• Journal of the Korean GEO-environmental Society
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• v.11 no.12
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• pp.37-45
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• 2010

The particle size of microfine cement(MC) is so small that it can be injected into silt layer. But the more particle size is miniaturized, the more the cohesion increases. This phenomenon results in the decrease of the perviousness of MC. In this study, the grouting effects of microfine cement with superplasticizer to maintain cohesion low and that of normal cement were investigated in rock. To estimate the grouting effects, TCR/RQD test for rock quality, lugeon test, borehole loading test for coefficients of elastic and deformative stress, borehole shear test for shear stress, detection p~q~t(pressure~flow~time) chart tests were carried out. The results using MC show a better permeability, modulus of elasticity, deformation, charge per unit, and recover efficiency of grouting material than those of ordinary portland cement except shear stress.

• Journal of the Korean Society of Fashion and Beauty
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• v.4 no.3 s.9
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• pp.13-17
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• 2006

Perm is one the of the most common thing in a beauty salon like hair-cut and hair perm needs processing solutions which is chemical substances. Those chemical substances damage the hair cuticle. Damaged hair cuticles with mistakes of perm will follow with the next performance and it will cause more damage to hair. As damage of hair cuticle become worse, it is harder to recover the hair cuticle like before. Therefore, this study shows that plain rinse is the way to reduce the damage of hair cuticle with perm as much as possible. With experiments, I suggest the right way to do plain rinse to satisfy customers' demand and reduce the damage. During the research, I figured that plain rinse with the knowledge, structure of hair cuticle, principle of perm and plain rinse, is very needed. The hair with plain rinse have more elastic curl and have less scales which came off from hair cuticle than the hair without plain rinse. This experiment concludes that hairdresser has to figure out about the time, temperature and type of water depends on the degree of damaged hair of customers. In order to perm, there is no way to not to use chemical substances to perm. Therefore, hairdresser has to choose suitable processing solutions and right steps, and as this is the age of 'well-being' boom, hairdresser must try to keep the healthy hair. Consequently, in order to meet the demands and conditions of customers, hairdresser needs to find the right method to do plain rinse and use the method in perm.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.2
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• pp.133-139
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• 2024

The purpose of this study is to propose a new material called polyketone to overcome the limitations of polyurethane, which is currently used as a compression member in the field of earthquake-resistant structures. Although existing polyurethane has excellent elastic properties, it tends to be insufficient to recover the displacement that occurs in the structure. On the other hand, polyketone has excellent strength performance and is attracting attention as an eco-friendly material. In order to evaluate the compression properties of polyketone, which has these advantages, we would like to conduct a comparative experiment with polyurethane that was previously used. The speed dependence of polyketone was identified through simple compression experiments and experimental speed changes under repeated loading conditions, and additional compression behavior was applied to confirm compression behavior characteristics. Polyketone showed compressive strength about 10 times higher than that of polyurethane, and its excellent recovery characteristics were demonstrated by its deformation recovery ability about 14 times higher at relatively small displacements.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.1
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• pp.72-79
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• 2014

Cleft lip and palate(CLP) is one of the most common craniofacial deformities that requires systemic management involving a multidisciplinary team approach. Although there has been great improvement in the field of cleft surgery, surgical approach alone cannot resolve the various problems in treating cleft lip and palate. Hence the need for presurgical treatment was appreciated and especially, the concept of presurgical nasoalveolar molding was applied to treat unilateral and bilateral cleft lip and palate patients. Presurgical nasoalveolar molding(PNAM) of unilateral cleft mainly aims to recover nasal symmetry while the objectives of pre-surgical nasoalveolar molding in the bilateral cleft are to elongate the columella, to erect the tip of nose, and to reposition the forward displaced premaxillary region. This report covers the case of fraternal twins diagnosed with bilateral cleft. Retraction of the premaxillary region and nasoalveolar molding were conducted for 70 days until cheiloplasty, using elastic bands and nasoalveolar molding appliances. After cheiloplasty, there had been improvements in the length of columella and the position of forward-displaced premaxilla for both patients compared to their initial states. The esthetics was also satisfactory for both the surgery and the parents. In order to maximize the efficacy of the appliance, three components should be in balance; patients' adaptation to the appliance, parents' cooperation and proper selection and careful adjustment of the appliance by the dentist.