• Journal of Korean Society of Environmental Engineers
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• v.28 no.8
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• pp.866-871
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• 2006

The nutrient recovery in phosphate crystallization process was investigated by using laboratory scale uptlow reactors, adopting sequencing batch type configuration. The industrial waste lime was used as potential cation source with magnesium salt($MgCl_2$) as control. The research was focused on its successful application in a novel integrated sludge treatment process, which is comprised of a high performance fermenter followed by a crystallization reactor. In the struvite precipitation test using synthetic wastewater first, which has the similar characteristics with the real fermentation effluent, the considerable nutrient removal(about 60%) in both ammonia and phosphate was observed within $0.5{\sim}1$ hr of retention time. The results also revealed that a minor amount(<5%) of ammonia stripping naturally occurred due to the alkaline(pH 9) characteristic in feed substrate. Stripping of $CO_2$ by air did not increase the struvite precipitation rate but it led to increased ammonia removal. In the second experiment using the fermentation effluent, the optimal dosage of magnesium salt for struvite precipitation was 0.86 g Mg $g^{-1}$ P, similar to the mass ratio of the struvite. The optimal dosage of waste lime was 0.3 g $L^{-1}$, resulting in 80% of $NH_4-N$ and 41% of $PO_4-P$ removal, at about 3 hrs of retention time. In the microscopic analysis, amorphous crystals were mainly observed in the settled solids with waste lime but prism-like crystals were observed with magnesium salt. Based on mass balance analysis for an integrated sludge treatment process(fermenter followed by crystallization reactor) for full-scale application(treatment capacity Q=158,880 $m^3\;d^{-1}$), nutrient recycle loading from the crystallization reactor effluent to the main liquid stream would be significantly reduced(0.13 g N and 0.19 g P per $m^3$ of wastewater, respectively). The results of the experiment reveal therefore that the reuse of waste lime, already an industrial waste, in a nutrient recovery system has various advantages such as higher economical benefits and sustainable treatment of the industrial waste.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.16-27
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• 2010

Purpose: The aim of this experimental study is to observe the effect of platelet-rich plasma (PRP) on early bone regeneration of rats both in normal condition and in osteoporosis induced by ovariectomy. Material and methods: Total 40 Sprague-Dawley female rats were divided into 4 groups. A 8-mm-diameter calvarial critical-sized defect (CSD) was made by drilling with trephine at the center of calvaria in cranium of every rat. Every CSD was augmented with an osteoconductive synthetic alloplastic substitute ($MBCP^{TM}$) and PRP as follows. Group A; 10 non-ovariectomized rats grafted with only $MBCP^{TM}$. Group B; 10 non-ovariectomized rats grafted with $MBCP^{TM}$ and PRP. Group C; 10 ovariectomized rats grafted with only $MBCP^{TM}$. Group D; 10 ovariectomized rats grafted with $MBCP^{TM}$ and PRP. At 4 weeks after graft, every rat was sacrificed. And histomorphometric analysis was performed by measuring calcified area of new bone formation within the CSD. Results: Comparing four groups, results were obtained as follows. 1. In non-ovariectomized groups, PRP showed a positive effect somewhat but not significant (P > .05). 2. In ovariectomized groups, PRP showed a positive effect significantly (P < .05). 3. In PRP untreated groups, ovariectomy diminished bone regeneration significantly (P < .05). 4. In PRP treated groups, ovariectomy diminished bone regeneration somewhat but not significant (P > .05). Conclusion: Within the limitation of this study, it can be concluded that PRP in combination with an osteoconductive synthetic alloplastic substitute has an effect on bone regeneration more significantly in ovariectomized osteoporotic rats than in normal rats.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.98-103
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• 2001

In order to understand the characteristics of leachate at the Seokdae municipal waste landfill in the Pusan city, the correlation between leachate pollution loading and volume of gas production. concentration of gas and subsidence of ground, the characteristical methos, geochemical analyses and laboratory column tests using samples of gases, leachate and surface soil of Seokdae waste landfill area. Through the analysis of water balance, leachate flow rate and pollution loading were estimated. Geistatistical analysis of four gas components ( $O_2$, C $H_4$, $H_2$S and CO) shows the possibility of ground subsidence around the group of a site with high concentration of gas. From geochemical analyses of leachate, EC and Total-Alkalinity of ground subsidence around the group of a site with high concentration of gas. From geochemical analysis of leachate, Ec and Total-Alkalinity were increased, and Cl, Cr, Mn, Cu, Zn, Cd and Pb were decreassed comparing to the part, and the type of water quality was Na-HC $O_3$ in trilinear diagram. It shows that biodecomposition of municipal wastes continues actively. From the analysis of water balance, the total leachate flow rate is about 465.11㎥/day and pure pollution loading of Cl, Mn and Fe are estimated to 223.8kg/day, 0.2kg/day, 0.3kg/day, respectively. The laboratory column test of residual soil and landfill soil shows 0.206cm and 0.019cm for linear velocity(equation omitted), 0.234 $\textrm{cm}^2$/min and 0.018$\textrm{cm}^2$/min for diffusion coefficient ( $D_{ι}$), and 1.136cm and 0.095cm longitudinal dispersion index ($\alpha$$_{ι}$), respective]y. It demonstrates that the delay time of contamination for residual soil is shorter than that of landfill soil.

• Biomolecules & Therapeutics
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• v.24 no.6
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• pp.595-603
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• 2016

(E)-3-Phenyl-1-(2-pyrrolyl)-2-propenone (PPP) is a pyrrole derivative of chalcone, in which the B-ring of chalcone linked to ${\beta}$-carbon is replaced by pyrrole group. While pyrrole has been studied for possible Src inhibition activity, chalcone, especially the substituents on the B-ring, has shown pharmaceutical, anti-inflammatory, and anti-oxidant properties via inhibition of NF-${\kappa}B$ activity. Our study is aimed to investigate whether this novel synthetic compound retains or enhances the pharmaceutically beneficial activities from the both structures. For this purpose, inflammatory responses of lipopolysaccharide (LPS)-treated RAW264.7 cells were analyzed. Nitric oxide (NO) production, inducible NO synthase (iNOS) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) mRNA expression, and the intracellular inflammatory signaling cascade were measured. Interestingly, PPP strongly inhibited NO release in a dose-dependent manner. To further investigate this anti-inflammatory activity, we identified molecular pathways by immunoblot analyses of nuclear fractions and whole cell lysates prepared from LPS-stimulated RAW264.7 cells with or without PPP pretreatment. The nuclear levels of p50, c-Jun, and c-Fos were significantly inhibited when cells were exposed to PPP. Moreover, according to the luciferase reporter gene assay after cotransfection with either TRIF or MyD88 in HEK293 cells, NF-${\kappa}B$-mediated luciferase activity dose-dependently diminished. Additionally, it was confirmed that PPP dampens the upstream signaling cascade of NF-${\kappa}B$ and AP-1 activation. Thus, PPP inhibited Syk, Src, and TAK1 activities induced by LPS or induced by overexpression of these genes. Therefore, our results suggest that PPP displays anti-inflammatory activity via inhibition of Syk, Src, and TAK1 activity, which may be developed as a novel anti-inflammatory drug.

• International Journal of Highway Engineering
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• v.14 no.1
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• pp.95-102
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• 2012

This study has been conducted to characterize the relations between the accident rate and the overlap section elements where the horizontal alignment and vertical alignment are overlapped. The researches were performed on Horizontal curve sections of 4-lane highways with 100km/h of design speed and speed limit. Korea Highway Corporation's Geographic Figurative Information System was adopted for geometric organization and Highway Traffic Accident Statistics was used. The results reveal that sections made of a single slope without vertical curve has greater accident rate than those with vertical curve, and that sections with 1 vertical curve are higher in the accident rate than those with over 2 vertical curve. For the sections with 1 vertical curve, SAG sections are higher than CREST sections and for the previous straight section of horizontal curve are higher than curved ones. In particular, when the road surface is wet, the accident rate is closely related with SAG vertical curves or leftward horizontal curved sections. This study will have meanings that it proposes the importance of design of road alignment by taking consideration of 3D synthetic alignment conditions for improvement of the road safety.

• Journal of Korean Society of Forest Science
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• v.12 no.1
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• pp.23-29
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• 1971

In order to see a possible strengthening of much injection of synthetic resin into timber by way of electric osmosis, Authors examined the change of the bending strength of the sample timber piece after being injected. 1. Three kinds of sample tree species, Pinus rigida, Magnolia and Populus were used and the size of the sample timber pieces was $30mm{\times}30mm{\times}330mm$. 2. Each of the electric osmosis was made with 250V of D. C. voltage and $0.01A/cm^2$ of the current for 2 hours and the experimenter hardened the injected resin by putting the sample in an oven of $120^{\circ}{\pm}2^{\circ}C$ temperature for 24 hours. 3. The size of the test sample piece for bending strength measurement was $20mm{\times}20mm{\times}320mm$ and Amsler type universal timber test machine was used for the measurement. 4. The strength difference between treated and untreated samples was as follows. Pinus rigida high sig. Magnolia None Sig. Populus Sig.

• Journal of Life Science
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• v.29 no.3
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• pp.362-368
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• 2019

For the practical application and development of biopolymer flocculant Biopol32 produced by Pseudomonas sp. GP32, its flocculation effect on wastewater from food processing, slaughter houses, and the dyeing industry was investigated. In the food processing wastewater, Biopol32 led to a chemical oxygen demand (COD) reduction rate of 70% and a suspended solid (SS) removal rate of 49% at pH 6.0. In the slaughter house wastewater at pH 4.0, a COD reduction rate of 61% and SS removal rate of 91% were observed, and in the dyeing wastewater, the rates were 72% and 92%, respectively, at pH 5.0. The size of floc formed during the flocculation process was 10 mm at a final concentration of 20 ppm, and the dehydration efficiency was 62%. In both the bioflocculant Biopol32 group and a PAA synthetic flocculant group, optimal flocculant concentration that yielded the best overall dehydration efficiency was 20 ppm, and, at this concentration, the shortest filtration time to reach the natural critical moisture content of 78.1% was attained.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.503-514
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• 2021

Rice production with adequate level of area is important for decision making of rice supply and demand policy. It is essential to grasp rice cultivation areas in advance for estimating rice production of the year. This study was carried out to classify paddy rice cultivation in Gimje-si using sentinel-1 SAR (synthetic aperture radar) and UAV imagery in early July. Time-series Sentinel-1A and 1B images acquired from early May to early July were processed to convert into sigma naught (dB) images using SNAP (SeNtinel application platform, Version 8.0) toolbox provided by European Space Agency. Farm map and parcel map, which are spatial data of vector polygon, were used to stratify paddy field population for classifying rice paddy cultivation. To distinguish paddy rice from other crops grown in the paddy fields, we used the decision tree method using threshold levels and random forest model. Random forest model, trained by mainly rice cultivation area and rice and soybean cultivation area in UAV image area, showed the best performance as overall accuracy 89.9%, Kappa coefficient 0.774. Through this, we were able to confirm the possibility of early estimation of rice cultivation area in Gimje-si using UAV image.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.1
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• pp.1-12
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• 2021

Here, we introduce a laser-induced graphene synthesis technology and its applications for the electric/electronic device manufacturing process. Recently, the micro/nanopatterning technique of graphene has received great attention for the utilization of these new graphene structures, which shows progress developments at present with a variety of uses in electronic devices. Some examples of practical applications suggested a great potential for the tunable graphene synthetic manners through the control of the laser set-up, such as a selection of the wavelength, power adjustment, and optical techniques. This emerging technology has expandability to electric/electronic devices combined together with existed micro-packaging technology and can be integrated with the new processing steps to be applied for the operation in the fields of biosensors, supercapacitors, electrochemical sensors, etc. We believe that the laser-induced graphene technology introduced in this paper can be easily applied to portable small electronic devices and wearable electronics in the near future.

• Korean Journal of Remote Sensing
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• v.35 no.6_3
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• pp.1235-1249
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• 2019

Kilauea Volcano is one of the most active volcano in the world. In this study, we used the ALOS-2 PALSAR-2 satellite imagery to measure the surface deformation occurring near the summit of the Kilauea volcano from 2015 to 2017. In order to measure two-dimensional surface deformation, interferometric synthetic aperture radar (InSAR) and multiple aperture SAR interferometry (MAI) methods were performed using two interferometric pairs. To improve the precision of 2D measurement, we compared root-mean-squared deviation (RMSD) of the difference of measurement value as we change the effective antenna length and normalized squint value, which are factors that can affect the measurement performance of the MAI method. Through the compare, the values of the factors, which can measure deformation most precisely, were selected. After select optimal values of the factors, the RMSD values of the difference of the MAI measurement were decreased from 4.07 cm to 2.05 cm. In each interferograms, the maximum deformation in line-of-sight direction is -28.6 cm and -27.3 cm, respectively, and the maximum deformation in the along-track direction is 20.2 cm and 20.8 cm, in the opposite direction is -24.9 cm and -24.3 cm, respectively. After stacking the two interferograms, two-dimensional surface deformation mapping was performed, and a maximum surface deformation of approximately 30.4 cm was measured in the northwest direction. In addition, large deformation of more than 20 cm were measured in all directions. The measurement results show that the risk of eruption activity is increasing in Kilauea Volcano. The measurements of the surface deformation of Kilauea volcano from 2015 to 2017 are expected to be helpful for the study of the eruption activity of Kilauea volcano in the future.