In-depth study of kinetics, thermodynamics, and reaction mechanism of catalytic pyrolysis of disposable face mask using spent adsorbent based catalysts

Millions of face mask has been converted to waste since the onset of COVID-19 virus. Hence, present study explores the feasibility of converting disposable face masks to energy through catalytic pyrolysis process using a low-cost waste (spent aluminum hydroxide/oxide nanoparticle adsorbent) derived catalyst. Thermogravimetric analysis of the non-catalytic and catalytic pyrolysis of disposable face mask was conducted at varied heating rates of 10 °C/min, 20 °C/min, 30 °C/min, 40 °C/min, and 50 °C/min, respectively. Iso-conversional methods, Kissinger Akahira Sunose (KAS) and Ozawa Flynn Wall (OFW) were used for the kinetic study. The reaction mechanism was analyzed using Criado's z-master plot (CZMP) method along with the determination of thermodynamic parameters of the process. Results found that the addition of a catalyst to the process benefits the overall efficacy of the process by reducing the activation energy (Ea) (without catalyst;OFW-Ea: 188.7 kJ/mol, KAS-Ea: 186.2 kJ/mol) as well as lowering the disordered state of the process. Metal doped catalyst (Ni/ γ-Al2O3) (OFW-Ea: 168.4 kJ/mol, KAS-Ea: 167.8 kJ/mol) shows a larger reduction in activation energy in comparison to bare alumina (γ-Al2O3) (OFW-Ea: 183.2 kJ/mol, KAS-Ea: 180.4 kJ/mol). The current study presented disposable face masks as reclaimable in terms of energy and waste-derived catalyst as a potent solution to be explored in place of high-cost commercial catalysts. © 2023 Energy Institute

Virus models in complex frameworks: Towards modeling space patterns of SARS-CoV-2 epidemics

This paper deals with the micro–macro-derivation of virus models coupled with a reaction–diffusion system that generates the dynamics in space of the virus particles. The first part of the presentation focuses, starting from [N. Bellomo, K. Painter, Y. Tao and M. Winkler, Occurrence versus absence of taxis-driven instabilities in a May–Nowak model for virus infection, SIAM J. Appl. Math. 79 (2019) 1990–2010;N. Bellomo and Y. Tao, Stabilization in a chemotaxis model for virus infection, Discrete Contin. Dyn. Syst. S 13 (2020) 105–117], on a survey and a critical analysis of some phenomenological models known in the literature. The second part shows how a Hilbert type can be developed to derive models at the macro-scale from the underlying description delivered by the kinetic theory of active particles. The third part deals with the derivation of macroscopic models of various virus models coupled with the reaction–diffusion systems. Then, a forward look to research perspectives is proposed. [ FROM AUTHOR]

MULTISCALE MODELS OF COVID-19 WITH MUTATIONS AND VARIANTS

This paper focuses on the multiscale modeling of the COVID-19 pandemic and presents further developments of the model [7] with the aim of showing how relaxations of the confinement rules can generate sequential waves. Subsequently, the dynamics of mutations into new variants can be modeled. Simulations are developed also to support the decision making of crisis managers.

Optimal control of epidemic spreading in the presence of social heterogeneity.

The spread of COVID-19 has been thwarted in most countries through non-pharmaceutical interventions. In particular, the most effective measures in this direction have been the stay-at-home and closure strategies of businesses and schools. However, population-wide lockdowns are far from being optimal, carrying heavy economic consequences. Therefore, there is nowadays a strong interest in designing more efficient restrictions. In this work, starting from a recent kinetic-type model which takes into account the heterogeneity described by the social contact of individuals, we analyse the effects of introducing an optimal control strategy into the system, to limit selectively the mean number of contacts and reduce consequently the number of infected cases. Thanks to a data-driven approach, we show that this new mathematical model permits us to assess the effects of the social limitations. Finally, using the model introduced here and starting from the available data, we show the effectiveness of the proposed selective measures to dampen the epidemic trends. This article is part of the theme issue 'Kinetic exchange models of societies and economies'.

Numerical simulation of pulmonary airway reopening by the multiphase lattice Boltzmann method[Formula presented]

Not only coughing and sneezing, but even normal breathing can produce aerosols, because rupture of liquid plugs forms microdroplets during pulmonary airway reopening. Aerosols are important carriers of various viruses, such as influenza, SARS, MERS, and COVID-19. To control airborne disease transmission, it is important to understand aerosol formation, which is related to the pressure drop, liquid plug, and film. In addition, the detrimental pressure and shear stress at the airway wall produced in the process of airway reopening have also attracted a lot of attention. In this paper, we proposed a multiphase lattice Boltzmann method to numerically simulate pulmonary airway reopening, in which the gas-liquid transition is directly driven by the equation of state. After validating the numerical model, two rupture cases with and without aerosol formation were compared and analyzed. We found that injury of the epithelium in the case with aerosol formation was almost the same as that without aerosol formation, even though the pressure drop in the airway increased by about 50%. Further investigation showed that the aerosol size and maximum differences of the wall pressure and shear stress increased with pressure drop in the pulmonary airway. A similar trend was observed when the thickness of the liquid plug became larger, while an opposite trend occurred when the thickness of the liquid film increased. The model can be extended to study generation and transmission of bioaerosols carrying the influenza or coronavirus. © 2022 Elsevier Ltd

Gases Theory Representation Instrument (GeTRI): A Practical Tool to Analyze Sundanese Students’ Conception in the COVID-19 Pandemic

This research purposes to promote a Gases Theory Representation Instrument (GTRI) as a tool to identify the students’ conception on kinetic theory of gases. The method used in this research was FODEM (Formative Development Methods) model which has three comprehensive steps, which are need analysis, implementation, and formative evaluation. The participants involved in this research were 26 high school students in Sundanese tribe. The students’ responses were analyzed using Rasch model, which involved item reliability, person reliability, validity, difficulty level and students’ conception distributions. Students’ conception were classified into six categories which are Sound Understanding (SU), Partial Positive (PP), Partial Negative (PN), Misconception (MC), No Understanding (NU), and No Coding (NC). Based on the data analysis, it can be concluded that students’ conception are typically in the SU and PP categories. Besides, the Gases Theory Representation Instrument (GTRI) is reliable and valid to identify students’ conception on kinetic theory of gases. © 2021 Institute of Physics Publishing. All rights reserved.