1. INTRODUCTION In a previous study, Weir & Schluter [1] (hereafter WS2007) argue that smaller average genetic distances between species in cooler latitudes represent faster rates of speciation relative to tropical species. Such an interpretation assumes clades evolve at constant rates across latitudes so that a hypothetical molecular clock ticks at the same rate, regardless of climate. By cont...

Subject to the assumption that sub-barrier fusion is described by an effective one-dimensional energy-independent local potential barrier, the Jeffreys-Wentzel-Kramers-Brillouin approximation for the fusion cross sections is inverted to determine this effective potential. Potential barriers, with their associated experimental errors, are presented for 13C+ 13C and 40Ca+ 40Ca, and the assumption...

In this paper, the concept of ∂-quasiconvexity is introduced by using convexifactors. Mond-Weir-type and Schaible-type duals are associated with a multiobjective fractional programming problem, and various duality results are established under the assumptions of ∂-pseudoconvexity and ∂-quasiconvexity.

In this paper, we are concerned with a nondifferentiable multiobjective programming problem with inequality constraints. We introduce four new classes of generalized convex functions by combining the concepts of weak strictly pseudoinvex, strong pseudoinvex, weak quasi invex, weak pseudoinvex and strong quasi invex functions in Aghezzaf and Hachimi [Numer. Funct. Anal. Optim. 22 (2001) 775], d-...

At high water stages, obstacles (submerged and particularly emerged vegetation) in the flood plains of a river contribute to the flow resistance and hamper the conveyance capacity. In particular the elevated vegetated parts are expected to play an important role. The objective of this research work is to determine the form drag due to vegetated oblique weir-like obstacles. Experiments have been...

Sedimentation upstream of a weir is common phenomenon, especially for river with high sedimentation. In the long term, this can lead to problems since discharge capacity will decrease due rise riverbed, as experienced in Bekasi Weir, West Java, Indonesia. The accumulated sediments increased up 1.5 m from its original riverbed decade. One easiest ways overcome issue return elevation actual by ma...