Search results for "production [photon]"
showing 10 items of 138 documents
Seed Activation Scheduling for Influence Maximization in Social Networks
2018
This paper addresses the challenge of strategically maximizing the influence spread in a social network, by exploiting cascade propagators termed “seeds”. It introduces the Seed Activation Scheduling Problem (SASP) that chooses the timing of seed activation under a given budget, over a given time horizon, in the presence/absence of competition. The SASP is framed as a blogger-centric marketing problem on a two-level network, where the decisions are made to buy sponsored posts from prominent bloggers at calculated points in time. A Bayesian evidence diffusion model – the Partial Parallel Cascade (PPC) model – allows the network nodes to be partially activated, proportional to their accumulat…
Measuring Excellence and Equity in Education : Conceptual and Methodological Issues
2011
The text focuses on the measurement problems both equity and excellence does imply, and on the "technical" choices that are to be made. It aims at showing that those choices are not neutral and have plenty of political consequences. Starting with the problems of definition of both excellence and equity, which should be considered jointly, the paper examines i) how the indicators and methods implemented do have some impact on the amount of inequalities, and ii) on the necessity of a time dimension to figure out how inequalities are generated, along with a system-wide perspective.
Special applications of reverse electrodialysis
2016
Reverse electrodialysis (RED) is a process for direct electricity production from salinity gradients, based on the use of suitable exchange membranes. To develop the RED process on an applicative scale and to add value to the overall process, a key role is entrusted to the selection of electrodic system, redox species, and electrode materials. In particular, it was shown that a proper selection of redox processes allows the use of a RED cell for the wastewater treatment of organic and inorganic pollutants resistant to conventional biological methods and for the synthesis of chemicals without energy supply. The utilization of microbial reverse electrodialysis cells was also proposed to incre…
Could the recent zika epidemic have been predicted?
2017
AbstractGiven knowledge at the time, the recent 2015-2016 zika virus (ZIKV) epidemic probably could not have been predicted. Without the prior knowledge of ZIKV being already present in South America, and given the lack of understanding of key epidemiologic processes and long-term records of ZIKV cases in the continent, the best related prediction was for potential risk of an Aedes-borne disease epidemic. Here we use a recently published two-vector capacity model to assess the predictability of the conditions conducive to epidemics of diseases like zika, chikungunya or dengue, transmitted by the independent or concurrent presence of Aedes aegypti and Aedes albopictus. We compare the potenti…
Multi-Objective and Multi-Criteria Analysis for Optimal Pump Scheduling in Water Systems
2018
This contribution focuses on the problem of optimal pump scheduling, a fundamental element in pursuing operation optimization of water distribution systems. A combined approach of multi-objective optimization and multi-criteria analysis is herein suggested to first find the Pareto front of non-dominated solutions and then to rank them based on a set of weighted criteria. The Non-Dominated Sorting Genetic Algorithm (NSGA-II) is proposed to solve the multi-objective problem, while the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) is used to achieve the final ranking.
Viaggi nell’immaginario: il turismo virtuale nel sito UNESCO di Tarragona
2023
Le nuove tecnologie hanno trasformato in modo radicale non solo la geografia come disciplina, ma anche le geografie del mondo. Il digitale ha assunto, infatti, un ruolo di mediazione sempre più pervasivo nella produzione dello spazio, come delle conoscenze e degli immaginari geografici. Le possibilità offerte dal virtuale, in particolare, offrono oggi un contributo decisivo nella comunicazione dei significati attribuiti ai luoghi e rispondono in modo sempre più efficace ai bisogni emergenti del settore turistico. Le esperienze di visita mediate dal digitale mirano a coinvolgere i sensi e risultano efficaci quando promuovono immersioni rigorosamente realistiche. Nel quadro di queste riflessi…
Measurements of forward proton production with incident protons and charged pions on nuclear targets at the CERN Proton Synchroton
2010
Measurements of the double-differential proton production cross-section d(2 sigma)/dpd Omega in the range of momentum 0.5 GeV/c <= p < 8.0 GeV/c and angle 0.05 rad <= theta < 0.25 rad in collisions of charged pions and protons on beryllium, carbon, aluminium, copper, tin, tantalum, and lead are presented. The data were taken with the large acceptance HARP detector in the T9 beam line of the CERN Proton Synchrotron. Incident particles were identified by an elaborate system of beam detectors and impinged on a target of 5% of a nuclear interaction length. The tracking and identification of the produced particles was performed using the forward spectrometer of the HARP experiment. Results are o…
Seawater carbonate chemistry and kelp densities and coral coverages at three study locations and photosynthesis and calcification of corals measured …
2021
Ocean warming is altering the biogeographical distribution of marine organisms. In the tropics, rising sea surface temperatures are restructuring coral reef communities with sensitive species being lost. At the biogeographical divide between temperate and tropical communities, warming is causing macroalgal forest loss and the spread of tropical corals, fishes and other species, termed “tropicalization”. A lack of field research into the combined effects of warming and ocean acidification means there is a gap in our ability to understand and plan for changes in coastal ecosystems. Here, we focus on the tropicalization trajectory of temperate marine ecosystems becoming coral-dominated systems…
Macroalgal responses to ocean acidification depend on nutrient and light levels
2015
Ocean acidification may benefit algae that are able to capitalize on increased carbon availability for photosynthesis, but it is expected to have adverse effects on calcified algae through dissolution. Shifts in dominance between primary producers will have knock-on effects on marine ecosystems and will likely vary regionally, depending on factors such as irradiance (light vs. shade) and nutrient levels (oligotrophic vs. eutrophic). Thus experiments are needed to evaluate interactive effects of combined stressors in the field. In this study, we investigated the physiological responses of macroalgae near a CO2 seep in oligotrophic waters off Vulcano (Italy). The algae were incubated in situ …
Seagrass ecosystem response to long-term high CO2 in a Mediterranean volcanic vent
2014
We examined the long-term effect of naturally acidified water on a Cymodocea nodosa meadow growing at a shallow volcanic CO2 vent in Vulcano Island (Italy). Seagrass and adjacent unvegetated habitats growing at a low pH station (pH = 7.65 ± 0.02) were compared with corresponding habitats at a control station (pH = 8.01 ± 0.01). Density and biomass showed a clear decreasing trend at the low pH station and the below- to above-ground biomass ratio was more than 10 times lower compared to the control. C content and delta 13C of leaves and epiphytes were significantly lower at the low pH station. Photosynthetic activity of C. nodosa was stimulated by low pH as seen by the significant increase in…