Diffusion measurement from observed transverse beam echoes

We study the measurement of transverse diffusion through beam echoes. We revisit earlier observations of echoes in RHIC and apply an updated theoretical model to these measurements. We consider three possible models for the diffusion coefficient and show that only one is consistent with measured echo amplitudes and pulse widths. This model allows us to parameterize the diffusion coefficients as functions of bunch charge. We demonstrate that echoes can be used to measure diffusion much quicker than present methods and could be useful to a variety of hadron synchrotrons.Comment: 25 pages, 10 figure

The emergence of social scientific history and the analysis of process-produced data: some introductory remarks

Der Autor stellt die Frage, welchen wissenschaftlichen Nutzen die Verwendung computerisierten Daten für die Soziologie haben. Einerseits vermitteln sie ein vollständigeres Bild des Untersuchungsgegenstandes, andererseits ist dieses Verfahren bisher nicht geeignet, tiefere theoretische Einsichten zu erlangen. Die grundlegenden theoretischen Konzeptionen der Soziologie stammen aus der Zeit vor der Einführung des Computers und nach Ansicht des Autors verführt die Anwendung dieser Technik dazu, theoretische Reflexionen gegenüber der Materialsammlung und Bearbeitung zu vernachlässigen. (BG

Patientenarbeit: biographischer und alltagsweltlicher Umgang mit medizinisch-therapeutischer Hochtechnologie

Aus phänomenologisch-empirischer Sicht wird der Wandel der Einstellung zur Technik am Beispiel des Lebens und Gewöhnens von Patienten an eine Dialysestation in einem Krankenhaus analysiert. Bei dieser Population stellt sich die Frage nach der Einstellung radikaler als bei anderen, denn hier ist "Technik" äquivok mit "Leben", ihre Verneinung wäre Selbstmord. Der Autor konzipiert Patientenarbeit als Arbeit der Patienten im Sinne einer Verknüpfungsleistung biographischer und trajektoraler Erfahrungs- und Handlungsketten zur Wiederherstellung lebensweltlicher Idealisierungen in einem Rahmen, der durch die medizinische Technologie gesetzt wird. (psz

Sensual Construction of Body and Biography. Suggestions to Mutually Improve Deficient but Widespread Body Concepts and Biographical Research

Against the backdrop of an increasing interest in visual methods in social research, this paper examines some theoretical foundations of human (inter-)action by reflecting on the interplay between senses, the body, and biography. The main purpose of the paper is to combine an integral, non-Cartesian concept of the self as body (respectively the lived body as self) with biographical research—thus enriching research on the body, as well as on biography. Criticizing the Cartesian split of body and mind, classical phenomenological (Leib) and recent concepts of the body (“embodiment”) are sketched, resulting in a processual model of the sensual construction of the lived and living body in its environment. Given the interplay of bodily foundations of the self and processes of biographical structuring, so far, distant fields of research are converged. Some suggestions for conceptual improvements, an attentional shift to body aspects, respective research topics, and the extension of methods exceeding the narrative biographical interview in biographical research are indicated

Micro- and Macroscopic Modeling of Crowding and Pushing in Corridors

Experiments with pedestrians revealed that the geometry of the domain, as well as the incentive of pedestrians to reach a target as fast as possible have a strong influence on the overall dynamics. In this paper, we propose and validate different mathematical models at the micro- and macroscopic levels to study the influence of both effects. We calibrate the models with experimental data and compare the results at the micro -- as well as macroscopic levels. Our numerical simulations reproduce qualitative experimental features on both levels, and indicate how geometry and motivation level influence the observed pedestrian density. Furthermore, we discuss the dynamics of solutions for different modeling approaches and comment on the analysis of the respective equations.Comment: 22 pages, 14 figure