• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.11
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• pp.1696-1706
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• 2009

Nonwoven fabrics have been widely used in various fields that include household, industrial, agricultural, medical goods, especially in the automobile industry. In this study, eco-friendly fiber materials were developed and investigated as a substitute material for polyester fibers in nonwovens. To make plant fiber bundles, stems of Indian mallow (IM), and Kuzu vine (KV) were retted; in addition, the non-cellulose component was partially removed. Plant fiber bundles and polyester fibers (P) were blended and needle punched to produce nonwovens. Five kinds of nonwovens were manufactured: P100 (Polyester 100%), IM10 (IM 10% and Polyester 90%), IM20 (IM 20% and Polyester 80%), KV10 (KV 10% and Polyester 90%), and KV20 (KV 20% and Polyester 80%). The color values, surface appearance, tensile strength, elongation, tear strength, abrasion strength, flexstiffness, moisture regain, water or oil absorbency, and static electricity of manufactured nonwovens are investigated. As the blended ratios of IM or KV increased, the brightness of nonwovens decreased compared to that of polyester 100%. Tensile strength, tear strength, abrasion strength, and flexstiffness of IM10 as well as KV10 were higher than those of P100, IM20, and KV20, resulting from the influence of the structure and properties of nonwoven fibers. Moisture regain and water or oil absorbency increased, while static electricity decreased in proportion to the amount of plant fibers. IM or KV and polyester blended nonwovens showed improved properties over P100 that could be substituted for P100 as a novel material for textiles.

• International Journal of Highway Engineering
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• v.15 no.2
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• pp.113-119
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• 2013

PURPOSES : The objectives of this study are to develop the eco-friendly pavement material using polyurethane binder and evaluate mechanical properties of the developed binder and concrete. METHODS : The bending beam test was conducted to select the sample candidates of polyurethane binder based on the bending strength. The characteristics of viscosity, curing time, and temperature change of sample binder was examined on different temperature conditions. The mechanical properties of polyurethane binder was estimated using the dynamic modulus testing. The indirect tensile strength test was conducted on polyurethane binder concrete with different gradation and binder content for evaluating the mechanical properties of concretes. RESULTS : Based on the beading beam test, four different binder samples were prepared for estimate the mechanical properties. The viscosity of polyurethane binder tends to increase with increase of liquid temperature and the hardening phenomenon begins 10 to 15 minutes at room temperature after mixing the resin and hardener. It is observed that the dynamic modulus of binder increases as loading frequency increases and change of modulus is found to be the highest in the PU-2I binder type. The PU-2I binder concretes shows the largest value of indirect tensile strength and indirect tensile energy. CONCLUSIONS : The use of polyurethane binder as pavement materials is capable of increasing the pavement performance and reducing the detrimental environmental effect during the highway construction.

• Journal of the Korean GEO-environmental Society
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• v.14 no.6
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• pp.39-46
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• 2013

The field of ground amelioration, many construction methods have been developed more prosperously up to now, but even now, the majority focuses on the improvement of ground strength. And they could not suggest concrete solutions to the occurrence of environmental issues. To address this problem, soil improvement methods employing organic acid materials have recently been developed as eco-friendly technologies for increasing the soil strength, but details regarding the basic stabilization mechanism are not known yet. Against this background, this research was conducted to examine the soil stabilization mechanism; for this purpose, unconfined compressive strength and pH tests were conducted by using an improved eco-friendly organic acid material. The test results revealed that the samples processed with the organic acid showed a considerable increase in the unconfined compressive strength over time as compared to the strength of the samples that were processed without the organic acid. It was also confirmed that the organic acid material promoted microbial breeding and improved the soil structure by reducing the volume of the voids in the soil. Therefore, the sustainable development of this method needs to be analysed more in the future.

• Journal of Fashion Business
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• v.18 no.5
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• pp.159-170
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• 2014

Recent concerns about the PFOA(perfluorooctanoic acid), have been increasing, which is generally applied in the water-repellent finishing process of textile products. It has been proven through animal testing to be harmful to humans, as possible carcinogens and neuro-toxic material. Thus U. S. Environmental Agency has gone as far as requiring the material to be eliminated in its entirety by 2015. As a viable alternative to this water-repellent finishing agent, the development of C6 product is gaining its popularity. The effects of PFOA finishing on the silk fabrics were examined, and we reviewed parameters of the needed process for optimizing appearance and functionality of silk fabrics treated with eco-friendly water-repellent finishing agent. Cross-linking agent affected the most on black color of reactive ink, among the physical properties. The contact angle reading was the highest in $8g/{\ell}$ of concentration for all fabrics. All the fabric specimens, subjected to the DTP and water repellent finishing, exhibited higher stiffness, where rayon specimen showed the highest, compared to the untreated specimens. The results may provide basic information leading to the development of value-added silk fabrics with water-repellency without excessive deterioration of the delicate appearance and inherent soft touch.

• Resources Recycling
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• v.25 no.3
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• pp.20-28
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• 2016

Assessment on adequate dosage of superplasticizer in eco-friendly ultra-high performance concrete (UHPC) containing industrial by-products was carried out from the standpoint of workability. Various types of industrial by-products, including blast-furnace slag, coal bottom ash and rapid-cooled electric arc furnace oxidizing slag, were utilized, and the effects of dosage of superplasticizer on the workability and strength of UHPC containing the by-products were evaluated. By utilizing the by-products, the workability of UHPC was improved and required dosage of superplasticizer was reduced. In addition, the material cost for UHPC with by-products was decreased due to reduced dosage of superplasticizer.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.17-22
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• 2021

Eco-friendly magnesium-air battery is a kind of metal-air battery known as a primary battery with a very high theoretical discharge capacity. This battery is also called a metal-fuel cell from the viewpoint of using oxygen in the atmosphere as a cathode active material and magnesium alloy as a fuel. Since battery performance is determined by the properties of the magnesium alloy used as a anode, more research and development of the magnesium alloy electrode as a anode material are required in order to commercialize it as a high-performance battery. In this study, the commercialized magnesium alloys(AZ31, AZ61) were selected and then electrochemical measurements and discharge test were conducted. Electrochemical properties of magnesium alloys were investigated by OCP changes, Tafel parameters and CV measurement, and the feasibilities of AZ61 alloy with excellent discharge capacity(1410mAhg^-1) as electrode materials were evaluated through CC discharge experiments.

• Composites Research
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• v.36 no.1
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• pp.32-36
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• 2023

Recently, as global environmental issues for sustainable development, such as carbon neutrality, have emerged, disposal methods of glass fiber composites, a material of existing wind turbines, have become a problem. To solve this problem, in this study, 30kW wind turbine blades were manufactured using flax fiber-based composites, which are eco-friendly natural fiber composites that can replace existing glass fiber composites, and their suitability was evaluated. First, mechanical strength tests were conducted to verify the feasibility of using eco-friendly natural flax fiber composites as a wind turbine blade material, and as a result, better strength were confirmed compared to previous studies on the properties of flax fiber composites. In addition, the suitability was confirmed through a static strength performance evaluation test to measure the static strength of the flax fiber composite blade using the manufactured 30kW class flax fiber composite blade.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.851-856
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• 2017

The mechanical properties of coating resin on stainless steel were measured by SEM, FT-IR spectra, tensile properties, mole ％ of [NCO/OH], and particle size analyzer. Growing concerns in the environment-friendly coating resin, we have synthesized the solvent-free coating resin to be coating on metals such as stainless steel. The properties of the synthesized coating resin to be contained polyols, MDI, silicone surfactant, fillers and vegetable oil(castor oil), that they have highly stronger in intensity and longer durability than general coating resin of polyurethane resin on stainless steel. The rigid segments of polyurethane in mechanical properties of coatings were due to unsaturated vegetable oil and the increase mole % of [NCO/OH]. In conclusion, the coating microstructure with castor oil can be good material for coatings of anticorrosion of metal substrates such as stainless steel.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.814-819
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• 2008

The purpose of this study was developing the building materials for creation the comfortable IAQ. By reducing formaldehyde(HCHO) known as the main factors of Sick House Syndrome. This material must be revealed the physical and eco-friendly performance, so this study set up the basic standards for building materials. The source of physical performance evaluation is Korea Industrial Standards and the base of environmental ability is the Eco Label considering certificated system related to an apartment house. Because the developed material was satisfied with the established standards, it was tested in mock-up room for obtaining the real date from indoor air. The mock-up test was conducted according environmental standard method for indoor air Quality of the ministry of environment. The result of this study were as follows; the functional building materials had a effect to reduce the formaldehyde concentration for a initial period without wall paper, so additional development is needed for application with the wall paper and the available period.

• Transactions on Electrical and Electronic Materials
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• v.12 no.3
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• pp.98-101
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• 2011

A 10 nm nano-silica was introduced to a conventional 3 ${\mu}M$ micro-silica composite to develop an eco-friendly new electric insulation material for heavy electric equipment. Thermal and mechanical properties, such as glass transition temperature (Tg), dynamic mechanical analysis, tensile and flexural strength, were studied. The mechanical results were estimated by comparing scale and shape parameters in Weibull statistical analysis. The thermal and mechanical properties of conventional epoxy/micro-silica composite were improved by the addition of nano-silica. This was due to the increment of the compaction via the even dispersion of the nano-silica among the micro-silica particles.