• 제목/요약/키워드: Scavenging System

검색결과 625건 처리시간 0.027초

Circuit Components Based on New Materials: The Reality of Multitechnology System on Systems Hyperintegration

  • Eshraghian, Kamran;Cho, Kyoung-Rok
    • Transactions on Electrical and Electronic Materials
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    • 제11권3호
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    • pp.106-111
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    • 2010
  • The convergence of significantly different and disparate technologies such as spintronics, carbon nano tube field effect transistors, photon and bio-responsive molecular switches, memristor and memristive systems and metamaterials, coupled with energy scavenging sources are gaining a renewed focus in the quest for new products. This paper will provide an insight into an anticipated technological revolution and will highlight a futuristic Roadmap to capture opportunities that are brought about as the results of formulation of new circuit components basically driven by emergence of nanoscale materials as part of System on System integration. Challenges as the result of new lumped components such as memristor, metamaterial-based lumped components and the like that will challenge the designers' comfort zone will also be discussed.

저속 장행정 박용디젤기관의 속도제어에 관한 연구 (A STUDY ON THE SPEED CONTROL OF A LOW SPEED-LONG STROKE MARINE DIESEL ENGINE)

  • 유영호;하주식
    • Journal of Advanced Marine Engineering and Technology
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    • 제13권3호
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    • pp.26-36
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    • 1989
  • Recently digital governor system is commonly adapted for the speed control of the marine diesel engine because of too much fluctuation of rpm resulted by the low speed, long stroke, high efficiency and a small number of cylinder of it, and versatile studies on the development of digital governor system are progressed. On this subject the new control method in which the fuel is controlled by feedforwarding the change of load as well as the feedback of angular velocity in case of disregarding the engine dead time and influence of scavenging air was proposed by the authors, and found the method has shown quite a good control performance in comparision to the conventional control method by the simulation using a digital computer for various load change. In this paper the speed control system of a diesel engine is simulated in case of regarding the engine dead time by the proposed method, and also confirm a good control performance of it under even more realistically simulated environment.

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환경오염(環境汚染)에 의한 산화(酸化)스트레스와 식물체(植物體)의 방어기작(防禦機作) (Oxidative Stress Resulting from Environmental Pollutions and Defence Mechanisms in Plants)

  • 심상인;강병화
    • 한국환경농학회지
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    • 제12권3호
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    • pp.264-280
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    • 1993
  • The environmental pollutions were a serious problem in Korea recently. So many researcher have studied the effect of environmental pollution on plants and agro-ecosystem, but the basic mechanisms of environmental stresses were various. One of the important mechanisms was oxidative stress caused by active toxic oxygen. The toxic oxygen was generated by several stresses, abnormal temperature, many xenobiotics, air pollutants, water stress, fugal toxin, etc. In the species of toxic oxygen which is primary inducer of oxidative stresses, superoxide, hydrogen peroxide, hydroxyl radical and singlet oxygen were representative species. The scavenging systems were divided into two groups. One was nonenzymatic system and the other enzymatic system. Antioxidants such as glutathione, ascorbic acid, and carotenoid, have the primary function in defense mechanisms. Enzymatic system divided into two groups; First, direct interaction with toxic oxygen(eg. superoxide dismutase). Second, participation in redox reaction to maintain the active antioxidant levels(eg. glutathione reductase, ascorbate peroxidase, etc.).

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스마트 팜 시스템으로 재배된 표고의 외형평가 및 항산화능 활성 (Characterization of the morphology and antioxidant content of shiitake cultivated in smart farm system)

  • 조재한;엽소진;한재구;이강효;박혜성
    • 한국버섯학회지
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    • 제15권4호
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    • pp.206-209
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    • 2017
  • 스마트 팜 시스템을 이용하여 재배한 표고와 일반재배 시스템으로 재배한 표고의 갓 직경과 두께를 조사한 결과로 갓 직경과 굵기, 대 길이와 굵기, 개체중 모두 스마트팜 시스템을 이용하여 재배한 버섯이 조금 높게 나왔고, 갓과 대의 경도는 일반 재배된 버섯이 더 높게 나왔는데 이는 수분 함량이 더 적기 때문에 경도가 높은 것으로 사료된다. DPPH 라디칼 소거능에서는 스마트 팜 시스템에서 재배하여 동결건조한 후에 $60^{\circ}C$에서 추출한 처리구에서 37.8%의 라디칼 소거능을 보여 가장 높은 활성을 보였고, 열풍건조하여 70% 발효주정에서 추출한 처리구가 12.2%로 가장 낮은 활성을 보인 것을 확인하였다. 총 폴리페놀 함량 역시 열수 추출한 처리구가 70% 발효주정에서 추출한 처리구보다 모두 높은 폴리페놀 함량을 가졌고, 동결건조 샘플이 열풍건조 샘플보다 폴리페놀 함량이 높았으며, 스마트 팜 시스템에서 재배한 버섯이 각각의 처리구에서 일반 재배된 버섯보다 조금씩 높은 함량을 가진 것을 확인하였다. 스마트 팜 시스템을 이용하여 표고버섯을 재배했을 때 일반 재배방식으로 재배된 버섯보다 항산화 활성과 폴리페놀 함량이 높게 나와 일반 재배방식보다 더욱 기능성이 향상된 버섯을 만드는데 도움이 될 것이라 생각된다.

마이크로파처리에 의한 심황색소의 화학안정성 및 세포독성 변화 (Changes in chemical properties and cytotoxicity of turmeric pigments by microwave treatment)

  • 송이슬;홍정일
    • 한국식품과학회지
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    • 제49권6호
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    • pp.693-698
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    • 2017
  • 다양한 생리활성을 가진 심황과 쿠쿠미노이드가 가공식품류 등에 광범위하게 적용되는 바, 실제 식품 중에 이용되는 oleoresin turmeric 색소에 대해 마이크로파처리에 의한 화학안정성 및 생리활성의 변화를 분석하였다. 심황색소는 마이크로파 가열처리에 의해 황색도와 화학안정성이 감소하였으며 특히 3종의 쿠쿠미노이드 중 쿠쿠민이 마이크로파처리에 가장 민감하였고 BMC가 가장 안정하였다. 마이크로파처리 후 심황색소의 ABTS, AAPH peroxyl radical 및 아질산염 제거활성은 증가하였으며, DPPH 라디칼 제거활성에는 변화가 없었다. 심황색소에서 생성되는 활성 산소종은 마이크로파처리 후 증가하였으나, 정상장관계 세포 INT 407과 대장암 세포 HCT 116을 대상으로 한 세포독성 효과는 두 종류의 세포에서 모두 약화되었다. 본 연구에서는 다양한 식품 중에 첨가되는 심황색소가 마이크로파처리에 의해 화학적변화 및 생리활성에 영향을 가져올 수 있음을 보여주며, 이를 함유한 식품의 적절한 가공 및 조리방법이 고려되야 함을 제시하고 있다.

Adenophora remotiflora protects human skin keratinocytes against UVB-induced photo-damage by regulating antioxidative activity and MMP-1 expression

  • Kim, Hye Kyung
    • Nutrition Research and Practice
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    • 제10권4호
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    • pp.371-376
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    • 2016
  • BACKGROUND/OBJECTIVES: Chronic ultraviolet (UV) exposure-induced reactive oxygen species (ROS) are commonly involved in the pathogenesis of skin damage by activating the metalloproteinases (MMP) that break down type I collagen. Adenophora remotiflora (AR) is a perennial wild plant that inhabits Korea, China, and Japan. The present study investigated the protective effects of AR against UVB-induced photo-damage in keratinocytes. MATERIALS/METHODS: An in vitro cell-free system was used to examine the scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and nitric oxide (NO). The effect of AR on ROS formation, antioxidant enzymes, elastase, MMP-1 level, and mRNA expression of MMP-1 were determined in UVB-irradiated human keratinocyte HaCaT cells. RESULTS: AR demonstrated strong DPPH free radical and NO scavenging activity in a cell-free system exhibiting $IC_{50}$ values of 1.88 mg/mL and 6.77 mg/mL, respectively. AR pretreatment dose-dependently attenuated the production of UVB-induced intracellular ROS, and antioxidant enzymes (catalase and superoxide dismutase) were enhanced in HaCaT cells. Furthermore, pretreatment of AR prevented UVB-induced elastase and collagen degradation by inhibiting the MMP-1 protein level and mRNA expression. Accordingly, AR treatment elevated collagen content in UVB-irradiated HaCaT cells. CONCLUSION: The present study provides the first evidence of AR inhibiting UVB-induced ROS production and induction of MMP-1 as a result of augmentation of antioxidative activity in HaCaT human keratinocytes. These results suggest that AR might act as an effective inhibitor of UVB-modulated signaling pathways and might serve as a photo-protective agent.

천식모델생쥐에서 선폐탕(宣肺湯)의 면역조절 효과 (Effects of Seonpye-tang on OVA-Induced Asthmatic Mice)

  • 이주관;박양춘
    • 동의생리병리학회지
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    • 제23권2호
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    • pp.457-463
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    • 2009
  • This study aimed to evaluate the anti-asthmatic effects of Seonpye-tang (SPT) using OVA-induced asthmatic mice model. Scavenging activity of SPT on DPPH free radical and SOD-like activity of SPT were measured at final concentration 62.5, 125, 250, 500 (${\mu}g/m{\ell}$), RBL-2H3 cells were treated with DNP IgE for 24hr, and treated with SPT (1, 10, 100 ${\mu}g/m{\ell}$) for 1hr, followed by treatment with DNP-HSA for 1hr at $37^{\circ}C$. The level of IL-4 and TNF-${\alpha}$ were measured by ELISA. Asthmatic mice model was conducted by repeated challenge of OVA using C57BL/6 mice. Each group was treated with distilled water, SPT (400 mg/kg and 200 mg/kg) extract or cyclosporin A (10 mg/kg) for the later 8 weeks. Immune cells subpopulation, eotaxin, IL-5 and TNF-${\alpha}$ in BALF were analyzed. SPT dose-dependently increased Scavenging activity on DPPH free radical and SOD-like activity. SPT significantly ameliorated the increase of total cells number and eosinophil including of immune cell subpopulation of $CD3^+/CD69^+$, $CCR3^+$, $B220^+/CD22^+$, $B220^+/CD45^+$ and $B220^+/IgE^+$ cells in BALF comparing to control group. Eotaxin and IL-5 level in BALF were significantly decreased by SPT. These results strongly suggest that SPT would be a effective candidate for herbal-originated anti-asthmatic drug. However, this drug should be further studied for characterization of the accurate action and underlying mechanisms using variant disease model in the future.

황련청심음(黃連淸心飮)의 항산화 및 AChE 억제 효과에 관한 연구 (Antioxidant Property and Inhibitory Effects of an Water Extract of Hwang-Ryun-Chung-Sim-Um on the Acetylcholinesterase)

  • 유종호;이상택;한윤승;김근우;구병수;김헌일
    • 동의신경정신과학회지
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    • 제17권1호
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    • pp.1-16
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    • 2006
  • Objective: An water extract of the Hwang-Ryun-Chung-Sim-Um (HRC) was assessed to determine the mechanisms of its antioxidant activity. In addition, the HRC was examined in vitro for the inhibitory effect on the acetylcholinesterse (AChE). Methods: The HRC exhibited a concentration-treatment; scavenging ${\alpha},{\alpha}-diphenyl-{\beta}-picrylhydrazyl$ (DPPH) radical, linoleic acid oxidation in a thiocyanate assay system, hydroxyl radical-induced DNA nicking. We investigated mRNA levels such as catalase activity, superoxide-dismutase and glutathione peroxidase. The water extract of HRC showed inhibitory effect on AChE activity. Result: The HRC extract showed dose-dependent free radical scavenging activity, including DPPH radicals and hydroxyl radicals, using different system. The HRC was also found to be effective in protecting plasmid DNA against the strand breakage induced by Hydroxyl radicals in Fenton's reaction mixture. Futhermore, catalase mRNA expression levels increased, but SOD1 and MnSOD was not expressed. HRC in a various concentration-dependent decreased AChE mRNA levels and inhibitory effect showed AChE. Conclusion: According to the above results, it is supposed that HRC is applicable to the Dementia-type of Alzheimer clinically.

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Towards Conservation of Omani Local Chicken: Phenotypic Characteristics, Management Practices and Performance Traits

  • Al-Qamashoui, B.;Mahgoub, O.;Kadim, I.;Schlecht, E.
    • Asian-Australasian Journal of Animal Sciences
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    • 제27권6호
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    • pp.767-777
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    • 2014
  • Characterizing local chicken types and their mostly rural production systems is prerequisite for designing and implementing development and conservation programs. This study evaluated the management practices of small-scale chicken keepers and the phenotypic and production traits of their chickens in Oman, where conservation programs for local livestock breeds have currently started. Free-range scavenging was the dominant production system, and logistic regression analysis showed that socio-economic factors such as training in poultry keeping, household income, income from farming and gender of chicken owners influenced feeding, housing, and health care practices (p<0.05). A large variation in plumage and shank colors, comb types and other phenotypic traits within and between Omani chicken populations were observed. Male and female body weight differed (p<0.05), being $1.3{\pm}0.65$ kg and $1.1{\pm}0.86$ kg respectively. Flock size averaged $22{\pm}7.7$ birds per household with 4.8 hens per cock. Clutch size was $12.3{\pm}2.85$ and annual production $64.5{\pm}2.85$ eggs per hen. Egg hatchability averaged $88{\pm}6.0%$ and annual chicken mortality across all age and sex categories was $16{\pm}1.4%$. The strong involvement of women in chicken keeping makes them key stakeholders in future development and conservation programs, but the latter should be preceded by a comprehensive study of the genetic diversity of the Omani chicken populations.

Isolation and Identification of Antioxidants from Peanut Shells and the Relationship between Structure and Antioxidant Activity

  • Wee, Ji-Hyang;Moon, Jae-Hak;Eun, Jong-Bang;Chung, Jin-Ho;Kim, Young-Gook;Park, Keun-Hyung
    • Food Science and Biotechnology
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    • 제16권1호
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    • pp.116-122
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    • 2007
  • Four compounds with antioxidant activity were isolated from the MeOH extract of peanut shells (pod) and identified as 5,7-dihydroxychromone (1), eriodictyol (2), 3',4',7-trihydroxyflavanone (3), and luteolin (4) by electron impact-mass spectrometry (EI-MS) and nuclear magnetic resonance (NMR) analyses. The relationship between antioxidant activity and chemical structure of the isolated compounds with their analogues [(-)-epicatechin, quercetin, taxifolin] was examined by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and using the 2-deoxy-D-ribose degradation system. The order of antioxidant activity on the basis of DPPH radical-scavenging was quercetin = (-)-epicatechin (6.0 molecules) > taxifolin (4,5 molecules) > 4 (luteolin; 4.0 molecules) > 2 (eriodictyol; 2.5 molecules) > 3 (3',4',7-trihydroxy-flavanone; 2.0 molecules) > 1 (5,7-dihydroxychromone; 0.5 molecules). On the other hand, using the 2-deoxy-D-ribose degradation system, the order of antioxidant activity was quercetin > 4 >> (-)-epicatechin ${\geq}\;2\;{\geq}$ taxifolin > 3 > 1. These compounds from peanut shells may provide defensive measures against oxidative stress and insects in the soil.