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1.
Environ Sci Pollut Res Int ; 30(12): 33206-33228, 2023 Mar.
Article in English | MEDLINE | ID: covidwho-2289596

ABSTRACT

This paper presents the numerical results of particle propagation in open space, taking into account the temperature of the human body and the surface of the ground. And also, the settling of particles or droplets under the action of gravitational force and transport in the open air is taken into account, taking into account the temperature during the process of breathing and sneezing or coughing. The temperature of the body and the surface of the ground, different rates of particle emission from the mouth, such as breathing and coughing or sneezing, are numerically investigated. The effect of temperature, cross-inlet wind, and the velocity of particle ejection from a person's mouth on social distancing is being investigated using a numerical calculation. The variable temperature of the human body forms a thermal plume, which affects the increase in the trajectory of the particle propagation, taking into account the lateral air flow. The thermal plume affects the particles in the breathing zone and spreads the particles over long distances in the direction of the airflow. The result of this work shows that in open space, taking into account the temperature of the body and the surface of the ground, a 2-m social distance may be insufficient for the process of sneezing and social distance must be observed depending on the breathing mode.


Subject(s)
Human Body , Wind , Humans , Temperature , Particle Size , Physical Distancing , Respiratory Aerosols and Droplets , Sneezing
2.
Environ Sci Pollut Res Int ; 29(44): 66808-66840, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-1826846

ABSTRACT

The new coronavirus disease COVID-19 has caused a worldwide pandemic to be declared in a very short period of time. The complexity of the infection lies in asymptomatic carriers that can inadvertently transmit the virus through airborne droplets. This kind of viral disease can infect the human body with tiny particles that carry various bacteria that are generated by the respiratory system of infected patients. In this study, numerical results are proposed that demonstrate the effect of human body temperature and temperature from radiators in a room on the spread of the smallest droplets and particles in an enclosed space. The numerical model proposed in this work takes into account the sedimentation of particles and droplets under the action of gravitational sedimentation and transport in a closed room during the processes of breathing, sneezing or coughing. Various cases were considered, taking into account normal human breathing, coughing or sneezing, as well as three different values of the rate of emission of particles from the human mouth. The heat plume, which affects the concentration of particles in the breathing zone, spreads the particle up to a distance of 4.29 m in the direction of the air flow. It can also be seen from the results obtained that the presence of radiators strongly affects the propagation of particles of various sizes in a closed room. From the obtained results, it should be noted that in order to recommend the optimal social distance, it is necessary to take into account many factors, especially momentum, gravity, human body temperature, as well as the process of natural convection, which greatly affect the propagation of particles in a closed room. The conclusions drawn from the results of this work show that, given the environmental conditions, the social distance of 2 m may not be enough.


Subject(s)
COVID-19 , Cough , Humans , Pandemics , Physical Distancing , Respiratory Aerosols and Droplets , Sneezing
3.
International Journal of Chemical Engineering (1687806X) ; : 1-9, 2021.
Article in English | Academic Search Complete | ID: covidwho-1268146

ABSTRACT

COVID-19 was identified all over the world as a pandemic in December 2019. This novel coronavirus affects the lower respiratory area, which causes pneumonia in the human body and transfers from human to human. Every day, the number of new patients and the number of deaths are increasing immensely, while specific drugs for this virus are still being developed. Hospitals are struggling to accommodate patients, resulting in a large number of temporary hospitals. These makeshift hospitals need an uninterrupted power supply to continuously maintain all the electrical facilities. Fuel cells, especially solid oxide fuel cells, play an essential role in meeting the additional energy needs of humankind during this critical moment. SOFCs are able to supply power to those makeshift hospitals from the main hospital building, as well as supplying electricity to locked-down residential areas to ease the strain on the electrical grid during this pandemic situation. As a result of their extensive applicability and numerous uses, SOFCs can be used to address electrical needs challenges in various sectors. [ABSTRACT FROM AUTHOR] Copyright of International Journal of Chemical Engineering (1687806X) is the property of Hindawi Limited and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

4.
Sci Rep ; 11(1): 9412, 2021 05 03.
Article in English | MEDLINE | ID: covidwho-1213938

ABSTRACT

The spread of the novel coronavirus disease (COVID-19) continues to show that geographic barriers alone cannot contain the virus. Asymptomatic carriers play a critical role in the nature of this virus, which is rapidly escalating into a global pandemic. Asymptomatic carriers can inadvertently transmit the virus through the air stream. Many diseases can infect human bodies with tiny droplets or particles that carry various viruses and bacteria that are generated by the respiratory system of infected patients. This article presents the numerical results of the spread of droplets or particles in a room. The proposed numerical model in this work takes into account the sedimentation of particles or droplets under the action of gravitational sedimentation and transport in the room during the process of breathing and sneezing or coughing. Three different cases are numerically investigated taking into account normal breathing and coughing or sneezing, respectively, and three different rates of particle ejection from the mouth are considered. Navier-Stokes equations for incompressible flows were used to describe three-dimensional air flow inside ventilated rooms. The influence of ventilation rate on social distancing is also computationally investigated. It was found that particles can move up to 5 m with a decrease in concentration in the direction of the air flow. The conclusions made in this work show that, given the environmental conditions, the two meter social distance recommended by WHO is insufficient.


Subject(s)
Air Microbiology , COVID-19/prevention & control , COVID-19/transmission , Cough , Exhalation , Sneezing , Humans , Models, Theoretical , Pandemics , Particle Size , Physical Distancing , SARS-CoV-2
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