Education for sustainable development : current discourses and practices and their relevance to technology education

Technology education is a well-established field of knowledge whose applications have many ramifications. For example, technology education may be used as a tool in meeting the challenges of sustainable development. However, the usefulness of technology education to the sustainability debate as a whole and to education for sustainable development in particular, has largely been overlooked in the past. Indeed, there is a paucity of academic studies which examine the contribution technology education may provide to education for sustainable development. On the basis of the need to address this knowledge gap, this paper reviews the state of affairs in relation to education for sustainable development and considers its links and appropriateness to technology education. A further objective of this paper is to present examples of initiatives and existing practices around the world, drawing partly from the results of the 1st European Conference on Education for Sustainable Development held in Greece in October 2007, as well as from other initiatives undertaken in Europe and North America. Finally, some measures that may be adopted in order to enhance the contribution of technology education to education for sustainable development are outlined.peer-reviewe

Prediction of 3D High Frequency Eddy Current Loss in Rotor Magnets of SPM Machines

This paper proposes a computationally efficient method, for accurate prediction of 3-dimensional (3D) high frequency eddy current loss in the rotor magnets of surface mounted permanent magnet machines employing the imaging method. 2D finite element analysis (FEA) is used to generate the information on radial and tangential 2D magnetic field variations (eddy current sources) within the magnet. The diffusion of eddy current sources along the axial plane of the magnet computed analytically is incorporated in the imaging method to establish the 3D eddy current source variations within the magnet. The modified method is validated with results from 3D time-stepped finite element analysis (FEA) for an 8-pole, 18-slot permanent magnet machine, evaluating its magnet loss considering axial and circumferential segmentation

Computationally Efficient 3D Eddy Current Loss Prediction in Magnets of Interior Permanent Magnet Machines

This paper proposes a computationally efficient method based on imaging technique, for accurate prediction of 3- dimensional (3D) eddy current loss in the rotor magnets of interior permanent magnet (IPM) machines. 2D time-stepped finite element analysis is employed to generate the radial and the tangential 2D magnetic field information within the magnet for application of the 3D imaging technique. The method is validated with 3D time-stepped finite element analysis (FEA) for an 8 pole-18 slot IPM machine evaluating its resistance limited magnet loss with increase in axial and tangential segmentation. Magnet loss considering eddy current reaction at high frequencies is evaluated from the proposed method by employing the diffusion of the 2D magnetic field variation along the axial plane. The loss associated with all the frequencies together in the armature currents is evaluated by considering each of the harmonics separately in the proposed method employing the frozen permeability to account for magnetic saturation. The results obtained are verified with 3D FEA evaluating the magnet loss at fundamental, 10 and 20 kHz time harmonics in armature currents

Parathyroid apoplexy, the explanation of spontaneous remission of primary hyperparathyroidism: a case report

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Experimental validation of 3D magnet eddy current loss prediction in Surface Mounted Permanent Magnet Machines

This paper presents the experimental validation of 3D Fourier method employed for predicting magnet eddy current loss in surface mounted permanent magnet (SPM) machines. The magnet loss is measured for a 12-slot,14-pole SPM machine from experimental tests when the machine is operated with inverter under locked rotor conditions by repeating tests with two rotors, one with magnets and one without. The eddy current loss associated with each significant harmonic in the captured armature currents is predicted separately employing the developed method and the total magnet loss is evaluated by applying the principle of superposition. The magnet loss at real operating conditions of the machine is predicted from the method using the phase current captured when the SPM is operating at its maximum speed conditions. The result is used as example to devise an effective means of further reduction in the total magnet loss

The contribution of education towards meeting the challenges of climate change

This paper outlines the contribution the education sector can provide in meeting the challenges of climate change, worldwide. It offers an analysis of the means via which education, awareness and training can help the global efforts to tackle climate change and lists a set of practical activities which may assist various groups in handling climate matters as part of formal and non-formal education. The paper concludes by providing a warning: without proper emphasis to educational approaches, the desired (and indeed) changes in attitudes and behaviour as well as the motivation needed in order to engage people in reducing the impacts they may have on the climate, may not be fully achieved.peer-reviewe

Echocardiographic changes in the development of the athlete's heart in 9 to 20-year-old male subjects

The purpose of this cross-sectional investigation was to estimate the age at which specific traits of the “athlete's heart”first appear and how they evolve from the beginning of regular physical training until young adulthood in healthy active males. Male athletes (n=389) and non-athletes (n=55) aged between 9 and 20 years were examined by two-dimensionally guided M-mode and Doppler echocardiography. Intragroup differences were examined by t-tests for independent samples between age groups of two years each. Morphologic variables were related to body size by using ratio indices in which the power terms of numerator and denominator were matched. Relative left ventricular muscle mass (LVMM) was significantly larger in the athletic males at age of 11–12, and this significant difference was maintained with advancing age. Most of this increase of LVMM could be attributed to the increase in wall thickness that became significantly manifest first in the 13- to 14-year-old athletic subjects but was demonstrable in all the other groups. A significantly larger left ventricular internal diameter was only found in the age-group of 15–16. Fractional shortening percentage (FS%) did not show any change, while resting heart rate was decreased in our athletic groups

Peptic Ulcer Perforation as the First Manifestation of Previously Unknown Primary Hyperparathyroidism

A patient admitted for acute abdomen was incidentally found with elevated serum calcium level. In surgery, under conservative treatment of the hypercalcemia, a perforated duodenal ulcer was found and simple closure was performed. Postoperatively, calcium level continued to rise, parathyroid hormone was elevated and ultrasonographic examination showed a lesion in the right anterior neck, while serum gastrin level was normal, thus documenting the diagnosis of primary hyperparathyroidism. Conservative treatment had no effect on calcium level and the patient was subjected to emergency neck exploration, where a large parathyroid adenoma was removed. After surgery, calcium and PTH levels were normalized and the patient was discharged on the 5th postoperative day. Peptic ulcer and its complications are usual manifestations of primary hyperparathyroidism, with or without increased gastrin level. On the other hand, cases of a perforation of peptic ulcer as the first clinical manifestation of primary hyperparathyroidism are extremely rare