A virucidal face mask based on the reverse-flow reactor concept for thermal inactivation of SARS-CoV-2.
Ontology highlight
ABSTRACT:
SUBMITTER: Faucher S
PROVIDER: S-EPMC7995042 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:The thermal reverse flow reactor is an effective technical equipment for dealing with ventilation air methane, which has been causing a significant greenhouse effect. An experimental study on the thermal oxidation of ventilation air methane in a thermal reverse flow reactor was conducted. A mixture of domestic gas and ambient air was used to simulate ventilation air methane in the experiments, and the methane conversion efficiency was analyzed based on the concentration of combustion products determined by gas chromatography equipment. In addition, the effects of the switching time, the inlet methane concentration, the flow rate, and heat extraction were studied. The experimental results show that the reverse flow reactor system can run under a wide range of operating conditions with autothermal operation and high methane conversion. In addition, this system can even work with methane concentrations as low as 0.30% in the autothermal operation mode without NO x emission. Unlike previous studies, this study shows that the flow rate has little effect on the methane conversion rate in the cyclic steady state over a wide range of operating conditions. In addition, methane conversion and reaction zone change as the inlet methane concentration varies during the reaction process in the cyclic steady state. The combined optimization of operating parameters can effectively improve the stability of the reverse flow reactor system and methane conversion efficiency.
| S-EPMC6751547 | biostudies-literature
Project description:Popular press outlets have proposed that older individuals are less likely to wear face masks despite health benefits of doing so during the COVID-19 pandemic. The current article investigates this notion in four separate studies, and we also assess the mediating effect of face mask perceptions between age and face mask wearing using the eight-dimension Face Masks Perceptions Scale (FMPS). The sample-size weighted average correlation between age and face mask wearing was -.07 (95%C.I.[-.14, .001], Z-value = -1.928, P = .054, n = 824), indicating that older individuals are slightly less likely to wear face masks compared to younger individuals. Age did not have significant relations with any face mask perceptions, and the mediating effect of face mask perceptions was not robust or consistent. This indicates that the relation between age and face mask wearing is not explained by face mask perceptions, and researchers must turn to other explanatory mechanisms to understand this relation. We propose possible avenues, such as dual-system theories, to further investigate this research question as well as others associated with face mask perceptions, face mask wearing and the COVID-19 pandemic.
| S-EPMC7928787 | biostudies-literature
Project description:Airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is one of the leading mechanisms of spread, especially in confined environments. The study aims to assess the thermal inactivation of SARS-CoV-2 at high temperatures in the time scale of seconds. An electric heater with a coiled resistance wire is located perpendicularly to the airflow direction inside an air tunnel. The airflow rate through the tunnel was 0.6 m3/h (10 L/ min). SARS-CoV-2 were suspended in Dulbecco's modified Eagle's medium (DMEM) with 10 % fetal bovine serum (FBS), aerosolized by a nebulizer at a rate of 0.2 L/min and introduced to the airflow inside the heater with the use of a compressor and an aspirator. In the control experiment, with the heater off, SARS-CoV-2 passed through the system. In the virus inactivation test experiments, the heater's outlet air temperature was set to 150 ± 5 °C and 220 ± 5 °C, and the air traveling through the tunnel was exposed to heat for 1.44 s. An inline gelatine filter harvested SARS-CoV-2 that passed through the system. The viral titer obtained from the gelatine filter in the control experiment was about 5.5 log10 TCID50. The virus's loss in viability in test experiments at 150 °C and 220 °C were 99.900 % and 99.999 %, respectively. The results indicate that high-temperature thermal inactivation substantially reduces the concentration of SARS-CoV-2 in the air within seconds.
| S-EPMC8757645 | biostudies-literature
Project description:Based on a model of protein denaturation rate limited by an entropy-related barrier, we derive a simple formula for virus inactivation time as a function of temperature. Loss of protein structure is described by two reaction coordinates: conformational disorder of the polymer and wetting by the solvent. These establish a competition between conformational entropy and hydrophobic interaction favoring random coil or globular states, respectively. Based on the Landau theory of phase transition, the resulting free energy barrier is found to decrease linearly with the temperature difference T - Tm, and the inactivation rate should scale as U to the power of T - Tm. This form recalls an accepted model of thermal damage to cells in hyperthermia. For SARS-CoV-2 the value of U in Celsius units is found to be 1.32. Although the fitting of the model to measured data is practically indistinguishable from Arrhenius law with an activation energy, the entropy barrier mechanism is more suitable and could explain the pronounced sensitivity of SARS-CoV-2 to thermal damage. Accordingly, we predict the efficacy of mild fever over a period of ∼24 h in inactivating the virus.
| S-EPMC7695547 | biostudies-literature
Project description:COVID-19 pandemic has posed severe threats to the society globally. World Health Organization (WHO) guidelines suggest that people wear face masks as a precautionary measure daily. This has resulted in the generation of massive amounts of mask-associated waste in the environment. Owing to the criticality of the epidemic, there has not been a large-scale investigation on where to discard masks, making this situation daunting. As the pandemic continues, the use of masks continues to increase; repeated use and disposal of masks has become an imperative issue. Most disposable masks comprise chemical fibers in the filter layer. Without proper treatment and disposal, these large amounts of chemical waste will eventually flow into rivers or oceans, leading to serious pollution. Therefore, to reduce the negative effects on the marine environment, it is crucial that we produce reusable masks and reduce disposable wearing habits. This study aimed to resolve this challenge using textile materials created by recycling fish-scale waste. Functional and comfortable masks manufactured without chemical additives to achieve multiple functions can increase the willingness to wear and be reused. Hence, product use can be prolonged, and the use of disposable masks can be curtailed. The product manufactured herein is biodegradable in nature, thus conforming to the green sustainable initiative. Graphical abstract Unlabelled Image
| S-EPMC9355742 | biostudies-literature
Project description:Face masks are used to protect the wearer from harmful external air and to prevent transmission of viruses from air exhaled by potentially infected wearers to the surrounding people. In this study, we examined the potential utility of masks for collecting viruses contained in exhaled breath and detected the collected viruses via various molecular tests. Using KF94 masks, the inner electrostatic filter was selected for virus collection, and an RNA extraction protocol was developed for the face mask. Virus detection in worn mask samples was performed using PCR and rolling circle amplification (RCA) tests and four different target genes (N, E, RdRp, and ORF1ab genes). The present study confirmed that the mask sample tests showed positive SARS-CoV-2 results, similar to the PCR tests using nasopharyngeal swab samples. In addition, the quantity of nucleic acid collected in the masks linearly increased with wearing time. These results suggest that samples for SARS-CoV-2 tests can be collected in a noninvasive, quick, and easy method by simply submitting worn masks from subjects, which can significantly reduce the hassle of waiting at airports or public places and concerns about cross-infection. In addition, it is expected that miniaturization technology will integrate PCR assays on face masks in the near future, and mask-based self-diagnosis would play a significant role in resolving the pandemic situation.
| S-EPMC9387863 | biostudies-literature
Project description:The Face Mask Wearing Image Dataset is a comprehensive collection of images aimed at facilitating research in the domain of face mask detection and classification. This dataset consists of 24,916 images, carefully categorized into two main folders: "Correct" and "Incorrect" representing instances of face masks being worn properly and improperly, respectively. Each folder is further divided into four subfolders, each denoting a specific type of face mask - Bandana, Cotton, N95, and Surgical. In the "Correct" folder, images depict individuals correctly wearing their respective face masks, while the "Incorrect" folder contains images of improper face mask usage. To capture variations in face mask application across different demographics, such as age and gender, each subfolder also includes three additional subfolders - Child, Male, and Female. The dataset's diverse content encompasses different face mask types, covering bandana-style, cloth, N95 respirators, and surgical masks, across various age groups and genders. This design ensures a comprehensive representation of real-world scenarios, enabling the evaluation of machine learning algorithms for face mask detection and classification. Researchers can leverage this dataset to develop and assess models that can accurately identify and distinguish between correct and incorrect face mask usage. By contributing to the advancement of face mask detection technologies, this dataset further supports public health initiatives and encourages proper mask-wearing behavior to mitigate the spread of infectious diseases, particularly during times of heightened health concerns such as the COVID-19 pandemic.
| S-EPMC10700517 | biostudies-literature
Project description:Recent popular press authors have proposed that men are less likely to wear face masks during the COVID-19 pandemic. We investigate this notion in the current article by analyzing three extant datasets. We also assess the mediating effect of eight different face mask perceptions in the relation between gender and face mask wearing via the Face Mask Perceptions Scale. Across the three datasets, the sample-size weighted meta-analytic correlation between gender and face mask wearing was not statistically significant, and no face mask perception was a consistent mediator of this effect. Gender did have significant relations with two face mask perceptions, however. Men were more likely to perceive face masks as infringing on their independence, whereas women were more likely to perceive face masks as uncomfortable. Therefore, although gender does not relate to whether a person wears a face mask, it does relate to face mask perceptions. We offer several suggestions for research and practice from these results, such as the positioning of face mask wearing alongside passive health behaviors, the broader study of face mask perceptions' outcomes beyond face mask wearing, as well as the creation of interventions to target differing face mask perceptions across genders.
| S-EPMC7543707 | biostudies-literature
Project description:Recent studies have found that face masks affect social cognition and behaviour in the context of the novel coronavirus (COVID-19) pandemic. The eyes, the only part of the face not covered by face masks, are an important spatial attention cue that can trigger social attention orienting. Here, we adopted a spatial gaze-cueing task to investigate whether face masks affect social attention orienting triggered by eye gaze cues. In Experiment 1, participants were asked to determine the orientation of a target line under two types of cues-masked and non-masked faces-and two stimulus onset asynchrony (SOA) conditions (300 ms and 1000 ms). The results showed that masked faces induced a smaller gaze-cueing effect (GCE) compared to non-masked faces at 300 ms SOA, while two face types induced similar GCEs at 1000 ms SOA. Experiment 2 used mouth-obscured faces and non-masked faces as cues and found that no significant difference in GCE between the two types at either 300 ms or 1000 ms SOA, indicating that the reduction of GCE caused by the masked face was due to the social meaning expressed by the mask rather than a physical effect of masking. The present study extends previous findings to support the idea that high-level social information affects the processing of eye gaze direction and provides evidence that face masks affect social cognition and behaviour in the context of COVID-19.
| S-EPMC10423210 | biostudies-literature
Project description:ObjectivePortable gas exchange instruments allow the assessment of peak oxygen uptake (V̇O2peak) but are often bulky, expensive and require wearing a face mask thereby limiting their routine application. A newly developed miniaturized headset (VitaScale, Nuremberg, Germany) may overcome these barriers and allow measuring V̇O2peak without applying a face mask. Here we aimed (i) to disclose the technical setup of a headset incorporating a gas and volume sensor to measure volume flow and expired oxygen concentration and (ii) to assess the concurrent criterion-validity of the headset to measure V̇O2peak in 44 individuals exercising on a stationary cycle ergometer in consideration of the test-retest reliability of the criterion measure.ResultsThe coefficient of variation (CV%) while measuring V̇O2peak during incremental cycling with the headset was 6.8%. The CV% for reliability of the criterion measure was 4.0% for V̇O2peak. Based on the present data, the headset might offer a new technology for V̇O2peak measurement due to its low-cost and mask-free design.
| S-EPMC8742938 | biostudies-literature