• Title/Summary/Keyword: pre-activation

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Ceramic barrier coated Pd hydrogen membrane on a porous nickel support (수소 분리용 팔라듐계 분리막의 세라믹 코팅 영향)

  • Lee, Chun-Boo;Lee, Sung-Wook;Park, Jin-Woo;Kim, Kwang-Ho;Hwang, Kyung-Ran;Park, Jong-Soo;Kim, Sung-Hyun
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.114.1-114.1
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    • 2010
  • A highly performed Pd-based hydrogen membrane has prepared successfully on a modified porous nickel support. The porous nickel support modified by impregnation method of $Al(NO_3)_3{\cdot}9H_2O$ (Aldrich Co.) over the nickel powder showed a strong resistance to hydrogen embrittlement and thermal stability. Plasma surface modification treatment was introduced as a pre-treatment process instead of conventional HCl wet activation. Ceramic barrier was coated on the external surface of the prepared nickel supports to prevent intermetallic diffusion and to enhance the affinity between the support and membrane. Palladium and copper were deposited at thicknesses of $4\mu}m$ and $0.5{\mu}m$, respectively, on a barrier-coated support by DC sputtering process. The permeation measurement was performed in pure hydrogen at $400^{\circ}C$. The single gas permeation of our membrane was two times higher than that of the previous membrane which do not have ceramic barrier.

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Development of a Dan J eon Breathing Model for Health Promotion in Middle-aged Women (중년여성의 건강증진을 위한 단전호흡 모형 개발)

  • Kim Kyung-Won
    • Journal of Korean Academy of Nursing
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    • v.35 no.3
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    • pp.565-574
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    • 2005
  • Purpose: The purpose of this study was to develop a Dan Jeon Breathing Model and to identify effects of the developed Dan Jeon Breathing Model for maintenance and promotion of health and improvement of health problems in middle-aged women. Method: This study was constructed with two procedures. The first procedure was to develop appropriate movements for middle-aged women, performing a focus group discussion and developing a Dan Jeon Breathing Model in qualitative research. The collected data from focus group discussions was categorized for fitting movements. The second procedure was to verify and conclude a Hypothetic Dan Jeon Breathing Model through a quasi-experimental nonequivalent control group pre-post test design. Result: The developed Dan Jeon Breathing Model was composed of 28 preparation movements to accept Ki comfortably, 10 breathing movements to accumulate Ki for activation of metabolic function in organs and 14 finishing movements to transmit activated Ki to organs. It took 40 minutes to do them. In the Second procedure, the score of physical health (t=4.205, p=.000), psycho-social health(t=3.292, p=.002) and physical strength of the experimental group(t=5.905, p=.000) was higher than that of the control group. Conclusion: The Dan Jeon Breathing Model developed in this study is the correct health promotion model for middle-aged women, their demand, developmental traits and health problems.

Effect of Surface-Modified Carbon Fiber on the Mechanical Properties of Carbon/Epoxy Composite for Bipolar Plate of PEMFC (표면처리 탄소섬유가 PEMFC용 탄소/에폭시 복합재료 분리판의 기계적 강도에 미치는 영향)

  • LEE, HONGKI;HAN, KYEONGSIK
    • Transactions of the Korean hydrogen and new energy society
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    • v.31 no.1
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    • pp.49-56
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    • 2020
  • Epoxy/carbon composite was used to prepare a bipolar plate for polymer electrolyte membrane fuel cell (PEMFC). Phenol novolac-type epoxy and diglycidyl ether of bisphenol A (DGEBA)-type epoxy mixture was used as a matrix and graphite powder, carbon fiber (CF) and graphite fiber (GF) were used as carbon materials. In order to improve the mechanical properties of the bipolar plate, surface-modified CF was incorporated into the epoxy/carbon composite. To determine the cure temperature of the epoxy mixture, differential scanning calorimetry (DSC) analysis was performed and the data were introduced to Kissinger equation in order to get reaction activation energy and pre-exponential factor. Tensile and flexural strength was obtained by using universal testing machine (UTM). The surface morphology of the fractured specimen and the interfacial morphology between epoxy matrix and CF or GF were observed by a scanning electron microscopy (SEM).

The Protective Effects of Insulin on Hydrogen Peroxide-Induced Oxidative Stress in C6 Glial Cells

  • Mahesh, Ramalingam;Kim, Sung-Jin
    • Biomolecules & Therapeutics
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    • v.17 no.4
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    • pp.395-402
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    • 2009
  • Insulin appears to play a role in brain physiology, and disturbances of cerebral insulin signalling and glucose homeostasis are implicated in brain pathology. The objective of the present study was to investigate the protective effects of insulin under conditions of oxidative stress induced by hydrogen peroxide ($H_2O_2$) in C6 glial cells. Insulin at concentration of $10^{-7}$ M could prevent 12 h $H_2O_2$-induced cell death. The formation of reactive oxygen species (ROS), nitric oxide (NO) and 2-thiobarbituric acid-reactive substances (TBARS) were significantly scavenged by insulin pre-treatment in C6 glial cells after $H_2O_2$-induced oxidative stress. Insulin significantly stimulated the phosphorylation of Akt in the cells and the activation of Akt was maintained in response to insulin under $H_2O_2$ incubation for 12 h. In conclusion, these results provide evidence that insulin acts as a free radical scavenger and stimulating Akt activity. These data suggest that insulin may be effective in degenerative diseases with oxidative stress.

Reliable preparation of [11C]GR205171, a selective NK1 radioligands for noninvasive imaging

  • Park, Jae-kyung;Cho, Young Jin;Lee, Sang-Yoon
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.5 no.2
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    • pp.158-162
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    • 2019
  • [11C]GR205171, a Neurokinin 1 (NK1) radioligand, has been known as such a promising PET probe for quantitation of NK1 receptors in the brain by positron emission tomography (PET) imaging. First trial to synthesis of [11C]GR205171 was to use methylene chloride and tetrabutylammonium hydroxide for preactivation of precursor, but the result was not successful in radiochemical yield (0~25%) and unreliable. 7 years later, inorganic base (Cs2CO3) was tried to achieve higher radiochemical yield, and they showed higher yield (~53%). We have tried to repeat the same synthesis method, but it did not work properly, because there were the lack of the detail procedure and still reproducibility in radiochemical yield. Here we report the improved synthesis protocol to produce [11C]GR205171 in high yield via commercial automated synthesizer. The sonicator which combines water heating bath was used to activate desmethyl-GR205171, and this method showed high efficiency and reasonable yields (4.7 ± 0.6%, non-decay corrected from molecular sieve trap) with >95% radiochemical purity.

The Decomposition Kinetics of PET Microfiber Fabrics by Saturated CaO/Ethylene glycol Solution (CaO/Ethylene glycol 용액에 의한 Polyester섬유의 분해에 관한 연구)

  • Yoon, Jong Ho;Huh, Man Woo;Kim, Kyung Jae
    • Textile Coloration and Finishing
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    • v.9 no.3
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    • pp.18-26
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    • 1997
  • Polyester microfiber fabrics were decomposed at 100, 110, and 12$0^{\circ}C$ in saturated CaO/ethylene glycol solutions(CaO/EG), and the characteristics of decomposition kinetics were discussed in comparison to those by hot aqueous hydroxide solution(NaOH). The Arrhenius pre-exponential factor(A) was 9.17x $10^{14}$/M $sec^{-1}$and the activation energy($E_{a}$) was 8.19kcal/mol. While the A value was 1.947x $10^{14}$/M $sec^{-1}$ and the ($E_{a}$ value was about 15~19kcal/mol in NaOH-PET decomposition reaction. The much higher A value of the CaO/EG-PET decomposition reaction means that CaO/EG-PET decomposition reaction will occur in a less selective fashion in comparison to the NaOH-PET decomposition reaction. On the other hand, the lower ($E_{a}$) value of the CaO/EG-PET decomposition reaction than that of the NaOH-PET decomposition reaction means that CaO/EG-PET decomposition reaction is less sensitive on the variation of temperature than NaOH-PET decomposition reaction.

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Estimation of the Properties for a Charring Material Using the RPSO Algorithm (RPSO 알고리즘을 이용한 탄화 재료의 열분해 물성치 추정)

  • Chang, Hee-Chul;Park, Won-Hee;Yoon, Kyung-Beom;Kim, Tae-Kuk
    • The KSFM Journal of Fluid Machinery
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    • v.14 no.1
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    • pp.34-41
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    • 2011
  • Fire characteristics can be analyzed more realistically by using more accurate properties related to the fire dynamics and one way to acquire these fire properties is to use one of the inverse property estimation techniques. In this study two optimization algorithms which are frequently applied for the inverse heat transfer problems are selected to demonstrate the procedure of obtaining pyrolysis properties of charring material with relatively simple thermal decomposition. Thermal decomposition is occurred at the surface of the charring material heated by receiving the radiative energy from external heat sources and in this process the heat transfer through the charring material is simplified by an unsteady 1-dimensional problem. The basic genetic algorithm(GA) and repulsive particle swarm optimization(RPSO) algorithm are used to find the eight properties of a charring material; thermal conductivity(virgin, char), specific heat(virgin, char), char density, heat of pyrolysis, pre-exponential factor and activation energy by using the surface temperature and mass loss rate history data which are obtained from the calculated experiments. Results show that the RPSO algorithm has better performance in estimating the eight pyrolysis properties than the basic GA for problems considered in this study.

Analysis of Novelty Detection Properties of Autoassociative MLP (자기연상 다층퍼셉트론의 이상 탐지 성질 분석)

  • Lee, Hyoung-joo;Hwang, Byung-ho;Cho, Sungzoon
    • Journal of Korean Institute of Industrial Engineers
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    • v.28 no.2
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    • pp.147-161
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    • 2002
  • In novelty detection, one attempts to discriminate abnormal patterns from normal ones. Novelty detection is quite difficult since, unlike usual two class classification problems, only normal patterns are available for training. Auto-Associative Multi-Layer Perceptron (AAMLP) has been shown to provide a good performance based upon the property that novel patterns usually have larger auto-associative errors. In this paper, we give a mathematical analysis of 2-layer AAMLP's output characteristics and empirical results of 2-layer and 4-layer AAMLPs. Various activation functions such as linear, saturated linear and sigmoid are compared. The 2-layer AAMLPs cannot identify non-linear boundaries while the 4-layer ones can. When the data distribution is multi-modal, then an ensemble of AAMLPs, each of which is trained with pre-clustered data is required. This paper contributes to understanding of AAMLP networks and leads to practical recommendations regarding its use.

Activation of Defense Responses in Chinese Cabbage by a Nonhost Pathogen, Pseudomonas syringae pv. tomato

  • Park, Yong-Soon;Jeon, Myeong-Hoon;Lee, Sung-Hee;Moon, Jee-Sook;Cha, Jae-Soon;Kim, Hak-Yong;Cho, Tae-Ju
    • BMB Reports
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    • v.38 no.6
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    • pp.748-754
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    • 2005
  • Pseudomonas syringae pv. tomato (Pst) causes a bacterial speck disease in tomato and Arabidopsis. In Chinese cabbage, in which host-pathogen interactions are not well understood, Pst does not cause disease but rather elicits a hypersensitive response. Pst induces localized cell death and $H_2O_2$ accumulation, a typical hypersensitive response, in infiltrated cabbage leaves. Pre-inoculation with Pst was found to induce resistance to Erwinia carotovora subsp. carotovora, a pathogen that causes soft rot disease in Chinese cabbage. An examination of the expression profiles of 12 previously identified Pst-inducible genes revealed that the majority of these genes were activated by salicylic acid or BTH; however, expressions of the genes encoding PR4 and a class IV chitinase were induced by ethephon, an ethylene-releasing compound, but not by salicylic acid, BTH, or methyl jasmonate. This implies that Pst activates both salicylate-dependent and salicylate-independent defense responses in Chinese cabbage.

Phospholipase D Is Not Involved in Rho A-Mediated Activation of Stress Fiber Formation

  • Leem, Sun-Hee;Shin, In-Cheol;Kweon, Soo-Mi;Kim, Seung-Il;Kim, Jae-Hong;Ha, Kwon-Su
    • BMB Reports
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    • v.30 no.5
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    • pp.337-341
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    • 1997
  • In order to investigate the role of a small GTP-binding protein RhoA in lysophosphatidic acid (LPA)-induced stress fiber formation, C3 ADP-ribosyltransferase was prepared by expressing in E. coli and then applied to Rat-2 fibroblasts. C3 transferase isolated from E. coli was as effective as the toxin from Clostridium botulinum in ADP-ribosylation of RhoA. Incubation of the cells with C3 transferase for 2 days induced ADP-ribosylation of RhoA by a dose-dependent manner, with a sub-maximal induction at $25\;{\mu}g/ml$. As expected, LPA-induced stress fiber formation was completely blocked by pre-incubation with C3 transferase for 2 days. However, exogenously added C3 transferase had no significant effect on the formation of phosphatidylethanol by LPA. These results suggested that phospholipase D was not activated by RhoA in the LPA-induced stress fiber formation.

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