First Operational Experience with DORIS II
DORIS II is a completely new designed e+-e- storage ring with a mini-beta scheme. After first runs with a 8 cm optic, the vertical amplitude functions in the interaction points were reduced to 4 cm. This yielded luminosities of L = 1.5 . l031 cm-2sec-1 with 2 × 27 mA at E = 5 GeV. Because of the short injection time, an integrated luminosity of more than 600 nb-1 per day has been obtained.
Modern and future colliders
Since the initial development of charged particle colliders in the middle of the 20th century, these advanced scientific instruments have been at the forefront of scientific discoveries in high energy physics. Collider accelerator technology and beam physics have progressed immensely and modern facilities now operate at energies and luminosities many orders of magnitude greater than the pioneering colliders of the early 1960s. In addition, the field of colliders remains extremely dynamic and continues to develop many innovative approaches. Indeed, several novel concepts are currently being considered for designing and constructing even more powerful future colliders. In this paper, we first review the colliding beam method and the history of colliders, and then present the major achievements of operational machines and the key features of near-term collider projects that are currently under development. We conclude with an analysis of numerous proposals and studies for far-future colliders. The evaluation of their respective potentials reveals tantalizing prospects for further significant breakthroughs in the collider field.
A Construction of Bullying in a Primary School in an Underprivileged Community: An Ecological Case Study
This article is based on a master's dissertation completed through the University of Pretoria. Conversations around behavioural problems in three primary schools in Mamelodi, an underprivileged community in South Africa, explored contextually relevant ideas, in the form of discourse, focusing on the experience of bullying from the perspective of the participants (children identified by the school as engaging in bullying behaviour, school staff, and the children's families). Semi-structured interviews were conducted with the principals (school gatekeepers), and with other participants identified by each other during the interview process. Two figures prominent in the media on the topic at the time of this study were also included to provide discourses on bullying from wider society. An ecological approach within a post-modern social constructionist theoretical framework was used. In this article one ecological case study from one of the three schools was used to explore the aims. Discourse analysis was used in the construction of the various discourses emerging from the conversations. The participants' ideas around bullying are described, focusing on the discourse themes of “community and bullying”, “profile of teachers in the community”, “bad child, good child”, “undefined problems” and “family discord”. The aim of this article is to provide an ecological description of bullying, through discourse, in the context of this case study by exploring the participants' ideas on and experience of bullying in a primary school situated in the township of Mamelodi. Implications for intervention are considered.