193 research outputs found
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A study of panel ridges effect on heat transfer and pressure drop in a ventilation duct
CFD simulations were conducted to assess turbulent forced convection heat transfer and pressure drop through a ventilation channel using a stack of panels with different ridge configurations containing Phase Change Material (PCM). First, an experimental rig using an existing commercial panel provided by a PCM manufacturer validates the model simulated in Ansys FLUENT. After that, 3D simulations with different designs were tested until the optimum configuration in terms of heat transfer and pressure drop was achieved. The optimum design by geometry and performance was drawn in 2D and a parametric analysis was performed by varying the spacing between ridges, height and ridge radius to identify difference in heat transfer performance. For both experiment and simulation, the flow rate in terms of Reynolds number based on the inlet hydraulic diameter of the channel ranged from 7200 to 21600. When compared with a flat and existing commercial panel, results show that the inclusion of ridges increase the Nusselt Number by 68 and 93% respectively at a Reynolds number of 21600. At a Reynolds number of 18736, the Nusselt number of the optimum panel is enhanced by 64 and 111% when compared to the flat and existing commercial panel, respectively. This panel was then taken forward to allow further refinements which include changes in panel thickness and number of panels per module. After more than 200 different panel designs and airflows simulations, a new design is proposed which reduces the number of panels per module from 9 to 6, thus reducing production costs but keeping nearly the same heat flux and pressure drop as the existing commercial panel. When 7 panels are used, it is possible to hold 13.68% more material with an increased pressure drop 3.36 times higher than the existing commercial panel (176.80 against 52.69 Pa) at a Reynolds number of 18736
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Carbon brainprint - An estimate of the intellectual contribution of research institutions to reducing greenhouse gas emissions
This is the accepted manuscript of a paper published in Process Safety and Environmental Protection (Chatterton J, et al., Process Safety and Environmental Protection, 2015, 96, 74-81, doi:10.1016/j.psep.2015.04.008). The final version is available at http://dx.doi.org/10.1016/j.psep.2015.04.008Research and innovation have considerable, currently unquantified potential to reduce greenhouse gas emissions by, for example, increasing energy efficiency. Furthermore, the process of knowledge transfer in itself can have a significant impact on reducing emissions, by promoting awareness and behavioural change. The concept of the ‘carbon brainprint’ was proposed to convey the intellectual contribution of higher education institutions to the reduction of greenhouse gas emissions by other parties through research and teaching/training activities. This paper describes an investigation of the feasibility of quantifying the carbon brainprint, through six case studies. The potential brainprint of higher education institutes is shown to be significant: up to 500 kt CO2e/year for one project. The most difficult aspect is attributing the brainprint among multiple participants in joint projects.The Carbon Brainprint project was supported by the Higher Education Funding Council for England (HEFCE) under its Leading Sustainable Development in Higher Education programme, with support for case studies from Santander Universities. HEFCE, Research Councils UK and the Carbon Trust were members of the Steering Committee, which provided guidance, but did not direct the research. The Carbon Trust also advised on best practice in carbon footprinting.
We are grateful to the many university staff at Cranfield, Cambridge and Reading Universities who shared their work with us so enthusiastically.
We also thank the external partners and clients for the projects on which these case studies are based: Rolls-Royce plc, the ETI NOVA consortium, IGD, the Environment Agency, Esso, Repsol YPF, Carnego Systems Ltd. and Newera Controls Ltd
Barriers and opportunities for evidence-based health service planning: the example of developing a Decision Analytic Model to plan services for sexually transmitted infections in the UK
Decision Analytic Models (DAMs) are established means of evidence-synthesis to differentiate between health interventions. They have mainly been used to inform clinical decisions and health technology assessment at the national level, yet could also inform local health service planning. For this, a DAM must take into account the needs of the local population, but also the needs of those planning its services. Drawing on our experiences from stakeholder consultations, where we presented the potential utility of a DAM for planning local health services for sexually transmitted infections (STIs) in the UK, and the evidence it could use to inform decisions regarding different combinations of service provision, in terms of their costs, cost-effectiveness, and public health outcomes, we discuss the barriers perceived by stakeholders to the use of DAMs to inform service planning for local populations, including (1) a tension between individual and population perspectives; (2) reductionism; and (3) a lack of transparency regarding models, their assumptions, and the motivations of those generating models
Myocarditis in CD8-Depleted SIV-Infected Rhesus Macaques after Short-Term Dual Therapy with Nucleoside and Nucleotide Reverse Transcriptase Inhibitors
Background: Although highly active antiretroviral therapy (HAART) has dramatically reduced the morbidity and mortality associated with HIV infection, a number of antiretroviral toxicities have been described, including myocardial toxicity resulting from the use of nucleotide and nucleoside reverse transcriptase inhibitors (NRTIs). Current treatment guidelines recommend the use of HAART regimens containing two NRTIs for initial therapy of HIV-1 positive individuals; however, potential cardiotoxicity resulting from treatment with multiple NRTIs has not been addressed. Methodology/Principal Findings: We examined myocardial tissue from twelve CD8 lymphocyte-depleted adult rhesus macaques, including eight animals infected with simian immunodeficiency virus, four of which received combined antiretroviral therapy (CART) consisting of two NRTIs [(9-R-2-Phosphonomethoxypropyl Adenine) (PMPA) and (+/−)-beta-2′,3′-dideoxy-5-fluoro-3′-thiacytidine (RCV)] for 28 days. Multifocal infiltrates of mononuclear inflammatory cells were present in the myocardium of all macaques that received CART, but not untreated SIV-positive animals or SIV-negative controls. Macrophages were the predominant inflammatory cells within lesions, as shown by immunoreactivity for the macrophage markers Iba1 and CD68. Heart specimens from monkeys that received CART had significantly lower virus burdens than untreated animals (p<0.05), but significantly greater quantities of TNF-α mRNA than either SIV-positive untreated animals or uninfected controls (p<0.05). Interferon-γ (IFN-γ), IL-1β and CXCL11 mRNA were upregulated in heart tissue from SIV-positive monkeys, independent of antiretroviral treatment, but CXCL9 mRNA was only upregulated in heart tissue from macaques that received CART. Conclusions/Significance: These results suggest that short-term treatment with multiple NRTIs may be associated with myocarditis, and demonstrate that the CD8-depleted SIV-positive rhesus monkey is a useful model for studying the cardiotoxic effects of combined antiretroviral therapy in the setting of immunodeficiency virus infection
HIV-1 Disease Progression Is Associated with Bile-Salt Stimulated Lipase (BSSL) Gene Polymorphism
Background: DC-SIGN expressed by dendritic cells captures HIV-1 resulting in trans-infection of CD4+ T-lymphocytes. However, BSSL (bile-salt stimulated lipase) binding to DC-SIGN interferes with HIV-1 capture. DC-SIGN binding properties of BSSL associate with the polymorphic repeated motif of BSSL exon 11. Furthermore, BSSL binds to HIV-1 co-receptor CXCR4. We hypothesized that BSSL modulates HIV-1 disease progression and emergence of CXCR4 using HIV-1 (X4) variants. Results: The relation between BSSL genotype and HIV-1 disease progression and emergence of X4 variants was studied using Kaplan Meier and multivariate Cox proportional hazard analysis in a cohort of HIV-1 infected men having sex with men (n = 334, with n = 130 seroconverters). We analyzed the association of BSSL genotype with set-point viral load and CD4 cell count, both pre-infection and post-infection at viral set-point. The number of repeats in BSSL exon 11 were highly variable ranging from 10 to 18 in seropositive individuals and from 5-17 in HRSN with 16 repeats being dominant (>80% carry at least one allele with 16 repeats). We defined 16 to 18 repeats as high (H) and less than 16 repeats as low (L) repeat numbers. Homozygosity for the high (H) repeat number BSSL genotype (HH) correlated with high CD4 cell numbers prior to infection (p = 0.007). In HIV-1 patients, delayed disease progression was linked to the HH BSSL genotype (RH = 0.462 CI = 0.282-0.757, p = 0.002) as was delayed emergence of X4 variants (RH = 0.525, 95% CI = 0.290-0.953, p = 0.034). The LH BSSL genotype, previously found to be associated with enhanced DC-SIGN binding of human milk, was identified to correlate with accelerated disease progression in our cohort of HIV-1 infected MSM (RH = 0.517, 95% CI = 0.328-0.818, p = 0.005). Conclusion: We identify BSSL as a marker for HIV-1 disease progression and emergence of X4 variants. Additionally, we identified a relation between BSSL genotype and CD4 cell counts prior to infectio
From 'trading zones' to 'buffer zones': Art and metaphor in the communication of psychiatric genetics to publics
Psychiatric genetics has a difficult relationship with the public given its unshakeable connection to eugenics. Drawing from a five-year public engagement programme that emerged from an internationally renowned psychiatric genetics centre, we propose the concept of the Buffer Zone to consider how an exchange of viewpoints between groups of people – including psychiatric geneticists and lay publics - who are often uneasy in one another’s company can be facilitated through the use of art and metaphor. The artwork at the exhibitions provided the necessary socio-cultural context for scientific endeavours, whilst also enabled public groups to be part of, and remain in, the conversation. Crucial to stress is that this mitigation was not to protect the science; it was to protect the discussion
Collaborative International Research in Clinical and Longitudinal Experience Study in NMOSD
OBJECTIVE: To develop a resource of systematically collected, longitudinal clinical data and biospecimens for assisting in the investigation into neuromyelitis optica spectrum disorder (NMOSD) epidemiology, pathogenesis, and treatment. METHODS: To illustrate its research-enabling purpose, epidemiologic patterns and disease phenotypes were assessed among enrolled subjects, including age at disease onset, annualized relapse rate (ARR), and time between the first and second attacks. RESULTS: As of December 2017, the Collaborative International Research in Clinical and Longitudinal Experience Study (CIRCLES) had enrolled more than 1,000 participants, of whom 77.5% of the NMOSD cases and 71.7% of the controls continue in active follow-up. Consanguineous relatives of patients with NMOSD represented 43.6% of the control cohort. Of the 599 active cases with complete data, 84% were female, and 76% were anti-AQP4 seropositive. The majority were white/Caucasian (52.6%), whereas blacks/African Americans accounted for 23.5%, Hispanics/Latinos 12.4%, and Asians accounted for 9.0%. The median age at disease onset was 38.4 years, with a median ARR of 0.5. Seropositive cases were older at disease onset, more likely to be black/African American or Hispanic/Latino, and more likely to be female. CONCLUSION: Collectively, the CIRCLES experience to date demonstrates this study to be a useful and readily accessible resource to facilitate accelerating solutions for patients with NMOSD
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