Determinación de los mecanismos de filtración mediante métodos geólogo-geofísicos en la presa El Cuchillo-Solidaridad, China, Nuevo León, México

Tesis (Maestría en Ciencias Geológicas) UANLUANLhttp://www.uanl.mx

A Review of the Techniques Used to Reduce the Thermal Load of Buildings in Mexico's Warm Climate

The heat transfer of buildings contributes directly to the consumption of electricity, because the most common alternative to reduce the internal temperature has been the disproportionate use of conventional air conditioning systems. The bioclimatic architecture is an alternative of a still limited application. However, nowadays, several investigations indicate a significant correlation between heat gain and internal thermal comfort perceived in built spaces. This proposal reviews the techniques studied and used to reduce the thermal load coming from outside and generated inside buildings located in a warm weather zone in Mexico. These cases are intended to show the current status of this research topic, as well as identify areas of opportunity relevant to the analysis and its implementation especially in coastal areas. Critical factors to explore include the influence of relative humidity on the thermal sensation, as well as warm geographical and climatic conditions, which can be humid tropical or arid and dry

Determining the In Situ Apparent Thermal Diffusivity of a Sandy Soil

ABSTRACT: The thermal wave amplitude method is used to determine soil thermal diffusivity in situ for a sandy soil in Mexico (Coatzacoalcos, Veracruz). Soil diurnal temperature fluctuations were measured from depths of 0.05 to 0.65 m, in 0.01 m increments, during the months of April and August. Five mean diffusivity values were obtained experimentally, corresponding to the different depths combination. The soil thermal diffusivity ranged between 2.26 × 10−7 and 8.71 × 10−7 m2 s−1. The diffusivity values obtained are within the absolute ranges reported in the literature. A positive linear effect between the diffusivity values and depth was observed on a homogeneous sandy soil. These increments are due to the soil moisture variations and the volumetric calorific capacity of the soil. An uncertainty analysis was made to validate our results, resulting in a relative standard deviation with values in the range of 4.51 to 27.37 %. The uncertainties of 0.49 to 26.66 % RSD in the amplitude of the thermal wave are the factor that contributes most to the propagation of errors of the diffusivity

Altered volcanic ash layers of the Late Cretaceous San Felipe Formation, Sierra Madre Oriental (Northeastern Mexico): U-Pb geochronology, provenance and tectonic setting

A detailed petrographic, geochemical, and UePb geochronological study of altered volcanic ash layers, collected in eight outcrops of the Late Cretaceous San Felipe Formation (Sierra Madre Oriental, North- eastern Mexico), has been carried out. The main objectives have been: (1) to establish a deposit period, and (2) to propose a reliable provenance-transport-deposit-diagenetic model. These volcano- sedimentary strata represent the altered remains of vitreous-crystalline ash (main grains: quartz + K- feldspar (sanidine) + Na-plagioclase + zircon + biotite; groundmass: glass + calcite + clinochlore + illite) deposited and preserved in a shallow, relatively large in area, open platform environment. Major and trace element geochemistry indicate that parent volcanism was mainly rhyodacitic to rhyolitic in composition. Discrimination diagrams suggest a link to continental arc transitional to extension tectonic setting. UePb geochronology in zircon has revealed that the volcanic ash was released from their sources approximately during the range 84.6 ± 0.8 to 73.7 ± 0.3 Ma, being transported to the depocenters. Burial diagenesis process was marked by: (a) a limited recycling, (b) the partial loss of original components (mainly K-feldspar, plagioclase, biotite and glass), and (c) the addition of quartz, calcite, illite and cli- nochlore. The location of the source area remains uncertain, although the lack of enrichment in Zr/Sc ratio suggests that ashes were subjected to relatively fast and short-distance transport process. El Peñuelo intrusive complex, at 130-170 km west of the depocenters, is the nearest known zone of active magmatism during the Upper Cretaceous. This intermediate to felsic pluton, characterized by a geochemical affinity to post-orogenic tectonic setting, could be linked to the volcanic sources