• Title/Summary/Keyword: ${\omega}-3$

Search Result 2,914, Processing Time 0.037 seconds

Preparation and Properties of Polyorganosiloxane Modified Maleated EPDM/EPDM Rubber Vibration Isolator (Polyorganosiloxane 변성 말레화 EPDM/EPDM 방진고무의 제조와 그 특성)

  • Kang, Doo-Whan;Kim, So-Mi
    • Applied Chemistry for Engineering
    • /
    • v.21 no.5
    • /
    • pp.581-585
    • /
    • 2010
  • The surface of Alnico, one of the industrial dust waste, was treated with 1,3,5-trivinyl-1,3,5-trimethylcyclotrisilazane (VMS) as a surface treating agent and used as the filler for vibration isolator rubber. Maleated EPDM prepared from bulk polymerization of EPDM with maleic anhydride was copolymerized with ${\alpha},{\omega}$-bis(3-aminopropyl)polydimethylsiloxane to obtain maleated EPDM-polydimethylsiloxane copolymer (MEPDM-PDMS). EPDM/Alnico/MEPDM-PDMS vibration isolator rubber was prepared from compounding with Alnico treated with surface treating agent, 25 and 50 phrs to EPDM, respectvely based on 1 to 10 wt% of MEPDM-PDMS to EPDM. From the measurement of the thermal properties to the rubber, the glass transition temperatures (Tg) for the rubber containing maleated EPDM-PDMS copolymer was slightly lower temperature, $33^{\circ}C$ than EPDM rubber, and also DMA results showed higher tan ${\delta}$ peak to the rubber prepared from compounding with EPDM-PDMS copolymer. From the results, rubber prepared using EPDM-PDMS copolymer had better vibration isolator property.

Effect of n-6/n-3 fatty acid ratio on hepatic glycerolipid partitioning in second generation rats (n-6/n-3 지방산 비율이 차세대 랫드의 지질대사 분할에 미치는 영향)

  • Park, Byung-Sung
    • Journal of the Korean Applied Science and Technology
    • /
    • v.34 no.4
    • /
    • pp.839-850
    • /
    • 2017
  • The objective of this study was to investigate the effect of diets with different omega-6 (n-6) and omega-3 (n-3) fatty acid ratios (0, 1.2: 1, 8: 1, 19: 1) on mechanisms of partitioning of in vivo hepatic glycerolipid metabolism in next generation rats. Biomonitoring techniques were used in rats (jugular vein cannula were attached). The range of $^{14}CO_2$ exhaled by glycerolipid metabolism was 7.05-20.17% in the group having diet with n-6/n-3 ratio less than 8:1. It was the lowest in the control group. Total glycerolipid was the highest in the control group. For groups with different n-6/n-3 ratio, it had the following order: 19:1>8:1>1.2:1. Secreted triglyceride was decreased by 36.35%, 20.93%, and 13.72% in 1.2:1,8:1, and 19:1 groups, respectively, compared to that in the control group. The ratio of phospholipid to total glycerolipid was 1.38, 1.29, and 1.17 times higher in 1.2:1, 8:1, and 19:1 groups, respectively, compared to that in the control group. The ratio of $^{14}CO_2$ to total glycerolipid was 1.61, 1.52, and 1.29 times higher in 1.2:1, 8:1, and 19:1 groups, respectively, compared to that in the control group.

Omega-3 Oxidation State of Fish and Algae Oil Supplements in South Korea (오메가-3 제품의 산화에 대한 안정성 조사)

  • Park, Geon-Yeong;Kim, Young-Suk;Kim, Yang-Hui;Shin, Sang-Woon;Cho, Sang-Hun;Eum, Kyoung-Suk;Hong, Se-Ra;Yoon, Mi-Hye
    • Journal of Food Hygiene and Safety
    • /
    • v.34 no.5
    • /
    • pp.480-488
    • /
    • 2019
  • To ensure the safety of products containing omega-3 fatty acids, twenty fish and algae oil omega-3 products available in a Gyeonggi Province, South Korea market were analyzed for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content, as well as for oxidative status. Of the tested products, 90% complied with the CODEX/FAO fish oil standards on a p-anisidine value (p-AV) limit of 20, and 80% complied with the CODEX/FAO fish oil standards on the TOTOX limit of 26, respectively. Fully 100% of the products complied with EPA/DHA content levels. In addition, 90% of the tested products met with a peroxide value (PV) limit of 10 meq/kg while 95% of products were within the a p-AV limit of 30. Also, 95% of the products had a calculated TOTOX value of 50, which is lower than the stringent limits used by the European and British Pharmacopeia and Australian authorities.

On the Envelopes of Homotopies

  • Choyy, Jae-Yoo;Chu, Hahng-Yun
    • Kyungpook Mathematical Journal
    • /
    • v.49 no.3
    • /
    • pp.573-582
    • /
    • 2009
  • This paper is indented to explain a dynamics on homotopies on the compact metric space, by the envelopes of homotopies. It generalizes the notion of not only the envelopes of maps in discrete geometry ([3]), but the envelopes of flows in continuous geometry ([5]). Certain distinctions among the homotopy geometry, the ow geometry and the discrete geometry will be illustrated. In particular, it is shown that any ${\omega}$-limit set, as well as any attractor, for an envelope of homotopies is an empty set (provided the homotopies that we treat are not trivial), whereas it is nonempty in general in discrete case.

TURBULENT FLOW SIMULATIONS ABOUT THE AIRCRAFT CONFIGURATION (항공기 주위 난류 유동장 해석)

  • Kim YoonSik;Park Soo Hyung;Kwon Jang-Hyuk
    • Journal of computational fluids engineering
    • /
    • v.10 no.4 s.31
    • /
    • pp.39-50
    • /
    • 2005
  • An application of the KFLOW3D code which has been developed at KAIST is presented. This paper briefly describes the underlying methodology and summarizes the results for the DLR-F6 transport configuration recently presented in the second AIAA CFD Drag Prediction Workshop held in Orlando, FL, June 2003. KFLOW3D is a parallelized Reynolds averaged Navier-Stokes solver for multi-block structured grids. For the present computations, 2-equation k-$\omega$ WD+ nonlinear eddy viscosity model is used. The emphasis of the paper is placed on the implementation of the k-$\omega$ WD+ model in the multigrid framework and practicality of KFLOW3D for accurately predicting not only the integrated aerodynamic property such as the drag coefficient but pressure distributions.

Study on the Electric Continuity Measurements of Green Car for Human Body Safety (친환경자동차의 인체 안전을 위한 전기적 연속성 측정 연구)

  • Kim, Hyang-Kon;Lee, Ki-Yeon;Kim, Dong-Ook;Choi, Hyo-Sang
    • The Transactions of the Korean Institute of Electrical Engineers P
    • /
    • v.58 no.3
    • /
    • pp.351-356
    • /
    • 2009
  • In this study, we analyzed and experimented about electric continuity for human body safety from green cars. And we compared power systems of HEV and examined about human body effect of current and time. We investigated internal and external standards and regulations for human body safety from high voltage electrical equipments. Indirect contact refers to contact between the human body and exposed conductive parts. According to UNECE R100, ISO 23273-3, ISO 6469-3 and Japanese Regulation Attachment 101, electric continuity between any two exposed conductive parts shall not exceed $0.1{\Omega}$. The value of electric continuity was measured below $0.1{\Omega}$ at the actual condition of green car. We expected that the results of these experiments can utilize to data for electrical safety of green car.

Development of thin-film liquid-level sensors using AC heating method (교류 가열법을 이용한 박막 액체 레벨 센서 개발)

  • Hong, Jong-Gan;Choi, Sun-Rock;Kim, Dong-Sik
    • Proceedings of the KSME Conference
    • /
    • 2008.11a
    • /
    • pp.1842-1846
    • /
    • 2008
  • This work reports development of novel liquid-level sensors based on the $3{\omega}$ method. The sensors determine the liquid level by measuring the thermal response as in the conventional hot-wire technique. However the sensors employ an AC heating method to enhance the sensitivity, noise resistance and time response. Also, the microfabricated thin-film structure of the sensor provides mass-producibility as well as improved sensor performance owing to the increase in the surface-volume ratio of the sensor. Two different types of the sensor are developed: one for point detection of the fluid phase and the other for monitoring continuous variation of liquid level. Notable is that the performance of the sensor is not considerably affected by the liquid flow.

  • PDF

PERIODIC SOLUTIONS FOR NONLINEAR PARABOLIC SYSTEMS WITH SOURCE TERMS

  • Jung, Tacksun;Choi, Q-Heung
    • Korean Journal of Mathematics
    • /
    • v.16 no.4
    • /
    • pp.553-564
    • /
    • 2008
  • We have a concern with the existence of solutions (${\xi},{\eta}$) for perturbations of the parabolic system with Dirichlet boundary condition $$(0.1)\;\begin{array}{lcr}{\xi}_t=-L{\xi}+{\mu}g(3{\xi}+{\eta})-s{\phi}_1-h_1(x,t)\;in\;{\Omega}{\times}(0,2{\pi}),\\{\eta}_t=-L{\eta}+{\nu}g(3{\xi}+{\eta})-s{\phi}_1-h_2(x,t)\;in\;{\Omega}{\times}(0,2{\pi})\end{array}.$$ We prove the uniqueness theorem when the nonlinearity does not cross eigenvalues. We also investigate multiple solutions (${\xi}(x,t),\;{\eta}(x,t)$) for perturbations of the parabolic system with Dirichlet boundary condition when the nonlinearity f' is bounded and $f^{\prime}(-{\infty})<{\lambda}_1,{\lambda}_n<(3{\mu}+{\nu})f^{\prime}(+{\infty})<{\lambda}_{n+1}$.

  • PDF