1,752 research outputs found

    Electron and trap dynamics in As-ion-implanted and annealed GaAs

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    The ultrafast dynamics of As-ion-implanted and annealed GaAs is investigated using transmission pump–probe measurements.Carrier recombination time was found to increase from 4 to 40 ps with increasing annealing temperature. At lower annealing temperatures, the transmitted optical signal is dominated by induced absorption and at higher annealing temperatures this effect is replaced by induced transparency.This work was supported in part by the EC INCOCOPERNICUS project ‘‘DUO—devices for ultrafast optoelectronics’’ and the Lithuanian Science and Study Foundation

    The Effect of Planting Density and Supports on the Seed Yield of Mucuna cochinchinensis

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    Mucuna cochinchinensis was planted for seed production using six planting systems. These comprised combinations of two planting distances; 1. 0 m x 1.0 m and 2.0 m x 2.0 m with three types of supports; no support, individual pole support for each plant or the wire-trellis type of support. Plants using either type of support outyielded the seed production from plants which received no support. Mean yield of normal seeds for unsupported plants, plants with individual support and plants with the wire trellis type of support were 76,677 and 736 kg/ha respectively. The lower yield of normal seeds from unsupported plants resulted from a combination of a lower total seed yield and a higher percentage of rotten seeds. Rotten seeds in unsupported plants comprised 68 percent of total seed yield compared to 38 percent and 33 percent for individually supported and wire-trellis supported plants respectively. Differences between the two types of supports were not significant. Planting distance did not have a significant effect on seed yield. However, for plants without any support there was a higher percentage of ;otten seeds (78%) for the more closely spaced plants than for plants planted at the wider spacing (54%)

    Teacher Compensation and School Quality: New Findings from National and International Data.

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    High quality education is critical to both the individual and the nation. At the country level, as Ireland’s minister for education and science, put it, “The never ending search for competitive advantage in the global knowledge economy has led all public policymakers to focus on education as a key factor in strengthening competitiveness, employment and social cohesion.

    Observational Methods for Predicting Embankment Settlement

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    The one dimensional Terzaghi method is still widely used for prediction of settlement. Its differential equation is solved on the assumption that coefficient of consolidation is a constant, in which case the equation becomes linear. But in reality this equation is non linear because compressibility, permeability and coefficient of consolidation changes with settlement. This is why the capability of predicting the rate of settlement or time-settlement relationship remains rather poor. In this paper a number of high quality long-term field settlement data are used to verify the applicability of the observational methods, namely the hyperbolic and the Asaoka method. The field data were from the Tangkak trial embankment (1987-1996) and the Juru trial embankment (1990-1992). Based on the available settlement record for embankment on soft ground, it can be concluded that the prediction of settlement using the hyperbolic method is significantly improved using the start of construction settlement data, notably after more than 50% of the settlements have occurred. Long-term settlement predicting using the early stage data (6 months or less) could be misleading. The capability of the method can also be diagnosed from the characteristics of the CUIVe plotted. For the case of hyperbolic method, it is evident that if a close linear relation of t/p and p is obtained, then the prediction is seemingly good. Prediction of settlement using the Asaoka method is also improved using larger settlement database

    FINITE ELEMENT METHOD FOR HEAT TRANSFER PHENOMENON ON A CLOSED RECTANGULAR PLATE

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    In the diagnosis and control of various thermal systems, the philosophy of heat fluxes, and temperatures are very crucial. Temperature as an integral property of any thermal system is understood and also, has well-developed measurement approaches. Though finite difference (FD) had been used to ascertain the distribution of temperature, however, this current article investigates the impact of finite element method (FEM) on temperature distribution in a square plate geometry to compare with finite difference approach. Most times, in industries, cold and hot fluids run through rectangular channels, even in many technical types of equipment. Hence, the distribution of temperature of the plate with different boundary conditions is studied. In this work, let’s develop a finite element method (code) for the solution of a closed squared aluminum plate in a two-dimensional (2D) mixed boundary heat transfer problem at different boundary conditions. To analyze the heat conduction problems, let’s solve the two smooth mixed boundary heat conduction problems using the finite element method and compare the temperature distribution of the plate obtained using the finite difference to that of the plate obtained using the finite element method. The temperature distribution of heat conduction in the 2D heated plate using a finite element method was used to justify the effectiveness of the heat conduction compared with the analytical and finite difference method

    Temperature dependent photoluminescence in oxygen ion implanted and rapid thermally annealed ZnO/ZnMgO multiple quantum wells

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    The authors investigate the effect of oxygen implantation and rapid thermal annealing in ZnO∕ZnMgOmultiple quantum wells using photoluminescence. A blueshift in the photoluminescence is observed in the implanted samples. For a low implantation dose, a significant increase of activation energy and a slight increase of the photoluminescence efficiency are observed. This is attributed to the suppression of the point defect complexes and transformation between defect structures by implantation and subsequent rapid thermal annealing. A high dose of implantation leads to lattice damage and agglomeration of defects leading to large defect clusters, which result to an increase in nonradiative recombination.The authors gratefully acknowledge the Australian Research Council for financial support and Swinburne University of Technology for Strategic Initiative funding. One of the authors X.W. acknowledges partial financial support of the Chinese National Natural Science Foundation 10364004 and the Yunnan Natural Science Foundation 2003E0013M

    Support Systems Designed for Older Drivers to Achieve Safe and Comfortable Driving

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    Background: The number of older people is increasing. Many of them expect to maintain a rich social life and to continue driving at an older age. Objective: The present study investigates the mechanisms behind self-regulation and driving cessation in order to suggest development of support systems to prolong older drivers’ safe mobility. Method: Three focus groups were conducted with 19 older active drivers aged 65+ who were divided according to annual mileage driven. Results: A content analysis revealed broad self-regulatory behaviour as already reported in the literature, e.g., avoiding driving at rush hour and at night. The participants also reported difficulty in finding the way to their final destination and an increasing need to plan their travelling. Co-piloting was a behaviour applied by couples to cope with difficulties encountered in traffic. A large part of the discussion was focused on emerging feelings of stress, anxiety and fear when driving in recent years, a feeling induced by external factors e.g., other road users’ behaviour, traffic density or high speed. Apart from health problems, high levels of stress could explain driving cessation, especially for women. An increased feeling of safety and comfort could be achieved by an increased use of support systems specifically designed to respond to older drivers’ needs. Conclusion: Support systems for older drivers should increase comfort and decrease their stress levels. New systems, such as co-pilot function and more developed Global Positioning System (GPS) supporting of the entire travel from door to door, should be developed to respond to the market needs

    An exploration of how specialist dementia nurses perceive and maintain the skills and competencies that frame their specialism: A qualitative survey.

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    BACKGROUND: UK policy for complex and long-term health conditions including dementia has recommended that specialist nursing intervention is offered across the trajectory of the condition, but there is a lack of agreement regarding the skills and competencies that specialist nurses are expected to possess. Admiral Nurses are the largest UK group of specialist dementia nurses. OBJECTIVE: To explore how Admiral Nurses met and were supported to meet competencies as defined in the Admiral Nurse Competency Framework, and to develop and maintain skills as dementia specialists. DESIGN: Cross-sectional, semi-structured survey. SETTING: Online national survey. PARTICIPANTS: Admiral (specialist dementia) Nurses. METHODS: We co-designed our survey with Admiral Nurses; then invited Admiral Nurses to complete it in 2022-23 Data were analysed thematically. RESULTS: 68 (20% of all Admiral Nurses) completed the survey; most were female (85.2%), from a white ethnic group (88.2%); they reported on average 24 years of nursing experience. We identified three themes in responses: 1.Having time and skills for meaningful support, explored how participants were resourced with time and skills to understand and address family carer client needs by active listening, tailoring person-centred support, and "walking alongside" families. 2.Partnering family carers, concerned how they co-designed interventions with family carers, learning from these collaborative partnerships where expertise was shared. 3.Practice and peer-based learning, explored how participants took responsibility for using available training, peer learning and self-reflection to develop their practice. CONCLUSIONS: Admiral Nurse roles enabled respondents to develop as autonomous practitioners and to access resources that supported them to build and sustain their dementia specialist practice. Learning was practice based, through partnerships with family carer clients, peer support and self-directed learning. Specialist nursing models may help address the global health workforce emergency, through enabling creative practice development and valued roles that support retention of experienced nurses

    Multiscale boundary element method for Laplace equation

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    In this paper, the multiscale boundary element method is applied to solve the Laplace equation numerically. The new technique is the coupling of the multiscale technique and the boundary element method in order to speed up the computation. A numerical example is given to illustrate the efficiency of the proposed method. The computed numerical solutions by the proposed method will be compared with the solutions obtained by the conventional boundary element method with the help of Fortran compiler. By comparison, results show that the new technique use less iterations to arrive at the solutions
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