High Resolution RPC's for Large TOF Systems

Here we report on a particular type of RPC that presents up to 99% efficiency for minimum ionizing particles and a very sharp time resolution, below 50 ps sigma in the most optimized conditions. Our 9 cm2 cells, made with glass and metal electrodes that form accurately spaced gaps of a few hundred micrometers, are operated at atmospheric pressure in non-flammable gases and can be economically produced in large quantities, opening perspectives for the construction of large area time of flight systems.Comment: 10 pages, 8 figure

The Development and Study of High-Position Resolution (50 micron) RPCs for Imaging X-rays and UV photons

Nowadays, commonly used Resistive Plate Chambers (RPCs) have counting rate capabilities of ~10E4Hz/cm2 and position resolutions of ~1cm. We have developed small prototypes of RPCs (5x5 and 10x10cm2) having rate capabilities of up to 10E7Hz/cm2 and position resolutions of 50 micron("on line" without application of any treatment method like "center of gravity"). The breakthrough in achieving extraordinary rate and position resolutions was only possible after solving several serious problems: RPC cleaning and assembling technology, aging, spurious pulses and afterpulses, discharges in the amplification gap and along the spacers. High-rate, high-position resolution RPCs can find a wide range of applications in many different fields, for example in medical imaging. RPCs with the cathodes coated by CsI photosensitive layer can detect ultraviolet photons with a position resolution that is better than ~30 micron. Such detectors can also be used in many applications, for example in the focal plane of high resolution vacuum spectrographs or as image scanners.Comment: 6 pages, 5 figures, other comment

High Resolution Timing of MIPs with RPCs

Proposal of abstract for RPC99, Bari, Italy, 28-29 October 1999. RPCs made with glass and metal electrodes, forming accurately spaced gaps of a few hundred micrometres, have reached timing accuracies below 70 ps with efficiencies above 95This type of detector, operating at atmospheric pressure with non-flammable gases, seems well suited for large area TOF sytems, providing performances comparable to the existing scintillator-based TOF technology but with significantly lower price per channel.In this work we describe the principles of operation and the performance of several chamber configurations

Improving count rate capability of timing RPCs by increasing the detector working temperature

This communication describes test beam results, focusing on detection efficiency and timing precision, of common float glass timing Resistive Plate Chambers (tRPCs) exposed to a $2.7$~GeV proton beam and operated at above ambient temperature in order to increase the count rate capability of the chambers, by exploiting the reduction in the resistivity of the glass electrodes. Results suggest that the count rate capability can be extended at least up to $1500~Hz/cm^2$ when the detector is operated at $40.6^{\circ}$C without noticeable loss of efficiency or timing precision degradation with values of $90\%$ and $100$~ps, respectively, for this specific timing RPC arrangement.Comment: to be published in Proceedings of 15th Pisa Meeting on Advanced Detector

The Role of Volunteered Geographic Information towards 3D Property Cadastral Systems (2): A Purpose Driven Web Application

VGI has not proved to be readily suitable to replace well-established accurate methods and technologies such as those of full standard cadastral surveys. Even so, VGI potentialities as relevant source of geospatial data have been widely acknowledged. As such, some authors have defended that VGI may in fact play an important role such as at a local cadastral jurisdiction level towards local spatial data infrastructures. As far as property cadastre is concerned, the full extent 3D complexity inside a property is in many instances only known to their occupants, thus making crowd sourcing perhaps the only economically feasible approach for its capture. While the crowd cannot be expected to conduct a full cadastral survey, it may be possible to ask them to indicate at least the location of complex 3D situations and thus to facilitate local authorities’ understanding of the extent of some cadastral issues. As such, it was argued in our previous work that geoinformation from the crowd might in fact be taken into account as an interim step before a full surveyed 3D cadastre is eventually achieved. As such, possible room for VGI in the context of 3D cadastre was discussed, and a hierarchical framework of levels of data acquisition to be used at local cadastral jurisdiction level was proposed. Such framework is revisited in this paper.Given context above, this paper focuses primarily on two aspects. Firstly, to review technical requirements of the official cadastral process in Portugal in order to identify which sorts of cadastral data are likely to be acquirable/not acquirable through VGI. Secondly, to design and to implement the prototype of a web-based application (IGV3Dcad) envisaged for general public usage to flag different land and property ownership situations. Having information about the extent of the 2D/3D issue is also fundamental to making a decision as to whether a 3D cadastral approach is actually needed and hence to further invest resources in even more expensive 3D survey

Dataset associated with "Artefactual depiction of predator–prey trophic linkages in global soils"

This database contains results from an exploratory literature search (carried out over May-July 2020) to detect the trophic linkages that departed from an initial set of 36 common soil-dwelling invertebrate taxa (i.e., in the capacity of either predator or prey items). It consists of a non-exhaustive list of macro-, meso- and micro-fauna which did not necessarily include all common soil fauna (e.g., Amphipoda). For each literature record, we logged the resource and consumer organisms for each trophic linkage. For generalist (i.e., polyphagous) predators that foraged within/on soil substrates, we logged all trophic linkages that were outlined in each literature record (i.e., involving other organisms beyond the initial set of 36 taxa). Taxa were identified either at the taxonomic hierarchy of phylum, sub-class or order and comprised a diverse set of common, globally-distributed soil-foraging biota.Soil invertebrates contribute to multiple ecosystem services, including pest control, nutrient cycling, and soil structural regulation, yet trophic interactions that determine their diversity and activity in soils remain critically understudied. Here, we systematically review literature (1966–2020) on feeding habits of soil arthropods and macrofauna and summarize empirically studied predator–prey linkages across ecosystem types, geographies and taxa. Out of 522 unique predators and 372 prey organisms (constituting 1947 predator–prey linkages), the vast majority (> 75%) are only covered in a single study. We report a mean of just 3.0 ± 4.7 documented linkages per organism, with pronounced taxonomic biases. In general, model organisms and crop pests (generally Insecta) are well-studied, while important soil-dwelling predators, fungivores and detritivores (e.g., Collembola, Chilopoda and Malacostraca) remain largely ignored. We argue that broader food-web based research approaches, considering multiple linkages per organism and targeting neglected taxa, are needed to inform science-driven management of soil communities and associated ecosystem services