In three-phase squirrel-cage ac traction motor, temperature-rise calculation during variable-voltage and variable-frequency starting is of vital importance and has to be predicted and critically ...examined. Under voltage source inverter supply with PWM, the generation of harmonics by inverter supply reduces the output during starting due to higher harmonic losses, thereby reducing the starting tractive effort in kN on locomotive wheel. Stator and rotor temperature-rises during starting have been determined for average acceleration torque in segmental zone (calculated from variable acceleration) which have been presented in the paper with both copper and aluminium alloy rotor bars.
The electromagnetic levitation system (EMLS) is inherently unstable and strongly non-linear in nature. A linearized model has been developed for the proposed levitated system and different classical ...controllers have been designed for providing overall closed loop stability as well as satisfactory performance for such an unstable system. The main aim of this part of work is to compare with the different designed controllers for the proposed designed EMLS at different operating points and to suggest a suitable classical controller that will provide fast response without any overshoot and steady-state error which is generally required for such type of critical systems. Experimental comparison of different simulated controllers with the existing prototype has been highlighted.
Purpose
Confined disposal facilities (CDFs) are widely used for disposal of navigation dredged material, but many are running out of capacity. Removal of dredged material for beneficial use offers ...potential for sustainable operations, but requires characterization with a high degree of confidence. Few data are available to inform characterization efforts in these artificial depositional environments; thus, a CDF case study was used to demonstrate a structured approach to sampling and data analysis.
Materials and methods
Selected data analysis procedures were applied to data collected from a CDF, with the objective of illustrating the utility of these procedures in (1) maximizing information obtained from limited data and (2) assessing the adequacy of the data in terms of estimating parameters of interest. In this case, the data were used to estimate the abundance of the desired fraction (sand), the contaminant levels in the sand and residual fractions, and the uncertainty of the parameters measured. From the outcome of this analysis, a stepwise approach to CDF characterization and data analysis was developed.
Results and discussion
The available dataset proved sufficient to estimate the distribution of sand in the CDF, although estimate reliability was constrained by the small number of samples and the lack of samples along the western facility boundary. Soot, organic carbon, and oil and grease were statistically significant regressors for many contaminants of concern; however, data were too limited and variable to permit prediction of contaminant concentrations in unanalyzed samples on the basis of the sorptive phases. A contour surface of benzo(a)pyrene concentration was generated to illustrate the utility in identifying areas of the CDF that may be problematic with respect to meeting regulatory criteria or guidelines for beneficial use; such areas may require additional processing to remove more highly contaminated fractions.
Conclusions
Of the graphical data analysis techniques evaluated, the most useful were: the aerial site view showing sample locations and per cent sand; the ternary diagram comparing sample characteristics; the contour map and the sand isopach map, representing aerial variation of sand thickness; and the depiction of contaminant concentrations as a contour surface. The predictive capability of the data was limited, but may have been aided with the addition of density fractionation and a larger dataset.
This paper proposes an efficient assessment scheme for curriculum quality of higher education by using of fuzzy analytic hierarchy process. The influencing factors of assessment quality are analyzed ...in terms of knowledge instruction, personnel cultivation and social service, and then a multi-parameter assessment index system for curriculum quality of higher education and its corresponding mathematical assessment model are established based on fuzzy analytic hierarchy process (FAHP). Meanwhile, the concrete assessment steps of curriculum quality are presented in detail. Additionally, to verify the rationality and feasibility of the proposed assessment method, the higher education course of Military History as the example would be studied.
Universities are social universes in their own right. They are the site of multiple, complex and diverse social relations, identities, communities, knowledges and practices. At the heart of this book ...are people enrolling at university for the first time and entering into the broad variety of social relations and contexts entailed in their ‘coming to know’ at, of and through university. By recasting ‘the transition to university’ as simultaneously and necessarily entailing a transition of university — indeed universities — and of their many and varied constitutive relations, structures and practices, the contributors to this book seek to reconceptualise the ‘first-year experience’ in terms of multiple and dynamic processes of dialogue and exchange amongst all participants. They interrogate taken-for-granted understandings of what ‘the university’ is, and consider what universities might yet become.
In exploring new ways of teaching students how to use Medical Subject Headings (MeSH), librarians at Boston University's Alumni Medical Library (AML) integrated social tagging into their instruction. ...These activities were incorporated into the two-credit graduate course, "GMS MS 640: Introduction to Biomedical Information," required for all students in the graduate medical science program. Hands-on assignments and in-class exercises enabled librarians to present MeSH and the concept of a controlled vocabulary in a familiar and relevant context for the course's Generation Y student population and provided students the opportunity to actively participate in creating their education. At the conclusion of these activities, students were surveyed regarding the clarity of the presentation of the MeSH vocabulary. Analysis of survey responses indicated that 46% found the concept of MeSH to be the clearest concept presented in the in-class intervention.
Universities are social universes in their own right. They are the site of multiple, complex and diverse social relations, identities, communities, knowledges and practices. At the heart of this book ...are people enrolling at university for the first time and entering into the broad variety of social relations and contexts entailed in their ‘coming to know’ at, of and through university. By recasting ‘the transition to university’ as simultaneously and necessarily entailing a transition of university — indeed universities — and of their many and varied constitutive relations, structures and practices, the contributors to this book seek to reconceptualise the ‘first-year experience’ in terms of multiple and dynamic processes of dialogue and exchange amongst all participants. They interrogate taken-for-granted understandings of what ‘the university’ is, and consider what universities might yet become.
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