PMC:7796291 / 15208-16443 JSONTXT

{"project":"LitCovid-PubTator","denotations":[{"id":"170","span":{"begin":492,"end":499},"obj":"Chemical"},{"id":"171","span":{"begin":622,"end":635},"obj":"Chemical"}],"attributes":[{"id":"A170","pred":"tao:has_database_id","subj":"170","obj":"MESH:D011108"},{"id":"A171","pred":"tao:has_database_id","subj":"171","obj":"MESH:D011126"}],"namespaces":[{"prefix":"Tax","uri":"https://www.ncbi.nlm.nih.gov/taxonomy/"},{"prefix":"MESH","uri":"https://id.nlm.nih.gov/mesh/"},{"prefix":"Gene","uri":"https://www.ncbi.nlm.nih.gov/gene/"},{"prefix":"CVCL","uri":"https://web.expasy.org/cellosaurus/CVCL_"}],"text":"Physical treatments employing UV irradiation, oven-dry, and microwave irradiation caused little impact on the filtration efficiency or resistance. Previous studies reported the deteriorated performance with thermal treatment of electret filters [10,41], but most of the performance deterioration occurred with harsher conditions (120 °C, 48 h) and especially for materials with high dielectric constants. Aging the electret filter at an extremely high temperature can trigger the mobility of polymer chains and charge carriers, leading to the loss of charges and increased particulate penetration [41]. In this study, the polypropylene electret filters were treated by the oven-dry condition that was relatively mild and short-term (90 °C, 1 h); and for this reason, the oven-dry treatment caused negligible effect on the performance change. UV irradiation may influence the performance by causing the surface oxidation, turning the surface hydrophilic [42]; and the increased conductivity in a humid condition can lead to the loss of charges, reducing the filtration efficiency [43,44]. However, UV irradiation, at the level of 10 W power with 253.7 nm wavelength, of this study did not significantly affect the filtration efficiency."}

{"project":"LitCovid-sentences","denotations":[{"id":"T134","span":{"begin":0,"end":146},"obj":"Sentence"},{"id":"T135","span":{"begin":147,"end":404},"obj":"Sentence"},{"id":"T136","span":{"begin":405,"end":602},"obj":"Sentence"},{"id":"T137","span":{"begin":603,"end":841},"obj":"Sentence"},{"id":"T138","span":{"begin":842,"end":1087},"obj":"Sentence"},{"id":"T139","span":{"begin":1088,"end":1235},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"Physical treatments employing UV irradiation, oven-dry, and microwave irradiation caused little impact on the filtration efficiency or resistance. Previous studies reported the deteriorated performance with thermal treatment of electret filters [10,41], but most of the performance deterioration occurred with harsher conditions (120 °C, 48 h) and especially for materials with high dielectric constants. Aging the electret filter at an extremely high temperature can trigger the mobility of polymer chains and charge carriers, leading to the loss of charges and increased particulate penetration [41]. In this study, the polypropylene electret filters were treated by the oven-dry condition that was relatively mild and short-term (90 °C, 1 h); and for this reason, the oven-dry treatment caused negligible effect on the performance change. UV irradiation may influence the performance by causing the surface oxidation, turning the surface hydrophilic [42]; and the increased conductivity in a humid condition can lead to the loss of charges, reducing the filtration efficiency [43,44]. However, UV irradiation, at the level of 10 W power with 253.7 nm wavelength, of this study did not significantly affect the filtration efficiency."}