1,555 research outputs found

    Application of nanotechnology in the agro-food sector

    Get PDF
    Nanotechnology is an emerging field of research that has been widely applied in different scientific and engineering areas. The agro-food sector is not an exception, which considers its applicability in several areas of major interest for both consumers and producers. This review considers major concepts related to nanostructures and nano-based instruments used in the food sector, as well as their applications in agro-food products. Food safety through the use of nanosensors for pathogen detection, smart packaging, and valorisation of food products by nanoencapsulation/nanodelivery of food ingredients (e.g. flavours) are examples of important areas of nanotechnology. Consumers' apprehension regarding food stability and safety issues is also considered.info:eu-repo/semantics/publishedVersio

    Methods for estimating the upcrossings index: improvements and comparison

    Get PDF
    The upcrossings index 0≤η≤1, as a measure of the degree of local dependence in the upcrossings of a high level by a stationary process, plays, together with the extremal index θ, an important role in extreme events modelling. For stationary processes, verifying a long range dependence condition, upcrossings of high thresholds in different blocks can be assumed asymptotically independent and therefore blocks estimators for the upcrossings index can be easily constructed using disjoint blocks. In this paper we focus on the estimation of the upcrossings index via the blocks method and properties such as consistency and asymptotic normality are studied. Besides this new estimation approach for this parameter, we also enlarge its family of runs estimators and improve estimation within this class by providing an empirical way of checking local dependence conditions that control the clustering of upcrossings. We compare the performance of a range of different estimators for η and illustrate the methods using simulated data and financial data.info:eu-repo/semantics/publishedVersio

    The effect of a home-based, gamified stability skills intervention on 4-5-year-old children's physical and cognitive outcomes:A pilot study

    Get PDF
    Background: Stability skills (e.g., static/dynamic balance) are a precursor for other movement skill development (e.g., jumping, catching). However, young children consistently demonstrate low stability and movement skill ability. There is therefore a need to develop effective strategies to improve stability skills in early childhood. Aim: To pilot the effect of a home-based gamified stability skills intervention on 4-5-year-old children's physical skills, self-perceptions and cognitions. Methods: One-hundred-and-eleven 4-5-year-old children participated from three schools. Two schools were allocated into the intervention group (n = 66 children, 33 boys) and one to the control group (n = 45 children, 25 boys). Stability, fundamental movement skills, perceived motor competence, and cognition were assessed at baseline and at post-intervention. The intervention group was given a booklet detailing the 12-week gamified stability skill intervention. The control group participated in their usual weekly activities. Results: A series of ANCOVAs controlling for baseline values demonstrated significantly higher stability skills (F(1,93) = 24.79, p &lt; 0.001, partial η2 = 0.212), fundamental movement skills (F(1,94) = 15.5, p = &lt; 0.001, partial η2 = 0.139), perceived motor competence (F(1,96) = 5.48, p = 0.021, partial η2 = 0.054) and cognition (F(1,96) = 15.5, p = &lt; 0.001, partial η2 = 0.139) at post-test for the intervention versus control groups. Discussion: This study demonstrates that a home-based, gamified, stability skills intervention enhances stability skills, fundamental movement skills, perceived motor competence and cognition in children aged 4-5-years old.</p

    Life cycle assessment of a renewable energy generation system with a vanadium redox flow battery in a NZEB household

    Get PDF
    6th International Conference on Energy and Environment ResearchBuildings are responsible for a significant part of the global energy consumption. Besides the need to improve their energy efficiency, new buildings also need to generate their own energy, preferably from renewable sources, to become more sustainable. As renewable energy generation is strongly dependent on the climatic conditions, energy storage must be considered when designing such a system. In this study, a cradle-to-grave life cycle assessment (LCA) study of a renewable energy generation system with a prototype Vanadium flow battery integrated in a Near Zero Energy Building (NZEB) is performed. A combined grid-connected PV and a solar thermal system generates the energy, and it was dimensioned to supply the annual energy needs of a household in Porto, Portugal considering the local climatic conditions. As an end of life scenario, it is assumed that the battery is dismantled and most of the materials are recycled. A functional unit of 1 kWh of supplied energy to the system was considered, and study results show that environmental impacts are reduced when the energy is produced onsite and the battery components are recycled or reused. A sensitivity analysis was conducted changing the household’s geographic location.Authors thank the financial support of projects “SunStorage - Harvesting and storage of solar energy”, with reference POCI-01-0145-FEDER-016387, funded by European Regional Development Fund (ERDF), through COMPETE 2020 - Operational Programme for Competitiveness and Internationalization (OPCI), and to FCT - Fundação para a Ciência e a Tecnologia I.P., for funding project IF/01093/2014/CP1249/CT0003, research grants IF/01093/2014 and SFRH/BPD/112003/2015, and financial support of POCI-01-0145-FEDER-006939 (Laboratory for Process Engineering, Environment, Biotechnology and Energy - LEPABE, UID/EQU/00511/2019) funded by FEDER through COMPETE2020-POCI and by national funds through FCT/MCTES (PIDDAC). Authors would also like to thank Dr. Ricardo André Ribeiro Monteiro for the valuable information regarding the vanadium battery prototype obtained within the Sunstorage project.info:eu-repo/semantics/publishedVersio

    Graph Creation, Visualisation and Transformation

    Full text link
    We describe a tool to create, edit, visualise and compute with interaction nets - a form of graph rewriting systems. The editor, called GraphPaper, allows users to create and edit graphs and their transformation rules using an intuitive user interface. The editor uses the functionalities of the TULIP system, which gives us access to a wealth of visualisation algorithms. Interaction nets are not only a formalism for the specification of graphs, but also a rewrite-based computation model. We discuss graph rewriting strategies and a language to express them in order to perform strategic interaction net rewriting

    Identifying and prioritising services in European terrestrial and freshwater ecosystems

    Get PDF
    Ecosystems are multifunctional and provide humanity with a broad array of vital services. Effective management of services requires an improved evidence base, identifying the role of ecosystems in delivering multiple services, which can assist policy-makers in maintaining them. Here, information from the literature and scientific experts was used to systematically document the importance of services and identify trends in their use and status over time for the main terrestrial and freshwater ecosystems in Europe. The results from this review show that intensively managed ecosystems contribute mostly to vital provisioning services (e.g. agro-ecosystems provide food via crops and livestock, and forests provide wood), while semi-natural ecosystems (e.g. grasslands and mountains) are key contributors of genetic resources and cultural services (e.g. aesthetic values and sense of place). The most recent European trends in human use of services show increases in demand for crops from agro-ecosystems, timber from forests, water flow regulation from rivers, wetlands and mountains, and recreation and ecotourism in most ecosystems, but decreases in livestock production, freshwater capture fisheries, wild foods and virtually all services associated with ecosystems which have considerably decreased in area (e.g. semi-natural grasslands). The condition of the majority of services show either a degraded or mixed status across Europe with the exception of recent enhancements in timber production in forests and mountains, freshwater provision, water/erosion/natural hazard regulation and recreation/ecotourism in mountains, and climate regulation in forests. Key gaps in knowledge were evident for certain services across all ecosystems, including the provision of biochemicals and natural medicines, genetic resources and the regulating services of seed dispersal, pest/disease regulation and invasion resistance

    Positivity Bias in Customer Satisfaction Ratings

    Full text link
    Customer ratings are valuable sources to understand their satisfaction and are critical for designing better customer experiences and recommendations. The majority of customers, however, do not respond to rating surveys, which makes the result less representative. To understand overall satisfaction, this paper aims to investigate how likely customers without responses had satisfactory experiences compared to those respondents. To infer customer satisfaction of such unlabeled sessions, we propose models using recurrent neural networks (RNNs) that learn continuous representations of unstructured text conversation. By analyzing online chat logs of over 170,000 sessions from Samsung's customer service department, we make a novel finding that while labeled sessions contributed by a small fraction of customers received overwhelmingly positive reviews, the majority of unlabeled sessions would have received lower ratings by customers. The data analytics presented in this paper not only have practical implications for helping detect dissatisfied customers on live chat services but also make theoretical contributions on discovering the level of biases in online rating platforms.Comment: This paper will be presented at WWW'18 conferenc

    Absorption of nutrients by grapevine under field conditions

    Get PDF
    From a well fertilized 7 years-old vineyard var. 'Niagara Rosada' (Vinis labrusca L. X Vitis vinifera L.). situated on an Entisol at country of Jundiaí, SP, Brazil, plants were harvested every fifteen days up to 150 days. The plants were divided into: terminal and basal leaves, terminal and basal shoots, and canes, as well grapes. The plant material was analysed by conventional methods for B, Cu, Fe, Mn and Zn. The research was conducted in order: a. to obtain data on the absorption and distribution of the nutrients by the grapevine; b. to obtain data on the exportation of nutrients by the shoots and by the grapes. Conclusions: The leaves present always a higher concentration in nutrients than the other parts of the plant. The leaves, shoots and grapes present different concentrations of the nutrients during the year. The maximum absorption by the leaves, shoots and grapes in mg per plant was observed at the following age (days): The grapevine exported by shoots (pruned) and by grapes the following quantities of nutrients in mg per plant: A vineyeard of 5,000 plants per hectare contains the following quantitites of nutrients: B = 145.45 g.; Cu = 33.60 g.; Fe = 588.85 g.; Mn = 4,093,35 g.; Za = 373.30 g.Ensaio foi conduzido com viderias da cultivar 'Niagara Rosada' (Vitis labrusca L. X Vitis vinifera L.) com 7 anos de idade, no município de Jundiaí, SP, (23°12' de latitude sul e 46°33' de longitude oeste e 715 m de altitude), situadas sobre um Regossolo unidade Currupira, com os objetivos de: (1) determinar as quantidades de nutrientes absorvidos pela videira nos diferentes estádios de desenvolvimento; (2) avaliar a exportação de nutrientes pela cultura durante um ciclo vegetativo. Após a brotação da videira, foram realizadas 17 coletas quinzenais de material. Foram coletadas e separadas as folhas das partes terminal e basal, sarmentos das partes terminal e basal e cachos. No material coletado foram determinados os teores de micronutrientes, com exceção do molibdênio e cloro. Curvas representativas das concentraçoes dos nutrientes nas partes da planta, em função da idade, foram obtidas a partir dos dados calculados através de equações de regressão. Pelos pontos de máximo estimaram-se as quantidades máximas de nutrientes extraídos. Concluiu-se que: - A concentração dos nutrientes é sempre maior nas folhas do que nos sarmentos e existem diferenças nas concentrações de nutrientes das folhas, sarmentos e cachos, em função da idade. - Os acúmulos máximos de nutrientes nas folhas, sarmentos e cachos ocorrem nas seguintes idades: - A exportação de nutrientes em mg por planta pelos cachos e sarmentos removidos pelas colheitas e poda é a seguinte

    Acúmulo de nitrogênio, fósforo, potássio, cálcio, magnésio e enxofre pela videira (Vitis labrusca L. X Vitis vinifera L.) cv. 'Niágara rosada', durante um ciclo vegetativo

    Get PDF
    Plant material from a well fertilized 7 years-old vineyard var. 'Niagara Rosada' (Vitis labrusca L. X Vitis vinifera L.), situated on an Entisol at country of Jundiai, SP, Brazil, was harvested every fifteen days up to 150 days. The plants were divided into: terminal and basal leaves, terminal and basal shoots, and canes, as well grapes. The plant material was analysed by conventional methods for N, P, K, Ca, Mg, S. The research was conducted in order: a. to obtain information on the accumulation of dry matter, during a period of one year; b. to obtain data on the absorption and distribuition of the nutrients by the grapevine; c. to obtain data on the exportation of nutrients by the shoots and by the grapes. Conclusions : The maximum accumulation of the dry matter took place at the age of 148 days. The leaves present always a higher concentration in nutrients than the other parts of the plant. The leaves, shoots and grapes present different concentration of the nutrients during the year. The maximun absorption by the leaves, shoots and grapes in mg per plant was observed at the following age (days): The grapevine exported by shoots (pruned) and by grapes the following quantities of nutrients in mg per plant: A vineyeard of 5.000 plants per hectare content the following quantities of nutrients: N: 90.85 kg; P:28.40 kg; K: 97.60 kg; Ca: 41.20 kg; Mg: 8.10 kg; S: 9.30 kg.Ensaio foi conduzido com videiras de cultivar 'Niagara Rosada' (Vitis labrusca L. X Vitis vinifeva L.) com 7 anos de idade, no município de Jundiaí, SP (23°12' de latitude sul e 46º33' de longitude oeste e 715 m de altitude), situadas sobre um Regossolo unidade Currupira, com os objetivos de: (1) analisar o crescimento (produção de materia seca); (2) determinar as quantidades de nutrientes absorvidos pela videira nos diferentes estádios de desenvolvimento e (3) avaliar a exportação de nutrientes pela cultura durante o ciclo vegetativo. Após a brotação da videira, foram realizadas 17 coletas quinzenais de material. Foram coletadas e separadas as folhas das partes terminal e basal, sarmentos das partes terminal e basal e cachos. No material coletado foram determinados os teores de N, P, K, Ca, Mg e S. Curvas representativas dos acúmulos de matéria seca e das concentrações dos nutrientes nas partes da planta, em função da idade, foram obtidas a partir dos dados calculados através de equações de regressão. Pelos pontos de máximo estimaram-se a produção maxima de matéria seca e as quantidades de nutrientes extraídos. Conclui-se que: . A produção maxima de materia seca ocorre aos 148 dias. . A concentração dos nutrientes é sempre maior nas folhas do que nos sarmentos e existem diferenças nas concentrações de nutrientes das folhas, sarmentos e cachos, em função da idade. . Os acúmulos máximos de nutrientes nas folhas, sarmentos e cachos ocorrem nas seguintes idades
    • …
    corecore