• 제목/요약/키워드: Optimum Temperature

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Beta-gamma TiAl 합금의 고온변형거동 (High Temperature Deformation Behavior of Beta-gamma TiAl Alloy)

  • 김지수;김영원;이종수
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2006년도 춘계학술대회 논문집
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    • pp.429-433
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    • 2006
  • High Temperature deformation behavior of newly developed beta-gamma TiAl alloy was investigated in this study. The optimum processing condition was investigated with the aid of Dynamic Materials Model (DMM). Processing maps representing the efficiency of power dissipation for microstructural evolution and instability were constructed utilizing the results of hot compression test at temperatures ranging from $1000^{\circ}C$ to $1200^{\circ}C$ and strain rate ranging from $10^{-4}/s$ to $10^2/s$. The Artificial Neural Network (ANN) simulation was adopted to consider the deformation heating. With the help of processing map and microstructural analysis, the optimum processing condition was presented and the role of $\beta$ phase was also discussed in this study.

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반응표면분석법에 의한 늙은 호박 추출조건의 모니터링 (Monitoring on Extraction Conditions of Old Pumpkin Using Response Surface Methodology)

  • 정용진
    • 한국식품영양과학회지
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    • 제30권3호
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    • pp.466-470
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    • 2001
  • Response surface methodology was used for monitoring extraction conditions, based on quality properties of old pumpkin extracts. Hunter's color L value of extracts was maximized at 101℃, 2.6 hr and decreased gradually after maximum point. The polynomial equation for Hunter's color L value showed 10% of significance level and 0.8799 of R². Hunter's color a value was minimized at 117℃, 3.9 hr and R² of polynomial equation was 0.9852 within 1% significance level. Hunter's color b value and ΔE value increased as the extracting temperature and time increased. Extraction yield of old pumpkin was maximized at 110℃, 4 hr and increased in proportional to the extracting temperature and time, but decreased after 113℃ and 2 hr. Viscosity of pumpkin extracts were maximized at 120℃, nearly 3 hr. R² of polynomial equations for yield, viscosity and sugar content were 0.9532, 0.9812 and 0.8869, respectively. Optimum ranges of extraction conditions for quality properties of old pumpkin were 102∼109℃, 2.5∼3.5 hr, respectively. Predicted values at the optimum extraction condition agreed with experimental values.

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$Sr_{0.7}Bi_{2.3}Nb_2O_9$ 박막의 구조적인 특성 (Structural Properties of $Sr_{0.7}Bi_{2.3}Nb_2O_9$ Thin Film)

  • 김진사;최영일;조춘남;최운식;김충혁
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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    • pp.185-186
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    • 2008
  • The $Sr_{0.7}Bi_{2.3}Nb_2O_9$(SBN) thin films are deposited on Pt-coated electrode(Pt/Ti/SiO2/Si) using RF sputtering method at various substrate temperature. The optimum conditions of RF power and Ar/O2 ratio were 60[W] and 70/30, respectively. The rougness showed about 4.33[nm]. Deposition rate of SBN thin films was about 4.17[nm/min]. The capacitance of SBN thin films were increased with the increase of substrate temperature.

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Botrytis cinerea에 의한 감나무 잿빛곰팡이병 (Persimmon Gray Mold Caused by Botrytis cinerea)

  • 권진혁;강수웅;경상대
    • 식물병과 농업
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    • 제5권1호
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    • pp.55-57
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    • 1999
  • Botrytis cinerea was isolated from a gray mo이 leaf lesion on persimmon in fields of Kyeonsangnam-do from 1996 to 1998, and etiological study was conducted including physiological characteristics. It formed gray mold lesion with light green color on leaves of persimmon (Diospyros kaki). The temperature range for mycelial growth was between $5^{\circ}C$ and $30^{\circ}C$ with the optimum temperatures of $20^{\circ}C$ to $25^{\circ}C$. Conidia were oviod, cylindric, and colorless and their dimensions in culture were $8.4~11.5\times7.0~8.9\mu\textrm{m}$. The optimum temperature of conidial germination was $25^{\circ}C$. Sclerotia on potato dextrose agar medium were well formed and brownish condiophores were observed with their size of $18.5~64.9\times4.5~8.0\mu\textrm{m}$. Symptoms on artificially inoculated plants were similar to those of gray mold disease on persimmon caused by Botrytis cinerea in fields.

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생표고의 저온 및 냉동저장시 선도유지의 최적화 (Optimum Conditions for Keeping the Fresh Quality of Shiitake(Lentinus erodes) by Low-temperature and Frozen Storage)

  • 이기순;이주찬
    • 한국식품저장유통학회지
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    • 제4권2호
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    • pp.115-122
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    • 1997
  • This experiment was hocused on the improvement of postharvest management of fresh shiitake to increase the marketing duration. the respiration rate of fresh shiitake at 2$0^{\circ}C$ was ranged from 395mg to 551mg CO2/kg/hr depending on the cultural condition. The rapid precooling is considered as one of the most important postharsvest management to remain shiitake quality. The optimum temperature for precooling and storage was -3$^{\circ}C$ because the occurrence of physical damage on frozen tissue at below -5$^{\circ}C$. Frozen storage at -3$^{\circ}C$ had benefits to minimize weight loss, browning induction at gill tissue and consumption of stored materials where as storage at $0^{\circ}C$ appeared not to be adequite for the extension of marking duration. Frozen shiitake was succesefully thawed when exposed to RH 40-50% at below 1$0^{\circ}C$.

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Dry Film Photoresist를 이용한 테프론 PCB 위 미세 피치 솔더 범프 형성 (Formation of Fine Pitch Solder Bumps on Polytetrafluoroethylene Printed Circuit Board using Dry Film Photoresist)

  • 이정섭;주건모;전덕영
    • 한국마이크로전자및패키징학회:학술대회논문집
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    • 한국마이크로전자및패키징학회 2003년도 기술심포지움 논문집
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    • pp.169-173
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    • 2003
  • We demonstrated the applicability of dry film photoresist (DFR) in photolithography process for fine pitch solder bumping on the polytetrafluoroethylene (PTFE/Teflon) printed circuit board (PCB). The copper lines were formed with $100\;{\mu}m$ width and $18\;{\mu}m$ thickness on the PTFE test board, and varying the gaps between two copper lines in a range of $100-200\;{\mu}m$. The DFRs of $15\;{\mu}m$ thickness were laminated by hot roll laminator, by varying laminating temperature from $100^{\circ}C\;to\;150^{\circ}C$ and laminating speed. We found the optimum process of DFR lamination on PTFE PCB and accomplished the formation of indium solder bumps. The optimum lamination condition was temperature of $150^{\circ}C$ and speed of about 0.63 cm/s. And the smallest size of indium solder bump was diameter of $50\;{\mu}m$ with pitch of $100\;{\mu}m$.

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개방관과 밀폐관의 열음향 효과에 관한 하모닉 특성 연구(1) - 1차 하모닉 (An Experimental Study on the Characteristics for Open-Tube and Close-Tube Thermoacoustic Effects(1) - The 1st Harmonic)

  • 송규조;이성노
    • 한국초전도ㆍ저온공학회논문지
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    • 제4권1호
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    • pp.129-134
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    • 2002
  • In this study, the experimental open-tube and close-tube thermoacoustic apparatuses were constructed. In order to determine the optimum length of resonant tube, frequency and the optimum length of stack, the resonant characteristics of thermoacoustic apparatuses were investigated, The length of resonant tube varies from 400mm to 850 mm. The experimental frequency varies from 100 Hz to 1000 Hz. In case of first harmonic, the maximum temperature difference of the open-tube thermoacoustic apparatus is 41$^{\circ}C$)resonator length: 500 mm), and the maximum temperature difference of the close-tube thermoacoustic apparatus is 42$^{\circ}C$ (resonator length : 850 mm).

개방관과 밀폐관의 열음향 효과에 관한 하모닉 특성 연구(2) - 2차, 3차 하모닉 (An Experimental Study on the Characteristics for Open-Tube and Closed-Tube Thermoacoustic Effects (2)- The 2nd, 3rd Harmonic)

  • 송규조;박종호;이성노
    • 한국초전도ㆍ저온공학회논문지
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    • 제4권1호
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    • pp.135-139
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    • 2002
  • In this study, the experimental open-tube and close-tube thermoacoustic apparatuses were built. In order to determine the optimum length of resonant tube and the optimum length of stack, the resonant characteristics of thermoacoustic apparatuses were investigated, The length of resonant tube varies from 400mm to 850mm. The experimental frequency varies from 100Hz to 1000Hz. In case of the second and third harmonics, the maximum temperature difference of open-tube thermoacoustic apparatus is 53$^{\circ}C$ (resonator length: 400mm) and the maximum temperature difference of closed-tube thermoacoustic apparatus is 51$^{\circ}C$ (resonator length: 500mm). In the open-tube thermoacoustic apparatus, the peak efficiency point is about 2%, 55%, 69% in the resonant tube and in the closed-tube thermoacoustic apparatus, the peak efficiency point is about 2%, 41%, 50% in the resonant tube.

The Effect of Solution Heat Treatments on the Microstructure and Corrosion Behaviour for a Duplex Stainless Steel

  • Kim, Ki-Joon;Lee, Joon-Goo;Oh, Jae-Whan;Lee, Myung-Hoon;Moon, Kyung-Man
    • Journal of Advanced Marine Engineering and Technology
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    • 제28권2호
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    • pp.217-227
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    • 2004
  • The bowl in a ship purifier suffers from high stress and high temperature in a detrimental heavy fuel oil environment. Duplex stainless steel(DSS) is a primary material to withstand this harsh condition. Newly-manufactured STS 329 grade DSS has been evaluated by various mechanical and electrochemical test methods. Eight heat treatment(HT) conditions with different temperature and time were applied to the DSS samples to improve corrosion resistance. Microstructure and polarization test results concluded the optimum HT condition was $1.090^{\circ}C$-60 minutes. Confirmation experiments for applying to a real bowl including stress corrosion cracking test exhibited the reproducibility of the optimum HT condition.

당밀을 이용한 곤충병원성 곰팡이 Beauveria bassiana 726의 포자생산 (Spore Production of Entomopathogenic Fungus, Beauveria bassiana 726, Using Molasses)

  • 김병혁;강성우;윤철식;성재모;홍석인;김승욱
    • KSBB Journal
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    • 제14권3호
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    • pp.365-370
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    • 1999
  • To optimize the culture conditions for Beauveria bassiana 726, the effects of culture medium, pH, and temperature on mycelium and spore production were investigated. The optimum temperature and pH for the cultivation of B. bassiana 726 were 28 $^{\circ}C$ and 5.0, respectively. The optimized medium was composed of 1.0~2.0% total sugar from molasses, 0.5% corn steep liquor and 0.05% KH$_2$PO$_4$. In the cultivation of B. bassiana 726 with the optimum medium, the specific growth rate and substrate utilization were well-fitted with the proposed kinetic model in the shake flask and stirred tank reactor. When the fed-batch cultivation using carbon suorce, nitrogen source, and mineral salt as a feeding medium was compared with batch cultivation in stirred tank reactor, mycelium (12.7 g/L) and spore production (5.4$\times$$10^8/mL$) were enhanced up to 110% and 85%, respectively.

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