6,361 research outputs found

    Phonon Thermodynamics versus Electron-Phonon Models

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    Applying the path integral formalism we study the equilibrium thermodynamics of the phonon field both in the Holstein and in the Su-Schrieffer-Heeger models. The anharmonic cumulant series, dependent on the peculiar source currents of the {\it e-ph} models, have been computed versus temperature in the case of a low energy oscillator. The cutoff in the series expansion has been determined, in the low TT limit, using the constraint of the third law of thermodynamics. In the Holstein model, the free energy derivatives do not show any contribution ascribable to {\it e-ph} anharmonic effect. We find signatures of large {\it e-ph} anharmonicities in the Su-Schrieffer-Heeger model mainly visible in the temperature dependent peak displayed by the phonon heat capacity

    Student progress monitoring: teachers\u27 perceptions

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    The Mississippi Student Progress Monitoring System (MSPMS) was developed for the Mississippi Department of Education to be used to monitor student progress on the state framework which constitutes the curriculum for each course taught in Mississippi schools. This study was designed to investigate teachers’ perceptions of the implementation and use of the MSPMS. Research question 1 was to determine if the various independent variables of age, level of education, years of experience as an educator, level of school where teaching, perceived level of computer and/or technology comfort, perceived level of computer and/or technology experience, subject area taught, number of MSPMS tests created, number of MSPMS tests given, amount of support provided, whether program works, and importance of information gained from MSPMS made any difference in teachers’ perceptions of the implementation and use of the MSPMS; and research question 2 was to determine whether the teachers’ perceptions and the various independent variables had any significant relationships. Research question 3 looked at teachers’ attitudes toward MSPMS. There were no statistically significant differences among the dependent and independent variables. Findings for research question 2 showed that there were no statistically significant correlations among the dependent and independent variables. However, correlations among the independent variables revealed statistically significant relationships between age and years of experience, subjects taught and school level taught, technology experience and level of education, and subjects taught and number of tests given. Examination of the response frequencies for situations in the vignettes for research question 3 revealed that teachers reported feeling more frustrated than anything else when confronted with adversities with the technologies or the MSPMS. All of the findings in this study are limited to a rural Mississippi school district using MSPMS

    Establishing Criteria for the Pre-Service Selection of Teachers with Special Application to the Utah State Agricultural College

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    Our American culture and civilization depends in large measure upon the recruiting of the right kind of men and women to be teachers in our American schools and colleges. All professions depend on effective teaching for their life blood. Many educators and colleges during the past few years have become concerned with pre-service selection methods for improving the teaching personnel. This concern has become somewhat intensified at the present time, largely as a result of four factors. One factor is the large number of returning servicemen, who are turning to teaching as a career. A second factor is improved salaries and tenure laws. A third factor, suggested by Dr. Ray C. Maul is that many people are turning to teaching only because schools continue to operate though good times and bad. A fourth factor common to many prospective teachers is that the idealism connected with teaching attracts them into the profession. The objective of this study is to obtain evidence from a reveiw of literature, opinions of educators and the preservice selection practices used in other colleges to establish criteria that are considered to be the most desirable factors and techniques used in the pre-service selection of teachers as found by an investigation of the literature. The criteria will be used as a basis for making an analysis of the available records of the students and practices used in the guidance program in the School of Education at Utah State Agricultural College. In this manner the limitations or success of the guidance program as indicated will be somewhat more meaningful

    Heat capacity and thermal expansion at low temperatures

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