4,936 research outputs found

    Adaptation Strategies and Microwave Drying of Amaranth Species with a High Nutritional Value to the Ecuadorian Andean Region

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    In the Andean region of Ecuador, amaranth is a key species not only for its high nutritional value but also for its association with Ecuadorian culture, since it is one of the main indigenous crops of the pre-Columbian era. Over the time, the cultivation of this species ceased for several reasons result. However, in recent years, a number of strategies have been developed to retrieve it on a national level. In accordance with these strategies, the “Amaranth Improvement Program for Cotopaxi” (PROMAC) is being developed at the Technical University of Cotopaxi, with the main objective of selecting varieties with high levels of biologically active substances. This program is been executed through two main lines of investigation: (a) selection of varieties of amaranth of high nutritional value and (b) the improvement of techniques for conservation of the seeds. This chapter analyzes and shows the main results obtained to date from the study of eight varieties of amaranth seeds and the drying of one of the seeds by means of microwave energy in order to improve its conservation. In the light of the results obtained, the strategies to develop the following research lines within the PROMAC framework are exposed

    Study through Geant4, for Time Resolution characterization of different detectors arrays coupled with two SiPMs, as a function of: the scintillator plastic material, its volumetric dimensions and the location of the radiation emission source

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    The high time resolution detectors are relevant in those experiments or simulations were the particles to detect, have a very short time of flight (TOF), and due this it´s required that the detections times are ranged between ns. & ps.Using Geant4 software, it was made thirty simulations of coupled detectors to plastic scintillators with two silicon photomultipliers (SiPMs) located on the scintillator’s central sides. To characterize the time resolution, it was required to quantify the optical photons that reach the Score in a certain time, which are generated by muons on the surface of the plastic scintillator. Different configurations of muon beams were simulated at energy of 1 GeV, to interact with the configuration of the scintillator material of its corresponding arrangement. The simulations were made varying three parameters: the scintillator material “BC404 & BC422”, its size, and the location of the radiation source. Fifteen simulations correspond to BC404 material & fifteen simulations to BC422 material respectively. The first five simulations consisted in varying the scintillator’s volumetric size and collocate the muons beam guided randomly distributed over it, the next five simulations differentiate from setting up a directly centered beam, and the last five simulations for guide the beam on the left lower corner of each scintillator.The best time resolution achieved was σ= 8.67 +/− 0.26 ps., reported by the detector with BC422 scintillator material which has a volume of 20x20x3 mm3

    Study of the oxygen reduction reaction on pure and Zr-doped YMnO3+δ SOFC electrode

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    The effect of Zr-doping on the novel SOFC cathode YMnO3 and its O2-Reduction Reaction (ORR) was studied using electrochemical impedance spectroscopy (EIS) as a function of temperature (500 < T < 800 °C) and the oxygen partial pressure (10−4 < pO2 < 1 atm). EIS technique allows identifying three processes controlling the ORR for each electrode, differentiated by their characteristic frequency, activation energies and pO2 dependence. High frequency contribution, only observed at 600°C for both electrodes, was attributed to oxygen ion transfer trough the electrode/electrolyte interface. In both electrodes, the Intermediate frequency contribution was described by a Gerischer impedance, related to a co-limiting process between oxygen ion diffusion and a surface process. However, whereas the EIS characteristics for YMnO3 can be explained by a surface process controlled by the electron transfer from oxide to O-adsorbed, it seems related for Y0.9Zr0.1MnO3 to the probability of finding a second free-surface site near to a diatomic intermediated for the O2 dissociation. These differences are in agreement with the improvement of the electrical properties when YMnO3 is doped with Zr. The low frequency contribution became important as pO2 decreased and temperature increased, and its characteristics would indicate a secondary surface process, co-limited with O2 gas diffusion for Y0.9Zr0.1MnO3 porous electrode.Fil: Moreno Botello, Zulma L.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Universidad Industrial Santander; ColombiaFil: Montenegro Hernández, Alejandra. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche | Comision Nacional de Energia Atomica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche.; ArgentinaFil: Mogni, Liliana Verónica. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche | Comision Nacional de Energia Atomica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche.; ArgentinaFil: Gauthier, Gilles H.. Universidad Industrial Santander; Colombi

    Porous Titanium surfaces to control bacteria growth: mechanical properties and sulfonated polyetheretherketone coating as antibiofounling approaches

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    Here, titanium porous substrates were fabricated by a space holder technique. The relationship between microstructural characteristics (pore equivalent diameter, mean free-path between pores, roughness and contact surface), mechanical properties (Young’s modulus, yield strength and dynamic micro-hardness) and bacterial behavior are discussed. The bacterial strains evaluated are often found on dental implants: Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. The colony-forming units increased with the size of the spacer for both types of studied strains. An antibiofouling synthetic coating based on a sulfonated polyetheretherketone polymer revealed an effective chemical surface modification for inhibiting MRSA adhesion and growth. These findings collectively suggest that porous titanium implants designed with a pore size of 100–200 µm can be considered most suitable, assuring the best biomechanical and bifunctional anti-bacterial properties.University of Seville VI Plan Propio de Investigación y Transferencia—US 2018, I.3A

    Art museums as a source of well-being for people with dementia: an experience in the Prado Museum

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    Background: Several studies have revealed the positive effects that cultural activities may have on people with dementia (PWD). The goal of this study was to describe the design, development and evaluation of a programme of artistic education activities for these people based on visits to the Prado Museum. Methods: 12 people participated for two months in a program of artistic activities consisting of visits to the Prado. To determine the participants’ response to the programme, information was gathered through participant observation. Results: During the development of the program, the participant’s reactions of interest, engagement and satisfaction, as well as a positive effect on mood and social relations, were observed. Conclusion: The cognitive difficulties did not deter them from participating in the program, which had positive effects on the participants. It was concluded that the museum can be an important resource for the promotion of PWDs’ well-being and social inclusion

    The Bulgeless Seyfert/LINER Galaxy NGC 3367: Disk, Bar, Lopsidedness and Environment

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    NGC3367 is a nearby isolated active galaxy that shows a radio jet, a strong bar and evidence of lopsidedness. We present a quantitative analysis of the stellar and gaseous structure of the galaxy disk and a search for evidence of recent interaction based on new UBVRI Halpha and JHK images and on archival Halpha Fabry-Perot and HI VLA data. From a coupled 1D/2D GALFIT bulge/bar/disk decomposition an (B/D ~ 0.07-0.1) exponential pseudobulge is inferred in all the observed bands. A NIR estimate of the bar strength = 0.44 places NGC 3367 bar among the strongest ones. The asymmetry properties were studied using (1) optical and NIR CAS indexes (2) the stellar (NIR) and gaseous (Halpha, HI) A_1 Fourier mode amplitudes and (3) the HI integrated profile and HI mean intensity distribution. While the average stellar component shows asymmetry values close to the average found in the Local Universe for isolated galaxies, the young stellar component and gas values are largely decoupled showing significantly larger A_1 mode amplitudes suggesting that the gas has been recently perturbed. Our search for (1) faint stellar structures in the outer regions (up to u_R ~ 26 mag arcsec^{-2}), (2) (Halpha) star-forming satellite galaxies and (3) regions with different colors (stellar populations) along the disk all failed. Such an absence is interpreted using recent numerical simulations to constrain a tidal event with an LMC like galaxy to some dynamical times in the past or to a current very low mass, gas rich accretion. We conclude that a cold accretion mode (gas and small/dark galaxies) may be responsible of the nuclear activity and peculiar (young stars and gas) morphology regardless of the highly isolated environment. Black hole growth in bulgeless galaxies may be triggered by cosmic smooth mass accretion.Comment: 27 pages, 12 figures, accepted for publication in The Astronomical Journa

    Encapsulation of Lactobacillus fermentum K73 by Refractance Window drying

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    The purpose of this work was to model the survival of the microorganism and the kinetics of drying during the encapsulation of Lactobacillus fermentum K73 by Refractance Window drying. A whey culture medium with and without addition of maltodextrin were used as encapsulation matrices. The microorganism with the encapsulation matrices was dried at three water temperatures (333, 343 and 353 K) until reaching balanced moisture. Microorganism survival and thin layer drying kinetics were studied by using mathematical models. Results showed that modified Gompertz model and Midilli model described the survival of the microorganism and the drying kinetics, respectively. The most favorable process conditions found with the mathematical modelling were a drying time of 2460 s, at a temperature of 353 K. At these conditions, a product with 9.1 Log CFU/g and a final humidity of 10% [wet basis] using the culture medium as encapsulation matrix was obtained. The result shows that Refractance Window can be applied to encapsulate the microorganism probiotic with a proper survival of the microorganism

    Análisis de los contenidos curriculares de la formación de los docentes de Educación Física en Iberoamérica: los casos de República Dominicana, Puerto Rico y México

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    El presente estudio forma parte del proyecto de investigación “La elaboración de una propuesta de diseño del currículo para la formación de docentes de Educación Física en Iberoamérica”, proyecto dedicado a examinar y describir el componente del campo curricular de la formación específica en Institutos y Universidades de Educación Física de los países Iberoamericanos. Utilizando como metodología el análisis de contenido, y la referencia conceptual originada en la Praxiología motriz pretende analizar el porcentaje de contenidos que pueden ser considerados específicos en el sentido disciplinar, utilizando las categorías praxiomotrices, nominadas como Deporte, Juego motor, Expresión corporal, Introyección motriz, Adaptación ambiental.Departamento de Educación Físic
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