scholarly journals Airborne transmission of virus-laden aerosols inside a music classroom: Effects of portable purifiers and aerosol injection rates

2021 ◽  
Vol 33 (3) ◽  
pp. 033307
Author(s):  
Sai Ranjeet Narayanan ◽  
Suo Yang
Keyword(s):  
Airborne Transmission ◽  
Music Classroom ◽  
Classroom Effects ◽  
Injection Rates

scholarly journals Airborne Transmission of Virus-Laden Aerosols inside a Music Classroom: Effects of Portable Purifiers and Aerosol Injection Rates

2020 ◽  
Author(s):  
Sai Ranjeet Narayanan ◽  
Suo Yang
Keyword(s):  
Aerosol Deposition ◽  
Injection Rate ◽  
Musical Instruments ◽  
World Health ◽  
Indoor Environments ◽  
Airborne Transmission ◽  
Classroom Effects ◽  
Airborne Concentration ◽  
Health Organization ◽  
Injection Rates

The ongoing COVID-19 pandemic has shifted attention to the airborne transmission of exhaled droplet nuclei within indoor environments. The spread of aerosols through singing and musical instruments in music performances has necessitated precautionary methods such as masks and portable purifiers. This study investigates the effects of placing portable air purifiers at different locations inside a classroom, as well as the effects of different aerosol injection rates (e.g., with and without masks, different musical instruments and different injection modes). Aerosol deposition, airborne concentration and removal are analyzed in this study. It was found that using purifiers could help in achieving ventilation rates close to the prescribed values by the World Health Organization (WHO), while also achieving aerosol removal times within the Center of Disease Control and Prevention (CDC) recommended guidelines. This could help in deciding break periods between classroom sessions, which was around 25 minutes through this study. Moreover, proper placement of purifiers could offer significant advantages in reducing airborne aerosol numbers (offering orders of magnitude higher aerosol removal when compared to nearly zero removal when having no purifiers), and improper placement of the purifiers could worsen the situation. The study suggests the purifier to be placed close to the injector to yield a benefit, and away from the people to be protected. The injection rate was found to have an almost linear correlation with the average airborne aerosol suspension rate and deposition rate, which could be used to predict the trends for scenarios with other injection rates.

CALCULATION OF OPTIMAL INJECTION RATE FOR DISPERSED WATERFLOODING SYSTEM

2017 ◽  
pp. 63-67
Author(s):  
L. A. Vaganov ◽  
A. Yu. Sencov ◽  
A. A. Ankudinov ◽  
N. S. Polyakova
Keyword(s):  
Injection Rate ◽  
Oil Field ◽  
Injection Well ◽  
Water Migration ◽  
Mutual Location ◽  
Optimal Injection ◽  
Technical Measures ◽  
Injection Rates

The article presents a description of the settlement method of necessary injection rates calculation, which is depended on the injected water migration into the surrounding wells and their mutual location. On the basis of the settlement method the targeted program of geological and technical measures for regulating the work of the injection well stock was created and implemented by the example of the BV7 formation of the Uzhno-Vyintoiskoe oil field.

Habits of Mind as a Framework for Assessment in Music Education

2019 ◽  
pp. 201-224
Author(s):  
Jillian Hogan ◽  
Ellen Winner
Keyword(s):  
Music Education ◽  
Arts Education ◽  
Habits Of Mind ◽  
Public High School ◽  
Student Agency ◽  
Thinking Dispositions ◽  
Music Classroom ◽  
Music Ensembles ◽  
School Music ◽  
High School Music

Music making requires many kinds of habits of mind—broad thinking dispositions potentially useful outside of the music room. Teaching for habits of mind is prevalent in both general and other areas of arts education. This chapter reports a preliminary analysis of the habits of mind that were systematically observed and thematically coded in twenty-four rehearsals of six public high school music ensembles: band, choir, and orchestra. Preliminary results reveal evidence of eight habits of mind being taught: engage and persist, evaluate, express, imagine, listen, notice, participate in community, and set goals and be prepared. However, two habits of mind that the researchers expected to find taught were not observed: appreciate ambiguity and use creativity. These two nonobserved habits are ones that arts advocates and theorists assume are central to arts education. The chapter discusses how authentic assessment of habits of mind in the music classroom may require novel methods, including the development of classroom environments that foster additional levels of student agency.

scholarly journals Peering inside a cough or sneeze to explain enhanced airborne transmission under dry weather

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kai Liu ◽  
Majid Allahyari ◽  
Jorge S. Salinas ◽  
Nadim Zgheib ◽  
S. Balachandar
Keyword(s):  
High Fidelity ◽  
Substantial Variation ◽  
Ambient Conditions ◽  
Airborne Transmission ◽  
Social Distancing ◽  
Virtual Experiments ◽  
Long Time ◽  
Simulation Results ◽  
High Fidelity Simulations ◽  
Droplet Nuclei

AbstractHigh-fidelity simulations of coughs and sneezes that serve as virtual experiments are presented, and they offer an unprecedented opportunity to peer into the chaotic evolution of the resulting airborne droplet clouds. While larger droplets quickly fall-out of the cloud, smaller droplets evaporate rapidly. The non-volatiles remain airborne as droplet nuclei for a long time to be transported over long distances. The substantial variation observed between the different realizations has important social distancing implications, since probabilistic outlier-events do occur and may need to be taken into account when assessing the risk of contagion. Contrary to common expectations, we observe dry ambient conditions to increase by more than four times the number of airborne potentially virus-laden nuclei, as a result of reduced droplet fall-out through rapid evaporation. The simulation results are used to validate and calibrate a comprehensive multiphase theory, which is then used to predict the spread of airborne nuclei under a wide variety of ambient conditions.

scholarly journals Air circulation in a gastrointestinal light source box and endoscope in the era of SARS-CoV-2 and airborne transmission of microorganisms

2021 ◽  
Vol 09 (03) ◽  
pp. E482-E486
Author(s):  
Stanislas Chaussade ◽  
Einas Abou Ali ◽  
Rachel Hallit ◽  
Arthur Belle ◽  
Maximilien Barret ◽  
...  
Keyword(s):  
Light Source ◽  
Cooling System ◽  
Air Cooling ◽  
Airborne Transmission ◽  
Plastic Tube ◽  
Care Workers ◽  
Air Cooling System ◽  
Forced Air ◽  
Air Circulation ◽  
Closed Environment

Abstract Background and study aims The role that air circulation through a gastrointestinal endoscopy system plays in airborne transmission of microorganisms has never been investigated. The aim of this study was to explore the potential risk of transmission and potential improvements in the system. Methods We investigated and described air circulation into gastrointestinal endoscopes from Fujifilm, Olympus, and Pentax. Results The light source box contains a lamp, either Xenon or LED. The temperature of the light is high and is regulated by a forced-air cooling system to maintain a stable temperature in the middle of the box. The air used by the forced-air cooling system is sucked from the closed environment of the patient through an aeration port, located close to the light source and evacuated out of the box by one or two ventilators. No filter exists to avoid dispersion of particles outside the processor box. The light source box also contains an insufflation air pump. The air is sucked from the light source box through one or two holes in the air pump and pushed from the air pump into the air pipe of the endoscope through a plastic tube. Because the air pump does not have a dedicated HEPA filter, transmission of microorganisms cannot be excluded. Conclusions Changes are necessary to prevent airborne transmission. Exclusive use of an external CO2 pump and wrapping the endoscope platform with a plastic film will limit scatter of microorganisms. In the era of pandemic virus with airborne transmission, improvements in gastrointestinal ventilation systems are necessary to avoid contamination of patients and health care workers.

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