{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/18132"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/18132","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"Studies of alpha-radioactivity in the marine environment","abstract":"This dissertation deals with the alpha-radioactivity in the marine environment around South Africa, and the published literature relating to alpha-emitting nuclides in sea water and in marine organisms is surveyed in Chapter 1. As a first step in the investigation, the total alpha-activity of some 400 samples of marine life was determined using the thick-source alpha-particle detection technique. The relative contributions of the thorium series nuclides and \"excess\" unsupported polonium-210 were determined by using the \"thorium pairs\" technique and by studying the variation of the total alpha count-rate with time. This is considered in Chapter 2. The 'second phase of the investigation was to investigate the alpha-spectrum of marine life. This was done for several plankton samples using a large capacity ion-chamber. As expected several disequilibria were found to exist and the findings are discussed in Chapter 3. Unsupported polonium-210 accounted for the major proportion of the total alpha-activity in several marine groups, while radium-226 and daughters accounted for most of the long-lived radioactivity. Thorium series elements were also present. Using the ion-chamber data together with total alpha-counting data, an estimate of the radium-226 content of plankton was made.","abstract_html":"This dissertation deals with the alpha-radioactivity in the marine environment around South Africa, and the published literature relating to alpha-emitting nuclides in sea water and in marine organisms is surveyed in Chapter 1. As a first step in the investigation, the total alpha-activity of some 400 samples of marine life was determined using the thick-source alpha-particle detection technique. The relative contributions of the thorium series nuclides and "excess" unsupported polonium-210 were determined by using the "thorium pairs" technique and by studying the variation of the total alpha count-rate with time. This is considered in Chapter 2. The 'second phase of the investigation was to investigate the alpha-spectrum of marine life. This was done for several plankton samples using a large capacity ion-chamber. As expected several disequilibria were found to exist and the findings are discussed in Chapter 3. Unsupported polonium-210 accounted for the major proportion of the total alpha-activity in several marine groups, while radium-226 and daughters accounted for most of the long-lived radioactivity. Thorium series elements were also present. Using the ion-chamber data together with total alpha-counting data, an estimate of the radium-226 content of plankton was made.","abstract_has_math":false,"creators":["Shannon, L V"],"institution":"Department of Physics","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Cherry, R D"],"committee_chairs":[],"committee_members":[],"year":1970,"date_issued":"1970","date_published":"1970","updated_at":"2026-07-22T22:22:58Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/18132","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Cherry, R D"]},{"key":"dc:creator","label":"Author","values":["Shannon, L V"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2016-03-21T19:26:52Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2016-03-21T19:26:52Z"]},{"key":"dc:date.issued","label":"Date","values":["1970"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Department of Physics"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Doctoral Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["PhD"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/18132"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This dissertation deals with the alpha-radioactivity in the marine environment around South Africa, and the published literature relating to alpha-emitting nuclides in sea water and in marine organisms is surveyed in Chapter 1. As a first step in the investigation, the total alpha-activity of some 400 samples of marine life was determined using the thick-source alpha-particle detection technique. The relative contributions of the thorium series nuclides and \"excess\" unsupported polonium-210 were determined by using the \"thorium pairs\" technique and by studying the variation of the total alpha count-rate with time. This is considered in Chapter 2. The 'second phase of the investigation was to investigate the alpha-spectrum of marine life. This was done for several plankton samples using a large capacity ion-chamber. As expected several disequilibria were found to exist and the findings are discussed in Chapter 3. Unsupported polonium-210 accounted for the major proportion of the total alpha-activity in several marine groups, while radium-226 and daughters accounted for most of the long-lived radioactivity. Thorium series elements were also present. Using the ion-chamber data together with total alpha-counting data, an estimate of the radium-226 content of plankton was made."]},{"key":"dc:title","label":"Title","values":["Studies of alpha-radioactivity in the marine environment"]}]}],"canonical_facts":{"dc:contributor.advisor":["Cherry, R D"],"dc:creator":["Shannon, L V"],"dc:date.accessioned":["2016-03-21T19:26:52Z"],"dc:date.available":["2016-03-21T19:26:52Z"],"dc:date.issued":["1970"],"dc:description.abstract":["This dissertation deals with the alpha-radioactivity in the marine environment around South Africa, and the published literature relating to alpha-emitting nuclides in sea water and in marine organisms is surveyed in Chapter 1. As a first step in the investigation, the total alpha-activity of some 400 samples of marine life was determined using the thick-source alpha-particle detection technique. The relative contributions of the thorium series nuclides and \"excess\" unsupported polonium-210 were determined by using the \"thorium pairs\" technique and by studying the variation of the total alpha count-rate with time. This is considered in Chapter 2. The 'second phase of the investigation was to investigate the alpha-spectrum of marine life. This was done for several plankton samples using a large capacity ion-chamber. As expected several disequilibria were found to exist and the findings are discussed in Chapter 3. Unsupported polonium-210 accounted for the major proportion of the total alpha-activity in several marine groups, while radium-226 and daughters accounted for most of the long-lived radioactivity. Thorium series elements were also present. Using the ion-chamber data together with total alpha-counting data, an estimate of the radium-226 content of plankton was made."],"dc:identifier.uri":["http://hdl.handle.net/11427/18132"],"dc:language.iso":["eng"],"dc:publisher.department":["Department of Physics"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["Studies of alpha-radioactivity in the marine environment"],"dc:type":["Doctoral Thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["PhD"]},"updated_at":"2026-07-22T22:22:58Z"}