82 research outputs found

    Modelling the thermal effects on structural components of composite slabs under fire conditions

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    This paper presents a finite-element-based computational model to evaluate the thermal behaviour of composite slabs with a steel deck submitted to standard fire exposure. This computational model is used to estimate the temperatures in the slab components that contribute to the fire resistance according to the load-bearing criterion defined in the standards. The numerical results are validated with experimental results, and a parametric study of the effect of the thickness of the concrete on the temperatures of the slab components is presented. Composite slabs with normal or lightweight concrete and different steel deck geometries (trapezoidal and re-entrant) were considered in the simulations. In addition, the numerical temperatures are compared with those obtained using the simplified method provided by the standards. The results of the simulations show that the temperatures predicted by the simplified method led, in most cases, to an unsafe design of the composite slab. Based on the numerical results, a new analytical method, alternative to the simplified method, is defined in order to accurately determine the temperatures at the slab components and, thus, the bending resistance of the composite slabs under fire conditions.info:eu-repo/semantics/publishedVersio

    Use of Olive and Sunflower Oil Hydrogel Emulsions as Pork Fat Replacers in Goat Meat Burgers: Fat Reduction and Effects in Lipidic Quality

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    [EN] Diversified strategies to incorporate healthier lipids in processed meat products are being developed. Alternative fat sources to replace animal fat associated with the reduction of fat content are some of the methods used to obtain healthier meat products well recognized by consumers. In order to create a healthier product that can also be consumed in the Halal and Kosher consumer markets, an experimental study was developed to assess the effects of replacing the pork fat (4%) with the same amount of hydrogel emulsion incorporating olive oil or sunflower oil. Three burgers were randomly selected from each lot manufactured and analyzed in triplicate. Burgers were physicochemical analyzed for pH, water activity, composition, fatty acid profile, color, yield, texture, oxidative stability, and volatile compounds and compared according to the fat source. Burgers with hydrogel emulsions can be considered reduced-fat meat products with a healthier fatty acid profile than pork fat burgers. The use of hydrogel emulsions did not negatively affect the quality characteristics assessed in the product and improved the oxidative stability during the storage of cooked burgers. By the characteristics and formulations evaluated, the replacement of pork fat with olive oil hydrogel emulsion proved to be the most effective strategy for obtaining a healthier goat meat productSIThis research received no external fundin

    Ghanaian Cocoa (Theobroma cacao L.) Bean Shells Coproducts: Effect of Particle Size on Chemical Composition, Bioactive Compound Content and Antioxidant Activity

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    The worldwide cocoa bean shell (CBS) generation is estimated at around 900,000 tons. In their composition, this coproduct showed several bioactive compounds like methylxanthines or polyphenolic compounds. Thus, the aim of this work was to investigate the effects of different particle sizes on the chemical composition, physico-chemical, bioactive compounds content, and antioxidant properties of flours obtained from cocoa (Theobroma cacao L.) bean shells. The flours obtained from CBS with different particle sizes had high content of dietary fiber (61.18–65.58 g/100 g). The polyphenolic profile identified seven compounds being epicatechin and catechin (values ranged 4.56–6.33 and 2.11–4.56 mg/g, respectively) as the most abundant compounds. Additionally, the methylxanthines theobromine and caffeine were quantified with values ranging from 7.12 to 12.77 and 4.02 to 6.13 mg/g, respectively. For the fatty acid profile, the principal compounds identified were oleic, stearic and palmitic acids. CBS had antioxidant capacity with all methods assayed. For DPPH, ABTS and FRAP assays values ranged between 2.35–5.53, 3.39–11.55, and 3.84–7.62 mg Trolox equivalents/g sample, respectively. This study suggests that cocoa bean shells may constitute a valuable coproduct for the food industry due to its high content in valuable bioactive compounds

    Improving the lipid profile of beef burgers added with chia oil (Salvia hispanica L.) or hemp oil (Cannabis sativa L.) gelled emulsions as partial animal fat replacers

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    New gelled emulsions (GE) based on amaranth flour mixed with chia or hemp oil were developed and used as partial pork back-fat replacer (25 and 50%) in beef burgers. The addition of GE decreased the fat content in the burgers between 12% and 33%. The use of GE decreased the amount of palmitic, stearic, and oleic fatty acids and increased the amount of linolenic (higher in amaranth-hemp GE) and α-linolenic (higher in amaranth-chia GE) fatty acids. Both GE improved the n-6/n-3 and PUFA/SFA nutritional ratios in burgers and the AI, TI, h/H indices related to healthy properties of lipid fractions. Color, water activity, pH, and texture were not affected by the addition of GE but cooking loss, shrinkage, and thickness changes were increased (higher in amaranth-hemp GE). Burgers containing amaranth-chia GE (both raw and cooked) resulted in more susceptibility to lipid oxidation than the others and also resulted in lower sensorial acceptability. As a general conclusion, the use of amaranthhemp GE as pork backfat substitute improve nutritional characteristics of the burgers without affecting technological or sensory properties

    Focused Coordination Models towards Sustainability in Higher Education. Case of Quevedo State Technical University (Ecuador)

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    This research studied the relationship between coordination models (CM) focused on sustainability and satisfaction, as a competitive advantage, which increases sustainability at the Quevedo State Technical University (UTEQ) in Ecuador. A survey in situ on a random sample of 3200 students was done in 2019. By using multivariate methods, an organizational typology was built. Next, CM were related to the level of student satisfaction by general linear model (GLM). Twenty-three organizational variables were grouped into six components that explained 66.23% of the variance. A typology with three groups was built: Cluster 1 with a moderate CM level (44.57% of the sample), Cluster 2 with a low level of CM (38.18%), and Cluster 3 with a high level of CM (15.25%). By GLM, a positive relation between typology and students’ levels of satisfaction was found. Therefore, an increase of CM turned into a major satisfaction level at UTEQ. We suggest, as a priority, to improve communication amongst students and administrative staff. Communication should be frequent, accurate, on time, and oriented to solve problems. It would also be positive to increase the CM amongst students and representatives in solving communication problems, sharing knowledge, goals, and mutual respect

    Structural control of the non-ionic surfactant alcohol ethoxylates (AEOs) on transport in natural soils

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    Surfactants, after use, enter the environment through diffuse and point sources such as irrigation with treated and non-treated waste water and urban and industrial wastewater discharges. For the group of non-ionic synthetic surfactant alcohol ethoxylates (AEOs), most of the available information is restricted to the levels and fate in aquatic systems, whereas current knowledge of their behavior in soils is very limited. Here we characterize the behavior of different homologs (C12-C18) and ethoxymers (E03, E06, and E08) of the AEOs through batch experiments and under unsaturated flow conditions during infiltration experiments. Experiments used two different agricultural soils from a region irrigated with reclaimed water (Guadalete River basin, SW Spain). In parallel, water flow and chemical transport were modelled using the HYDRUS-1D software package, calibrated using the infiltration experimental data. Estimates of water flow and reactive transport of all surfactants were in good agreement between infiltration experiments and simulations. The sorption process followed a Freundlich isotherm for most of the target compounds. A systematic comparison between sorption data obtained from batch and infiltration experiments revealed that the sorption coefficient (K-d) was generally lower in infiltration experiments, performed under environmental flow conditions, than in batch experiments in the absence of flow, whereas the exponent (beta) did not show significant differences. For the low clay and organic carbon content of the soils used, no clear dependence of K-d on them was observed. Our work thus highlights the need to use reactive transport parameterization inferred under realistic conditions to assess the risk associated with alcohol ethoxylates in subsurface environments. (C) 2020 The Authors. Published by Elsevier Ltd

    Construction and content validation of a measurement tool to evaluate person-centered therapeutic relationships in physiotherapy services

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    Objectives: this study sought to develop a tool for evaluating person-centered therapeutic relationships within physiotherapy services, and to examine the content validity of the same. Methods: a mixed qualitative and quantitative study was performed in three distinct phases: 1) the items were generated based on a literature review and a content analysis of focus groups of patients and physiotherapists; 2) an e-Delphi survey process was performed based on three rounds to select and refine the proposed questionnaire; 3) two rounds of cognitive interviews were conducted to evaluate the comprehension of items, the clarity of language and the appropriateness and relevance of content. Results: thirty-one items were generated based on the seven domains identified after the analysis of four focus groups of physiotherapists and four patient focus groups. Nine experts participated in the e-Delphi survey. Fifty-five patients participated in the two rounds of the cognitive pre-tests. Participating patients were from public and private physical therapy services. Based on the participants' suggestions, four items were removed, and four were added, whereas 16 were reworded. Conclusions: the final tool comprised 31 items divided into seven domains. The response format was based on a 5-point Likert frequency scale. The response options ranged from "strongly agree" to "strongly disagree"

    Distributed radio map reconstruction for 5G automotive

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    Se espera que los mapas de entorno radio sean una herramienta esencial para la optimización y gestión de recursos del 5G en vehículos. En este trabajo, consideramos el problema de la reconstrucción del mapa de entorno radio utilizando una red de sensores inalámbricos formada por nodos sensores en vehículos, nodos de acceso de una infraestructura de ciudad inteligente, etc. Debido a las limitaciones de recursos en las redes de sensores, es crucial seleccionar un pequeño número de mediciones de los sensores para reconstruir el campo. En este contexto, presentamos un novedoso algoritmo distribuido basado en el método de regresión Kriging para la reconstrucción del mapa de entorno radio en términos de potencia media recibida en lugares donde no se dispone de mediciones de los sensores. Los componentes de pérdida de trayectoria y de sombra del canal inalámbrico se estiman por separado. Para la estimación de las pérdidas por sombra, se forman grupos de sensores de forma adaptativa y su tamaño se optimiza en en términos del menor número de sensores posible minimizando la varianza ordinaria de Kriging. Se obtiene la complejidad del algoritmo propuesto y se presentan resultados de simulación para mostrar la eficacia del algoritmo para la reconstrucción del campo.GRISOLIA/2012/028, RACHEL TEC2013-47141-C4-4-RRadio maps are expected to be an essential tool for the resource optimization and management of 5G automotive. In this paper, we consider the problem of radio map reconstruction using a wireless sensor network formed by sensor nodes in vehicles, access nodes from a smart city infrastructure, etc. Due to limited resource constraints in sensor networks, it is crucial to select a small number of sensor measurements for field reconstruction. In this context, we present a novel distributed incremental clustering algorithm based on the regression Kriging method for radio map reconstruction in terms of average received power at locations where no sensor measurements are available. The path-loss and shadowing components of the wireless channel are separately estimated. For shadowing estimation, clusters of sensors are adaptively formed and their size is optimized in terms of the least number of sensors by minimizing the ordinary Kriging variance. The complexity of the proposed algorithm is analyzed and simulation results are presented to showcase the algorithm efficacy to field reconstruction

    Radio environment map estimation based on communication cost modeling for heterogeneous networks

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    Los mapas del entorno radioeléctrico pueden ser una poderosa herramienta para lograr una asignación de recursos eficiente y consciente del contexto en las redes heterogéneas 5G. En este trabajo, consideramos una red heterogénea formada por una red celular tradicional y una red de sensores inalámbricos. El papel de la red de sensores inalámbricos es estimar el mapa del entorno radioeléctrico de la célula utilizando una técnica de interpolación geoestadística denominada Kriging. En un trabajo anterior se propuso un algoritmo de agrupación distribuida de sensores para reducir la complejidad de la estimación. En nuestra contribución, el proceso de formación de clústeres se modifica para incluir el coste de la comunicación como métrica para determinar qué nodos se incluyen en cada clúster. Los resultados de la simulación muestran que el algoritmo propuesto mejora la calidad de la estimación en redes de sensores inalámbricos dispersos, y preserva la vida útil de la red al formar clústeres con una media de 5 nodos.RACHEL TEC2013-47141-C4-4-RRadio environment maps can be a powerful tool for achieving efficient context-aware resource allocation in 5G heterogeneous networks. In this paper, we consider an heterogeneous network formed by a traditional cellular network and a wireless sensor network. The role of the wireless sensor network is to estimate the radio environment map of the cell using a geostatistical interpolation technique named Kriging. A distributed clustering algorithm was proposed in a previous work in order to decrease the complexity of the estimation. In our contribution, the clustering formation process is modified to include the communication cost as a metric to determine which nodes are included in each cluster. Simulation results show that the proposed algorithm improves the estimation quality for sparse wireless sensor networks, and preserves the network lifetime by forming clusters with an average of 5 nodes

    Semantically-enhanced advertisement recommender systems in social networks

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    El suministro de recomendaciones en los sistemas sociales lleva ya algún tiempo en el punto de mira tanto de los académicos como de la industria. Los gigantes de las redes sociales como Facebook, LinkedIn, Myspace, etc., están ansiosos por encontrar la bala de plata de la recomendación. Estas aplicaciones permiten a los clientes dar forma a unas determinadas redes sociales a través de sus comunicaciones sociales cooperativas cotidianas. Mientras tanto, la experiencia online actual depende progresivamente de la asociación social. Una de las principales preocupaciones en la red social es establecer un plan de negocio exitoso para obtener más beneficios de la red social. Hacer un negocio en cada plataforma necesita un buen plan de negocio con algunas soluciones importantes, como anunciar los productos o servicios de otras empresas, lo que sería una especie de marketing para esos negocios externos. En este estudio se presentará una filosofía de un sistema que habla de una estructura integral de sistema de recomendación de publicidad para las redes sociales. El marco utiliza una lógica semántica para proporcionar los productos recomendados y esta capacidad puede diferenciar la parte de recomendación del marco de los métodos clásicos de recomendación. En resumen, el marco propuesto en este estudio se ha diseñado de forma que pueda generar recomendaciones publicitarias de forma simplificada y eficaz para los usuarios de las redes sociales.RACHEL TEC2013-47141-C4-4-RProviding recommendations on social systems has been in the spotlight of both academics and industry for some time already. Social network giants like Facebook, LinkedIn, Myspace, etc., are eager to find the silver bullet of recommendation. These applications permit clients to shape a few certain social networks through their day-by-day social cooperative communications. In the meantime, today's online experience depends progressively on social association. One of the main concerns in social network is establishing a successful business plan to make more profit from the social network. Doing a business on every platform needs a good business plan with some important solutions such as advertise the products or services of other companies which would be a kind of marketing for those external businesses. In this study a philosophy of a system speaking to of a comprehensive structure of advertisement recommender system for social networks will be presented. The framework uses a semantic logic to provide the recommended products and this capability can differentiate the recommender part of the framework from classical recommender methods. Briefly, the framework proposed in this study has been designed in a form that can generate advertisement recommendations in a simplified and effective way for social network users
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