Vacuum interrupter, high reliability component of distribution switches, circuit breakers and contactors

The use of vacuum interrupters(VIs)as the current interruption component for switches,circuit breakers,reclosers and contactors operating at distribution voltages has escalated since their introduction in the mid-1950’s.This electrical product has developed a dominating position for switching and protecting distribution circuits.VIs are even being introduced into switching products operating at transmission voltages.Among the reasons for the VI’s popularity are its compactness,its range of application,its low cost,its superb electrical and mechanical life and its ease of application.Its major advantage is its well-established reliability.In this paper we show how this reliability has been achieved by design,by mechanical life testing and by electrical performance testing.We introduce the“sealed for life”concept for the VI’s integrity.We discuss this in terms of what is meant by a practical leak rate for VIs with a life of over 30 years.We show that a simple high voltage withstand test is an easy and effective method for monitoring the long-term vacuum integrity.Finally we evaluate the need for routine inspection of this electrical product when it is used in adverse ambient environments.     

Construction of “glocal” (global–local) identity among Israeli graduate students in the USA

Abstract This study focuses on the effect of doctoral and postdoctoral studies at leading research universities in the USA on constructing the academic identity of Israeli students. The findings are based on constant comparative analysis of semi-structured interviews with 27 Fulbright alumni. The results show that while American scientific standards become a model for the Israeli scientists, Israeli culture and identity become much more evident, for better or worse. Several ways of handling these identities were recognized and include: the intertwine method, ordering, and buffering. Further theoretical and practical implications are discussed.     

What drives teacher engagement: a study of different age cohorts

Despite the growing body of research on work engagement, little is known about what drives work engagement among different age cohorts. This study aims to investigate whether engagement varies across age cohorts and examine the job resources that foster teacher engagement. A questionnaire was distributed to 537 teachers who were employed in elementary, lower and upper secondary school. Findings show that work engagement did indeed vary across the diverse age group and is influenced by different resources. In line with previous studies, data revealed that the engagement of younger teachers is driven by the opportunity for development and interaction with colleagues, while older employees appreciate the opportunity to see their competencies acknowledged. What is most noteworthy is the opportunity to design practices and to provide every age group with the appropriate set of motivators.     

Retrospective Integration of Research Conducted on a Multi-Section Educational Psychology Course over a Fifteen-Year Period

This article integrates a series of studies conducted over a 15-year period in a multi-section educational course taught by the same supervising professor and his GTAs . The purpose of each study was to determine whether particular interventions or student characteristics affected performance levels in the course. Over the extended period of research, approximately 6000 undergraduate students, with 25 to 55 students in each of more than 200 sections, participated in a variety of research projects related to student performance in the course. The principal research themes addressed were (1) critical thinking, (2) additional cognitive measures (e.g., initial course knowledge, generic vocabulary), (3) class participation, (4) in-class writing activities, and (5) cooperative learning.     

Sense of Place in Child Care Environments

The exterior design of existing preschool environments is evaluated in the context of contemporary writings by architects focusing on creating designs that nurture children’s emotions. Sense of place research is discussed in relation to young children’s experiences. Findings reveal that the majority of sites included in the study incorporated many physical design elements that create a sense of place for children in preschool environments, including small-scale structures, windows, landscaping, natural wall materials, and thresholds. Recommendations for administrators and directors planning and designing a new or remodeled preschool environment include incorporating features that reflect home-like environments with windows, thresholds, and landscaping.     

Empirische Bildungsforschung in der Kritik – ein Überblick über Themen und Kontroversen

This article overviews the criticism which has been published since about 2001 concerning educational research and the related debates. Discussion contributions are classified into six different topics, four of which are expatiated on in this issue: the topic of (1) education theory, (2) discipline policy, (3) governance theory, and (4) teaching theory. To all these four topics the course of debate is shortly presented regarding criticism and counter criticism, in order to give a view to more articles of this issue. Thus a continuous controversial, partly even polemical discussion is described, which will be proceeded in this issue factually and argumentative.     

Self Reflections of Undergraduate Students on Using Web-Supported Counterintuitive Science Demonstrations

Analysis of self-reflections of undergraduate education students in a project involving web-supported counterintuitive science demonstrations is reported in this paper. Participating students (N?=?19) taught science with counterintuitive demonstrations in local elementary school classrooms and used web-based resources accessed via wireless USB adapters. Student reflections to seven questions were analyzed qualitatively using four components of reflection (meeting objectives/perception of learning, dynamics of pedagogy, special needs accommodations, improving teaching) deriving 27 initial data categories and 12 emergent themes. Overall the undergraduates reported meeting objectives, engaging students in pedagogically relevant learning tasks including, providing accommodations to students with special needs, and gaining practice and insight to improve their own teaching. Additional research is needed to arrive at generalizable findings concerning teaching with web-supported counterintuitive science demonstrations in elementary classrooms.     

Shear capacity of reinforced concrete columns strengthened with CFRP sheet

INTRODUCTION There is increased need in recent years for strengthening or rehabilitation of existing reinforced concrete structures adversely affected by overloading, construction material deterioration, seismic loads, structural deformation, etc. An effective method for increasing the shear capacity of reinforced concrete columns is the use of externally bonded carbon fiber reinforced plastic (CFRP) systems (ACI, 2002). FRP systems were first applied to reinforced concrete col-umns i…     

Bolstering the quality and integrity of online collaborative university- level courses via an open Sim standalone server in conjunction with sloodle

The contemporary era provides several challenges which extend from the reconstitution of an innovative knowledge domain and curricula to candidate learning platforms that support online course delivery methods. Educators and scholars on these demands have recently started to rethink alternative ways for the assimilation of the experiential knowledge in three-dimensional (3D) technologically advanced environments, like 3D multi-user virtual worlds. In spite the widespread dissemination and proliferation of novel educational implications by utilizing 3D multi-user virtual worlds combined with the 2D interface of LMS (Learning Management Systems) and the assessment of the effectiveness based on the online course delivery method in a long-term usability is still absent from the international academic literature. This study presents interoperability issues focused on the utilization of the virtual world Open Simulator (Open Sim) in conjunction with Sloodle (Simulation Linked Object Oriented Dynamic Learning Environment) as a free plug-in module. The evaluation of this online learning process according to an empirical research method became possible with the assistance of ninety-five (95) students by two different academic sectors that participated in this project and measured the capabilities and instructional affordances of this platform. The evaluation process was focused on four multi-dimensional parameters (psychological-pedagogical, technical-operational, organizational-financial, and socio-cultural). The study findings based on students’ experiences revealed that both platforms could be sufficiently connected as a unique platform which can increase the users’ learning abilities. This “hybrid” platform can adequately convert the ordinary multi-user virtual world of Open Sim and Sloodle in a common “incubator” of knowledge for online courses at university level. At the end, the instructional affordances and implications for future-driven directions are also discussed.