• Title/Summary/Keyword: reduction effect

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도그본 고려한 조압연 압연하중 예측모델 개발 (Model for the prediction of Roll Force of Roughing Mill considering Width reduction)

  • 곽우진;이성진
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2007년도 춘계학술대회 논문집
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    • pp.223-225
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    • 2007
  • Online models predicting roll force and forward slip of roughing mill was developed using nondimensional parameters. Using the effective inlet thickness, roll force model take into account the effect of inlet dog-bone shape of slab which take places after width reduction through edger rolling in roughing mill. The prediction accuracy of the proposed model is examined through comparison with measurements.

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단순화도니 트랙터-트레일러의 기저 압력저항 감소에 관한 실험적 연구 (An experimental study on the base pressure drag reduction of a simplified tractor-trailer)

  • 고상호;박승오
    • 오토저널
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    • 제14권4호
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    • pp.90-96
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    • 1992
  • The effect of base cavities on the drag of a simplified tractor-trailor model for Re=4.1*10$^{5}$ is investigated experimentally. Three different types of base cavities are studied in this work. They are solid-wall, slitted-wall, and slotted-wall cavities. Slotted-wall cavity is found to be most effective for drag reduction. A maximum of 11% reduction in the zero-yaw drag coefficient is achieved with the slotted wall cavity.

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가리염 첨가가 궐련 주류연중 타르, 니코틴, 일산화탄소 이행량에 미치는 영향 (Effect of Exogenous Potassium on the Reduction in Tar, Nicotine and Carbon Monoxide Deliveries in the Mainstream smoke of Cigarettes)

  • 안기영;김천석
    • 한국연초학회지
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    • 제17권1호
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    • pp.62-67
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    • 1995
  • Deliveries of tar, nicotine and carbon monoxide in mainstream smoke decreased with increment of exogenous potassium content of tobacco. Potassium malate was more effective than potassium nitrate, potassium carbonate, potassium citrate and potassium oxalate for the reduction of carbon monoxide, but potassium nitrate was more effective than potassium palate, potassium carbonat, potassium citrate and potassium oxalate for the reduction of carbon in the case of nicotine. Puff count and burning rate were slightly changed with added potassium salts.

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슬래브궤도의 방진효율성 평가기법 개발 (Development of Evaluation Method of Vibration-Reduction Efficiency in Slab Track)

  • 양신추;강윤석;김만철;이종득
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 1999년도 추계학술대회 논문집
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    • pp.463-470
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    • 1999
  • In this paper, a numerical method for evaluating the efficiency of vibration reduction of substructure under slab track is developed for optimal design of floating slab track. The equation of motion for train and track interaction system is derived by applying compatibility condition at the contact points between wheels and rails. The train is modelled by 3-masses system and the track by continuous support beam system. Numerical analyses are carried out to investigate the effect of train speed, stiffness and damping of slab-pad, and track irregularity upon vibration reduction in substructure under the track.

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청혈단(淸血丹)의 6-hydroxydopamine에 의해 유발된 독성에 대한 신경세포보호효과 (The Protective Effect of Chunghyul-dan(Qingxuedan) Against 6-hydroxydopamine Induced Neurotoxicity.)

  • 김광호;김종우;정선용;조성훈;오명숙;황의완
    • 동의신경정신과학회지
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    • 제20권1호
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    • pp.21-42
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    • 2009
  • Objectives : This Study was performed to assess the antioxidant and neuroprotective effect of Chunghyul-dan(Qingxuedan) in PC12 cells and primary rat mesencephalic dopaminergic neurons. Methods : The anioxidant effect was investigated using the DPPH radical and ABTS cation scavenging assays and total polyphenol amout of Chunghyul-dan(Qingxuedan). The neuroprotective effect of Chunghyul-dan(Qingxuedan) in PC12 cells was evaluated using MTT assay. The scavenging activity of Chunghyul-dan(Qingxuedan) on ROS production induced by 6-OHDA(6-hydroxydopamine) in PC12 cells was evaluated, as well as the attenuating effect on GSH reduction. Finally, we examined the neuroprotective effect of Chunghyul-dan(Qingxuedan) against 6-0HDA-induced toxicity in the primary culture of rat mesencephalic doperminergic neurons. Results : Chunghyul-dan(Qingxuedan) showed concentration-dependent scavenging activities in DPPH radical and ABTS cation scavenging assays and it was not cytotoxic to PC12 cells. In postand co-treatment, Chunghyul-dan(Qingxuedan) protected PC12 cells from the 6-OHDA induced toxicity at 50 and 100 ${\mu}$g/mL significantly. And Chunghyu!-dan(Qingxuedan) decreased the 6-OHDA induced ROS production at a dose dependent manner, while increaing the 6-OHDA induced GSH reduction at 50 and 100 ${\mu}$g/mL significantly. Finally, Chunghyul-dan(Qingxuedan) showed signicant protection of rat mescencephalic dopaminergic neurons from 6-OHDA at 1 ${\mu}$g/mL. Conclusions : These results demonstrate that Chunghyul-dan(Qingxuedan) has the antioxidant and neuroprotective effect against 6-0HDA induced cytotoxicity through decreasing ROS production and increasing GSH reduction.

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Redox Reaction Investigation of Graphene Nanoribbon

  • Yu, Young-Jun
    • Applied Science and Convergence Technology
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    • 제27권2호
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    • pp.35-37
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    • 2018
  • The redox reaction on graphene nanoribbon (GNR) field effect transistors(FET) has been studied. In detail, upon employing an electrolyte gating, we verified electron transport performance modulation of GNR FET by monitoring conductance variation under oxidation and reduction processes. The conductance enhancement of GNR via removal of PMMA residue on graphene surface during redox cycles was also observed.