• 제목/요약/키워드: Initial growth

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Influences of Ginseng Component on Cell Growth and Acid Production by Lactobacillus casei Burins Yogurt Fermentation (Yogurt 제조시 인삼성분이 Lactobacillus casei의 증식과 산생성에 미치는 영향)

  • 소명환
    • The Korean Journal of Food And Nutrition
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    • v.1 no.2
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    • pp.76-85
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    • 1988
  • In order to obtain the basic data for the preparation of yogurt containing ginseng component, the effect of ginseng component on cell growth of Lactobacillus casei YIT 9018 and on lactic acid production were investigated. Initial cell growth and acid production were markedly inhibited by the addition of ethanol extracts in the level of 8% into 15% skim milk. Crude saponin did not show any inhibitory effect on cell growth and acid production, but ether layer fraction showed inhibitory effect. It was thought to be more advantageous to add ginseng extracts after the fermentation of milk than before. The addition of ginseng extract at 8% level into liquid yogurt was most suitable in organoleptic test. Cell viability was not affected by the addition of ethanol extracts up to 8% level during storage of liquid yogurt.

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A Study for the Fatigue Crack Growth Behavior of Concrete (콘크리트의 피로균열 성장거동에 관한 연구)

  • 김진근;김윤용
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.10a
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    • pp.101-107
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    • 1996
  • In this study, the wedge splitting test (WST) specimens with various strength levels were tested to investigate the fatigue crack growth behavior of concrete. Selected test variables were concrete compressive strength with 2 levels (28 MPa, 60 MPa, 100 MPa) and maximum fatigue loading with 2 levels (75%, 85%). Fatigue testing was preceded by fracture energy test and the crack growth was measured by means of the compliance calibration method, 60 WST specimens were cast for the fatigue test, and 6 companion cylinders ($\phi$100${\times}$ 200 mm) for each batch. In fatigue test, the frequency of loading cycle was 1 Hz, and the minimum fatigue loading level was 5~10 % of ultimate monotonic loading. On the basis of the experimental results, a fracture mechanics-based empirical relationships for fatigue crack growth rate (da/dN-$\Delta$KI relationships) were presented. In addition, the effect of initial notch depth on the fracture energy and the validity of compliance calibration technique for the WST were shown.

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Isolation and Characterization of a Phenol-Degrading Bacteria (Phenol 분해 균주의 분리 및 특성)

  • 정경훈;차진명;오인숙;고한철;정오진;이용보
    • KSBB Journal
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    • v.13 no.2
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    • pp.119-124
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    • 1998
  • Twelve bacterial strains capable of growing on phenol minimal medium were isolated from iron foundry activated sludge by enrichment culture, and amount them, one isolate which was the best in cell growth and phenol degradation was selected and identified as Acinetobacter junii POH. The optimal temperature, initial pH and phenol concentration in the above medium were 3$0^{\circ}C$, 7.5 and 1000 ppm, respectively. Cell growth of Acinetobacter junii POH dramatically increased 20 hrs cultivation-time and reached a almost stationary phsae 40 hrs cultivation-time then phenol was degraded about 98%. Cell growth was inhibited y phenol at concentrations over 1500 ppm. The isolate was resistant to several antibiotics as well as various heavy metal ions. The growth-limiting log P value of Acinetobacter junii POH on organic solvents was 2.9 in the LB medium. Therefore, it is suggested that Acinetobacter junii POH could be effectively used for the biological treatment of wastewater containing the presence of heavy metal ions and organic solvents.

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Optimal Culture Conditions for Mycelial Growth and Exo-polymer Production of Ganoderma applanatum

  • Jeong, Yong-Tae;Jeong, Sang-Chul;Yang, Byung-Keun;Islam, Rezuanul;Song, Chi-Hyun
    • Mycobiology
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    • v.37 no.2
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    • pp.89-93
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    • 2009
  • The effect of fermentation parameters and medium composition on the simultaneous mycelial growth and exo-polymer production from submerged cultures of Ganoderma applanatum was investigated in shake-flask cultures. The optimum initial pH for mycelial growth and exo-polymer production was 5.0 and 6.0, respectively. The optimum temperature was $25^{\circ}C$ and the optimum inoculum content was 3.0% (v/v). The optimal carbon and nitrogen sources were glucose and corn steep powder, respectively. After 12 days fermentation under these conditions, the highest mycelial growth was 18.0 g/l and the highest exo-polymer production was 3.9 g/l.

Isolation and Characterization of Pseudomonas sp. DCB3 Degrading 1.2-Dichlorobenzene (1.2-Dichlorobenzene을 분해하는 Pseudomonas sp. DCB3의 분리 및 특성)

  • 서승교;우철주;이창호
    • Journal of Environmental Health Sciences
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    • v.23 no.4
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    • pp.33-38
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    • 1997
  • Four bacterial strains able to degrade dichlorobenzene as the sole source of carbon and energy were isolated from soil by selective enrichment culture, and among them, one isolation was the best in the cell growth and identified as Pseudomonas sp. DCB3 by its morphology and physiological properties. Cell growth dramatically increased in a minimal medium containing 500ppm of dichlorobenzene was not detected any more at 72 hours after cultivation. The optimal temperature and initial pH for the growth of the isolated strain were 30$\circ$C and 7.0, respectively. Cell growth was increased by supplementing $(NH_2)_2CO$ and 50 ppm yeast extract as additional nutrients. Therefore, it was suggested that Pseudomonas sp. DCB3 could be effectively used for the biological treatment of wastewater containing dichlorobenzene.

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Simulation of Stress Corrosion Crack Growth in Steam Generator Tubes (증기발생기 전열관에서의 응력부식 균열성장해석)

  • Shin, K.I.;Park, J.H.;Joo, J.W.;Shin, E.S.;Kim, H.D.;Chung, H.S.
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.19-24
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    • 2000
  • Stress corrosion crack growth is simulated after assuming a small axial surface crack inside a S/G tube. Internal pressure and residual stresses are considered as applied forces. Stress intensity factors along crack front, variation of crack shape and crack growth rate are obtained and discussed. It is noticed that the aspect ratio of the crack is not depend on the initial crack shape but depend on the residual stress distribution.

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Growth and Electronic Properties of Ag Overlayers on Stepped Pt(211) Surface

  • 김유권;김정원;김세훈
    • Bulletin of the Korean Chemical Society
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    • v.17 no.12
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    • pp.1154-1157
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    • 1996
  • The growth and electronic properties of ultrathin silver films deposited onto Pt(211) surface were studied using Auger electron spectroscopy (AES), low-energy electron diffraction (LEED), and x-ray photoelectron spectroscopy. The AES and LEED results indicate that the silver grows by a layer by layer growth followed by three dimensional islands growth. The XPS results show that the Ag 3d core-level binding energy of Ag overlayers on Pt(211) shifts toward lower binding energy relative to the bulk value at lower Ag coverage. This negative binding energy shift of the Ag 3d core level is explained by the reduced coordination number of the overlayer atoms and the resulting initial state band narrowing effect suggested by Wertheim and Citrin [Phys. Rev. Lett. 1978, 41, 1425].

Development of Allometry and Individual Basal Area Growth Model for Major Species in Korea (우리나라 주요수종의 Allometry와 개체목 흉고단면적 생장모델 개발)

  • Choi, Jung-Kee
    • Journal of Forest and Environmental Science
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    • v.27 no.1
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    • pp.47-54
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    • 2011
  • Allometry and basal area equations were developed with various tree measurement variables for the major species; Quercus variabilis, Quercus mongolica, Pinus koraiensis and Larix leptolepis in Korea. For allometry models, the relationships between total height-DBH, crown width-DBH, height to the widest portion of the crown-total height, and height to base of crown-total height were investigated. Multiple regression methods were used to relate annual basal area growth to tree variables of initial size (DBH, total height, and crown width), relative size (relative diameter and relative height) as well as competition measures (competition index, crown class, and live crown ratio).

Effects of iron injection in suckling piglets on growth performance, fecal score, and hematological criteria

  • Madesh Muniyappan;In Ho Kim
    • Korean Journal of Agricultural Science
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    • v.50 no.2
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    • pp.155-164
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    • 2023
  • A total of 16 sows (average parity = 3.5 ± 0.10, standard deviation = 2.05) and their newborn pigs (Duroc × [Landrace × Yorkshire], initial body weight 1.53 ± 0.07 kg) were used in a 21-day study. On day 3 of age, piglets along with their dam were divided into two groups: CON and TRT. CON group piglets did not receive any iron injection while, TRT group piglets received 200 mg of injectable iron (GleptoForte) in a single dose. The administration of iron at day-3 of birth improved weaning body weight and overall average daily gain in sucking piglets compared with their control counterparts. For blood criteria, injection of 200 mg of iron improved serum iron values and hematocrit and decreased total iron binding capacity (TIBC) during the day 21 period. In summary, 200 mg iron injection at birth resulted in greater growth performance and blood iron status. These results indicate that providing 200 mg of injectable iron is sufficient to optimize the growth performance and blood iron status of suckling piglets.

Effect of channel hight on Bubble growth under Saturated Nucleate Pool Boiling for Various Channel Height using Heater with Artificial Cavity (인공 캐비티를 가진 히터를 이용한 가열면의 채널 높이가 풀비등시 기포성장에 미치는 영향에 대한 기초연구)

  • Kim, Jeong-Bae;Park, Moon-Hee;Jeon, Woo-Cheol
    • Journal of the Korean Solar Energy Society
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    • v.30 no.5
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    • pp.93-99
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    • 2010
  • Nucleate pool boiling experiments with constant heat flux condition were performed using pure R113 for various channel heights under saturated pool condition. A circular heater of 1mm diameter, with artificial cavity in the center, fabricated using MEMS technique and the high-speed controller were used to maintain the constant heat flux. Images of bubble growth were taken at 5,000 frames per second using a high-speed CCD camera. The bubble geometry was obtained from the captured bubble images. The effects of channel height on the bubble growth behaviors were analyzed as dimensional scales for the initial and thermal growth regions. The parameters for the bubble growth behaviors were bubble radius, bubble growth rate, and bubble shapes. These phenomena require further analysis for various surface angles, but this study will provide good experimental data with constant heat flux boundary condition for such works.