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V. B. M. Sayana ¹, E. Arunbabu ², L. Mahesh Kumar , S. Ravichandran ², K. Karunakaran ²

Affiliations
1 St. Peters Engineering College, Avadi, Chennai- 600054, IN
2 Centre for Water Resources, Anna Univ.-Chennai, Chennai 600025

Abstract

This paper reports the response of the groundwater in the St Peter's Engineering College campus, Avadi, near Chennai, India. Artificial recharge of rainwater was done through roof top harvesting methods during 2004 to 2007. Based on a hydro geological survey of the campus, eleven bore well were sunk for augmenting water supply to the campus. The lithology of each bore well was also recorded. A percolation pond in 1 ha area on the south eastern side of the campus was dug to collect and store the rainwater harvested from rooftops of the campus buildings. The survey also assisted in the identification and location of about 70 number of recharge wells in the campus. Pumping test was conducted in well no:3 to assess the hydraulic conductivity and calculate other aquifer parameters during 2005. A three layer hydro geological model of the aquifer was applied in Visual Modflow ver 4.1 environment and the model fit was 84% between observed and predicted values (R² = 0.844). Significant increase in water level in the top aquifer during 2007 was recorded when compared to 2004. The flow profiles in the middle and deep aquifer showed responses, through changes in the direction of flow to the pumping wells (5, 6 in 2004 and 2, 3 in 2007). In 2007, with improved recharge, changes in the direction of groundwater flow and discharge of water from the aquifer in the southern part of the campus can be noticed. The flow directions in the three aquifer layers also indicated that the northern part of the study area serves as an effective recharge zone for the St Peter's Engineering College Campus. Rainwater harvesting and recharge studies form important part in groundwater restoration and management in intensely urbanized cities/townships.

Keywords

Rainwater Harvesting Methods, Aquifer Recharge, Groundwater Flow, Aquifer Test Pro, Visual Modflow

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G. Raja ¹, B. K. Gnanavel ², T. Ramesh ³, L. Mahesh Kumar ¹

Affiliations
1 Department of Mechanical Engineering, St. Peter’s University, Chennai − 600054, Tamil Nadu, IN
2 2Department of Mechanical Engineering, Saveetha Engineering College, Chennai – 602105,Tamil Nadu, IN
3 Department of Mechanical Engineering, National Institute of Technology, Tiruchirapalli – 620015, Tamil Nadu,, IN

Abstract

Objectives: This work investigates the mechanical behaviour of lead cable used in cardiac pacemaker and comparing with theoretical values of equilibrium equations. Methods/Analysis: A pacemaker is a medical device which uses electrical impulses to regulate the heartbeat. The lead inside the pacemaker cable fails due to various reasons. One such reason is lead fracture which occurs long after the implantation procedure. The pacemaker is considered as a multi-layered assembly with 1+6+12 helical wires and a straight cylindrical core has been chosen for analysing the mechanical properties which plays an important role in the failure of the lead cable. Any lead cable which is considered as rope has general equations of equilibrium. The mechanical property involves tr and force, strand twisting moment, strand axial strain and contact stress. The same mechanical properties are found by writing programs in MATLAB. Findings: The study of mechanical properties of lead cable used in cardiac pacemaker is as same as possible with that of the values checked with the equations of equilibrium and the variations are also less than 2 percentage. Novelty/ Improvements: With the change in orientation of helix angle which is always assumed to be constant, is made as 82.53˚/-75.62˚, 73.29˚/62.36˚ and 62.24˚/-71.02˚. This change in orientation has made the better comparison of the mechanical properties of the lead cable used in cardiac pacemaker

Keywords

Contact Stress, Cable Mechanics, Friction, Strand

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