79 research outputs found

    Changes in cocoa properties induced by the alkalization process: A review

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    [EN] Alkalization, also known as "Dutching," is an optional, but very useful, step taken in the production chain of cocoa to darken its color, modify its taste, and increase natural cocoa solubility. Over the years, various attempts have been made to design new and more effective alkalization methods. Moreover, different authors have attempted to elucidate the impact of alkalization on the physicochemical, nutritional, functional, microbiological, and sensory characteristics of alkalized cocoa. The aim of this review is to provide a clear guide about not only the conditions that can be applied to alkalize cocoa, but also the reported effects of alkalization on the nutritional, functional, microbiological, and sensory characteristics of cocoa. The first part of this review describes different cocoa alkalization systems and how they can be tuned to induce specific changes in cocoa properties. The second part is a holistic analysis of the effects of the alkalization process on different cocoa features, performed by emphasizing the biochemistry behind all these transformations.European Regional Development Fund, Grant/Award Number: Project RTC-2016-5241-2; Ministerio deEconomia y Competitividad, Grant/Award Number: Project RTC-2016-5241-2Valverde-Garcia, D.; PĂ©rez-Esteve, É.; Barat Baviera, JM. (2020). Changes in cocoa properties induced by the alkalization process: A review. Comprehensive Reviews in Food Science and Food Safety. 19(4):2200-2221. https://doi.org/10.1111/1541-4337.12581S22002221194Ilesanmi Adeyeye, E. (2016). Proximate, Mineral And Antinutrient Compositions Of Natural Cocoa Cake, Cocoa Liquor And Alkalized Cocoa Powders. Journal of Advanced Pharmaceutical Science And Technology, 1(3), 12-28. doi:10.14302/issn.2328-0182.japst-15-855Ajandouz, E. H., Tchiakpe, L. S., Ore, F. D., Benajiba, A., & Puigserver, A. (2001). 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    Moduli Spaces for Four- and Five- Dimensional Black Holes

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    We propose a universal expression for the moduli metric of a class of four- and five-dimensional black holes which preserve at least four supersymmetries. These include the black holes that are associated with various intersecting branes in ten and eleven dimensions, the electrically charged black holes of N=2 D=5 and N=2 D=4 supergravities with any number of vector multiplets, and dyonic black holes of N=2 D=4 supergravity. The moduli metric of electrically charged N=2 D=4 black holes coupled to any number of vector multiplets is explicitly computed. We also investigate the superconformal symmetries of the black hole moduli spaces for small black hole separations.Comment: 44 pages, phyzzx.tex, minor corrections, some more references adde

    Apnea of prematurity: from cause to treatment

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    Apnea of prematurity (AOP) is a common problem affecting premature infants, likely secondary to a “physiologic” immaturity of respiratory control that may be exacerbated by neonatal disease. These include altered ventilatory responses to hypoxia, hypercapnia, and altered sleep states, while the roles of gastroesophageal reflux and anemia remain controversial. Standard clinical management of the obstructive subtype of AOP includes prone positioning and continuous positive or nasal intermittent positive pressure ventilation to prevent pharyngeal collapse and alveolar atelectasis, while methylxanthine therapy is a mainstay of treatment of central apnea by stimulating the central nervous system and respiratory muscle function. Other therapies, including kangaroo care, red blood cell transfusions, and CO2 inhalation, require further study. The physiology and pathophysiology behind AOP are discussed, including the laryngeal chemoreflex and sensitivity to inhibitory neurotransmitters, as are the mechanisms by which different therapies may work and the potential long-term neurodevelopmental consequences of AOP and its treatment

    Suppression of Penning discharges between the KATRIN spectrometers

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    The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to determine the effective electron (anti)-neutrino mass with a sensitivity of 0.2eV/c2^{2} by precisely measuring the endpoint region of the tritium ÎČ-decay spectrum. It uses a tandem of electrostatic spectrometers working as magnetic adiabatic collimation combined with an electrostatic (MAC-E) filters. In the space between the pre-spectrometer and the main spectrometer, creating a Penning trap is unavoidable when the superconducting magnet between the two spectrometers, biased at their respective nominal potentials, is energized. The electrons accumulated in this trap can lead to discharges, which create additional background electrons and endanger the spectrometer and detector section downstream. To counteract this problem, “electron catchers” were installed in the beamline inside the magnet bore between the two spectrometers. These catchers can be moved across the magnetic-flux tube and intercept on a sub-ms time scale the stored electrons along their magnetron motion paths. In this paper, we report on the design and the successful commissioning of the electron catchers and present results on their efficiency in reducing the experimental background

    Analysis methods for the first KATRIN neutrino-mass measurement

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    We report on the dataset, data handling, and detailed analysis techniques of the first neutrino-mass measurement by the Karlsruhe Tritium Neutrino (KATRIN) experiment, which probes the absolute neutrino-mass scale via the ÎČ-decay kinematics of molecular tritium. The source is highly pure, cryogenic T2 gas. The ÎČ electrons are guided along magnetic field lines toward a high-resolution, integrating spectrometer for energy analysis. A silicon detector counts ÎČ electrons above the energy threshold of the spectrometer, so that a scan of the thresholds produces a precise measurement of the high-energy spectral tail. After detailed theoretical studies, simulations, and commissioning measurements, extending from the molecular final-state distribution to inelastic scattering in the source to subtleties of the electromagnetic fields, our independent, blind analyses allow us to set an upper limit of 1.1 eV on the neutrino-mass scale at a 90% confidence level. This first result, based on a few weeks of running at a reduced source intensity and dominated by statistical uncertainty, improves on prior limits by nearly a factor of two. This result establishes an analysis framework for future KATRIN measurements, and provides important input to both particle theory and cosmology

    Quantitative Long-Term Monitoring of the Circulating Gases in the KATRIN Experiment Using Raman Spectroscopy

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    The Karlsruhe Tritium Neutrino (KATRIN) experiment aims at measuring the effective electron neutrino mass with a sensitivity of 0.2 eV/c2^{2}, i.e., improving on previous measurements by an order of magnitude. Neutrino mass data taking with KATRIN commenced in early 2019, and after only a few weeks of data recording, analysis of these data showed the success of KATRIN, improving on the known neutrino mass limit by a factor of about two. This success very much could be ascribed to the fact that most of the system components met, or even surpassed, the required specifications during long-term operation. Here, we report on the performance of the laser Raman (LARA) monitoring system which provides continuous high-precision information on the gas composition injected into the experiment’s windowless gaseous tritium source (WGTS), specifically on its isotopic purity of tritium—one of the key parameters required in the derivation of the electron neutrino mass. The concentrations cx_{x} for all six hydrogen isotopologues were monitored simultaneously, with a measurement precision for individual components of the order 10−3^{-3} or better throughout the complete KATRIN data taking campaigns to date. From these, the tritium purity, ΔT, is derived with precision of <10−3^{-3} and trueness of <3 × 10−3^{-3}, being within and surpassing the actual requirements for KATRIN, respectively

    Precision measurement of the electron energy-loss function in tritium and deuterium gas for the KATRIN experiment

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    The KATRIN experiment is designed for a direct and model-independent determination of the effective electron anti-neutrino mass via a high-precision measurement of the tritium ÎČ\beta-decay endpoint region with a sensitivity on mÎœm_\nu of 0.2 \,eV/c2^2 (90% CL). For this purpose, the ÎČ\beta-electrons from a high-luminosity windowless gaseous tritium source traversing an electrostatic retarding spectrometer are counted to obtain an integral spectrum around the endpoint energy of 18.6 \,keV. A dominant systematic effect of the response of the experimental setup is the energy loss of ÎČ\beta-electrons from elastic and inelastic scattering off tritium molecules within the source. We determined the \linebreak energy-loss function in-situ with a pulsed angular-selective and monoenergetic photoelectron source at various tritium-source densities. The data was recorded in integral and differential modes; the latter was achieved by using a novel time-of-flight technique. We developed a semi-empirical parametrization for the energy-loss function for the scattering of 18.6-keV electrons from hydrogen isotopologs. This model was fit to measurement data with a 95% T2_2 gas mixture at 30 \,K, as used in the first KATRIN neutrino mass analyses, as well as a D2_2 gas mixture of 96% purity used in KATRIN commissioning runs. The achieved precision on the energy-loss function has abated the corresponding uncertainty of σ(mÎœ2)<10−2 eV2\sigma(m_\nu^2)<10^{-2}\,\mathrm{eV}^2 [arXiv:2101.05253] in the KATRIN neutrino-mass measurement to a subdominant level.Comment: 12 figures, 18 pages; to be submitted to EPJ

    Direct neutrino-mass measurement with sub-electronvolt sensitivity

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