Lifetime of Magnetically Trapped Antihydrogen in ALPHA

How long antihydrogen atoms linger in the ALPHA magnetic trap is an important characteristic of the ALPHA apparatus. The initial trapping experiments in 2010 [1] were conducted with 38 detected antiatoms confined for 172 ms and in 2011 [2] with seven for 1000 s. Long confinement times are necessary to perform detailed frequency scans during spectroscopic measurements. An analysis carried out, using machine learning methods, on more than 1000 antiatoms confined for several hours in the ALPHA-2 magnetic trap, yields a preliminary lower limit to the lifetime of 66 hours. Hence this observation suggests that the measured confinement time of antihydrogen is extended by more than two orders of magnitude. [1] Andresen, G. B. et al. (ALPHA collaboration), Nature 468, 673-676 (2010) [2] Andresen, G. B. et al. (ALPHA collaboration), Nature Phys. 7, 558-564 (2011

The Influence of short-term land use change on soil evolution in the centre-south coastal areas of Sardinia

The land use change in short-term (time and space) in the Mediterranean context can be induced by phenomena like destruction of the autochthonous plant species, land abandonment, overgrazing, fire, urbanization (above all for touristic purpose), etc. These phenomena can lead to soil’s degradation conditions causing a loss of physical and biological productivity and the consequent emphasis in desertification processes. Desertification is considered one of the biggest environmental problems in Mediterranean areas (ICCD, 1994), and Sardinia is one of the most affected regions in Europe (UNEP, 1992; Imeson and Emmer, 1992). In Sardinia changes happened during the last decades (such as industrialization, coastal urban areas expansion, etc.) have often resulted in repercussions on the environmental ecosystems and foremost on soils. An important decrease of fertile lands and a consequent increase of marginal and unproductive areas have been observed; this fact has taken to manifest environmental and economic repercussions. In Sardinia such degradation phenomena are particularly evident in coastal areas, where the uncontrolled urbanization and the natural touristic vocation represent relevant impact types. In fact, in 1897 km of coastal lands (500 km are represented by dunal systems) 40% is subjected to deep erosion phenomena, that often are caused by wrong management actions. For these reasons the knowledge of their nature and expansion is of primary importance to carry out correct choices in land use. This work shows an example of a comparative investigation on coastal ecosystems particularly under human pressure. The investigated areas are located along the Centre–North coast of Sardinia. Particularly they concern: a) soils on limestone formations, forestry live oak cover and pasture land use (goat and swine); b) soils on fixed dunes, reforestation with pine and touristic-recreational land use foremost. In the areas several soil profiles have been realized to investigate the influence of the land use change, occurring in short-term in both places, on the evolution and degradation processes of soils

A Quali-quantitative evaluation approach to pedodiversity by multivariate analysis: introduction to the concept of "pedocharacter"

A model has been developed for the interpretation of the complexity of pedological systems; this is referred to as “pedocharacter”. The main aim of the model was to reduce the variables able to define soils and their relationships with the environment through the following quali-quantitative approach: i) definition of a fair number of qualitative characters; and ii) development of an analytic function, defined as “Land Relevance of the Factor”

New Trends in Homeric Scholarship Homer’s Name, Underworld and Lyric Voice

This paper hosts three case-studies that are meant to be representative of paradigm-shifting trends in Homeric Studies and to cater to specialists and non-specialists alike. Boosted by new archaeological findings and by an increased awareness of Homer’s Near-Eastern entanglements, the “historicity” of the poems has regained centre stage. Against this backdrop, Andrea Debiasi develops a persuasive interpretation of Homer’s name, whose meaning points to the performative-agonistic dimension of Homeric poetry in the context of the clashes that characterized Euboia in the archaic age. By contrast, George Gazis focuses on the one aspect of the Homeric world that cannot possibly be mapped onto space and history, namely Hades. The underworld is unfathomable even for the gods, which accounts for its potential as a trigger of poetic invention. No less than Debiasi’s, this approach resonates with recent scholarship: a return to “history” is often complemented by an opposite, but fully compatible, “symbolic” trend, which has unraveled the systematic juxtaposition, in Homer’s world, between “history” and symbolic constructs. Finally, Cecilia Nobili shows that Homeric epics builds on pre-existing poetic genres such as elegy, although the earliest extant examples of the latter date to a later time. The claim that lyric poetry emerges though a confrontation with epics, then, is no less plausible than its opposite. One more important consequence of Nobili’s approach is that the “subjective” turn scholars have long recognized in Hellenistic and Roman epics is in fact firmly grounded in Homer himself.L’articolo presenta un saggio di alcune fra le tendenze che più hanno rinnovato gli studi omerici negli ultimi anni e che più possono interessare anche i non specialisti. Nel quadro del rinnovato interesse per la “storicità” dei poemi, favorita da nuove scoperte archeologiche e da una migliore conoscenza degli stretti rapporti fra epica greca e tradizioni vicino-orientali, Andrea Debiasi propone una convincente interpretazione del nome di Omero, che indica in lui il “performer-agonista” per eccellenza e ne proietta la biografia fantastica sullo sfondo delle guerre che segnarono l’Eubea in età arcaica. Quello che in Omero è chiaramente fuori dalla carta geografica e dal tempo storico è invece oggetto dello studio di George Gazis, dedicato all’Ade: un mondo invisibile agli stessi dèi, sottratto al tempo allo spazio e quindi luogo di incubazione per la consapevole invenzione, anche poetica – negli studi recenti, il ritorno della “storia” è andato di pari passo con la tendenza opposta ma perfettamente compatibile di ritrovare nei poemi una giustapposi-zione continua e sistematica fra realia e rappresentazioni simboliche. Infine, Cecilia Nobili mostra che l’epica omerica presuppone l’esistenza di generi poetici, come l’elegia, che sono attestati solo in epiche più tarde: dire che la lirica nasce da un confronto oppositivo con l’epica si rivela quindi non più vero del suo contrario, e la svolta “soggettiva” spesso attribuita all’epica ellenistica e poi romana ha in realtà un saldo ancoraggio nello stesso Omero

Categorizing basic factors driving soil genesis, pedovariability and plant assemblages in Mediterranean Temporary Wetlands (TWs)

A research was carried out in six Temporary Wetlands (TWs), located in north-western Sardinia (Italy), with the aim to categorize the basic factors driving and linking soil genesis and plant assemblages in Mediterranean basin

Testing CPT And Antigravity With Trapped Antihydrogen At ALPHA

High precision antihydrogen experiments allow tests of fundamental theoretical descriptions of nature. These experiments are performed with the ALPHA apparatus, where ultra-low energy antihydrogen is produced and confined in a magnetic trap. Antihydrogen spectroscopy is of primary interest for precision tests of CPT invariance - one of the most important symmetries of the Standard Model. In particular, the 1S-2S transition frequency in hydrogen is the most precisely known quantity in Physics thus measuring the same quantity with antihydrogen provides the most stringent comparison between matter and antimatter. Antimatter gravity is an open experimental question that deserves to be directly addressed in order to test the foundation of the General Theory of Relativity. Methods to produce, trap, detect and identify antihydrogen are presented in this work, alongside the first high precision measurement of an antihydrogen property, i.e., the electric neutrality of an antiatom. This measurement also constitutes a three-fold improvement to the measured value of the positron charge. The focus is then shifted to the proposed experiment to measure the antihydrogen gravitational acceleration, with particular attention to the antihydrogen detector

Seeing through Plato’s Looking Glass. Mythos and Mimesis from Republic to Poetics

This paper revisits Plato’s and Aristotle’s views on mimesis with a special emphasis on mythos as an integral part of it. I argue that the Republic’s notorious “mirror argument” is in fact ad hominem: first, Plato likely has in mind Agathon’s mirror in Aristophanes’ Thesmoforiazusae, where tragedy is construed as mimesis; second, the tongue-in-cheek claim that mirrors can reproduce invisible Hades, when read in combination with the following eschatological myth, suggests that Plato was not committed to a mirror-like view of art; third, the very omission of mythos shows that the argument is a self-consciously one-sided one, designed to caricature the artists’ own pretensions of mirror-like realism. These points reinforce Stephen Halliwell’s claim that Western aesthetics has been haunted by a «ghostly misapprehension» of Plato’s mirror. Further evidence comes from Aristotle’s “literary” (as opposed to Plato’s “sociological”) discussion: rather than to the “mirror argument”, the beginning of the Poetics points to the Phaedo as the best source of information about Plato’s views on poetry

Pedotechniques strategies to improve soil resilience against the impact of irrigation by municipal wastewater: using zeolitized tuffs as soil amendments

A research was started aiming at evaluating the possible use of natural zeolites as exchange conditioners to improve and make durable the soil resilience against the adverse effects of the use of anomalous wastewater, for irrigation purposes. To satisfy such aims, two zeolitized tuffs (ZTs), viz. a Neapolitan yellow tuff (NYT) and a clinoptilolite bearing tuff (ZCL), were tested as pedotechnical materials to improve soil resilience against the impact of treatment by a ‘dirty’ municipal wastewater (DMW)