Synchronized mode-locked erbium fibre lasers with intracavity dispersion control using chirped in-fibre Bragg gratings

We demonstrate a dual-wavelength fibre laser system using chirped fibre Bragg gratings as reflectors and dispersive elements. The system produces two synchronized trains of soliton pulses with rms jitter of 620 fs.

Picosecond soliton control using nonlinear optical loop mirrors

We show that by inserting nonlinear optical loop mirrors into an optical fibre transmission line, that 1.5 ps solitons may be transmitted over at least 750 km, with amplifiers spaced at 15 km intervals.

Synchronized mode-locked erbium fibre lasers with intracavity dispersion control using chirped in-fibre Bragg gratings

We demonstrate a dual-wavelength fibre laser system using chirped fibre Bragg gratings as reflectors and dispersive elements. The system produces two synchronized trains of soliton pulses with rms jitter of 620 fs.

Picosecond soliton control using nonlinear optical loop mirrors

We show that by inserting nonlinear optical loop mirrors into an optical fibre transmission line, that 1.5 ps solitons may be transmitted over at least 750 km, with amplifiers spaced at 15 km intervals.

From experience to knowledge in ELT

From Experience to Knowledge in ELT investigates the developing discourses of English Language teachers in a variety of international contexts. By analysing how professional development takes place through participation in professional discourse, the chapters shed light on what teachers do and why they do it. - Better understand what they have already learned through their teaching - use that new understanding to develop their teaching - prepare to gain a recognised qualification (such as the Cambridge Teacher Knowledge Test) Using short extracts from published course books as examples, From Experience to Knowledge in ELT offers the teacher reliable procedures and alternatives, as well as ways of thinking about developing a personal teaching style.

A comparative study of hospital management in Great Britain and Brazil : cost information use

In Great Britain and Brazil healthcare is free at the point of delivery and based study only on citizenship. However, the British NHS is fifty-five years old and has undergone extensive reforms. The Brazilian SUS is barely fifteen years old. This research investigated the middle management mediation role within hospitals comparing managerial planning and control using cost information in Great Britain and Brazil. This investigation was conducted in two stages entailing quantitative and qualitative techniques. The first stage was a survey involving managers of 26 NHS Trusts in Great Britain and 22 public hospitals in Brazil. The second stage consisted of interviews, 10 in Great Britain and 22 in Brazil, conducted in four selected hospitals, two in each country. This research builds on the literature by investigating the interaction of contingency theory and modes of governance in a cross-national study in terms of public hospitals. It further builds on the existing literature by measuring managerial dimensions related to cost information usefulness. The project unveils the practice involved in planning and control processes. It highlights important elements such as the use of predictive models and uncertainty reduction when planning. It uncovers the different mechanisms employed on control processes. It also depicts that planning and control within British hospitals are structured procedures and guided by overall goals. In contrast, planning and control processes in Brazilian hospitals are accidental, involving more ad hoc actions and a profusion of goals. The clinicians in British hospitals have been integrated into the management hierarchy. Their use of cost information in planning and control processes reflects this integration. However, in Brazil, clinicians have been shown to operate more independently and make little use of cost information but the potential signalled for cost information use is seen to be even greater than that of their British counterparts.

Transdisciplinarity and reflective practice in sustainable development learning

Using various extracts from the reflective commentaries of MSc students, this article explores how transdisciplinarity and reflective practice operate in the programme. It shows how learners managed the uncertainties of sustainable development through regular critical and evaluative reflections. Students were able to apprehend the several worlds making up the sustainable development project and their own personal learning journey through the various competing, complementary and occasionally contradictory perspectives, modes of learning, sources of knowledge and information. One conceptual device facilitating this process was offering an understanding of sustainable development as constituting a ‘dialogue of values’, an approach that effectively invites students to square the metaphorical circle - i.e. broadly reconciling (ecological) sustainability with (economic) development.

Food avoidance in children:the influence of maternal feeding practices and behaviours

The aim of this study was to examine the contribution of a broad range of maternal feeding practices in predicting parental reports of food avoidance eating behaviours in young children, after controlling for child temperament, and maternal dietary restraint which have previously been associated with feeding problems. One hundred and four mothers of children aged between 3 and 6 years completed self report measures of their child's eating behaviour and temperament, maternal dietary restraint and child feeding practices. Maternal reports of food avoidance eating behaviours were associated with an emotional child temperament, high levels of maternal feeding control, using food for behaviour regulation and low encouragement of a balanced and varied food intake. Maternal feeding practices, predominantly pressure to eat, significantly predicted food avoidance eating behaviours after controlling for child emotionality and maternal dietary restraint. The significant contribution of maternal feeding practices, which are potentially modifiable behaviours, suggests that the feeding interactions of parents and their children should be targeted for intervention and the prevention of feeding difficulties during early childhood. Future research should continue to explore how a broader range of feeding practices, particular those that may be more adaptive, might influence child eating behaviour. © 2011 Elsevier Ltd.

Improved robust control of nonlinear stochastic systems using uncertain models

We introduce a technique for quantifying and then exploiting uncertainty in nonlinear stochastic control systems. The approach is suboptimal though robust and relies upon the approximation of the forward and inverse plant models by neural networks, which also estimate the intrinsic uncertainty. Sampling from the resulting Gaussian distributions of the inversion based neurocontroller allows us to introduce a control law which is demonstrably more robust than traditional adaptive controllers.

Optimization of chemical plant simulation using double collocation

A method has been constructed for the solution of a wide range of chemical plant simulation models including differential equations and optimization. Double orthogonal collocation on finite elements is applied to convert the model into an NLP problem that is solved either by the VF 13AD package based on successive quadratic programming, or by the GRG2 package, based on the generalized reduced gradient method. This approach is termed simultaneous optimization and solution strategy. The objective functional can contain integral terms. The state and control variables can have time delays. Equalities and inequalities containing state and control variables can be included into the model as well as algebraic equations and inequalities. The maximum number of independent variables is 2. Problems containing 3 independent variables can be transformed into problems having 2 independent variables using finite differencing. The maximum number of NLP variables and constraints is 1500. The method is also suitable for solving ordinary and partial differential equations. The state functions are approximated by a linear combination of Lagrange interpolation polynomials. The control function can either be approximated by a linear combination of Lagrange interpolation polynomials or by a piecewise constant function over finite elements. The number of internal collocation points can vary by finite elements. The residual error is evaluated at arbitrarily chosen equidistant grid-points, thus enabling the user to check the accuracy of the solution between collocation points, where the solution is exact. The solution functions can be tabulated. There is an option to use control vector parameterization to solve optimization problems containing initial value ordinary differential equations. When there are many differential equations or the upper integration limit should be selected optimally then this approach should be used. The portability of the package has been addressed converting the package from V AX FORTRAN 77 into IBM PC FORTRAN 77 and into SUN SPARC 2000 FORTRAN 77. Computer runs have shown that the method can reproduce optimization problems published in the literature. The GRG2 and the VF I 3AD packages, integrated into the optimization package, proved to be robust and reliable. The package contains an executive module, a module performing control vector parameterization and 2 nonlinear problem solver modules, GRG2 and VF I 3AD. There is a stand-alone module that converts the differential-algebraic optimization problem into a nonlinear programming problem.