Currently, COVID-19 is a global pandemic that scientists and engineers around the world are aiming to understand further through rigorous testing and observation. This paper aims to provide safe distance recommendations among individuals and minimize the spread of COVID-19, as well as examine the efficacy of face coverings as a tool to slow the spread of respiratory droplets. These studies are conducted using computational fluid dynamics analyses, where the infected person breathes, coughs, and sneezes at various distances and environmental wind conditions and while wearing a face-covering (mask or face shield). In cases where there were no wind conditions, the breathing and coughing simulations display 1–2 m physical distancing to be effective. However, when sneezing was introduced, the physical distancing recommendation of 2 m was deemed not effective; instead, a distance of 2.8 m and greater was found to be more effective in reducing the exposure to respiratory droplets. The evaluation of environmental wind conditions necessitated an increase in physical distancing measures in all cases. The case where breathing was measured with a gentle breeze resulted in a physical distancing recommendation of 1.1 m, while coughing caused a change from the previous recommendation of 2 m to a distance of 4.5 m or greater. Sneezing in the presence of a gentle breeze was deemed to be the most impactful, with a recommendation for physical distancing of 5.8 m or more. It was determined that face coverings can potentially provide protection to an uninfected person in static air conditions. However, the uninfected person's protection can be compromised even in gentle wind conditions.

This comprehensive review paper compares the different methods developed experimentally to produce hydrogen by reacting aluminum and water. The alumina oxide layer which forms on the exterior surface of aluminum inhibits the reaction from taking place. Therefore, this paper presents a variety of techniques used to eliminate the oxide layer so that the reaction can continuously take place. The review paper aims to evaluate these techniques by comparing the hydrogen yield and maximum hydrogen production rate. On the basis of the analyses conducted, it was identified that the addition of hydroxide promoters, such as NaOH and KOH, is highly beneficial. This was also evident in the various studies where yields greater than 99% are achieved. Additionally, it is determined that the addition of NaCl or KCl to ball-milled samples of aluminum can be extremely advantageous when examining the maximum hydrogen production rate. For instance, an experimental sample composed of 2% NaCl was able to achieve a maximum hydrogen production rate of 1140 mL/min. Furthermore, numerous other studies are discussed by considering their specific advantages and disadvantages.

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