, K99 antigen, heat stable enterotoxin, and the isolation of plasmid DNA. Among 42 $Cit^+$ E. coli, 12 strains were 020, 9 strains 08, 5 strains 045, 3 strains 0115, 1 strain 064, 1 strain 0139 and remaining strains(11) were untypable. Thirty-nine(81.3%) out of 48 $Cit^+$ E. coli were produced colicin and 13(27.0%) were produced hemolysin. Of 12 $Cit^+$ E. coli bearing K99 antigen, 6(50.0%) were produced heat stable enterotoxin. In gel electrophoresis for the isolation of plasmid DNA, the number of plasmids varied from 1 to 7 in 10 $Cit^+$ E. coli. It's molecular weight ranged from 2 to 50 Mdalton, and 50 Mdalton plasmid was commonly existed in all strains.

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Nonlinear Behaviors of Pulsating Instabilities in Counterflow Diffusion Flames with Radiation Heat Loss (복사 열손실을 받는 대향류 확산화염의 맥동 불안정성의 비선형 거동)

  • Lee, Su Ryong;Park, Sung Cheon
    • Journal of the Korean Society of Combustion
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    • v.17 no.3
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    • pp.9-16
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    • 2012
  • Nonlinear dynamics of pulsating instability in radiating counterflow diffusion flames is numerically investigated by imposing Damk$\ddot{o}$hler number perturbation. Stable limit-cycle solutions occur in small ranges of Damk$\ddot{o}$hler numbers past bifurcation point of instability. Period doubling cascade and chaotic behaviors appear just before dynamic extinction occurs. Nonlinear dynamics is also studied when large disturbances are imposed to flames. For weak steady flames, the dynamic extinction range shrinks as the magnitudes of disturbances are increased. However, strong steady flames can overcome relatively large disturbances, thereby the dynamic extinction range extending. Stable limit-cycle behaviors reappears prior to dynamic extinction when the steady flames are strong enough.

Growth Retardation of Escherichia coli and Staphylococcus aureus by Leek Extract (부추 추출무에 의한 Escherichia coli 및 Staphylococcus aureus의 생육 저해효과)

  • 이민경;이정아;박인식
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.1
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    • pp.196-198
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    • 2001
  • The growth retardation of Escherichia coli and Staphylococcus aureus by heat or acid treated leek (Allium tuberosum) extract was observed. Antimicrobial activity of the leek was the most effective when fresh leek extract was used, but it was stable after heat treatment at 68$^{\circ}C$ for 30 min or 98$^{\circ}C$ for 20 min. It was also relatively stable after incubated at pH 2.0 for 3 hrs. The antimicrobial activity in leek was not detected after dialysis with molecular weight cutoff of 12,000. Therefore it seems to be small molecule with molecular weight lower than 12,000.

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Design and evaluation of laser module for light delivery in heat assisted magnetic recording (열 보조 자기기록용 광 전달 레이저 모듈의 설계 및 평가)

  • Choi, Yong-Bok;Lee, Moon-Ho;Kim, Young-Joo
    • Transactions of the Society of Information Storage Systems
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    • v.7 no.1
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    • pp.36-41
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    • 2011
  • The micro laser module was designed and prepared to deliver the light to the HAMR head. It consists of laser diode, photo diode and actuator to realize stable light delivery even though the head is fluctuated during the disk rotation. The optical evaluation was carried out with the actual distance between the light source and HAMR head with a range of reflectivity and it was found that the incident angle could be controlled within ${\pm}0.125^{\circ}$ to maintain same intensity into the HAMR head. It was also confirmed that the designed micro laser module is thermally stable without any severe effect on the magnetic head.

A Study on the Performance Characteristics of a Heat Pipe Combined with PCM (상변화 물질을 조합한 히트파이프의 성능 특성에 관한 연구)

  • Park, Young-Hark;Jung, Eui-Guk;Boo, Joon-Hong
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2119-2123
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    • 2007
  • This study deals with performance characteristics of heat pipe combined with a solid-liquid phase change material(PCM). The outer diameter of the heat pipe was 9.5 mm and the total length was 600 mm, where the evaporator, the adiabatic section and the condenser lengths were equally 200 mm. A paraffin wax having a melting point of 58.5$^{\circ}C$ was used as PCM. The paraffin container was attached to the adiabatic section of the heat pipe. The paraffin container had outer diameter of 18 mm, wall thickness of 1.2 mm and the total length of 100 mm. The heat pipe was tested with tilt angle of horizontal degree and favorite angle 10 degree, with evaporator lower position to provide stable operation of the heat pipe. Input thermal load was varied from 40 W, with increment of 40 W, to above 100 W until the maximum temperature of the heat pipe wall reached 200$^{\circ}C$. Test results of the PCM heat pipe were presented in comparison with conventional heat pipe of the same basic dimensions. The performance was analyzed in terms of temperature distribution, thermal resistance and heat transport capability.

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Performance Characteristics and Economic Assessment of Heat Pump Systems with the Various Heat Source (열원에 따른 열펌프의 성능 비교 및 경제성 평가)

  • Park, Cha-Sik;Park, Kyoung-Woo;Kwon, Oh-Kyung
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.7 no.1
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    • pp.23-31
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    • 2011
  • The objectives of this study are to analyze the performance of a heat pump system with the various heat source and to carry out economic assessment for the heat pump system. The COP of the river water and ground source heat pump system was 20% higher than that of the air source heat pump system because river water and geothermal provide stable operating temperature compared with air temperature throughout the year. In addition, the economic assessment of a heat pump system using air, river water, and geothermal as a heat source was carried out. The ratio of the life cycle operating cost to the life cycle cost increased with the increase of building capacity. The payback period was found to be less than 3.3 and 4.5 years, respectively when the capacity of the river water and ground source heat pump was larger than 10 RT.

Effects of Ca Implantation on the Sintering and Crack Healing Behavior of High Purity $Al_2$O$_3$ Using Micro-Lithographic Technique-III: Stability of Crack-Like Pore (Ion Implantation으로 Ca를 첨가된 단결정 $Al_2$O$_3$의 Crack-Like Pore의 Healing 거동-III: Stability of Crack-Like Pore)

  • 김배연
    • Journal of the Korean Ceramic Society
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    • v.36 no.9
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    • pp.887-892
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    • 1999
  • The inner crack-like pore with controlled amount of Ca impurity in the high purity alumina single crystal sapphire had been created by micro-fabrication technique which includes ion implanation photo-lithography Ar ion milling and hot press technique. The crack-like pores in two-hour hot pressed specimen were extremely stable even after heat treating at 1,80$0^{\circ}C$ for 5 hours almost no healing was observed. But the crack-like pores in one-hour hot pressed specimen at 1,30$0^{\circ}C$ were healed by heat treatment and the amount of healing was increased with the heat treatment time and temperature and the amount of Ca addition. The edges of crack-like pore parallel to <1100> direction in (001) basal plane were stable but the edges normal to this direction in (00101) plane <1120> direction were unstable to facetting This means that the surface energy of alumina along the <1100> direction in (0001) basal plane in much lower than <1120> direction.

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Lysozyme Activity in Buffalo Milk: Effect of Lactation Period, Parity, Mastitis, Season in India, pH and Milk Processing Heat Treatment

  • Priyadarshini, Subhadra;Kansal, Vinod K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.6
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    • pp.895-899
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    • 2002
  • Lysozyme activity in buffalo milk in relation to the period of lactation, parity of animal, weather conditions and udder infections was studied. Effect of storage and heat processing of milk on lysozyme activity was determined. Lysozyme activity was higher in buffalo milk than in cow milk. Buffalo colostrum showed lysozyme activity 5 times of that in mature milk. Lysozyme activity in buffalo milk was not influenced by the parity of animal and the stage of lactation, however, it increased during extreme whether conditions (winter and summer). Lysozyme in both cow and buffalo milk exhibited maximum activity at pH 7.4. Buffalo milk lysozyme was fully stable while the cow milk lysozyme was partly inactivated by pasteurization (low temperature-long time as well as high temperature-short time treatments). Lysozyme in buffalo milk was more stable than in cow milk during storage and heat treatment. A 10 to 50-fold increase in milk lysozyme activity was observed in mastitic cows. An assay of lysozyme activity in milk can be used to diagnose mastitis in cattle but not in buffaloes. Some buffaloes exhibited 1000 fold greater lysozyme activity and moderately raised somatic cell count in milk, but there was no sign of mastitis in these animals. A possible role of milk lysozyme in prevention of mastitis in buffaloes is discussed.