Influencia del tipo de derivado celulósico sobre la textura y la estabilidad oxidativa y térmica de oleogeles de aceite de soja

The use oleogels (defined as edible oils entrapped in a three-dimensional network employing a self-assembled structuring agent) has recently been proposed to replace saturated fat or trans-fats in foods. In this work the effects of different cellulose derivative mixtures (Avicel, ethyl cellulose and α-cellulose) on lipid stability, glass transition temperature and the texture of soybean oil oleogels were determined by employing a mixture design approach. Avicel affected lipid stability, increasing the oxidative rancidity and peroxide values of oleogels. Oleogels with higher proportions of Avicel also presented higher transition temperatures. A higher percent of ethyl cellulose and α-cellulose in the oleogel mixture resulted in a more stable system with lower oil rancidity and lower glass transition temperatures. In addition, Avicel resulted in a softer and less tacky texture, an important characteristic to consider for food applications.Recientemente, ha sido propuesto el uso de oleogeles (definido como aceites comestibles atrapados en una red tridimensional que ocupa un agente estructurante de auto-ensamblado) como substituto de grasa saturada o grasas trans en alimentos. En este trabajo el efecto de mezclas de diferentes derivados celulósicos (Avicel, etil celulosa y α-celulosa) sobre la estabilidad de lípidos, temperaturas de transición térmica y textura de oleogeles de aceite de soja fueron determinados utilizando un diseño de mezclas. Avicel afectó la estabilidad de lípidos, aumentando la rancidez oxidativa y valores de peróxido en los oleogeles. Oleogeles con mayores proporciones de Avicel también presentaron temperaturas de transición térmica más altas. Porcentajes más altos de etil celulosa y α-celulosa resultaron en un sistema más estable con menor rancidez oxidativa y menores temperaturas de transición térmica. Sin embargo, Avicel resultó en una textura más suave y menos pegajosa, una característica importante a considerar para su aplicación en alimentos

Influence of the type of cellulosic derivatives on the texture, and oxidative and thermal stability of soybean oil oleogel

The use oleogels (defined as edible oils entrapped in a three-dimensional network employing a self-assembled structuring agent) has recently been proposed to replace saturated fat or trans-fats in foods. In this work the effects of different cellulose derivative mixtures (Avicel, ethyl cellulose and α-cellulose) on lipid stability, glass transition temperature and the texture of soybean oil oleogels were determined by employing a mixture design approach. Avicel affected lipid stability, increasing the oxidative rancidity and peroxide values of oleogels. Oleogels with higher proportions of Avicel also presented higher transition temperatures. A higher percent of ethyl cellulose and α-cellulose in the oleogel mixture resulted in a more stable system with lower oil rancidity and lower glass transition temperatures. In addition, Avicel resulted in a softer and less tacky texture, an important characteristic to consider for food applications.<br><br>Recientemente, ha sido propuesto el uso de oleogeles (definido como aceites comestibles atrapados en una red tridimensional que ocupa un agente estructurante de auto-ensamblado) como substituto de grasa saturada o grasas trans en alimentos. En este trabajo el efecto de mezclas de diferentes derivados celulósicos (Avicel, etil celulosa y α-celulosa) sobre la estabilidad de lípidos, temperaturas de transición térmica y textura de oleogeles de aceite de soja fueron determinados utilizando un diseño de mezclas. Avicel afectó la estabilidad de lípidos, aumentando la rancidez oxidativa y valores de peróxido en los oleogeles. Oleogeles con mayores proporciones de Avicel también presentaron temperaturas de transición térmica más altas. Porcentajes más altos de etil celulosa y α-celulosa resultaron en un sistema más estable con menor rancidez oxidativa y menores temperaturas de transición térmica. Sin embargo, Avicel resultó en una textura más suave y menos pegajosa, una característica importante a considerar para su aplicación en alimentos

North African dust intrusions and increased risk of respiratory diseases in Southern Portugal

The study of dust intrusions in Portugal is still a subject on which little investigation has been made, especially in terms of their effects. Thus, this work aims to achieve two goals: firstly, to characterize the dust intrusions in the study area; and secondly, to evaluate the possible statistical association between the dust intrusion days and hospital admissions due to respiratory diseases. Dust intrusions in Portugal are prevalent during the summer season. During this season, the dust plumes tend to cover broader areas than in the other seasons and they have origin in the North African countries. In the study area for the period between 2005 and 2015, the relative risk of urgent hospitalizations due to respiratory diseases was 12.6% higher during dust intrusion days. In order to obtain this statistical association, a Distributed Lag Nonlinear Model was developed. With this work, we expect to help the development of further studies regarding North African dust intrusions in Portugal, more precisely their effects on human health.info:eu-repo/semantics/acceptedVersio

Rainfall-triggered landslides in the Lisbon region over 2006 and relationships with the North Atlantic Oscillation

International audienceLandslides occurred in the Lisbon area during the last 50 years were almost always induced by rainfall and have been used to establish rainfall thresholds for regional landslide activity. In 2006, three new rainfall-triggered landslide events occurred in the study area, namely on the 20 March, the 25?27 October, and the 28 November. Landslide events occurred in March and October 2006 include shallow translational slides and few debris flows, and the corresponding absolute antecedent rainfall was found to be above the threshold for durations ranging from 4 to 10 days. These events also fit the combined threshold of daily precipitation and 5 days calibrated antecedent rainfall values. Likewise the landslide event that took place in late November 2006 includes some slope movements with deeper slip surfaces, when compared with landslides dating from March and October. Moreover, the corresponding absolute antecedent rainfall was also found to be above the 40-day period rainfall threshold. Here we characterize in detail the short and long-term atmospheric circulation conditions that were responsible for the intense rainfall episodes that have triggered the corresponding landslide events. It is shown that the three rainfall episodes correspond to considerably different synoptic atmospheric patterns, with the March episode being associated to an intense cut-off low system while the October and November episodes appear to be related to more typical Atlantic low pressure systems (and associated fronts) travelling eastwards. Finally, we analyse the role played by the North Atlantic Oscillation (NAO) during those months marked by landslide activity. It is shown that the NAO index was consistently negative (usually associated with above average precipitation) for the months prior to the landslide events, i.e. between October 2005 and March 2006, and again between August and October 2006

Forestry restoration in abandoned pastures of Urochloa by different sizes of brushwood.

A galharia é um método de complexação ambiental, que consiste no aproveitamento de resíduos vegetais. Esse método, quando bem estabelecido tecnicamente, pode exercer influência sobre a qualidade da cama de sementes, favorecendo o estabelecimento de plantas nativas e a restauração do ecossistema. Dessa forma, objetivou-se avaliar a eficiência de galharia para a indução da regeneração natural de espécies nativas em área coberta por gramíneas exóticas inibidoras do gênero Urochloa, bem como verificar o tamanho mínimo necessário para conter a reinvasão das forrageiras. Como hipótese, adotou-se a largura mínima de 4 m como suficiente para o estabelecimento da regeneração natural, antes da reocupação das forrageiras. O experimento foi conduzido entre maio 2014 e maio 2016 em Morretes-PR, na Floresta Ombrófila Densa de Terras Baixas. Foram implantados sete tamanhos de galharia: 6 x 1, 6 x 2, 6 x 3, 6 x 4, 6 x 5, 6 x 6 m e testemunha. As espécies lenhosas foram identificadas e contadas e a porcentagem de cobertura herbácea estimada após 4, 8, 12, 18 e 24 meses. Não se verificou retomada da sucessão natural por espécies nativas. Independentemente do tamanho, a galharia foi ineficiente para conter a reinvasão pelas gramíneas a partir das bordas das parcelas e, como pilha de resíduos, dificultou o estabelecimento de espécies lenhosas. Para a criação de safe sites e consequente restauração via regeneração natural, faz-se necessária a eliminação local das forrageiras Urochloa, sem a qual espécies nativas terão pouca probabilidade de sobreviver

Stereo vision-based obstacle avoidance for micro air vehicles using an egocylindrical image space representation

Micro air vehicles which operate autonomously at low altitude in cluttered environments require a method for onboard obstacle avoidance for safe operation. Previous methods deploy either purely reactive approaches, mapping low-level visual features directly to actuator inputs to maneuver the vehicle around the obstacle, or deliberative methods that use on-board 3-D sensors to create a 3-D, voxel-based world model, which is then used to generate collision free 3-D trajectories. In this paper, we use forward-looking stereo vision with a large horizontal and vertical field of view and project range from stereo into a novel robot-centered, cylindrical, inverse range map we call an egocylinder. With this implementation we reduce the complexity of our world representation from a 3D map to a 2.5D image-space representation, which supports very efficient motion planning and collision checking, and allows to implement configuration space expansion as an image processing function directly on the egocylinder. Deploying a fast reactive motion planner directly on the configuration space expanded egocylinder image, we demonstrate the effectiveness of this new approach experimentally in an indoor environment

Rainfall-triggered landslides in the Lisbon region over 2006 and relationships with the North Atlantic Oscillation

Landslides occurred in the Lisbon area during the last 50 years were almost always induced by rainfall and have been used to establish rainfall thresholds for regional landslide activity. In 2006, three new rainfall-triggered landslide events occurred in the study area, namely on the 20 March, the 25–27 October, and the 28 November. Landslide events occurred in March and October 2006 include shallow translational slides and few debris flows, and the corresponding absolute antecedent rainfall was found to be above the threshold for durations ranging from 4 to 10 days. These events also fit the combined threshold of daily precipitation and 5 days calibrated antecedent rainfall values. Likewise the landslide event that took place in late November 2006 includes some slope movements with deeper slip surfaces, when compared with landslides dating from March and October. Moreover, the corresponding absolute antecedent rainfall was also found to be above the 40-day period rainfall threshold. Here we characterize in detail the short and long-term atmospheric circulation conditions that were responsible for the intense rainfall episodes that have triggered the corresponding landslide events. It is shown that the three rainfall episodes correspond to considerably different synoptic atmospheric patterns, with the March episode being associated to an intense cut-off low system while the October and November episodes appear to be related to more typical Atlantic low pressure systems (and associated fronts) travelling eastwards. Finally, we analyse the role played by the North Atlantic Oscillation (NAO) during those months marked by landslide activity. It is shown that the NAO index was consistently negative (usually associated with above average precipitation) for the months prior to the landslide events, i.e. between October 2005 and March 2006, and again between August and October 2006.info:eu-repo/semantics/publishedVersio

Utilização de cartas de controle multivariado no monitoramento de nutrientes em solo in situ.

A análise de solos engloba um complexo processo que demanda tempo e custos, e dificulta o fornecimento de informações em tempo real dos cultivos. A análise de solos in situ usando sensores é de grande importância na agricultura moderna, fornecendo informação contínua de diversos parâmetros físico-químicos do solo. Neste trabalho apresentamos a aplicação de sondas de análise multiparamétrica constituídas de quatro sensores químicos ? eletrodos íon-seletivos para K+, NH4 +, PO3 4- e NO3 - ? e um sensor de temperatura no monitoramento de um solo adubado com vinhaça e cultivado com alfafa (Medicago sativa L.). A avaliação da evolução do sistema ? preparo do solo, adubação com a vinhaça, plantio e crescimento da alfafa ? foi realizada com o emprego de cartas de controle estatístico multivariado sobre os sinais fornecidos pelas sondas