Basic parameters of the static stability,loads and strength of the vital parts of a bucket wheel excavator’s slewing superstructure

Determining a bucket wheel excavator (BWE)’s slewing superstructure weight and its center of gravity (COG) is of extreme importance not only in the design phase, but also after the completion of the erection process and during the operation of the machine. This paper presents a critical comparative analysis of the basic parameters of the static stability of a BWE 1600 superstructure, with the parameters being obtained by both analytical and experimental procedures. The analysis shows that a relatively small difference in superstructure mass, obtained by calculation, leads to a relatively large unfavorable shifting of its COG, necessitating a significant increase in counterweight mass for balancing. A procedure for superstructure 3D model mass correction is presented based on results obtained by weighing after the completion of the erection process. The developed model provides enough accuracy to determine the superstructure’s COG in the entire domain of the bucket wheel boom inclination angle, and enables accurate load analysis of the superstructure’s vital parts. The importance of this analysis is reinforced by the finding that the procedure prescribed by standard DIN 22261-2 gives results which are not on the side of safety, as shown by an example of strength analysis of a bucket wheel boom stays’ end eyes.     

Effects of self-monitoring training on reading accuracy and fluency of poor readers

The effect of the self-monitoring training on reading accuracy and fluency of second-grade poor readers was examined. The participants were assigned in one experimental and three control groups. The experimental group was reinforced with token-economy for self-correction and fluent reading. One control group practiced reading without feedback, the second one practiced the calculation of simple arithmetic tasks, and the third one received no training at all. The improvement in reading accuracy was obtained only in the self-monitoring group, and remained for five months. However, the improvement in reading fluency was obtained in the two reading groups, but only the self-monitoring group showed further improvement during five months after training. The results confirmed the importance of self-monitoring already at the level of lexical access in reading and that of local text comprehension.     

Transdisciplinary qualitative paradigm in applied linguistics: autoethnography,participatory action research and minority language teaching and learning*

The paper emphasizes the crucial importance of transdisciplinary approach to qualitative research methodology in teaching and learning contexts involving highly stigmatized minority languages. Autoethnography and participatory action research are herein employed as constructive, critical, qualitative methodological procedures relevant to transdisciplinary research on minority languages in applied linguistics. An international project on teaching and learning Romani, QUALIROM, is used as a case study in order to emphasize the fact that mere theoretical knowledge and professional expertise are important but not sufficient for successful implementation and sustainability of outcomes in this field of linguistic research. The analysis suggests that socially engaged minority language learning and teaching projects should be understood as transdisciplinary, collaborative activities that transcend academic boundaries, and in which research participants create a number of interactive contexts within project-oriented communities of practice aimed at reshaping dominant social relations and practices.     

Lifelong education in Yugoslavia

Conclusion Notwithstanding the weaknesses noted in theory and practice, tangible results have been achieved in Yugoslavia in the domain and policy of permanent education. Many obstacles stood in the way of this progress and resistance was encountered on various sides to the introduction of lifelong education. This resistance was overcome by the adoption of the Resolution on the Development of Education on an Autonomous Basis which is deeply permeated by the ideas of lifelong education, thus opening broad avenues for its development in Yugoslavia.     

Student Peer Review as a Tool for Efficiently Achieving Subject‐Specific and Generic Learning Outcomes: Examples in Botany at the Faculty of Agriculture,University of Belgrade

Several teachers at the Faculty of Agriculture at the University of Belgrade recognised the need to improve teaching methods in order to actively involve students in the teaching process, help them learn more effectively, and reduce the low exam pass rate. This led to a purpose‐designed course on improving academic skills, after which the author has been implementing interactive teaching methods for the past three academic years, with positive results in improving student exam performances as well as enabling the acquisition of valuable generic skills. Presented here are attempts to test students' ability to assess themselves and each other by introducing student peer reviewing and student self‐assessment exercises.     

Literacy development beyond early schooling: a 4-year follow-up study of Croatian

Reading and Writing - The purpose of this study was to investigate literacy development beyond the early school years. We investigated mean-level and rank-order changes in two reading (word...     

Teaching about thermal expansion: investigating the effectiveness of a cognitive bridging approach

Background: It is widely known that for many students it is very difficult to correctly predict how thermal expansion affects the appearance of a metal plate with a circular hole. Interviews with school teachers show that the source of this difficulty could stem from the fact that students’ internal visualizations of an arbitrary object’s thermal expansion often boil down to visualizing changes along one dimension only.

Purpose: In this study, we investigated how students’ mental models about one-dimensional expansion can be extended for purposes of running mental simulations about expansion along two dimensions.

Sample: To that end a pretest-posttest quasi-experiment has been conducted, with 100 students in the control group and 95 students in the experimental group.

Design and methods: Whereas control group students received traditional instruction with a focus on formal representations, in the experimental group the students were led to draw an analogy between heating of a straight rod and a circular rod of same length, whereby the internal structure of the rods was represented by springs.

Results: Eventually, it has been found that students from the experimental group were significantly more successful at predicting the effects of thermal expansion, especially within contexts of objects with holes.

Conclusion: Analogies and extreme case reasoning can be effectively used for helping the students to correctly transfer their mental models about one-dimensional expansion to situations that require reasoning about expansion along two dimensions.     

Stories From Intercultural Education in Serbia: Teacher Leadership and Parent Participation

This article explores the potential of teacher leadership as a strategy to promote intercultural education by empowering parents and members of ethnic minority groups to participate in the life of the school. It links the idea of participation for social justice with the goals of intercultural education within the context of the APREME (Advancing Participation and Representation of Ethnic Minority Groups in Education) project, which is located within a wider program of research, development, and advocacy designed to promote inclusion and social cohesion in the western Balkans. The outcomes of this action-based stage of the program are presented in the form of vignettes that portray teachers’ projects designed to enable parents and community members to participate more fully in the life of the school. Conclusions are drawn about the relationship between teacher leadership and a transformative approach to the intercultural education.