Safety enhancement of water-filled road safety barrier using interaction of composite materials

Road safety barriers are used to redirect traffic at roadside work-zones. When filled with water, these barriers are able to withstand low to moderate impact speeds up to 50kmh-1. Despite this feature, Portable Water-filled barriers (PWFB) face challenges such as large lateral displacements, tearing and breakage during impact; especially at higher speeds. This study explores the use of composite action to enhance the crashworthiness of PWFBs and enable their usage at higher speeds. Initially, energy absorption capability of water in PWFB is investigated. Then, composite action of the PWFB with the introduction of steel frame is considered to evaluate its enhanced impact performance. Findings of the study show that the initial height of the impact must be lower than the free surface level of water in a PWFB in order for the water to provide significant crash energy absorption. In general, an impact of a road barrier with 80% filled is a good estimation. Furthermore, the addition of a composite structure greatly reduces the probability of tearing by decreasing the strain and impact energy transferred to the shell container. This allows the water to remain longer in the barrier to absorb energy via inertial displacements and sloshing response. Information from this research will aid in the design of new generation roadside safety structures aimed to increase safety in modern roadways.

Nuclear instruments and methods in physics research section B : beam interactions with materials and atoms

The impact-induced deposition of Al13 clusters with icosahedral structure on Ni(0 0 1) surface was studied by molecular dynamics (MD) simulation using Finnis–Sinclair potentials. The incident kinetic energy (Ein) ranged from 0.01 to 30 eV per atom. The structural and dynamical properties of Al clusters on Ni surfaces were found to be strongly dependent on the impact energy. At much lower energy, the Al cluster deposited on the surface as a bulk molecule. However, the original icosahedral structure was transformed to the fcc-like one due to the interaction and the structure mismatch between the Al cluster and Ni surface. With increasing the impinging energy, the cluster was deformed severely when it contacted the substrate, and then broken up due to dense collision cascade. The cluster atoms spread on the surface at last. When the impact energy was higher than 11 eV, the defects, such as Al substitutions and Ni ejections, were observed. The simulation indicated that there exists an optimum energy range, which is suitable for Al epitaxial growth in layer by layer. In addition, at higher impinging energy, the atomic exchange between Al and Ni atoms will be favourable to surface alloying.

The architecture of children’s use of language and tools when problem solving collaboratively with robotics

This paper demonstrates, following Vygotsky, that language and tool use has a critical role in the collaborative problem-solving behaviour of school-age children. It reports original ethnographic classroom research examining the convergence of speech and practical activity in children’s collaborative problem solving with robotics programming tasks. The researchers analysed children’s interactions during a series of problem solving experiments in which Lego Mindstorms toolsets were used by teachers to create robotics design challenges among 24 students in a Year 4 Australian classroom (students aged 8.5–9.5 years). The design challenges were incrementally difficult, beginning with basic programming of straight line movement, and progressing to more complex challenges involving programming of the robots to raise Lego figures from conduit pipes using robots as pulleys with string and recycled materials. Data collection involved micro-genetic analysis of students’ speech interactions with tools, peers, and other experts, teacher interviews, and student focus group data. Coding the repeated patterns in the transcripts, the authors outline the structure of the children’s social speech in joint problem solving, demonstrating the patterns of speech and interaction that play an important role in the socialisation of the school-age child’s practical intellect.

Electrical property and characterization of nano-SnO2/wollastonite composite materials

Nano-tin oxide was deposited on the surface of wollastonite using the mixed solution including stannic chloride pentahydrate precursor and wollastonite by a hydrolysis precipitation process. The antistatic properties of the wollastonite materials under different calcined conditions and composite materials (nano-SnO2/wollastonite, SW) were measured by rubber sheeter and four-point probe (FPP) sheet resistance measurement. Effects of hydrolysis temperature and time, calcination temperature and time, pH value and nano-SnO2 coating amount on the resistivity of SW powders were studied, and the optimum experimental conditions were obtained. The microstructure and surface properties of wollastonite, precipitate and SW were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), specific surface area analyzer (BET), thermogravimetry (TG), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Fourier translation infrared spectroscopy (FTIR) respectively. The results showed that the nano-SnO2/wollastonite composite materials under optimum preparation conditions showed better antistatic properties, the resistivity of which was reduced from 1.068 × 104 Ω cm to 2.533 × 103 Ω cm. From TG and XRD analysis, the possible mechanism for coating of SnO2 nanoparticles on the surface of wollastonite was proposed. The infrared spectrum indicated that there were a large number of the hydroxyl groups on the surface of wollastonite. This is beneficial to the heterogeneous nucleation reaction. Through morphology, EDS and XPS analysis, the surface of wollastonite fiber was coated with a layer of 10–15 nm thickness of tin oxide grains the distribution of which was uniform.

Revisiting educational equity and quality in China through confucianism, policy, research, and practice

The promotion of educational equity and improvement of educational quality in China are contextualised in tenets of Confucianism and policy directives, inspiring educational research and practice. In this paper, we first explore the historical and cultural roots of educational equity and quality through Confucianism and elaborate on the current policy priority that aims to address educational equity and quality. We then present an overview of research on equity and quality in Chinese education. Informed by Confucianism, policy, and research, we pose a framework to structure our investigation and analysis of three illustrative examples, namely the Special Post Teacher Plan, amalgamation of rural schools, and schooling of floating children. Drawing insights from Confucianism, policy, research, and practice, we conclude that the promotion of educational equity through high quality provision of education for disadvantaged groups can help to narrow the gap in educational quality currently existing in China.

Open educational resources in China : a governmentality analysis

Using a sociological approach, this study examines China’s reform of open educational resources (OER), which has prompted significant changes to the nation’s higher education sector. Through an analysis of the policy processes that have driven the reform, this study demonstrates that the reform has involved and brought significant changes to its participants as resource administrators, providers, and receivers. By using governmentality as a poststructuralist analytical framework, this study shows the particular ways in which the reform process has been governed and the ways in which the governing practices have changed the conduct of higher education. The study reveals the power relations exercised through the reform and offers a critique of China’s higher education sector.

How to improve pupils' literacy? A cost-effectiveness analysis of a French educational project

The Action Lecture program is an innovative teaching method run in some nursery and primary schools in Paris and designed to improve pupils’ literacy. We report the results of an evaluation of this program. We describe the experimental protocol that was built to estimate the program’s impact on several types of indicators. Data were processed following a Differences-in-Differences (DID) method. Then we use the estimation of the impact on academic achievement to conduct a cost-effectiveness analysis and take a reduction of the class size program as a benchmark. The results are positive for the Action Lecture program.

Developing media production skills for literacy in a primary school classroom : digital materials, embodied knowledge and material contexts

This chapter investigates the relationship between technical and operational skills and the development of conceptual knowledge and literacy in Media Arts learning. It argues that there is a relationship between the stories, expressions and ideas that students aim to produce with communications media, and their ability to realise these in material form through technical processes in specific material contexts. Our claim is that there is a relationship between the technical and the operational, along with material relations and the development of conceptual knowledge and literacy in media arts learning. We place more emphasis on the material aspects of literacy than is usually the case in socio-cultural accounts of media literacy. We provide examples from a current project to demonstrate that it is just as important to address the material as it is the discursive and conceptual when considering how students develop media literacy in classroom spaces.

Safety enhancement of water-filled road safety barrier using interaction of composite materials

Road safety barriers are used to redirect traffic at roadside work-zones. When filled with water, these barriers are able to withstand low to moderate impact speeds up to 50kmh-1. Despite this feature, there are challenges when using portable water-filled barriers (PWFBs) such as large lateral displacements as well as tearing and breakage during impact, especially at higher speeds. In this study, the authors explore the use of composite action to enhance the crashworthiness of PWFBs and enable their use at higher speeds. Initially, we investigated the energy absorption capability of water in PWFB. Then, we considered the composite action of a PWFB with the introduction of a steel frame to evaluate its impact on performance. Findings of the study show that the initial height of impact must be lower than the free surface level of water in a PWFB for the water to provide significant crash energy absorption. In general, impact of a road barrier that is 80% filled is a good estimation. Furthermore, the addition of a composite structure greatly reduces the probability of tearing by decreasing the strain and impact energy transferred to the shell container. This allows the water to remain longer in the barrier to absorb energy via inertial displacement and sloshing response. Information from this research will aid in the design of next generation roadside safety structures aimed to increase safety on modern roadways.

Towards connoisseurship in educational leadership : following the data in a three stage line of inquiry

Following an epistemic frame advanced by Elliott Eisner (2002), it is argued that the tradition of the arts and perspectives from artists have the potential to yield refreshing and interesting insights for the field of educational leadership. Moreover, it is argued that Eisner’s work on tacit knowledge which he advanced as an example of connoisseurship has important implications and posits the possibility of developing a more discerning “eye” in describing the work of educational leaders. To assess these assertions, the paper reports on two stages of interviews with nine former and current artists from Australia in order to understand the processes in which they engaged when they create art and how they encountered and managed barriers. The implications of this preliminary investigation are explored in this paper as they related to how leadership is defined and the issues pertaining to claims that leadership studies must be “scientific” to have currency and credibility. The article begins by making an argument for the value of the arts to advanced a more nuanced view of leadership, considers the importance of connoisseurship as a frame for understanding it, and then explores the cognitive functions performed by the arts before turning to the study at hand.

A commentary on the current and future status of educational and developmental psychology in Australia

Educational and developmental psychology faces a number of current and future challenges and opportunities in Australia. In this commentary we consider the identity of educational and developmental psychology in terms of the features that distinguish it from other specialisations, and address issues related to training, specialist endorsement, supervision and rebating under the Australian government's Medicare system. The current status of training in Australia is considered through a review of the four university programs in educational and developmental psychology currently offered, and the employment destinations of their graduates. Although the need for traditional services in settings such as schools, hospitals, disability and community organisations will undoubtedly continue, the role of educational and developmental psychologists is being influenced and to some extent redefined by advances in technology, medicine, genetics, and neuroscience. We review some of these advances and conclude with recommendations for training and professional development that will enable Australian educational and developmental psychologists to meet the challenges ahead.

A human rights analysis of a claim for educational negligence in Australian schools

This thesis argues that an action in educational negligence should be available in Australia to provide a remedy for failure by schools and teachers to provide an adequate education as required by Australia’s human rights obligations. The thesis substantiates a duty of care to provide an adequate education under general principles of the law of negligence in appropriate cases. Although some protection exists for disabled students in Australia’s anti-discrimination and other legislation, non-disabled students are not afforded redress under existing causes of action. The educational negligence action provides a suitable remedy in an era of professional educational accountability.

Fibroin-based materials support cultivation of limbal stromal cells

Purpose: The silk protein fibroin provides a potential substrate for use in ocular tissue reconstruction. We have previously demonstrated that transparent membranes produced from fibroin support cultivation of human limbal epithelial cells (Tissue Eng A. 14(2008)1203-11). We presently extend this body of work to studies of human limbal stromal cell (HLS) growth on fibroin in the presence and absence of serum. Methods: Primary cultures of HLS cells were established in DMEM/F12 medium supplemented with either 10% fetal bovine serum (FBS) or 2% B27 supplement. Defined keratinocyte serum-free medium (DK-SFM, Invitrogen) was also tested. The resulting cultures were analysed by flow cytometry for expression of CD34, CD90, CD45, and CD141. Cultures grown under each condition were subsequently passaged either onto transparent fibroin membranes prepared from purified fibroin or within 3D scaffolds prepared from partially-solubilised fibroin. Results: HLS cultures were successfully established under each condition, but grew more slowly and passaged poorly in the absence of serum. Cultures grown in 10% FBS were <0.5% CD34+ (keratocytes) and >97% CD90+ (fibroblasts). Cultures established in 2% B27 formed floating spheres and contained >8% CD34+ cells and reduced CD90 expression. Cultures established in DK-SFM displayed traces of epithelial cell growth (CD141), but mostly consisted of CD90+ cells with <1% CD34+ cells. Cells of bone marrow lineage (CD45) were rarely observed under any conditions. Cultures grown in 10% FBS were able to adhere to and proliferate on silk fibroin 3-D scaffolds and transparent films while those grown serum-free could not. Adhesion of HLS cells to fibroin was initially poorer than that displayed on tissue culture plastic. Conclusions: HLS cultures containing cells of predominantly fibroblast lineage can be grown on fibroin-based materials, but this process is dependent upon additional ECM factors such as those provided by serum.

Spin-polarization and ferromagnetism of graphitic carbon nitride materials

Polymeric graphitic carbon nitride materials have attracted increasing attention in recent years owning to their potential applications in energy conversion, environment protection, and so on. Here, from first-principles calculations, we report the electronic structure modification of graphitic carbon nitride (g-C3N4) in response to carbon doping. We showed that each dopant atom can induce a local magnetic moment of 1.0 μB in non-magnetic g-C3N4. At the doping concentration of 1/14, the local magnetic moments of the most stable doping configuration which has the dopant atom at the center of heptazine unit prefer to align in a parallel way leading to long-range ferromagnetic (FM) ordering. When the joint N atom is replaced by C atom, the system favors an antiferromagnetic (AFM) ordering at unstrained state, but can be tuned to ferromagnetism (FM) by applying biaxial tensile strain. More interestingly, the FM state of the strained system is half-metallic with abundant states at the Fermi level in one spin channel and a band gap of 1.82 eV in another spin channel. The Curie temperature (Tc) was also evaluated using a mean-field theory and Monte Carlo simulations within the Ising model. Such tunable electron spin-polarization and ferromagnetism are quite promising for the applications of graphitic carbon nitride in spintronics.