785 research outputs found
Il futuro della città
No full textIn questa pubblicazione è raccolto il testo del dialogo tenuto da Gabriele Pasqui e Carlo Sini alla Casa della Cultura di Milano l’11 dicembre 2019 nell’ambito del ciclo “Città Bene Comune – Conferenze” curato da Oriana Codispoti.
Il dialogo tra Gabriele Pasqui e Carlo Sini propone una riflessione su che cos’è la città oggi, sollecitandoci ad adottare una prospettiva che, partendo dal nostro punto di vista particolare e parziale, sia capace di guardare alla complessa varietà dei fenomeni urbani contemporanei.
“Città Bene Comune” è un ambito di dibattito sulla città, il territorio, il paesaggio e le relative culture progettuali, ideato e diretto da Renzo Riboldazzi e prodotto dalla Casa della Cultura di Milano in collaborazione con il Dipartimento di Architettura e Studi Urbani del Politecnico di Milano
Radiological Pre-Characterisation for Decommissioning of L-54M Nuclear Research Reactor and Waste Management Strategy
No full textCeSNEF L-54M (Nuclear Studies Centre Enrico Fermi) is a research reactor owned by Politecnico di Milano
(POLIMI) that was shut down in 1979 and since then kept in safe storage condition. In 2014 POLIMI decided to proceed towards an active decommissioning strategy aiming towards a greenfield status.
In the following paper, a discussion of the methodologies defined in the POLIMI pre-characterization campaign of the reactor Systems, Structures, and Components (SSC), and its waste management strategy will be discussed. The obtained plant data herein described provides useful references for similar decommissioning projects as they were utilized for the creation of benchmark analyses in two IAEA and
OECD/NEA Collaborative Research Projects (GRAPA, DACCORD phase II)
Topsoil radiological characterisation of L-54M reactor surroundings preliminary to decommissioning operations
Get PDFThe radiological characterization of the topsoil of the L-54M reactor surroundings carried out in this work aims at obtaining the reference blank point for the forthcoming decommissioning operations and ascertain if unexpected radionuclide release occurred during the operational life of the plant. Standardised methods have been employed in order to collect representative samples and reliable results. Suitable sample pre-treatment procedures were applied. Gamma and beta spectrometric analyses were carried out to measure the activity concentrations of Co-60 Cs-137, Eu-152, Am-241 and Sr-90. These have been considered as representative radionuclides that could have been originated from reactor operations and that could still be present at four decades post reactor shutdown
DECOMMISSIONING OF CESNEF L-54M RESEARCH REACTOR: RADIOLOGICAL PRE-CHARACTERISATION OF GRAPHITE AND BIOLOGICAL SHIELD
No full textThe L-54M thermal research reactor was commissioned by Politecnico di Milano to Atomic International in 1958. It was shut down in 1979 after around 20 years of operations for research purposes. Subsequently it was put under Safe Storage. Several operations have to be managed in order to restore the reactor site to the status of “unrestricted re-use”, the socalled “greenfield” status. This work concerns the preliminary radiological characterization of graphite and concrete, which are the main constituents of the moderator/reflector and the biological shield respectively. The main purpose of this work is the assessment of conventional and radioactive wastes volumes in view of the final decommissioning. In this context, the key radionuclides deriving from neutron activation are: 3H, 14C, 60Co, 152Eu. The first part of the research was based on neutron diffusion theory for the computational evaluation of the activity of these activation products. The second part of the work was focused on Non-Destructive Analyses (NDA) and DA of few graphite and concrete representative sample
MCNP model of L-54M nuclear research reactor: validation by preliminary graphite radiological characterization
Get PDFSince its shutdown in 1979, L-54M nuclear research reactor of Politecnico di Milano has been kept in safe storage configuration. In view of forthcoming decommissioning activities, many characterization activities have been performed on its matrices. Regarding the L-54M graphite stack, a neutron activation model was developed and validated by a graphite sampling and preliminary radiological characterization campaign focused on the most significant gamma-emitting radionuclides. Even if slightly underestimating the measured values, between − 5% and − 49% for 152Eu, between − 41% and − 67% for 154Eu, the simulated activity concentrations promisingly reproduce the experimental radial profile
Tropospheric Scintillation and Simultaneous Rain Attenuation at 19.7 GHz and 39.4 GHz for Tito Scalo and Spino d'Adda
No full textAttentional capture by simultaneous pleasant and unpleasant emotional distractors
No full textBoth high-arousal pleasant and unpleasant task-irrelevant stimuli capture attention and divert processing away from the main task leading to impaired behavioral performance in concurrent tasks. Most studies have separately investigated interference effects of unpleasant and pleasant stimuli on behavior. Thus, little is known about how pleasant and unpleasant task-irrelevant stimuli influence behavior simultaneously. In the present study, we investigated this question during a visual-letter search task. We tested two alternative hypotheses about the influence of simultaneous pleasant and unpleasant task-irrelevant stimuli on task performance. If behavior is purely determined by the intensity of the distractor stimuli (independent of valence), then we would expect the interference effect of simultaneous pleasant and unpleasant distractors to be similar to the influence of two pleasant or two unpleasant distractor stimuli. In contrast, because of opponent interactions between appetitive and aversive motivational systems, the interference effect of simultaneous pleasant and unpleasant stimuli might be weakened. We found that the interference effect of a compound pleasant-plus-unpleasant stimulus was greater than that of a neutral-plus-emotional stimulus and similar to that of two pleasant or two unpleasant stimuli. These results suggest that at the level of behavior, the influence of joint pleasant and unpleasant task-irrelevant stimuli during perception is mainly determined by the intensity of the stimuli, and independent of their valence
Selectively attending to natural scenes after alcohol consumption: an ERP analysis
No full textAlcohol effects on cognitive, emotional and behavioral processes have been linked to an impairment of attention. Because attention operates at the level of specific cognitive subsystems, recent studies demonstrated alcohol effects in specific post-perceptual processes such as response selection and working memory. Measuring event-related potentials, the present study focused on perceptual processes by utilizing a categorization task where participants had to decide whether briefly presented images contained an animal or not. Findings demonstrate an early differential ERP activity for target compared to non-target images, which was reduced after alcohol intoxication. Thus, alcohol intoxication had deleterious effects at the perceptual level of processing considered to reflect the interaction of top-down (category-related) and bottom-up (stimulus-driven) processes. In addition, post-perceptual processes were also impaired by alcohol intoxication
Optimization of ACM algorithms over Q/V-band satellite channels with the Alphasat Aldo Paraboni P/L
No full textFuture satellite communication systems providing broadband access to Internet require high throughput connectivity in the order of hundreds of Gbps or Tbps. Radical changes in technologies are needed to support these demanding requirements. One of the most important changes is the use of Q/V band frequencies which offer larger bandwidths with respect to the Ka band. However, Q/V band communication suffers from highly variable propagation losses and the use of Propagation Impairment Mitigation Techniques (PIMTs) is mandatory for an efficient use of radio resources such as power and bandwidth. In this paper we describe the first Q/V band satellite communication experiments that have been performed through the Alphasat 'Aldo Paraboni' hosted payload. In particular, experimental results on ACM optimization will be presented
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