• 제목/요약/키워드: Transfer center

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계면활성제가 첨가된 관내 난류의 열유동 특성에 관한 고찰 (Fluid and Heat Transfer Characterization of Surfactant Turbulent Pipe Flows)

  • 신광호;윤형기;장기창;나호상
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.982-987
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    • 2006
  • The fluid mechanics and heat transfer of surfactant turbulent pipe flows are characterized with particular emphasis on the effects of surfactant concentration and solution temperature on drag reduction and heat transfer reduction. The test fluids are the surfactant solutions of DR-IW616 supplied by Akzo Nobel Chemical in concentration of $100{\sim}3000ppm$. The solution temperatures studied are $5^{\circ}C$ to $50^{\circ}C$. The critical values of surfactant concentration and solution temperature are clearly identified for drag reduction phenomena.

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응고중 구리 주형과 알루미늄 용탕의 계면열전달계수에 미치는 용탕과열도와 도형재의 영향 (Effects of Superheat and Coating Layer on Interfacial Heat Transfer Coefficient between Copper Mold and Aluminum Melt during Solidification)

  • 김희수;신제식;이상목;문병문
    • 한국주조공학회지
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    • 제24권5호
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    • pp.281-289
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    • 2004
  • The present study focused on the estimation of the interfacial heat transfer coefficient as a function of the surface temperature of the aluminum casting at the mold/casting interface to investigate the effects of superheat and coating layer. The casting experiments of aluminum into a cylindrical copper mold were systematically conducted to obtain the thermal history during solidification. The thermal history recorded by four thermocouples embedded both in the mold and the casting was used to solve the inverse heat conduction problem using Beck's method. The effects of superheat and coating on the interfacial heat transfer coefficient in the liquid state, during the solidification, and in the solid state were comparatively discussed. In the liquid state, the interfacial heat transfer coefficient is thought to be affected by the roughness of the mold, the wettability of the casting on the mold surface, and the thermophysical properties of the coating layer. When the solidification begins, the air gap forms between the casting and the mold, and the interfacial heat transfer coefficient becomes a function of the air gap as well as surface roughness and the superheat. In the solid phase, it depends only upon the thermal conductivity and the thickness of the air gap. The coating layer reduces seriously the interfacial heat transfer coefficient in the liquid state and during the solidification.

Facial reanimation with masseter nerve-innervated free gracilis muscle transfer in established facial palsy patients

  • Oh, Tae Suk;Kim, Hyung Bae;Choi, Jong Woo;Jeong, Woo Shik
    • Archives of Plastic Surgery
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    • 제46권2호
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    • pp.122-128
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    • 2019
  • Background The masseter nerve is a useful donor nerve for reconstruction in patients with established facial palsy, with numerous advantages including low morbidity, a strong motor impulse, high reliability, and fast reinnervation. In this study, we assessed the results of masseter nerve-innervated free gracilis muscle transfer in established facial palsy patients. Methods Ten patients with facial palsy who received treatment from January 2015 to January 2017 were enrolled in this study. Three patients received masseter nerve-only free gracilis transfer, and seven received double-innervated free gracilis transfer (masseter nerve and a cross-face nerve graft). Patients were evaluated using the Facial Assessment by Computer Evaluation software (FACEgram) to quantify oral commissure excursion and symmetry at rest and when smiling after muscle transfer. Results The mean time between surgery and initial movement was roughly 167.7 days. A statistically significant increase in excursion at rest and when smiling was seen after muscle transfer. There was a significant increase in the distance of oral commissure excursion at rest and when smiling. A statistically significant increase was observed in symmetry when smiling. Terzis' functional and aesthetic grading scores showed significant improvements postoperatively. Conclusions Masseter nerve innervation is a good option with many uses in in established facial palsy patients. For some conditions, it is the first-line treatment. Free gracilis muscle transfer using the masseter nerve has excellent results with good symmetry and an effective degree of recovery.

Development and pregnancy rates of Camelus dromedarius-cloned embryos derived from in vivo- and in vitro-matured oocytes

  • Son, Young-Bum;Jeong, Yeon Ik;Jeong, Yeon Woo;Olsson, Per Olof;Hossein, Mohammad Shamim;Cai, Lian;Kim, Sun;Choi, Eun Ji;Sakaguchi, Kenichiro;Tinson, Alex;Singh, Kuhad Kuldip;Rajesh, Singh;Noura, Al Shamsi;Hwang, Woo Suk
    • Animal Bioscience
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    • 제35권2호
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    • pp.177-183
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    • 2022
  • Objective: The present study evaluated the efficiency of embryo development and pregnancy of somatic cell nuclear transfer (SCNT) embryos using different source-matured oocytes in Camelus dromedarius. Methods: Camelus dromedarius embryos were produced by SCNT using in vivo- and in vitro- matured oocytes. In vitro embryo developmental capacity of reconstructed embryos was evaluated. To confirm the efficiency of pregnancy and live birth rates, a total of 72 blastocysts using in vitro- matured oocytes transferred into 45 surrogates and 95 blastocysts using in vivo- matured oocytes were transferred into 62 surrogates by transvaginal method. Results: The collected oocytes derived from ovum pick up showed higher maturation potential into metaphase II oocytes than oocytes from the slaughterhouse. The competence of cleavage, and blastocyst were also significantly higher in in vivo- matured oocytes than in vitro- matured oocytes. After embryo transfer, 11 pregnant and 10 live births were confirmed in in vivo- matured oocytes group, and 2 pregnant and 1 live birth were confirmed in in vitro- matured oocytes group. Furthermore, blastocysts produced by in vivo-matured oocytes resulted in significantly higher early pregnancy and live birth rates than in vitro-matured oocytes. Conclusion: In this study, SCNT embryos using in vivo- and in vitro-matured camel oocytes were successfully developed, and pregnancy was established in recipient camels. We also confirmed that in vivo-matured oocytes improved the development of embryos and the pregnancy capacity using the blastocyst embryo transfer method.

Analysis of Gene Expression in Cloned Bovine Placentae

  • Kim, Hong-Rae;Kang, Jae-Ku;Yoon, Jong-Taek;Seong, Hwan-Hoo;Jo, Min-Rae;Park, Chang-Sik;Jin, Dong-Il
    • 한국수정란이식학회:학술대회논문집
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    • 한국수정란이식학회 2004년도 제4회 발생공학 국제심포지움 및 학술대회
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    • pp.62-62
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    • 2004
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