LoCaL: Link-optimized cone-assisted location routing in flying ad hoc networks

Recently, flying ad hoc networks (FANETs) has become a core research area in wireless networks that involves multiple unmanned aerial vehicles (UAVs). It is widely used in modern warfare for surveillance, monitoring and reconnaissance. The routing in FANETs poses a more significant challenge due to limited energy and frequent link disconnection between the UAVs. Consequently, an effective route is always required to ensure data transmission between UAVs. Therefore, this research proposes a link-optimized cone-assisted location (LoCaL) routing protocol for FANETs. The main goal of the proposed LoCaL is to enhance the link duration between the UAVs in which a source selects a forwarding UAV from a given set of neighbours by estimating the residual energy, link duration time and safety degree parameters. Proposed LoCaL provides better stability and less frequent route breaks between source and destination. Further, the mathematical formulation of the proposed approach is presented through the utility function to enhance the route stability by selecting all those relay UAVs in the cone-shaped request zone, which reduces the routing overhead in discovering the route. Finally, the performance of the LoCaL has been presented through key indicators such as energy consumption, routing overhead, message delivery ratio, network lifetime and delay compared to the existing approaches.     

Role of alkyl moieties in the antiwear and antioxidant performance of alkyl phosphorodithioates

Phosphorodithioate derivatives having different alkyl substitu‐ents have been synthesised, while keeping the core phosphorus‐sulphur moiety intact. The change in antiwear, extreme‐pressure, and antioxidant properties with the variation in sub‐stituents at oxygen and at sulphur linkages in the phosphorodithioates has been studied. The role of the heteroatoms with regard to the alkyl substituents has been examined. The experimental data show that the chemical structure of an additive influences its physicochemical and tribological properties.     

Do Energy Resources matter for Growth Level? The dynamic effects of different strategies of renewable energy,carbon emissions on sustainable economic growth

Clean Technologies and Environmental Policy - This study examines the association between renewable energy strategies and carbon emissions on sustainable economic growth under affordable and clean...     

Transmissive Labyrinthine Acoustic Metamaterial-Based Holography for Extraordinary Energy Harvesting

Conventional energy sources are continuously depleting, and the world is actively seeking new green and efficient energy solutions. Enormous amounts of acoustic energy are dissipated daily, but the low intensity and limited efficiency of current harvesting techniques are preventing its adoption as a ubiquitous method of power generation. Herein, a strategic solution to increase acoustic energy harvesting efficiency using a specially designed metamaterial is implemented. A scalable transmissive labyrinthine acoustic metamaterial (LAM) is designed, developed, and employed to maximize ultrasound (40 kHz) capture over its large surface area (>27 k mm²), which is focused onto a piezoelectric film (78.6 mm²), thus magnifying incident sound pressure by 13.6 times. Three different piezoelectric films – two commercial and one lab-made nanocomposite film are tested with LAM in the acoustic energy harvesting system. An extraordinary voltage gain of 157–173% and a maximum power gain of 272% using the LAM compared to the case without the LAM are achieved. Multipoint focusing using holographic techniques, showcasing acoustic patterning to allow on-demand simultaneous harvesting in separate locations, is demonstrated. Our versatile approach for high-intensity acoustic energy harvesting opens future opportunities to exploit sound energy as a resource to contribute toward global sustainability.     

Design of a wide bandwidth terahertz MEMS Ohmic switch for 6G communication applications

Microsystem Technologies - With the new arena of smart and Internet of things (IoT) enabled devices, a terahertz frequency-based network like 6G with high speed and low latency is required....     

Charge Storage Capabilities of Fractal Porous Silicon Obtained Using Simple Metal Assisted Porosification Method

Silicon - Simpler methods for fabricating electrodes for charge storage applications are required because electrode materials have appreciable significance to enhance the electrochemical...     

Synthesis of Benzenesulfonamide Derivatives via Ring Opening of Aziridines in the Presence of Magnetically Retrievable Graphene Based (CoFe@rGO) Nanohybrid

Graphene based magnetic nanohybrids have engrossed considerable research curiosity because of their exceptional properties and diverse applications associated with green chemistry. In this regard, a practical, facile and regioselective preparation of 1,2-diamines from N-tosylaziridine/(S)-(+)-2-Benzyl-1-(p-tolylsulfonyl)aziridine and aryl amines in the presence of magnetically separable graphene based nanohybrid (CoFe@rGO) has been proposed under mild and solvent free conditions. The FT-IR, FE-SEM, XPS, XRD and TEM spectroscopic analysis confirmed the formation of the CoFe@rGO nanohybrids. For unsymmetrical aziridine, nucleophilic attack of aryl amines was observed to take place selectively at the more substituted carbon atom of aziridine ring. Environmentally benign, efficient, shorter reaction time, solvent-free conditions, low catalyst loading, excellent reaction yields and reusability of the catalyst for six consecutive runs without significant loss in its activity are the key advantages of this protocol.

Graphical Abstract