120 resultados para Systemic Approach


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Spent coffee grounds (SCG) represent a high-volume food waste worldwide, and several reuse approaches have been attempted. Herein, a greenhouse field experiment was carried out by cultivating Batavia lettuce with 5%, 10%, 15%, 20% and 30% (v/v) espresso SCG directly composted in the soil. Healthy vegetables were obtained for all treatments, without yield loss for up to 10% SCG. A progressive increment of green color intensity with increasing SCG content was observed, corroborated by the increase of their photosynthetic pigments (chlorophylls and carotenoids). Furthermore, total ascorbic acid and tocopherols showed statistical significant increases (p < 0.001) between control and all tested groups. Marked variations of nutritionally relevant minerals, particularly potassium, phosphorous and sodium were also revealed at higher percentage treatments (20% and 30%). This approach constitutes a clean, direct, simple and cost-effective measure to produce value-added vegetables, while reducing food waste disposal.

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A voltammetric biosensor for Ara h 6 (a peanut allergen) detection in food samples was developed. Gold nanoparticle-modified screen-printed carbon electrodes were used to develop a sandwich-type immunoassay using two-monoclonal antibodies. The antibody-antigen interaction was detected through the electrochemical detection of enzymatically deposited silver. The immunosensor presented a linear range between 1 and 100 ng/ml, as well as high precision (inter-day RSD ≤9.8 %) and accuracy (recoveries ≥96.7 %). The detection and quantification limits were 0.27 and 0.88 ng/ml, respectively. It was possible to detect small levels of Ara h 6 in complex food matrices.

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Background Over the years, food industry wastes have been the focus of a growing interest due to their content in high added-value compounds. A good example are the olive oil by-products (OOBP), which retain a great amount of phenolic compounds during olive oil production. Their structure and biological properties justify their potential use as antioxidants in other food products. The efficient recovery of phenolic compounds has been extensively studied and optimized in order to maximize their reintroduction in the food chain and contribute to a higher valorization and better management of wastes from olive oil industry. Scope and approach This paper reviews the most representative phenolic compounds described in OOBP and their biological properties. New extraction procedures to efficiently recover these compounds and the most advanced chromatographic techniques that have been used for a better understanding of the phenolic profile of these complex matrices are also referred. Finally, this paper reports the main applications of OOBP, with emphasis on their phenolic content as natural antioxidants for food applications. Key findings and conclusions Besides their antioxidant activity, phenolic compounds from OOBP have also shown antimicrobial and antitumoral properties. Their application as food antioxidants requires new extraction techniques, including the use of non-toxic solvents and, in a pilot scale, the use of filters and adsorbent resins. The inclusion of phenolic compounds from OOBP in some food matrices have improved not only their antioxidant capacity but also their sensory attributes.

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A vitamin E extraction method for rainbow trout flesh was optimized, validated, and applied in fish fed commercial and Gracilaria vermiculophylla-supplemented diets. Five extraction methods were compared. Vitamers were analyzed by HPLC/DAD/fluorescence. A solid-liquid extraction with n-hexane, which showed the best performance, was optimized and validated. Among the eight vitamers, only α- and γ-tocopherol were detected in muscle samples. The final method showed good linearity (>0.999), intra- (<3.1%) and inter-day precision (<2.6%), and recoveries (>96%). Detection and quantification limits were 39.9 and 121.0 ng/g of muscle, for α-tocopherol, and 111.4 ng/g and 337.6 ng/g, for γ-tocopherol, respectively. Compared to the control group, the dietary inclusion of 5% G. vermiculophylla resulted in a slight reduction of lipids in muscle and, consequently, of α- and γ-tocopherol. Nevertheless, vitamin E profile in lipids was maintained. In general, the results may be explained by the lower vitamin E level in seaweed-containing diet. Practical Applications: Based on the validation results and the low solvent consumption, the developed method can be used to analyze vitamin E in rainbow trout. The results of this work are also a valuable information source for fish feed industries and aquaculture producers, which can focus on improving seaweed inclusion in feeds as a source of vitamin E in fish muscle and, therefore, take full advantage of all bioactive components with an important role in fish health and flesh quality.

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Smart Grids (SGs) have emerged as the new paradigm for power system operation and management, being designed to include large amounts of distributed energy resources. This new paradigm requires new Energy Resource Management (ERM) methodologies considering different operation strategies and the existence of new management players such as several types of aggregators. This paper proposes a methodology to facilitate the coalition between distributed generation units originating Virtual Power Players (VPP) considering a game theory approach. The proposed approach consists in the analysis of the classifications that were attributed by each VPP to the distributed generation units, as well as in the analysis of the previous established contracts by each player. The proposed classification model is based in fourteen parameters including technical, economical and behavioural ones. Depending of the VPP strategies, size and goals, each parameter has different importance. VPP can also manage other type of energy resources, like storage units, electric vehicles, demand response programs or even parts of the MV and LV distribution network. A case study with twelve VPPs with different characteristics and one hundred and fifty real distributed generation units is included in the paper.

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This study proposes a new methodology to increase the power delivered to any load point in a radial distribution network, through the identification of new investments in order to improve the repair time. This research work is innovative and consists in proposing a full optimisation model based on mixed-integer non-linear programming considering the Pareto front technique. The goal is to achieve a reduction in repair times of the distribution networks components, while minimising the costs of that reduction as well as non-supplied energy costs. The optimisation model considers the distribution network technical constraints, the substation transformer taps, and it is able to choose the capacitor banks size. A case study based on a 33-bus distribution network is presented in order to illustrate in detail the application of the proposed methodology.

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In recent years, organizational culture has become one of the common themes of interest of scientific and academic research. Each organization has its own unique cultural identity. Based on the recognition that organizational culture is considered important to an organization’s results, and social economy organizations are concerned with improving managerial practices and results, our objective is to study organizational culture in cooperatives: identifying their organizational culture as a specific type of organization of the social economy, recognized as increasingly important economic agents; and in doing so, explore the usage of a widely known model, the Competing Values Framework (Quinn & Rohrbaugh 1983). Three cooperatives were studied. Their presidents were interviewed, and a questionnaire was applied to cooperative members to obtain demographic and organizational culture data. Differences between the cooperatives’ cultural profiles seem to be consistent with both the circumstances of Portuguese social economy organizations (SEOs), and to the organizations’ uniqueness regarding their trade, focuses, and history. International firm trends were compared with this study’s results, and also appear to be explained by the SEO’s management practices evolution standpoint: lack of structured way of working, and the need to improvise and innovate in order to get things done. The importance of our research is held in the fact that social economy, and the cooperative movement in particular, has a developing importance in the expansion of many economies, the lack of literature on culture in SEOs, and the exploratory usage of a well-known model of management literature in cooperatives.

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This work explores the use of fluorescent probes to evaluate the responses of the green alga Pseudokirchneriella subcapitata to the action of three nominal concentrations of Cd(II), Cr(VI), Cu(II) and Zn(II) for a short time (6 h). The toxic effect of the metals on algal cells was monitored using the fluorochromes SYTOX Green (SG, membrane integrity), fluorescein diacetate (FDA, esterase activity) and rhodamine 123 (Rh123, mitochondrial membrane potential). The impact of metals on chlorophyll a (Chl a) autofluorescence was also evaluated. Esterase activity was the most sensitive parameter. At the concentrations studied, all metals induced the loss of esterase activity. SG could be used to effectively detect the loss of membrane integrity in algal cells exposed to 0.32 or 1.3 μmol L−1 Cu(II). Rh123 revealed a decrease in the mitochondrial membrane potential of algal cells exposed to 0.32 and 1.3 μmol L−1 Cu(II), indicating that mitochondrial activity was compromised. Chl a autofluorescence was also affected by the presence of Cr(VI) and Cu(II), suggesting perturbation of photosynthesis. In conclusion, the fluorescence-based approach was useful for detecting the disturbance of specific cellular characteristics. Fluorescent probes are a useful diagnostic tool for the assessment of the impact of toxicants on specific targets of P. subcapitata algal cells.

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The painting activity is one of the most complex and important activities in automobile manufacturing. The inherent complexity of the painting activity and the frequent need for repainting usually turn the painting process into a bottleneck in automobile assembly plants, which is reflected in higher operating costs and longer overall cycle times. One possible approach for optimizing the performance of the paint shop is to improve the efficiency of the color planning. This can be accomplished by evaluating the relative merits of a set of vehicle painting plans. Since this problem has a multicriteria nature, we resort to the multicriteria decision analysis (MCDA) methodology to tackle it. A recent trend in the MCDA field is the development of hybrid approaches that are used to achieve operational synergies between different methods. Here we apply, for the first time, an integrated approach that combines the strengths of the analytic hierarchy process (AHP) and the Preference Ranking Organization METHod for Enrichment Evaluations (PROMETHEE), aided by Geometrical Analysis for Interactive Aid (GAIA), to the problem of assessing alternative vehicle painting plans. The management of the assembly plant found the results of value and is currently using them in order to schedule the painting activities such that an enhancement of the operational efficiency of the paint shop is obtained. This efficiency gain has allowed the management to bid for a new automobile model to be assembled at this specific plant.

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Sectorization means dividing a set of basic units into sectors or parts, a procedure that occurs in several contexts, such as political, health and school districting, social networks and sales territory or airspace assignment, to achieve some goal or to facilitate an activity. This presentation will focus on three main issues: Measures, a new approach to sectorization problems and an application in waste collection. When designing or comparing sectors different characteristics are usually taken into account. Some are commonly used, and they are related to the concepts of contiguity, equilibrium and compactness. These fundamental characteristics will be addressed, by defining new generic measures and by proposing a new measure, desirability, connected with the idea of preference. A new approach to sectorization inspired in Coulomb’s Law, which establishes a relation of force between electrically charged points, will be proposed. A charged point represents a small region with specific characteristics/values creating relations of attraction/repulsion with the others (two by two), proportional to the charges and inversely proportional to their distance. Finally, a real case about sectorization and vehicle routing in solid waste collection will be mentioned.

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For efficient planning of waste collection routing, large municipalities may be partitioned into convenient sectors. The real case under consideration is the municipality of Monção, in Portugal. Waste collection involves more than 1600 containers over an area of 220 km2 and a population of around 20,000 inhabitants. This is mostly a rural area where the population is distributed in small villages around the 33 boroughs centres (freguesia) that constitute the municipality. In most freguesias, waste collection is usually conducted 3 times a week. However, there are situations in which the same collection is done every day. The case reveals some general and specific characteristics which are not rare, but are not widely addressed in the literature. Furthermore, new methods and models to deal with sectorization and routing are introduced, which can be extended to other applications. Sectorization and routing are tackled following a three-phase approach. The first phase, which is the main concern of the presentation, introduces a new method for sectorization inspired by Electromagnetism and Coulomb’s Law. The matter is not only about territorial division, but also the frequency of waste collection, which is a critical issue in these types of applications. Special characteristics related to the number and type of deposition points were also a motivation for this work. The second phase addresses the routing problems in each sector: new Mixed Capacitated Arc Routing with Limited Multi-Landfills models will be presented. The last phase integrates Sectoring and Routing. Computational results confirm the effectiveness of the entire novel approach.

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Previously we have presented a model for generating human-like arm and hand movements on an unimanual anthropomorphic robot involved in human-robot collaboration tasks. The present paper aims to extend our model in order to address the generation of human-like bimanual movement sequences which are challenged by scenarios cluttered with obstacles. Movement planning involves large scale nonlinear constrained optimization problems which are solved using the IPOPT solver. Simulation studies show that the model generates feasible and realistic hand trajectories for action sequences involving the two hands. The computational costs involved in the planning allow for real-time human robot-interaction. A qualitative analysis reveals that the movements of the robot exhibit basic characteristics of human movements.

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In recent years, organizational culture has become one of the common themes of interest of scientific and academic research. Each organization has its own unique cultural identity. Based on the recognition that organizational culture is considered important to an organization’s results, and social economy organizations are concerned with improving managerial practices and results, our objective is to study organizational culture in cooperatives: identifying their organizational culture as a specific type of organization of the social economy, recognized as increasingly important economic agents; and in doing so, explore the usage of a widely known model, the Competing Values Framework (Quinn & Rohrbaugh 1983). Three cooperatives were studied. Their presidents were interviewed, and a questionnaire was applied to cooperative members to obtain demographic and organizational culture data. Differences between the cooperatives’ cultural profiles seem to be consistent with both the circumstances of Portuguese social economy organizations (SEOs), and to the organizations’ uniqueness regarding their trade, focuses, and history. International firm trends were compared with this study’s results, and also appear to be explained by the SEO’s management practices evolution standpoint: lack of structured way of working, and the need to improvise and innovate in order to get things done. The importance of our research is held in the fact that social economy, and the cooperative movement in particular, has a developing importance in the expansion of many economies, the lack of literature on culture in SEOs, and the exploratory usage of a well-known model of management literature in cooperatives.

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This study aims to analyze and compare micro-firms’ organizational culture related to organizational performance. A case study methodology was used based on four firms, competitors among themselves in the Information Technology business, focusing on the years between 2008-2013. Findings pointed out many similarities to larger firms, but some specificities of micro-firms were found and propositions were defined: clan culture predominance is related to best performing micro-firms; the configuration of several culture types seemed to be the most suitable for obtaining good organizational results, provided that they do not focus only on hierarchy and market types of culture; the market culture predominance perception by employees is associated with low job satisfaction; and, after a certain time in business, micro-firms, as do larger companies, seek to standardize and control processes. Recognizing that organizational culture is considered important to firms’ results, this study sheds some light on that important factor for micro-firms.

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É possível assistir nos dias de hoje, a um processo tecnológico evolutivo acentuado por toda a parte do globo. No caso das empresas, quer as pequenas, médias ou de grandes dimensões, estão cada vez mais dependentes dos sistemas informatizados para realizar os seus processos de negócio, e consequentemente à geração de informação referente aos negócios e onde, muitas das vezes, os dados não têm qualquer relacionamento entre si. A maioria dos sistemas convencionais informáticos não são projetados para gerir e armazenar informações estratégicas, impossibilitando assim que esta sirva de apoio como recurso estratégico. Portanto, as decisões são tomadas com base na experiência dos administradores, quando poderiam serem baseadas em factos históricos armazenados pelos diversos sistemas. Genericamente, as organizações possuem muitos dados, mas na maioria dos casos extraem pouca informação, o que é um problema em termos de mercados competitivos. Como as organizações procuram evoluir e superar a concorrência nas tomadas de decisão, surge neste contexto o termo Business Intelligence(BI). A GisGeo Information Systems é uma empresa que desenvolve software baseado em SIG (sistemas de informação geográfica) recorrendo a uma filosofia de ferramentas open-source. O seu principal produto baseia-se na localização geográfica dos vários tipos de viaturas, na recolha de dados, e consequentemente a sua análise (quilómetros percorridos, duração de uma viagem entre dois pontos definidos, consumo de combustível, etc.). Neste âmbito surge o tema deste projeto que tem objetivo de dar uma perspetiva diferente aos dados existentes, cruzando os conceitos BI com o sistema implementado na empresa de acordo com a sua filosofia. Neste projeto são abordados alguns dos conceitos mais importantes adjacentes a BI como, por exemplo, modelo dimensional, data Warehouse, o processo ETL e OLAP, seguindo a metodologia de Ralph Kimball. São também estudadas algumas das principais ferramentas open-source existentes no mercado, assim como quais as suas vantagens/desvantagens relativamente entre elas. Em conclusão, é então apresentada a solução desenvolvida de acordo com os critérios enumerados pela empresa como prova de conceito da aplicabilidade da área Business Intelligence ao ramo de Sistemas de informação Geográfica (SIG), recorrendo a uma ferramenta open-source que suporte visualização dos dados através de dashboards.