Análisis del ciclo de vida de dos sistemas de manejo para la producción de piña en México

El objetivo de este trabajo es realizar un análisis de ciclo de vida sobre dos técnicas de cultivo de piña: el sistema tradicional con suelo desnudo y cielo abierto y el sistema tecnológico con uso de acolchado plástico y malla sombra. La mayor parte de siembra de piña en México es en el estado de Veracruz. Por está razón los productores de esta región proporcionarán datos de campo mediante la respuesta a una encuesta.La agricultura es una de las actividades que emiten gases de efecto invernadero (GEI) y contribuye alrededor del 10-12% del total de emisiones antropogénicas de dichos gases. El crecimiento acelerado de la población trae consigo una fuerte demanda en los mercados locales y de exportación de la piña (Ananas comosus). Por ello, se hace necesario buscar estrategias o alternativas para los sistemas de producción agrícolas. En los últimos diez años en México, principalmente en la Región del Papaloapan y la Chontalpa, se han utilizado dos sistemas de manejo para el cultivo de piña totalmente contrastantes. El sistema Convencional basa la producción en suelo desnudo y cielo abierto, mientras el sistema Ambiente Protegido se fundamenta en proteger al suelo, la humedad y las plantas con los frutos, mediante el uso del acolchado plástico total y la malla-sombra. El sistema de manejo de Ambiente Protegido fue desarrollado por el Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP), a través de su Campo Experimental Papaloapan, reportando que, mediante estas técnicas se acortan de 2 a 3 meses los ciclos de cultivo, mayor rendimiento y productividad, evita que salgan malezas y se reduce la aplicación de insumos y agroquímicos. En los sistemas de manejo utilizados para la producción intensiva de piña fresca de exportación se aplican de manera intensiva, insumos como herbicidas, plaguicidas, hormonas y fertilizantes químicos. El presente estudio se realizó para analizar y comparar los sistemas de manejo para la producción de piña, mediante una encuesta realizada a 3 grandes empresas que se dedican a su cultivo y comercialización. De esta forma fue posible contabilizar los insumos utilizados en todas las actividades involucradas en el proceso de producción y se obtuvo el inventario. La metodología del Análisis del Ciclo de Vida (ACV) nos ha permitido caracterizar ambientalmente los dos sistemas de manejo para la producción de piña. Los resultados indican que, en todos los casos de las 18 categorías de impactos evaluadas, el sistema Ambiente Protegido resulta tener menor impacto ambiental. La producción de 1 kg de piña convencional en México equivale a 0,1375 0,0106 kg CO2 eq y para la producción de 1 kg de piña con el sistema ambiente protegido 0,0873 0,0055 kg CO2 eq. En ambos sistemas analizados, se encontró que la etapa de fertilización es la que se lleva la mayoría de las cargas ambientales, seguido por la fabricación y uso combustibles. Los parámetros financieros de estos sistemas indican que la tasa interna de retorno y periodo de recuperación para el sistema convencional es de 8% y 18 meses, y para el sistema Ambiente protegido es de 5.6% y 15.6 meses respectivamente.Agriculture is one of the main activities that emits greenhouse gases (GHG), with a contribution of around 10-12% of the total anthropogenic GHG emissions. The fast growing population brings with it a strong demand in the local and export markets of pineapple (Ananas comosus). Therefore, it is necessary to look for strategies or alternatives for agricultural production systems. In the past ten years in Mexico, mainly in the Region of Papaloapan and the Chontalpa, it two totally contrasting management systems have been used for pineapple agriculture. The “Conventional System” bases production on bare ground and open sky, while the “Protected Environment System” is based on protecting the soil, moisture and plants with the fruits, through the use of total plastic mulching and shade cloth. The Protected Environment management system was developed by the National Institute of Forestry, Agriculture and Livestock Research (INIFAP), through its Papaloapan Experimental Field, reporting that these techniques shorten the crop cycles by 2 to 3 months, gets higher yield and productivity, prevents weeds from growing and reduces the application of inputs and agrochemicals. In the management systems used for the intensive production of fresh export pineapples, inputs such as herbicides, pesticides, hormones and chemical fertilizers are intensively applied. The present study was carried out to analyze and compare management systems for pineapple production, through a survey of 3 large companies engaged in the cultivation and commercialization of pineapples, it was possible to account for the inputs used in all the activities involved in the production process, this way the inventory was gathered. Life Cycle Analysis (LCA) methodology has allowed us to characterize the two management systems for the production of pineapple. Results indicate that, in all cases of the 18 evaluated impact categories, the Protected Environment system has a lower environmental impact. The production of 1 kg of conventional pineapple in Mexico is equivalent to 0.1375 0.0106 kg CO2 eq and for the production of 1 kg of pineapple with the protected environment system 0.0873 0.0055 kg CO2 eq. In both analyzed systems, it was found that the fertilization stage is the one that takes most of the environmental loads, followed by the manufacture and fuel consumption. The financial parameters of these systems indicate that the internal rate of return and recovery period for the conventional system is 8% and 18 months, and for the protected environment system it is 5.6% and 15.6 months respectively

El modelo de negocio de las estaciones de servicio frente al mercado de los autos eléctricos en Argentina

La siguiente tesis presenta el cambio actual que está comenzando a ocurrir en mayor o menor medida dependiendo del país en el negocio de las estaciones de servicio ante el cambio tecnológico que atraviesa la industria automotriz al migrar los motores a combustión a motores eléctricos. El proceso de cambio llevará varios años, pero implica resolver diversas cuestiones en lo que hace a la cadena de valor que actualmente tienen las empresas petroleras que presencia en el negocio de venta de combustibles líquidos. El objetivo es comprender el modelo de negocios actual de las estaciones de servicio e investigar posibilidades de reconversión de dicho modelo para adaptarse al cambio tecnológico mediante un análisis cualitativo del mercado de los autos eléctricos, analizar las acciones que se han llevado a cabo en países que llevan más tiempo de desarrollo en esta evolución tecnológica y de infraestructura necesaria y describir, investigación de por medio, casos de empresas globales petroleras que actualmente están en plena revisión estratégico de sus modelos de negocio. Como principales conclusiones, se obtiene que el modelo de negocio de estaciones de servicio tiene dos grandes drivers importantes, el foco en el cliente, el cual hay que entender cómo cambian los patrones de consumo ante nuevas alternativas, competidores que entran en escena, y la necesidad de realizar una migración completa de la cadena de valor en una integración desde la generación eléctrica hasta la venta al consumidor final, replicando el modelo anterior de obtención de petróleo hasta la venta del producto refinado

Are smiles a sign of happiness?: spontaneous expressions of judo winners

Which is the strongest predictor of Duchenne smiles? Is it emotion or sociality? Two field studies on the production of facial behavior by winning judo fighters (N = 174) are presented, testing if judo fighters smiled while being happy or while they were engaged in social interaction with the audience. Our studies simultaneously meet important methodological requirements: intense emotions; precise moment-to-moment coding of facial expressions; behavioral records long enough to allow smiles to unfold; discrimination between records of interactive and non-interactive behavior, and self-reports of emotional experience after winning a medal. We found that Duchenne smiles were not a necessary sign of happiness. Although all the judo fighters won their respective matches, they displayed a very low proportion of Duchenne smiles (.15 in Study 1, and .21 in Study 2). Being engaged in social interaction (communicative gestures with arms and hands while facing the audience) was found to be the strongest predictor for the occurrence of Duchenne smiles. Our studies provide support for the view that facial expressions are tools for social interaction (Behavioral Ecology Theory), rather than read-outs of basic emotions (Facial Expression Program).This research was supported by the Spanish Government’s grant PSI2011-28720 and by a Predoctoral Fellowship (FPI-UAM2012) awarded to Carlos Crivell

Configuration optimization of space structures

The objective is to develop a computer aid for the conceptual/initial design of aerospace structures, allowing configurations and shape to be apriori design variables. The topics are presented in viewgraph form and include the following: Kikuchi's homogenization method; a classical shape design problem; homogenization method steps; a 3D mechanical component design example; forming a homogenized finite element; a 2D optimization problem; treatment of volume inequality constraint; algorithms for the volume inequality constraint; object function derivatives--taking advantage of design locality; stiffness variations; variations of potential; and schematics of the optimization problem

A survey of the core-congruential formulation for geometrically nonlinear TL finite elements

This article presents a survey of the core-congruential formulation (CCF) for geometrically nonlinear mechanical finite elements based on the total Lagrangian (TL) kinematic description. Although the key ideas behind the CCF can be traced back to Rajasekaran and Murray in 1973, it has not subsequently received serious attention. The CCF is distinguished by a two-phase development of the finite element stiffness equations. The initial phase developed equations for individual particles. These equations are expressed in terms of displacement gradients as degrees of freedom. The second phase involves congruential-type transformations that eventually binds the element particles of an individual element in terms of its node-displacement degrees of freedom. Two versions of the CCF, labeled direct and generalized, are distinguished. The direct CCF (DCCF) is first described in general form and then applied to the derivation of geometrically nonlinear bar, and plane stress elements using the Green-Lagrange strain measure. The more complex generalized CCF (GCCF) is described and applied to the derivation of 2D and 3D Timoshenko beam elements. Several advantages of the CCF, notably the physically clean separation of material and geometric stiffnesses, and its independence with respect to the ultimate choice of shape functions and element degrees of freedom, are noted. Application examples involving very large motions solved with the 3D beam element display the range of applicability of this formulation, which transcends the kinematic limitations commonly attributed to the TL description

Facial displays are tools for social influence

Open access articleBased on modern theories of signal evolution and animal communication, the behavioral ecology view of facial displays (BECV) reconceives our ‘facial expressions of emotion’ as social tools that serve as lead signs to contingent action in social negotiation. BECV offers an externalist, functionalist view of facial displays that is not bound to Western conceptions about either expressions or emotions. It easily accommodates recent findings of diversity in facial displays, their public context-dependency, and the curious but common occurrence of solitary facial behavior. Finally, BECV restores continuity of human facial behavior research with modern functional accounts of non-human communication, and provides a non-mentalistic account of facial displays well-suited to new developments in artificial intelligence and social robotics

Recognizing spontaneous facial expressions of emotion in a small-scale society of Papua New Guinea

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.We report two studies on how residents of Papua New Guinea interpret facial expressions produced spontaneously by other residents of Papua New Guinea. Members of a small-scale indigenous society, Trobrianders (Milne Bay Province; N = 32, 14 to 17 years) were shown 5 facial expressions spontaneously produced by members of another small-scale indigenous society, Fore (Eastern Highlands Province) that Ekman had photographed, labeled, and published in The Face of Man (1980), each as an expression of a basic emotion: happiness, sadness, anger, surprise, and disgust. Trobrianders were asked to use any word they wanted to describe how each person shown felt and to provide valence and arousal ratings. Other Trobrianders (N = 24, 12 to 14 years) were shown the same photographs but asked to choose their response from a short list. In both studies, agreement with Ekman’s predicted labels was low: 0 to 16% and 13 to 38% of observers, respectively

Inside-Out: From Basic Emotions Theory to the Behavioral Ecology View

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI or URI link.Basic Emotions Theory (BET) is the most popular and deeply rooted psychological theory of both emotion and the facial behavior held to express it. We review its Western foundations and the key developments in its evolution, focusing on its parsing of facial expressions into two kinds: biological, categorical, iconic, universal “facial expressions of emotion,” versus modified, culturally diverse versions of those iconic expressions due to intermediation by learned “display rules.” We suggest that this dichotomy and its many corollaries are oversimplified, and that many of BET’s recent modifications are inconsistent in ways that may render it impossible to test and immune to falsification. In contrast, we suggest that the behavioral ecology view of facial displays, as an externalist and functionalist approach, resolves the quandaries and contradictions embedded in BET’s precepts and extensions

The fear gasping face as a threat display in a Melanesian society

Theory and research showthat humans attribute both emotions and intentions to others on the basis of facial behavior: A gasping face can be seen as showing “fear” and intent to submit. The assumption that such interpretations are pancultural derives largely from Western societies. Here, we report two studies conducted in an indigenous, small-scale Melanesian society with considerable cultural and visual isolation from the West: the Trobrianders of Papua New Guinea. Our multidisciplinary research team spoke the vernacular and had extensive prior fieldwork experience. In study 1, Trobriand adolescents were asked to attribute emotions, social motives, or both to a set of facial displays. Trobrianders showed a mixed and variable attribution pattern, although with much lower agreement than studies of Western samples. Remarkably, the gasping face (traditionally considered a display of fear and submission in the West) was consistently matched to two unpredicted categories: anger and threat. In study 2, adolescents were asked to select the face that was threatening; Trobrianders chose the “fear” gasping face whereas Spaniards chose an “angry” scowling face. Our findings, consistent with functional approaches to animal communication and observations made on threat displays in small-scale societies, challenge the Western assumption that “fear” gasping faces uniformly express fear or signal submission across cultures

A survey of the core-congruential formulation for geometrically nonlinear TL finite elements

This article presents a survey of the Core-Congruential Formulation (CCF) for geometrically nonlinear mechanical finite elements based on the Total Lagrangian (TL) kinematic description. Although the key ideas behind the CCF can be traced back to Rajasekaran and Murray in 1973, it has not subsequently received serious attention. The CCF is distinguished by a two-phase development of the finite element stiffness equations. The initial phase develop equations for individual particles. These equations are expressed in terms of displacement gradients as degrees of freedom. The second phase involves congruential-type transformations that eventually binds the element particles of an individual element in terms of its node-displacement degrees of freedom. Two versions of the CCF, labeled Direct and Generalized, are distinguished. The Direct CCF (DCCF) is first described in general form and then applied to the derivation of geometrically nonlinear bar, and plane stress elements using the Green-Lagrange strain measure. The more complex Generalized CCF (GCCF) is described and applied to the derivation of 2D and 3D Timoshenko beam elements. Several advantages of the CCF, notably the physically clean separation of material and geometric stiffnesses, and its independence with respect to the ultimate choice of shape functions and element degrees of freedom, are noted. Application examples involving very large motions solved with the 3D beam element display the range of applicability of this formulation, which transcends the kinematic limitations commonly attributed to the TL description