• Title/Summary/Keyword: seeding time

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해상 유출 기름 제거 시 미생물을 이용한 제거 기술의 종류와 고려하여야 할 문제점 분석

  • 장승룡
    • 한국석유지질학회:학술대회논문집
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    • autumn
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    • pp.68-84
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    • 1999
  • Biodegradation is a natural weathering process by microorganisms to decompose spilled oil or environmental contaminants. To accelerate this process, applying nutrients (fertilizer) or more microorganisms to naturally occurring microorganisms is called 'Bioremediation.' Presently, most popular response technique to spilled oil is mechanical cleanup using booms or skimmers. For the alternative to this technique, chemical dispersants, in-situ burning are used. Another promising alternative is bioremediation and it can clean oil contaminated seashore during enough time. In this paper, types of bioremediation technologies, its usage potential, and important consideration issues when applying this technique were summarized.

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Effect of the grain boundary on the magnetic properties of the multi-seeded melt growth processed YBCO superconductors (다중종자결정성장법으로 제조한 YBCO 초전도체의 결정입계에 따른 자기적 성질의 영향)

  • Kim, Chan-Joong;Joo, Jin-Ho;Han, Young-Hee;Han, Sang-Chul;Sung, Tae-Hyun;Hong, Gye-Won;Kim, Ho-Jin
    • 한국초전도학회:학술대회논문집
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    • v.10
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    • pp.293-297
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    • 2000
  • Multiseeding with (100)/(100) grain junctions of top-seeded melt growth (TSMG) processed YBCO superconductors was studied. The effect of the number of seeds and the distance between two seeds on the levitation forces and the trapped magnetic fields of the TSMG-processed YBCO samples was investigated. Multiple seeding shortened the processing time for the fabrication of TSMC-processed YBCO superconductors. The large magnetic field was trapped at the grain junction when two seeds was placed without spacing, while the amount of the magnetic field decreased when the seed distance increased. This is attributed to the increased amount of the residual melt phases around the grain junctions.

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Crystal growing of NaX type zeolite

  • Ha, Jong-Pil;Seo, Dong-Nam;Jung, Mi-Jeong;Moon, In-Ho;Cho, Sang-Joon;Park, Hyun-Min;Kim, Ik-Jin
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.4
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    • pp.371-376
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    • 1999
  • A large NaX type zeolite crystal of a uniform particle size of 20$\mu\textrm{m}$ are grown with various {{{{{H}_{2}O}}}} content by hydrothermal reaction and added seed crystal (2~3$\mu\textrm{m}$) to reactant solution as a function of different adding seed levels from 3 to 15%. The result that increased purity of NaX zeolite above 95% and homogeneity of crystal size by increasing adding seed levels, also decreased crystallization time. It was explained that adding seed to synthesis solution leaded out increase of surface area for physical contact reaction and directed growth of seed crystal, so more rapid consumption of reaction gel as increase seeding levels.

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Theory and Practice of Cover Crops Growing in Orchard (과수원 피복작물 재배의 이론과 실제)

  • 송기철
    • Korean Journal of Organic Agriculture
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    • v.9 no.4
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    • pp.95-111
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    • 2001
  • To carry out the Integrated Fruit Production(IFP), researches on cover crops as well the Integrated Pest Management(IPM) and the Integrated Nutrition Management(INM) should be very important. These concepts are neither clear nor connective till now. The researches on cover crops in Europe and USA are being kept within the category of IFP. Main researches on fruit trees for sustainable agriculture in Italy are new variety creation, development of growing techniques, pest and disease control, and cover crops management, etc. It is necessary of fruit industry in Korea to maintain good quality and taco-friendly fruit production. For this goal, we need international cooperation with highly developed countries in Europe. In first step, we should enlarge research areas and analyze results obtained to get farmers understood the concept of cover crop growing, Furthermore, we make researches more profoundly on cover crops growing considering tree age, mixing rates among cover crops, seeding and cutting time for cover crops, and so on. Researchers, specialists of agricultural extensions, and farmers should concentrate their opinions and conduct IFP together. The IFP should go on systematically and reach finally to get certificates internationally by the International Organization for Biological and integrated Control of Noxious Animals and Plants(IOBC) to enhance selling and exporting fruits.

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Cryopreservation (Vitrification) of Mouse Embryos (마우스의 배의 동결보존)

  • 강민수
    • Journal of Embryo Transfer
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    • v.6 no.2
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    • pp.30-36
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    • 1991
  • The method of vitnilcation has various merits. It needs neither seeding nor slow freezing. It can freeze embryo by putting it directly into liquid nitrogen at the indoor temperature to $0^{\circ}C$. The operation process is quite easy. Moreover, higher promise of survival can be expected as there is no physical damage by any lumps of ice with the exception of cells. In Kasal's experiment (1990) using EFS liquid and Kang's experiment (1991) using GFS liquid the ratio of the damaged embryo was only 2-3%. But, the method of vitrification is now on the process of improvement, and the final or united method is not yet established. At the present time, most of the major institutes all over the world are using the traditional freezing method in the preservation of mouse embryo, but it is very likely that the vitrification will prevaIl in the near future considering the various merits of it. Calves can be begotten from the embryo by means of vitriilcated preservation in the cases of cow, rat, and rabbit as well as of mouse. In addition, recent experiments have shown that vitrificated preservation was successful in the case of drosophila embryo which was much bigger than mammalian embryo, which fact tells that this method is expected to be preferably used even in the preservation of living organs in the near future.

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A Study on Phase Transformation and Microstructure Control of $Al_2O_3$ ($Al_2O_3$의 상전이 및 그에 따른 미세구조 제어에 관한 연구)

  • 신상현;오창섭;최성철
    • Journal of the Korean Ceramic Society
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    • v.34 no.6
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    • pp.553-560
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    • 1997
  • A fine $\alpha$-Al2O3 powder was prepared by sol-gel process for membrane application. And it was carried out by adding 1.5wt% $\alpha$-Al2O3 powders(mean size : 87 nm) as seeds to the prepared sols and by controlling the heating schedule (the heating rate and the soaking time) to prevent the microstructural change, which occured during $\theta$-to $\alpha$Al2O3 phase transformation. The seeded $\alpha$-Al2O3 particles acted as the heterogeneous nucleation sites for the $\alpha$-Al2O3 nucleation during the transformation of $\theta$- to $\alpha$-Al2O3 and resulted in increasing the driving force of phase transformation to activate the formation of $\alpha$-Al2O3 phase at 82$0^{\circ}C$. By $\alpha$-Al2O3 seeding and controlling of heating condition the phase transformation of $\theta$- to $\alpha$-Al2O3 was accomplished at low temperature and the grain growth process was depressed. Therefore, the unsupported membrane could be fabricated in $\alpha$-Al2O3 . The average diameter of pores in the fabricated membrane was 7 nm and the porosity was 47%.

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A Study on the Fatigue and Data Retention Characteristics of Single Grained PZT Thin Films (단결정립 PZT 박막의 피로 및 정보 유지 특성에 관한 연구)

  • Lee, Jang-Sik;Ju, Seung-Gi
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.5
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    • pp.1-8
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    • 2000
  • Fatigue and data retention characteristics of the Pt/PZT/Pt structure using single grain PZT thin films by PZT seeding method were investigated. In case of fatigue, there is no loss in switched polarization up to 2$\times$10$^{11}$ cycles using 1MHz square wave form at $\pm$10V and no data loss after 30000sec of memory retention at room temperature. From the activation energy measured at high temperatures, the time required 20% loss in remanent polarization is estimated to be 6.6$\times$10$^{7}$ years at room temperature.

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Development of Revegetation Method Using Forest Topsoils for Ecological Restoration of the Slopes(I) (산림표층토를 활용한 비탈면 생태복원녹화에 관한 연구(I))

  • Nam, Sang-Jun;Yeo, Hwan-Joo;Choi, Jae Yong;Kim, Namchoon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.4
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    • pp.110-119
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    • 2004
  • This research was conducted to develop spraying cultivation method using forest topsoils in order to restore the disturbed slopes. In November the researcher collected a depth of 5 cm of topsoils from a well developed forest, after the fallen leaves were cleared. The essential results of the research are as follows: In the case of using the forest topsoils, during the early stages of planting, time is necessary for the desired vegetation to reach a similar state to the vegetation being restored. The best possible effect is obtained through a method utilizing forest topsoil(30%)+loam silt soil(70%)+seeding with grasses and native plants including trees, shrubs, and herbs. Several plants such as Pinus densiftora, Potentilla fragarioides, Miscanthus sinensis, Erigeron canadensis seemed to be naturally emerged from the topsoils From this experiment, it was recommended that environment potential within topsoil should be comprehended. Also, topsoil deposit and gathering methods should be experimented properly.

Transition of Rice Cultural Practices during Chosun Dynasty through Old References. III. Differentiation of Rice Varieties in the Dynasty (주요 고농서를 통한 조선시대의 도작기술 전개과정 연구 III. 조선시대의 벼 품종 분석)

  • Lee, Sung-Kyum;Guh, Ja-Ok;Lee, Eun-Woong;Lee, Hong-Suk
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.36 no.4
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    • pp.370-381
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    • 1991
  • In Nongsajiksul, rice varieties were not appeared but varieties groups were introduced and divided according to growth periods, or 'Sun, Gang, Na'or introduced names of some of local varieties. However, the weather conditions for rice culture in Korea were characterized by 'early drought and late flooding', and winds and rains in summer, so that rice safe harvest by avoiding these disasters was the most important. Thus, development of rice varieties after the 15th century has gradually been adapted for ‘early-seeding and early-harvesting’, and for disaster tolerance. With time, rice varieties, which were early maturing, had awned, had color on panicles, had tolerance for grain shattering, had tolerance for winds, and had good responses to fertilizers, were grown in large areas.rown in large areas.

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Measuring Glutathione Regeneration Capacity in Stem Cells

  • Jihye Kim;Yi-Xi Gong;Eui Man Jeong
    • International Journal of Stem Cells
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    • v.16 no.3
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    • pp.356-362
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    • 2023
  • Glutathione (GSH) is a chief cellular antioxidant, affecting stem cell functions. The cellular GSH level is dynamically altered by the redox buffering system and transcription factors, including NRF2. Additionally, GSH is differentially regulated in each organelle. We previously reported a protocol for monitoring the real-time GSH levels in live stem cells using the reversible GSH sensor FreSHtracer. However, GSH-based stem cell analysis needs be comprehensive and organelle-specific. Hence, in this study, we demonstrate a detailed protocol to measure the GSH regeneration capacity (GRC) in living stem cells by measuring the intensities of the FreSHtracer and the mitochondrial GSH sensor MitoFreSHtracer using a high-content screening confocal microscope. This protocol typically analyses the GRC in approximately 4 h following the seeding of the cells onto plates. This protocol is simple and quantitative. With some minor modifications, it can be employed flexibly to measure the GRC for the whole-cell area or just the mitochondria in all adherent mammalian stem cells.