Use of Soft Heterocyclic N‑Donor Ligands To Separate Actinides and Lanthanides

The removal of the most long-lived radiotoxic elements from used nuclear fuel, minor actinides, is foreseen as an essential step toward increasing the public acceptance of nuclear energy as a key component of a low-carbon energy future. Once removed from the remaining used fuel, these elements can be used as fuel in their own right in fast reactors or converted into shorter-lived or stable elements by transmutation prior to geological disposal. The SANEX process is proposed to carry out this selective separation by solvent extraction. Recent efforts to develop reagents capable of separating the radioactive minor actinides from lanthanides as part of a future strategy for the management and reprocessing of used nuclear fuel are reviewed. The current strategies for the reprocessing of PUREX raffinate are summarized, and some guiding principles for the design of actinide-selective reagents are defined. The development and testing of different classes of solvent extraction reagent are then summarized, covering some of the earliest ligand designs right through to the current reagents of choice, bis­(1,2,4-triazine) ligands. Finally, we summarize research aimed at developing a fundamental understanding of the underlying reasons for the excellent extraction capabilities and high actinide/lanthanide selectivities shown by this class of ligands and our recent efforts to immobilize these reagents onto solid phases

A distributed fuzzy logic controller for a prosthetic hand / Mohd Yazed Ahmad

A Fuzzy Logic with distributed control monitoring (D S) sy tern i implemented to control multiple degree-of-freedom (DOF) prosthetic fingers. Ther are four fingers with 3-DOF and a thumb with 4-DOF. Five identical microcontrollers programmed with Fuzzy Logic ontroller (FLC) and a ystem Handler are employed to control and monitor the fingers and the thumb to replicate the desired hand action of the grasp, the key pinch, the pulp to pulp pinch, the tripod pinch, and the open hand. Each finger is equipp d with position sensors at the pi ot joints and a tactile-pressure sensor at the fingertip. The finger mo ements are programmed to follow given set points and stopped ,. h ne er an obstacle is encountered and the pressure of the tactile sensor exceeds a specified limit. This allows the fingers and thumb to wrap round an object without crushing it. DC motors with reduced gear heads are used as actuators and they are dri en by H-Bridge sv itches. Input signals to the switches in the form of Pulse Width Modulation (PWM) and direction signals are generated by the microcontroller . The signal r present control action of the FLC. Membership functions of the FLC were tuned and the rule \ ere formed to obtain the desired response. Distributed control is implemented by conn cting all finger microcontrollers to a main microcontroller that can b integrated with the Brain omputer Interface. The o erall system was constructed and te ted successfully to control the prosthetic hand