The critical zones are the discontinuities along a railway line that highly susceptible to differential settlement, due an abrupt variation in support conditions over short span. Consequently, these require frequent maintenance ensure adequate levels of passenger safety and comfort. A proper understanding behavior tracks at is imperative enhance their performance reduce frequency costly operati...

<p style='text-indent:20px;'>In this paper, we consider the nonsmooth bifurcation around a class of critical crossing cycles, which are codimension-2 closed orbits composed tangency singularities and regular orbits, for two-parameter family planar piecewise smooth system with two zones. By construction suitable displacement function (equivalently, Poincar<inline-formula><tex-math...

The effect of quench rate on the natural aging behavior was examined using microhardness, conductivity and the differential scanning calorimeter. The data indicated that GPZ formed during extended natural aging of 7075, while extended aging of 7050 resulted in the precipitation of η’. Introduction The aluminum alloy system Al-Zn-Mg-Cu is the mainstay of aluminum alloys used in the aerospace ind...

Identification of critical habitat is a key step in conservation and recovery of endangered and threatened freshwater fish. Critical habitat under Canadian and US legislation may include habitat that is not directly used by listed fish, provided it is necessary for species conservation or recovery. Riparian habitat meets biological criteria for critical habitat because riparian zones are integr...

Our morphological studies have demonstrated that the appearance of localized, paired zones of primary calcification on either side of the midline of the 19-d embryonic chick sternum is heralded by the development of paired, translucent zones 2 d previously. Histological studies demonstrated that the majority of chondrocytes within these translucent zones are hypertrophic, and that the zones are...

The survival of oceanic organisms in oxygen minimum zones (OMZs) depends on their total oxygen demand and the capacities for oxygen extraction and transport, anaerobic ATP production and metabolic suppression. Anaerobic metabolism and metabolic suppression are required for daytime forays into the most extreme OMZs. Critical oxygen partial pressures are, within a range, evolved to match the mini...

[1] Subduction zones are where sediments, oceanic crust, and mantle lithosphere return to and reequilibrate with Earth’s mantle. Subduction zones are interior expressions of Earth’s 55,000 km of convergent plate margins and are the geodynamic system that builds island arcs. Excess density of the mantle lithosphere in subduction zones provides most of the power needed to move the plates while in...

[1] We give an explanation for the polarity, localization, shape, size, and initiation of subduction zones on Earth. By considering a soft, thin, curved lithospheric cap with either elastic or viscous rheology supported by a thick, nearly incompressible mantle, we find two different characteristic subduction geometries arise depending on boundary conditions: (1) plate boundaries where subductio...