Unsteady flow of an incompressible fluid in a horizontal porous medium with suction

A theoretical analysis of two-dimensional unsteady flow in a porous medium bounded by a horizontal wall is presented as a perturbation on a basic flow. It is assumed that the perturbation is occasioned by a sudden suction at the wall. Even for a highly permeable medium, the characteristic Reynolds number in porous media flow is usually small and asymptotic solutions are developed by the Laplace transform technique. It is observed that the perturbed shear stress at the wall decays exponentially with time

Natural convection boundary layer with suction and mass transfer in a porous medium

The free convection boundary layer flow with simultaneous heat and mass transfer in a porous medium is studied when the boundary wall moves in its own plane with suction. The study also incorporates chemical reaction for the very simple model of a binary reaction with Arrhenius activation energy. For large suction, asymptotic approximate solutions are obtained for the flow variables for various values of the activation energy

Free convection heat and mass transfer to steady flow in a semi-infinite vertical porous medium

Analytical solutions are derived for flow in a semi-infinite vertical porous medium with heat and mass transfer. When the temperature and mass concentration are uniform a constant pressure is possible and sustains a fully developed flow. Thereafter there is a small perturbation of the wall temperature and concentration, and the subsequent two-dimensional problem is tackled for large Prandtl number and free convection parameters and small Reynolds number. The heat transfer rate at the wall is discussed quantitatively

Global models for the biomechanics of green plants. Part 3

As a result of dehydration, there are daily changes in the stem diameters of green plants. This transient phenomenon is addressed. It is assumed that a small time perturbation is superimposed on an otherwise constant radius. By employing Laplace transforms, analytical solutions are developed for this peculiar phenomenon. The results are discussed quantitatively

Kip in 't fruit, boom in de uitloop: Samenwerking fruittelers en pluimveebedrijven biedt kansen.

Het beplanten van een kippenuitloop kan veel geld kosten. Met fruitbomen kun je op termijn een deel van de kosten terug verdienen, maar dan moet de fruitteelt wel professioneel aangepakt worden. In dit artikel worden de voorwaarden en mogelijkheden verkend

Walnoten in de uitloop

Bomen voor Buitenkippen is op excursie geweest naar enkele beplantingen waar al veel ervaring is opgedaan met walnotenbomen

Difficulties faced by older Rohingya (forcibly displaced Myanmar nationals) adults in accessing medical services amid the COVID-19 pandemic in Bangladesh

Background COVID-19 has seriously disrupted health services in many countries including Bangladesh. This research aimed to explore whether Rohingya (forcefully displaced Myanmar nationals) older adults in Bangladesh faced difficulties accessing medicines and routine medical care services amid this pandemic. Methods This cross-sectional study was conducted among 416 Rohingya older adults aged 60 years and above residing in Rohingya refugee camps situated in the Cox's Bazar district of Bangladesh and was conducted in October 2020. A purposive sampling technique was followed, and participants' perceived difficulties in accessing medicines and routine medical care were noted through face-to-face interviews. Binary logistic regression models determined the association between outcome and explanatory variables. Results Overall, one-third of the participants reported difficulties in accessing medicines and routine medical care. Significant factors associated with facing difficulties accessing medicine included feelings of loneliness (adjusted OR (AOR) 3.54, 95% CI 1.93 to 6.48), perceptions that older adults were at the highest risk of COVID-19 (AOR 3.35, 95% CI 1.61 to 6.97) and required additional care during COVID-19 (AOR 6.89, 95% CI 3.62 to 13.13). Also, the notable factors associated with difficulties in receiving routine medical care included living more than 30 min walking distance from the health centre (AOR 3.57, 95% CI 1.95 to 6.56), feelings of loneliness (AOR 2.20, 95% CI 1.25 to 3.87), perception that older adults were at the highest risk of COVID-19 (AOR 2.85, 95% CI 1.36 to 5.99) and perception that they required additional care during the pandemic (AOR 4.55, 95% CI 2.48 to 8.35). Conclusion Many Rohingya older adults faced difficulties in accessing medicines and routine medical care during this pandemic. This call for policy-makers and relevant stakeholders to re-assess emergency preparedness plans including strategies to provide continuing care

Attitudes towards community gambling venues and support for regulatory reform: An online panel study of residents in New South Wales, Australia

Background: Harmful gambling has been identified as an important public health issue that affects individuals, families and the broader community. One gambling product, electronic gambling machines (EGMs), has been associated with significant gambling harm in Australia. There has been limited research that has explored community perceptions of EGMs and attitudes towards reform. This study, conducted in NSW, Australia, aimed to explore community use of EGM venues (clubs and hotels containing EGMs), attitudes towards EGMs and whether the use of these venues influenced attitudes towards EGM reform. Methods: An online survey was conducted with 500 adults aged 16 years and over, representative of the population for age and gender. Discrete choice and open-ended questions were used to gather data on gambling behaviours, use of and attitudes towards EGMs and EGM venues and support for gambling harm reduction measures. Results: Three quarters of participants had visited an EGM venue in the previous year. Participants who had attended such venues were significantly more likely to use EGMs at least once per month. Participants attended EGM venues for a range of reasons including use of non-gambling facilities such as restaurants, the social aspects of the venue and ease of access to the venue. Some participants also attended EGM venues specifically for the gambling facilities. Most participants identified some negative impacts of EGMs for local communities and were supportive of measures to reduce the number of EGMs and prevent children's exposure to EGMs in such venues. Conclusions: This study shows a high level of support for EGM reform amongst both individuals who attend EGM venues and also those who do not. There is potential for government to further regulate EGMs and the environments where they are located

Promoting health and welfare in organic laying hens. Recommendations to ensure hen health and welfare in organic husbandry

In the HealthyHens project we investigated laying hen health and welfare in organic poultry systems in eight European countries. This leaflet presents our findings and recommendations. Most of our recommendations are also relevant for conventional poultry systems

Bacteriën en schimmels op melkveebedrijf in beeld

Environmental Biolog