RESUMO
In this work, a new chlorophyll dye-sensitiser derived from mitragyna speciosa (MS) leaves, also known as Kratom, was employed for dye-sensitised solar cells (DSSCs). The influence of magnesium sulfate (MgSO4), a low-cost dye additive, and suitable extraction solvents on the performance of DSSCs were examined. Here, the optical properties were investigated using UV-Visible spectroscopy and the functional anchoring group were investigated by FTIR spectroscopy. Meanwhile, the photovoltaic parameters were investigated by I-V measurements. The highest conversion efficiency is obtained when using a dye extracted from methanol solvent in combination with MgSO4 additive, namely methanolic magnesium sulfate (MMSO). This higher power conversion efficiency is mainly attributed to the enhancement of the hydroxyl group in the MMSO dye solutions, which promotes higher dye adsorption and provides an organic dye passivation layer that reduces back-recombination in the cell. Furthermore, MgSO4 aids in the replenishment of magnesium lost in the chlorophyll porphyrin ring during the degradation process. These combined effects have contributed to the overall conversion efficiency of the MMSO cell at 0.26 %, followed by 0.24 % for ethanolic magnesium sulfate (EMSO), respectively.
Assuntos
Corantes , Energia Solar , Clorofila/química , Corantes/química , Sulfato de Magnésio , Solventes/química , Luz SolarRESUMO
Supracondylar humeral fracture is the most common elbow injury in children. It may be associated with a vascular injury in nearly 20% of the cases with a pink pulseless limb. We present a unique case of a paediatric pink pulseless supracondylar humeral fracture, seen late, on the 16th-day post-trauma. Open reduction, cross Kirschner wiring, and brachial artery exploration and repair were performed, and the patient recovered well. Early open reduction and exploration of the brachial artery with or without prior CT angiography was a safe approach in treating patients who presented at 16 days.