Tribute and Dismay: A Coda to the Scholarly Friendship of Eduard Fraenkel and Roger Mynors

The article presents and provides context for the address that Roger Mynors gave at the memorial service for Eduard Fraenkel in May 1970. Mynors spoke of Fraenkel’s origins and international connections, his career, especially at Oxford, his teaching and scholarly method, his character and dependence on his wife. He also said that Fraenkel was ‘quite wrong’ to end his own life but adds nuance to that judgement. An introduction and annotations to the address draw on archival testimony to the two scholars’ friendship (including letters) and on contact with people who knew both, some of whom attended the memorial service. A 1967 letter from Fraenkel to Mynors is included. The documents illuminate the role of academic networks and labour and both scholars’ place in the history of classical scholarship. The article concludes with personal recollections from three scholars who were close to the events of the time, in response to the documents discussed here

Incorporating intra-hour renewable variability into the design of stand-alone electrolytic hydrogen production systems

The integration of variable renewable energy sources (VRE) and electrolytic hydrogen production is a key factor in the cost-effective production of hydrogen. The challenge lies in designing systems where electrolyzers can flexibly adapt to the inherent temporal variability of VRE sources. This relationship is difficult to model, as it involves phenomena across a wide range of timescales, from sub-hourly fluctuations to long-term operational dynamics. In this work, we propose a mathematical model to represent the behavior of a renewable hydrogen production system over its lifetime, incorporating sub-hourly information on the balance between renewable generation and the flexibility of the electrolysis stage. Our approach is unique because it takes detailed sub-hourly behavior and efficiently embeds it into a standard hourly framework. It allows to realistically model the complex interplay between VRE generation and electrolyzer flexibility over a system’s entire lifespan. The model is evaluated at four locations in Chile – two wind-based and two solar PV-based – and a variety of scenarios are constructed considering factors such as the temporal hydrogen dispatch profile, the flexibility of the alkaline electrolysis stage, and the electrolysis technology mix. Based on projected costs for the year 2030, the main results show that the levelized cost of hydrogen across the four sites ranges from $2.96 to$7.59/kgH2, although these values can be significantly affected by the temporal profiles of hydrogen dispatch. It was found that modeling intra-hourly characteristics can alter levelized cost predictions by up to 10%. We also found that the optimal technology mix is influenced by the renewable resource. Specifically, wind-based sites need more flexible proton exchange membrane electrolysis capacity to handle their high sub-hour variability, whereas sites with less variable photovoltaic sources can rely more on alkaline technology

Comparative assessment of retrofit strategies for progressive collapse mitigation in steel-framed structures

A large proportion of the existing building stock has been designed without consideration for progressive collapse and may therefore need retrofitting. To this end, this study compares the performance of three typical retrofit strategies for existing multi-story steel-framed structures subjected to column loss scenarios. The strategies include global measures, such as horizontal bracings placed above the removal zone and a truss system added at the rooftop level, and a local measure based on strengthening the 1st story columns through concrete encasement. Five moment resisting frames, prone to different progressive collapse mechanisms, are considered for case study purposes. Detailed numerical models validated against experimental results are developed to investigate the robustness of the frames before and after retrofitting. Parametric non-linear static analyses are also conducted to optimize the design of the retrofit measures. Additionally, the study assesses the impact of retrofitting on the dynamic response through non-linear dynamic analyses. The results show that the effectiveness of retrofitting depends on several factors, including, most significantly, their ability to redistribute loads, the number of stories, and the type of collapse mechanism (e.g., failure of beams or columns). Moreover, it is shown that global measures have the most favorable influence on the dynamic behavior. The study reveals that no single strategy is effective across all configurations and that case-specific decisions are typically necessary, based on the vulnerabilities in each structure. The paper offers fundamental insights and practical considerations for designing and implementing the various retrofit measures, enabling more holistic and informed selection approaches

An Approach for the Comparative Evaluation of Requirements Formalisation Approaches

Various approaches have been proposed to automate the formalisation of software requirements from semi-formal or informal documents. However, this area of research lacks well-established case studies to serve as benchmarks for comparing different methods. Additionally, there is a need for clear, objective criteria to effectively assess the outcomes of these formalisation approaches. These gaps make it challenging to identify which techniques are most suitable for specific formalisation tasks. This paper addresses these issues by introducing a set of standardized case studies and a structured framework for evaluating the performance of requirements formalisation techniques using measurable criteria. We apply this evaluation framework to assess five different formalisation methods, which include both rule-based and machine learning-driven approaches

Advancing biocompatible metal-organic frameworks in personalized biomedical applications

The widespread of the global epidemic has prompted our human beings to pay unprecedented attention to their own health and safety, and the demand for advanced biomedical treatment options has been continuously increasing. Among many emerging medical materials, metal-organic frameworks (MOFs) stand out due to their high specific surface areas and tunable pore sizes, design versatility, biocompatibility, and the ability to generate reactive oxygen species (ROS). In order to bridge the gap between MOFs materials and modern biomedical applications, this review discusses the applications of MOFs in multiple fields from both in vivo and in vitro perspectives, including in vitro applications such as disinfectants, self-cleaning materials, drug adsorption, antibacterial MOF membranes and films, MOF antimicrobial pharmaceuticals and tissue engineering, and in vivo applications such as MOF dynamic therapy, targeted drug delivery, MOF contrast agents, and MOF vaccines. We hope to prompt and unleash the immense potential of MOFs as an emerging biomedical material and provides valuable insights for the future development of MOFs in modern biomedical and healthcare applications