scholarly journals Measuring 3D indoor air velocity via an inexpensive low-power ultrasonic anemometer

2020 ◽  
Vol 211 ◽  
pp. 109805 ◽  
Author(s):  
Edward Arens ◽  
Ali Ghahramani ◽  
Richard Przybyla ◽  
Michael Andersen ◽  
Syung Min ◽  
...  
Author(s):  
Ali Ghahramani ◽  
Megan Zhu ◽  
Richard Przybyla ◽  
Michael Andersen ◽  
Syung Min ◽  
...  

Author(s):  
Purva Shoor ◽  
Gagan Deep Kaur ◽  
Amanjot Kaur Chauhan

The physical environment plays an important role in the transmission of respiratory infections like COVID-19. Atmospheric conditions associated to diseases like influenza, adenovirus infections, parainfluenza, common cold viruses and so on. But we are still lacking in evidence to support the influence of meteorological conditions in spreading COVID-19. We have discussed air pollution, smoking, low air temperature, and proximity to equator, low humidity and air velocity as contributing factors in the spread of SARS-CoV-2 through this narrative synthesis. Bio-aerosol or ultra-fine particulate matter seems to be the most promising mode of transmission of COVID-19. Other methods are direct contact and droplet infection. Air pollution control can prevent priming of respiratory system which shall further protect from pulmonary infections. Air sanitization and humidifiers can be considered to modify the indoor air and prevent contracting infection at workplaces, schools and other gatherings.


2012 ◽  
Vol 538-541 ◽  
pp. 1267-1271
Author(s):  
Le Ping Chen ◽  
Yan Yan Han ◽  
Quan Zhou

The influences of different preheating temperature of mold and treatment temperature on solidified structure of LC9 alloy were studied by low-power ultrasonic vibration melt-treatment. The results show that grain of LC9 alloy can be refined greatly by low-power ultrasonic vibration melt-treatment. The dendrite growth is restrained and the microstructure is changed from larger dendrite grains to dominant fine none-dendritic and globular grains. With the decrease of preheating temperature of mold, grain size decreases. The efficiency of grain refinement is better at low preheating temperature. With the increase of ultrasonic vibration temperature, grain size decreases firstly, then increases, and the turning point is 660 °C. At 640 °C, grain size of the alloy with US vibration treatment changes slightly compared with non US-treated alloy.


Sensor Review ◽  
2002 ◽  
Vol 22 (3) ◽  
pp. 218-222 ◽  
Author(s):  
Chris Stock

Describes the developments of a small, robust ultrasonic wind speed and direction indicator. Gill’s patented ultrasonic technology is based on the time‐of‐flight operating principle, which provides vector measurement of air velocity, given the dimensions and geometry of pairs of transducers. In this case, two pairs of transducers are used such that the air velocity can be derived along orthogonal axes and hence the air speed and direction can be computed.


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