OAK (Online Access to Knowledge) Commons (Young Harris College)
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An online data driven fault diagnosis and thermal runaway early warning for electric vehicle batteries
No full textBattery fault diagnosis is crucial for stable, reliable, and safe operation of electric vehicles, especially the thermal runaway early warning. Developing methods for early failure detection and reducing safety risks from failing high energy lithium-ion batteries has become a major challenge for industry. In this work, a real-time early fault diagnosis scheme for lithiumion batteries is proposed. By applying both the discrete Fréchet distance (DFD) and local outlier factor (LOF) to the voltage and temperature data of the battery cell/module that measured in real time, the battery cell that will have thermal runaway is detected before thermal runaway happens. Compared with the widely used single parameter based diagnosis approach, the proposed one considerably improve the reliability of the fault diagnosis and reduce the false diagnosis rate. The effectiveness of the proposed method is validated with the operational data from electric vehicles with/without thermal runaway in daily use
Responding to the Ockenden Review: safe care for all needs evidence-based system change - and strengthened midwifery
No full textSave money to lose money? Implications of opting out of a voluntary audit review for a firm’s cost of debt
No full textAn audit review (AR) is a mechanism used by boards to assess the quality of interim financial reports on a timely basis. In Canada, the AR is voluntary, with listed firms mandated to disclose when they choose not to purchase additional audit verification. Given the relatively low cost of an AR, opting out of it can be regarded as a negative signal, especially in the context of lenders’ sensitivity to downside risk. Using a sample of 7,585 firm-year observations from 1,616 public firms in Canada over the period 2004-2015, we document that firms without a voluntary AR have a higher cost of debt than firms with an AR. Furthermore, after firms opt out of the AR, the increase in the cost of debt is accompanied by a rise in discretionary abnormal accruals and managers’ stock-based compensation. Moreover, no-AR firms are more likely to reduce post-switch private borrowing and have lower equity analyst following. Our study is the first to document that although listed borrowers that opt out of an AR have a higher cost of debt financing, they are concurrently able to engage in more earnings management and grant their managers higher stock-based compensation because of lower external monitoring
Clinical outcome and underlying genetic cause of functional terminal complement pathway deficiencies in a multi-center UK cohort
No full textBackground: Terminal complement pathway deficiencies often present with severe and recurrent infections. There is a lack of good quality data on these rare conditions. This study investigated the clinical outcome and genetic variation in a large UK multi-center cohort with primary and secondary terminal complement deficiencies. Methods: Clinicians from seven UK centers provided anonymised demographic, clinical and laboratory data on patients with terminal complement deficiencies, which were collated and analysed. Results: Forty patients, median age 19 (range 3 62) years, were identified with terminal complement deficiencies. Ten (62%) of 16 patients with low serum C5 concentrations had underlying pathogenic CFH or CFI gene variants. Two-thirds were from consanguineous Asian families and 80% had an affected family member. The median age of first infection was nine years. Forty-three percent suffered meningococcal serotype B, and 43% serotype Y infections. Nine (22%) were treated in intensive care for meningococcal septicemia. Two patients had died, one from intercurrent COVID-19. Twenty-one (52%) were asymptomatic and diagnosed based on family history. All but one patient had received booster meningococcal vaccines and 70% were taking prophylactic antibiotics. Discussion: The genetic etiology and clinical course of patients with primary and secondary terminal complement deficiency is variable. Patients with low antigenic C5 concentrations require genetic testing, as the low level may reflect consumption secondary to regulatory defects in the pathway. Screening of siblings is important. Only half of patients develop septicemia, but all should have a clear management plan. Key words: terminal complement pathway; Factor H; Factor I; meningococcal infection; genetic
ENVIRONMENTAL SUSTAINABILITY PERFORMANCE OF A MEMBRANE-BASED TECHNOLOGY FOR LIVESTOCK WASTEWATER TREATMENT WITH NUTRIENT RECOVERY
No full textThe gas-permeable membrane (GPM) technology is one of the most novel techniques capable of minimizing ammonia (NH3) emissions associated to wastewaters, while recovering nitrogen as nutrient. This study conducted for the first time a life cycle assessment of this technology (treatment scenario), to compare the environmental trade-offs with the conventional manure management (conventional scenario), and determine which strategy performs better. The environmental impact results per m3 of manure, estimated using the ReCiPe method V 1.1, indicated that the treatment scenario reduces global warming (GW) by 14% and marine eutrophication (ME) by 32% with respect to the conventional scenario, whilst it increases particulate matter formation (PMF) and terrestrial acidification (TA) by 16% and 17%, respectively, due to some NH3 volatilization. Other impact categories considered were ozone formation (affecting human health (HOF) and ecosystems (EOF)), where the treatment scenario was able to reduce this impact by 48% and 50%, respectively. For freshwater eutrophication (FE), the net value was similar for both scenarios. A sensitivity analysis looking at optimum membrane design parameters (optimized treatment scenario) resulted in further reductions between 26% and 86% for GW, ME, PMF and TA with respect to the conventional scenario, although one potential drawback is the application of higher amount of phosphorous with the organic fertilizer, which resulted in higher FE impacts. Overall, the GPM system-based treatment is more environmentally sustainable compared to the conventional scenario thus making this an attractive option for environmental management systems, especially in areas with low water quality or high nutrient imbalance. Keywords: Life cycle assessment, manure treatment, ammonia reduction, nutrient imbalance, agricultural effluents.<br/
The long-term influence of Open Access on the scientific and social impact of dental journal articles: An updated analysis
No full textObjectives: To investigate whether dental journal articles that are open access (OA) receive greater citation counts and higher Altmetric Attention Scores (AAS) than articles that are non-OA in the long term.Methods: Eligible dental journal articles published in 2013 were identified via PubMed, and Web of science, Unpaywall and corresponding URLs were manually checked to determine the OA status of each included article 7 years after publication. Citation counts were extracted from Web of Science and Scopus, and AAS was harvested from the Altmetric Explorer. Multivariable general linear regression analyses were performed to investigate the association between OA and citation count, as well as between OA and AAS.Results: Among the 755 included articles, 309 (40.9%) were freely available online. Among the 309 OA articles, articles available from publishers accounted for 64.4% (199/309) of all OA articles, and those available through self-archiving accounted for 56.0% (173/309). According to regression analyses, OA articles had significantly greater citation counts (P = 0.001) and AAS (P < 0.001) than non-OA articles.Conclusions/clinical significance: In the field of dentistry, about 41% of journal articles are OA 7 years after publication, and OA articles available from the publishers are more common than those from authors through self-archiving. OA articles tend to have greater scientific and social impact than non-OA articles in the long term.Keywords: open access; dentistry; bibliometrics; altmetrics; evidence-based dentistry; research wast
Young children rely on gossip when jointly reasoning about whom to believe
No full textPeople rely on reputational information communicated via gossip when deciding about with whom to cooperate, whom to believe, and whom to trust. In two studies, we investigated whether 5 and 7-yearold children trust in gossip when determining a course of action. In Study 1, 5 and 7-year-old Germanspeaking peer dyads (N = 64 dyads, 32 female dyads) were presented with a collaborative problem-solving task (e.g., deciding together what a creature eats). Each child individually received conflicting information about the solution from a different informant (e.g., one proposed rocks; the other proposed sand). Each child additionally heard gossip about the informant’s reputation: one informant had a good reputation; the other had a bad reputation. In the experimental condition, the reputation was relevant to the task (honesty), whereas it was irrelevant in the control condition (tidiness). Seven-year-old dyads, and 5-year-old dyads to a lesser extent, settled on the items suggested by the informant with good reputation in the experimental but not in the control condition. Only 7-year-old children explicitly referred to the information conveyed via gossip, engaging in metatalk about the reputations of the informants. In Study 2, we replicated these findings in a more controlled experiment in which 5 and 7-year-old American English-speaking children (N = 48, 27 girls) tried to convince an adult partner who proposed the item suggested by the informant with bad reputation. Thus, starting around age 5, and more reliably at age 7, children selectively rely on gossip in identifying trustworthy individuals in their collaborative reasoning with partners.</p
A System Identification Procedure Using Compressive Sensing
No full textThe conventional system identification, which is a branch of machine learning, takes advantages of the whole sampling data to identify the system. To identify a system with less sampling density, compressive sensing is applied on system identification, which randomly extracts the sampling data from the system response. Hence a novel identification procedure is proposed using compressive sensing techniques. Then a second order system is selected as the system to be identified using such identification procedure. The identification performances of estimated systems are investigated from the scenario randomly extracting 10% of total sampling data to the scenario using 90% of total sampling data. Each scenario consists of three noise cases with different levels of SNRs to test the robustness of the signal recovery algorithms of compressive sensing. The results show that the system identification using compressive sensing has are relatively high identification performance and is robust to noise when using 30% or more of total sampling data
Host-guest interactions and confinement effects in HZSM-5 and chabazite zeolites studied by low-field NMR spin relaxation
No full textCharacterisation of fluid/solid interactions in porous materials is crucial for their design and optimisation, most notably in applications such as adsorption and catalysis. Yet, probing interfacial phenomena of fluids confined in porous systems is particularly challenging. NMR spin relaxation has emerged in recent years as a rapid, non-invasive experimental technique to probe adsorbate/adsorbent interactions in mesoporous catalytic materials. More recently, NMR relaxation measurements performed on high-field (300 MHz) superconducting magnets have been successfully validated as a robust method to characterise acidity in HZSM-5 zeolites. Expanding such techniques in the context of low-field, bench-top NMR instruments would be highly beneficial as it would make NMR relaxation a much more appealing and accessible tool for non-invasive, rapid characterisation of adsorbate/adsorbent interactions in zeolites and microporous materials. Herein, we validate the use of low-field, bench-top NMR spin relaxation as an indicator for characterising host-guest interactions in microporous zeolitic materials, using water as guest molecules confined within two different zeolite frameworks, HZSM-5 and chabazite, with varying silica/alumina ratio (SAR). The results reported here demonstrate the robustness and sensitivity of low-field NMR relaxation measurements as a rapid screening tool for characterising adsorption and molecular dynamics in microporous materials, with important implications for both academics and industrialists in terms of making the method more widely accessible, hence expanding the set of tools for material chemistry and characterisation
Peer-to-Peer, Community Self-Consumption, and Transactive Energy: A Systematic Literature Review of Local Energy Market Models
No full textPeer-to-peer, community or collective self-consumption, and transactive energy markets offer new models for trading energy locally. Over the past five years, there has been significant growth in the amount of academic literature examining how these local energy markets might function. This systematic literature review of 139 peer-reviewed journal articles examines the market designs used in these energy trading models. A modified version of the Business Ecosystem Architecture Modelling framework is used to extract market model information from the literature, and to identify differences and similarities between the models. This paper examines how peer-to-peer, community self-consumption and transactive energy markets are described in current literature. It explores the similarities and differences between these markets in terms of participation, governance structure, topology, and design. This paper systematises peer-to-peer, community self-consumption and transactive energy market designs, identifying six archetypes. Finally, it identifies five evidence gaps which require future research before these markets could be widely adopted. These evidence gaps are the lack of: consideration of physical constraints; a holistic approach to market design and operation; consideration about how these market designs will scale; consideration of information security; and, consideration of market participant privacy