2,988 research outputs found

    Aplicación Práctica de Métodos para Evaluar In-Situ el Rendimiento Instantáneo de Máquinas Frigoríficas de Compresión Mecánica

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    Libro de actas completo disponible en :http://repositorio.bib.upct.es:8080/dspace/handle/10317/4709Los equipos de aire acondicionado, bombas de calor y refrigeración suponen un elevado consumo de energía eléctrica en los países industrializados. Es frecuente que, en la práctica, estos equipos no estén operando con la eficiencia que debieran. De ahí la importancia de realizar inspecciones periódicas, que incluyan mediciones de los diferentes parámetros de operación de los equipos, destacando por su importancia la medición de su rendimiento (EER/COP). La medición precisa in-situ del EER/COP sobre una instalación frigorífica de compresión mecánica, fuera de un banco de ensayo de laboratorio, ha sido desde siempre una cuestión muy complicada, con muchas dificultades prácticas. Un punto crítico es la medición del caudal de fluido refrigerante. Si no se dispone de un caudalímetro instalado, que es la situación más habitual, hay que recurrir a mediciones indirectas. Hay varios métodos indirectos para estimar el caudal de refrigerante, que se pueden clasificar en los que se basan en: a) el rendimiento volumétrico del compresor, b) el rendimiento global del compresor, c) un balance de energía sobre el condensador y d) un balance de energía sobre el compresor. En este trabajo se ponen en práctica y analizan estos cuatro métodos sobre instalaciones frigoríficas existentes en el laboratorio docente del Departamento de Máquinas y Motores Térmicos de la Universidad de Málaga [1]. Para ello se utiliza un sistema de medición de bajo coste, basado en sensores ONSET [2]. El procesado y análisis de los datos se hace mediante el software Engineering Equation Solver [3]. Se discuten los resultados y dificultades encontradas en la aplicación de los diferentes métodos y se ofrecen recomendaciones a tener en cuenta para abordar instalaciones más complejas.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Valor proteico de las distintas partes de la leguminosa Vigna unguiculata en función de la variedad y práctica de manejo

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    [ESP] Las leguminosas de grano, plantas de la familia Leguminosae, son cultivadas principalmente por sus semillas, ricas en proteínas y energía. Su consumo puede sustituir parcial o totalmente a fuentes tradicionales de proteínas de origen animal como carne o pescado. En este estudio se determinó el contenido en proteínas de las distintas partes de dos variedades de Vigna unguiculata (semillas, vaina, tallo con hojas y raíz) bajo prácticas de manejo convencional y orgánica. Los resultados mostraron un contenido en proteínas más alto en semillas frescas frente a secas, por tanto mayor beneficio nutricional independientemente de la variedad y práctica de manejo. [ENG] The grain legumes (belonging to Leguminosae), are cultivated mainly for their seeds, rich in proteins and energy. Consumption of seeds in these legumes can replace part or totally to conventional sources of animal proteins like meat and fish. In this study, the protein content in the different parts of two varieties of Vigna unguiculata (seeds, pod, stem with leaves and root) was determined, under conventional and organic management practices. The results showed a higher protein content in fresh seeds against dry seeds, and therefore a higher nutritional benefit regardless of cultivar and management practice.Centro Universitario de la Defensa. Escuela de Turismo de Cartagena. Escuela Técnica Superior de Ingeniería Industrial UPCT. Escuela Técnica Superior de Ingeniería de Telecomunicación (ETSIT). Escuela de Ingeniería de Caminos y Minas (EICM). Escuela de Arquitectura e Ingeniería de Edificación (ARQ&IDE). Parque Tecnológico de Fuente Álamo. Navantia. Campus Mare Nostrum. Estación Experimental Agroalimentaria Tomás Ferr

    Reproductive inequalities in the acanthocephalan Corynosoma cetaceum: looking beyond "crowding" effects

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    Background: At present, much research effort has been devoted to investigate overall (average) responses of parasite populations to specific factors, e.g., density-dependence in fecundity or mortality. However, studies on parasite populations usually pay little attention to individual variation (inequality) in reproductive success. A previous study on the acanthocephalan Corynosoma cetaceum in franciscana dolphins, Pontoporia blainvillei, revealed no overall intensity-dependent, or microhabitat effects, on mass and fecundity of worms. In this study, we investigated whether the same factors could influence mass inequalities for this species of acanthocephalan.Methods: A total of 10,138 specimens of C. cetaceum were collected from 10 franciscana dolphins accidentally caught in Buenos Aires Province between 1988-1990. To investigate mass inequalities, all the specimens were sexed, and females were classified according to their developmental stage and weighted. Additionally, the relationship between biomass and fecundity (estimated as the number of acanthors) was investigated for some females. Inequalities in fecundity and biomass were assessed using standard methods, i.e. the Lorenz curve and the Gini coefficient (G).Results: We found a modest, but highly significant linear relationship between mass and fecundity. The G was very low (0.314) compared with that from other helminth species. G values were significantly lower in gravid females, which presumably exhibit a slow rate of growth. Also, G values significantly increased with total intensity, but only for gravid females, and the effect was more predictable considering only the number of gravid females.Conclusions: Apparently, competition between reproducing females increases inequality without producing crowding effects. Although the mechanism whereby this occurs is unclear, gravid females, at higher intensities, expanded their distribution and occupied gut chambers with contrasting environmental conditions, which might result in greater variability in body size. The observed inequalities are not expected to strongly influence the population genetics of C. cetaceum, but they reveal subtle individual effects beyond an overall population impact.Fil: Aznar Avendaño, Francisco Javier. Universidad de Valencia; EspañaFil: Hernández Orts, Jesús Servando. Universidad Nacional del Comahue. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". - Provincia de Río Negro. Ministerio de Agricultura, Ganadería y Pesca. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Centro Nacional Patagónico. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni"; ArgentinaFil: Vélez Rubio, Gabriela Manuela. Universidad de Valencia; España. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de la República; UruguayFil: Fernández, Luis M.. Ceiba Foundation for Tropical Conservation; Estados UnidosFil: Muriel, Nadia T.. No especifíca;Fil: Raga, Juan Antonio. Universidad de Valencia; Españ

    Influencia de diferentes temperaturas de sustrato y concentraciones de ácido indolbutírico en el esquejado de Coriaria myrtifolia

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    Se estudia Coriaria myrtifolia Linn., especie autóctona de interés ecológico (fijadora de N), medicinal (coriamirtina en los frutos) y ornamental (uso en reforestación de zonas pobres en N y como verde de complemento en floristería y en jardinería). Se pretende mejorar su multiplicación por esqueje, mediante uso de ácido indolbutírico (AIB) como hormona favorecedora del enraizamiento que ya ha mostrado su efectividad en numerosas especies, entre ellas Nerium oleander (Kose, 2000), también autóctona del Mediterráneo.Trabajo financiado por los proyectos: MCYT-FEDER AGL2001-2249-C03-01 y AGL2000-052 CICYT-FEDER. Expresamos nuestro agradecimiento a la Dir. Gral. de Investigación y Transf. Tecnológica de la Consejería de Agricultura, Agua y Medio Ambiente de la Región de Murcia por su colaboración para la ejecución de este trabaj

    Classification of mild cognitive impairment and Alzheimer’s Disease with machine-learning techniques using 1H Magnetic Resonance Spectroscopy data

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    [Abstract] Several magnetic resonance techniques have been proposed as non-invasive imaging biomarkers for the evaluation of disease progression and early diagnosis of Alzheimer’s Disease (AD). This work is the first application of the Proton Magnetic Resonance Spectroscopy 1H-MRS data and machine-learning techniques to the classification of AD. A gender-matched cohort of 260 subjects aged between 57 and 99 years from the Alzheimer’s Disease Research Unit, of the Fundación CIEN-Fundación Reina Sofía has been used. A single-layer perceptron was found for AD prediction with only two spectroscopic voxel volumes (Tvol and CSFvol) in the left hippocampus, with an AUROC value of 0.866 (with TPR 0.812 and FPR 0.204) in a filter feature selection approach. These results suggest that knowing the composition of white and grey matter and cerebrospinal fluid of the spectroscopic voxel is essential in a 1H-MRS study to improve the accuracy of the quantifications and classifications, particularly in those studies involving elder patients and neurodegenerative diseases.Instituto de Salud Carlos III; PI13/0028

    Enriched-biochar application increase broccoli nutritional and phytochemical content without detrimental effect on yield

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    BACKGROUND Soil fertility is a major concern during vegetable production. Conventional versus organic fertilization has been studied in order to conserve soil properties. While some reports point out an increase in food nutritional properties, the loss of crop yield under organic conditions continues to be a problem. Thus, an experiment with broccoli in the field was carried out, comparing crop management under conventional fertilization (CF) and two soil amendment treatments: manure pellet (M) and an enriched-biochar (EB) supplemented by an organic fertilizer (AND) applied alone (M + CF; EB+AND) or in combination (M + EB + AND). Crop yield and the nutritional properties in the flowering heads (mineral content, phenolic compounds and glucosinolates (GSLs)), were determined. RESULTS Enriched-biochar and manure as a standalone amendment resulted in higher crop yield regarding CF, but not when they were applied in combination. The number of flowering heads with no-commercial characteristics was lower after enriched-biochar soil application. Finally, enriched-biochar treatment enhanced NO3−, PO43− and SO42− levels in the flowering heads, and some of the ion contents can be associated with mineral changes in the soil after the biochar amendment. Also, the contents of phenolic compounds and indole GSLs were higher after enriched-biochar application compared with the other treatments, GSL increase being due to the higher percentage of sulfur in the plant rather that an adequate N/S ratio. CONCLUSION Application of enriched-biochar amendment in the cultivation of broccoli is appropriate, since there are no losses of yield and an increase in nutritional compounds in the flowering heads. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.The authors thank Carbuna SL for the supply of biochar. The authors thank Pedro Mínguez from El Mirador-CDTA experimental station for availability of the production data. The authors thank Diego Moreno from CEBAS-CSIC for support with glucosinolate analysis. Experiments were funded by Carbuna AG

    Distribution in plant ,substrate and leachate of paclobutrazol following application to containerized Nerium oleander L.seedlings

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    [ENG]Paclobutrazol(PBZ)is a retardant often used in potted ornamental plants to control their growth and compactness. The distribution in plant,substrate and leachate of PBZ applied to containerized oleander seedlings were studied after a single liquid drench application to the substrate surface(20mga.i.perplant) in a nursery dedicated to pot production in SE Spain. PBZ significantly reduced all growth parameters, providing more compact plants of good commercial value and confirming its ability to reduce the vertical growth of native oleander in the nursery. The level of PBZ residues in leaves washigh-erat the end of pot cultivation (156 days post PBZ application) than at the first sampling time(30 days after PBZ applica-tion), where as the level in stems decreased for the same period of time. PBZ residues in roots remained constant during the experimental period. The high level of PBZ residues detected in the substrate 30 days after application had decreased significantly(by67%) by the end of the experiment. A greater leaching fraction was detected for PBZ-treated seedlings and so a greater amount of PBZ was leached into the nursery soil with the irrigation water attheend of the experiment. This greater amount of PBZ leached into the soil represents an important way of contamination in the nursery and a substantial risk to the environment. [ESP] Paclobutrazol (PBZ) es un retardante del crecimiento frecuentemente utilizado en el cultivo de plantas ornamentales en maceta para el control de su crecimiento y compacidad. La distribución en el sustrato, planta y drenaje de PBZ aplicado a plántulas de adelfa en contenedor fue estudiada tras la aplicación de una única dosis a la superficie del sustrato de la maceta (20 mgi.a.por planta) en una plantación comercial de un vivero localizado en el Sureste de España. PBZ redujo significativamente todos los parámetros del crecimiento, proporcionando plantas más compactas de buen valor comercial y conformando su capacidad para reducir el fuerte crecimiento vertical de la adelfa nativa en el vivero. El nivel de residuos de PBZ en hojas resultó más elevado al final del ciclo de cultivo en maceta (156 días tras la aplicación) que a los 30 días de la aplicación, mientras que la cantidad de residuos presentes en el tallo disminuyó para el mismo periodo de tiempo. Los residuos de PBZ en las raíces permanecieron constantes durante todo el período experimental. El elevado contenido de residuos de PBZ detectadosen el sustrato 30 días después de la aplicación se redujo significativamente (enun 67%) al final del experimento. Una mayor fracción de drenaje fue detectada en las plántulas tratadas con PBZ, a la vez que una mayor cantidad de PBZ fue drenado en el suelo del vivero conjuntamente con el agua de riego al final del experimento. Esta mayor cantidad de PBZ drenado en el suelo representa una vía importante de contaminación en el vivero así como un riesgo importante de contaminación medioambiental.This research was supported by CICYT projects(AGL2005-05588-C02-1 and AGL2005-05588-C02-2)and by the Consejería de Agricultura y Agua de la Región de Murcia,program (UPCT-CEBAS-IMIDA 2005)

    Comparative Study of Moodle Plugins to Facilitate the Adoption of Computer-Based Assessments

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    Featured Application This study helps Moodle users to choose the plugin that best suits their needs to create large question banks. The use of Learning Management Systems (LMS) has had rapid growth over the last decades. Great efforts have been recently made to assess online students' performance level, due to the COVID-19 pandemic. Faculty members with limited experience in the use of LMS such as Moodle, Edmodo, MOOC, Blackboard and Google Classroom face challenges creating online tests. This paper presents a descriptive and comparative study of the existing plugins used to import questions into Moodle, classifying them according to the necessary computing resources. Each of the classifications were compared and ranked, and features such as the support for gamification and the option to create parameterised questions are explored. Parameterised questions can generate a large number of different questions, which is very useful for large classes and avoids fraudulent behaviour. The paper outlines an open-source plugin developed by the authors: FastTest PlugIn, recently approved by Moodle. FastTest PlugIn is a promising alternative to mitigate the detected limitations in analysed plugins. FastTest PlugIn was validated in seminars with 230 faculty members, obtaining positive results about expectations and potential recommendations. The features of the main alternative plugins are discussed and compared, describing the potential advantages of FastTest PlugIn

    Application of directly brewed compost extract improves yield and quality in baby leaf lettuce grown hydroponically

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    The aim of this work was to study whether the application of a directly brewed compost extract (added in the nutrient solution or by microsprinkler) could be used to improve the yield and quality of baby leaf red lettuce growing in a floating system, and to control the incidence of Pythium irregulare. Its e_ect on the quality of fresh-cut red lettuce was also studied. For this, two experiments were carried out over two growing cycles (winter–spring and autumn). The results showed that the use of compost extract added to the nutrient solution improved baby leaf lettuce growth and quality, reducing the nitrate content and enhancing the content of potentially health-promoting compounds such as phenols and flavonoids and the antioxidant capacity. Microbial quality was maintained during storage and the compost extract had no negative e_ect on the microbial load of the final product. In addition, application of the compost decreased the population of P. irregulare in the water. It is concluded that the application of directly brewed compost extract is of potential use in a sustainable soilless production system for baby leaf red lettuce, since it improves the yield and quality of the product and is able to control the incidence of P. irregulare.This work was supported by projects AGL2017-84085-C3-3-R and AGL2017-84085-C3-1-R from the Ministerio de Economía y Competitividad of Spain
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