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This year, 2023, marks the sixtieth anniversary of Jeremy Seabrook's authorial career as one of our finest and most impassioned writers on the nexus of the personal, the political and the global. And, it is just over three decades since he first wrote in Race & Class. With a depth and range that spans the life situation of the poor in Britain, the underprivileged and precariat of the Asian sub-continent, the impact of imperialism and consumerism on the psyche, the meaning of work, the impact of environmental disaster and the essence of what it is to be human – and a gift for striking prophecy – Seabrook's career has been marked by the telling of beautifully expressed but often deeply uncomfortable and challenging truths. Yet always with immense feeling for the other at their heart. As expressed in his seminal piece, 'The soul of man under globalism' ( Race & Class 43, no. 4, 2002), 'There are many macro-economic accounts of globalisation, but we rarely learn how it affects the psyche and sensibility of lives uprooted and radically reshaped by the penetration of their world by the market economy.' We are therefore delighted to publish in this issue and this anniversary year, not only Jeremy Seabrook's latest article for us, 'The present imperium', but also this response, by a contemporary, to his recently published autobiography, Private Worlds: growing up gay in post-war Britain (Pluto Press, 2023) which raises not only fundamental themes relating to the gay community in the UK and its history, but also profound, wider societal issues.

Through the medium of a review article of I You We Them by Dan Gretton, the author explores the significance for the shaping of our current world of the desk killers of modern history. He reflects on what this means for human beings and human relationships today, in the light not only of the ongoing and accelerating climate crisis, but the immediate existential upheaval caused by Covid-19. For this is reshaping our society even as we go to press.

The author, who directs Soul of Europe, a mediation project working in the Balkans for the last fifteen years, assesses the changes that have taken place in Bosnia - 'a broken country'. He contrasts the thoughtful creative work of community-based people's plenums with the crushing uncaring bureaucracy of international agencies, particularly via the EU - the latest imperial power. It is, he argues, the clarity and practicality of the plenum movement's demands in dealing with corruption and the need for justice that puts it in the political vanguard. [Reprinted by permission of Sage Publications Ltd., copyright, the Institute of Race Relations.]

The author, who directs Soul of Europe, a mediation project working in the Balkans for the last fifteen years, assesses the changes that have taken place in Bosnia – 'a broken country'. He contrasts the thoughtful creative work of community-based people's plenums with the crushing uncaring bureaucracy of international agencies, particularly via the EU – the latest imperial power. It is, he argues, the clarity and practicality of the plenum movement's demands in dealing with corruption and the need for justice that puts it in the political vanguard.

This open access book reports on methods and technologies to describe, evaluate and control uncertainty in mechanical engineering applications. It brings together contributions by engineers, mathematicians and legal experts, offering a multidisciplinary perspective on the main issues affecting uncertainty throughout the complete system lifetime, which includes process and product planning, development, production and usage. The book is based on the proceedings of the 4th International Conference on Uncertainty in Mechanical Engineering (ICUME 2021), organized by the Collaborative Research Center (CRC) 805 of the TU Darmstadt, and held online on June 7–8, 2021. All in all, it offers a timely resource for researchers, graduate students and practitioners in the field of mechanical engineering, production engineering and engineering optimization.

The optimal head and volume flow rate for hydropower are determined through axiomatic and analytical considerations by Pelz in 2011. Based on these results the Cordier-diagram and its asymptotes are discussed. The technological progress causes that nowadays machines of high specific speed and hence small specific diameter, like Kaplan turbines, can be used, delivering the same power as the antiquated machines of low specific speed, like water wheels, did during the last centuries. Therefore the power-specific investment costs decrease. Within the legal borders, which are given by the legislative organs and due to the responsibility towards the environment, systems of robust technologies with minimal impact on nature at the same time are required. Considering all this, the present paper proposes an innovative concept for a fish permeable hydraulic machine for small hydropower.

Die Europäische Union will den Energieverbrauch in der EU senken. Ein Werkzeug dazu ist die 2009 eingeführte Ökodesign-Richtlinie. Sie legt Anforderungen an die energieeffiziente Gestaltung von Produkten fest, die besonders viel Energie verbrauchen. Verdrängerpumpen gehören bislang zwar noch nicht dazu. Da sich die EU aber immer ehrgeizigere Klimaziele setzt, ist es sehr wahrscheinlich, dass weitere Produktgruppen unter die Ökodesign-Richtlinie fallen werden. Darunter könnten sich dann auch Verdrängerpumpen befinden. Deshalb arbeiten der VDMA und das Institut für Fluidsystemtechnik der TU Darmstadt seit 2014 zusammen, um mit eigenen Forschungsaktivitäten die Grundlage für die Gestaltung einer Energie effizienzrichtlinie für Verdrängerpumpen zu legen.

There is a high probability that the Ecodesign Directive of the European Union will include positive displacement pumps in the near future. The Ecodesign Directive sets the framework of a legislative efficiency guidelines of energy-related products (ERP) to reduce their energy consumption. However, positive displacement pumps are used in various applications that affect the attainable efficiencies. Consequently, a regulation for all positive displacement pumps on the pure basis of the efficiency is not sufficient. This paper illustrates the necessity of an application-related consideration of positive displacement pumps and provides two major steps towards an application-related efficiency guideline: firstly, a concept of data acquisition and analysis is presented and discussed. The concept aims to identify the energetically relevant applications of positive displacement pumps and to determine a relationship between the various pump types, their applications and energy consumption. Secondly, a physically based, type independent and easy to apply model of the efficiency of positive displacement pumps is presented and its suitability in the context of an efficiency guideline is discussed. The model has been introduced by the authors recently and describes the efficiency as a function of four dimensionless variables. A parameter identification and model application on four different pump types and 155 different pump sizes including 2680 operating points proves its practicability to compare different pump types.

Dissipative structures known from non-equilibrium thermodynamics can form patterns. Cities are regarded as open, dissipative structures due to their self-organisation and thus in theory are also capable of pattern formation. In a first step to understand similarities between nonlinear pattern formation and inter-urban systems, we investigate how inter-urban structures are arranged. We use data from the Global Urban Footprint to identify spatial regularities in seven regions (Argentina, China, Egypt, France, India, Ghana and USA) and to quantitatively describe settlement patterns by number of objects and density. We find that small areas of the examined data sets show a regular arrangement, the density and number of settlements differ widely between the different regions and the portion of regular areas within this regions strongly correlates with these two parameters. The results can be used to develop mathematical models that describe inter-urban pattern formation on the one hand and to investigate to what extent the respective settlement patterns are related to infrastructural, economic or political boundary conditions on the other.

The European Union pursues ambitious objectives reducing greenhouse gas emissions. Thus, energy related products (ERP) are regulated by the European Union's Ecodesign Directive in terms of energy efficiency. Until now positive displacement pumps are not involved. However, considering the EU strategy in similar domains, the probability is high that the Ecodesign Directive will focus on positive displacement pumps in the future due to the large quantity of sold pumps and the collective energy consumption. Positive displacement pumps are characterized by their wide range of applications, e.g. mobile hydraulics, chemical, or food industry, with very different application-relevant requirements (low pulsation, high precision etc.). For this reason, a variety of pump designs exist, e.g. piston pumps, gear pump or screw pumps. From a scientific and technical point of view, legal requirements are considered adequate if they take into account the physical behavior of the machines as well as the application-relevant requirements. Against this background, the authors presented a physically based approach towards an application-related efficiency guideline at IREC 2016 considering a methodology to identify the energetically relevant applications of positive displacement pumps and introducing a physically based, type independent and easy to apply efficiency model. Since 2017, within the framework of an AiF project, the authors collaborate with the VDMA to validate the above mentioned efficiency model by means of precise experimental measurements. Until the submission of this paper, efficiency measurements are conducted on gear pumps, screw pumps and rotary piston pumps. The full paper presents the validation results and discusses the conclusions in the context of a future energy efficiency guideline of positive displacement pumps.