Renewable Hybrid Power Generation System

Abstract— In parallel to developing technology, demand for more energy makes us seek new energy sources. Wind and solar energy are the most popular ones owing to their abundance, ease of availability and convertibility to electric energy. This work covers realization of a hybrid renewable energy system. The scheme involves conversion of solar power and wind power into usable electrical energy using solar panel and by designing a wind turbine with appropriate calculations and specifications. Battery in this system is charged by both solar and wind power, the DC output is then converted to AC using an inverter and fed to the load. The idea of water conservation through rain water collection and storage with the use of solar panel is also implemented. The main aim of the design is to create a system suitable to provide continuous power by utilization of non-conventional energy resources and making use of the additional advantage of the solar panel in the conservation of water. Power resources and load in the system are monitored and controlled in real time

Hybrid s-wave superconductivity in CrB2_2

In a metal with multiple Fermi pockets, the formation of s-wave superconductivity can be conventional due to electron-phonon coupling or unconventional due to spin fluctuations. We analyze the hexagonal diboride CrB$_2$, which is an itinerant antiferromagnet at ambient conditions and turns superconducting upon increasing pressure. While the high pressure behavior of T$_c$ suggests conventional s-wave pairing, we find that spin fluctuations promoting unconventional s-wave pairing become important in the vicinity of the antiferromagnetic dome. As the symmetry class of the s-wave state is independent of its underlying mechanism, we argue that CrB$_2$ is a realization of a hybrid s-wave superconductor where unconventional and conventional s-wave mechanisms team up to form a joint superconducting dome

Magnetic anisotropy reversal driven by structural symmetry-breaking in monolayer {\alpha}-RuCl3

Layered {\alpha}-RuCl3 is a promising material to potentially realize the long-sought Kitaev quantum spin liquid with fractionalized excitations. While evidence of this exotic state has been reported under a modest in-plane magnetic field, such behavior is largely inconsistent with theoretical expectations of Kitaev phases emerging only in out-of-plane fields. These predicted field-induced states have been mostly out of reach due to the strong easy-plane anisotropy of bulk crystals, however. We use a combination of tunneling spectroscopy, magnetotransport, electron diffraction, and ab initio calculations to study the layer-dependent magnons, anisotropy, structure, and exchange coupling in atomically thin samples. Due to structural distortions, the sign of the average off-diagonal exchange changes in monolayer {\alpha}-RuCl3, leading to a reversal of magnetic anisotropy to easy-axis. Our work provides a new avenue to tune the magnetic interactions in {\alpha}-RuCl3 and allows theoretically predicted quantum spin liquid phases for out-of-plane fields to be more experimentally accessible

Bromine as a Preferred Etchant for Si Surfaces in the Supersaturation Regime: Insights from Calculations of Atomic Scale Reaction Pathways

Etching of semiconductors by halogens is of vital importance in device manufacture. A greater understanding of the relevant processes at the atomistic level can help determine optimal conditions for etching to be carried out. Supersaturation etching is a seemingly counterintuitive process where the coverage of the etchant molecules on the surface to be etched is >1. Here we use density functional theory computations of reaction pathways and barriers to suggest that supersaturation etching of Si(001) by Br₂ should be more effective than conventional etching by Br₂, as well as both conventional and supersaturation etching by Cl₂. Analysis of our results shows that this is due in part to the larger size of bromine atoms, and partly due to Br–Si bonds being weaker than Cl–Si bonds. We also show that, for both conventional and supersaturation etching, the barrier for the rate-limiting step of desorption of SiX₂ units is lower when the halogen X is Br rather than Cl. This contributes to the overall reaction barrier for supersaturation etching being lower for Br₂ than for Cl₂

Ab initio study of the LiH phase diagram at extreme pressures and temperatures

The effect of anharmonic vibrational contributions to the finite-temperature pressure-driven B1-B2 structural phase transition of LiH is studied by using the stochastic self-consistent harmonic approximation method in combination with ab initio density functional theory and the quasiharmonic approximation. Contrary to previous experimental results based on multiple-shock compression, we find that the B1-B2 transition pressure is not significantly reduced at high temperatures. Moreover, we find that the B2 phase is dynamically unstable at low temperatures within harmonic theory in a wide range of pressures where its enthalpy is lower than that of the B1 phase, and the inclusion of anharmonic effects stabilizes the B2 phase in this pressure range. Our results imply that a third, yet unknown phase must exist in the phase diagram of LiH, in addition to the B1 and B2 phases, in order to explain the shock compression result