Effects of prolonged annealing on NiSi at low temperature (500°C)

Journal of Electronic Materials3481110-1114JECM

Cooling of air using heptadecane phase change material in shell and tube arrangement: Analytical and experimental study

A shell and tube latent heat storage (LHS) system using heptadecane with melting point 22.33 degrees C for active cooling of air has been analyzed analytically and experimentally in this paper. A theoretical model of laminar forced convection with varying wall temperature due to phase change material (PCM) outside a double wall circular tube and air as heat transfer fluid (HTF) inside a tube was employed to analyze active cooling of air. The analytical prediction in terms of outlet temperature was validated with experimental data. Furthermore, influences of some important design parameters (e.g. inner radius and thickness of the tube) on cooling effect were investigated. It was found that an optimum inner radius and thickness of the tube should be considered to design an LHS system. Better co-efficient of performance (COP) was observed for higher inlet air temperature while the outlet air temperature was almost identical. In this study, the COP of cooling was found 4.16 for 34.5 degrees C inlet air temperature using tube with 5.35 mm inner radius and 1 mm thickness. Some important thermophysical properties of heptadecane e.g. specific heat, thermal conductivity and density at liquid state were also examined and found 2.66 kJ kg(-1) K-1, 0.151 W m(-1) K-1 and 774 kg m(-3), respectively. (C) 2014 Elsevier B.V. All rights reserved

Hexagonal Boron Nitride Impregnated Silane Composite Coating for Corrosion Resistance of Magnesium Alloys for Temporary Bioimplant Applications

Magnesium and its alloys are attractive potential materials for construction of biodegradable temporary implant devices. However, their rapid degradation in human body fluid before the desired service life is reached necessitate the application of suitable coatings. To this end, WZ21 magnesium alloy surface was modified by hexagonal boron nitride (hBN)-impregnated silane coating. The coating was chemically characterised by Raman spectroscopy. Potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) of the coated alloy in Hanks’ solution showed a five-fold improvement in the corrosion resistance of the alloy due to the composite coating. Post-corrosion analyses corroborated the electrochemical data and provided a mechanistic insight of the improvement provided by the composite coating

Hexagonal Boron Nitride Impregnated Silane Composite Coating for Corrosion Resistance of Magnesium Alloys for Temporary Bioimplant Applications

Magnesium and its alloys are attractive potential materials for construction of biodegradable temporary implant devices. However, their rapid degradation in human body fluid before the desired service life is reached necessitate the application of suitable coatings. To this end, WZ21 magnesium alloy surface was modified by hexagonal boron nitride (hBN)-impregnated silane coating. The coating was chemically characterised by Raman spectroscopy. Potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) of the coated alloy in Hanks’ solution showed a five-fold improvement in the corrosion resistance of the alloy due to the composite coating. Post-corrosion analyses corroborated the electrochemical data and provided a mechanistic insight of the improvement provided by the composite coating

Curbing global warming with phase change materials for energy storage

The application of thermal energy storage (TES) system with phase change material (PCM) is an effective way for energy conservation and greenhouse gas (GHG) emission reduction. Global warming is increasing along with the energy consumption. Many researchers are concerned about this present global environmental problem for fossil-fuel burning. Thermal energy storage system with phase change material is observed as a potential candidate for mitigating this problem. This paper emphasizes the opportunities for energy savings and greenhouse-gas emissions reduction with the implementation of PCM in TES systems. For instance, about 3.43 of CO 2 emission by 2020 could be reduced through the application of PCM in building and solar thermal power systems. Similarly, energy conservation and GHGs emission reduction by other PCM applications for thermal comfort of vehicles, transport refrigeration, engine cold start, greenhouse and waste heat management are also presented. In addition, some present investigations on the performance improvement of the phase change materials are addressed