Characterization of light production and transport in tellurium dioxide crystals

Simultaneous measurement of phonon and light signatures is an effective way to reduce the backgrounds and increase the sensitivity of CUPID, a next-generation bolometric neutrinoless double-beta decay (0νββ) experiment. Light emission in tellurium dioxide (TeO2) crystals, one of the candidate materials for CUPID, is dominated by faint Cherenkov radiation, and the high refractive index of TeO2 complicates light collection. Positive identification of 0νββ events therefore requires high-sensitivity light detectors and careful optimization of light transport. A detailed microphysical understanding of the optical properties of TeO2 crystals is essential for such optimization. We present a set of quantitative measurements of light production and transport in a cubic TeO2 crystal, verified with a complete optical model and calibrated against a UVT acrylic standard. We measure the optical surface properties of the crystal, and set stringent limits on the amount of room-temperature scintillation in TeO2 for β and α particles of 5.3 and 8 photons/MeV, respectively, at 90% confidence. The techniques described here can be used to optimize and verify the particle identification capabilities of CUPID

Cherenkov and Scintillation Light Separation in Organic Liquid Scintillators

The CHErenkov / Scintillation Separation experiment (CHESS) has been used to demonstrate the separation of Cherenkov and scintillation light in both linear alkylbenzene (LAB) and LAB with 2g/L of PPO as a fluor (LAB/PPO). This is the first such demonstration for the more challenging LAB/PPO cocktail and improves on previous results for LAB. A time resolution of 338 +/- 12 ps FWHM results in an efficiency for identifying Cherenkov photons in LAB/PPO of 70 +/- 3% and 63 +/- 8% for time- and charge-based separation, respectively, with scintillation contamination of 36 +/- 5% and 38 +/- 4%. LAB/PPO data is consistent with a rise time of 0.75 +/- 0.25 ns

Incorporación de metodologías participativas al proceso de formación del alumnado universitario

Con el objetivo de mejorar la participación del alumnado en las aulas y la calidad del proceso enseñanza-aprendizaje, se han utilizado técnicas participativas en el desarrollo dela asignatura de Agricultura Ecológica en la Escuela de Ingeniería Técnica Agrícola. Las técnicas empleadas proceden del ámbito del Diagnóstico Rural Participativo, la Educación Social y la Animación Sociocultural. Los resultados nos han permitido concluir que, a pesar de la escasa formación previa de los alumnos en la materia, la adopción de técnicas participativas estimula al alumnado y mejora el proceso de aprendizaje y su interés por la asignatura. Es interesante seguir trabajando en la aplicación de estas metodologías en la docencia universitaria porque facilitan al alumnado la adquisición de un conocimiento holístico en la materia y habilidades para el trabajo en grupo

Nutritional and functional advantages of the use of fermented black chickpea flour for semolina-pasta fortification

Pasta represents a dominant portion of the diet worldwide and its functionalization with high nutritional value ingredients, such as legumes, is the most ideal solution to shape consumers behavior towards healthier food choices. Aiming at improving the nutritional quality of semolina pasta, semi-liquid dough of a Mediterranean black chickpea flour, fermented with Lactiplantibacillus plantarum T0A10, was used at a substitution level of 15% to manufacture fortified pasta. Fermentation with the selected starter enabled the release of 20% of bound phenolic compounds, and the conversion of free compounds into more active forms (dihydrocaffeic and phloretic acid) in the dough. Fermented dough also had higher resistant starch (up to 60% compared to the control) and total free amino acids (almost 3 g/kg) contents, whereas antinutritional factors (raffinose, condensed tannins, trypsin inhibitors and saponins) significantly decreased. The impact of black chickpea addition on pasta nutritional, technological and sensory features, was also assessed. Compared to traditional (semolina) pasta, fortified pasta had lower starch hydrolysis rate (ca. 18%) and higher in vitro protein digestibility (up to 38%). Moreover, fortified cooked pasta, showing scavenging activity against DPPH and ABTS radicals and intense inhibition of linoleic acid peroxidation, was appreciated for its peculiar organoleptic profile. Therefore, fermentation technology appears to be a promising tool to enhance the quality of pasta and promote the use of local chickpea cultivars while preventing their genetic erosion

HPLC-DAD-ESI-QTOF-MS and HPLC-FLD-MS as valuable tools for the determination of phenolic and other polar compounds in the edible part and by-products of avocado

Avocado is a tropical fruit increasingly cultivated around the world due to global interest and rising consumption. Thus, there is also a surge in avocado by-products that needs assessment. The aim of this work is to compare the phenolic profile of avocado pulp, peel and seed when the fruit is at optimal ripeness for consumption and when overripe. Two analytical techniques were used: (1) HPLC-DAD-ESI-QTOF-MS was used for the first time to determine phenolic and other polar compounds in avocado peel and seed. Phenolic compounds quantified with these methods were in higher concentration in overripe than in pulp and seed of optimally ripe fruit. (2) HPLC-FLD-MS was used to specifically determine flavan-3-ols. Procyanidins to degree of polymerization 13 have been quantified singularly here for the first time. In addition, A- and B-type procyanidins from the degree of polymerization 2 to 6 were differentiated and quantified. The procyanidin concentration increased after ripening probably due to the release of tannins linked to cell-wall structures. Because of this situation and the presence of A-type procyanidins, avocado peel and seed from overripe fruit, the main by-products of avocado processing, hold interest for developing functional foods, nutraceuticals and cosmetics

Radiologia médico-legal. Um dilema ético para o técnico de Radiologia

The medico-legal, radiological examinations include those medical exposures to radiation conducted by court order a person who is not sick. The radiologic technologist has a duty to minimize the dose to patients and the population as a whole, therefore, make this type of exploration conflicts with the maximum of Radiation Protection and its ethical code. We present a review study where we analyze whether these medical practices are contrary to professional ethics of the Radiologic technologist.Las exploraciones radiológicas médico-legales incluyen exposiciones médicas a radiaciones que se realizan por orden judicial a una persona que no está enferma. El técnico o tecnólogo médico en radiología tiene el deber de minimizar las dosis a pacientes y a la población en su conjunto; por ello, realizar este tipo de exploraciones entra en conflicto con las máximas de la protección radiológica y de su código ético. Presentamos un estudio de revisión donde se analiza si estas prácticas médicas son contrarias a la ética profesional del técnico en radiología.As explorações radiológicas médico-legais incluem aquelas exposições médicas a radiações que se realizam por ordem judicial a uma pessoa que não está doente. O técnico ou tecnólogo médico em radiologia tem o dever de minimizar a dose para os pacientes e a população como um todo; portanto, realizar este tipo de exploração entra em conflito com os princípios da proteção radiológica e de seu código de ética. Apresentamos um estudo de revisão no qual analisamos se estas práticas médicas são contrárias à ética profissional do técnico em radiologia

Estructura electrónica del Cd como impureza en Si

Se analiza la estructura electrónica del Cd como impureza en Si. Utilizando el método de Huckel extendido, se presentan resultados de clusters para impurezas de Cd en sitios sustitucionales e intersticiales de simetría tetrahédrica. Los niveles profundos obtenidos experimentalmente en el gap del Si pueden explicarse a partir de la geometría sustitucional, siempre que se distorsionen los primeros vecinos del Cd según una relajación que conserve la simetría Td, junto con pequeñas distorsiones trigonales del Cd. Estos resultados son consistentes con la información experimental dada por experiencias de correlaciones angulares perturbadas y mediciones de efecto Hall.Facultad de Ciencias Exacta