Really focused stellar winds in X-ray binaries

We investigate the anisotropy of stellar winds in binaries to improve the models of accretion in high-mass X-ray binaries. We model numerically the stellar wind from a supergiant component of a binary in radial and three-dimensional radiation hydrodynamic approximation taking into account the Roche potential, Coriolis force, and radiative pressure in the continuum and spectral lines. The Coriolis force influences substantially the mass loss and thus also the accretion rate. The focusing of the stellar wind by the gravitational field of the compact companion leads to the formation of a gaseous tail behind the companion.Comment: 10 figure

Conceptual System Dynamics and Agent-Based Modelling Simulation of Interorganisational Fairness in Food Value Chains: Research Agenda and Case Studies

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/)System dynamics and agent-based simulation modelling approaches have a potential as tools to evaluate the impact of policy related decision making in food value chains. The context is that a food value chain involves flows of multiple products, financial flows and decision making among the food value chain players. Each decision may be viewed from the level of independent actors, each with their own motivations and agenda, but responding to externalities and to the behaviours of other actors. The focus is to show how simulation modelling can be applied to problems such as fairness and power asymmetries in European food value chains by evaluating the outcome of interventions in terms of relevant operational indicators of interorganisational fairness (e.g., profit distribution, market power, bargaining power). The main concepts of system dynamics and agent-based modelling are introduced and the applicability of a hybrid of these methods to food value chains is justified. This approach is outlined as a research agenda, and it is demonstrated how cognitive maps can help in the initial conceptual model building when implemented for specific food value chains studied in the EU Horizon 2020 VALUMICS project. The French wheat to bread chain has many characteristics of food value chains in general and is applied as an example to formulate a model that can be extended to capture the functioning of European FVCs. This work is to be further progressed in a subsequent stream of research for the other food value chain case studies with different governance modes and market organisation, in particular, farmed salmon to fillet, dairy cows to milk and raw tomato to processed tomato.Peer reviewedFinal Published versio

Scenario analysis report with policy recommendations: An assessment of sustainability, resilience, efficiency and fairness and effective chain relationships in VALUMICS case studies : Deliverable 8.4

This is an open access article distributed under the Creative Commons Attribution License, to view a copy of the license, see: https://creativecommons.org/licenses/by/4.0/. The final version of this report is available at https://doi.org/10.5281/zenodo.6534011The functioning of food value chains entails a complex organisation from farm to fork which is characterised by various governance forms and externalities which have shaped the overall food system. VALUMICS food value chain case studies: wheat to bread, dairy cows to milk, beef cattle to steak, farmed salmon to fillets and tomato to processed tomato were selected to enable explorative and empirical analysis to better understand the functioning of the food system and, to identify the main challenges that need to be addressed to improve sustainability, integrity, resilience, and fairness of European food chains. The VALUMICS system analysis was executed through four operational phases starting with Groundwork & analysis including mapping specific attributes and impacts of food value chains and their externalities. This was followed by Case study baseline analysis, which provided input to the third phase on Modelling and exploration of future scenarios and finally Policy and synthesis of the overall work. This report is an overall synthesis of the VALUMICS results as follows: • Key findings from the VALUMICS project on the functioning of European food value chains and their impacts on more sustainable, resilient, fairer, and transparent food system are summarised through a compilation of 25 Research Findings and Policy Briefs. • By highlighting the major contributions from the research activities throughout the four phases of the VALUMICS project, this report delivers an assessment of various factors influencing sustainability, resilience, efficiency and fairness and effective chain relationships of different food value chains, and their determinants. • The synthesis of the outcome allows the identification of opportunities and challenges characterising the functioning of food supply chains, and thus, the prospects and potentials for strengthening the EU food sector

Simulations at Czech poultry market

This paper defines the possible scenarios of the development of the poultry market in the Czech Republic, in view of the trends in production, consumption and foreign trade. The individual scenarios are based upon the forecasts of selected factors that have a substantial impact on the poultry market and whose changes can be expected in the subsequent years with great likelihood. The article sets out and addresses various scenarios for the period of 2012–2014. The scenarios are based upon the partial equilibrium model of the poultry market, which has been derived on the basis of time series and panel data within the years 1995–2009. The conducted analysis clearly shows that changes in the prices of agricultural producers will have an effect on changes in the production of poultry meat, an increase in VAT through consumer prices will impact the rate of domestic consumption, as well as changes in disposable income. Similarly, a change in the exchange rate will have an effect on the amount of poultry imported into the Czech Republic