3,785 research outputs found

    InGaN epilayer characterization by microfocused x-ray reciprocal space mapping

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    We report the use of microfocused three-dimensional x-ray reciprocal space mapping to study InGaN epilayers with average InN content 20%-22%. Analysis of the full volume of reciprocal space, while probing samples on the microscale with a focused x-ray beam, allowed us to gain valuable information about the nanostructure of InN-rich InGaN epilayers. It is found that “seed” InGaN mosaic nanocrystallites are twisted with respect to the ensemble average and strain-free. The initial stages of InGaN-on-GaN epitaxial growth, therefore, conform to the Volmer-Weber growth mechanism with “seeds” nucleated on strain fields generated by the a-type edge dislocations

    Foreword: The Klein Criteria Project

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    Background: IT development has in recent decades been fast progressing. In Sweden many schools have begun to invest in IT and new technologies. What happens at the schools that are investing in IT equipment and modern technology? Purpose: The purpose of this study is to elucidate the conditions for and the success factors and barriers that principals and teachers will experience in IT. Principals' experiences are complemented and mirrored against the teachers. The following issues are in focus: 1. What basic conditions are necessary for IT equipment and modern technology to be used in education? 2. What are the success factors and how do the principals create these? 3. What are the difficulties / obstacles and how do the principals overcome these difficulties? Result: Based on the study, one can see that certain conditions are required in order for IT ventures to succeed. The most important requirement is supporting principals. Conditions such as finance, technology and effective IT support also seem to be important. Another conclusion is that is not only the principalsÂŽ responsibility to create all conditions that are needed; municipalities need to centrally decide how to organize their schools, what they want with IT and then sets the stage for it to work. Key words: IT ventures, school improvement, principals, teachers, conditions, barriers and success factors

    Non-equilibrium two-phase coexistence in a confined granular layer

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    We report the observation of the homogenous nucleation of crystals in a dense layer of steel spheres confined between two horizontal plates vibrated vertically. Above a critical vibration amplitude, two-layer crystals with square symmetry were found to coexist in steady state with a surrounding granular liquid. By analogy to equilibrium hard sphere systems, the phase behavior can be explained through entropy maximization. However, dramatic non-equilibrium effects are present, including a significant difference in the granular temperatures of the two phases.Comment: 4 pages, 3 figures, RevTex4 forma

    Group perceptions of knowledge management

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    This paper reports preliminary results of a project investigating how staff in UK organisations perceive knowledge management in their organisation as a group. The group setting appears to be effective in surfacing opinions and enabling progress in both understanding and action to be made. Among the findings thus far are the importance of the knowledge champion role and the state of the “knowledge management life cycle” in each organisation, and continuing confusion between knowledge, information and mechanisms

    Communicating knowledge about police performance

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    This paper describes the organizational processes of knowledge acquisition, sharing, retention and utilisation as it affected the internal and external communication of knowledge about performance in an English police force. The research was gathered in three workshops for internal personnel, external stakeholders and chief officers, using Journey Making, a computer-assisted method of developing shared understanding. The research concluded that there are multiple audiences for the communication of knowledge about police performance, impeded by the requirement to publish performance data. However, the intelligence-led policing model could lead to a more focused means of communication with various stakeholder groups. Although technology investment was a preferred means of communicating knowledge about performance, without addressing cultural barriers, an investment in technology may not yield the appropriate changes in behaviour. Consequently, technology needs to be integrated with working practices in order to reduce organizational reliance on informal methods of communication

    Comparing knowledge management between organisations:searching for good practice

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    This paper reports ongoing work that is attempting to find out ‘what is good practice for knowledge management’. The data we have to analyse this issue is 109 maps of knowledge (on knowledge management) which were built during 18 group workshops with 152 people from 15 different organisations. The maps contain data on the aspirations and action plans which UK managers have to improve knowledge management practices in their organisation. So far we have attempted a number of approaches to analysing this data, both inductive and deductive, but we still feel there is more to be learned from the rich data set we have. The paper presents a flavour of the work we have done, have considered doing, and have resisted doing. The aim of the paper is to stimulate debate on the strengths of our analyses and, more importantly, on amassing views of how it can be further strengthened, and the difficulties and dilemmas which might need to be overcome

    Cone beam CT evaluation of the presence of anatomic accessory canals in the jaws

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    Objectives: To assess the prevalence, location and anatomical course of accessory canals of the jaws using cone beam CT. Methods: A retrospective analysis of 4200 successive cone beam CT scans, for patients of both genders and ages ranging from 7 to 88 years, was performed. They were exposed at the School of Dentistry, University of Michigan, Ann Arbor, MI. After applying the exclusion criteria (the presence of severe ridge resorption, pre-existing implants, a previously reported history of craniofacial malformations or syndromes, a previous history of trauma or surgery, inadequate image quality and subsequent scans from the same individuals), 4051 scans were ultimately included in this study. Results: Of the 4051 scans (2306 females and 1745 males) that qualified for inclusion in this study, accessory canals were identified in 1737 cases (42.9%; 1004 females and 733 males). 532 scans were in the maxilla (13.1%; 296 females and 236 males) and 1205 in the mandible (29.8%; 708 females and 497 males). Conclusions: A network of accessory canals bringing into communication the inner and outer cortical plates of the jaws was identified. In light of these findings, clinicians should carefully assess for the presence of accessory canals prior to any surgical intervention to decrease the risk for complications
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