3,327 research outputs found
The high temperature creep behavior of oxides and oxide fibers
A thorough review of the literature was conducted on the high-temperature creep behavior of single and polycrystalline oxides which potentially could serve as fiber reinforcements in ceramics or metal matrix applications. Sapphire when oriented with the basal plane perpendicular to the fiber axis (c-axis oriented) is highly creep resistant at temperatures in excess of 1600 C and applied loads of 100 MPa and higher. Pyramidal slip is preferentially activated in sapphire under these conditions and steady-state creep rates in the range of 10(exp -7) to 10 (exp -8)/s were reported. Data on the creep resistance of polycrystalline beryllia suggest that C-axiz oriented single crystal beryllia may be a viable candidate as a fiber reinforcement material; however, the issure of fabricability and moisture sensitivity must be addressed for this material. Yttrium aluminum garnet (YAG) also appears to be a fiber candidate material having a high resistance to creep which is due to it's complex crystal structure and high Peierl resistance. The high creep resistance of garnet suggests that there may be other complex ternary oxides such as single crystal mullite which may also be candidate materials for fiber reinforcements. Finally, CVD and single crystal SiC, although not oxides, do possess a high resistance to creep in the temperature range between 1550 and 1850 C and under stresses of 110 to 220 MPa. From a review of the literature, it appears that for high creep resistant applications sapphire, silicon carbide, yttrium aluminum garnet, mullite, and beryllia are desirable candidate materials which require further investigation
Community environment, cognitive impairment and dementia in later life: results from the Cognitive Function and Ageing Study
Background: Few studies have investigated the impact of the community environment, as distinct from area deprivation, on cognition in later life. This study explores cross-sectional associations between cognitive impairment and dementia and environmental features at the community level in older people. Method: The postcodes of the 2424 participants in the year-10 interview of the Cognitive Function and Ageing Study in England were mapped into small area level geographical units (Lower-layer Super Output Areas) and linked to environmental data in government statistics. Multilevel logistic regression was conducted to investigate associations between cognitive impairment (defined as MMSE3 in GMS-AGECAT) and community level measurements including area deprivation, natural environment, land use mix and crime. Sensitivity analyses tested the impact of people moving residence within the last two years. Results: Higher levels of area deprivation and crime were not significantly associated with cognitive impairment and dementia after accounting for individual level factors. Living in areas with high land use mix was significantly associated with a nearly 60% reduced odds of dementia (OR: 0.4; 95% CI: 0.2, 0.8) after adjusting for individual level factors and area deprivation, but there was no linear trend for cognitive impairment. Increased odds of dementia (OR: 2.2, 95% CI: 1.2, 4.2) and cognitive impairment (OR: 1.4, 95% CI: 1.0, 2.0) were found in the highest quartile of natural environment availability. Findings were robust to exclusion of the recently relocated. Conclusion: Features of land use have complex associations with cognitive impairment and dementia. Further investigations should focus on environmental influences on cognition to inform health and social policies
Community environment, cognitive impairment and dementia in later life: results from the Cognitive Function and Ageing Study
Background: Few studies have investigated the impact of the community environment, as distinct from area deprivation, on cognition in later life. This study explores cross-sectional associations between cognitive impairment and dementia and environmental features at the community level in older people. Method: The postcodes of the 2424 participants in the year-10 interview of the Cognitive Function and Ageing Study in England were mapped into small area level geographical units (Lower-layer Super Output Areas) and linked to environmental data in government statistics. Multilevel logistic regression was conducted to investigate associations between cognitive impairment (defined as MMSE3 in GMS-AGECAT) and community level measurements including area deprivation, natural environment, land use mix and crime. Sensitivity analyses tested the impact of people moving residence within the last two years. Results: Higher levels of area deprivation and crime were not significantly associated with cognitive impairment and dementia after accounting for individual level factors. Living in areas with high land use mix was significantly associated with a nearly 60% reduced odds of dementia (OR: 0.4; 95% CI: 0.2, 0.8) after adjusting for individual level factors and area deprivation, but there was no linear trend for cognitive impairment. Increased odds of dementia (OR: 2.2, 95% CI: 1.2, 4.2) and cognitive impairment (OR: 1.4, 95% CI: 1.0, 2.0) were found in the highest quartile of natural environment availability. Findings were robust to exclusion of the recently relocated. Conclusion: Features of land use have complex associations with cognitive impairment and dementia. Further investigations should focus on environmental influences on cognition to inform health and social policies
Scotland Registry for Ankylosing Spondylitis (SIRAS) – Protocol
Funding SIRAS was funded by unrestricted grants from Pfizer and AbbVie. The project was reviewed by both companies, during the award process, for Scientific merit, to ensure that the design did not compromise patient safety, and to assess the global regulatory implications and any impact on regulatory strategy.Publisher PD
Predicting response to anti-TNFα therapy among patients with axial spondyloarthritis (axSpA) : results from BSRBR-AS
We are grateful to the staff of the British Society for Rheumatology Biologics Register in Axial Spondyloarthritis register and to the recruiting staff at the clinical centres, details of which are available at: https://www.abdn.ac.uk/iahs/research/epidemiology/spondyloarthritis.php#panel1011. We are grateful to Jonathan Lock for commenting on the manuscript. Funding: This work was supported by the British Society for Rheumatology (BSR) who have funded the BSRBR-AS. The BSR received funding for this from Pfizer, AbbVie and UCB. These companies receive advance copies of manuscripts for comments but have no input in to the topics for analysis in the register nor the work involved in undertaking analysis. Analysis of data was supported by the Versus Arthritis/Medical Research Council Centre for Musculoskeletal Health and Work [grant number 20665].Peer reviewe
Evaluation of the McKnight Low Income Single Parent Loan Program: Second Year.
School of Social Work and the Center for Urban and Regional Affairs, University of Minnesota, with funding from the McKnight Foundation
Evaluation of the McKnight Low-Income Single Parent Loan Program.
School of Social Work and the Center for Urban and Regional Affairs, University of Minnesota, with funding from the McKnight Foundation
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Sodium sulfate decomposition in dry atmospheres
Na2SO4 in silicate glass batches is an environmental issue, since it releases SOx upon decomposition. Decomposition of Na2SO4 in different environments is studied by mass-loss measurements combined with evolved gas analysis, and thermochemical modeling. The decomposition experiments are undertaken in dry, pure O2(g), Ar(g), N2(g), and air(g) at 95 kPa total pressure. Thermochemical calculations using the code F*A*C*T predict SO2(g), Na(g), Na2SO4(g), NaO(g), and, in some cases, NO(g) as major emission species. The concentrations of these species increase with temperature. Na2SO4 decomposition initiates at ≈1373 K. Isothermal decomposition exhibits linear behavior with respect to time in 1473 to 1673 Κ range. At 1673 K, the decomposition rate is 24 · 10^-4 mg/(mm2 min) in UHP (ultra-high purity) O2 and 69 · 10^-4 mg/(mm2 min) in UHP N2. Evolved gas analyses identify SO(g)/SO2(g) as the emitted pollutants. In O2-rich atmospheres, SO(g) is a significant product as well as SO2(g). In inert atmospheres, SO2(g) is the sole decomposition product. At 1673 Κ in UHP O2, the concentration is 55 ppm (by volume) for SO(g) and 61 ppm for SO2. At 1673 Κ in UHP N2, SO2(g) concentration is 651 ppm. The decomposition is described by a surface reaction mechanism, in which SOx is generated by surface rearrangement of sulfur-oxygen complexes on the Na2So4 melt surface. Inert atmospheres increase SOx emission by facilitating this rearrangement process. O2-rich atmospheres passivate the melt surface, which favors the emission of lighter molecules such as SO(g)
Real-world evidence of TNF inhibition in axial spondyloarthritis : can we generalise the results from clinical trials?
Funding This work was supported by the British Society for Rheumatology (BSR) who funded the BSRBR-AS. The BSR received funding for this from Pfizer, AbbVie and UCB. These companies receive advance copies of manuscripts for comments but have no input in to the topics for analysis in the register nor the work involved in undertaking analysis. Analysis of data was supported by the Versus Arthritis/Medical Research Council Centre for Musculoskeletal Health and Work (grant number 20665).Peer reviewedPostprin
Land use mix and five-year mortality in later life: Results from the Cognitive Function and Ageing Study.
This study explores the potential modifying effect of age and mediation effect of co-morbidity on the association between land use mix, a measure of neighbourhood walkability, and five-year mortality among the 2424 individuals participating in the year-10 follow-up of the Cognitive Function and Ageing Study in England. Postcodes of participants were mapped onto Lower-layer Super Output Areas, a small area level geographical unit in the UK, and linked to Generalised Land Use data. Cox regression models were fitted to investigate the association. For the younger older age group (75-79 years), the effect of high land use mix on an elevated risk of mortality was mediated by co-morbidity. For older old age groups (80-84, 85+ years), a higher land use mix was directly associated with a 10% lower risk of five-year mortality. The findings suggest differential impacts of land use mix on the health of the younger and older old.Medical Research Council Cognitive Function and Ageing Study (MRC CFAS) was funded by the Department of Health and the Medical Research Council, [Grant number G9901400]; Fiona E Matthews and Matthew Prina are supported by the Medical Research Council [Grant number U105292687 & MR/K021907/1]; Yu-Tzu Wu received a PhD scholarship from Cambridge Trust, University of Cambridge. We thank the participants, their families, general practitioners and their staff, and the primary care trusts for their cooperation and support.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.healthplace.2015.12.00
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