996 resultados para Flight safety


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This paper describes the use of the Euler equations for the generation and testing of tabular aerodynamic models for flight dynamics analysis. Maneuvers for the AGARD Standard Dynamics Model sharp leading-edge wind-tunnel geometry are considered as a test case. Wind-tunnel data is first used to validate the prediction of static and dynamic coefficients at both low and high angles, featuring complex vortical flow, with good agreement obtained at low to moderate angles of attack. Then the generation of aerodynamic tables is described based on a data fusion approach. Time-optimal maneuvers are generated based on these tables, including level flight trim, pull-ups at constant and varying incidence, and level and 90 degrees turns. The maneuver definition includes the aircraft states and also the control deflections to achieve the motion. The main point of the paper is then to assess the validity of the aerodynamic tables which were used to define the maneuvers. This is done by replaying them, including the control surface motions, through the time accurate computational fluid dynamics code. The resulting forces and moments are compared with the tabular values to assess the presence of inadequately modeled dynamic or unsteady effects. The agreement between the tables and the replay is demonstrated for slow maneuvers. Increasing rate maneuvers show discrepancies which are ascribed to vortical flow hysteresis at the higher rate motions. The framework is suitable for application to more complex viscous flow models, and is powerful for the assessment of the validity of aerodynamics models of the type currently used for studies of flight dynamics.

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BACKGROUND: Safe drug prescribing and administration are essential elements within undergraduate healthcare curricula, but medication errors, especially in paediatric practice, continue to compromise patient safety. In this area of clinical care, collective responsibility, team working and communication between health professionals have been identified as key elements in safe clinical practice. To date, there is limited research evidence as to how best to deliver teaching and learning of these competencies to practitioners of the future.

METHODS: An interprofessional workshop to facilitate learning of knowledge, core competencies, communication and team working skills in paediatric drug prescribing and administration at undergraduate level was developed and evaluated. The practical, ward-based workshop was delivered to 4th year medical and 3rd year nursing students and evaluated using a pre and post workshop questionnaire with open-ended response questions.

RESULTS: Following the workshop, students reported an increase in their knowledge and awareness of paediatric medication safety and the causes of medication errors (p < 0.001), with the greatest increase noted among medical students. Highly significant changes in students' attitudes to shared learning were observed, indicating that safe medication practice is learnt more effectively with students from other healthcare disciplines. Qualitative data revealed that students' participation in the workshop improved communication and teamworking skills, and led to greater awareness of the role of other healthcare professionals.

CONCLUSION: This study has helped bridge the knowledge-skills gap, demonstrating how an interprofessional approach to drug prescribing and administration has the potential to improve quality and safety within healthcare.

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The construction industry is inherently hazardous, with a significant number of accidents and incidents occurring, particularly on confined construction sites. This research identifies, clarifies and tabulates the various managerial health and safety issues encountered on confined construction sites, based on a qualitative approach, to aid in the management of the complex health and safety concerns. The methodology is based on qualitative research incorporating case studies, interviews, causal loop diagrams and mind mapping. The key findings in the managerial issues in the management of health and safety on confined construction sites can be summarised as follows; (1) A lack of space, (2) Increased management of site personnel, (3) Overcrowding of the work place. The implication for the industry is that due to the sustained development of urban centres on a global scale, coupled with the increasing complexity of architectural designs, the majority of on-site project management professionals are faced with the onerous task of completing often intricate designs within a limited spatial environment, under strict health and safety parameters. The value of such research is to aid management professionals successfully identify the various managerial issues highlighted, resulting in the successful management of health and safety on a confined construction site.

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The construction industry is inherently risky, with a significant number of accidents and disasters occurring, particularly on confined construction sites. This research investigates and identifies the various issues affecting successful management of health and safety in confined construction sites. The rationale is that identifying the issues would assist the management of health and safety particularly in inner city centres which are mostly confined sites. Using empiricism epistemology, the methodology was based on qualitative research approach by means of multiple case studies in three different geographical locations of Ireland, UK and USA. Data on each case study were collected through individual interviews and focus group discussion with project participants. The findings suggest that three core issues are the underlying factors affecting management of health and safety on confined construction sites. It include, (i) lack of space, (ii) problem of co-ordination and management of site personnel, and (iii) overcrowding of workplace. The implication of this is that project teams and their organisations should see project processes from a holistic point of view, as a unified single system, where quick intervention in solving a particular issue should be the norm, so as not to adversely affect interrelated sequence of events in project operations. Proactive strategies should be devised to mitigate these issues and may include detail project programming, space management, effective constructability review and efficient co-ordination of personnel, plant and materials among others. The value of this research is to aid management and operation of brownfield sites by identifying issues impacting on health and safety management in project process.

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A clinical trial using human embryonic stem cell (hESC) therapy for an inherited retinal degenerative disease is about to commence. The Advanced Cell Technology (ACT) trial will treat patients with Stargardt's macular dystrophy using transplanted retinal pigment epithelium derived from hESCs. Currently, no effective treatment is available for Stargardt's disease so a stem cell-based therapy that can slow progression of this blinding condition could represent a significant breakthrough. While there are some hurdles to clear, the ACT trial is a fine example of translational research that could eventually pave the way for a range of stem cell therapies for the retina and other tissues.

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Mass spectrometry (MS)-based metabolomics is emerging as an important field of research in many scientific areas, including chemical safety of food. A particular strength of this approach is its potential to reveal some physiological effects induced by complex mixtures of chemicals present at trace concentrations. The limitations of other analytical approaches currently employed to detect low-dose and mixture effects of chemicals make detection very problematic. Besides this basic technical challenge, numerous analytical choices have to be made at each step of a metabolomics study, and each step can have a direct impact on the final results obtained and their interpretation (i.e. sample preparation, sample introduction, ionization, signal acquisition, data processing, and data analysis). As the application of metabolomics to chemical analysis of food is still in its infancy, no consensus has yet been reached on defining many of these important parameters. In this context, the aim of the present study is to review all these aspects of MS-based approaches to metabolomics, and to give a comprehensive, critical overview of the current state of the art, possible pitfalls, and future challenges and trends linked to this emerging field. (C) 2010 Elsevier Ltd. All rights reserved.