{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/45147"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/45147","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Transient Radicals Produced by Sonication and the Investigation of Paramagnetic Effects","abstract":"Ultrasound can be used to create free radicals by growth and collapse of cavitation bubbles. These free radicals have potential use in various fields. The formation of free radicals can be monitored by decrease in T1 during NMR experiments due to paramagnetic effects. Our goal is to develop a method in which ultrasound is used to enhance NMR. By irradiating the sample during analytical measurements, we can decrease T1 which can be used as a non-toxic contrast agent1 producing hydroxyl radicals from the water in the body, invoke NMR enhancement using dynamic nuclear polarization2, control and understand polymer reactions3,4, and study the formation of radicals in chemical systems with EPR5. The experiments conducted indicated a decrease in T1 when ultrasound was applied. A maximum decrease was observed when 104 W of ultrasound power was applied and with higher concentrations of radical producing species. Through the experiments it was evident that the sample temperature increased during sonication. To counter this, gated sonication was used to minimize temperature increase. During sonication, the sample was vigorously mixed. Experiments where the sample was mixed through alternate means and theoretical simulations indicate that sample mixing gives an apparent decrease in T1. In situ sonication to decrease T1 shows promise. The question remains if the decrease is due to a combination of radical production and mixing or just an artifact of sample mixing. This is a difficult parameter to determine but future experiments will attempt to supply further conclusions.","abstract_html":"Ultrasound can be used to create free radicals by growth and collapse of cavitation bubbles. These free radicals have potential use in various fields. The formation of free radicals can be monitored by decrease in T1 during NMR experiments due to paramagnetic effects. Our goal is to develop a method in which ultrasound is used to enhance NMR. By irradiating the sample during analytical measurements, we can decrease T1 which can be used as a non-toxic contrast agent1 producing hydroxyl radicals from the water in the body, invoke NMR enhancement using dynamic nuclear polarization2, control and understand polymer reactions3,4, and study the formation of radicals in chemical systems with EPR5. The experiments conducted indicated a decrease in T1 when ultrasound was applied. A maximum decrease was observed when 104 W of ultrasound power was applied and with higher concentrations of radical producing species. Through the experiments it was evident that the sample temperature increased during sonication. To counter this, gated sonication was used to minimize temperature increase. During sonication, the sample was vigorously mixed. Experiments where the sample was mixed through alternate means and theoretical simulations indicate that sample mixing gives an apparent decrease in T1. In situ sonication to decrease T1 shows promise. The question remains if the decrease is due to a combination of radical production and mixing or just an artifact of sample mixing. This is a difficult parameter to determine but future experiments will attempt to supply further conclusions.","abstract_has_math":false,"creators":["McCreary, Kacey"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Chemistry","degree_department":"Chemistry","school":null,"contributors":[],"advisors":[],"committee_chairs":["Madsen, Louis A."],"committee_members":["Brewer, Karen J.","Tanko, James M."],"year":2012,"date_issued":"2012-09-28","date_published":"2012-09-28","updated_at":"2026-07-22T22:19:03Z","subjects":["free radical","sonication","T1 relaxation","Nuclear Magnetic Resonance"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-10112012-224257"],"render_values":[{"text":"etd-10112012-224257","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/45147","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Madsen, Louis A."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Brewer, Karen J.","Tanko, James M."]},{"key":"dc:contributor.department","label":"Department","values":["Chemistry"]},{"key":"dc:creator","label":"Author","values":["McCreary, Kacey"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:47:28Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:47:28Z","2012-11-13"]},{"key":"dc:date.issued","label":"Date","values":["2012-09-28"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["free radical","sonication","T1 relaxation","Nuclear Magnetic Resonance"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-10112012-224257"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/45147"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Ultrasound can be used to create free radicals by growth and collapse of cavitation bubbles. These free radicals have potential use in various fields. The formation of free radicals can be monitored by decrease in T1 during NMR experiments due to paramagnetic effects. Our goal is to develop a method in which ultrasound is used to enhance NMR. By irradiating the sample during analytical measurements, we can decrease T1 which can be used as a non-toxic contrast agent1 producing hydroxyl radicals from the water in the body, invoke NMR enhancement using dynamic nuclear polarization2, control and understand polymer reactions3,4, and study the formation of radicals in chemical systems with EPR5. The experiments conducted indicated a decrease in T1 when ultrasound was applied. A maximum decrease was observed when 104 W of ultrasound power was applied and with higher concentrations of radical producing species. Through the experiments it was evident that the sample temperature increased during sonication. To counter this, gated sonication was used to minimize temperature increase. During sonication, the sample was vigorously mixed. Experiments where the sample was mixed through alternate means and theoretical simulations indicate that sample mixing gives an apparent decrease in T1. In situ sonication to decrease T1 shows promise. The question remains if the decrease is due to a combination of radical production and mixing or just an artifact of sample mixing. This is a difficult parameter to determine but future experiments will attempt to supply further conclusions."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Transient Radicals Produced by Sonication and the Investigation of Paramagnetic Effects"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Madsen, Louis A."],"dc:contributor.committeemember":["Brewer, Karen J.","Tanko, James M."],"dc:contributor.department":["Chemistry"],"dc:creator":["McCreary, Kacey"],"dc:date.accessioned":["2014-03-14T21:47:28Z"],"dc:date.available":["2014-03-14T21:47:28Z","2012-11-13"],"dc:date.issued":["2012-09-28"],"dc:description.abstract":["Ultrasound can be used to create free radicals by growth and collapse of cavitation bubbles. These free radicals have potential use in various fields. The formation of free radicals can be monitored by decrease in T1 during NMR experiments due to paramagnetic effects. Our goal is to develop a method in which ultrasound is used to enhance NMR. By irradiating the sample during analytical measurements, we can decrease T1 which can be used as a non-toxic contrast agent1 producing hydroxyl radicals from the water in the body, invoke NMR enhancement using dynamic nuclear polarization2, control and understand polymer reactions3,4, and study the formation of radicals in chemical systems with EPR5. The experiments conducted indicated a decrease in T1 when ultrasound was applied. A maximum decrease was observed when 104 W of ultrasound power was applied and with higher concentrations of radical producing species. Through the experiments it was evident that the sample temperature increased during sonication. To counter this, gated sonication was used to minimize temperature increase. During sonication, the sample was vigorously mixed. Experiments where the sample was mixed through alternate means and theoretical simulations indicate that sample mixing gives an apparent decrease in T1. In situ sonication to decrease T1 shows promise. The question remains if the decrease is due to a combination of radical production and mixing or just an artifact of sample mixing. This is a difficult parameter to determine but future experiments will attempt to supply further conclusions."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-10112012-224257"],"dc:identifier.uri":["http://hdl.handle.net/10919/45147"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["free radical","sonication","T1 relaxation","Nuclear Magnetic Resonance"],"dc:title":["Transient Radicals Produced by Sonication and the Investigation of Paramagnetic Effects"],"dc:type":["Thesis"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:03Z"}