Flow Percolation in non homogeneous Hele-Shaw flows

The wetting front zone where water invades and advances into an initially dry porous material plays a crucial role in solute transport through many environmental flows, such as the unsaturated zone. The leaching of chemicals by wetting fronts seems influenced by two major factors, namely: the irregularity of the fronts and the heterogeneity in the distribution of chemicals, both of which have been described using fractal techniques. This works presents an experimental and theoretical framework for studying the physical interplay between a stationary wetting front of fractal dimension D with different porous materials. Simple wetting experiments are easy to compare with theoretical studies defining the physical interations between a stationary wetting front of maximum fractal dimension D and a multifractal distribution of chemicals around it with a singularity spectrum f( ). If D1 is the entropy dimension of the distribution and 0 is the point where f() attains its maximum value, then, as revealed by mathematical analysis, the fractal curve must have a fractal dimension D equal to or greater than the entropy dimension D1 of the distribution for a positive amount of mass to be accommodated inside it. Also, 0 D constitutes a scaling exponent for the likely mass inside an " -covering of the curve reflecting the potential for leaching on the sole basis of the physical interplay between the wetting front and the surrounding chemical molecules. Different shapes of the multifractal D(c) curves are compare

Empirical Evidence Of Verdoorns Law In Mexican Manufacturing

In this document we use the model called Verdoorns Law that has been widely favored with the empirical evidence as being able to explain the persistence of divergences in growth rates, which establishes a positive relation between product growth and productivity. The goal is to estimate the Verdoorns coefficients for the 32 states in Mexico for the period of 1985-2004 through the use of the Ordinary Least Square method (OLS) and the pool data technique for an added analysis at subsector levels of the manufacturing industry. The purpose of this paper is to explain regional divergences in Mexico by identifying those factors that influence economic growth and that would allow the proposal of regional policies that can help reduce the observed differences, and by contributing to the development of the country as a whole. Consistent results were found with Verdoorns Law by detecting increasing returns in the manufacturing industry, both by regions and by subsectors. The states that show lower Verdoons coefficients (higher returns to scale) are definitely the ones that have grown the most

Data driven process for the energy assessment of building envelope retrofits

In the last decades, a growing industry has been created in relation to building envelope retrofits. Linked to the lack of financial capacity of many building owners, innovative instruments such as energy performance contracts have been promoted by public bodies. This kind of instruments require of detailed energy assessment processes in order to define the expected heat load reduction and the associated economic flows between building owners and Energy Services Companies. When dealing with building envelopes, existing methods for building envelope heat loss characterization require of substantial efforts in terms of equipment and time, which makes them difficult to apply in real practice. In this paper, a novel method is proposed based on whole-building heat load assessment by means of heat meters, and analytical calculations of building envelope transmission heat load coefficients. This method, which requires minimal or no additional equipment, can be used over historical data from District Heating systems. It assigns a specific load fraction to building envelope heat transfer and allows to assess the expected reduction due to the building envelope retrofit. Numerical and experimental data is presented based on an educational building in the city of Burgos, Spain.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 768567

Optimum Efficiency on Broadcasting Communications

This chapter is devoted to review a set of new technologies that we have developed and to show how they can improve the process of broadcasting in two principal ways: that is, one of these avoiding the loss of transmission signals due to abrupt changes in sign of the diffraction index and the other, preventing the mutual perturbation between signals generating information leak. In this manner, we propose the join of several of the mentioned technologies to get an optimum efficiency on the process of broadcasting communications showing the theoretical foundations and discussing some experiments that bring us to create the plasma sandwich model and others. Despite our very innovative technology, we underline that a complete recipe must include other currently in use like multiple-input multiple-output (MIMO) simultaneously. We include some mathematical proofs and also give an academic example

Efecto del nivel de concentrado sobre el perfil de ácidos grasos de la leche de vacas holstein en pastoreo

El contenido de ácido linoléico conjugado (CLA c9 t11) en leche depende principalmente de la producción en el rumen de ácido vaccénico, el cual está influenciado por el aporte de los ácidos linoléico y linolénico en la dieta. El objetivo de este estudio fue evaluar el efecto del nivel de concentrado en la producción, composición y perfil de ácidos grasos de la leche de nueve vacas Holstein en praderas asociadas de gramíneas y leguminosas. El diseño experimental fue un cuadro latino 3×3 y los tratamientos fueron: 1) 8 kg concentrado y 8 h en la pradera (8c); 2) 5 kg concentrado y 12 h en la pradera (5c), y 3) 3 kg de concentrado y 12 h en la pradera (3c). Los datos se analizaron con el procedimiento MIXTO de SAS y las medias de los tratamientos se compararon con la prueba de Tukey (p £ 0.05). La producción de leche y el contenido de grasa, proteína y lactosa fueron mayores (p £ 0.05) en el tratamiento 8c. La concentración de los ácidos grasos (AG) láurico, mirís - tico y palmítico se incrementó en la leche (p £ 0.05) al aumen - tar el nivel de concentrado. El contenido de los AG de cadena larga ( ³ C18) fue mayor (p £ 0.05) con 3 kg de concentrado, excepto para C18:2 c9c12. La reducción del concentrado su - ministrado a vacas Holstein en praderas asociadas disminuye el contenido de AG saturados, pero aumenta el contenido de los insaturados, especialmente de los ácidos oleico, linoléni - co, vaccénico y CLA c9 t11

Farmacología de la nicotina y sus efectos en el sistema nervioso central.

capitulo del libroLos niveles más altos de nicotina en sangre se alcanzan al terminar de fumar un cigarrillo y declinan rápidamente en los siguientes 20 minutos por la amplia distribución en los tejidos corporales. El volumen de distri- bución en humanos es 2.6 veces el peso corporal (Rose et al., 1999). La nicotina es metabolizada por el hígado y se han identificado al menos seis metabolitos primarios, siendo cuantitativamente el más importante la cotinina. Otros metabolitos primarios son la nicotina-N-óxido y el glu- curónido de nicotina. Los metabolitos de cotinina son los siguientes: glu- curónido de cotinina, trans-3-hidroxicotinina y glucurónido trans-3-hi- droxicotininaconacy

Organic Dairy Sheep Production Management

Organic production systems are based on natural processes, the use of local feed resources, and the maintenance of biodiversity in all senses. Several studies have noted the positive effects of organic sheep milk production systems on animal welfare, animal health, product quality, and environmental impact. On the other hand, it has been reported that dairy sheep organic farms show lower milk yields and increase the susceptibility to environmental impacts compared with conventional farms. The standards that regulate feeding management in organic systems are one of the most critical factors that influence milk production performance. Lower milk production is also associated with poor ability to adapt specialized dairy breeds to organic management, low genetic potential for milk production in native and local breeds, and elevated dependence on environmental conditions. However, the aim of organic dairy production is not to reach maximum dairy productivity but rather to integrate animal and crop production and to develop a symbiotic relationship between recyclable and renewable resources; furthermore, organic production positively affects the employment rate and quality of life in rural communities. Organic dairy sheep production is one means of improving the balance between society’s demand for food and the ecological impact of the agro-alimentary industry

Ayotzinapa: Viejas luchas, nuevas formas

En el presente documento se brinda una breve crónica de lo acontecido cuando en septiembre de 2014, con la participación de elementos de la fuerza pública, se desapareció a 43 estudiantes de la Normal Rural Isidro Burgos de Ayotzinapa, Guerrero. Se da cuenta tanto de las inconsistencias de la verdad histórica presentada por el gobierno federal, como de la crisis de legitimidad que vive la actual administración que, si bien llegó con el apoyo de un porcentaje muy bajo del electorado, con el paso de los años ha visto disolver su popularidad. Por otro lado, siguiendo las ideas de Raul Zibechi y Ana Esther Ceceña se menciona que lo sucedido en Ayotzinapa debe ser visto como un emblema del capitalismo neoextractivista que aqueja nuestra región. En dicho sentido se hace énfasis a la agenda política y económica de la actual administración, con el objetivo de dar cuenta de una agudización de las contradicciones sociales, sobre todo en territorios rurales de nuestro país