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Interface phenomena in synroc, a titanate-based nuclear waste ceramic
(Elsevier, 1995) Vance, ER; Ball, CJ; Blackford, MG; Day, RA; Lumpkin, GR; Smith, KL; Hart, KP; McGlinn, PJ; Thorogood, GJ
Several aspects of Synroc which fall into the broad class of interface phenomena are discussed. These are radiation damage processes which give rise to interfaces between damage tracks and neighbouring unirradiated material, intergranular films which have deleterious effects on chemical durability, and aqueous leaching of Synroc which takes place primarily at the interface between the solid and groundwater. © 1995 Elsevier B.V.
Uranium VI adsorption on model minerals: controlling factors and surface complexation modeling
(Elsevier, 1998) Payne, TE; Lumpkin, GR; Waite, TD
Uranium VI sorption on ferrihydrite and kaolinite is influenced by a large number of factors, including pH, ionic strength, partial pressure of CO2, adsorbent loading, total amount of U present, and the presence of ligands such as phosphate and humic acid. The effect of complexing ligands may be to enhance or reduce U uptake. The adsorption model being used for ferrihydrite is a surface complexation model with a diffuse double layer, and both strong and weak sites for U sorption. In terms of the amount of U sorbed per gram of adsorbent, U uptake on kaolinites KGa-1 and KGa-1B is much weaker than U uptake on ferrihydrite under similar experimental conditions. Titanium-rich impurity phases play a major role in the sorption of U by these standard kaolinites. Trace impurities and mineral coatings such as ferrihydrite can play a dominant role in determining U sorption in both environmental and model systems. © 1998 Elsevier Inc.
Development of a modular ceramic knee prosthesis
(Humana Press, 2000) Payten, WM; Ben-Nissan, B
Degenerative joint disease, recognized as an increasing problem for society, is a direct result of an aging population (1). When patients present with joint pain, their primary concern is the relief of pain and return to a mobile life style. This often requires replacement of skeletal parts, such as hips, knees, elbows, finger joints, shoulder, and teeth, or fusion of vertebrae, and repair or augmentation of the jaw and bones of the skull. The result is a current worldwide orthopedic market valued at over $5 billion; joint replacement represents 68% of this market. The demand for knee replacements is increasing at approx 17%/yr, with some 300,000 knee joints replaced each year in the United States alone (2). This increase results in part from increased confidence in using such prostheses. Unfortunately, results do not reinforce this confidence: Long-term clinical results are scattered (3), and, although the overall rate of failure is reasonably low, it remains unacceptable. A further complication arises because the increase in younger patients undergoing total knee arthroplasty (TKA) may well lead to a higher incidence of eventual failure. © Springer Science+Business Media New York 2000
Characterisation of natural substrates with regard to application of surface complexation models
(OECD, 2001) Waite, TD; Fenton, BR; Payne, TE; Lumpkin, GR; Davis, JA; McBeath, M
While good correspondence between laboratory sorption data and surface complexation modelling results has been obtained for single oxide phase, much poorer correspondence has been obtained for natural substrates. This result arises, at least in part, from the difficulty in ascertaining the identity of sorbing surfaces and in assigning appropriate values for sorbing surface site concentrations. In an attempt to clarify the nature of possible sorbing phases, we have used a variety of techniques to investigate the surfaces of natural solid substrates from the Koongarra weathered zone. Based on insights gained from the surface characterisation studies, we have then proceeded to assess the applicability of various surface complexation modelling approaches as applied to U(VI) uptake. © 2001 OECD
Mechanical stability of a Ti02 coating deposited on a polycarbonate substrate
(Routledge, 2005) Ignat, M; Getin, S; Latella, BA; Barbé, CJ; Triani, G
The demands imposed on mechanical durability of film-substrate systems in many leading technologies (particularly microelectronics, photonics and biomaterials) are becoming more stringent and, thus, associated problems have to be understood and solved. Film-substrate systems are subjected to internal stresses, caused by thermoelastic mismatch, or to external mechanical stresses applied monotonically or cyclically. When reaching critical levels, these stresses may activate damage mechanisms such as cracking and de-adhesion of the film. Identifying these failures and understanding the critical conditions which cause them is essential, prior to any technological application of the system. © 2005 CRC Press
Radiocarbon dating of Kharosthi fragments from the Schøyen and senior manuscript collections
(Hermes Publishing, 2006) Allon, M; Salomon, R; Jacobsen, GE; Zoppi, U
Slow, patchy landscape evolution in northern Sweden despite repeated ice sheet glaciation
(Geological Society of America, 2006-01-01) Stroeven, AP; Harbor, J; Fabel, D; Kleman, J; Hättestrand, C; Elmore, D; Fink, D; Fredin, O
The conventional assumption that erosion by ice sheets is pervasive and effective in landscape evolution is tested in northern Sweden using geomorphic mapping and cosmogenic nuclide analyses of formerly glaciated surfaces. The following evidence indicates that recent glaciations in this region have produced only slow and patchy landscape evolution: (1) Geomorphic mapping shows that at least 20% of the repeatedly glaciated study region in the northern Swedish mountains has landforms that are relict, i.e., clearly nonglacial in origin. (2) The contrast between cosmogenic apparent exposure ages from relict landforms in the northern Swedish mountains and from overlying glacial erratics and juxtaposed glacially eroded bedrock surfaces, which are consistent with last deglaciation, implies that the relict landforms have been preserved through multiple glacial cycles. (3) Apparent 10Be and 26Al exposure ages for tor summit bedrock surfaces in the northern Swedish lowlands reveal that these relict landforms have survived at least eleven exposure and ten burial events with little or no erosion over the past ∼1 m.y. (4) The northern Swedish lowland and mountains are primarily covered by glacial landforms. However geomorphic mapping suggests that even these landforms may have undergone limited erosion during the last glacial cycle. Cosmogenic 10Be and 36Cl data from what appear to be heavily scoured areas in one glacial corridor indicate erosion of only ∼2 ± 0.4 m of bedrock during the last glaciation. These results suggest that in some areas the overall modification produced by ice sheets may be more restricted than previously thought, or it has occurred preferentially during earlier Quaternary glacial periods. © 2020 GeoScienceWorld
Data report: Radiocarbon dating and sedimentation rates for Holocene-upper Pleistocene sediments, eastern equatorial pacific and Peru continental margin
(International Ocean Discovery Program (IODP), 2006-06-19) Skilbeck, CG; Fink, D
As part of a wider paleoclimate and paleoceanographic study of Holocene–upper Pleistocene laminated sediments from the eastern equatorial Pacific and Peru continental margin, we completed 32 accelerator mass spectrometry (AMS) 14C dates from cores recovered during Ocean Drilling Program (ODP) Leg 201. Sample preparation and measurement were carried out at the ANTARES AMS facility, Australian Nuclear Science and Technology Organisation (ANSTO), in Sydney, Australia (Lawson et al., 2000; Fink et al., 2004). Although the sediments are predominantly diatomaceous oozes (D'Hondt, Jørgensen, Miller, et al., 2003), they contain sufficient inorganic (e.g., foraminifer tests and nannofossil plates) and organic (Meister et al., this volume) carbon to allow 14C dating. These dates permitted us to reconstruct a history of sediment accumulation over the past 20 k.y., particularly on the Peru continental margin.
Characteristic cosmogenic nuclide concentrations in relict surfaces of formerly glaciated regions
(Wiley, 2006-08-21) Stroeven, AP; Harbor, J; Fabel, D; Kleman, J; Hättestrand, C; Elmore, D; Fink, D
This chapter contains sections titled: Significance of relict surfaces Characteristic cosmogenic nuclide concentrations in relict surfaces Conclusions © 2006 by Blackwell Science Ltd
Comparative evaluation of surface complexation models for radionuclide uptake by diverse geologic materials
(Elsevier, 2006-09) Payne, TE; Davis, JA; Ochs, M; Olin, M; Tweed, CJ; Altmann, S; Askarieh, MM
This chapter summaries a major international modelling exercise, co-ordinated by the OECD Nuclear Energy Agency, in which independent scientific teams applied thermodynamic sorption models (TSMs) to a number of experimental adsorption data sets. A wide variety of models was employed to simulate and predict the data. In all the test cases, reasonable, broadly similar TSM approaches were adopted, but based on wide diversity of assumptions and methods of parameter estimation. The models were able to realistically, and with some predictive power, simulate the experimental data for a range of substrates, radionuclides and chemical conditions. However, sorption modelling has not reached a stage approaching standardisation. Basic features such as the stoichiometry and structure of surface complexes and mathematical formulations for such model components as the EDL are subject to debate. In addition, key model input parameters such as site populations are not well defined (particularly for natural substrates). As a result, the numerical values of optimised model parameters are highly model- dependent, which means that, in the present study, it has not been meaningful to compare individual model parameters (such as log K values for surface complexes). If a consensus is reached on model components, and uniform modelling approaches are adopted, it will be appropriate to do such a comparison. Until that time, modellers need to recognise that model parameters can typically not be used directly in other models, but that they need to be scaled or re-fitted. Although the modelling strategies differed among the teams, all were guided by a single principle, representation of sorption in terms of mass action and mass balance laws. The generally satisfactory results of this intercomparison suggest that these types of models have inbuilt chemical plausibility and predictive capabililty. © 2006, Elsevier Ltd.
Mapping the early inflammation process that leads to epilepsy in rodents
(Australian Nuclear Science and Technology Organisation, 2009-01-09) Callaghan, PD; Dedeurwaerdere, S; Grégoire, MC; Pham, TQ; Katsifis, A
Imaging of the living brain using Positron Emission Tomography (PET), a noninvasive, sensitive and quantitative imaging methodology, allows us to investigate neurobiological mechanisms involved in the onset of the neurological disease. Our work has focused on investigating the pre-symptomatic neuroinflammatory processes (called epileptogenesis) that lead development of chronic seizures, in an animal model of epilepsy. We have used our in-house radiotracer (18F-PBR111) which is highly specific for receptors expressed in the inflammatory response within the brain. Performing pre-clinical PET imaging with this radioligand allowed us to map and quantify neuroinflammation in vivo, and to correlate this with full in vitro assessment of the neuroinflammation response. The in vivo ligand binding patterns highly correlate with the structures involved in the generation of seizures, and these data reflect the in vitro data, illustrating that the PET binding represents true neuroinflammation. Thus, longitudinal PET studies will be possible in order to follow-up the evolution of the inflammatory regions during the onset of the disease, and test new preventive therapies that modulate this disease process.
Examining late holocene marine reservoir effect in archaeological fauna at Hope Inlet, Beagle Gulf, North Australia.
(The Australian National University (ANU), 2009-02) Bourke, P; Hua, Q
This study examines the marine reservoir effect during the Late Holocene evolution of a small estuary in the Beagle Gulf (12°S, 131°E). The paper aims at refining the local marine reservoir ages (R) and correction values (ΔR), by 14C analysis of stratigraphically associated archaeological fauna (marine shell, charcoal and fish otoliths) from five proximate middens of different chronologies. The results suggest that a marine reservoir age of 340 ± 70 yrs is applicable to the Beagle Gulf for the Late Holocene, which is not significantly different from that determined for nearby Van Dieman Gulf and the north Australian coast. © 2009, The Australian National University (ANU)
Ecology of burrowing crabs in temperate saltmarsh of south-east Australia
(CSIRO Publishing, 2009-02-01) Mazumder, D
Saltmarshes are considered to be important coastal habitats because of their role in filtering surface water prior to its entering the sea, their contribution to coastal productivity (Morrisey 1995), and because they are a source of organic material and nutrients for a wide range of marine communities (Boorman 1999). One important visual feature of a saltmarsh is the presence of a large number of crab burrows, and this indicates an abundance of crabs within the saltmarsh environment. Crabs inhabiting saltmarshes excavate burrows over extensive areas, profoundly modiyfing the physical structure of the environment (Jones et al. 1994, 1997). The excavation activities of crabs and the resulting burrows may have important ecological significance on ecosystem functioning. Results from a mangrove habitat study found that burial of plant detritus by the excavation activities of sesarmid crabs, or litter directly pulled into their burrows, enhance the heterogeneity and thereby the efficiency of microbial decomposition in subsurface mangrove sediments (Kristensen 2008). Crabs living in the mangrove habitat are relatively well studied compared to those occupying the saltmarsh, and recognised for their role in contributing to the structure and function of mangrove habitats through burrowing and feeding activities (Warren and Underwood, 1986; Smith 1987). Mangrove crabs are also recognised for their role as food for higher-order predators (Robertson 1988) and their contribution to the foodweb through processing of leaf litter into more palatable forms, thereby contributing to nutrient cycling and energy flow (Lee 1995, 1997; Skov and Hartnoll 2002). By contrast very little is known about the ecology of crab species in temperate Australian saltmarsh, and in particular the degree to which saltmarsh crabs support the adjacent estuarine foodwebs. © 2009, CSIRO Publishing
Minerals, ceramics, and glasses.
(CRC Press, 2009-06-24) Smart, RStC; Zhang, Z
The surfaces of minerals and ceramics have many features in common. This statement can be justi- ed by comparison of the nature of the information required from their respective surface analyses [1-3]. Indeed, tailored ceramics often result from judicious design involving combinations of mineral structures [4,5]. Similarities in phase structure and composition, surface structure and surface sites, microstructure, and surface reactivity have been demonstrated in numerous studies. Surface reactions involving oxidation, leaching, dissolution, weathering, precipitation, and phase transformation, are now well documented. Surface modi cation of minerals as a result of adsorption, reaction, processing (e.g., plasma spraying), and surface coatings (e.g., sol-gel deposition), has been found to be equally applicable to ceramic materials. Hence the methodologies for determining the surface properties that control the mechanisms of reaction and transformation of surfaces of minerals and ceramics will in general require similar surface analytical techniques. © 2020 Informa UK Limited
Preparation of inorganic polymer sorbents and their application in radionuclide generator technology
(International Atomic Energy Agency, 2009-07-01) Le, VS; Nguyen, CD; Bui, VC; Vo, CH
Absorbents based on poly zirconium compound (PZC) and poly titanium compound (PTC) were synthesized for the preparation of 188W/188Re generators. The chemical composition, molecular structure and physicochemical characteristics of these adsorbents were investigated. The adsorption properties of PZC and PTC sorbents in different tungstate solutions and the elution performance were investigated. Tungsten adsorption capacities of about 520 mg of tungsten per gram of PZC and 515 mg of tungsten per gram of PTC and a 188Re elution yield greater than 80% for both PZC and PTC sorbents were achieved. A 188Re eluate concentration process was developed by eluting 188Re from the tandem system of 188W-PTC-alumina columns with two different concentrations of saline solution, which gave a concentration factor of about 6. The technology developed can be used for the preparation of clinically applicable 188W/188Re generators using low specfic radioactivity 188W produced in medium flux research reactors. Copyright 2009 © IAEA. All rights reserved
Alkali metal cation and proton conductors: relationships between composition, crystal structure, and properties
(Wiley, 2009-07-15) Avdeev, M; Nalbandyan, VB; Shukaev, IL
This chapter contains sections titled: Principles of Classification, and General Comments; Crystal‐Chemistry Factors Affecting Cationic Conductivity; Crystal Structural Screening and Studies of Conduction Paths; Conductors with Large Alkali Ions; Lithium Ion Conductors; Proton Conductors; References. © 2009 Wiley‐VCH Verlag GmbH & Co. KGaA
10Be concentrations in snow at Law Dome, Antarctica following the 29 October 20 and 20 January 2005 solar cosmic ray events
(World Scientific, 2009-08) Pedro, JB; Smith, AM; Duldig, ML; Klekociuk, AR; Simon, KJ; Curran, MAJ; van Ommen, TD; Fink, D; Morgan, VI; Galton-Fenzi, BK
Recent model calculations have attempted to quantify the contribution of major energetic solar cosmic ray (SCR) events to 10Be production.1,2 In this study we compare modeled 10Be production by SCR events to measured 10Be concentrations in a Law Dome snow pit record. The snow pit record spans 2.7 years, providing a quasi-monthly 10Be sampling resolution which overlaps with the SCR events of 29 Oct 2003 and 20 Jan 2005. These events were calculated to increase monthly 10Be production in the polar atmosphere (>65° S geomagnetic latitude) by ~60% and ~120% above the GCR background, respectively2. A strong peak in 10Be concentrations (>4σ above the 2.7 y mean value) was observed ~1 month after the 20 Jan 2005 event. By contrast, no signal in 10Be concentrations was observed following the weaker 29 Oct 2003 series of events. The concentration of 10Be in ice core records involves interplay between production, transport, and deposition processes. We used a particle dispersion model to assess vertical and meridional transport of aerosols from the lower stratosphere where SCR production of 10Be is expected to occur, to the troposphere from where deposition to the ice sheet occurs. Model results suggested that a coherent SCR production signal could be transported to the troposphere within weeks to months following both SCR events. We argue that only the 20 Jan 2005 SCR event was observed in measured concentrations due to favorable atmospheric transport, relatively high production yield compared to the 29 Oct 2003 event, and a relatively high level of precipitation in the Law Dome region in the month following the event. This result encourages further examination of SCR signals in 10Be ice core data. © 2009 World Scientific Publishing
Social interaction test
(Springer-Verlag Berlin Heidelberg, 2010) Callaghan, PD; McGregor, IS; Thompson, MR
Two animals, typically rats or mice, are placed into an arena and their interactions, for example, investigation, following, and grooming, are recorded for a period of time, usually 5 to 10 min. Social behaviors such as following, adjacent lying, and anogenital sniffing are recorded by an observer or via automated image analysis. Many drugs modulate behavior on the social interaction test: benzodiazepines, MDMA, and oxytocin tend to increase social interaction while amphetamines, cannabinoids, NMDA antagonists, and withdrawal from various drugs of abuse tend to decrease social interaction. In the high-light version of the then test, the arena is brightly illuminated and this creates an aversive situation for the animals, which results in low levels of social interaction. In this configuration, it is possible to identify drugs or manipulations that reduce the inferred level of anxiety in the animals, that is, they result in an increased level of social interaction. In the low-light version, the arena is only illuminated with low, typically red light in order to minimize aversive cues. In this configuration, the level of interaction will be maximal and it is possible to test drugs or manipulations that reduce the normal level of social interactions. In addition to light level, which is the strongest experimental factor, the animals’ familiarity with the arena can be varied, for example, by having been introduced to the arena prior to the testing session, and whether the animals know each other prior to the testing session. Familiarity with the arena will reduce the level of aversive cues, but will also increase the level of territorial behavior, resulting in more fighting between the animals. Familiarity between the animals being tested can reduce the level of aversive cues during the testing situation and the level of fighting, because a hierarchy does not have to be established, but it may also increase variability in the data, because the animals will have a preestablished rank that not will be present if they are unfamiliar to each other. © 2010 Springer-Verlag Berlin Heidelberg
Entactogen
(Springer-Verlag Berlin Heidelberg, 2010) Callaghan, PD; McGregor, IS; Thompson, MR
Entactogens are drugs, including MDMA (Ecstasy) and other MDxx structure compounds, that cause distinctive prosocial, emotional, and sensory effects in users. Most of them are substituted amphetamine compounds of the phenethylamine class. © 2010 Springer-Verlag Berlin Heidelberg
The psychopharmacology of MDMA
(National Drug and Alcohol Research Centre, 2010) Thompson, MR; Callaghan, PD; McGregor, IS
The psychoactive drug 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy, E, XTC) has an interesting history and a fascinating pharmacology. As discussed in Chapter 2, MDMA was first synthesised in 1912 and patented by the company E. Merck in 1914. Although commonly thought to have been designed as an appetite suppressant, the original patent bears no record of this and simply states that MDMA was deemed to contain primary constituents for therapeutically active compounds. The first reported pharmacological study involving MDMA occurred in 1927 although it was of limited scope and basic toxicology studies were not undertaken until the 1950s. Toxicology studies by Merck in 1952 provided little insight into the pharmacology of MDMA focusing on its effects on flies. Further studies at the University of Michigan, supported by the US Army, reported LD values for five different species, the lowest LD value being found in dogs, the highest in mice. As mentioned in Chapters 3 and 13, the first systematic use of MDMA was as an adjunct to insight-oriented psychotherapy4, with administration of MDMA producing an easily controllable altered state of consciousness with positive emotional and sensual overtones. The colloquial term for MDMA changed from “Empathy” as had been used by therapists in the 1970s, to “Ecstasy”, emphasising the drug’s euphoric effects. Heavy media attention in 1985 sensationalised Ecstasy’s euphoric effects. Despite this surge in popularity, the settings in which Ecstasy was used in the middle of the 1980’s typically involved two individuals or a small and intimate group5. This was soon to change with the emergence of the “rave” scene. In 1986, MDMA became a Schedule 1 drug in the USA, deemed to possess no recognised therapeutic value despite claims to the contrary. By the 1990s, ecstasy had became intrinsically linked to the club and rave culture, with use by groups of young people attending all-night dance parties where vigorous dancing occurred to highly repetitive and hypnotic “techno” music. This was thought to have originated in Europe in the late 1980s. Patterns of use in Australia largely mimicked those seen abroad, with dance parties, private parties and nightclubs listed as the most popular venues for use. Its popularity has continued to grow, and the contexts of use broadened. © 2010 NDARC

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