• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.247-255
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• 2016

Non-point pollutants from surface runoff during rainfall exert adverse effects on urban river water quality management. In particular, the first flush effect during the initial phase of rainfall can deliver significant amounts of pollutant loads to surface waters with extremely high concentrations. In this study, a sustainable first flush effect management system was developed by using settling and filtration that require no additional power or chemicals. A pilot scale experiment has shown that the removal of total suspended solid (TSS), total nitrogen (TN) and total phosphorus (TP) are in ranges of 84 - 95%, 31 - 46%, and 42 - 86%, respectively. An Integrated Stormwater Runoff Management System (ISTORMS) was also developed to efficiently manage the developed system by linking weather forecast, flow rate and water quality modeling of surface runoff and automatic monitoring systems in fields and in the system. This study can provide effective solutions for the management of urban river in terms of both quantity and quality.

• Journal of the Korean Society for Nondestructive Testing
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• v.14 no.4
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• pp.237-243
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• 1995

We have studied methods of detecting attenuation of solid materials such as silicon wafer and piezoelectric $LiTaO_3$ by means of optical probing techniques. We have performed measurements of surface acoustic waves(SAW) generated from 90 degree wedge type transducer and also from inter-digital transducers(IDT). SAW of 20.0 MHz was generated on a silicon wafer from the 90 degree wedge type transducer and those of 20.8 and 14.5 MHz are generated on a $LiTaO_3$ from the IDT. Then any surface-corrugation resulted from the above SAW was investigated by He-Ne laser beams. We projected laser beams, which were modulated by an optical chopper, on the SAW of the same frequency and then measured the scattered beam by the lock-in amplifier. We modulated and synchronized both SAW and the incident laser beam as well as the phase sensitive detector(PSD) to the same frequency in order to simplify our measurement system. We obtained the attenuation coefficients of SAW to be $0.62{\sim}0.75dB/mm$(from IDT1, 20.8 MHz), and $0.60{\sim}0.72dB/mm$(from IDT2, 14.5 MHz), $0.83{\sim}1.28dB/mm$(from the wedge type), respectively.

• Applied Chemistry for Engineering
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• v.17 no.5
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• pp.451-457
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• 2006

We synthesized phase pure CrN having surface areas up to $47m^2/g$ starting from $CrCl_{3}$ with $NH_{3}$. Thermal Gravimetric Analysis coupled with X-ray diffraction was carried out to identify solid state transition temperatures and the phase after each transition. In addition, the BET surface areas, pore size distributions, and crystalline diameters for the synthesized materials were analyzed. Space velocity influenced a little to the surface areas of the prepared materials, while heating rate did not. We believe it is due to the fast removal of reaction by-products from the system. Temperature programmed reduction results revealed that the CrN was hardly passivated by 1% $O_{2}$. Molecular nitrogen was detected from CrN at 700 and $950^{\circ}C$, which may be from lattice nitrogen. In temperature programmed oxidation with heating rate of 10 K/min in flowing air, oxidation started at or higher than $300^{\circ}C$ and resulting $Cr_{2}O_{3}$ phase was observed with XRD at around $800^{\circ}C$. However the oxidation was not completed even at $900^{\circ}C$. CrN catalysts were highly active for n-butane dehydrogenation reaction. Their activity is even higher than that of a commercial $Pt-Sn/Al_{2}O_{3}$ dehydrogenation catalyst in terms of volumetric reaction rate. However, CrN was not active in pyridine hydrodenitrogenation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.1
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• pp.66-71
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• 2008

This study was conducted to predict optimum leaching conditions for functional components of black tea. Two variables were used to determine the optimum leaching temperature and leaching time with a five-level central composite design and response surface methodology. Soluble solid, reducing sugar, total phenolics, and total flavonoid contents increased as leaching temperature and time increased. The ranges of maximum leaching conditions for these components were $78.28{\sim}87.08^{\circ}C$ and $3.97{\sim}4.27min$. Vitamin C level was maximal at $61.29^{\circ}C$ and 2.68 min. Electron donating ability showed the highest values at $68.30^{\circ}C$ and 0.54 min. Based upon the superimposed results, it was predicted that the optimal ranges of leaching conditions for some functional components from black tea were $63{\sim}79^{\circ}C$ for $1.5{\sim}2.1$ min.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.5
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• pp.738-746
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• 2011

We manufactured rice-whole soybean curd by a microbial transglutaminase (MTGase) with a mixture of hydrolyzed rice and micronized whole soybean powder (MWSP) and analyzed its rheological properties, including texture, viscoelasticity, protein cross-linking, and surface structure. A 40% rice suspension digested with a Termamyl enzyme at $85^{\circ}C$ for 20 min showed a 9.0% reducing sugar and a consistency of $1.27\;Pa{\cdot}s^n$, resulting in a great reduction in consistency. A MWSP suspension with 22% solid content was transformed into a typical tofu texture. MWSP curd fortified with 7.5% rice showed enhanced texture properties, with a hardness of 639.6 dyne/$cm^2$, and a springiness of 0.96. In a MWSP suspension (18~22% w/v) treated with 5% MTGase, viscoelasticity increased dependently with MWSP concentration, and a 22% MWSP indicated a G' value of 5.1 Pa and a G'' value of 9.0 Pa. Furthermore, soybean proteins present in the 22% MWSP curd largely disappeared or formed polymers with a high molecular weight by MTGase reaction within 30 min. MWSP (22%) fortified with 7.5% rice showed similar polymerization patterns on SDS-PAGE. The surface structure of the rice-MWSP curds was more dense and homogeneous network due to the addition of hydrolyzed rice. However, the surface structure of all rice-MWSP curds became rough and showed a non-homogeneous network after cold storage.

• Spatial Information Research
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• v.17 no.4
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• pp.469-481
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• 2009

Due to the increasing demands on the efficient use of land and the fast growth of construction technologies, human living space is expanded from on the surface to above and under the surface. By recognizing that the current cadastre system based on 2D was not appropriate to reflect the trend, the researchers are interested in a 3D cadastre. This paper proposed the 3D cadastre data model that is appropriate to protect ownership effectively in Korea. The 3D cadastre data model consists of a 3D cadastre feature model and a 3D cadastre geometry model, and the data are produced by a 3D cadastre data structure. A 3D cadastre feature model is based on 3D rights and features derived from case studies. A 3D cadastre geometry model based on ISO19107 Spatial Schema is modified to be good for 3D cadastre in Korea. A 3D cadastre data structure consists of point, line, polygon and solid primitives. This study finally purposes 1) serving and managing land information effectively, 2) creating rights and displaying ranges about infrastructures above and under surface, 3) serving ubiquitous-based geoinformation, 4) adapting ubiquitous-based GIS to urban development, and 5) regulating relationships between rights of land and registration and management systems.

• Journal of Korean Society of Forest Science
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• v.106 no.1
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• pp.26-32
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• 2017

We studied the effects of dip treatments of natural extracts (Camellia sinensis, Angelica gigas, Astragalus membranaceus, Glycyrrhiza uralensis: 1% extract) on the quality of peeled 'Daebo' chestnut. After dipping treatment peeled chestnuts were vacuum packaged with $75{\mu}m$ PE+Nylon 7-layer film then stored in $4^{\circ}C$ incubator for 35days. The quality changes including the surface color and off-odor were evaluated for storage days. The natural extracts dipping treatment on peeled chestnut was effective on skin browning inhibition. Especially, Astragalus membranaceus and Glycyrrhiza uralensis extract treatments was significantly effective in reducing surface browning. The color change (${\Delta}E$) of peeled chestnut was the highest (5.6) in control, whereas that was the lowest (3.4) under Astragalus membranaceus extract treatment at 35 storage day. The natural exteacts treatments had no effect on the weight, the mositure loss rate, the firmness and the soluble solid contencts of peeled chestnuts during storage after treatment. The decaying rate of peeled chestnut was 9.0% in control, 9.0% in Camellia sinensis extract treatment, 9.0% in Angelica gigas extract treatment, 21.0% in Astragalus membranaceus extract treatment, and 7.0% Glycyrrhiza uralensis extract treatment at 35 storage day. Sensory evaluation revealed significant differences in off-odor and color attributes. After all, the score of overall sensory evaluation was the lowest in Astragalus membranaceus extract treatment and the highest in Glycyrrhiza uralensis extract treatment. As the results, the natural extract treatments, especially with vacuum packing after Glycyrrhiza uralensis extract treatment, extended the shelf-life of the peeled chestnut by inhibiting the surface browning.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.3
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• pp.69-75
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• 2016

This study investigated the effect of heat treatment conditions not only on the Cr surface crack propagation behaviors but also on the Ni/Cr interfacial reaction characteristics in electroless Ni/electroplated Cr double coating layers on Cu substrate. Clear band layer of Ni-Cr solid solutions were developed at Ni/Cr interface after heat treatment at $750^{\circ}C$ for 6 h. Channeling cracks formed in Cr layer after 1 step heat treatment, that is, heat treatment after Ni/Cr plating, while little channeling cracks formed after 2 step heat treatment, that is, same heat treatments after Ni and Cr plating, respectively, due to residual stress relaxation due to crystallization of Ni layer before Cr plating.

• Journal of the Korean Society of Safety
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• v.26 no.4
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• pp.47-58
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• 2011

Halogen free intumescent flame retardants(IFRS), such as the mixture of melamine phosphate(MP) and char forming agents(pentaerythritol(PER), di-pentaerythritol(DiPER), tris(2-hydroxyethyl) isocyanurate(THEIC)), were prepared and characterized. Polypropylene(PP)/$IFR_S$ composites were also prepared in the presence of ethylene diamine phosphate(EDAP) as a synergist and used into flame retardant PP powder coatings. Thermoplastic PP powder coatings at 20 wt% flame retardant loading were manufactured by extruded and then mechanical cryogenic crushed to bring them in fine powder form. These intumescent flame retardant powder coatings($IFRPC_S$) were applied on mild steel surface for the purpose of protection and decorative. It is a process in which a $IFRPC_S$ particles coming in contact with the preheated mild steel surface melt and form a thin coating layer. The obtained MP flame retardant was analyzed by utilizing FTIR, solid-state $^{31}P$ NMR, ICP, EA and PSA. The mechanical properties as tensile strength, melt flow index(MFI) and the thermal property as TGA/DTA and the fire safety characteristics as limiting oxygen index(LOI), UL94 test, SEM were used to investigate the effect of $IFRPC_S$. The experimental results show that the presence of $IFR_S$ considerably enhanced the fire retardant performances as evidenced by the increase of LOI values 17.3 vol% and 32.6 vol% for original PP and $IFRPC_S$-3(PP/MP-DiPER/EDAP), respectively, and a reduction in total flaming combustion time(under 15 sec) in UL94 test of $IFRPC_S$. The prepared $IFRPC_S$-3 have good comprehensive properties with fire retardancy 3.2 mm UL94 V-0 level, LOI value 32.6%, tensile strength $247.3kg/cm^2$, surface roughness Ra $0.78{\mu}m$, showing a better application prospect. Through $IFRPC_S$-2(PP/MP-PER/EDAP) and $IFRPC_S$-3 a better flame retardancy than that of the $IFRPC_S$-1(PP/MP/EDAP) was investigated which was responsible for the formed more dense and compact char layer, improved synergy effect of MP and PER/DiPER.

• Food Science and Preservation
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• v.19 no.6
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• pp.841-848
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• 2012

Response surface methodology was applied to the processing conditions to investigate the physicochemical properties of ramie porridge. In the processing conditions based on the central composite design with the addition of ramie leaf powder (0-4 g) and water (700-1100 g), the coefficients of determination (R2) of the models were above 0.9141 for the physicochemical properties, above 0.7627 for the Hunter color parameters, and above 0.8975 for the rheological properties. The soluble solid content, viscosity, and gumminess of the sample decreased significantly with an increase in the water added, whereas the spreadability and adhesiveness increased significantly. The Hunter color L value of the sample decreased significantly with an increase in the amount of ramie leaf powder added, whereas the Hunter b value increased significantly. The estimated maximum viscosity of the ramie porridge was shown to be 24,643 cp when 1.90 g ramie leaf powder and 700.24 g water were added; the estimated maximum lightness of the ramie porridge was shown to be 59.11 when 0.02 g ramie leaf powder and 869.30 g water were added; and the estimated maximum gumminess of the ramie porridge was shown to be 21.46 g when 2.12 g ramie leaf powder and 700.35 g water were added.