Shape determining of a loaded cable via total displacements
Abstract Cable structures are very efficient (in economic aspect) when applied to cover large spans. The cable structure consists of a single cable or a network of cables. The cable attractive feature is the highest ratio of strength to weight amongst other carrying structural elements, usually applied in engineering practice. But a cable is a specific structural element able to response only one type of deforming ‐ tension (flexural rigidity actually vanishes). Therefore, when loaded a cable shapes the form to resist tension only. This adaptation is followed by large nonlinear displacements. Thus, the nature of geometrical nonlinear cable behavior is quitie a different from that of rigid structural elements. Both elements response via small deformations when loaded, but large displacements of a cable are conditioned by its adaptation to loading, and those of rigid structural elements ‐ by actual deformations. One can also note that deformations of a cable are significantly less than those of rigid struct...
Half-span loading of cable structures
Abstract Continuous analysis of prestressed cable structures under the action of symmetrical loads leads us to a cubic equation in regard to relative deflection of the structure. For the case of nonsymmetrical loads, a simple solution may be derived only for a single cable. For composite cable structures, a direct solution to the problem requires the use of relatively complicated expansion into a series in terms of deflection parameters. A simpler solution may be found by means of division of the load into a symmetrical and an antisymmetrical part and subsequent equations to provide the solution. The validity of this will be substantiated in the first part of this presentation. As a result of using this method we can obtain a relatively simple solution to the problem for different prestressed cable structures. The corresponding dependence of deflections and inner forces of the structure upon the main cable parameters and comparison of the solution obtained with the exact results is presented.
Exopolysaccharide biosynthesis and related enzyme activities of the medicinal fungus, Ganoderma lucidum, grown on lactose in a bioreactor
Exopolysaccharide (EPS) production and biosynthesis were studied in Ganoderma lucidum, a fungus used in traditional Chinese medicine, grown with lactose in a bioreactor. β-Galactosidase activity, which implies the existence of a lactose permease system, was induced by lactose. Lactose feeding also increased α-phosphoglucomutase activity and EPS accumulation but decreased phosphoglucose isomerase activity and lactate concentration in the culture broth. A maximum cell density of 22 g l−1 and EPS at 1.25 g l−1 were obtained in fed-batch bioreactor culture.