ORCID Profile
0000-0003-2866-4944
Current Organisation
Australian National University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Geology | Soil Sciences | Land Capability And Soil Degradation | Instruments And Techniques | Geomorphology | Geochronology | Synchrotrons; Accelerators; Instruments and Techniques | Sedimentology | Climatology (Incl. Palaeoclimatology) | Atomic, Molecular, Nuclear, Particle and Plasma Physics | Geochemistry | Physical Geography and Environmental Geoscience | Applied Hydrology (Drainage, Flooding, Irrigation, Quality, Etc.) | Geochronology And Isotope Geochemistry | Exploration Geochemistry | Environmental Management And Rehabilitation | Archaeological Science | Marine Geoscience | Geochronology | Groundwater Hydrology | Isotope Geochemistry | Environmental Management | Land Capability and Soil Degradation | High Energy Astrophysics; Cosmic Rays | Nuclear Physics |
ANZSRC Socio-Economic Objective (SEO)
Land and water management | Climate change | Land and water management | Land and water management | Expanding Knowledge in the Earth Sciences | Expanding Knowledge in the Physical Sciences | Climate Variability (excl. Social Impacts) | Marine protected areas | Biological sciences | Climate variability | Land and water management | Oceanic processes (excl. climate related) | Farmland, Arable Cropland and Permanent Cropland Land Management | Forest and Woodlands Land Management | Other
Related Links
Publications
Time-resolved record of 236U and 239,240Pu isotopes from a coral growing during the nuclear testing program at Enewetak Atoll (Marshall Islands)
Publisher: Elsevier BV
Date: 12-2016
DOI: 10.1016/J.JENVRAD.2016.09.015
Abstract: A comprehensive series of nuclear tests were carried out by the United States at Enewetak Atoll in the Marshall Islands, especially between 1952 and 1958. A Porites Lutea coral that was growing in the Enewetak lagoon within a few km of all of the high-yield tests contains a continuous record of isotopes, which are of interest (e.g.
In situ cosmogenic 53Mn production rate from ancient low-denudation surface in tropic Brazil
Publisher: Elsevier BV
Date: 04-2010
Yangtse River sediments and erosion rates from source to sink traced with cosmogenic 10Be: Sediments from major rivers
Publisher: Elsevier BV
Date: 11-2006
Masses and level schemes of 33Si and 34Si
Publisher: Elsevier BV
Date: 07-1985
Measurement of a highly retarded α-particle decay in 20Ne
Publisher: Elsevier BV
Date: 04-1984
AMS of natural 236U and 239Pu produced in uranium ores
Publisher: Elsevier BV
Date: 06-2007
First measurements of 236U concentrations and 236U/239Pu isotopic ratios in a Southern Hemisphere soil far from nuclear test or reactor sites
Publisher: Elsevier BV
Date: 06-2014
DOI: 10.1016/J.JENVRAD.2014.02.022
Abstract: The variation of the (236)U and (239)Pu concentrations as a function of depth has been studied in a soil profile at a site in the Southern Hemisphere well removed from nuclear weapon test sites. Total inventories of (236)U and (239)Pu as well as the (236)U/(239)Pu isotopic ratio were derived. For this investigation a soil core from an undisturbed forest area in the Herbert River catchment (17°30' - 19°S) which is located in north-eastern Queensland (Australia) was chosen. The chemical separation of U and Pu was carried out with a double column which has the advantage of the extraction of both elements from a relatively large soil s le (∼20 g) within a day. The s les were measured by Accelerator Mass Spectrometry using the 14UD pelletron accelerator at the Australian National University. The highest atom concentrations of both (236)U and (239)Pu were found at a depth of 2-3 cm. The (236)U/(239)Pu isotopic ratio in fallout at this site, as deduced from the ratio of the (236)U and (239)Pu inventories, is 0.085 ± 0.003 which is clearly lower than the Northern Hemisphere value of ∼0.2. The (236)U inventory of (8.4 ± 0.3) × 10(11) at/m(2) was more than an order of magnitude lower than values reported for the Northern Hemisphere. The (239)Pu activity concentrations are in excellent agreement with a previous study and the (239+240)Pu inventory was (13.85 ± 0.29) Bq/m(2). The weighted mean (240)Pu/(239)Pu isotopic ratio of 0.142 ± 0.005 is slightly lower than the value for global fallout, but our results are consistent with the average ratio of 0.173 ± 0.027 for the southern equatorial region (0-30°S).
Settling the Half-Life ofFe
Publisher: American Physical Society (APS)
Date: 28-01-2015
Hydrogeology of Palm Valley, central Australia; A Pleistocene flora refuge?
Publisher: Elsevier BV
Date: 06-2004
Erosion rates and weathering history of rock surfaces associated with Aboriginal rock art engravings (petroglyphs) on Burrup Peninsula, Western Australia, from cosmogenic nuclide measurements
Publisher: Elsevier BV
Date: 06-2013
Accelerator mass spectrometry of plutonium at 300 kV
Publisher: Elsevier BV
Date: 08-2004
New mass measurements of neutron-rich nuclei near N=20
Publisher: Elsevier BV
Date: 04-1991
Measurements of Pu and Ra isotopes in soils and sediments by AMS
Publisher: Elsevier BV
Date: 08-2004
Production of21Ne in depth-profiled olivine from a 54 Ma basalt sequence, Eastern Highlands (37° S), Australia
Publisher: Elsevier BV
Date: 2018
A new technique for removing geometrical resolution effects in focal plane detectors
Publisher: Elsevier BV
Date: 02-1983
Extension of New Zealand kauri (agathis australis) tree-ring chronologies into Oxygen Isotope Stage (OIS) 3
Publisher: Wiley
Date: 2006
DOI: 10.1002/JQS.1075
Measurements of the radiative widths of the first T = 1, 2+ state of 20Ne and their relationship to analog β-decays
Publisher: Elsevier BV
Date: 09-1977
Physical hydrogeology and environmental isotopes to constrain the age, origins, and stability of a low-salinity groundwater lens formed by periodic river recharge: Murray Basin, Australia
Publisher: Elsevier BV
Date: 2010
Association of plutonium with sediments from the Ob and Yenisey Rivers and Estuaries
Publisher: Elsevier BV
Date: 04-2009
DOI: 10.1016/J.JENVRAD.2008.12.016
Abstract: The present study applied sequential extraction techniques to investigate the binding and mobility of plutonium (Pu) in sediments from the rivers and estuaries of the Ob and Yenisey. As a study site, the Ob and Yenisey are particularly interesting as both rivers have weapons-grade Pu sources in their catchment areas, including the Russian Pu production and reprocessing plants at Mayak, Tomsk-7 and Krashnoyarsk, and the Semipalantinsk nuclear weapons testing site in Kazakhstan. Plutonium activity and (240)Pu/(239)Pu ratios were determined using accelerator mass spectrometry (AMS). Sequential extractions showed that between 47 and 80% of the Pu in Yenisey River sediments and 35-53% of the Pu in soils around the Techa River are mobilized with weak oxidising agents, which can indicate that Pu is bound to organic material. In contrast, Pu in Ob and Yenisey Estuarine sediments was more strongly bound, with 60-100% being found in the HNO(3)-extractable fraction. This change in speciation could reflect either that Pu bound to organic material in the Techa and Yenisey River sediments becomes more fixed to the sediments with time, or that organic-bound Pu is mobilized and released to the water when the sediments encounter the more saline water of the Ob and Yenisey estuaries. In general, (240)Pu/(239)Pu ratios were relatively consistent between different extraction fractions, although, in whole sediments, an increase in ratio was observed with distance from the source. This reflects the increased influence of weapon fallout from catchment runoff within the river systems, as compared to the weapons-grade sources close to the production and reprocessing plants. Knowledge of Pu speciation in the Ob and Yenisey Rivers, and the processes controlling its behaviour in estuarine systems, can improve predictions of its transfer and subsequent environmental impact to Arctic Seas.
Ground-state mass excesses and low-lying levels of the neutron-rich nuclei 36P, 35P and 34P
Publisher: Elsevier BV
Date: 07-1985
Preparation of a multi-isotope plutonium AMS standard and preliminary results of a first inter-lab comparison
Publisher: Elsevier BV
Date: 10-2015
A study of 25Ne via the 26Mg(13C, 14O)25Ne reaction
Publisher: Elsevier BV
Date: 04-1985
Lifetime of the 1.04 MeV 0+, T = 1 state in 18F
Publisher: Elsevier BV
Date: 10-1983
Plutonium AMS measurements in Yangtze River estuary sediment
Publisher: Elsevier BV
Date: 04-2010
Comparison of Pu and 137Cs as tracers of soil and sediment transport in a terrestrial environment
Publisher: Elsevier BV
Date: 02-2008
DOI: 10.1016/J.JENVRAD.2007.10.019
Abstract: Following atmospheric nuclear weapons testing in the 1950s and 1960s significant quantities of (137)Cs and (239+240)Pu were deposited worldwide. In recent decades, (137)Cs has been commonly used as a tracer of soil erosion and sedimentation, particularly in the Northern Hemisphere where atomic deposition was three times as great as in the Southern Hemisphere. The relatively short 30-year half-life of this isotope means that its sensitivity as a tracer is rapidly decreasing. In contrast, with half-lives of 24,110 and 6561 years, the sensitivity of the two plutonium isotopes remains essentially the same as when it was deposited. Here we use the technique of Accelerator Mass Spectrometry to demonstrate the potential of anthropogenic Pu as an alternative to (137)Cs as a tracer of soil transport in Australia. We measure an average (137)Cs/(239+240)Pu activity ratio of 27.3+/-1.5 and an average (240)Pu/(239)Pu atom ratio of 0.149+/-0.003, both slightly lower than the global average.
Plutonium as a tracer of soil and sediment movement in the Herbert River, Australia
Publisher: Elsevier BV
Date: 04-2010
10Be-derived denudation rates from the Burdekin catchment: The largest contributor of sediment to the Great Barrier Reef
Publisher: Elsevier BV
Date: 07-2015
Australian desert dune fields initiated with Pliocene - Pleistocene global climatic shift
Publisher: Geological Society of America
Date: 2009
DOI: 10.1130/G25042A.1
60 Fe deposition during the late Pleistocene and the Holocene echoes past supernova activity
Publisher: Proceedings of the National Academy of Sciences
Date: 24-08-2020
Abstract: Nearby supernova explosions shape the interstellar medium. Ejecta, containing fresh nucleosynthetic products, may traverse the solar system as a transient passage, or alternatively the solar system may traverse local clouds that may represent isolated remnants of supernova explosions. Such scenarios may modulate the galactic cosmic-ray flux intensity to which Earth is exposed. Varying conditions of the traversed interstellar medium could have impacts on climate and can be imprinted in the terrestrial geological record. Some radionuclides, such as 60 Fe, are not produced on Earth or within the solar system in significant quantities. Their existence in deep-sea sediments demonstrates recent production in close-by supernova explosions with a continued influx of 60 Fe until today.
Limestone erosion measurements with cosmogenic chlorine-36 in calcite — preliminary results from Australia
Publisher: Elsevier BV
Date: 06-1994
Studies of the nuclei 31Al and 29Mg
Publisher: Elsevier BV
Date: 1988
New frontiers in glacier ice dating: Measurement of natural 32Si by AMS
Publisher: Elsevier BV
Date: 10-2000
Developments in AMS of 99Tc
Publisher: Elsevier BV
Date: 08-2004
Global cooling intiated stony deserts in central Australia 2-4 Ma, dated by cosmogenic 21Ne-10Be
Publisher: Geological Society of America
Date: 2005
DOI: 10.1130/G21746.1
The 240Pu/239Pu atom ratio in Chinese soils
Publisher: Elsevier BV
Date: 08-2019
DOI: 10.1016/J.SCITOTENV.2019.04.251
Abstract: The
The β-decay of 47V
Publisher: Elsevier BV
Date: 04-1973
5 − Publisher:
American Physical Society (APS)
Date:
03-1993
Publisher: American Physical Society (APS)
Date: 03-1993
C
Publisher:
American Physical Society (APS)
Date:
04-1977
Publisher: American Physical Society (APS)
Date: 04-1977
Determination of plutonium isotopes in seawater samples by Semiconductor Alpha Spectrometry, ICP-MS and AMS techniques
Publisher: Springer Science and Business Media LLC
Date: 16-07-2009
Last Ice Age Millennial Scale Climate Changes Recorded in Huon Peninsula Corals
Publisher: Cambridge University Press (CUP)
Date: 2000
DOI: 10.1017/S0033822200030320
Abstract: Uranium series and radiocarbon ages were measured in corals from the uplifted coral terraces of Huon Peninsula (HP), Papua New Guinea, to provide a calibration for the 14 C time scale beyond 30 ka (kilo annum). Improved analytical procedures, and quantitative criteria for s le selection, helped discriminate diagenetically altered s les. The base-line of the calibration curve follows the trend of increasing ergence from calendar ages, as established by previous studies. Superimposed on this trend, four well-defined peaks of excess atmospheric radiocarbon were found ranging in magnitude from 100% to 700%, relative to current levels. They are related to episodes of sea-level rise and reef growth at HP. These peaks appear to be synchronous with Heinrich Events and concentrations of ice-rafted debris found in North Atlantic deep-sea cores. Relative timing of sea-level rise and atmospheric 14 C excess imply the following sequence of events: An initial sea-level high is followed by a large increase in atmospheric 14 C as the sea-level subsides. Over about 1800 years, the atmospheric radiocarbon drops to below present ambient levels. This cycle bears a close resemblance to ice-calving episodes of Dansgaard-Oeschger and Bond cycles and the slow-down or complete interruption of the North Atlantic thermohaline circulation. The increases in the atmospheric 14 C levels are attributed to the cessation of the North Atlantic circulation.
Reference material for radionuclides in sediment IAEA-384 (Fangataufa Lagoon sediment)
Publisher: Springer Science and Business Media LLC
Date: 30-07-2007
Accelerator mass spectrometry, large and small
Publisher: Elsevier BV
Date: 11-1996
Deposition of artificial radionuclides in sediments of Loch Etive, Scotland
Publisher: Elsevier BV
Date: 07-2018
DOI: 10.1016/J.JENVRAD.2018.02.001
Abstract: The nuclear fuel reprocessing plants on the Sellafield site (UK) have released low-level effluents into the Irish Sea under authorisation since 1952. This has led to the labelling of nearby offshore sediments with a range of artificial radionuclides. In turn, these sediments act as a long-term secondary source of both soluble and particle-associated radionuclides to coastal areas. These radionuclides are of interest both in assessing possible environmental impacts and as tracers for marine processes. Here we present results from a study of the geochemistry of natural (
Determination of U-236 in sediment samples by accelerator mass spectrometry
Publisher: Royal Society of Chemistry (RSC)
Date: 2001
DOI: 10.1039/B009764K
Abstract: 236U is produced only by neutron irradiation of uranium and therefore is potentially useful as a marker for anthropogenic uranium in the environment. Accelerator mass spectrometry (AMS) provides a technique for the determination of very low concentrations of actinide nuclides, and has now been applied to the determination of 236U:235U ratios in an intertidal sediment core collected from the North Irish Sea. Combining measurements of the 238U mass concentrations calculated from alpha spectrometry with 238U:235U ratios from ICP-MS and 236U:235U ratios from AMS has allowed the estimation of the mass concentrations of 236U in the sediments. 236U mass concentrations are in the range 10(-8) to 10(-9) g kg-1, and 236U:238U atom ratios in the range from 10(-5) to 10(-6), well above natural baseline levels. Uncertainties based on propagation of measurement errors were less than +/- 10% although +/- 15% is perhaps a more realistic estimate of overall uncertainty.
Determination of Aluminium-26 in Biological Materials by Accelerator Mass Spectrometry
Publisher: Royal Society of Chemistry (RSC)
Date: 1997
DOI: 10.1039/A702002C
Abstract: Studies of the biological chemistry of aluminium can gain significantly from the use of the long-lived isotope 26Al as a tracer, although the cost of the isotope often precludes its determination by radiochemical counting techniques. Accelerator mass spectrometry (AMS) provides an ultra-sensitive method of determination, free from isobaric interference from atomic (26Mg) or molecular species. The source materials for AMS can be aluminium oxide or phosphate, both of which can be readily prepared at a sufficient level of purity from biological substrates. Natural aluminium (27Al, 100%) is added to the preparations as a chemical yield monitor and to provide the reference for the isotope ratio measurement. 26Al/27Al ratios can be determined over the range 10(-14)-10(-7), implying a limit of detection for 26Al of around 10(-18) g. The precision of measurement and long-term reproducibility are < 5% and < 7% (RSD), respectively. Chemical methodologies for routine measurements on blood and urine s les have been developed.
Actinides AMS at CIRCE and 236U and Pu measurements of structural and environmental samples from in and around a mothballed nuclear power plant
Publisher: Elsevier BV
Date: 2013
Absence of cooling in New Zealand and the adjacent ocean during the younger dryas chronozone
Publisher: American Association for the Advancement of Science (AAAS)
Date: 05-10-2007
Abstract: As the climate warmed at the end of the last glacial period, a rapid reversal in temperature, the Younger Dryas (YD) event, briefly returned much of the North Atlantic region to near full-glacial conditions. The event was associated with climate reversals in many other areas of the Northern Hemisphere and also with warming over and near Antarctica. However, the expression of the YD in the mid- to low latitudes of the Southern Hemisphere (and the southwest Pacific region in particular) is much more controversial. Here we show that the Waiho Loop advance of the Franz Josef Glacier in New Zealand was not a YD event, as previously thought, and that the adjacent ocean warmed throughout the YD.
The second state in 19F
Publisher: Elsevier BV
Date: 08-1976
The cold climate geomorphology of the Eastern Cape Drakensberg: A reevaluation of past climatic conditions during the last glacial cycle in Southern Africa
Publisher: Elsevier BV
Date: 02-2017
A study of soil formation rates using10Be in the wet-dry tropics of northern Australia
Publisher: EDP Sciences
Date: 2012
Manganese-53: Development of the AMS technique for exposure-age dating applications
Publisher: Elsevier BV
Date: 06-2007
Charge-exchange reactions on 36S
Publisher: Elsevier BV
Date: 02-1993
Uptake by man of aluminium in a public water supply
Publisher: SAGE Publications
Date: 06-1998
Actinides, accelerators and erosion
Publisher: EDP Sciences
Date: 2012
The Mass Programme at GANIL Using the CSS2 and CIME Cyclotrons
Publisher: Springer Science and Business Media LLC
Date: 2001
The behaviour of the Leeuwin Current offshore NW Australia during the last five glacial-interglacial cycles
Publisher: Elsevier BV
Date: 02-2011
Problems of contamination in 36Cl studies
Publisher: Elsevier BV
Date: 12-1990
Radiocarbon analysis of the early archaeological site of Nauwalabila I, Arnhem Land, Australia: Implications for sample suitability and stratigraphic integrity
Publisher: Elsevier BV
Date: 04-2002
The chlorine-36 measurement program at the Australian National University
Publisher: Elsevier BV
Date: 11-1987
Mass measurements with the GANIL cyclotrons
Publisher: IOP Publishing
Date: 12-1991
Rabbit Sphincter of Oddi and Duodenum are Regulated by Slow Waves with a Common Basic-Mode Activity
Publisher: Informa UK Limited
Date: 1990
DOI: 10.3109/00365529009095526
Abstract: Simultaneous recordings of pressure and slow-wave activity were obtained from the sphincter of Oddi (SO) and the duodenum in anesthetized rabbits. Histographic analysis of the recordings was performed when the following criteria were fulfilled: 1) slow waves must be present in the EMG recordings from both compartments and 2) only pressure recordings with sufficient pressure activity (greater than 50 peaks in 10 min) would be considered. Of 12 animals fulfilling the criteria for histographic analysis of 4 channels, a common basic-mode activity was found in all channels in 9 animals (75%). Of three animals fulfilling the criteria for histographic analysis of three channels, a common basic-mode activity was seen in all channels in all animals (100%). A correlation between the litude of the slow waves and the litude of the elicited pressure peaks in the SO was significant at a 5% level or better in 12 animals (80%). In some of the animals episodes of low- litude pressure activity was observed in the SO, occurring synchronously with slow waves devoid of spike activity. It is concluded that rabbit SO and duodenum are paced by slow waves with a common basic-mode activity in most animals. Slow waves may not only be the chief determinant of the contractile rhythm but may also have a certain influence on the force of the in idual SO contractions. It is suggested that slow waves per se may be able to mediate contractile activity.
Exposure dating (10Be, 26Al) of natural terrain landslides in Hong Kong, China
Publisher: Geological Society of America
Date: 2006
The mass of 18C from a heavy ion double-charge-exchange reaction
Publisher: Elsevier BV
Date: 09-1982
Isovector magnetic dipole transition in22Na
Publisher: IOP Publishing
Date: 06-1980
O
Publisher:
American Physical Society (APS)
Date:
11-1984
Publisher: American Physical Society (APS)
Date: 11-1984
Stratigraphy, pollen and 14C dating of Johnston's Gum Hole, a late Quaternary fossil kauri (Agathis australis) site, Northland, New Zealand
Publisher: Wiley
Date: 2009
DOI: 10.1002/JQS.1179
Coral reef sedimentation on Rodrigues and the Western Indian Ocean and its impact on the carbon cycle
Publisher: The Royal Society
Date: 15-01-2005
Abstract: Coral reefs in the southwest Indian Ocean cover an area of ca. 18530 km 2 compared with a global reef area of nearly 300000 km 2 . These regions are important as fishing grounds, tourist attractions and as a significant component of the global carbon cycle. The mass of calcium carbonate stored within Holocene neritic sediments is a number that we are only now beginning to quantify with any confidence, in stark contrast to the mass and sedimentation rates associated with pelagic calcium carbonate, which have been relatively well defined for decades. We report new data that demonstrate that the reefs at Rodrigues, like those at Réunion and Mauritius, only reached a mature state (reached sea level) by 2–3 ka: thousands of years later than most of the reefs in the Australasian region. Yet field observations show that the large lagoon at Rodrigues is already completely full of carbonate detritus (typical lagoon depth less than 1 m at low spring tide). The presence of aeolian dunes at Rodrigues indicates periodic exposure of past lagoons throughout the Pleistocene. The absence of elevated Pleistocene reef deposits on the island indicates that the island has not been uplifted. Most Holocene reefs are between 15 and 20 m in thickness and those in the southwest Indian Ocean appear to be consistent with this observation. We support the view that the CO 2 flux associated with coral–reef growth acts as a climate change lifier during deglaciation, adding CO 2 to a warming world. southwest Indian Ocean reefs could have added 7–10% to this global flux during the Holocene.
Unnatural parity levels at high excitation inNe
Publisher:
American Physical Society (APS)
Date:
09-1976
Publisher: American Physical Society (APS)
Date: 09-1976
Sea-level at the Last Glacial Maximum: evidence from northwestern Australia to constrain ice volumes for oxygen isotope stage 2
Publisher: Elsevier BV
Date: 2001
Lifetime of the 2795 keV level in 21Ne
Publisher: Elsevier BV
Date: 04-1983
Climate, people and faunal succession on Java, Indonesia
Publisher: Elsevier BV
Date: 07-2008
Decay properties of exoticN≃28 S and Cl nuclei and the
Publisher:
American Physical Society (APS)
Date:
06-1993
Publisher: American Physical Society (APS)
Date: 06-1993
Soil production in heath and forest, Blue Mountains, Australia
Publisher: Wiley
Date: 2005
DOI: 10.1002/ESP.1254
Co-precipitated silver–metal oxide aggregates for accelerator mass spectrometry of 10Be and 26Al
Publisher: Elsevier BV
Date: 08-2004
The age of Wolfe Creek meteorite crater (Kandimalal), Western Australia
Publisher: Wiley
Date: 09-2019
DOI: 10.1111/MAPS.13378
Spectroscopy of A = 16 from 13C(6Li, t)16O
Publisher: Elsevier BV
Date: 08-1983
Cosmogenic Cl-36 dating of postglacial landsliding at The Storr, Isle of Skye, Scotland
Publisher: SAGE Publications
Date: 04-1998
DOI: 10.1191/095968398666797200
Abstract: Major postglacial rock slope failures are a common feature of the Scottish Highlands and other mountainous areas that were deglaciated at the end of the Pleistocene, but evaluation of the causes and triggers of failure has been hindered by a lack of reliable dating evidence. We report the result of a pilot study designed to establish the absolute age of a large postglacial rotational rockslide at The Storr on the Isle of Skye, Scotland, using 36 Cl surface exposure dating. Exposure ages of 6.3 ± 0.7 cal. ka BP and 6.6 ± 0.8 cal. ka BP were obtained for rock s les from two separate landslide blocks, giving an overall age estimate of 6.5 ± 0.5 cal. ka BP for rock slope failure at this site. This date is consistent with AMS radiocarbon dating of windblown sand derived from the failure scarp, and with previous inferences (based on relative dating evidence) concerning an early-Holocene age for most rock slope failures in the Scottish Highlands. The long time lag (. 7 ka) between deglaciation and failure suggests that progressive joint extension and shearing of rock bridges and asperities were of critical importance in conditioning failure, though a seismic trigger cannot be ruled out. The methodology of surface exposure dating in this context is described and its future potential assessed.
Kinetics of uptake and elimination of silicic acid by a human subject: A novel application of 32Si and accelerator mass spectrometry
Publisher: Elsevier BV
Date: 02-1998
DOI: 10.1016/S0162-0134(97)10016-2
Abstract: Silicon is possibly important in human physiology in protecting against the toxic effects of aluminium, but the kinetics of uptake and excretion of silicic acid, the bioavailable form, are not well characterised. We have used 32Si as a tracer in a human uptake experiment to determine a gastrointestinal uptake factor for silicic acid, and to elucidate the kinetics of renal elimination. Urine collections were made for extending intervals from 2 to 12 h over 2 days following ingestion by a single human subject of a neutral silicic acid solution containing tracer levels of 32Si (t1/2 approximately 150 y). Silicon was isolated as SiO2 and the 32Si content determined by accelerator mass spectrometry (AMS), using a gas-filled magnet technique to eliminate a prolific isobaric interference from 32S. Silicon uptake appears to have been essentially complete within 2 h of ingestion. Elimination occurred by two simultaneous first-order processes with half-lives of 2.7 and 11.3 h, representing around 90% and 10%, respectively, of the total output. The rapidly eliminated 32Si was probably retained in the extracellular fluid volume, whilst the slower component may represent intracellular uptake and release. Elimination of absorbed 32Si was essentially complete after 48 h and was equivalent to 36% of the ingested dose. This establishes only a lower limit for gastrointestinal absorption as, although there was no evidence for longer term retention of additional 32Si, the possibility could not be excluded by these results.
The next chapter in radiocarbon dating at the Australian National University: Status report on the single stage AMS
Publisher: Elsevier BV
Date: 04-2010
Background reduction in 236U/238U measurements
Publisher: Elsevier BV
Date: 10-2015
Escarpment erosion and landscape evolution in southeastern Australia
Publisher: Geological Society of America
Date: 2006
No Fukushima Dai-ichi derived plutonium signal in marine sediments collected 1.5–57 km from the reactors
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.APRADISO.2017.08.015
Abstract: Based on AMS analysis, it is shown that no Pu signals from the Fukushima accident could be discerned in marine sediments collected 1.5-57km away from the Fukushima Da-ichi power plant (FDNPP), which were clearly influenced by accident-derived radiocesium. The
Geochronology of cave deposits at Liang Bua and of adjacent river terraces in the Wae Racang valley, western Flores, Indonesia
Publisher: Elsevier BV
Date: 11-2009
DOI: 10.1016/J.JHEVOL.2009.01.003
Abstract: A robust timeframe for the extant cave deposits at Liang Bua, and for the river terraces in the adjoining Wae Racang valley, is essential to constrain the period of existence and time of extinction of Homo floresiensis and other biota that have been excavated at this hominin type locality. Reliable age control is also required for the variety of artifacts excavated from these deposits, and to assist in environmental reconstructions for this river valley and for the region more broadly. In this paper, we summarize the available geochronological information for Liang Bua and its immediate environs, obtained using seven numerical-age methods: radiocarbon, thermoluminescence, optically- and infrared-stimulated luminescence (collectively known as optical dating), uranium-series, electron spin resonance, and coupled electron spin resonance/uranium-series. We synthesize the large number of numerical age determinations reported previously and present additional age estimates germane to questions of hominin evolution and extinction.
Mass Measurement of100
Publisher: American Physical Society (APS)
Date: 16-09-1996
Evolution of the Sungei Buloh–Kranji mangrove coast, Singapore
Publisher: Elsevier BV
Date: 07-2004
The Search for Supernova-Produced Radionuclides in Terrestrial Deep-Sea Archives
Publisher: Cambridge University Press (CUP)
Date: 2012
DOI: 10.1071/AS11070
Abstract: An enhanced concentration of 60 Fe was found in a deep ocean crust in 2004 in a layer corresponding to an age of ∼2 Myr. The confirmation of this signal in terrestrial archives as supernova-induced and the detection of other supernova-produced radionuclides is of great interest. We have identified two suitable marine sediment cores from the South Australian Basin and estimated the intensity of a possible signal of the supernova-produced radionuclides 26 Al, 53 Mn, 60 Fe, and the pure r -process element 244 Pu in these cores. The finding of these radionuclides in a sediment core might allow us to improve the time resolution of the signal and thus to link the signal to a supernova event in the solar vicinity ∼2 Myr ago. Furthermore, it gives us an insight into nucleosynthesis scenarios in massive stars, condensation into dust grains and transport mechanisms from the supernova shell into the solar system.
Radiocarbon dating from 40 to 60kaBP at Border Cave, South Africa
Publisher: Elsevier BV
Date: 04-2003
The identification and rejection of energy-degraded events in gas ionization counters
Publisher: Elsevier BV
Date: 11-1988
Evolution of vertical knickpoints (waterfalls) with resistant caprock: Insights from numerical modeling
Publisher: American Geophysical Union (AGU)
Date: 24-08-2010
DOI: 10.1029/2008JF001187
The timing of the last glacial maximum in Australia
Publisher: Elsevier BV
Date: 2002
Patterns of denudation through time in the San Bernardino Mountains, California: Implications for early-stage orogenesis
Publisher: Elsevier BV
Date: 11-2008
Novel matching lens and spherical ionizer for a cesium sputter ion source
Publisher: Springer Science and Business Media LLC
Date: 12-2002
Optical dating of deep-sea sediments using single grains of quartz: A comparison with radiocarbon
Publisher: Elsevier BV
Date: 07-2004
Accelerator mass spectrometry of plutonium isotopes
Publisher: Elsevier BV
Date: 09-1996
Landscape responses to intraplate tectonism: Quantitative constraints from 10Be nuclide abundances
Publisher: Elsevier BV
Date: 09-2007
Assessment of the radiological impact of a decommissioned nuclear power plant in Italy
Publisher: EDP Sciences
Date: 04-2012
A cyclotron as a high resolution mass spectrometer for fast secondary ions
Publisher: Elsevier BV
Date: 10-1994
Accelerator mass spectrometry with the 14UD accelerator at the Australian National University
Publisher: Elsevier BV
Date: 04-2010
Late-surviving megafauna in Tasmania, Australia, implicate human involvement in their extinction
Publisher: Proceedings of the National Academy of Sciences
Date: 26-08-2008
Abstract: Establishing the cause of past extinctions is critical if we are to understand better what might trigger future occurrences and how to prevent them. The mechanisms of continental late Pleistocene megafaunal extinction, however, are still fiercely contested. Potential factors contributing to their demise include climatic change, human impact, or some combination. On the Australian mainland, 90% of the megafauna became extinct by ≈46 thousand years (ka) ago, soon after the first archaeological evidence for human colonization of the continent. Yet, on the neighboring island of Tasmania (which was connected to the mainland when sea levels were lower), megafaunal extinction appears to have taken place before the initial human arrival between 43 and 40 ka, which would seem to exonerate people as a contributing factor in the extirpation of the island megafauna. Age estimates for the last megafauna, however, are poorly constrained. Here, we show, by direct dating of fossil remains and their associated sediments, that some Tasmanian megafauna survived until at least 41 ka (i.e., after their extinction on the Australian mainland) and thus overlapped with humans. Furthermore, a vegetation record for Tasmania spanning the last 130 ka shows that no significant regional climatic or environmental change occurred between 43 and 37 ka, when a land bridge existed between Tasmania and the mainland. Our results are consistent with a model of human-induced extinction for the Tasmanian megafauna, most probably driven by hunting, and they reaffirm the value of islands adjacent to continental landmasses as tests of competing hypotheses for late Quaternary megafaunal extinctions.
Assessment of isotopically exchangeable Al in soil materials using 26Al tracer
Publisher: Elsevier BV
Date: 11-2005
Late pleistocene glaciation of the kosciouszko massif, snowy mountains, Australia
Publisher: Cambridge University Press (CUP)
Date: 03-2001
Abstract: Late Pleistocene glaciation of the Australian mainland was restricted to a small area of the southeastern highlands. Geomorphic mapping of the area and exposure dating using the in situ produced cosmogenic isotope 10 Be provides evidence for at least two distinct glaciations. The Early Kosciuszko glaciation consisted of a single glacier advance before 59,300 ± 5400 years ago (Snowy River Advance). The Late Kosciuszko glaciation comprised three glacier advances 32,000 ± 2500 (Headley Tarn Advance), 19,100 ± 1600 (Blue Lake Advance), and 16,800 ± 1400 years ago (Mt. Twynam Advance). The Early Kosciuszko glaciation was the most extensive and the Late Kosciuszko advances were progressively less extensive. These periods of glaciation in the highlands correspond to episodes of periglacial activity and peaks in lake levels and river discharge at lower elevations in southeastern Australia. Glacier advances on the Kosciuszko Massif correlate with advances in Tasmania, South America, and New Zealand and are broadly representative of hemispheric climate changes during the last glacial cycle.
Glaciation and deglaciation of the SW Lake District, England: implications of cosmogenic 36Cl exposure dating
Publisher: Elsevier BV
Date: 2009
Cosmogenic chlorine-36 from calcium spallation
Publisher: Elsevier BV
Date: 02-1996
Aspects of breakdown product contamination of sulphur hexafluoride in electrostatic accelerators
Publisher: Elsevier BV
Date: 12-1983
Phasing of millennial-scale climate variability in the Pacific and Atlantic Oceans
Publisher: American Association for the Advancement of Science (AAAS)
Date: 06-11-2020
Abstract: Walczak et al. report that increases in Pacific Ocean ventilation and periods of rapid production of icebergs from the Cordilleran Ice Sheet during the last glacial period preceded episodic iceberg discharges into the Atlantic Ocean (see the Perspective by Jaeger and Shevenell). Marine sediments from the Gulf of Alaska show that increases in vertical mixing of the ocean there correspond with intense iceberg calving from the ice sheet that covered much of high-latitude western North America and that these changes occurred before the analogous Heinrich events in the North Atlantic. Thus, these Pacific climate system reorganizations may have been an early part of a cascade of dynamic climate events with global repercussions. Science , this issue p. 716 see also p. 662
Radiocarbon dating of old charcoal using a wet oxidation, stepped-combustion procedure
Publisher: Cambridge University Press (CUP)
Date: 1999
DOI: 10.1017/S0033822200019482
Abstract: We present results that validate a new wet oxidation, stepped-combustion procedure for dating “old” charcoal s les. An acid–base–wet oxidation (ABOX) pretreatment procedure has been developed that is used in place of the conventional acid-base-acid (ABA) pretreatment. Combustions and graphitizations are performed in a vacuum line that is insulated from the atmosphere by a second backing vacuum to eliminate the risk of atmospheric leakage into the line at any stage of the procedure. Combustions are performed at 3 temperatures (330 °, 630 ° and 850 °) with a graphite target produced from the CO 2 evolved during each combustion step. In this way, the removal of any contamination can be monitored, and a high degree of confidence can be placed on the final age. The pretreatment, combustion, graphitization, and measurement blank for the procedure, based on the analysis of a “radiocarbon-dead” graphite, is 0.5 ± 0.5 μg C (1σ, n=14), equivalent to 0.04 ± 0.02 pMC or an “age” of approximately 60 ka for a 1 mg graphite target. Analyses of a “radiocarbon-dead” natural charcoal after ABOX pretreatment and stepped combustion suggest that the total blank (including contamination not removed by pretreatment) may be higher than for graphite, ranging up to 0.10 ± 0.02 pMC. Additional experiments confirm good agreement with accepted values for the international low- 14 C “New Kauri” standard (0.16–0.25 pMC). They also confirm excellent reproducibility, with 3 separate dates on different aliquots of a charcoal s le from Ngarrabullgan Cave (Queensland, Australia) ranging from 35.2 to 35.5 ka 14 C BP. It is also demonstrated that the ABOX pretreatment, in conjunction with the new vacuum line described here, is able to remove contamination not removed by the conventional ABA pretreatment, suggesting that the technique can be used to produce reliable 14 C dates on charcoal up to at least 50 ka.
Simple concepts for ion source improvement
Publisher: Elsevier BV
Date: 05-2002
Chemical and isotopic indicators of point-source recharge to a karst aquifer, South Australia
Publisher: Elsevier BV
Date: 05-1997
Chlorine-36 production and distribution in Australia
Publisher: Elsevier BV
Date: 05-1991
Cosmogenic 10Be and 26Al exposure ages of tors and erratics, Cairngorm Mountains, Scotland: Timescales for the development of a classic landscape of selective linear glacial erosion
Publisher: Elsevier BV
Date: 02-2006
Seasonal Variations in Interstitial Water Transuranium Element Concentrations
Publisher: American Chemical Society (ACS)
Date: 02-09-2000
DOI: 10.1021/ES0009976
A novel roller pump for physiological flow
Publisher: Wiley
Date: 25-03-2020
DOI: 10.1111/AOR.13670
Preliminary results of CoQtz-N: A quartz reference material for terrestrial in-situ cosmogenic 10Be and 26Al measurements
Publisher: Elsevier BV
Date: 10-2019
Certified reference material for radionuclides in seawater IAEA-381 (Irish Sea Water)
Publisher: Springer Science and Business Media LLC
Date: 2002
Amplified erosion above waterfalls and oversteepened bedrock reaches
Publisher: American Geophysical Union (AGU)
Date: 24-10-2006
DOI: 10.1029/2006JF000461
Lake George revisited: New evidence for the origin and evolution of a large closed lake, Southern Tablelands, NSW, Australia
Publisher: Informa UK Limited
Date: 03-10-2015
A cryogenically pumped gas target for the study of angular distributions of gamma rays following radiative capture
Publisher: Elsevier BV
Date: 05-1978
Erratum Marshall T. Wilkinson, John Chappell, Geoff S. Humphreys, Keith Fifield, Bart Smith and Paul Hesse, ‘Soil Production in Heath and Forest, Blue Mountains, Australia: Influence of Lithology and
Publisher: Wiley
Date: 2005
DOI: 10.1002/ESP.1311
In-situ production of natural 236U in groundwaters and ores in high-grade uranium deposits
Publisher: Elsevier BV
Date: 09-2015
Time-of-flight system for a heavy ion magnetic spectrometer
Publisher: Elsevier BV
Date: 10-1987
High‐resolution reconstruction of the last ice sheet in NW Scotland
Publisher: Wiley
Date: 03-1998
High-Spin States in the Continuum. I.Ne
Publisher:
American Physical Society (APS)
Date:
12-1973
Publisher: American Physical Society (APS)
Date: 12-1973
Timing of the Last Glacial Maximum from observed sea-level minima
Publisher: Springer Science and Business Media LLC
Date: 17-08-2000
DOI: 10.1038/35021035
Abstract: During the Last Glacial Maximum, ice sheets covered large areas in northern latitudes and global temperatures were significantly lower than today. But few direct estimates exist of the volume of the ice sheets, or the timing and rates of change during their advance and retreat. Here we analyse four distinct sediment facies in the shallow, tectonically stable Bonaparte Gulf, Australia--each of which is characteristic of a distinct range in sea level--to estimate the maximum volume of land-based ice during the last glaciation and the timing of the initial melting phase. We use faunal assemblages and preservation status of the sediments to distinguish open marine, shallow marine, marginal marine and brackish conditions, and estimate the timing and the mass of the ice sheets using radiocarbon dating and glacio-hydro-isostatic modelling. Our results indicate that from at least 22,000 to 19,000 (calendar) years before present, land-based ice volume was at its maximum, exceeding today's grounded ice sheets by 52.5 x 10(6) km. A rapid decrease in ice volume by about 10% within a few hundred years terminated the Last Glacial Maximum at 19,000 +/- 250 years.
Potential of lichens for monitoring iodine-129 and chlorine-36
Publisher: Springer Science and Business Media LLC
Date: 27-06-2009
The missing mirror state in 9B
Publisher: Elsevier BV
Date: 12-1992
In situ cosmogenic nuclide production rate calibration for the CRONUS-Earth project from Lake Bonneville, Utah, shoreline features
Publisher: Elsevier BV
Date: 02-2015
Ultra-sensitive measurements of 36Cl and 236U at the Australian National University
Publisher: Elsevier BV
Date: 2013
Comparison between biokinetics of inhaled plutonium nitrate and gadolinium oxide in humans and animals
Publisher: Springer Science and Business Media LLC
Date: 2002
Denudation rates for the southern Drakensberg escarpment, SE Africa, derived from in-situ- produced cosmogenic 36 C1: initial results
Publisher: Geological Society of London
Date: 03-1999
The longevity of hillslope soil in SE and NW Australia
Publisher: Elsevier BV
Date: 04-2010
26Al measurements with 10Be counting statistics
Publisher: Elsevier BV
Date: 06-2007
Glacial/interglacial changes in the East Australian current
Publisher: Springer Science and Business Media LLC
Date: 06-01-2006
Coulomb explosion of BeO− molecular ions – Revisited
Publisher: Elsevier BV
Date: 05-2023
New and upgraded ionization chambers for AMS at the Australian National University
Publisher: Elsevier BV
Date: 2019
Bedrock erosion and relief production in the northern Flinders Ranges, Australia
Publisher: Wiley
Date: 2007
DOI: 10.1002/ESP.1459
Stranded landscapes in the humid tropics: Earth's oldest land surfaces
Publisher: Elsevier BV
Date: 08-2019
Exposure ages for Pleistocene periglacial deposits in Australia
Publisher: Elsevier BV
Date: 03-2004
The 26Mg(18O, 17F)27Na and 26Mg(18O, 15O)29Mg reactions and the level schemes of 27Na and 29Mg
Publisher: Elsevier BV
Date: 04-1985
States in 21Ne via the reaction
Publisher: Elsevier BV
Date: 12-1981
Uranium from German Nuclear Power Projects of the 1940s— A Nuclear Forensic Investigation
Publisher: Wiley
Date: 02-11-2015
Late Quaternary siliciclastic/carbonate sedimentation model for the Capricorn Channel, southern Great Barrier Reef province, Australia
Publisher: Elsevier BV
Date: 02-2009
Cosmogenic nuclide ages for Last Glacial Maximum moraine at Schnells Ridge, Southwest Tasmania
Publisher: Cambridge University Press (CUP)
Date: 05-2004
DOI: 10.1016/J.YQRES.2004.02.004
Abstract: Moraines on Schnells Ridge, southwest Tasmania, have been dated using in situ 10 Be. An age of 19,400 ± 600 yr is indicated for the well-preserved innermost moraine from consistent measurements on four large quartzite boulders. This corresponds closely with exposure ages reported by T.T. Barrows et al. (2002, Quaternary Science Reviews 21, 159–173) for Last Glacial Maximum glacial features farther north in Tasmania and southeast Australia. In contrast, ages between 39,000 and 141,000 yr were obtained from a series of boulders on a more extensive outer moraine, indicating that this has had a more complex history.
Plutonium isotope ratios in the Yenisey and Ob estuaries
Publisher: Elsevier BV
Date: 02-2004
Improving the detection limit for 182Hf
Publisher: Elsevier BV
Date: 06-2007
Unsaturated zone tritium and chlorine 36 profiles from southern Australia: Their use as tracers of soil water movement
Publisher: American Geophysical Union (AGU)
Date: 06-1994
DOI: 10.1029/94WR00161
L-X-ray production cross-sections for PXAMS: Target and energy dependence for 50–200MeV hafnium ions
Publisher: Elsevier BV
Date: 06-2007
Calculating Sediment Compaction for Radiocarbon Dating of Intertidal Sediments
Publisher: Cambridge University Press (CUP)
Date: 2004
DOI: 10.1017/S0033822200039734
Abstract: This study estimates the maximum and minimum degrees of autocompaction for radiocarbon-dated Holocene mangrove sediments in Singapore, in order to correct apparent sediment accretion rates for the effects of sediment compression due to autocompaction. Relationships developed for a suite of modern (surface) sediment s les between bulk density, particle-size distribution, and organic matter content were used to estimate the initial (uncompacted) bulk density of buried and variably compressed Holocene sediments, based on the grain-size distribution and organic matter content of the sediment. The difference between measured (compacted) and initial (uncompacted) bulk density of each buried sediment interval can be interpreted as the amount of length shortening experienced by each interval since burial. This allows the elevation of s les selected for 14 C dating to be corrected for the effects of autocompaction of the underlying sediment sequence, so that accurate estimates of vertical sediment accretion rates can be calculated. The 3 Holocene mangrove sequences analyzed and dated for this study ranged in age from 2000 to 8500 cal BP. The effects of autocompaction are significant, even in comparatively thin sequences, with subsidence of up to 56 cm calculated for carbon-dated s les presently 2 m above incompressible basement. The vertical sediment accretion rates for these mangrove sequences ranged from 0.99 to 6.84 mm/yr and carbon sequestration rates ranged from 0.9 to 1.7 t/ha/yr, all within the range observed for comparable Holocene and modern mangrove sediments elsewhere.
Nucleogenic 36Cl, 236U and 239Pu in uranium ores
Publisher: Elsevier BV
Date: 08-2008
Injection optics for fast mass switching for accelerator mass spectrometry
Publisher: AIP
Date: 2013
DOI: 10.1063/1.4792817
Absorption of Aluminium-26 in Alzheimer’s Disease, Measured Using Accelerator Mass Spectrometry
Publisher: S. Karger AG
Date: 2000
DOI: 10.1159/000017216
Abstract: Although chromosomal abnormalities underpin some early onset cases of familial Alzheimer’s disease (AD), most cases are sporadic and not associated with such abnormalities. Aluminium (Al) is a significant but controversial risk factor for sporadic AD, and studies have reported associations between Al and the principal pathological features of AD, senile plaques and neurofibrillary tangles. The present study measured gastrointestinal (GI) absorption of Al under normal dietary conditions using sup /sup Al tracer and accelerator mass spectrometry (AMS). Following overnight fast, 13 AD patients (aged 63–76 years) and 13 age-matched controls (aged 62–76 years) ingested a fruit drink containing 27 ng sup /sup Al. Plasma s les were obtained before and 1 h after the drink and from these the fraction of sup /sup Al absorbed across the GI tract was estimated. The GI tract rigorously excludes Al with only 0.06–0.1% of the ingested Al being absorbed. The mean fraction absorbed by AD subjects exceeded controls by a factor of 1.64 (p≤0.05, Anova). AMS is capable of determining sup –16 /sup g of sup /sup Al with many orders of magnitude more sensitivity than other techniques. Using this sensitivity, we have shown, under normal physiological conditions, that the ability of the GI tract to exclude Al is reduced in AD, possibly leading to greater systemic exposure to Al. Public health measures to limit Al dietary uptake or bioavailability may decrease the prevalence of AD in the community and should be considered.
Accelerator mass spectrometry of 99Tc
Publisher: Elsevier BV
Date: 07-2000
New measurements of the masses of 15B and 19N
Publisher: Elsevier BV
Date: 04-1983
A study of excited states in 33Cl by elastic proton scattering on 32S
Publisher: Elsevier BV
Date: 02-1974
Measurement of actinides on a compact AMS system working at 300kV
Publisher: Elsevier BV
Date: 10-2005
Measurement of 236U on the 1 MV AMS system at the Centro Nacional de Aceleradores (CNA)
Publisher: Elsevier BV
Date: 09-2015
The influence of dissolved silicate on the physiological chemistry of aluminium, studied in humans using tracer 26Al and accelerator mass spectrometry
Publisher: Elsevier BV
Date: 03-1997
High 36Cl/Cl ratios in Chernobyl groundwater
Publisher: Elsevier BV
Date: 12-2014
DOI: 10.1016/J.JENVRAD.2014.07.008
Abstract: After the explosion of the Chernobyl Nuclear Power Plant in April 1986, contaminated material was buried in shallow trenches within the exclusion zone. A (90)Sr plume was evidenced downgradient of one of these trenches, trench T22. Due to its conservative properties, (36)Cl is investigated here as a potential tracer to determine the maximal extent of the contamination plume from the trench in groundwater. (36)Cl/Cl ratios measured in groundwater, trench soil water and leaf leachates are 1-5 orders of magnitude higher than the theoretical natural (36)Cl/Cl ratio. This contamination occurred after the Chernobyl explosion and currently persists. Trench T22 acts as an obvious modern point source of (36)Cl, however other sources have to be involved to explain such contamination. (36)Cl contamination of groundwater can be explained by dilution of trench soil water by uncontaminated water (rainwater or deep groundwater). With a plume extending further than that of (90)Sr, radionuclide which is impacted by retention and decay processes, (36)Cl can be considered as a suitable tracer of contamination from the trench in groundwater provided that modern release processes of (36)Cl from trench soil are better characterized.
93Zr developments at the Heavy Ion Accelerator Facility at ANU
Publisher: Elsevier BV
Date: 2019
Lake George revisited: new evidence for the origin and evolution of a large closed lake, Southern Tablelands, NSW, Australia 2: earliest Pleistocene (Gelasian) environments.
Publisher: Informa UK Limited
Date: 18-05-2016
Shock Melting of the Canyon Diablo Impactor: Constraints from Nickel-59 Contents and Numerical Modeling
Publisher: American Association for the Advancement of Science (AAAS)
Date: 02-07-1999
DOI: 10.1126/SCIENCE.285.5424.85
Abstract: Two main types of material survive from the Canyon Diablo impactor, which produced Meteor Crater in Arizona: iron meteorites, which did not melt during the impact and spheroids, which did. Ultrasensitive measurements using accelerator mass spectrometry show that the meteorites contain about seven times as much nickel-59 as the spheroids. Lower average nickel-59 contents in the spheroids indicate that they typically came from 0.5 to 1 meter deeper in the impactor than did the meteorites. Numerical modeling for an impact velocity of 20 kilometers per second shows that a shell 1.5 to 2 meters thick, corresponding to 16 percent of the projectile volume, remained solid on the rear surface that most of the projectile melted and that little, if any, vaporized.
A precise measurement of the lifetime of the lowest 4+state in22Ne
Publisher: IOP Publishing
Date: 03-1978
Dating ancient wood by high-sensitivity liquid scintillation counting and accelerator mass spectrometry-Pushing the boundaries
Publisher: Elsevier BV
Date: 12-2006
Inter-comparison in 10Be analysis starting from pre-purified quartz
Publisher: Elsevier BV
Date: 06-2007
The decay modes of proton drip-line nuclei with A between 42 and 47
Publisher: Springer Science and Business Media LLC
Date: 06-1992
DOI: 10.1007/BF01291696
Plutonium isotope measurements from across continental Australia
Publisher: Elsevier BV
Date: 2013
Precision Doppler-shift attenuation lifetime measurements in28Si and31P
Publisher: IOP Publishing
Date: 04-1979
Plutonium from Global Fallout Recorded in an Ice Core from the Belukha Glacier, Siberian Altai
Publisher: American Chemical Society (ACS)
Date: 27-10-2004
DOI: 10.1021/ES0492900
Abstract: Ice cores from glaciers situated near anthropogenic sources of air pollution provide important archives of the emissions of species with short atmospheric lifetimes. Here we present the history of atmospheric Pu fallout reconstructed from an ice core from the Belukha glacier in the Siberian Altai. Fourteen ice core s les covering the time period 1941-1986 were selected for Pu analysis, chemically processed, and measured using accelerator mass spectrometry. The Pu concentration peaks in 1963, coinciding with the maximum of the nuclear weapons tests and in concordance with the 3H activity concentration peak. The shapes of the 239Pu and 3H profiles reflect two main periods of atmospheric nuclear test activity: premoratorium testing before 1958 and postmoratorium testing in 1961 and 1962. Premoratorium tests contribute about 45% of the integrated Pu inventory. The average 240Pu/239Pu isotopic ratio is 0.18 +/- 0.05, indicating that a large majority of the Pu in the Belukha glacier originates from global stratospheric fallout rather than from direct tropospheric input.
Using239Pu as a tracer for fine sediment sources in the Daly River, Northern Australia
Publisher: EDP Sciences
Date: 2015
Uranium comparison by means of AMS and ICP-MS and Pu and137Cs results around an Italian Nuclear Power Plant
Publisher: EDP Sciences
Date: 2015
Identification and lifetime determination of the6 +
Publisher: American Physical Society (APS)
Date: 11-1974
New 14C Ages on Cellulose from Diprotodon Gut Contents: Explorations in Oxidation Chemistry and Combustion
Publisher: Cambridge University Press (CUP)
Date: 2008
DOI: 10.1017/S003382220004337X
Abstract: We report radiocarbon ages on cellulose isolated from the gut contents of a Diprotodon found at Lake Callabonna, South Australia. The maximum age obtained corresponds to a minimum age of ,400 BP for this extinct giant marsupial. This is older than, and hence consistent with, the generally accepted Australian megafauna extinction window. We argue that dichromate and other strong oxidants are less selective than chlorite for lignin destruction in wood, and our results suggest that ages approaching laboratory background can be obtained using a repeated pretreatment sequence of chlorite-alkali-acid and measurement of the sometimes discarded 330°C combustion fraction.
Nuclear weapons produced 236U, 239Pu and 240Pu archived in a Porites Lutea coral from Enewetak Atoll
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.JENVRAD.2017.05.009
Abstract: A slice from a Porites Lutea coral core collected inside the Enewetak Atoll lagoon, within 15 km of all major nuclear tests conducted at the atoll, was analysed for
Anthropogenic 236U and Pu at remote sites of the South Pacific
Publisher: Elsevier BV
Date: 09-2019
DOI: 10.1016/J.JENVRAD.2019.05.003
Abstract: Anthropogenic radionuclides, like
Accelerator mass spectrometry and its applications
Publisher: IOP Publishing
Date: 30-07-1999
Redating the onset of burning of Lynch's Crater (North Queensland): Implications for human settlement in Australia
Publisher: Wiley
Date: 2001
DOI: 10.1002/JQS.643
Comment on Absence of Cooling in New Zealand and the Adjacent Ocean During the Younger Dryas Chronozone
Publisher: American Association for the Advancement of Science (AAAS)
Date: 09-05-2008
Abstract: Barrows et al . (Reports, 5 October 2007, p. 86) presented cosmogenic exposure dates and data from an ocean sediment core that challenge evidence for glacier advance in New Zealand during the Younger Dryas event. We use modeling of geomorphic processes to argue that their cosmogenic exposure dates are inconclusive.
High-Spin States in the Continuum. II.Mg
Publisher:
American Physical Society (APS)
Date:
12-1973
Publisher: American Physical Society (APS)
Date: 12-1973
Punctuated eustatic sea-level rise in the early mid-Holocene
Publisher: Geological Society of America
Date: 09-2010
DOI: 10.1130/G31066.1
Comparative optical and radiocarbon dating of laminated Holocene sediments in two maar lakes: Lake Keilambete and Lake Gnotuk, south-western Victoria, Australia
Publisher: Elsevier BV
Date: 06-2012
Radiative decays of unbound high spin states in 24Mg
Publisher: Elsevier BV
Date: 10-1978
Radiative decays of unbound levels in 20Ne
Publisher: Elsevier BV
Date: 1980
Measurements of 59Ni in meteorites by accelerator mass spectrometry
Publisher: Elsevier BV
Date: 10-1993
Hemodynamic Comparison of Stent-Grafts for the Treatment of Aortoiliac Occlusive Disease
Publisher: SAGE Publications
Date: 02-06-2021
DOI: 10.1177/15266028211016431
Abstract: To compare the flow patterns and hemodynamics of the AFX stent-graft and the covered endovascular reconstruction of aortic bifurcation (CERAB) configuration using laser particle image velocimetry (PIV) experiments. Two anatomically realistic aortoiliac phantoms were constructed using polydimethylsiloxane polymer. An AFX stent-graft with a transparent cover made with a new method was inserted into one phantom. A CERAB configuration using Atrium’s Avanta V12 with transparent covers made with a previously established method was inserted into the other phantom, both modified stent-grafts were suitable for laser PIV, enabling visualization of the flow fields and quantification of time average wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT). Disturbed flow was observed at the bifurcation region of the AFX, especially at the end systolic velocity (ESV) time-point where recirculation was noticeable due to vortical flow. In contrast, predominantly unidirectional flow was observed at the CERAB bifurcation. These observations were confirmed by the quantified hemodynamic results from PIV analysis where mean TAWSS of 0.078 Pa (range: 0.009–0.242 Pa) was significantly lower in AFX as compared with 0.229 Pa (range: 0.013–0.906 Pa) for CERAB (p .001). Mean OSI of 0.318 (range: 0.123–0.496) in AFX was significantly higher than 0.252 (range: 0.055–0.472) in CERAB (p .001). Likewise, mean RRT of 180 Pa −1 (range: 9–3603 Pa −1 ) in AFX was also significantly higher than 88 Pa −1 (range: 2–840 Pa −1 ) in CERAB (p=0.0086). In this in vitro study, the flow pattern of a modified AFX stent-graft was found to be more disturbed especially at the end systolic phase, its hemodynamic outcomes less desirable than CERAB configuration. While the AFX stent-graft has an advantage over the CERAB configuration in eliminating radial mismatch, and maintaining the anatomical bifurcation for future endovascular intervention, this in vitro study revealed that the associated lower TAWSS, higher OSI and RRT may predispose to thrombosis and are, thus, less desirable as compared to a CERAB configuration. Further investigation is warranted to confirm whether these findings translate into the clinical setting.
Late Pleistocene glaciation of the Mt Giluwe volcano, Papua New Guinea
Publisher: Elsevier BV
Date: 09-2011
Assessment of recharge to groundwater systems in the arid southwestern part of Northern Territory, Australia, using chlorine-36
Publisher: Springer Science and Business Media LLC
Date: 08-1999
Biological chemistry of aluminium studied using 26Al and accelerator mass spectrometry
Publisher: Elsevier BV
Date: 06-1994
A novel beam focus control at the entrance to the ANU 14UD accelerator
Publisher: EDP Sciences
Date: 2013
Determination of total I and129I concentrations in freshwater of Argentina
Publisher: EDP Sciences
Date: 2013
Backgrounds and blanks in Iodine-129 measurements at the Australian National University
Publisher: Elsevier BV
Date: 11-2022
AMS measurements of cosmogenic and supernova-ejected radionuclides in deep-sea sediment cores
Publisher: EDP Sciences
Date: 2013
The 40Ar(13C, 14O)39S reaction and the ground-state mass of 39S
Publisher: Elsevier BV
Date: 06-1989
Accelerator mass spectrometry measurement of 240Pu/239Pu isotope ratios in Novaya Zemlya and Kara Sea sediments
Publisher: Elsevier BV
Date: 08-2004
Continuous transport of Pacific-derived anthropogenic radionuclides towards the Indian Ocean
Publisher: Springer Science and Business Media LLC
Date: 17-03-2017
DOI: 10.1038/SREP44679
Abstract: Unusually high concentrations of americium and plutonium have been observed in a sediment core collected from the eastern Lombok Basin between Sumba and Sumbawa Islands in the Indonesian Archipelago. Gamma spectrometry and accelerator mass spectrometry data together with radiometric dating of the core provide a high-resolution record of ongoing deposition of anthropogenic radionuclides. A plutonium signature characteristic of the Pacific Proving Grounds (PPG) dominates in the first two decades after the start of the high yield atmospheric tests in 1950’s. Approximately 40–70% of plutonium at this site in the post 1970 period originates from the PPG. This sediment record of transuranic isotopes deposition over the last 55 years provides evidence for the continuous long-distance transport of particle-reactive radionuclides from the Pacific Ocean towards the Indian Ocean.
Mass and abundance 236U sensitivities at CIRCE
Publisher: Elsevier BV
Date: 10-2015
Cl/Br ratios and environmental isotopes as indicators of recharge variability and groundwater flow: An example from the southeast Murray Basin, Australia
Publisher: Elsevier BV
Date: 07-2006
A comparison of fallout 236U and 239Pu uptake by Australian vegetation
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.JENVRAD.2015.06.021
Abstract: The isotopes (236)U and (239)Pu, both produced during nuclear weapons tests carried out in the 1950s and 1960s, are present in the environment and may be used as tracers for soil erosion studies. Although these radionuclides occur only at ultra-trace levels in nature, they can be readily measured by accelerator mass spectrometry with the 14UD heavy ion accelerator at the Australian National University. We have analysed a series of vegetation s les for their (236)U and (239)Pu concentration and compared the results with those found in the surrounding soil. (236)U could be measured in all collected s les whereas (239)Pu could not be detected in several vegetation s les due to its very low concentration, although it was readily detectable in the soil. We find that, relative to plutonium, (236)U is preferentially taken up by plants with enrichment factors ((236)U/(239)Pu)veg/((236)U/(239)Pu)soil that range between 7 and 52 in the present study.
Transport and accumulation of actinide elements in the near-shore environment: field and modelling studies
Publisher: Wiley
Date: 02-2006
A new fast-cycling system for AMS at ANU
Publisher: Elsevier BV
Date: 10-2015
236U and 239,240Pu ratios from soils around an Australian nuclear weapons test site
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.JENVRAD.2015.06.020
Abstract: The isotopes (236)U, (239)Pu and (240)Pu are present in surface soils as a result of global fallout from nuclear weapons tests carried out in the 1950's and 1960's. These isotopes potentially constitute artificial tracers of recent soil erosion and sediment movement. Only Accelerator Mass Spectrometry has the requisite sensitivity to measure all three isotopes at these environmental levels. Coupled with its relatively high throughput capabilities, this makes it feasible to conduct studies of erosion across the geographical extent of the Australian continent. In the Australian context, however, global fallout is not the only source of these isotopes. As part of its weapons development program the United Kingdom carried out a series of atmospheric and surface nuclear weapons tests at Maralinga, South Australia in 1956 and 1957. The tests have made a significant contribution to the Pu isotopic abundances present in the region around Maralinga and out to distances ∼1000 km, and impact on the assessment techniques used in the soil and sediment tracer studies. Quantification of the relative fallout contribution derived from detonations at Maralinga is complicated owing to significant contamination around the test site from numerous nuclear weapons safety trials that were also carried out around the site. We show that (236)U can provide new information on the component of the fallout that is derived from the local nuclear weapons tests, and highlight the potential of (236)U as a new fallout tracer.
Timing and dynamics of Late Wolstonian Substage ‘Moreton Stadial’ (MIS 6) glaciation in the English West Midlands, UK
Publisher: The Royal Society
Date: 06-2022
DOI: 10.1098/RSOS.220312
Abstract: Glaciation during the late Middle Pleistocene is widely recognized across continental northwest Europe, but its extent and palaeoenvironmental significance in the British Isles are disputed. Although glaciogenic sediments at Wolston, Warwickshire, in the English West Midlands, have been used to define the stratotype of the Wolstonian Stage, their age has been variably assigned between marine isotope stages (MIS) 12 and 6. Here we present sedimentological and stratigraphical observations from five sites across the English West Midlands whose chronology is constrained by new luminescence ages from glaciofluvial sediments, supplemented by cosmogenic 36 Cl exposure dating of erratic boulders. The ages suggest that between 199 ± 5 and 147 ± 2.5 ka the British Ice Sheet advanced into the English West Midlands as far south as Moreton-in-Marsh, Gloucestershire. This advance is assigned to the Moreton Stadial of the Late Wolstonian Substage. Dating of the glaciation to this substage allows correlation of the Moreton Stadial glacial deposits in the English West Midlands with those of the Drenthe Stadial during the Late Saalian Substage across continental northwest Europe.
Quality assurance in accelerator mass spectrometry: Results from an international round-robin exercise for 10Be
Publisher: Elsevier BV
Date: 10-2012
Differences in groundwater and chloride residence times in saline groundwater: The Barwon River Catchment of Southeast Australia
Publisher: Elsevier BV
Date: 02-2017
Scavenger hunt: Searching for the optimal target material for low-level 210Pb accelerator mass spectrometry
Publisher: Elsevier BV
Date: 10-2022
New dating method: Groundwater residence time estimated from the4He accumulation rate calibrated by using cosmogenic and subsurface-produced36Cl
Publisher: EDP Sciences
Date: 2012
Nuclear Forensics: A Methodology Applicable to Nuclear Security and to Non-Proliferation
Publisher: IOP Publishing
Date: 23-09-2011
Aluminium and Alzheimer's disease: sites of aluminium binding in human neuroblastoma cells determined using 26Al and accelerator mass spectrometry
Publisher: Elsevier BV
Date: 06-1994
The production of isotopic 36S targets by ion implantation into carbon foils
Publisher: Elsevier BV
Date: 03-1990
Exposure dating and glacial reconstruction at Mt. Field, Tasmania, Australia, identifies MIS 3 and MIS 2 glacial advances and climatic variability
Publisher: Wiley
Date: 2006
DOI: 10.1002/JQS.989
Limits on Supernova-Associated
Fe
Publisher:
American Physical Society (APS)
Date:
27-11-2018
Publisher: American Physical Society (APS)
Date: 27-11-2018
Concentration and characterization of plutonium in soils of Hubei in central China
Publisher: Elsevier BV
Date: 2010
DOI: 10.1016/J.JENVRAD.2009.08.011
Abstract: To study the Pu concentration and isotope ratio distributions present in China, the (239+240)Pu total activities and (240)Pu/(239)Pu atom ratios in core soil s les from Hubei Province in central China were investigated using Accelerator Mass Spectrometry (AMS). The activities ranged from 0.019 to 0.502 mBqg(-1) and the (239+240)Pu inventories of 45 and approximately 55 Bqm(-2) agree well with that expected from global fallout. The (240)Pu/(239)Pu atom ratios in the soil ranged from 0.172 to 0.220. The ratios are similar to typical global fallout values. Hence, any close-in fallout contribution from the Chinese nuclear weapons tests, mainly conducted in the 1970s, must have either been negligible or had a similar (240)Pu/(239)Pu ratio to that of global fallout. The top 10 cm layer of the soil contributes approximately 90% of the total inventory and the maximum concentrations appeared in the 2-4 cm or 4-6 cm layers. It is suggested that climatic conditions and organic content are the two main factors that affect the vertical migration of plutonium in soil.
The carbon isotope composition of organic matter occluded in iron nodules
Publisher: Elsevier BV
Date: 06-1994
Geomorphic and cosmogenic nuclide constraints on escarpment evolution in an intraplate setting, Darling Escarpment, Western Australia
Publisher: Wiley
Date: 10-03-2011
DOI: 10.1002/ESP.2058
Decoupling of solutes and water in regional groundwater systems: The Murray Basin, Australia
Publisher: Elsevier BV
Date: 09-2017
A study of soil erosion rates using 239Pu, in the wet-dry tropics of northern Australia
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.JENVRAD.2019.106085
Abstract: The Daly River drains a large (52500 km
Origin of artificial radionuclides in soil and sediment from North Wales
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.JENVRAD.2015.10.013
Abstract: During the operations at the Sellafield nuclear fuel reprocessing complex, artificial radionuclides are discharged to the Irish Sea under authorisation, where they are dispersed. In this study, the southern distribution and transport of Sellafield derived radionuclides have been investigated. Both natural and artificial radionuclides have been studied in a soil core from the riverbank of the Afon Goch in Anglesey, North Wales. Particulate input is dominant for all artificial radionuclides (including the more soluble (137)Cs and (236)U) with an estimated lag time of about a decade. The preferential northward seawater movement in the NE Irish Sea limits solution input of (137)Cs and (236)U to the areas south of Sellafield. The relatively long lag time reflects both the water circulation pattern and distance between the study site in north Wales and the source point in Cumbria. Two redox active zones are observed in the top and the bottom of this core, although there is no evidence for any redistribution of Pu and natural uranium by these redox processes. However, (236)U, derived from irradiated uranium, showed variable distribution in the core. This could be a potential response to the geochemical conditions, showing that (236)U may be a promising tracer for the environmental processes and a signature of the Sellafield historical discharges of irradiated uranium.
Lifetimes of excited states in40Ar
Publisher: IOP Publishing
Date: 02-1976
Campo del Cielo iron meteorite: Sample shielding and meteoroid's preatmospheric size
Publisher: Wiley
Date: 02-2002
Interpreting erosion rates from cosmogenic radionuclide concentrations measured in rapidly eroding terrain
Publisher: Wiley
Date: 2007
DOI: 10.1002/ESP.1415
Spin Assignments to Highly Excited States inMg
Publisher:
American Physical Society (APS)
Date:
18-09-1972
Publisher: American Physical Society (APS)
Date: 18-09-1972
Reinterpretation of 36Cl data: physical processes, hydraulic interconnections and age estimates in groundwater systems— discussion
Publisher: Elsevier BV
Date: 11-1993
A study of the15N(α,γ)19F reaction for bombarding energies between 5.2 and 8.4 MeV. I. Yield curves and γ decay schemes
Publisher: IOP Publishing
Date: 03-1978
Uranium beam characterization at CIRCE for background and contamination determinations
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.APRADISO.2015.06.011
Abstract: The Accelerator Mass Spectrometry (AMS) is the most sensitive technique, compared either to the Inductively Coupled Plasma (ICP-MS) or Thermal Ionization (TI-MS) mass spectrometer, for the actinide (e.g. (236)U, (x)Pu isotopes) measurements. They are present in environmental s les at the ultra trace level since atmospheric tests of Nuclear Weapons (NWs) performed in the past, deliberate dumping of nuclear waste, nuclear fuel reprocessing, on a large scale, and operation of Nuclear Power Plants (NPPs), on a small scale, have led to the release of a wide range of radioactive nuclides in the environment. At the Center for Isotopic Research on Cultural and Environmental heritage (CIRCE) in Caserta, Italy, an upgraded actinide AMS system, based on a 3-MV pelletron tandem accelerator, has been developed and routinely operated. At CIRCE a charge state distribution as a function of terminal voltage, the beam emittance, measured in the 20° actinides dedicated beam line, as well as the energy and position validation of the U ions were performed in order to determine the best measurement conditions. A (236)U/(238)U isotopic ratio background level of about 5×10(-12) or 3×10(-13), depending on the Time of Flight-Energy (TOF-E) configurations, as well as the spatial distribution of the (235)U, (238)U interferences ions and a (236)U contamination mass of about 0.5 fg have been determined.
Tectonic and climatic controls of denudation rates in active orogens: The San Bernardino Mountains, California
Publisher: Elsevier BV
Date: 06-2010
Cosmogenic Chlorine-36 Production in Calcite by Muons
Publisher: Elsevier BV
Date: 02-1998
Cosmogenic exposure dating constraints for coastal landslide evolution on the Island of Malta (Mediterranean Sea)
Publisher: Springer Science and Business Media LLC
Date: 27-09-2017
Sources of chloride and implications for 36 Cl dating of old groundwater, Southwestern Great Artesian Basin, Australia
Publisher: American Geophysical Union (AGU)
Date: 02-2000
DOI: 10.1029/2000WR900019
The bioavailability of26Al-labelled aluminium citrate and aluminium hydroxide in volunteers
Publisher: Springer Science and Business Media LLC
Date: 07-1996
DOI: 10.1007/BF00817919
The ANU AMS system and research program
Publisher: Elsevier BV
Date: 06-1994
Holocene lake-level fluctuations in Lakes Keilambete and Gnotuk, southwestern Victoria, Australia
Publisher: SAGE Publications
Date: 06-02-2013
Abstract: Reconstructed Holocene lake-level curves from two saline, hydrologically closed maar crater lakes in southwestern Victoria, Australia, show near synchronous lake-level changes throughout the Holocene. We show that lake levels, reconstructed from sediment particle size and ostracod valve chemistry (δ 18 O and Sr/Ca) have undergone rapid ( yr), large ( m) fluctuations throughout the Holocene. Finer s ling resolution shows a more sensitive response to Holocene climate than was previously presented for Lake Keilambete. Both maar crater lakes show a short-lived maximum in Holocene lake levels around 7.2 ka. The period of lake filling leading to peak lake levels matches the phase of most effective precipitation (7.4–7.0 ka) reconstructed from a high-resolution speleothem record from northern Tasmania. Water levels declined in both lakes during the mid Holocene, with a more substantive decline after ~5 ka which coincides with the end of the Southern Hemisphere hypsithermal. Water levels continued to oscillate with a periodicity of around 300–700 years, before reaching a late-Holocene nadir around 1.8 ka (Keilambete) and 1.3 ka (Gnotuk). The trend and periodicity of oscillations in the maar water levels show commonalities to δD in the Dome C ice core, and suggest that temperature may be a significant component in influencing the Precipitation/Evaporation (P/E) ratio in southeastern Australia during the Holocene.
European roe deer antlers as an environmental archive for fallout 236U and 239Pu
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.JENVRAD.2015.06.008
Abstract: Anthropogenic (236)U and (239)Pu were measured in European roe deer antlers hunted between 1955 and 1977 which covers and extends beyond the period of intensive nuclear weapons testing (1954-1962). The antlers were hunting trophies, and hence the hunting area, the year of shooting and the approximate age of each animal is given. Uranium and plutonium are known to deposit in skeletal tissue. Since antler histology is similar to bone, both elements were expected in antlers. Furthermore, roe deer shed their antlers annually, and hence antlers may provide a time-resolved environmental archive for fallout radionuclides. The radiochemical procedure is based on a Pu separation step by anion exchange (Dowex 1 × 8) and a subsequent U purification by extraction chromatography using UTEVA(®). The s les were measured by Accelerator Mass Spectrometry at the VERA facility (University of Vienna). In addition to the (236)U and (239)Pu concentrations, the (240)Pu/(239)Pu isotopic ratios were determined with a mean value of 0.172 ± 0.023 which is in agreement with the ratio of global fallout (∼0.18). Rather high (236)U/(238)U ratios of the order of 10(-6) were observed. These measured ratios, where the (236)U arises only from global fallout, have implications for the use of the (236)U/(238)U ratio as a fingerprint for nuclear accidents or releases from nuclear facilities. Our investigations have shown the potential to use antlers as a temporally resolved archive for the uptake of actinides from the environment.
Radiocarbon dating of organic- and carbonate-carbon in Genyornis and Dromaius eggshell using stepped combustion and stepped acidification
Publisher: Elsevier BV
Date: 07-2003
Measurement of 237Np in environmental water samples by accelerator mass spectrometry
Publisher: Royal Society of Chemistry (RSC)
Date: 2001
DOI: 10.1039/B007493O
Abstract: Accelerator mass spectrometry (AMS) was used to measure 237Np in environmental water s les extracted from Irish Sea sediments. The s les were of limited volume (approximately 700 ml) and of low activity (0.06-0.79 mBq l-1 2.30-30.3 pg l-1). AMS proved to have the required sensitivity for measuring these s les, and was in principle capable of measuring much smaller amounts, as low as 0.4 microBq (3.9 x 10(7) atoms). However, the background level in the procedural blanks showed that there was a systematic low level 237Np contamination of each s le, arising from the 239Np yield monitor used in the separations procedure, which effectively increased the detection limit of these analyses.
129I Dispersion in Argentina: Concentrations in Fresh and Marine Water and Deposition Fluences in Patagonia
Publisher: American Chemical Society (ACS)
Date: 23-08-2013
DOI: 10.1021/ES400610H
Abstract: Measurements of total iodine (I) and iodine-129 ((129)I) concentrations in rivers and lakes of Argentina are presented. Their latitudinal distribution can be explained by taking into account their main sources (oceanic emissions and biomass burning for I, and atmospheric nuclear tests for (129)I), transport mechanisms, and fallout patterns. From the measured (129)I concentrations in the studied lakes, deposition fluences for their catchment areas were estimated. These results agree with a model of the global deposition pattern due to the (129)I released by atmospheric nuclear weapon tests and with other fluences reported for the southern hemisphere. In addition, the first measurements of (129)I in shallow seawater from the South Atlantic Ocean are presented and discussed.
High-spin negative parity states in 19F
Publisher: Elsevier BV
Date: 05-1977
Eroding Australia: rates and processes from Bega Valley to Arnhem Land
Publisher: Geological Society of London
Date: 2010
DOI: 10.1144/SP346.12
Constraining groundwater flow, residence times, inter-aquifer mixing, and aquifer properties using environmental isotopes in the southeast Murray Basin, Australia
Publisher: Elsevier BV
Date: 09-2012
Carbon isotope evidence for changes in Antarctic Intermediate Water circulation and ocean ventilation in the southwest Pacific during the last deglaciation.
Publisher: American Geophysical Union (AGU)
Date: 10-11-2004
DOI: 10.1029/2004PA001047
A revised chronology of the lowest occupation layer of Pedra Furada Rock Shelter, Piauı́, Brazil: the Pleistocene peopling of the Americas
Publisher: Elsevier BV
Date: 11-2003
239Pu fallout across continental Australia: Implications on 239Pu use as a soil tracer
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.JENVRAD.2017.08.009
Abstract: At present there is a need for the development of new radioisotopes for soil erosion and sediment tracing especially as fallout
A study of states in 57Co via the reaction 56Fe(7Li, 6He)57Co at 38 MeV
Publisher: Elsevier BV
Date: 08-1987
Tectonic uplift, threshold hillslopes, and denudation rates in a developing mountain range
Publisher: Geological Society of America
Date: 2007
DOI: 10.1130/G23641A.1
Accelerator mass spectrometry of the actinides
Publisher: Elsevier BV
Date: 08-2008
Investigation of an 8p-4h state at Ex = 12.44 MeV in 20Ne
Publisher: Elsevier BV
Date: 12-1981
An inflection in the rate of early mid-Holocene eustatic sea-level rise: A new sea-level curve from Singapore
Publisher: Elsevier BV
Date: 02-2007
Along-strike variation in catchment morphology and cosmogenic denudation rates reveal the pattern and history of footwall uplift, Main Gulf Escarpment, Baja California
Publisher: Geological Society of America
Date: 17-02-2017
DOI: 10.1130/B31373.1
Applicability of 239Pu as a tracer for soil erosion in the wet-dry tropics of northern Australia
Publisher: Elsevier BV
Date: 2013
Reply to Watchman, Taçon and Aubert
Publisher: Elsevier BV
Date: 05-2014
Study of 51Ca via three-neutron transfer
Publisher: Elsevier BV
Date: 11-1988
The release and persistence of radioactive anthropogenic nuclides
Publisher: Geological Society of London
Date: 2014
DOI: 10.1144/SP395.15
Long-range tropospheric transport of uranium and plutonium weapons fallout from Semipalatinsk nuclear test site to Norway
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.ENVINT.2013.05.017
Abstract: A combination of state-of-the-art isotopic fingerprinting techniques and atmospheric transport modelling using real-time historical meteorological data has been used to demonstrate direct tropospheric transport of radioactive debris from specific nuclear detonations at the Semipalatinsk test site in Kazakhstan to Norway via large areas of Europe. A selection of archived air filters collected at ground level at 9 stations in Norway during the most intensive atmospheric nuclear weapon testing periods (1957-1958 and 1961-1962) has been screened for radioactive particles and analysed with respect to the concentrations and atom ratios of plutonium (Pu) and uranium (U) using accelerator mass spectrometry (AMS). Digital autoradiography screening demonstrated the presence of radioactive particles in the filters. Concentrations of (236)U (0.17-23nBqm(-3)) and (239+240)Pu (1.3-782μBqm(-3)) as well as the atom ratios (240)Pu/(239)Pu (0.0517-0.237) and (236)U/(239)Pu (0.0188-0.7) varied widely indicating several different sources. Filter s les from autumn and winter tended to have lower atom ratios than those s led in spring and summer, and this likely reflects a tropospheric influence in months with little stratospheric fallout. Very high (236)U, (239+240)Pu and gross beta activity concentrations as well as low (240)Pu/(239)Pu (0.0517-0.077), (241)Pu/(239)Pu (0.00025-0.00062) and (236)U/(239)Pu (0.0188-0.046) atom ratios, characteristic of close-in and tropospheric fallout, were observed in filters collected at all stations in Nov 1962, 7-12days after three low-yield detonations at Semipalatinsk (Kazakhstan). Atmospheric transport modelling (NOAA HYSPLIT_4) using real-time meteorological data confirmed that long range transport of radionuclides, and possibly radioactive particles, from Semipalatinsk to Norway during this period was plausible. The present work shows that direct tropospheric transport of fallout from atmospheric nuclear detonations periodically may have had much larger influence on radionuclide air concentrations and deposition than previously anticipated.
β
Publisher:
American Physical Society (APS)
Date:
08-1975
Publisher: American Physical Society (APS)
Date: 08-1975
Radiative decays of unbound high-spin states in 24Mg (II)
Publisher: Elsevier BV
Date: 06-1979
Gamma-ray decaying states at high excitation in 20Ne
Publisher: Elsevier BV
Date: 02-1987
Accelerator mass spectrometry at the Australian National University's 14UD accelerator: experience and developments
Publisher: Elsevier BV
Date: 12-1990
MicroRNA-mediated immune regulation in rheumatic diseases
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.CANLET.2018.05.044
Abstract: MicroRNAs (miRNAs) are endogenous small, non-coding RNAs that regulate genome expression at the post-transcriptional level. They are involved in a wide range of physiological processes including the maintenance of immune homeostasis and normal function. Accumulating evidence from animal studies show that alterations in pan or specific miRNA expression would break immunological tolerance, leading to autoimmunity. Differential miRNA expressions have also been documented in patients of many autoimmune disorders. In this review, we highlight the evidence that signifies the critical role of miRNAs in autoimmunity, specifically on their regulatory roles in the pathogenesis of several rheumatic diseases including systemic lupus erythematosus, rheumatoid arthritis and spondyloarthritis. The potential of miRNAs as biomarkers and therapeutic targets is also discussed. Manipulation of dysregulated miRNAs in vivo through miRNA delivery or inhibition offers promise for new therapeutic strategies in treating rheumatic diseases.
Observations of 20n via the heavy-ion transfer reaction 48Ca(18O, 20N)46Sc
Publisher: Elsevier BV
Date: 1989
Using fallout plutonium as a probe for erosion assessment
Publisher: Elsevier BV
Date: 10-2011
DOI: 10.1016/J.JENVRAD.2010.06.010
Abstract: A study has been carried out to assess the potential of using fallout plutonium (Pu), which originated from atmospheric nuclear-weapons tests, as a tool to investigate recent erosional processes within the lower Cotter water-supply catchment in the Australian Capital Territory. This catchment, which was predominantly pine plantation, was severely affected by a major bush fire in 2003. Accelerator mass spectrometry has been used to measure Pu in soil s les collected from a number of sites across the catchment. The results indicate that less than 1cm of surface soil had been lost since the early 1960s over much of the catchment. Areas of more erodible soil have, however, lost 2-4cm of topsoil, and a loss of ∼6cm of soil was identified at one particular site.
Geochemistry of artificial actinide isotopes in west Cumbrian sediments
Publisher: Informa UK Limited
Date: 11-2002
Exposure-age constraints on the extent, timing and rate of retreat of the last Irish Sea ice stream
Publisher: Elsevier BV
Date: 07-2010
Accelerator mass spectrometry of long-lived heavy radionuclides
Publisher: Elsevier
Date: 2008
Geochemical changes recorded in Lynch's Crater, Northeastern Australia, over the past 50 ka
Publisher: Elsevier BV
Date: 04-2006
Study of 19N and 21O by multinucleon transfer
Publisher: Elsevier BV
Date: 10-1989
Exposure history of the Torino meteorite
Publisher: Wiley
Date: 03-1996
Transport of low 240Pu/239Pu atom ratio plutonium-species in the Ob and Yenisey Rivers to the Kara Sea
Publisher: Elsevier BV
Date: 11-2006
Silicon-32 as a tool for dating the recent past
Publisher: Elsevier BV
Date: 10-2009
Applications of accelerator mass spectrometry: advances and innovation
Publisher: Elsevier BV
Date: 08-2004
Chronology of Pu isotopes and 236U in an Arctic ice core
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.SCITOTENV.2013.05.054
Abstract: In the present work, state of the art isotopic fingerprinting techniques are applied to an Arctic ice core in order to quantify deposition of U and Pu, and to identify possible tropospheric transport of debris from former Soviet Union test sites Semipalatinsk (Central Asia) and Novaya Zemlya (Arctic Ocean). An ice core chronology of (236)U, (239)Pu, and (240)Pu concentrations, and atom ratios, measured by accelerator mass spectrometry in a 28.6m deep ice core from the Austfonna glacier at Nordaustlandet, Svalbard is presented. The ice core chronology corresponds to the period 1949 to 1999. The main sources of Pu and (236)U contamination in the Arctic were the atmospheric nuclear detonations in the period 1945 to 1980, as global fallout, and tropospheric fallout from the former Soviet Union test sites Novaya Zemlya and Semipalatinsk. Activity concentrations of (239+240)Pu ranged from 0.008 to 0.254 mBq cm(-2) and (236)U from 0.0039 to 0.053 μBq cm(-2). Concentrations varied in concordance with (137)Cs concentrations in the same ice core. In contrast to previous published results, the concentrations of Pu and (236)U were found to be higher at depths corresponding to the pre-moratorium period (1949 to 1959) than to the post-moratorium period (1961 and 1962). The (240)Pu/(239)Pu ratio ranged from 0.15 to 0.19, and (236)U/(239)Pu ranged from 0.18 to 1.4. The Pu atom ratios ranged within the limits of global fallout in the most intensive period of nuclear atmospheric testing (1952 to 1962). To the best knowledge of the authors the present work is the first publication on biogeochemical cycles with respect to (236)U concentrations and (236)U/(239)Pu atom ratios in the Arctic and in ice cores.
137Cs, 239+240Pu concentrations and the 240Pu/239Pu atom ratio in a sediment core from the sub-aqueous delta of Yangtze River estuary
Publisher: Elsevier BV
Date: 10-2011
DOI: 10.1016/J.JENVRAD.2010.05.012
Abstract: A sediment core collected from the sub-aqueous delta of the Yangtze River estuary was subjected to analyses of (137)Cs and plutonium (Pu) isotopes. The (137)Cs was measured using γ-spectrometry at the laboratories at the Nanjing University and Pu isotopes were determined with Accelerator Mass Spectrometry (AMS), measurements made at the Australian National University. The results show considerable structure in the depth concentration profiles of the (137)Cs and (239+240)Pu. The shape of the vertical (137)Cs distribution in the sediment core was similar to that of the Pu. The maximum (137)Cs and (239+240)Pu concentrations were 16.21 ± 0.95 mBq/g and 0.716 ± 0.030 mBq/g, respectively, and appear at same depth. The average (240)Pu/(239)Pu atom ratio was 0.238 ± 0.007 in the sediment core, slightly higher than the average global fallout value. The changes in the (240)Pu/(239)Pu atom ratios in the sediment core indicate the presence of at least two different Pu sources, i.e., global fallout and another source, most likely close-in fallout from the Pacific Proving Grounds (PPG) in the Marshall Islands, and suggest the possibility that Pu isotopes are useful as a geochronological tool for coastal sediment studies. The (137)Cs and (239+240)Pu inventories were estimated to be 7100 ± 1200 Bq/m(2) and 407 ± 27 Bq/m(2), respectively. Approximately 40% of the (239+240)Pu inventory originated from the PPG close-in fallout and about 50% has derived from land-origin global fallout transported to the estuary by the river. This study confirms that AMS is a useful tool to measure (240)Pu/(239)Pu atom ratio and can provide valuable information on sedimentary processes in the coastal environment.
Using 3H and 14C to constrain the degree of closed-system dissolution of calcite in groundwater
Publisher: Elsevier BV
Date: 05-2013
Chlorine-36 in groundwater as a palaeoclimatic indicator: the East Midlands Triassic sandstone aquifer (UK)
Publisher: Elsevier BV
Date: 03-1994
Millennial and orbital variations of El Niño/Southern Oscillation and high-latitude climate in the last glacial period
Publisher: Springer Science and Business Media LLC
Date: 03-2004
DOI: 10.1038/NATURE02386
A cyclotron as a powerful tool for mass measurements of exotic nuclei
Publisher: Elsevier BV
Date: 04-1997
A measurement of the mass of 39Sc
Publisher: Elsevier BV
Date: 07-1988
β
Publisher:
American Physical Society (APS)
Date:
10-1974
Publisher: American Physical Society (APS)
Date: 10-1974
Evidence for isovector parity mixing in the 11.264 MeV 1+ T = 1 state in 20Ne
Publisher: Elsevier BV
Date: 02-1983
Development of 231Pa AMS measurements to improve radiological dose assessment from uranium mining and milling
Publisher: Elsevier BV
Date: 2019
CRONUS-Earth calibration samples from the Huancané II moraines, Quelccaya Ice Cap, Peru
Publisher: Elsevier BV
Date: 02-2016
Uplift rates defined by U-series and 14C ages of serpulid-encrusted speleothems from submerged caves near Siracusa, Sicily (Italy)
Publisher: Elsevier BV
Date: 02-2009
The potential of New Zealand kauri (Agathis australis) for testing the synchronicity of abrupt climate change during the Last Glacial Interval (60,000–11,700 years ago)
Publisher: Elsevier BV
Date: 12-2010
Correspondence between glass-FT and 14C ages of silicic pyroclastic flow deposits sourced from Maninjau caldera, west-central Sumatra
Publisher: Elsevier BV
Date: 10-2004
The radiative width of the 8+ member of the Kπ = 2+ band in 24Mg
Publisher: Elsevier BV
Date: 07-1977
Recent near-Earth supernovae probed by global deposition of interstellar radioactive 60Fe
Publisher: Springer Science and Business Media LLC
Date: 06-04-2016
DOI: 10.1038/NATURE17196
Plutonium measurement using accelerator mass spectrometry: Methodology and applications
Publisher: Elsevier
Date: 2001
The mass and low-lying levels of 40Cl
Publisher: Elsevier BV
Date: 04-1984
Concerning high-spin negative parity states in 20Ne
Publisher: Elsevier BV
Date: 05-1973
Plutonium from Mayak: Measurement of Isotope Ratios and Activities Using Accelerator Mass Spectrometry
Publisher: American Chemical Society (ACS)
Date: 14-04-2000
DOI: 10.1021/ES990847Z
An alpha-capture measurement of the radiative width of the first 8+state in20Ne
Publisher: IOP Publishing
Date: 07-1980
Climatic variability in the southwest Pacific during the Last Termination (20-10 kyr BP)
Publisher: Elsevier BV
Date: 05-2006
Analysis of plutonium isotopes in marine samples by radiometric, ICP-MS and AMS techniques
Publisher: Springer Science and Business Media LLC
Date: 2001
Reaction studies of the neutron-rich nuclei 22, 23F
Publisher: Elsevier BV
Date: 1989
Angular correlation and lifetime measurements inNe
Publisher:
American Physical Society (APS)
Date:
04-1976
Publisher: American Physical Society (APS)
Date: 04-1976
Ultra-trace analysis of 36Cl by accelerator mass spectrometry: an interlaboratory study
Publisher: Springer Science and Business Media LLC
Date: 30-04-2011
DOI: 10.1007/S00216-011-4979-2
Abstract: A first international (36)Cl interlaboratory comparison has been initiated. Evaluation of the final results of the eight participating accelerator mass spectrometry (AMS) laboratories on three synthetic AgCl s les with (36)Cl/Cl ratios at the 10(-11), 10(-12), and 10(-13) level shows no difference in the sense of simple statistical significance. However, more detailed statistical analyses demonstrate certain interlaboratory bias and underestimation of uncertainties by some laboratories. Following subsequent remeasurement and reanalysis of the data from some AMS facilities, the round-robin data indicate that (36)Cl/Cl data from two in idual AMS laboratories can differ by up to 17%. Thus, the demand for further work on harmonising the (36)Cl-system on a worldwide scale and enlarging the improvement of measurements is obvious.
Development of a robust 14C chronology for Lynch's crater (North Queensland, Australia) using different pretreatment strategies
Publisher: Cambridge University Press (CUP)
Date: 2001
DOI: 10.1017/S0033822200031611
Abstract: Lynch's Crater in northeastern Australia provides a long, continuous record of environmental change within the Late Quaternary. Here, we present newly determined radiocarbon ages, using acid-base-acid stepped combustion (ABA-SC) and acid-base-wet oxidation stepped combustion (ABOX-SC) pretreatment strategies. The new results largely confirm the original untreated radiocarbon results for the uppermost 9 m of sediments, (ca. 35 ka BP). Below this depth, results from both pretreatment methods are in stratigraphic agreement and extend the dating of the record from 38 ka BP to about 48 ka BP, although an apparent increased sedimentation rate below 12 m is questionable. The scarcity of “charcoal” in several of the s les raises questions regarding the application of ABOX-SC to lake or sw sediments, with evidence for contributions from younger, chemically resistant bacterial carbon along with fine “charcoal” in some s les. However, the extent to which this phenomenon is significant to the final age estimate appears to be s le specific, and is probably dependent upon the length of the wet oxidation step in the pretreatment.
Archaeology and age of a new hominin from Flores in eastern Indonesia
Publisher: Springer Science and Business Media LLC
Date: 10-2004
DOI: 10.1038/NATURE02956
Abstract: Excavations at Liang Bua, a large limestone cave on the island of Flores in eastern Indonesia, have yielded evidence for a population of tiny hominins, sufficiently distinct anatomically to be assigned to a new species, Homo floresiensis. The finds comprise the cranial and some post-cranial remains of one in idual, as well as a premolar from another in idual in older deposits. Here we describe their context, implications and the remaining archaeological uncertainties. Dating by radiocarbon (14C), luminescence, uranium-series and electron spin resonance (ESR) methods indicates that H. floresiensis existed from before 38,000 years ago (kyr) until at least 18 kyr. Associated deposits contain stone artefacts and animal remains, including Komodo dragon and an endemic, dwarfed species of Stegodon. H. floresiensis originated from an early dispersal of Homo erectus (including specimens referred to as Homo ergaster and Homo georgicus) that reached Flores, and then survived on this island refuge until relatively recently. It overlapped significantly in time with Homo sapiens in the region, but we do not know if or how the two species interacted.
14C-AMS as a tool for the investigation of mercury deposition at a remote Amazon location
Publisher: Elsevier BV
Date: 08-2004
Related Organisations
University Of Oxford
Location: United Kingdom of Great Britain and Northern Ireland
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