Feasibility of high-voltage systems for a very long drift in liquid argon TPCs

Designs of high-voltage (HV) systems for creating a drift electric field in liquid argon TPCs are reviewed. In ongoing experiments systems capable of approx. 100 kV are realised for a drift field of 0.5-1 kV/cm over a length of up to 1.5 m. Two of them having different approaches are presented: (1) the ICARUS-T600 detector having a system consisting of an external power supply, HV feedthroughs and resistive voltage degraders and (2) the ArDM-1t detector having a cryogenic Greinacher HV multiplier inside the liquid argon volume. For a giant scale liquid argon TPC, a system providing 2 MV may be required to attain a drift length of approx. 20 m. Feasibility of such a system is evaluated by extrapolating the existing designs.Comment: 8 pages, 13 figures, to appear in Proc. of 1st International Workshop towards the Giant Liquid Argon Charge Imaging Experiment (GLA2010), Tsukuba (Japan), March 201

poly generation capability of a biogas plant with upgrading system

Abstract Biomass, together with other renewable sources, is increasingly used to provide energy to minigrids and distributed generation systems. Particularly, biogas production seems an interesting solution as it can be used to produce electricity, heat and bio-methane (through an upgrading system). In addition, biogas can be relatively easily stored in gasometers to compensate for small request variations. On the other hand, the amounts of heat, electricity and bio-methane produced are strictly dependent one on the others. A poly-generation scenario was considered starting from an existing case study made up of a digester, a 600kWel micro gas turbine and an upgrading system for bio-methane production. An off-design system simulation was carried out to analyze the energy and mass fluxes between plant components as a function of the fraction of the biogas sent to the upgrader. The constraints and relations between heat, electricity and bio-methane production were extensively analyzed. Results show that this system can be a versatile poly-generation unit

Role of fetal MRI in the evaluation of isolated and non-isolated corpus callosum dysgenesis: results of a cross-sectional study

PURPOSE: The aims of this study were to characterize isolated and non-isolated forms of corpus callosum dysgenesis (CCD) at fetal magnetic resonance imaging (MRI) and to identify early predictors of associated anomalies. METHODS: We retrospectively analyzed 104 fetuses with CCD undergoing MRI between 2006 and 2016. Corpus callosum, cavum septi pellucidi, biometry, presence of ventriculomegaly, gyration anomalies, cranio-encephalic abnormalities and body malformations were evaluated. Results of genetic tests were also recorded. RESULTS: At MRI, isolated CCD was 26.9%, the rest being associated to other abnormalities. In the isolated group, median gestational age at MRI was lower in complete agenesis than in hypoplasia (22 vs 28 weeks). In the group with additional findings, cortical dysplasia was the most frequently associated feature (P = 0.008), with a more frequent occurrence in complete agenesis (70%) versus other forms; mesial frontal lobes were more often involved than other cortical regions (P = 0.006), with polymicrogyria as the most frequent cortical malformation (40%). Multivariate analysis confirmed the association between complete agenesis and cortical dysplasia (odds ratio = 7.29, 95% confidence interval 1.51-35.21). CONCLUSIONS: CCD is often complicated by other intra-cranial and extra-cranial findings (cortical dysplasias as the most prevalent) that significantly affect the postnatal prognosis. The present study showed CCD with associated anomalies as more frequent than isolated (73.1%). In isolated forms, severe ventriculomegaly was a reliable herald of future appearance of associated features

Giant Liquid Argon Observatory for Proton Decay, Neutrino Astrophysics and CP-violation in the Lepton Sector (GLACIER)

GLACIER (Giant Liquid Argon Charge Imaging ExpeRiment) is a large underground observatory for proton decay search, neutrino astrophysics and CP-violation studies in the lepton sector. Possible underground sites are studied within the FP7 LAGUNA project (Europe) and along the JPARC neutrino beam in collaboration with KEK (Japan). The concept is scalable to very large masses.Comment: 4 pages, 1 figure, Contribution to the Workshop "European Strategy for Future Neutrino Physics", CERN, Oct. 200

Cell cultures of the Manila clam and their possible use in biomonitoring and species preservation

A huge progress has been achieved in mammalian in vitro technique. Instead, of the many trials to develop marine invertebrate cell cultures, only a few have obtained them and only from few tissues. Since in vitro cell culture of invertebrates could be very useful for many aspects of basic and applied science, in this work we investigate and describe the development of a technique for the establishment of cell cultures from gill, mantle and gonadic tissue of the Manila clam (Ruditapes philippinarum). We maintained viable cultures for up to 25 days. Culture viability and proliferation were tested with 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) and with trypan blue, while an antibody against the ATP-dependent RNA helicase VASA, a protein expressed in the germline, and in multipotent stem cells of some animals, was used to verify the presence of these cell types. Following the described protocol: 1) explant resulted the better source to obtain cell cultures, when compared to enzymatic dissociation; 2) cultures of suspended cells were viable for longer period than adherent cells; 3) cell cultures obtained from tissues sampled in September-October performed better compared to other periods of the year, regarding maintenance and growth; 4) the tissue from which we obtained longer-lived cell cultures was gonadic tissue, especially form samples that show more undifferentiated germ cells and more VASA-stained cells. This study describes the challenges concerning the development of in vitro culture techniques for aquatic invertebrates

Stable operation with gain of a double phase Liquid Argon LEM-TPC with a 1 mm thick segmented LEM

In this paper we present results from a test of a small Liquid Argon Large Electron Multiplier Time Projection Chamber (LAr LEM-TPC). This detector concept provides a 3D-tracking and calorimetric device capable of charge amplification, suited for next-generation neutrino detectors and possibly direct Dark Matter searches. During a test of a 3~lt chamber equipped with a 10$\times$10~cm$^2$ readout, cosmic muon data was recorded during three weeks of data taking. A maximum gain of 6.5 was achieved and the liquid argon was kept pure enough to ensure 20~cm drift (O(ppb)~O$_2$ equivalent).Comment: 7 pages, 6 figures, to appear in Proc. of 1st International Workshop towards the Giant Liquid Argon Charge Imaging Experiment (GLA2010), Tsukuba (Japan), March 201