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R. N. Athavale ¹, R. Rangarajan ¹, D. Muralidharan ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad, 500 007, IN

Abstract

The broad pattern, emerging from recharge measurements in various basins ranging in area from few tens to few thousands of square km indicates an annual input of about 16% (or 100 mm) of the precipitation in the Indo-Gangetic alluvial tract and about 8% (or 60 mm) ofthe precipitation in the Peninsular hard-rock areas. The Tritium recharge measurements are compared with those obtained by using hydro-meteorological and hydrogeological methods. The relation between recharge values and water level fluctuations in open wells is studied and regression plots showing dependence of recharge rate on rainfall over granitic, basaltic, sedimentary and alluvial provinces are presented. Data on temporal variation in recharge due to variation in rainfall over three hydrological cycles in a granitic watershed in the semi-arid area is presented. The utility of such studies in prediction of recharge from rainfall data is illustrated.

Keywords

Hydrogeology, Groundwater, Rainfall, Recharge, Tritium.

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R. N. Athavale ¹, R. Rangarajan ¹, S. M. Rao ²

Affiliations
1 Geohydrology Group, National Geophysical Research Institute, Hyderabad, IN
2 Isotope Division, Bhabha Atomic Research Centre, Bombay, IN

Abstract

Borehole tracer studies were carried out to determine the direction of flow of thermal waters in Manikharn hot-springs area. Inactive potassium iodide and radioactive bromine-82 were injected in one deep geothermal well (DGW) and tritium and bromine-82 were injected in another deep geothermal well on March 31 and April 1, 1984 respectively. Several wells and springs were monitored for a few days in the field itself for bromine-82 activity and samples collected from hot springs and wells over a period of three months were analysed in the laboratory for tritium and iodide. The results show a steeply high value for tritium in the sample collected on 6.4.1984 from a well located 350 m due south of the injection well and on the opposite bank of Parvati river. No significant concentration of iodide and Br-82 nor any discernible trend in their distribution was shown by any of the samples. Results of the multiple tracer injection study favour the model advocating movement of geothermal water from North to South. The velocity of flow through fractured and jointed quartzites was calculated as about 72 m/day.

Keywords

Geothermal Waters, Tracer Technique, Manikaran, Himachal Pradesh.

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R. Rangarajan ¹, P. Shashikala ¹

Affiliations
1 Department of Studies in Mathematics, University of Mysore, Manasagangotri, Mysore - 570 006, IN

Abstract

In the present paper the orthogonality relations, exhibited by both numerator and denominator polynomials of both [n/n] and [n−1/n] Pade approximants for power series expansion of e^-x, given by regular C-fraction expansion, are described. The four orthogonal polynomials thus derived are shown to form classical orthogonal polynomials.

Keywords

Pade Approximants, Regular C-Fraction, Exponential Function, Classical Orthogonal Polynomials.

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G. S. Trivedi ¹, B. G. Shah ¹, S. K. Adhikary ¹, R. Rangarajan ¹

Affiliations
1 Central Salt & Marine Chemicals Research Institute, Bhavnagar-364 002, IN

Abstract

Ion-exchange membrane process can be applied in many areas of science and chemical technology. An area where major developments are predicted is in the applications of bipolar membranes (BPM). Details of theory, applications, advantages and disadvantages of BPM technology are discussed. R&D work on BPM technology was initiated at CSMCRI. Some of the experimental results on the conversion of sodium sulphate, sodium acetate and sodium phosphate are reported.

Keywords

Membranes, Cation-Exchange Membranes, Anion-Exchange Membranes, Bipolar Membranes, Electrodialytic Water Dissociation Process, Acids and Bases.

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S. Chandra ¹, S. Atal ¹, N. S. Krishnamurthy ¹, k. Subrahmanyam ¹, R. Rangarajan ¹, D. V. Reddy ¹, P. Nagbhushanam ¹, J. V. S. Murthy ¹, S. Ahmed ¹, V. P. Dimri ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad - 500 007, IN

Abstract

No Abstract.

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D. Muralidharan ¹, R. Rangarajan ¹, G. K. Hodlur ¹, U. Sathyanarayana ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad - 500 007, IN

Abstract

A research study has been carrted out to evaluate the economically viable depth of desiltation in old tanks to achieve a substantial increase in percolation and storage Two tanks -an old minor irrigation tank and a newly constructed percolation tank were selected in a granite terrain and infiltration studies were carried out with different thickness of silt removal Tritium tracer studies were coupled with the infiltration studies to follow the infiltrated water and evaluate the effectiveness of silt removal in percolation The study lndicated that in the case of irrigation tank, a steady state infiltration rate of 67 mm/h has increased to 350 mm/h with the removal of 65 cm silt showing a six-fold increase in infiltration rate Infiltration rate was found to be reducing by removal of 25 vm and 50 cm silt and the analysis of soil fraction indicated presence of clay at these depths The study at percolation tank indicated that the infiltration rate of 10-20 mm/h has increased to a maximum of 310 mm/h with removal of 40 cm silt The tritium tracer migration study supported a faster movement of percolated water at desilted sites by showing a greater dilution of tracer concentration and deeper penetration The research study strongly supports a necessity of carrying out infiltration studies at different places within the tank bed area with removal of varying thickness of silt to decide the optimal level of desiltation especially in old tanks before commencing revival of tank system.

Keywords

Tanks, lnfiltration rate, Optimal desilting, Percolation efficiency, Anantapur District, Andhra Pradesh.

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R. Rangarajan ¹, S. R. Ananth Kumar ¹

Affiliations
1 Department of Studies in Mathematics, University of Mysore, Manasagangotri, Mysore - 570006, IN

Abstract

Laplace decomposition methods are based on Laplace transform method and Adomian decomposition method or modified Adomian decomposition method. In this paper we show that the methods are applicable to the class of successive interval valued linear as well as nonlinear differential-difference equations with the differential order two and the difference order one involving a two variable function admitting Taylor series expansion. Two test problems are selected to illustrate the applicability of methods. In both the problems, when the difference parameter w = 0, the resulting differential equations have exact solution. The exact solution is used to compare approximate solutions obtained by Laplace decomposition methods. Numerical results show good convergence of approximate solutions.

Keywords

Differential-Difference Equation, Laplace Decomposition Method, Laplace Transform Method, Modified Adomian Decomposition Method, Successive Interval Valued Problem.

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R. Rangarajan ¹, H. Muneer Basha ²

Affiliations
1 Department of Mathematics, University of Mysore, Mysore-570 006, IN
2 Department of Mathematics, G. C. E., Ramanagaram, 571 511, IN

Abstract

The present paper is on two Numerical-Analytic methods- (i) A combined method of Pade approximation and method of successive approximations and (ii) A combined method of Pade approximation and method of homotopy analysis. They provide typical approximate solutions for a singular boundary value problem for nonlinear diffusiontype differential equation of heat transfer.

Keywords

Singular Boundary Value Problems of Heat Transfer, Nonlinear Diffusion Type Differential Equations, Methods of Pade Approximation, Methods of Successive Approximations, Methods of Homotopy Analysis.

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D. V. Reddy ¹, R. Rangarajan ¹, Simanchal Padhy ¹, G. B. K. Shankar ¹, G. Rajender Reddy ¹

Affiliations
1 NGRI, Hyderabad, IN

Abstract

No Abstract.

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V. Anandi ¹, R. Rangarajan ², M. Ramesh ³

Affiliations
1 MSRIT, Bangalore, IN
2 VSB Engineering College, Karur, IN
3 AIMS, Bangalore, IN

Abstract

The increasing prominence of portable systems and the need to limit power consumption and hence, heat dissipation in very high density VLSI chips have led to rapid and innovative developments in low power design recently. Leakage control is becoming critically important for deep sub-100nm technologies due to the scaling down of threshold voltage and gate oxide thickness of transistors. In this paper, we discuss major sources of power dissipation in VLSI systems, and various low power design techniques on the technology and circuit level, logic level, and system level.

Keywords

High Density VLSI Chips, Low Power.

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V. Anandi ¹, R. Rangarajan ², M. Ramesh ³

Affiliations
1 MSRIT, Bangalore, IN
2 Department of ECE, VSB Engineering College, Karur, IN
3 AIMS, Bangalore, IN

Abstract

This paper presents a study on RT level power optimization techniques in terms of their applicability on data-low intensive data path designs and their efficiency. The dynamic power management techniques of clock gating is investigated and their efficiency evaluated by sample designs. The static RTL power optimization methods are discussed. More specifically, the design of power efficient data path components for use in Application Specific Processors is going to be investigated.

Keywords

Clock Gating, Dynamic Power, Data Path, Simulation.

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U. Saravanakumar ¹, R. Rangarajan ², K. Rajasekar ¹

Affiliations
1 Department of Electronics and Communication Engineering, PSG College of Technology, IN
2 Department of Electronics and Communication Engineering, Indus College of Engineering, IN

Abstract

As the feature size is continuously decreasing and integration density is increasing, interconnections have become a dominating factor in determining the overall quality of a chip. Due to the limited scalability of system bus, it cannot meet the requirement of current System-on-Chip (SoC) implementations where only a limited number of functional units can be supported. Long global wires also cause many design problems, such as routing congestion, noise coupling, and difficult timing closure. Network-on-Chip (NoC) architectures have been proposed to be an alternative to solve the above problems by using a packet-based communication network. In this paper, the Circuit-Switched (CS) Router was designed and analysed the various parameters such as power, timing and area. The CS router has taken more number of cycles to transfer the data from source to destination. So the pipelining concept was implemented by adding registers in the CS router architecture. The proposed architecture increases the speed of operation and reduces the critical path of the circuit. The router has been implemented using Verilog HDL. The parameters area, power and timing were calculated in 130 nm CMOS technology using Synopsys tool with nominal operating voltage of 1V and packet size is 39 bits. Finally power, area and time of these two routers have been analysed and compared.

Keywords

SoC, NoC, Circuit Switched Router, Worm-Hole Router, Latency.

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R. Rangarajan ¹, S. R. Ananth Kumar ²

Affiliations
1 Department of Studies in Mathematics, University of Mysore, Manasagangotri, Mysore - 570 006, IN
2 Department of Mathematics, S.S.S.S. Govt. First Grade College, Channagiri, Davangere - 577 213, IN

Abstract

In the recent literature, nonlinear differential equations, integro- differential equations, differential-difference equations and integro-differential-difference equations are studied. Laplace decomposition method and Homotopy analysis method are two powerful decomposition methods employed in the recent literature, nonlinear dierential equations, integro-differential equations, differential-difference equations and integro-differential-difference equations are studied. Laplace decomposition method and Homotopy analysis method are two powerful decomposition methods employed in the literature to solve above nonlinear problems. In the present paper a new method is proposed motivated by the above two methods to solve both nonlinear differential-difference equations and integro-differential-difference equations.

Keywords

Differential-Difference Equation, Integro-Differential-Difference Equation, Laplace Transform, Adomian Polynomials, Laplace Decomposition Method and Homotopy Analysis Method.

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Rolland Andrade ¹, D. Muralidharan ², R. Rangarajan ²

Affiliations
1 Central Water and Power Research Station, Pune 411 024, IN
2 National Geophysical Research Institute, Hyderabad 500 007, IN

Abstract

Attempts were made to understand moisture movement in soil and unsaturated zones under a transient saturation phase created through an infiltration test using conventional self-potential (SP) survey and supportive studies of resistivity profiling and tracer, over a granite terrain having coarse sandy soil cover. The SP behaviour at various time intervals of infiltration stages qualitatively indicated a preferential soil moisture movement after an initial vertical downward movement at deeper depths. As inferred from the SP survey, tracer and conventional resistivity profiling studies substantiate the flow direction by means of highest concentration of tritium content in deep soil cores and significant reduction in apparent resistivity along the direction. The results demonstrate that the SP method could be a useful tool to understand the rainfall recharge process and in surface-induced contamination studies.

Keywords

Infiltration Test, Soil Moisture Movement, Water Flux.

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