• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.224-227
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• 2004

A computer program for composite pressure vtlssel design is developed. In-puts are : material-property(young's modulus, shear modulus, tensile strength, poisson's ratio, density), operating pressure, burst pressure, liner thickness, boss diameter, boss weight and number of helical angles. Out-puts are; thickness of each layer, weight of the vessel, dimension of the vessel, inner volume, dome-shape and helical winding angle. Also filament winding angles can be selected various kinds of utilizing virtual boss diameter.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1988.10a
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• pp.30-35
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• 1988

An analytical study was conducted using the Galerkin technique to determine the behaviour of thin fibre-reinforced and laminated composite pipes under soil pressure. Geometric nonlinearity and material linearity have been assumed. We assumed that vertical and lateral soil pressure are proportional to the depth and lateral displacement of the pipe respectively. And we also assumed that radial shear stress is negligible because the ratio of the thickness to the radius of pipe is very small. We, in this paper, discuss the effect of the number of layer, fiber orientation, and soil property.

• Journal of Fashion Business
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• v.12 no.6
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• pp.46-60
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• 2008

Lyocell is a regenerated cellulosic fiber manufactured by an environmentally friendly process. The major advantages of lyocell are the excellent drape forming property, the genuine bulkiness, smooth surface, and high dry/wet tenacities. However, one drawback of lyocell is its fibrillation property, which would degrade its aesthetic quality and lower the consumer satisfaction. In our previous studies, lyocell was treated with epichlorohydrin, a non-formalin based crosslinker, to reduce its fibrillation tendency. To investigate the changes of physical properties upon ECH-treatment, the hand characteristics of ECH-treated fabric were observed using KES-FB system and the 3D-virtual sewing image of the fabrics were obtained using 3D CAD simulation system in this study. Since epichlorohydrin(ECH) treatment was conducted in the alkaline medium, the weight reduction was observed in all treated lyocell. The treated lyocell became light, smooth and flexible in spite of ECH crosslinker application. LT and RT in tensile property upon the ECH treatment did not change significantly, however, EMT and WT in the tensile property increased. The significant decrease in bending rigidity was resulted in all ECH-treated lyocell, which is the result of the weight loss upon the alkali condition of ECH treatment. The bending rigidity increased again in the ECH 30% treated lyocell, however, the B value is still lower than the original. Therefore, the ECH-treated lyocell would be more stretchable and softer than the original. Shear rigidity was also decreased in all ECH-treated lyocell, which would result in more drape and body fitting when it is made as a garment. The ECH-treated fabric showed the softer smoother surface according to SMD value from KES evaluation. The virtual 3D sewing image of the ECH-treated lyocell did not show a significant change from that of the original except ECH 30% treated lyocell. ECH 30% treated lyocell showed a stiffer and more puckered image than the original.

• Journal of the Korean Wood Science and Technology
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• v.33 no.1 s.129
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• pp.7-16
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• 2005

This study was carried out to evaluate the structural property of double shear bolted connections in Korean Larch. For the main member, sawn lumber and Glulam were used in which thickness of lumber is 39 mm, 89 mm, 139 mm, 189 mm and Glulam 80 mm, 140 mm, 170 mm. For the side member, sawn lumber and steel plate were used in which thickness of lumber is the same of the main member and steel plate is 6mm. And connections were jointed by M12, M16, M20 bolts which were usually used for wood constructions in Korea. Directions of loading to connections were perpendicular and parallel to grain of main and side member. First, through the dowel bearing test, the dowel bearing strength was evaluated and through the bolt bending tests, the bolt bending strength was evaluated. And then experiments for the connection were performed. Obtained results from experiments were compared with calculated values by EYM and analyzed. Strength of double shear bolted connections in Korean Larch was similar or higher than calculated value by EYM. Especially when the side member was made by the sawn lumber, it was similar to the calculated value. In failure mode, the mode was effected by the knot and the dry defect. In the thin main member, it was shown mode I and as the thickness of the main member was thicker, it was changed into mode III.

• Korean Journal of Food Science and Technology
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• v.51 no.4
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• pp.330-335
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• 2019

The aim of this study was to investigate the rheological properties of arabinogalactans (AGs) solution isolated from moth bean (MB), navy bean (NB), and soybean (SB) including monosaccharide compositions, intrinsic viscosity, steady shear and dynamic shear rheological properties. The major monosaccharides in MB, NB, and SB were arabinose (64.8, 51.4, and 42.6%) and galactose (13.4, 19.6, and 46.2%). The yield stresses for 5% (w/v) NB and 2.5% (w/v) SB solutions were assessed as 2.10 Pa and 1.98 Pa, respectively, but in case of MB solution, it was observed to be negligible. While 5% MB solution showed rheopectic property, 5% NB and SB solutions showed thixotropic properties. As a result of frequency sweep experiment, the G' values in 2.5% MB and NB were larger than the G" value showed but 2.5% SB exhibited G" value greater than G'. These results would be useful for future application as a food additive in the food industry.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.1
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• pp.112-124
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• 1997

According to extensive use of composite resin which have superior esthetic property, every effort on improving bonding strength between a tooth and composite resin has been continued. Acid etching technique is a method that micro-etches the tooth surface which provides bonding with composite resin possible. Recently, there were several reports that mechanical treatment obtained from air-abrasion can provide similar bonding strength with acid etching technique. So, this experimental study was designed to compare the shear bonding strength between using air-abrasion technique and using acid etching technique. Initially, bovine teeth were divided into enamel and dentin experimental groups. Respectively each group was categorized into three subgroups. One subgroup was acid etched with 35% phosphoric acid, then bonded with composite resin. The other subgroup was air-abraded with $50{\mu}m$ $Al_2O_3$ particles sprayed with 160psi air pressure using air abrasion unit(KCP-1000, A.D.T., U.SA), and composite resin was bonded. In another subgroup, composite resin was bonded after acid etching following air-abrasion. So, enamel experimental groups were made of E1 (acid etched only), E2(air-abraded only), E3(acid etched following air-abraded), and dentin experimental groups were made of D1(acid etched only), D2(air-abraded only), D3(acid etched following air-abraded). Each subgroup had 10 specimens. Dentin bonding system(Scotchbond Multi-purpose, 3M Co., U.S.A.) and composite resin(Z-100, 3M Co., U.S.A.) were applied on treated surface using 5mm diameter gelatin capsule as manufacturer's direction. After 1200 times thermocycling between $5^{\circ}C$ and $55^{\circ}C$, shear bond strength was measured in 5mm/min crosshead speed with Instron(Instron Co., U.S.A.), and also treated enamel and dentin were observed with SEM(JEOL Co., Japan). The following results were obtained: 1. In the enamel experimental groups, acid etched following air-abraded group had highest shear bond strength, but there was no significant difference compared to acid etched group. Air-abraded only group had lowest shear bond strength, and there was significant difference compared to the rest of groups. 2. In the dentin experimental groups, acid etched following air-abraded group had highest shear bond strength, but there was no significant difference compared to acid etched group. Air-abraded only group had lowest shear bond strength, and there was significant difference compared to the rest of groups. 3. In the SEM study, air-abraded enamel and dentin had irregular and rough surfaces.

• International Journal of Highway Engineering
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• v.20 no.1
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• pp.87-95
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• 2018

PURPOSES : A geo-grid pavement, e.g., a stress-absorbing membrane interlayer (SAMI), can be applied to an asphalt-overlay method on the existing surface-pavement layer for pavement maintenance related to reflection cracking. Reflection cracking can occur when a crack in the existing surface layer influences the overlay pavement. It can reduce the pavement life cycle and adversely affect traffic safety. Moreover, a failed overlay can reduce the economic value. In this regard, the objective of this study is to evaluate the bonding properties between the rigid pavement and a SAMI by using the direct shear test and the pull-off test. The predicted fractural energy functions with the shear stress were determined from a numerical analysis of the moving average method and the polynomial regression method. METHODS : In this research, the shear and pull-off tests were performed to evaluate the properties of mixtures constructed using no interlayer, a tack-coat, and SAMI with fabric and without fabric. The lower mixture parts (describing the existing pavement) were mixed using the 25-40-8 joint cement-concrete standard. The overlay layer was constructed especially using polymer-modified stone mastic asphalt (SMA) pavement. It was composed of an SMA aggregate gradation and applied as the modified agent. The sixth polynomial regression equation and the general moving average method were utilized to estimate the interlayer shear strength. These numerical analysis methods were also used to determine the predictive models for estimating the fracture energy. RESULTS : From the direct shear test and the pull-off test results, the mixture bonded using the tack-coat (applied as the interlayer between the overlay layer and the jointed cement concrete) had the strongest shear resistance and bonding strength. In contrast, the SAMI pavement without fiber has a strong need for fractural energy at failure. CONCLUSIONS : The effects of site-reflection cracking can be determined using the same tests on cored specimens. Further, an empirical-mechanical finite-element method (FEM) must be done to understand the appropriate SAMI application. In this regard, the FEM application analy pavement-design analysis using thesis and bonding property tests using cored specimens from public roads will be conducted in further research.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.85-89
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• 2000

There has recently been some trials to add the fluoride-releasing property to existing fissure sealants and some of them are already commercially available. But, some questions mat naturally be arisen regarding the potential decrease of physical properties by adding the fluoride despite its new caries-inhibiting abilities. This study was performed for the purpose of comparing the shear bond strengths of conventional composite sealant, Fluoride-releasing sealant and glass ionomer sealant, and obtained the results as fellows. 1. Two kinds of composite sealants (Helioseal and Teethmate-A) showed slightly higher bond strength than Fluoride-releasing sealant(Teethmate-F) without any significance(p>0.05). 2. Class ionomer sealant (Fuji III) was much lower than composite sealant in shear bond strength(p<0.05). 3. With the result of this study, it was found that there is little effect on retentive properties of sealants by adding fluoride to amplify the caries-inhibiting properties.

• Journal of the Korean Geotechnical Society
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• v.21 no.3
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• pp.5-17
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• 2005

Spatial uncertainty of Busan marine clay ground, which commonly occurs during site investigation testing, data analysis and transformation modeling, has been described. In this paper geotechnical uncertainty of shear strength indicator $N_k$ has been quantified in both horizontal direction and vertical direction using geostatistical Kriging method. Most of soil data used are from 25 boring tests, 75 laboratory tests, 124 field vane tests and 25 cone penetration tests (CPT). CPT-$N_k$ data for undrained shear strength determination, which are the most important properties in geotechnical design stages, have been analysed. Comparison between cone factor from conventional CPT-based method and that of geostatistical method shows that geostatistical Kriging method is an ideal tool to quantify the spatial variability of uncertainty from self-correlation of soil property of interest, and can be recommended to identify the spatial distribution of consolidation .md shear strength of soils at any sites concerned.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4A
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• pp.303-309
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• 2011

Laminated rubber bearing is the most commonly used device for seismic base isolation of bridge structures. It is important to know performance and behavior characteristics of the laminated rubber bearings. The main evaluation factors of the rubber bearing are classified as compressive, shear and tensile behavior characteristics. The reference data of compressive and shear characteristics are rich, but the reference data of tensile characteristics is scarce. In this study, tensile test results of the rubber bearing with variation of shape factor and shear deformation are investigated for mechanical property. When tensile deformation in normal condition is increasing, tensile cycle behavior curve becomes non-linear and tensile breaking point is 300%. On the other hand, tensile breaking point is shear deformation condition is about 40%. Furthermore, when shape factor is lower, tensile breaking point is decrease. This results mean that tensile breaking point is decreased in triaxial tensile deformation because of cracks caused by internal void of the rubber bearings. This experimental data can be used as the reference data of tensile characteristics for designing seismic isolation of structures.