• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.558-563
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• 2007

This study was conducted to analyze the cytotoxic effects of butylated hydroxytoluene (BHT) and propyl gallate (PG) in WB-F344 rat liver epithelial cells. Here we measured the inhibition level of gap junctional intercellular communication (GJIC) and elucidated the relationships between GJIC and mitogen-activated protein kinases (MAPKs) such as ERK, JNK, and p38. The cytotoxicities of BHT and PG appeared at concentrations of 1.0mM and 0.25mM, respectively, in the WB-F344 cells; and GJIC inhibition, which was analyzed by a scrape-loading/dye transfer assay and Western blotting analysis, appeared at 0.6mM for BHT and 0.1mM for PG, respectively. Also, the phosphorylations of Cx43, ERK, JNK, and p38 increased in dose-dependent manners. This suggests that BHT and PG treatments inhibited GJIC by the phosphorylation of MAPKs prior to cell damage.

• Journal of the Korean Vacuum Society
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• v.18 no.3
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• pp.164-175
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• 2009

CFD is used to analyze gas flow characteristics, power absorption, electron temperature, electron density and chemical species profile of an internal antenna type inductively coupled plasma system. An optimized grid generation technology is used for a complex real-scale models for industry. A bare metal antenna shows concentrated power absorption around rf a feeding line. Skin depth of power absorption for a system is modeled to 50 mm, which is reported 53 mm by experiments. For an application of bipolar plates for hydrogen fuel cells, multi-sheet loading ICP nitriding system is proposed using an internal ICP antenna. It shows higher atomic nitrogen density than reported simple pulsed dc nitriding systems. Minimum gap between sheets for uniform nitriding is modeled to be 39 mm.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.1
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• pp.1-10
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• 2011

Recently harbor remodeling projects are seriously considered to enhance the loading and unloading capability of old container terminals and to make decrepit ports as eco-friendly harbor and waterfront spaces in many countries. In such a case, quantitative and qualitative evaluations on concrete harbor facilities are mandatory to determine the current structural integrity condition of aged materials. Once the remodeling project is determined to be carried out, the reusability of individual structural members and facilities including caissons, cell-blocks, and tetra-pods need to be decided based on the simple and economic visual inspection and/or nondestructive testing. In this study, the systematic quantitative evaluation procedure for determining the structural integrity condition and the reusability is studied based the nondestructive testing and evaluation methods. Conventional methods including Schmidt hammer test and ultrasonicpulse velocity methods and elastic wave based methods including impact echo test and surface wave test are applied to the old harbor facilities in five different sites. The compressive tests are also carried out to determine the elastic modulus and compressive strength of concrete materials.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.554-560
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• 2013

This study proposes an structure that fixes the shielding device to two parts of the board by its two arranged clips. Said structure evenly distributes its loading/unloading load of the board and maintains the flatness of soldering area of the board. The structure of this study comprises a base part fixed to a printed circuit board and a clip part fixing a side wall of a shield can to the board, wherein the clip part is constituted with two clips fixable to two part of the shield can. Also, the structure of this study comprises a dented groove in order to easily solder the base part of clips and the printed circuit board. A mechanism is established and a design parameter was determined by a structure analysis and a vibration mode analysis. A single purpose machine for the production of the product was developed, the final workpiece was produced and the measuring-data and the computered-data was compared and reviewed.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.151-151
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• 2011

Large amounts of natural gas, mainly methane, in the form of hydrates are stored on continental margins. When gas hydrates are dissociated by any environmental trigger, generation of excess pore pressure due to released free gas may cause sediment deformation and weakening. Hence, damage on offshore structures or submarine landslide can occur by gas hydrate dissociation. Therefore, geotechnical stability of gas hydrate bearing sediments is in need to be securely assessed. However, geotechnical characteristics of gas hydrates bearing sediments including small-strain elastic moduli have been poorly identified. Synthesizing gas hydrate in natural seabed sediment specimen, which is mainly composed of silty-to-clayey soils, has been hardly attempted due to their low permeability. Moreover, it has been known that hydrate loci in pore spaces and heterogeneity of hydrate growth in specimen scale play a critical role in determining physical properties of hydrate bearing sediments. In the presented study, we synthesized gas hydrate containing sediments in an instrumented oedometric cell. Geotechnical and geophysical properties of gas hydrate bearing sediments including compressibility, small-strain elastic moduli, elastic wave, and electrical resistivity are determined by wave-based techniques during loading and unloading processes. Significant changes in volume change, elastic wave, and electrical resistivity have been observed during formation and dissociation of gas hydrate. Experimental results and analyses reveal that geotechnical properties of gas hydrates bearing sediments are highly governed by hydrate saturation, effective stress, void ratio, and soil types as well as morphological feature of hydrate formation in sediments.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.3835-3838
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• 2016

Background: Breast cancer is one of the most frequent cancer types within female populations. Silibinin is a chemotherapeutic agent ative against cancer. Niosomes are biodegradable, biocompatible, safe and effective carriers for drug delivery. Objective:To prepare nanoniosomal silibinin and evaluate its cytotoxicity inthe T-47D breast cancer cell line. Materials and Methods: Niosomes were prepared by reverse phase evaporation of a mixture of span 20, silibinin, PEG-2000 and cholesterol in chloroform and methanol solvent (1:2 v/v). The solvent phase was evaporated using a rotary evaporator and the remaining gel phase was hydrated in phosphate buffer saline. Mean size, size distribution and zeta potential of niosomes were measured with a Zetasizer instrument and then nanoparticles underwent scanning electron microscopy. The drug releasing pattern was evaluated by dialysis and the cytotoxicity of nanoniosomes in T-47D cells was assessed by MTT assay. Results: Particle size, size variation and zeta potential of the niosomal nanoparticles were measured as $178.4{\pm}5.4nm$, $0.38{\pm}0.09$ and $-15.3{\pm}1.3mV$, respectively. The amount of encapsulated drug and the level of drug loading were determined $98.6{\pm}2.7%$ and $22.3{\pm}1.8%$, respectively; released drug was estimated about $18.6{\pm}2.5%$ after 37 hours. The cytotoxic effects of nanoniosome were significantly increased when compared with the free drug. Conclusions: This study finding suggests that silibinin nanoniosomes could serve as a new drug formulation for breast cancer therapy.

• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.784-790
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• 2003

Present investigation shows the analysis results for ceramic reinforced metal matrix composite under uniaxial transverse tensile loading. The resulting deformation, the projected damage type, and stress-strain behavior were computed depending on microstructure details such as the type of periodic reinforcement array, and the type of interface bonding. A two-dimensional finite element analysis was conducted based on the unit-cell of square, hexagonal, or diagonal periodic away For composite with strong interface bonding, the transverse stress vs. strain curve was generally increased with the increase of the ceramic volume fraction. For the composite with weakly bonded interface, however, the transverse stress vs. strain curve was reduced against the ceramic volume fraction. The decrease was caused by the interface debonding-induced stiffness reduction of the composite. For the composite of weakly bonded interface, the relative reduction rate in the final limit stress for hexagonal array was larger than that for square array. Outcome of the present study was compared favorably with the published literature data.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.2
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• pp.95-103
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• 2009

In order to improve the electrochemical, mechanical and electrocatalytic characteristics, engineering plastic of polyether ether ketone (PEEK) as polymer matrix was sulfonated (SPEEK) and the organic-inorganic blend composite membranes has been prepared by loading heteropoly acids (HPAs), including tungstophosphoric acid (TPA), molybdophosphoric acid (MoPA), and tungstosilicic acid (TSiA). And then these were covalently cross-linked (CL-SPEEK/HPA) as the electrolyte and MEA of polymer electrolyte membrane electrolysis (PEME). As a result, the optimum reaction conditions of CL-SPEEK/HPA was established and the electrochemical characteristics such as ion conductivity ($\sigma$) were in the order of magnitude: CL-SPEEK /TPA30 (${\sigma}=0.128\;S/cm^{-1}$) < /MoPA40 (${\sigma}=0.14\;S/cm^{-1})$ < /TSiA30 (${\sigma}=0.22\;S/cm^{-1}$) at $80^{\circ}C$, and mechanical characteristics such as tensile strength: CL-SPEEK /TSiA30 $\fallingdotseq$ /MoPA40 < /TPA30. Consequently, in regards of above characterisitics and oxidation durability, the CL-SPEEK/TPA30 exhibited a better performance in PEME than the others, but CL-SPEEK/MoPA40 showed the best electrocatalytic activity of cell voltage 1.71 V among the composite membranes. The dual effect of higher proton conductivity and electrocatalytic activity with the addition of HPAs, causes a synergy effect.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.450-455
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• 2005

To treat wastewater efficiently by a one-step process of nitrogen removal, a new strain of $N_2-producing$ bacteria from $NH{_4}{^+}$ under an aerobic condition was isolated and identified. By 16S-rDNA analysis, the isolate was identified as Enterobacter asburiae with 96% similarity. The isolate shows that the capacity of $N_2$ production under an oxic condition was approximately three times higher than that under an anoxic condition. The optimal conditions (pH, temperature and C/N ratio) of the immobilized isolate for $N_2$ production were found to be 7.0, $30^{\circ}C$ and 5, respectively. Under all the optimum reaction conditions, the removal efficiency of $COD_{Cr}$ and TN reached 56.1 and 60.9%, respectively. The removal rates of $COD_{Cr}$ and TN were highest for the first 2.5 hrs (with the removal $COD_{Cr}$ ratios of 32.1), and afterwards the rates decreased as reaction proceeded. For application of the immobilized isolate to a practical process of ammonium removal, a continuous bioreactor system exhibited a satisfactory performance at HRT of 12.1 hr, in which the effluent concentrations of $NH{_4}{^+}-N$ was measured to be 15.4 mg/L with its removal efficiency of 56.0%. The maximum removal rate of $NH{_4}{^+}-N$ reached 1.6 mg $NH{_4}{^+}-N/L/hr$ at HRT of 12.1 hr (with N loading rate of 0.08 $Kg-N/m^3-carrier/d)$. As a result, the application of the immobilized isolate appears a viable alternative to the nitrification-denitrification processes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7A
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• pp.757-767
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• 2008

Start Ongoing next generation networks are expected to be deployed over current existing networks, in the form of overlayed heterogeneous networks, in particular, in hot spot areas. Therefore, it will be necessary to develop an interworking technique such as load balancing, to achieve increased overall resource utilization in the various heterogeneous networks. In this paper, we present a new load balancing mechanism termed 'soft' load balancing where the IP(Internet Protocol) traffic of a user is divided into sub-traffic, each of which flows into a different access network. The terminology of soft load balancing involves the use of both load sharing and handover techniques. Through a numerical analysis, we obtain an optimal LBR (Load Balancing Ratio) for determining the volume of traffic delivered to each network over an overlayed multi-cell environment. Using the optimal LBR, a more reliable channel transmission can be achieved by reducing the outage probability efficiently for a given user traffic.