50 research outputs found

    From Indymedia to Anonymous: rethinking action and identity in digital cultures

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    The period following the social mobilizations of 2011 has seen a renewed focus on the place of communication in collective action, linked to the increasing importance of digital communications. Framed in terms of personalized ‘connective action’ or the social morphology of networks, these analyses have criticized previously dominant models of ‘collective identity’, arguing that collective action needs to be understood as ‘digital networking’. These influential approaches have been significantly constructed as a response to models of communication and action evident in the rise of Independent Media Centres in the period following 1999. After considering the rise of the ‘digital networking’ paradigm linked to analyses of Indymedia, this article considers the emergence of the internet-based collaboration known as Anonymous, focusing on its origins on the 4chan manga site and its 2008 campaign against Scientology, and also considers the ‘I am the 99%’ microblog that emerged as part of the Occupy movement. The emergence of Anonymous highlights dimensions of digital culture such as the ephemeral, the importance of memes, an ethic of lulz, the mask and the grotesque. These forms of communication are discussed in the light of dominant attempts to shape digital space in terms of radical transparency, the knowable and the calculable. It is argued that these contrasting approaches may amount to opposing social models of an emerging information society, and that the analysis of contemporary conflicts and mobilizations needs to be alert to novel forms of communicative practice at work in digital cultures today

    A Digital data acquisition system for PRIN- A Facility for neutron production using Accelerator.

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    International audienceAll most all the nuclear physics experiments involves ion beam (projectile) of different species and energies. The intensity of the beam, the beam energy, the beam uniformity & divergence including stability of the ion beam is of fundamental importance for any Accelerator. In addition with ion beam the study of neutrons are demanding subject now days. There are lack of reliable nuclear data [1], especially around 5 to 14 MeV range and still it is an open field of study. The neutron cross-section data at these high energies are very much important for fusion reactor development. More over there is a need for calibrated neutron (n) detectors to be used for reliable cross-section measurements. In addition to the above the dark matter group wants to investigate the experimental study using recoil range analysis method in liquid Ar/Xe where they need more precise neutron energy and crosssection. Now days the imaging (neutron imaging) is another emerging field for non-destructive study of many thing starting from industrial to defences research where the high energy neutron cross section are very much important. All the above requirement lead to the development of a dedicated neutron source and dedicated fast data acquisition system which can able to do quick analysis at the site for better understanding. Keeping all the things on mind a dedicated beam line for n production has been developed which uses a two body D(d, n)3He reaction to produce mono energetic neutron [2] of desired energies at 3.3MV Tandem Accelerator (TTT-3) at Department of Physics, University of Naples Federico II [3]. The neutron beam line including specially designed chamber for neutron Production has been shown in Fig.1. There are many other reactions are available to produce neutron whereas D(d, n)3He reaction has some better advantage which will be presented and discussed. To support the above experimental facility a dedicated digital data acquisition system have been installed and new algorithm using ROOT has been developed for the analysis purpos

    H-1, H-2, H-3, HE-4 EMISSION FROM RU-96 NUCLEI (E-ASTERISK-SIMILAR-TO-113 MEV) - TEST FOR TRANSMISSION COEFFICIENTS IN THE EVAPORATION MODEL

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    A detailed comparison between measured energy spectra and cross sections of H-1, H-2, H-3, and He-4, evaporated from the composite system 96Ru (E* congruent-to 113 MeV), and the predictions of the statistical model, has been carried out. Results obtained with transmission coefficients derived from optical model (OM), ingoing-wave boundary-condition model (IWBCM) and fusion systematics (FS) are presented. The best overall description of the data is obtained using IWBCM transmission coefficients, with reduced s-wave barriers, including, in the level density, deformations slightly larger than those predicted by the rotating liquid drop model (RLDM). H-2, H-3 yields are well reproduced by IWBCM transmission coefficients, while they are largely overestimated by the OM ones; the failure is found to be related to the imaginary part of the optical potential which accounts for the absorption of nonfusion reactions, in peripheral collisions. No combination of phase space and transmission coefficients is able to reproduce, simultaneously, the low emission barrier and the cross section observed for protons

    H-1, H-2, H-3, He-4 Emission From Ru-96 Nuclei (e-asterisk-similar-to-113 Mev) - Test For Transmission Coefficients In the Evaporation Model

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    A detailed comparison between measured energy spectra and cross sections of H-1, H-2, H-3, and He-4, evaporated from the composite system 96Ru (E* congruent-to 113 MeV), and the predictions of the statistical model, has been carried out. Results obtained with transmission coefficients derived from optical model (OM), ingoing-wave boundary-condition model (IWBCM) and fusion systematics (FS) are presented. The best overall description of the data is obtained using IWBCM transmission coefficients, with reduced s-wave barriers, including, in the level density, deformations slightly larger than those predicted by the rotating liquid drop model (RLDM). H-2, H-3 yields are well reproduced by IWBCM transmission coefficients, while they are largely overestimated by the OM ones; the failure is found to be related to the imaginary part of the optical potential which accounts for the absorption of nonfusion reactions, in peripheral collisions. No combination of phase space and transmission coefficients is able to reproduce, simultaneously, the low emission barrier and the cross section observed for protons

    The 8pLP project at LNL: A detection system for light charged particles with deexcitation channel selection

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    A 4 pi detection system sensitive to light charged particles is being developed at the Laboratori Nazionali di Legnaro (LNL) for the study of the reaction mechanisms produced in heavy-ion collisions at energies up to 20 AMeV. The 8 pi LP apparatus is a telescope assembly characterized by large solid angle (90% of 4 pi) and high granularity (262 modules). Particle identification at low energy is enhanced by combining Delta E-E, TOF and PSD techniques. Thresholds for particle identification range from 1 MeV for protons and 3 MeV for alpha particles to about 2-3 AMeV for C ions. The system is fully operational for experiments

    The 8pLP Project: a 4pi Light Charged Particle Detection Array at LNL

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    A 4 pi detection system sensitive to light charged particles is being developed at the Laboratori Nazionali di Legnaro (LNL) for the study of the reaction mechanisms produced in heavy ion collisions at energies up to 20 AMeV. The 8 pi LP apparatus is a telescope assembly characterized by large solid angle (90% of 4 pi) and high granularity (262 modules). Particle identification at low energy is obtained by combining Delta E-E, TOF and PSD techniques. Each telescope is made of a 300 mu m passivated silicon detector and a 15 mm (or 5 mm) CsI(TI) crystal with photodiode readout. Thresholds for particle identification range from 1 MeV for protons and 3 MeV for alpha particles to about 2-3 AMeV for C ions. A low-cost trigger and readout bus system has been developed to cope with the large number of parameters and the high counting rate. The system will be fully operational for experiments in the Summer of 1997

    Autologous peripheral blood progenitor cell transplantation with <2 x 10(6) CD34(+)/kg: an analysis of variables concerning mobilisation and engraftment

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    INTRODUCTION: This study analyses the factors affecting mobilisation and engraftment in autologous peripheral blood progenitor cell transplantation according to the number of CD34(+) re-infused. MATERIALS AND METHODS: A total of 190 patients underwent mobilisation with G-CSF alone (n=113) or in combination with chemotherapy (n=77). A total of 116 patients (61%) were autografted with 2 x 10(6) CD34(+) cells/kg. Rates of granulocyte and platelet recovery were estimated using the product-limit method of Kaplan-Meier and compared using a log-rank test. The Cox regression model was used for the multivariate analysis of factors influencing engraftment. Differences between cohorts were evaluated by one-way ANOVA or Mann-Whitney tests, and multivariate analysis was performed using a stepwise lineal regression. RESULTS: Neutrophil and platelet engraftment was significantly longer with 2 x 10(6)/CD34(+)/kg, the Cox model did not identify prognostic factors for haematopoietic recovery. CONCLUSION: Although mobilisation schedules and disease status influenced not only the yield of progenitor cells, but also the engraftment kinetics, the number of CD34(+) re-infused was the main predictor of haematopoietic recovery. While engraftment succeeded in most of the cases, the re-infusion of >2 x 10(6)/CD34(+)/kg resulted in significantly shorter recovery times
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