scholarly journals Face mask fit modifications that improve source control performance

2021 ◽  
Author(s):  
Francoise M. Blachere ◽  
Angela R. Lemons ◽  
Jayme P. Coyle ◽  
Raymond C. Derk ◽  
William G. Lindsley ◽  
...  
Keyword(s):  
Measurement System ◽  
Human Subjects ◽  
Face Mask ◽  
Source Control ◽  
Control Performance ◽  
Control Measurement ◽  
Infected People ◽  
Control Devices

BACKGROUND During the COVID-19 pandemic, face masks are used as source control devices to reduce the expulsion of respiratory aerosols from infected people. Modifications such as mask braces, earloop straps, knotting and tucking, and double masking have been proposed to improve mask fit however the data on source control are limited. METHODS The effectiveness of mask fit modifications was determined by conducting fit tests on human subjects and simulator manikins and by performing simulated coughs and exhalations using a source control measurement system. RESULTS Medical masks without modification blocked ≥56% of cough aerosols and ≥42% of exhaled aerosols. Modifying fit by crossing the earloops or placing a bracket under the mask did not increase performance, while using earloop toggles, an earloop strap, and knotting and tucking the mask increased performance. The most effective modifications for improving source control performance were double masking and using a mask brace. Placing a cloth mask over a medical mask blocked ≥85% of cough aerosols and ≥91% of exhaled aerosols. Placing a brace over a medical mask blocked ≥95% of cough aerosols and ≥99% of exhaled aerosols. CONCLUSION Fit modifications can greatly improve the performance of face masks as source control devices for respiratory aerosols.

scholarly journals Efficacy of face masks, neck gaiters and face shields for reducing the expulsion of simulated cough-generated aerosols

2020 ◽  
Author(s):  
William G. Lindsley ◽  
Francoise M. Blachere ◽  
Brandon F. Law ◽  
Donald H. Beezhold ◽  
John D. Noti
Keyword(s):  
Double Layer ◽  
Aerosol Particles ◽  
Single Layer ◽  
Face Mask ◽  
Cotton Cloth ◽  
Source Control ◽  
The Face ◽  
Community Transmission ◽  
Small Aerosol ◽  
Control Devices

AbstractFace masks are recommended to reduce community transmission of SARS-CoV-2. One of the primary benefits of face masks and other coverings is as source control devices to reduce the expulsion of respiratory aerosols during coughing, breathing, and speaking. Face shields and neck gaiters have been proposed as an alternative to face masks, but information about face shields and neck gaiters as source control devices is limited. We used a cough aerosol simulator with a pliable skin headform to propel small aerosol particles (0 to 7 µm) into different face coverings. An N95 respirator blocked 99% of the cough aerosol, a medical grade procedure mask blocked 59%, a 3-ply cotton cloth face mask blocked 51%, and a polyester neck gaiter blocked 47% as a single layer and 60% when folded into a double layer. In contrast, the face shield blocked 2% of the cough aerosol. Our results suggest that face masks and neck gaiters are preferable to face shields as source control devices for cough aerosols.

scholarly journals Face mask fit modifications that improve source control performance

2021 ◽  
Author(s):  
Francoise M. Blachere ◽  
Angela R. Lemons ◽  
Jayme P. Coyle ◽  
Raymond C. Derk ◽  
William G. Lindsley ◽  
...  
Keyword(s):  
Face Mask ◽  
Source Control ◽  
Control Performance

scholarly journals A comparison of performance metrics for cloth face masks as source control devices for simulated cough and exhalation aerosols

2021 ◽  
Author(s):  
William G. Lindsley ◽  
Francoise M. Blachere ◽  
Donald H. Beezhold ◽  
Brandon F. Law ◽  
Raymond C. Derk ◽  
...  
Keyword(s):  
Performance Metrics ◽  
Construction Materials ◽  
Correlation Coefficients ◽  
Filtration Efficiency ◽  
The Other ◽  
Source Control ◽  
Control Performance ◽  
Control And Prevention ◽  
Control Devices ◽  
Alternative Metrics

AbstractUniversal mask wearing is recommended by the Centers for Disease Control and Prevention to help control the spread of COVID-19. Masks reduce the expulsion of respiratory aerosols (called source control) and offer some protection to the wearer. However, masks vary greatly in their designs and construction materials, and it is not clear which are most effective. Our study tested 15 reusable cloth masks (which included face masks, neck gaiters, and bandanas), two medical masks, and two N95 filtering facepiece respirators as source control devices for aerosols ≤ 7 µm produced during simulated coughing and exhalation. These measurements were compared with the mask filtration efficiencies, airflow resistances, and fit factors. The source control collection efficiencies for the cloth masks ranged from 17% to 71% for coughing and 35% to 66% for exhalation. The filtration efficiencies of the cloth masks ranged from 1.4% to 98%, while the fit factors were 1.3 to 7.4 on an elastomeric manikin headform and 1.0 to 4.0 on human test subjects. The correlation coefficients between the source control efficacies and the other performance metrics ranged from 0.31 to 0.66 and were significant in all but one case. However, none of the alternative metrics were strong predictors of the source control performance of cloth masks. Our results suggest that a better understanding of the relationships between source control performance and metrics like filtration efficiency, airflow resistance, and fit factor are needed to develop simple methods to estimate the effectiveness of masks as source control devices for respiratory aerosols.

scholarly journals A comparison of performance metrics for cloth masks as source control devices for simulated cough and exhalation aerosols

2021 ◽  
pp. 1-21
Author(s):  
William G. Lindsley ◽  
Francoise M. Blachere ◽  
Donald H. Beezhold ◽  
Brandon F. Law ◽  
Raymond C. Derk ◽  
...  
Keyword(s):  
Performance Metrics ◽  
Source Control ◽  
Control Devices

A Novel Artificial Face Mask based Nanofibers with Special Intelligent Engineered Nanocomposite Against Covid-19

2021 ◽  
pp. PP. 21-22
Author(s):  
Ahmed A. Elngar ◽  
◽  
◽  
S.I. El El-Dek
Keyword(s):  
Artificial Intelligence ◽  
Resource Allocation ◽  
Pattern Recognition ◽  
Disease Management ◽  
Face Mask ◽  
Vital Role ◽  
Mobile Unit ◽  
Disease Clusters ◽  
Infected People ◽  
The Face

We introduce our idea about a new face mask against Covid-19. Herein our novel face mask is a polymeric matrix of nanofibers. These nanofibers are decorated with special engineered nanocomposite. The later possesses antiviral, antimicrobial. A well-established IR temperature biosensor will be implanted in the face mask and connected to the mobile phone using App (Seek thermal) to allow temperature monitoring. Artificial Intelligence can play a vital role in the fight against COVID-19. AI is being successfully used in the identification of disease clusters, monitoring of cases, prediction of the future outbreaks, mortality risk, diagnosis of COVID-19, disease management by resource allocation, facilitating training, record maintenance and pattern recognition for studying the disease trend. Therefore, AI is used as a type of alarm which be connected through Global Position System (GPS) to a central networking system to monitor the crowded areas of probable infections. In this case, the hospital in this neighborhood will be charged to let a mobile unit of assessment travel quickly to the infected people areas.

Micro-Anode Guided Electroplating (MAGE) Control System

2006 ◽  
Vol 505-507 ◽  
pp. 115-120
Author(s):  
Dong Liang Lee ◽  
Jui Chang Lin ◽  
P.F. Kao ◽  
S.B. Jiang
Keyword(s):  
Control System ◽  
Surface Morphology ◽  
Measurement System ◽  
System Architecture ◽  
Power Source ◽  
Source Control ◽  
Equipment Development ◽  
Machine Interface ◽  
Man Machine Interface ◽  
Control System Architecture

This article releases the details of the equipment development for the micro-anode guided electroplating MAGE fabrication. The microstepping architecture, electroplating power source, control system architecture, measurement system, man machine interface and the control prodedure will be described. Metallic columns around 100 micrometers in diameter were fabricated up to 2cm long with this equipment to demonstrate its performance. An innovative intermittent MAGE mode is supported by this equipment so that it can produce micro columns of finer surface morphology and better circumferential uniformity than the conventional continuous electroplating.

COVID-19: Epidemiology, Pathology, Diagnosis, Treatment, and Impact

2021 ◽  
Vol 27 ◽  
Author(s):  
Saimon Shahriar ◽  
Md. Sohel Rana ◽  
Md. Sabbir Hossain ◽  
Ariful Karim ◽  
Tasneem Nayla Mredula ◽  
...  
Keyword(s):  
Drug Targets ◽  
Face Mask ◽  
Rt Pcr ◽  
Comprehensive Overview ◽  
Infected People ◽  
Respiratory Problems ◽  
Wide Range ◽  
Critical Patients ◽  
Physical And Chemical ◽  
Second Wave

: The pandemic, well-known as COVID-19, has been brought about by the coronavirus SARS-CoV-2 and it has distinct characteristics from other coronavirus-related epidemics. This pandemic has been ravaging the whole world for more than a year now and no drugs or vaccines have been found to eliminate this virus from the infected people effectively; only physical measures like social distancing, hand washing and face-mask wearing have been taken to reduce its spreading and very recently Veklury (remdesivir) has been permitted by the USFDA to manage the critical patients. This disease can be asymptomatic but when it is symptomatic, it presents with respiratory problems and cold- or flu-like symptoms which can be diagnosed with a chest CT and confirmed with RT-PCR tests. In this review, the taxonomy and structure of SARS-CoV-2 and history, transmission, epidemiology, pathology, clinical features and impacts of the COVID-19 have been discussed. A summary of possible drug targets, attempted physical and chemical measures, as well as vaccine candidates, have also been provided. How this coronavirus is different from other coronaviruses, the obstacles in managing this disease and the possibility of a second wave have also been reviewed. This review represents a wide range of information regarding COVID-19 and intends to be used as a comprehensive overview in this regard.

Semi-Active Control of Structural Systems Aiming to Approximate the Performance of the Targeted Active Control Law: Output Emulation Approach

2013 ◽  
Author(s):  
Kazuhiko Hiramoto ◽  
Taichi Matsuoka ◽  
Katsuaki Sunakoda
Keyword(s):  
Control System ◽  
Active Control ◽  
Variable Parameter ◽  
Control Law ◽  
Structural Systems ◽  
Control Force ◽  
Control Performance ◽  
Control Devices ◽  
Active Control System ◽  
Control Output

As a method for semi-active control of structural systems, the active-control-based method that emulates the control force of a targeted active control law by semi-active control devices has been studied. In the active-control-based method, the semi-active control devices are not necessarily able to generate the targeted active control force because of the dissipative nature of those devices. In such a situation, the meaning of the targeted active control law becomes unclear in the sense of the control performance achieved by the resulting semi-active control system. In this study, a new semi-active control strategy that approximates the control output (not the control force) of the targeted active control is proposed. The variable parameter of the semi-active control device is selected at every time instant so that the predicted control output of the semi-active control system becomes close to the corresponding predicted control output of the targeted active control as much as possible. Parameters of the targeted active control law are optimized in the premise of the above “output emulation” strategy so that the control performance of the semi-active control becomes good and the “error” of the achieved control performance between the targeted active control and the semi-active control becomes small.

scholarly journals The Timing and Intensity of Social Distancing to Flatten the COVID-19 Curve: The Case of Spain

2020 ◽  
Vol 17 (19) ◽  
pp. 7283 ◽  
Author(s):  
Miguel Casares ◽  
Hashmat Khan
Keyword(s):  
Dynamic Model ◽  
Early Phase ◽  
Threshold Level ◽  
Face Mask ◽  
The State ◽  
Social Distancing ◽  
Infected People ◽  
Preventive Actions ◽  
The Impact

The continued spread of COVID-19 suggests a significant possibility of reimposing the lockdowns and stricter social distancing similar to the early phase of pandemic control. We present a dynamic model to quantify the impact of isolation for the contagion curves. The model is calibrated to the COVID-19 outbreak in Spain to study the effects of the isolation enforcement following the declaration of the state of alarm (14 March 2020). The simulations indicate that both the timing and the intensity of the isolation enforcement are crucial for the COVID-19 spread. For example, a 4-day earlier intervention for social distancing would have reduced the number of COVID-19 infected people by 67%. The model also informs us that the isolation enforcement does not delay the peak day of the epidemic but slows down its end. When relaxing social distancing, a reduction of the contagion probability (with the generalization of preventive actions, such as face mask wearing and hands sanitizing) is needed to overcome the effect of a rise in the number of interpersonal encounters. We report a threshold level for the contagion pace to avoid a second COVID-19 outbreak in Spain.

scholarly journals SARS-CoV-2 Transmission and Epidemic Characteristics in Jining City, China

2021 ◽  
Vol 8 (2) ◽  
pp. 63-69
Author(s):  
Jianwei Zhou ◽  
Yu Li ◽  
Cui Kong ◽  
Jiang Yu ◽  
Yizhao Li ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Face Mask ◽  
Descriptive Study ◽  
Global Village ◽  
Travel History ◽  
Infected People ◽  
Aged People ◽  
Modes Of Transmission ◽  
Gender And Age ◽  
History Of

Background: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that causes severe acute respiratory syndrome has spread to hundreds of countries and infected millions of people, causing more than a hundred thousand deaths. This study aimed to describe the epidemic characteristics of SARS-CoV-2 and its transmission in a city in China.Methods: This was a descriptive study on retrospective data collected from January to February 2020 from reports issued by the authority of Jining City, China, including data on travel history, transmission, gender, and age of infected persons. Results: During the period January and February 2020, 52 cases were confirmed to be SARS-CoV-2 infections with more than half were males (n=32, 61.5%) and and in the age grup of 31–50 yars old (53.8%). The modes of transmission were mostly primary infections (n=23) and a history of travel to and from outside of Shandong Province (n=14). Interestingly, the infection was the 4th transmission and most primary infectious persons did not transmit the virus to others.Conclusions: The key characters of infected people in Jining City in early epidemic time with the exception of exogenous inputs are male gender, city dweller, and middle-aged people of 31–50 years old. There is a restricted transmission in Jining City of China at the early phrase of the SARS-CoV-2 epidemic, indicating that the strategy for the fight against SARS-CoV-2 is effective to some extent and worth to be learned by the members of the global village. This strategy includes actions such as home isolation, collective centralized quarantine, social distancing, and face mask use.

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