15 research outputs found

    High-Performance SiC–Based Solar Receivers for CSP: Component Manufacturing and Joining

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    Concentrated solar power (CSP) is an important option as a competitive, secure, and sustainable energy system. At the moment, cost-effective solutions are required for a wider-scale deployment of the CSP technology: in particular, the industrial exploitation of CSP has been so far hindered by limitations in the materials used for the central receiver—a key component in the system. In this context, the H2020 NEXTOWER project is focused on next-generation CSP technologies, particularly on advanced materials for high temperatures (e.g., >900 °C) and extreme applications environments (e.g., corrosive). The research activity described in this paper is focused on two industrial solutions for new SiC ceramic receivers for high thermal gradient continued operations: porous SiC and silicon-infiltrated silicon carbide ceramics (SiSiC). The new receivers should be mechanically tough and highly thermally conductive. This paper presents the activity related to the manufacturing of these components, their joining, and characterization

    The identification & optimisation of endogenous signalling pathway modulators

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    Chapter 1 Provides an overview of drug discovery with particular emphasis on library selection and hit identification methods using virtual based approaches. Chapter 2 Gives an outline of the bone morphogenetic protein (BMP) signalling pathway and literature BMP pathway modulators. The association between the regulation of BMP pathway and cardiomyogenesis is also described. Chapter 3 Describes the use of ligand based virtual screening to discover small molecule activators of the BMP signalling pathway. A robust cell based BMP responsive gene activity reporter assay was developed to test the libraries of small molecules selected. Hit molecules from the screen were synthesised to validate activity. It was found that a group of known histone deacetylase (HDAC) inhibitors displayed most promising activity. These were evaluated in a secondary assay measuring the expression of two BMP pathway regulated genes, hepcidin and Id1, using reverse transcription polymerase chain reaction (RT-PCR). 188 was discovered to increase expression of both BMP-responsive genes. Chapter 4 Provides an overview of existing cannabinoid receptor (CBR) modulating molecules and their connection to progression of atherosclerosis. Chapter 5 Outlines the identification and optimisation of selective small molecule agonists acting at the cannabinoid 2 receptor (CB2R). Ligand based virtual screen was undertaken and promising hits were synthesised to allow structure activity relationship (SAR) to be developed around the hit molecule providing further information of the functional groups tolerated at the active site. Subsequent studies led to the investigation and optimisation of physicochemical properties around 236 leading to the development of a suitable compound for in vivo testing. Finally, a CB2R selective compound with favourable physicochemical properties was evaluated in vivo in a murine inflammation model and displayed reduced recruitment of monocytes to the site of inflammation.</p

    The identification & optimisation of endogenous signalling pathway modulators

    No full text
    Chapter 1 Provides an overview of drug discovery with particular emphasis on library selection and hit identification methods using virtual based approaches. Chapter 2 Gives an outline of the bone morphogenetic protein (BMP) signalling pathway and literature BMP pathway modulators. The association between the regulation of BMP pathway and cardiomyogenesis is also described. Chapter 3 Describes the use of ligand based virtual screening to discover small molecule activators of the BMP signalling pathway. A robust cell based BMP responsive gene activity reporter assay was developed to test the libraries of small molecules selected. Hit molecules from the screen were synthesised to validate activity. It was found that a group of known histone deacetylase (HDAC) inhibitors displayed most promising activity. These were evaluated in a secondary assay measuring the expression of two BMP pathway regulated genes, hepcidin and Id1, using reverse transcription polymerase chain reaction (RT-PCR). 188 was discovered to increase expression of both BMP-responsive genes. Chapter 4 Provides an overview of existing cannabinoid receptor (CBR) modulating molecules and their connection to progression of atherosclerosis. Chapter 5 Outlines the identification and optimisation of selective small molecule agonists acting at the cannabinoid 2 receptor (CB2R). Ligand based virtual screen was undertaken and promising hits were synthesised to allow structure activity relationship (SAR) to be developed around the hit molecule providing further information of the functional groups tolerated at the active site. Subsequent studies led to the investigation and optimisation of physicochemical properties around 236 leading to the development of a suitable compound for in vivo testing. Finally, a CB2R selective compound with favourable physicochemical properties was evaluated in vivo in a murine inflammation model and displayed reduced recruitment of monocytes to the site of inflammation.This thesis is not currently available in OR

    Sex-based differences in neurocognitive functioning in HIV-infected young adults.

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    INTRODUCTION:Sex differences in cognition of HIV positive (HIV) patients are controversial. We aimed to investigate the relationship between cognition, HIV status, and sex, in a highly homogenous cohort of young Romanians parenterally infected during early childhood. METHODS:In total, 250 HIV participants were compared with age-matched HIV negative (HIV) controls (n = 72) in a cross-sectional study. After standardized neurocognitive, psychological testing and medical evaluation, linear regression was used to assess the effect of sex and HIV on neurocognitive outcomes. RESULTS:Study participants were on average 23 years old with balanced sex distribution (% women = 52% vs. 43%). HIV were more educated (12.7 vs. 11.6 years, P = 0.002).HIV status was associated with a lower global performance (β = -0.22, P &lt; 0.001), after controlling for age and education. HIV women had better previous and current HIV-associated markers. The effect of HIV on global cognition did not differ between sexes in most cognitive domains (β = 0.07, P = 0.14). An interaction between sex, HIV status, and cognitive functioning was found in the psychomotor domain. HIV women had worse motor skills than HIV women (β = -0.32, P &lt; 0.001) suggesting a specific effect of HIV on motor functioning in women only. Moreover, current CD4 less than 200 cells/μl (P = 0.013) and longer time lived with CD4 less than 200 cells/μl (P = 0.023) were negatively correlated with the motor scaled score in women (β = -0.22, P = 0.034). CONCLUSION:Despite less advanced disease in women, long-term HIV infection has an equally detrimental effect on cognitive performances of both sexes, in all cognitive domains, except the psychomotor domain where women are preferentially affected

    Dynamic modeling, simulation and optimization of the partially-autothermal reforming of biogas in coated monolith channels

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    A dynamic model is proposed describing a catalyst-coated SiSiC monolithic structure taking as a case study the autothermal reforming of biogas (SCR=3; OCR=0.66) in an adiabatic mode of operation. A single channel 2-D representation is assumed including dimensionless mass and energy transport equations solved in gPROMS platform resembling the performance of the whole monolith by breaking down the channel topology into three computational layers, namely the channel, the porous catalytic washcoat, where catalytic reforming and oxidation reactions take place, and the supporting wall. The model is verified using literature kinetics data in comparison with thermodynamic equilibrium analysis in HSC Chemistry software, which hints an optimization scheme for the optimal washcoat thickness to maximize H2 formation. The optimal values are applied to the three-layer model in order to track the dynamic evolution of the dependent variables of temperature and compositions from start-up of the monolith to the introduction of the biogas-O2 feed at the desired temperature to the response of the system to any disturbances being imposed after steady-state is reached. The overall dynamic model can interpret various aspects of the combined combustion and reforming of biogas in catalytic monolithic structures and can be used as an assistance for experiment design and process optimization

    Sandwich structured ceramic matrix composites with periodic cellular ceramic cores: an active cooled thermal protection for space vehicles

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    Ceramic cellular structures and ceramic matrix composites (CMCs), are promising materials for thermal protection systems (TPS) of future space vehicles. This is because of the good thermal properties of their cellular cores coupled with the matchless thermo-mechanical resistance of their CMC skins. A high temperature TPS with active cooling accomplished by flowing a gas into the sandwich’s core is investigated in this work. Three-dimensional thermo fluid dynamics analysis was first performed to evaluate the heat exchange in the ceramic sandwich under a Earth re-entry condition. The simulations, aiming at optimizing the TPS configuration, analysed several cellular ceramics structures by varying inlet and outlet positions, the coolant fluid and mass flows. A hexagonal cell was chosen as basic element of the porous ceramic. Sandwich structure components were produced and assembled by joining. Finally a prototypic leading edge was produced and tested in plasma wind tunnel in a standard re-entry condition. Cooling was performed with different gases and mass flows. Results are reported and discussed.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement N° 312807

    Assessing the Long-Term Role of Vaccination against HPV after Loop Electrosurgical Excision Procedure (LEEP): A Propensity-Score Matched Comparison

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    Background: Primary prevention through vaccination is a prophylactic approach aiming to reduce the risk of developing human papillomavirus (HPV)-related lesions. No mature and long-term data supported the adoption of vaccination in women undergoing conization. Methods: This is a retrospective multi-institutional study. Charts of consecutive patients undergoing conization between 2010 and 2014 were collected. All patients included had at least 5 years of follow-up. We compared outcomes of patients undergoing conization plus vaccination and conization alone. A propensity-score matching algorithm was applied in order to reduce allocation biases. The risk of developing recurrence was estimated using Kaplan-Meir and Cox hazard models. Results: Overall, charts of 1914 women were analyzed. The study group included 116 (6.1%) and 1798 (93.9%) women undergoing conization plus vaccination and conization alone, respectively. Five-year recurrence rate was 1.7% (n = 2) and 5.7% (n = 102) after conization plus vaccination and conization alone, respectively (p = 0.068). After the application of a propensity-score matching, we selected 100 patients undergoing conization plus vaccination and 200 patients undergoing conization alone. The crude number of recurrences was 2 (2%) and 11 (5.5%) for patients undergoing conization plus vaccination and conization alone, respectively (p = 0.231). Vaccination had no impact on persistent lesions (no negative examination between conization and new cervical dysplasia; p = 0.603), but reduced the risk of recurrent disease (patients who had at least one negative examination between conization and the diagnosis of recurrent cervical dysplasia; p = 0.031). Conclusions: Patients having vaccination experience a slightly lower risk of recurrence than women who had not, although not statistically significantly different. Further evidence is needed to assess the cost effectiveness of adopting vaccination in this setting
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