126 research outputs found

    Handbook of recommended practices for the determination of liquid monopropellant rocket engine performance

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    The design, installation, and operation of systems to be used for directly measuring quantities of fundamental importance to the determination of monopropellant thruster performance is described. Areas covered include: (1) force and impulse measurement; (2) propellant mass usage and flow measurement; (3) pressure measurement; (4) temperature measurement; (5) exhaust gas composition measurement; and (6) data reduction and performance determination

    Sensitivity of a tonne-scale NEXT detector for neutrinoless double beta decay searches

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    The Neutrino Experiment with a Xenon TPC (NEXT) searches for the neutrinoless double-beta decay of Xe-136 using high-pressure xenon gas TPCs with electroluminescent amplification. A scaled-up version of this technology with about 1 tonne of enriched xenon could reach in less than 5 years of operation a sensitivity to the half-life of neutrinoless double-beta decay decay better than 1E27 years, improving the current limits by at least one order of magnitude. This prediction is based on a well-understood background model dominated by radiogenic sources. The detector concept presented here represents a first step on a compelling path towards sensitivity to the parameter space defined by the inverted ordering of neutrino masses, and beyond.Comment: 22 pages, 11 figure

    In vitro and In vivo toxicology evaluation to determine suitable biomedical Polymers for development of a papain-containing drug delivery system

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    Papain has been known by many decades for wounded tissues repair. However, papain stability is not high enough to be commercialized in a stable pharmaceutical form; therefore its use is limited. The strategy to entrap papain into a polymeric matrix to provide an adequate drug delivery system consists of an alternative to this problem. The purpose of this study was to assess in vitro and in vivo four polymers cytotoxicity and ability to cause cutaneous irritation to be applied as a suitable papain delivery system. A Monocomponent (MSD) and Bicomponent Silicone Dispersions (BSD) and, Natural Rubber Bicentrifuged Latex (NRBL) and an Acrylic Adhesive (AA) were selected. The cytotoxicity was firstly assessed by the Neutral Red Uptake Method. Non-cytotoxic polymers were then submitted to in vivo Cutaneous Irritation Test. Both silicone dispersions were found non-cytotoxic, and NRBL and AA polymers showed cytotoxicity. MSD and BSD polymers did not cause any cutaneous reactions.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Social times, reproduction and social inequality at work : contrasts and comparative perspectives between countries

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    Production of INCASI Project H2020-MSCA-RISE-2015 GA 691004If the focus is placed specifically on the problem of work and family, the daily life of people and their use of time are a main problem. This time is expressed in both freely available time, which is related to activities, and time of the productive and reproductive sphere. This chapter considers work in a broad sense and takes into account the sexual division of labour. Specifically, this chapter will explore transformations in time use and social inequality in unpaid work. For this purpose, a comparative analysis of time-use surveys will be used, analysing the time spent, and the time dedicated to household chores in Chile, Argentina, Uruguay and Spain. From an analytical viewpoint, the analysis will place social reproduction at the centre of the socio-economic system, showing that the economic crisis has affected women and men differently, and that in both Europe and Latin America the family pattern is being replaced by a dominant family model of a male provider and a double presence of women. The large-scale incorporation of women into the labour market has emphasised the role that women assume in the domestic sphere perpetuating gender segregation in employment and in domestic and care work

    A Compact Dication Source for Ba2+^{2+} Tagging and Heavy Metal Ion Sensor Development

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    We present a tunable metal ion beam that delivers controllable ion currents in the picoamp range for testing of dry-phase ion sensors. Ion beams are formed by sequential atomic evaporation and single or multiple electron impact ionization, followed by acceleration into a sensing region. Controllability of the ionic charge state is achieved through tuning of electrode potentials that influence the retention time in the ionization region. Barium, lead, and cobalt samples have been used to test the system, with ion currents identified and quantified using a quadrupole mass analyzer. Realization of a clean Ba2+\mathrm{Ba^{2+}} ion beam within a bench-top system represents an important technical advance toward the development and characterization of barium tagging systems for neutrinoless double beta decay searches in xenon gas. This system also provides a testbed for investigation of novel ion sensing methodologies for environmental assay applications, with dication beams of Pb2+^{2+} and Cd2+^{2+} also demonstrated for this purpose

    NEXT-CRAB-0: A High Pressure Gaseous Xenon Time Projection Chamber with a Direct VUV Camera Based Readout

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    The search for neutrinoless double beta decay (0νββ0\nu\beta\beta) remains one of the most compelling experimental avenues for the discovery in the neutrino sector. Electroluminescent gas-phase time projection chambers are well suited to 0νββ0\nu\beta\beta searches due to their intrinsically precise energy resolution and topological event identification capabilities. Scalability to ton- and multi-ton masses requires readout of large-area electroluminescent regions with fine spatial resolution, low radiogenic backgrounds, and a scalable data acquisition system. This paper presents a detector prototype that records event topology in an electroluminescent xenon gas TPC via VUV image-intensified cameras. This enables an extendable readout of large tracking planes with commercial devices that reside almost entirely outside of the active medium.Following further development in intermediate scale demonstrators, this technique may represent a novel and enlargeable method for topological event imaging in 0νββ0\nu\beta\beta.Comment: 32 Pages, 22 figure

    Sensitivity of a tonne-scale NEXT detector for neutrinoless double-beta decay searches

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    The Neutrino Experiment with a Xenon TPC (NEXT) searches for the neutrinoless double-beta (0¿ßß) decay of 136Xe using high-pressure xenon gas TPCs with electroluminescent amplification. A scaled-up version of this technology with about 1 tonne of enriched xenon could reach in less than 5 years of operation a sensitivity to the half-life of 0¿ßß decay better than 1027 years, improving the current limits by at least one order of magnitude. This prediction is based on a well-understood background model dominated by radiogenic sources. The detector concept presented here represents a first step on a compelling path towards sensitivity to the parameter space defined by the inverted ordering of neutrino masses, and beyond. [Figure not available: see fulltext.] © 2021, The Author(s)

    Boosting background suppression in the NEXT experiment through Richardson-Lucy deconvolution

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    Next-generation neutrinoless double beta decay experiments aim for half-life sensitivities of ~102710^{27} yr, requiring suppressing backgrounds to <1 count/tonne/yr. For this, any extra background rejection handle, beyond excellent energy resolution and the use of extremely radiopure materials, is of utmost importance. The NEXT experiment exploits differences in the spatial ionization patterns of double beta decay and single-electron events to discriminate signal from background. While the former display two Bragg peak dense ionization regions at the opposite ends of the track, the latter typically have only one such feature. Thus, comparing the energies at the track extremes provides an additional rejection tool. The unique combination of the topology-based background discrimination and excellent energy resolution (1% FWHM at the Q-value of the decay) is the distinguishing feature of NEXT. Previous studies demonstrated a topological background rejection factor of ~5 when reconstructing electron-positron pairs in the 208^{208}Tl 1.6 MeV double escape peak (with Compton events as background), recorded in the NEXT-White demonstrator at the Laboratorio Subterr\'aneo de Canfranc, with 72% signal efficiency. This was recently improved through the use of a deep convolutional neural network to yield a background rejection factor of ~10 with 65% signal efficiency. Here, we present a new reconstruction method, based on the Richardson-Lucy deconvolution algorithm, which allows reversing the blurring induced by electron diffusion and electroluminescence light production in the NEXT TPC. The new method yields highly refined 3D images of reconstructed events, and, as a result, significantly improves the topological background discrimination. When applied to real-data 1.6 MeV ee+e^-e^+ pairs, it leads to a background rejection factor of 27 at 57% signal efficiency.Comment: Submitted to JHE
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