• 제목/요약/키워드: ethanol resistance

검색결과 169건 처리시간 0.026초

Evaluation of Metals (Al, Fe, Zn) in Alternative Fuels by Electrochemical Impedance Spectroscopy in Two Electrode Cell

  • Song, Yon-Kyun;Lim, Geun-Woong;Kim, Hee-San
    • Corrosion Science and Technology
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    • 제9권2호
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    • pp.92-97
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    • 2010
  • Many kinds of alternative fuels such as biodiesel, ethanol, methanol, and natural gas have been developed in order to overcome the limited deposits in fossil fuels. In some cases, the alternative fuels have been reported to cause degrade materials. The corrosion rates of metals were measured by immersion test, a kind of time consuming test because low conductivity of these fuels was not allowed to employ electrochemical tests. With twin two-electrode cell newly designed for the study, however, electrochemical impedance spectroscopy (EIS) test was successfully applied to evaluation of the corrosion resistance ($R_p$) of zinc, iron, aluminum, and its alloys in an oxidized biodiesel and gasoline/ethanol solutions and the corrosion resistance from EIS was compared with the corrosion rate from immersion test. In biodiesel, $R_p$ increased in the order of zinc, iron, and aluminum, which agreed with the corrosion resistance measured from immersion test. In addition, on aluminum showing the best corrosion resistance ($R_p$), the effect of magnesium as an alloying element was evaluated in gasoline/ethanol solutions as well as the oxidized biodiesel. $R_p$ increased with addition of magnesium in gasoline/ethanol solutions containing chloride and the oxidized biodiesel. In the mean while, in gasoline/ethanol solutions containing formic acid, Al-Mg alloy added 1% magnesium had the highest $R_p$ and the further addition of magnesium decreased $R_p$. It can be explained with the fact that the addition of more than 1% magnesium increases the passive current density of Al-Mg alloys.

$^{31}p$ Nuclear Magnetic Resonance Studies of Acetic Acid Inhibition of Ethanol Production by Strains of Zymomonas mobilis

  • Kim, In-Seop;Barrow, Kevin D.;Rogers, Peter L.
    • Journal of Microbiology and Biotechnology
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    • 제13권1호
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    • pp.90-98
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    • 2003
  • In vivo $^31p$ Nuclear Magnetic Resonance ($^31p$NMR) and metabolic studies were carried out on an acetic acid tolerant mutant, Zymomonas mobilis $ZM4/Ac^R$, and compared to those of the parent strain, Z. mobilis ZM4, to evaluate possible mechanisms of acetic acid resistance. This investigation was initiated to determine whether or not the mutant strain might be used as a suitable recombinant host far ethanol production from lignocellulose hydrolysates containing various inhibitory compounds. $ZM4/Ac^R$ showed multiple resistance to other lignocellulosic toxic compounds such as syringaldehyde, furfural, hydroxymethyl furfural, vanillin, and vanillic acid. The mutant strain was resistant to higher concentrations of ethanol or lower pH in the presence of sodium acetate, compared to ZM4 which showed more additive inhibition. in vivo $^31p$ NMR studies revealed that intracellular acidification and de-energization were two mechanisms by which acetic acid exerted its inhibitory effect. For $ZM4/Ac^R$, the internal pH and the energy status were less affected by sodium acetate compared to the parent strain. This resistance to pH change and de-energization caused by acetic acid is a possible explanation for the development of resistance by this strain.

Effect of Enhancers on the Electrical Properties of Skin: The Effect of Azone and Ethanol

  • Oh, Seaung-Youl;Guy, Richard H.
    • Journal of Pharmaceutical Investigation
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    • 제24권3호spc1호
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    • pp.41-47
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    • 1994
  • The effect of Azone and ethanol on the electrical properties of human and hairless mouse skin was studied and the results were compared. The complex electrical impedance was measured as a function of frequency, and resistance and capacitance were determined from Nyquist plot. After the treatment of human-heat separated epidermis with Azone, contrary to the expectation, resistance increased about 60% and it did not change with time. Capacitance also increased; immediately after the treatment, it was about 110% of pretreatment value and it increased further with time. On the other hand, when hairless mouse skin was treated with Azone, marked changes occured; resistance fell almost to the value of bathing medium itself and capacitance increased to about 200% of its pretreatment value. Similar result were obtained when hairless mouse skin was treated with 100% ethanol. The results suggest that there are differences in the strength of barrier properties of stratum corneum (SC) between human and hairless mouse skin. Overall, the results provide further mechanistic insight into ion conduction through the skin and into the role of SC lipids in skin capacitance.

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Acanthopanax senticosus Reverses Fatty Liver Disease and Hyperglycemia in ob/ob Mice

  • Park, Sang-Hyun;Lee, Sang-Gil;Kang, Sung-Keel;Chung, Sung-Hyun
    • Archives of Pharmacal Research
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    • 제29권9호
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    • pp.768-776
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    • 2006
  • Non-alcoholic fatty liver disease (NAFLD) is common in obesity. However, weight reduction alone does not prevent the progression of NAFLD to end-stage disease associated with the development of cirrhosis and liver disease. In a previous experiment, 50% ethanol extract of Acanthopanax senticosus stem bark (ASSB) was found to reduce body weight and insulin resistance in high fat diet-induced hyperglycemic and hyperlipidemic ICR mice. To evaluate the anti-steatosis action of ASSB, insulin-resistant ob/ob mice with fatty livers were treated with ASSB ethanol extract for an 8 week-period. ASSB ethanol extract reversed the hepatomegaly, as evident in reduction of % liver weight/body weight ratio. ASSB ethanol extract also specifically lowered circulating glucose and lipids, and enhanced insulin action in the liver. These changes culminated in inhibition of triglyceride synthesis in non-adipose tissues including liver and skeletal muscle. Gene expression studies confirmed reductions in glucose 6-phosphatase and lipogenic enzymes in the liver. These results demonstrate that ASSB ethanol extract is an effective treatment for insulin resistance and hepatic steatosis in ob/ob mice by decreasing hepatic lipid synthesis.

Saccharomyces cerevisiae Strain Improvement Using Selection, Mutation, and Adaptation for the Resistance to Lignocellulose-Derived Fermentation Inhibitor for Ethanol Production

  • Jang, Youri;Lim, Younghoon;Kim, Keun
    • Journal of Microbiology and Biotechnology
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    • 제24권5호
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    • pp.667-674
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    • 2014
  • Twenty-five Saccharomyces cerevisiae strains were screened for the highest sugar tolerance, ethanol-tolerance, ethanol production, and inhibitor resistance, and S. cerevisiae KL5 was selected as the best strain. Inhibitor cocktail (100%) was composed of 75 mM formic acid, 75 mM acetic acid, 30 mM furfural, 30 mM hydroxymethyl furfural (HMF), and 2.7 mM vanillin. The cells of strain KL5 were treated with ${\gamma}$-irradiation, and among the survivals, KL5-G2 with improved inhibitor resistance and the highest ethanol yield in the presence of inhibitor cocktail was selected. The KL5-G2 strain was adapted to inhibitor cocktail by sequential transfer of cultures to a minimal YNB medium containing increasing concentrations of inhibitor cocktail. After 10 times of adaptation, most of the isolated colonies could grow in YNB with 80% inhibitor cocktail, whereas the parental KL5 strain could not grow at all. Among the various adapted strains, the best strain (KL5-G2-A9) producing the highest ethanol yield in the presence of inhibitor cocktail was selected. In a complex YP medium containing 60% inhibitor cocktail and 5% glucose, the theoretical yield and productivity (at 48 h) of KL5-G2-A9 were 81.3% and 0.304 g/l/h, respectively, whereas those of KL5 were 20.8% and 0.072 g/l/h, respectively. KL5-G2-A9 reduced the concentrations of HMF, furfural, and vanillin in the medium in much faster rates than KL5.

에타놀투여가 마우스의 면역반응에 미치는 영향에 관한 실험적 연구 (The Effect of Ethanol Administration on The Immune Response of Mice)

  • 김금재
    • 대한간호학회지
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    • 제21권1호
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    • pp.5-15
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    • 1991
  • The present study was undertaken in an effort to investigate the effects of alcohol on survival of mice and on their humoral and cellular immune responses, The immune responses examined were Arthus and delayed-type hyperrsnesitivity(DTH) reactions to sheep red blood cells(SRBC), contact hypersensitivity to dinitrofluorobenzend(DNFB), antibody response to thymus - dependent SRBC and to thymus -independent polyvinylpyroridone(PVP), and the recovery of Crytococcus neoformans from the liver, spleen, kidney and brain of experimentally infected mice. The administration of ethanol concentrations of 20% or less did not cause any change in survival rates as compared withs saline injected control group. In general, ethanol administration inhibited the Arthus and DTH reactions to SRBC, contact hypersensitivity to DNFB, and antibody response to both SRBC and PVP and it also decreased the resistance of mice to C. neoformans infection. Taken together, the present study stongly suggested that ethanol inhibits immune response and decrease the resistance of mice to C. neoformans infection.

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Corrosion and Adhesion of Electrophoretic Paint on AZ31 Magnesium Alloy Pretreated in Cerium Chemical Conversion Coating Solution

  • Phuong, Nguyen Van;Moon, Sungmo
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2015년도 추계학술대회 논문집
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    • pp.189-189
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    • 2015
  • In this study, the corrosion resistance and adhesion of electrophoretic paint (E-paint) were studied on AZ31 magnesium alloy pretreated in cerium chemical conversion coating solutions with the addition of various ethanol concentrations. It was found that with increasing ethanol concentration from 0 to 90 percent can decrease the formation of $Mg(OH)_2/MgO$ and increase the formation of nano-crystalline cerium oxides on the coating. Both corrosion resistance and adhesion of E-painted AZ31 increased with increasing ethanol concentration. The best E-paint sample was observed on the sample pretreatment in cerium chemical conversion coating solution with the addition of 80 percent of ethanol. This sample showed an excellent adhesion without paint detached after water immersion test for 500 h at $40^{\circ}C$, and only a few blisters observed at the near scratched sites after 1000 h salt-spray test.

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항암제 내성 유방암 MCF7/adR 세포주에 대한 보정방암탕과 홍삼산성다당체의 세포고사 유도효과 (Apoptotic Effect of Ethanol Extracts of Bojungbangamtang and Acidic Polysaccharide of Korea Red Ginseng in a MCF7/adR Multidrug-resistance Breast Cancer Cells)

  • 안귀인;박철환;이은옥;이효정;이재호;김관현;이연희;장유성;김상태;김성훈
    • 약학회지
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    • 제50권4호
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    • pp.272-277
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    • 2006
  • This study was undertaken to determine whether the 9 herbal complex induces apoptosis in human breast cancer MCF-7 cells and adriamycin-resistant MCF7/adR cells. Ethanol extracts of Bojungbangamtang (BBTE) and acidic polysaccharide of Red Ginseng (GIN) induced cell death in both MCF-7 and MCF7/adR cells. Ethanol extracts of Bojungbangamtang and acidic polysaccharide of Red Ginseng also induced $G_2/M$ cell cycle arrest and increased TUNEL positive cells in MCF7/adR cells. In addition, flow cytometric analysis revealed the decreased expression of P-glycoprotein (P-gp) in ethanol extracts of Bojungbangamtang and acidic polysaccharide of Red Ginseng treated MCF7/adR cells. Similarly, decreased protein levels of P-glycoprotein and multidrug resistance associated proteins-1 were also determined by immunocytometry in ethanol extracts of Bojungbangamtang treated MCF7/adR cells. Taken together these data indicate that ethanol extracts of Bojungbangamtang and acidic polysaccharide of Red Ginseng inhibit the function of ABC transporters such as multi drug resistance associated proteins (MRPs) and P-glycoprotein as well as induce apoptosis in MCF7/adR cells. Thus, these data suggest that ethanol extracts of Bojungbangamtang and polysaccharide of Red Ginseng can be candidates for the treatment of multidrug-resistant MCF7/adR cells.

Impedance를 이용한 전도성고분자 센서의 에탄올 가스 감응특성 (Ethanol Gas Sensing Characteristics of Conducting Polymer Sensor Using Impedance)

  • 이경문;유준부;전희권;이병수;이덕동;허증수
    • 한국재료학회지
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    • 제13권3호
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    • pp.155-159
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    • 2003
  • The polypyrrole and polyaniline thin film sensors which were made by chemical polymerization were employed to detect ethanol gas. With a single sensor element we can obtain characteristic patterns of behaviour across a very wide frequency range when measuring either resistance or capacitance. Impedance spectroscopy was employed to study the gas sensing behavior of both capacitance and resistance based sensors with conducting polymer as the active sensing element.

히트파이프 응축부의 초음파 분무냉각에 관한 실험적 연구 (An Experimental Study on Ultrasonic Spray Cooling of Heat Pipe Condenser)

  • 김영찬;한양호
    • 설비공학논문집
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    • 제16권1호
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    • pp.77-83
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    • 2004
  • In this study, the spray cooling heat transfer and working characteristics of the screen wick heat pipe with ultrasonic spray cooling system in condenser were experimentally investigated. The heat pipe was made of copper tube 300 mm long with inner diameter of 11.1 mm. The evaporator and condenser lengths of heat pipe were 40, 200 mm and the wick structure consists of two layer of 100 mesh copper screen. The experimental results show that the ultrasonic spray cooling increases the heat transfer rate on the condenser surface, and the total thermal resistance of heat pipe system decreases remarkably. A comparison is made for the two working fluids, water and ethanol. The surface temperature of the ethanol tube in evaporator section becomes higher than that of the water tube. Thus, the experimental result shows that water is more useful than ethanol as the working fluid because of increasing the operational limit within this experimental conditions.