Experiments are undertaken to determine the efficiency of an evacuated tube solar collector using water-based Titanium Oxide (TiO2) nanofluid at the Pekan Campus (3 ̊32’ N, 103 ̊25’ E), Faculty of Mechanical Engineering, University Malaysia Pahang, for the conversion of solar thermal energy. Malaysia lies in the equatorial zone with an average daily solar insolation of more than 900 W/m2, which c...

the aim of this study is to find the optimal water pressure and percentage of supply vapour in the feed water heaters (fwhs) of steam power plants, such that they maximize the thermal efficiency of the rankine cycle within pre-specified values of minimum and maximum pressures of the thermodynamic cycle. thermal efficiency is defined as a function of unknown variables (fluid pressure and vapour ...

this paper presents a simplifiedlagrangian multiplier based algorithm to solve the fixed head hydrothermalscheduling problem. in fixed head hydrothermal scheduling problem, waterdischarge rate is modeled as quadratic function of hydropower generation andfuel cost is modeled as quadratic function of thermal power generation. thepower output of each hydro unit varies with the rate of water discha...

Long-term water temperature records are necessary for better understanding climate change impacts on freshwaters. We reconstruct summer water temperatures from three climatically sensitive mountain lakes in Austria using paleolimnological methods aiming to examine long-term thermal dynamics and lakes' responses to regional climate variability since the Little Ice Age. Our results indicate diver...

The enhancement of the thermal performance of Vacuum Tube Solar Collectors (VTSC) was studied by using alumina nanofluid as working fluid. VTSC is a simple and commonly utilized type of collector. This study established the heat transfer experimental model of all glass VTSCs used in a forced-circulation solar water heating system using alumina nanofluid as base fluid. Al2O3 (with an average par...

nanofluids are colloidal suspension of nanoparticles in a base fluid and have superior thermal properties in comparison to their base fluids. novel properties of nanofluids are yet to be explored to the highest potential. currently extensive investigation has been done on thermal conductivity of metallic and oxide nanofluids. composites offer the advantage of tailor made properties and fluids w...

Temporal variability in water temperature plays an important role in aquatic ecosystems, yet the thermal regime of streams has mainly been described in terms of mean or extreme conditions. In this study, annual and diel variability in stream water temperature was described at 135 unregulated, gauged streams across the USA. Based on magnitude, amplitude and timing characteristics of daily water ...

1. Water and the Environment 1.1. The Hydrological Cycle 1.2. Surface Water and Groundwater 1.3. Aquatic Ecosystems 1.4. Water Quality and Health 1.5. Climate Variability and Water Resources 1.6. Climate Change and Water Resources 1.7. Other Threats Linked to Water Resources 2. Water and Food: Agriculture 2.1. Water Requirements 2.2. Farming with Agrochemicals 2.3. Water and Animal Production S...

in this research, graphene was synthesized by chemical vapor deposition (cvd) method in atmosphere pressure (14.7 psi). different functionalization method was used for oxidizing of graphene such as acid and alkaline treatments. the functionalized graphene (fg) was characterized by ftir and raman spectroscopy. nanofluid with water and different concentration (0.05, 0.15 and 0.25 wt %) of fg were...

We study dynamic duopolistic competition between hydro and thermal generators under demand uncertainty. Producers compete in quantities and each is constrained: the thermal generator by capacity and the hydro generator by water availability. Two versions of the model are analysed: an infinite-horizon game emphasizing water withholding incentives of the hydro generator and the distribution of pr...