• Advanced Composite Materials
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• v.16 no.4
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• pp.299-314
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• 2007

In the present study, natural fibers (jute, kenaf and henequen) reinforced thermoplastic (poly(lactic acid) and polypropylene) and thermosetting (unsaturated polyester) matrix composites were well fabricated by a compression molding technique using all chopped natural fibers of about 10 mm long, respectively. Prior to green composite fabrication, natural fiber bundles were surface-treated with tap water by static soaking and dynamic ultrasonication methods, respectively. The interfacial shear strength, flexural properties, and dynamic mechanical properties of each green composite system were investigated by means of single fiber microbonding test, 3-point flexural test, and dynamic mechanical analysis, respectively. The result indicated that the properties of the polymeric resins were significantly improved by incorporating the natural fibers into the resin matrix and also the properties of untreated green composites were further improved by the water treatment done to the natural fibers used. Also, the property improvement of natural fiber-reinforced green composites strongly depended on the treatment method. The interfacial and mechanical results agreed with each other.

• The Korean Journal of Food And Nutrition
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• v.31 no.5
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• pp.631-639
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• 2018

The purpose of this study was to investigate the characteristics of macaroons prepared using natural color materials (Opuntia ficus-indica var. saboten (Re-N), mulberry leaf (Gr-N), pumpkin (Ye-N), and cocoa powder (Br-N)) and corresponding artificial food colorants (red (Re-A), yellow (Ye-A), green (Gr-A) and brown (Br-A)). The moisture content of macaroons prepared using natural color material was higher compared to the macaroons prepared using artificial food colorant. DPPH and ABTS radical scavenging activity was similar in both types of macaroons. Lightness and redness of Re-N, Gr-N, Ye-N, and Br-N macaroons were lower than Re-A, Gr-A, Ye-A and Br-A macaroons. Yellowness of Re-N was higher because of the browning reaction. The texture profile analysis revealed lower hardness when natural color powder was employed. In the sensory evaluation, overall acceptability was not significantly different between natural colored and artificial colored macaroons. As a result, macaroons with the natural color material were softer and showed higher antioxidative activity, however, organoleptic properties were not much different when compared with macaroons with artificial colors. Apparently, it is stated that more studies on the development of macaroons with more enhanced physical functionality and good taste using natural materials should be performed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.486-490
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• 1997

Composite materials have varios complicated characteristics to the ply materials, ply orientations, ply stacking sequences and boundary conditions. Therefore, it is difficult to analysis composite materials. For efficient use of composite materials in engineering applications the dynamic behavior, that is, natural frequencies, nodal patterns should be informed. This study presents the experimental and FEM results for the free vibration of symmetrically and antisymmetrically laminated composite and hybrid composite rectangular plates. In order to demonstrate the validity of the experiment, FEM analysis using ANSYS was performed and natural frequencies experimentally obtined is compared with that calculated by FEM analysis. The results obtained from both experiment and FEM analysis show a good agreement.

• Journal of the Korea Fashion and Costume Design Association
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• v.2 no.1
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• pp.5-20
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• 2000

This study classified the new fabrics of apparel Which was published in the domestic magazines newspapers since late nineteen-nineties and analyzed the characteristics of each new fabrics. We propose the recent trend of the development of new fabrics and therefore, predict the new fabric trend of the future. The new fabrics of apparel were classified as, 1. Sanitation and health promoting new fabric. 2. Aesthetic promoting new ones. 3. High functional new ones. 4. Natural fabric oriented new ones. 5. Pro-environmental new ones. The developmental trend of future new fabrics were predicted as followings 1. The pursuit of development of Pro-environmental textile materials 2. The pursuit of development of health enhancing textile materials 3. The pursuit of development of easy-controlling textile materials 4. The pursuit of development of long lasting-comfortable textile materials 5. The pursuit of development of high-aesthetic textile materials 6. The pursuit of development of textile materials Which have the advantages of the natural fabrics Conclusively, the new fabrics of apparel will be developed as the one which has above complicated multi-function and chaotic ability to fitting to environmental change.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1044-1046
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• 2009

Here we report the architecture for a non-volatile n-type memory paper field-effect transistor. The device is built using the hybrid integration of natural cellulose fibers (pine and eucalyptus fibers embedded in an ionic resin), which act simultaneously as substrate and gate dielectric, with amorphous GIZO and IZO oxides as gate and channel layers, respectively. This is complemented by the use of continuous patterned metal layers as source/drain electrodes.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2249-2252
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• 2009

The clay-based Fe-bearing catalyst was successfully prepared through ion-exchange reaction and applied as heterogeneous catalyst for discoloration of acid fuchsine (AF) in an aqueous solution by Fenton-like reaction. Experimental results demonstrated that the AF discoloration ratios increased by increasing Fe-loaded clay dosage and initial $H_2O_2$ concentration, and by decreasing the pH, respectively. The lower the initial AF concentration, the shorter the reaction time needed to achieve complete discoloration of AF. Comparative studies indicated that AF discoloration ratios were much higher in presence of Fe-loaded clay and $H_2O_2$ than those in presence of $H_2O_2$, raw natural clay or Fe-loaded clay only and raw natural clay and $H_2O_2$ jointly. After AF discoloration, there existed no new phases in the clay samples detected by XRD and no change in the clay crystal morphology observed by SEM. A mechanism proposed suggested adsorption and Fenton-like reaction were responsible for discoloration of AF.

• Geomechanics and Engineering
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• v.37 no.4
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• pp.359-370
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• 2024

The primary goal of this study is to evaluate the migration of fine granular materials into overlying layers under cyclic loading using a modified large-scale triaxial system as a physical model test. Samples prepared for the modified large-scale triaxial system comprised a 60 mm thick gravel layer overlying a 120 mm thick subgrade layer, which could be either tailings or railway sand. A quantitative analysis of the migration of fine granular materials was based on the mass percentage and grain size of migrated materials collected in the gravel. In addition, the cyclic characteristics, i.e., accumulated axial strain and excess pore water pressure, were evaluated. As a result, the total migration rate of the railway sand sample was found to be small. However, the total migration rate of the sample containing tailings in the subgrade layer was much higher than that of the railway sand sample. In addition, the migration analysis revealed that finer tailings particles tended to be migrated into the upper gravel layer easier than coarser tailings particles under cyclic loading. This could be involved in significant increases in excess pore water pressure at the last cycles of the physical model test.

• Applied Chemistry for Engineering
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• v.34 no.2
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• pp.199-205
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• 2023

Arsenic is a highly toxic element, and its contamination is widespread around the world. The natural materials with high selectivity and efficiency toward pollutants are important in wastewater treatment technology. In this study, the mesoporous synthetic hectorite was synthesized by facile hydrothermal crystallization of gels comprising silica, magnesium hydroxide, and lithium fluoride. Additionally, the naturally available clay was modified using zirconium at room temperature. Both synthetic and modified natural clays were employed in the removal of arsenate from aquatic environments. The materials were fully characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transform-infrared (FT-IR) analyses. The synthesized materials were used to remove arsenic (V) under varied physicochemical conditions. Both materials, i.e., Zr-bentonite and Zr-hectorite, showed high percentage removal of arsenic (V) at lower pH, and the efficiency decreased in an alkaline medium. The equilibrium-state sorption data agrees well with the Langmuir and Freundlich adsorption isotherms, and the maximum sorption capacity is found to be 4.608 and 2.207 mg/g for Zr-bentonite and Zr-hectorite, respectively. The kinetic data fits well with the pseudo-second order kinetic model. Furthermore, the effect of the background electrolytes study indicated that arsenic (V) is specifically sorbed at the surface of these two nanocomposites. This study demonstrated that zirconium intercalated synthetic hectorite as well as zirconium modified natural clays are effective and efficient materials for the selective removal of arsenic (V) from aqueous medium.

• KIEAE Journal
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• v.12 no.5
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• pp.71-76
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• 2012

As reviewed of developments of Korean earth architecture, earth-made buildings have been dwindled gradually since "the new community movement" and earth have been recognized as materials which are not so good to human health and in result, earth-related techniques have been also forgotten. However, recently the earth architecture has been more attracting back many attentions thanks to the people who are interested in health and wellbeing and the earth related techniques or skills got keenly required. The present study has investigated and reproduced earth finishing materials which are based on natural materials as basic stuffs to use them as the finishing materials of the modern earth architecture. For the test, the finishing materials have been divided roughly into sorts of pastes and oils. In case of applying finishing materials onto earth surfaces, the moisture permeability test was conducted to measure a water-absorbing speed, and at the case of using finishing materials for interior works moisture adsorption/desorption test was performed to verify the indoor humidity regulation ability, and further a test to check whether to be stained when contacted with the finishing materials, was conducted. If there is not any stain it might be recognized to be high quality of moisture adsorption/desorption and so seaweed pastes or starches might be used for paste finishing materials and for natural oils, beans are desirable in practical ways. As low-quantity of moisture adsorption materials, linseed oil is most desirable and also beaned water over75% are thought to be useful.

• Korean Institute of Interior Design Journal
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• v.21 no.3
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• pp.111-118
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• 2012

The purpose of this study is to focus on living rooms that are preferred as a place for changing space image to the maximum and to find a method how finishing materials are expressed by selecting space with mix & match of many images. The study methods are as follows. First, understand the expressive trend of space images through the precedent studies and magazines, and examine its relationship with finishing materials. Second, select space images based on the contents understood earlier and extract adjective words that represent each space image through an expert survey. Third, find the cases where space images are expressed based on the extracted words and analyze expression methods of finishing materials. The results of the study are as follows. First, it was confirmed that recent space images are actively expressed through finishing materials. Second, space images selected through data related to the trend were classified as modern+natural, modern+traditional, modern+retro, classic+natural, classic+humor, and futurism+natural and 4 adjective words for each space image were extracted. Third, expressive elements of finishing materials were extracted as 'material'. 'texture', 'color', and 'pattern' through the precedent studies. Fourth, expressive methods of finishing materials for each space image could be suggested by analyzing the examples that show mix & match based on the contents extracted earlier. Lastly, it is expected to find various methods that lead space image into finishing materials by evaluating responses and changes in visual perception of residents according to expression of finishing materials based on this study.