The coronavirus disease 2019 or Covid-19 pandemic has affected many operations worldwide. This predicament also owes to the lockdown measures imposed by the affected countries. The total lockdown or partial lockdown devised by countries all over the world meant that most economic activities, be put on hold until the outbreak is contained. The decisions made by authorities of each affected country differs according to various factors, including the country's financial stability. This paper reviews the impact of Covid-19 pandemic on maritime sectors, specifically shipping, fisheries, maritime tourism, and oil and gas sector. The period of this study covers economic activities between the month of January towards the end of July 2020. Also discussed in this journal, is the analysis of the potential post-outbreak situation and the economic stimulus package. This paper serves as a reference for future research on this topic.
Excessive use of tetracycline (TC) is alarming owing to its increased detection in water systems. In this study, a photocatalyst was developed to degrade TC using a Ce-N-co-doped AC/TiO2 photocatalyst, denoted as Ce/N-AC/TiO2, prepared using the sol-gel method assisted by microwave radiation, speeding up the synthesis process. Ce/N-AC/TiO2 achieved maximum TC degradation of 93.1% under UV light with optimum sorption system conditions of an initial concentration of 10 mg L-1, pH 7, and 30 ℃, under 120 min. Scavenger experiments revealed that holes and superoxide radicals were the active species influencing the photodegradation process. The TC degradation was appropriately fitted with Langmuir isotherms and a pseudo-second-order (PSO) kinetic model. The change in enthalpy (ΔH) (2.43 kJ mol-1), entropy (ΔS) (0.024 kJ mol-1), and Gibbs free energy (ΔG) (- 4.941 to - 5.802 kJ mol-1) suggested that the adsorption process was spontaneous, favourable, and endothermic. Electrostatic interaction, hydrogen bonding, pore-filling, cationic-π, n-π, and π-π interaction were among the interactions involved between TC and Ce/N-AC/TiO2. Furthermore, Ce/N-AC/TiO2 stability was confirmed through 80% removal efficiency even after the fifth reuse cycle. Notably, this work provides new insight into the production of efficient, reusable, and enhanced photocatalysts using a rapid and cost-effective microwave-assisted synthesis process for pollutant remediation.
This work evaluates the fungicidal effect of essential oil from Coleus aromaticus (C. aromaticus) by solvent-free microwave-assisted extraction with a yield of 0.54%. Fourier-transform infrared spectroscopy was utilised to identify the functional groups, which were O-H, C-O, C-H, and C=C. Gas chromatography-mass spectrometry analysis was performed to determine the primary essential oil components, namely, thymol (92.62%), thymoquinone (2.64%), creosol (1.77%), linalool (1.68%), p-Cymene-2,5-diol (0.73%), and p-Cymene (0.56%). The inhibitory effect of essential oil extracted from C. aromaticus against the isolated fungi, Aspergillus niger from mango, was investigated. The mycelial growth inhibition of the extracted essential oil by the poisoned food test and disc diffusion assay showed the reduction at 79.63 ± 1.7 and 70.45 ± 6.54%, respectively. In vivo experiment was conducted with artificially wounded and unwounded mangoes, applying the extracted essential oil to the wounded mangoes inoculated with A. niger that could decrease the disease incidence from 100 to 58.33 ± 14.43%. Meanwhile, the treatment of the extracted essential oil did not affect the quality of the mango and it also shows improvement in weight loss reduction of the mango in comparison to the chemical fungicide and untreated mango. Hence, essential oil from C. aromaticus by solvent-free microwave-assisted extraction could be used as an effective control for the fruit spoilage and potential source of fruit preservative.