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.

Characterising one-to-one conservatoire teaching : Some implications of a quantitative analysis

Despite the significant recent growth in research relating to instrumental, vocal and composition tuition in higher education, little is known about the diversity of approaches that characterise one-to-one teaching in the Conservatoire, and what counts as optimal practice for educating 21st-century musicians. Through analysis of video-recorded one-to-one lessons that draws on a ‘bottom up’ methodology for characterising pedagogical practices (Taylor, 2012; Taylor et al, 2012), this paper provides empirical evidence about the nature of one-to-one pedagogy in one Australian institution. The research aims (1) to enable a better understanding of current one-to-one conservatoire teaching; and (2) to build and improve upon existing teaching practice using authentic insights gained through systematic investigation. The authors hope the research will lead to a better understanding of the diversity and efficacy of the pedagogical practice within the specific context in which the study was conducted, and beyond, to Conservatoire pedagogy generally.

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.

Building the computer mediated distance learning community: Issues and observations drawn from teaching and learning

This paper discusses computer mediated distance learning on a Master's level course in the UK and student perceptions of this as a quality learning environment.

Teaching end-user remote online searching

The Queensland University of Technology (QUT) Library bas recently commenced teaching higher degree students to search online systems such as BRS, ORBIT and STN. The emphasis is on education rather than training. with students being required to familiarise themselves with system commands and database structures whilst receiving necessarily limited tutorial help. The teaching strategies used and problems encountered in the program are outlined. Student responses to the experience of learning to online search are discussed.

Planning to Manage My Teaching in a Democratic Classroom

Preservice teachers consistently report that managing student behaviour is one of their major concerns prior to and during practicum (Capel, 1997; Kyriacou & Stephens, 1999). Not surprisingly, preservice teachers are keen to gain knowledge and understanding of effective classroom management approaches that facilitate the development of positive learning environments in which students are engaged in learning. Establishing democratic teaching practices that allow student choice, communicating in a positive, helpful manner, ensuring the right to teach and the right to learn without disruptions is upheld, and promoting self-discipline are important steps in preventing misbehavior and developing a democratic community of learners.

Community college faculty's teaching social networks and their implications for librarians

Collaboration between faculty and librarians is an important topic of discussion and research among academic librarians. These partnerships between faculty and librarians are vital for enabling students to become lifelong learners through their information literacy education. This research developed an understanding of academic collaborators by analyzing a community college faculty's teaching social networks. A teaching social network, an original term generated in this study, is comprised of communications that influence faculty when they design and deliver their courses. The communication may be formal (e.g., through scholarly journals and professional development activities) and informal (e.g., through personal communication) through their network elements. Examples of the elements of a teaching social network may be department faculty, administration, librarians, professional development, and students. This research asked 'What is the nature of faculty's teaching social networks and what are the implications for librarians?' This study moves forward the existing research on collaboration, information literacy, and social network analysis. It provides both faculty and librarians with added insight into their existing and potential relationships. This research was undertaken using mixed methods. Social network analysis was the quantitative data collection methodology and the interview method was the qualitative technique. For the social network analysis data, a survey was sent to full-time faculty at Las Positas College, a community college, in California. The survey gathered the data and described the teaching social networks for faculty with respect to their teaching methods and content taught. Semi-structured interviews were conducted following the survey with a sub-set of survey respondents to understand why specific elements were included in their teaching social networks and to learn of ways for librarians to become an integral part of the teaching social networks. The majority of the faculty respondents were moderately influenced by the elements of their network except the majority of the potentials were weakly influenced by the elements in their network in their content taught. The elements with the most influence on both teaching methods and content taught were students, department faculty, professional development, and former graduate professors and coursework. The elements with the least influence on both aspects were public or academic librarians, and social media. The most popular roles for the elements were conversations about teaching, sharing ideas, tips for teaching, insights into teaching, suggestions for ways of teaching, and how to engage students. Librarians' weakly influenced faculty in their teaching methods and their content taught. The motivating factors for collaboration with librarians were that students learned how to research, students' research projects improved, faculty saved time by having librarians provide the instruction to students, and faculty built strong working relationships with librarians. The challenges of collaborating with librarians were inadequate teaching techniques used when librarians taught research orientations and lack of time. Ways librarians can be more integral in faculty's teaching social networks included: more workshops for faculty, more proactive interaction with faculty, and more one-on-one training sessions for faculty. Some of the recommendations for the librarians from this study were develop a strong rapport with faculty, librarians should build their services in information literacy from the point of view of the faculty instead of from the librarian perspective, use staff development funding to attend conferences and workshops to improve their teaching, develop more training sessions for faculty, increase marketing efforts of the librarian's instructional services, and seek grant opportunities to increase funding for the library. In addition, librarians and faculty should review the definitions of information literacy and move from a skills based interpretation to a learning process.

Teaching design thinking and design led innovation to non-designers : a tertiary facilitator multidisciplinary study

This paper aims to address the knowledge gap in regards to the potential intermediary role tertiary institutions can play in developing generic design thinking/design led innovation capabilities in non-designers. Specifically, it investigates the value derived from the contribution of postgraduate design students as facilitators/educators for undergraduate non-design student cohorts. It examines a design immersion workshop designed to encourage the use of design thinking capabilities for project brief development for undergraduate multi-disciplinary student teams involved in a community service learning project for a social enterprise. The workshop was facilitated by design led innovation masters students embedded in industry organisations to research the integration of design led innovation capabilities in business. Data was collected from participating non-design students and postgraduate facilitators’ in the form of reflective journals and semi-structured interviews. The thematic analysis provided insight into the value of design thinking/design led innovation immersion programs for both the postgraduate facilitators and the undergraduate non-design students. The research results will inform a tentative foundation prototype framework to allow for ongoing program developments and research in design thinking/design led innovation integration in higher education, facilitating the development of generic capabilities required to empower future generations for business innovation and active citizenship in the 21st century knowledge economy.

Mixing higher education teaching and learning with mobile devices and social media

The use of mobile devices and social media technologies are becoming all-pervasive in society: they are both transformative and constant. The high levels of mobile device ownership and increased access to social media technologies enables the potential for ‘anytime, anywhere’ cooperation and collaboration in education. While recent reports into emerging technologies in higher education predict an increase in the use of mobile devices and social media technologies (Horizon Report, 2013), there is a lack of theory-based research to indicate how these technologies can be most effectively harnessed to support and enhance student learning and what the impacts of these technologies are on both students and educators. In response to the need to understand how these technologies can be better embraced within higher education, this study investigated how first year education students used mobile devices and social media technologies. More specifically, the study identified how students spent most of their time when connected online with mobile devices and social media technologies and whether the online connected time engaged them in their learning or whether it was a distraction.

Comments on the phase diagrams and crystallisation paths of Y-Ba-Cu-O materials

Our micro structural characterisation of Y-Ba-Cu-O quenched partial melts shows that the BaCuO2 (BC1) phase is crystalline at temperatures as high as 1100°C, and that the partial melt self-establishes a micro structural gradient from the surface towards the interior of the samples, which can be associated with a gradient in an equivalent partial pressure of O2 (pO2). The extension of the Y2BaCuO5-YBa2Cu3O7-x (Y211-Y123) tie-line intersects the primary crystallisation field of BC1 first. The actual peritectic reaction that takes place is Y2BaCuO5(s) + BaCuO2(s) + 2BaCu2O2(L) + 1/2O2 → 2YBa2Cu3O6(s). Two schematic representations which allow an analysis of the pO2 dependence are given. The gradient in micro structure self-established by the sample acts as a driving force for texturing. With this new perspective gained about the actual peritectic reaction and mechanisms of melt-texturing of Y123, it is possible to explain most of the aspects about partial melt-texturing. In addition, it seems possible to devise heat treatments that may allow for the production of well-oriented single domains with very large diameters. © 1999 Elsevier Science B.V.

Observation of exsolution textures within Ba-Cu-O-rich solidified melts of Y-Ba-Cu-O materials and their relationship to Y123 nucleation and texturing

Layers (about 60-100 μm thick) of almost pure BaCuO2 (BC1), as determined using X-ray diffractometry (XRD) and scanning electron microscopy (SEM), coat the surfaces of YBa2Cu3O7-x (Y123) samples partial melt processed using a single-zone vertical furnace. The actual Cu/Ba ratio of the BC1 phase is 1.2-1.3 as determined using energy dispersive X-ray spectrometry (EDS). The nominally BC1 phase displays an exsolution of BC1.5 or BC2 in the form of thin plates (about 50-100 nm thick) along {100}-type cleavage planes or facets. The exsolved phase also fills cracks within the BC1 layer that require it to be in a molten state at some stage of processing. The samples were influenced by Pt contamination from the supporting wire, which may have stabilised the BC1.5 phase. Many of the Y123 grains have the same morphology as the exsolution domains, and run nearly parallel to the thin plates of the exsolved phases, strongly indicating that Y123 nucleation took place at the interface between the BC1 and the BC1.5 or BC2 exsolved phases. The network of nearly parallel exsolved 'channels' provides a matrix and a mechanism through which a high degree of local texture can be initiated in the material.

Studies of the phase evolution of YBCO materials with different additives

Y123 samples with varying amounts of added Y211, PtO 2 and CeO 2 have been melt processed and quenched from temperatures between 960°C and 1100°C. The microstructures of the quenched samples have been characterized using a combination of x-ray diffractometry, optical microscopy, scanning electron microscopy, microprobe analysis, energy-dispersive x-ray spectroscopy and wavelength-dispersive x-ray spectroscopy. The Ba-Cu-O-rich melt undergoes complex changes as a function of temperature and time. A region of stability of BaCuO 2 (BC1) and BaCu 2O 2 (BC2) exists below 1040°C in samples of Y123 + 20 mol% Y211. Ba 2Cu 3O 5 is stabilized by rapid quenching but appears to separate into BC1 and BC2 at lower quenching rates. PtO 2 and CeO 2 additions affect the distribution and volume fractions of the two Ba-Cu-oxide phases.