Modeling an Aquifer: Numerical Solution to the Groundwater Flow Equation

We present a model of groundwater dynamics under stationary flow and governed by Darcy's Law of water motion through porous media, we apply it to study a 2D aquifer with water table of constant slope comprised of an homogeneous and isotropic media, the more realistic case of an homogeneous anisotropic soil is also considered. Taking into account some geophysical parameters we develop a computational routine, in the Finite Difference Method, that solves the resulting elliptic partial equation, both in a homogeneous isotropic and homogeneous anisotropic media. After calibration of the numerical model, this routine is used to begin a study of the Ayamonte-Huelva aquifer in Spain, a modest analysis of the system is given, we compute the average discharge vector as well as its root mean square as a first predictive approximation of the flux in this system, providing us a signal of the location of best exploitation; long term goal is to develop a complete computational tool for the analysis of groundwater dynamics.Comment: 13 pages and 12 figure

Load Distribution on PET-G 3D Prints of Honeycomb Cellular Structures under Compression Load.

Energy resulting from an impact is manifested through unwanted damage to objects or persons. New materials made of cellular structures have enhanced energy absorption (EA) capabilities. The hexagonal honeycomb is widely known for its space-filling capacity, structural stability, and high EA potential. Additive manufacturing (AM) technologies have been effectively useful in a vast range of applications. The evolution of these technologies has been studied continuously, with a focus on improving the mechanical and structural characteristics of three-dimensional (3D)-printed models to create complex quality parts that satisfy design and mechanical requirements. In this study, 3D honeycomb structures of novel material polyethylene terephthalate glycol (PET-G) were fabricated by the fused deposition modeling (FDM) method with different infill density values (30%, 70%, and 100%) and printing orientations (edge, flat, and upright). The effectiveness for EA of the design and the effect of the process parameters of infill density and layer printing orientation were investigated by performing in-plane compression tests, and the set of parameters that produced superior results for better EA was determined by analyzing the area under the curve and the welding between the filament layers in the printed object via FDM. The results showed that the printing parameters implemented in this study considerably affected the mechanical properties of the 3D-printed PET-G honeycomb structure. The structure with the upright printing direction and 100% infill density exhibited an extension to delamination and fragmentation, thus, a desirable performance with a long plateau region in the load-displacement curve and major absorption of energy

Características de crecimiento de cabritos de raza Murciano-Granadina comparando un sistema de media leche y uno de lactación artificial

publishedTomo I . Sección: Sistemas Ganaderos-Economía y Gestión. Sesión: Producción de leche. Ponencia nº 2

Laser-writing of ring-shaped waveguides in BGO crystal for telecommunication band

We report on the fabrication of ring-shaped waveguides operating at the telecommunication band in a cubic Bi4Ge3O12 (BGO) crystal by using technique of femtosecond laser writing. In the regions of laser written tracks in BGO crystal, positive refractive index is induced, resulting in so-called Type I configuration. The modal profiles are within the designed track cladding with ring-shaped geometries, which are analogous to circular optical lattices. The homogenous guidance along both TE and TM polarizations has been obtained at telecommunication wavelength of 1.55 μm. Both straight and S-curved waveguiding structures have been produced with ring-shaped configurations. This work paves the way to fabricate complex photonic networks for telecommunications by using ring-shaped waveguides in compact chips.National Natural Science Foundation of China (NSFC) (61775120); Junta de Castilla y León (Project SA046U16); Spanish Ministerio de Economía y Competitividad (MINECO, FIS2013-44174-P, FIS2015-71933-REDT)

Spatial Modulation of linear and quadratic susceptibilities in Lithium Niobate crystals by using femtosecond laser pulses

In this work we present the spatial control of the linear susceptibility (χ1) in Lithium Niobate crystals by means of infrared (800 nm) femtosecond interaction. Diffraction gratings have been performed on the surface (relief) and inside (phase) of these samples by femtosecond laser writing. Also we have performed a spatial control of the quadratic susceptibility (χ 2 ) by direct writing of a pattern of ferroelectric domains on the surface of z cut substrates by using the second harmonic femtosecond pulses (400 nm). Finally, efficient photonic devices for second harmonic generation via quasi phase matching could be obtained following the experimental procedure presented in this work

New approaches targeting brown adipose tissue transplantation as a therapy in obesity

Brown adipose tissue (BAT) is raising high expectations as a potential target in the fight against metabolic disorders such as obesity and type 2 diabetes. BAT utilizes fuels such as fatty acids to maintain body temperature by uncoupling mitochondrial electron transport to produce heat instead of ATP. This process is called thermogenesis. BAT was considered to be exclusive to rodents and human neonates. However, in the last decade several studies have demonstrated that BAT is not only present but also active in adult humans and that its activity is reduced in several pathological conditions, such as aging, obesity, and diabetes. Thus, tremendous efforts are being made by the scientific community to enhance either BAT mass or activity. Several activators of thermogenesis have been described, such as natriuretic peptides, bone morphogenic proteins, or fibroblast growth factor 21. Furthermore, recent studies have tested a therapeutic approach to directly increase BAT mass by the implantation of either adipocytes or fat tissue. This approach might have an important future in regenerative medicine and in the fight against metabolic disorders. Here, we review the emerging field of BAT transplantation including the various sources of mesenchymal stem cell isolation in rodents and humans and the described metabolic outcomes of adipocyte cell transplantation and BAT transplantation in obesity. KEYWORDS: Brown adipose tissue; Obesity; Transplantatio