Free and Dissolved Gases in Castrocaro Spa Waters (Italy)

Free and dissolved gases in cold water samples from the Castrocaro spa, Northern Italy, were analyzed for their chemical composition. These gases were interpreted as the result of the binary mixing between a N2- and a CH4-rich component. CO2 is generally a minor constituent. N2/Ar ratios below the air typical value suggest that air saturated water (ASW) is the most likely source of atmospheric-derived components. This atmospheric end-member is predominant in low-salinity waters. Conversely, CH4-enriched gases are mainly associated with brackish to saline waters. The occurrence of minor amounts of light hydrocarbons (C2-C3) indicates a predominant biogenic origin of CH4. The He isotopic composition of the CH4-richest sample (3He/4He = 0.22 Ra) is in the range of values measured for cold seeps and mud volcanoes along the Northern Apennines foothills, and indicates a predominant crustal origin of this gas

Analisi e ottimizzazione di uno scheduler Round Robin per unita' a disco

Lo scopo di questa tesi e’ quello di analizzare e ottimizzare uno scheduler per unita’ a disco in ambiente FreeBSD, che dia garanzie di servizio per l'utente e che assicuri equita’ di utilizzo di tale risorsa da parte dei processi che hanno bisogno di accedervi. Lo scheduler e’ realizzato mediante l'ausilio di geom_sched, che e’ un modulo GEOM e come tale ne sfrutta le capacita’ nel manipolare semplicemente le richieste di I/O, indipendentemente dal disco utilizzato. Nello specifico si va ad analizzare, sia a livello funzionale che prestazionale, l'implementazione di un algoritmo Round Robin, che ha la caratteristica di effettuare prelazione sul processo in esecuzione, a differenza del classico algoritmo Elevator offerto da FreeBSD. I test effettuati, dopo aver portato a galla e permesso la correzione di un errore implementativo dell’algoritmo, hanno dimostrato che nel caso di accesso multiutente le prestazioni in lettura subiscono un significativo incremento, mentre in scrittura, nonostante si abbia una lieve riduzione delle prestazioni, viene garantita una maggiore equita’ di servizio

Occurrence of ochratoxin a in different types of cheese offered for sale in Italy

The detection of Ochratoxin A (OTA) in the milk of ruminants occurs infrequently and at low levels, but its occurrence may be higher in dairy products such as cheese. The aim of this study was to investigate the presence of OTA in cheeses purchased in the metropolitan city of Bologna (Italy) and the surrounding area. For the analysis, a LC-MS/MS method with a limit of quantification (LOQ) of 1 µg/kg was used. OTA was detected in seven out of 51 samples of grated hard cheese (concentration range 1.3–22.4 µg/kg), while it was not found in the 33 cheeses of other types which were also analysed. These data show a low risk of OTA contamination for almost all types of cheese analysed. To improve the safety of cheese marketed in grated form, more regulations on cheese rind, which is the part most susceptible to OTA-producing moulds, should be implemented or, alternatively, producers should consider not using the rind as row material for grated cheese. It would be interesting to continue these investigations particularly on grated hard cheeses to have more data to update the risk assessment of OTA in cheese, as also suggested by EFSA in its 2020 scientific opinion on OTA

Occurrence of Histamine in Commercial Cat Foods under Different Storage Conditions

In fish-based foods, one of the effects of inappropriate storage can be the formation of biogenic amines. Among these, histamine is considered one of the most toxic. The purpose of the present study is to assess the occurrence of histamine in fish-based pet foods, and to evaluate the changes in histamine content during storage at different temperatures. For the analysis, an LC-MS/MS method was used. Fifty-eight pet foods were purchased, and an aliquot of them was analyzed just after opening the packages. Histamine was detected in 12 samples and concentrations ranged from 1.5 to 30.1 mg/kg. The remaining of each positive sample was divided into seven subsamples. One of them was used as a control sample and kept at -20 °C, while the other six were exposed to different environmental conditions. Samples exposed to room temperature showed no significant changes in histamine levels, while samples exposed to high temperatures showed significant increases in histamine content. Finally, samples exposed to refrigerator temperature showed a slight decrease in histamine levels. Under the experimental conditions, the EU limit of 100 mg/kg established for fishery products was never exceeded. These results seem to indicate a low risk of histamine intoxication in cats fed fish-based pet food

Architecture and First Characterization of the Microstrip Silicon Detector Data Acquisition of the FOOT experiment

Oncological hadrontherapy is a novel technique for cancer treatment that improves over conventional radiotherapy by having higher effectiveness and spatial selectivity. The FOOT (FragmentatiOn Of Target) experiment studies the nuclear fragmentation caused by the interactions of charged particle beams with patient tissues in Charged Particle Therapy. Among the several FOOT detectors, the silicon Microstrip Detector is part of the charged-ions-tracking magnetic spectrometer. The detector consists of three x-y planes of two silicon microstrip detectors arranged orthogonally between each other to enable tracking capabilities. Ten analog buffer chips and fi ve ADCs read out each detector. A Field-Programmable Gate Array collects the output of the ADCs of an x-y plane, possibly processes the data, and forms a packet to be sent to the experiment central data acquisition. This data acquisition system shall withstand the trigger rate and detector’s throughput at any time. In this work, we discuss the architecture of the data acquisition system—in particular of the silicon microstrip detector one—and the fi rst results obtained from the x-y plane’s prototype

Characterization and possible astrophysics applications of UV sensitive SiPM devices

The National Institute of Nuclear Physics (INFN) is involved in the R&D of Silicon Photomultiplier (SiPM) sensors optimized to detect near-UV (NUV) photon radiation in low-intensity photons and high-precision time mesaurements, in collaboration with the Bruno Kessler Foundation (FBK). The performances of 6×6 mm2 NUV-HD SiPMs with 30×30 μm2 microcell area and the possible prospects for production and packaging of multi-sensor modules for astrophysical applications are discussed in this paper

Fabrication of a hydrogenated amorphous silicon detector in 3-d geometry and preliminary test on planar prototypes

Hydrogenated amorphous silicon (a-Si:H) can be produced by plasma-enhanced chemical vapor deposition (PECVD) of SiH4 (silane) mixed with hydrogen. The resulting material shows outstanding radiation hardness properties and can be deposited on a wide variety of substrates. Devices employing a-Si:H technologies have been used to detect many different kinds of radiation, namely, minimum ionizing particles (MIPs), X-rays, neutrons, and ions, as well as low-energy protons and alphas. However, the detection of MIPs using planar a-Si:H diodes has proven difficult due to their unsatisfactory S/N ratio arising from a combination of high leakage current, high capacitance, and limited charge collection efficiency (50% at best for a 30 µm planar diode). To overcome these limitations, the 3D-SiAm collaboration proposes employing a 3D detector geometry. The use of vertical electrodes allows for a small collection distance to be maintained while preserving a large detector thickness for charge generation. The depletion voltage in this configuration can be kept below 400 V with a consequent reduction in the leakage current. In this paper, following a detailed description of the fabrication process, the results of the tests performed on the planar p-i-n structures made with ion implantation of the dopants and with carrier selective contacts are illustrated