In the last three decades the design of stepped spillways regained some interest because of their suitability with new construction methods including gabion placement. In this study, the hydraulic performances of gabion stepped weirs were investigated experimentally in terms of the air-water flow properties and energy dissipation rate. A physical study was performed in a relatively large size f...

This paper describes the design and analysis of planar dual-band bandpass filters using stepped impedance resonators. In the proposed filter configurations, dual-band bandpass filters are designed, and realized by using inverted stepped impedance (SIR) resonators. The conventional half wavelength open circuited stub single frequency resonators are replaced with dual band simple two section step...

Background/Aims We sought to optimise the design of stepped wedge trials with an equal allocation of clusters to sequences and explored sample size comparisons with alternative trial designs. Methods We developed a new expression for the design effect for a stepped wedge trial, assuming that observations are equally correlated within clusters and an equal number of observations in each period b...

For overflow weirs and embankments, the stepped chute profile may increase the rate of energy dissipation on the waterway. Herein four different stepped chute configurations were tested with a focus on the cavity flow processes, flow aeration and energy dissipation performances. Detailed flow visualisations and air-water flow measurements were conducted for all configurations. The results highl...

Researchers should consider five questions before starting a stepped wedge trial. Why are you planning one? Researchers sometimes think that stepped wedge trials are useful when there is little doubt about the benefit of the intervention being tested. However, if the primary reason for an intervention is to measure its effect, without equipoise there is no ethical justification for delaying imp...

In recent years a number of embankments were designedwith concrete overtopping protection shaped in a stepped fashion. During large overflows on stepped chutes, there is no skin friction between mainstream and steps, and flow resistance is basically form drag. Alterations of flow recirculation and of fluid exchanges between free-stream and cavity flow are discussed in this study. A comprehensiv...

We present our latest model of lightning process. The model has two main advantages: computations were made using adaptable (e.g. non-fixed) computational mesh and we allowed branching of the stepped leader. The electrodes and the stepped leader were modelled as conductors surrounded by a homogenous dielectric media. We took in account observations of stepped leader in atmosphere and used a qua...

This work introduces a new non-isolated buck-boost DC-DC converter. Interleaved configuration of the suggested structure increases the voltage conversion ratio. The voltage rate of the suggested converter can be stepped-up and stepped down for lower values of duty-cycle, which causes to decrease in the conduction losses of the system. The voltage conversion ratio of the recommended structure is...

Stepped spillways have become a popular method for handling flood releases. The steps increase significantly the rate of energy dissipation taking place on the spillway face and reduce the size of the required downstream energy dissipation basin. The compatibility of stepped spillways with roller compacted concrete (RCC) and gabion construction techniques results in low additional cost for the ...