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Routing protocol for low-power lossy network (RPL) being the de facto routing protocol used by low power lossy networks needs to provide adequate routing service to mobile nodes (MNs) in the network. As RPL is designed to work under constraint power requirements, its route updating frequency is not sufficient for MNs in the network. The purpose of this study is to ensure that MNs enjoy seamless connection throughout the network with minimal handover delay.

This study proposes a load balancing mobility aware secure hybrid – RPL in which static node (SN) identifies route using metrics like expected transmission count, and path delay and parent selection are further refined by working on remaining energy for identifying the primary route and queue availability for secondary route maintenance. MNs identify route with the help of smart timers and by using received signal strength indicator sampling of parent and neighbor nodes. In this work, MNs are also secured against rank attack in RPL.

This model produces favorable result in terms of packet delivery ratio, delay, energy consumption and number of living nodes in the network when compared with different RPL protocols with mobility support. The proposed model reduces packet retransmission in the network by a large margin by providing load balancing to SNs and seamless connection to MNs.

In this work, a novel algorithm was developed to provide seamless handover for MNs in network. Suitable technique was developed to provide load balancing to SNs in network by maintaining appropriate secondary route.

The complex geometries of human tissues are characterized by the employment of phantoms in various fields of medicine ranging from active treatment stages to educational purposes. Despite the exceptional abilities of the fused filament fabrication (FFF) technology to produce rapid and patient-specific complex anatomical models, the issue of human tissue-filament material incompatibilities persists owing to the lack of attenuation coefficients in the same range as biological tissues. The purpose of this study is to develop a novel biodegradable filament that can mimic human hard tissues by addressing the challenge mentioned above.

The current study addresses the issue through proposing a novel biodegradable radiopaque filament containing poly (lactic acid) (PLA) and antimony trioxide (Sb₂O₃) with increasing amounts (3 wt%, 5 wt% and 10 wt%) for hard tissues. Other than the thermal/flow characterization and internal structural analyses, as for evaluating the effectiveness of the produced filament under computed tomography (CT) imaging, two detailed anthropomorphic phantoms (L3 vertebra and femur bone) are produced and tested.

Results show that Sb₂O₃ disperse homogeneously and serve as a nucleating agent for PLA crystallization. Gyroid pattern gets very close isotropic structure with the highest hounsfield unit (HU) values. 5 wt% Sb₂O₃ is required to get the HU values of cortical bone. The produced model hard tissues are in very compatible with patient images in all details including cortical thickness.

The results of this study will contribute to the development of radiopaque products in medical applications using three-dimensional printing.

The current research shows that inexpensive, patient-specific, detailed medical models can be produced with a novel biodegradable radiopaque filament containing PLA/Sb₂O₃. To the best of the authors’ knowledge, no study has examined the use of Sb₂O₃ in radiopacity applications in any polymeric material.