Search

The present investigation reports on the interaction of M@C60(M = Be, Mg, Ca) with solvents (H2O, CH3OH, HF, NH3) using Density Functional Theory calculations. Our computations reveal that the interaction of the fullerene species increases when endohedral metal atoms are inserted into its cavity. The most profound interaction of the fullerene systems is with water and hydrogen fluoride. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 [ABSTRACT FROM AUTHOR]

Water is a common resource shared by many agents or farmers in irrigation districts, where water management is, therefore, a very complex problem if the target is the equitable distribution of resources or the efficient use of water. This paper aims to present the design and implementation of an Irrigation Agent-Based Model (IABM) for the distribution of water in an irrigation district. In the IABM proposed, each field or farm can be considered as a micro-level and a region or irrigation district as a macro-level. The most approximated irrigation scheduling at each micro-level allows determining the water needs at the macro-level, as a reference for the negotiation of water distribution. A Geographical Information System (GIS) was used to manage georeferenced field information. Field capacity and permanent wilting point values, initial soil moisture, crop types, crop coefficients, root depth, sowing dates and weather data were incorporated into the IABM model for determining irrigation prescriptions. When water available in the irrigation district is insufficient to supply water requirements of all the irrigation fields, the IABM allows water distribution among them according to the cultivated field sizes, irrigation priorities, phenological states and the behavior of neighbors. When water resources are distributable, the proposed negotiation algorithm ensures that fields will use irrigation prescriptions defined with technical and agronomic criteria, thus avoiding the waste of water resource. The IABM developed meets the satisfaction requirement of the greatest number of agents by avoiding as much as possible that the soil water stress increases, using 25% of permissible level of moisture depletion respect to the total available water in each field. • An Agent-Based model (ABM) was implemented for negotiation of water in an irrigation district. • The irrigation ABM was made up of the perception, negotiation and satisfaction algorithms. • Agent behavior was influenced by the agent own interests, but also by their neighbors. • The soil water stress coefficient was used for implementing the satisfaction algorithm. [ABSTRACT FROM AUTHOR]

Abstract: In this study we have investigated the interaction of M@C60 (M=H, Li, Na, K, Be, Mg, Ca) with a (16,0) Zigzag SWNT using Density Functional Theory (DFT) calculations. The calculations reveal that in all the computed cases the metallo-endofullerene M@C60 complexes with the nanotubes are more stable than without internal cation species. Structural, electronic, vibrational and energetic descriptions of various fullerene–SWNT frameworks will also be shown and discussed. The physical nature of the interaction has been addressed and potential applications discussed. [Copyright &y& Elsevier]

This review paper provides a synthetic yet critical overview of the key biomechanical principles of human bipedal walking and their current implementation in robotic platforms. We describe the functional role of human joints, addressing in particular the relevance of the compliant properties of the different degrees of freedom throughout the gait cycle. We focused on three basic functional units involved in locomotion, i.e. the ankle-foot complex, the knee, and the hip-pelvis complex, and their relevance to whole-body performance. We present an extensive review of the current implementations of these mechanisms into robotic platforms, discussing their potentialities and limitations from the functional and energetic perspectives. We specifically targeted humanoid robots, but also revised evidence from the field of lower-limb prosthetics, which presents innovative solutions still unexploited in the current humanoids. Finally, we identified the main critical aspects of the process of translating human principles into actual machines, providing a number of relevant challenges that should be addressed in future research.