• 제목/요약/키워드: Maximum-minimum temperature variation

검색결과 155건 처리시간 0.031초

Influence of Temperature and Relative Humidity in Infection of Nosema bombycis (Microsporidia: Nosematidae) and Cross-infection of N. mylitta on Growth and Development of Mulberry Silkworm, Bombyx mori

  • Chakrabarti, Satadal;Manna, Buddhadeb
    • International Journal of Industrial Entomology and Biomaterials
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    • 제17권2호
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    • pp.173-180
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    • 2008
  • The influence of temperature and relative humidity in infection and cross-infection of Nosema bombycis and N. mylitta respectively in mulberry silkworm, Bombyx mori L. on larval mortality, multiplication of pathogens, larval weight and growth rate in three different seasons were studied. Seasons were selected in such condition, when very less fluctuations between minimum and maximum temperature and minimum and maximum relative humidity ($25{\sim}28^{\circ}C$ and $65{\sim}72%$ R.H) was observed i.e., season-1. Fluctuations between minimum and maximum temperature were less ($28.05{\sim}34.50^{\circ}C$) but R.H % was more ($55{\sim}81%$) in season-2. Fluctuations between minimum and maximum temperature and R.H % were more ($20.00{\sim}40.5^{\circ}C$ and $64.00{\sim}90.00%$) in season-3. Growth rate of microsporidian-infected silkworm is directly related to the prevailing temperature and relative humidity in silkworm. Silkworm can tolerate slight variation of temperature but slight variation of relative humidity disfavours the development of silkworm and favours the multiplication of pathogens.

단위 전류당 최대 토크 제어기 성능에 미치는 로터 온도 변화의 영향에 대한 연구 (Study on Influence of Rotor Temperature Variation on the Performance of Maximum Torque Per Amp Control Strategy)

  • 권춘기
    • 한국산학기술학회논문지
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    • 제10권11호
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    • pp.3110-3114
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    • 2009
  • 회전자 온도 변화는 유도 전동기 제어기 설계에 있어서 중요한 쟁점이다. 문헌에서, 수많은 연구들이 회전자 온도 변화를 고려하지 않는다면, 그에 기인한 심각한 성능 저하를 언급해왔다. 하지만, 이러한 연구들은 추종 성능 관점에서 주로 Field-oriented 제어기에 초점을 두고 있으며, 단위 전류당 최대 토크 제어기와 같이 최적 제어의 경우에서의 성능에 미치는 회전자 온도 변화의 영향에 대한 연구는 전무하다. 본 연구는 회전자 온도가 시간에 따라 변화함에 따라, 단위 전류당 최대 토크 제어기의 성능에 어떻게 영향을 미치는지를 조사한다. 이를 위해, 두 가지 방법으로 단위 전류당 최대 토크 제어기의 목적이 성취되는 지를 점검한다. 즉, 요구되는 토크를 발생시키면서 동시에 최소 가능한 고정자 전류를 필요로 하는 것이다. 실험실 실험결과는 추종 성능과 단위 전류당 최대 토크 조건이 회전자 온도가 변화함에 따라 심각한 영향을 받으며, 결과적으로 단위 전류당 최대 토크 제어기의 성능저하를 초래함을 보여준다.

동계 시각별 외기온의 변동 특성에 관한 연구 (Variation Characteristics of Hourly Atmospheric Temperature Throughout a Winter)

  • 이승언;손장열
    • 태양에너지
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    • 제12권2호
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    • pp.1-8
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    • 1992
  • 본 연구는 동계 외기온 데이타의 시각별 변동특성을 파악하기 위하여 연변동 성분 및 기간변동 성분을 제거한 일변동 성분의 매 시각별 외기온 데이타에 대해서 일교차의 발생요인에 대해서 분석하였다. 또한 동계시각별 외기온의 주파수 특성에 대해서 검토하였으며 외기온 데이타의 수식화의 가능성을 제시하였다.

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PCW-PNN-PZT계 세라믹의 유전 특성에 관한 연구 (A Study on Dielectric Properties of PCW-PNN-PZT ceramics)

  • 신혜경;이성호;정보람;배선기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.51-53
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    • 2005
  • This study was to measure the minuteness structure, dielectric properties of 0.03PCW-0.07PNN-0.9PZT ceramics according to sintering temperature manufacture the specimens with a general method. The results of this study were gotten such as follows. The crystal structure of ceramic changed the rombohedral structure into teteragonal structure according to rising sintering temperature in XRD. Dielectric constant at $20^{\circ}C$ showed its maximum value 510.599 in specimens sintered at $1100^{\circ}C$ and dielectric loss showed its minimum value 7.43% in specimens sintered at $1100^{\circ}C$. The variation rate of dielectric constant according to the change of frequency showed its minimum value 0.029/kHz at $1100^{\circ}C$. The variation rate of dielectric constant according to the change of temperature showed its minimum value $1.40/^{\circ}C$ at $1500^{\circ}C$.

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리브 구조에 따른 머시닝센터 베드의 열적 특성 평가 (Thermal Characteristic Estimation of NC Machining Center Bed following Rib Structure)

  • 김양진
    • 한국생산제조학회지
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    • 제19권6호
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    • pp.746-752
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    • 2010
  • Rib structure has been used to bed and column of machine tool to heighten weight stiffness ratio, cost performance and weight saving. In this paper the bed rib structure was estimated with thermal characteristics. Using superposition principle, machine tool designer can describe every complicated heat generation in the machine tool thermal source. As thermal characteristics, thermal deformation of guide rail and column and Maximum-minimum temperature variation were selected. The size, configuration and direction against the thermal loading surface operated to the thermal characteristics. The DB chart was made following rib structure estimating thermal characteristics. With superposition principle and DB chart, machine tool designer can prognosticate the thermal characteristics without FEM analysis to every bed rib structure.

Intraspecific Variation in the Temperature Niche Component of the Diatom Skeletonema costatum from Korean Coastal Waters

  • YIH Wonho;SHIM Jae Hyung
    • 한국수산과학회지
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    • 제28권6호
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    • pp.805-811
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    • 1995
  • Final biomass yields (peak optical density) and growth rates (divisions/day) of seven clones of Skeletonema costatum from Korean coastal waters were measured to understand their intraspecific variations in the light intensity niche component under $25^{\circ}C$ condition. Daily growth rates of 6 of 7 S. costatum, clones were maximum at 6000 lux while that of YS4, a neritic clone, was maximum at 9000 lux. The final biomass yields of 4 of the 7 S. costatum clones were maximum at the lowest light intensity of 2000 lux. Minimum final biomass yields were found at 9000 lux in all the S. costatum clones other than an estuarine clone, HDC9. The intraspecific variations of the mean growth rate and mean final biomass yield under each of the three different light intensity in terms of the coefficient of variation were not greater than 10% in any of the 7 S. costatum clones.

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도시 공원 내 식생 수관에 의한 기온 변화 (Air Temperature Change by Vegetation Canopy in Urban Park)

  • 이상화;이규석;정해연;김문성
    • 한국환경복원기술학회지
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    • 제12권1호
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    • pp.44-51
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    • 2009
  • In order to determine air temperature difference by canopy layer in the forest, air temperatures were observed at Seolleung Park, Gahngnam-ku, Seoul. from November 9, 2007 to November 8, 2008 by 10 minute interval. The data were analyzed in terms of diurnal variation based on annual and monthly temperature difference. Using calm, less cloudy and no rainy weather data, average air temperature difference between forest and grass was observed as $0.8^{\circ}C$. The maximum air temperature difference was observed at 22:10, 23:20, 23:30 and 23:40 by $2.13^{\circ}C$ and the minimum one observed at 13:00 by $-0.84^{\circ}C$ in diurnal variation. The maximum temperature difference occurred at 19 : 50 on September by $3.67^{\circ}C$, Overall the air temperature in the forest was higher than that of grass at night and lower in midday.