A novel continuously adjustable hydrodynamic bearing

A novel form of adjustable fluid film bearing has been devised whereby the hydrodynamic conditions can be changed in a continuously controlled manner during operation. The principle can be applied to conventionally orientated journal bearings, i.e. a shaft rotating within a stationary bearing housing; to inverse orientations, i.e. a rotor on a stationary shaft; and to thrust bearings. A theoretical model and computerised solution technique were developed in which the fluid film profile, temperature, viscosity and pressure fields were simultaneously solved. Experiments were conducted on journal bearing versions for which recently developed measurement techniques demonstrated stable operation at zero eccentricity, and the ability to move the rotational centre whilst in operation. Performance characteristics predicted by the computer model have been demonstrated in practice. The novel bearing has shown significant improvements over conventional designs in tems of stiffness, damping, rotational accuracy, power losses and temperature rise

The Role of Agricultural Colleges and Universities in Rural Development and Lifelong Learning in Asia

The paper expounds on the challenges confronting institutions of higher agricultural education (HAE) in the context of the significant role of education in alleviating poverty, especially in rural areas, and in light of the changing needs of rural areas and economies. Specifically, HAE institutions are called upon to initiate and lead in articulating a vision for the future that serves the needs not only of agriculture but also of all who inhabit the rural areas. They can step beyond their traditional role by merging forces with other stakeholders to enrich and support other levels of education with critical knowledge and information on agriculture and natural resources management (NRM), the latter being crucial in the pursuit of rural development, poverty education, and food security. To perform an active and constructive role in rural development, agricultural universities need to adjust their programs to accommodate new topics, as well as teaching and learning models; forge new partnerships with schools, academia and rural space stakeholders; expand its representation in governance; and hold continuous dialogue with policymakers. Their extension services could include support to education for rural people that encompasses primary, secondary, vocational, and adult education. University-school linkages are perceived to be illustrative of a decentralized, democratic, and community-based response to rural development problems. It is noted that universities can potentially become showcases of local traditions and knowledge, reflecting the regional, cultural, and ethical traditions of their society, as well as global movements and forces. In reinforcing their roles as contributors to a culture of learning and rural development, it is emphasized that HAE institutions need to engage more directly and more effectively in partnerships and dialogue with other local educational institutions and their surrounding communities. Findings of the ongoing IIEP-UNESCO/FAO program of research on HAE institutions in Asia are expected to provide information on how higher education institutions contribute to learning and rural development, and insights on how their strategic role in this field could be strengthened and further developed.higher agricultural education, rural development, Asia, lifelong learning

Collaborate to innovate

Innovation is something that many governments strive to support, in both the private and public sectors. By bridging the two sectors and creating novel partnerships, public sector expenditure can be reduced

Bypassing the selection rule in choosing controls for a case-control study

Objectives It has been argued that in case–control studies, controls should be drawn from the base population that gives rise to the cases. In designing a study of occupational injury and risks arising from long-term illness and prescribed medication, we lacked data on subjects' occupation, without which employed cases (typically in manual occupations) would be compared with controls from the general population, including the unemployed and a higher proportion of white-collar professions. Collecting the missing data on occupation would be costly. We estimated the potential for bias if the selection rule were ignored. Methods: We obtained published estimates of the frequencies of several exposures of interest (diabetes, mental health problems, asthma, coronary heart disease) in the general population, and of the relative risks of these diseases in unemployed versus employed individuals and in manual versus non-manual occupations. From these we computed the degree of over- or underestimation of exposure frequencies and exposure ORs if controls were selected from the general population. Results: The potential bias in the OR was estimated as likely to fall between an underestimation of 14% and an overestimation of 36.7% (95th centiles). In fewer than 6% of simulations did the error exceed 30%, and in none did it reach 50%. Conclusions: For the purposes of this study, in which we were interested only in substantial increases in risk, the potential for selection bias was judged acceptable. The rule that controls should come from the same base population as cases can justifiably be broken, at least in some circumstances. <br/