• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.3
• /
• pp.323-328
• /
• 2004

Down-conversion of Eu$^{3+}$ doped LiGdF$_4$ (LGF) for increasing the cell efficiency on dye-sensitized Ti $O_2$ solar cells has been studied. The dye sensitized solar cell (DSC) consisting of mesoporous Ti $O_2$ electrode deposited on transparent substrate, an electrolyte containing I$^{[-10]}$ /I$_3$$^{[-10]}$ redox couple, and Pt counter electrode is a promising alternative to the inorganic solar cell. The structure of DSC is basically a sandwich type, viz., FTO glass/Ru-red dye-absorbed Ti $O_2$/iodine electrolyte/sputtered Pt/FTO glass. The cell without down converter had open circuit potential of approximately 0.66 Volt, the short circuit photocurrent density of 1.632 mA/$\textrm{cm}^2$, and fill factor of about 50 ％ at the excitation wavelength of 550 nm. In addition, 5.6 mW/$\textrm{cm}^2$ incident light intensity beam was used as a light source. From this result, the calculated monochromatic efficiency at the wavelength of 550 nm of this cell was about 9.62 ％. The incident photon to current conversion efficiency (IPCE) of N3 used as a dye in this work is about 80 ％ at around 590 nm and 610 nm, which is the emission spectrum of Eu$^{3+}$ doped LGF, results in efficiency increasing of DSC.C.

• KSBB Journal
• /
• v.11 no.4
• /
• pp.420-430
• /
• 1996

One-step immuno-chromatography assay system for heat-killed Salmonella typhimurium antigens was developed. Three major components used were a glass fiber membrane (placed at the bottom of the system) with an antibody (specific to the analyse, detection antibody)-gold conjugate deposited in a dry state on the surface, a nitrocellulose membrane (middle) with an antibody (also, specific to the analyse but recognized different epitome: capture antibody) and anti-detection antibody immobilized in spatially separated areas, and a cellulose membrane (top) as absorption pad. These membranes were partially superimposed such that a wicking of aqueous solution containing sample can continuously take place through membranes. Variables that affected the system performance were the concentration of capture antibody, the location on the membrane, inert protein used for blocking of the membrane and for carrying the sample, and the concentration of the gold conjugate. Under optimal conditions, within 15 minutes after absorption of a sample solution from the bottom of the system antigen-antibody complexes of sandwich type were formed on the membrane surface area with immobilized capture antibody and a color signal was generated in proportion to the analyse concentration. The minimum do tection limit of the analyse was $1{\times}106$ Salmonella cells/mL.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.4
• /
• pp.630-648
• /
• 1992

The minimum weight design for simply-supported isotropic or symmetrically laminated stiffened cylindrical shells subjected to various loads (axial compression or combined loads) is studied by a nonlinear mathematical search algorithm. The minimum weight design in accomplished with the CONMIN optimizer by Vanderplaats. Several types of buckling modes with maximum allowable stresses and strains are included as constraints in the minimum weight design process, such as general buckling, panel buckling with either stingers or rings smeared out, local skin buckling, local crippling of stiffener segments, and general, panel and local skin buckling including stiffener rolling. The approach allows the consideration of various shapes of stiffening members. Rectangular, I, or T type stringers and rectangular rings are used for stiffened cylindrical shells. Several design examples are analyzed and compared with those in the previous literatures. The unstiffened glass/epoxy, graphite/epoxy(T300/5208), and graphite/epoxy aluminum honeycomb cylindrical shells and stiffened graphite/epoxy cyindrical shells under axial compression are analyzed through the present approach.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.12
• /
• pp.4215-4220
• /
• 2011

This study introduces a new concept for a simple, efficient and cheap sensitivity amplification of a Quartz Crystal Microbalance (QCM) based immunosensor system for the detection of tumor necrosis factor-alpha (TNF-${\alpha}$, TNF) by using an in-built magnetic system. The frequency shift due to the applied magnetic field was successfully observed on magnetic particles labeled detection antibodies, anti-human TNF-${\alpha}$, which were bound to the immunologically captured TNF-${\alpha}$ on the gold coated quartz crystals. In the present system, the magnitude of frequency shift depends on both the strength of magnetic field and the amount of target antigen applied. Significant signal amplification was observed when the additional built-in residual stress generated by the modified magnetic particles under the magnetic field applied. Used in conjunction with a sandwich type non-competitive immunoassay format, the lower detection limit was calculated to be 25 $ngmL^{-1}$ and showed good linearity up to TNF-${\alpha}$ concentrations as high as 2.0 ${\mu}gmL^{-1}$. The sensitivity, most importantly, was improved up to 4.3 times compared with the same QCM system which was used only an antigen-antibody binding without additional magnetic amplification.

• The Journal of Internal Korean Medicine
• /
• v.26 no.1
• /
• pp.129-142
• /
• 2005

Objective : Asthma is known as chronic airway inflammatory disease. This inflammation is conducted by various inflammatory cells including eosihophil. Chemotaxis is one way that circulating inflammatory cells invade a specific lesion. This study examines the degree to which Lonicerae Flos inhibits eosinophil chemotaxis at pulmonary epithelium after allergic stimulation. Material and Methods : Water extracts of Lonicerae Flos and pulmonary epithelial cell lines A549(human type II-like epithelial cells) and human eosinophils were used. Cytotoxic effects of Lonicerae Flos via MTS assay were estimated, as well as the effects of Lonicerae Flos on chemokines from prestimulated A549 cells by sandwich ELISA and RT-PCR. Chemotaxis assay was conducted on prestimulated eosinophils treated with Lonicerae Flos. Result : In this study $TNF-{\alpha}$ and IL-4, $IL-l{\beta}$ were seen to induced the accumulation of chemokines mRNA in the pulmonary epithelial cell lines A549 in a dose-dependent manner. Chemokines were inhibited by Liripois Tuber in a dose-dependent manner and especially, IL-8 and ICAM-l were inhibited considerably at $100\;{\mu}g/ml$ concentration of Lonicerae Flos. The eosinophil migration is inhibited in high concentration of Lonicerae Flos in a dose-dependent manner. Conclusion : These findings indicate that the supression of the expression of chemokines can be accomplished by Lonicerae Flos treatment, raising the possibility that Lonicerae Flos might be of therapeutic value in diseases such as asthma.

• The Journal of Internal Korean Medicine
• /
• v.26 no.1
• /
• pp.199-212
• /
• 2005

Objective : Airway inflammation is now regarded as a defining feature of asthma. The importance of eosinophits in the airway inflammation of asthma patients is widely recognized, and eosinophils mobilization in the respiratory epithelium is activated by chemoattractants and cytokines. This study was designed to examine the extent of the ability of Moutan Cortex Radicis to inhibit eosinophil chemotaxis of pulmonary epithelium after allergic stimulation. Material and Methods : Water extracts of Moutan Cortex Radicis and pulmonary epithelial cell lines A549(human type II-like epithelial cells) and human eosinophils were used. Cytotoxic effects of Moutan Cortex Radicis were estimated via MTS assay, and the effects of Moutan Cortex Radicis on chemokines from prestimulated A549 cells were estimated by sandwich ELISA and RT-PCR. Chemotaxis assay on prestimulated eosinophils treated with Moutan Cortex Radicis. was conducted Result : In this study we demonstrated that $TNF-{\alpha}$ and IL-4, $IL-1{\beta}$ induced the accumulation of chemokines' mRNA in the pulmonary epithelial cell lines A549 in a dose-dependent manner. Chemokines of eotaxin, ICAM-1, YCAM-1, IL-8, IL-16 were inhibited by Moutan Cortex Radicis in a dose dependent manner, but RANTES showed no inhibition due to Moutan Cortex Radicis. Eosinophil migration was inhibited at high concentrations of Moutan Cortex Radicis. Conculusion : These findings are indicative of supression of chemokines accomplished by Moutan Cortex Radicis treatment, demonstrating the potential therapeutic value of Moutan Cortex Radicis for treating diseases such as asthma.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.42 no.4
• /
• pp.336-343
• /
• 2014

Modern advanced-turboprop propellers are required to have high structural strength to cope with the thrust requirement at high speed. The high stiffness and strength carbon/epoxy composite material is used for the major structure and skin-spar-foam sandwich structural type is adopted for advantage in terms of the blade weight. As a design procedure for the present study, the structural design load is estimated through investigation on aerodynamic load and then flanges of spars from major bending loads and the skin from shear loads are sized using the netting rule and Rule of Mixture. In order to investigate the structural safety and stability, stress analysis is performed by finite element analysis code MSC. NASTRAN. It is found that current methodology of composite structure design is a valid method through the static structural test of prototype blade.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.6
• /
• pp.1601-1608
• /
• 2010

A scandium(III) porphyrin-based fluoride-selective potentiometric sensor and its application in the analysis of hydrofluoric acid is described. Scandium(III) octaethylporphyrin, an ionophore recently developed for the optical fluoride sensor, was employed as a host molecule for the selective binding with fluoride in the plasticized PVC membrane. Nernstian response for $F^-$ between $10^{-4.6}$ to $10^{-1}$ M was observed at a glycine-phosphate buffer (pH 3.0). The selectivity pattern was observed as $F^-$, salicylate $\gg$ $SCN^-$ > $Cl^-$, $Br^-$, $NO_3{^-}$, $ClO_4{^-}$, which is consistent with the binding constant data measured in the plasticized PVC membrane based on a sandwich membrane method. This highly selective and reversible fluoride-sensitive electrode was employed for the analysis of hydrofluoric acid (HF). A disposable differential-type HF sensor was fabricated on the screen-printed electrode and demonstrated its ability to detect the neutral HF in the acidic solution.

• Computational Structural Engineering
• /
• v.7 no.4
• /
• pp.103-111
• /
• 1994

Based on a variational principle of the consistent shear deformable discrete laminate theory derived in the companion paper Part I, a finite element procedure for the vibration analysis of laminated composite plates is presented. The present formulation takes the in-plane displacements of an arbitrary layer, the rotations of the cross section of each layer and transverse displacement of the plate as the state variables at a nodal point of finite element, resulting in total nodal degree of freedom of 2(n+l) +1 for the n-layered laminate. Thus, it allows to specify displacement boundary conditions of layer stretching and/or rotation of layer cross sections around the plate edge and/or lateral displacement. The developed procedure is applied to the free vibration problem for sandwich-type hybrid laminates composed of layers with drastically different material properties whose elasticity solutions are known. Comparison of analysis results with other FEM solutions showed that the present formulation yields better accuracy.

• Korean Journal of Food Science and Technology
• /
• v.30 no.6
• /
• pp.1409-1414
• /
• 1998

To develop zearalenone-specific monoclonal antibodies, hybridoma cells were produced by fusion of myeloma cells $(P3{\times}63Ag\;V653)$ and spleen cells from BALB/c female mice immunized with zearalenone-oxime coupled to bovine serum albumin (BSA). After screening of antibody titer of them with a sandwich type enzyme-linked immunosorbent assay (ELISA), 5 hybridomas which could produced monoclonal antibodies with a high affinity for zearalenone were selected. The monoclonal antibody produced by Z-2-M26 hybridoma exhibited the high sensitivity to zearalenone and a little cross-reactivity to ${\alpha}-zearalenol$ (11%), but did not react with ${\beta}-zearalenol,\;{\alpha}-zearalenol,\;{\beta}-zearalenol$ and DON. In conclusion, the developed monoclonal antibody appeared to be a very promising immunoreagent for the future development of a specific and sensitive quantitative ELISA for zearalenone.