A Simple and Complete Supercapacitor Characterization System Using a Programmable Sourcemeter

The development of new materials and systems capable of storing energy efficiently with a fast power delivering has been the subject of several studies. Many techniques and instruments are used for the characterization of these systems. Some involve the use of electrochemical techniques, such as cyclic voltammetry and electrochemical impedance spectroscopy, while others use instruments specially developed for this purpose. In this study, we provide a simple and functional supercapacitor characterization system using a programmable sourcemeter with an embedded scripting language. For the validation of the system, commercial capacitors and supercapacitors devices based on activated carbon and manganese dioxide were used. In a few steps, the system is capable of efficiently determine the main parameters used in the characterization of supercapacitors, for instance, specific capacitance, specific energy density, specific power density and equivalent series resistance. From the data collected, the system can also determine the stability and performance of supercapacitors, which are fundamental parameters used in the development of new electrodes for energy storage devices. DOI: http://dx.doi.org/10.17807/orbital.v11i2.1374 <br /

Brazilian Agroindustrial Wastes as a Potential Resource of Bioative Compounds and Their Antimicrobial and Antioxidant Activities

The study of the recovery of bioactive compounds from natural resources and its implications in several areas is very significant for the scientific community. This work aimed to study Brazilian agroindustrial wastes&rsquo; antioxidant and antimicrobial activities using green extraction. Olive leaves, jaboticaba peel, ara&ccedil;&aacute; peel, and pecan nut shells were evaluated under four conditions: (1) convective-drying and aqueous extraction, (2) convective-drying and ethanolic extraction, (3) freeze-drying and aqueous extraction, and (4) freeze-drying and ethanolic extraction. The results demonstrated that all samples showed high antioxidant potential, and the highest antioxidant activity was obtained for the extract of pecan nut shell. As for the quantification of compounds by HPLC, the olive leaf presented the highest content of phenolic compounds in the extract, mainly oleuropein. Finally, the antimicrobial activity analysis revealed the extracts&rsquo; bactericidal potential against Staphylococcus aureus and Escherichia coli. The present study shows that green extraction can extract bioactive compounds with antioxidant and antimicrobial properties, highlighting the importance of choosing the drying method and solvent for future uses of these natural resources by the industry

Green Composites from Thiophene Chalcones and Rice Husk Lignin: An Alternative of Powder for Latent Fingermark

This study reports a route to obtaining a novel and cost-effective rice husk-derived lignin/thiophene chalcone green composite for application in forensic science as a fingermark developer through high energy milling. The material was properly characterized by UV-Vis, IR, fluorescence, X-ray diffraction and scanning electron microscopy. The product provided clear and sharp images of latent fingermarks with minimal background staining, revealing all ridge details. Thus, the composite presented good performance as a fingermark developer, becoming an interesting alternative to being applied as a technological, reproducible and renewable product

Green Composites from Thiophene Chalcones and Rice Husk Lignin: An Alternative of Powder for Latent Fingermark

This study reports a route to obtaining a novel and cost-effective rice husk-derived lignin/thiophene chalcone green composite for application in forensic science as a fingermark developer through high energy milling. The material was properly characterized by UV-Vis, IR, fluorescence, X-ray diffraction and scanning electron microscopy. The product provided clear and sharp images of latent fingermarks with minimal background staining, revealing all ridge details. Thus, the composite presented good performance as a fingermark developer, becoming an interesting alternative to being applied as a technological, reproducible and renewable product