• Title/Summary/Keyword: density of media

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Effects of Cell Size, Density, Conditioned Media and pH on Carrot (Daucus carota L.) Cell Embryogenesis (당근(Daucus carota L.) 세포 배양시 세포의 크기, 밀도, Conditioned 배지 및 pH가 배발생에 미치는 영향)

  • 백기엽;이철희;황주광
    • Journal of Plant Biology
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    • v.28 no.2
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    • pp.141-148
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    • 1985
  • The effects of sizes and densities of cells cultured, conditioned medium, and media pH on the somatic embryogenesis of carrot (Daucus carota L.) were examined. A large number of globular embryoids was formed after 4 days in cell culture, and later globular embryoids developed into heart and torpedo shape. High cell density resulted in higher number and better growth of embryos, especially on conditioned medium than Murashige-Skoog medium. The fresh weight and number of embryoids formed increased with the decrease in cell size. The significant reduction in fresh weight and number of embryoids was obtained when culturing cells with diameter of over 90 ${\mu}{\textrm}{m}$. Dry weight and number of embryoids were markedly reduced with medium pH of 4 or 7, but promoted with pH 6.0.

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Self-Organized Nano Structure in Co-22% Cr Alloy Thin Films with Substrate Temperatures (기판온도에 따른 Co-22%Cr 합금박막의자가정렬형 나노구조)

  • 송오성;이영민
    • Journal of Surface Science and Engineering
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    • v.34 no.6
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    • pp.531-536
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    • 2001
  • Co-22 %Cr alloy films are promising for high-density perpendicular magnetic recording media with their perpendicular anisotropy and large coercivity of 3000 Oe. We observed that a self organized nano structure (SONS) of fine ferromagnetic Co-enriched phase and paramagnetic Cr-enriched phase appears inside the grain of Co-Cr magnetic alloy thin films at the elevated substrate temperature after do-sputtering. The periodic fine Co-enriched phase and Cr-enriched phase is the plate shape of 80 (equation omitted)-wide and 1000 (equation omitted)-long. Cr-enriched phases are located at the center of grains. We prepared 5000 (equation omitted) -thick Co-22 %Cr films on polyimide substrate with varying substrate temperature of $ 30^{\circ}C$, $ 150^{\circ}C$ ,200 $^{\circ}C$, $300^{\circ}C$, and $400^{\circ}C$, respectively. A transmission electron microscope equipped with energy dispersive X-ray analyzer is employed to observe the microstructure of each samples after Co-enri-ched phase are etched selectively. The self organized nano structure of Co-enriched and Cr-enriched lamellar is observed above the substrate temperture of $150^{\circ}C$. No compositional change is observed with substrate temperature. The compositional phase separation in self organized structure becomes clear as the substrate temperature increases. Our results implies that the self organized nano structure in Co-22 %Cr film is ideal for ultra high density recording media by recording selectively on Co-enri-ohed phase.

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OPTIMAL SPUTTERING CONDITIONS FOR HIGH-DENSITY MAGNETIC RECORDING MEDIA BY FTS

  • Noda, Kohki;Kawanabe, Takashi;Naoe, Masahiko
    • Journal of Surface Science and Engineering
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    • v.29 no.6
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    • pp.824-828
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    • 1996
  • Co-based alloy thin films ddeposited by fcing targets sputtering(FTS) were investigated for use in high-density magnetic recording media to determine how their magnetic properties are dependent on the sputtering conditions, and thus to find appropriate parameters that allow the sputtering and thin films to meet the specificiations for magnetic properties. FTS can discharge at lower working gas pressure than other sputtering methods such as dcmagnetron sputteing because the plasma is sufficiently confined by a magnetic field applied perpendicular to both of the target planes, which results in plasma-free substrates. Co-Cr-Ta films were deposited by FTS on glass and silicon substrates at substrate temperature between room temperature and $350^{\circ}C$, and at argon gas pressure between 0.1 and 10mTorr. The films were also deposited on polyimide tapes at substrate temperature of $130^{\circ}C$ and argon gas pressure of 1 mTorr. The effective advantages of Ta as an additional element were investigated, using the same films on the tapes. As a result of the experiment, it was found that better magnetic properties were obtained in the ranges of higher temperature and lower argon gas pressure with background pressure in thr range of $1.5 \times 10^{-6}$ Torr. Ta addition at 2 to 4 atomic percent almost havled the Co-Cr grain sizes, indicating that Ta addition at an appropriate atomic percent is effective for improving the microstructure and characteristics of Co-Cr films.

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Dependence of Ultrasonic Nonlinear Parameter B/A on Fat (지방질에 대한 초음파 비선형 파라메타 B/A의 의존성)

  • 김정구;배종림
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.4
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    • pp.101-106
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    • 2000
  • This study deals with the relationship between the magnitude of ultrasonic nonlinear parameter B/A, sound speed of amount of fat present in biological media for measuring B/A system using a wide band ultrasonic transducer. To represent this case, mixtures of egg white and egg yolk were studied. Even though the differences in density and sound speed of the two egg components were within 1% of each other, B/A were increases parabolically as a function of the fat density, which is not in agreement with the Yoshizumi et al's suggestion. In skim milk that does not contain fat, both the B/A and the sound speed increase with the solubility. It is proposed that protein could affect these values.

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Characteristics of Metacordyceps yongmunensis, a New Species from Korea

  • Sung, Gi-Ho;Shrestha, Bhushan;Sung, Jae-Mo
    • Mycobiology
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    • v.38 no.3
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    • pp.171-175
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    • 2010
  • Metacordyceps yongmunensis is a newly reported species from Korea, which is very similar to Cordyceps species in morphological characters. It grows on large lepidopteran pupa, and numerous white stromata grow on a single host. Mycelial growth characteristics of M. yongmunensis isolates were studied in different media and at different temperatures. Also, different carbon sources, nitrogen sources, and mineral salts were tested for mycelial growth of M. yongmunensis. Schizophyllum (mushroom) genetics complete medium plus yeast extract, Schizophyllum (mushroom) genetics minimal medium, and Martin's peptone dextrose agar produced longer colony diameters and more compact mycelial density than other media. The optimum temperature for mycelial growth was $25^{\circ}C$. Carbon sources such as sucrose, soluble starch, dextrose, glucose, dextrin, maltose, and fructose showed better mycelial growth, whereas peptone, yeast extract and tryptone resulted in the best mycelial growth of all of the nitrogen sources tested. All of the mineral salts tested showed similar growth as the control, except $K_2HPO_4$ which showed longer colony diameter and more compact mycelial density. The compact colonies were white and cottony with a greenish margin. The results showed that M. yongmunensis is an easy fungus to growas it grew from 30 to more than 50 mm in 2 wk.

Color image segmentation by level set method (레벨셋 기법을 이용한 컬러 이미지 분할)

  • Yoo, Ju-Han;Jung, Moon-Ryul
    • Journal of the Korea Computer Graphics Society
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    • v.18 no.2
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    • pp.9-15
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    • 2012
  • In this paper, we propose a method to segment a color image into several meaningful regions. We suppose that the meaningful region has a set of colors with high frequency in the color image. To find these colors, the color image is represented as several sets of color points in RGB space. And when we use the density of points defined in this method, color belonging to a dense region of color points in RGB space refers to the color that appeared frequently in the image. Eventually, we can find meaningful regions by looking for regions with high density of color points using our level set function in RGB space. However, if a meaningful region does not have a contiguous region of the sufficient size in the image, this is not a meaningful region but meaningless region. Thus, the pixels in the meaningless region are assigned to the biggest meaningful region belonging to its neighboring pixels in the color image. Our method divides the color image into meaningful regions by applying the density of color points to level set function in RGB space. This is different from the existing level set method that is defined only in 2D image.

Sutdy of Appropriate Media Selection and Early Life Cycle of Marine Free-Living Nematodes, Enoplolaimus sp. (Enoplida: Thoracostomopsidae) and Bathylaimus sp. (Enoplida: Tripyloididae) (해양 자유생활형 선충류 Enoplolaimus sp. (Enoplida: Thoracostomopsidae)와 Bathylaimus sp. (Enoplida: Tripyloididae)의 배양용 적합배지 선정 및 초기 생활사 연구)

  • SHIN, AYOUNG;KIM, DONGSUNG;KANG, TEAWOOK;OH, JE HYEOK;LEE, JIMIN;HONG, JAE-SANG
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.23 no.3
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    • pp.109-124
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    • 2018
  • In order to find the optimum culture condition for marine free-living nematoda in the laboratory, various agar media were developed and experiments were carried on nematodes. Nematodes have collected from the bottom of the sandy sediments' surface layer (about 5cm sediment) of Taean Mallipo beach's intertidal zone. Especially, with regard to agar medium, Killian medium was transformed slightly, density of agar had made a difference and this agar medium(height 2.0 mm on diameter 60 mm Petri dish) was divided. It was mixed with 5 different species of microorganism as nematodes' live food and added each culture medium. Five individuals of Enoplolaimus sp. on each culture medium were grown in a culture medium which was set on $20^{\circ}C$ and light blocked. Moreover, as a result of the optimum culture condition, 1.0% density of agar showed the highest survival rates (the average time of survival is 246.8 hours). On the other hand, the 0.4% density of agar adding Killian medium, bacto peptone and beef extract showed the lowest survival rates, which indicates the average time of survival is 27.6 hours. About Bathylaimus sp., on Killian medium's 1.0% density of agar(no feeding amount) showed the highest survival rates, which connects that the hatching rate 94.7% after 99.5 hours and it laid 7 eggs averagely on the spawning amount and the hatching rate experiment.

Laboratory Culture Media-Dependent Biocontrol Ability of Burkholderia gladioli strain B543

  • Bae, Yeoung-Seuk;Park, Kyung-Seok;Choi, Ok-Hee
    • The Plant Pathology Journal
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    • v.23 no.3
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    • pp.161-165
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    • 2007
  • Cultivation of a biocontrol agent on a certain medium often results in reduced biocontrol efficacy and alters physiological state. In our previous study, Burkholderia gladioli strain B543 with long-term subculture on tryptic soy agar resulted in significantly reduced biocontrol ability against cucumber damping-off caused by P. ultimum. Therefore, we investigated the influence of laboratory culturing media on biocontrol activity and physiological state of Burkholderia gladioli strain B543 by using long-term repeated culture on a certain medium. When isolate B543 were successionally cultured on King's B agar (KBA), tryptic soy agar, nutrient agar (NA), or soil extract agar more than 20 times, the isolate cultured on KBA or NA showed a significantly enhanced biocontrol efficacy and higher population density in the rhizosphere of cucumber compared to that of the others. However, the isolates cultured on KBA more than 20 times showed the lowest production of protease, siderophore, or antifungal substance(s), measured by skim milk agar, Chrome-Azurol-S agar, and potato dextrose agar amended with 10% of the culture filtrate, respectively. Our results suggest that adaptation to proper culturing medium can alter biocontrol ability and physiological state, and we must consider laboratory media in optimizing the use of biocontrol agents.

Theoretical and Experimental Studies on the Adsorption of N-[(E)-Pyridin-2-ylmethylidene] Aniline, a Schiff Base, on Mild Steel Surface in Acid Media

  • N, Mohanapriya.;M, Kumaravel.;B, Lalithamani.
    • Journal of Electrochemical Science and Technology
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    • v.11 no.2
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    • pp.117-131
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    • 2020
  • The adsorption of N-[(E)-Pyridin-2-ylmethylidene] aniline, a Schiff base, on to mild steel surface in 1M HCl and 0.5 M H2SO4 solutions and the consequent corrosion protection were studied employing weight loss method, electrochemical impedance spectroscopy and potentiodynamic polarization measurements. DFT calculations were performed to investigate its interaction with the metal surface at the atomic level to understand its inhibition mechanism. The adsorption process is well described by the Langmuir isotherm. The thermodynamic parameters indicated that the adsorption is spontaneous and the interaction of the inhibitor at the mild steel surface is mainly through physisorption. The Ra values obtained in AFM studies for the uninhibited and inhibited sample in HCl media respectively are 0.756 and 0.559 ㎛, and that in H2SO4 media are 0.411 and 0.406 ㎛. The lesser roughness values of the inhibited sample shows the adsorption of the molecules onto the mild surface. The inhibition efficiencies were found to improve with concentration of the inhibitor and the maximum efficiency was observed at 400ppm in all the investigation methods adopted. The inhibitor was found to exhibit a higher efficiency in HCl media (95.7%) than in H2SO4 (92.8%). The theoretical and experimental results are found to be in good agreement.

Physiological characteristics of Fomitopsis pinicola in sawdust media (소나무잔나비버섯(Fomitopsis pinicola) 톱밥재배 연구)

  • Chang, Hyun-You;Oh, Seung-Hee;Lee, Hoo-Jin
    • Journal of Mushroom
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    • v.2 no.4
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    • pp.214-217
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    • 2004
  • This study was carried out to investigate the physiological charateristics of F. pinicola in sawdust media. The optimum temperature in sawdust media was $30^{\circ}C$ in of F. pinicola. The optimum pH was 5 in F. pinicola. Mycelial growth and density of F. pinicola was quite good when birch tree and oak sawdust, respectively were used as cultural substrates. The best mycelial growth in F. pinicola was observed when beer waste was added as supplement on sawdust substrates. The optimum supplement ratios of beer waste and a magnecium sulfate were 20%, and 0.1% respectively. However, optimun supplement ratios of a calcium oxide and a LVD were different as 0.1% in F. pinicola.

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