Significance Our results identify the prime driver of climate variation in Africa’s low latitudes over past 620 ky—the key time frame for evolution our species. Warming and cooling tropical Pacific Ocean paced by insolation changes modulated Walker circulation, driving opposing wet–dry states eastern western Africa. We show that effects glacial/interglacial cycles were not predominant source en...

the monolithic catalytic converter is still the main pollution control device for modern vehicles in order to reach the ever-increasing legislative demands for low emission standards. the catalytic converters require a large expansion from the exhaust pipe to the front face of the monolith. unfortunately, packaging constraints often do not permit the use of long diffusers. hence, flow separatio...

In this paper, sliding mode control (SMC) for a bidirectional buck/boost DC-DC converter (BDC) with constant frequency in continuous conduction mode (CCM) is discussed. Since the converter is a high-order converter, the reduced-order sliding manifold is exploited. Because of right-half-plan zero (RHPZ) in the converter’s duty ratio to output voltage transfer function, sliding mode current...

In this paper, a generalized buck-boost Z-H converter based on switched inductors is proposed. This structure consists of a set of series connected switched-inductor cells. The voltage conversion ratio of the proposed structure is adjusted by changing the number of cells and the duty cycle. Like the conventional Z-H converter, the shoot-through switching state and the diode before LC network ar...