Comparison of Bacterial Filtration Efficiency vs. Particle Filtration Efficiency to Assess the Performance of Non-Medical Face Masks in the Emergency Context of COVID-19 Pandemic

As a result of the current COVID-19 pandemic, the use of facemasks has become commonplace. The performance of medical facemasks is assessed using Bacterial Filtration Efficiency (BFE) tests. However, as BFE tests, require specific expertise and equipment and are time-consuming, the performance of non-medical facemasks is assessed with non-biological Particle Filtration Efficiency (PFE) tests which are comparatively easier to implement. It is necessary to better understand the possible correlations between BFE and PFE to be able to compare the performances of the different types of masks (medical vs. non-medical). In this study BFE results obtained in accordance with the standard EN 14683 are compared to the results of PFE from a reference test protocol defined by AFNOR SPEC S76-001 with the aim to determine if BFE could be predicted from PFE. Our results showed a correlation between PFE and BFE. It was also observed that PFE values were higher than BFE and this was attributed to the difference in particle size distribution considered for efficiency calculation. In order to properly compare these test protocols for a better deduction, it would be interesting to compare the filtration efficiency for a similar granulometric range.

Ultraviolet germicidal irradiation of melted snow and ice samples: inactivation of microorganisms and effects on insoluble microparticles

The long-term refrigerated storage of melted snow and/or ice samples for analyses of insoluble microparticles (hereafter, microparticles) may be limited by increases in the biological particle concentration caused by microbial growth after ~1–2 weeks. In this study, we examined an ultraviolet (UV) disinfection method for the storage of melted snow and/or ice samples and determined the effects of this method on microparticles. Surface snow obtained from Glacier No. 31 in the Suntar-Khayata Range, eastern Siberia, Russia was divided into two portions for UV treatment and untreated controls. Microparticle concentrations and size distributions (in the range of 0.52–12.0 μm) in the samples were measured using a Coulter counter. Whereas the microparticle concentration in untreated samples increased, no obvious increase was observed over 53 d in the samples subjected to UV treatment. Microbial growth was detected in only untreated samples using a viable particle counter. In addition, the original microparticle concentrations and size distributions were unaffected by UV treatment. Our results demonstrated that the microparticle size distribution in untreated melted water samples reflects the growth, decomposition and succession of microorganisms over time and further indicate that UV irradiation is effective for long-term storage for microparticle analysis.

Based on a biological particle model to predict the trace behavior of fish

A biological particle model is used to predict the upward trajectory of fish under a dam, the biological particle model refers to a fish as a particle and considers the flow rate, velocity gradient and turbulent energy of the fish, as a condition of retrospective behaviour, a control equation is used to simplify the fish's retroactive behaviour and establish a model programmed in MATLAB to develop a fish traceability prediction program. According to the program, the upward trajectory of the fish under the dam is predicted, there are three types of up-tracking channels under the dam according to the average widths of the up-tracking channels along the right bank of the channel, along the middle of the channel, and along the left bank of the channel and the average widths are 10, 14 and 7 m, respectively. The three existing fish import locations in fishway project are evaluated, and optimization recommendations are provided, it's recommended to add a fishway inlet along the right bank of upstream channel. In addition, this paper provides a feasible technical methodology that a biological particle model can be used to predict the upward trajectory of fish in similar fishway projects.

Intercomparison of Multiple UV-LIF Spectrometers Using the Aerosol Challenge Simulator

Measurements of primary biological aerosol particles (PBAPs) have been conducted worldwide using ultraviolet light-induced fluorescence (UV-LIF) spectrometers. However, how these instruments detect and respond to known biological and non-biological particles, and how they compare, remains uncertain due to limited laboratory intercomparisons. Using the Defence Science and Technology Laboratory, Aerosol Challenge Simulator (ACS), controlled concentrations of biological and non-biological aerosol particles, singly or as mixtures, were produced for testing and intercomparison of multiple versions of the Wideband Integrated Bioaerosol Spectrometer (WIBS) and Multiparameter Bioaerosol Spectrometer (MBS). Although the results suggest some challenges in discriminating biological particle types across different versions of the same UV-LIF instrument, a difference in fluorescence intensity between the non-biological and biological samples could be identified for most instruments. While lower concentrations of fluorescent particles were detected by the MBS, the MBS demonstrates the potential to discriminate between pollen and other biological particles. This study presents the first published technical summary and use of the ACS for instrument intercomparisons. Within this work a clear overview of the data pre-processing is also presented, and documentation of instrument version/model numbers is suggested to assess potential instrument variations between different versions of the same instrument. Further laboratory studies sampling different particle types are suggested before use in quantifying impact on ambient classification.

(DIS)ABLING BODY AND CONSCIOUSNESS: TECHNOLOGICAL AFTERNESS AND AFTER-HUMANS IN REALIVE AND UPGRADE

ABSTRACT My paper talks about post-human spaces and technological afterness associated with the physiognomy of humans. Mechanical alteration in biological mechanisms is directly experienced in seizing of organic consciousness. The rupture in consciousness splits it into two distinct parts-one belonging to the disappearing human, the other to the emerging cybernetic. The new being is not another human, but (an)other human, an evolved different sameness. In the film Realive (2016) we encounter an extension of the self beyond death by re-placing it into another body. However, this enhancement diffuses all ‘natural’ responses and meaning-making vehicles, primarily the cognizance of death and mortality. In a classic Frankensteinian restoration, Marc is reanimated in 2084 through extensive methods of cryonization under the banner ‘Lazarus project’. The post-human ‘humachines’ dissolve the position of the teleological man and stretch DNA to digitality. Upgrade (2018) shows us the metamorphosis of Grey Trace, a luddite, by an installed biomechanical enhancer chip, Stem. The roach-like implant not only erases Grey’s quadriplegic body, but ironically ‘desires’ to possess and manoeuver the host’s body. Robotic consciousness in these assimilated after-humans is borrowed consciousness activated by infusing the evanescent biological particle - life. Nanotechnology, molecular machines, nerve manipulators, cameras implanted inside the brain, self-generating nanobots, artificial mechanical limbs have emerged as elements of posthuman utopia/dystopia. Paradoxically, in both the films the protagonists, after their reanimation and upgradation, try to return to their original position of death and disability. In their quest to retrieve the lived body they lose their embodied reciprocations with animals, machines and other forms of life. The mysterious, irreducible, unknown and unknowable potentiality of life is levelled and dissipated by surplus information. This paper attempts to discuss the reactions of embodied body as memory post-cryonization, and to understand limits of psychological disability and death of consciousness after technological reconstruction of the disabled body.