• 제목/요약/키워드: early growth stage

검색결과 1,469건 처리시간 0.031초

Assessment of Critical Temperature for the Growth and Development of Early Transplanted Temperate Rice

  • Wbonho Yang;Shingu Kang;Dae-Woo Lee;Jong-Seo Choi
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2022년도 추계학술대회
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    • pp.171-171
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    • 2022
  • Effect of temperature during the period of 10 days from transplanting (10 DFT) on the growth and development of rice plants was investigated by transplanting semi-adult seedlings six times from 5 April to 15 May at 10-day interval in the field conditions of 2020 and 2021, with aims to investigate the critical temperature for early transplanting of temperate rice. In the two experimental years, mean temperature for 10 DFT appeared 9.1, 10.5, 11.6, 13.8, 13.9, 16.2, 16.4, 16.7, 17.1, 17.8℃ depending on the transplanting date. Mean temperature of 9.1℃ and 10.5℃ for 10 DFT appeared in the April 5 and April 15 transplants in 2020 showed negative or no effect on the increase of rice growth and acceleration of heading date when compared to those of right after transplanting treatments in the same year. Mean temperature of 11.6℃ for 10 DFT appeared in the April 5 transplant in 2021 demonstrated greater biomass from early to heading stage but the same heading date compared to April 15 transplant, indicating that 11.6℃ for 10 DFT had a positive effect on rice growth but no effect on advanced heading. Both more biomass and advanced heading stage were observed when the mean temperature for 10 DFT was 13.8℃ or higher, compared to those of right after transplanting treatments. These findings indicate that effective 10-DFT mean temperature for rice growth exists between 10.5 and 11.6℃, and that for rice development in terms of heading stage lies between 11.6 and 13.8℃ in natural condition. Further field and indoor studies are suggested to narrow down the critical temperature for early transplanting of temperate rice, which will enable to maximize the crop period in high altitude regions with low temperature.

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Effects of a pineapple (Ananas comosus L.) cannery by-product on growth performance and carcass characteristics in finishing Hanwoo steers

  • Choi, Yongjun;Lee, Sangrak;Na, Youngjun
    • Animal Bioscience
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    • 제34권2호
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    • pp.233-242
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    • 2021
  • Objective: The aim of this study was to determine the effect of pineapple cannery by-product (PCB) level on the growth performance and carcass characteristics of finishing Hanwoo steers. Methods: The feeding stage was divided into early and late finishing stages. A total of 60 castrated Hanwoo steers (13.9±0.8 months old, 418.8±36.5 kg initial body weight [BW]) were blocked by initial BW and then randomly allotted into 12 pens (five head/pen). The pens were randomly assigned to control (CONT), low PCB (LPCB), or high PCB (HPCB) treatments. These diets contained 0%, 1.5%, or 3.0% of PCB (on a dry matter [DM] basis; as-fed basis was 0%, 10.6%, or 21.2%), respectively. Results: For the early finishing stage, body weight gain (BWG) and average daily gain (ADG) of the CONT and LPCB feeding groups were greater (p<0.05) than those of the HPCB feeding group. In addition, there were linear and quadratic effects on BWG and ADG with increasing dietary PCB level (p<0.05). The gain to feed (G:F) ratio tends to quadratically decrease with an increasing PCB level in the early finishing stage (p = 0.076). Growth performances of late finishing stage were not affected by PCB level. The marbling score of the LPCB feeding group was similar to that of the CONT feeding group. However, there was a linear decrease (p< 0.05) in marbling score and quality grade among treatments as PCB was increased in the diet. In the longissimus muscle free amino acid profile, histidine composition increased linearly (p<0.05) with an increasing level of PCB. Conclusion: The level of PCB 1.5% DM in diet can be used for finishing steers without any adverse effects on growth and carcass performances. However, there were some negative effects on growth and carcass performance in the HPCB feeding group.

쇼트피이닝 가공된 스프링강의 고온 피로균열진전 평가 (A Study on the Shot Peening on the High Temperature Fatigue Crack Propagation)

  • 박경동;정찬기;하경준
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2001년도 추계학술대회 논문집
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    • pp.264-268
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    • 2001
  • In this study, CT specimens were prepared from spring steel(SUP9) processed shot peening which was room temperature, low temperature and high temperature experiment. And we got the following characteristics from fatigue crack growth test carried out in the environment of room, and high temperature at $25^{\circ}C,\; 50^{\circ}C, \;100^{\circ}C,\; 150^{\circ}C,\; and\; 180^{\circ}C$ in the range of stress ratio of 0.05 by means of opening mode displacement. The threshold stress intensity factor range $\DeltaK_{th}$ in the early stage of fatigue crack growth (Region I ) and stress intensity factor range $\Delta$K in the stable of fatigue crack growth (Region II) was decreased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at low temperature and high temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region.

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SUP9강의 저온피로크랙 전파특성에 관한 연구 (A Study on the Fatigue Crack Propagation Characteristics for SUP9 Steel at Low Temperature)

  • 박경동;박상오
    • 한국해양공학회지
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    • 제16권5호
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    • pp.80-87
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    • 2002
  • In this study, CT specimens were prepared from spring steel(SUP9) which was used in suspension of automobile for room temperature and low temperature service. We got the following characteristics from fatigue crack growth test carried out in the environment of room temperature and low temperature at $25^{\circ}C$, ­3$0^{\circ}C$, ­5$0^{\circ}C$, ­7$0^{\circ}C$ and ­10$0^{\circ}C$ in the range of stress ratio of 0.05 by means of opening mode displacement. The threshold stress intensity factor range ΔKth in the early stage of fatigue crack growth (Region I) and stress intensity factor range ΔK in the stable of fatigue crack growth (Region II) was decreased in proportion to descend temperature. It is assumed that the fatigue resistance characteristics and fracture strength at low temperature and high temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region.

차량용 스프링강의 피로거동에 미치는 온도의 영향 (An Effect of Temperature on the Fatigue Crack Propagation Behavior of Spring Steel for Vehicle)

  • 박경동;류찬욱
    • 한국자동차공학회논문집
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    • 제12권1호
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    • pp.83-90
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    • 2004
  • In this study, CT specimens were prepared from spring steel(SUP9) processed shot peening which was room temperature and low temperature experiment. And we got the following characteristics from fatigue crack growth test carried out in the environment of room temperature and low temperature at $25^{\circ}C$, $-30^{\circ}C$, $-50^{\circ}C$, $-70^{\circ}C$,$-100^{\circ}C$, and $-150^{\circ}C$, in the range of stress ratio of 0.05 by means of opening mode displacement. The threshold stress intensity factor range ΔKth in the early stage of fatigue crack growth (Region I)was increased but stress intensity factor range ΔK in the stable of fatigue crack growth (Region II) was decreased in proportion to decrease temperature. It is assumed that the fatigue resistance characteristics and fracture strength at low temperature and high temperature is considerably higher than that of room temperature in the early stage and stable of fatigue crack growth region.

숏피닝 가공재의 저온 피로 강도 평가 (An Evaluation on the Fatigue Strength Characteristics for the Shot Peening Spring Steel at Low Temperature)

  • 박경동;권오헌
    • 한국안전학회지
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    • 제18권3호
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    • pp.1-7
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    • 2003
  • In this study, CT specimens were prepared from spring steel(SPS5) processed shot peening. The fatigue crack growth tests were carried out in the environment of the room temperature md low temperature at $25^{\circ}C$, $-30^{\circ}C$, $-50^{\circ}C$, $-70^{\circ}C$ $-100^{\circ}C$ and $-150^{\circ}C$ in the range of stress ratio of 0.05 by means of opening mode displacement. The threshold stress intensity factor range ΔKth in the early stage of fatigue crack growth (Region I) and stress intensity factor range $\Delta$K in the stable of fatigue crack growth (Region II) were decreased in proportion to descend temperature. It was shown that the fatigue resistance characteristics and fracture strength at low temperature are considerable higher than those of mom temperature in the early stage and stable of fatigue crack growth region.

Managing Information Asymmetry Risks Using Deal Syndication and Domain Specialization: An Indian Context

  • Joshi, Kshitija
    • Asian Journal of Innovation and Policy
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    • 제7권1호
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    • pp.150-177
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    • 2018
  • We review two specific risk management strategies of venture capitalists (VCs): deal syndication and domain specialization with respect to their explicit role in adjudging and managing the overall magnitude of information asymmetry risks. These are analyzed for three distinct categories of VC firms as classified by their funding stage focus (early vs. late), ownership type (foreign vs. domestic) and the human capital composition of the core VC team (entrepreneurial vs. investor). The analysis is based on both secondary data and primary data for active 72 VC firms in India. Syndication is moderately important for entrepreneurial VC firms, but not at all important for early-stage focused and foreign VC firms. This finding is distinctly different from what has been conventionally observed in the literature. Among the various arenas of domain specialization, high-technology focus is important for all segments of VC firms. In the context of investment-stage focus, foreign VC firms exhibit growth-stage specialization, while entrepreneurial VC firms concentrate on earlier investment stages.

Formation of Sensory Pigment Cells Requires Fibroblast Growth Factor Signaling during Ascidian Embryonic Development

  • Kim, Gil-Jung
    • Animal cells and systems
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    • 제7권3호
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    • pp.221-225
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    • 2003
  • The tadpole larva of the ascidian Halocynthia roretzi has two sensory pigment cells in its brain vesicle. To elucidate the temporal requirement for FGF signaling in formation of the pigment cells, embryos were treated with an FGF receptor 1 inhibitor, SU5402, or an MEK inhibitor, U0126 during various embryonic stages. In the present study, it is shown that the embryos treated with SU5402 from the 16-cell stage to the early gastrula stage do not form pigment cells, whereas those treated after the early gastrula stage form pigment cells. In pigment cell formation, embryos suddenly exhibited the sensitivity to SU5402 only for 1 h at the neural plate stage(-4 h after the beginning of gastrulation). When U0126 treatment was carried out at various stages between the 8-cell and late neurula stages, the embryos scarcely formed pigment cells. Pigment cell formation occurred when the embryos were placed in U0126 at early tail bud stage. These results indicate that FGF signaling is involved in pigment cell formation at two separate processes during ascidian embryogenesis, whereas more prolonged period is required for MEK signaling.

Cyclosulfamuron이 벼의 생육과 Acetolactate Synthase 활성에 미치는 영향 (Effect of Cyclosulfamuron on Rice Growth and Acetolactate Synthase Activity)

  • 지승환;송성도;정병룡
    • 한국환경농학회지
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    • 제22권1호
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    • pp.36-40
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    • 2003
  • 토양혼화실험을 통한 초장의 신장 억제를 조사한 결과 초장이 50% 억제되었을 때의 cyclosulfamuron의 농도를 품종별로 비교하여 보면 동진벼, 화성벼, 일품벼의 경우 각각 6.3, 9.2 146.8 mg/kg으로 동진벼가 제초제 cyclosulfamuron에 가장 민감하게 지상부의 생육이 억제되었다. 또한 cyclosulfamuron은 동일한 농도에서 지상부보다는 지하부의 생육을 더 크게 억제하였으며, 0.3mg/kg 처리 수준에서 동진벼의 경우 건물중의 억제정도는 지상부가 4.8% 정도이었으나 지하부는 38.9%이었다. 벼의 acetolactae synthase 활성을 cyclosulfamuron의 농도별로 검정한 결과 공시된 품종간에 큰 차이가 없었으며 50% 억제되는 농도는 화성벼, 동진벼 및 일품벼의 경우 각각 42.7, 32.7 및 $56.7\;{\mu}M$이었다.

벼 생육시기별 염수처리 농도와 기간에 따른 생육 및 수량 (Growth and Yield of Rice as Affected by Saline Water Treatment at Different Growth Stages)

  • 이충근;윤영환;신진철;이변우;김정곤
    • 한국작물학회지
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    • 제47권6호
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    • pp.402-408
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    • 2002
  • 본 연구는 염수 농도, 처리기간 및 처리시기가 벼의 생육 및 수량에 미치는 영향을 검토하고자 한 것이다. 처리시기는 분얼기, 감수분열초기, 출수기였으며, 염수처리 농도는 고농도(3.0%), 중농도(1.5%) 및 저농도(0.5%)로 하여, 고농도와 중농도는 4일간, 저농도는 30일간 처리하였다. 공시품종은 장안벼로 하여 시험을 수행한 결과를 요약하던 다음과 같다. 1. 잎 피해율은 처리시기에 관계없이 고농도 단기처리에서 가장 심하였으며, 1999년에는 분얼기, 출수기, 감수분열초기 순으로 및 피해율이 높았으나, 2000년도에는 출수기, 감수분열초기 , 분얼기 순이었다. 2. 출수기는 분얼기 염수처리에서 1-5일 지연되었다. 간장 및 수장의 단축은 감수분열초기에 염수를 처리하였을 때 가장 심하였다. 3. 감수분열초기 염수처리에서 수량감소가 가장 켰고, 다음이 출수기, 분얼기 순이었으며, 이삭수를 제외한 수량 및 수량 구성요소에서 무처리>중농도 단기처리>저농도 장기처리>고농도 단기처리 순으로 낮게 나타났다 수량구성요소중 등숙률과 천립중이 염수처리에 의한 감소가 가장 현저하였다. 4. 감수분열초기 염수처리에서 다른 생육시기에 비해 많은 지발이삭의 발생으로 이삭수가 많았으며, 지발이삭에 의한 수량 보상력은 2.1-12.0%이었다. 5. 립중, 등숙속도 및 등숙기간에 대하여 분얼기 처리에서는 처리농도 및 처리기간별로 차이가 크지 않았으며, 감수분열초기 처리에서는 저농도 장기처리 및 고농도 단기처리에서, 출수기 처리에서는 고농도 단기처리에서 크게 감소하였다.