2,289 research outputs found
Ultra-Broadband Directional Couplers Using Microstrip with Dielectric Overlay in Millimeter-Wave Band
Nowadays, millimeter-wave systems are being a key factor to develop wide band applications. In this paper, a directional coupler in millimeter-wave band using dielectric overlay is presented. This leads us to technology aspects, in directional coupler design, are key points to achieve the proper response of the circuit. The coupler proposed in this paper covers the 15-45 GHz band and its response has 15-dB coupling-level, 1-dB coupling-ripple and a reflection coefficient better than 10 dB
La Psicología Colectiva de Maurice Halbwachs
El artículo a cuya lectura invita esta introducción puede ubicarse en el contexto de un conjunto de trabajos sobre la noción de Psicología colectiva que marcaron el trabajo de Maurice Halbwachs (1877-1945) desde sus primeros textos. No es, sin embargo, un texto sobre memoria. Ciertamente podemos encontrar el desarrollo más acabado de lo que implica una Psicología colectiva en los trabajos de Halbwachs sobre las relaciones entre memoria y sociedad. El mismo concepto de memoria colectiva queda perfectamente desarrollado en tres de sus principales obras: Los marcos sociales de la memoria (1925), recientemente traducida al castellano, la investigación sobre la memoria de los lugares evangélicos en Tierra Santa (La Topologie littéraire des Evangiles en Terre sainte, étude de mémoire collective (1941) y su obra póstuma La Memoria Colectiva (1950) de la cual se publicó una selección en el número 2 de esta misma revista
Els textos pusissimers barcelonesos de 1415-1432 en el manuscrit 35 del Monestir de Poblet
El Dr. Josep Perarnau va publicar a l’Arxiu de Textos Catalans Antics 3 (1984) 58-191 uns escrits
teològics medievals en favor de l’extensió universal de la festa de la Immaculada Concepció. Per a la
seva edició va recórrer a diversos manuscrits d’arreu d’Europa sense haver arribat a conèixer el
manuscrit núm. 35 del monestir de Poblet, que conté els textos esmentats. Aquí s’ofereix la descripció
codicològica d’aquest manuscrit i també la col·lació de totes les seves variants de lectura respecte al
text establert aleshores
Peer effects in risk aversion
Utilizando datos sobre adolescentes uruguayos se estima el efecto de los pares en las actitudes hacia el riesgo, en un entorno experimental sobre una muestra de estudiantes de secundari
External validation of the GrazeIn model of pasture dry matter intake and milk yield prediction for cows managed at different calving dates and stocking rates
The aim was to evaluate the prediction accuracy of pasture dry matter intake (PDMI) and milk yield (MY) predicted by the GrazeIn model using a database representing 124 PDMI measurements at paddock level and 2232 MY measurements at cow level. External validation of the model was conducted using data collected from a trial carried out with Holstein-Friesian cows (n=72) while grazed 28 paddocks and were managed in a 2×2 factorial design by considering two calving dates (CD), with different number of days in milk (DIM), early (E, 29 DIM) vs. middle (M, 167 DIM), and two stocking rates (SR), medium (M, 3.9 cows ha-1) vs. high (H, 4.8 cows ha-1), under a rotational grazing system. Cows were randomly assigned to four grazing scenarios (EM, EH, MM and MH). The mean observed PDMI of the total database was 14.2 kg DM cow-1 day-1 while GrazeIn predicted a mean PDMI for the database of 13.8 kg DM cow-1 day-1. The mean bias was −0.4 kg DM cow-1 day-1. GrazeIn predicted PDMI for the total database with a relative prediction error (RPE) of 10.0% at paddock level. The mean observed MY of the database was 23.2 kg cow-1 day-1 while GrazeIn predicted a MY for the database of 23.1 kg cow-1 day-1. The mean bias was –0.1 kg cow-1 day-1. GrazeIn predicted MY for the total database with a mean RPE of 17.3% at cow level. For the scenarios investigated, GrazeIn predicted PDMI and MY with a low level of error which made it a suitable tool for decision support systems
FTIR characterization of isolated fruit cuticles from tomato species
La comunicación arriba reseñada ha sido presentado como póster.The plant cuticle is a lipid extracellular membrane which covers the outer surface of leaves, stems and fruits of higher plants acting as a real interphase between the plant and the environment. The cuticle plays a pivotal role in epidermal development, control of water loss, fruit integrity, firmness and resistance to various disorders [1]. From a morphological point of view, the cuticle (Figure 1) can be described as acutinizedepidermal cell wall [2]. Based on its structural and chemical composition, the cuticle is mainly constituted by a polyester matrix of long chainpolyhydroxy fatty acids named cutin. Additionally, a significant amount of polysaccharides (mainly cellulose, hemicellulose and pectin) is also present. Cuticular waxes, a mixture of different very long chain aliphatic compounds, can be either embedded into the cutin matrix (intracuticular waxes) or deposited on the outer surface of the cuticle (epicuticular waxes) [3]. Finally, phenolic compounds (cinnamic acid derivatives and flavonoids) are also present. In tomato, cuticular flavonoids participate in fruit coloration and their presence is influenced by environmental conditions and the stage of development.As it can be observed in Figure 1, the cuticle has an asymmetrical distribution of its components. In its outer surface waxes and aliphatic compounds are very abundant, while the inner surface is rich in polysaccharides from epidermal cell wall.
Two parameters have been studied, the esterification index (the ratio between the intensities of the stretching vibration band related to ester functional groups (1730 cm-1) and the stretching vibration associated with methylene groups (2918 cm-1)), which isa relative measure of the cross-linking degree of the cutin matrix, and the amount of flavonoids, calculated as the sum of 1606 cm-1and 1624 cm-1 band areas.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
CRECIMIENTO Y CONTENIDO TOTAL DE CAROTENOIDES EN CUATRO CEPAS CHILENAS DE HAEMATOCOCCUS PLUVIALIS FLOTOW, BAJO CONDICIONES DE LABORATORIO
Haematococcus pluvialis is a unicellular green microalga cultivated on a large scale as a natural source of astaxanthin, aketocarotenoid of high commercial value due to its colorant and antioxidant properties. The aim of this study was tocompare growth and total carotenoids among four strains of H. pluvialis isolated from different microhabitats in twogeographical locations in Chile. Growth was carried out under autotrophic and mixotrophic conditions and under twophoton flux densities (PFD) (20 and 85 µmol m-2s -1). Total carotenoid content was estimated on day 45. Most of thestrains grew better under the autotrophic conditions; the highest exponential growth rates were exhibited at the high PFDin all the strains (ranging from 0.73 to 1.20 div day-1) with the exception of CCM-UDEC 023 which showed the sameexponential growth rate with either PFD (0.73 div day-1). However, the cell density estimated on day 14 was higher at thelow PFD in CCM-UDEC 022 and CCM-UDEC 023 (4.4 x 105 and 8.9 x 104 cells ml-1, respectively). The mixotrophiccondition slightly improved the growth rate of the strain CCM-UDEC 021 at the high PFD (from 1.04 div day-1 atautotrophic condition to 1.25 and 1.14 div day-1 at 2mMand 10mM sodium acetate, respectively). The algal dry weightestimated on day 14 was not significantly correlated with the cell density, but it was, to a certain extent, related to theproportion and size of the different cell types quantified on that day. The strain with the highest dry weight at the endof the experimental period and under all the assayed conditions was CCM-UDEC 023. It was also the strain thatproduced the highest total carotenoid content under both autotrophic (5.6 mg l-1 and 95.6 pg cell-1 at the high PFD) andmixotrophic (with 2mM acetate) conditions (10.8 mg l-1 and 297 pg cell-1 at the high PFD). A high intraspecific variabilityin the physiological attributes analyzed existed among the strains under study. Even though the mixotrophic conditionassayed did not substantially improve the growth rate of any strain, it did improve the total carotenoid yield in the strainCCM-UDEC 023.Haematococcus pluvialis es una microalga unicelular verde cultivada masivamente como fuente natural de astaxantina,un cetocarotenoide de alto valor comercial debido a sus propiedades como colorante y antioxidante. El objetivo de esteestudio fue comparar el crecimiento y el contenido de carotenoides totales en 4 cepas de H. pluvialis aisladas dediferentes microhabitats de dos regiones geográficas de Chile. El crecimiento se llevó a cabo en condiciones autotróficasy mixotróficas a dos densidades de flujo fotónico (DFF) (20 y 85 µmol m-2s -1). El contenido de carotenoides totales seestimó el día 45. La mayoría de las cepas crecieron mejor en condiciones autotróficas; las más altas tasas de crecimientoexponencial se presentaron a la mayor DFF en todas las cepas (fluctuó entre 0,73 y 1,20 div día-1) a excepción de lacepa CCM-UDEC 023 la cual mostró la misma tasa de crecimiento exponencial a cualquier DFF (0,73 div día-1). Sinembargo, la densidad celular estimada el día 14 fue mayor a la menor DFF en CCM-UDEC 022 y CCM-UDEC 023(4,4 x 105 y 8,9 x 104 céls ml-1, respectivamente). La condición mixotrófica mejoró levemente la tasa de crecimiento dela cepa CCM-UDEC 021 a la mayor DFF (de 1,04 div día-1 en condición autotrófica a 1,25 y 1,14 div día-1 a 2mM y10mM de acetato de sodio, respectivamente). El peso seco algal estimado el día 14 no mostró correlación significativa
con la densidad celular, pero sí, en un cierto sentido, con la proporción y el tamaño de los diferentes tipos celulares a esedía. La cepa que presentó el mayor peso seco al final del periodo experimental y bajo todas las condiciones ensayadas fueCCM-UDEC 023. Esta fue también la cepa que produjo la cantidad de carotenoides totales más alta, tanto en condicionesautotróficas (5,6 mg l-1 y 95,6 pg cél-1 a la mayor DFF) como mixotróficas (con 2mM acetato) (10,8 mg l-1 y 297 pg cél-1 a lamayor DFF). Las cepas en estudio presentaron una alta variabilidad intraespecífica en los atributos fisiológicos analizados.Aún cuando las condiciones mixotróficas ensayadas no aumentaron sustancialmente las tasas de crecimiento de alguna de lascepas (CCM-UDEC 020, CCM-UDEC 022), esta condición sí mejoró la producción de carotenoides totales en la cepaCCM-UDEC 023
SoNeUCONADM: the administrative model for SoNeUCONABC usage control model
The popularity of Web Based Social Networks (WBSNs) encourages their enhancement. Many WBSN data is considered personal data and access control management plays a key role in this regard. The point is not only to manage access control but to determine how administration should be performed. Based on SoNeUCONABC, an expressive usage control model that allows fine-grained access control management, this paper presents SoNeUCONADM, the complementary administrative model. Based on a pair of related and popular administrative models, the evaluation proves the completeness of SoNeUCONADM
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