APPLICATION OF INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS ON ICE CORE SAMPLES

A first application of INAA (Instrumental Neutron Activation Analysis) to ice core sample

Short-term effects of game on visual-spatial attention: an empirical research on preschool children

openIl presente elaborato riguarda lo studio condotto presso il laboratorio di Neuroscienze cognitive e dello sviluppo del Dipartimento di Psicologia Generale dell'Università degli Studi di Padova. L’obiettivo della ricerca è stato quello di valutare gli effetti a breve termine del gioco sulle competenze cognitive e sociali dei bambini, concentrandosi in particolare sull’attenzione visuo-spaziale. Inoltre, si voleva valutare anche il ruolo del divertimento e delle emozioni sulle funzioni cognitive coinvolte nei futuri apprendimenti scolastici. L’ipotesi di partenza è stata che il gioco producesse uno stato di attivazione capace di portare ad un miglioramento delle prestazioni e delle capacità cognitive. Per raggiungere lo scopo è stata svolta una ricerca in doppio cieco in cui i dati sono stati raccolti in tre incontri: un momento di baseline seguito da due sessioni di gioco di 30 minuti ciascuna, la prima con un videogioco d’azione, la seconda, invece con un gioco da tavolo tradizionale, dopo le quali i bambini sono stati nuovamente valutati. Lo studio ha coinvolto 45 bambini di età prescolare presso due scuole dell’infanzia ai quali sono stati somministrati un test di valutazione del funzionamento cognitivo generale, un compito di ricerca visiva per valutare le capacità visuo-attentive ed un questionario sulle emozioni post gioco. Dall’analisi dei risultati è emerso che il Central Executive Network, che controlla la ricerca visiva complessa, è stato disturbato dal gioco che, invece, ha portato ad una maggiore efficienza dei centri automatici di elaborazione del Salience Network. Tuttavia, gli studi suggeriscono che, in seguito al momento stressante generato dall'esperienza ludica, si verifica una riallocazione delle risorse energetiche a favore della rete esecutiva di controllo che porterebbe ad un potenziamento delle funzioni cognitive a lungo termine

JUNO Conceptual Design Report

The Jiangmen Underground Neutrino Observatory (JUNO) is proposed to determine the neutrino mass hierarchy using an underground liquid scintillator detector. It is located 53 km away from both Yangjiang and Taishan Nuclear Power Plants in Guangdong, China. The experimental hall, spanning more than 50 meters, is under a granite mountain of over 700 m overburden. Within six years of running, the detection of reactor antineutrinos can resolve the neutrino mass hierarchy at a confidence level of 3-4$\sigma$, and determine neutrino oscillation parameters $\sin^2\theta_{12}$, $\Delta m^2_{21}$, and $|\Delta m^2_{ee}|$ to an accuracy of better than 1%. The JUNO detector can be also used to study terrestrial and extra-terrestrial neutrinos and new physics beyond the Standard Model. The central detector contains 20,000 tons liquid scintillator with an acrylic sphere of 35 m in diameter. $\sim$17,000 508-mm diameter PMTs with high quantum efficiency provide $\sim$75% optical coverage. The current choice of the liquid scintillator is: linear alkyl benzene (LAB) as the solvent, plus PPO as the scintillation fluor and a wavelength-shifter (Bis-MSB). The number of detected photoelectrons per MeV is larger than 1,100 and the energy resolution is expected to be 3% at 1 MeV. The calibration system is designed to deploy multiple sources to cover the entire energy range of reactor antineutrinos, and to achieve a full-volume position coverage inside the detector. The veto system is used for muon detection, muon induced background study and reduction. It consists of a Water Cherenkov detector and a Top Tracker system. The readout system, the detector control system and the offline system insure efficient and stable data acquisition and processing.Comment: 328 pages, 211 figure

Steps towards the hyperfine splitting measurement of the muonic hydrogen ground state: pulsed muon beam and detection system characterization

The high precision measurement of the hyperfine splitting of the muonic-hydrogen atom ground state with pulsed and intense muon beam requires careful technological choices both in the construction of a gas target and of the detectors. In June 2014, the pressurized gas target of the FAMU experiment was exposed to the low energy pulsed muon beam at the RIKEN RAL muon facility. The objectives of the test were the characterization of the target, the hodoscope and the X-ray detectors. The apparatus consisted of a beam hodoscope and X-rays detectors made with high purity Germanium and Lanthanum Bromide crystals. In this paper the experimental setup is described and the results of the detector characterization are presented.Comment: 22 pages, 14 figures, published and open access on JINS

Artificial and natural radionuclides in cryoconite as tracers of supraglacial dynamics: Insights from the Morteratsch glacier (Swiss Alps)

Cryoconite, a sediment found on the surface of glaciers, is known for its ability to accumulate radionuclides. New data on cryoconite from the Morteratsch glacier (Switzerland) are presented to shed light on the mechanisms that control the distribution of radioactivity in cryoconite. Among the radionuclides detected in our samples, we have identified 108mAg, an artificial species which has never been observed in terrestrial environments before. This finding supports that cryoconite has an extraordinary ability to accumulate radioactivity. Our results also show that the radioactivity of cryoconite from a single glacier is far from uniform. Both the absolute amount of radioactivity and the relative contribution of single radionuclides are highly variable in samples from the Morteratsch glacier. To investigate the processes responsible for such variability, we have explored the correlation between radionuclides, organic and inorganic carbon fractions and the morphological features of cryoconite deposits. We have found that the degree of connection between cryoconite and supraglacial hydrology is particularly important, since it strongly influences the accumulation of radionuclides in cryoconite. Cryoconite holes connected with supraglacial channels are rich in cosmogenic 7Be; in contrast, poorly connected deposits are rich in artificial fallout radionuclides and elemental carbon. The very different half-lives of 7Be and artificial radionuclides allowed us to discuss our findings in relation to the age and maturity of cryoconite deposits, highlighting the potential use of radionuclides to investigate hydrological supraglacial processes and material cycling at the surface of glaciers