• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.185-192
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• 2010

The objective of this study was to investigate the effectiveness of stabilization for army firing range soil highly contaminated with Pb (total Pb: 29,000 mg/kg) using calcined waste oyster shells. The calcination was conducted to activate quicklime from calcite. In order to evaluate the effectiveness of calcination, both natural oyster shells (NOS) and calcined oyster shells (COS) were applied to the Pb contaminated soil. Stabilization was conducted by mixing the contaminated soil with oyster shell media at 5-20 wt% and cured for 28 days. Following 28 days of curing, Pb leachability was measured based on the Korean Standard Test method (0.1 N HCl extraction). The treatment results showed that the COS treatment outperformed the NOS treatment. All of the NOS treatments failed to meet the Korean warning standard of 100 mg/kg. However, the Pb concentrations were significantly reduced to 47 mg/kg and 3 mg/kg upon 15 wt% and 20 wt% COS treatments, respectively which passed the Korean warning standard. Moreover, -#20 mesh materials were more effective than the -#10 mesh materials in effectively reducing Pb leachability. The scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX) results indicated that Pb immobilization was strongly linked to Al and Si.

• Spatial Information Research
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• v.23 no.5
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• pp.9-19
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• 2015

The popularity of smart devices and Location Based Services (LBSes) is increasing in part due to users demand for personalized information associated with their location. These services provide intuitive and realistic information by adopting Augmented Reality (AR) technology. This technology utilizes various sensors embedded in the mobile devices. However, these services have inherent problems due to the devices small screen size and the complexity of the real world environment; overlapping content on a small screen and placing icons without considering the user's possible movement. In order to solve these problems, this paper proposes a Mobile Augmented Reality Model with the application of Street Data. The model consists of two layers: "Real Space" and "Information Space". In the model, a user creates a query by scanning the nearby street with a camera in real space and searches accessible content along the street through the use of the information space. Furthermore, the results are placed on both sides of the street to solve the issue of Overlapping. Also, the proposed model is implemented for region "Aenigol", and the efficiency and usefulness of the model are verified.

• Journal of Periodontal and Implant Science
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• v.36 no.4
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• pp.797-808
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• 2006

Objective : The purpose of this study was to evaluate the physicochemical properties and cytocompatibility of microporous, spherical biphasic calcium phosphate(BCP) ceramics with a 60/40 $hydroxyapatite/{\beta}$ -tricalcium phosphate weight ratio for application as a bone graft substitute. Materials and Methods : Microporous, spherical BCP granules(MGSB) were prepared and their basic characteristics were compared with commercially available BCP(MBCP; Biomatlante, France) and deproteinized bovine bone mineral(Bio-Oss; GBistlich-Pharma, Switzerland, BBP; Oscotec. Korea), Their physicochemical properties were evaluated by scanning electron microscopy, X-ray diffractometry, Fourier-transform infrared spectroscopy, inductively coupled plasma atomic emission spectrometer, and Brunauer-Emmett-Teller method. Cell viability and proliferation of MC3T3-El cells on different graft materials were evaluated. Results : MGSB granules showed a chemical composition and crystallinity similar with those in MBCP, they showed surface structure characteristic of three dimensionally, well-interconnected micropores. The results of MTT assay showed increases in cell viablity with increasing incubation times. At 4d of incubation, MGSB, MBCP and BBP showed similar values in optical density, but Bio-Oss exhibited significantly lower optical density compared to other bone substitutes(p <0,05). MGSB showed significantly greater cell number compared to other bone substitutes at 3, 5, and 7d of incubation(p <0,05), which were similar with those in polystyrene culture plates. Conclusion: These results indicated the suitable physicochemical properties of MGSB granules for application as an effective bone graft substitute. which provided compatible environment for osteoblast cell growth. However, further detailed studies are needed to confirm its biological effects on bone formation in vivo.

• Journal of the Korean Ceramic Society
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• v.50 no.6
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• pp.353-358
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• 2013

The hot corrosion behavior of plasma sprayed 4 mol% $Y_2O_3-ZrO_2$ (YSZ) thermal barrier coatings (TBCs) with volcanic ash is investigated. Volcanic ash that deposited on the TBCs in gas-turbine engines can attack the surface of TBCs itself as a form of corrosive melt. YSZ coating specimens with a thickness of 430-440 ${\mu}m$ are prepared using a plasma spray method. These specimens are subjected to hot corrosion environment at $1200^{\circ}C$ with five different duration time, from 10 mins to 100 h in the presence of corrosive melt from volcanic ash. The microstructure, composition, and phase analysis are performed using Field emission scanning electron microscopy, including Energy dispersive spectroscopy and X-ray diffraction. After the heat treatment, hematite ($Fe_2O_3-TiO_2$) and monoclinic YSZ phases are found in TBCs. Furthermore the interface area between the molten volcanic ash layers and YSZ coatings becomes porous with increases in the heat treatment time as the YSZ coatings dissolved into molten volcanic ash. The maximum thickness of this a porous reaction zone is 25 ${\mu}m$ after 100 h of heat treatment.

• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.119-129
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• 2006

The antennal receptors of the adult male and female of the American leafminer, Liriomyza trifolii (Diptera: Agromyzidae) was studied using the scanning electron microscopy. This antennal receptors were developed to accept the chemical or mechanical signal in the environment. The antennae of L. trifolii is 317.52 $\mu$m long and composed of the scape, pedicel, funicle, arista. Antennae located between compounds eye on the middle in the head. The result of SEM observation, four types of receptors were characterized and grouped into morphological classes: Trichoid, Basiconic, Coeloconic, Chetiform sensilla. Trichoid sensilla are located on the all segment. As a rule, female is more than male. This sensilla are long and slender hair with straight or slightly curved, and taper to a sharp point apically. Basiconic sensilla are observed only on the funicle. The number of basiconic sensilla in male and female are almost same in both sexes. This sensilla are long and thick hair with stright or slightly curved, and taper to a blunt point apically. Coeloconic sensilla are observed only on the funicle. This sensilla were showed a finger-like projections the peg apex. The number of basiconic sensilla in male and female are almost same in both sexes. Chetifarm sensilla are located on the all segment. This sensilla are needle-like, tapering sharply. Pedicel are more than scape. The number of Chetiform sensilla in male and female are almost same in both sexes.

• The Journal of the Petrological Society of Korea
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• v.24 no.2
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• pp.77-90
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• 2015

The fission track registration techniques for accurate determinations of uranium in solid- and liquid-state geological materials were recommended and their applicability were examined. The determination of uranium can be achieved by optical counting of neutron-induced fission tracks of $^{235}U$ registered on solid-state track detectors under high magnification. In a dry registration method using powdered pellets of rocks (e.g., granite and coal) showing good uranium-affinity, it was not easy to decide an overall mean concentration over the total sample owing to track-clusters caused by frequent presence of uranium-bearing minerals. Separate scanning for homogeneous and track-clustered parts may be an alternative choice. Assuring the homogeneity over the whole sample, high reproducibilities were confirmed both from duplicate detections using mica and Lexan polycarbonate detectors and from multiple measurements at different thermal neutron fluences. The wet registration method using sealed quartz tubes is recommended to overcome the common heterogeneity in uranium concentrations of $10^1ppm$ and more. Adopting the wet registration, the uranium homogeneity was recovered below the $10^0ppm$ level and the lower detection limit was proved to reach without difficulty the $10^2ppb$ (i.e. $ng\;g^{-1}$) level.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.5
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• pp.181-187
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• 2016

In this study, new composition of orange color pigment was developed by replacing formerly used lead and chromium with environment-friendly elements. $TiO_2-SnO-ZnO$ composite was synthesized using the solid state reaction under the reducing atmosphere with the LPG and air mixture gas. The synthesized pigments were characterized by spectrophotometer, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). The colorimetric analysis of pigments exhibited color values ranging from yellow to orange-red. Five different crystalline phases were formed after the heat treatment for 4 and 6 hours. The color of pigments was strongly influenced by the crystalline structure of $SnO_2$, having either cubic or tetragonal structure. The oxidation state study of elements revealed that the color of pigment is getting close to rYR with the increase of $Sn^{4+}$ ratio.

• Journal of Adhesion and Interface
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• v.13 no.1
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• pp.31-37
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• 2012

In this study, we investigated the curing properties of UV-LED curable color coating. Specially, the effects of UV-LED wavelength (365, 395, and 405 nm), inert gas, the concentration of photosensitizer, and dual curing on the curing behavior of UV-LED coating systems were studied. The photopolymerization behaviors and the unreacted acrylate groups at Film-air (FA) interface and Film-substrate (FS) interface were investigated by photo differential scanning calorimetry (Photo-DSC) and Fourier-transform infrared spectroscopy with attenuated total reflection (FT-IR/ATR), respectively. Photo-DSC results showed that the heat flow and the ultimate conversion for coating system cured by 405 nm UV-LED were higher than the corresponding values for coating systems cured by 395 and 365 nm UV-LED. FT-IR/ATR results showed that the UV-LED curing systems improved interior and through curing of the coating film, but significantly are affected by oxygen inhibition at FA-interface. The inert environment such as nitrogen purging and the dual curing improved the surface and interior curing of the coating films.

• Korean Journal of Plant Resources
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• v.18 no.1
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• pp.123-130
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• 2005

High salt concentrations in the ginseng nursery soil environment of Korea is one of important reducing factors for the stable production of quality ginseng. These studies were accomplished for check the response on germination of ginseng seed, somatic embryogenesis of zygotic embryo, and biosynthesis of ginsenoside from ginseng hairy root against NaCl. Ratio of germination was at the $3\%\;and\;84.5\%$ on the basic media with 0.1M and free of NaCl repectedly, but $0\%$ at the upper of 0.2M NaCl. Somatic embryogenesis from zygotic embryo were the highest when immatured embryo was cultured on free of NaCl concentration, and which was intend to decrease at treatment of NaCl. However, in case of using the matured embryo, treatment of 0.05M NaCl resulted in better embryogenesis than NaCl free media. Red pigment was synthesized from ginseng hairy root cultured on the medium with various NaCl concentration(from 0.04 to 0.08M) and its pigment was analyzed as spectrum of anthocyane by spectrophoto- meter scanning. This cell line biosynthesized lots of crude saponin and total ginsenoside than other cell lines, also had 2 times of panaxadiol than panaxatriol.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.49-57
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• 2014

Orb-web spiders can be considered as an effective bio-indicative animal to monitor the ecological air pollution of certain habitat since they have limited shifting ability during their life spans. In this study we revealed the fine structural characteristics of booklung in the orb-web spider Nephila clavata, and its bio-indicative significance in the monitoring environmental asbestos exposure. The high resolution scanning electron microscopy results suggest that the cuticular spikes near the atrium could be act as an effective filtering structure for dust materials. Furthermore, inner cuticular spikes which protruded across the air sacs, have the functions not only sustaining appropriate respiratory volume of each air sac but also help to enhance respiratory capacity by maximizing the gross surface area for gas exchange. Interestingly, in spite of short exposure, the asbestose fibrils were effectively captured on the surface of the atrial cuticular spikes. Furthermore, histologic damages were observed due to penetration of asbestos fibrils through air sacs and fixed on the hemolymph space. In addition, although accumulated mass of hemocytes were observed near the fibrils, there were no asbestos bodies or coagulated hemocytes were found on the surface of the fibrils, This could be mainly due to the short exposure period towards asbestos. Briefly, these results indicate the spider's booklung could be valuable tool in the detection ecological air pollutants.