• 대한기계학회논문집A
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• 제36권9호
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• pp.961-970
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• 2012

두께가 다른 이종강도 배관 용접부에서 인장, 내압 및 굽힘응력에 대한 하중지지능력을 평가하였다. 1.22, 1.54 및 1.89의 두께비를 갖는 API X65-API X80, API X42-API X65 및 API X42-API X80 배관 용접부를 유한요소해석을 통하여 하중지지능력을 평가하였다. 이종강도 배관의 두께비가 1.5 이하에서 인장강도와 최대모멘트는 면삭각도 변화에 큰 영향을 받지 않으나 두께비가 1.5 이상에서는 큰 영향을 받는다. 저강도 배관의 길이방향 면삭각도와 두께비 변화에 따라서는 내압에 의한 파열압력은 영향을 받지 않는다.

• Steel and Composite Structures
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• 제22권5호
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• pp.1073-1084
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• 2016

Rectangular concrete-filled steel tubular columns with unequal wall thickness were investigated in the paper. The physical centroid, the centroidal principal axes of inertia, and the section core were given. The generalized bending formula and the generalized eccentric compression formula were deduced, and the equation of the neutral axis was also provided. The two rectangular concrete-filled steel tubular stub specimens subjected to the compression load on the physical centroid and the geometric centroid respectively were tested to verify the theoretical formulas.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.258-262
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• 2004

An analytical method for the free vibration of two circular plates coupled with a fluid was developed by the Rayleigh-Ritz method. The two plates with unequal thickness and diameter are clamped along the cylindrical vessel wall. It is assumed that the fluid bounded by a rigid cylindrical vessel is incompressible and non-viscous. The wet mode shape of the circular plates is assumed as a combination of the dry mode shapes of the plates. The fluid motion is described by using the fluid displacement potential and determined by using the compatibility conditions along the fluid interface with the plate. Minimizing the Rayleigh quotient based on the energy conservation gives a eigenvalue problem. It is found that the theoretical results can predict well the fluid-coupled natural frequencies with excellent accuracy comparing with the finite element analysis result.

• Applied Microscopy
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• 제14권2호
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• pp.38-51
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• 1984

Fine structure of dormant and swollen conidiospore from Trichoderma koningii and the mechanism of protoplasting from the conidiospore were studied by scanning and transmission electron microscopy. The cell wall of dormant conidiospore was two-layered structure which consisted of electron dense outer layer and electron transparent inner layer. After 8.5 hrs incubation. the conidiospore was swollen and the outer layer of cell wall shown unequal thickness and partial breakage. Protoplast was released through the pore which has been formed by the breakage of outer layer and dissolution of newly synthesized cell wall for germ-tube formation. Swollen conidiospore and protoplast in releasing process contained various cell organelles and vacuoles with electron dense materials. The protoplast contained looser cytoplasm and had no cell wall materials outside of plasmamembrane.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.906-910
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• 2004

An analytical method for the free vibration of two annular plates coupled with water was developed by the Rayleigh-Ritz method. The two plates with unequal thickness are clamped along a rigid cylindrical vessel wall. It is assumed that the fluid bounded by a rigid cylindrical vessel is incompressible and non-viscous. The wet mode shape of the annular plates Is assumed as a combination of the dry mode shapes of the plates. The fluid motion is described by using the fluid displacement potential and determined by using the compatibility conditions along the fluid interface with the plate. Minimizing the Rayleigh quotient based on the energy conservation gives an eigenvalue problem. It is found that the theoretical results can predict well the fluid-coupled natural frequencies comparing with the finite element analysis result.

• Journal of Plant Biology
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• 제30권1호
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• pp.21-30
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• 1987

The effects of abscisic acid(ABA) spraying for 12 weeks on the stomatal types and frequencies of O. malacophyllus leaves were summarized as follows. ABA inhibited the growth of O. malacophyllus. The prominent effect of ABA on the epidermal structure was the promotion of senescence such as thickness of cell walls, smooth sinuosity of cell walls, and large size of epidermal cells. The stomatal frequency was decreased to 23% by 10$\mu\textrm{g}$ ml-1 ABA and to 48% by 100$\mu\textrm{g}$ml-1, and also the stomatal size was more or less smaller than that of control. The developing secondary stomatal mother cell was not found in both 10 and 100$\mu\textrm{g}$ml-1ABA, but the arrested secondary stomatal mother cell was rarely found in 10$\mu\textrm{g}$ ml-1 ABA. The formation of normal stomatal types such as helico-eumesogenous and aniso-eumesogenous was found in both 10 and 100 $\mu\textrm{g}$ ml-1 ABA asin well as control. Also nine abnormal stomatal types were found, and the frequencies were promoted to 6% by 10 $\mu\textrm{g}$ ml-1 ABA and to 17% by 100 $\mu\textrm{g}$ ml-1 ABA. Among these abnomal stomata, four types such as aborted stomata, single-aborted guard cells, arrested stomata, and modified stomatal complexes were found in control as well as in 10 and 100 $\mu\textrm{g}$ ml-1 ABA, but five types such as wrenched stomata, unequal stomata, wavy guard cells, guard cells overlapped by guard cells, and dissolved cell wall stomata were found in both 10 and 100 $\mu\textrm{g}$ ml-1ABA. The modified stomata complexes were abnormal stomatal types which were newly found and also were varied in types.