Opening up and closing down : how teachers and TAs manage turn-taking, topic and repair in mathematics lessons

Support for children with special educational needs in inclusive classrooms is increasingly provided by teaching assistants (TAs). They often have a direct pedagogical role, taking responsibility for instruction in mathematics. The quality of TAs' oral skills is crucial for learning but has rarely been researched. Using conversation analysis, this study compares teacher and TA talk in terms of turn allocation, topic generation and repair. From 130 recordings, transcripts of mathematics teaching in four lessons were analysed in depth. We found that teachers open up students whilst TAs close down the talk. Teachers, with whole classes, adopt inclusive teaching strategies to ensure oral participation whereas TAs, working with individuals, emphasise task completion. Teachers use open strategies for topic generation whilst TAs ask closed questions. Teachers withhold correction with prompts and hints whilst TAs supply answers. The findings are interpreted with reference to the TA role and implications for management and training

The Inclusion Illusion: How children with special educational needs experience mainstream schools

Inclusion conjures images of children with special educational needs and disabilities (SEND) learning in classes alongside peers in a mainstream school. For pupils in the UK with high-level SEND, who have an Education, Health and Care Plan (formerly a Statement), this implies an everyday educational experience similar to that of their typically-developing classmates. Yet in vital respects, they are worlds apart. Based on the UK’s largest observation study of pupils with high-level SEND, The Inclusion Illusion exposes how attendance at a mainstream school is no guarantee of receiving a mainstream education. Observations of nearly 1,500 lessons in English schools show that their everyday experience of school is characterised by separation and segregation. Furthermore, interviews with nearly 500 pupils, parents and school staff reveal the effect of this marginalisation on the quality of their education. The way schools are organised and how classrooms are composed creates a form of ‘structural exclusion’ that preserves mainstream education for typically-developing pupils and justifies a diluted pedagogical offer for pupils with high-level SEND. Policymakers, not mainstream schools, are indicted over this state of affairs. This book prompts questions about what we think inclusion is and what it looks like. Ultimately, it suggests why a more authentic form of inclusion is needed, and how it might be achieved

Expert Report of Robert B. Webster

The author’s opinions are based primarily upon knowledge and insight gained in the forty years in which he has been a practicing attorney, counselor, arbitrator, mediator, bar officer, and state court judge. Webster’s opinions are also based in part upon materials described in Section IV.B, within

Experimental improvement of flyash as a growth medium for plants through addition of selected solid wastes

Large quantities of coal are consumed in South Africa as a result of the generation of electricity and the manufacture of automotive fuel. A consequence of this was the production of more than 15 Mt of ash and associated coal combustion by-products in 1987 alone. This poses a large scale waste-disposal problem. Flyash, the major waste product is from South African coal sources, an alkaline, saline material the pozzolanic nature of which results in the formation of massive, compacted and cemented ash deposits which have significant environmental impacts. Efforts made to limit this impact by revegetation, in many locations throughout the world, have had limited success due to the mobility of phytotoxic concentrations of some elements, including As, B, Cr, Cu, Mo, Ni, S and Se. Flyash also has limited quantities of bioavailable Fe, Mn, P and Zn and these elemental limitations are associated with the alkaline nature of the flyash. Another element that is deficient, is N, it is unavailable in flyash as it is lost from coal during combustion. Aside from the chemical limitations to plant growth, the compacted nature results in low porosity which can limit plant available moisture. Plant root penetration is also impeded which limits nutrient uptake. The basis of this study was to incorporate other selected waste materials into the flyash to produce, by co-disposal, a combined waste material that is geochemically inert and a satisfactory plant growth medium. The ameliorants selected for inclusion in this study included interphase sulphur, a Vcontaminated waste sulphur product from the sulphur recovery plant at the SASOL' s Secunda petrochemical production facility and Catpoly, a spent catalyst consisting of phosphoric acidimpregnated diatomaceous earth, also obtained from SASOL's Secunda operation

PYROLYSIS MODEL PARAMETER OPTIMIZATION USING A CUSTOMIZED STOCHASTIC HILL-CLIMBER ALGORITHM AND BENCH SCALE FIRE TEST DATA

This study examines the ability of a stochastic hill-climber algorithm to develop an input parameter set to a finite difference one-dimensional model of transient conduction with pyrolysis to match experimentally determined mass loss rates of three sample materials exposed to a range of constant incident heat flux. The results of the stochastic hill-climber algorithm developed as part of the present study are compared to results obtained with genetic algorithms. Graphical documentation of the impact of single parameter mutation is provided. Critical analysis of the physical meaning of parameter sets, and their realistic range of application, is presented. Criteria are also suggested for stability and resolution of solid phase temperature and fuel mass loss rate in an implicit Crank-Nicolson scheme with explicit treatment of the heat generation source term

A Numerical Study of the Conjugate Conduction-Convection Heat Transfer Problem

This study investigates some of the basic aspects of conjugate, or coupled, heat transfer problems. The ultimate interest is in the improvement of an existing computational fluid dynamics (CFD) code by the inclusion of such a coupling capability. Many CFD codes in the past have treated the thermal boundary conditions of a bounding solid as the simple cases of either a surface across which there is no heat flux, or as a surface along which the temperature is a constant with respect to both space and time. These conditions are acceptable for some applications, but many real-world problems require a more-realistic treatment of the thermal wall condition. A thermal coupling may be accomplished by maintaining a continuous heat flux and temperature across the fluid-solid boundary. A heat flux is calculated on the fluid-side of the interface, and this is used as a boundary condition for a heat-conduction solver to calculate the temperature field within the solid and return an interface temperature to the fluid. This process is executed for each time-step iteration of the code, and, therefore, the temperature field of the solid and the fluid-solid interface temperature are allowed to evolve with time and space. A new heat-conduction solver is developed and coupled with an existing flow solver. For this reason, some of the study is devoted to the testing of the accuracy of the new heat-conduction solver on simple problems for which there exist analytical solutions. Additional coverage is devoted to the possibility of thermal communication between solid grid blocks. This is due to the fact that multiple grid blocking of the solid may be required for more complex geometries. For such cases, a similar procedure as that described for the fluid-solid interface is used to accomplish the solid-solid block-to-block communication. Relatively simple test cases of fluid-solid and solid-solid coupling are conducted; these cases are limited to two-dimensional grids. Other limitations include: the assumption of constant thermophysical properties for the solid, no consideration for thermal expansion of the solid, and no consideration for the radiation mode of heat transfer. The results indicate that the heat-conduction/flow solver shows potential

Smart Grid communications in high traffic environments

The establishment of a previously non-existent data class known as the Smart Grid will pose many difficulties on current and future communication infrastructure. It is imperative that the Smart Grid (SG), as the reactionary and monitory arm of the Power Grid (PG), be able to communicate effectively between grid controllers and individual User Equipment (UE). By doing so, the successful implementation of SG applications can occur, including support for higher capacities of Renewable Energy Resources. As the SG matures, the number of UEs required is expected to rise increasing the traffic in an already burdened communications network. This thesis aims to optimally allocate radio resources such that the SG Quality of Service (QoS) requirements are satisfied with minimal effect on pre-existing traffic. To address this resource allocation problem, a Lotka-Volterra (LV) based resource allocation and scheduler was developed due to its ability to easily adapt to the dynamics of a telecommunications environment. Unlike previous resource allocation algorithms, the LV scheme allocated resources to each class as a function of its growth rate. By doing so, the QoS requirements of the SG were satisfied, with minimal effect on pre-existing traffic. Class queue latencies were reduced by intelligent scheduling of periodic traffic and forward allocation of resources. This thesis concludes that the SG will have a large effect on the telecommunications environment if not successfully controlled and monitored. This effect can be minimized by utilizing the proposed LV based resource allocation and scheduler system. Furthermore, it was shown that the allocation of periodic SG radio channels was optimized by continual updates of the LV model. This ensured the QoS requirements of the SG are achieved and provided enhanced performance. Successful integration of SG UEs in a wireless network can pave the way for increased capacity of Renewable and Intermittent Energy Resources operating on the PG

Precise nanoscale characterisation of novel Heusler thermoelectrics via analytical electron microscopy

Thermoelectric power generation presents an opportunity to `scavenge' energy that would otherwise be wasted as heat. Heusler alloys, a class of materials often comprising inexpensive, non-toxic elements, are promising for practical use in a new generation of thermoelectric devices. Recently, efficient thermoelectric Heusler alloys have overcome a performance-limiting thermal conductivity through the introduction of nanostructures that scatter phonons and impede thermal transport. However, the nature and stability of nanostructures can be difficult to discern, especially the minor compositional variations that derive from inhomogeneous phase segregation. Throughout this thesis TiNiSn, which forms the basis for some of the most promising n-type half-Heusler thermoelectrics, is studied through a unique combination of elemental and diffractive analysis in the scanning transmission electron microscope (STEM). Epitaxial thin films of TiNiSn are grown by pulsed laser deposition and FIB-prepared cross-sections of these are characterised in STEM with a focus on aberration-corrected STEM-EELS spectrum imaging and scanning precession electron diffraction (SPED), yielding precise chemical and structural quantification with nanoscale spatial resolution. The results throughout this thesis demonstrate the importance of STEM for quantitative studies of thermoelectric materials, as it can provide the analytical precision required for accurate identification of minority phases in TiNiSn specimens that would otherwise be overlooked in bulk analytical techniques. Sensitivity to very small elemental concentrations is a cornerstone of the use of STEM-EELS for chemical characterisation. Precisions of 0.3 % were achieved through adoption and development of refined, reference-based, absolute elemental quantification protocols which were essential in overcoming difficulties with large uncertainties posed by conventional methods. The success of this approach, in part, is due to advances made in characterisation of experimental conditions including, for the first time, an automated, standard-less approach to the measurement and correction of energy dispersion non-uniformities. Dispersion correction enables reliable, absolute calibration of energy-loss in spectra to yield a precision better than 0.1 eV. These developments in STEM-EELS were then used in three investigations of TiNiSn thin films exploring aspects of nanostructuring, phase segregation and crystrallographic strain and coherency. We discovered the spontaneous formation of nanostructures during thin film growth, gaining some insight into the phase segregation mechanisms that lead to their nucleation. Novel in situ STEM studies of phase segregation facilitated direct observations of the thermal evolution of nanoscale phases and results enabled characterisation of diffusion rates of Ni migration between full- and half-Heusler phases, for which the activation energy was calculated as 0.3~eV. Combining SPED with advances in detector technology, STEM structural investigations highlighted an interesting strain texture associated with nanostructuring of the half-Heusler thin films. Finally, combining SPED results with STEM-EELS measurements is proposed as a route to `correlative-STEM' analysis, which unifies nanoscale chemical and structural information for greater insights into the impact of nanostructures in thermoelectrics