On integration of mirror collector and Stirling engine for solar power system

In the current work, several types of solar collectors, i.e. parabolic, cylindrical, and mirrors, were designed and fabricated. The aim of this study is to integrate the optimum collector with Stirling engine in Malacca city, Malaysia. Stirling engine was designed using CATIA software. The solar collectors were tested for several sunny days and the temperature in the focus point was mea- sured. Comparing the experiment results shows that mirror solar collector introduces highest temperature among others, which was about 190 C. According to that tem- perature, the Stirling engine has been designed in bore piston dimension of 50 mm. Alpha Stirling engine type was selected for this purpose, which may run in this range of temperature

Electrically active magnetic excitations in antiferromagnets (Review Article)

The magnetic resonance operation by electric field is highly nontrivial but the most demanding function in the future spin-electronics. Recently observed in a variety of multiferroics materials named the collective electrically active magnetic excitations, frequently referred to as “electromagnons”, reveal a possible way to implement such a function. Experimental advances in terahertz spectroscopy of electromagnons in multiferroics as well as related theoretical models are reviewed. The earlier theoretical works, where the existence of electric-dipole active magnetic excitations in antiferro- and ferrimagnets with collinear spin structure has been predicted, are also discussed. Multi-sublattice magnets with electrically active magnetic excitations at room temperature give a direct possibility to transform one type of excitation into another in a terahertz time-domain. This is of crucial importance for the magnon-based spintronics as only the short-wavelength exchange magnons allow the signal processing on the nanoscale distance