{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/29708"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/29708","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Assessment of brown-rot decay using X-ray computer tomography and ultrasonic measurements","abstract":"Loblolly pine (Pinus taeda) wood cube specimens were exposed to Gloeophyllum fungus (Gloeophyllum trabeum) for increasing periods of time ranging from one week to twelve weeks. The corresponding mass of each of these specimens was recorded before and after they were subjected to the controlled decay. X-ray computed tomography (CT) was then carried out. From the CT scans and recorded mass data, the specimens’ corresponding volumes and densities were calculated. Blocks decayed for twelve weeks experienced, on the average, the greatest loss of mass (≈40%), volume (≈30%), and density (≈37%). The observations quantified the well-known effect of non-uniform decay, with the greatest occurring at the surface in contact with the fungi and decreasing to the opposite surface. Wood blocks subjected to controlled decay for twelve weeks lost 47% of density at the surface in contact with the fungi and 28% at the opposite surface, while blocks subjected to only one week of decay experienced over 5% density loss at the surface in contact with fungi and nearly 0% at the opposite surface. While the mass loss of specimens exposed to only one week of controlled decay was difficult to evaluate because of initial moisture absorption, these results indicate that x-ray CT can detect decay in wood specimens exposed to only one week of controlled decay using density measurements. For each of the three principal material directions of these specimens with controlled decay, ultrasonic longitudinal and (polarized) shear velocity measurements along with the corresponding attenuation measurements are presented. The measurements were carried out using longitudinal and shear ultrasonic transducers with a center frequency of 100 kHz. A steel delay line was used because of the relative small size of the wooden specimens relative to the used wavelengths. Waveform averaging was used along with the phase-slope method to measure velocities. It was observed that the velocities increase with increasing frequency and decrease with increasing amount of decay, while the corresponding attenuations increase with increasing frequency and with amount of decay.","abstract_html":"Loblolly pine (Pinus taeda) wood cube specimens were exposed to Gloeophyllum fungus (Gloeophyllum trabeum) for increasing periods of time ranging from one week to twelve weeks. The corresponding mass of each of these specimens was recorded before and after they were subjected to the controlled decay. X-ray computed tomography (CT) was then carried out. From the CT scans and recorded mass data, the specimens’ corresponding volumes and densities were calculated. Blocks decayed for twelve weeks experienced, on the average, the greatest loss of mass (≈40%), volume (≈30%), and density (≈37%). The observations quantified the well-known effect of non-uniform decay, with the greatest occurring at the surface in contact with the fungi and decreasing to the opposite surface. Wood blocks subjected to controlled decay for twelve weeks lost 47% of density at the surface in contact with the fungi and 28% at the opposite surface, while blocks subjected to only one week of decay experienced over 5% density loss at the surface in contact with fungi and nearly 0% at the opposite surface. While the mass loss of specimens exposed to only one week of controlled decay was difficult to evaluate because of initial moisture absorption, these results indicate that x-ray CT can detect decay in wood specimens exposed to only one week of controlled decay using density measurements. For each of the three principal material directions of these specimens with controlled decay, ultrasonic longitudinal and (polarized) shear velocity measurements along with the corresponding attenuation measurements are presented. The measurements were carried out using longitudinal and shear ultrasonic transducers with a center frequency of 100 kHz. A steel delay line was used because of the relative small size of the wooden specimens relative to the used wavelengths. Waveform averaging was used along with the phase-slope method to measure velocities. It was observed that the velocities increase with increasing frequency and decrease with increasing amount of decay, while the corresponding attenuations increase with increasing frequency and with amount of decay.","abstract_has_math":false,"creators":["Mcgovern, Megan"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Systems & Entrepreneurial Engr Civil Engineering","degree_department":null,"school":null,"contributors":["Reis, Henrique M."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-02-06T20:12:13Z","date_published":"2012-02-06T20:12:13Z","updated_at":"2026-07-22T22:25:27Z","subjects":["Loblolly pine","wood","wood decay","rot","X-ray computed tomography","wood density","ultrasonic velocity","attenuation."],"languages":["en"],"rights":["Copyright 2011 Megan E McGovern"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/29708","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Reis, Henrique M."]},{"key":"dc:creator","label":"Author","values":["Mcgovern, Megan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2012-02-06T20:12:13Z","2011-12"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation / Thesis","text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Systems & Entrepreneurial Engr Civil Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"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":["Loblolly pine","wood","wood decay","rot","X-ray computed tomography","wood density","ultrasonic velocity","attenuation."]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2011 Megan E McGovern"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/29708"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Loblolly pine (Pinus taeda) wood cube specimens were exposed to Gloeophyllum fungus (Gloeophyllum trabeum) for increasing periods of time ranging from one week to twelve weeks. The corresponding mass of each of these specimens was recorded before and after they were subjected to the controlled decay. X-ray computed tomography (CT) was then carried out. From the CT scans and recorded mass data, the specimens’ corresponding volumes and densities were calculated. Blocks decayed for twelve weeks experienced, on the average, the greatest loss of mass (≈40%), volume (≈30%), and density (≈37%). The observations quantified the well-known effect of non-uniform decay, with the greatest occurring at the surface in contact with the fungi and decreasing to the opposite surface. Wood blocks subjected to controlled decay for twelve weeks lost 47% of density at the surface in contact with the fungi and 28% at the opposite surface, while blocks subjected to only one week of decay experienced over 5% density loss at the surface in contact with fungi and nearly 0% at the opposite surface. While the mass loss of specimens exposed to only one week of controlled decay was difficult to evaluate because of initial moisture absorption, these results indicate that x-ray CT can detect decay in wood specimens exposed to only one week of controlled decay using density measurements. For each of the three principal material directions of these specimens with controlled decay, ultrasonic longitudinal and (polarized) shear velocity measurements along with the corresponding attenuation measurements are presented. The measurements were carried out using longitudinal and shear ultrasonic transducers with a center frequency of 100 kHz. A steel delay line was used because of the relative small size of the wooden specimens relative to the used wavelengths. Waveform averaging was used along with the phase-slope method to measure velocities. It was observed that the velocities increase with increasing frequency and decrease with increasing amount of decay, while the corresponding attenuations increase with increasing frequency and with amount of decay.","Item withdrawn by Rebecca Bryant (rabryant@illinois.edu) on 2011-11-29T20:41:05Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 McGovern_Megan.docx: 6200587 bytes, checksum: cd9adb36d1811ed2814befe635876608 (MD5) McGovern_Megan.pdf: 3386649 bytes, checksum: 8fd1d77997e030937c9f3893084ee7ce (MD5)","Made available in DSpace on 2012-02-06T20:12:13Z (GMT). No. of bitstreams: 3 McGovern_Megan.pdf: 3386649 bytes, checksum: 8fd1d77997e030937c9f3893084ee7ce (MD5) license.txt: 4064 bytes, checksum: cacc42e99ea3ce44ff39d8f8d473298b (MD5) McGovern_Megan.docx: 6200587 bytes, checksum: cd9adb36d1811ed2814befe635876608 (MD5)"]},{"key":"dc:title","label":"Title","values":["Assessment of brown-rot decay using X-ray computer tomography and ultrasonic measurements"]}]}],"canonical_facts":{"dc:contributor":["Reis, Henrique M."],"dc:creator":["Mcgovern, Megan"],"dc:date":["2012-02-06T20:12:13Z","2011-12"],"dc:description":["Loblolly pine (Pinus taeda) wood cube specimens were exposed to Gloeophyllum fungus (Gloeophyllum trabeum) for increasing periods of time ranging from one week to twelve weeks. The corresponding mass of each of these specimens was recorded before and after they were subjected to the controlled decay. X-ray computed tomography (CT) was then carried out. From the CT scans and recorded mass data, the specimens’ corresponding volumes and densities were calculated. Blocks decayed for twelve weeks experienced, on the average, the greatest loss of mass (≈40%), volume (≈30%), and density (≈37%). The observations quantified the well-known effect of non-uniform decay, with the greatest occurring at the surface in contact with the fungi and decreasing to the opposite surface. Wood blocks subjected to controlled decay for twelve weeks lost 47% of density at the surface in contact with the fungi and 28% at the opposite surface, while blocks subjected to only one week of decay experienced over 5% density loss at the surface in contact with fungi and nearly 0% at the opposite surface. While the mass loss of specimens exposed to only one week of controlled decay was difficult to evaluate because of initial moisture absorption, these results indicate that x-ray CT can detect decay in wood specimens exposed to only one week of controlled decay using density measurements. For each of the three principal material directions of these specimens with controlled decay, ultrasonic longitudinal and (polarized) shear velocity measurements along with the corresponding attenuation measurements are presented. The measurements were carried out using longitudinal and shear ultrasonic transducers with a center frequency of 100 kHz. A steel delay line was used because of the relative small size of the wooden specimens relative to the used wavelengths. Waveform averaging was used along with the phase-slope method to measure velocities. It was observed that the velocities increase with increasing frequency and decrease with increasing amount of decay, while the corresponding attenuations increase with increasing frequency and with amount of decay.","Item withdrawn by Rebecca Bryant (rabryant@illinois.edu) on 2011-11-29T20:41:05Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 McGovern_Megan.docx: 6200587 bytes, checksum: cd9adb36d1811ed2814befe635876608 (MD5) McGovern_Megan.pdf: 3386649 bytes, checksum: 8fd1d77997e030937c9f3893084ee7ce (MD5)","Made available in DSpace on 2012-02-06T20:12:13Z (GMT). No. of bitstreams: 3 McGovern_Megan.pdf: 3386649 bytes, checksum: 8fd1d77997e030937c9f3893084ee7ce (MD5) license.txt: 4064 bytes, checksum: cacc42e99ea3ce44ff39d8f8d473298b (MD5) McGovern_Megan.docx: 6200587 bytes, checksum: cd9adb36d1811ed2814befe635876608 (MD5)"],"dc:identifier":["http://hdl.handle.net/2142/29708"],"dc:language":["en"],"dc:rights":["Copyright 2011 Megan E McGovern"],"dc:subject":["Loblolly pine","wood","wood decay","rot","X-ray computed tomography","wood density","ultrasonic velocity","attenuation."],"dc:title":["Assessment of brown-rot decay using X-ray computer tomography and ultrasonic measurements"],"dc:type":["Dissertation / Thesis","text"],"thesis:degree_discipline":["Systems & Entrepreneurial Engr Civil Engineering"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:27Z"}