A novel water filter technology for rural areas

Most of rural community in India does not have access to safe drinking water. The purpose of this work is to provide a technology for obtaining safe drinking water for rural population by a low cost, easy to make, domestic water filter system. The filter is made of rice husk ash (RHA) which is available in abundant quantity in rural India. The performance of the RHA based water filter is good with the bacterial trapping of 96±3% and turbidity removal of 94±3%. A field study of filter has been carried out at KEM Rural Hospital Vadu, which shows similar performance as in laboratory. Our studies also showed RHA based water filter is better then ceramic candle filter. We are working with several NGO's and UNICEF, India to proliferate this water filter. We have trained 40 NGO's with this innovative technology. More than 3000 filters made by village volunteers are presently in use

Simulation of viscoelastic flows of polymer solutions in abrupt contractions using an Arbitrary Lagrangian Eulerian (ALE) based finite element method

We present a method for simulation of viscoelastic flows using an Arbitrary Lagrangian Eulerian (ALE) technique based finite element formulation. The ALE technique provides advantages of both Lagrangian and Eulerian frameworks by allowing the computational mesh to move in an arbitrary manner, independent of the material motion. In the present method, a fractional step ALE technique is employed in which the Lagrangian phase of material motion and convection arising out of mesh motion are decoupled. In the first step the relevant flow and constitutive equations are solved in Lagrangian framework. The simpler representation of polymer constitutive equations in a Lagrangian framework avoids the difficulties associated with convective terms thereby resulting in a robust numerical formulation. In the second step the mesh is moved in ALE mode and the associated convection of the stress is performed using a Godunov type scheme. This ALE technique is easy to implement and can accurately simulate the complex viscoelastic behaviour of transient polymer flow through complex geometries. In the present study, steady flows through abrupt contractions of planar and axisymmetric geometries are studied by performing transient flow simulations until steady state is achieved. The proposed method is validated with previously published numerical and experimental studies for polymer solutions obeying the Oldroyd B and Phan Thien Tanner (PTT) models. The simulated corner and lip vortex enhancement mechanism and flow behavior are in good agreement with experimentally obtained flow visualization photographs. The strength of the proposed method lies in its ability to simulate free surface flows such as swell.© Elsevie

Prediction of extrudate swell in polymer melt extrusion using an Arbitrary Lagrangian Eulerian (ALE) based finite element method

Accurate prediction of extrudate (die) swell in polymer melt extrusion is important as this helps in appropriate die design for profile extrusion applications. Extrudate swell prediction has shown significant difficulties due to two key reasons. The first is the appropriate representation of the constitutive behavior of the polymer melt. The second is regarding the simulation of the free surface, which requires special techniques in the traditionally used Eulerian framework. In this paper we propose a method for simulation of extrudate swell using an Arbitrary Lagrangian Eulerian (ALE) technique based finite element formulation. The ALE technique provides advantages of both Lagrangian and Eulerian frameworks by allowing the computational mesh to move in an arbitrary manner, independent of the material motion. In the present method, a fractional-step ALE technique is employed in which the Lagrangian phase of material motion and convection arising out of mesh motion are decoupled. In the first step, the relevant flow and constitutive equations are solved in Lagrangian framework. The simpler representation of polymer constitutive equations in a Lagrangian framework avoids the difficulties associated with convective terms thereby resulting in a robust numerical formulation besides allowing for natural evolution of the free surface with the flow. In the second step, mesh is moved in ALE mode and the associated convection of the variables due to relative motion of the mesh is performed using a Godunov type scheme. While the mesh is fixed in space in the die region, the nodal points of the mesh on the extrudate free surface are allowed to move normal to flow direction with special rules to facilitate the simulation of swell. A differential exponential Phan Thien Tanner (PTT) model is used to represent the constitutive behavior of the melt. Using this method we simulate extrudate swell in planar and axisymmetric extrusion with abrupt contraction ahead of the die exit. This geometry allows the extrudate to have significant memory for shorter die lengths and acts as a good test for swell predictions. We demonstrate that our predictions of extrudate swell match well with reported experimental and numerical simulations.© Elsevie

Alternative mechanisms of drop breakup in stirred vessels

Kumar et al. (1991, Chem. Engng Sci. 46, 2483-2489) have shown that in a stirred vessel, size of the largest stable drop, dmax, first increases with φ (holdup of the dispersed phase) at low φ, but decreases with φ at high φ. They have proposed two additional mechanisms of breakage-in shear and elongational flow regions in the front of the impeller blade-that operate along with the hitherto accepted mechanism due to turbulent fluctuations, and conclude that dmax at high φ is controlled by breakage in shear flows in the range of parameters investigated by them. We show in this paper that their model is deficient on various counts. The new model proposed here overcomes these deficiencies. It predicts that at high φ, dmax is controlled by breakage in the accelerating flow in the tip region of a rotating blade. The model predicts the data of Kumar et al. (1991) and Boye et al. (1996, Chem. Engng Commun. 143, 149-167). New experiments were also conducted to discriminate between the two proposed mechanisms. The experiments independently confirm that drop breakage at high φ is indeed controlled by accelerating flow. The model could predict the new experimental data also quite well

Assessment of Home-Based Care for Young Child (HBYC) program in aspirational districts of Madhya Pradesh, India: A cross-sectional study

Context: In 2018, Government of India initiated Home-Based Care for Young Child (HBYC) program having five quarterly structured home visits for children age 3 to 15 months to promote early childhood development. Assess knowledge and practices of Accredited Social Health Activist (ASHAs), other health functionaries, and mothers related to HBYC. Cross-sectional evaluation design with ASHAs, AWWs, ANMs, ASHA, and mothers of 3 to 15 month's children as participants. Material and Methods: Knowledge and practices of 801 ASHAs, 200 other health functionaries, and 787 mothers were assessed on exclusive breastfeeding, complementary feeding, hand washing, iron folic acid (IFA) and oral rehydration solution (ORS) supplementation, danger referral signs in eight aspirational districts of Madhya Pradesh. Results: 88% ASHAs had correct knowledge on ORS, 85% on complementary feeding, 85% on adequacy of IFA, and 47% on danger signs which required child referral. Similarly, 85% of mothers had knowledge on exclusive breastfeeding, 40% mothers knew about complementary feeding, and only 18% knew correct ORS preparation. Statistically significant association was observed between ASHAs home visits and availability of ORS with mothers and their knowledge on correct Initiation of IFA (p < 0.001). Conclusion: Findings of study confirmed majority of health functionaries were aware about roles, responsibilities, and key tasks under HBYC. However, there observed a gap in knowledge transfer by health functionaries and thus inadequate translation of knowledge into practices among mothers on HBYC. This necessitates the need of appropriate actions from health system strengthening to capacity building to accelerate uptake of HBYC program