Time of flight detectors with SiPMT array readout

none6noTime-of-flight detectors, based on scintillation counters, may use conventional photomultipliers for the readout. Problems arise in presence of external magnetic fields. SiPMT arrays are insensitive to magnetic fields and may be a suitable option to replace photomultipliers. Timing performances for several types of SiPMT arrays have been studied and results are presented.Bonesini, M; Bertoni, R.; de Bari, A.; Nardò, R.; Prata, M.; Rossella, M.Bonesini, M; Bertoni, R.; DE BARI, Antonio; Nardo', Roberto; Prata, M.; Rossella, M

Carrapato e vermes: inimigos do gado e do produtor.

bitstream/item/65290/1/CT-95-Carrapato-e-vermes.pd

Improving the Time Resolution of Large-Area LaBr3:Ce Detectors with SiPM Array Readout

LaBr3:Ce crystals have good scintillation properties for X-ray spectroscopy. Initially, they were introduced for radiation imaging in medical physics with either a photomultiplier or SiPM readout, and they found extensive applications in homeland security and gamma-ray astronomy. We used 1 inch round LaBr3:Ce crystals to realize compact detectors with the SiPM array readout. The aim was a good energy resolution and a fast time response to detect low-energy X-rays around 100 keV. A natural application was found inside the FAMU experiment, at RIKEN RAL. Its aim is a precise measurement of the proton Zemach radius with impinging muons, to contribute to the solution to the so-called proton radius puzzle. Signals to be detected are characteristic X-rays around 130 KeV. A limit for this type of detector, as compared to the ones with a photomultiplier readout, is its poorer timing characteristics due to the large capacity of the SiPM arrays used. In particular, long signal falltimes are a problem in experiments such as FAMU, where a prompt background component must be separated from a delayed one (after 600 ns) in the signal X-rays to be detected. Dedicated studies were pursued to improve the timing characteristics of the used detectors, starting from hybrid ganging of SiPM cells; then developing a suitable zero pole circuit with a parallel ganging, where an increased overvoltage for the SiPM array was used to compensate for the signal decrease; and finally designing ad hoc electronics to split the 1 inch detector SiPM array into four quadrants, thus reducing the involved capacitances. The aim was to improve the detectors timing characteristics, especially falltime, while keeping a good FWHM energy resolution for low-energy X-ray detection

Influence of extraction process on the luminescent properties of carbon nanomaterials derived from olive mill wastewaters

Este trabalho foi financiado pelo Concurso Anual para Projetos de Investigação, Desenvolvimento, Inovação e Criação Artística (IDI&CA) 2016 do Instituto Politécnico de Lisboa. Código de referência IPL/2016/NANOLIVE/ISELIn an accompanying communication [1], we have revealed that nanosized carbon materials could be easily obtained from olive mil wastewater (OMWW) using green, sustainable and simple technological processes. In this contribution we will essentially focus on the study of the impact of the effluent nature on the structural, morphological and luminescente characteristics of synthesized carbon nanodots (CNDs).info:eu-repo/semantics/publishedVersio

Carbon nanodots from olive mill wastewater: a sustainable route

Este trabalho foi financiado pelo Concurso Anual para Projetos de Investigação, Desenvolvimento, Inovação e Criação Artística (IDI&CA) 2016 do Instituto Politécnico de Lisboa. Código de referência IPL/2016/NANOLIVE/ISELOlive oils are obtained from the fruit of the olive tree (Olea europaea L.) by combined mechanical and physical operations. Portugal has a significant production of olive oil (76 k tonnes/year over the last 5 years, 2010-2015) [1]. Olive oil is typically obtained by two main processes: batch press and continuous centrifugation. Depending on the particular process used, 200-1600 L of olive mill wastewater (OMWW) is produced per tonne of processed olives. Taken the lowest of these values, an estimate points to around 15 million L of OMWW may be produced each year in Portugal. The OMWW exhibits very low biodegradability parameters which pose serious issues for its treatment. Sustainable production of high-valued carbon materials from industrial lowvalued and problematic wastes is particularly appealing and highly desirable.info:eu-repo/semantics/publishedVersio

Bright nanoparticles for an even brighter future: efficient production of luminescent carbon nanodots from olive mill wastewater

Este trabalho foi financiado pelo Concurso Anual para Projetos de Investigação, Desenvolvimento, Inovação e Criação Artística (IDI&CA) 2016 do Instituto Politécnico de Lisboa. Código de referência IPL/2016/NANOLIVE/ISELCarbon nanodots (CNDs) are a very recent class of spherical-shaped nanosized carbon materials possessing average typical diameters < 10 nm. Since the very first reports on carbon dots,1,2 a variety of methods (top-down and bottom-up strategies), carbon sources and passivating agents, have dealt with their synthesis.3 The bottom-up approach, encompassing the use of pyrolytic/solvothermal processes, is more amenable for large-scale production and can cope with a large diversity of carbon precursors, either from natural or synthetic sources, typically endowed with acid, alcohol and amine functionalities.4 Some of the interesting CNDs properties include tunable photoluminescence, outstanding photostability and negligible cytotoxicity. These unique properties have prompted their intense and widespread use in several fields, such as fluorescent bioimaging and nanomedicine, chemo/biosensing, photocatalysis and optoelectronics.4info:eu-repo/semantics/publishedVersio

Carrapato dos bovinos: controle estratégico nas diferentes regiões brasileiras.

bitstream/item/65401/1/COT-36-Carrapato-dos-bovinos.pd

WARP: a WIMP double phase Argon detector

The WARP programme for dark matter search with a double phase argon detector is presented. In such a detector both excitation and ionization produced by an impinging particle are evaluated by the contemporary measurement of primary scintillation and secondary (proportional) light signal, this latter being produced by extracting and accelerating ionization electrons in the gas phase. The proposed technique, verified on a 2.3 liters prototype, could be used to efficiently discriminate nuclear recoils, induced by WIMP's interactions, and measure their energy spectrum. An overview of the 2.3 liters results and of the proposed 100 liters detector is shown.Comment: Proceeding for IDM200

Chondrosia reniformis marine-sponge collagen membranes for skin re-epithelialization

Chondrosia reniformis collagen has been identified as mainly of type IV. Being collagen IV the main component of the epidermal basal layer [1], C. reniformis represents a valuable source to be explored in the skin regeneration field. This work envisaged the production of C. reniformis collagen membranes for the selection of rapidly adherent epidermal cells, like the commercial collagen coatings, and for their subsequent culture. This approach would permit a single system for culturing and carrying basal epidermal cells aimed at re-epithelialize skin wounds. Materials and Methods The collagen of C. reniformis marine-sponge was extracted with 100mM Tris-HCl, 10mM EDTA, 8M urea and 100mM 2-mercaptoethanol. To define the best re-solubilization conditions, the obtained precipitate was dissolved in five different solutions: Solution A: 100mM Tris-HCl+8M Urea+10mM EDTA (pH 9.5); Solution B: 50mM Tris-HCl+1M NaCl (pH 7.4); Solution C: 100mM Tris-HCl (pH 7.4); Solution D: 0.5% H2O2 (v/v) (pH 11) and Solution E: 100mM Tris-HCl (pH 9.5). Solutions of 1% collagen were prepared and cross-linking was performed with HMDI, genipin and EDC/NHS at different concentrations. The membranes were obtained by solvent-casting and/or freeze-drying, and their stability was tested both in PBS and culture medium, for at least 7 days. Morphological characterization of the membranes was carried out by scanning electron microscopy (SEM). Cytotoxicity, based on metabolic activity (MTS assay) and cell proliferation (DNA quantification) analysis of the 100mM Tris-HCl (pH 9.5) and 8mM EDC/NHS cross-linked collagen membranes, was assessed with L929 cells. Results were analyzed by IBM SPSS Statistics Version 20 using one-way ANOVA and Kruskall-Wallis test. Significance was set for