• Transactions of the Korean Society of Machine Tool Engineers
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• 제15권5호
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• pp.97-103
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• 2006

A meso-scale analysis method using the natural element method, which is a kind of meshless method, is proposed for the analysis of material damage of brittle microcracking solids such as ceramic materials, concrete and rocks. The microcracking is assumed to occur along Voronoi edges in the Voronoi diagram generated using the nodal points as the generators. The mechanical effect of microcracks is considered by controlling the material constants in the neighborhood of the microcracks. The macro elastic moduli of anisotropic as well as isotropic solids containing a number of randomly distributed microcracks are calculated in order to demonstrate the validity of the proposed method.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.383-388
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• 2000

In these days, there are out of natural sands in the construction field. It is required that development of substitute material for natural material. The blast-furnace slag could be a good alternative material in this situation. It can help resource recycling and the protection of environment. This study presents that the strength properties of mortar using air-cooled blast-furnace slag sand and water-cooled blast-furnace slag sand. The mixing design of this study have a few factors, three type of unit water, four types of W/C, five types of substitution rate. When air-cooled furnace slag sand used in mortar, as substitution rate is higher, 3, 7-days compression strength and flexural strength are going up. But, in case of water-cooled furnace slag sand mortar, strengths are going down.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제20권8호
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• pp.691-696
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• 2007

In this study accelerated aging test equipment was developed to simulate domestic weather condition for accelerated aging test of polymer housed distribution surge arresters. Polymer arresters were aged for 3,000 hours by this test equipment and chemical and electrical characteristics analysis of surge arresters were conducted after aging test. In addition, performance assessment of outdoor installed arresters for 3 years was conducted to compare aging effect between accelerated aging test and natural aging. Through this experiment it is verified that the capability of the proposed aging test for simulating natural aging and the housing material and disconnector of domestic polymer arresters can be deteriorated by the long time field operation.

• Journal of the Korea Fashion and Costume Design Association
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• 제2권2호
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• pp.137-154
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• 2000

The purpose of this study is to investigate the transition of luster material after the tweentieth century. This study was conducted by means of designer collection, journal of fashion, museum data, fabric exhibition and Internet data. The results of this study were as follows: Before the synthetic fiber period, the luster materials were used satin, chamuse, gauze, damask brocade and velvet, except cashmere, mohair and rayon. They are made from silk by the way of giving difference surface property. But since 1960s, it has used not only synthetic fiber with smooth surface but also vinyl, latex, natural leather, synthetic leather and metal. Luster material recently has a tendency to natural and soft shiny, example silket finish, chintz finish, silico coating finish with paper touch feel and so forth.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.57-59
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• 2015

A method to measure heating value of natural gas using sound velocity and thermal conductivity is proposed to solve the low heating value issues of imported natural gas in South Korea. Natural gas generally consists of methane, butane, ethane, and inert gases. Heating value changes as the gas material properties, such as density, wobbe index, etc., varies. It is highly important to measure heating values of natural gases accurately because measuring the heating value depends on the given natural gases' components. Therefore, sound velocity and thermal conductivity is measured to estimate indirectly heating value of Natural gas with their changed components.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2630-2634
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• 2014

The surface of natural graphite was modified by the use of hydrogen peroxide and evaluated as an anode material for lithium ion capacitors (LICs). The surface treatment was carried out under various ultrasonic conditions of 200, 300, and 400W, which were applied to a mixture of natural graphite and hydrogen peroxide solution for 1 h. While the bulk structure was maintained, the hexagonal symmetry and physical properties of natural graphite, such as BET surface area, tap density, and particle size, were affected by the surface treatment. FT-IR and XPS measurements confirmed the signature of C=O on the surface of graphite samples after treatment. Both the pristine and surface-treated graphites showed a similar reversible capacity of $370mAhg^{-1}$, and the coulombic efficiency of surface-treated graphite decreased with higher ultrasonic energies (89.1%, 89.0%, and 88.0% for 200, 300, and 400 W) comparing with pristine graphite (89.4%). The capacity retention of LICs was greatly improved with the treated natural graphite. The graphite treated under the ultrasonic energy of 300 W and pristine natural graphite showed capacity retention of 77.5% and 42.9%, implying that the surface treatment was an effective method for the improvement of natural graphite as an anode material for LICs.

• Journal of the Korea Fashion and Costume Design Association
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• 제19권2호
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• pp.15-28
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• 2017

Today, modern people are exposed to various environmental pollutants such as harmful substances and stress, which can compromise health. Therefore, a healing culture that seeks to enjoy human life based on the healing of body and mind is attracting great attention. The purpose of this study is to develop environmentally friendly natural dyeing considering a healing concept with four elements: color, dye, material, and pattern. The research methods and scope are based on a theoretical review of healing and research on the literature of bedding related to natural dyes, national and international books, the Internet, etc., and naturally dyed bedding. This paper presents actual production research. The results of this study are as follows. First, the elements of color, dyeing, material and pattern were developed through the process of a bedding design development model that applies a healing concept and can be commercialized as a healing bedding product. Second, a healing color proposal was expressed in an intermediate color system of pink, ocher, lavender, and indigo colors for emotional stability, warmth, calmness, comfort and softness. Third, eco-friendly bedding using natural dyes with medicinal efficacy can obtain the healing effect of the natural treatment method, which can aid healthy sleep. Fourth, the pattern used in the bedclothes was a motif of Sarasa embroidery, flower embroidery, ribbon embroidery, and wave quilting motifs to provide psychological stability as a healing concept in the sleeping environment. The natural healing bedding with the healing concept proposed in this study has natural treatment that is beneficial to human health and the development of bedding with natural dyes will lead to an increase of demand for the sleeping environment.

• International Journal of Molecular Medicine
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• 제44권6호
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• pp.2171-2180
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• 2019

Pistacia weinmannifolia (Anacardiaceae) has been used in herbal medicine for the treatment of influenza, dysentery and enteritis in China. It was recently observed that P. weinmannifolia root extract (PWRE) exerts anti-inflammatory effects both in in vitro and in vivo models. Based on the results from previous studies, the present study investigated the protective effect of PWRE on airway inflammation and mucus hypersecretion. Treatment with PWRE significantly decreased the number of eosinophils and the levels of Th2 cytokines, such as interleukin (IL)-4, IL-5 and IL-13, in the bronchialveolar lavage fluid (BALF) of OVA-exposed mice. PWRE decreased the high serum levels of total and OVA-specific immunoglobulin E. PWRE also effectively inhibited the influx of inflammatory cells into the lung, as well as airway mucus hypersecretion. In addition, the increased level of monocyte chemoattractant protein-1 was significantly decreased with the PWRE treatment in the BALF of OVA-exposed mice and in lipopolysaccharide-stimulated RAW264.7 macrophages. These protective effects of PWRE on OVA-induced pulmonary inflammation were accompanied by the downregulation of mitogen associated protein kinases and nuclear factor-κB activation. Thus, the results from the present study indicate that PWRE could be valuable adjuvant for the treatment of asthma.

• International Journal of Molecular Medicine
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• 제44권3호
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• pp.949-959
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• 2019

Pistacia weinmannifolia (PW) has been used in traditional Chinese medicine to treat headaches, dysentery, enteritis and influenza. However, PW has not been known for treating respiratory inflammatory diseases, including chronic obstructive pulmonary disease (COPD). The present in vitro analysis confirmed that PW root extract (PWRE) exerts anti-inflammatory effects in phorbol myristate acetate- or tumor necrosis factor α (TNF-α)-stimulated human lung epithelial NCI-H292 cells by attenuating the expression of interleukin (IL)-8, IL-6 and Mucin A5 (MUC5AC), which are closely associated with the pulmonary inflammatory response in the pathogenesis of COPD. Thus, the aim of the present study was to evaluate the protective effect of PWRE on pulmonary inflammation induced by cigarette smoke (CS) and lipopolysaccharide (LPS). Treatment with PWRE significantly reduced the quantity of neutrophils and the levels of inflammatory molecules and toxic molecules, including tumor TNF-α, IL-6, IL-8, monocyte chemoattractant protein-1, neutrophil elastase and reactive oxygen species, in the bronchoalveolar lavage fluid of mice with CS- and LPS-induced pulmonary inflammation. PWRE also attenuated the influx of inflammatory cells in the lung tissues. Furthermore, PWRE downregulated the activation of nuclear factor-κB and the expression of phosphodiesterase 4 in the lung tissues. Therefore, these findings suggest that PWRE may be a valuable adjuvant treatment for COPD.

• Macromolecular Research
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• 제17권10호
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• pp.821-824
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• 2009