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Abstract: The adequacy of the 30%-rule to predict the seismic demand on bridge columns subjected to bi-directional earthquake components is examined for two North American sites in areas of moderate seismic hazard: Montreal, in the east, and Vancouver, along the west coast. For both sites, historical and simulated ground motion earthquake ensembles are considered. Time history analyses were performed on generic bridge models to determine the critical response of the columns under pairs of orthogonal seismic ground motion time histories. Response spectrum analyses were also carried out to determine the maximum response in each direction and the critical response was estimated using the 30%-rule. The results show that the combination rule is tributary of both ground motion and bridge characteristics. Results also show that the 30%-rule as currently prescribed in codes leads to an adequate estimation of the bi-directional elastic seismic demand on regular bridge columns. [Copyright &y& Elsevier]

Flounders (Pleuronectiformes) from eastern North America have been extensively studied over the last few decades, and most of that work has been oriented towards different aspects related to fish production, i.e., aquaculture. However, aquaculture production has not progressed as it might have been expected. Flounders are omnivorous, euryhaline, inhabit shore habitats, and offer good potential for aquaculture diversification. They are found all along the eastern coast of Canada and the US, and different species occupy coastal habitats with some species overlapping in certain areas. Despite specific biological and ecological requirements for each species, the accumulated knowledge on breeding, larval rearing, juveniles, and stock enhancement creates a frame of reference that is often underestimated but that indicates a promising future for the production of these fishes. [ABSTRACT FROM AUTHOR]

Hollow structural sections for onshore steel construction are manufactured in diverse locations around the world, by either a hot-finishing or seamless process or - far more commonly - by cold-forming. The implications of using material by a particular process in various statically loaded or dynamically loaded applications are not fully appreciated. This paper hence reviews some of the key geometric and material properties that are inherent in several common hollow section production standards. Problems that have been encountered with certain cold-formed square and rectangular hollow sections, particularly with regard to hot-dip galvanising in North America and Asia, are elaborated. Besides galvanising, these same sections are now also subject to constraints for seismic applications. The difference in seismic performance between cold-formed, cold-formed and stress-relieved, and hot-finished hollow sections, when used as energy-dissipating members such as braces, has been a point of debate and speculation to date. An experimental project, in which the relative performance of each material type is evaluated by performing inelastic cyclic testing of large-scale tubular braces, is described, with comments on the suitability of various tube material types for concentrically braced steel frames under severe seismic loading. Considering all of these material and production issues, an industry-driven reappraisal of the cold-formed hollow structural section manufacturing specification in North America is being undertaken, which is also presented herein. [ABSTRACT FROM AUTHOR]