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S. Yousefikhatoni, H. Shokati, M. Shaikhbagloo,
Volume 11, Issue 4 (12-2011)
Abstract
Steel shear walls has been noticed against wind and earthquake lateral loads about high
buildings in the last three decades. This modern phenomenon is growing rapidly worldwide so
that system have been employed highly in construction of new buildings and seismic
upgrading of existing buildings in some countries such as USA and JAPAN. That is a very
simple system from viewpoint of implementing and there isn’t particular complexity. High
strength and ductility are main advantages of these systems. Current paper has investigated
comparatively behavior of steel shear walls made of smooth and corrugated sheets. Also the
paper has assessed push-over curves and cyclic binding. According to this result of the
research, corrugated steel shear walls have lower ductility than smooth shear walls. The
research also founded that despite the high strength of corrugated sheets in low displacement,
behavior of flat shear walls is more stable than corrugated shear walls. On the other hand flat
steel shear walls attract energy more than corrugated shear walls. Therefore using of flat shear
walls is recommended in high seismic regions.
In this research, 18 samples of flat steel shear walls and corrugated shear walls were
modulated. In all models, panels height were 3 m and panels span were 3, 4 and 5 m. the
thickness of sheets in the samples were 3, 4 and 5mm.
According to results of the research:
1- Corrugated sheets are unstable and unpredictable in high thinness. In the low displacements
occurs a mutation state, so it distinguishes the corrugated and flat shear walls behavior.
2- At low displacement, a corrugated sheet bears greater load than a flat sheet.
3- In a constant thickness for thinner corrugated sheets is increased the mutation rate and its
behavior becomes more non-uniform.
4- Despite of the fact, pynchyng phenomenon appears in all samples, but all samples behavior
is stable and significant energy attraction is observed.
Volume 13, Issue 3 (8-2010)
Abstract
Objective: As we are approaching the global eradication of wild poliovirus, laboratory surveillance of poliovirus by the gold standard cell culture method becomes increasingly important. As there is a lot of concern about accurate and sensitive detection of imported wild and Vaccine Derived Polioviruses (VDPVs) in Polio-Free countries, in this study we assessed and compared the sensitivity of the cell lines used in polio laboratory simultaneously to standard poliovirus and Oral Polio Vaccine (OPV) polioviruses, to ensure the accurate detection of circulating and imported polioviruses in the society.
Materials and Methods: Cell sensitivity test was performed according to the World Health Organization (WHO), Polio Laboratory Manual for RD, L20B and Hep2 cell lines using 3 serotypes of standard monovalent and OPV polioviruses. The test was repeated every four passages for all cell lines.
Results: The sensitivity of L20B and Hep2 cell lines for standard poliovirus type 1 and 2 is more than sensitivity for the same types of OPV virus but for poliovirus type 3 it is vice versa. Also RD cell line is more sensitive to all 3 types of OPV virus. In addition, the test showed that increasing the passage number will decrease the sensitivity of all cell lines.
Conclusion: Using RD & L20B cell lines simultaneously (with low passage number) will assure us of sensitivity and accuracy of the cell lines for detection of circulating and imported polioviruses.