2,262 research outputs found
Lexical Pragmatics and the nature of word meaning
Estudio de los procesos de ajuste léxico de extensión y especificación aplicados al significado de las palabras, examinando los usos que los hablantes hacen de las mismas que abarcan un continuo desde los más literales a los más metafóricos.Este artículo trata sobre los procesos de ajuste léxico de extensión y especificación del significado léxico codificado, así como con la naturaleza del significado de las palabras analizando desde los usos más literales hasta los más metafóricos, pasando por las aproximaciones y extensiones de categorías
Optimization of the production of milk in Brown Swiss cows supplemented with concentrate
Se realizó un análisis del óptimo técnico y óptimo económico, a través de modelos no lineales, para determinar el punto de máxima producción en leche y máxima ganancia en dinero con vacas PArdo-Suizo. Se demostró que la máxima producción del líquido no necesariamente implica la máxima ganancia en dinero para el productor
Customer unit substation of collective heat distribution system : Benchmark of hot water comfort test standard and methodologies
The performance assessment of dwelling heating substations in terms of level of comfort is usually studied regarding temperature overshoots, stationary temperature deviations and settling time among other parameters. In fact, several standards and test methods can be found focusing on a specific target or technology. However, these methods do not always provide clear information about hot water comfort. As a result planners, developers and customers have difficulties to compare a substation product with products using other technologies for the heating of sanitary hot water. The study investigates the compatibility of already existing methods and intends to evaluate their applicability to systems where the sanitary hot water is prepared in an instantaneous way by using a heat exchanger in a district heating substation. In order to achieve that aim, a dynamic simulation model of a test setup (using TRNSYS) has been developed. The test procedures, as well as the simulation results, are described and discussed. This analysis is expected to provide the basis for an integrated performance assessment test of this kind of devices
Sensitivity analysis of heat losses in distribution systems : impact of different buildings typologies
This paper focuses on the sensitivity of heat losses in collective heat distribution systems using a simplified calculation method. The methodology considers several parameters influencing the performance of heat distribution systems. Hence, the thermal properties of the heat exchanger in the dwelling heating substation and the return temperature of sanitary hot water are considered. In addition, the recirculation control strategy, the length of service branch which is included or not in the recirculation as well as, the share in a building of dwelling heating substation with similar characteristic and control strategy are also taken into account. The present study assess the impacts of some potential variations in the input variables, on the conclusions of the methodology. A comparison of the sensitivity of heat losses in the heating distribution system between four different buildings typologies, i.e. with 13, 24, 25 and 49 apartments, is provided. In order to identify the influence of building typology and pipe layout in the heat losses calculation, for the four cases the sensitivity analysis was carried out. A study was conducted through sensitivity analysis by means of an experimental design, consisting of the combinations of parameters which were varied from the levels at which they were set. Results shows how sensitive the solution is in the face of different parameter values as well as under what circumstances the solution would change. The suitability of the improved method which allow more flexibility to consider different pipe layout characteristic within a heating distribution system was demonstrated
Dinámica regional de la producción porcina en México, 1994-2012
Las políticas macroeconómicas y sectoriales adoptadas por México, en las últimas dos décadas, causaron una modificación en la estructura productiva de la porcicultura nacional y local, que fue distinta entre las regiones. El objetivo de este estudio fue cuantificar el crecimiento o decremento de la producción de carne de cerdo en canal y evaluar su dinámica económica de 1994 a 2012, en ocho regiones de México (Noroeste NO, Norte NR, Noreste NE, Centro-Occidente CO, Centro-Este CE, Sur SU, Oriente OR y Península de Yucatán PE). Para ello se usó la tasa de crecimiento anual, la tasa de crecimiento media anual (TCMA) y técnicas de análisis regional, como cociente de localización, coeficiente de especialización y método diferencial-estructural. Los resultados indicaron que durante el periodo de estudio las regiones OR, PE y NO tuvieron el crecimiento mayor de la producción de carne de cerdo y las TCMA mayores (5.07, 2.73 y 2.39 %). Pero las regiones OR, NO, CE, NE y NR tuvieron el grado mayor de dinamismo económico porque todos sus efectos (total, diferencial y estructural) fueron positivos, con una ganancia hipotética de 24.11, 17.80, 6.91, 4.89 y 3.60 miles t. Esto implicó especialización mayor, competitividad interregional mayor y mejores condiciones productivas. La región CO se rezagó durante todo el periodo de estudio
La caprinocultura en Amatepec y Tejupilco, Estado de México
Se utiliza el método del diagnóstico para determinar la situación actual de la caprinocultura en los municipios de Amatepec y Tejupilco, Estado de México
Simulation models and performance assessment of district heating substations
Development of new technologies and methodologies regarding district heating substation operational control strategies are increasingly found nowadays. At the same time a great number of modern buildings
are provided with energy monitoring and control systems which supervise and collect operating data from different energy components. Accordingly, an exemplary district heating systems is being implemented
in the city of Kortrijk in Belgium, as part of a demonstration zero-carbon neighborhood. This study deals with the energy performance assessment of one of the systems component -the consumer substationinstalled in this low-temperature district heating system. A comparative analysis of the energy performance with several existing district heating substations was carried out. Three different district heating substation models are set up (using TRNsys) for investigation of the gross energy use, energyefficiency and comfort issues. In order to evaluate the performance of the analyzed substations two scenarios concerning the space heating system (radiator or floor heating system) were considered. The study aims to investigate the impact of different operational circumstances on the performance of district heating substations. The study generate understandings for energy saving operational strategies to be developed. Results indicate that the design concept together with a suitable selection of the substation has an important impact on the energy performance of the entire system
The Cobb-Douglas function of semi-intensive milk production in the south of the state of Mexico
Se estimó una función de produccióntipo Cobb-Douglas bivariada seudocuadrática para determina el nivel óptimo técnica en la oferta intensiva de leche, mediante dos procedimientos matemáticos y probar si conducen a la misma solución. La función de producción Cobb-Douglas representa una excelente para otpimizar el uso de recursos y la oferta en sistemas de producción de bovinos leche
Thermal comfort and indoor air quality on end-user satisfaction level evaluation in a Nearly Zero Carbon neighbourhood
End-user satisfaction studies in residential buildings has to be approached combining the user’s perspective and technical criteria to consider the complex interactions influencing the building energy performance. Therefore, in this study the physical characteristics of dwellings and their environments are assessed, user satisfaction is examined, and the relationship between them is investigated. The study aims to illustrate the end-user satisfaction in exemplary high performance buildings and to investigate how the users are interacting with these buildings. Examination of the building performance, thermal comfort and indoor air quality are the main focal points of the work. In general, results reflect a significant improvement on the satisfaction level of the inhabitants with the comfort of the dwelling after the refurbishment of the district. Findings from the cross-analysis of both surveys and measurements are used to further refine conclusions and identify the driving factors of the interrelationship between building performance and end-user satisfaction
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