• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.857-864
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• 2011

Oxy-fuel combustion with many advantages such as high combustion efficiency, low flue gas flow rate and low NOx emission has emerged as a promising CCS technology for coal combustion facilities. In this study, the effects of the direct sulfation reaction on $SO_2$ removal efficiency were evaluated in a drop tube furnace under typical oxy-fuel combustion conditions represented by high concentrations of $CO_2$ and $SO_2$ formed by gas recirculation to control furnace combustion temperature. The effects of the operating parameters including the reaction temperature, $CO_2$ concentration, $SO_2$ concentration, Ca/S ratio and humidity on $SO_2$ removal efficiency were investigated experimentally. $SO_2$ removal efficiency increased with reaction temperature up to 1,200 due to promoted calcination of limestone reagent particles. And $SO_2$ removal efficiency increased with $SO_2$ concentrations and the humidity of the bulk gas. The increase of $SO_2$ removal efficiency with $CO_2$ concentrations showed that $SO_2$ removal by limestone was mainly done by the direct sulfation reaction under oxy-fuel combustion conditions. From the impact assessment of operation parameters, it was shown that these parameters have an effects on the desulfurization reaction by the order of the Ca/S ratio > residence time > $O_2$ concentration > reaction temperature > $SO_2$ concentration > $CO_2$ concentration > water vapor. The semi-empirical model equation for to evaluate the effect of the operating parameters on the performance of in-furnace desulfurization for oxy-fuel combustion was established.

• Journal of Environmental Health Sciences
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• v.41 no.4
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• pp.241-248
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• 2015

Objectives: This study was conducted to provide scientific and effective information on phytoncides, which are associated with forest healing, and to activate recreational forests. Methods: The target sites were natural recreation forests, a forest park and an arboretum, and the control sites were three urban parks. The samples were collected at a volume of 6.0 L and a flow rate of 0.1 L/min for one hour using a low volume pump and the solid adsorbent sampling method. The phytoncide compounds adsorbed in the Tenax TA tube were analyzed by a automatic heat desorption unit and GC-MS. Results: By type of recreational forest, the annual concentrations of phytoncide (monoterpene) for the forest park showed the highest concentration with $1.450{\mu}g/m^3$, while those for the arboretum showed the lowest concentration at $0.892{\mu}g/m^3$, and thus the concentration of the forest park was approximately 1.6 times higher than the arboretum. The season showing the highest concentration of phytoncides was summer (June) and the forest park was the highest among the recreational forests. The concentrations of major components for phytoncide showed in descending order: ${\alpha}-pinene$, ${\beta}-pinene$, camphene, 3-carene and limonene. The seasonal concentration of ${\alpha}-pinene$, camphene and ${\beta}-pinene$ by type of recreational forest increased in April, which is characterized by low temperature and humidity, and the seasonal concentration of camphene decreased with higher humidity. The meteorological factors which had the high correlation with the concentration of total terpene were temperature and humidity. $CO_2$ and $O_2$ showed an inverse correlation. Conclusion: The major components of phytoncide were ${\alpha}-pinene$, ${\beta}-pinene$, camphene, 3-carene and limonene in descending order of concentration. Further and systematic study on the chemical nature of individual phytoncides, and on the effect of phytoncides on humans needs to be performed.

• Ocean Systems Engineering
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• v.6 no.1
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• pp.61-97
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• 2016

This is the second of two papers on the 3D numerical modeling of nearshore hydro- and morphodynamics. In Part I, the focus was on surf and swash zone hydrodynamics in the cross-shore and longshore directions. Here, we consider nearshore processes with an emphasis on the effects of oceanic forcing and beach characteristics on sediment transport in the cross- and longshore directions, as well as on foreshore bathymetry changes. The Delft3D and XBeach models were used with four turbulence closures (viz., ${\kappa}-{\varepsilon}$, ${\kappa}-L$, ATM and H-LES) to solve the 3D Navier-Stokes equations for incompressible flow as well as the beach morphology. The sediment transport module simulates both bed load and suspended load transport of non-cohesive sediments. Twenty sets of numerical experiments combining nine control parameters under a range of bed characteristics and incident wave and tidal conditions were simulated. For each case, the general morphological response in shore-normal and shore-parallel directions was presented. Numerical results showed that the ${\kappa}-{\varepsilon}$ and H-LES closure models yield similar results that are in better agreement with existing morphodynamic observations than the results of the other turbulence models. The simulations showed that wave forcing drives a sediment circulation pattern that results in bar and berm formation. However, together with wave forcing, tides modulate the predicted nearshore sediment dynamics. The combination of tides and wave action has a notable effect on longshore suspended sediment transport fluxes, relative to wave action alone. The model's ability to predict sediment transport under propagation of obliquely incident wave conditions underscores its potential for understanding the evolution of beach morphology at field scale. For example, the results of the model confirmed that the wave characteristics have a considerable effect on the cumulative erosion/deposition, cross-shore distribution of longshore sediment transport and transport rate across and along the beach face. In addition, for the same type of oceanic forcing, the beach morphology exhibits different erosive characteristics depending on grain size (e.g., foreshore profile evolution is erosive or accretive on fine or coarse sand beaches, respectively). Decreasing wave height increases the proportion of onshore to offshore fluxes, almost reaching a neutral net balance. The sediment movement increases with wave height, which is the dominant factor controlling the beach face shape.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.11
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• pp.1205-1211
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• 2011

In this paper, we developed a pacemaker that can increase the efficacy of a left ventricular assist device (LVAD) and increase the survival rate for patients suffering end-stage heart failure. Because LVAD patients can experience arrhythmia, the pacemaker incorporated into the LVAD has the important role of sustaining sufficient blood circulation during arrhythmia. The electrode of the pacemaker is located at the apex of the left ventricle, where the VAD's inlet cannula is connected. This is efficient placement, in that the electrode can transmit electrical stimulation directly to the Purkinje fibers of the myocardium. The pacemaker can change the stimulation rate from 0 bpm to 191.4 bpm when a button is pressed on the external control module, and the pacemaker normally stimulates the heart at 60 bpm with 0.25 J of energy. We performed animal experiments to evaluate the performance and reliability of the combination of the LVAD and pacemaker. At pacemaker stimulation rates of 86.4 bpm, 100.2 bpm, 126.6 bpm, we recorded the ECGs, aortic pressures, and flow rates to analyze the heart loads.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.3
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• pp.258-268
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• 2001

The compression method is necessarily used to send the high quality moving picture that contains a number of data in image processing. In the field of moving picture compression method, the motion estimation algorithm is used to reduce the temporal redundancy. Block matching algorithm to be usually used is distinguished partial search algorithm with full search algorithm. Full search algorithm be used in this paper is the method to compare the reference block with entire block in the search window. It is very efficient and has simple data flow and control circuit. But the bigger the search window, the larger hardware size, because large computational operation is needed. In this paper, we design the full search block matching motion estimator. Using the DCT DC values, we decide luminance. And we apply 3 bit compare-selector using bit plane to I(Intra coded) picture, not using 8 bit luminance signals. Also it is suggested that use the same selective bit for the P(Predicted coded) and B(Bidirectional coded) picture. We compare based full search method with PSNR(Peak Signal to Noise Ratio) for C language modeling. Its condition is the reference block 8$\times$8, the search window 24$\times$24 and 352$\times$288 gray scale standard video images. The result has small difference that we cannot see. And we design the suggested motion estimator that hardware size is proved to reduce 38.3％ for structure I and 30.7％ for structure II. The memory is proved to reduce 31.3％ for structure I and II.

• The Korea Journal of Herbology
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• v.25 no.2
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• pp.129-136
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• 2010

Objective : Sinapis alba L. (SA) is a korean traditional herbal medicine that is usually used to prevent or treat inflammatory diseases, such as respiratory infection and rheumatoid arthritis. However, the effects of SA supplementation in vitro on serum antibody levels, splenocyte and peritoneal macrophage immune responses have not yet been determined. In this study, we examined the effect of SA on the production of Th1/Th2 cytokines. Methods : Splenocytes were isolated from naive C57BL/6 mice. Cells were enriched for CD4+ cell populations by first staining the cells with anti-CD4 (BD PharMingen, Calif, USA). CD4+ T cells were selected on a (CS) column, and the flow-through was collected as CD4+ T cells. Isolated cells were activated by overnight incubation on 24-well plates coated with $1{\mu}g/mL$ anti-CD3, $1{\mu}g/mL$ anti-CD28 and with SA ($100{\mu}g/mL$). Primary macrophages were collected from the peritoneal cavities of mice (8-week-old female C57BL/6). The peritoneal macrophages were washed and plated with RPMI-1640 overnight for the experiments. After 48-hours cultures, samples were centrifuged at 2000 rpm for 10 minutes, and the supernatants were stored at $-80^{\circ}C$. Mouse IL-4, IFN-$\gamma$ and TNF-$\alpha$ were quantified using ELISA kits (BioSource International, Camarillo, Calif, USA) according to the manufacturer's protocols. Results : SA at 100ug/ml decreased the generation of Th1 cytokine (IFN-$\gamma$) by 0.5-fold. However, SA has no effect on Th2 (IL-4) production. Conclusions : These results suggest that SA may play an important role in the control of T-cell-mediated autoimmunity by down-regulation of Th1 cytokine (especially IFN-$\gamma$, TNF-$\alpha$). These data may contribute to the design of new immunomodulating treatments for a group of autoimmune diseases.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.1
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• pp.1-9
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• 2010

Numerical study on coastal water quality management was conducted to examine the response of summer water quality to the flow into the sea of land based pollution load in Ulsan Bay, Korea The abatement of pollution load. from point sources of land was estimated on the basis of Korean coastal water quality standard using an ecosystem model. The results of the ecological model simulation showed that COD values in the inner part of the bay were greater than 280mg/L, and exceeded the grade III limit of Korean coastal water quality standard 30% of all land based pollution loads or organic and inorganic material loads from point sources should be cut down to keep the COD levels below 2mg/L. As environmental carrying capacity was estimated to be 7,193kgCOD/day to keep the COD levels below 2mg/L in Ulsan Bay, 3,083kgCOD/day of land based organic loads should be reduced. The phytoplankton blooms have occurred in the Teahwa river mouth or estuary repetitively, so it is important to control land based nutrients loads for removal of autochthonous organic loads around Ulsan Bay.

• Polymer(Korea)
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• v.36 no.2
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• pp.177-181
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• 2012

This study presents the preparation of double emulsions in a poly(dimethylsiloxane) (PDMS)-based microfluidic device. To improve the wettability of hydrophilic continuous phase onto a hydrophobic PDMS microchannel, the surface was modified with 3-(trimethoxysilyl) propyl methacrylate (TPM) and then sequentially reacted with acrylic acid monomer solution, which produced selective covalent bonding between acrylic acids and methacrylate groups. For the proof of selective surface modification, tolonium chloride solution was used to identify the modified region and we confirmed that the approach was successfully performed. When water containing 0.5% w/w sodium dodecyl sulfate and 1% w/w Span80 with hexadecane were loaded into the selectively modified microfluidic channels, we can produce stable double emulsion. Based on the spreading coefficients, we predict the morphology of double emulsions. Our proposed method efficiently produces monodisperse double emulsions having 48.5 ${\mu}m$(CV:1.6%) core and 65.1 ${\mu}m$ (CV:1.6%) shell. Furthermore, the multiple emulsions having different numbers of core were easily prepared by simple control of flow rates.

• Journal of Korea Water Resources Association
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• v.36 no.2
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• pp.285-300
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• 2003

An event-based, kinematic, infiltration-excess, and distributed rainfall-runoff model using weather radar and Geographic Information System(GIS) was developed to acknowledge and account lot the spatial variability and uncertainty of several parameters relevant to storm surface runoff and surface flow The developed model is compatible with raster GIS and spatially and temporally varied rainfall data. To calibrate the model, Monte Carlo simulation and a likelihood measure are utilized; allowing for a range of possible system responses from the calibrated model. Using rain gauge adjusted radar-rainfall estimates, the developed model was applied and evaluated to a limited number of historical events for the Ralston Creek and Goldsmith Gulch basins within the Denver Urban Drainage and Flood Control District (UDFCD) that contain mixed land use classifications. While based on a limited number of Monte Carlo simulations and considered flood events, Nash and Sutcliffe efficiency score ranges of -0.19∼0.95 / -0.75∼0.81 were obtained from the calibrated models for the Ralston Creek and Goldsmith Gulch basins, based on a comparison of observed and simulated hydrographs. For the Ralston Creek and Goldsmith Gulch basins, Nash and Sutcliffe efficiency scores of 0.88/0.10, 0.14/0.71, and 0.99/0.95 for runoff volume, peak discharge, and time to peak, respectively, were obtained from the model.

• Journal of Life Science
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• v.16 no.4
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• pp.589-597
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• 2006

Genistein, a natural isoflavonoid phytoestrogen, is a strong inhibitor of protein tyrosine kinase and DNA topoisomerase activities. There are several studies documenting molecular alterations leading to cell cycle arrest and induction of apoptosis by genistein as a chemopreventive agent in a variety of cancer cell lines; however, its mechanism of action and its molecular targets on human bladder carcinoma and leukemic cells remain unclear. In the present study, we have addressed the mechanism of action by which genistein suppressed the proliferation of T24 bladder carcinoma and U937 leukemic cells. Genistein significantly inhibited the cell growth and induced morphological changes, and induced the G2/M arrest of the cell cycle in both T24 and U937 cells with a relatively stronger cytotoxicity in U937. The G2/M arrest in T24 cells was associated with the inhibition of cyclin A, cyclin B1 and Cdc25C protein expression without alteration of tumor suppressor p53 and cyclin-dependent kinase (Cdk) inhibitor p21(WAF1/CIP1). However, the inhibitory effects of genistein on the cell growth of U937 cells were connected with a marked inhibition of cyclin B1 and an induction of Cdk inhibitor p21 proteins by p53-independent manner. These data suggest that genistein may exert a strong anticancer effect and additional studies will be needed to evaluate the different mechanisms between T24 and U937 cells.