• Korean journal of applied entomology
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• v.18 no.1 s.38
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• pp.11-14
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• 1979

Spinaches showing dark green mosaic symptoms were used for identification of broad bean wilt virus. In host reaction test, that virus caused local lesions on the inoculated leaves and mosaic symptoms on upper leaves of Chenopodium amaranticolor, Chenopodium quinoa and Vicia faba, and developed mosaic symptoms on Physalis floridana, Spinacia oleracea, Nicotiana tabacum, (White burley, Bright yellow) Nicotiana glutinusa. In agar gel-diffusion test, the virus showed positive reaction with broad bean wilt virus antiserum. Spherical virus particles with size of 25nm in diameter were observed in electron microscope.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.1
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• pp.49-55
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• 2009

This paper presents the optimal shape of microelectrode that generates dielectrophoretic(DEP) force to separate particles in homogeneous medium. The principle of the particles sorting is based on the use of the relative strengths of negative DEP (nDEP) and drag forces, as in a general DEP-activated cell sorter (DACS). To numerically calculate the DEP force and drag force, the simulation is implemented in MATLAB 7.0. The properties of particles, which are used in simulation, are similarly selected as those of cells to apply cell separation. The most optimized shape of electrode is selected by numerical simulation according to a variety of electrode shape such as rectangle, trapezoidal, and right-triangle. Through, in addition, parameter study, we found that applied frequency is more significant factor on the separation than various parameters, such as applied voltage and permittivity of medium, that decide on the strength of DEP force.

• New & Renewable Energy
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• v.1 no.4 s.4
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• pp.19-24
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• 2005

수소 여과용 치밀질 membrane의 제조는 기존의 SC($SrCeO_3$)보다 높은 여과특성을 가지는 BC($BaCeO_3$)구조의 재료를 이용하여 시편을 제조하였고, 시편의 물성은 기공율, 수분에 대한 내구성 그리고 여과 특성을 측정하였다. 우선 열적 안정성 및 수분에 대한 내구성 향상은 $Y_2O_3$를 0.1mol첨가 하였을 때 1% 이내의 기공율을 가지고 있었으며 수분에 대한 안정성을 위해 boiling test에서도 균열이 발생되지 않고 안정적인 것을 확인할 수 있었다. 또한 여과 특성을 향상시키기 위해 Ce과 치환이 가능하고 전도성을 향상시킬 수 있는 $Ga_2O_3$, $La_2O_3$을 치환하여 물성을 측정한 결과 $Ga_2O_3$은 0.05, $La_2O_3$ 0.1mol%가 최적이었으며, 이들 중 $Ga_2O_3$가 0.05mol 첨가 되었을 때 가장 높은 이온 전도도 값을 얻었으며, $La_2O_3$이 첨가된 경우가 다음으로 높게 나타났다. 전자 전도성을 높이기 위하여 Pt를 sol로 만들어 나노 입자로 분산 시키는 방법으로 실험을 실시 $500^{\circ}C$ 이상의 온도에서는 복합전도에 의해 전도도가 향상되어지는 것을 확인할 수 있다. 또한 이들 시편의 여과 특성을 측정한 전도도 측정의 결과와 동일한 결과를 얻을 수 있었다.

• Membrane Journal
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• v.9 no.4
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• pp.221-229
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• 1999

The nominal pore size 0.2 ${\mu}m polytetrafluroethylene(PTFE, Satorius Co,) membrane was used for the filtration of 0.1 wt% kaolin, bentonite, yeast, and starch solution, respectively. After filtration, the membrane was cleaned and the pore size was measured by liquid displacement method(LDMl using water/iso-butanol system. The pore size for new PTFE membrane evaluated by LDM was comparable with those of which were measured by mercury porosimetry and scanning electron microscope. The membrane pores were severely fouled, and constricted to below 0.3 ${\mu}m in the cases of bentonite and starch solution which contained smaller particles than pores. However, in the case of kaolin - solution, only some parts of membrane pores above 0.35 ${\mu}m were slightly fouled. Hence, the phenomena of membrane fouling could be identified quantitatively by the evaluation of pore size using LDM.

• Membrane Journal
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• v.26 no.3
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• pp.173-178
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• 2016

In this short review, the polymer electrolyte membranes consisting of polymer and Ag salts were introduced and various approaches to solve the long-term stability were summarized. In particular, utilizing $AgNO_3$ as carriers with ionic liquid, the replacement of polymer matrix as poly(ethylene phthalate) (PEP) for strong coordinative interactions with Ag ions and the introduction of $Al(NO_3)_3$ to $polymer/AgBF_4$ complexes were introduced for long-term stable facilitated olefin transport membranes. For the polymer nanocomposite membranes, the role of electron acceptors as polarizer on the surface of AgNPs and the approach to solve the low permeance were introduced.

• Journal of Conservation Science
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• v.23
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• pp.73-80
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• 2008

This article aims to turn out the authentication of archaeological materials by using the paleodose measurement to fine sand-size quartz grains obtained by micro sampling technique. We firstly revealed the validity of micro sampling technique from the paleodoses of two bricks related to Muryong Royal Tomb of Baekje Kingdom. For the purpose of authentication test, four archaeological materials were selected, because they have been insisted that they were manufactured in Goguryeo Kingdom era. After obtaining very few quartz grains by micro sampling technique, each paleodose was evaluated by using SGR (single grain regenerative dose method). All values were very low below 0.2Gy and the reliability was found from those values by using SAR (single aliquot regenerative dose method). Considering the archaeological situation and the general paleodose, the burial time for 1,000 years generally corresponds to about 3.5Gy in Korea, it is concluded that these archaeological materials are all modern counterfeits.

• Clean Technology
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• v.10 no.4
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• pp.195-201
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• 2004

Cellulase was modified with copolymer with polyethylene(PE)/polypropylene(PP) oxide and maleic anhydride(MA) by maleylation reaction, and modified cellulase was applied to the reprocessing of old newsprint (ONP). Cellulase of modified cellulase enhanced the detachment of ink particles by fibrillation of fiber. The copolymer, which acted as the surfactant formed bubbles and removed the ink particles in the floatation process. Modified cellulase showed the same deinking ability without excess dosage compared with the conventional method. And, it improved the physical properties including tensile strength, brightness, and whiteness compared with the conventional deinking process. The bond between the ink and fiber got stronger as the storage time increased, and it became very difficult to remove the ink particle. But, modified cellulase increased the deinking ability by 41% compared with the conventional process at the experiment of the ONP for 1 year storage time. It removed the yellowing and increased the whiteness and brightness as well as tensile strength and internal bond strength.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.3
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• pp.226-232
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• 2000

Corrosion mechanisms by molten steel and slag were investigated in the zirconia/graphite composite as a material of submerged entry nozzle (SEN) using for producing high quality steel. Most of corrosions were started by the dissolution of zirconia particles into molten steel and oxidation of graphite, but subsequently three modes of corrosion were observed. Firstly, the penetration of slag into zirconia matrix was induced to the diffusion of stabilizing agent outward cubic zirconia grains, and the destabilization of cubic to fine monoclinic zirconia particles, which is enhanced to the decomposition and dissolution of them into slag. Secondly, molten slag penetrates into large cubic zirconia particles along grain boundary and decomposed them to fine cubic grains, which is also enhanced to the dissolution of zirconia grains into slag. Lastly, reaction between carbon and cubic zirconia was formed porous ZrC and enhanced the dissolution of it into slag.

• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.167-175
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• 2014

The influences of fluorescence, scattering, and flocculation in turbid material were interpreted for the scattered fluorescence intensity and wavelength, it has been studied the molecular properties by the spectroscopy of laser induced fluorescence(LIF). The effects of optical properties in scattering media have been found by the optical parameters(${\mu}_s$, ${\mu}_a$, ${\mu}_t$). Flocculation is an important step in many solid-liquid separation processes and is widely used in Photodynamic therapy. The interactions of several colloid particles can come into play which have major effect on the flocculation and LIF process. We measured scattering and fluorescence spectra of the sample for in vitro as function of concentration from lase source to detector. The value of scattering coefficient ${\mu}_s$ is large by means of the increasing particles of scatterer. Therefore, Phorphyrin A is larger than Phorphyrin C in scattering intensity ${\mu}_s$, but Phorphyrin A is smaller than Phorphyrin C in penetration depth ${\delta}$.

• Journal of the Korean Society of Tobacco Science
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• v.11 no.1
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• pp.11-17
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• 1989

Inhibition of tobacco mosaic virus (TMV) infection by 4 surfactants, sodium salts of alpha olefin (AOS), linear alkylbenzene (LAS), dioctyl sulfosuccinate (OSS), and dodecyl benzene sulfonic acid (SAS), was examined on tobacco cv. Xanthi-nc and NC 82. Infection of virions or TMV RNA was inhibited over 98% by the surfactants (2500 rpm). However, symptom development and viral concentration in tobacco plants treated with the surfactants into the rhizosphere soil 3 days before inoculation with TMV on leaves were not different from those in untreated tobacco plants. This indicates no significant systemic effects of the surfactants on the inhibition of TMV infection. The surfactants, except LAS, had no effect on the inhibition of viral infection when purified virions mixed with each surfactant and ultracentrifuged were inoculated on the tobacco plants. The virus was almost inactivated by LAS, showing that the viral infection was reduced more than 96%. The virus particles treated with the surfactants were not distinguishable in size and dimension from untreated normal particles, suggesting that the inhibitory action of the surfactants to TMV infection may not involve disintergration or uncoating of the virus at the early stage of infection.