309 research outputs found
Does the ATAR Predict Pre-service Teacher Capacity for Inclusive Classroom Practice?
In this study, we examined whether the Australian Tertiary Admissions Rank (ATAR) predicted pre-service teachers\u27 schema development for inclusive classroom teaching. Where previous studies have employed grade point average (GPA) as a criterion measure, this study employed a validated measure linked to standards-based classroom practice. The study was conducted in the final semester of the teacher education programs at three Australian universities. The results showed the explanatory power of the ATAR was close to zero for the students studied. The implications of the findings for teacher education and for using the ATAR as an indicator of teacher quality are discussed
A Theory-driven Approach to Subject Design in Teacher Education
The intent of this study was to examine how a theoretically-designed subject in an undergraduate teacher education course impacted on the learning and confidence of pre-service teachers in catering for the needs of students with diverse needs. The subject design utilised theoretical principles of self-organisation that were incorporated with the teaching and application of three evidence-based pedagogies of inclusion: explicit teaching, cooperative learning and collaborative practice. The study examined how the principles were enacted throughout the delivery of the subject and sought pre-service teacher reflections after completion. Initial findings suggest that embedding these principles and incorporating practical application throughout the subject assisted pre-service teachers with their learning, the completion of assessment and enhanced their confidence in being able to meet the needs of students with diverse needs
Rheological and Mechanical Gradient Properties of Polyurethane Elastomers for 3D-Printing with Reactive Additives
Polyurethane (PU) elastomers with their broad range of strength and elasticity are ideal materials for additive manufacturing of shapes with gradients of mechanical properties. By adjusting the mixing ratio of different polyurethane reactants during 3D-printing it is possible to change the mechanical properties. However, to guarantee intra- and inter-layer adhesion, it is essential to know the reaction kinetics of the polyurethane reaction, and to be able to influence the reaction speed in a wide range. In this study, the effect of adding three different catalysts and two inhibitors to the reaction of polyurethane elastomers were studied by comparing the time of crossover points between storage and loss modulus G′ and G′′ from time sweep tests of small amplitude oscillatory shear at 30°C. The time of crossover points is reduced with the increasing amount of catalysts, but only the reaction time with one inhibitor is significantly delayed. The reaction time of 90% NCO group conversion calculated from the FTIR-spectrum also demonstrates the kinetics of samples with different catalysts. In addition, the relation between the conversion as determined from FTIR spectroscopy and the mechanical properties of the materials was established. Based on these results, it is possible to select optimized catalysts and inhibitors for polyurethane 3D-printing of materials with gradients of mechanical properties.DFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität Berli
Equilibration of Long Chain Polymer Melts in Computer Simulations
Several methods for preparing well equilibrated melts of long chains polymers
are studied. We show that the standard method in which one starts with an
ensemble of chains with the correct end-to-end distance arranged randomly in
the simulation cell and introduces the excluded volume rapidly, leads to
deformation on short length scales. This deformation is strongest for long
chains and relaxes only after the chains have moved their own size. Two methods
are shown to overcome this local deformation of the chains. One method is to
first pre-pack the Gaussian chains, which reduces the density fluctuations in
the system, followed by a gradual introduction of the excluded volume. The
second method is a double-pivot algorithm in which new bonds are formed across
a pair of chains, creating two new chains each substantially different from the
original. We demonstrate the effectiveness of these methods for a linear bead
spring polymer model with both zero and nonzero bending stiffness, however the
methods are applicable to more complex architectures such as branched and star
polymer.Comment: 12 pages, 9 figure
Mesoscale modeling of the rheology of pressure sensitive adhesives through inclusion of transient forces
For optimal application, pressure-sensitive adhesives must have rheological
properties in between those of a viscoplastic solid and those of a viscoelastic
liquid. Such adhesives can be produced by emulsion polymerisation, resulting in
latex particles which are dispersed in water and contain long-chain acrylic
polymers. When the emulsion is dried, the latex particles coalesce and an
adhesive film is formed. The rheological properties of the dried samples are
believed to be dominated by the interface regions between the original latex
particles, but the relation between rheology and latex particle properties is
poorly understood. In this paper we show that it is possible to describe the
bulk rheology of a pressure-sensitive adhesive by means of a mesoscale
simulation model. To reach experimental time and length scales, each latex
particle is represented by just one simulated particle. The model is subjected
to oscillatory shear flow and extensional flow. Simple order of magnitude
estimates of the model parameters already lead to semi-quantitative agreement
with experimental results. We show that inclusion of transient forces in the
model, i.e. forces with memory of previous configurations, is essential to
correctly predict the linear and nonlinear properties.Comment: 29 pages, 8 figure
Improving Pre-service teachers’ understanding of complexity of mathematics instructional practice through deliberate practice
Many teacher education programs are criticized for their failure to prepare pre-service teachers to utilize and transfer their knowledge of content and educational principles into authentic classroom teaching. Studies also consistently report that pre-service teachers’ ability to identify what is noteworthy about a mathematics classroom situation was lacking. This study investigated the effect of the intervention program, Study of Teaching, on pre-service teachers’ acquisition of three designated mathematics teaching skills, how much they understood about the complexity of mathematics teaching, and their professional growth. We began with the assumption that preservice teachers’ ability to discern the ‘critical aspects’ of mathematics classroom instruction could be enhanced through enacting reduced length microteaching sessions. Our results indicate that reduced microteaching in the setting, as in our intervention program, provide pre-service teachers with a safe environment to practise teaching. In general, this project found that preservice teachers’ awareness of the complexity and intricacy of actual classroom teaching of mathematics had been greatly enhanced following this intervention
Direct conversion of rheological compliance measurements into storage and loss moduli
We remove the need for Laplace/inverse-Laplace transformations of
experimental data, by presenting a direct and straightforward mathematical
procedure for obtaining frequency-dependent storage and loss moduli
( and respectively), from time-dependent experimental
measurements. The procedure is applicable to ordinary rheological creep
(stress-step) measurements, as well as all microrheological techniques, whether
they access a Brownian mean-square displacement, or a forced compliance. Data
can be substituted directly into our simple formula, thus eliminating
traditional fitting and smoothing procedures that disguise relevant
experimental noise.Comment: 4 page
Rocker-sole footwear versus prefabricated foot orthoses for the treatment of pain associated with first metatarsophalangeal joint osteoarthritis: Study protocol for a randomised trial
BACKGROUND: Osteoarthritis affecting the first metatarsophalangeal joint of the foot is a common condition which results in pain, stiffness and impaired ambulation. Footwear modifications and foot orthoses are widely used in clinical practice to treat this condition, but their effectiveness has not been rigorously evaluated. This article describes the design of a randomised trial comparing the effectiveness of rocker-sole footwear and individualised prefabricated foot orthoses in reducing pain associated with first metatarsophalangeal joint osteoarthritis. METHODS: Eighty people with first metatarsophalangeal joint osteoarthritis will be randomly allocated to receive either a pair of rocker-sole shoes (MBT® Matwa, Masai Barefoot Technology, Switzerland) or a pair of individualised, prefabricated foot orthoses (Vasyli Customs, Vasyli Medical™, Queensland, Australia). At baseline, the biomechanical effects of the interventions will be examined using a wireless wearable sensor motion analysis system (LEGSys™, BioSensics, Boston, MA, USA) and an in-shoe plantar pressure system (Pedar®, Novel GmbH, Munich, Germany). The primary outcome measure will be the pain subscale of the Foot Health Status Questionnaire (FHSQ), measured at baseline and 4, 8 and 12 weeks. Secondary outcome measures will include the function, footwear and general foot health subscales of the FHSQ, severity of pain and stiffness at the first metatarsophalangeal joint (measured using 100 mm visual analog scales), global change in symptoms (using a 15-point Likert scale), health status (using the Short-Form-12® Version 2.0 questionnaire), use of rescue medication and co-interventions to relieve pain, the frequency and type of self-reported adverse events and physical activity levels (using the Incidental and Planned Activity Questionnaire). Data will be analysed using the intention to treat principle. DISCUSSION: This study is the first randomised trial to compare the effectiveness of rocker-sole footwear and individualised prefabricated foot orthoses in reducing pain associated with osteoarthritis of the first metatarsophalangeal joint, and only the third randomised trial ever conducted for this condition. The study has been pragmatically designed to ensure that the findings can be implemented into clinical practice if the interventions are found to be effective, and the baseline biomechanical analysis will provide useful insights into their mechanism of action. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN1261300124578
- …