• Clean Technology
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• v.19 no.3
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• pp.347-350
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• 2013

Desorption characteristics for ions adsorbed onto sericite was performed by means of $HNO_3$ solution which was selected as the best desorbing agent in the previous work. Elution of nickel ions adsorbed onto sericite using $HNO_3$ solution was confirmed by means of scanning electron microscopy (SEM) & energy dispersive X-ray spectroscopy (EDX) analysis. Desorption efficiency for nickel ions was 100% at the 20 mM of concentration. Also, nickel ions was completely desorbed within 1.0 of S/L (mg/mL) ratio which is defined as the ratio of adding amount of adsorbent and volume of desorbing agent and desorption process was quickly carried out within 60min. Finally, removal efficiency of reused sericite for nickel ions was constantly maintained until the 4th cycle.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.6
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• pp.739-747
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• 2014

The aim of the study was to determine the effects of Ixeris dentata extract (IDE) on anticancer activity in human breast cancer MDA-MB-231 cells at both cellular and molecular levels. The cells were cultured in the presence of 0, 20, 30 and $40{\mu}g/mL$ Ixeris dentata extract for 24 hours, respectively. At the end of culture, cytochemical analyses for MTT activity, trypan blue dye exclusion, Annexin V-FITC Apoptosis, and radical oxygen species (ROS) were conducted. RT-PCR was also performed to determine whether or not alterations in cell viability affect the Bax/Bcl-2 ratio. MTT assay showed that relative cell viability decreased in a dose-dependent manner (p<0.05). Reduction of cell viability matched well with increased cell membrane permeability as determined by trypan blue dye exclusion test (p<0.05). The rates of intracellular ROS also increased in a similar manner to those of TB-stained cells. There was an associated shift of apoptotic cells from early to late apoptosis between the 30 and $40{\mu}g/mL$. Bax/Bcl-2 ratio significantly increased along with significant decreases in Bcl-2 expression between 30 and $40{\mu}g/mL$ groups (p<0.05). In conclusion, anticancer activity of Ixeris dentata extract is modulated by a reduction in cell viability along with increased membrane permeability, leading to ROS accumulation within cells, and subsequently cell death through an apoptotic pathway that involves Bax and Bcl-2 in human breast cancer MDA-MB-231 cells.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.30-37
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• 2005

To mass-produce useful biopolymer films, chitosan/gelatin blend films were prepared by solution casting method. Effects of mixing ratio, tensile strength (TS), elongation (E) at break, total color difference (${\Dalta}E$), opacity, water vapor permeability (WVP), oxygen permeability (OP), and thermal properties on chitosan/gelatin blend films properties were investigated. TS, E, ${\Dalta}E$, opacity, WVP, and OP values were 58.24-22.01 MPa, 13.11-24.67%, 1.86-17.45, 0.3104-1.2161 nmO.D./${\mu}m$, $1.6875-1.7225ng{\cdot}m/m^{2}{\cdot}s{\cdot}Pa$, and $2.2380{\times}10^{-7}-2.2975{\times}10^{-7}\;mL{\cdot}{\mu}m/m^{2}{\cdot}s{\cdot}Pa$, respectively. TS of blend films decreased, while E, ${\Dalta}E$, and opacity increased with increasing chitosan content. WVP of blend films did not show any significant relationship with mixing ratio and thickness of blend films. Miscibility of films was examined over entire composition range by thermogravimetric analyzer (TGA) and dynamic mechanical analyzer (DMA). TGA results showed gelatin is more thermally stable than chitosan and some interactions among functional groups of two biopolymers. Glass transition temperature $(T_{2})$ of films as determined by DMA decreased with increasing content of chitosan in the blend. Results of thermal analysis indicate high miscibility among polymer components in the blend.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.7
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• pp.1013-1021
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• 1998

Various vortical structures are investigated by using three kinds of flow visualization methods in branch pipe flows. There are two typical flow patterns when a jet from the branch pipe with various angles is injected to the main pipe cross flow. The velocity range of cross flow of the main pipe is 0.2 m/s ~ 1.2 m/s and the corresponding Reynolds number, R$_{p}$ is of the range 1.5 * 10$^{3}$ ~ 9.02 * 10$^{3}$. The velocity ratio(R), jet velocity/cross flow velocity, is chosen from 1.3 to 4. The subsequent behavior and development of the ring vortices which are created at the jet boundary mainly depend on the velocity ratio. An empirical relation for the shedding frequency of the ring vortices is derived. It is also found that there are two different vortex shedding mechanism in the mixing of two fluid streams.s.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.10
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• pp.1373-1383
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• 2001

The desulfurization characteristics of anthracite in a bench scale pressurized fluidized bed combustor are investigated. The coal used in the experiment is domestic anthracite from Kangwon Taeback area. The desulphurization experiment is performed with limestone from Chungbuk Danyang. The pressure of the combustor is maintained at 6 atm, and the combustion temperatures are 850, 900, and 950$\^{C}$. The superficial gas velocities are 0.9, 1.1, and 1.3 m/s. The excess air ratio is varied from 5 to 35%. The Ca/S mole ratios are 0.5, 1.5, 2.5 and 4.5 mole. All experiments are executed at 2m bed height. Consequently, SO$_2$ concentration in the flue gas is increased with incresing bed temperature and superficial gas velocity. However SO$_2$ concentration is decreased with incresing excess air ratio and Ca/S mole ratio.

• Korean Journal of Remote Sensing
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• v.36 no.6_1
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• pp.1291-1302
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• 2020

To verify the field-effectiveness of Terrestrial Laser Scanner (TLS), a terrestrial LiDAR was deployed to examine the damage properties of woods in forest fire area, then the data was compared with the results surveyed by a forestry expert. Four sample plots (30 m × 50 m, 0.15 ha) were set from the foot to the top of the mountain, and DBH, height, clear length, burned height, and crown length were investigated. Next, TLS collected information on damage characteristics found in the sample plots. This information was then compared with that amassed by the expert. The expert and the TLS survey results showed 30.8 cm and 29.9 cm for DBH, 15.8 m and 17.5 m for tree height, 8.4 m and 8.4 m for clear length, 4.0 m, 3.5 m for burned height, and 7.4 cm and 9.1 cm for crown length. With the exceptions of height and clear length, no notable discrepancy was observed between two methods. H/D ratio, CL/H ratio, and BH/CL ratio, all of which contribute to stability and decay rate of the stand, from the two methods were also compared. The human survey rated each ratio (H/D, CL/H, BH/CL in order) 51.3%, 47.1%, and 53.6%, while the TLS presented the results of 58.8%, 52.0%, and 38.7%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.193-196
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• 2001

Single phase $CuInS_2$ thin film with the highest diffraction peak (112) at diffraction angle $(2\theta)$ of $27.7^{\circ}$ and the second highest diffraction peak (220) at diffraction angle $(2\theta)$ of $46.25^{\circ}$ was well made with chalcopyrite structure at substrate temperature of $70^{\circ}C$, annealing temperature of $250^{\circ}C$, annealing time of 60 min. The $CuInS_2$ thin film had the greatest grain size of $1.2{\mu}m$ and Cu/In composition ratio of 1.03. Lattice constant of a and c of that $CuInS_2$ thin film was 5.60 A and 11.12 A respectively. Single phase $CuInS_2$ thin films were accepted from Cu/In composition ratio of 0.84 to 1.3. P-type $CuInS_2$ thin films were appeared at over Cu/In composition ratio of 0.99. Under Cu/In composition ratio of 0.96, conduction types of $CuInS_2$ thin films were n-type. Also, fundamental absorption wavelength, the absorption coefficient and optical energy band gap of p-type $CuInS_2$ thin film with Cu/In composition ratio of 1.3 was 837 nm, $3.0{\times}104cm^{-1}$ and 1.48 eV respectively. When Cu/In composition ratio was 0.84, fundamental absorption wavelength, the absorption coefficient and optical energy band gap of n-type $CuInS_2$ thin film was 821 nm, $6.0{\times}10^4cm^{-1}$ and 1.51 eV respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.193-196
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• 2001

Single phase CuInS$_2$ thin film with the highest diffraction peak (112) at diffraction angle (2$\theta$) of 27.7$^{\circ}$ and the second highest diffraction peak (220) at diffraction angle (2$\theta$) of 46.25$^{\circ}$ was well made with chalcopyrite structure at substrate temperature of 70 $^{\circ}C$, annealing temperature of 25$0^{\circ}C$, annealing time of 60 min. The CuInS$_2$ thin film had the greatest grain size of 1.2 ${\mu}{\textrm}{m}$ and Cu/In composition ratio of 1.03. Lattice constant of a and c of that CuInS$_2$ thin film was 5.60 $\AA$ and 11.12 $\AA$ respectively. Single phase CuInS$_2$ thin films were accepted from Cu/In composition ratio of 0.84 to 1.3. P-type CuInS$_2$ thin films were appeared at over Cu/In composition ratio of 0.99. Under Cu/In composition ratio of 0.96, conduction types of CuInS$_2$ thin films were n-type. Also, fundamental absorption wavelength, the absorption coefficient and optical energy band gap of p-type CuInS$_2$ thin film with Cu/In composition ratio of 1.3 was 837 nm, 3.0x10 $^4$ $cm^{-1}$ / and 1.48 eV respectively. When CuAn composition ratio was 0.84, fundamental absorption wavelength, the absorption coefficient and optical energy band gap of n-type CuInS$_2$ thin film was 821 nm, 6.0x10$^4$ $cm^{-1}$ / and 1.51 eV respectively.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.12
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• pp.1272-1278
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• 2012

The micro barrier rip array structures have been applied in a variety of areas including as privacy films, micro heat sinks, touch panel and optical waveguide. The increased aspect ratio (AR) of barrier rip array structures is required in order to increase the efficiency and performance of these products. There are several problems such as burr, defect of surface roughness and deformation and breakage of barrier rip structure with machining high-aspect ratio micro barrier rip array structure using orthogonal cutting method. It is essential to develop technological methods to solve these problems. The optimum machining conditions for machining micro barrier rip array structures having high-aspect ratio were determined according to lengths ($200{\mu}m$ and $600{\mu}m$) and shape angles ($2.89^{\circ}$ and $0^{\circ}$) of diamond tool, overlapped cutting depths ($5{\mu}m$ and $10{\mu}m$), feed rates (100 mm/s) and three machining processes. Based on the optimum machining conditions, micro barrier rib array structures having aspect ratio 30 was machined in this study.

• Journal of Nutrition and Health
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• v.31 no.5
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• pp.897-905
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• 1998

Docosahexaenoic acid(DHA), a $\omega$3 series fatty acid and arachidonic acid(AA). a $\omega$6 series fatty acid were found in relatively high concentrations in the phospholipids(PLs) of cell membranes of nerve tissues, and they can be affected by various factors. The present study examined the effects of dietary $\omega$6 and $\omega$3 fatty acid composition on P/M/S and on $\omega$3/$\omega$6 fatty acid ratios in brain PLs of 2nd generation rats. The expeimental diets consisted of 10% fat(by wt), which were computer- searched mixed oil('M') with P/M/S ratio, 1 : 1.4 : 1 and $\omega$6/$\omega$3 ratio, 6 : 1 and safflower oil('S') poor in $\omega$3 fatty acids. The experimental diets were started 3-4 wks prior to conception. During the lactation period, the feeding mothers were switched 1 wk after birth and provided the pups for 2 wks with milk which had compositions different from that of their natural mother. The same diet as their mothers was provided from weaning to 9 wks of age. The 'M'and 'S' rats were again subdivided into MM, MS, SS, SM rats according to diet which their lactating mothers were fed from the begining of the experiment. The relative percentage of P/M/S fatty acids in brain PLs in all experimental groups converged to a very similar value at 9 wks of age, indicating the existence of a control mechanism for the degree of fatty acids, unsaturation. The $\omega$3/$\omega$6 fatty acid ratios of brain PLs converged to about 1.0 in MM & SM groups and to 0.7 in SS & MS groups, suggesting also the existence of some balance between $\omega$3 and $\omega$6 fatty acids in developing rat brain. The concentrations of $\omega$3 fatty acids, especially DHA, in the SM group were increased and became similar to those in MM group at 9 wks of age. The increase in DHA of brain PLs was counterbalanced b)r a decrease in 22 5$\omega$6. Therefore, the ratios of 22 : 6$\omega$6/22 : 5$\omega$6 were higher in both MM & SM groups than those of SS & MS groups at 9 wak of age. Although dietary $\omega$3 and $\omega$6 fatty acids affected 22 : 6$\omega$S and 22 : 5$\omega$6 contained in rat brain PLs reciprocally, the relative percentage of AA did not appear to be significantly influenced by the diet in all groups at 9 wks of age, suggesting that a mechanism for the maintenance of a certain level of AA in brain PLs exists. In conclusion, the $\omega$3/$\omega$6 fatty acid and 22 : 6$\omega$3/22 : 5$\omega$6 ratios, but not P/M/S ratio, of rat brain PLs were affected by the postnatal dietary changes. Futher studies are required to clarify the mechanism(S) of ensuring a certain level of DHA and of maintaining a similar level of AA in rat brain PLs after. weaning(9 wk) regardless of prenatal and postnatal dietary changes. (Korean J Nutrition 31(5) : 897-905, 1998)