Are Core Measures Improving Health Outcomes?

https://digitalcommons.misericordia.edu/research_posters2020/1062/thumbnail.jp

The application of time-flow curves in hydropower calculations

Curves developed by hydrologists are used to assess energy resources of rivers, and determine installation parameters of hydroelectric plants. They facilitate the determination of the flows’ value, as well their long-term, annual and seasonal volatility. The installation flow rates of small-scale lowland hydroelectric plants are determined on the basis of the energy resources of watercourses, the value of net head streams and the criteria of economic feasibility of the investment. The article presents the method of applying time–flow curves in order to determine the installation flow rate of small-scale lowland hydropower plants. The analysis was carried out for the projected flows, and for the flows assumed in the development of water energy cadastre. The effective head stream was assumed as a constant unit value, presupposing the same changes in the upper and lower water level. The obtained values of annual installation flow rates were referred to the mean values of annual flow in the base years, and the mean flow in the multiyear period. The rate of growth and the amount of available energy constitute suitable criteria for the selection of installation flow rate in small-scale hydropower plants

Water surface profile of the trapezoidal permeable sill with sharp-crested weir on the upstream slope

The aim of the study was to analyse the possibility of using dimensionless coordinates in order to determine the typical shape of the overflow stream at the gabion sill, as well as identify the flow zone therein and evaluate the characteristic dimensions of the profile. The analysed weir consists of a permeable part filled with natural stone material, and a solid part in the form of sharp-crested weir on sloping upstream face. The shape of the upper profile of the stream has been determined along with its parameters. Three flow zones at the length of the crest sill were identified: the free flow zone, the inlet wave zone and the sill part, which is free of water. The water flow rate influences the formation of water stream profile flowing over the tested sill. The full correlation dependence of variables was obtained in the analysis. The obtained results can be used in the design of this type of field structures

Bridge headwater afflux estimation using bootstrap resampling method

The bridge structure’s development causes a riverbed cross-sections contraction. This influences the flow regime, being visible during catastrophic floods. Then the flow velocity increases and water piles up upstream the bridge, where headwater afflux could be observed. These changes depend on the watercourse geometry and the bridge cross-section properties, especially on the degree of flow contraction under the bridge. Hydraulic conditions under the bridge depend on flow velocity, dimensions, and shape of abutments, the granulometric composition of bedload, which can be quantitatively characterized by hydraulic resistance coefficients. The research subject of headwater afflux is equated with the recognition of morphodynamic processes occurring along the passage route. The headwater afflux could be estimated by empirical formulas and by the energy method using Bernoulli’s law. Empirical methods are optimized by adopting various statistical criteria. This paper compares the headwater afflux values calculated using two existing empirical formulas, Rehbock and Yarnell, and compares them with the results of laboratory tests. Following the assumption that the free water surface is influenced by flow resistance, an attempt was made to include friction velocity in the empirical formulas. Based on the Authors’ database, the coefficients used were optimized using bootstrap resampling in Monte Carlo simulation. The analyses demonstrated that the formula best describing the phenomenon of headwater afflux upstream the bridge is an empirical formula built based on the historical Yarnell formula, which includes friction velocity value. The optimized equation provides an average relative error of 12.9% in relation to laboratory observations

Zredukowane współrzędne obrysu strumienia na trapezowym progu przepuszczalnym z przelewem o ostrej krawędzi na skarpie górnej

Celem pracy było opracowanie typowego kształtu górnego obrysu strumienia trapezowego progu gabionowego ze szczelnym ekranem na skarpie górnej. Opracowano zredukowane współrzędne górnego obrysu strumienia trapezowego progu gabionowego ze szczelnym ekranem na skarpie górnej. Rzędne punktów obrysu zredukowano względem wysokości warstwy wody górnej nad koroną przelewu skarpowego. Odcięte punktów obrysu zredukowano według długości strefy wpływania strumienia do wnętrza kamiennego progu. W analizach wykorzystano wyniki badań laboratoryjnych, według których opracowano kształt swobodnego zwierciadła wody we współrzędnych zredukowanych. Analizowany próg składał się z części przepuszczalnej wypełnionej naturalnym kruszywem oraz stałej w formie nachylonego przelewu o ostrej koronie. Próg miał kształt trapezowy symetryczny o nachyleniu obu skarp 1 : 1. Kształt strumienia przepływającego nad analizowanym progiem zależy od wzniesienia zwierciadła wody górnej nad koroną przelewu skarpowego. W efekcie przeprowadzonych analiz otrzymano ujednolicony kształt strumienia zarówno dla przepływu swobodnego, jak i falowej strefy zaburzeń. Uzyskane profile cechuje silna zależność korelacyjna. Otrzymane wyniki mogą być brane pod uwagę przy projektowaniu podobnych budowli wodnych