Investigating the influence of local porosity variations and anisotropy effects on the permeability of fibrous media for air filtration

Abstract This study presents two methods to improve the air filtration performance of konjac glucomannan (KGM)-based aerogel air filters through physical structure design by changing the pore-size distribution and the surface area, using an air purifier. Results indicated that KGM-based aerogels had a comparable filtration effect with the commercial air filter with a longer purification time. This purification time could be shortened by over 50%, by changing the pore-size distribution from large size to small size or increase the surface area with the fold structure. This should boost the development of polysaccharide-based aerogel used as the air filter.

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Awareness of aerosol-related transmission of COVID-19 among the dentists of Nepal

BDJ Open ◽

10.1038/s41405-021-00079-0 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Nashib Pandey ◽

Buddha Bahadur Basnet ◽

Sushmit Koju ◽

Anju Khapung ◽

Alka Gupta

Keyword(s):

Social Sciences ◽

Particle Size ◽

High Efficiency ◽

Emergency Services ◽

Uv Light ◽

Ventilation System ◽

Age Groups ◽

Air Filtration ◽

Online Questionnaire ◽

Dental Practitioners

Abstract Objective To access the awareness of dental practitioners of Nepal towards COVID-19 transmission through aerosols. Materials and methods The study involved 384 dentists from all over Nepal and was conducted for a period of 3 months. A self-reported online questionnaire was developed using Google forms and the link was shared. It emphasized the awareness related to the aerosol and ventilation system in their daily practices was prepared. The data were analyzed in Statistical Package for Social Sciences version 20.0 software. Results The majority of participants were female 52.9% (n = 203) and within the age groups of <30 years 57% (n = 219). Participants from Bagmati Province were 60.4% (n = 232), with least from Sudurpaschim Province 0.5% (n = 2). 60% of participants provided only emergency services during the COVID-19 pandemic and few (7%) provided consultations via telephone. The current ventilation system used was a well-ventilated room with open windows 65.4% (n = 251). However, 52.8% (n = 203) preferred specialized operatory incorporating high-efficiency particulate air (HEPA) filters and ultraviolet (UV) light. More than 60% of respondents were unaware of the particle size of the aerosol. Conclusions The obtained results signify the need for the proper ventilation system with appropriate air filtration systems in dental clinical setups.

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Recent Progress in Polysaccharide Aerogels: Their Synthesis, Application, and Future Outlook

Polymers ◽

10.3390/polym13081347 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1347

Author(s):

Arbanah Muhammad ◽

Dabin Lee ◽

Yonghun Shin ◽

Juhyun Park

Keyword(s):

Drug Delivery ◽

Supercritical Co2 ◽

Wound Dressing ◽

Freeze Drying ◽

Recent Progress ◽

Present Review ◽

Porous Structures ◽

Air Filtration ◽

Future Outlook ◽

Synthetic Process

Porous polysaccharides have recently attracted attention due to their porosity, abundance, and excellent properties such as sustainability and biocompatibility, thereby resulting in their numerous applications. Recent years have seen a rise in the number of studies on the utilization of polysaccharides such as cellulose, chitosan, chitin, and starch as aerogels due to their unique performance for the fabrication of porous structures. The present review explores recent progress in porous polysaccharides, particularly cellulose and chitosan, including their synthesis, application, and future outlook. Since the synthetic process is an important aspect of aerogel formation, particularly during the drying step, the process is reviewed in some detail, and a comparison is drawn between the supercritical CO2 and freeze drying processes in order to understand the aerogel formation of porous polysaccharides. Finally, the current applications of polysaccharide aerogels in drug delivery, wastewater, wound dressing, and air filtration are explored, and the limitations and outlook of the porous aerogels are discussed with respect to their future commercialization.

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