Evoluçao e aplicaçao da mecatronica em maquinas agricolas.

Em Ciências Agronómicas, a constante adoção de novas tecnologias, faz com que cada vez mais se alargue o conhecimento em torno de novas áreas técnicas e científicas. Hoje, a incorporação de sistemas mecatrónicos na arquitetura de conceção de tratores e máquinas agrícolas, além de tornar a máquina mais amiga do operador, tem permitido a otimização da sua utilização e rentabilidade de operação. O significado de Mecatrónica e algumas considerações sobre a sua aplicação em máquinas agrícolas são descritas neste artigo.

Priorización Ejidal De Criterios Sobre Bienes Públicos: El Caso De Caminos Rurales

En este artículo se fijó como objetivo definir las preferencias de la población sobre el mantenimiento de los caminos rurales como vías de flujo de bienes y servicios que usan cotidianamente, para ello se presenta un modelo de participación de la sociedad rural donde se integra la opinión de los beneficiarios en el mantenimiento de los caminos rurales basado en un proceso de análisis jerárquico que valora la importancia de criterios económicos, sociales y ambientales

Assessment of Hydrogen as suistinable clean energy

The progressive depletion of fossil fuels and their high contribution to the energy supply in this modern society forces that will be soon replaced by renewable fuels. But the dispersion and alternation of renewable energy production also undertake to reduce their costs to use as energy storage and hydrogen carrier. It is necessary to develop technologies for hydrogen production from all renewable energy storage technologies and the development of energy production from hydrogen fuel cells and cogeneration and tri generation systems. In order to propel this technological development discussed where the hydrogen plays a key role as energy storage and renewable energy, the National Centre of Hydrogen and Fuel Cell Technology Experimentation in Spain equipped with installations that enable scientific and technological design, develop, verify, certify, approve, test, measure and, more importantly, the facility ensures continuous operation for 24 hours a day, 365 days year. At the same time, the system is scalable so as to allow continuous adaptation of new technologies are developed and incorporated into the assembly to verify integration at the same time it checks the validity of their development. The transformation sector can be said to be the heart of the system, because without neglecting the other sectors, this should prove the validity of hydrogen as a carrier - energy storage are important efforts that have to do to demonstrate the suitability of fuel cells or internal combustion systems to realize the energy stored in hydrogen at prices competitive with conventional systems. The multiple roles to meet the fuel cells under different conditions of operation require to cover their operating conditions, many different sizes and applications. The fourth area focuses on integration is an essential complement within the installation. We must integrate not only the electricity produced, but also hydrogen is used and the heat generated in the process of using hydrogen energy. The energy management in its three forms: hydrogen chemical, electrical and thermal integration requires complicated and require a logic and artificial intelligence extremes to ensure maximum energy efficiency at the same time optimum utilization is achieved. Verification of the development and approval in the entire production system and, ultimately, as a demonstrator set to facilitate the simultaneous evolution of production technology, storage and distribution of hydrogen fuel cells has been assessed.

Repeatability and Two-Dimensionality of Model Scale Sloshing Impacts

Canonical test cases for sloshing wave impact problems are pre-sented and discussed. In these cases the experimental setup has been simpli?ed seeking the highest feasible repeatability; a rectangular tank subjected to harmonic roll motion has been the tested con?guration. Both lateral and roof impacts have been studied, since both cases are relevant in sloshing assessment and show speci?c dynamics. An analysis of the impact pressure of the ?rst four impact events is provided in all cases. It has been found that not in all cases a Gaussian ?tting of each individual peak is feasible. The tests have been conducted with both water and oil in order to obtain high and moderate Reynolds number data; the latter may be useful as simpler test cases to assess the capabilities of CFD codes in simulating sloshing impacts. The re-peatability of impact pressure values increases dramatically when using oil. In addition, a study of the two-dimensionality of the problem using a tank con?guration that can be adjusted to 4 di?erent thicknesses has been carried out. Though the kinemat-ics of the free surface does not change signi cantly in some of the cases, the impact pressure values of the ?rst impact events changes substantially from the small to the large aspect ratios thus meaning that attention has to be paid to this issue when reference data is used for validation of 2D and 3D CFD codes.

Use of alternative fuels obtained from renewable sources in brayton cycles

Analysis and simulation of the behaviour of gas turbines for power generation using different nonconventional fuels obtained from different renewable sources are presented. Three biomass-tobiofuel processes are considered: anaerobic digestion of biomass (biogas), biomass gasification (synthesis gas) and alcoholic fermentation of biomass and dehydration (bioethanol), each of them with two different biomass substrates (energy crops and municipal solid waste) as input. The gas turbine behaviour in a Brayton cycle is simulated both in an isolated operation and in combined cycle. The differences in gas turbine performance when fired with the considered biofuels compared to natural gas are studied from different points of view related with the current complex energetic context: energetic and exergetic efficiency of the simple/combined cycle and CO2 emissions. Two different tools have been used for the simulations, each one with a different approach: while PATITUG (own software) analyses the behaviour of a generic gas turbine allowing a total variability of parameters, GT-PRO (commercial software) is more rigid, albeit more precise in the prediction of real gas turbine behaviour. Different potentially interesting configurations and its thermodynamic parameters have been simulated in order to obtain the optimal range for all of them and its variation for each fuel.

Running away from side effects: physical exercise as a complementary intervention for breast cancer patients

The number of breast cancer survivors increases every year, thanks to the development of new treatments and screening techniques. However, patients present with numerous side effects that may affect their quality of life. Exercise has been demostrated to reduce some of these side effects, but in spite of this, few breast cancer patientes know and follow the exercise recommendations needed to remain healthy. In this review, we describe the differente breast cancer treatments and the related side effects and implications of exercise in relation to these. We propose that exercise could be and integrative complementary intervention to improve physiological, physical and psychological factors that affect survival and quality of life of these patients. For that reason, the main objective of this review is to provide a general overview of exercise benefits in breast cancer patients and recommendations of how to design exercise interventions in patients with different side effects.

Signwalling: signals derived from arabiopsis cell wall activate specific resistance to pathogens

The cell wall is a dynamic structure that regulates both constitutive and inducible plant defence responses. Different molecules o DAMPs (damage-associated molecular patterns) can be released from plant cell walls upon pathogen infection or wounding and can trigger immune responses. To further characterize the function of cell wall on the regulation of these immune responses, we have performed a biased resistance screening of putative/well-characterized primary/secondary Arabidopsis thaliana cell wall mutants (cwm). In this screening we have identified more than 20 cwm mutants with altered susceptibility/resistance to at least one of the following pathogens: the necrotrophic fungi Plectosphaerella cucumerina, the vascular bacterium Ralstonia solanacearum, the biotrophic oomycete Hyaloperonospora arabidopsidis and the powdery mildew fungus Erisyphe cruciferarum. We found that cell wall extracts from some of these cwm plants contain novel DAMPs that activate immune responses and conferred enhanced resistance to particular pathogens when they were applied to wild-type plants. Using glycomic profiling we have performed an initial characterization of the active carbohydrate structures present in these cwm wall fractions, and we have determined the signalling pathways regulated by thesse fractions. . The data generated with this collection of wall mutants support the existence of specific correlations between cell wall structure/composition, resistance to particular type of pathogens and plant fitness. Remarkably, we have identified specific cwm mutations that uncoupled resistance to pathogens from plant trade-offs, further indicating the plasticity of wall structures in the regulation of plant immune responses.

Factores determinantes en la eficiencia técnica de explotaciones de frijol

Se evaluó la eficiencia técnica de 30 explotaciones de frijol ubicadas en el estado Portuguesa, Venezuela, considerando cinco insumos y un producto, que fue relacionada con variables de tipo socioeconómico y geoespacial. Se empleó el método Análisis Envolvente de Datos (DEA), por sus siglas en inglés, con un modelo orientado al producto. Según los resultados, en promedio, la eficiencia técnica global (ETG) fue 81.2%, desglosada en una eficiencia técnica pura (ETP) de 86.0% y una eficiencia de escala (EE) de 95.1%. Las ineficiencias causadas por la tecnología son mayores que las generadas por un tamaño o escala de producción subóptimo. Según las metas de planificación se puede elevar la producción agregada de frijol en 23.1%, sin aumentar la cantidad de insumos aplicados actualmente. Las variables socioeconómicas y las de tipo geoespacial no determinaron los niveles de eficiencia técnica de las fincas.