5,563 research outputs found
Thermal fatigue and oxidation data on TAZ-8A, MAR-M 200, and Udimet 700 superalloys
The fluidized bed technique was used to determine the relative thermal fatigue and oxidation resistance of three superalloys: TAZ-8A, Mar-M 200, and Udimet 700. The alloys TAZ-8A and MAR-M 200 were also tested in the directionally-solidified form. For the 13 combinations of composition, solidification method, surface protection, and specimen geometry, the cycles to cracking varied from 1250 to 15,000. The alloy/coating having the best resistance to thermal fatigue cracking was coated directionally-solidified NASA TAZ-8A. This combination also had excellent oxidation resistance
Loudness (annoyance), prediction procedure for steady sounds
Method has been devised to predict loudness level of any steady sound solely from its measured power spectrum level. Method is based on assumption that, with respect to loudness sensation, the human auditory system acts as open-loop transmission system with transmittance function determined from measured tone curves
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Imagining inclusive teachers: contesting policy assumptions in relation to the development of inclusive practice in schools
In this paper we reflect on data from two research projects in which inclusive practice in schools is at issue, in the light of wider field experience (our own and others’) of school and teacher development. We question what we understand to be relatively common, implicit policy assumptions about how teachers develop, by examining the way in which teachers are portrayed and located in these projects. The examples discussed in this paper draw on experience in Lao PDR and Bangladesh, critically exploring teachers’ roles, position and agency in practice. Similarities and differences rooted in cultural, political and institutional contexts highlight in a very productive way the significance and potential dangers of policy assumptions about teachers within the process of development.
In Bangladesh, a success story is presented: the case of a group of schools in which an institutional context for learning appears to sustain teachers’ commitment and motivation, with the effect of creating meaningful outcomes for young people who were previously outside the education system. These data raise questions about the significance of institutional context to teachers’ practices, and questions about approaches to teacher development which omit consideration of that context by, for example, focusing inadvertently on features of individual teachers.
We then consider teachers’ responses to the movement for inclusive education in a school in the Lao PDR since 2004. Inclusion here was understood to require a significant shift in teacher identity and a movement away from authoritative pedagogy towards the facilitation of a pedagogy which aimed to encourage the active participation of all students. Through a longitudinal study of teachers in one school, the conditions for such change were identified and again cast doubt on some of the assumptions behind large-scale attempts at teacher development. Reflecting on these experiences and the evidence they provide, we suggest that teacher development programmes are more likely to be effective where teachers are considered not as individuals subject to training but as agents located in an influential institutional context
Analytical model for determining spacecraft impact velocity and orientation relative to an impact surface
Development of analytical model for determining spacecraft impact velocity and orientation relative to impact surface for variable dynamic condition
Polarized Neutron Matter: A Lowest Order Constrained Variational Approach
In this paper, we calculate some of the polarized neutron matter properties,
using the lowest order constrained variational method with the
potential and employing a microscopic point of view. A comparison is also made
between our results and those of other many-body techniques.Comment: 23 pages, 8 figure
Analysis of Magnetic Fields in Inertial Alfven Wave Collisions
Turbulence in astrophysical and space plasmas is dominated by the nonlinear
interaction of counterpropagating Alfven waves. Most Alfven wave turbulence
theories have been based on ideal plasma models, such as incompressible MHD,
for Alfven waves at large scales. However, in the inertial Alfven wave regime
(vA > vthe), relevant to magnetospheric plasmas, how the turbulent nonlinear
interactions are modified by the dispersive nature of the waves remains to be
explored. Here we present the first laboratory evidence of the nonlinear
interaction in the inertial regime. A comparison is made with the theory for
MHD Alfven waves.Comment: 2 pages, 1 figur
Excitation Spectrum and Correlation Functions of the Z_3-Chiral Potts Quantum Spin Chain
We study the excitation spectrum and the correlation functions of the Z_3-
chiral Potts model in the massive high-temperature phase using perturbation
expansions and numerical diagonalization. We are mainly interested in results
for general chiral angles but we consider also the superintegrable case. For
the parameter values considered, we find that the band structure of the low-
lying part of the excitation spectrum has the form expected from a
quasiparticle picture with two fundamental particles. Studying the N-dependence
of the spectrum, we confirm the stability of the second fundamental particle in
a limited range of the momentum, even when its energy becomes so high that it
lies very high up among the multiparticle scattering states. This is not a
phenomenon restricted to the superintegrable line. Calculating a
non-translationally invariant correlation function, we give evidence that it is
oscillating. Within our numerical accuracy we find a relation between the
oscillation length and the dip position of the momentum dispersion of the
lightest particle which seems to be quite independent of the chiral angles.Comment: 19 pages + 6 PostScript figures (LaTeX); BONN-TH-94-2
Concepts and procedures used to determine certain sea wave characteristics
A technique and its application are presented by which wave parameters, critical to spacecraft water impact load analysis, may be determined
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