680 research outputs found

    Control and Instrumentation Topologies for an Integrated Wave Energy Array

    Get PDF
    SubmittedControl and Instrumentation (C&I) systems provide the framework for monitoring critical data streams and implementing control functions during the operation of a wave energy converter. However, cost and power constraints of wave energy converters present a challenge in designing a C&I architecture that is appropriate for the application. This study describes the design of a C&I system for an integrated wave en-ergy array. A specification is first developed by defining operational requirements and design principles, measurement and control priorities are then identified, incorporating a failure mode and effects analysis. Available instrumentation options in the industry are reviewed and C&I topologies are presented. A distribut-ed control system is proposed for the Albatern WaveNET Array, allowing for the implementation of control and protection strategies and condition monitoring. Improved C&I allows for the reduction of unplanned maintenance, maximising device availability for energy production.The author would like to thank the industrial and academic supervisors, in addition to many industrial representatives whom provided valuable input to this paper. The support of the ETI and RCUK Energy Programme funding for IDCORE (EP/J500847/1) is gratefully acknowledged

    Lessons Learned from 3 Years of Failure: Validating an FMEA with Historical Failure Data

    Get PDF
    This is the author accepted manuscript. The final version is available from EWTEC via the link in this record.Device reliability is often considered essential to the performance of a wave energy converter. Developers may undertake a Failure Mode and Effects Analysis (FMEA) as a design process to evaluate the high priority failure modes of a prototype to approximate device reliability. However, failures identified by this process are typically predicted, and often lack validation from actual marine operations history. In view of this, an FMEA undertaken for the Albatern Squid 6 Series Wave Energy Converter (WEC) has been validated using historical failure rate and marine operations data. Results indicate that a high volume of major structural and hydraulic failures occurred in the initial stages of deployment, whilst minor electrical and instrumentation failures occurred towards the latter. A notable observation is that human driven failures constituted a much larger portion of failure occurrences than the FMEA predicted. As a general observation, the retrospective analysis of failure rate requires consistent data recording procedures, especially given the introduction of new innovations, which may cause a resurgence of early-stage faults. Lessons learned in the operation of a redundant, modular and accessible array are discussed in the view of designing devices that are not immune, but resilient to failure.The author gratefully acknowledges the support of the ETI and RCUK Energy Programme funding for IDCORE (EP/J500847/1), and the support of Wave Energy Scotland during the installation and commissioning of the Mingary Bay wave array

    Development of a Condition Monitoring System for an Articulated Wave Energy Converter

    Get PDF
    ESREL 2016: European Safety and Reliability Conference 2016, Glasgow, UK, 25-29 September, 2016This is the author accepted manuscript. The final version is available from the publisher.Condition monitoring systems (CMS) in renewable energy devices allow for the detection of oncoming faults, providing data to undertake pre-emptive maintenance. By defining a systems functional re-quirements and identifying of critical failure modes, proactive maintenance strategies to be produced. The lack of operational data in the marine energy industry, and lack of consensus in operating principles between devic-es, means that a non-standardised CMS package is available for wave energy converters (WECs). In this study a Failure Modes and Effects Analysis (FMEA) is undertaken in order to identify the critical failure modes of an articulated WEC, measurement priorities are identified and a set of monitoring solutions provided. Installing a CMS provides the framework for collecting quality component reliability data, however further development is required for building a proactive maintenance strategy and for continuous reliability improvement

    Thermographic imaging in sports and exercise medicine: A Delphi study and consensus statement on the measurement of human skin temperature

    Get PDF
    This is an accepted manuscript of an article published by Elsevier in Journal of Thermal Biology on 18/07/2017, available online: https://doi.org/10.1016/j.jtherbio.2017.07.006 The accepted version of the publication may differ from the final published version.© 2017 Elsevier Ltd The importance of using infrared thermography (IRT) to assess skin temperature (tsk) is increasing in clinical settings. Recently, its use has been increasing in sports and exercise medicine; however, no consensus guideline exists to address the methods for collecting data in such situations. The aim of this study was to develop a checklist for the collection of tsk using IRT in sports and exercise medicine. We carried out a Delphi study to set a checklist based on consensus agreement from leading experts in the field. Panelists (n  =  24) representing the areas of sport science (n = 8; 33%), physiology (n = 7; 29%), physiotherapy (n = 3; 13%) and medicine (n = 6; 25%), from 13 different countries completed the Delphi process. An initial list of 16 points was proposed which was rated and commented on by panelists in three rounds of anonymous surveys following a standard Delphi procedure. The panel reached consensus on 15 items which encompassed the participants’ demographic information, camera/room or environment setup and recording/analysis of tsk using IRT. The results of the Delphi produced the checklist entitled “Thermographic Imaging in Sports and Exercise Medicine (TISEM)” which is a proposal to standardize the collection and analysis of tsk data using IRT. It is intended that the TISEM can also be applied to evaluate bias in thermographic studies and to guide practitioners in the use of this technique.Published versio

    Pituitary pathology and gene expression in acromegalic cats

    Get PDF
    © 2019 Endocrine Society. The prevalence of GH-secreting pituitary tumors in domestic cats (Felis catus) is 10-fold greater than in humans. The predominant inhibitory receptors of GH-secreting pituitary tumors are somatostatin receptors (SSTRs) and D2 dopamine receptor (DRD2). The expression of these receptors is associated with the response to somatostatin analog and dopamine agonist treatment in human patients with acromegaly. The aim of this study was to describe pathological features of pituitaries from domestic cats with acromegaly, pituitary receptor expression, and investigate correlates with clinical data, including pituitary volume, time since diagnosis of diabetes, insulin requirement, and serum IGF1 concentration. Loss of reticulin structure was identified in 15 of 21 pituitaries, of which 10 of 15 exhibited acinar hyperplasia. SSTR1, SSTR2, SSTR5, and DRD2 mRNA were identified in the feline pituitary whereas SSTR3 and SSTR4 were not. Expression of SSTR1, SSTR2, and SSTR5 was greater in acromegalic cats compared with controls. A negative correlation was identified between DRD2 mRNA expression and pituitary volume. The loss of DRD2 expression should be investigated as a mechanism allowing the development of larger pituitary tumors

    Reproducibility of quantitative F-18-3'-deoxy-3'-fluorothymidine measurements using positron emission tomography

    Get PDF
    Positron emission tomography (PET) using F-18-3'-deoxy-3'-fluorothymidine ([F-18]FLT) allows noninvasive monitoring of tumour proliferation. For serial imaging in individual patients, good reproducibility is essential. The purpose of the present study was to evaluate the reproducibility of quantitative [F-18]FLT measurements. Nine patients with non-small-cell lung cancer (NSCLC) and six with head-and-neck cancer (HNC) underwent [F-18]FLT PET twice within 7 days prior to therapy. The maximum pixel value (SUVmax) and a threshold defined volume (SUV41%) were defined for all delineated lesions. The plasma to tumour transfer constant (K-i) was estimated using both Patlak graphical analysis and nonlinear regression (NLR). NLR was also used to estimate k(3), which, at least in theory, selectively reflects thymidine kinase 1 activity. The level of agreement between test and retest values was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. All primary tumours and > 90% of clinically suspected locoregional metastases could be delineated. In total, 24 lesions were defined. NLR-derived K-i, Patlak-derived K-i, SUV41% and SUVmax showed excellent reproducibility with ICCs of 0.92, 0.95, 0.98 and 0.93, and SDs of 16%, 12%, 7% and 11%, respectively. Reproducibility was poor for k(3) with an ICC of 0.43 and SD of 38%. Quantitative [F-18]FLT measurements are reproducible in both NSCLC and HNC patients. When monitoring response in individual patients, changes of more than 15% in SUV41%, 20-25% in SUVmax and Patlak-derived K-i, and 32% in NLR3k-derived K-i are likely to represent treatment effect

    Evaluation of the current knowledge limitations in breast cancer research: a gap analysis

    Get PDF
    BACKGROUND A gap analysis was conducted to determine which areas of breast cancer research, if targeted by researchers and funding bodies, could produce the greatest impact on patients. METHODS Fifty-six Breast Cancer Campaign grant holders and prominent UK breast cancer researchers participated in a gap analysis of current breast cancer research. Before, during and following the meeting, groups in seven key research areas participated in cycles of presentation, literature review and discussion. Summary papers were prepared by each group and collated into this position paper highlighting the research gaps, with recommendations for action. RESULTS Gaps were identified in all seven themes. General barriers to progress were lack of financial and practical resources, and poor collaboration between disciplines. Critical gaps in each theme included: (1) genetics (knowledge of genetic changes, their effects and interactions); (2) initiation of breast cancer (how developmental signalling pathways cause ductal elongation and branching at the cellular level and influence stem cell dynamics, and how their disruption initiates tumour formation); (3) progression of breast cancer (deciphering the intracellular and extracellular regulators of early progression, tumour growth, angiogenesis and metastasis); (4) therapies and targets (understanding who develops advanced disease); (5) disease markers (incorporating intelligent trial design into all studies to ensure new treatments are tested in patient groups stratified using biomarkers); (6) prevention (strategies to prevent oestrogen-receptor negative tumours and the long-term effects of chemoprevention for oestrogen-receptor positive tumours); (7) psychosocial aspects of cancer (the use of appropriate psychosocial interventions, and the personal impact of all stages of the disease among patients from a range of ethnic and demographic backgrounds). CONCLUSION Through recommendations to address these gaps with future research, the long-term benefits to patients will include: better estimation of risk in families with breast cancer and strategies to reduce risk; better prediction of drug response and patient prognosis; improved tailoring of treatments to patient subgroups and development of new therapeutic approaches; earlier initiation of treatment; more effective use of resources for screening populations; and an enhanced experience for people with or at risk of breast cancer and their families. The challenge to funding bodies and researchers in all disciplines is to focus on these gaps and to drive advances in knowledge into improvements in patient care

    Role of A Novel Angiogenesis FKBPL-CD44 Pathway in Preeclampsia Risk Stratification and Mesenchymal Stem Cell Treatment.

    Full text link
    ContextPreeclampsia is a leading cardiovascular complication in pregnancy lacking effective diagnostic and treatment strategies.ObjectiveTo investigate the diagnostic and therapeutic target potential of the angiogenesis proteins, FK506-binding protein like (FKBPL) and CD44.Design and interventionFKBPL and CD44 plasma concentration or placental expression were determined in women pre- or postdiagnosis of preeclampsia. Trophoblast and endothelial cell function was assessed following mesenchymal stem cell (MSC) treatment and in the context of FKBPL signaling.Settings and participantsHuman samples prediagnosis (15 and 20 weeks of gestation; n ≥ 57), or postdiagnosis (n = 18 for plasma; n = 4 for placenta) of preeclampsia were used to determine FKBPL and CD44 levels, compared to healthy controls. Trophoblast or endothelial cells were exposed to low/high oxygen, and treated with MSC-conditioned media (MSC-CM) or a FKBPL overexpression plasmid.Main outcome measuresPreeclampsia risk stratification and diagnostic potential of FKBPL and CD44 were investigated. MSC treatment effects and FKBPL-CD44 signaling in trophoblast and endothelial cells were assessed.ResultsThe CD44/FKBPL ratio was reduced in placenta and plasma following clinical diagnosis of preeclampsia. At 20 weeks of gestation, a high plasma CD44/FKBPL ratio was independently associated with the 2.3-fold increased risk of preeclampsia (odds ratio = 2.3, 95% confidence interval [CI] 1.03-5.23, P = 0.04). In combination with high mean arterial blood pressure (>82.5 mmHg), the risk further increased to 3.9-fold (95% CI 1.30-11.84, P = 0.016). Both hypoxia and MSC-based therapy inhibited FKBPL-CD44 signaling, enhancing cell angiogenesis.ConclusionsThe FKBPL-CD44 pathway appears to have a central role in the pathogenesis of preeclampsia, showing promising utilities for early diagnostic and therapeutic purposes

    The sensuous secrets of shelter: how recollections of food stimulate Irish men's reconstructions of their early formative residential experiences in Leicester, Sheffield and Manchester

    Get PDF
    This paper examines the intersection between food, recollection and Irish migrants’ reconstructions of their housing pathways in the three English cities of Leicester (East Midlands), Sheffield (South Yorkshire) and Manchester (North). Previous studies have acknowledged more implicitly the role of memory in representing the Irish migrant experience in England. Here, we adopt a different stance. We explore the mnemonic power of food to encode, decode and recode Irish men’s reconstructions of their housing pathways in England when constructing and negotiating otherness. In doing so, we apply a ‘Proustian anthropological’ approach in framing the men’s representations of their formative residential experiences in the boarding houses of the three English cities during the 1950s and 1960s are examined. The extent to which food provided in the boarding houses was used as an instrument of discipline and control is examined. The relevance of food related acts of resistance, food insecurity and acts of hedonic meat-centric eating in constructing the men’s sociocultural identity are also explored
    corecore