Mechanical properties of BeO-(UTh)O2 dispersion fuels.

Dispersions of (UTh)02 in BeO were fabricated using (UTh)02 particles made from mixed powders of U02 and Th02 or by co-precipitation of U02 and Th02. The behaviour of the dispersions was studied by measuring the modulus of rupture and Young's modulus. Modulus of rupture measurements were made by four-point bending of cylindrical specimens, and Young's modulus was calculated from the deflection of rectangular beams. The out-of-pile control specimens for two irradiation experiments, X121 and X105, were also tested. Examination of matching fracture faces showed that cracks passed through (UTh)02 particles, indicating that they were bonded to the matrix. The results were compared with previous results on BeO-Th02 dispersions. The strength of dispersions of (UTh)02 in BeO decreased with increasing (UTh)02 particle size and increasing (UTh)02 concentration. For dispersions of 1.7 v/o (UTh)02 made from mixed oxides in BeO, the strength increased with increasing temperature while for dispersions of (UTh)02 made by co-precipitation, the strength remained unchanged with temperature up to 500ºC and decreased as the temperature was raised to 1000ºC, Young's modulus decreased with increasing (UTh)02 concentration. Young's modulus of 1.7 v/o (UTh)Oa dispersions remained unchanged up to about 600ºC} then decreased slightly as the temperature was raised to 1000ºC, Increasing the (UTnJOa concentration from 1.7 to 20 v/o displaced the curve to lower values. In general, the behaviour of dispersions of (UTh)02 in BeO was similar to that of ThOa in BeO. The differences in behaviour between dispersions of (UTh)Oa made from mixed oxides and by co-precipitation, observed in modulus of rupture tests, were attributed to variations in matrix grain size caused by iron cexamination of the co-precipitated (UThJOg. It was concluded that to obtain maximum strength, the particle size of the (UThJOg should not exceed 5jj., and the particles should contain no impurity which could cause grain growth in the beryllia matrix

Variation with temperature and porosity, of the moduli rupture and elasticity of standard isostatically pressed and sintered beryllia.

Some properties of isostatically pressed and sintered UOX beryllia, fabricated at Lucas Heights to a grain size of ≤3μ were measured. The modulus of rupture of material of density 2.86 to 2.90 g cm-3 was measured in four-point bending over the temperature range 20ºC to 1000ºC. The data could be represented by the equation: σf = 33,000 - 7.46T p.s.i. The total variance was 19.5 x 10 6 p.s.i. made up of a "within" batch variance, of 15.8 x 10 6 p.s.i. and a "between" batch variance of 3.7 x 10 6 p.s.i. The modulus of rupture at 20ºC was measured on material with a total porosity range of 4 to 35 per cent; the data could be represented by the equation: σ = σ0 exp(-2.44P) p.s.i. The modulus of elasticity was measured in four-point bending on 97-5 per cent, dense material and the data could be represented by the equation: E = (51.45 x 10 6)+(l.264x10 2 T)-(1.442+10-1T2)-(2.595x10-3T3) p.s.i. The modulus of elasticity was measured as a function of porosity in the range 2 to 36.4 per cent. The data could be represented by the equations E = Eo (1-1.47P) x 10 6 p.s.i

Early Jurassic palaeoenvironments in the Surat Basin, Australia - marine incursion into eastern Gondwana

Interpretations of palaeodepositional environments are important for reconstructing Earth history. Only a few maps showing the Jurassic depositional environments in eastern Australia currently exist. Consequently, a detailed understanding of the setting of Australia in Gondwana is lacking. Core, wireline logs, two‐dimensional and three‐dimensional seismic from the Precipice Sandstone and Evergreen Formation in the Surat Basin have been used to construct maps showing the evolution of depositional environments through the Early Jurassic. The results indicate the succession consists of three third‐order sequences (Sequence 1 to Sequence 3) that were controlled by eustatic sea level. The lowstand systems tract in Sequence 1 comprises braidplain deposits, confined to a fairway that parallels the basin centre. The strata were initially deposited in two sub‐basins, with rivers flowing in different orientations in each sub‐basin. The transgressive systems tract of Sequence 1 to lowstand systems tract of Sequence 3 is dominated by fluvio–deltaic systems infilling a single merged basin centre. Finally, the transgressive and highstand systems tracts of Sequence 3 show nearshore environments depositing sediment into a shallow marine basin. In the youngest part of this interval, ironstone shoals are the most conspicuous facies, the thickness and number of which increase towards the north and east. This study interprets a corridor to the open ocean through the Clarence–Moreton Basin, or the Carpentaria and Papuan basins, evidence of which has been eroded. These results challenge a commonly held view that eastern Australia was not influenced by eustasy, and propose a more dynamic palaeogeographic setting comprising a mixture of fluvial, deltaic and shallow marine sedimentary environments. This work can be used to unravel the stratigraphic relationships between Mesozoic eastern Australian basins, or in other basins globally as an analogue for understanding the complex interplay of paralic depositional systems in data poor areas

Multiple Motherhoods: The Effect of the Internalization of Motherhood Ideals on Life Satisfaction

Purpose – This study examined whether life satisfaction varied among women who occupy different motherhood statuses, and if these variations were influenced by differences in women’s internalization of cultural motherhood norms. We distinguished among women as biological mothers, stepmothers, and “double mothers,” who were both biological and stepmothers. We also included two groups of women without children: voluntary childfree and involuntary childless women. Design/methodology/approach – Data were drawn from the National Study of Fertility Barriers and analyzed using OLS regression. Findings – Biological mothers reported greater life satisfaction than women in other motherhood statuses. Accounting for the internalization of motherhood norms, double mothers had significantly lower life satisfaction compared to biological mothers, but voluntary childfree women had significantly greater life satisfaction. More detailed analyses indicated that internalization of cultural norms only appears to influence the life satisfaction of women with biological children. Research limitations/implications – The results suggest that it may not simply be motherhood that affects women’s well-being, but rather that women’s internalization of motherhood ideals, particularly when it corresponds with their motherhood status, significantly impacts well-being. Limitations of this study include small cell sizes for some categories of women where additional distinctions may have been useful, such as lesbian or adoptive mothers. Future work should incorporate diverse family forms and expand on the newly named category “double mothers.” Originality/value – By providing a more nuanced approach to categorizing motherhood status, including identifying double mothers, stepmothers-only, and two groups of childless women, the study added detail that has been overlooked in previous work on well-being

Analyzing Childlessness

Childlessness has been on the rise in many European societies. In Germany, the UK, Austria, the Netherlands, and Switzerland, childlessness has increased starting with the 1950s cohorts. In these countries, about 20 % of the women born around 1965 will remain childless. In southern Europe and the former state-socialist countries of Central and Eastern Europe, the rise in levels of childlessness is a more recent phenomenon. Yet among younger cohorts in these countries, childlessness has reached levels of 15 % or higher. In this introductory chapter, we summarize the long-term trends in childlessness and discuss the differences between European countries in the prevalence of childlessness. We also outline the structure and the logic of this volume

The planform of epeirogeny: vertical motions of Australia during the Cretaceous

Estimates of dynamic motion of Australia since the end of the Jurassic have been made by modeling marine flooding and comparing it with palaeogeographical reconstructions of marine inundation. First, sediment isopachs were back stripped from present-day topography. Dynamic motion was determined by the displacement needed to approximate observed flooding when allowance is made for changes in eustatic sea-level. The reconstructed inundation patterns suggest that during the Cretaceous, Australia remained a relatively stable platform, and flooding in the eastern interior during the Early Cretaceous was primarily the result of the regional tectonic motion. Vertical motion during the Cretaceous was much smaller than the movement since the end of the Cretaceous. Subsidence and marine flooding in the Eromanga and Surat Basins, and the subsequent 500 m of uplift of the eastern portion of the basin, may have been driven by changes in plate dynamics during the Mesozoic. Convergence along the north-east edge of Australia between 200 and 100 Ma coincides with platform sedimentation and subsidence within the Eromanga and Surat Basins. A major shift in the position of subduction at 140 Ma was coeval with the marine incursion into the Eromanga. When subduction ended at 95 Ma, marine inundation of the Eromanga also ended. Subsidence and uplift of the eastern interior is consistent with dynamic models of subduction in which subsidence is generated when the dip angle of the slab decreases and uplift is generated when subduction terminates (i.e. the dynamic load vanishes). Since the end of the Cretaceous, Australia has uniformly subsided by about 250 m with little apparent tilting. This vertical subsidence may have resulted from the northward migration of the continent from a dynamic topography high and geoid low toward lower dynamic topography and a higher geoid.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71983/1/j.1365-2117.1994.tb00076.x.pd

Co-resident Parents and Young People Aged 15–34: Who Does What Housework?

Young adults are now more likely to co-reside with their parents than previous generations, but domestic work patterns among this family type are largely unexplored. This study addresses this issue using Australian Bureau of Statistics Time Use Surveys (1992, 1997, 2006) and Poisson–Gamma regression analyses. It examines patterns in and correlates of domestic labor in two-generation households in which young people aged 15–34 co-reside with their parents (n = 1,946 households comprised of 2,806 young people and 5,129 parents). It differentiates between routine indoor tasks (cooking, cleaning, laundry), non-routine tasks (outdoor work, household management and maintenance, car care) and grocery shopping. Predictors of more time in some domestic activities by young people include being in neither employment nor education/training (NEET), being older, having a single parent and being in a non-English speaking household (young women). Young people being NEET, or female, are associated with less cooking time for mothers, but in the main when young people do perform domestic activities, they do not relieve their parents of those same activities, suggesting more time is spent by the household in total

Growth Dynamics of Australia's Polar Dinosaurs

Analysis of bone microstructure in ornithopod and theropod dinosaurs from Victoria, Australia, documents ontogenetic changes, providing insight into the dinosaurs' successful habitation of Cretaceous Antarctic environments. Woven-fibered bone tissue in the smallest specimens indicates rapid growth rates during early ontogeny. Later ontogeny is marked by parallel-fibered tissue, suggesting reduced growth rates approaching skeletal maturity. Bone microstructure similarities between the ornithopods and theropods, including the presence of LAGs in each group, suggest there is no osteohistologic evidence supporting the hypothesis that polar theropods hibernated seasonally. Results instead suggest high-latitude dinosaurs had growth trajectories similar to their lower-latitude relatives and thus, rapid early ontogenetic growth and the cyclical suspensions of growth inherent in the theropod and ornithopod lineages enabled them to successfully exploit polar regions

African ancestry of New World, Bemisia tabaci-whitefly species

Bemisia tabaci whitefly species are some of the world’s most devastating agricultural pests and plant-virus disease vectors. Elucidation of the phylogenetic relationships in the group is the basis for understanding their evolution, biogeography, gene-functions and development of novel control technologies. We report here the discovery of five new Sub-Saharan Africa (SSA) B. tabaci putative species, using the partial mitochondrial cytochrome oxidase 1 gene: SSA9, SSA10, SSA11, SSA12 and SSA13. Two of them, SSA10 and SSA11 clustered with the New World species and shared 84.8‒86.5% sequence identities. SSA10 and SSA11 provide new evidence for a close evolutionary link between the Old and New World species. Re-analysis of the evolutionary history of B. tabaci species group indicates that the new African species (SSA10 and SSA11) diverged from the New World clade c. 25 million years ago. The new putative species enable us to: (i) re-evaluate current models of B. tabaci evolution, (ii) recognise increased diversity within this cryptic species group and (iii) re-estimate divergence dates in evolutionary time

Bone Marrow Derived Mesenchymal Stem Cells Inhibit Inflammation and Preserve Vascular Endothelial Integrity in the Lungs after Hemorrhagic Shock

Hemorrhagic shock (HS) and trauma is currently the leading cause of death in young adults worldwide. Morbidity and mortality after HS and trauma is often the result of multi-organ failure such as acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), conditions with few therapeutic options. Bone marrow derived mesenchymal stem cells (MSCs) are a multipotent stem cell population that has shown therapeutic promise in numerous pre-clinical and clinical models of disease. In this paper, in vitro studies with pulmonary endothelial cells (PECs) reveal that conditioned media (CM) from MSCs and MSC-PEC co-cultures inhibits PEC permeability by preserving adherens junctions (VE-cadherin and β-catenin). Leukocyte adhesion and adhesion molecule expression (VCAM-1 and ICAM-1) are inhibited in PECs treated with CM from MSC-PEC co-cultures. Further support for the modulatory effects of MSCs on pulmonary endothelial function and inflammation is demonstrated in our in vivo studies on HS in the rat. In a rat “fixed volume” model of mild HS, we show that MSCs administered IV potently inhibit systemic levels of inflammatory cytokines and chemokines in the serum of treated animals. In vivo MSCs also inhibit pulmonary endothelial permeability and lung edema with concurrent preservation of the vascular endothelial barrier proteins: VE-cadherin, Claudin-1, and Occludin-1. Leukocyte infiltrates (CD68 and MPO positive cells) are also decreased in lungs with MSC treatment. Taken together, these data suggest that MSCs, acting directly and through soluble factors, are potent stabilizers of the vascular endothelium and inflammation. These data are the first to demonstrate the therapeutic potential of MSCs in HS and have implications for the potential use of MSCs as a cellular therapy in HS-induced lung injury