Crystallography of zirconium hydrides in recrystallized Zircaloy-2 fuel cladding lay electron backscatter diffraction

Precipitation morphology and habit planes of the delta-phase Zr hydrides, which were precipitated within the a-phase matrix grains and along the grain boundaries of recrystallized Zircaloy-2 cladding tube, have been examined by electron backscatter diffraction (EBSD). Radially-oriented hydrides, induced by residual tensile stress, precipitated in the outside region of the cladding, and circumferentially-oriented hydrides in the stress-free middle region of the cladding. The most common crystallographic relationship for both types of the hydrides precipitated at the inter- and intra-granular sites was identical at (0001)(alpha) // {111}(delta), with {1017}(alpha) // {111}(delta) being the occasional exception only for the inter-granular radial hydrides. When tensile stress was loaded, the intra-granular hydrides tended to preferentially precipitate in the grains with circumferential basal pole textures. The inter-granular hydrides tended to preferentially precipitate on the grain faces opposite to tensile axis. The change of prioritization in the precipitation sites for the hydrides due to tensile stress could be explained in terms of the relaxation effect of constrained elastic energy on the terminal solid solubility of hydrogen at hydride precipitation.

Measuring the global burden of disease and epidemiological transitions: 2002-2030

Any planning process for health development ought to be based on a thorough understanding of the health needs of the population. This should be sufficiently comprehensive to include the causes of premature death and of disability, as well as the major risk factors that underlie disease and injury. To be truly useful to inform health-policy debates, such an assessment is needed across a large number of diseases, injuries and risk factors, in order to guide prioritization. The results of the original Global Burden of Disease Study and, particularly, those of its 2000-2002 update provide a conceptual and methodological framework to quantify and compare the health of populations using a summary measure of both mortality and disability: the disability-adjusted life-year (DALY). Globally, it appears that about 5 6 million deaths occur each year, 10. 5 million (almost all in poor countries) in children. Of the child deaths, about one-fifth result from perinatal causes such as birth asphyxia and birth trauma, and only slightly less from lower respiratory infections. Annually, diarrhoeal diseases kill over 1.5 million children, and malaria, measles and HIV/AIDS each claim between 500,000 and 800,000 children. HIV/AIDS is the fourth leading cause of death world-wide (2.9 million deaths) and the leading cause in Africa. The top three causes of death globally are ischaemic heart disease (7.2 million deaths), stroke (5.5 million) and lower respiratory diseases (3.9 million). Chronic obstructive lung diseases (COPD) cause almost as many deaths as HIV/AIDS (2.7 million). The leading causes of DALY, on the other hand, include causes that are common at young ages [perinatal conditions (7. 1 % of global DALY), lower respiratory infections (6.7%), and diarrhoeal diseases (4.7%)] as well as depression (4.1%). Ischaemic heart disease and stroke rank sixth and seventh, retrospectively, as causes of global disease burden, followed by road traffic accidents, malaria and tuberculosis. Projections to 2030 indicate that, although these major vascular diseases will remain leading causes of global disease burden, with HIV/AIDS the leading cause, diarrhoeal diseases and lower respiratory infections will be outranked by COPD, in part reflecting the projected increases in death and disability from tobacco use.

Biodiversity conservation planning tools: Present status and challenges for the future

Species extinctions and the deterioration of other biodiversity features worldwide have led to the adoption of systematic conservation planning in many regions of the world. As a consequence, various software tools for conservation planning have been developed over the past twenty years. These, tools implement algorithms designed to identify conservation area networks for the representation and persistence of biodiversity features. Budgetary, ethical, and other sociopolitical constraints dictate that the prioritized sites represent biodiversity with minimum impact on human interests. Planning tools are typically also used to satisfy these criteria. This chapter reviews both the concepts and technical choices that underlie the development of these tools. Conservation planning problems can be formulated as optimization problems, and we evaluate the suitability of different algorithms for their solution. Finally, we also review some key issues associated with the use of these tools, such as computational efficiency, the effectiveness of taxa and abiotic parameters at choosing surrogates for biodiversity, the process of setting explicit targets of representation for biodiversity surrogates, and