Abstract We study the chameleon Key Holders field dark matter, dubbed scalaron, in F (R) gravity in the Big Bang Nucleosynthesis (BBN) epoch.With an R 2-correction term required to solve the singularity problem for F (R) gravity, we first find that the scalaron dynamics is governed by the R 2 term and the chameleon mechanism in the early universe,
Back-stepping sliding mode control method for quadrotor UAV with actuator failure
In this article, a fault tolerant controller (FTC) based on back-stepping sliding mode is proposed for a quadrotor unmanned aerial vehicle (UAV) with single-rotor failure.According to the working mechanism of the quadrotor, the control system of UAV is divided into position subsystem and attitude subsystem.Then, the yaw control is abandoned because
A Tacholess Order Tracking Method Based on Inverse Short Time Fourier Transform and Singular Value Decomposition for Bearing Fault Diagnosis
Order tracking has been widely used to diagnose failures of variable speed rotating machines.The performance of the TOT (Time-Frequency Domain Tacholess Order Tracking) methods is based on the correct separation of the target component strictly related to the shaft rotation frequency.Currently, most of the methods have focused on obtaining the inst
AN INVESTIGATION INTO THE NORMALISATION OF WATER AND ENERGY USAGE IN THE BREWERY INDUSTRY
Benchmarks are often used to assist brewers in identifying improvement opportunities; but a comparison of water and energy performances in breweries is deficient without normalising for differences between facilities.The normalisation of water and energy use was subsequently investigated, using SABMiller breweries as a case study.Drivers of water,