• Journal of the Korean Geotechnical Society
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• v.31 no.6
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• pp.15-25
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• 2015

This study aimed at the strength increase of the soft ground and analyzed the strength characteristics of clay soil reinforced with hair fiber which is environmentally friendly. The study varied the length of hair fiber, the amount of hair fiber, the amount of cement, and curing days to investigate both the compressive and tensile strengths and the stress-strain relationship of hair fiber mixed clay soils. The test results indicated that both the compressvie and tensile strengths increased with hair fiber mixed, especially in the tensile strength. In addition, the hair fiber mixed clay soil allowed larger displacement to failure. Based on the test results, it is thought that the environmentally friendly hair fiber could be utilized practically to increase the clay strength in the future.

• Journal of the Korean GEO-environmental Society
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• v.17 no.2
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• pp.23-29
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• 2016

This study was carried out with a view to increasing the tensile strength of sand soil and examined the characteristics of the tensile strength of sand soil reinforced by hair fiber which is environmentally friendly. The study investigated the change of the tensile strength and the stress-strain relationship varying the length of hair fiber, the amount of hair fiber, the amount of cement, and curing days. The test results indicated that the tensile strength increased significantly with hair fiber mixed. In addition, the sand soil mixed with hair fiber had larger displacement at failure. Based on the test results, it is appeared that the environmentally friendly hair fiber could be utilized practically to increase the tensile strength of sand soil in the future.

• Journal of the Korean GEO-environmental Society
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• v.19 no.4
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• pp.17-26
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• 2018

This study systematically examines the changes in the compressive and tensile strength of soil cement reinforced by natural hair fiber, which is regularly produced from human. Extensive experimental tests of various test specimens have been carried out in a laboratory. Several factors are considered, including the soil type, amount of cement, amount of fiber, fiber length, loading type, and curing age. The test results indicate that both the compressive and tensile strengths are significantly affected by the fiber, either increasing or decreasing depending on the conditions. The increase in tensile strength is significant in the sand-based soil cement due to the tensile resistance of the fiber which is interlocked with the surrounding soil or cement particles. The natural fiber provides a larger strain to failure due to its extensibility, which allows greater deformation. Based on the test results, natural hair fibers can be an effective and environmentally friendly way to improve soil ground subjected to tensile loading, such as an embankment slope, road subgrade, or landfill, thus reducing the cost for cement and waste treatment. The study results provide a useful information of better understanding the mechanical behavior of natural hair fiber in soil cement and the practical use of waste materials in civil engineering. The findings can be practically applied for improving earth structures under tensile loading.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.5
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• pp.1304-1316
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• 1996

In this paper, A VCO(Voltage Controlled Oscillator) in use of clock recovery/data regeneration circuit for 10 Gbps fiber optic receivers was developed. The improved hair-pin resonator with a parallel coupled lines, which has been applied to microstrip filters, was used as a resonance part. As a frequcncy tuning device by substituting 3-terminalMESFET vaaractor for varactor diode, an MMIC manufacturing process will be simplified. Since a hair-pin resonator is planar type compared to the dielectric resonator and has a relatively flat reactance verus frequency, it will be favorable to apply a hair-pin resonator to an MMIC, in addition wideband frequency tuning range is able to be obtained.

• Journal of Fashion Business
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• v.10 no.5
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• pp.45-57
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• 2006

In the previous study, african marigold petals extract was valued as an excellent natural yellow dye because of its distinguished reactivity with various mordants and color fastness. In this study, we were studied on effect of absorbed metal ion by after-treatment of mordants on the color and fastness in human hair and wool fiber dyed with african marigold petals extract because the proteinic and cellulosic fiber were very well dyed. The dyed human hair showed better dyeing ability in the color fastness than wool fiber on tests of light, wash and perspiration. The absorbed metal ion concentration of mordanted human hairs were 1 or 5 times higher than wool fibers. However, excess of absorbed metal ion haven't consistent effect on K/S and surface color. Human hairs dyed using african marigold extract and mordanted with Al, Sn, Cu and Fe were showed various reddish yellow color groups and good dyeing ability on african marigold extract.

• Textile Coloration and Finishing
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• v.24 no.1
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• pp.27-32
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• 2012

Generally, hair treatments by complementary actions to give a sense of activity are permanent setting, dyeing, and bleaching, etc. In this study, we investigated the wave formation ability and hair damage occuring in permanent setting and bleaching process. The wave formation ability was evaluated by the differences of length and curl diameter after permanent setting. And the hair damage was also evaluated by the protein release ability and SEM of hair. The bleached hair immediately after permanent setting treatment has better wave formation ability, but much more damaged than the bleached hair after rinsing thoroughly with warm water. It was considered that the chain of hair keratin broke down easily by the bleaching action in the existence of permanent setting agents.

• Textile Coloration and Finishing
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• v.22 no.2
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• pp.110-117
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• 2010

Recently, there is a trend to utilize natural dyes in many dyeing fields. In this work, the effects of benzyl alcohol in human hair dyeing with cochineal, a natural dye, was investigated. We investigated the K/S value and color value of dyed hair, water retention of dyed hair, protein release-ability of dyed hair, and wash fastness of dyed hair according to dyeing time and temperature. The shade of dyed hair was reddish. By adding benzyl alcohol in cochineal dyeing, the dyeing rate was increased and the dyeing equilibrium was established at early stage. The water retention of dyed hair was increased and the protein release-ability of dyed hair was decreased, meaning that the hair was less damaged during dyeing, The dyed hair showed a good wash fastness.

• Textile Coloration and Finishing
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• v.24 no.4
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• pp.305-312
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• 2012

In this study, we investigated the effects of oxidative permanent hair coloring agents on the dyeability and the damage of human hair. p-phenylenediamine and toluene-2.5-diamine sulfate were used as a hair coloring agent precursers. The degree of dyeability was checked by the change of CIELAB $L^*$ value according to dyeing time. And the damage of hair was evaluated by the tensile strength and morphological change of hair in SEM. When the hair was dyed, the CIELAB $L^*$ value was decreased with dyeing time regardless of the type of precursers. But when the hair was dyed after nutritional treatment, the CIELAB $L^*$ value showed lower level. This means that the nutritional treatment covers the scale of hair and protects the hair from the chemicals.

• Journal of Fashion Business
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• v.9 no.5
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• pp.136-144
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• 2005

Oxidative hair color is currently widely used because of its beautiful light color and good dyeability. In this study, hair color, oxidative agents, and dye intermediate were reacted. Modifier, which changes color with various hue, and alkaline agent, which opens the cuticle of hair fiber and enhances the dyeing reaction, were added. For gel formation, isocetyl alcohol was used as solvent in preparing three kinds of permanent oxidative hair color. Physiochemical study of prepared permanent oxidative hair color was done for basic information acquisition. Acid perspiration test, pH measurement both at room temperature and at high temperature, drop movement test, dyeability efficiency upon the amount of hydrogen peroxide added, and humidity fastness were studied. Shampoo fastness and light fastness of prepared permanent oxidative hair color dyed hair sample were also investigated. All three kinds of hair color prepared showed good properties overall, however, dyed hair sample became reddish upon shampoo fastness and lightfastness tests.

• Journal of Fashion Business
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• v.11 no.5
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• pp.51-63
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• 2007

Chitosan, a natural cationic macromolecular material, has been known for its moisturizing and healing effect due to the coating action based on strong ionic bonding when the chitosan is treated on hair strands. In this study, the acidic aqueous chitosan solution was prepared to treat healthy hair, and damaged hair due to bleaching, relatively thin hair and thick hair specimens. The chitosan treatment effect was reviewed by comparing spectrophotometric and mechanical characteristics of the chitosan treated and untreated specimens. Electrostatic voltage was somewhat reduced after the chitosan treatment. Smoothly coated surface was observed, in the SEM images, especially for damaged hair specimens. The values of breaking strength, which is one of the indicators of the internal characteristics of hair, was high in the case of chitosan treated samples. The values of elongation was also high in the case of chitosan treated samples, which proves the chitosan treatment effect. The friction force, one of the indicators of surface characteristics, was reduced for the case of chitosan treated samples.