Estimating Forage Biomass using Unmanned Ground and Aerial Vehicles

The assessment of the amount of biomass in the field is one of the critical factors that helps to manage and optimize numerous operations associated with forage management in the livestock industry. Pasture management decisions about stocking rate, grazing duration, and fertilizer application rate depend on accurate forage availability measurements. The objective of this study was to develop different nondestructive methods of forage biomass estimation using unmanned vehicles based on the relationship between crop height (CH) and the measured above-ground biomass. The unmanned vehicle-based methods were developed and tested on Alfalfa (Medicago Sativa) and Tall Fescue (Schedonorus phoenix (Scop.) Holub) fields. The real-time compressed crop height was measured using the ultrasound proximal sensor and a compression ski installed on the unmanned ground vehicle (UGV) and orthomosaic from aerial images was used for plot identification for site-specific analysis. The experiment was carried out before and after harvest to calculate the harvested CH to generate its regression relation with wet and dry biomass yield of forage. The results show that these systems produce promising results with R-square values of 0.8 and 0.5 for biomass estimation in Alfalfa and Tall Fescue respectively. These methods will significantly reduce the on-field destructive forage sampling for biomass estimation and aid in predicting the available biomass along with reducing the human efforts and resources for performing biomass sampling tasks, resulting in reduction of time and cost

The relative role of executive control and personality traits in grit

Although grit is predictive of wellbeing, educational achievement, and success in life, it has been conceptualized as largely distinct from cognitive ability. The present study investigated the link between grit and executive functions since regulation abilities might underlie the expression of grit. A hundred thirty-four people were administered personality questionnaires (grit, impulsiveness, and mindfulness) and four experimental tasks tapping into Miyake’s and Braver’s models of executive functioning (including measures of flexibility, inhibition, working memory, and control mode dimensions). Multivariate analyses showed that two composite scores (trait and executive functioning) were reliably predictive of grit, although it was the trait composite (characterized by low impulsivity and high mindfulness) that explained more variance. Importantly, gritty participants did not demonstrate enhanced executive functioning. Instead, they exhibited a different pattern of performance that might be reflecting a cautious profile of control, characterized by paying attention to all available information, less reliance on previous contextual cues but sensitive to conflicting information of the current context. These findings converge with Duckworth’s idea that high grit people do not necessarily have a greater cognitive capacity. Rather, they use it in a different way.This work was supported by the Spanish Ministry of Economy and Competitiveness and the Andalusian Government (Fondos FEDER) grants: doctoral research Grant ES-2016-078667 to NA; PSI2015-65502-C2-1-P, A.CTS.111.UGR18 and PGC2018-093786-B-I00 to TB; and PSI2015- 65502-C2-2-P to CG-A. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Numerical simulation of partially premixed combustion using a flame surface density approach

Partially premixed combustion is characterized by a variable equivalence ratio of the mixture in space and time, and where there are both lean and rich mixture zones. Thus the reaction evolves along with a turbulent mixture process, which modifies the composition of reactants and products. In this situation a so-called triple flame could be encountered, in which a rich and a lean premixed flame front as well as a diffusion flame are present. The diffusion flame develops behind the premixed flame front due to turbulent mixing in the hot combustion products. This kind of combustion could be found in Direct Injection Spark Ignition (DISI) engines when they are operated in the stratified charge mode. The model considered in this work assumes a simplified one-step irreversible chemical reaction in which fuel and oxidant react together in stoichiometric proportions giving products with the composition corresponding to a complete combustion. A transport equation is solved for the oxidant and fuel, from which the amount of products and the combustion progress are computed, while the turbulence is modeled with RANS (Reynolds-Average Navier-Stokes). The reaction rate is assumed in the model as proportional to the product of the Flame Surface Density (FSD) by the local laminar flame speed. Aside from the state and composition of the mixture, the local laminar flame speed is afected by the turbulent mixing process. This mixing process is taken into account by means of the classical β-PDF (Probability Density Function), which is a function of the mixture fraction and its variance. A transport equation is solved for both, the mixture fraction and its variance, and the FSD is computed through a transport equation where several models are available for the source terms. The model is implemented in the open-source toolkit OpenFOAM®. Computational results are obtained for partially premixed combustions inside constant-volume vessels with several initial configurations, which are compared with numerical results available in the literature.Publicado en: Mecánica Computacional vol. XXXV, no. 16.Facultad de Ingenierí

Numerical simulation of partially premixed combustion using a flame surface density approach

Partially premixed combustion is characterized by a variable equivalence ratio of the mixture in space and time, and where there are both lean and rich mixture zones. Thus the reaction evolves along with a turbulent mixture process, which modifies the composition of reactants and products. In this situation a so-called triple flame could be encountered, in which a rich and a lean premixed flame front as well as a diffusion flame are present. The diffusion flame develops behind the premixed flame front due to turbulent mixing in the hot combustion products. This kind of combustion could be found in Direct Injection Spark Ignition (DISI) engines when they are operated in the stratified charge mode. The model considered in this work assumes a simplified one-step irreversible chemical reaction in which fuel and oxidant react together in stoichiometric proportions giving products with the composition corresponding to a complete combustion. A transport equation is solved for the oxidant and fuel, from which the amount of products and the combustion progress are computed, while the turbulence is modeled with RANS (Reynolds-Average Navier-Stokes). The reaction rate is assumed in the model as proportional to the product of the Flame Surface Density (FSD) by the local laminar flame speed. Aside from the state and composition of the mixture, the local laminar flame speed is afected by the turbulent mixing process. This mixing process is taken into account by means of the classical β-PDF (Probability Density Function), which is a function of the mixture fraction and its variance. A transport equation is solved for both, the mixture fraction and its variance, and the FSD is computed through a transport equation where several models are available for the source terms. The model is implemented in the open-source toolkit OpenFOAM®. Computational results are obtained for partially premixed combustions inside constant-volume vessels with several initial configurations, which are compared with numerical results available in the literature.Publicado en: Mecánica Computacional vol. XXXV, no. 16.Facultad de Ingenierí

Numerical simulation of partially premixed combustion using a flame surface density approach

Partially premixed combustion is characterized by a variable equivalence ratio of the mixture in space and time, and where there are both lean and rich mixture zones. Thus the reaction evolves along with a turbulent mixture process, which modifies the composition of reactants and products. In this situation a so-called triple flame could be encountered, in which a rich and a lean premixed flame front as well as a diffusion flame are present. The diffusion flame develops behind the premixed flame front due to turbulent mixing in the hot combustion products. This kind of combustion could be found in Direct Injection Spark Ignition (DISI) engines when they are operated in the stratified charge mode. The model considered in this work assumes a simplified one-step irreversible chemical reaction in which fuel and oxidant react together in stoichiometric proportions giving products with the composition corresponding to a complete combustion. A transport equation is solved for the oxidant and fuel, from which the amount of products and the combustion progress are computed, while the turbulence is modeled with RANS (Reynolds-Average Navier-Stokes). The reaction rate is assumed in the model as proportional to the product of the Flame Surface Density (FSD) by the local laminar flame speed. Aside from the state and composition of the mixture, the local laminar flame speed is afected by the turbulent mixing process. This mixing process is taken into account by means of the classical β-PDF (Probability Density Function), which is a function of the mixture fraction and its variance. A transport equation is solved for both, the mixture fraction and its variance, and the FSD is computed through a transport equation where several models are available for the source terms. The model is implemented in the open-source toolkit OpenFOAM®. Computational results are obtained for partially premixed combustions inside constant-volume vessels with several initial configurations, which are compared with numerical results available in the literature.Publicado en: Mecánica Computacional vol. XXXV, no. 16.Facultad de Ingenierí

Electrophysiological correlates of dispositional mindfulness: A quantitative and complexity EEG study

While growing evidence supports that dispositional mindfulness relates to psychological health and cognitive enhancement, to date there have been only a few attempts to characterize its neural underpinnings. In the present study, we aimed at exploring the electrophysiological (EEG) signature of dispositional mindfulness using quantitative and complexity measures of EEG during resting state and while performing a learning task. Hundred twenty participants were assessed with the Five Facet Mindfulness Questionnaire and underwent 5 min eyes-closed resting state and 5 min at task EEG recording. We hypothesized that high mindfulness individuals would show patterns of brain activity related to (a) lower involvement of the default mode network (DMN) at rest (reduced frontal gamma power) and (b) a state of ‘task readiness’ reflected in a more similar pattern from rest to task (reduced overall q-EEG power at rest but not at task), as compared to their low mindfulness counterparts. Dispositional mindfulness was significantly linked to reduced frontal gamma power at rest and lower overall power during rest but not at task. In addition, we found a trend towards higher entropy during task performance in mindful individuals, which has recently been reported during mindfulness meditation. Altogether, our results add to those from expert meditators to show that high (dispositional) mindfulness seems to have a specific electrophysiological pattern characteristic of less involvement of the DMN and mind-wandering processes.The current research was financially supported by the Spanish Ministry of Science, Innovation and Universities and the Andalusian Government (Fondos FEDER) grants: doctoral research grant ES-2016-078667 to NA, PSI2015-65502-C2-2-P to CG-A and A-CTS-111-UGR18, PGC2018-093786-B-I00, and PID2021-127728NB-100 to TB. Funding for open acces charge: Universdad de Granada / CBUA

Noticia del Alero Alejandro: un nuevo componente de la Cueva de las Manos : Río Pinturas, provincia de Santa Cruz

En el transcurso del mes de febrero de 1994, mientras realizábamos una nueva medición y recuento de las improntas negativas de la conocida Cueva de las Manos del río Pinturas, provincia de Santa Cruz tuvimos la oportunidad de localizar un alero con pinturas rupestres, en el mismo farallón donde se halla ubicada la referida cueva, pero a mayor altura, escondido en una retracción rocosa, configurando algo así como una "ceja" de la cueva.Sociedad Argentina de Antropologí

Noticia del Alero Alejandro: un nuevo componente de la Cueva de las Manos : Río Pinturas, provincia de Santa Cruz

En el transcurso del mes de febrero de 1994, mientras realizábamos una nueva medición y recuento de las improntas negativas de la conocida Cueva de las Manos del río Pinturas, provincia de Santa Cruz tuvimos la oportunidad de localizar un alero con pinturas rupestres, en el mismo farallón donde se halla ubicada la referida cueva, pero a mayor altura, escondido en una retracción rocosa, configurando algo así como una "ceja" de la cueva.Sociedad Argentina de Antropologí

Diseño de automóviles de competición mediante fluidodinámica computacional

Impulsado por el incremento de las capacidades de cómputo en los últimos años, el CFD se ubica como herramienta indispensable para los ingenieros en la optimización de diseños de automóviles. Particularmente en la competición, estos se encuentran acotados a un reglamento siempre restrictivo, y se deben evaluar diferentes diseños para los pocos componentes plausibles de ser modificados para lograr optimizar la respuesta en pista. En nuestro país también se dió un salto muy importante en cuanto a la capacidad de cómputo, lo que permite incorporar la tecnología de simulación CFD en los desarrollos de las categorías locales. Sin embargo aparecen nuevos retos relacionados con la simulación a gran escala: generación de mallas de calidad, selección de modelos de turbulencia, planificación de estrategias robustas y precisas de discretización espacial y temporal, y por último la automatización de procesos que disminuyan el trabajo de preproceso para dedicarlo al post-proceso y al análisis de resultados para la toma de decisiones. Este trabajo presenta entonces un recorrido por los desarrollos efectuados durante el último tiempo en CIMEC en donde se evaluan simulaciones conceptuales como el flujo alrededor de una rueda o de un spoiler para establecer una guía de modelos numéricos a utilizar y describir la fenomenología de estos componentes. A su vez se presentan algunas de las diferentes simulaciones de producción en donde en base a la aplicación de rutinas automatizadas, empleo de las configuraciones apropiadas y herramientas de cómputo de gran rendimiento, se logran respuestas en tiempo y forma a las necesidades y urgencias del mundo del automovilismo.Publicado en: Mecánica Computacional vol. XXXV, no. 7.Facultad de Ingenierí

Diseño de automóviles de competición mediante fluidodinámica computacional

Impulsado por el incremento de las capacidades de cómputo en los últimos años, el CFD se ubica como herramienta indispensable para los ingenieros en la optimización de diseños de automóviles. Particularmente en la competición, estos se encuentran acotados a un reglamento siempre restrictivo, y se deben evaluar diferentes diseños para los pocos componentes plausibles de ser modificados para lograr optimizar la respuesta en pista. En nuestro país también se dió un salto muy importante en cuanto a la capacidad de cómputo, lo que permite incorporar la tecnología de simulación CFD en los desarrollos de las categorías locales. Sin embargo aparecen nuevos retos relacionados con la simulación a gran escala: generación de mallas de calidad, selección de modelos de turbulencia, planificación de estrategias robustas y precisas de discretización espacial y temporal, y por último la automatización de procesos que disminuyan el trabajo de preproceso para dedicarlo al post-proceso y al análisis de resultados para la toma de decisiones. Este trabajo presenta entonces un recorrido por los desarrollos efectuados durante el último tiempo en CIMEC en donde se evaluan simulaciones conceptuales como el flujo alrededor de una rueda o de un spoiler para establecer una guía de modelos numéricos a utilizar y describir la fenomenología de estos componentes. A su vez se presentan algunas de las diferentes simulaciones de producción en donde en base a la aplicación de rutinas automatizadas, empleo de las configuraciones apropiadas y herramientas de cómputo de gran rendimiento, se logran respuestas en tiempo y forma a las necesidades y urgencias del mundo del automovilismo.Publicado en: Mecánica Computacional vol. XXXV, no. 7.Facultad de Ingenierí