Verification and validation of COMSOL magnetohydrody-namic models for liquid metal breeding blankets technologies

Liquid metal breeding blankets are extensively studied in nuclear fusion. In the main proposed systems, the Water Cooled Lithium Lead (WCLL) and the Dual Coolant Lithium Lead (DCLL), the liquid metal flows under an intense transverse magnetic field, for which a magnetohy-drodynamic (MHD) effect is produced. The result is the alteration of all the flow features and the increase in the pressure drops. Although the latter issue can be evaluated with system models, 3D MHD codes are of extreme importance both in the design phase and for safety analyses. To test the reliability of COMSOL Multiphysics for the development of MHD models, a method for verification and validation of magnetohydrodynamic codes is followed. The benchmark problems solved regard steady state, fully developed flows in rectangular ducts, non-isothermal flows, flow in a spatially varying transverse magnetic field and two different unsteady turbulent problems, quasi-two-di-mensional MHD turbulent flow and 3D turbulent MHD flow entering a magnetic obstacle. The computed results show good agreement with the reference solutions for all the addressed problems, suggesting that COMSOL can be used as software to study liquid metal MHD problems under the flow regimes typical of fusion power reactors

Landslides and geophysical investigations: advantages and limitations

This special issue is dedicated to the geophysical methods applied to investigate, characterize, and monitor landslides. Over the years, both the advantages and limitations of these techniques have been highlighted, and some drawbacks are still open. Some papers were submitted to this special issue, and, after a thorough peer review process, only five articles were selected to be included in this special issue. This relatively small number is probably caused by the difficulty in applying geophysical techniques on slope movements given hard-operating conditions (e.g., high slopes, distance from access roads, and lack of security for the technical operator) and not because the methods limitations are greater than the advantages

DEM of triaxial tests on crushable cemented sand

Using the discrete element method, triaxial simulations of cemented sand consisting of crushable particles are presented. The triaxial model used features a flexible membrane, allowing realistic deformation to occur, and cementation is modelled using inter-particle bonds. The effects of particle crushing are explored, as is the influence of cementation on the behaviour of the soil. An insight to the effects that cementation has on the degree of crushing is presented

Modelling the PbLi flow including tritium transport and permeation with GETTHEM

One of the main challenges to be addressed to achieve a reliable electricity production from the EU DEMO reactor is the realization of a closed fuel cycle, for which a suitable Tritium Extraction and Removal System (TERS) is required. One of the possible technologies identified for the EU DEMO TERS is the Permeator Against Vacuum (PAV): the tritium dissolved in the liquid PbLi flowing within several parallel channels will permeate towards the vacuum pumped on the other side of the channel wall (the membrane). A recently-developed model of the tritium permeation across the membrane in the PAV, involving both transport phenomena in the wall and surface processes, was already used to size the EU DEMO PAV. However, besides the component itself, it is important to properly define the interfaces of the PAV in the TERS, and of the TERS in the entire PbLi and tritium loops. The model of such a complex system is therefore implemented here in the Modelica object-oriented language used by system-level tool GETTHEM, that already includes a model of the PbLi loop. The resulting, lumped-parameter component will be able to capture the thermal-hydraulic behaviour of the PbLi, to model the tritium transport in the fluid and to estimate the tritium permeated flux supplied to the tritium processing. Such a model is tested here on a sub-scale circuit to demonstrate its capability to simulate the operation of the EU DEMO TERS using the GETTHEM code. As the physical parameters of the model are subject to a large uncertainty, an uncertainty propagation analysis is also performed, to have a preliminary quantification of the impact of such uncertainties on the model output and, therefore, on the TERS efficiency, and to drive further investigations of these physical properties. In particular, results show how the uncertainty on the solubility constant of hydrogen in PbLi represents the dominant contribution on the total variance, highlighting the need for a better accuracy of such parameter

Status of maturation of critical technologies and systems design: Breeding blanket

The scope of the EUFOfusion Work Package Breeding Blanket is to develop a blanket concept for the EU DEMO reactor; this includes the blanket segments inside the Vacuum Vessel and the related Tritium Extraction/Removal Systems. In the Pre-Concept Design (PCD) Phase, two concepts have been selected as candidates; a solid and a liquid breeder blanket cooled with helium and water, respectively. The design of these two blanket systems has been adapted to the DEMO plant design developed in the PCD Phase and performances assessed. A large R&D programme has been implemented with the scope to evaluate different technologies for these blankets; including the development of breeders, tritium extraction and cooling technologies, and the manufacturing of the blanket system. A major milestone in the subsequent Concept Design Phase is the final selection of the blanket concept for DEMO

Labour politics and society in South Yorkshire.

This doctoral thesis looks at Labour politics and society in South Yorkshire between the start of the Second World War in September 1939 and the fall from office of the Attlee Labour Government in October 1951. While it accepts the predominating effects of national and international factors in providing challenges which Labour councils and local Labour Parties had to find solutions to - such as the effects of the Sheffield Blitz in 1940 and the need to re-plan Sheffield and the maintaining of the organisational existence of Labour Parties during the Second World War - it nevertheless examines those 'micro-historical' factors which made for the local diversity of the party in South Yorkshire. It tries to create a holistic and rounded portrait of the local Labour movement based mainly on fragmentary archival and newspaper evidence and examines current historical debates for local relevance such as whether a post-war consensus actually existed, whether popular political attitudes were radical or conservative and, whether such popular attitudes favoured or disfavoured Labour. It also looks at Marxist debates over the concept of 'Labourism' and whether Labour was narrowly culturally determined or whether other factors were equally important. Chapter One introduces the thesis. Chapter Two examines the fears over the post-war industrial future of Sheffield which took place during the Second World War within the City Council and between it and organisations like the trade unions and the Chamber of Commerce. It also looks at City Council debates over the proposed post-war regionalisation of local government and how that was prevented by a united council. This shows that the centralising tendencies of the London government could be resisted by the peripheries and that such tendencies were not inevitable. Chapter Three examines town planning in Sheffield during the Second World War after the Blitz in December 1940 provided an opportunity to create a more modem, better planned and less ugly city. The planning process is examined and the secrecy of the City Council noted at a time when the country was fighting to defend an open and democratic society from the Nazis. Chapter Three also looks at the wartime context of the acute post-war housing crisis. Chapter Four looks at the wartime Labour Party in South Yorkshire, its ebb in membership prior to 1942 and its resurgence after that date ending with an examination of the 1945 General Election in Sheffield. Chapter Five looks at local government between 1945 and 1951, examining the factors which prevented the reform of the local structure of local government, the effect on Sheffield and Rotherham Councils of the nationalisation of electricity, gas and local authority hospitals, and the attempts to implement the Butler Education Act of 1944 in South Yorkshire. Chapter Six looks at the attempts to implement the 1945 Collie town plan for Sheffield and the reasons for the lack of progress as well as at the contrasting housing records of Sheffield and Rotherham Councils. It attempts to account for the latter's better record when compared with the former. Chapter Seven looks the ideology and cultural determinants of the Labour Party in South Yorkshire between 1945 and 1951. It also examines Labour organisation noting the essential role of women as unpaid voluntary labour and contrasting it with their limited entry to local political office. Finally it looks at and comments on the municipal and general election results in Sheffield of the Labour Party between 1945 and 1951. Chapter Eight provides a conclusion

Expression of cytokine and chemokine mRNA and secretion of tumor necrosis factor-α by gallbladder epithelial cells: Response to bacterial lipopolysaccharides

BACKGROUND: In addition to immune cells, many other cell types are known to produce cytokines. Cultured normal mouse gallbladder epithelial cells, used as a model system for gallbladder epithelium, were examined for their ability to express the mRNA of various cytokines and chemokines in response to bacterial lipopolysaccharide. The synthesis and secretion of the tumor necrosis factor-α (TNF-α) protein by these cells was also measured. RESULTS: Untreated mouse gallbladder cells expressed mRNA for TNF-α, RANTES, and macrophage inflammatory protein-2 (MIP-2). Upon treatment with lipopolysaccharide, these cells now produced mRNA for Interleukin-1β (IL-1β), IL-6, monocyte chemoattractant protein-1 (MCP-1), and showed increased expression of TNF-α and MIP-2 mRNA. Untreated mouse gallbladder cells did not synthesize TNF-α protein; however, they did synthesize and secrete TNF-α upon treatment with lipopolysaccharide. METHODS: Cells were treated with lipopolysaccharides from 3 strains of bacteria. Qualitative and semi-quantitative RT-PCR, using cytokine or chemokine-specific primers, was used to measure mRNA levels of TNFα, IL-1β, IL-6, IL-10, KC, RANTES, MCP-1, and MIP-2. TNF-α protein was measured by immunoassays. CONCLUSION: This research demonstrates that gallbladder epithelial cells in response to lipopolysaccharide exposure can alter their cytokine and chemokine RNA expression pattern and can synthesize and secrete TNFα protein. This suggests a mechanism whereby gallbladder epithelial cells in vivo may mediate gallbladder secretory function, inflammation and diseases in an autocrine/paracrine fashion by producing and secreting cytokines and/or chemokines during sepsis

Perceptions of STEM and Liberal Arts Policy in Florida

The promotion of STEM (Science, Technology, Engineering, and Mathematics) education is similar to the rhetoric of the Space Race. Only 19% of U.S. degrees are in STEM fields, compared to over 50% in China (National Science and Technology Council, 2013). Policy makers like President Obama, New Jersey Governor Chris Christie, and Maryland Governor Martin O'Malley tie STEM investment directly to economic impact, using language similar to the rhetoric President Eisenhower utilized to promote the National Defense Education Act (NDEA) of 1958. Florida Governor Rick Scott places STEM in zero-sum competition against liberal arts subjects with the rationale of stimulating economic growth. I surveyed and interviewed Florida policy makers to explore their perceptions of STEM and liberal arts fields. I wanted to know how these perceptions influenced policy formation. I examined press releases to identify trends and messaging from Governor Scott's office. The majority of policy actors supported balanced positions on the 7-point Likert scale survey items, recognizing the economic importance of STEM education while also noting the value of liberal arts disciplines. However, when given the freedom to respond in open-ended survey items and semi-structured interviews, many policy makers revealed positions closer to the zero-sum strategies of Governor Scott. They were dismissive of the utility of liberal arts subjects, and saw them as frivolous and unnecessary. Other participants defended the value of the liberal arts and saw them as a necessary component of a tertiary education. My research demonstrates that the relationship between higher education and economic impact is unpredictable. To maximize economic growth, universities should produce opportunistic communicators who recognize opportunities in the Information Age economy and communicate to consumers across state and national borders. Zero-sum competitions between STEM and the liberal arts are unnecessary and detrimental in a non-zero-sum global economy