• Structural Engineering and Mechanics
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• 제71권5호
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• pp.469-483
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• 2019

In this paper, an improved mathematical model is presented for the bending analysis of doubly curved functionally graded material (FGM) sandwich rhombic conoids. The mathematical model includes expansion of Taylor's series up to the third degree in thickness coordinate and normal curvatures in in-plane displacement fields. The condition of zero-transverse shear strain at upper and lower surface of rhombic conoids is implemented in the present model. The newly introduced feature in the present mathematical model is the simultaneous inclusion of normal curvatures in deformation field and twist curvature in strain-displacement equations. This unique introduction permits the new 2D mathematical model to solve problems of moderately thick and deep doubly curved FGM sandwich rhombic conoids. The distinguishing feature of present shell from the other shells is that maximum transverse deflection does not occur at its center. The proposed new mathematical model is implemented in finite element code written in FORTRAN. The obtained numerical results are compared with the results available in the literature. Once validated, the current model was employed to solve numerous bending problems by varying different parameters like volume fraction indices, skew angles, boundary conditions, thickness scheme, and several geometric parameters.

• 대한수의학회지
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• 제37권4호
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• pp.817-823
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• 1997

Suckling piglets and weaned pigs showed anorexia, dehydration, severe abdominal breathing, emaciation and paresis from Oct. 1993. to Nov. 1993. Five 2-week-old piglets were submitted for diagnosis in Kangwon National University. At necropsy, the pin-point well demarcated yellowish white foci were scattered on the surface of the lung, heart, liver, spleen and kidney. Histologically, multifocal areas of necrosis with mononuclear cells infiltration were found in the lung, heart, liver, lymph node, spleen, kidney and small intestine. These lesions tended to be associated with blood vessels. Variable round to ovoid tachyzoites were located at the periphery of the lesions. The organisms were demonstrated as Toxoplasma gondii by immunohistochemical staining method. Ultrastructurally, this parasite was surrounded with parasitophorous vacuole in alveolar macrophage. The parasite was crescent-shaped and $6{\sim}8{\times}1{\sim}2{\mu}m$ in size. It was enclosed by an thick outer membrane and an underlying thin inner membrane. Several club-shaped paired organelles and conoids lay in the cytoplasm at the anterior. Numerous round body and one to several mitochondria were presented in the cytoplasm. Based on the gross findings, histopathology, immunohistochemical and electron microscopic findings, this case was diagnosed as toxoplasmosis in piglets.