• Composites Research
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• v.36 no.4
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• pp.281-287
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• 2023

Environmental pollution from waste and the climate crisis, due to rising global average temperatures, are reaching critical levels threatening human survival. Research is ongoing across various fields to solve this problem, with a key focus on developing eco-friendly, carbon-neutral materials. Our study aimed to integrate natural fibers, known for their environmentally friendly properties and lower carbon emissions, with carbon fibers. In general, combining high-strength and low-strength materials results in intermediate properties. However, we found that certain properties in our study exceeded those of typical carbon fiber composite materials. To validate this, we produced both carbon fiber composite materials and carbon fiber/natural fiber hybrid composite materials. We then compared their mechanical properties using a range of specific tests. Our results revealed that the hybrid composite material exhibited superior bending strength and fracture toughness compared to the carbon fiber composite material. We also identified the underlying mechanisms contributing to this strength enhancement. This breakthrough suggests that the use of hybrid composite materials may allow the production of stronger structures. Moreover, this can play a significant role in mitigating environmental pollution and the climate crisis by reducing carbon emissions, a major contributing factor to these global challenges.

• Journal of Mushroom
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• v.22 no.1
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• pp.17-21
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• 2024

Mushroom-based vegan meat has thus far been used as a food for humans instead of pets. However, based on its texture and nutritional content, it is considered suitable for processing into pet treats. In the present study, we developed a prototype dog chew with a sweetening coating added to a fungal mycelium mat obtained by culturing the Basidiomycetous fungus Trametes orientalis. The palatable coating applied to the mycelium mat by plasticizing the mat with glycerol improved the taste and aroma of the existing mat, and the dog consumed it without difficulty. Future improvements may include a softening process to reduce the chewiness level and a procedure to reduce the crude fiber content. Mycelium-mat-based dog chews, manufactured using eco-friendly materials and processes that are not harmful to the environment are expected to enter the market as eco-friendly alternatives to conventional pet treats. Controlling their physical properties require further study.

• Elastomers and Composites
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• v.47 no.1
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• pp.65-74
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• 2012

Recently, the need of developing eco-friendly materials has been required with restriction strengthening on environment and energy saving by the resource depletion worldwide. These trends are not an exception in transport industry including automobile. In addition, these materials have to fulfill not only the high quality and cheap price but also the high-performance which meet the needs of costumer and society. Among the various materials, carbon fiber-reinforced composite which is actively studying for lightweight of the automobile is one of the most suitable candidates. Indeed, the carbon fiber-reinforced composites are used as the essential materials to substitute body and other parts in automobile and the demand is increasing largely. Carbon fiber-applied automobile has improved brake, steering, durability and high fuel efficiency, leading to the energy conservation and minimizing carbon dioxide emissions. This paper focuses on the necessity of carbon fiber-reinforced composites for lightweight of automobile and its technical trends.

• Journal of Powder Materials
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• v.25 no.1
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• pp.30-35
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• 2018

The friction characteristics of Al-Fe alloy powders are investigated in order to develop an eco-friendly friction material to replace Cu fiber, a constituent of brake-pad friction materials. Irregularly shaped Al-Fe alloy powders, prepared by gas atomization, are more uniformly dispersed than conventional Cu fiber on the brake pad matrix. The wear rate of the friction material using Al-8Fe alloy powder is lower than that of the Cu fiber material. The change in friction coefficient according to the friction lap times is 7.2% for the Cu fiber, but within 3.8% for the Al-Fe alloy material, which also shows excellent judder characteristics. The Al-Fe alloy powders are uniformly distributed in the brake pad matrix and oxide films of Al and Fe are homogeneously formed at the friction interface between the disc and pad, thus exhibiting excellent friction and lubrication characteristics. The brake pad containing Al-Fe powders avoids contamination by Cu dust, which is generated during braking, by replacing the Cu fiber while maintaining the friction and lubrication performance.

• Computers and Concrete
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• v.30 no.6
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• pp.421-432
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• 2022

Recently, the interminable ozone depletion and the global warming concerns has led to construction industries to seek for construction materials which are eco-friendly. Regarding this, Geopolymer Concrete (GPC) is getting great interest from researchers and scientists, since it can operate by-product waste to replace cement which can lead to the reduction of greenhouse gas emission through its production. Also, compared to ordinary concrete, geopolymer concrete belongs improved mechanical and durability properties. In spite of its positive properties, the practical use of geopolymer concrete is currently limited. This is primarily owing to the scarce structural, design and application knowledge. This study investigates the Mechanical and Durability of Geopolymer Concrete Containing Fibers and Recycled Aggregate. Mixtures of elastoplastic fiber reinforced geopolymer concrete with partial replacement of recycled coarse aggregate in different proportions of 10, 20, 30, and 40% with natural aggregate were fabricated. On the other hand, geopolymer concrete of 100% natural aggregate was prepared as a control specimen. To consider both strength and durability properties and to evaluate the combined effect of recycled coarse aggregate and elastoplastic fiber, an elastoplastic fiber with the ratio of 0.4% and 0.8% were incorporated. The highest compressive strength achieved was 35 MPa when the incorporation of recycled aggregates was 10% with the inclusion of 0.4% elastoplastic fiber. From the result, it was noticed that incorporation of 10% recycled aggregate with 0.8% of the elastoplastic fiber is the perfect combination that can give a GPC having enhanced tensile strength. When specimens exposed to freezing-thawing condition, the physical appearance, compressive strength, weight loss, and ultrasonic pulse velocity of the samples was investigated. In general, all specimens tested performed resistance to freezing thawing. the obtained results indicated that combination of recycled aggregate and elastoplastic fiber up to some extent could be achieved a geopolymer concrete that can replace conventional concrete.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.4
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• pp.337-344
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• 2017

This experiment was carried out to determine the effect of organic fertilizer and seed mixture on productivity, botanical composition and forage quality in middle areas(Geumsan, 250m sea level) pasture. Total six experimental pastures (orchardgrass, timothy and tall fescue based seed mixture and with or without organic fertilizer) were established in autumn, 2014 and evaluated productivity and agronomic characteristics from 2015 to 2016. Plant heigh was higher in orchardgrass based mixture and orchardgrass and tall fescue based mixture were higher in $2^{nd}$ harvest. There was not found the significant difference among treatment(P<0.05) in dry matter (DM) content. Botanical composition in $1^{st}$ harvest was higher weed portion in orchardgrass based mixture and legumes was disappeared at $3^{rd}$ harvest in all treatments. Fresh and dry matter yield was higher in $2^{nd}$ year than $1^{st}$ year. In $1^{st}$ year, orchardgrass based mixture with organic fertilizer plot was the highest(P<0.05) DM yield, but tall fescue based mixture with organic fertilizer was the highest in $2^{nd}$ year. Content of crude protein (CP) was the highest in tall fescue based mixture and Timothy based mixture showed low in ADF (acid detergent fiber) and NDF (neutral detergent fiber) content. But the content if in virto dry matter digestibility was higher than others. In $2^{nd}$ year, the nutritive value of $2^{nd}$ and $4^{th}$ harvested grasses were higher and average RFV (relative feed value) value was the highest at $4^{th}$ harvest. According to this result, orchardgrass and tall fescue based mixture would be recommendable for farm who considering productivity and timothy based mixture would be recommendable for considering forage quality in middle areas of Korea.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.7
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• pp.1075-1081
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• 2008

Eco-friendly processing using enzymes has been focused in textile industry in order to reduce environmental pollutions. This paper was suggested to hydrolyze non-cellulose, such as fats and waxes in cotton fabrics by lipase treatment. Enzymatic treatment conditions were controlled according to pH, temperature, enzyme concentration, and treatment time. The physical properties of the lipase-treated cotton fabrics were evaluated by measuring weight loss, moisture regain and dyeing properties. The surface morphology of lipase-treated cotton fabrics were observed by SEM. As a result, the optimum conditions for the lipase treatment were at pH 4.2, temperature 50$^{\circ}C$, concentration 50%, and treatment time 90 minutes. Calcium chloride and Triton X-100 were effective auxiliaries in lipase treatment.

• Journal of the Korea Fashion and Costume Design Association
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• v.12 no.4
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• pp.173-182
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• 2010

In this study, textile designs were developed by applying Norigae for motives, were digital-printed for it's eco-friendly, delicate and short printing time and as final products, necktie, bag and bedding was developed with them. The purposes of this study were to develop a unique textile design, and then to enhance the competitiveness of Korean textile industry in the world market and pass down a Korean traditional fiber art cultural legacy. The results are as follows Norigaes are a sort of Korean traditional ornaments worn on women's Korean traditional costume. These can vary in color, material, shape, composition and said to have very high artistic value from the standpoint of the modern view. And these are symbols of happiness and women's longing of Korean traditional society. So Norigaes are worthy of applying Korean traditional motive for modern textile design. The textile designs applied a Norigae in this study were estimated comparatively high.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.7 s.144
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• pp.938-947
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• 2005

Kenaf basts were double retted by using water and enzyme. The best conditions were enzyme concentration $0.125\%$ and 1 day treatment at $50^{\circ}C$, 4 days treatment at $20^{\circ}C$. It was showed that the double rotting could be more economical and eco-friendly than just water rotting or enzyme rotting. Kenaf fibers have been cottonized by removing lignin and hemicellulose partially. In order to cottonize kenaf fiber, lignin of kenaf fibers were removed by sodium chlorite and then hemicellulose of kenaf fibers were removed by sodium hydroxide. The cottonizing phenomenon of kenaf fibers were was confirmed in transversal and longitudinal photograph of SEM. The tensile strength and crystallinity of cottonized fiber were investigated. The tensile strength and crystallinity were lower as the lignin and hemicellulose of kenaf fibers were less.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.2
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• pp.95-99
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• 2017

The recent development of core techniques in the IT industry can be summarized as a technical advancement for safety and convenience, and mechanical technology for being "eco-friendly" and lightweight. Under these circumstances, research of lightweight material has become attractive. In this study, CFRP (Carbon Fiber Reinforced Plastic) laminate specimens are subjected to a tensile test using the UTM(Universal Testing Machine, AG-IS 100 kN) to estimate their mechanical properties in terms of the Hole machining impact evaluation. The FEM (Finite Elements Method) analysis method is applied and the material properties obtained from basic experiments such as the Tensile test, the compressive test, and the shear test. CFRP materials properties from a previous study, as well as a finite element analysis program for Hole machining CFRP was compared with the experiments.