• 대한조선학회 특별논문집
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• 대한조선학회 2007년도 특별논문집
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• pp.135-141
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• 2007

CSR(Common Structure Rules) enter into force on $1^{st}$ April 2006. Generally for double hull tankers of less than 150m in length, the Rules of the individual Classification Society are to be applied. Where high tensile stresses act through an intermediate plate, increased fillet welds or penetration welds are to be used longitudinal/transverse bulkhead primary support member end connections to the double bottom. If workers have begun to make used of established procedures between corrugated BHD and lower stool joint, first to welding on groove of face and then it has to gouging to blow on groove of root. So amount of man-hour increased, productivity secreased.

• 한국가구학회지
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• 제18권2호
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• pp.161-165
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• 2007

An experiment was conducted to observe the safranine flow depth in longitudinal direction of Populus tomentiglandulosa. Longitudinal flow of safranine was considered from bottom to top end of the tree. Vessel and wood fiber were considered for the measurement of safranine flow depth. It was found that sapwood conducted safranine 12.25% higher in longitudinal direction compared with heartwood. Vessel was found the main avenue for safranine flow. Vessel conducted safranine 41.94% higher than that of wood fiber. Safranine penetrated through vessel and fiber forming a curved meniscus.

• 한국가구학회지
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• 제12권1호
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• pp.1-9
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• 2001

This study was carried out to elucidate the relationship between wood anatomy and the water flow path in P. koraiensis and L. leptolepis. through the experiment of penetration of the dye solution. The experiment was performed by permeating 1% acid, alkali and direct solution into the xylem just after being cut. The results obtained were summarized as follows : 1. In P. koraiensis and L. leptolepis, the dye solution penetrated into sapwood and annual rings adjacent to cambial zone were only dyed according to ascent of tree height. 2. The penetrability of latewood was better than that of earlywood. 3. In P. koraiensis and L. leptolepis, the main water flow path in longitudinal direction was the trachied and that in transverse direction was ray trachied and ray parenchyma. Also, the dye solution was found in resin canal. 4. P. koraiensis was more permeable than L. leptolepis. 5. Among the acid, alkali and direct dye solution, the acid dye solution was the most permeable.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 봄 학술발표회 논문집
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• pp.343-350
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• 1999

Orthotropic steel bridge decks are potentially liable to cause fatigue cracks due to weld defects, residual stresses, and in-plane or out-of-plane stresses. In particular, the cracks propagated through deckplate in longitudinal rib to deckplate joints occur at weld toe and weld root due to stress concentrations. Numerical parametric studies are performed to show the Influence of the parameters on the stress concentration at the connection between the longitudinal rib and the deckplate. The parameters include root gap, toe angle $\theta$, toe radius $\rho$, and weld penetration. This study provides a fundamental point for the improvement of fatigue resistance and the estimation of the fatigue crack propagation in wekded joint details.

• 한국해양공학회지
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• 제13권2호통권32호
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• pp.51-57
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• 1999

In this study, one side fillet welded T-joint, used in box type girder and other welding structure, was investigated by stress analysis and bending fatigue test without edge preparation, with variation of joint shape. The purpose of this study is to give the welding condiltion and design standard on manufacturing one side fillet welded T-joint. As a result, the following conclusions were obtained. 1) In one side fillet welded T-joint, the larger the leg length and the penetration depth, the greater the bending fatigue strength because reduction of stress and strain on toe and root. The increase of the longitudinal leg length rather than vertical leg length contributed to the increase in bending fatigue strength. 2) In one side fillet welded T-joint without edge preparation, both general manual welding and general automatic welding were carried out with same condition. In this case, automatic welding showed deeper penetration and more increased longitudinal leg length than manual welding, so that automatic welding offers greater bending fatigue strength. 3) For one side fillet welded T-joint without edge preparation with automatic welding, the ratio(h/t) of the leg length(h) and the main plate thickness(t) in which toe crake can occur was 1.0 over.

• Steel and Composite Structures
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• 제22권3호
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• pp.567-587
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• 2016

The present investigation is to study the plane wave propagation and reflection of plane waves in a homogeneous transversely isotropic magnetothermoelastic medium with two temperature and rotation in the context of GN Type-II and Type-III (1993) theory of thermoelasticity. It is found that, for two dimensional assumed model, there exist three types of coupled longitudinal waves, namely quasi-longitudinal wave (QL), quasi-transverse wave (QTS) and quasi-thermal waves (QT). The different characteristics of waves like phase velocity, attenuation coefficients, specific loss and penetration depth are computed numerically and depicted graphically. The phenomenon of reflection coefficients due to quasi-waves at a plane stress free with thermally insulated boundary is investigated. The ratios of the linear algebraic equations. These amplitude ratios are used further to calculate the shares of different scattered waves in the energy of incident wave. The modulus of the amplitude and energy ratios with the angle of incidence are computed for a particular numerical model. The conservation of energy at the free surface is verified. The effect of energy dissipation and two temperatures on the energy ratios are depicted graphically and discussed. Some special cases of interest are also discussed.

• 한국수소및신에너지학회논문집
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• 제11권3호
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• pp.127-136
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• 2000

Molecular dynamics simulations have been carried out to investigate the scattering and penetration properties of hydrogen ions with the normal incident angle to Ni (100) surface. The initial kinetic energies of hydrogen ions range from 100 to 1,600 eV. The simulation results are used to assess the applicabilities of theoretical predictions based on the binary collision approximation, and, in the high kinetic regime, theoretical results for scattering energies were shown to he a good agreement with molecular simulations. The angle dependencies on both scattering and penetration distributions were found in the longitudinal direction, but not in the azimuthal direction except for the high kinetic energy of 1,600 eV.

• Journal of Welding and Joining
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• 제28권1호
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• pp.72-76
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• 2010

Irregular fluctuation of penetration depth in CW single mode fiber laser welding is analyzed statistically and chaotically. Among various chaos theories, one of the basic concept referred as Lyapunov exponent is applied to the analysis to quantify the irregularity of penetration. Especially, maximal Lyapunov exponent (MLE) is known as the representative value indicating chaotic degree of the system dynamics. MLE calculation method of experimental data is applied to longitudinal spiking defect in fiber laser weld. Laser power modulation is suggested as a remedy then the computed MLE value is compared to CW case. It is shown that the adoption of chaos theory, MLE computation, can be used as a measurement standard to prove the validity of the solutions to prevent the unexpected chaotic behavior of weld through this work.

• Coupled systems mechanics
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• 제12권2호
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• pp.103-125
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• 2023

The present research is focused on the study of plane harmonic waves in a two-dimensional orthotropic magneto-thermoelastic media with fractional order theory of generalized thermoelasticity in the light of two-temperature and rotation due to time harmonic sources. Here, we studied three types of waves namely quasi-longitudinal (QL), quasi-transverse (QTS) and quasi thermal (QT) waves. The variations in the wave properties such as phase velocity, attenuation coefficient and specific loss have been noticed with respect to frequency for the reflected waves. Further the value of amplitude ratios, energy ratios and penetration depth are computed numerically with respect to angle of incidence. The numerical simulated results are presented graphically to show the effect of fractional parameter based on its conductivity (0<α<1 for weak, α=1 for normal, 1<α≤2 for strong conductivity) on all the components.

• Restorative Dentistry and Endodontics
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• 제12권2호
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• pp.17-23
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• 1987

The purpose of this study was to evaluate the sealing properties of endodontic cavity filling materials according to the time intervals after filling. Access cavities were prepared in extracted human premolar or molar teeth and filled with caviton, zinc oxide eugenol cement, zinc oxide eugenol cement with a base of gutta percha stopping and gutta percha stopping. After filling at the intervals of immediate, 2 days and 2 weeks the teeth were immersed for 2 weeks in 1% methylene blue solutions. Longitudinal sections were obtained from approximately center of teeth and the depth of dye penetration into the access cavities were observed by 10${\times}$macrolens. The following results were obtained. I. All the materials experimented showed varying depth of dye penetration. 2. Of the material tested, caviton showed the best marginal sealing qualities regardless of the time intervals after filling and the sealing properties of the gutta percha stopping was the worst. 3. Both in zinc oxide eugenol cement and zinc oxide eugenol cement with a base of gutta percha stopping, the fillings allowed to mature for 2 days in normal saline solution showed the best sealing properties and those with no maturing time revealed the worst sealing qualities. 4. The sealing qualities of zinc oxide eugenol cement with a base of gutta percha stopping revealed slightly lower depth of dye penetration than that of zinc oxide eugenol cements.