Sharif Digital Repository

Multispeed resolvers are used in the applications that need higher accuracy. However, they suffer from losing absolute position information. To overcome this challenge and improve the reliability of detecting position, the use of multiturn resolvers is recommended. The conventional configuration of multiturn resolver is using two individual resolvers on one shaft and into a common frame. Using such configuration needs special care on setting the distance between two resolvers. In this article, a new structure based on a dual side configuration is proposed. The performance of the double-sided resolver is analyzed and optimized using an analytical model based on a magnetic equivalent circuit.... 

In this work, synthesis of CuIn0.75Ga0.25S2 (CIGS) nanoparticles, the formation of stable dispersion, deposition of high-quality films and, fabrication of thin-film Perovskite solar cells are reported. The stability of nanoparticle ink is crucial in the formation of device-quality films. The chalcogenide-based materials are widely used in thin-film solar cells; in particular, Cu(In,Ga)S2 are used as an absorber and hole transporting layer. In the present study, the nanoparticles of about 20 nm size and bandgap of 1.5 eV are synthesized using a heat-up method. A variety of solvents are used as dispersing media and the stability of the inks is evaluated by precise optical monitoring. We... 

In this paper, the effect of geometrical parameters on the fretting fatigue of a half-plane in contact with a flat and rounded pad is studied. This is accomplished by calculating and comparing the stress states and stress intensity factors of fretting cracks for a number of pad geometries. The pad geometry is represented by the radius of its rounded corners and the width of its central flat part. The distribution of dislocation method is employed to calculate the stress intensity factors of fretting induced cracks of different lengths for different values of geometrical parameters. The results of this study can be insightful for improving the geometrical design of an aero-engine compressor... 

Microfluidics is a promising approach for the facile and large-scale fabrication of monodispersed droplets for various applications in biomedicine. This technology has demonstrated great potential to address the limitations of regenerative medicine. Microfluidics provides safe, accurate, reliable, and cost-effective methods for encapsulating different stem cells, gametes, biomaterials, biomolecules, reagents, genes, and nanoparticles inside picoliter-sized droplets or droplet-derived microgels for different applications. Moreover, microenvironments made using such droplets can mimic niches of stem cells for cell therapy purposes, simulate native extracellular matrix (ECM) for tissue...