Chapter Hybrid-Powered Autonomous Robots for Reducing Both Fuel Consumption and Pollution in Precision Agriculture Tasks

Environmental contamination and the resulting climate change are major concerns worldwide. Agricultural vehicles that use fossil fuels emit significant amounts of atmospheric pollutants. Thus, this study investigates techniques to reduce fuel consumption in robotic vehicles used for agricultural tasks and therefore reduce atmospheric emissions from these automated systems. A hybrid energy system for autonomous robots devoted to weed and pest control in agriculture is modeled and evaluated, and its exhaust emissions are compared with those of an internal combustion engine-powered system. Agricultural implements require power for hydraulic pumps and fans; this energy is conventionally provided by power take-off (PTO) systems, which waste substantial amounts of energy. In this work, we examine a solution by designing and assessing a hybrid energy system that omits the alternators from the original vehicle and modifies the agricultural implements to replace the PTO power with electrical power. The hybrid energy system uses the original combustion engine of the tractor in combination with a new electrical energy system based on a hydrogen fuel cell. We analyze and compare the exhaust gases resulting from the use of (1) an internal combustion engine as the single power source and (2) the hybrid energy system. The results demonstrate that the hybrid energy system reduced emissions by up to approximately 50%

Hybrid-Powered Autonomous Robots for Reducing Both Fuel Consumption and Pollution in Precision Agriculture Tasks

Environmental contamination and the resulting climate change are major concerns worldwide. Agricultural vehicles that use fossil fuels emit significant amounts of atmospheric pollutants. Thus, this study investigates techniques to reduce fuel consumption in robotic vehicles used for agricultural tasks and therefore reduce atmospheric emissions from these automated systems. A hybrid energy system for autonomous robots devoted to weed and pest control in agriculture is modeled and evaluated, and its exhaust emissions are compared with those of an internal combustion engine-powered system. Agricultural implements require power for hydraulic pumps and fans; this energy is conventionally provided by power take-off (PTO) systems, which waste substantial amounts of energy. In this work, we examine a solution by designing and assessing a hybrid energy system that omits the alternators from the original vehicle and modifies the agricultural implements to replace the PTO power with electrical power. The hybrid energy system uses the original combustion engine of the tractor in combination with a new electrical energy system based on a hydrogen fuel cell. We analyze and compare the exhaust gases resulting from the use of (1) an internal combustion engine as the single power source and (2) the hybrid energy system. The results demonstrate that the hybrid energy system reduced emissions by up to approximately 50%

Kinematics of planet-host stars and their relation with dynamical streams in the solar neighbourhood

We present a detailed study on the kinematics of metal-rich stars with and without planets, and their relation with the Hyades, Sirius and Hercules dynamical streams in the solar neighbourhood. Accurate kinematics have been derived for all the stars belonging to the CORALIE planet search survey. We used precise radial velocity measurements and CCF parameters from the CORALIE database, and parallaxes, photometry and proper motions from the HIPPARCOS and Tycho-2 catalogues. The location of stars with planets in the thin or thick discs has been analysed using both kinematic and chemical constraints. We compare the kinematic behaviour of known planet-host stars to the remaining targets belonging to the volume-limited sample, in particular to its metal-rich population. The high average metallicity of the Hyades stream is confirmed. The planet-host targets show a kinematic behaviour similar to that of the metal-rich comparison subsample, rather than to that of the comparison sample as a whole, thus supporting a primordial origin for the metal excess observed in stars with known planetary companions. According to the scenarios proposed as an explanation for the dynamical streams, systems with giant planets could have formed more easily in metal-rich inner Galactic regions and then been brought into the solar neighbourhood by dynamical streams.Comment: 14 pages, 12 figures, accepted for publication in A&A (28 August 2006

El turismo en el espacio rural en la mitad sur de Río Grande do Sul, Brasil (1997-2005)

Con el objetivo de analizar la evolución de las propiedades rurales, así como diferenciar las que practican agroturismo de las que ofrecen turismo rural, se investigaron nueve propiedades rurales en la mitad sur del estado de Rio Grande do Sul, Brasil. El estudio se llevó a cabo en dos fases: una cualitativa con carácter exploratorio y otra cuantitativa con carácter descriptivo que consistió en la aplicación de encuestas en tres momentos diferentes: 1997, 2002 y 2005. Los resultados permiten concluir que la pluriactividad es la estrategia más adoptada para enfrentar las condiciones macroeconómicas; asimismo, se detectó predominancia del agroturismo sobre el turismo rural. El estudio mostró la viabilidad de las actividades turísticas en algunas fincas, toda vez que generan ingresos adicionales y permiten el contacto con los habitantes urbanos

Ectopic application of the repressive histone modification H3K9me2 establishes post-zygotic reproductive isolation in Arabidopsis thaliana

Hybrid seed lethality as a consequence of interspecies or interploidy hybridizations is a major mechanism of reproductive isolation in plants. This mechanism is manifested in the endosperm, a dosage-sensitive tissue supporting embryo growth. Deregulated expression of imprinted genes such as ADMETOS (ADM) underpin the interploidy hybridization barrier in Arabidopsis thaliana; however, the mechanisms of their action remained unknown. In this study, we show that ADM interacts with the AT hook domain protein AHL10 and the SET domain-containing SU (VAR) 3-9 homolog SUVH9 and ectopically recruits the heterochromatic mark H3K9me2 to AT-rich transposable elements (TEs), causing deregulated expression of neighboring genes. Several hybrid incompatibility genes identified in Drosophila encode for dosage-sensitive heterochromatin-interacting proteins, which has led to the suggestion that hybrid incompatibilities evolve as a consequence of interspecies divergence of selfish DNA elements and their regulation. Our data show that imbalance of dosage-sensitive chromatin regulators underpins the barrier to interploidy hybridization in Arabidopsis, suggesting that reproductive isolation as a consequence of epigenetic regulation of TEs is a conserved feature in animals and plants

Amplifying Reactivity of Metal Hydrides: A Heterotrimetallic NiAl2(μ2-H)2 Catalyst for the Facile Dearomatization of N-Heterocycles

Identifying methods to modulate the reactivity of metal-hydrides are lacking yet highly desirable given the role they play in a plethora of catalytic applications. Herein we report novel methodology to amplify reactivity of metal hydrides through the design of well-defined heterometallic bridged hydride species. Catalytic hydroboration of quinolines was dramatically altered by the addition of a secondary metal to bridge the Al-hydride species LAlH. Specifically, the addition of Ni(COD)2 led to the formation of novel heterotrimetallic species 1 which features Ni participating in 3-center- bonding with sterically accessible Al-H species and exhibits catalytic hydroboration of sterically encumbered quinolines and approximately a 400 times enhancement in catalytic reactivity in comparison to LAlH

Uma viagem ao sul: do ‘el sur’, de borges, ao roteiro turístico rural em bagé-rs, brasil

O artigo propõe realizar visita ao Sul, acompanhando a viagem de Juan Dahlmann, personagem criado por Jorge Luis Borges (1975) no conto El Sur, assim como apresentar resgate histórico dos bens culturais presentes em roteiro de turismo rural, no município de Bagé. El Sur foi escolhido, pelas possibilidades de leitura que permite, e por se tratar de um relato de viagem ao Pampa, onde Dahlmann vai em busca de uma história não vivida, de um passado reverenciado apenas por símbolos, mas que alimenta a vida urbana do personagem, definindo sua identidade e pertencimento. Tenta-se estabelecer a conexão entre a paisagem [o Pampa] e a construção da identidade do personagem Juan Dahlmann, que se sentia ͚profundamente argentinoArgentina, Uruguai e Brasil, no Estado do Rio Grande do Sul, compartilham o ecossistema Pampa e, cada um ao seu modo, tem na figura do gaucho / gaúcho, um referencial. Na elaboração dessa identidade, o Pampa – o El Sur, de Borges - apresenta alto valor simbólico no imaginário social construído na literatura, mas também na música e no folclore de ambos os países. O presente artigo aproxima o El Sur borgeano, presente na viagem do personagem Dahlmann, ao Sul presente em roteiro turístico rural em Bagé, um dos municípios melhor associados ao imaginário gaúĐho͛, no Brasil. Bagé apresenta patrimônio material relevante e diversificado. Tanto o texto de Borges como o roteiro turístico rural configuram o Pampa como um lugar de memória a expressar origem e pertencimento. Uma pesquisa bibliográfica sobre pontos turísticos mencionados no roteiro revela uma história rica e complexa que vai além da visão míticofundadora, em geral presente nas narrativas sobre o regional. Conclui-se pela importância da preservação do patrimônio histórico existente no roteiro mencionado e o turismo rural como uma alternativa para viabilizá-la

Combining series elastic actuation and magneto-rheological damping for the control of agile locomotion

All-terrain robot locomotion is an active topic of research. Search and rescue maneuvers and exploratory missions could benefit from robots with the abilities of real animals. However, technological barriers exist to ultimately achieving the actuation system, which is able to meet the exigent requirements of these robots. This paper describes the locomotioncontrol of a leg prototype, designed and developed to make a quadruped walk dynamically while exhibiting compliant interaction with the environment. The actuation system of the leg is based on the hybrid use of series elasticity and magneto-rheological dampers, which provide variable compliance for natural-looking motion and improved interaction with the ground. The locomotioncontrol architecture has been proposed to exploit natural leg dynamics in order to improve energy efficiency. Results show that the controller achieves a significant reduction in energy consumption during the leg swing phase thanks to the exploitation of inherent leg dynamics. Added to this, experiments with the real leg prototype show that the combined use of series elasticity and magneto-rheologicaldamping at the knee provide a 20 % reduction in the energy wasted in braking the knee during its extension in the leg stance phase