ion; depletion; hydropower; river; run-of-river; small-scale; weir.

The effect of the outlet weir height on sieve tray performance is described in this paper. The studies were made to investigate the effect of the outlet weir height on sieve tray mass transfer efficiency and hydraulic performance. Tests were conducted in the 1.22 m diameter section of the Fractionation Research, Inc. (FRI) low-pressure column. Sieve trays with nominal hole areas of 14%, 13%, an...

The purpose of this research is examining the performance rectangular broad and sharp crested weirs in terms cavity index discharge coefficient. For purpose, a computational fluid dynamics CFD code FLUENT applied. Firstly, verified by applies on experiments work Hagre et al 1994 results show excellent agreements between Hager 1994. Secondly applied both weirs. demonstrate that have lower coeffi...

An experimental campaign is undertaken in order to investigate the hydraulic features of a vertical drop shaft, also considering the influence of a venting system consisting of a coaxial vertical pipe, projecting within the drop shaft with different plunging rates. Three different flow regimes are observed: a “weir flow” for very low head values, where the flow profile is subject to the atmosph...

This study presents a spatial analysis of physical and biotic river conditions below a low head hydro scheme in the River Goyt, UK. The overall aim was to assess whether changes in localized hydrological features, introduced by low head hydro, affect phytobenthic biomass. Single point and profile measurements of flow velocity and velocity vectors, elevation, depth and biofilm biomass were mappe...

This article presents the longue durée social history of a medieval fish weir. It reveals significant role fishing and weirs in construction reconstruction structures cultural identities. focuses on an enigmatic annual ceremony – Horngarth or Penny Hedge at Whitby, North Yorkshire. The begins by arguing that descends from intertidal weir, before exploring possible contexts which weir originated...

We show that the class of level-k control languages, as defined by Weir, is properly included in the class of 2 k−1-multiple context-free languages for each k ≥ 2. The proof of inclusion uses a representation of the set of derivation trees for a level-k control language in terms of a second-order abstract categorial grammar. 1.1 Introduction Weir (1992a) introduced a hierarchy of language class...

Thin-plate weirs are commonly used as measuring devices in flumes and channels, enabling an accurate discharge measurement with simple instruments. The calibration formulae of such devices rely upon some empirical coefficients and there is a need to obtain new accurate physical data to complement the existing evidence. In the present study, the discharge calibration of a large 901 V-notch thin ...

This paper is concerned with monitoring the hourly event-based river suspended sediment concentration (SSC) due to storms in Jiasian diversion weir in southern Taiwan. The weir is built for supplying 0.3 million tons of water per day averagely for civil and industrial use. Information of suspended sediments fluxes of rivers is crucial for monitoring the quality of water. The issue of water qual...