726 resultados para Physics teachers’ professional performance


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Molecular size and structure of the gluten polymers that make up the major structural components of wheat are related to their rheological properties via modem polymer rheology concepts. Interactions between polymer chain entanglements and branching are seen to be the key mechanisms determining the rheology of HMW polymers. Recent work confirms the observation that dynamic shear plateau modulus is essentially independent of variations in MW amongst wheat varieties of varying baking performance and is not related to variations in baking performance, and that it is not the size of the soluble glutenin polymers, but the structural and rheological properties of the insoluble polymer fraction that are mainly responsible for variations in baking performance. The rheological properties of gas cell walls in bread doughs are considered to be important in relation to their stability and gas retention during proof and baking, in particular their extensional strain hardening properties. Large deformation rheological properties of gas cell walls were measured using biaxial extension for a number of doughs of varying breadmaking quality at constant strain rate and elevated temperatures in the range 25-60 degrees C. Strain hardening and failure strain of cell walls were both seen to decrease with temperature, with cell walls in good breadmaking doughs remaining stable and retaining their strain hardening properties to higher temperatures (60 degrees C), whilst the cell walls of poor breadmaking doughs became unstable at lower temperatures (45-50 degrees C) and had lower strain hardening. Strain hardening measured at 50 degrees C gave good correlations with baking volume, with the best correlations achieved between those rheological measurements and baking tests which used similar mixing conditions. As predicted by the Considere failure criterion, a strain hardening value of I defines a region below which gas cell walls become unstable, and discriminates well between the baking quality of a range of commercial flour blends of varying quality. This indicates that the stability of gas cell walls during baking is strongly related to their strain hardening properties, and that extensional rheological measurements can be used as predictors of baking quality. (C) 2004 Elsevier B.V. All rights reserved.

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Molecular size and structure of the gluten polymers that make up the major structural components of wheat are related to their rheological properties via modern polymer rheology concepts. Interactions between polymer chain entanglements and branching are seen to be the key mechanisms determining the rheology of HMW polymers. Recent work confirms the observation that dynamic shear plateau modulus is essentially independent of variations in MW amongst wheat varieties of varying baking performance and is not related to variations in baking performance, and that it is not the size of the soluble glutenin polymers, but the structural and rheological properties of the insoluble polymer fraction that are mainly responsible for variations in baking performance. The rheological properties of gas cell walls in bread doughs are considered to be important in relation to their stability and gas retention during proof and baking, in particular their extensional strain hardening properties. Large deformation rheological properties of gas cell walls were measured using biaxial extension for a number of doughs of varying breadmaking quality at constant strain rate and elevated temperatures in the range 25oC to 60oC. Strain hardening and failure strain of cell walls were both seen to decrease with temperature, with cell walls in good breadmaking doughs remaining stable and retaining their strain hardening properties to higher temperatures (60oC), whilst the cell walls of poor breadmaking doughs became unstable at lower temperatures (45oC to 50oC) and had lower strain hardening. Strain hardening measured at 50oC gave good correlations with baking volume, with the best correlations achieved between those rheological measurements and baking tests which used similar mixing conditions. As predicted by the Considere failure criterion, a strain hardening value of 1 defines a region below which gas cell walls become unstable, and discriminates well between the baking quality of a range of commercial flour blends of varying quality. This indicates that the stability of gas cell walls during baking is strongly related to their strain hardening properties, and that extensional rheological measurements can be used as predictors of baking quality.

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This paper describes a region-based algorithm for deriving a concise description of a first order optical flow field. The algorithm described achieves performance improvements over existing algorithms without compromising the accuracy of the flow field values calculated. These improvements are brought about by not computing the entire flow field between two consecutive images, but by considering only the flow vectors of a selected subset of the images. The algorithm is presented in the context of a project to balance a bipedal robot using visual information.

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Current limitations in piezoelectric and electrostatic transducers are discussed. A force-feedback electrostatic transducer capable of operating at bandwidths up to 20 kHz is described. Advantages of the proposed design are a linearised operation which simplifies the feedback control aspects and robustness of the performance characteristics to environmental perturbations. Applications in nanotechnology, optical sciences and acoustics are discussed.

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Overseas trained teachers (OTTs) have grown in numbers during the past decade, particularly in London and the South East of England. In this recruitment explosion many OTTs have experienced difficulties. In professional literature as well as press coverage OTTs often become part of a deficit discourse. A small-scale pilot investigation of OTT experience has begun to suggest why OTTs have been successful as well as the principal challenges they have faced. An important factor in their success was felt to be the quality of support in school from others on the staff. Major challenges included the complexity of the primary curriculum. The argument that globalisation leads to brain-drain may be exaggerated. Suggestions for further research are made, which might indicate the positive benefits OTTs can bring to a school.

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A spectral performance model, designed to simulate the system spectral throughput for each of the 21 channels in the HIRDLS radiometer, is described. This model uses the measured spectral characteristics of each of the components in the optical train, appropriately corrected for their optical environment, to determine the end-to-end spectral throughput profile for each channel. This profile is then combined with the predicted thermal emission from the atmosphere, arising from the height of interest, to establish an in-band (wanted) to out-of-band (unwanted) radiance ratio. The results from the use of the model demonstrate that the instrument level radiometric requirements for the instrument will be achieved. The optical arrangement and spectral design requirements for filtering in the HIRDLS instrument are described together with a presentation of the performance achieved for the complete set of manufactured filters. Compliance of the predicted passband throughput model to the spectral positioning requi rements of the instrument is also demonstrated.

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A low-temperature model is described for infrared multilayer filters containing PbTe (or other semiconductor) and ZnSe (or other II/VI). The model is based on dielectric dispersion with semiconductor carrier dispersion added. It predicts an improved performance on cooling such as would be useful to avoid erroneous signals from optics in spaceflight radiometers. Agreement with measurement is obtained over the initial temperature range 70-400K and wavelength range 2.5-20µm.

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There is limited understanding of the role of services in the wave of globalisation and how the strengths of the UK service sector help to respond to the challenge of global competition. The way in which the construction export data are collected does not reflect the impact of globalisation and the changes in the construction business environment, such as increasing foreign ownership, foreign affiliates, and changing forms of procurement. The paper describes construction service exports, how they are collected and classified, highlighting the challenges of recording the export performance of construction services in a changing world. A case for change is made to ensure the collection of statistics better reflects the role of construction professional services

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This paper reports on a survey conducted in 2010 among ASTs who identified themselves as being specialists in, or having responsibility for, the subject of drama. The survey endeavoured to explore the professional backgrounds and experiences of these ASTs and gain insights into what they enjoyed about the role. It was especially concerned to address the following questions: 1. What general skills do ASTs in drama think they need to possess? 2. What subject specific knowledge and skills do they feel are needed to satisfy the demands of their role? In addition, insights were sought into what training and support had been afforded them, how they regarded themselves and were regarded by others in the role.

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Starting point for these outputs is a large scale research project in collaboration with the Zurich University for the Arts and the Kunstmuseum Thun, looking at a redefinition of Social Sculpture (Joseph Beuys/ Bazon Brock, 1970) as a functional device re-deployed to expand the art discourse into a societal discourse. Although Beuys‘ version of a social sculpture involved notions of abstruse mysticism and reformulations of a national identity these were never-the less part of a social transformation that shifted and re-arranged power relations. Following Laclau and Mouffe in their contention that democray is a fundamentally antagonistic process and contesting Grant Kester’s understanding of a ethically based relational practice, this work is alignes itself with Hirschhorn’s claim to an aesthetic practice within communities, following the possibility to view a socially based practice from both ends of the ethics debate, whereby ethical aspects fuels the aethetic to “create situations that are beautiful because they are ethical and shocking because they are ethical, thus in turn aesthetic because they are ethical” (O’Donnell). This project sets out to engage in activities which interact with surrounding communities and evoce new imaginations of site, thereby understanding site as a catalysts for subjective emergences. Performance is tested as a site for social practice. Archival research into local audio/visual resources, such as the Swiss Radio Archive, the Swiss Military Film Archives and zoological film archives of the Basel Zoo, was instrumental to the navigation of this work, under theme of crisis, catastrophy, landscape, fallout, in order to create a visual language for an active performance site. Commissioned by the Kunstmuseum Thun in collaboration with the University for the Arts in Zurich as part of a year long exhibition programme, (other artists are Jeanne Van Heeswijk (NL) and San Keller (CH), ) this project brings together a series of different works in a new performace installation. The performance process includes a performance workshop with 30 school children from local Swiss schools and their teachers, which was conducted publicly in the museum spaces. It enabled the children to engage with an unexpected set of tribal and animalistic behaviours, looking at situations of flight and rescue, resulting in a large performance choreography orchestration without an apparent conductor, it includes a collaboration with renowned Swiss zoologist, Prof Klaus Zuberbühler(University of St Andrews) and the Colonal General Haldimann commander of the military base in Thun. The installation included 2 static video images, shot in an around spectacular local cave site (Beatus Caves) including 3 children. The project will culminate in an edited edition of the Oncurating Journal, (issue no, tbc, in 2012) including interviews and essays from project collaborators. (Army Commander General, Thun, Jörg Hess, performance script, Timothy Long, and others)

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The policy context for mother-tongue educators at all levels in England has been dominated by a matrix with four key elements,running along two spectra, one of learning (content↘assessment) and one of teaching (autonomy↘accountability). In each case the trend has been towards increasing external control and decreasing professional autonomy. Whilst some imposed changes have been recognised as intrinsically valuable, the majority are viewed as detrimental to teachers' status and obstructive for students. The research community has been largely marginalised and has had little scope to influence proceedings. A rapidly developing crisis in teacher retention may yet reverse these trends as the government is forced to recognise the long-term implications of their treatment of the profession.

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Professional services firms (PSFs) have been the subject of much attention in the literature in recent years, ranging across a number of distinct but related disciplines including economics, sociology, organization and management studies. Analysis has tended to concentrate on law and accounting firms in particular, and although there is a growing academic interest in construction/built environment professional services firms (CPSFs), these have received much less scrutiny. However, many of the changes taking place among PSFs – in particular, growth in firm size, moves towards external ownership and greater service/geographical diversification – are also taking place among the larger CPSFs. The CPSF sector is not especially well documented and there is little understanding of the motives for, and implications of, these changes in the firms, their clients and wider society. CPSFs are reviewed in the context of the more general PSF literature and a set of questions is posed for future research on CPSFs. These questions include the need to understand the implications of firm type on performance, the form of ownership that might confer the greatest financial benefits for different stakeholder groups, and the wider societal consequences of continuing growth in size and diversification of CPSFs.

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Construction professional services (CPSs), such as architecture, engineering, and consultancy, are not only high value-added profit centers in their own right but also have a knock-on effect on other businesses, such as construction and the export of materials and machinery. Arguably, competition in the international construction market has shifted to these knowledge-intensive CPS areas. Yet CPSs represent a research frontier that has received scant attention. This research aims to enrich the body of knowledge on CPSs by examining strengths, weaknesses, opportunities, and threats (SWOT) of Chinese CPSs (CCPSs) in the international context. It does so by triangulating theories with quantitative and qualitative data gleaned from yearbooks, annual reports, interviews, seminars, and interactions with managers in major CCPS companies. It is found that CCPSs present both strengths and weaknesses in talents, administration systems, and development strategies in dealing with the external opportunities and threats brought about by globalization and market evolution. Low price, which has helped the Chinese construction business to succeed in the international market, is also a major CCPS strength. An opportunity for CCPSs is the relatively strong delivery capability possessed by Chinese contractors; by partnering with them CCPSs can better establish themselves in the international arena. This is probably the first ever comprehensive study on the performance of CCPSs in the international marketplace. The research is conducted at an opportune time, particularly when the world is witnessing the burgeoning force of Chinese businesses in many areas including manufacturing, construction, and, potentially, professional services. It adds new insights to the knowledge body of CPSs and provides valuable references to other countries faced with the challenge of developing CPS business efficiently in the international market.

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In contrast to their bustling construction counterparts, Chinese construction professional services (CPS) such as architecture, engineering, and consultancy, seem still to be stagnant in the international market. CPS are not only high value-added profit centers in their own right, but also have a knock-on effect on subsequent businesses such as construction, and the export of materials and machinery. Arguably, competition in the international construction market has shifted to knowledge-intensive CPS. Yet,CPS represent a research area that has been paid scant attention. This research aims to add to the body of knowledge of CPS by examining strengths, weaknesses, opportunities, and threats (SWOT) of Chinese CPS (CCPS) in the international context. It does so by triangulating theories with quantitative and qualitative data gleaned from yearbooks, annual reports, interviews, seminars, and interactions with managers in major CCPS companies. It is found that CCPS present both strengths and weaknesses in talents, administration systems, and development strategies in dealing with the external opportunities and threats brought about by globalization and market evolvement. Low price, which has helped the Chinese construction business to succeed in the international market, is also a CCPS major strength. An opportunity for CCPS is the relatively strong delivery capability possessed by Chinese contractors. By partnering with them CCPS can better edge into the international arena. This is probably the first ever comprehensive study in investigating the performance of CCPS in the international market. The research is also timely, particularly when the world is witnessing the burgeoning force of Chinese businesses in many areas including manufacturing, construction, and potentially, professional services.

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This paper addresses beginning teachers thinking about the nature and purposes of their subject and the impact of this on their practice. Individual qualitative interviews were undertaken with 11 history teachers at the beginning of their teaching careers. Data was analysed using writing as the method of analysis and revealed that teachers whose thinking was at odds with dominant discourses, for example in the form of a national curriculum, encountered difficulties embracing pedagogies and aspects of the curriculum that do not accord with their own deep-seated beliefs, demonstrating a need for the initial training and professional development of teachers to forefront consideration of subject understandings.