4,964 research outputs found
Making connections: problems, progress and priorities – a practitioner’s viewpoint
No full textIn this thesis, the reader is invited to ‘think with the story’ (Bochner, 1997) as the issues arising from a research project undertaken by a full-time classroom teacher are explored. The study began with the intention to help children make connections in their learning. Taking an action research approach, over a span of two and a half years, ways to help children link ideas were investigated, their responses observed and their views explored through techniques such as interviews, games and stimulated recall. As the study progressed, it developed a stronger focus on practitioner research, especially in relation to teacher research with children. Following a change of school, the research focused on working with a ‘pupil research group’ over a six-month period. The thesis addresses the learning of the teacher-researcher about the connections and challenges involved, including contextual issues, different methodological strategies, power relationships, different voices and viewpoints in research and the process of change. A narrative approach is used to tell much of the story, in the form of an informal dialogue between the author as a teacher and the author as a researcher. Thus, the common and conflicting demands and benefits of research and teaching in such a project are explored in dynamic fashion. Ultimately, a framework to support practitioner researchers, based on the problems and progress in the study, is presented with some priorities for the future
Wealth and risk implications of the Dodd-Frank Act on the U.S. financial intermediaries
No full textWe contribute to the current regulatory debate by examining the wealth and risk effects of the Dodd-Frank Act on U.S. financial institutions. We measure the effects of key legislative events of the Act by means of a multivariate regression model using the seemingly unrelated regression (SUR) framework. Our results indicate a mixed reaction by financial institutions during the various stages of the Act's legislative process. Further tests reveal that any positive reactions are driven by small and/or low risk institutions, while negative ones are consistent across subsets; except for investment banks. We also find market risk increases for most financial institutions that are dominated by small and/or low risk firms. The cross-section results reveal that large institutions fare better than their smaller counterparts and that large investment banks gain value at the expense of others. Overall, the Dodd-Frank Act may have redistributed value among financial institutions, while not necessarily reducing the industry's riskiness
Partial Discharge Source Characterization within a HV Cable Joint
No full textA parameter for partial discharge (PD) source location within a joint bay of a three phase cross-bonded high voltage cable circuit has been assessed. Locally placed sensors can detect PD pulses that propagate within the fault related phase. However, when a cable joint bay is cross-bonded then PD signals from one phase may be measured by sensors on the other two phases as well. Current research at Southampton is considering the practical application of on-line PD monitoring techniques to three phase high voltage cable joints. A simple model, using 66kV cable sections to represent a cross-bonded circuit has been implemented. The model uses one capacitive coupler per phase. Measurement data was obtained by injecting pulses into the core conductor. Data was analysed using a clustering technique in order to determine the PD source location
The Influence of Absorbed Gases on Electroluminescence Phenomenon in Polymeric Materials Subjected to High Electrical Stress
No full textWhenever a polymeric material is subjected to an electrical stress, imperfections such as protrusions, contaminants and microvoids, will all act as points where the field is enhanced, causing the degradation processes to be initiated. However, as manufacturing technology improves, insulation systems are of higher quality and their interfaces smoother. The reduction in concentration and size of impurities has led to more research at the atomic scale where space charges can play a fundamental role in triggering ageing phenomena. Since space charges seem to play a significant role in long-term electrical degradation of polymeric insulation, researchers are investigating the energy dissipation of mobile and trapped charges in the molecules of a dielectric medium. The dissipation process is associated with the emission of visible photons, a process known as electroluminescence (EL), which has been observed in various materials. This paper presents the series of experiments completed in the study of EL phenomenon in low-density polyethylene (LDPE); the most common type of material used for high voltage cable insulation. In addition to that, the role of gas diffusion into the polymer on the processes leading to EL has also been examined
Podagrion nigriclava Dodd. We 1917
No full textPodagrion nigriclava Dodd, 1917 Podagrion nigriclava Dodd, 1917: 360. NT: Darwin. Bouček (1988): 141. Material examined: 1 ♀ type (slide), QMB; labelled: Podagrion pax Girault, nigriclavum Dodd, ♀ types, 5093. 5094. Remarks. There are two coverslips on the slide. According to Dahms (1986) one almost complete coverslip belongs to the holotype of Podagrion pax (for details see P. pax paragraph) and the second (just a fragment) coverslip belongs to the syntypes of Podagrion nigriclava Dodd. We clearly identified parts of a destroyed head, two female antennae and one hind female leg under this coverslip which most probably belongs to a (syn)type of P. nigriclava. Examination of these fragments can still clearly assign this species to the genus Podagrion.Published as part of Janšta, Petr, Delvare, Gérard, Baur, Hannes, Wipfler, Benjamin & Peters, Ralph S., 2020, Data-rich description of a new genus of praying mantid egg parasitoids, Lasallegrion gen. n. (Hymenoptera: Torymidae: Podagrionini), with a re-examination of Podagrion species of Australia and New Caledonia, pp. 755-790 in Journal of Natural History 54 (9) on page 785, DOI: 10.1080/00222933.2020.1778112, http://zenodo.org/record/429054
Comparison of electroluminescence phenomenon in LDPE, PET and PEN under the application of high electrical stress
No full textAccount Statement, P. C. Knowlton Co., Inc., Fancy Grocers to Mrs. S. L. Dodd, September 8, 1914
No full textThis account statement records grocery items ordered from P. C. Knowlton Co., Inc. in Memphis Tennessee by Mrs. S. L. Dodd in Kosciusko, Mississippi. The total of the order comes to three dollars and sixty-three cents. Paid Sept 20 1914 P. C. Knowlton Co., Inc. is stamped in pink in the center of the page.https://scholarsjunction.msstate.edu/mss-webb-collection/2181/thumbnail.jp
Determining the Occurrence of Electroluminescence in Polymeric Materials with respect to the Applied Alternating Electrical Stress
No full textThe emission of low level of light known as the electroluminescence (EL) has been used extensively to study charge injection and recombination mechanisms at the metal-polymer interface. This phenomenon has also been used as a probe to study early electrical ageing in high voltage cable insulation system since it can be associated with the energy dissipation of mobile and trapped charges in the molecules of the dielectric medium. Nowadays many works have been undertaken in order to understand the nature of EL in polymeric materials and its relationship with electrical ageing. This paper attempts to lay down the basic theory of the mechanism accountable for the phenomenon and relate it with some experimental observations made on typical polymers; namely lowdensity polyethylene (LDPE) and polyethylene naphthalate (PEN)
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