Fast, Cheap and Reliable Monitoring of Microalgae-Based Paracetamol Removal from Aquatic Environment Using Electrochemical Sensor Technology

Paracetamol (PRL) is an analgesic and antipyretic drug, and its consumption has increased all across the world during the COVID-19 pandemic era. However, its excessive consumption makes it an endocrine-disrupting factor, and it is toxic for the liver. It easily contaminates water resources due to its high solubility, and has substantial potential to access both aquatic life and humans. Therefore, its removal by sustainable methods is a highlighted issue for today's world that has experienced increasing scarcity of water. Herein, microalgae-based PRL removal and its electrochemical monitoring were performed. The removal performed with Scenedesmus sp. was monitored by disposable pencil graphite electrodes and cyclic voltammetry. The removal was achieved without the requirement of complex procedures, and the monitoring of this removal finished in less than 1 min. Application of the system in real life was tested in the presence of tap water. The biosorption kinetics, isoterms, and changes in chlorophyll content of the microalgae were calculated, and the microscopic characterizations of the biosorption were performed. The selectivity of the system was studied against other water contaminants. This is the first study about the removal of PRL using Scenedesmus sp. and the monitoring of the removal using disposable electrochemical sensor technology.

The analysis of cross-correlation between Istanbul Stock Exchange and major stock markets and indices: An empirical analysis using Random Matrix Theory

This study attempts to investigate the cross-correlation between stocks listed under the XU100 index of Borsa Istanbul with several ratios and indices of the stock markets worldwide by using the Random Matrix Theory approach through a correlation matrix. In addition, Eigenvector Analysis, Network Analysis, Dimension Reduction will be carried out to investigate cross-correlation between markets. It was found that XU100, which is an index that includes 100 stocks highest in volume, has a distinguishing behavior compared to other indices and rates in terms of eigenvalue and related eigenvector structures. Furthermore, mean-value portfolio analysis showed that the empirical correlation matrix underestimates the portfolio risks than the correlation matrix obtained by filtering the noise. Coronavirus pandemic also affected Borsa Istanbul by breaking periodic behavior of volatility and correlation cycle. © 2022 John Wiley & Sons, Ltd.