Comparison of flight data and analysis for hingeless rotor regressive inplane mode stability

Analytical and experimental data obtained during the development of the AH-56A covering stability of the regressive inplane mode, including coupling with other modes such as body and rotor plunge are reported. Data were obtained on two distinctly different control systems; both gyro controlled, but one with feathering moment feedback and the other with direct flapping feedback. A review was made of analytical procedures employed in investigating the stability of this mode and a comparison was made of the analytical and experimental data. The effect of certain parameters including blade droop, sweep, delta 3, alpha 1, vehicle roll inertia, inplane frequency, and rpm and forward speed on the mode were also reviewed. It was shown that the stability of this mode is treatable by analysis and that adequate stability is achievable without recourse to auxiliary inplane damping devices

Strain Analysis of Initial Stage Sintering of 316L SS Three Dimensionally Printed (3DP TM) Components

Mechanical Engineerin

Teacher career trajectories and aspirations in context: A mixed methods study of second-stage teachers in New South Wales

The aim of this thesis is to describe, interpret and explain the career trajectories and aspirations of second-stage teachers in New South Wales and to identify the key contextual factors influencing their careers. Successive government reforms targeting teacher quality and professionalism have significantly shifted the work landscape for teachers. The concept of ‘career’ provides a useful conceptual lens through which to analyse teachers’ work patterns and goals. Recent studies suggest that some teachers are redefining what it means to have a teaching career and seeking alternative trajectories that may expand their job roles (Peske, Liu, Johnson, Kauffman, & Kardos, 2001; Rinke, 2009, 2011; Rippon, 2005; Smethem, 2007). Whilst levels of teacher attrition are described as having “reached epidemic proportions” in Australia, the U.S and U.K (Gallant & Riley, 2014, p. 562), current research has given insufficient attention to the within-career issues that shape teacher career decision-making (Buchanan, 2009b; Clandinin et al., 2015; Lindqvist & Nordänger, 2016). Whereas beginning teachers have been given considerable research attention, this thesis examined ‘second-stage teachers’ in their fourth to tenth year of teaching (Kirkpatrick & Johnson, 2014). Having overcome their early survival concerns, second-stage teachers shift focus to the future and contemplate how, if at all, they might develop a teaching career. This study used a convergent parallel mixed methods design, wherein both qualitative and quantitative data were collected in parallel, analysed separately and finally integrated. This study had three data sets: policy documents, workforce statistics and semi-structured interviews with twenty-four second-stage teachers representing a range of ages and school levels, sectors and locations. This cohort of teachers is the first generation for whom compulsory Standards and accreditation has applied under the New Scheme system. This thesis offers two original contributions to the knowledge base. Firstly, this thesis identifies six specific career trajectories that second-stage teachers aspire to, recognising these as different roles that teachers may shift between rather than pre-determined pathways. The model presented here offers a more nuanced understanding of teacher retention/attrition that extends beyond classifying teachers as stayers/leavers.Secondly, this thesis brings to light three key contextual factors that influence second-stage teachers’ careers: professional cultures amongst teachers, the current status of teaching and the practical implementation and enactment of policy agendas. The thesis concludes by highlighting points of convergence and divergence within the data to show how the current policy context is not well aligned with second-stage teachers’ lived career experiences

Magnetic instability of a two-dimensional Anderson non-Fermi liquid

We show that in the Anderson model for a two-dimensional non-Fermi liquid a magnetic instability can lead to the itinerant electron ferromagnetism. The critical temperature and the susceptibility of the paramagnetic phase have been analytically calculated. The usual Fermi behaviour is re-obtained taking the anomalous exponent to be zero.Comment: 3 pages, Revte

Palladium-bismuth intermetallic and surface-poisoned catalysts for the semi-hydrogenation of 2-methyl-3-butyn-2-ol

The effects of poisoning of Pd catalysts with Bi and annealing in a polyol (ethylene glycol) were studied on the semi-hydrogenation of 2-methyl-3-butyn-2-ol (MBY). An increase in the Pd:Bi ratio from 7 to 1 in the Bi-poisoned catalysts decreased the hydrogenation activity due to blocking of active sites, but increased maximum alkene yield from 91.5% for the Pd catalyst to 94–96% for all Bi-poisoned Pd catalysts, by decreasing the adsorption energy of alkene molecules and suppressing the formation of β-hydride phase. Annealing of the catalysts induced the formation of intermetallic phases and decreased its activity due to sintering of the catalytic particles and low activity of intermetallic compounds. Langmuir–Hinshelwood kinetic modelling of the experimental data showed that poisoning of Pd with Bi changed the relative adsorption constants of organic species suggesting ligand effects at high Bi content

Preferences for Residential Development Attributes and Support for the Policy Process: Implications for Management and Conservation of Rural Landscapes

The rural public may not only be concerned with the consequences of land management; residents may also have systematic preferences for policy instruments applied to management goals. Preferences for outcomes do not necessarily imply matching support for the underlying policy process. This study assesses relationships among support for elements of the policy process and preferences for management outcomes. Preferences are examined within the context of alternative proposals to manage growth and conserve landscape attributes in southern New England. Results are based on (a) stated preferences estimated from a multi-attribute contingent choice survey of rural residents, and (b) Likert-scale assessment of strength of support for land use policy tools. Findings indicate general but not universal correlation among policy support indicators and preferences for associated land use outcomes, but also confirm the suspicion that policy support and land use preference may not always coincide.Agricultural and Food Policy,

Particle Size Influence Upon Sintered Induced Strains Within 3DP� Stainless Steel Components

Three-dimensional printing (3DP™ 1 ) is a layer-by-layer manufacturing process whereby a three-dimensional (3D) component is created by the distribution of a liquid binder onto a powder media. A 3DP™ process using stainless steel powder as its printing media requires post-printing thermal processing for debinding and sintering of the printed green component. To minimize dimensional distortion while increasing structural integrity of the green component, 3DP™ thermal post-processing is designed to produce only neck growth between particles, defined as initial stage sintering. The accepted theoretical model governing initial stage sintering strain for spherical powder particles provides a qualitative account of strain development with respect to time and temperature variance; however, the model does not produce an accurate quantitative account for the magnitude of the strain when compared to dimensional experimental results. The theoretical model indicates that powder particle size is the dominant parameter governing sintering strain. The purpose of this study is to introduce an effective particle size into the theoretical model, thus enabling the application of the theoretical model to estimate dimensional change for components produced by 3DP™. Dimensional sintering experimentation has been performed using 3DP™ test specimens with spherical powder particles having mean diameters of 20 Pm, 80 Pm, and 200 Pm. Experimental results and progress on the theoretical model are discussed.Financial support for this work is provided by the Office of Naval Research, Contract #N00014-C-00-0378.Mechanical Engineerin