129 research outputs found

    Circuit breaker prognostics using SF6 data

    Get PDF
    Control decisions within future energy networks may take account of the health and condition of network assets, pushing condition monitoring within the smart grid remit. In order to support maintenance decisions, this paper proposes a circuit breaker prognostic system, which ranks circuit breakers in order of maintenance priority. By monitoring the SF6 density within a breaker, the system not only predicts the number of days to a critical level, but also incorporates uncertainty by giving upper and lower bounds on the prediction. This prognostic model, which performs linear regression, will be described in this paper, along with case studies demonstrating ranking breakers based on maintenance priority and prognosis of a leaking breaker. Providing an asset manager with this type of information could allow improved management of his/her assets, potentially deferring maintenance to a time when an outage is already scheduled

    Identifying harmonic attributes from online partial discharge data

    Get PDF
    Partial discharge (PD) monitoring is a key method of tracking fault progression and degradation of insulation systems. Recent research discovered that the harmonic regime experienced by the plant also affects the PD pattern, questioning the conclusions about equipment health drawn from PD data. This paper presents the design and creation of an online system for harmonic circumstance monitoring of distribution cables, using only PD data. Based on machine learning techniques, the system can assess the prevalence of the 5th and 7th harmonic orders over the monitoring period. This information is key for asset managers to draw correct conclusions about the remaining life of polymeric cable insulation, and prevent overestimation of the degradation trend

    Intelligent monitoring of the health and performance of distribution automation

    Get PDF
    With a move to 'smarter' distribution networks through an increase in distribution automation and active network management, the volume of monitoring data available to engineers also increases. It can be onerous to interpret such data to produce meaningful information about the health and performance of automation and control equipment. Moreover, indicators of incipient failure may have to be tracked over several hours or days. This paper discusses some of the data analysis challenges inherent in assessing the health and performance of distribution automation based on available monitoring data. A rule-based expert system approach is proposed to provide decision support for engineers regarding the condition of these components. Implementation of such a system using a complex event processing system shell, to remove the manual task of tracking alarms over a number of days, is discussed

    Shared mission operations concept

    Get PDF
    Historically, new JPL flight projects have developed a Mission Operations System (MOS) as unique as their spacecraft, and have utilized a mission-dedicated staff to monitor and control the spacecraft through the MOS. NASA budgetary pressures to reduce mission operations costs have led to the development and reliance on multimission ground system capabilities. The use of these multimission capabilities has not eliminated an ongoing requirement for a nucleus of personnel familiar with a given spacecraft and its mission to perform mission-dedicated operations. The high cost of skilled personnel required to support projects with diverse mission objectives has the potential for significant reduction through shared mission operations among mission-compatible projects. Shared mission operations are feasible if: (1) the missions do not conflict with one another in terms of peak activity periods, (2) a unique MOS is not required, and (3) there is sufficient similarity in the mission profiles so that greatly different skills would not be required to support each mission. This paper will further develop this shared mission operations concept. We will illustrate how a Discovery-class mission would enter a 'partner' relationship with the Voyager Project, and can minimize MOS development and operations costs by early and careful consideration of mission operations requirements

    Providing Family Education for Grandparent Caregivers: Lessons from the GRandS Program

    Get PDF
    Grandparents who take on primary responsibility for raising grandchildren face unique family challenges while helping reduce the burden on the foster care system. The GRandS (Grandfamily Resilience and Sustainability) Program was a family life education program designed with three fundamental goals: (a) increase grandparent caregivers\u27 knowledge and skills in parenting and child development, (b) fortify their relationships with spouses and grandchildren, and (c) inform them about, and connect them to, available community resources. In this article, we describe the program implementation and evaluation, including the use of quantitative analysis and anecdotal accounts. Additionally, on the basis of our findings and experience with the program, we identify factors important to Extension\u27s successfully serving grandfamilies

    The social norms of suicidal and self-harming behaviours in Scottish adolescents

    Get PDF
    Although the suicidal and self-harming behaviour of individuals is often associated with similar behaviours in people they know, little is known about the impact of perceived social norms on those behaviours. In a range of other behavioural domains (e.g., alcohol consumption, smoking, eating behaviours) perceived social norms have been found to strongly predict individuals’ engagement in those behaviours, although discrepancies often exist between perceived and reported norms. Interventions which align perceived norms more closely with reported norms have been effective in reducing damaging behaviours. The current study aimed to explore whether the Social Norms Approach is applicable to suicidal and self-harming behaviours in adolescents. Participants were 456 pupils from five Scottish high-schools (53% female, mean age = 14.98 years), who completed anonymous, cross-sectional surveys examining reported and perceived norms around suicidal and self-harming behaviour. Friedman’s ANOVA with post-hocWilcoxen signed-ranks tests indicated that proximal groups were perceived as less likely to engage in or be permissive of suicidal and self-harming behaviours than participants’ reported themselves, whilst distal groups tended towards being perceived as more likely to do so. Binary logistic regression analyses identified a number of perceived norms associated with reported norms, with close friends’ norms positively associated with all outcome variables. The Social Norms Approach may be applicable to suicidal and self-harming behaviour, but associations between perceived and reported norms and predictors of reported norms differ to those found in other behavioural domains. Theoretical and practical implications of the findings are considered

    An Interdisciplinary Approach to Experiential Learning in Cyberbiosecurity and Agriculture Through Workforce Development

    Get PDF
    Cyberbiosecurity and workforce development in agriculture and the life sciences (ALS) is a growing area of need in the curriculum in higher education. Students that pursue majors related to ALS often do not include training in cyber-related concepts or expose the ‘hidden curriculum’ of seeking internships and jobs. Exposing students through workforce development training and hands-on engagement with industry professionals can provide learning opportunities to bridge the two and is an area of growth and demand as the workforce evolves. The objectives of this work were 1) to learn key concepts in cybersecurity, including data security, visualization, and analysis, to name a few, through class activities and engagement with professional partners and 2) to understand what knowledge students gained from participating in the course could transfer over for when they enter the workforce. Three themes emerged from the study where students, through direct engagement with industry partners, gained more insight about the industry applicable to their studies; they established work environment expectations for entering internships and official job placements and established ways in which the workforce development training informed their future careers

    Iron Oxide Nanoparticles as a Contrast Agent for Synchrotron Imaging of Sperm

    Full text link
    Fast phase-contrast imaging offered by modern synchrotron facilities opens the possibility of imaging dynamic processes of biological material such as cells. Cells are mainly composed of carbon and hydrogen, which have low X-ray attenuation, making cell studies with X-ray tomography challenging. At specific low energies, cells provide contrast, but cryo-conditions are required to protect the sample from radiation damage. Thus, non-toxic labelling methods are needed to prepare living cells for X-ray tomography at higher energies. We propose using iron oxide nanoparticles due to their proven compatibility in other biomedical applications. We show how to synthesize and attach iron oxide nanoparticles and demonstrate that cell-penetrating peptides facilitate iron oxide nanoparticle uptake into sperm cells. We show results from the TOMCAT Nanoscope (Swiss Light Source), showing that iron oxide nanoparticles allow the heads and midpiece of fixed sperm samples to be reconstructed from X-ray projections taken at 10 keV.Comment: 21 pages, 6 figure

    Mechanistic Insight into the Precursor Chemistry of ZrO₂ and HfO₂ Nanocrystals; towards Size-Tunable Syntheses

    Get PDF
    ne can nowadays readily generate monodisperse colloidal nanocrystals, but a retrosynthetic analysis is still not possible since the underlying chemistry is often poorly understood. Here, we provide insight into the reaction mechanism of colloidal zirconia and hafnia nanocrystals synthesized from metal chloride and metal isopropoxide. We identify the active precursor species in the reaction mixture through a combination of nuclear magnetic resonance spectroscopy (NMR), density functional theory (DFT) calculations, and pair distribution function (PDF) analysis. We gain insight into the interaction of the surfactant, tri-n-octylphosphine oxide (TOPO), and the different precursors. Interestingly, we identify a peculiar X-type ligand redistribution mechanism that can be steered by the relative amount of Lewis base (L-type). We further monitor how the reaction mixture decomposes using solution NMR and gas chromatography, and we find that ZrCl4 is formed as a by-product of the reaction, limiting the reaction yield. The reaction proceeds via two competing mechanisms: E1 elimination (dominating) and SN1 substitution (minor). Using this new mechanistic insight, we adapted the synthesis to optimize the yield and gain control over nanocrystal size. These insights will allow the rational design and synthesis of complex oxide nanocrystals
    corecore