Non-linear soil structure interaction of shear wall system with super element
Shear wall is commonly employed as a principal element to resist lateral loads due to wind or earthquake forces. An accurate model for shear wall system needs to consider the effect of all components for analyses i.e. shear wall, foundation and subsoil. This investigation presents modeling of shear wall structure - foundation and soil system using the super element, finite and infinite elements after considering soil nonlinearity. A finite element program has been written based on the proposed physical and material model for the analysis of the system. The applicability of the proposed idealization has been shown by analyzing a shear wall structure under static loading. In order to explore the efficiency of using super elements, an attempt has also been made to model the shear wall building using fully conventional finite element discretization. Furthermore the paper investigates the necessity of including soil structure interaction in analyzing shear wall structures. The results obtained from the analysis of shear wall model considering five different types of soil for the soil media show that the influence of soil interaction is very significant in the displacement as well as stresses induced in shear wall. Furthermore this investigation highlighted the effect of considering nonlinearity of soil in total displacement and stresses in shear wall system.
A quadratic order elastic foundation finite element
A new quadratic order elastic foundation element is presented. It models the vertical subgrade reaction and the shear stiffness of the soil as well as the friction between the super structure and the soil. This element gives the ability to analyze the super structure with the nine-noded quadrilateral plane elements as it has the same quadrature order. Three different applications are analyzed to adapt the accuracy of the new model. All of the results are in good shape.
BIOSYNTHESIS OF DAUNORUBICIN GLYCOSIDES: ANALYSIS WITH BLOCKED MUTANTS
ABSTRACT Daunorubicin (daunomycin; NSC 82151) is an anthracycline antibiotic that is useful in the treatment of human leukemias. Several Streptomyces species accumulate higher glycosides of daunorubicin, which can be converted to daunorubicin by simple hydrolysis. We isolated a number of mutants of a daunorubicin glycoside-producing streptomycete, and found that some were deficient in accumulation of daunorubicin glycosides. One such mutant accumulated no detectable anthracyclines, while other mutants accumulated anthracyclines or aglycones that have not been reported before or have been described as co-metabolites of daunorubicin glycosides. Some of these anthracyclines and aglycones were purified and used as substrates in bioconversion experiments with various mutants. The results allowed us to construct a proposed pathway for the biosynthesis of daunorubicin glycosides by this streptomycete. KEYWORDS Anthracycline; daunorubicin; biosynthesis; blocked mutants; biotransformation.