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This paper describes a sudden spill of waste rock used for backfilling from a waste pass at an underground mine in Canada, thus causing a major failure/accident. The mine operator immediately launched a detailed investigation to u...
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This paper describes a sudden spill of waste rock used for backfilling from a waste pass at an underground mine in Canada, thus causing a major failure/accident. The mine operator immediately launched a detailed investigation to understand the causes of this accident and develop procedures to prevent any recurrence of such events in the future. The authors from McGill university were invited to collaborate with the engineers at the mine to examine this accident. The events leading to the accident were studied, appropriate measurements were taken and samples of the waste material were collected for further testing and analysis. The field visit and the interview of the witnesses allowed the detailed documentation of the events. The sequence of events related to the incident, along with the experimental results obtained in the course of the investigation, are presented. The waste material was characterized in the laboratory with regard to its behaviour in the presence of water. This information is discussed and the failure mechanism involved in the accident is identified. Finally, the full recommendations as well as the immediate operational measures implemented by the mine to prevent the future occurrence of such events are presented and discussed.
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The knowledge transfer type class was performed in the first half of knowledge engineering. The knowledge construction type class was performed by group study in the second half. Each group considers the support system to learn ab...
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The knowledge transfer type class was performed in the first half of knowledge engineering. The knowledge construction type class was performed by group study in the second half. Each group considers the support system to learn about the favorite subject matter. The contents, the function, and so on for the study support systems are discussed by brainstorming. After post-its on which the contents were written were attached on Japanese vellum, each group arranged and explained them. Then, each group creates slides and presents about the contents of which they conceived. In such practice a series of activity is analyzed and the results are reported by using the evaluation sheet.
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In this study, raised pedestrian crosswalks were installed at non-signalized mid-block crosswalks situated on urban arterial and collector roads. A raised crosswalk is built by installing a trapezoidal speed hump on the crosswalk ...
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In this study, raised pedestrian crosswalks were installed at non-signalized mid-block crosswalks situated on urban arterial and collector roads. A raised crosswalk is built by installing a trapezoidal speed hump on the crosswalk area, building a preceding circular speed hump, in each travel direction, and adding traffic signs. A controlled field-study was conducted at eight sites, sixteen pedestrian crosswalks, where road user behaviors were compared in the after versus before the treatment periods. Two settings of raised crosswalks were applied at the study sites: a 15 cm high trapezoidal hump combined with 8-10 cm high circular humps, and a 10-12 cm high trapezoidal hump combined with 6-8 cm high circular humps. Field observations included video-recordings and free-flow speed measurements. Following the installation of the raised crosswalks, at most sites, a substantial decrease was observed in vehicle travel speeds while approaching the crosswalks, which was maintained over-time. In addition, at some crosswalks, improvements were found in the rates of giving-way to pedestrians by the vehicles, vehicle-pedestrian conflicts and shares of pedestrians who cross within the crosswalk boundaries, while the changes in keeping safe crossing rules by pedestrians were mixed. Overall, the changes in road user behaviors following the installation of the raised crosswalks were positive and associated with safety improvement of pedestrian crossing conditions. Based on the study results, raised crosswalks with preceding speed humps can be promoted as a pedestrian safety-improving measure on busy urban roads. (C) 2016 Elsevier Ltd. All rights reserved.
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Oskar Heinroth was a pioneering German ornithologist of the early-mid 20th century whose three major contributions to ornithology have been largely overlooked. First, he conducted a systematic comparative study of the avian social...
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Oskar Heinroth was a pioneering German ornithologist of the early-mid 20th century whose three major contributions to ornithology have been largely overlooked. First, he conducted a systematic comparative study of the avian social signals and other behaviours (in waterfowl, including hybrids) and was the first to recognise that their instinctive, ritualized displays could serve as taxonomic criteria. Konrad Lorenz later developed the idea and also gained most of the credit for it. Second, Heinroth,together with his first wife Magdalena, hand-reared about 1,000 individuals of 286 species of birds in their apartment over 28 years, documenting and photographing their development. The results, published in four substantial volumes (1924-1933) were well received, but the deteriorating financial and political situation in Germany before WWII, together with the lack of an English translation, meant that the project received less attention than it warranted. Third, Heinroth provided a framework for studying and understanding the behaviour of birds that included detailed observations throughout the animals' life; making use of tame individuals; and comparisons between captive and wild individuals. The value of this approach to the study of behaviour is exemplified by the Heinroths' results from rearing European Nightjars Caprimulgus europaeus in their apartment. We propose that these contributions as well as numerous other anecdotes and observations in Heinroth's publications merit further examination.
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Objectives: Sleep disturbances are common in preschoolers, and profoundly affected by parenting. Grandparents are increasingly involved in childcare and have attracted worldwide attention for their potential impacts on child well-...
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Objectives: Sleep disturbances are common in preschoolers, and profoundly affected by parenting. Grandparents are increasingly involved in childcare and have attracted worldwide attention for their potential impacts on child well-being. However, no studies have explored child sleep health within the context of grandparental care. We aimed to explore the association between grandparents as primary caregivers and children's sleep disturbances. Methods: Participants included 20,324 preschoolers from the Shanghai Children's Health, Education and Lifestyle Evaluation-Preschool (SCHEDULE-P) in Shanghai, China. They were initially assessed in November 2016 and were reassessed in April 2018 and April 2019. Children's primary caregivers were collected at each survey. Sleep disturbances were assessed by the Children's Sleep Habits Questionnaire (CSHQ). Results: At baseline, 84.4% of children had global sleep disturbances (CSHQ total score >41). Compared with parents, random-effects model indicated that grandparents as primary caregivers increased the adjusted odds ratio (OR) for children's global sleep disturbances by 30% (OR [95%CI]: 1.30 [1.21, 1.40]). To the specific domains of CSHQ, two-way repeated-measures ANOVA showed significant "caregiver transition" group x wave interaction in the behavioral sleep disturbances, such as "Bedtime Resistance" (p < 0.001). At each survey, children with grandparents as primary caregivers demonstrated significant higher behavioral sleep disturbances than their counterparts with parental care. Conclusions: Grandparental care is associated with increased sleep disturbances, particularly behavioral sleep disturbances, in preschoolers. Future studies should explore the underlying mechanisms and whether sleep programs targeting grandparents can decrease children's sleep disturbances. (C) 2021 Elsevier B.V. All rights reserved.
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Objectives: Sleep disturbances are common in preschoolers, and profoundly affected by parenting. Grandparents are increasingly involved in childcare and have attracted worldwide attention for their potential impacts on child well-...
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Objectives: Sleep disturbances are common in preschoolers, and profoundly affected by parenting. Grandparents are increasingly involved in childcare and have attracted worldwide attention for their potential impacts on child well-being. However, no studies have explored child sleep health within the context of grandparental care. We aimed to explore the association between grandparents as primary caregivers and children's sleep disturbances. Methods: Participants included 20,324 preschoolers from the Shanghai Children's Health, Education and Lifestyle Evaluation-Preschool (SCHEDULE-P) in Shanghai, China. They were initially assessed in November 2016 and were reassessed in April 2018 and April 2019. Children's primary caregivers were collected at each survey. Sleep disturbances were assessed by the Children's Sleep Habits Questionnaire (CSHQ). Results: At baseline, 84.4% of children had global sleep disturbances (CSHQ total score >41). Compared with parents, random-effects model indicated that grandparents as primary caregivers increased the adjusted odds ratio (OR) for children's global sleep disturbances by 30% (OR [95%CI]: 1.30 [1.21, 1.40]). To the specific domains of CSHQ, two-way repeated-measures ANOVA showed significant "caregiver transition" group x wave interaction in the behavioral sleep disturbances, such as "Bedtime Resistance" (p < 0.001). At each survey, children with grandparents as primary caregivers demonstrated significant higher behavioral sleep disturbances than their counterparts with parental care. Conclusions: Grandparental care is associated with increased sleep disturbances, particularly behavioral sleep disturbances, in preschoolers. Future studies should explore the underlying mechanisms and whether sleep programs targeting grandparents can decrease children's sleep disturbances. (C) 2021 Elsevier B.V. All rights reserved.
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We compared the swimming performance of juvenile blue catfish Ictalurus furcatus and hybrid catfish (female channel catfish I. punctatus X male blue catfish) using it protocol in which fish were forced to swim at a fixed velocity ...
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We compared the swimming performance of juvenile blue catfish Ictalurus furcatus and hybrid catfish (female channel catfish I. punctatus X male blue catfish) using it protocol in which fish were forced to swim at a fixed velocity and their time to fatigue recorded at speeds of 30-120 cm/s. Hybrid catfish swain significantly longer than blue catfish at all of the speeds tested except 30 and 40 cm/s. The maximum sustained swimming speed (no fatigue in times >= 200 min) was 30 and 40 cm/s for blue catfish and hybrid catfish, respectively. The maximum prolonged swimming speed (fatigue in times >20 s but <200 min) was 100 cm/s for blue catfish and 120 cm/s for hybrid catfish. The burst swimming speed (fatigue in times <20 s) for blue catfish was 110 cm/s. The burst swimming speed for hybrid catfish was not determined; however, it is higher than its maximum prolonged swimming speed of 120 cm/s (highest speed tested). Hybrid catfish were able to swim longer before fatiguing than were blue catfish at 50 cm/s (156 versus 97 min) and at 60 cm/s (33 versus 6 min). Both blue catfish and hybrid catfish fatigued in less than 5 min at 70 cm/s, less than 3 min at 80 cm/s, and less than 60 s at 110 cm/s. No blue catfish swam at 120 cm/s while hybrids swam for 26 s at that speed. The results of this study will help fish producers understand the relationship between the speed of water currents produced by various aeration equipment and fatigue in pond-raised blue and hybrid catfish fingerlings.
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