{"id":{"repo_id":"brazil-uerj","oai_identifier":"oai:pantheon.ufrj.br:11422/3545"},"canonical_url":"https://search.dev.ndltd.org/etd/brazil-uerj/oai:pantheon.ufrj.br:11422/3545","repository":{"repo_id":"brazil-uerj","name":"Brazil UERJ","base_url":"https://pantheon.ufrj.br/oai/request"},"display":{"title":"Tubos de impedância e suas aplicações na determinação de propriedades acústicas de meios porosos","abstract":"Acoustic impedances and absortion coefficients in fluid-saturated porous solids are experimentally determined in air and water in impedance tubes. An experimental methodology is developed for the measurements in water. A study is made of the ways in which the experimentally measured parameters porosity, density, permeability and sample thickness, influence acoustic impedance and absortion. Those parameters are introduced into an existent theory of propagation in porous media and the resulting absortion is compared with the one obtained experimentally. The higher values of the measured acoustic absortion as compared to the ones predicted by the theory are atributed to resonancess in the cavities of the porous esqueleton.","abstract_html":"Acoustic impedances and absortion coefficients in fluid-saturated porous solids are experimentally determined in air and water in impedance tubes. An experimental methodology is developed for the measurements in water. A study is made of the ways in which the experimentally measured parameters porosity, density, permeability and sample thickness, influence acoustic impedance and absortion. Those parameters are introduced into an existent theory of propagation in porous media and the resulting absortion is compared with the one obtained experimentally. The higher values of the measured acoustic absortion as compared to the ones predicted by the theory are atributed to resonancess in the cavities of the porous esqueleton.","abstract_has_math":false,"creators":["Stross, Antonio Carlos Távora"],"institution":"Universidade Federal do Rio de Janeiro","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Ripper Neto, Arthur Palmeira"],"committee_chairs":[],"committee_members":[],"year":1975,"date_issued":"1975-09","date_published":"1975-09","updated_at":"2026-07-24T01:16:04Z","subjects":["Tubos","Testes de impedância acústica"],"languages":["por"],"rights":["Acesso Aberto"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11422/3545","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Ripper Neto, Arthur Palmeira"]},{"key":"dc:creator","label":"Author","values":["Stross, Antonio Carlos Távora"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2018-01-25T16:25:00Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2026-05-16T03:05:18Z"]},{"key":"dc:date.issued","label":"Date","values":["1975-09"]},{"key":"dc:publisher","label":"Institution","values":["Universidade Federal do Rio de Janeiro"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia"]},{"key":"dc:type","label":"Dc Type","values":["Dissertação"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Tubos","Testes de impedância acústica"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["por"]},{"key":"dc:rights","label":"Dc Rights","values":["Acesso Aberto"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11422/3545"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Acoustic impedances and absortion coefficients in fluid-saturated porous solids are experimentally determined in air and water in impedance tubes. An experimental methodology is developed for the measurements in water. A study is made of the ways in which the experimentally measured parameters porosity, density, permeability and sample thickness, influence acoustic impedance and absortion. Those parameters are introduced into an existent theory of propagation in porous media and the resulting absortion is compared with the one obtained experimentally. The higher values of the measured acoustic absortion as compared to the ones predicted by the theory are atributed to resonancess in the cavities of the porous esqueleton."]},{"key":"dc:title","label":"Title","values":["Tubos de impedância e suas aplicações na determinação de propriedades acústicas de meios porosos"]}]}],"canonical_facts":{"dc:contributor.advisor":["Ripper Neto, Arthur Palmeira"],"dc:creator":["Stross, Antonio Carlos Távora"],"dc:date.accessioned":["2018-01-25T16:25:00Z"],"dc:date.available":["2026-05-16T03:05:18Z"],"dc:date.issued":["1975-09"],"dc:description.abstract":["Acoustic impedances and absortion coefficients in fluid-saturated porous solids are experimentally determined in air and water in impedance tubes. An experimental methodology is developed for the measurements in water. A study is made of the ways in which the experimentally measured parameters porosity, density, permeability and sample thickness, influence acoustic impedance and absortion. Those parameters are introduced into an existent theory of propagation in porous media and the resulting absortion is compared with the one obtained experimentally. The higher values of the measured acoustic absortion as compared to the ones predicted by the theory are atributed to resonancess in the cavities of the porous esqueleton."],"dc:identifier.uri":["http://hdl.handle.net/11422/3545"],"dc:language":["por"],"dc:publisher":["Universidade Federal do Rio de Janeiro"],"dc:publisher.department":["Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia"],"dc:rights":["Acesso Aberto"],"dc:subject":["Tubos","Testes de impedância acústica"],"dc:title":["Tubos de impedância e suas aplicações na determinação de propriedades acústicas de meios porosos"],"dc:type":["Dissertação"]},"updated_at":"2026-07-24T01:16:04Z"}