1,860 research outputs found

    Temporal Variation In The Abundance And Richness Of Foliage-dwelling Ants Mediated By Extrafloral Nectar

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Plants bearing extrafloral nectaries (EFNs) are common in the Brazilian cerrado savanna, where climatic conditions having marked seasonality influence arboreal ant fauna organization. These ant-plant interactions have rarely been studied at community level. Here, we tested whether: 1) EFN-bearing plants are more visited by ants than EFN-lacking plants; 2) ant visitation is higher in the rainy season than in dry season; 3) plants producing young leaves are more visited than those lacking young leaves in the rainy season; 4) during the dry season, plants with old leaves and flowers are more visited than plants with young leaves and bare of leaves or flowers; 5) the composition of visiting ant fauna differs between plants with and without EFNs. Field work was done in a cerrado reserve near Uberlandia, MG State, Brazil, along ten transects (total area 3,000 m(2)), in the rainy (October-January) and dry seasons (April-July) of 2010-2011. Plants (72 species; 762 individuals) were checked three times per season for ant presence. Results showed that 21 species (29%) and 266 individuals (35%) possessed EFNs. These plants attracted 38 ant species (36 in rainy, 26 in dry season). In the rainy season, plants with EFNs had higher ant abundance/richness than plants without EFNs, but in the dry season, EFN presence did not influence ant visitation. Plant phenology affected ant richness and abundance in different ways: plants with young leaves possessed higher ant richness in the rainy season, but in the dry season ant abundance was higher on plants possessing old leaves or flowers. The species composition of plant-associated ant communities, however, did not differ between plants with and without EFNs in either season. These findings suggest that the effect of EFN presence on a community of plant-visiting ants is context dependent, being conditioned to seasonal variation.117Conselho Nacional de Desenvolvimento Cientifico e TecnologicoFundacao de Amparo a Pesquisa do Estado de Sao PauloConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Implementación de un sistema de gestión de personal orientado a la mejora continua de los procesos de producción en una fábrica de alimentos

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    El manejo de la motivación, involucramiento y participación de las personas dentro de una fábrica o empresa es un tema que suele ser tratado de manera empírica, o en ocasiones simplemente no se tiene en consideración dentro de su organización. Por otro lado, es también evidente que en muchas industrias no existe un sistema estructurado de gestión de mejora y optimización de los recursos y procesos. El presente trabajo ilustra un caso exitoso de implementación en una fábrica de alimentos de un sistema de gestión de personal orientado a la mejora continua de los procesos de producción, en el que se combinó justamente la necesidad de solucionar los dos problemas planteados que existían también en dicha instalación fabril. El objetivo principal trazado fue el de inculcar en las personas la búsqueda continua de mejorar, y que esta manera de actuar resulte en ideas y proyectos presentados e implementados por el propio personal que generen ahorros y mejoras tangibles para la empresa. Como resultado final se consiguieron los ahorros fijados como meta, se consiguió infundir la cultura de mejora continua reflejada en la participación activa del personal, y como logro adicional se tiene un proceso estructurado, sostenible y auto sustentable que puede tener resultados positivos por mucho tiempo

    Lorentz-violating effects in the Bose-Einstein condensation of an ideal bosonic gas

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    We have studied the effects of Lorentz-violation in the Bose-Einstein condensation (BEC) of an ideal boson gas, by assessing both the nonrelativistic and ultrarelativistic limits. Our model describes a massive complex scalar field coupled to a CPT-even and Lorentz-violating background. We irst analyze the nonrelativistic case, at this level by using experimental data, we obtain upper-bounds for some LIV parameters. In the sequel, we have constructed the partition function for the relativistic ideal boson gas which to be able of a consistent description requires the imposition of severe restrictions on some LIV coefficients. In both cases, we have demonstrated that the LIV contributions are contained in an overall factor, which multiplies almost all thermodynamical properties. An exception is the fraction of the condensed particles.Comment: 7 pages Latex2e. To be published in Modern Physics Letters

    Diseño e implementación del programa anual de conservación integrado para la gestión de los recursos de la facultad de ingeniería en mecánica y ciencias de la producción (fimcp), con enfoque en la mejora continua

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    El objetivo es diseñar e implementar un programa anual de conservación integrado, con enfoque en la mejora continua, para la gestión e integración de los procesos de conservación de construcciones y equipos de los laboratorios de la FIMCP. “Conservación es toda actividad humana que, mediante la aplicación de los conocimientos científicos y técnicos, contribuye al óptimo aprovechamiento de los recursos“[2]. La Metodología de la Conservación consta de tres etapas. En la primera se identifican los problemas, recolectan los datos y se levanta la información; la segunda etapa incluye las herramientas para administrar la conservación, optimizar el presupuesto de manutención con el índice de clasificación para los gastos de conservación [3], jerarquizar el inventario, por medio de Pareto, para la mejor gestión de los recursos, minimizar los costos y la optimización de los intervalos de conservación y finalmente elaborar los planes contingentes. En la tercera etapa, se utilizan las herramientas de la ingeniería industrial como diagramas de flujo, estudio de tiempos y balanceo, rediseño de descripción del puesto y estudio de requerimientos de materiales. Por último, con el análisis de tendencias y financiero se estimó el ahorro (beneficio) para la FIMCP, y la inversión requerida para la ejecución de las mejoras y la viabilidad del proyecto. The objective is to design and to implement an integrated annual program of conservation, focus in the continuous improvement for the administration and integration of the processes of conservation of constructions and teams of the laboratories of the FIMCP. "Conservation is all human activity that, by means of the application of the scientific and technical knowledge, it contributes to the good use of the resources" [2] The Methodology of the Conservation consists of three stages. In the first one, to identify problems, to gather data and to lift the information; the second, include the tools to administer the conservation, to optimize the maintenance budget with the Ranking index for Maintenance Expenditure [3], to rank the inventory, by means of Pareto, for the best administration in the resources, to minimize the costs and the optimization of the conservation intervals, to elaborate the contingent plans. In the third stage, the tools of the industrial engineering are used as diagrams of flow, study of times and balancing, redesign of description of the position and study of requirements of materials. Lastly, with the analysis of tendencies and financial, it was considered the saving (benefit) for the FIMCP, and the investment required for the execution of the improvements and the viability of the project

    Aplicación de la metodología smed para la reducción de los tiempos de cambio de formato en una línea de producción de helados

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    El presente estudio se basa en la implementación de la metodología SMED (“Single Minute Exchange of Die”) en una planta manufacturera de helados, líder en el mercado nacional y pionera en la implementación de sistemas de mejora continua. La optimización de la eficiencia como fundamento para la reducción de costos y cumplimiento de los volúmenes demandados por el mercado llevaron a la planta a buscar maneras de reducir las pérdidas más significativas de la planta lo que convierte a la perdida por cambio de formato en la más representativa en todas las plantas de helados. La metodología utilizada consiste en la identificación de la línea más significativa para la planta basada en un análisis de volumen, numero de SKUs y tiempos perdidos. Una vez identificada la línea se identificará a través de la matriz de cambios de formato cual es el cambio más significativo para la línea. En este paso restringimos el análisis al proceso más completo y complejo de la línea por la cantidad de equipos y ajustes necesarios, el cual servirá de base de mejora para todos los procesos de la línea

    Temperature dependence of chemical and biophysical rate processes: Phenomenological approach to deviations from Arrhenius law

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    Arrhenius plots, which are used to represent the effects of temperature on the rates of chemical and biophysical processes and on various transport phenomena in materials science, may exhibit deviations from linearity. Account of curvature is provided here by a formula which involves a deformation of the exponential function, of the kind recently encountered in treatments of non-extensivity in statistical mechanics. We present here examples on diverse topics – respiration rates of plants, speed of gliding of bacteria, quantum mechanical tunneling in a chemical reaction – illustrating the variety of possible applications and the additional insight that can be gained

    Quantitative supply chain segmentation model for dynamic alignment

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    [EN] Companies deal with different customer groups, requirements differ among them, which makes it important to define the service level precisely and improve customer service through different supply chain strategies for each group. An alternative to deal with imprecision related to the segmentation processes suggested by either the Leagile or the Dynamic Alignment Schools is the application of fuzzy set theory. The objective of this work is to develop a quantitative model that uses the fuzzy set theory and, based on sales data, assess the company s supply chain(s). The model's aim is to facilitate managers' decision-making processes to achieve the dynamic alignment. It was possible to identify the supply chains that serve the client groups evaluated, providing answers faster than the analysis proposed by the models found in the literature. The application in two real situations validated the model since the results obtained were consistent with the reality pointed out by the experts of the companies assessed. The model indicates possible actions for the realignment of the supply chain by their managers. Results obtained should improve practice, preparing managers to cope with the organizations` multiple supply chains. This study is the first one that aims to segment quantitatively supply chains on a company applying fuzzy set theory, providing a novel approach to align operations and supply chain strategy dynamically.Alves Ferreira, R.; A. S. Santos, L.; Espôsto, KF. (2022). Quantitative supply chain segmentation model for dynamic alignment. International Journal of Production Management and Engineering. 10(2):99-113. https://doi.org/10.4995/ijpme.2022.16494OJS9911310

    "Desempenho em exportação e as práticas gerenciais de controle de qualidade"

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