scholarly journals Numerical Modeling of Face Shield Protection against a Sneeze

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1582
Author(s):  
Ainara Ugarte-Anero ◽  
Unai Fernandez-Gamiz ◽  
Iñigo Aramendia ◽  
Ekaitz Zulueta ◽  
Jose Manuel Lopez-Guede

The protection provided by wearing masks has been a guideline worldwide to prevent the risk of COVID-19 infection. The current work presents an investigation that analyzes the effectiveness of face shields as personal protective equipment. To that end, a multiphase computational fluid dynamic study based on Eulerian–Lagrangian techniques was defined to simulate the spread of the droplets produced by a sneeze. Different scenarios were evaluated where the relative humidity, ambient temperature, evaporation, mass transfer, break up, and turbulent dispersion were taken into account. The saliva that the human body generates was modeled as a saline solution of 8.8 g per 100 mL. In addition, the influence of the wind speed was studied with a soft breeze of 7 km/h and a moderate wind of 14 km/h. The results indicate that the face shield does not provide accurate protection, because only the person who is sneezed on is protected. Moreover, with a wind of 14 km/h, none of the droplets exhaled into the environment hit the face shield, instead, they were deposited onto the neck and face of the wearer. In the presence of an airflow, the droplets exhaled into the environment exceeded the safe distance marked by the WHO. Relative humidity and ambient temperature play an important role in the lifetime of the droplets.

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 1240-1243
Author(s):  
Pradyuman Singh Rajput ◽  
Asish Kumar Saha ◽  
Insiya Gangardiwala ◽  
Anand Vijayakumar Palur Ramakrishnan

The COVID-19 pandemic initially started from the Wuhan capital city of Hubei Province in the People's Republic of China had now led to a severe public health hazard across the globe, the recorded death is approximately 958 thousand globally and counting. With the enormous amount of spread of the disease, a severe crisis for Personal Protective Equipment (PPE) is being noticed across the globe. Face masks being the first line of defence for all the healthcare workers as well for the common public. It became mandatory to wear face masks before entering the patient care area. The countries who are not manufacturing it locally had to depend on other countries for the procurement. As there is a severe supply chain disruption due to the lockdown measures taken by all the countries to contain the disease, so it had become difficult to procure the face masks from the manufacturing countries. The price for these PPEs is also rising at an alarming rate with the increase in the COVID-19 cases and the huge rate of consumption by the healthcare and other sectors. Therefore, with limited resources, the hospital has to run its services. The CDC, WHO and ICMR have released several guidelines from time to time for sterilization and reuse of face masks. This article will discuss the various methods that can be utilized to sterilize the face masks and reuse of it.


2012 ◽  
Vol 2 (1) ◽  
pp. 14-20
Author(s):  
Yuwana Yuwana

Experiment on catfish drying employing ‘Teko Bersayap’ solar dryer was conducted. The result of the experiment indicated that the dryer was able to increase ambient temperature up to 44% and decrease ambient relative humidity up to 103%. Fish drying process followed equations : KAu = 74,94 e-0,03t for unsplitted fish and KAb = 79,25 e-0,09t for splitted fish, where KAu = moisture content of unsplitted fish (%), KAb = moisture content of splitted fish (%), t = drying time. Drying of unsplitted fish finished in 43.995 hours while drying of split fish completed in 15.29 hours. Splitting the fish increased 2,877 times drying rate.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Kazuyuki Miyamoto ◽  
Keisuke Suzuki ◽  
Hirokazu Ohtaki ◽  
Motoyasu Nakamura ◽  
Hiroki Yamaga ◽  
...  

Abstract Background Heatstroke is associated with exposure to high ambient temperature (AT) and relative humidity (RH), and an increased risk of organ damage or death. Previously proposed animal models of heatstroke disregard the impact of RH. Therefore, we aimed to establish and validate an animal model of heatstroke considering RH. To validate our model, we also examined the effect of hydration and investigated gene expression of cotransporter proteins in the intestinal membranes after heat exposure. Methods Mildly dehydrated adult male C57/BL6J mice were subjected to three AT conditions (37 °C, 41 °C, or 43 °C) at RH > 99% and monitored with WetBulb globe temperature (WBGT) for 1 h. The survival rate, body weight, core body temperature, blood parameters, and histologically confirmed tissue damage were evaluated to establish a mouse heatstroke model. Then, the mice received no treatment, water, or oral rehydration solution (ORS) before and after heat exposure; subsequent organ damage was compared using our model. Thereafter, we investigated cotransporter protein gene expressions in the intestinal membranes of mice that received no treatment, water, or ORS. Results The survival rates of mice exposed to ATs of 37 °C, 41 °C, and 43 °C were 100%, 83.3%, and 0%, respectively. From this result, we excluded AT43. Mice in the AT 41 °C group appeared to be more dehydrated than those in the AT 37 °C group. WBGT in the AT 41 °C group was > 44 °C; core body temperature in this group reached 41.3 ± 0.08 °C during heat exposure and decreased to 34.0 ± 0.18 °C, returning to baseline after 8 h which showed a biphasic thermal dysregulation response. The AT 41 °C group presented with greater hepatic, renal, and musculoskeletal damage than did the other groups. The impact of ORS on recovery was greater than that of water or no treatment. The administration of ORS with heat exposure increased cotransporter gene expression in the intestines and reduced heatstroke-related damage. Conclusions We developed a novel mouse heatstroke model that considered AT and RH. We found that ORS administration improved inadequate circulation and reduced tissue injury by increasing cotransporter gene expression in the intestines.


2020 ◽  
pp. 153537022097781
Author(s):  
Douglas J Perkins ◽  
Robert A Nofchissey ◽  
Chunyan Ye ◽  
Nathan Donart ◽  
Alison Kell ◽  
...  

The ongoing pandemic of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has placed a substantial strain on the supply of personal protective equipment, particularly the availability of N95 respirators for frontline healthcare personnel. These shortages have led to the creation of protocols to disinfect and reuse potentially contaminated personal protective equipment. A simple and inexpensive decontamination procedure that does not rely on the use of consumable supplies is dry heat incubation. Although reprocessing with this method has been shown to maintain the integrity of N95 respirators after multiple decontamination procedures, information on the ability of dry heat incubation to inactivate SARS-CoV-2 is largely unreported. Here, we show that dry heat incubation does not consistently inactivate SARS-CoV-2-contaminated N95 respirators, and that variation in experimental conditions can dramatically affect viability of the virus. Furthermore, we show that SARS-CoV-2 can survive on N95 respirators that remain at room temperature for at least five days. Collectively, our findings demonstrate that dry heat incubation procedures and ambient temperature for five days are not viable methods for inactivating SARS-CoV-2 on N95 respirators for potential reuse. We recommend that decontamination procedures being considered for the reuse of N95 respirators be validated at each individual site and that validation of the process must be thoroughly conducted using a defined protocol.


Work ◽  
2021 ◽  
pp. 1-14
Author(s):  
Mojtaba K. Danesh ◽  
Ehsan Garosi ◽  
Hamedeh Golmohamadpour

BACKGROUND: The COVID-19 pandemic has put health systems under unprecedented pressure, challenging their workforce, especially nurses. OBJECTIVE: The current paper presented a review of the early literature concerning emerging nursing challenges during the early stages of the COVID-19 pandemic. METHODS: A systematic search of the published literature between January and May 2020 was carried out in Medline, Science Direct, and Google Scholar to identify relevant quantitative and qualitative studies. RESULTS: Twenty-two original articles were retrieved, the majority of which were survey studies from China. Synthesis of the evidence resulted in four overarching themes including “being physically and mentally drained in the face of fear and uncertainty,” “shortage of personal protective equipment and usability issues,” “psychosomatic disturbances among nurses,” and “moderators to mitigate nurses’ challenges.” CONCLUSIONS: Providing care for demanding COVID-19 patients, nurses experienced a gruelling situation, during which a significant amount of psychological and physical distress was inflicted to them. However, receiving proper support from their organization and society could improve the condition substantially. Further research is required to explore the impact of the COVID-19 pandemic on nurses, especially from Western countries.


2002 ◽  
Vol 28 (11) ◽  
pp. 1763-1785 ◽  
Author(s):  
Gustavo C. Buscaglia ◽  
Fabián A. Bombardelli ◽  
Marcelo H. Garcı́a

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