189 research outputs found

    A benchmark activity on the fatigue life assessment of AlSi10Mg components manufactured by L-PBF

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    One of the challenges associated with additive manufacturing (AM) is the definition of an assessment route which considers the main process signatures of the AM process. To this end, this work presents a complete benchmark activity for the assessment of an AlSi10Mg component produced by a laser pow- der bed fusion process, aimed at advancing the understanding of the fatigue resistance of AM materials with particular focus on the comparison between the fatigue performances of small coupons and demon- strators. Four builds of AlSi10Mg specimen geometries were manufactured to: (i) determine the fatigue curves for both as-built and machined conditions; (ii) measure the fatigue crack growth rate; (iii) produce and test under fatigue a benchmark component used as a reference for the validation of the fatigue assessment procedure. Tools and concepts of flaw tolerance were then used to perform the fatigue assess- ment of the benchmark component and were shown to be successful in the life prediction. Results obtained from this wide database (related to internal defects and surface features) show that only a fracture-based fatigue assessment is able to provide precise life estimates consistent with material crack growth properties. Eventually, all the experimental results including specimens design, analysis of frac- ture surfaces and raw tests’ data will be made available in a database which can be accessed and used by the industrial and scientific communities to calibrate and validate alternative fatigue assessment proce- dures of AM parts

    Early conscious prone positioning in patients with COVID-19 receiving continuous positive airway pressure: A retrospective analysis

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    The global pandemic of COVID-19 has challenged the management of hypoxaemic respiratory failure and strained intensive care unit resources. While prone positioning (PP) is an established therapy in mechanically ventilated patients with acute respiratory distress syndrome (ARDS), its role in conscious patients is less well defined. We retrospectively reviewed our experience of implementing early PP in a cohort of 24 patients with acute hypoxaemic respiratory failure due to COVID-19 who required support with continuous positive airway pressure (CPAP). The use of PP alongside CPAP significantly increased both the ROX index and arterial oxygen pressure:fractional inspired oxygen (PaO 2:FiO 2) ratio from baseline values (ROX index: 7.0±2.5 baseline vs 11.4±3.7 CPAP+PP,

    Trolling in asynchronous computer-mediated communication: From user discussions to academic definitions

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    Whilst computer-mediated communication (CMC) can benefit users by providing quick and easy communication between those separated by time and space, it can also provide varying degrees of anonymity that may encourage a sense of impunity and freedom from being held accountable for inappropriate online behaviour. As such, CMC is a fertile ground for studying impoliteness, whether it occurs in response to perceived threat (flaming), or as an end in its own right (trolling). Currently, first and secondorder definitions of terms such as im/politeness (Brown and Levinson 1987; Bousfield 2008; Culpeper 2008; Terkourafi 2008), in-civility (Lakoff 2005), rudeness (Beebe 1995, Kienpointner 1997, 2008), and etiquette (Coulmas 1992), are subject to much discussion and debate, yet the CMC phenomenon of trolling is not adequately captured by any of these terms. Following Bousfield (in press), Culpeper (2010) and others, this paper suggests that a definition of trolling should be informed first and foremost by user discussions. Taking examples from a 172-million-word, asynchronous CMC corpus, four interrelated conditions of aggression, deception, disruption, and success are discussed. Finally, a working definition of trolling is presented

    Special Libraries, October 1922

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    Volume 13, Issue 8https://scholarworks.sjsu.edu/sla_sl_1922/1007/thumbnail.jp

    Privacy in crowdsourcing:a systematic review

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    The advent of crowdsourcing has brought with it multiple privacy challenges. For example, essential monitoring activities, while necessary and unavoidable, also potentially compromise contributor privacy. We conducted an extensive literature review of the research related to the privacy aspects of crowdsourcing. Our investigation revealed interesting gender differences and also differences in terms of individual perceptions. We conclude by suggesting a number of future research directions.</p

    Cisplatin neurotoxicity in the treatment of metastatic germ cell tumour: time course and prognosis

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    In order to ascertain the incidence and prognosis of cisplatin-induced neurotoxicity in testis cancer patients undergoing combination chemotherapy, 29 patients with metastatic disease were studied prospectively. Assessments included enquiry into neurological symptoms, measurement of sural nerve sensory action potential and conduction velocity, and vibration threshold in the left big toe. At the end of chemotherapy (3 to 4 cycles) only 3 out of 26 (11%) patients had paraesthesiae, but 3 months later the proportion rose to 65%. Resolution occurred in the majority over the ensuing 12 months so that only 17% had persistent symptoms. None of the 11 patients treated with 3 cycles of chemotherapy had persisting symptoms. Vibration thresholds showed a significant deterioration during chemotherapy (P = 0.032), further deterioration in the 3 months following chemotherapy (P = 0.009) and significant improvement between 3 and 12 months after chemotherapy (P = 0.038). Sural nerve sensory action potentials and conduction velocities were unhelpful.© 2001 Cancer Research Campaignhttp://www.bjcancer.co

    Costs and effectiveness of a brief MRI examination of patients with acute knee injury

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    The aim of this study was to assess the costs and effectiveness of selective short magnetic resonance imaging (MRI) in patients with acute knee injury. A model was developed to evaluate the selective use of MRI in patients with acute knee injury and no fracture on radiography based on the results of a trial in which 208 patients were randomized between radiography only and radiography plus MRI. We analyzed medical (diagnostic and therapeutic) costs, quality of life, duration of diagnostic workup, number of additional diagnostic examinations, time absent from work, and time to convalescence during a 6-month follow-up period. Quality of life was lowest (EuroQol at 6 weeks 0.61 (95% CI 0.54–0.67)); duration of diagnostic workup, absence from work, and time to convalescence were longest; and the number of diagnostic examinations was largest with radiography only. These outcomes were more favorable for both MRI strategies (EuroQol at 6 weeks 0.72 (95% CI 0.67–0.77) for both). Mean total costs were 2,593 euros (95% CI 1,815–3,372) with radiography only, 2,116 euros (95% CI 1,488–2,743) with radiography plus MRI, and 1,973 euros (95% CI 1,401–2,543) with selective MRI. The results suggest that selective use of a short MRI examination saves costs and potentially increases effectiveness in patients with acute knee injury without a fracture on radiography

    L’accompagnement-citoyen en soutien à la participation sociale des aînés ayant un traumatisme craniocérébral

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    Hautement valorisée par les aînés, la participation sociale a des effets bénéfiques sur leur santé biopsychosociale. Tous n’ont pas cependant les mêmes opportunités pour s’investir dans ce type d’activités; particulièrement ceux ayant un traumatisme craniocérébral (TCC) qui sont plus susceptibles d’être limités dans leurs capacités à participer à la vie de la communauté. Les initiatives les plus courantes pour aider ces personnes consistent en une assistance humaine visant àpallierleurs limitations et ne misent pas, en priorité, sur la promotion de leurs compétences. Afin d’optimiser l’aide reçue, un accompagnementcitoyen personnalisé à l’intégration communautaire (APIC) a été développé, implanté et évalué. Cet article documente l’impact de l’APIC sur la participation sociale d’aînés ayant un TCC. Une analyse de contenu thématique a été réalisée sur les données issues d’entrevues semi-dirigées auprès des participants et des journaux de bord des accompagnateurs. Les résultats montrent trois grandes retombées de l’APIC : une meilleure assurance et un plus grand sentiment d’autonomie, un goût retrouvé de s’investir dans des activités de loisirs signifiantes, et une plus grande ouverture vers de nouvelles possibilités de relations.Abstract : Highly valued by seniors, community integration has beneficial effects on their biopsychosocial health. However, not all of them have the same opportunities to engage in social participation activities, particularly those with traumatic brain injury (TBI) who are more likely to be limited in their abilities to participate in the life of the community. The most common initiatives to help these people consist of human assistance to overcome their limitations and which do not focus on skills promotion. In order to optimize the available services and resources, personalized citizen assistance for community integration (APIC) has been developed, implemented, and evaluated. This article documents the impact of APIC on the community integration of seniors with TBI. A thematic content analysis was conducted on data from semi-structured interviews with participants and from attendant logbooks. The results show three major spin-offs from APIC: better insurance and a greater sense of autonomy, a renewed taste for investing in meaningful leisure activities, and greater openness to new relationship opportunities
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