Financial Planning for a Farmer Undergoing Organic Conversion

The switch to organic farming may be the biggest farm management decision you ever undertake so careful planning is essential. The vast majority of organic farmers have no regrets once converted. Organic farming can be a profitable option due mainly to lower costs of production, an attractive organic farming scheme and attractive market premiums. However the change requires preparation, an attention to detail and good husbandry skills - a poor conventional farmer may make an even worse organic farmer. From the financial viewpoint, the Teagasc “Farm Business Planner” program will help you in making the decision to convert or not. Like conventional farming, organic farmers should not solely depend on unsustainable schemes and grant aid for future profits. The organic market is a “niche” but growing market and it is important to follow that market

Travelling waves in the cool flame regime

Hydrocarbon oxidation develops through a complex network of elementary steps. Depending on the initial thermodynamic conditions, different behaviours are observed ranging from slow combustion to hot ignition [1]. Chain reactions involving radicals, govern all the combustion processes. Most of the time, the operating kinetic mechanism can be approximated by a reduced kinetic scheme which is depending on the initial conditions. In an intermediate range of temperature, cool flames appear as a transition between slow combustion and hot ignition. The existence of cool flames is often associated with knocking is engines

Linking Research and Policy: Assessing a Framework for Organic Agricultural Support in Ireland

This paper links social science research and agricultural policy through an analysis of support for organic agriculture and food. Globally, sales of organic food have experienced 20% annual increases for the past two decades, and represent the fastest growing segment of the grocery market. Although consumer interest has increased, farmers are not keeping up with demand. This is partly due to a lack of political support provided to farmers in their transition from conventional to organic production. Support policies vary by country and in some nations, such as the US, vary by state/province. There have been few attempts to document the types of support currently in place. This research draws on an existing Framework tool to investigate regionally specific and relevant policy support available to organic farmers in Ireland. This exploratory study develops a case study of Ireland within the framework of ten key categories of organic agricultural support: leadership, policy, research, technical support, financial support, marketing and promotion, education and information, consumer issues, inter-agency activities, and future developments. Data from the Irish Department of Agriculture, Fisheries and Food, the Irish Agriculture and Food Development Authority (Teagasc), and other governmental and semi-governmental agencies provide the basis for an assessment of support in each category. Assessments are based on the number of activities, availability of information to farmers, and attention from governmental personnel for each of the ten categories. This policy framework is a valuable tool for farmers, researchers, state agencies, and citizen groups seeking to document existing types of organic agricultural support and discover policy areas which deserve more attention

Reap the rewards from reseeding

Permanent grass clover leys are a vital component of productive organic grassland farms. In all, there are 3 main ways to re-seed - full reseeding of permanent pastures, under-sowing with a cereal crop and thirdly over-sowing onto an existing sward. In this article aspects of full reseeding of permanent pastures will be discussed

Participative critical enquiry in graduate field-based learning

This paper outlines a critical pedagogic approach to field-based learning (FBL) at graduate level. Drawing on student experience stemming from a FBL module and as part of an MA programme in Environment, Society and Development, the paper addresses the complexities associated with student-led, participative critical enquiry during fieldwork in Sarajevo, Bosnia-Herzegovina. The paper examines emerging student discourses through a group assessment and a series of individual reflective journals. Both are contextualised in relation to FBL module learning outcomes. Finally, aspects of fieldwork influencing the feasibility and effectiveness of participative critical enquiry as a field-based pedagogic endeavour are considered

Asymptotic behaviour of the Rayleigh--Taylor instability

We investigate long time numerical simulations of the inviscid Rayleigh-Taylor instability at Atwood number one using a boundary integral method. We are able to attain the asymptotic behavior for the spikes predicted by Clavin & Williams\cite{clavin} for which we give a simplified demonstration. In particular we observe that the spike's curvature evolves like $t^3$ while the overshoot in acceleration shows a good agreement with the suggested $1/t^5$ law. Moreover, we obtain consistent results for the prefactor coefficients of the asymptotic laws. Eventually we exhibit the self-similar behavior of the interface profile near the spike.Comment: 4 pages, 6 figure

Linear relaxation to planar Travelling Waves in Inertial Confinement Fusion

We study linear stability of planar travelling waves for a scalar reaction-diffusion equation with non-linear anisotropic diffusion. The mathematical model is derived from the full thermo-hydrodynamical model describing the process of Inertial Confinement Fusion. We show that solutions of the Cauchy problem with physically relevant initial data become planar exponentially fast with rate s(\eps',k)>0, where \eps'=\frac{T_{min}}{T_{max}}\ll 1 is a small temperature ratio and $k\gg 1$ the transversal wrinkling wavenumber of perturbations. We rigorously recover in some particular limit (\eps',k)\rightarrow (0,+\infty) a dispersion relation s(\eps',k)\sim \gamma_0 k^{\alpha} previously computed heuristically and numerically in some physical models of Inertial Confinement Fusion

Premixed flames with nonbranching chain-reactions (structure and dynamics)

A description of the flame structure, and its response to wrinkling and unsteady perturbations, is given for a simplified multiple step reaction mechanism (representative for example of halogen-hydrogen reactions), involving a dissociation reaction, a nonbranching chain reaction, both with high activation energy, and a recombination reaction. We describe the changes in flame structure that take place with increasing values of the flame temperature. We encounter first a "merged" flame regime, for which the chemical reactions are confined to a thin zone, on the hot side of the flame, and the quasi-steady state approximation, applicable at lower flame temperatures can no longer be used. Then, we reach a slow recombination regime for which the radical is produced in a thin zone and diffuses out to recombine in the outer transport zones. New effects, due to the radical diffusivity on the flame dynamics, are found in this regime. Finally, in describing the flame structure for high enough flame temperatures, the effects of radical recombination can be neglected, but no longer the endothermic effect of dissociation

Model Equation for the Dynamics of Wrinkled Shockwaves: Comparison with DNS and Experiments

International audienceA model equation for the dynamics and the geometry of the wrinkled front of shock waves, obtained for strong shocks in the Newtonian limit, is tested by comparison with direct numerical simulations and a shock tube experiment