The flow of viscoelastic non-Newtonian fluid in the Ekman layer

In this paper the unsteady flow in the Ekman layer of a visco-elastic non-Newtonian fluid near a flat plate is discussed. Laplace transform technique has been employed to show the basic differential equations. Expressions for velocity profile, the skin friction have been calculated. It is shown that the time to attain the steady state increases with the elastic parameter. It is shown that normally the ultimate steady state is reached through a decay of inertial oscillations whose frequency decreases with increase in the elastic parameter. In the present study we examine the following unsteady problem in non-Newtonian fluid. Consider an infinite plate coinciding with the platez=0 and rotating in unison with elasticoviscous liquid occupying the regionz>0 with a uniform angular velocity about thez-axis for timet<-0. At timet>0, the plate starts moving with a uniform velocityU _o along thex-axis relative to the rotating frame of reference. The horizontal homogeneity of the problem demands that conditions depend onz andt only. The equation of continuity together with the no slip condition at the plate then shows that thez-component of the velocity vanishes everywhere.     

The stabilization value of groundwater: evidence from Indian tank irrigation systems

Groundwater is now a major source of agricultural water supply in many parts of the world. The value of groundwater as a new source of supply is well known. However, its additional buffering or stabilization value is less appreciated and even less analysed. Knowledge on groundwater’s stabilization value is advanced by developing and estimating an empirical model using the case of tank irrigation systems in Tamil Nadu, India. Unlike previous work, the model uses cross-sectional rather than time-series data. The results show that for the case-study region, the stabilization function added approximately 15% to supply value. Scenarios with surface water and electricity price were incorporated in the model. Increased surface-water supply and electricity price caused reduction in groundwater use but the percent of stabilization value of groundwater increased. The findings are used both to suggest improvements in tank irrigation systems and to further contextualize knowledge of groundwater’s stabilization value.     

Heavy metal distribution and contamination in soils of Thane–Belapur industrial development area,Mumbai, Western India

There is a growing public concern over the potential accumulation of heavy metals in soil, owing to rapid urban and industrial development in the last decade in India. Therefore, an attempt was made to investigate the pollution caused due to excessive accumulation of heavy metals in soils near Thane–Belapur industrial belt of Mumbai. Soil samples were collected from surrounding industrial areas and were analyzed for toxic/heavy metals by X-ray fluorescence spectrometer. The analytical results indicate that the soils in the study area were enriched with Cu, Cr, Co, Ni and Zn. The concentration ranges were: Cu 3.10–271.2 mg/kg (average 104.6 mg/kg), Cr 177.9–1,039 mg/kg (average 521.3 mg/kg), Co 44.8–101.6 mg/kg (average 68.7 mg/kg), Ni 64.4–537.8 mg/kg (average 183.6 mg/kg) and Zn 96.6–763.2 mg/kg (average 191.3 mg/kg). The visualization of spatial data is made by preparing distribution maps of heavy metal concentration in soils and co-relation diagrams. These results highlight the need for instituting a systematic and continuous monitoring of the study area for heavy metals and other forms of pollution to ensure that pollution does not become a serious problem in future.