This survey paper explores advanced nonlinear control strategies for Unmanned Aerial Vehicles (UAVs), including systems such as the Twin Rotor MIMO system (TRMS) and quadrotors. UAVs, with their high nonlinearity and significant coupling effects, serve as crucial benchmarks for testing control algorithms. Integration of sophisticated sensors enhances UAV versatility, making traditional linear control techniques less effective. Advanced nonlinear strategies, including sensor-based adaptive controls and AI, are increasingly essential. Recent years have seen the development of diverse sliding surface-based, sensor-driven, and hybrid control strategies for UAVs, offering superior performance over linear methods. This paper reviews the significance of these strategies, emphasizing their role in addressing UAV complexities and outlining future research directions.

Highly crystalline bare and N-doped SrTiO₃ nanoparticles were effectively synthesized with strontium acetate, titanium isopropoxide, hexamethylenetetramine as precursor via citric acid assisted hydrothermal process followed by calcination. The hydrothermally synthesized bare and N-doped SrTiO₃ NPs possessed monodispersity throughout with particle size diameter 50±5 nm but because of annealing at 750 °C temperature the synthesized NPs got agglomerate which created rough surface and induces oxygen vacancy in the NPs. Introducing N³⁻ ions impurity into SrTiO₃ lattice tailored the electronic band structure of SrTiO₃ and extends its absorption into the visible region. It would display the p-type conductivity and facilitate the photoinduced electron–hole pairs towards respective site which diminishes the chances of recombination of electron–hole pairs that enhances photocatalytic degradation reaction. The results showed MB degraded about ~88 in just 140 min and followed first order reaction kinetics with rate constant k = 0.01489 mint⁻¹.

An efficient in vitro regeneration procedure using thidiazuron (TDZ) has been developed to allow high frequency, multiple shoot induction from cotyledonary node explants of cluster bean (Cyamopsis tetragonoloba). Shoot bud induction occurred on Murashige and Skoog (MS) medium after 4 weeks in the presence of TDZ, followed by transfer onto shoot multiplication and elongation media containing MS salts, B5 vitamins, and different combinations of auxins and cytokinins. Multiple shoots were induced at all levels of TDZ in the medium, but the best proliferation capacity occurred at 5 µM TDZ. Combinations of auxins and cytokinins showed a stimulatory effect on shoot multiplication and also on the length of the newly formed shoots. Maximum shoot induction [i.e., the highest number of shoots (16.0 ± 0.94) per explant] was obtained on agar-solidified medium containing 5 µM benzyladenine (BA) with 0.5 µM indole-3-acetic acid (IAA). Rooting of in vitro-regenerated shoots was achieved in ex vitro conditions by a pulse treatment with 300 µM indole-3-butyric acid (IBA) for 15 min. Rooted plantlets were transferred to soil where 70 – 75% attained sexual maturity and produced viable seeds under greenhouse conditions. The present regeneration system is efficient and can be used in various in vitro manipulation studies.