CO2 pipelines material and safety considerations

This paper presents an overview of some of the most important factors and areas of uncertainty affecting integrity and accurate hazard assessment of CO2 pipelines employed as part of the Carbon Capture and Sequestration (CCS) chain. These include corrosion, hydrate formation, hydrogen embrittlement and propensity to fast running ductile and brittle factures. Special consideration is given to the impact of impurities within the CO2 feed from the various capture technologies on these possible hazards. Knowledge gaps in the modelling of outflow and subsequent dispersion of CO2 following the accidental rupture of pressurised CO2 pipelines, central to their safety assessment, are also presented

Infertility problems and mental health symptoms in a community-based sample: depressive symptoms among infertile men, but not women

Most researchers agree that men’s and women’s experiences of infertility are fundamentally different, and impacts upon the nature of psychological distress encountered. However, design flaws, including non-random samples unrepresentative of the general population, compromise many existing studies. Data derived from a random general community sample provides prevalence of current infertility, and permits examination of longitudinal associations between mental health symptoms and infertility among 1,978 participants aged 28-32 years. In the previous 12-months, infertility was experienced by 2.1% and 5.4% partnered men and women. Infertility independently predicted depressive symptomatology in men, and anxiety symptoms among women. Gender differences were sustained, even controlling for prior depression and anxiety. Health professionals are encouraged to proactively enquire about affective symptoms experienced by both women and men with infertility problems

New Zealand farm structure change and intensification

This report presents information about the numbers of farms in New Zealand. The different sources providing such data report very different figures and trends over time, but they all seem to indicate an overall trend of decrease in total farm numbers over the last decades, which appears to be due mainly to a decrease in the numbers of grazing and fattening farms and in the number of arable farms. The distribution of farms by size range over time shows an increase in the proportion of both the smallest and the largest ones, at the expense of the midsized categories. However, different trends can be observed depending on the farm type. The report then explores the change in livestock numbers over time. Thus, during the last 20 years, the main trends consist in an overall decrease in sheep and beef numbers, while dairy and deer numbers increased. To conclude, the report deals with the question of intensification in New Zealand farming systems. It underlines the increase in numbers of cows per hectare and production per cow in the dairy sector, and the increase in lambing rates and carcase weights in the sheep and beef sector. These changes can be linked to the increasing expenditure in agricultural research and development as well as the increasing use of services such as herd testing. Also reported is the growing use of fertilisers in New Zealand agriculture

Engaging Undergraduates in Science Research: Not Just About Faculty Willingness.

Despite the many benefits of involving undergraduates in research and the growing number of undergraduate research programs, few scholars have investigated the factors that affect faculty members' decisions to involve undergraduates in their research projects. We investigated the individual factors and institutional contexts that predict faculty members' likelihood of engaging undergraduates in their research project(s). Using data from the Higher Education Research Institute's 2007-2008 Faculty Survey, we employ hierarchical generalized linear modeling to analyze data from 4,832 science, technology, engineering, and mathematics (STEM) faculty across 194 institutions to examine how organizational citizenship behavior theory and social exchange theory relate to mentoring students in research. Key findings show that faculty who work in the life sciences and those who receive government funding for their research are more likely to involve undergraduates in their research project(s). In addition, faculty at liberal arts or historically Black colleges are significantly more likely to involve undergraduate students in research. Implications for advancing undergraduate research opportunities are discussed

The 2018 Operational Management Procedure for the South African Merluccius paradoxus and M. capensis resources.

Specifications and projection results for the 2018 OMP used for setting SA hake TACs are provided along with various background information, including details of the metarule process

An evaluation of the largest resource efficiency club programme in England (2005-2008) to underpin future design and delivery of a cost effective policy instrument.

In England, the Department of Environment, Food and Rural Affairs (Defra) allocated £5 million over three years from 2005 to 2008 to support the establishment of a wide range of innovative Resource Efficiency Clubs (RECs). During the funding period (2005 – 2008) the programme funded 70 RECs with 45 remaining active at the end of the three years (2008). Some 1,330 businesses were active in the 70 RECs with 1,014 providing data including potential and actual savings. In excess of £50 million of potential savings were identified and by the end of 2008 some £25 million were achieved. The total savings to total grant ratio for all RECs was, by 2008, some 5.8; this was in excess of the original ratio set by Defra. The Programme made clear to key decision makers that well designed RECs are a key policy instrument. The research showed that the future for RECs in England is uncertain and strategists should consider innovative ways to fund their continued contribution to national, regional and local practice

An X-ray Tomography Study of Gas Retention in Nuclear Legacy Waste

The retention and release of flammable gases from corroded Magnox sludge waste at Sellafield, UK and secondary reprocessing waste at Hanford, USA has significant economic and safety implications for decommissioning various nuclear legacy buildings. Magnesium hydroxide is the primary precipitation product from the corrosion of first generation nuclear fuel in the UK, with hydrogen gas produced as a reaction by-product. Depending on the bed microstructure, wettability and shear yield stress behaviour, some consolidated sediments of these corrosion products are able to trap a substantial volume of gas, sufficient in some instances to become buoyant with respect to a water supernatant, resulting in an undesirable upward transfer of radioactive material from the consolidated bed. These phenomena are investigated using the decomposition of hydrogen peroxide to produce oxygen bubbles within magnesium hydroxide soft sediments at laboratory scale. X-ray tomography analysis showed that high strength sediments of 1112 Pa shear yield stress supported much larger bubbles up to 20 mm equivalent spherical diameter than beds in the 7-234 Pa range, which demonstrated almost identical bubble size distributions across the range. The largest retained bubbles became progressively more distorted with increased sediment strength until the lateral cracks consistent with tensile fracture became apparent in the 1112 Pa bed. These cracks significantly limited the capacity for bed swell as gas diffusion along the cracks to the container walls provided a continuous escape route. The capacity for gas retention was also substantially reduced when gas generation was not homogeneous through the bed as localised gas generation promoted the formation of low density pathways, rich with micro-bubbles, which enable gas transport through the bed

Yield stress dependency on the evolution of bubble populations generated in consolidated soft sediments

Retention of hydrogen bubbles within consolidated soft sediments represents an important safety consideration for the management of legacy nuclear wastes due to the potential for acute gas release. Gas retention sufficiently reduced the bulk density of intermediate yield stress (< 800 Pa) sediments for the bed to become buoyant with respect to an aqueous supernatant, potentially inducing Rayleigh-Taylor instabilities. X-ray computed tomography revealed that beds of 7-234 Pa yield stress retained very similar, steady state size distributions of mature bubbles, limited to 9 mm equivalent spherical diameter, for long residence times. This implied a dominant gas release mechanism dictated by the pore to millimeter scale bubble population, not previously identified in such weak sediments and unrelated to the bubbles' buoyant force. At 1112 Pa yield stress, large bubbles of up to 20 mm diameter were observed to grow through induction of lateral cracks, facilitating gas transport to the bed periphery, thereby limiting the maximum void fraction, while non-homogeneous gas generation promoted the formation of low density regions rich with micro-bubbles which similarly provide pathways for gas release