• Title/Summary/Keyword: BHP

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A Study on Trim Optimization by using CFD Analysis (CFD를 이용한 트림 최적화 연구)

  • Kim, In-Chul;Yoon, Ji-Hyun;Jeong, Young-Jun
    • Special Issue of the Society of Naval Architects of Korea
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    • 2015.09a
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    • pp.41-45
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    • 2015
  • In this study reviewed the validity of the estimated optimum trim by the numerical analysis. For this purpose, the numerical analysis of the trim optimization for 6500TEU container carrier and capesize bulk carrier were carried out using Star-CCM+, which results were compared with the results of model tests. The reliability of results of the numerical analysis was confirmed via comparing the resistance determined by the numerical analysis and model test. The performance of self-propulsion at each trim conditions were estimated using the calculated resistance by numerical analysis. The BHP at each trim condition were calculated by estimated performance of self-propulsion, which trend of results were confirmed similar trend of result of model test.

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Performances of the Used Frying Oil on a Small Diesel Engine (폐식용유를 이용한 소형 디젤기관의 성능)

  • 김성태;정형길;김영복
    • Journal of Biosystems Engineering
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    • v.26 no.3
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    • pp.209-220
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    • 2001
  • This study was carried out to investigate the usability of the used frying oil, which was extracted from soybean, as one of the alternative fuel of a small diesel engine. For the experiment, NO. 2 diesel oil [D], used frying oil [UF], and their volumetric blends were applied and analysis of the properties and compositions of the experimental fuels were conducted. A four cycle diesel engine with single cylinder, water cooling system, maximum output 8.1 ㎾/2,200 rpm was selected and a direct injection chamber and a precombustion chamber were attached alternately. The results obtained were as follows: 1. Engine power (BHP) were increased from 4.13~4.27㎾ to 9.08~9.15㎾ for diesel oil, from 4.05~4.19㎾ to 8.44~8.92㎾ for UF, and from 4.01~4.48㎾ to 8.69~9.16㎾ for blend fuel, as the engine speed increased from 1,000 rpm to 2,200 rpm. The BHP in case of the direct combustion chamber were fluctuated higher than those of the pre-combustion chamber. 2. With the engine speed increased, torque of the engine were increased from 39.50~40.80 N.m to 42.89 N.m, then decreased to 39.44~39.77 N.m for diesel oil, and increased from 38.73~40.04 N.m to 40.12~40.82 N.m then decreased as 36.53~38.76 N.m for UF. Torque of the blend fuels were increased from 38.75~41.76 N.m to 40.47~42.89 N.m then decreased to 37.73~39.78 N.m. There is no significant difference of torque between the type of combustion chambers. 3. The specific fuel consumption of the UF was increased about 20 percent depending on the engine speed variations. And in case of direct injection chamber, about 12 percent lower fuel consumption was observed than that of precombustion chamber. 4. NOx emission of the UF was higher than that of diesel oil at above 1,800rpm of the engine speed. In case of the direct injection chamber, NOx emission was revealed higher about 59 percent than that of the precombustion chamber, depending on the range of the engine speeds. 5. Smoke emission was decreased in case of UF compared with diesel oil on direct injection chamber. When using precombustion chamber smoke emission was a little higher than that of the direct injection chamber were showed at the engine speed range. 6. At all the engine speed range, exhaust gas temperatures were decreased 2~3$^{\circ}C$ for UF used engine compared with those of the diesel oil. The exhaust gas temperature of the direct injection chamber was higher than that of the precombustion chamber by 72$^{\circ}C$. 7. Unburnt materials remained in the cylinder in case of the pre-combustion chamber was smaller and softer than that of the direct combustion chamber. 8. The feasibility of the blend fuel B-1 and B-2 were verified as a direct combustion chamber was attached to the diesel engine, with respect to the power performance of the engine.

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온라인 증권거래 서비스의 고객만족 요인에 대한 실증적 연구

  • Choe, Don-Hwang;Hong, Jae-Beom;Yang, Jeong-Sik
    • Proceedings of the Korea Association of Information Systems Conference
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    • 2005.05a
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    • pp.161-175
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    • 2005
  • 본 연구에서는 온라인 증권거래 서비스 품질과 고객만족 나아가 고객행동을 분석한 연구이다. 이를 위해 설문조사를 실시하였으며 조사원이 직접 증권사 객장을 방문하여 운라인 증권거래경험이 있는 고객을 대상으로 설문조사를 실시하였다. 이를 위해 40개 증권사, 420여개설문이 회수되었다. 분석결과, 첫째, 온라인 증권거래를 이용하는 고객층을 분석하면, 여성보다는 남성이 온라인 증권거래를 활발히 이용하고 있으며 연령별로는 40대, 50대, 30대 순으로 나타났으며 직업은 대부분 근로생활자가 많이 활용하고 있는 것으로 나타났으며 전체 50%이상이 매일 접속하고 거래하는 것으로 나타났으며 운영 규모는 1천만원이하가 다수로 나타났다. 둘째, 온라인 증권거래 서비스 품질요인으로 지각된 신뢰성, 지각된 편의성, 지각된 유형성, 지각된 응답성 순으로 고객만족에 영향을 미치는 것으로 나타났다. 지각된 신뢰성은 약속된 서비스를 정확하게 수행하는 능력에 대한 지각으로 나타내며, 지각된 편의성은 온라인증권거래를 이용하기에 얼마나 용이한 지에 대한 지각을 나타낸다. 지각된 유형성은 물적 시설, 장비, 사람, 의사소통 도구의 외형과 같은 부분에 대한 지각을 나타내는 것이다 지각된 응답성은고객을 돕고 즉각적인 서비스를 제공하려는 의지에 대한 지각을 나타낸다. 마지막으로 고객만족은 재이용이나 구전의도에 긍정적인 효과를 미치는 것으로 나타났다. 이러한 결과는 고객지향적인 온라인 증권거래 서비스 시스템 구축 및 운영이 이용확대에 중요한 요인임을 제시한다. 본 연구는 온라인 증권거래에 대한 고객만족의 탐색적인 연구로써 보다 심도 있는 연구를 위한 기초를 제공하였다는 점과 온라인 증권거래 성과측정요소로써 고객만족에 영향을 미치는 요인을 제시했다는 점에서 의미를 지닌다.에 의해 유도된 single-strand 절단을 억제하였다. 이상과 같이 간세포 일차배양에서 양파추출물은 t-BHP에 의해 유발된 간독성, 간세포 생존율 감소, 지질과산화를 농도 의존적으로 억제시켰고 또한 t-BHP에 의해 억제된 GSH-Px, GSH-Rd 및 catalase의 활성을 증가시켰다. 이와 같이 양파추출물의 간보호 및 항산화 효과는 항산화 효소, 특히 catalase의 활성 증가와 hydroxyl radical에 의해 유도된 산화억제 및 이에 따른 지질과산화 억제에 기인하는 것으로 사료된다.chno-economic paradigm)의 시각에서 제시하는 한국경제의 성장 ${\cdot}$ 고용 ${\cdot}$ 분배를 위한 정책방향은 다음과 같은 동태적발전과정으로 요약할 수 있다 : 기초과학연구능력 확충 ${\rightarrow}$ 소화 ${\cdot}$ 흡수 ${\cdot}$ 개량 ${\rightarrow}$ 토착화 능력의 배양 ${\rightarrow}$ 자체기술개발, 선진기술 도입, 산업간 및 산업내 기술확산, 국제기술협력 ${\rightarrow}$ 기술혁신의 촉진 ${\rightarrow}$ 총요소생산성과 기업경쟁력(자원 및 역량, 프로세스 경쟁력, 품질경쟁력, 시장경쟁력, 고객성과, 시장성과, 재무성과)의 제고 ${\rightarrow}$ 가격경쟁력(임금, 금리, 물류비용, 환율 등)과 비(非)가격경쟁력(디자인, 에프터서비스, 품질, 운송 등)의 제고 ${\rightarrow}$ 국가경쟁력의 제고 ${

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Fortified Antioxidative Potential by Chrysoeriol through the Regulation of the Nrf2/MAPK-mediated HO-1 Signaling Pathway in RAW 264.7 Cells (생쥐 대식세포에서 HO-1 발현 유도를 통한 chrysoeriol의 항산화 효과)

  • Park, Chung Mu
    • Journal of Life Science
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    • v.28 no.1
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    • pp.43-49
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    • 2018
  • Chrysoeriol is a widespread flavone, and it is usually found in alfalfa, which has been used as a traditional medicine to treat dyspepsia, asthma, and urinary system disorders. Recently, analysis has been conducted on the anti-inflammatory activity of chrysoeriol, but information on its antioxidative capacity is limited. In this study, the antioxidative potential of chrysoeriol against oxidative damage and its molecular mechanisms were evaluated by analysis of the cell viability, reactive oxygen species (ROS) formation, and Western blots in the RAW 264.7 cell line. Chrysoeriol significantly scavenged lipopolysaccharide (LPS)-induced intracellular ROS formation in a dose-dependent manner, without any cytotoxicity. Heme oxygenase-1 (HO-1), a phase II enzyme that exerts antioxidative activity, was also potently induced by chrysoeriol treatment, which corresponded to the translocation of nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) into the nucleus. Moreover, mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) were analyzed due to their important role in maintaining cellular redox homeostasis against oxidative stress. As a result, chrysoeriol-induced HO-1 upregulation was mediated by extracellular signal - regulated kinase (ERK), c-Jun $NH_2$-terminal kinase (JNK), and p38 phosphorylation. To identify the antioxidative potential exerted by HO-1, tert-butyl hydroperoxide (t-BHP)-induced oxidative damage was applied and mitigated by chrysoeriol treatment, which was confirmed by the HO-1 selective inhibitor and inducer, respectively. Consequently, chrysoeriol strongly strengthened the HO-1-mediated antioxidative potential through the regulation of the Nrf2/MAPK signaling pathways.

Characteristics of Fermented Dropwort Extract and Vinegar Using Fermented Dropwort Extract and Its Protective Effects on Oxidative Damage in Rat Glioma C6 Cells (미나리 발효액과 미나리 발효액을 이용한 식초의 특성 분석 및 glioma C6 세포에서 산화적 손상에 대한 보호 효과)

  • Kim, Min-Ju;Lee, Sam-Pin;Choi, Jun-Hyeok;Kwon, Seung-Hyuk;Kim, Hyung-Dae;Bang, Myun-Ho;Yang, Seun-Ah
    • Korean Journal of Food Science and Technology
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    • v.45 no.3
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    • pp.350-355
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    • 2013
  • The quality of fermented dropwort extract (FDE) and fermented dropwort vinegar (FDV) was assessed for free sugar, organic acid and free and total amino acid content. Major organic acids were lactic acid in FDE and acetic acid in FDV. Free sugars in FDE were fructose and glucose, and those in FDV were fructose, sucrose, and maltose. Aspartic acid was the major free amino acid in both FDE and FDV. Additionally, the main free amino acids in FDE were alanine and ${\gamma}$-amino-n-butyric acid (GABA), while those in FDV were arginine and valine. Moreover, to investigate the protective effects of FDE and FDV against oxidative stress induced by t-BHP and $H_2O_2$, C6 cells were treated with FDE or FDV prior to inducing the oxidative damage. FDE and FDV inhibited cell death significantly in a dose-dependent manner. These data imply that FDE and FDV may be effective in neuronal cell protection against oxidative damage.

Effect of Scutellaria Baicalensis Georgi. Extract on Cisplatin-Induced Acute Renal Failure in Rabbits (토끼에서 cisplatin에 의해 유도된 급성 신부전시 황금(黃芩; Scutellaria Baicalensis Georgi.) 추출물의 효과)

  • Kim, Soo-Chang;Song, Yeong-Min;Lee, Sung-Dae;Song, Seung-Hee;Koh, Phil-Ok;Kim, Jong-Su;Kim, Chung-Hui;Kang, Chung-Boo
    • Journal of Veterinary Clinics
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    • v.24 no.3
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    • pp.392-399
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    • 2007
  • Scutellaria baicalensis Georgi. (SBGE) is known to be antioxidant effect. In addition of the effects, we further investigated the SBGE on the antioxidant effect on a renal cortical slices cell and kidney protecting effects. The results were as follows. 1 When renal cortical slices separated from a rabbit's kidney were treated with 1mM tert-Butylhydroperoxide (t-BHP) in the presence of SBGE. SBGE significant prevented t-BHP induced increase in lactate dehydrogenase (LDH) release and lipid peroxidation. 2. When renal cortical slices separated from a rabbit's kidney were treated with oxidant $300{\mu}M$ cisplatin in the presence of SBGE. SBGE significant prevented cisplatin-induced increase in LDH release and lipid peroxidation. 3. Pretreatment with 0.1g/kg SBGE for seven day and treatment with 5 mg/kg cisplatin by the intraperitoneal injection The results were that the pretreatment group with SBGE showed a significant decrease in lipid peroxidation, increase in clearance rate of blood urea nitrogen (BUN) and creatinine in the kidney than the administering single agent group of cisplatin. and pretreatment group with SBGE showed intact microvillus of proximal tubule and no contraction of rumen, it was a similar result with normal group. With the results SBGE showed to be highly effective on antioxidant effect and cellular protection activity against cisplatin that was a toxic agent on a kidney. Therefore, SBGE is considered to have protective effective on a disordered kidney or kidney diseases such as nephritis or renal failure that cause tissue damages in a kidney.

Effect of Juglandis Semen Herbal Acupuncture on Toxic Agent-Induced Liver Cell Damage ((호도약침액)胡桃藥鍼液 독성물질(毒性物質)에 의한 간조직(肝組織) 손상(損傷)에 미치는 영향(影響))

  • Lee, Kyung-Tae;Kim, Cheol-Hong;Youn, Hyoun-Min;Jang, Kyung-Jeon;Ahn, Chang-Beohm;Song, Choon-Ho
    • Korean Journal of Acupuncture
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    • v.22 no.1
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    • pp.117-132
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    • 2005
  • Objectives : This study was carried out to determine whether Juglandis Semen herbal acupuncture (JSA) exerts the protective effect against toxic agent-induced live. cell damage. Methods : The cell damage was estimated by measuring lactate dehydrogenase (LDH) release, and lipid peroxidation was estimated by measuring maiondialdehyde (MDA), a product of lipid peroxidation, in rabbit liver slices. Results : When tissues were incubated with 0.5 mM Hg for $10{\sim}120\;min$, LDH release and lipid peroxidation were increased as a function of incubation time, and these effects were significantly prevented by addition of 0.1% JSA. Hg increased LDH release and lipid peroxidation in dose-dependent manner over the range of $0.1{\sim}l\;mM$ concentrations, which were reduced by 0.1% JSA. When tissues were treated with 0.5 mM Hg in the presence of $0.05{\sim}l\;%$ JSA, LDH release and lipid peroxidation induced by Hg were prevented by JSA in a dose-dependent fashion. JSA at 0.5 and 1% prevented completely effects of 0.5 mM Hg. When tissues were treated with 0.5 mM Hg for 60 min, LDH release and lipid peroxidation were increased, which were significantly prevented by addition of 0.1 % JSA. tert-Butyl hydroperoxide (tBHP) increased LDH release and lipid peroxidation, which were significantly reduced by 0.1 % JSA. Such protective effects were similar to those of N,N'-diphenyl-p-phenylenediamine (DPPD), a potent antioxidant. When tissues were treated with 0.5 mM Hg, activities of catalase and glutathione peroxidase were inhibited, and glutathione content was also reduced. Such effects were prevented by JSA, but not by DPPD. JSA prevented Hg-induced morphological changes. Conclusions : These results indicate that JSA exerts the protective effect against liver cell injury induced by toxic agents through antioxidant action, and this effect may be attributed to an increase in activities of endogeous anitoxidant enzymes and GSH content. However, antioxidant effect of JSA is different from that of a well-known potent antioxidant DPPD.

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Anti-Oxidative Effects of Cymbopoton Citratus Ethanol Extract through the Induction of HO-1 Expression in RAW 264.7 Cells (RAW264.7 세포에서 Cymbopogon Citratus 에탄올 추출물의 HO-1 유도를 통한 항산화 효과)

  • Chung-Mu Park;Hyun-Seo Yoon
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.4
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    • pp.73-82
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    • 2023
  • Purpose : Cymbopogon citratus, also known as lemongrass, has widely spread around the world and its essential oil is usually applied in food, perfume, and other industrial purposes. In addition, C. citratus has also been used for the treatment of inflammation, digestive disorders, and diabetes in traditional medicine. In this study, the antioxidative activity of C. citratus ethanol extract (CCEE) was analyzed in RAW 264.7 cells through the induction of one of phase II enzymes, heme oxygenase (HO)-1 by nuclear factor-erythroid 2 p45-related factor (Nrf)2, mitogen-activated protein kinase (MAPK), and phosphoinositide 3-kinase (PI3K)/Akt. Methods : The antioxidative activity of CCEE against oxidative stress and its underlying molecular mechanisms were analyzed by the cell viability assay, intracellular reactive oxygen species (ROS) formation assay, and Western blot analysis in RAW 264.7 cells. Results : The results exhibited that CCEE potently attenuated tert-butyl hydroperoxide (t-BHP) induced intracellular ROS levels in a dose-dependent manner without any cytotoxicity. CCEE treatment significantly induced the expression of HO-1 which is known for its antioxidative capacity. In addition, CCEE treatment significantly upregulated the expression of Nrf2, a corresponding transcription factor for the regulation of antioxidative enzymes, which was in accordance with the HO-1 overexpression. MAPK and PI3K/Akt were also evaluated for their important roles in the regulation of cellular redox homeostasis against oxidative damage. As a result, the potent HO-1 expression was mediated by not extracellular regulated kinase (ERK), c-Jun NH2 terminal kinase (JNK), p38, but phosphoinositide 3-kinase (PI3K) phosphorylation. To confirm the antioxidative activity of CCEE-induced HO-1 expression, oxidative damage was initiated by t-BHP and attenuated by CCEE treatment, which was identified by HO-1 selective inhibitor and inducer. Conclusion : Consequently, CCEE potently induced the HO-1-mediated antioxidative potential through the modulation of Nrf2 and PI3K/Akt signaling pathways in RAW 264.7 cells. These results suggest that CCEE could be a promising strategy for the mitigation against cellular oxidative damage.

The Effect of Kamihaengche-tang Plus Yukmijihwang-tangon Oxidant and Hg-induced Rabbit's Liver Cell Injury (가미행체탕 합 육미지황탕이 Oxidant 및 Hg에 의한 가토 간세포손상에 미치는 영향)

  • 이수행;김원길;김우환
    • The Journal of Korean Medicine
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    • v.23 no.3
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    • pp.174-187
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    • 2002
  • Objectives : This study was carried out to determine whether Kamihaengche-tang plus Yulanijihwang-tang (KCYH) exerts a protective effect against oxidant-induced liver cell injury. Methods : Cell injury was estimated by measuring lactate dehydrogenase (LDH) and alanine aminotransferase (ALT) release, and lipid peroxidation was estimated by measuring malondialdehyde, a product of lipid peroxidation in rabbit liver slices. Results : Oxidants (tBHP and $H_2O_2$) increased dose-dependently LDH release which was significantly prevented by 1% KCYH. The protective effect of KCYH against oxidant-induced cell injury was dose-dependent in the range of 0.05-1 % concentrations. Similarly, KCYH inhibited oxidant-induced lipid peroxidation in a dose-dependent manner. When liver tissues were exposed to Hg (0.5 mM), ALT activity in the medium and lipid peroxidation in tissues were markedly increased. These changes were prevented by 1% KCYH, KCYH restored toxicant-induced inhibition of cellular GSH content. KCYH increased the activities of catalase and glutathion peroxidase in oxidant-treated tissues. Conclusions : These results indicate that KCYH exerts a protective effect against oxidant-induced liver cell injury, and this effect is attributed to prevention of lipid peroxidation. These effects may be due to an increase in concentration of endogenous antioxidants.

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In vitro Antioxidant and Cytoprotective Activities of the Extract of Dangyuja (Citrus grandis Osbeck) Leaves

  • Kim, Yun-Jung;Cho, Moon-Jae;Kim Cho, So-Mi
    • Food Science and Biotechnology
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    • v.17 no.5
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    • pp.1086-1091
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    • 2008
  • The antioxidant activities of the extracts of dangyuja (Citrus grandis Osbeck) leaves were evaluated. The highest phenolic content was obtained from the ethyl acetate fraction (EF) (202.1$\pm$0.8 mg GAE/g dried extract) and it exhibited the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. The cytoprotective effects of EF on oxidative damage induced by tert-butyl hydroperoxide (t-BHP) in a human hepatoma cell line, HepG2 cells, were investigated to understand the intracellular antioxidant mechanisms. Treatment of HepG2 cells with EF prior to oxidative stress was found to inhibit reactive oxygen species (ROS) generation, lipid peroxidation, and DNA damage in a dose-dependent manner. Gas chromatography-mass spectrometry (GC-MS) studies on EF resulted in tentative identification of 19 compounds representing 94.3% of the total content. Taken together, these results demonstrated that EF has excellent antioxidant activities and thus dangyuja leaves have great potential as a source for natural antioxidant which can be applied in food products.