249 resultados para 090104 Aircraft Performance and Flight Control Systems


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In this work, we report design, synthesis and characterization of solution processable low band gap polymer semiconductors, poly{3,6-difuran-2-yl-2,5-di(2- octyldodecyl)-pyrrolo[3,4-c]pyrrole-1,4-dione-alt-phenylene} (PDPP-FPF), poly{3,6-difuran-2-yl-2,5-di(2-octyldodecyl)-pyrrolo[3,4-c]pyrrole-1, 4-dione-alt-naphthalene} (PDPP-FNF) and poly{3,6-difuran-2-yl-2,5-di(2- octyldodecyl)-pyrrolo[3,4-c]pyrrole-1,4-dione-alt-anthracene} (PDPP-FAF) using the furan-containing 3,6-di(furan-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (DBF) building block. As DBF acts as an acceptor moiety, a series of donor-acceptor (D-A) copolymers can be generated when it is attached alternatively with phenylene, naphthalene or anthracene donor comonomer blocks. Optical and electrochemical characterization of thin films of these polymers reveals band gaps in the range of 1.55-1.64 eV. These polymers exhibit excellent hole mobility when used as the active layer in organic thin-film transistor (OTFT) devices. Among the series, the highest hole mobility of 0.11 cm 2 V -1 s -1 is achieved in bottom gate and top-contact OTFT devices using PDPP-FNF. When these polymers are used as a donor and [70]PCBM as the acceptor in organic photovoltaic (OPV) devices, power conversion efficiencies (PCE) of 2.5 and 2.6% are obtained for PDPP-FAF and PDPP-FNF polymers, respectively. Such mobility values in OTFTs and performance in OPV make furan-containing DBF a very promising block for designing new polymer semiconductors for a wide range of organic electronic applications.

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Because of China's extremely rapid economic growth, the scale and seriousness of environmental problems is no longer in doubt. Whether pollution abatement technologies are utilized more efficiently is crucial in the analysis of environmental management in China. This study analyzes how the performance of environmental management has changed over time using province level data for 1992-2003. Mixed results for environmental performance are shown using nonparametric estimation technique. We find that environmental performance index, abatement effort, and increasing returns to pollution abatement play important roles in determining the pollution level over the period of the study.

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Background Situational driving factors, including fatigue, distraction, inattention and monotony, are recognised killers in Australia, contributing to an estimated 40% of fatal crashes and 34% of all crashes . More often than not the main contributing factor is identified as fatigue, yet poor driving performance has been found to emerge early in monotonous conditions, independent of fatigue symptoms and time on task. This early emergence suggests an important role for monotony. However, much road safety research suggests that monotony is solely a task characteristic that directly causes fatigue and associated symptoms and there remains an absence of consistent evidence explaining the relationship. Objectives We report an experimental study designed to disentangle the characteristics and effects of monotony from those associated with fatigue. Specifically, we examined whether poor driving performance associated with hypovigilance emerges as a consequence of monotony, independent of fatigue. We also examined whether monotony is a multidimensional construct, determined by environmental characteristics and/or task demands that independently moderate sustained attention and associated driving performance. Method Using a driving simulator, participants completed four, 40 minute driving scenarios. The scenarios varied in the degree of monotony as determined by the degree of variation in road design (e.g., straight roads vs. curves) and/or road side scenery. Fatigue, as well as a number of other factors known to moderate vigilance and driving performance, was controlled for. To track changes across time, driving performance was assessed in five minute time periods using a range of behavioural, subjective and physiological measures, including steering wheel movements, lane positioning, electroencephalograms, skin conductance, and oculomotor activity. Results Results indicate that driving performance is worse in monotonous driving conditions characterised by low variability in road design. Critically, performance decrements associated with monotony emerge very early, suggesting monotony effects operate independent of fatigue. Conclusion Monotony is a multi-dimensional construct where, in a driving context, roads containing low variability in design are monotonous and those high in variability are non-monotonous. Importantly, low variability in road side scenery does not appear to exacerbate monotony or associated poor performance. However, high variability in road side scenery can act as a distraction and impair sustained attention and poor performance when driving on monotonous roads. Furthermore, high sensation seekers seem to be more susceptible to distraction when driving on monotonous roads. Implications of our results for the relationship between monotony and fatigue, and the possible construct-specific detection methods in a road safety context, will be discussed.

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Purpose: Older adults have increased visual impairment, including refractive blur from presbyopic multifocal spectacle corrections, and are less able to extract visual information from the environment to plan and execute appropriate stepping actions; these factors may collectively contribute to their higher risk of falls. The aim of this study was to examine the effect of refractive blur and target visibility on the stepping accuracy and visuomotor stepping strategies of older adults during a precision stepping task. Methods: Ten healthy, visually normal older adults (mean age 69.4 ± 5.2 years) walked up and down a 20 m indoor corridor stepping onto selected high and low-contrast targets while viewing under three visual conditions: best-corrected vision, +2.00 DS and +3.00 DS blur; the order of blur conditions was randomised between participants. Stepping accuracy and gaze behaviours were recorded using an eyetracker and a secondary hand-held camera. Results: Older adults made significantly more stepping errors with increasing levels of blur, particularly exhibiting under-stepping (stepping more posteriorly) onto the targets (p<0.05), while visuomotor stepping strategies did not significantly alter. Stepping errors were also significantly greater for the low compared to the high contrast targets and differences in visuomotor stepping strategies were found, including increased duration of gaze and increased interval between gaze onset and initiation of the leg swing when stepping onto the low contrast targets. Conclusions: These findings highlight that stepping accuracy is reduced for low visibility targets, and for high levels of refractive blur at levels typically present in multifocal spectacle corrections, despite significant changes in some of the visuomotor stepping strategies. These findings highlight the importance of maximising the contrast of objects in the environment, and may help explain why older adults wearing multifocal spectacle corrections exhibit an increased risk of falling.

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This paper analyses the concept of ‘work-relatedness’ in Australian workers’ compensation and occupational health and safety (OHS) systems. The concept of work-relatedness is important because it is a crucial element circumscribing the limits of the protection afforded to workers under the preventative OHS statutes, and is a threshold element which has to be satisfied before an injured or ill worker can recover statutory compensation. While the preventive and compensatory regimes do draw on some similar concepts of work-relatedness, as this paper will illustrate, there are significant differences both between, and within, these regimes.

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Zinc-rich ethyl silicate coatings are quite successful in protecting steel against corrosion under severe exposing conditions. In spite of providing excellent cathodic protection to steel structure after film curing, two-component zinc-rich ethyl silicate coatings have some limitations, one of which is inadequate shelf life as a result of in-can binder gelation. In this work, the preparation steps of ethyl silicate such as pre-hydrolysis, dehydration and organometallic reactions were surveyed and herein an approach towards understanding the cause and effect relationship of the use of ingredients is presented. The effects of water and catalytic acid dosages on gel time under accelerated conditions and the effect of alcoholic solvent order on the rate of the hydrolysis and dehydration reactions were studied via Karl-Fischer test determining the water content of hydrolysate. A thriving optimization in shelf life without any loss in physical–mechanical characteristics of the final film (e.g. hardness, adhesion, solvent and salt spray resistance) was obtained.

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Electric distribution networks are now in the era of transition from passive to active distribution networks with the integration of energy storage devices. Optimal usage of batteries and voltage control devices along with other upgrades in network needs a distribution expansion planning (DEP) considering inter-temporal dependencies of stages. This paper presents an efficient approach for solving multi-stage distribution expansion planning problems (MSDEPP) based on a forward-backward approach considering energy storage devices such as batteries and voltage control devices such as voltage regulators and capacitors. The proposed algorithm is compared with three other techniques including full dynamic, forward fill-in, backward pull-out from the point of view of their precision and their computational efficiency. The simulation results for the IEEE 13 bus network show the proposed pseudo-dynamic forward-backward approach presents good efficiency in precision and time of optimization.

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Few studies have examined the effects of parental MS on children, and those that have suffered from numerous methodological weaknesses, some of which are addressed in this study. This study investigated the effects of parental MS on children by comparing youth of a parent with MS to youth who have no family member with a serious health condition on adjustment outcomes, caregiving, attachment and family functioning. A questionnaire survey methodology was used. Measures included youth somatisation, health, pro-social behaviour, behavioural-social difficulties, caregiving, attachment and family functioning. A total of 126 youth of a parent with MS were recruited from MS Societies in Australia and, were matched one-to-one with youth who had no family member with a health condition drawn from a large community sample. Comparisons showed that youth of a parent with MS did not differ on any of the outcomes except for peer relationship problems: adolescent youth of a parent with MS reported lower peer relationship problems than control adolescents. Overall, results did not support prior research findings suggesting adverse impacts of parental MS on youth.

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As part of Australian licensing requirements professional valuers are required to maintain a level of professional indemnity insurance. A core feature of any insurance cover is that the insured has an obligation to notify their insurer of both actual and potential claims. An actual claim clearly will impact upon future policies and premiums paid. Notification of a potential claim, whether or not the notification crystallises into an actual claim, also can have an impact upon the insured’s claims history and premiums. The Global Financial Crisis continues to impact upon business practices and land transactions both directly and indirectly. The Australian valuation profession is not exempt from this impact. One example of this ongoing impact is reflected in a worrying practice engaged in by some financial institutions in respect of their loan portfolios. That is, even though the mortgagor is not in default, some institutions are pre-emptively issuing notices of demand regarding potential losses. Further, in some instances such demands are based only on mass appraisal valuations without specific consideration being given to the individual lot in question. The author examines the impact of this practice for the valuation profession and seeks to provide guidance for the appropriate handling of such demands.

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India’s desire to transform itself into an international military power has brought about a rapid shift in its approach to procuring military hardware. The indigenization of India’s military manufacturing capacity forms an integral part of the strategic objectives of Indian military services, with its realization being a function of significant government investment in strategic technologies. This has a number of ramifications. An indigenous Indian military capacity, particularly in the field of aviation, forms a key part of India’s ambition of achieving regional air superiority, or even supremacy, and being capable of power projection. This is particularly in response to China’s increasing presence in South Asian airspace. A burgeoning Indian military manufacturing machine based on a comparative advantage in skilled technicians and lower-cost labour, together with strategic collaboration with foreign military hardware manufacturers, may also lead to neighbouring countries looking to India as a source of competitively priced military hardware. In short, this chapter seeks to analyse the rationale behind India’s attempt to become militarily self-sufficient in the field of aviation, discuss the technical, economic and political context in which it is achieving this transformation, and assess the potential outlook of success for India’s drive to achieve self-sufficiency in the arena of military aviation. This chapter will do so by using the case of India’s attempt to develop a fifth-generation fighter aircraft.

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Big Tobacco has been engaged in a dark, shadowy plot and conspiracy to hijack the Trans-Pacific Partnership Agreement (TPP) and undermine tobacco control measures – such as graphic health warnings and the plain packaging of tobacco products... In the context of this heavy lobbying by Big Tobacco and its proxies, this chapter provides an analysis of the debate over trade, tobacco, and the TPP. This discussion is necessarily focused on the negotiations of the free trade agreement – the shadowy conflicts before the finalisation of the text. This chapter contends that the trade negotiations threaten hard-won gains in public health – including international developments such as the WHO Framework Convention on Tobacco Control, and domestic measures, such as graphic health warnings and the plain packaging of tobacco products. It maintains that there is a need for regional trade agreements to respect the primacy of the WHO Framework Convention on Tobacco Control. There is a need both to provide for an open and transparent process regarding such trade negotiations, as well as a due and proper respect for public health in terms of substantive obligations. Part I focuses on the debate over the intellectual property chapter of the TPP, within the broader context of domestic litigation against Australia’s plain tobacco packaging regime and associated WTO disputes. Part II examines the investment chapter of the TPP, taking account of ongoing investment disputes concerning tobacco control and the declared approaches of Australia and New Zealand to investor-state dispute settlement. Part III looks at the discussion as to whether there should be specific text on tobacco control in the TPP, and, if so, what should be its nature and content. This chapter concludes that the plain packaging of tobacco products – and other best practices in tobacco control – should be adopted by members of the Pacific Rim.

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When thin steel roof and wall cladding systems are subjected to wind uplift/suction forces, local pull-through or pull-out failures occur prematurely at their screwed connections. During high wind events such as stom1s and cyclones, these localized failures then lead to severe damage to buildings and their contents. In recent times, the use of thin steel battens, purlins and girts has increased considerably, which has made the pull-out failures more critical in the design of steel cladding systems. An experimental investigation was therefore carried out to study the pull-out failure using both static and cyclic tests for a range of commonly used screw fasteners and steel battens, purlins and girts. This paper presents the details ofthis experimental investigation and its results.

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This study developed and tested a model of job uncertainty for survivors and victims of downsizing. Data were collected from three samples of employees in a public hospital, each representing three phases of the downsizing process: immediately before the announcement of the redeployment of staff, during the implementation of the downsizing, and towards the end of the official change programme. As predicted, levels of job uncertainty and personal control had a direct relationship with emotional exhaustion and job satisfaction. In addition, there was evidence to suggest that personal control mediated the relationship between job uncertainty and employee adjustment, a pattern of results that varied across each of the three phases of the change event. From the perspective of the organization’s overall climate, it was found that levels of job uncertainty, personal control and job satisfaction improved and/or stabilized over the downsizing process. During the implementation phase, survivors experienced higher levels of personal control than victims, but both groups of employees reported similar levels of job uncertainty. We discuss the implications of our results for strategically managing uncertainty during and after organizational change.