Active Vibration Control of a Single Mass Rotor on Flexible Supports

This paper considers vibration control of a single mass flexible rotor on damped flexible supports with active feedback control. Both proportional and derivative feedback control are utilized. Free vibrations and unbalance response of the rotor-control system are determined. The effect of proportional control is to increase the critical speed of rotating machinery while the effect of derivative control is to reduce the amplitude of vibration. Generally larger ratios of support stiffness to shaft stiffness require larger values of control parameters to produce given amplitudes of vibration.     

How are the Perceptions of Learning Networks Shaped Among School Professionals and Headteachers at an Early Stage in their Introduction?

This paper draws on the findings of a research project funded by the Liverpool City of Learning consortium in the UK. The aim is to explore the process of introduction of ten authority wide learning networks, the impact these have on school professionals practice, the opportunities they offer for CPD and the extent to which they may impact on pupil learning. The research presented here draws on findings from a questionnaire distributed to school professionals and key issues emerging from their analysis point to the influence of national government agendas on school professionals’ interpretation of the purpose of the networks. They also point to the views of staff regarding the impact of the attainment agenda as well as the extent to which an increased emphasis on social inclusion and wider understandings of learning and achievement (which are less well represented by results-based performance monitoring) are having on their hopes for what Learning Networks might deliver. The expectations of staff of the opportunities offered by learning networks for long term professional development provide some interesting insights, and perhaps, some useful pointers as to how networks of this kind might develop in the future.     

Tennessee meets the challenge of dyslexia

In 1993, the Tennessee General Assembly voted funds to establish a model unit of integrated services and research to address the full scope of issues associated with dyslexia. Dyslexia is characterized as significant difficulty in reading and spelling individual words. In the Tennessee Center for the Study and Treatment of Dyslexia, these problems are presumed to be the consequence of a phonological core deficit. When compared to typical readers, matched for age or reading level, dyslexic readers evidence average listening comprehension, a relative strength in reading comprehension, deficits in word recognition and spelling, and severe deficits in word analysis as well as in awareness and manipulation of phonemes. Integration of this information yields a diagnostic profile that may be applied in the differential diagnosis of dyslexia both in clinical and school settings. This paper presents an overview of the Tennessee Center for Dyslexia and the services it provides as well as its guidelines for interpreting the results of norm-referenced tests and criterion-referenced measures to diagnose dyslexia and plan appropriate intervention. Frith’s (1985, 1986) developmental framework for reading acquisition is integrated with the assessment data to outline an instructional plan that addresses mastery of skills within and across the hierarchical phases—logographic, alphabetic, and orthographic—of reading development.     

Collaborative epistemic discourse in classroom information-seeking tasks

The authors discuss the relationship between information seeking and epistemic beliefs – beliefs about the source, structure, complexity and stability of knowledge – in the context of collaborative information-seeking discourses. They further suggest that both information seeking, and epistemic cognition research agendas, have suffered from a lack of attention to how information seeking as a collaborative activity is mediated by talk between partners – an area they seek to address in this article. A small-scale observational study using sociocultural discourse analysis was conducted with eight 11-year-old pupils who carried out search engine tasks in small groups. Qualitative and quantitative analysis were performed on their discussions using sociocultural discourse analytic techniques. Extracts of the dialogue are reported, informed by concordance analysis and quantitative coding of dialogue duration. The authors find that: (1) discourse which could be characterised as ‘epistemic’ is identifiable in student talk; (2) it is possible to identify talk which is more or less productive; and (3) epistemic talk is associated with positive learning outcomes.     

How Do Low-Income Chilean Parents Support Their Preschoolers’ Writing and Math Skills in a Grocery Game?

This study examined how parents supported children’s writing and math and whether parents’ support predicted children’s academic skills from the beginning of pre-kindergarten to the end of kindergarten. Two hundred ten Chilean parents from low-income households were observed playing a grocery game with their preschoolers (M = 53 months). The grocery game (a game where dyads make a grocery list together and shop at a pretend store) could be used to foster writing and mathematics. Coders noted how often parents engaged in writing support, provided math support, and displayed directiveness (i.e., taking over the child’s activity). Children’s literacy and math skills were assessed at the beginning of pre-kindergarten and the end of kindergarten. Research Findings. Parents engaged in little writing support but displayed moderate levels of math support and high levels of directiveness in the grocery game. Parents’ math support uniquely predicted gains in children’s math skills, while parents’ directiveness negatively predicted gains in children’s literacy skills. Practice or Policy. Results from this study have the potential to inform parent-focused interventions. Findings highlight the need to provide parents with specific strategies to support their children’s literacy and math development and guidance about embedding these strategies into family routines.     

Technological innovation in developing countries: a review of the literature

The recent literature on the role of science and technology in developing countries is reviewed in order to assess the extent of our current knowledge concerning the sociological factors affecting the development of indigenous scientific and technological innovations. Existing studies provide some preliminary evidence in favor of the hypothesis that inadequate linkages between institutions in the various sectors of developing societies inhibit the development and utilization of indigenous technological innovations.In general, relationships between government research organizations and the potential users of their technological innovations are absent or unsatisfactory. Academic research tends to be oriented toward the interests of the international scientific community. The substantial literature on the problems of indigenous technological transfer in India suggests that inadequate coordination between different sectors of that society is in part responsible for its failure to develop its potential for technological innovation.Recent attempts to stimulate the production and diffusion of indigenous technology in developing countries by creating new types of research institutes in the university and coordinating agencies in the government are discussed. Systematic evaluations of these programs are lacking, but coordinating agencies have often performed poorly because of insufficient power to influence the policies of other organizations.A sociological approach based on interorganizational analysis is suggested for future studies of this problem. This literature identifies the optimal characteristics of coordinating organizations at the government level and of research utilizations systems which link research organizations to their clients at the local level.A bibliography comprising 102 references classified by region is included.     

Rapid bioparticle concentration and detection by combining a discharge driven vortex with surface enhanced Raman scattering

Rapid concentration and detection of bacteria in integrated chips and microfluidic devices is needed for the advancement of lab-on-a-chip devices because current detection methods require high concentrations of bacteria which render them impractical. We present a new chip-scale rapid bacteria concentration technique combined with surface-enhanced Raman scattering (SERS) to enhance the detection of low bacteria count samples. This concentration technique relies on convection by a long-range converging vortex to concentrate the bacteria into a packed mound of 200 μm in diameter within 15 min. Concentration of bioparticle samples as low as 10⁴ colony forming units (CFU)∕ml are presented using batch volumes as large as 150 μl. Mixtures of silver nanoparticles with Saccharomyces cerevisiae, Escherichia coli F-amp, and Bacillus subtilis produce distinct and noticeably different Raman spectra, illustrating that this technique can be used as a detection and identification tool.     

Medical student attitudes to the autopsy and its utility in medical education: A brief qualitative study at one UK medical school

Attending postmortems enables students to learn anatomy and pathology within a clinical context, provides insights into effects of treatment and introduces the reality that patients die. Rates of clinical autopsies have declined and medical schools have cut obligatory autopsy sessions from their curricula making it difficult to assess medical student perceptions of, and attitudes towards, the educational value of autopsy. Our aim was to investigate these perceptions by designing a brief qualitative study comprising nominal technique and focus group discussions with Cambridge Graduate Course students, all of whom had attended autopsies. Three general themes emerged from the focus group discussions: the value of autopsy as a teaching tool and ways the experience could be improved, the initial impact of the mortuary and the autopsy itself, and the “emerging patient”—an emotional continuum running from cadaver to autopsy subject and living patient. Educational benefits of autopsy‐based teaching included greater understanding of anatomy and physiology, greater appreciation of the role of other health care professionals and an enhanced appreciation of psycho‐social aspects of medical practice. Students suggested improvements for ameliorating the difficult emotional consequences of attendance. We conclude that autopsy‐based teaching represents a low‐cost teaching technique which is highly valued by students and has application to many diverse medical specialties and skills. However, careful preparation and organization of sessions is required to maximize potential educational benefits and reduce any negative emotional impact. Anat Sci Educ 7: 87–96. © 2013 American Association of Anatomists.