126 research outputs found
Handbook of recommended practices for the determination of liquid monopropellant rocket engine performance
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
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
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
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 Ba Tagging and Heavy Metal Ion Sensor Development
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
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 Pb and
Cd also demonstrated for this purpose
NEXT-CRAB-0: A High Pressure Gaseous Xenon Time Projection Chamber with a Direct VUV Camera Based Readout
The search for neutrinoless double beta decay () 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 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 .Comment: 32 Pages, 22 figure
Sensitivity of a tonne-scale NEXT detector for neutrinoless double-beta decay searches
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
Next-generation neutrinoless double beta decay experiments aim for half-life
sensitivities of ~ 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 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 pairs, it leads to a
background rejection factor of 27 at 57% signal efficiency.Comment: Submitted to JHE
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