4,319 research outputs found
Simulation-based model course to demonstrate seafarers' competence for deck officers' discipline
Postprint (published version
Investigating the baseline skills of research students using a competency-based self-assessment method
Recent government-led initiatives are changing the nature of the UK PhD to support the greater development of transferable skills. There are similar initiatives internationally. A key requirement and challenge is to effectively assess the `baseline' skills of a cohort on entry to a research programme and then monitor their progress in personal development. This article describes an innovative methodology that combines competence model and training needs analysis theory to create an effective self-assessment tool: the Development Needs Analysis (DNA), for collection of baseline data. The DNA provides a means for effective self-assessment of skills, and is capable of highlighting particular needs of students grouped by, for example, date of birth and home vs. overseas status. The methodology is broadly applicable in determination of the baseline skills of students and allows practitioners to tailor learning and teaching to the requirements of a cohort
BodyScan: Enabling Radio-based Sensing on Wearable Devices for Contactless Activity and Vital Sign Monitoring
Wearable devices are increasingly becoming mainstream consumer products carried by millions of consumers. However, the potential impact of these devices is currently constrained by fundamental limitations of their built-in sensors. In this paper, we introduce radio as a new powerful sensing modality for wearable devices and propose to transform radio into a mobile sensor of human activities and vital signs. We present BodyScan, a wearable system that enables radio to act as a single modality capable of providing whole-body continuous sensing of the user. BodyScan overcomes key limitations of existing wearable devices by providing a contactless and privacy-preserving approach to capturing a rich variety of human activities and vital sign information. Our prototype design of BodyScan is comprised of two components: one worn on the hip and the other worn on the wrist, and is inspired by the increasingly prevalent scenario where a user carries a smartphone while also wearing a wristband/smartwatch. This prototype can support daily usage with one single charge per day. Experimental results show that in controlled settings, BodyScan can recognize a diverse set of human activities while also estimating the user's breathing rate with high accuracy. Even in very challenging real-world settings, BodyScan can still infer activities with an average accuracy above 60% and monitor breathing rate information a reasonable amount of time during each day
Late Neoarchean crust-mantle geodynamics : evidence from Pingquan Complex of the Northern Hebei Province, North China Craton
This study is financially supported by the National Natural Science Foundation of China (Grant Nos. 41530207, 41502179, 41472165, 41602198) and Central University Basic Scientific Research Business Expenses (Grant No. 2652015038). PAC acknowledges support from Australian Research Council grant FL160100168.A late Neoarchean intra-oceanic arc along the northwestern margin of Eastern Block (EB), North China Craton, provides important insights into the nature of Archean mantle sources and crust-mantle geodynamics. The Pingquan Complex and the entire Northern Hebei Province (NHB) are located in the middle part of the arc, and overlap the northern extent of the Trans-North China Orogen. Zircon U-Pb isotopic age data reveal that the Pingquan Complex consists of ∼2537-2515 Ma dioritic gneisses, ∼2506-2503 Ma amphibolites, and ∼2491 Ma quartz monzodioritic to monzogranitic gneisses, and they show dominantly positive zircon εHf(t) (-0.6-+5.4) that are lower than coeval model depleted mantle values. Geochemical data for the Pingquan rocks and synchronous metabasalts and granitoid gneisses of Huai’an-Xuanhua and Dantazi complexes in the NHB are integrated. Except for the monzogranitic gneisses that were derived from partial melting of juvenile metagreywackes, the other rocks of the Pingquan Complex were derived from a metasomatized lithospheric mantle, and subjected to variable fractionation of clinopyroxene, hornblende and plagioclase, without significant crustal contamination. Moderately depleted zircon εHf(t), and high Sm/Hf and Nb/Ta (mostly of 1.34-3.96 and 15.50-32.58) suggest that the lithospheric mantle was enriched by subducted pelagic sediments metamorphosed to rutile-bearing eclogites before melting. Late Neoarchean crust-mantle geodynamic processes in the NHB are reconstructed. Intra-oceanic subduction initiated offshore of the northwestern margin of the EB at ∼2.55 Ga or earlier. Partial melting of slab basalts occurred at ∼2542-2499 Ma, with the melts contaminated by mantle wedge materials forming TTGs. Meanwhile, the sub-arc lithospheric mantle was enriched by fluids and melts released from slab basalts and pelagic sediments, and partial melting of this moderately depleted mantle generated ∼2537-2503 Ma diorites and basalts. Following final accretion of the arc onto the continental margin of the EB, the slab rollback/breakoff and asthenospheric mantle upwelling triggered partial melting of the metasomatized lithospheric mantle and crustal anatexis, generating ∼2491 Ma quartz monzodioritic and monzogranitic rocks. Accordingly, the NHB records Neoarchean crustal growth linked to oceanic subduction and arc-continent accretion, and highlights the importance of resolving the nature of mantle sources and crust-mantle interactions in understanding Archean crustal growth and evolution.PostprintPeer reviewe
Late Neoarchean subduction-related crustal growth in the Northern Liaoning region of the North China Craton : evidence from ∼2.55-2.50 Ga granitoid gneisses
This study is financially supported by the National Natural Science Foundation of China (Grant Nos. 41272209, 41472165, 41502179, 41530207) and the Central University Basic Scientific Research Business Expenses of China University of Geosciences (Beijing) (Grant No. 2652015038).The North China Craton (NCC), dominated by ∼2.6-2.5 Ga tectonothermal events, provides a natural laboratory to study Neoarchean crustal growth and geodynamic evolution. Late Neoarchean granitoid gneisses are well exposed in the Northern Liaoning Province, located north of the ancient Anshan-Benxi terrane along the northeastern margin of the Eastern Block (EB) of the NCC. LA-ICPMS zircon U-Pb isotopic dating reveal that granitoid gneisses in the Qingyuan area can be grouped into two major episodes, i.e., ∼2559-2534 Ma strongly gneissic quartz dioritic and tonalitic to trondhjemitic gneisses; and ∼2529-2495 Ma weakly gneissic to massive quartz monzodioritic and monzogranitic gneisses, with subordinate tonalitic to trondhjemitic gneisses. The late magmatic episode was accompanied by regionally high-grade metamorphism (∼2510-2495 Ma). Most granitoid gneisses display highly depleted zircon εHf(t2) values (+4.2-+8.1), whereas one monzogranitic gneiss shows negative values of -4.7 to -1.0, indicating late Neoarchean crustal growth with minor involvement of ancient continental materials probably sourced from the Anshan-Benxi terrane. Geochemical and petrogenetic studies reveal that the quartz dioritic magmas were derived from partial melting of plagioclase-poor garnet amphibolites or eclogites metamorphosed from oceanic slab materials, with slab melts contaminated by mantle wedge peridotites during ascent. The tonalitic to trondhjemitic magmas stemmed from partial melting of mainly juvenile metabasaltic rocks with minor metagreywackes of lower arc crust. In comparison, the quartz monzodioritic and monzogranitic magmas were derived respectively from partial melting of depleted mantle sources metasomatized by slab-derived fluids and metagreywackes with different crustal resident ages at middle to lower crustal levels. Combined with previous studies of metavolcanic rocks, the Northern Liaoning Province records late Neoarchean crustal growth, evolving from mid-ocean ridge, through initiation and maturation of an intra-oceanic arc, to arc-continent collision. Arc-continent accretion and possibly slab rollback processes may have triggered reworking of both juvenile arc crust and minor ancient continental margin materials, generating the magmatic precursors for the monzogranitic gneisses. Overall, the intense late Neoarchean crustal growth of the EB was controlled mainly by arc-continent accretion, possibly linked to global assembly of cratonic fragments.PostprintPeer reviewe
Risk of new-onset Long Covid following reinfection with SARS-CoV-2: community-based cohort study
Background:
Little is known about the risk of Long Covid following reinfection with SARS-CoV-2. We estimated the likelihood of new-onset, self-reported Long Covid after a second SARS-CoV-2 infection, and compared to a first infection.
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Methods:
We included UK COVID-19 Infection Survey participants who tested positive for SARS-CoV-2 between 1 November 2021 and 8 October 2022. The primary outcome was self-reported Long Covid 12 to 20 weeks after each infection. Separate analyses were performed for those <16 years and ≥16 years. We estimated adjusted odds ratios (aORs) for new-onset Long Covid using logistic regression, comparing second to first infections, controlling for socio-demographic characteristics and calendar date of infection, plus vaccination status in those ≥16 years.
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Results:
Overall, Long Covid was reported by those ≥16 years after 4.0% and 2.4% of first and second infections, respectively; the corresponding estimates among those <16 years were 1.0% and 0.6%. The aOR for Long Covid after second compared to first infections was 0.72 (95% confidence interval: 0.63–0.81) for those ≥16 years and 0.93 (0.57–1.53) for those <16 years.
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Conclusions:
The risk of new-onset Long Covid after a second SARS-CoV-2 infection is lower than that after a first infection for those ≥16 years, though there is no evidence of a difference in risk for those <16 years. However, there remains some risk of new-onset Long Covid after a second infection, with around 1 in 40 of those ≥16 years and 1 in 165 of those <16 years reporting Long Covid after a second infection
THE APPROACH TO THE ANALYSIS OF ELECTRICAL FIELD DISTRIBUTION IN THE SETUP OF PAPER INSULATED ELECTRODES IN OIL
Article presents the problem of the approach to the analysis of electrical field distribution in the model insulating system, which, in the author's experimental research, was used to the assessment of the influence of paper insulation on the mechanism of electrical discharge initiation in mineral oil. The main assumptions of the planned numerical works based on the finite element method were described and scientific aim of the numerical analysis were characterized in this paper. Both the assumptions and the scientific aim were related to the conclusions from the experimental works, especially to the measured times to initiation of the discharges developing in mineral transformer oil, indicating on the important role of the oil quality in the process of discharge initiation in the system of the insulated by paper electrodes immersed in oil
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