{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/22115"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/22115","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"The detection and measurement of the activity size distributions (d(p) greater than 0.5 nm) associated with radon decay products in indoor air","abstract":"The infiltration of radon into the indoor environment may cause the exposure of the public to excessive amounts of radioactivity and has spurred renewed research interest over the past several years into the occurrence and properties of radon and its decay products in indoor air. The public health risks posed by the inhalation and subsequent lung deposition of the decay products of Rn-222 have particularly warranted the study of their diffusivity and attachment to molecular cluster aerosols in the ultrafine particle size range (0.5$-$5 nm) and to accumulation mode aerosols.","abstract_html":"The infiltration of radon into the indoor environment may cause the exposure of the public to excessive amounts of radioactivity and has spurred renewed research interest over the past several years into the occurrence and properties of radon and its decay products in indoor air. The public health risks posed by the inhalation and subsequent lung deposition of the decay products of Rn-222 have particularly warranted the study of their diffusivity and attachment to molecular cluster aerosols in the ultrafine particle size range (0.5$-$5 nm) and to accumulation mode aerosols.","abstract_has_math":true,"creators":["Ramamurthi, Mukund"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Civil and Environmental Engineering","degree_department":null,"school":null,"contributors":["Hopke, Philip K."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T13:29:25Z","date_published":"2011-05-07T13:29:25Z","updated_at":"2026-07-22T22:25:19Z","subjects":["Engineering, Civil","Physics, Radiation","Environmental Sciences"],"languages":["eng"],"rights":["Copyright 1989 Ramamurthi, Mukund"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI8924924","(UMI)AAI8924924"],"render_values":[{"text":"AAI8924924","href":null,"code":true},{"text":"(UMI)AAI8924924","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/22115","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Hopke, Philip K."]},{"key":"dc:creator","label":"Author","values":["Ramamurthi, Mukund"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T13:29:25Z","10000-01-01","1989"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Civil and Environmental Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering, Civil","Physics, Radiation","Environmental Sciences"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1989 Ramamurthi, Mukund"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI8924924","(UMI)AAI8924924","http://hdl.handle.net/2142/22115"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The infiltration of radon into the indoor environment may cause the exposure of the public to excessive amounts of radioactivity and has spurred renewed research interest over the past several years into the occurrence and properties of radon and its decay products in indoor air. The public health risks posed by the inhalation and subsequent lung deposition of the decay products of Rn-222 have particularly warranted the study of their diffusivity and attachment to molecular cluster aerosols in the ultrafine particle size range (0.5$-$5 nm) and to accumulation mode aerosols.","In this research, a system for the detection and measurement of the activity size distributions and concentration levels of radon decay products in indoor environments has been developed. The system is microcomputer-controlled and involves a combination of multiple wire screen sampler-detector units operated in parallel. The detection of the radioactivity attached to the aerosol sampled in these units permits the determination of the radon daughter activity-weighted size distributions and concentration levels in indoor air on a semi-continuous basis. The development of the system involved the design of the detection and measurement system, its experimental characterization and testing in a radon-aerosol chamber, and numerical studies for the optimization of the design and operating parameters of the system.","Several concepts of utility to aerosol size distribution measurement methods sampling the ultrafine cluster size range evolved from this study, and are discussed in various chapters of this dissertation. The optimized multiple wire screen (Graded Screen Array) system described in this dissertation is based on these concepts. The principal facet of the system is its ability to make unattended measurements of activity size distributions and concentration levels of radon decay products on a semi-continuous basis. Thus, the capability of monitoring changes in the activity concentrations and size distributions as a function of both time and indoor events is now available. Future work with the system will involve field measurements of radon decay product activity size distributions and concentrations in various indoor environments. The resultant information should permit a better estimation of the potential human health hazard from the inhalation of radon decay products present in indoor air.","Made available in DSpace on 2011-05-07T13:29:25Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 8924924.pdf: 7315800 bytes, checksum: b968f3350f482f3bb6d86c7db7553292 (MD5) Previous issue date: 1989","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:55:25Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:25:50-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["The detection and measurement of the activity size distributions (d(p) greater than 0.5 nm) associated with radon decay products in indoor air"]}]}],"canonical_facts":{"dc:contributor":["Hopke, Philip K."],"dc:creator":["Ramamurthi, Mukund"],"dc:date":["2011-05-07T13:29:25Z","10000-01-01","1989"],"dc:description":["The infiltration of radon into the indoor environment may cause the exposure of the public to excessive amounts of radioactivity and has spurred renewed research interest over the past several years into the occurrence and properties of radon and its decay products in indoor air. The public health risks posed by the inhalation and subsequent lung deposition of the decay products of Rn-222 have particularly warranted the study of their diffusivity and attachment to molecular cluster aerosols in the ultrafine particle size range (0.5$-$5 nm) and to accumulation mode aerosols.","In this research, a system for the detection and measurement of the activity size distributions and concentration levels of radon decay products in indoor environments has been developed. The system is microcomputer-controlled and involves a combination of multiple wire screen sampler-detector units operated in parallel. The detection of the radioactivity attached to the aerosol sampled in these units permits the determination of the radon daughter activity-weighted size distributions and concentration levels in indoor air on a semi-continuous basis. The development of the system involved the design of the detection and measurement system, its experimental characterization and testing in a radon-aerosol chamber, and numerical studies for the optimization of the design and operating parameters of the system.","Several concepts of utility to aerosol size distribution measurement methods sampling the ultrafine cluster size range evolved from this study, and are discussed in various chapters of this dissertation. The optimized multiple wire screen (Graded Screen Array) system described in this dissertation is based on these concepts. The principal facet of the system is its ability to make unattended measurements of activity size distributions and concentration levels of radon decay products on a semi-continuous basis. Thus, the capability of monitoring changes in the activity concentrations and size distributions as a function of both time and indoor events is now available. Future work with the system will involve field measurements of radon decay product activity size distributions and concentrations in various indoor environments. The resultant information should permit a better estimation of the potential human health hazard from the inhalation of radon decay products present in indoor air.","Made available in DSpace on 2011-05-07T13:29:25Z (GMT). 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