278 research outputs found
Perfiles de profesores de secundaria en formación inicial en relación a la quÃmica cotidiana
Humanoid seminar assessment in high technological studies
This paper presents a qualitative assessment of the experience of integrating a humanoid robotics seminar in a mobile robotics-related subject at the Master’s degree on Automatic Control and Robotics. In this way, social robotics is included as a part of the syllabus of this Master’s subject taught using the Problem-Based Learning (PBL) methodology. The assessment of our experience shows high interest in the new robotics approach and students are satisfied.Peer ReviewedPostprint (author's final draft
An innovative pedagogical tool for robotics engineering studies
At the Engineering School of Barcelona (ETSEIB- UPC) a multimedia pedagogical tool has been developed in order to traini ng concepts and ecojustice, environmentalism and sustainability to the students in Technical degrees, specifically in Robotics Engineering. This didactical tool consists in a serial of multimedia world maps that describes the world situation in a wide range of different trends such as the nuclear energy, the fossil fuels, the electronic components of the machines, the atomic weapons, etc. The developed pedagogical instrument uses a slide presentation format in order to integrate the relevant information of different economical-environmental- social themes related with actual society. In this paper one of the multimedia maps is explained and discussed: the nuclear energy map. This pedagogical resource boosts the reflection in our students about several aspects of social interest in a sustainable overview and students are able to understand the role of Robotics in many and relevant applications.Peer ReviewedPostprint (author's final draft
Quadrotor multi-model for control purposes
In this work, a multi-model of a quadrotor is developed in order to control this system. The kinematic model of each part of the quadrotor will be derived using the Euler angles, and also the dynamics model of the quadrotor will be calculated based on the first principles of a rigid body using the Newton-Euler formulation. Furthermore, the following assumptions are used :1) The structure is completely rigid and perfectly symmetric. 2) The center of mass is in the origin of the quadrotor fixed frame. 3) The thrusts are proportional to the square of the motors rotational speed. A state-space model (kinematics and dynamics) is developed by physical laws. But, this deduced model presents several no linearities that are produced by three factors: the orientation (Pitch, Roll and Yaw), the control action and the angular velocities. To be able to control the quadrotor system in simple, linear and manageable way, it is necessary to linearize the system. Two method are possible: a classical linearization around several set-points and a multi-model linearization. In this case, a multi-model linearization is proposed due to the obtained control model will be used to compute a multi-model controller using fuzzy techniques. Fuzzy control techniques are suitable for linear parameter varying systems with no linearities, as our quadrotor.Peer ReviewedPostprint (published version
From research to teaching: Integrating social robotics in engineering degrees
Postprint (published version
Bacillus thuringiensis Toxins: Functional Characterization and Mechanism of Action
Bacillus thuringiensis (Bt)-based products are the most successful microbial insecticides to date. This entomopathogenic bacterium produces different kinds of proteins whose specific toxicity has been shown against a wide range of insect orders, nematodes, mites, protozoa, and human cancer cells. Some of these proteins are accumulated in parasporal crystals during the sporulation phase (Cry and Cyt proteins), whereas other proteins are secreted in the vegetative phase of growth (Vip and Sip toxins). Currently, insecticidal proteins belonging to different groups (Cry and Vip3 proteins) are widely used to control insect pests and vectors both in formulated sprays and in transgenic crops (the so-called Bt crops). Despite the extensive use of these proteins in insect pest control, especially Cry and Vip3, their mode of action is not completely understood
Impactos del cambio climático sobre las áreas óptimas de nueve cultivos en Cundinamarca - Colombia
Because changes in rainfall and temperature conditions due to climate change are expected, for the department of Cundinamarca, which will affect crop development, it is necessary to identify them in the areas of food production that are the most important for food security under climate change scenarios, Such identification will allow the implementation of timely adaptation measures for most affected areas. We investigated the impact of climate change on the best areas of nine crops in Cundinamarca - Colombia. There were interpolate data for each crop according their optimum ranges of precipitation and temperature, and with the preposition of these variables it was determined the current area and spacialization of crops, as well as the projections for the periods 2011 – 2040 and 2070 – 2100 under A2 (pessimistic) y B2 (optimistic), climate change scenarios. Results showed that under new climatic conditions, the potato and vetch crops tend to disappear, while for rice crop, it would hope an increase on optimum areas of production. A2 2011 - 2040 and B2 2011 - 2040 scenarios would show a decrease near 74% of cultivable area for all nine crops, against A2 2070 - 2100 and B2 2070 – 2100 scenarios which indicate a rise of optimum area close to 5% in relation to current area. Debido a que se esperan cambios en las condiciones de la precipitación y la temperatura por efectos del cambio climático, para el departamento de Cundinamarca los cuales afectarán el desarrollo de los cultivos, surge la necesidad de identificar los cambios en las áreas de producción de los alimentos más importantes para la seguridad alimentaria bajo escenarios de cambio climático, lo cual permitirá implementar medidas de adaptación oportunas para los municipios más afectados. Se interpolaron los datos para cada uno de los cultivos de acuerdo con sus rangos óptimos de temperatura y precipitación, y la modelación de estas variables se determinó el área y espacialización actual de los cultivos, asà como las proyecciones para los periodos 2011 – 2040 y 2070 – 2100 bajo los escenarios de cambio climático A2 (escenario pesimista) y B2 (escenario optimista), los cuales se obtienen a partir de escenarios de emisiones, introducidas en un modelo climático para obtener proyecciones climáticas; los resultados demostraron que bajo nuevas condiciones climáticas, los cultivos de arveja y papa pastusa tienden a desaparecer, mientras que en el cultivo de arroz se esperarÃa un aumento de las áreas óptimas de producción. Para los escenarios A2 2011 - 2040 y B2 2011 - 2040 se presentarÃa una reducción del 74% del área cultivable para los nueve alimentos evaluados, contrario a los escenarios A2 2070 - 2100 y B2 2070 - 2100 que indican un incremento del área óptima del 5% respecto a la actual
Tratamento de lixiviado de aterro sanitário com carvão ativado obtido de resÃduos de café
A set of experiments were carried out in order to establish and evaluate the
potential of activated carbon, produced from coffee waste in adsorption
process, in the depuration of landfill leachate. Different reagents were studied
in the activation of carbon: HCl, HCl + H2O2, H3PO4, H3PO4 + H2O2, all with an
impregnation rate of 1:1. The activated carbon that showed the best global
results was activated with H3PO4, obtaining a 51.0, 32.8, 66.0, 81.0 and 97.1%
elimination of chemical oxygen demand, ammonia, total chlorine, bromine
and copper, respectively. This activated carbon has a total pore area of
4.85 m2/g and a median pore diameter of 65.32 micrometers. When different
loads of this carbon were placed in a stirrer system in contact with landfill
leachate, with the aim of evaluating the effect of the adsorption load and
contact time, the concentration of ammonia decreased from the beginning
of the adsorption process to the end of it, and the removal of ammonia
increased with the increase in the adsorbent load. However, the trend of the
amount adsorbed per unit mass decreased with increased dosage. The model
Freundlich equilibrium isotherm fits experimental data adequately, giving R2
values of 0.95, 1/n of 0.5183, and a K value of 7.08*10-5 L/g, being favourable for
adsorption process.Foi realizada uma série de experimentos para estabelecer e avaliar o potencial
de carvão ativado produzido de resÃduos de café por meio de um processo
de adsorção na depuração do lixiviado de aterro sanitário. Foram estudados
diferentes reagentes para a ativação do carvão: HCl, HCl + H2O2, H3PO4, H3PO4
+ H2O2, todos com taxa de impregnação de 1:1. O carvão que apresentou os
melhores resultados foi ativado com H3PO4, obtendo uma eliminação de 51,0;
32,8; 66,0; 81,0; e 97,1% de demanda quÃmica de oxigênio e concentração de
amônia, cloro total, bromo e cobre, respetivamente. O referido carvão ativado
tem uma área total de poro de 4,85 m2/g e diâmetro médio de poro de
65,32 micrômetros. Com o objetivo de avaliar o efeito da carga de adsorção
e do tempo de contato, foram colocadas diferentes cargas desse carvão
em um sistema de agitação em contato com o lixiviado de aterro sanitário.
Observou-se que a concentração de amônia diminuiu e que sua remoção foi
maior à medida que a carga adsorvente aumentava. No entanto, a quantidade
adsorvida por unidade de massa diminuiu com o aumento da dosagem.
Os dados experimentais adequaram-se corretamente ao modelo de isoterma
de Freundlich, obtendo-se valores de R2 de 0,95, 1/n de 0,5183, e um valor de K
de 7,08*10-5 L/g, considerados favoráveis para o processo de adsorção.Ministerio de Educación (Chile) 1114021
Tendencias y problemas actuales relacionados con a actividad turÃstica
El texto que se ofrece es una construcción prospectiva sobre el comportamiento turÃstico en el contexto de las megatendencias de la economÃa global, la polÃtica, la sustentabilidad, la dinámica social y el desarrollo tecnológico. El análisis consisten en delinear elementos significativos del comportamiento turÃstico en el entorno de los aspectos mencionados
Accurate integration of forced and damped oscillators
The new methods accurately integrate forced and damped oscillators. A family of analytical functions is introduced known as T-functions which are dependent on three parameters. The solution is expressed as a series of T-functions calculating their coefficients by means of recurrences which involve the perturbation function. In the T-functions series method the perturbation parameter is the factor in the local truncation error. Furthermore, this method is zero-stable and convergent. An application of this method is exposed to resolve a physic IVP, modeled by means of forced and damped oscillators. The good behavior and precision of the methods, is evidenced by contrasting the results with other-reputed algorithms implemented in MAPLE
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