Sanjeeva Witharana

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This paper presents a control algorithm for pneumatic artificial muscles on bicep configuration. Due to the characteristics such as lower power to weight ratios, high strength and lightweight and easiness of employment, pneumatic artificial muscles have become more attractive actuators for robotics applications. The dynamics equations for bicep(More)
An experimental study was conducted to investigate the structural stability of ethylene glycol-based titanium dioxide nanoparticle suspensions (nanofluids) prepared by two-step method. The effects of particle concentration, fluid temperature, shear rate and shear duration were examined. Particle size and thermal conductivity measurements in quiescent state(More)
This article reports a recent study on the application of a two-phase closed thermosyphon (TPCT) in a thermosyphon for economizer (TPEC). The TPEC had three sections of equal size; the evaporator, the adiabatic section, and the condenser, of 250 mm × 250 mm × 250 mm (W × L × H). The TPCT was a steel tube of 12.7-mm ID. The filling ratios chosen to study(More)
The accurate prediction of runtimes of future job tasks on the nodes of a grid supplies vital information for the users to make CPU resource usage decisions. There are number of different approaches to predict runtimes of the future job tasks. These approaches range from the statistical to non statistical and some of them require expensive search algorithms(More)
The current Operating System (OS) kernels calculate the load average value as a lump sum. Also the algorithm for the calculation of load average does not separate CPU load from Disk load. This leads to the presentation of an incorrect measurement when both disk bound tasks and CPU bound tasks run simultaneously. In this paper a new algorithm is proposed to(More)
Hydro power is the major renewable energy contributor to the national grid in Sri Lanka amounting to 48% of the total installed capacity. Further expansion of hydropower however is limited due to environmental and resource constraints. Meanwhile the demand for electricity is estimated to rise at an annual rate of 8% - 10% prompting the need to find(More)
Nanoparticle suspensions have demonstrated superior heat transfer properties and hence appear to be a strong contender to become next generation coolants. While the presence of particles enhances thermal conductivity, they also contribute to increase the fluid viscosity. The latter will lead to demand more pumping power in convective systems, hence(More)
An experimental study was carried out to investigate tue structural stability of ethyleue glycol based titanium dioxide nauopa t'ticle suspensions (nanofluids) prepared ivith mo-step method. Effect of particle concentration, fluid temperature, shear rate and shear duration were investigated. It was fouud rhat tue temperature resolved thermal conductivity of(More)
A methodology to predict the thermal conductivity of nanofluids based on the suspension rheology is proposed and experimentally validated by using four types of nanofluids; the suspensions of titania nanoparticles and titanate nanotubes in water and ethylene glycol liquids. Such a methodology lies in the use of suspension rheological behaviour to determine(More)
This paper presents different roots of Ocean Thermal Energy Conversion (OTEC) strategies and challenges faced in terms of efficiency and economy of OTEC plants. The conversion strategies primarily focus on open cycle, closed cycle and hybrid plants. The efficiency studies mainly skew towards the effect of plant distance and thermal gradient towards plant(More)