14,254 research outputs found

    Experimental study of noise reduction for an unstiffened cylindrical model of an airplane fuselage

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    Noise reduction measurements were made for a simplified model of an airplane fuselage consisting of an unstiffened aluminum cylinder 0.5 m in diameter by 1.2 m long with a 1.6-mm-thick wall. Noise reduction was first measured with a reverberant field pink-noise load on the cylinder exterior. Next, noise reduction was measured by using a propeller to provide a more realistic noise load on the cylinder. Structural resonance frequencies and acoustic reverberation times for the cylinder interior volume were also measured. Comparison of data from the relatively simple test using reverberant-field noise with data from the more complex propeller-noise tests indicates some similarity in both the overall noise reduction and the spectral distribution. However, all of the test parameters investigated (propeller speed, blade pitch, and tip clearance) had some effect on the noise-reduction spectra. Thus, the amount of noise reduction achieved appears to be somewhat dependent upon the spectral and spatial characteristics of the flight conditions. Information is also presented on cyclinder resonance frequencies, damping, and characteristics of propeller-noise loads

    Static inverters which sum a plurality of waves Patent

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    Describing static inverter with single or multiple phase outpu

    The role of the Initial Teacher Training Coordinator in the school based element of partnership: to what extent does the Co-ordinator undertake supervision of aspects of quality assurance?

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    Over the last 14 years, Universities and colleges have organised school placements and award qualifications whilst teachers, acting as mentors take the lead in guiding, supervising and assessing students on lengthy teaching placements. Partnership developed quickly in response to legislation and Sheffield Hallam University was among the first of the Universities to 'sign up' to the new partnership model in 1992. The Partnership Survey 2006 reported on in this paper has focussed on the Senior Liaison Tutor with a view to finding out their views on their role, and perceived contributions to the quality assurance of the partnership. The survey focussed on some of the key issues identified in previous studies and meetings of the Partnership Management Board.</p

    The role of the initial teacher training co-ordinator: secondary headteachers' and ITT co-ordinators' perspectives

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    The roles of ITT co-ordinator (ITTC) and CPD co-ordinator have become well established in secondary schools in England. However there is usually a separation of responsibilities for these areas within schools. The introduction of a new Standards Framework and other government policies such as the remodelling of the workforce in schools (DfES, 2003, TDA, 2007a) provide schools with opportunity to revisit these roles. A consequence of remodelling has been a rapid expansion of support staff in schools to assist teachers and one aspect of this contractual change is that support staff are taking on administrative tasks, formerly done by teachers. A further aspect is that CPD Coordinators now have responsibility for staff development cross the wider workforce. During 2007, Schools have used remodelling as an opportunity to review their management structures throughout the school including the organisation of staff development and how the school is contributing to the training of new teachers. In this paper we consider how the role of the ITTC is changing using data from interviews with Head Teachers and ITTCs from a sample of secondary schools that are in partnership with Sheffield Hallam University. Data collection took place in April and May 2007.</p

    Prey selection by an apex predator : the importance of sampling uncertainty.

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    The impact of predation on prey populations has long been a focus of ecologists, but a firm understanding of the factors influencing prey selection, a key predictor of that impact, remains elusive. High levels of variability observed in prey selection may reflect true differences in the ecology of different communities but might also reflect a failure to deal adequately with uncertainties in the underlying data. Indeed, our review showed that less than 10% of studies of European wolf predation accounted for sampling uncertainty. Here, we relate annual variability in wolf diet to prey availability and examine temporal patterns in prey selection; in particular, we identify how considering uncertainty alters conclusions regarding prey selection. Over nine years, we collected 1,974 wolf scats and conducted drive censuses of ungulates in Alpe di Catenaia, Italy. We bootstrapped scat and census data within years to construct confidence intervals around estimates of prey use, availability and selection. Wolf diet was dominated by boar (61.5±3.90 [SE] % of biomass eaten) and roe deer (33.7±3.61%). Temporal patterns of prey densities revealed that the proportion of roe deer in wolf diet peaked when boar densities were low, not when roe deer densities were highest. Considering only the two dominant prey types, Manly's standardized selection index using all data across years indicated selection for boar (mean = 0.73±0.023). However, sampling error resulted in wide confidence intervals around estimates of prey selection. Thus, despite considerable variation in yearly estimates, confidence intervals for all years overlapped. Failing to consider such uncertainty could lead erroneously to the assumption of differences in prey selection among years. This study highlights the importance of considering temporal variation in relative prey availability and accounting for sampling uncertainty when interpreting the results of dietary studies

    Developing enterprise culture in a northern educational authority in the UK: involving trainee teachers in learning-orientated evaluation

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    In this paper we discuss our use of innovative methods - at least in the context of regeneration evaluation - to help evaluate an enterprise project in northern England, paying particular attention to the involvement of trainee teachers. We discuss the methods used and critically appraise the methods and methodology, present some emerging findings from the trainee teachers strand and conclude by discussing the place of what might be termed 'learning-orientated evaluation' in relation to the currently dominant output-focussed evaluation paradigm.</p
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