101 research outputs found

    A Multiscale Thermo-Fluid Computational Model for a Two-Phase Cooling System

    Get PDF
    In this paper, we describe a mathematical model and a numerical simulation method for the condenser component of a novel two-phase thermosyphon cooling system for power electronics applications. The condenser consists of a set of roll-bonded vertically mounted fins among which air flows by either natural or forced convection. In order to deepen the understanding of the mechanisms that determine the performance of the condenser and to facilitate the further optimization of its industrial design, a multiscale approach is developed to reduce as much as possible the complexity of the simulation code while maintaining reasonable predictive accuracy. To this end, heat diffusion in the fins and its convective transport in air are modeled as 2D processes while the flow of the two-phase coolant within the fins is modeled as a 1D network of pipes. For the numerical solution of the resulting equations, a Dual Mixed-Finite Volume scheme with Exponential Fitting stabilization is used for 2D heat diffusion and convection while a Primal Mixed Finite Element discretization method with upwind stabilization is used for the 1D coolant flow. The mathematical model and the numerical method are validated through extensive simulations of realistic device structures which prove to be in excellent agreement with available experimental data

    A glimpse into the biogeography, seasonality, and ecological functions of arctic marine Oomycota

    Get PDF
    Source at https://doi.org/10.1186/s43008-019-0006-6. © The Author(s). 2019High-latitude environments are warming, leading to changes in biological diversity patterns of taxa. Oomycota are a group of fungal-like organisms that comprise a major clade of eukaryotic life and are parasites of fish, agricultural crops, and algae. The diversity, functionality, and distribution of these organisms are essentially unknown in the Arctic marine environment. Thus, it was our aim to conduct a first screening, using a functional gene assay and high-throughput sequencing of two gene regions within the 18S rRNA locus to examine the diversity, richness, and phylogeny of marine Oomycota within Arctic sediment, seawater, and sea ice. We detected Oomycota at every site sampled and identified regionally localized taxa, as well as taxa that existed in both Alaska and Svalbard. While the recently described diatom parasite Miracula helgolandica made up about 50% of the oomycete reads found, many lineages were observed that could not be assigned to known species, including several that clustered with another recently described diatom parasite, Olpidiopsis drebesii. Across the Arctic, Oomycota comprised a maximum of 6% of the entire eukaryotic microbial community in Barrow, Alaska May sediment and 10% in sea ice near the Svalbard archipelago. We found Arctic marine Oomycota encode numerous genes involved in parasitism and carbon cycling processes. Ultimately, these data suggest that Arctic marine Oomycota are a reservoir of uncharacterized biodiversity, the majority of which are probably parasites of diatoms, while others might cryptically cycle carbon or interface other unknown ecological processes. As the Arctic continues to warm, lower-latitude Oomycota might migrate into the Arctic Ocean and parasitize non-coevolved hosts, leading to incalculable shifts in the primary producer community

    Child protection and family support: Experiences in a seaside resort

    Get PDF
    This is the final version. Available on open access from Elsevier via the DOI in this recordData availability: The data that has been used is confidential.Effective Early Help services are key to halting rising rates of children in care in the UK. Yet despite family support and child welfare interventions being unequally distributed across the country, the role of ‘place’ has received limited attention in the children’s social care arena. This paper examines the connections between coastal challenges, Early Help and child welfare interventions, drawing on embedded research undertaken within a Local Authority on England’s coast with elevated levels of children in care. We focus on families’ experiences raising children in a seaside resort area as well as professionals’ perspectives on the place-based challenges faced delivering effective and accessible Early Help support. The study generated data from ethnographic observations, semi-structured interviews, and focus groups with local parents/carers (n = 57), service managers and frontline professionals (n = 14), and the Voluntary, Community, and Social Enterprise (VCSE) sector (n = 22). The findings highlight how the socio-economic challenges associated with many seaside resort areas, including housing pressures, a seasonal and low-wage economy, and the transience of the population, present difficulties for parents/carers in raising and supporting their children. For professionals delivering Early Help, high levels of housing instability, elevated inward migration, resource constraints and challenges around recruitment and retention presented challenges to delivering services. This paper recommends increased emphasis in regulation and resourcing around family support that considers the spatial and geographic dynamics that influence the incidence, structuring, and experiences of child and family welfare.Torbay Medical Support FundWellcome Centre for Cultures and Environments of HealthNational Institute for Health and Care Research (NIHR

    The role of the voluntary, community and social enterprise sector in Early Help: Critical reflections from embedded social care research

    Get PDF
    This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The data that support the findings of this study are available on request from the corresponding author, Thomas El-Hoss. The data are not publicly available due to their containing sensitive information that could compromise the privacy of research participants.The independent review of children's social care (2022) has proposed a radical reset of England's children's services, shifting a remote, assessment heavy system towards one that works alongside communities to help prevent statutory interventions. However, notions around the harnessing of community resources to deliver Early Help are often underpinned by assumptions regarding the voluntary, community and social enterprise (VCSE) sector and the ease with which such organizations can be integrated into preventative strategies. This paper reports findings from embedded research within a unitary authority in Southwest England during remodelling of its Early Help service to work more collaboratively with local VCSE organizations. The study generated data from ethnographic observations, semi-structured interviews and focus groups with 95 participants, including local parents, service providers, VCSE organizations and Council leaders. The findings illustrate that families value the compassionate, responsive and flexible support available within many VCSE settings. However, differences in practice cultures, regulatory pressures on statutory providers, the need to (re)build trust in communities and sensitivities around power-sharing and resourcing meant negotiating VCSE sector integration was fraught with complexities. Few studies have gained such privileged access to a Local Authority's remodelling of Early Help services, and this paper has significant insights for the debates surrounding the independent review of children's social care (2022) and its recommendation to bring services ‘closer to communities’.Torbay Medical Research Fun

    Sclerosing Epithelioid Fibrosarcoma of the Bone: A Case Report of High Resistance to Chemotherapy and a Survey of the Literature

    Get PDF
    Sclerosing epithelioid fibrosarcoma (SEF) is a rare soft tissue sarcoma mostly occurring in extraosseous sites. SEF represents a clinically challenging entity especially because no standardized treatment regimens are available. Intraosseous localization is an additional challenge with respect to the therapeutical approach. We report on a 16-year-old patient with SEF of the right proximal tibia. The patient underwent standardized neoadjuvant chemotherapy analogous to the EURAMOS-1 protocol for the treatment of osteosarcoma followed by tumor resection and endoprosthetic reconstruction. Histopathological analysis of the resected tumor showed >90% vital tumor cells suggesting no response to chemotherapy. Therefore, therapy was reassigned to the CWS 2002 High-Risk protocol for the treatment of soft tissue sarcoma. To date (22 months after diagnosis), there is no evidence of relapse or metastasis. Our data suggest that SEF may be resistant to a chemotherapy regimen containing Cisplatin, Doxorubicin, and Methotrexate, which should be considered in planning treatment for patients with SEF

    Extrakorporale hydrostatische Hochdruckbehandlung als neues Verfahren zur Desinfektion infizierter Knochenpräparate

    Get PDF
    Background: Allogeneic bone transplantation is at risk of infection, and established disinfection methods typically compromise bone quality. High hydrostatic pressure (HHP) is well established for disinfection in food technology, and also it does protect biomechanical and biological properties of bone. This study is the first investigation of HHP regarding disinfection of bone biopsies. Materials and methods: Bone biopsies of 34 patients with chronic infections were subjected to HHP and assessed for persisting bacterial growth. In series 1, bone biopsies were proceeded directly to HHP (10 min; maximal pressure P-max 600 MPa). In series 2, HHP was applied after 5-day incubation in growth media (10 min or 2 x 30 min; P-max 600 MPa). Furthermore, HHP-induced changes of bacterial morphology on artificially infected bone samples were evaluated by scanning electron microscopy (SEM). Results: For series 1, 71% of the bone samples were sterilised by HHP (n = 17), compared to 38% of the untreated control samples, which were obtained during the same surgery (n = 8). For series 2, after prior incubation, HHP disinfected 7% of the bone specimens (n = 55), all control samples showed bacterial growth (n = 33). Destruction of cell wall integrity of Gram-negative strains was observed by SEM. Conclusion: The effectiveness of HHP for bone disinfection should be improved by optimising treatment parameters. Infections with barosensitive Gram-negative bacteria or yeast might represent possible clinical indications

    MOSAiC Extended Acknowledgement

    Get PDF
    For years, the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), together with the international MOSAiC partners, had been planning and developing the scientific, logistical and financial concept for the implementation of the MOSAiC expedition. The planning and organization of this endeavor was an enormous e˙ort, involving more than 80 institutions from 20 countries. The number of groups and individuals that significantly contributed to the success of the drift observatory goes far beyond the scope of usual polar expeditions

    Sea-ice retreat controls timing of summer plankton blooms in the Eastern Arctic Ocean

    Get PDF
    Two full-year mooring records of sea ice, physical and bio-optical parameters illuminate tight temporal coupling between the retreating seasonal ice edge and the summer phytoplankton bloom on the Laptev Sea shelf. Our records showed no sign of pelagic under-ice blooms despite available nutrients and thinning sea ice in early summer; presumably because stratification had not yet developed. Chlorophyll blooms were detected immediately after the ice retreated in late May 2014 and late July 2015. Despite radically different timing, the blooms were similar in both magnitude and length, interpreted as community-level nutrient limitation. Acoustic backscatter records suggest the delayed 2015-bloom resulted in lower zooplankton abundance, perhaps due to a timing mismatch between ice algal and pelagic blooms and unfavorable thermal conditions. Our observations provide classical examples of ice-edge blooms and further emphasize the complexity of high-latitude shelves and the need to understand vertical mixing processes important for stratification and nutrient fluxes
    corecore