Light weight sandwich laminated panels are increasingly being used as structural materials for a wide variety of applications in marine, aerospace, automobile, transportation and electronic packing sectors. These sandwich panels are separated by stiff and strong face sheets, with low density core such as polyurethane foam, corrugated polyvinyl chloride sheets, aluminum honeycomb or polystyrene cellular solids. The core provides the necessary section modulus as well as shear rigidity at a low weight premium and the facing provide the adequate flexural rigidity and strength. Such a combination is being referred to as sandwich effect. The application of sandwich panels is of recent origin and their heterogeneous nature makes the understanding of static behavior extremely complex.In this study attempts have been made to study the effect of change thickness of Fiber reinforced Polymer (FRP) facing sheets and inserts. The total thickness of the sandwich panels is kept constant to 20 mm. three point and four point tests are conducted in digital flexural testing machine according to ASTM standards. The span length during testing have been varied that is 200 mm and 400 mm. the results have been analyzed to conclude which combination of panel containing varied thickness of face sheets and inserts give best stiffness values.

Thermoacoustic refrigeration, a novel technology, uses eco-friendly gases like helium, air or the mixture of noble gases as working substances in the absence of moving parts. The design, optimization and analysis of thermoacoustic refrigerators using helium and air as oscillating gases are discussed. Pure helium is chosen since it is proven as the best and economical working gas compared to the alternate pure or the mixture of noble gases. Air is chosen since it is abundant in nature and the least cost of the pressurized dry air cylinders. The design optimization strategies discussed in this paper serve as a guide for aspiring researchers in the design and development of thermoacoustic coolers. Cooling power as a function of stack diameter is discussed. Theoretical results of the optimized coolers are compared with DeltaEC simulation results for validation and are in agreement with each other.

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