title: Towards achieving low background levels in routine dating by liquid scintillation spectrometry

authors: Hogg, Alan G.

subjects: liquid scintillation

abstract: International radiocarbon intercalibration studies have revealed that radiometric laboratories using liquid scintillation (LS) spectrometry of benzene reported, on average, younger ages for near-background standards than either gas proportional counter (GPC) or accelerator mass spectrometry (AMS) laboratories. These studies suggested that the younger LS ages are probably related to the use of spectrophotometric benzene as a background standard. An analysis of successive
110-ka subfossil wood (Airedale Reef Ancient Wood: ARAW) standards shows that vacuum line memory effects occur in LS spectrometry and, consequently, must be corrected to obtain accurate ¹⁴C dates. ARAW standards, measured at monthly intervals in the Waikato laboratory, are used to provide blank corrections for both research and routine dating applications. The strong correlation between the ARAW Δ¹⁴C data and the sample activities that preceded the standards may provide an opportunity to obtain sample-specific blank corrections. Lithium carbide synthesis is likely to prove a source of contamination. This work suggests that reproducible background levels for routine dating of less than 0.1 pMC (55 ka ¹⁴C yr) are achievable.

text: Towards achieving low background levels in routine dating by liquid scintillation spectrometry International radiocarbon intercalibration studies have revealed that radiometric laboratories using liquid scintillation (LS) spectrometry of benzene reported, on average, younger ages for near-background standards than either gas proportional counter (GPC) or accelerator mass spectrometry (AMS) laboratories. These studies suggested that the younger LS ages are probably related to the use of spectrophotometric benzene as a background standard. An analysis of successive
110-ka subfossil wood (Airedale Reef Ancient Wood: ARAW) standards shows that vacuum line memory effects occur in LS spectrometry and, consequently, must be corrected to obtain accurate ¹⁴C dates. ARAW standards, measured at monthly intervals in the Waikato laboratory, are used to provide blank corrections for both research and routine dating applications. The strong correlation between the ARAW Δ¹⁴C data and the sample activities that preceded the standards may provide an opportunity to obtain sample-specific blank corrections. Lithium carbide synthesis is likely to prove a source of contamination. This work suggests that reproducible background levels for routine dating of less than 0.1 pMC (55 ka ¹⁴C yr) are achievable.

year: 2004

title: Northeast Asian migration: recent change in New Zealand’s international migration system

authors: Lidgard, Jacqueline

abstract: This thesis examines the development of international migration from countries in Northeast Asia to New Zealand between 1986 and 1996 in the context of the restructuring of global capitalism. A part of the Fourth Labour Government’s economic restructuring programme was a change in New Zealand’s immigration policy. In 1986 New Zealand followed the example of the other three traditional countries of settlement, Canada, the United States and Australia, in trying to use immigration policy to attract skilled and wealthy immigrants to the country. Using world-systems analysis to illustrate the linkage between movements of people and periodic cycles of crisis and development, this thesis sources data from arrivals and departures records; census data from 1991 and 1996; and survey data from interviews. Statistical analysis is confined to the nationals of four Northeast Asian countries: the People’s Republic of China, Hong Kong, Taiwan and Korea. Survey data draws on insights provided by 42 interviews with participants from Hong Kong, Taiwan and Korea. The findings show that a new international migration sub-system had developed in New Zealand by the end of the 1980s aligning the country with Asia and the countries of the Pacific rim more than with its historical sources of migrants in Europe. Population flows from Northeast Asia grew rapidly after the introduction of a points system in 1991. By 1995 a non-traditional source of immigrants, Taiwan, contributed the largest number of new settlers to New Zealand. 

Nationality rather than country of last or next permanent residence was used to define the population flows. The research revealed significant inaccuracies using the latter classification for net migration. The nature of population flows to New Zealand differed between source countries. Labour force participation rates varied with self-employment higher for the Chinese and Korean immigrants than for New Zealand’s population as a whole. Census and survey data confirmed a considerable number of skilled immigrants were under- and unemployed. The analysis emphasised the need for caution when generalising about the impact of net migration gains and their impact on New Zealand’s population structure and labour force. These results suggest New Zealand needs flexible immigration policy more attuned to the needs of citizens who are part of a transnational circulatory migration process. Stronger government commitment to funding is necessary for informed policy development. As 1998 begins Northeast Asian migration to New Zealand is either at the end of a short-lived “age” or at the beginning of a new “era”. Regardless of short-term fluctuations New Zealand's migration system is firmly embedded in cycles of global capitalism.

text: Northeast Asian migration: recent change in New Zealand’s international migration system This thesis examines the development of international migration from countries in Northeast Asia to New Zealand between 1986 and 1996 in the context of the restructuring of global capitalism. A part of the Fourth Labour Government’s economic restructuring programme was a change in New Zealand’s immigration policy. In 1986 New Zealand followed the example of the other three traditional countries of settlement, Canada, the United States and Australia, in trying to use immigration policy to attract skilled and wealthy immigrants to the country. Using world-systems analysis to illustrate the linkage between movements of people and periodic cycles of crisis and development, this thesis sources data from arrivals and departures records; census data from 1991 and 1996; and survey data from interviews. Statistical analysis is confined to the nationals of four Northeast Asian countries: the People’s Republic of China, Hong Kong, Taiwan and Korea. Survey data draws on insights provided by 42 interviews with participants from Hong Kong, Taiwan and Korea. The findings show that a new international migration sub-system had developed in New Zealand by the end of the 1980s aligning the country with Asia and the countries of the Pacific rim more than with its historical sources of migrants in Europe. Population flows from Northeast Asia grew rapidly after the introduction of a points system in 1991. By 1995 a non-traditional source of immigrants, Taiwan, contributed the largest number of new settlers to New Zealand. 

Nationality rather than country of last or next permanent residence was used to define the population flows. The research revealed significant inaccuracies using the latter classification for net migration. The nature of population flows to New Zealand differed between source countries. Labour force participation rates varied with self-employment higher for the Chinese and Korean immigrants than for New Zealand’s population as a whole. Census and survey data confirmed a considerable number of skilled immigrants were under- and unemployed. The analysis emphasised the need for caution when generalising about the impact of net migration gains and their impact on New Zealand’s population structure and labour force. These results suggest New Zealand needs flexible immigration policy more attuned to the needs of citizens who are part of a transnational circulatory migration process. Stronger government commitment to funding is necessary for informed policy development. As 1998 begins Northeast Asian migration to New Zealand is either at the end of a short-lived “age” or at the beginning of a new “era”. Regardless of short-term fluctuations New Zealand's migration system is firmly embedded in cycles of global capitalism.

year: 1998

title: Initial report of the 2018 Census external data quality panel

authors: Bedford, Richard

abstract: One in six New Zealand residents did not complete a questionnaire for the 2018 New Zealand Census of Population and Dwellings. This was largely due to operational failures that made it difficult for a significant number of individuals and households to access census questionnaires, and to fulfill their statutory duty to participate.

text: Initial report of the 2018 Census external data quality panel One in six New Zealand residents did not complete a questionnaire for the 2018 New Zealand Census of Population and Dwellings. This was largely due to operational failures that made it difficult for a significant number of individuals and households to access census questionnaires, and to fulfill their statutory duty to participate.

year: 2019