8 research outputs found
Neoarchean-mesoproterozoic mafic dyke swarms of the indian shield mapped using google earth⢠images and arcgisâ˘, and links with large igneous provinces
We present dyke swarm maps generated using Google Earth⢠images, ArcGISâ˘, field data, and available geochronological ages of Neoarchean-Mesoproterozoic (ranging in age from ~2.80 to ~1.10Ă Ga) mafic dyke swarms and associated magmatic units of the different Archean cratons of the Indian shield which represent the plumbing system of Large Igneous Provinces (LIPs). The spatial and temporal distributions together with the trends of the dyke swarms provide important informations about geodynamics. Twenty four dyke swarms (17 have been precisely dated), mostly mafic in nature, have been mapped from the different cratons and named/re-named to best reflect their location, trend, distribution and distinction from other swarms. We have identified 14 distinct magmatic events during the Neoarchean-Mesoproterozoic in the Indian shield. These intraplate magmatic events (many of LIP scale) of the Indian shield and their matches with coeval LIPs on other crustal blocks suggest connections of the Indian shield within known supercontinents, such as Kenorland/Superia (~2.75â2.07Ă Ga), Columbia/Nuna (1.90â1.38Ă Ga), and Rodinia (1.20â0.72Ă Ga). However, further detailed UâPb geochronology and associated paleomagnetism are required to come to any definite constraints on the position of the Indian cratons within these supercontinents
Response reduction factor of irregular RC buildings in Kathmandu valley
Most current seismic design includes the nonlinear response of a structure through a response reduction
factor (R). This allows the designer to use a linear elastic force-based approach while accounting for nonlinear behavior and
deformation limits. In fact, the response reduction factor is used in modern seismic codes to scale down the elastic response
of a structure. This study focuses on estimating the actual âRâ value for engineered design/construction of reinforced concrete
(RC) buildings in Kathmandu valley. The ductility and overstrength of representative RC buildings in Kathmandu are
investigated. Nonlinear pushover analysis was performed on structural models in order to evaluate the seismic performance
of buildings. Twelve representative engineered irregular buildings with a variety of characteristics located in the Kathmandu
valley were selected and studied. Furthermore, the effects of overstrength on the ductility factor, beam column capacity ratio
on the building ductility, and load path on the response reduction factor, are examined. Finally, the results are further analyzed
and compared with different structural parameters of the buildings
Structure and Content of the Entamoeba histolytica Genome
The intestinal parasite Entamoeba histolytica is one of the first protists for which a draft genome sequence has been published. Although the genome is still incomplete, it is unlikely that many genes are missing from the list of those already identified. In this chapter we summarise the features of the genome as they are currently understood and provide previously unpublished analyses of many of the genes