• 제목/요약/키워드: formation period

검색결과 1,874건 처리시간 0.027초

UASB 공정에서 기질농도 및 기질주입 기간비가 슬러지 입상화에 미치는 영향 (Effect of Substrate Concentration and Feeding Period Ratio on Sludge Granulation in UASB Process)

  • 최영근;이헌모
    • 한국환경과학회지
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    • 제6권2호
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    • pp.113-124
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    • 1997
  • The basic mechanism of the granular sludge formation which is the most important factor in the start-up and stable operators is not confirmed yet. In this study, the effect of granular sludge formation was investigated with the different substrate concentrations and the various ratios of substrate supply/deficiency. The granular sludge formation in the UASB reactor was closely related to the substrate concentrations and the ratio of substrate supply/deficlency The granular sludge formation was not accelerated at low substrate concentration. It was convinced that granular sludge formation was accelerated when the substrate supply with high concentration was stopped at UASB reactor. From this experiment, it was estimated that granular sludge was formed by the combination of hydrogen utilizing bacteria that form hydrogen condition and acid forming bacteria at substrate deficit condition by mutual symbiosis. Though the removal efficiency of organic matter was decreased as the influent substrate concentration was Increased, the higher the influent substrate the better the granular sludge formation.

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강낭콩 하배축 절편의 부정근형성에 미치는 내재 IAA의 이동 (Effect of Endogenous IAA Transport on Adventitious Root Formation in Phaseolus vulgaris Hypocotyl Cuttings)

  • 조덕이
    • Journal of Plant Biology
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    • 제32권4호
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    • pp.323-330
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    • 1989
  • This work was carried out to elucidate effects of endogenous and exogenous IAA transport on adventitious root formation in Phaseolus vulgaris hypocotyl cuttings. For inverted or normal incubation in distilled water, the adventitious root is always formed at the morphological base but not at the morphological apex. For inverted incubation, in both distilled water and certain chemical solution, the root formation is retarded more at the first stage (0-24 hr) than at the second stage (24-48 hr). When p-chlorophenoxyisobutyric acid (PCIB) was applied to the cuttings at the first stage, theroot formation was inhibited more than at the second stage. Treatment of 2,3,5-triiodobenzoic aicd (TIBA)markedly inhibited the adventitious root formation in Phaseolus vulgaris hypocotyl cuttings. This inhibition influenced the root according to the applied stage and period. Therefore, the root formation is more related to the stage of root primordium formation than to the stage of root elongation from the primordium. Inhibition of auxin transport oraction by TIBA or PCIB could also be reversed when hypocotyl cuttings are incubated in exogenously applied IAA solution.

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느타리버섯 후배양 기간과 온도처리가 발이 균일도에 미치는 영향 (The effect of post-incubation period and temperature treatment on the uniform primordia formation of Pleurotus ostreatus)

  • 정윤경;백일선;김정한;지정현;임재욱
    • 한국버섯학회지
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    • 제13권3호
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    • pp.223-227
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    • 2015
  • 느타리버섯 '수한 1호'와 '곤지 7호'품종의 균사배양중 후배양 기간과 온도처리가 발이 균일도 및 생육에 미치는 영향을 조사한 결과는 다음과 같다. 배양중 전배양 $20^{\circ}C$, 20일 동안에는 두 품종 모두 11~15일에 $24{\sim}26^{\circ}C$까지 배지 내 온도가 상승되었다가 21일부터 후배양 온도처리와 동일한 수준으로 배지 내 온도가 유지되었다. 또한, 배지내 온도가 가장 높게 상승되는 시점에서 '수한 1호'의 $CO_2$는 6,500 ppm, '곤지 7호'는 5,800 ppm까지 발생되었으며 배양중인 균사생장에는 영향이 거의 없었다. '수한 1호'의 후배양 온도 $26^{\circ}C$에서 10일, 15일간 처리시 측발이율이 대조대비 40%, 비상품화율은 10.5% 감소 되었으며, '곤지 7호'는 후배양 온도 $26^{\circ}C$, 후배양 10일 처리에서만 측발이율은 19%, 비상품화율은 9.5% 감소되었다. 따라서, 느타리버섯 두 품종의 후배양 적합온도는 $26^{\circ}C$, 적합 후배양 처리기간은 '수한 1호'는 10일, 15일, '곤지 7호'는 10일이 발이 균일도가 높았다.

미세유체소자 내부에서의 Droplet 형성에 대한 Micro-PIV 측정 (Micro-PIV Measurement on the droplet formation in a microfluidic channel)

  • 윤상열;고춘식;김재민;김경천
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.1534-1539
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    • 2004
  • This experiment has been carried out to measure the process of droplet formation between water phase fluid(PVA 3%) and organic phase fluid(oil) and vector fields measured by a Dynamic Micro-PIV method in the inside of a droplet while generated. Droplet length controlled by changing flow rate conditions in microchannel. Water-in-oil(W/O) droplets successfully generated at a Y junction and cross microchannel. But oil-in-water(O/W) droplets could not be formed at a Y junction microchannel. That is, PVA 3% flow could not be detached from the PDMS surface and ran parallel with oil flow. When PVA 3% flow rate was constant, droplet length and time period decreased as oil flow rate increased, but droplet frequency increased. When PVA 3% and oil flow rate ratio was constant, droplet length and time period decreased as flow rate increased, but droplet frequency increased. All that case, Standard deviation of droplet formation have less than 5% at averaged droplet length and regular-sized droplets were reproducibly formed.

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A SIMPLE DISK-HALO MODEL FOR THE CHEMICAL EVOLUTION OF OUR GALAXY

  • Lee, S.W.;Ann, H.B.
    • 천문학회지
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    • 제14권2호
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    • pp.55-71
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    • 1981
  • On the basis of observational constraints, particularly the relationship between metal abundance and cumulative stellar mass, a simple two-zone disk-halo model for the chemical evolution of our Galaxy was investigated, assuming different chemical processes in the disk and halo and the infall rates of the halo gas defined by the halo evolution. The main results of the present model calculations are: (i) The halo formation requires more than 80% of the initial galactic mass and it takes a period of $2{\sim}3{\times}10^9$ yrs. (ii) The halo evolution is divided into two phases, a fast collapse phase ($t=2{\sim}3{\times}10^8$ yrs) during which period most of the halo stars $({\sim}95%)$ are formed and a later slow collapse phase which is characterized by the chemical enrichment due to the inflow of external matter to the halo. (iii) The disk evolution is also divided into two phases, an active disk formation phase with a time-dependent initial mass function (IMF) up to $t{\approx}6{\times}10^9$ yrs and a later steady slow formation phase with a constant IMF. It is found that at the very early time $t{\approx}5{\times}10^8$ yrs, the metal abundance in the disk is rapidly increased to ${\sim}1/3$ of the present value but the total stellar mass only to ${\sim}10%$ of the present value, finally reaching about 80% of the present values toward the end of the active formation phase.

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일본의 자연환경보전사조 및 관련제도의 변천에 관한 연구 (Studies on the Current Ideas and Institution of Natural Environmental Conservation in Japan -Policy and Institution of Open Space and Forest -)

  • 김승환
    • 한국조경학회지
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    • 제17권1호
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    • pp.1-16
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    • 1989
  • ^x As mentioned above, I consider the change of role that is related with Japanese thought of Natural Environmental Conservation, and I divide each part of periods into forest, farmland, open space, urban planning, environmental conservation etc. To summary the content of each period of Natural Environmental Conservation thought is as follows. 1) Previous period before formation(before 1919) In the previous period of Meiji, it could be said that the consciousness of the Natural Environmental Conservation was coming to existence. In this, so called, Natural Environmental Conservation, the thought of Forest Preservation was the main current and it was the thought of territorial integrity for the security of resource, the forestry conservancy and flood control in the forestry farmland. Since the age of Meiji, the theory of Natural Conservation appears from the theory of Japanese landscaping and systematic management about public parks was enforced, but the regular theory of Natural Environmental Conservation did not attain full growth. 2) The period of formation(1919~ 1954) In the period of formation, the base of Natural Environmental Conservation had been established. Parks and Open spaces were admitted as a public facilities in each city, and legislations which supported it had been continuously enacted and so on. In this period, the afforestation counter plan was emphasized on the side of territorial integrity. In the mountainous district. tree planting was emphasized to recover the forest which had been destroied by war. 3) The period of development(1955~ 1974) In the period of development, varied policies was institutionalized for the Natural Environmental Conservation. However, all sorts of development policy had performed simultaneously, thus development had complicated relation with preservation. But after 1970's the framework of system of Natural Environmental Conservation improvement was constituted to control the many kinds of development, and the spontaneous campaign of nature preservation by private lead was being taken root. This is the more progressive period. 4) The pried of root(after 1975) After the latter of 1970's, the role of Natural Environmental Conservation began to take root not in the direction of control but inducement, and, getting out of development - oriented policy, aimed at relation between human being and natural environment and the side of amenity of human environment. Besides, the current of Natural Environmental Conservation had been seperately progressed in the cities and forests. Since this period, it was the character that cities and forests began to be unified as 'amenity'space of man.

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프랭크 스텔라(Frank Stella)에 있어서 토톨로지 구조(Tautological Structure)의 형성과 해체 (A Study on the formation and dissolution of tautological structure in the Frank Stella's work)

  • 홍지석
    • 조형예술학연구
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    • 제5권
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    • pp.35-66
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    • 2003
  • This article dealt with the formation and dissolution of tautological structure in the Frank Stella's work from 1959 to 1980 years by the analysis of signifier. A characteristic of Stella's work change is that it has the gradual progress which condensed into three periods -1) the formation and fixation period of tautological structure 2) the relaxation period of tautological structure and 3) the dissolution period of tautological structure. In other words, the early works of stella in the early 1960s has the structure which minimize differences in one hand, and maximize strictness, clearness, and identity on the other hand However, the stella's work from mid 1960s to mid 1970s extend differences gradually, while keeping a characteristic of prior work. And the stella's work after late 1970s has the decentered disintegration, namely anti-tautological structure which maximize differences. 'The formation and dissolution of tautological structure' in the Stella's work could be understood in relation to the fact that the Greenberg's modernist canon has loss the power gradually after late 1960s. That is to say, the dissolution of tautological structure in the late stella's work could be interpreted as the inevitable product which is produced in the searching for a new canon of painting. However, on the other hand, the structural change of stella's work in the late 20th Century is also understood in relation to the broader context, the social, and cultural context. Here, it is interpreted as the one of typical example which reflect a social and cultural convulsion designated as a 'Coming of Postmodernism'. In short, the late Stella's work which emphasize differences and unclearness, while diverging from early Stella's work which stress identity and rationality could be interpreted that it has the homology with the change of ways of thinking in the late 20th century Society.

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KEOP 집중관측자료를 활용한 2004년 2월 4일 황해 남부해상의 강설세포 형성과정 특성 분석 (Characteristics of Snow-cell Formation Processes over the Southern Part of Yellow Sea on 4 February 2004 using the KEOP Intensive Observation Data)

  • 김백조;조천호;류찬수;정효상
    • 한국환경과학회지
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    • 제16권12호
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    • pp.1401-1409
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    • 2007
  • The formation mechanism of the snow cells of the Yellow Sea associated with snowfall over the southwestern part of Korea on 4 February, 2004 has been investigated using special upper-air sounding and radar data obtained for the KEOP(Korea Enhanced Observing Period) Intensive Observing Period(IOP). Results show that the types of snow cells for the selected period are classified into L(Longitudinal)-mode, Low-level convergence, and T(Transverse)-mode with their evolution from L-mode to T-mode. In particular, the existence of low-level warm and humid layer associated with temporally southwesterly inflow for about 4 hours provides a favorable condition in forming the T-mode snow cells. The vertical depth of the T-mode snow cells is deeper than that of L-mode ones due to the southeastward penetration of cold and dry air into relatively warm and humid air. In addition, it is found that wind shear vector between 1000 hPa and 600 hPa is one of the factors which control the orientation of snow cells in formation embedded into the snowbands for the both modes.

구 종연방적 광주공장의 형성 과정에 관한 조사연구 (A Study on the Formation Process of the Former Kanegafuchi Spinning Gwangju Factory)

  • 천열홍;이향미
    • 한국농촌건축학회논문집
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    • 제24권4호
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    • pp.133-139
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    • 2022
  • This study deals with the formation of Jongyeonbangjeok's Gwangju Factory in the 1930's to 80's, and the findings are shown below: In the period of formation, the factory was rectangular-shaped from north to south, and the structure was located at the center of the site, and in the east of it, there was a dormitory connected from south to north. The building was arranged with an open area on the south. In the east of the site where company houses were located, same-sized structures were arranged along the axis.In the period of change, the factory was restored about the damage from the Korean War, and it went through the process of division into two companies. As a result, the factory in the center of the site was divided into left and right ones, and the dormitory and the group of company houses were, too, divided into two, so division was made largely into southern and northern parts. In the period of stabilization, along with factory extension in each of the companies, welfare for factory workers was expanded by building more houses or opening sport facilities. After the 1980's, too, the existing factories were either extended or remodeled according to the induction of equipment, and some showed changes in their functions due to a fire or such.

마늘성분의 산화방지작용에 대한 연구 - 제 3 보 가열수용성분의 과산화지질 생성억제효과에 미치는 영향 - (Studies on Antoxidative Action of Garlic Components Isolated from Garlic(Allium Stivum, L) Part III : Effects of water soluble fractions from steamed garlic on inhibition of lipoperoxide formation.)

  • 전희정
    • 대한가정학회지
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    • 제24권4호
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    • pp.87-92
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    • 1986
  • In Order to study antioxidative action of water soluble fractions which had been steamed according to time as 15, 30, 60 and 120 minutes, they were compared through the inhibitory effect of lipoperoxide formation by TBA, peroxide value and induction time for the first period of lipoperoxide formation. Results are obtained as follows: 1. In vivo experiment with TBA value, water soluble fractions showed aninhibitory effect of lipoperoxide formation. 2. Comparing with the inhibitory effect of lipoperoxide formation with TBA value in vivo, water soluble fractions which had been steamed for 30 and 60 minutes and those from fresh garlic proved effective in the blood by intraperitoneal administration. But in the liver all of water soluble fractions showed distinctive effect as in the case of fresh garlic. 3. Effect of water soluble fractions which had been steamed for 15, 30 and 60 minutes showed a distinctive effect, water soluble fraction which had been steamed for 120 minutes and that from fresh garlic also showed effective in the blood as compared with control. 4. In oral administration, water soluble fraction of fresh garlic was the most effective in the liver. 5. In vitro experiment with peroxide value, water soluble fractions which had been steamed for 60 and 120 minutes were effective, all of water soluble fractions from steamed garlic were more effective than fresh garlic. 6. In Examining the induction time for the first period of lipoperoxide formation in vitro, water soluble fractions steamed for 30, 60 and 120 minutes were effective. Other fractions were also more effective than control.

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