Developing a Contextually Relevant Concept of Regional Hegemony: The Case of South Africa, Zimbabwe and “Quiet Diplomacy”

South Africa’s “quiet diplomacy” has been often used to reject the notion of South African leadership or regional hegemony in southern Africa. This article finds that this evaluation is founded on a misguided understanding of regional hegemony, which is based on conventional hegemony theories that are mostly derived from the global role of the United States after World War II. Alternatively, this article uses a concept of hegemony that, for example, takes into account the “regionality” of South Africa’s hegemony, which both allows external actors to impact on regional relations and allows South Africa to pursue its foreign policy goals on the global level of international politics. This concept helps to systemically analyze South Africa's foreign policy in the Zimbabwean crisis and to better integrate this policy into the broader framework of its regional and global ambitions.regional powers, hegemony, South Africa, Zimbabwe, quiet diplomacy

India and South Asia in the world: on the embeddedness of regions in the international system and its consequences for regional powers

Regions and the regional powers that characterize them stand in multiple inter-relations with the world system. Yet, theories of International Relations struggle with the conceptualization of this global-regional nexus. This article introduces an analytical tool that allows for the evaluation of the ‘embeddedness’ of regions into the international system and its consequences for a regional power in ‘its’ region. The theoretical tool shows in particular that regional powers do not necessarily have an inherent interest in ‘their’ region and its stabilization or, in general, the provision of public goods. Instead, global interests can prevail. Thus, the decision to engage positively in the region is one that does not automatically follow from relative preponderance as it is assumed by many analysts of regional powerhood in the case study chosen here, South Asia, and across the globe. The applicability of this analytical tool is illustrated with the help of two specific examples – India's conflict management in Sri Lanka and its role in the democratization process in Nepal

Competition and Cooperation: India and China in the Global Climate Regime

The need to cooperate in matters of climate change requires partnerships among states, such as India and China, that in other contexts are competitors - if not rivals. This simultaneity of cooperation and competition is one of the key features of the emerging multipolar order and should take centre stage for both policy and research. Climate change is the key challenge for the coming decade, requiring cooperation from major emitters on mitigation, adaptation, climate finance, and the decarbonisation of the energy supply. No state will be able to achieve sufficient climate action alone. Simultaneously, geopolitical and geo-economic tensions between these actors in the increasingly multipolar global order are growing, not only in today's most obvious case of Ukraine but also on the Indo-Chinese border. This juxtaposition of cooperation and conflict also plays out in the United Nations Framework Convention on Climate Change: at COP26 in 2021, India and China aligned to ensure that in the final agreement the commitment to a global coal phase-out became to a coal phase-down. Despite regional and global rivalry, cooperation at the intersection of issue-specific interests can yield both positive and negative outcomes. For example, the decarbonisation of energy systems and the expansion of renewables, including solar power and (green) hydrogen offers such a field of competition over technology and trade leadership. This competition increasingly draws in the European Union and other global actors who are looking for new and reliable energy partners. Climate change is a global challenge and requires cooperation at that level. Germany and the EU have an important role in helping to foster such cooperation even despite clashes of values and interests. Engagement with India has been given greater impetus more recently, also regarding diversification of energy sources. In the face of escalating geopolitical tensions this will be more difficult in the case of China, though nevertheless still crucial to achieve the Paris goals

Damage identification in composite laminates and sandwich structures using ultrasonic guided waves and a 3D laser vibrometer

This thesis addresses the feasibility of using ultrasonic guided waves (UGWs) to detect and characterise the barely visible impact damages (BVID) that can develop in thin composite laminates and composite sandwich structures (CSS) by carrying out a fundamental investigation into wave-damage interaction. The interaction of UGWs with BVID in a structure is analysed using full wavefield data obtained by a Laser Doppler Vibrometer (LDV) and by numerical simulations. Multiple signal and image processing techniques are proposed to enhance the features relating to damage. The findings from this analysis are then incorporated into an in-service structural health monitoring (SHM) methodology using a sparse network of piezoelectric transducers. For the laminated composite panels, isolated subsurface delaminations between plies and complex BVID caused by a low velocity impactor are investigated. Both cases show that the first symmetric mode, S0, causes mode conversions when interacting with the defects whilst the first anti-symmetric mode, A0, mainly causes a change in phase and amplitude across the defects. Both cases also show that as the damaged area got more severe, the effects of the damage became more pronounced. The findings are then integrated and validated by a delay & sum algorithm to show the UGWs potential as an in-service SHM methodology. The focus of research then turns to the theoretical fundamentals of UGW propagation through CSS. The underlying mechanics of UGWs in CSS, including the relation between panel thickness and the UGW wavelength as well as the energy transfer through the core are presented. It is noted that three main types of propagation can exist in CSS which are global Lamb waves, leaky Lamb waves and Rayleigh waves. Dispersion curves are obtained for the CSS and polar plots of group velocities show their anisotropic nature. The final part of the thesis focuses on damage detection and localisation in CSS using full wavefield analysis and a sparse network of transducers. Both fundamental modes can localise the BVID in the structure, even with the anisotropic behaviour of the core. Based on these results, this thesis concludes that UGW based SHM shows great promise as an in-service damage detection technique that can detect, localise and, in some cases, characterise impact induced defects in thin composite laminates and CSS.Open Acces

Differentiation as Affirmative Action: Transforming or Reinforcing Structural Inequality at the UNFCCC?

Structural inequality is at the heart of the struggle to prevent dangerous climate change. This makes the global climate regime a particularly interesting case, when it comes to conceptualising and assessing the role of international institutions as sites for the reproduction and transformation of macro-level inequalities that structure the international system. This article uses these interlinkages to, first, assess, in how far the debates, conflicts and doubts regarding effectiveness and justifications of affirmative action at the domestic level, introduced as a reaction to domestic structural inequality, can teach us something about the actual potential of and the obstacles to the transformation of structural inequalities through differentiation internationally. Second, it assesses whether and how institutional mechanisms of categorisation and (re-)distribution within the UNFCCC have led and are likely to lead in the future to a reinforcement or a transformation of global structural inequalities