First results from an aging test of a prototype RPC for the LHCb Muon System

Recent results of an aging test performed at the CERN Gamma Irradiation Facility on a single--gap RPC prototype developed for the LHCb Muon System are presented. The results are based on an accumulated charge of about 0.45 C/cm$^2$, corresponding to about 4 years of LHCb running at the highest background rate. The performance of the chamber has been studied under several photon flux values exploiting a muon beam. A degradation of the rate capability above 1 kHz/cm$^2$ is observed, which can be correlated to a sizeable increase of resistivity of the chamber plates. An increase of the chamber dark current is also observed. The chamber performance is found to fulfill the LHCb operation requirements.Comment: 6 pages, 9 figures, presented at the International Workshop on Aging Phenomena in Gaseous Detectors'', DESY-Hamburg (Germany), October 200

Preliminary results of an aging test of RPC chambers for the LHCb Muon System

The preliminary results of an aging test performed at the CERN Gamma Irradiation Facility on a single--gap RPC prototype developed for the LHCb Muon System are presented. The results are based on an accumulated charge density of 0.42 C/cm^2, corresponding to about 4 years of LHCb running at the highest background rate. We observe a rise in the dark current and noise measured with source off. The current drawn with source on steadily decreased, possibly indicating an increase of resistivity of the chamber plates. The performance of the chamber, studied with a muon beam under several photon flux values, is found to still fulfill the LHCb operation requirements.Comment: 4 pages, 6 figures, presented at RPC2001, VIth Workshop on Resistive Plate Chambers and Related Detectors, November 26-27 2001, Coimbra, Portuga

New results from an extensive aging test on bakelite Resistive Plate Chambers

We present recent results of an extensive aging test, performed at the CERN Gamma Irradiation Facility on two single--gap RPC prototypes, developed for the LHCb Muon System. With a method based on a model describing the behaviour of an RPC under high particle flux conditions, we have periodically measured the electrode resistance R of the two RPC prototypes over three years: we observe a large spontaneous increase of R with time, from the initial value of about 2 MOhm to more than 250 MOhm. A corresponding degradation of the RPC rate capabilities, from more than 3 kHz/cm2 to less than 0.15 kHz/cm2 is also found.Comment: 6 pages, 7 figures, presented at Siena 2002, 8th Topical Seminar on Innovative Particle and Radiation Detectors 21-24 October 2002, Siena, Ital

Synchronous bilateral Warthin's tumours of the parotid glands: a case report

Warthin's tumour is the most frequent monomorphic adenoma of the major salivary glands, representing about 2-15% of all parotid tumours. Most of the multifocal Warthin's tumours are unilateral, whereas bilateral Warthin's tumours are far less common; bilateral Warthin's tumours are metachronous with few synchronous cases having been described in the literature. The Authors present an interesting case of simultaneously occurring bilateral Warthin's tumours growing in the parotid glands

Development of a Digital Twin Model for Real-Time Assessment of Collisione Hazards

The AEC industry is nowadays one of the most hazardous industries in the world. The construction sector employees about 7% of the world’s work force but is responsible for 30-40% of fatalities. As statistics demonstrate, interferences between workers-on-foot and moving vehicles have caused several injuries and fatalities over the years. Despite safety organizational measures, passive safety devices imposed by regulations and efforts from training procedures, scarce improvements have been recorded. Recent research studies propose technology driven approaches as the key solutions to integrate standard health and safety management practices. This is motivated by the evidence that the dynamics of complex systems can hardly be predicted; rather a proactive approach to health and safety is more effective. Current technologies installed on construction equipment can usually react according to a strict logic, such as sending proximity alerts when workers and equipment are too close. Nevertheless, these approaches barely do make informed decisions in real-time, e.g. including the level of reactiveness of the endangered worker. In similar circumstances a digital twin of the construction site, updated by real-time data from sensors and enriched by artificial intelligence, can pro-actively support activities, forecasting dangerous scenarios on the base of several factors. In this paper a laboratory mock-up has been assumed as the test case, supported by a game engine, which is able to replicates the job site for the execution of bored piles. In such a scenario populated by an avatar of a sensor-equipped worker and a virtual driller, a Bayesian network, implemented within the game engine and fed in runtime by sensor data, works out collision probability in real-time in order to send warnings and avoid fatal accidents

u-RANIA: a neutron detector based on \mu -RWELL technology

In the framework of the ATTRACT-uRANIA project, funded by the European Community, we are developing an innovative neutron imaging detector based on micro-Resistive WELL ($\mu$ -RWELL) technology. The $\mu$ -RWELL, based on the resistive detector concept, ensuring an efficient spark quenching mechanism, is a highly reliable device. It is composed by two main elements: a readout-PCB and a cathode. The amplification stage for this device is embedded in the readout board through a resistive layer realized by means of an industrial process with DLC (Diamond-Like Carbon). A thin layer of B$_4$C on the copper surface of the cathode allows the thermal neutrons detection through the release of $^7$Li and $\alpha$ particles in the active volume. This technology has been developed to be an efficient and convenient alternative to the $^3$He shortage. The goal of the project is to prove the feasibility of such a novel neutron detector by developing and testing small planar prototypes with readout boards suitably segmented with strip or pad read out, equipped with existing electronics or readout in current mode. Preliminary results from the test with different prototypes, showing a good agreement with the simulation, will be presented together with construction details of the prototypes and the future steps of the project.Comment: Prepared for the INSTR20 Conference Proceeding for JINS

Approche décisionnelle géospatiale et multicritère dans l’identification des zones potentielles de recharge des eaux souterraines : cas du bassin versant du Mayo Bocki au Nord Cameroun

La présente étude a été effectuée pour déterminer les zones potentielles de recharge des eaux souterraines. Pour ce faire, la démarche  méthodologique était basée sur l’analyse multicritère associée aux techniques géospatiales. Les données utilisées étaient entre autres les images  satellitaires, les fonds cartographiques, les données pluviométriques et les niveaux statiques. Ces données ont permis d’exprimer sous forme de  carte thématique les facteurs régissant la recharge (pente, drainage, lithologie, fracturation, sol, pluviométrie et occupation du sol). L’analyse de  sensibilité par suppression d’un paramètre a permis d’établir l’ordre d’influence suivant : Lit > Sol > AACH > Df > Pl > Pe > Dd > OS. Le croisement de  tous ces paramètres après pondération a conduit à l’élaboration de la carte qui montre que les zones à ort potentiel occupent 3 % de la zone d’étude  pendant que les zones de faible à faible potentialité sont de l’ordre de 58 % dans le bassin. Les zones à potentialité moyenne quant à elles  représentent 39%. Ce support cartographique constitue indéniablement un outil d’aide à la décision pour les gestionnaires de l’eau.   This study was carried out to determine potential groundwater recharge areas. To do this, the methodological approach was based on multi-criteria  analysis associated with geospatial techniques. The data used were, among others, satellite images, base maps, rainfall data and static levels. These  data made it possible to express in the form of a thematic map the factors governing the recharge (slope, drainage, lithology, fracturing, soil,  rainfall and land use). The sensitivity analysis by deletion of a parameter made it possible to establish the following order of influence: Lit > Sol  > AACH > Df > Pl > Pe > Dd > OS. The crossing of all these parameters after weighting led to the development of the map of potential recharge zones  which revealed that the zones with high potential occupy 3% of the study zone while the zones with low to low potentiality are around 58% in  the basin. Areas with average potential represent 39%. This cartographic support is undeniably a decision-making tool for water managers

Antifungal Activity and DNA Topoisomerase Inhibition of Hydrolysable Tannins from Punica granatum L

Punica granatum L. (pomegranate) fruit is known to be an important source of bioactive phenolic compounds belonging to hydrolysable tannins. Pomegranate extracts have shown antifungal activity, but the compounds responsible for this activity and their mechanism/s of action have not been completely elucidated up to now. The aim of the present study was the investigation of the inhibition ability of a selection of pomegranate phenolic compounds (i.e., punicalagin, punicalin, ellagic acid, gallic acid) on both plant and human fungal pathogens. In addition, the biological target of punicalagin was identified here for the first time. The antifungal activity of pomegranate phenolics was evaluated by means of Agar Disk Diffusion Assay and minimum inhibitory concentration (MIC) evaluation. A chemoinformatic analysis predicted for the first time topoisomerases I and II as potential biological targets of punicalagin, and this prediction was confirmed by in vitro inhibition assays. Concerning phytopathogens, all the tested compounds were effective, often similarly to the fungicide imazalil at the label dose. Particularly, punicalagin showed the lowest MIC for Alternaria alternata and Botrytis cinerea, whereas punicalin was the most active compound in terms of growth control extent. As for human pathogens, punicalagin was the most active compound among the tested ones against Candida albicans reference strains, as well as against the clinically isolates. UHPLC coupled with HRMS indicated that C. albicans, similarly to the phytopathogen Coniella granati, is able to hydrolyze both punicalagin and punicalin as a response to the fungal attack. Punicalagin showed a strong inhibitory activity, with IC50 values of 9.0 and 4.6 µM against C. albicans topoisomerases I and II, respectively. Altogether, the results provide evidence that punicalagin is a valuable candidate to be further exploited as an antifungal agent in particular against human fungal infections

Cytotoxic flavonoids and other constituents from the stem bark of Ochna schweinfurthiana

Seven flavonoids, hemerocallone (1), 6,7-dimethoxy-3′,4′-dimethoxyisoflavone (2), amentoflavone (4), agathisflavone (6), cupressuflavone (8), robustaflavone (9) and epicatechin (10), together with three other compounds, lithospermoside (3), β-D- fructofuranosyl-α-D-glucopyranoside (5) and 3β-O-D-glucopyranosyl-β-stigmasterol (7), were isolated from the ethyl acetate extract of the stem bark of Ochna schweinfurthiana F. Hoffm. All the compounds were characterised by spectroscopic and mass spectrometric methods, and by comparison with literature data. Cytotoxicity of the extracts and compounds against cervical adenocarcinoma (HeLa) cells was evaluated by MTT assay. Compounds 4 and 6 exhibited good cytotoxic activity, with IC50 values of 20.7 and 10.0 μM, respectively