Polish School of Medicine at the University of Edinburgh (1941-1949): a case study in the transnational history of Polish wartime migration to Great Britain

More than 400 Polish medical refugees were associated with the Polish School of Medicine (PSM) at the University of Edinburgh between 1941 and 1949. This dissertation argues that the history of the PSM can fully be understood only as a part of the refugees’ broader experience of impelled or forced migration during and immediately after the Second World War. The key findings of this case study demonstrate that the opportunity to study or work at the PSM enabled the majority of Polish exiles to overcome, to a varying extent, their refugee predicament, while medical qualifications, transferable skills and trans-cultural competency obtained in wartime Britain allowed them to pursue professional and academic careers in different countries of post-war settlement, thus in turn contributing to a global circulation of medical knowledge and practice, especially between the University of Edinburgh and Poland. This specific case study contributes to the existing knowledge of Polish wartime migration to Britain in three interrelated ways. Firstly, an overarching transnational approach is used to combine and transcend Polish and British scholarly perspectives on, respectively, emigration or immigration. Secondly, the conceptual insularity of the existing literature on the topic is challenged by analysing archival, published and digital sources pertaining to the PSM with the help of various theoretical models and concepts borrowed from forced migration and diaspora studies. Thirdly, the conventional historiography of Polish-British wartime relations is challenged by emphasising the genuinely global ramifications of the PSM’s history. By interpreting the history of the PSM with the help of different analytical tools, such as Kunz’s and Johansson’s models of refugee movement and Tweed’s theory of diasporic religion, this dissertation provides a conceptual blueprint for further research on Polish wartime migration to Britain. In turn, this case study contributes to the development of forced migration and diaspora studies not only by empirically testing the explanatory power of existing theoretical models, but also by suggesting possible new conceptual avenues, such as analysing the pre-existing trans-cultural experiences of both Polish medical refugees and their hosts at the University of Edinburgh, and adding to the ‘triadic relationship’ of diaspora, homeland and host society a fourth dimension, i.e. conflict and cooperation between different migrant or refugee communities within the same host society

Development of the natural working fluid‐based refrigeration system for domestic scale freeze‐dryer

In this work, the analysis of the refrigeration system designed for the FrostX 10 freeze‐dryer is presented. The main goal of this study was to experimentally investigate the reference R452a freeze‐dryer and prepare recommendations for a machine based on the R290 refrigeration unit. In order to guarantee the temperature requirements and efficient operation of that unit, the analysis of suitable natural refrigerants was performed. Consequently, propane (R290) was selected. In addition, a number of modifications were introduced for the prototype system. System analysis showed that the replacement of the refrigerant in the existing system improves the system energy efficiency by approximately 18%. During the experimental campaign of the basic refrigeration unit, an unstable operation of the evaporator was found. The concept of a new cooling system for a prototype device was presented. The configuration and type of heat exchanger to maximise the performance of the ice trap of the freeze‐dryer were proposed.Development of the natural working fluid‐based refrigeration system for domestic scale freeze‐dryeracceptedVersio

Application range of the HEM approach for CO2 expansion inside two-phase ejectors for supermarket refrigeration systems

In this study, the accuracy of the homogeneous equilibrium (HEM) applied to 3-D CFD-based simulations of CO2 expansion inside two-phase ejectors is presented. The HEM approach previously reported in the literature were assessed by comparing the computed and measured mass flow rates that pass through an ejector motive nozzle. In addition, the HEM approach implemented using CFD was tested over a vast range of ejector operating regimes. To ensure that all of the computations were performed consistently, a validated CFD model combined within an in-house developed script was used. The comparison of the experimental and computational results showed that the HEM accuracy varied for the different sets of operating parameters. Accurate results were obtained for operating regimes near or above the CO2 critical point. The model accuracy decreased with the decreasing temperature and decreasing distance to the saturation line.acceptedVersio

Numerical investigation of an R744 liquid ejector for supermarket refrigeration systems

This paper presents a numerical investigation of an R744 liquid ejector applied to a supermarket refrigeration system. The use of the liquid ejector enables the operation of the evaporator in a flooded mode and recirculates the R744 liquid phase, which improves the energy efficiency of the refrigeration system. The investigation was performed using two ejectors of different sizes installed in a multi-ejector block. The numerical model was formulated based on the homogenous equilibrium model and validated with the experimental results. The influence of the pre-mixer, mixer and diffuser dimensions on the ejector performance measured using the mass entrainment ratio is presented. The results show that the best liquid ejector performance was obtained for the short lengths of the pre-mixer and mixer compared to the broadly investigated two-phase ejectors connected to the evaporator port. In addition, wide diffuser angles improved the mass entrainment ratio of both liquid ejectors, which may lead to a reduction in the diffuser length

Application range of the HEM approach for CO2 expansion inside two-phase ejectors for supermarket refrigeration systems

In this study, the accuracy of the homogeneous equilibrium (HEM) applied to 3-D CFD-based simulations of CO2 expansion inside two-phase ejectors is presented. The HEM approach previously reported in the literature were assessed by comparing the computed and measured mass flow rates that pass through an ejector motive nozzle. In addition, the HEM approach implemented using CFD was tested over a vast range of ejector operating regimes. To ensure that all of the computations were performed consistently, a validated CFD model combined within an in-house developed script was used. The comparison of the experimental and computational results showed that the HEM accuracy varied for the different sets of operating parameters. Accurate results were obtained for operating regimes near or above the CO2 critical point. The model accuracy decreased with the decreasing temperature and decreasing distance to the saturation line

Development of the natural working fluid‐based refrigeration system for domestic scale freeze‐dryer

In this work, the analysis of the refrigeration system designed for the FrostX 10 freeze‐dryer is presented. The main goal of this study was to experimentally investigate the reference R452a freeze‐dryer and prepare recommendations for a machine based on the R290 refrigeration unit. In order to guarantee the temperature requirements and efficient operation of that unit, the analysis of suitable natural refrigerants was performed. Consequently, propane (R290) was selected. In addition, a number of modifications were introduced for the prototype system. System analysis showed that the replacement of the refrigerant in the existing system improves the system energy efficiency by approximately 18%. During the experimental campaign of the basic refrigeration unit, an unstable operation of the evaporator was found. The concept of a new cooling system for a prototype device was presented. The configuration and type of heat exchanger to maximise the performance of the ice trap of the freeze‐dryer were proposed