• Journal of Fashion Business
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• v.13 no.3
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• pp.86-98
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• 2009

The fashion industry saw the emergence of environment-friendly and natural fabric materials recently. The naturalism trend has established sectors in the textile and fashion industry also. Ramie and hemp have long been favored fabric materials in Korea especially for summer. The hand-related mechanical/physical properties of the fabric specimens were analyzed using a fabric objective measurement system, KES(Kawabata Evaluation System). Subjective evaluation was also implemented based on a series of selected adjectives. Studies on natural dyeing methods are important since the establishment of scientific approach is needed in terms of environment and human safety along with the reproduction of traditional natural dyeing methods. In this study, linen, ramie, hemp, and cotton/polyester/linen union fabric specimens were used for the natural dyeing using Rubia akane Nakai with the mordant of gallnut. ${\Delta}E$ values of dyed fabric specimens, mordanted and dyed once using Rubia akane Nakai, increased significantly compared to those of repeatedly dyed fabric specimens without mordanting.

• Steel and Composite Structures
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• v.33 no.2
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• pp.299-306
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• 2019

The natural fibre composites are termed as bio-composites. They have shown a promising replacement to the current carbon/glass fibre reinforced composites as environmental friendly materials in specific applications. Natural fibre reinforced composites are potential materials for various engineering applications in automobile, railways, building and Aerospace industry. The natural fibre selected to fabricate the composite material is plant-based fibre e.g., sisal fibre. Sisal fibre is a suitable reinforcement for use in composites on account of its low density, high specific strength, and high hardness. Epoxy is a thermosetting polymer which is used as a resin in natural fibre reinforced composites. Hand lay-up technique was used to fabricate the composites by reinforcing sisal fibres into the epoxy matrix. Composites were prepared with the unidirectional alignment of sisal fibres. Test specimens with different fibre orientations were prepared. The fabricated composites were tested for mechanical properties. Impact test, tensile test, flexural test, hardness test, compression test, and thermal test of composites had been conducted to assess its suitability in industrial applications. Scanning electron microscopy (SEM) test revealed the microstructural information of the fractured surface of composites.

• Structural Engineering and Mechanics
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• v.76 no.5
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• pp.613-618
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• 2020

Exhausting oil resources and increasing pollution around the world are forcing researchers to look for new, renewable, biodegradable materials to lead sustainable development. The use of fiber reinforced composites based on natural fibres has increasingly begun as prospective materials for various engineering applications in the automotive, rail, construction and aerospace industries. The natural fiber chosen to make the composite material is plant-based fibre, e.g. jute fibre, and hemp fibre. Thermosetting polymer based Epoxy (LY556) was utilized as matrix material and The composites were produced using hand lay-up technique. The fabricated composites were tested for acoustic testing, thermo-gravimetric analysis (TGA) and flammability testing to asses sound absorption, thermal decomposition and fire resistivity of the structures. Hemp fibre composites have shown improved thermal stability over Jute fibre composites. However, the fire resistance characteristics of jute fibre composites are better as compared to hemp fibre composites. The sound absorption coefficient of composites was found to enhance with the increase of frequency.

• Journal of Community Nutrition
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• v.3 no.2
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• pp.110-119
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• 2001

This study was designed to assess the needs for nutrition education and educational materials for older adults. Two cross-sectional surreys were conducted. The first survey, conducted by personal interviews, was part of the large-scale elderly nutrition study. Subjects were adults aged 50 and over, recruited from 6 large cities and 8 middle-sized cities(n = 1,850). The second survey, done by mail survey using open-ended questions, was conducted with dietitians working at public health centers or hospitals(n = 53). Adults aged 50 and over were interested in topics such as healthly eating(32.1%), hypertension/stroke and diet(22.1%), osteoporosis and diet(11.4%), and diabetes and diet(9.2%). Television and radio(58.2%), health professionals(12.2%) and friends(7.9%) were common sources of nutrition information. Preferred topics of nutrition education and sources of nutrition information were different by general characteristics of subjects, suggesting that nutrition education or educational materials be planned considering the characteristics of subjects. About 70% of subjects indicated that they sometimes use or do not use nutrition information in daily lives, suggesting the need to provide more practical information. Among 53 facilities responding to the second survey, 73.6% provided nutrition education for older adults. Common topics for nutrition education included diabetes(39.3%), hypertension and stroke(19.1%) and general nutritional management(11.2％). These were consistent to the topics preferred by older adults. As materials In elderly education, dietitians wanted primarily to use leaflets and slides. Boards, booklets and posters were other commonly cited materials. For contents of elderly educational materials, dietitians mentioned the nutritional management for age-related diseases(33.8%), general nutritional management for older adults(25.4%) and practically applicable information(19.7%). They also suggested that nutrition education materials for the elderly should use larger print and attractive pictures, and be easily understood, as well as presenting simple, specific and practical information. These results provide baseline information for developing nutrition education and educational materials for older adults.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.3
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• pp.152-158
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• 2009

Various fabrication methods have been used to synthesize sapphire which has qualities of jewelry well beyond the industrial class. Among them, the flux sapphire of Chatham Company which has as high value as jewelry was selected in order to compare natural and synthetic sapphire. First, the WD-XRF (Wavelength dispersive x-ray fluorescence spectrometer) was used to analyze the chemical composition of natural and synthetic sapphire. Although natural sapphire had very diverse chemical compositions, flux sapphire had small quantities of Mo, Pt and Pb elements in addition to the similar chemical ingredients to natural one. Pt is decisive proof of flux sapphire. Next, by investigating spectroscopic characteristics using UV-VIS Spectrophotometer after heat treatment at high temperatures of $1300^{\circ}C$ and $1500^{\circ}C$, the variation of 690 nm absorbance related to $Cr^{3+}$ was detected in the natural sapphire while those of the 690 nm absorbance (related to $Cr^{3+}$) as well as absorbance of 376 nm and 388 nm ($Fe^{3+}$) were seen in the flux sapphire. It was found that the difference in the absorbance variation of flux sapphire is greater than that of natural sapphire after heat treatment. The chemical composition and spectrum analysis were utilized to compare the natural sapphire and the flux synthetic sapphire.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.1
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• pp.9-17
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• 2009

Twenty years have passed since the adoption of natural recreation forests and each forest has its own characteristics. However, there is hardly any classification among the natural recreation forests. The purpose of this study is to classify the forests by considering the supplier's perspective as well as the user's perspective in order to provide fundamental materials for the operation of the natural recreation forests. A factor analysis was conducted to identify the common characteristics of the selected twelve variables by pre-selection and survey of experts. K-means cluster analysis was conducted among those factors to classify the natural recreation forests in Korea. Four factors were drawn after the factor analysis and the factors were named according to the variables and sizes as 'The use performance and visiting condition factor', 'Education and settlement factor', 'Internal activation factor' and 'Potential factor' In addition, the cluster analysis of an $85{\times}4$ matrix was conducted for the points of the drawn factors and the final classification consists of five groups. The results of this study may contribute to providing fundamental materials for the operation and management of natural recreation forests. Also, it may act as a reference when investigating the natural recreation forests of Korea. Proposing the classification natural recreation forests could be helpful in selecting the proper recreation forest in the future. Based on the established model, fundamental materials could be provided to improve the profitability of the natural recreation forests by effectively expanding the number of tourists, creating new natural recreation forests and proper maintenance and management.

• Computers and Concrete
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• v.22 no.5
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• pp.449-459
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• 2018

Concrete is one of the most widely used construction materials in the world. Producing economical and durable concrete is possible by employing pozzolanic materials. The aim of this study is to underline the possibility of the utilization of natural zeolite in producing concrete and investigate its effects basically on the strength and durability of concrete. In the production of concrete mixes, Portland cement was replaced by the natural zeolite at ratios of 0%, 10%, 15%, and 20% by weight. Concretes were produced with total binder contents of $300kg/m^3$ and $400kg/m^3$, but with a constant water to cement ratio of 0.60. In addition to compressive and flexural strength measurements, freeze-thaw and high temperature resistance measurements, rapid chloride permeability, and capillary water absorption tests were performed on the concrete mixes. Compared to the rest mixes, concrete mixes containing 10% zeolite yielded in with the highest compressive and flexural strengths. The rapid chloride permeability and the capillary measurements were decreased as the natural zeolite replacement was increased. Freeze-thaw resistance also improved significantly as the replacement ratio of zeolite was increased. Under the effect of elevated temperature, natural zeolite incorporated concretes with lower binder content yielded higher compressive strength. However, the compressive strengths of concretes with higher binder content after elevated temperature effect were found to be lower than the reference concrete.

• Journal of The Korean Association For Science Education
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• v.24 no.1
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• pp.63-75
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• 2004

The purpose of this study is to explore characteristics of on-line teaching materials on websites of natural history museums, particularly with regard to educational perspectives and the nature of science. The target resources were selected from the websites of the Natural History Museum in London, the Australian Museum in Sydney, the Field Museum of Natural History in Chicago, and the Smithsonian Museum in Washington D.C.. A total of twelve on-line resources from these museums used in this study were selected as representative informal science teaching materials. For the investigation, this study developed a checklist with a total of nine items that were grounded on mostly reviewing previous literature and articles focusing on educational perspectives of natural history museums and science centers. Exciting and positive results were found in all four museums. The analyses, however, indicated weaknesses as well as strengths in on-line resources regarding their usages as informal science teaching venues.

• Korean Institute of Interior Design Journal
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• v.14 no.3 s.50
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• pp.46-54
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• 2005

This study explored how the elementary schools provided proper interior environments to the students in terms of ecological aspects. 14 cases-7 in Busan and 7 in Osaka which were newly built or remodelled since 2000 were selected. These schools were analyzed based on the eco-school guideline suggested In the former study. The guideline categorizes into three parts: 1) energy efficiency related with lighting, ventilation, heating and insulation, 2) greening, 3) sustainability including recycling water system and use of environmentally friendly materials. The results showed that Korean schools require more systematic planning for natural lighting, ventilation, Insulation, greening and new water system while Japanese schools need use of environmentally friendly materials and consideration for natural lighting, insulation and interior greening. Especially, natural lighting and natural ventilation through roof window, atrium, wind tower and use of natural insulation and blind window system should be basically considered at the Initial planning. Also, this study reveals that ecological approach including greening and natural lighting with various architectural form should be applied in future elementary school design to make the school environment more agreeable and economical.

• Composites Research
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• v.20 no.2
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• pp.32-38
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• 2007

Natural fibers can refer to all types of fibres only produced by nature. Their lengths vary from particles to long strands. Natural fibers are categorized roughly by six types, depending on the types of sources; base, leaf, seed, grasses, fruit and wood. Of these fibers, jute, flax, sisal and ramie are the most commonly used as reinforced materials in preparing polymer composites. In development and improvement of these composites, many studies have been implemented to overcome the drawbacks such as incompatibility, moisture problems and so on. The range of industry sectors of natural fiber-reinforced polymer composites becomes more extensive gradually and many of the companies all over the world are engaged in fabrications or applications. This paper mainly discussed the recent status of the domestic/overseas market and research issues of natural fiber-reinforced polymer composites. We made an exception of wood-polymer composites market which have played a great role because they had been often dealt with.