7,879 research outputs found
Measurement of the t-tbar differential cross-section in pp collisions at radq(s) = 7 TeV
No full textThree measurements of t-tbar differential cross section at √s = 7 TeV
in pp collisions at the Large Hadron Collider (LHC) are presented: with respect to transverse momentum, mass and rapidity of the ttbar system. Top pair production cross section measurements can be used to test perturbative QCD. In particular, with the high statistics collected in LHC it is possible to measure the differential cross section and look for possible deviations from the Standard Model. The results presented here have been obtained using part of the data collected by the ATLAS detector during the 2011 corresponding to an integrated luminosity of ∼
2fb^(−1). The extension of the analysis to the full 2011 data sample (∼
5fb(−1)) is ongoing. The events are selected with a cut-based approach in the single lepton plus jets decay channel, where the lepton can be either an electron or a muon. The final background-subtracted distributions are corrected for the distortion introduced by the detector and selection effects using unfolding methods. The measurements are dominated by the systematic uncertainties and show a good agreement with the Standard Model predictions
Ottimi risultati dal controllo e rilevamento dell’illuminazione e del microclima della sala principale del Museo di Carpineto Romano
No full text
Método do fluxo de massa na avaliação do intemperismo de fontes de contaminação em águas subterrâneas
No full textTCC(graduação) - Universidade Federal de Santa Catarina. Centro Tecnológico. Engenharia Sanitária e Ambiental.A água subterrânea exerce um papel fundamental na distribuição de água potável para a população. No entanto, esse recurso natural é constantemente ameaçado por contaminações oriundas de atividades humanas. Um dos casos mais alarmantes, é a contaminação pelo vazamento de derivados de petróleo, como ocorre em tanques de armazenamento nos postos de gasolina. Os riscos da gasolina na água subterrânea se traduzem na presença de hidrocarbonetos monoaromáticos, conhecidos como BTEX, os quais são altamente tóxicos mesmo em baixas concentrações. Para se evitar os impactos à saúde humana provenientes desse tipo de contaminação, é necessário o emprego de tecnologias de remediação que, muitas vezes, demandam um alto dispêndio de recursos financeiros. Nesse contexto, a atenuação natural monitorada se mostra uma estratégia viável, visto que os contaminantes são degradados e dissipados por processos naturais. Existem diferentes métodos para se avaliar a redução de massa dos contaminantes no meio. Este estudo avaliou o intemperismo de fontes de contaminação, em aquíferos impactados por derramamentos de misturas de gasolina e etanol, através do método do fluxo de massa. Neste trabalho, investigou-se a utilização do método do fluxo de massa como alternativa eficaz e econômica na avaliação do intemperismo de fontes, comparando-o com o método de interpolação espacial. A base de dados empregada foi referente ao monitoramento periódico, durante 10 anos, de um derramamento controlado de gasolina comercial brasileira na área experimental da Fazenda da Ressacada, propriedade da Universidade Federal de Santa Catarina. Os resultados apontaram a ocorrência da atenuação dos compostos BTEX na região da fonte de contaminação, evidenciando os efeitos positivos e negativos da presença do etanol. O método do fluxo de massa foi eficaz em determinar a tendência de variação da massa e o comportamento de expansão e retração das plumas dos compostos BTEX ao longo do tempo. Ele pode ser considerado uma alternativa econômica e eficaz para a avaliação qualitativa do intemperismo de fontes. Entretanto, o método não se mostra eficaz para avaliações quantitativas que impliquem na recuperação da massa derramada dos contaminantes
The Inextricable Intertwining of the Firm, the Platform and the Customer: the Case of a Social Media Platform for Innovation
No full textThe aim of this article is to explore the relationship between human actors and technology in the context of a social media platform, developed by a leading Italian firm in the food industry. In order to address these issues, we adopt a theoretical approach that is deeply rooted in Pickering's “mangle” theory, and Jones' subsequent metaphor of “double dance of agency”. We developed a longitudinal case study with two rounds of interviews with mar-keting and R&D managers. The paper provides three main theoretical contri-butions. It provides detailed attention to the co-evolution over time of hu-man-material entanglement, an aspect that papers in this area often omit. It provides a clear picture of a series of inter-related emergent phenomena, en-tangling managers, users, and the social media platform. It introduces fur-ther dimensions in the dancing metaphor. On the practical side, the double dance of agency perspective on this platform's evolution also offers useful insight for practitioners
New insights into long-period (>1 s) seismic amplification effects in deep sedimentary basins: A case of the po plain basin of Northern Italy
No full textThis study investigates and quantifies the influence of the shallower deposits (down to few hundreds of meters) of the Po Plain sedimentary basin (northern Italy) on the long-period component (i.e., 1 s < T < 3 s) of seismic groundmotion, inwhich amplification effects due to the soft sediments above seismic bedrock were observed.A new seismostratigraphic model of the shallow deposits of the entire basin is provided with an unprecedented detail by taking advantage of recently acquired geophysical data. The seismostratigraphic model is used to simulate the groundmotion amplification in the Po Plain bymeans of extensive 1D ground response analysis. Results are compared with seismic observations available at a number of sites equipped with borehole seismic stations, where earthquakes have been recorded both at the surface and at the seismic bedrock depth. Despite the general agreement with observations concerning the seismic resonance frequencies, our model may fail in capturing the amplitude of the actual seismic amplification of the basin in the long-period range. We observe that 3D basin effects related to surface waves generated at the edge of the basin may play a significant role in those zones where seismic hazard is controlled by distant sources. In these cases, 1Dmodeling leads to average underestimations of 30%, up to a maximum of 60%. The amplification functions need to be corrected for a basin-effects correction term, which in this case is provided by the ground-motion prediction equation of the study area. The corrected amplification functions agree with the empirical observations, overcoming the uneven distribution of the recording stations in strong-motion datasets. These results should be taken into account in future seismic microzonation studies in the Po Plain area, where the 1D approach is commonly adopted in ground response analyses, and in site-specific seismic hazard assessments aimed at the design of structures that are sensitive to the long-period component of seismic groundmotion (e.g., long-span bridges and tall buildings)
Portatori di tirso
No full textL'articolo è dedicato allo studio delle scene che compaiono sui due lati di un cratere etrusco conservato nel Museo di Montepulciano e datato alla fine del V sec. a.C. Si tratta nei due casi del defunto che si avvia all'Aldilà munito del tirso, strumento dionisiaco
Pamphagidae (Orthoptera: Caelifera) of North Africa: key to genera and the annotated check-list of the species.
No full textAt least 95 species of Pamphagidae belonging to 17 genera are known in North Africa. Taxonomic status is fairly known, with
some exception, mainly due to scarcity of available specimens of some genera in museums and collections. In this paper, the
author proposes a new key to genera and reports the annotated list of all the known species, based on specimens examined in
different European museums. Concerning the subfamily Thrinchinae, he proposes to consider only the following species of the
genus Tmethis: T. cisti, T. harterti new status, T. maroccanus and T. pulchripennis. He also considers Neotmethis bidentatus
synonym of T. harterti, and the three newly described species of the genus Tuarega as synonyms of T. insignis. In addition, he
proposes to remove Batrachotettix elephas from the synonyms of T. insignis, because its description consents to establish that it
belongs to a South African Porthetinae, not to a Thrinchinae. With regard to the subfamily Pamphaginae, the author recognizes
the presence in North Africa of three tribes, until now containing 90 species: Finotiini, Pamphagini and Euryparyphini; Amigus
is definitively considered a valid genus within the tribe Pamphagini, with the only species A. nigroadspersus. Additionally, he
proposes a new key to species of the genus Paracinipe. He considers Paracinipe theryi as a valid species; previously it has been
listed as subspecies of P. dolichocera. He also establishes that Acinipe calabra of Italy is the same taxon living in North Africa.
Further, he describes Euryparyphes rungsi new species from Middle Atlas, and Paraeumigus lopezi new species from West
Morocco, and synonymizes Eunapiodes granosus rungsi with E. atlantis. Finally, he reports biometric data of the genera
Tmethis, Paracinipe, Paraeumigus and Eunapiodes
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