Simply Speaking While Infected Can Potentially Spread COVID-19

COVID-19 can spread from asymptomatic but infected people through small aerosol droplets in their exhaled breath. Most studies of the flow of exhaled air have focused on coughing or sneezing; however, speaking while near one another is also risky. In Physics of Fluids, scientists used smoke and laser light to study the flow of expelled breath near and around two people conversing in various relative postures commonly found in the service industry, such as in hair salons, medical exam rooms, or long-term care facilities.

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Biomaterials Could Mean Better Vaccines, Virus-Fighting Surfaces

Advances in the fields of biomaterials and nanotechnology could lead to big breakthroughs in the fight against dangerous viruses like the novel coronavirus that causes COVID-19. In APL Bioengineering, researchers from the Indian Institute of Science describe possibilities being explored by scientists, combining biomaterials and nanotechnology, to make vaccines more effective and build surfaces that could fight and kill viruses on their own.

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Advanced Simulations Reveal How Air Conditioning Spreads COVID-19 Aerosols

A restaurant outbreak in China was widely reported as strong evidence of airflow-induced transmission of COVID-19, but it lacked a detailed investigation about exactly how transmission occurred. In Physics of Fluids, researchers at the University of Minnesota report using advanced simulation methods to capture the complex flows that occur when the cold airflow from air conditioners interacts with the hot plume from a dining table and the transport of virus-loading particles within such flows.

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Porous Materials Unfavorable for Coronavirus Survival

As COVID-19 spreads via respiratory droplets, researchers have become increasingly interested in the drying of droplets on impermeable and porous surfaces; surfaces that accelerate evaporation can decelerate the spread of the virus. In Physics of Fluids, researchers show a droplet remains liquid for a much shorter time on a porous surface, making it less favorable to survival of the virus. On paper and cloth, the virus survived for only three hours and two days, respectively.

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Air Purifiers May Do More Harm Than Good in Confined Spaces with Airborne Viruses

The positions of air inlets and outlets in confined spaces, such as elevators, greatly affect airborne virus transmission. In Physics of Fluids, researchers show air purifiers may actually increase the spread. They use ultraviolet radiation to kill viruses and other microbes, but they also circulate air, sucking it in and exhausting cleaned air. This adds to overall circulation.

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Masks Not Enough to Stop COVID-19’s Spread Without Distancing

Simply wearing a mask may not be enough to prevent the spread of COVID-19 without social distancing. In Physics of Fluids, researchers tested how different types of mask materials impacted the spread of droplets that carry the coronavirus when we cough or sneeze. Every material tested dramatically reduced the number of droplets that were spread. But at distances of less than 6 feet, enough droplets to potentially cause illness still made it through several of the materials.

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Fast Walking in Narrow Corridors Can Increase COVID-19 Transmission Risk

Simulations have been used to predict droplet dispersal patterns in situations where COVID-19 might be spread and results in Physics of Fluids show the importance of the space shape in modeling how droplets move. The simulations are used to determine flow patterns behind a walking individual in spaces of different shape. The results reveal a higher transmission risk for children in some instances, such as behind quickly moving people in a long narrow hallway.

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Face Shields No Match for Sneeze Vortex Rings

Do face shields provide enough protection to the wearers against COVID-19 if they don’t also wear a mask? No. But researchers in Japan are working to create face shields safe enough to be worn alone. In Physics of Fluids, Fujio Akagi and colleagues describe their work to gain a better understanding of what happens to the airflow around a face shield when someone nearby sneezes.

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Imitation Mosquito Ears Help Identify Mosquito Species and Sex

Using an imitation “ear” modeled on the organs that mosquitos use to hear, researchers have identified a mosquito’s species and sex using sound — just like mosquitos do themselves. The researchers hope this bioinspired detector could someday be used in the field to save lives by aiding in more selective pesticide use and possibly preventing mosquitos from mating. A presentation of the new research will be given as part of the 179th ASA Meeting.

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COVID-19 Virus Survives on Surfaces Within Thin Film

To find out how the COVID-19 virus survives on surfaces, researchers in India are exploring the drying times of thin liquid films that persist on surfaces after most respiratory droplets evaporate. While the drying time of typical respiratory droplets is on the order of seconds, the survival time of the COVID-19 virus was found to be on the order of hours. In Physics of Fluids, the researchers describe how a nanometers-thick liquid film clings to the surface, allowing the virus to survive.

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In a Pandemic, Migration Away from Dense Cities More Effective than Closing Borders

During the COVID-19 pandemic, closing national borders and borders between states and regions has been prevalent. But does it help? In a paper in Chaos, researchers decided to put this hypothesis to the test and discover if confinement and travels bans are really effective ways to limit the spread of a pandemic disease. Specifically, they focused on the movement of people from larger cities to smaller ones and tested the results of this one-way migration.

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Plasma Treatments Quickly Kill Coronavirus on Surfaces

Researchers from UCLA believe using plasma could promise a significant breakthrough in the fight against the spread of COVID-19. In Physics of Fluids, modeling conducted showed strains of the coronavirus on surfaces like metal, leather, and plastic were killed in as little as 30 seconds of treatment with argon-fed, cold atmospheric plasma. The researchers used an atmospheric pressure plasma jet they built with a 3D printer to spray surfaces that were treated with SARS-CoV-2 cultures.

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