• The Journal of Engineering Geology
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• v.7 no.2
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• pp.127-137
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• 1997

Bentonites that are used currently for the civil engineering puppose in our country were investigated to reveal their physico-chemical properties such as viscosity, swelling volume, cation exchange capacity (CEC) and chemical composition, and to compare the content of their constituting minerals and their characteristics using the X-ray diffraction and infrared spectrum methods. The content of montmorillonite in the hentonites ranges from 50 to 79%. As the content of montmorillonite in the hentonites increases, the viscosity, swelling volume, water content, methylene blue adsorption, CEC, and the amount of clay-size particles tend to increase in general. Because these properties also show good correlation within them, the results can he used to infer the characteristics of hentonites indirectly. However, a few samples do not show this correlation hetween the properties. This is probably due to the characteristics of constituting minerals of raw ore and manufacturing process. A saraple with lowest content of rnontrnofiiionite was shown to be inferior in the physico-chemical properties that are needed for the civil engineering-purpose bentonites.

• Journal of the Korean Applied Science and Technology
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• v.35 no.2
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• pp.502-508
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• 2018

The acrylate copolymer having good coating, water-repellent and adhesion properties was designed and prepared. We prepared copolymers with high yield of > 95% using methyl methacrylate(MMA), 2,2,2-trifluoroethyl acrylate (FMA) and 2-hydroxyethyl methacrylate monomers(HEMA) by either bulk or emulsion polymerization techniques. The $^1H-NMR$ spectrum was used to identify chemical structure and DSC and DMA analysis were conducted. As a result, the glass transition temperature decreased by $3^{\circ}C$ as FMA content increased from 5% to 10%, and decreased by $2{\sim}8^{\circ}C$ when HEMA content increased from 5 % to 10 %. The physical properties were measured using Instron and TGA. As FMA or HEMA content increased by 10%, tensile strength decreased from 29 MPa to 22 MPa and Td decreased from $200^{\circ}C$ to $180^{\circ}C$ in both bulk and emulsion. The contact angle relatively decreased as hydrophilic HEMA content increased.

• Restorative Dentistry and Endodontics
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• v.43 no.1
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• pp.11.1-11.10
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• 2018

Objectives: This study aimed to introduce the use of laser-induced breakdown spectroscopy (LIBS) for evaluation of the mineral content of root canal dentin, and to assess whether a correlation exists between LIBS and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) methods by comparing the effects of irrigation solutions on the mineral content change of root canal dentin. Materials and Methods: Forty teeth with a single root canal were decoronated and longitudinally sectioned to expose the canals. The root halves were divided into 4 groups (n = 10) according to the solution applied: group NaOCl, 5.25% sodium hypochlorite (NaOCl) for 1 hour; group EDTA, 17% ethylenediaminetetraacetic acid (EDTA) for 2 minutes; group NaOCl+EDTA, 5.25% NaOCl for 1 hour and 17% EDTA for 2 minutes; a control group. Each root half belonging to the same root was evaluated for mineral content with either LIBS or SEM/EDS methods. The data were analyzed statistically. Results: In groups NaOCl and NaOCl+EDTA, the calcium (Ca)/phosphorus (P) ratio decreased while the sodium (Na) level increased compared with the other groups (p < 0.05). The magnesium (Mg) level changes were not significant among the groups. A significant positive correlation was found between the results of LIBS and SEM/EDS analyses (r = 0.84, p < 0.001). Conclusions: Treatment with NaOCl for 1 hour altered the mineral content of dentin, while EDTA application for 2 minutes had no effect on the elemental composition. The LIBS method proved to be reliable while providing data for the elemental composition of root canal dentin.

• Journal of Conservation Science
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• v.37 no.4
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• pp.362-369
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• 2021

In museums, exhibition content focuses mostly on cultural heritage's historical values and functions, but doing so tends to limit visitors' interest and immersion. To counter this limitation, the study developed an experiential media art exhibition fusing bronze mirrors' traditional production technology and modern conservation science. First, for the exhibition system, scientific cultural heritage contents were projected on the three-dimensional (3D) printed bronze mirror through interactions between motion recognition digital information display (DID) and the projector. Then, a scenario of 17 missions in four stages (production process, corrosion mechanism, scientific analysis and diagnosis, and conservation treatment and restoration) was prepared according to the temporal spectrum. Additionally, various media art effects and interaction technologies were developed, so visitors could understand and become immersed in bronze mirrors' scientific content. A user test was evaluated through the living lab, reflecting generally high levels of satisfaction (90.2 points). Qualitative evaluation was generally positive, with comments such as "easy to understand and useful as the esoteric science exhibition was combined with media art" (16.7%), "wonderful and interesting" (11.7%), and "firsthand experience was good" (9.2%). By combining an esoteric science exhibition centered on principles and theories with visual media art and by developing an immersive directing method to provide high-level exhibition technology, the exhibition induced visitors' active participation. This exhibition's content can become an important platform for expanding universal museum exhibitions on archaeology, history, and art into conservation science.

• Journal of the Korean Geosynthetics Society
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• v.20 no.4
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• pp.141-149
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• 2021

In this study, an laboratory experiment was performed for prediction technology of water content in the ground using hyperspectral information. And the spectral reflectance with a specific wavelength band was obtained according to the fine and water content. Through it, the spectral information was normalized with the spectral index of the existing literature, and the relationship with the fine and water contents and the reliability of the prediction technology were analyzed. As a result of analysis, the spectral reflectance is decreased when the water and fine contents are increased under the high water contents. In addition, the reliability of prediction technology of water content was evaluated by examining 7 different spectral index calculation methods. Among them, DVI showed relatively high prediction reliability and was superior to other calculation methods in terms of sensitivity.

• Journal of Sericultural and Entomological Science
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• v.45 no.2
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• pp.90-95
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• 2003

This study was carried out to identify of C3G (cyanidin-3-glucoside) from mulberry fruits and quantify with different varieties. C3G of mulberry fruits was extracted with 1％ HCl-MeOH and purified with open column (5${\times}$90cm) which filled with Amberlite IRC-50 ion exchange resin. The $\lambda$max ranges of the purified C3G on UV/vis spectrum were 516nm and 280nm. Also, molecular weight of C3G from mulberry fruits by LC-Mass was determined as 449. From above results, we concluded that anthocyanin pigment of mulberry fruits was C3G only. The cyanidin-3-glucoside (C3G) was separated and quantified by High Performance Liquid Chromatography (HPLC) system using a Nova-Pack C$\_$18/ column. Mean content of the 35 tested accessions was 0.89％. Also fruity characteristics as well as C3G content to select the desirable mulberry varieties for the production of fruit were researched and analyzed. We selected three suitable varieties such as 'Susungppong', 'Kangsun', and 'Jeolgokchosaeng(Chungpuk)'.

• Journal of the Korea Concrete Institute
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• v.27 no.6
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• pp.695-703
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• 2015

Acceptance criteria for chemical admixtures of cement concrete were investigated in domestic and international specifications. The reliability was verified for solid content test method of chemical admixture examined statistical analysis by round robin test. The applicability of FT-IR spectroscopy for qualitative measurement of multi-compound chemical admixtures verified. From solid content experimental results, outlier analysed using Cochran, Grubbs and Dickson's Q test. Repeatability and reproducibility standard deviation for solid content results showed 0.25 and 0.098% respectively according to KS A ISO 5725-2 procedure, it can be confirmed reliability of test methods. FT-IR spectrum of liquefied or oven-dried chemical admixtures condition showed big differences. It is needed that the FT-IR analysis is performed on dry material. However there's no difference with the applicability of FT-IR spectroscopy for multi-compound chemical admixtures. So the utility of method analysis could not identify.

• Journal of Pharmaceutical Investigation
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• v.31 no.1
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• pp.37-41
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• 2001

Various characteristics of polyethylene oxide (PEO) are useful for drug delivery systems. In this study, PEO was used as a sustained release matrix system containing cefatrizine propyleneglycol (Cefa-PG) which is a new semi-synthetic broad-spectrum and orally active cephalosporin. Five kinds of sustained release matrix tablets were formulated with various content of PEO and other ingredients. And three types of matrix tablets were formulated of which compositions were the same but the hardness was different. It was found that PEO content influenced drug release rate. Increasing PEO content, the drug release rate from matrix tablets was decreased. In addition, Avicel, one of the ingredients of matrix components, changed the drug release from the sustained release PEO matrix tablets. With increasing Avicel content, the rate of drug release was increased. For the effect of hardness of matrix tablets, the rate of drug release is decreased with increasing hardness. In comparison of bioavailability parameters after oral administration of Cefa-PG PEO matrix tablets and general Cefa-PG capsule in beagle dog, the sustained release PEO matrix tablets is more useful than a general dosage form. $AUC^{0-12}$ of the sustained release PEO matrix tablet and the general dosage form was 1.16 and 0.644 respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.1
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• pp.29-35
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• 2009

The aim of the present study was to update the calibration that is used for the measurement of the total nitrogen content in the rice plant samples by using the visible and near infrared spectrum. Before the equation merge, correlation coefficient of calibration equation for nitrogen content on each rice parts was 0.945 (Leaf), 0.928 (Stem), and 0.864 (Whole plant), respectively. In the calibration models created by each part in the rice plant under the various regression method, the calibration model for the leaf was recorded with relatively high accuracy. Among of those, the calibration equation developed by Partial least squares (PLS) method was more accurate than the Multiple linear regression (MLR) method. The calibration equation was sensitive based on variety and location variations. However, we have merged and enlarged various of the samples that made not only to measure the nitrogen content more accurately, but also later sampling populations became more diversified. After merging, $R^2$ value becomes more accurate and significantly to 0.950 (L.), 0.974 (S.), 0.940 (W.). Also, after removal of outlier, R2 values increased into 0.998, 0.995, and 0.997. In view of the results so far achieved, Standard error of prediction (SEP) and SEP (C) were reduced in the stem and whole plant. Biases were reduced in the leaf, stem as well as whole plant. Slopes were high in the stem. Standard deviation reduced in the stem but $R^2$ was high in the stem and whole plant. Result was indicated that calibration equation make update, and updating robust calibration equation from merge function and multi-variate calibration.

• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.2
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• pp.103-109
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• 1999

This study was carried out to investigate spectral characterisistics and chlorophyll contents of Pinus koraiensis needles in Gwangju-gun, Kyunggi-do. In spectrum analysis by each age, needle showed difference on 700∼1,100 nm(NIR : near infrared ray). Light reflexibility keeps constant between 1st year needle and 3rd year needle, current year needle's value was higher than others and that was higher for 400∼500 nm and 600∼700 nm at 550 nm. Transmission to needle's age showed the highest result in current year needle. It showed in order of current, 1st, 2nd and 3rd year needle at 550 nm and 750 nm. Especially, current year needles of Pinus koraiensis showed a tendency to change transmission coefficient in NIR. The result of transmission coefficient measurement by each position of slope showed in order of middle slope, upper slope and lower slope. But the gathered needle in middle slope made marked change at NIR. Chlorophyll a content of the upper slope's needles was higher than other 4 positions but a component ratio was lower. In needle of the oppressed tree, Chlorophyll a content was rather low than others. Chlorophyll a content by slope positions, the upper slope's needle showed a highest value(4.48 mg/g) and lower slope was lowest value(1.35 mg/g). Chlorophyll b content also showed a similar tendency to chlorophyll a and chlorophyll(a+b) contents.