Jack's story: A need to know

This article examines a recent case study exploring evidence that children in early childhood services can use ICT to direct their own inquiry learning. A qualitative case study involving an interview and the learning story tool of assessment was conducted to describe the experience of one child and his teacher. They engaged in sustained shared thinking using ICT as a tool to facilitate inquiry in an early childhood setting. The findings indicate that children in early childhood settings can use ICT to direct their own inquiry learning. Two key factors are identified that enable this. These factors are the child as an active learner, and a supportive well resourced learning environment. In this article we argue that these factors need to be acknowledged in teaching practice if ICT is to be used in meaningful and purposeful ways

Podcasts as a conversational pedagogy

The use of technology such as podcasts, social networking sites, wikis, and Google docs for communicating information which supports teaching and learning in tertiary institutions is well documented (Bates, 2005). These tools have been shown to enhance traditional lectures and tutorials (Salmon, 2007). Little attention, however, has been given to the use of conversational approaches when using these tools and their potential in developing alternative pedagogical approaches to teaching. This article examines the use of a conversational style podcast in an online pre-service early childhood teacher education programme. The podcasts were initially used to disseminate information and respond to the students’ needs, however, their conversational use revealed a number of unexpected outcomes. Analysis of the podcast conversations that occurred between the two lecturers, and the student feedback to these, were used to identify unexpected outcomes for students enrolled in the programme. These included the ‘humanising’ of the e-learning environment and the sense of community that emerged. This paper argues that the affordance of conversational podcasts personalises the e-learning environment, enhances students’ and lecturers’ motivation, and engenders a greater connectedness with the university context

Hydrodynamics and Metzner-Otto correlation in stirred vessels for yield stress fluids

This paper investigates the hydrodynamics and power consumption in laminar stirred vessel flowusing numerical computation. The Metzner–Otto correlation was established for mixing in power-law fluids. This paper focuses on its application to yield stress fluids. Distributions of shear rates and their link to power consumption for helical and anchor agitators are discussed. Insight is sought from the analytical formula for Taylor–Couette flows. Laws are established for Bingham, Herschel-Bulkley and Casson fluids and reveal similar results. Fully or partially sheared flow situations with plug regions are considered. Depending on the fluid model, the concept is valid or constitutes a satisfactory approximation for fully sheared flows. When the flow is partially sheared, the expression depends on the Bingham number and the concept must be adapted. The results of the numerical simulations are interpreted in the light of this analysis and results from the literature

Aggregation of silica nanoparticles in concentrated suspensions under turbulent, shear and extensional flows.

The production of nanoparticles in concentrated suspensions requires strict control of the stability of the systems which are strongly influenced by the physico-chemical properties and the hydrodynamic conditions they are placed in. This study deals with the analysis of the aggregation processes of a colloidal silica suspension destabilized by addition of salt under different flows: a turbulent flow performed in a stirred tank, a pure shear flow created thanks to a Couette geometry and an extensional flow obtained in a four-roll mill (Taylor cell). During the aggregation process, the silica suspensions behave as shear-thinning fluids and the variation of their apparent viscosity can be related to the evolution of the size distribution of the aggregates in the suspension. Pure shear and turbulent flows at an equivalent strain rate exhibit almost the same behaviour. The viscosity and the aggregate size decrease with the shear rate. On the contrary, the apparent viscosity and the aggregate size distributions were not very sensitive to a change of an extensional constraint within the considered range. Indeed, although aggregates obtained in the Taylor cell were bigger than in the Couette cell, the apparent viscosity was higher in the latter case. Different aggregate structures, characterized by their fractal dimension, were finally predicted depending on the hydrodynamic nature of the main flow under which they were produced

In-situ and ex-situ rheometry of high density Yarrowia lipolytica broth: determination of critical concentration and impact of yeastmycelial transition

The specificity of microbial bioreactions which give rise to irreducible couplings with hydrodynamics and heat and mass transfers, led into complex (three phases medium) and dynamic (auto-biocatalytic reaction) systems. Cells (concentration, shape, dimension, physiology…) strongly affect physico-chemical properties of broth and the modification of these characteristics interacts with bioprocess performances (specific rates, yields…) with an improvement or, more generally, a decrease of yields

Rheological characterization of mixed liquor in a submerged membrane bioreactor: Interest for process management

Rheological analyses of a submerged membrane bioreactor mixed liquor were performed in the aim of characterizing the mixed liquor present in the bioreactor and thus proposing a process management. These analyses pointed out that the mixed liquor was characterized by its viscoplastic property, which leads to a possible restructuring ability when a shear stress lower than the yield stress is applied. As the shear stress in the bioreactor is essentially generated by coarse bubbles, specific experiments were carried out in which coarse bubbles were injected in an intermittent way. The results of these experiments showed that this method could avoid damage to the mixed liquor. So working with intermittent coarse bubbles is useful to prevent fouling, keep good flocculation and minimize the energy cost

Impact of cell physiology and densities during oxidative axenic cultures of Yarrowia lipolytica on physico-chemical properties of broth

Impact of cell physiology and densities during oxidative axenic cultures of Yarrowia lipolytica on physico-chemical properties of brot

Piv study of mixing characteristics in a stirred vessel with a non-Newtonian fluid

PIV is used to analyze the flow induced by a Rushton turbine in a shear-thinning fluid, at constant input power, constant impeller velocity but different concentrations. The rheology of each shear-thinning fluid is first addressed. The mean velocity fields are compared. POD methodology is applied to estimate coherent structures and turbulence levels. Finally, the heterogeneity of shear rate is estimated and the spatial distribution of dissipation rate of total kinetic energy is addressed

Democracy and Information, Communication Technology: A pedagogical Relationship

Democracy and the identification and application of democratic practices using ICT is important to declare and share. • Such democratic features further clarify ICT and its position in ECE and further legitimises its place. It adds to the defining of a pedagogy and practices that will inform, reassure and maximise purposeful uses of ICT by children and teachers. • These features of our teaching pedagogy and practices are powerful. • It is something that is enshrined in our curriculum . It enables us to define our identities as teachers, our children as learners and includes family/whaanau and community. It also affirms our contributions as a sector to a democratic and fair society. It is something we teach in the here and now with children, whatever their age

Aeration mode, shear stress and sludge rheology in a submerged membrane bioreactor: some keys of energy saving

Aeration mode, shear stress and sludge rheology in a submerged membrane bioreactor: some keys of energy savin