126 research outputs found

    Effects of tidal range on mooring systems of wave energy converters

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    Wave energy converters are currently proposed to be deployed near coastal area for the closeness to the infrastructure and for ease of maintenance in order to reduce operational costs. The motivation behind this work is the fact that the deployment depths during the highest and lowest tides will have a significant effect on the mooring system of WECs. In this paper, the issue will be investigated by numerical modelling (using ANSYS AQWA) for both catenary and taut moorings to examine the performance of the mooring system in varying tides. The case study being considered is the ¼- scale wave energy test site in Galway Bay off the west coast of Ireland where some marine renewable energy devices can be tested. In this test site, the tidal range is macro-tidal with a range of approximately 6 m which is a large value relative to the water depth. In the numerical analysis, ANSYS AQWA suite has been used to simulate moored devices under wave excitation at varying tidal ranges. Results show that the highest tide will give rise to larger forces. While at lower depths, slackening of the mooring occurs. Therefore, the mooring lines must be designed to accommodate both situations

    Techno-mathematical literacies in the workplace: a critical skills gap

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    There has been a radical shift in the mathematical skills required in modern workplaces. With the ubiquity of IT, employees now require Techno-mathematical Literacies, the mastery of new kinds of mathematical knowledge shaped by the systems that govern their work. The education system does not fully recognise these skills, employees often lack them, and companies struggle to improve them. This project has developed prototype learning resources to train a variety of employees in the mathematical awareness and knowledge that today?s employment require

    Tidal flyer; innovation, design & evolution (TIDE)

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    Open Ocean Energy (OOE) Ltd. is a tidal energy company developing a vertical hydrofoil based device, the Tidal Flyer. Following the initial years proving the concept and progressing the design of the system for the past 3 years OOE have been working intensively with Black & Veatch (B& V) on the techno-economic optimisation of the Tidal Flyer configuration. This paper will outline recently conducted Phase 1 physical testing of various aspects of the technical design evolving from the study. CFD work investigating critical features of the system dynamics was also undertaken but is not reported here. The Phase 1 testing was constructed to inform the design of a full, dynamic model due for testing at the combined wave and current tank, Flowave in Edinburgh, Scotland. The latter trials will be undertaken as a Phase 2 test programme. At the end of the physical test schedule, OOE will have completed up to TRL 4 and satisfied a series of predefined stage gates criteria. The programme of empirical testing involved two visits (8 testing days) to the IFREMER flow flume in Boulogne-sur-Mer, France. The CFD analysis is being undertaken at UCC as part of the SFI funded Marine Renewable Energy Ireland [MaREI] scheme. Initially the empirical setups were simulated to verify the test plan

    Numerical hydrodynamic modelling of a pitching wave energy converter

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    Two computational methodologies – computational fluid dynamics (CFD) and the numerical modelling using linear potential theory based boundary element method (BEM) are compared against experimental measurements of the motion response of a pitching wave energy converter. CFD is considered as relatively rigorous approach offering non-linear incorporation of viscous and vortex phenomenon and capturing of the flow turbulence to some extent, whereas numerical approach of the BEM relies upon the linear frequency domain hydrodynamic calculations that can be further used for the time-domain analysis offering robust preliminary design analysis. This paper reports results from both approaches and concludes upon the comparison of numerical and experimental findings

    Numerical hydrodynamic modelling of a pitching wave energy converter

    Get PDF
    Two computational methodologies – computational fluid dynamics (CFD) and the numerical modelling using linear potential theory based boundary element method (BEM) are compared against experimental measurements of the motion response of a pitching wave energy converter. CFD is considered as relatively rigorous approach offering non-linear incorporation of viscous and vortex phenomenon and capturing of the flow turbulence to some extent, whereas numerical approach of the BEM relies upon the linear frequency domain hydrodynamic calculations that can be further used for the time-domain analysis offering robust preliminary design analysis. This paper reports results from both approaches and concludes upon the comparison of numerical and experimental findings

    Numerical hydrodynamic modelling of a pitching wave energy converter

    Get PDF
    Two computational methodologies – computational fluid dynamics (CFD) and the numerical modelling using linear potential theory based boundary element method (BEM) are compared against experimental measurements of the motion response of a pitching wave energy converter. CFD is considered as relatively rigorous approach offering nonlinear incorporation of viscous and vortex phenomenon and capturing of the flow turbulence to some extent, whereas numerical approach of the BEM relies upon the linear frequency domain hydrodynamic calculations that can be further used for the time-domain analysis offering robust preliminary design analysis. This paper reports results from both approaches and concludes upon the comparison of numerical and experimental findings

    Identification of RdRp inhibitors against SARS-CoV-2 through E-pharmacophore-based virtual screening, molecular docking and MD simulations approaches

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    The outbreak of novel Coronavirus, an enduring pandemic declared by WHO, has consequences to an alarming ongoing public health menace which has already claimed several million human lives. In addition to numerous vaccinations and medications for mild to moderate COVID-19 infection, lack of promising medication or therapeutic pharmaceuticals remains a serious concern to counter the ongoing coronavirus infections and to hinder its dreadful spread. Global health emergencies have called for urgency for potential drug discovery and time is the biggest constraint apart from the financial and human resources required for the high throughput drug screening. However, computational screening or in-silico approaches appeared to be an effective and faster approach to discover potential molecules without sacrificing the model animals. Accumulated shreds of evidence on computational studies against viral diseases have revealed significance of in-silico drug discovery approaches especially in the time of urgency. The central role of RdRp in SARS-CoV-2 replication makes it promising drug target to curtain on going infection and its spread. The present study aimed to employ E-pharmacophore-based virtual screening to reveal potent inhibitors of RdRp as potential leads to block the viral replication. An energy-optimised pharmacophore model was generated to screen the Enamine REAL DataBase (RDB). Then, ADME/T profiles were determined to validate the pharmacokinetics and pharmacodynamics properties of the hit compounds. Moreover, High Throughput Virtual Screening (HTVS) and molecular docking (SP & XP) were employed to screen the top hits from pharmacophore-based virtual screening and ADME/T screen. The binding free energies of the top hits were calculated by conducting MM-GBSA analysis followed by MD simulations to determine the stability of molecular interactions between top hits and RdRp protein. These virtual investigations revealed six compounds having binding free energies of −57.498, −45.776, −46.248, −35.67, −25.15 and −24.90 kcal/mol respectively as calculated by the MM-GBSA method. The MD simulation studies confirmed the stability of protein ligand complexes, hence, indicating as potent RdRp inhibitors and are promising candidate drugs to be further validated and translated into clinics in future. © 202

    Collision tumors revealed by prospectively assessing subtype-defining molecular alterations in 904 individual prostate cancer foci.

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    BACKGROUNDProstate cancer is multifocal with distinct molecular subtypes. The utility of genomic subtyping has been challenged due to inter- and intrafocal heterogeneity. We sought to characterize the subtype-defining molecular alterations of primary prostate cancer across all tumor foci within radical prostatectomy (RP) specimens and determine the prevalence of collision tumors.METHODSFrom the Early Detection Research Network cohort, we identified 333 prospectively collected RPs from 2010 to 2014 and assessed ETS-related gene (ERG), serine peptidase inhibitor Kazal type 1 (SPINK1), phosphatase and tensin homolog (PTEN), and speckle type BTB/POZ protein (SPOP) molecular status. We utilized dual ERG/SPINK1 immunohistochemistry and fluorescence in situ hybridization to confirm ERG rearrangements and characterize PTEN deletion, as well as high-resolution melting curve analysis and Sanger sequencing to determine SPOP mutation status.RESULTSBased on index focus alone, ERG, SPINK1, PTEN, and SPOP alterations were identified in 47.5%, 10.8%, 14.3%, and 5.1% of RP specimens, respectively. In 233 multifocal RPs with ERG/SPINK1 status in all foci, 139 (59.7%) had discordant molecular alterations between foci. Collision tumors, as defined by discrepant ERG/SPINK1 status within a single focus, were identified in 29 (9.4%) RP specimens.CONCLUSIONInterfocal molecular heterogeneity was identified in about 60% of multifocal RP specimens, and collision tumors were present in about 10%. We present this phenomenon as a model for the intrafocal heterogeneity observed in previous studies and propose that future genomic studies screen for collision tumors to better characterize molecular heterogeneity.FUNDINGEarly Detection Research Network US National Cancer Institute (NCI) 5U01 CA111275-09, Center for Translational Pathology at Weill Cornell Medicine (WCM) Department of Pathology and Laboratory Medicine, US NCI (WCM SPORE in Prostate Cancer, P50CA211024-01), R37CA215040, Damon Runyon Cancer Research Foundation, US MetLife Foundation Family Clinical Investigator Award, Norwegian Cancer Society (grant 208197), and South-Eastern Norway Regional Health Authority (grant 2019016 and 2020063)

    The emergence of health inequalities in early adulthood: evidence on timing and mechanisms from a West of Scotland cohort

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    Background Evidence is inconsistent as to whether or not there are health inequalities in adolescence according to socio-economic position (SEP) and whether or when they emerge in early adulthood. Despite the large health inequalities literature, few studies have simultaneously compared the relative importance of ?health selection? versus ?social causation? at this life-stage. This study followed a cohort through the youth-adult transition to: (1) determine whether, and if so, when, health inequalities became evident according to both class of origin and current SEP; (2) compare the importance of health selection and social causation mechanisms; and (3) investigate whether these phenomena vary by gender. Methods Data are from a West-of-Scotland cohort, surveyed five times between age 15 (in 1987, N=1,515, response=85%) and 36. Self-reported physical and mental health were obtained at each survey. SEP was based on parental occupational class at 15, a combination of own education or occupational status at 18 and own occupational class (with an additional non-employment category) at older ages. In respect of when inequalities emerged, we used the relative index of inequality to examine associations between both parental and own current SEP and health at each age. In respect of mechanisms, path models, including SEP and health at each age, investigated both inter and intra-generational paths from SEP to health (?causation?) and from health to SEP (?selection?). Analyses were conducted separately for physical and mental health, and stratified by gender. Results Associations between both physical and mental health and parental SEP were non-significant at every age. Inequalities according to own SEP emerged for physical health at 24 and for mental health at 30. There was no evidence of selection based on physical health, but some evidence of associations between mental health in early adulthood and later SEP (intra-generational selection). Paths indicated intra-generational (males) and inter-generational (females) social causation of physical health inequalities, and intra-generational (males and females) and inter-generational (females) social causation of mental health inequalities. Conclusions The results suggest complex and reciprocal relationships between SEP and health and highlight adolescence and early adulthood as a sensitive period for this process, impacting on future life-chances and health

    Evaluation of the Viscous Drag for a Domed Cylindrical Moored Wave Energy Converter

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    Viscous drag, nonlinear in nature, is an important aspect of the fluid−structure interaction modelling and is usually not taken into account when the fluid is assumed to be inviscid. Potential flow solvers can competently compute radiation damping, which is related to the radiated wave field. However, the drag damping primarily related to the viscous effects is usually neglected in the radiation/diffraction problems solved by the boundary element method (BEM), also known as the boundary integral element method (BIEM). This drag force can have a significant impact in the case of structures extending much deeper below the free surface, or for those that are completely submerged. In this paper, the drag coefficient C d was quantified for the heave and surge response of a structure which consists of a moored horizontally oriented domed cylinder with two surface piercing square columns located at the top surface. The domed cylinder is the primary part and is submerged. The drag coefficient is estimated using the experimental measurements related to harmonic monochromatic wave−structure interaction. Finally, this estimated drag coefficient was used in the modified time domain model, which includes the nonlinear viscous correction term, and the resulting device response in heave and surge directions is presented for an irregular incoming wave field. The comparison of the numerical model and the experiments validates the estimated C d values obtained earlier. Prior to the time domain model, frequency-dependent parameters such as added mass, radiation damping, and excitation force were computed using three mainstream potential flow packages (that is, ANSYS AQWA, WAMIT, and NEMOH), and a comparison is presented. The effect of free surface on the drag coefficient is investigated through differences in C d values between heave and surge modes
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