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The use of empirical equations for seepage estimation in comparison with observed losses from irrigation canals

100%

Syed N. S. B. , Shuqi Z.

Journal of Water and Land Development

2023

tom no. 57

21--29

This study analyses and presents a technical comparison of seepage estimation from 11 empirical equations with measured seepage losses by the inflow-outflow method from two lined and unlined secondary irrigation canals sub-divided into different reach lengths. A significant margin of error was observed between empirical and inflowoutflow methods, hence modifications in empirical equations were performed. Results reveal that the average seepage losses observed in unlined and lined canals by inflow-outflow method were 9.15 and 3.89%, respectively. Moreover, only the Chinese equation estimated seepage losses for an unlined canal as similar to observed losses (0.11 m3 ∙s-1) whereas the Indian equation estimated similar results for a lined canal to those observed in the field (0.09 m3∙s-1). However, the rest of empirical equations were modified in accordance with error percentage with regard to the observed losses. The empirical equations were then observed to estimate reliable results of seepage.

Zeta potential of Polish copper-bearing shale in the absence and presence of flotation frothers

72%

Peng M. , Ratajczak T. , Drzymała J.

Mining Science

2014

tom Vol. 21

57--63

In this paper, zeta potential as a function of pH of copper-bearing shale, which is mined in Poland by KGHM, was investigated. The measurements were conducted in water and aqueous solutions of selected flotation frothers. It was established that for investigated copper-bearing shale, after dispersion in water, the isoelectric point (IEP) occurs at pH=3.5. Addition of frothers decreased the IEP on the pH scale and the IEP for butanol was 1.93, for MIBC 2.90 and for eicosaethylene glycol hexadecyl ether (C16E20) 2.76. In the case of introducing frothers changed, the zeta potential becomes less negative. An empirical equation, having two adjustable parameters, was used in the paper to approximate the course of the zeta potential-pH curve. The equation showed a very good approximation of the zeta potential of the investigated shale either in water or frother aqueous solutions.

Wpływ temperatury na przebieg transportu wilgoci w ziarnie pszenicy z użyciem sorbentu naturalnego

72%

Szwedziak K. , Woźniak A.

Inżynieria Rolnicza

2004

tom R. 8, nr 2

371--378

W artykule opisano wpływ stopnia nagrzania naturalnego sorbentu, jakim jest przesuszone ziarno na dynamikę wymiany wilgoci w mieszaninie ziarna nawilżonego i sorbentu z uwzględnieniem różnych udziałów masowych obu rodzajów ziarna dla dwóch zakresów temperatury ziarna przesuszonego.

Research has been designed to learn moisture transport using natural sorbent, i.e. grain of the same species as dried grain. It may allow for determining the proper and economical process of agricultural material drying in order to reasonable utilization of energy. An attempt was made to develop characteristics of water exchange process dynamics in a mixture of moist grain (sorbat) and dry grain (sorbent) considering temperature.