A Heated Debate: Climate Change and Conflict in Africa

The worst drought in a century in Southern Africa at the end of last year slowed the iconic Victoria Falls on the Zimbabwean–Zambian border to a rill, fuelling renewed discussion about climate change. It also epitomised the potential repercussions of the phenomenon for livelihoods and security on the African continent. However, current research only sees a weak connection between climate and violent conflict. Sub-Saharan Africa is the world region most affected by climate change. Parts of East Africa, the Sahel, and Southern Africa have been the most severely impacted on. Existing research largely sees climate change as a "threat multiplier," and perceives high poverty and low state capability as more influential drivers of conflict. General assessments of how climate affects conflict mask important differ­ences: In some parts of Africa, extreme weather events (such as droughts) and rising temperatures threaten the most vulnerable already - namely, those that are poor and rely on rain-fed agriculture. Pastoralist agricultural production and pronounced differences between ethnic groups are particularly dangerous risk factors. Yet uncertainty about climate's precise effects is still high. Under certain conditions, climate change can lead to increased conflict but also cooperation in affected communities across Africa. New research needs to investigate more thoroughly the mechanisms underlying how individuals and communities react to weather extremes and long-term climatic changes. It is of particular relevance to understand how increased societal cooperation as well as adequate state policies can help overcome climate change's adverse effects among those most vulnerable people. Following up on its last report from 2014, in 2022 the climate-conflict link will be re-evaluated for the next Intergovernmental Panel on Climate Change (IPCC) Assessment Report. Better understanding the pathways that lead to violent conflict and focusing on the most vulnerable members of society, namely those who directly rely on rain-fed agriculture, is a necessary precondition for devising adequate policies to tame climate change's adverse effects on security. Supporting the mitigation of climate change's detrimental effects for the most vulnerable in Africa should be a key focus for European and German Africa policy

Hot Single Point Incremental Forming of Ti-6Al-4V Alloy

The lightweight metal alloy Ti-6Al-4V is widely used in the aeronautical industry due to its excellent mechanical properties. However, it is known the difficulty to deform Ti-6Al-4V sheets at room temperature because of its microstructure conditions. The present work focuses on the evaluation of formability of Ti-6Al-4V sheets using hot single point incremental forming (SPIF) process which it seems appropriate to produce small batches of parts due to its flexibility as it allows a significant reduction of costs and lead times. In order to characterize the SPIF of Ti-6Al-4V under hot forming conditions, a set of forming trials evaluation tests was carried out. The obtained results have allowed identifying the key process features and have demonstrated the potential of the proposed approach to hot form of small amounts of Ti-6Al-4V parts.Research leading to these results was done within the project INMA – Innovative manufacturing of complex titanium sheet components. This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement No. 266208. Authors would also like to thank Joachim Zettler from Airbus Group Innovations and Alain Dupuy from Airbus for their support to define the scope of the tests and their analysis

Estudio de la influencia del usuario y los modos de vibración de la interfaz en la estabilidad y dinámica de sistemas hápticos

Las interfaces hápticas intentan recrear la sensacón transmitida por la interacción con un objeto representado en un escenario virtual, realizando esto a través de un brazo robótico. Los sistemas actuales se han visto beneficiados con respuestas más realistas visualmente, pero en cuanto a las técnicas de rendering háptico, en las cuales se necesita una retroalimentación en posición o en fuerza, no se ha logrado transmitir plenamente la sensación de rigidez de un objeto. En lugar de eso, los objetos rígidos virtuales no se sienten naturales, debido a que al ser tocados con la interfaz háptica no son lo suficientemente rígidos o presentan oscilaciones y rebotes. Esta tesis analiza la influencia de varios elementos presentes en el lazo de control que condicionan el funcionamiento y la estabilidad de sistemas hápticos basados en impedancias. Las conclusiones de este estudio pueden ser utilizadas en el diseño de interfaces hápticas, realizando también aportaciones a diferentes campos del conocimiento involucrados en este tipo de sistemas que influyen unidos en el mismo lazo de realimentación. Este estudio se ha enfocado principalmente en dos fenómenos. El primero es la influencia de la posición de agarre del usuario en la dinámica del sistema. Este objetivo requiere de la selección de un modelo mecánico diseñado con este propósito para identificar los parámetros donde influye el usuario. Debido a que las características humanas difieren de una persona a otra, se ha realizado un análisis estadístico para confirmar la repercusión de este factor, validando las conclusiones de su importancia frente a otros factores. La posición de agarre del stylus es uno de los principales factores que intervienen en la respuesta del sistema, afectando la percepción del amortiguamiento de los objetos rígidos virtuales. El segundo fenómeno estudiado ha sido el de los modos de vibración del dispositivo y la forma como afectan la estabilidad del sistema háptico. Se ha encontrado que los modos de resonancia modelados reducen significativamente los valores de la impedancia implementable o región-Z en la rigidez de objetos virtuales. Esto ha sido corroborado para la región-Z del PHANToM. Estos resultados han sido aplicados en un control adaptable para garantizar la transmisión de las propiedades de un escenario virtual, sin importar quién o dónde se agarre la interfaz háptica

End-effector for automatic shimming of composites

Gaps in composite structures are a risky factor in aeronautical assemblies. For mechanically joined composite components, the geometrical conformance of the part can be problematic due to undesired or unknown re-distribution of loads within a composite component, with these unknowns being potentially destructive. To prevent unnecessary preloading of a metallic structure, and the possibility of cracking and delamination in a composite structure, it is important to measure all gaps and then shim any gaps greater than 127 microns. A strategy to overcome the high relative tolerances for assemblies lies in the automated manufacturing of shims for the gaps previously predicted through the evaluation of their volumes via a simulation tool. This paper deals with the development of a special end-effector prototype to enable the shimming of gaps in composites structures using a pre-processed geometry. The aim of this end-effector is to provide movement to a temperature controlled hot-end in order to generate a solid shim of ABS on the target composite surface. This process is defined according to the trajectories and velocities marked by the 3D printing process using standard G-code. The geometry and material volume to be printed are indicated by the simulated gap volume which is based on previous metrological measurements. The final objective will be to attach this end-effector to an anthropomorphic robot to enable autonomous manufacturing. This work is part of the EU FP7 funded LOCOMACHS project, under grant agreement n◦314003.European Union Seventh Framework Programme FP7/2007-2013 under grant agreement n° 314003; Basque program Elkartek Basqtech 201