• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.242-242
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• 1994

Cortex mori (Morus alba L.), the root bark of mulberry tree, has been used as an antiphlogistic, diuretic, and expectorant in herbal medicine. The purpose of this study was to determine whether Cortex mori could inhibit the ovalbumin (OA) -induced late asthmatic reaction in guinea pigs. Guinea pigs were sensitized by two exposures to an aerosol of OA(1.0%) and then challenged with aerosolized antigen(2.0%), The animals were pretreated by three inhalations of the aerosoled Cortex mori either before antigen sensitization or cahllenge. Bronchoalveolar lavage fluid(BALF) and peripheral blood were collected at 17 hours after OA challenge. The cell populations in BALF and peripheral blood were examined to determine the changes of the relative proportions of eosinophils,neutrophils and mononuclear cells etc. Beta-glucuronidase activity in BALF was measured to evaluate the alveolar macrophage activation. OA-induced histamine release from guinea pig peritoneal fluid cells was measured by radioisotope enzymatic asssay. Results were as follows. The number of eosinophils, neutriphils and lymphocytes recovered in BALF were significantly increased in the 17h following aerosol challenge with OA. Among them, eosinophil and neutriphils were decreased remarkably in group that had been preinhalated with Cortex mori. The number of lymphocytes in BALF were not decreased in group pretreated with CM before sensitization but decreased in Group pretreated with CM before challenge. After OA challenge, the number of eosinophils in peripheral blood were markedly increased, but Cortex mori inhibited significantly the OA-induced eosinophilia. Beta-glucuronidase activity in the supernatants of BALF were significantly increased in the 17h following aerosol challenge with OA, however, pretreatment of Cortex mori had no influence on Beta-glucuronidase activity, suggesting that Cortex mori had no inhibitory effect on OA-induced alveolar macrophage activation. Cortex mori inhibited the OA-induced histamine release from guinea pig peritoneal fluid cells. From the above results, it is suggested that Cortex mori contains some substances with an activity to inhibit the the OA-induced late phase reaction of the bronchial asthma in guinea pigs.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.407-410
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• 2006

Selection of flow channel in the separation plate of PEMFC is very important parameter to improve its performance and reduce parasite loss. Flow patterns in the channel have great influence on the transport of hydrogen and all and water generated from electrochemical reaction in diffusion layer In this study, fluid flow in flow channel with parallel and interdigitated patterns are simulated three dimensionally on full flow domain including anode and cathode electrode together. The numerical results show that the fuel cell with interdigitated flow channel represents better performance than that with parallel flow channel due to its strong convective transport across the gas diffusion layer. But the pressure drop in parallel flow channel is much more than that in nterdigitated flow channel. The effect of temperature and stoichiometric number on performance can be calculated and analyzed as well.

• 신재생에너지
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• 제2권4호
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• pp.78-85
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• 2006

Selection of flow channel in the separation plate of PEMFC is very important parameter to improve its performance and reduce parasite loss. Flow patterns in the channel have great influence on the transport of hydrogen and air and removal of water generated from electrochemical reaction in diffusion layer. In this study. fluid flow in flow channel with parallel and interdigitated patterns are simulated three dimensionally on full flow domain including anode and cathode channel together. The numerical results show that the fuel cell with interdigitated flow channel represents better performance than that with parallel flow channel due to its strong convective transport across the gas diffusion layer. But the pressure drop in parallel flow channel is much more than that in interdigitated flow channel. And effects of temperature and stoichiometric number on performance can be calculated and analyzed as well. Nomenclature.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제20권4호
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• pp.333-354
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• 2016

The present investigation deals, heat and mass transfer characteristics with the effect of slip on the hydromagnetic pulsatile flow through a parallel plate channel filled with saturated porous medium. Based on the pulsatile flow nature, exact solution of the governing equations for the fluid velocity, temperature and concentration are obtained by using two term perturbation technique subject to physically appropriate boundary conditions. The expressions of skin friction, Nusselt number and Sherwood number are also derived. The numerical values of the fluid velocity, temperature and concentration are displayed graphically whereas those of shear stress, rate of heat transfer and rate of mass transfer at the plate are presented in tabular form for various values of pertinent flow parameters. By increasing the slip parameter at the cold wall the velocity increases whereas the effect is totally reversed in the case of shear stress at the cold wall.

• 접착 및 계면
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• 제4권3호
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• pp.14-20
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• 2003

UV 경화에 사용되는 poly(ethylene glycol 400) dimethacrylate(PEGA400DMA)와 ethylene glycol dimethacrylate(EGDMA)를 사용하여 모노머(monomer)의 종류에 따른 경화거동과 광개시제의 양과 온도에 따른 경화 거동을 photo-DSC를 사용하여 살펴보았다. Ethylene glycol의 단위길이가 늘어날수록, 광개시제의 양이 증가할수록, 반응 온도가 높을수록 경화속도가 빠르게 일어났다. 또한 PEG400DMA의 반응속도가 EGDMA보다 느리게 나타났지만 전환률은 높게 나타남을 알 수 있었다.

• 대한기계학회논문집B
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• 제20권3호
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• pp.1040-1049
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• 1996

The high loading combustion is accomplished by making the turbulent intensity strong and the scale small in the premixed combustor. The Da-mkoler number, which is decreased by short turbulent characteristic time or by long chemical reaction time, can make the distributed reaction flame. So we developed a doubled jet burner for high loading combustion. The doubled jet burner was designed to make the scale of the flame small by the effect of impingement and increasing shear stress with doubled jet. We investigated the turbulence characteristics of unburned mixture and visualized several flames with the typical schlieren photography. Then we studied the influence of several factors that related the scale of flame. Consequently, the doubled jet burner can make the eddy very small. And we can obtain the detail information of the flame scale through ADSF(the Average Distance between Successive Fringes) in the micro- schlieren photography. The ADSF is not a exact flame scale, but it has qualitative trend with increasing turbulent intensity. The ADSF is diminished remarkably with increasing turbulent intensity. The reason is that strong turbulent intensity makes the flame zone thick and flamelets numerous. We can confirm this fact by the signal analysis of ion currents.

• 한국조경학회지
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• 제15권2호
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• pp.67-78
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• 1987

This study was executed to measure the user\`s impact natural environment in National Park Campsite. Therefore, we choose Mt. Chiak National Park and the campsite in the district of Temple Ku-Ryong as a model of analysis, which is made by ecological approach, the number of the user has influence on the environment near the campsite. The result are as follows : 1. The more the number of users becomes, the more Na, Ca, Mg ion concentration and pH in the soil increase and the less K ion becomes. 2. Litter and humus depth, litter coverage, herb coverage, soil hardness, the surface of the ground layer and tree species numbers, density and coverage of lower layer shows a sensitive reaction to the number of the users. 3. The research shows that the tolerant trees against campsite impact are Lespedeza maximowiczii, Zanthoxylum schinifolium Staphylea bumalda, Smilax sieboldii, Quercus aliena, Euonymus oxyphyllus, Weigela subsessilis and Securinega suffruticosa, and the sensitive trees are Stephanandra incisa, Rubus trichocarpa, Rubus crataegifolius, Rhododendron mucronulatum, Styrax obassia, Acer palmatum, Lindera obtusiloba, Rhododendron suhlippenbachii, Rhus japonica and Callicarpa japonica. 4. The high density of the users made the simplication of a vegetation structure. So, as the number of the user increase the species showed severe heterogeniety between the heavy-use and nonuse site. 5. As considering the landscape management about campsite and surrounding area on the way of analysis of national landscape aspect and succession sere according to ecological aspect, it may be desirable that Pinus densiflora forest be conserved as Pinus densiflora landscape and mixed forest produce natural scenery with succession sere.

• 아시안잔디학회지
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• 제7권2_3호
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• pp.81-94
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• 1993

This study was conducted to investigate the influence of herbicides, simazine, pendimethalin, propyzamide and asulam on the growth of Zoysia matrella when they are treated at different growth stages of the plant. The reaction of Zoysia matrella to herbicides differed depending on kinds of herbicides, their concentcations, and time of treatment. Simazine at the higher concentration of 600g /l0a exhibited inhibitory effect on leaf dry matter and growth of runner when treated on April 5, 1991. The highest inhibition of leaf and runner was observed in the plot applied on May 23, 1990. The sprouting and growth of Zoysia matrella was not affected by all the concentrations of the herbicides applied on October 23,1991. Pendimethalin did not influence the growth of Zoysia matrella at he treatment of April 5. However, at the treatment of May 23, the number and growth of runner was inhibited although the plant height and leaf dry matter was not affected. When pendimethalin was treated on October 23, the growth of runner was very slightly reduced in the next year. In case of propyzamide, there was no inhibitory effect on the growth of Zoysia matrella regardless of treatment of times, methods, and dosages. Greater inhibition in the growth of Zoysia matrella was observed at higher dosage(1,ll0g /l0a)-treated plot on April 5 and all the concentrations treated on May 23. But, no inhibition was observed on the October 23 treatment.

• 한국재료학회지
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• 제23권12호
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• pp.695-701
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• 2013

To understand how reactivity between reinforcing nanoparticles and aqueous solution affects electrodeposited Cu thin films, two types of commercialized cerium oxide (ceria, $CeO_2$) nanoparticles were used with copper sulfate electrolyte to form in-situ nanocomposite films. During this process, we observed variation in colors and pH of the electrolyte depending on the manufacturer. Ceria aqueous solution and nickel sulfate ($NiSO_4$) aqueous solutions were also used for comparison. We checked several parameters which could be key factors contributing to the changes, such as the oxidation number of Cu, chemical impurities of ceria nanoparticles, and so on. Oxidation number was checked by salt formation by chemical reaction between $CuSO_4$ solution and sodium hydroxide (NaOH) solution. We observed that the color changed when $H_2SO_4$ was added to the $CuSO_4$ solution. The same effect was obtained when $H_2SO_4$ was mixed with ceria solution; the color of ceria solution changed from white to yellow. However, the color of $NiSO_4$ solution did not show any significant changes. We did observe slight changes in the pH of the solutions in this study. We did not obtain firm evidence to explain the changes observed in this study, but changes in the color of the electrolyte might be caused by interaction of Cu ion and the by-product of ceria. The mechanical properties of the films were examined by nanoindentation, and reaction between ceria and electrolyte presumably affect the mechanical properties of electrodeposited copper films. We also examined their crystal structures and optical properties by X-ray diffraction (XRD) and UV-Vis spectroscopy.

• Journal of Magnetics
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• 제21권3호
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• pp.468-475
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• 2016

In this article, entropy generation on MHD Williamson nanofluid over a porous shrinking sheet has been analyzed. Nonlinear thermal radiation and chemical reaction effects are also taken into account with the help of energy and concentration equation. The fluid is electrically conducting by an external applied magnetic field while the induced magnetic field is assumed to be negligible due to small magnetic Reynolds number. The governing equations are first converted into the dimensionless expression with the help of similarity transformation variables. The solution of the highly nonlinear coupled ordinary differential equation has been obtained with the combination of Successive linearization method (SLM) and Chebyshev spectral collocation method. Influence of all the emerging parameters on entropy profile, temperature profile and concentration profile are plotted and discussed. Nusselt number and Sherwood number are also computed and analyzed. It is observed that entropy profile increases for all the physical parameters. Moreover, it is found that when the fluid depicts non-Newtonian (Williamson fluid) behavior then it causes reduction in the velocity of fluid, however, non-Newtonian behavior enhances the temperature and nanoparticle concentration profile.