San Sebastian de los Reyes, Spain
San Sebastian de los Reyes, Spain

Saint Teresa of Jesus Catholic University, , commonly known as the Catholic University of Ávila , is a private, Catholic university, located in Ávila, Castile and León, Spain. It's named after Saint Teresa of Ávila.The current rector of the university is Maria Rosario Sáez Yuguero. Wikipedia.

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Cottle D.J.,University of New England of Australia | Romero C.,Technical University of Madrid | Romero C.,Catholic University of Avila
Animal Feed Science and Technology | Year: 2014

It is difficult to measure pasture feed intake. A common method is based on naturally occurring, indigestible plant markers, such as long chain alkanes. Least-squares procedures are used to estimate diet composition and intake. If actual intake of a supplement is known, then total intake and the intake of all dietary components can be estimated. This 'labelled-supplement' approach requires an estimate of the faecal recoveries of the markers. The accuracy and precision of intake solutions for each animal is also affected by the sampling and measurement precision of the plant and faecal marker concentrations. This work was conducted to study whether weighting each marker's sums of squares in the least-squares procedure could be used to provide a more robust solution.Cluster and discriminant analyses of a plant marker database determined the contribution of each marker to discrimination between categories of plants. The markers' cluster or discriminant weights were used to weight the sums of squares in the least squares procedures. The actual individual dry matter intakes (DMI) of 20 cattle were arbitrarily assigned for three different diets. Measurement and sampling variations in marker concentrations and/or faecal recoveries were simulated to generate predicted total pasture intakes around the actual values.Six marker weighting methods were compared for their DMI prediction error values and correlations between predicted and actual DMI: (A) all markers weighted by one; (B) separate cluster analyses of z scores for alkanes and alcohols; (C) combined cluster analyses for alkanes and alcohols; (D) discriminant analyses of z score marker data for plants categorized into grasses, legumes, shrubs and trees; (E) discriminant analyses of plants categorized on origin and plant, photosynthesis and reproduction type; and (F) discriminant analyses of plants categorized on plant, photosynthesis and reproduction type.The standard approach of weighting all markers by one (A) was satisfactory when marker concentration error was set at zero, however intake predictions were poor when the error was non-zero, which is likely. The weighted least-squares intake solutions that were more robust to variance in measured marker concentrations or in assumed faecal recovery rates were those using weights derived by methods D and F. Marker weights from Methods D, E and F resulted in similar intake prediction error variances and correlations. Methods E and F required more botanical information about plant species and method D was simpler, so method D is recommended rather than other methods studied here, including the standard method A. There are problems with using weights derived from an analysis of all published marker data, so better weighting methods may still be found for specific plant and marker datasets. © 2013 Elsevier B.V.

Hevia J.N.,University of Valladolid | de Araujo J.C.,Federal University of Ceará | Manso J.M.,Catholic University of Avila
Earth Surface Processes and Landforms | Year: 2014

This paper presents the history of badland generated in the Saldaña region, Spain; as well as the main responses eight decades after the start of restoration - in terms of vegetation, soil and erosive processes. The restoration consisted of intense reforestation and construction of more than 100 check dams and numerous wattle fences. Presently, the dense vegetation (87% cover) contrasts markedly with the degraded landscape from the early 20th century (5% cover). The thickness of litter and the natural presence of some species (Quercus pyrenaica, Paeonia broteroi and Lactarius deliciosus) clearly indicate the recovery of the site. The development of the forest cover shows that the intervention has the potential to recover almost 90% of the area. There is also evidence of soil regeneration, although some properties (erodibility, resistance to penetration and shear-strength resistance) are not that different between the forested and degraded areas. In the restored zones, runoffis negligible, since a thick layer of moss covers the spillways of all the check dams. Erosion has almost been stopped by the effects of vegetation cover, litter and higher infiltration rates (infiltration rate in forested slopes is 43.4 times greater than in bare slopes). Sediment detachment, such as landslides, mudflows and piping, still occur, but are restricted to the degraded zones. Furthermore, even when sediments are mobilized from the upper degraded hillslopes during the larger storms events (2000-2010), check dams and the lower elevation restored forest-buffers effectively work to reduce the sediment yield into the Carrión River by almost three orders of magnitude (<102 mg L-1), compared with data from the 1930s and 1940s (>105 mg L-1). © 2014 John Wiley & Sons, Ltd.

Pachon-Garcia F.T.,Catholic University of Avila
AEU - International Journal of Electronics and Communications | Year: 2016

This paper shows the calculation of electric field levels at MF band (medium frequency: 300. kHz-3. MHz) at different distances from the transmitter in environments where there are: (a) conductivity changes of the soil and (b) altitude variations. To assess the influence of these factors, a 2D tool named MF-FDTD (MF finite-difference time-domain) is implemented and it is calibrated and validated with the Millington method for flat land, and the FEM-PE (Finite Element Method-Parabolic Equation) for the inclusion of typified mountains. Then, this tool is also applied to real environments where certain AM (Amplitude Modulation) transmitters are located, selecting several profiles via a Geographic Information System. In our case, oscillations up to 10. dB have been obtained when comparing the results of irregular versus flat terrains with frequencies around 1. MHz. Part of the computation has been made using the Lusitania supercomputer, parallelizing tasks on multiple cores. © 2016 Elsevier GmbH.

SCS Curve Number Method estimates superficial runoff that a rainfall generates. Its practical application consists of locating in a table the curve number, which depends principally on soil use or type of vegetation, hydrological condition and type of soil (hydrologie soil groups). With this curve number, runoff is calculated through the equation proposed by the model. The mentioned tables are elaborated for the types of soils and vegetation of the United States. In this work, an adjustment of SCS Curve Number tables for forest covers of the "Caldera de Taburiente" National Park (La Palma island, Spain) is realized, through an analysis of factors that establish curve number.

Diaz V.,Catholic University of Avila | Mongil J.,Catholic University of Avila | Navarro J.,University of Valladolid
Journal of Soils and Sediments | Year: 2014

Purpose: The effects of check dams used in restoration projects have been discussed in a number of papers in recent years. This paper studies the effectiveness of retaining sediments from check dams constructed in the badlands restoration site of Tórtoles, located in the Corneja River basin (Spain), using a new topographical method.Materials and methods: In order to assess the sediment-retaining capacity of the check dams, we measured the volume of sediment trapped by 15 of the 123 check dams built in 1965. We carried out a detailed topographical survey using a Total Station, with an accuracy of ±1 cm, to measure cross sections of the sediment trapped by each check dam. The results were then compared with those of two simplified methods which consider the volume of retained sediment as a simple geometric figure.Results and discussion: According to our results, 258 m3 of sediment has been retained by the check dams. These results show a significant discrepancy between the topographical method and the two other methods, whose values are consistently lower (14 to 20 %). According to our survey, the mean value for the volume of sediment retained by each check dam is 17.23 m3, versus 13.86 and 14.74 m3 when applying the other methods. Although there is a strong correlation between the volume of retained sediment computed by the topographical method and the other two methods (r2 from 0.96 to 0.94), the differences between them increase with the increasing size of the check dams. Therefore, total differences are expected to be more significant with larger check dams. The erosion rates, calculated on the basis of the retained sediment in the Tórtoles check dams, are 16–21 % lower when using the simpler methods. The bed slopes of the streams were reduced 12.44 % because of the presence of the check dams.Conclusions: After having completed a more detailed topographical survey of the sediment trapped in the check dams, our results are more likely to estimate erosion rates and sediment yield correctly, thus leading to a better understanding of the effects of check dams on badlands restoration. © 2014, Springer-Verlag Berlin Heidelberg.

Pachon-Garcia F.T.,Catholic University of Avila
IEEE Antennas and Propagation Magazine | Year: 2015

This paper presents a study of electric field values at medium wave in an area of 160 x 160 km2, analyzing it under a theoretical point of view and contrasting the results with values from experimental campaigns. The implemented application is named 2-Dimensional Electric-Wave (2DE-WAVE), and it is based on the GRWAVE program from the ITU for flat land but incorporates the Millington method for mixed paths. The obtained results show the importance of characterizing the terrain with accurate conductivity and permittivity values due to the high influence that these parameters have on the electric field. When comparing theoretical and experimental values, we observed that, in general terms, they agree well for not very rough terrains but with certain field fluctuations, particularly in "shadow areasa" either by the presence of buildings or remarkable topographical irregularities. Absolute mean errors of theoretical versus experimental values between 2.4 and 2.9 dB with deviations of 2.8 and 3.3 dB were obtained in an area of 20 x 25 km2 surrounding the transmitters, which reaffirm us the need to validate the simulation values with field measurements. Illustrative maps of the difference between theoretical and experimental electric field values are also shown. © 1990-2011 IEEE.

Romero C.,Technical University of Madrid | Romero C.,Catholic University of Avila | Martinez E.,Technical University of Madrid
European Journal of Physics | Year: 2013

Among other skills, a capacity for abstraction and good spatial awareness are needed to succeed in physics courses. According to the prevailing low percentages of passed students on these courses, a great proportion of those students are likely to lack these skills. Our working hypothesis is that simulations could help engineering students visualize physical phenomena and thereby gain a better understanding of physical theoretical concepts and achieve higher grades. Two groups of students (n1 = 40 and n2 = 43) took the same fluid mechanics course at an engineering school. Both groups took the same end-of-course examination, but only group 1 was simulation-taught. For that purpose, 15 original simulations were created with GeoGebra software. Simulation-taught students completed a questionnaire on the interest of using simulations to teach fluid mechanics. Simulations designed in this work covered all the concepts taught on the course and overcame criticisms made on previous simulations also created to teach fluid mechanics. At the examination, the average grade and the percentage of passed students were higher in group 1 than in group 2. When surveyed, group 1 students declared that they enjoyed interacting with the simulations and considered them to be a good complement to the theoretical explanations because simulations helped them revise previously explained concepts. Simulations assisted students with difficulties to visualize and understand physical theoretical concepts but still students performed poorly on the examination. Additional strategies need to be adopted in order to help students develop the skills required to succeed in physics courses. © 2013 IOP Publishing Ltd.

Diaz V.,Catholic University of Avila | Mongil J.,Catholic University of Avila | Navarro J.,University of Valladolid
Cuadernos de Investigacion Geografica | Year: 2014

Check dams are transverse structures that are built in some streams to mitigate erosion, and frequently used in forest-hydrology restoration projects in Spain. Their main functions are: controlling and retaining solid particles transported by flow discharge; slope and bed stream stabilization; reducing flow water velocities and their erosivity. Nevertheless, the erosion control effectiveness of check dams is a matter under discussion during the last years. Because of this, we want to verify how the check dams work controlling sediment yields, and so on how they reduce soil losses in gullies. We propose a method based in estimating the sediment volume retained through an accurate topographical survey. Our results have been compared with two other methods, most frequently used because of their geometric simplicity. A significant variation appears between the three methods. Therefore, to probe the effectiveness of the check dams a better estimation of their sediment retained surface justifies the full topographical survey. We have worked in Tórtoles (Ávila, Spain), in a deep gully from the Corneja river headwaters. There is a forest-hydrological restoration that was projected in 1964 and executed one year later. The topographical survey results show that check dams in the gully have retained 237.95 m3 of sediments. This is a 30.3% and a 7.9% bigger than the calculated by the other two methods. The unit volumes of the check dams range between ± 5% y ± 50% respect the obtained with our method. Our results show important differences compared with the other methodologies, but a better land surveying justifies the use of the topographic method to estimate the check dams effectiveness. © 2014 Universidad de La Rioja.

Hernando A.,Technical University of Madrid | Arroyo L.A.,Research Center del Fuego | Velazquez J.,Technical University of Madrid | Velazquez J.,Catholic University of Avila | Tejera R.,Technical University of Madrid
Photogrammetric Engineering and Remote Sensing | Year: 2012

Natura 2000 is a European network of protected areas established under the Habitats Directive (92/43/EEC). According to the Habitats Directive, habitat maps must be periodically updated, which requires the development of cost- and time-efficient mapping practices. In this study, we propose a methodology for habitat mapping using very high spatial resolution (QuickBird) images with Object-Based Image Analysis (OBIA). We classified five segmentation levels: level 5 incorporated the prior knowledge of the study area into the analysis; level 4 and 1 were used to identify arable areas and land covers, respectively. The information contained in levels 1, 4, and 5 was then combined to classify plant species in level 2. Finally, habitats were classified in level 3 using level 2 class-related features. The habitat map obtained had an overall accuracy of 86.3 percent. Classification accuracies were higher for treeand pasture-dominated habitats than for shrub-dominated habitats. © 2012 American Society for Photogrammetry and Remote Sensing.

Mongil J.,Catholic University of Avila | Navarro J.,University of Valladolid
Cuadernos de Investigacion Geografica | Year: 2012

We show the results of three soil infiltration tests that were made in the slopes under the typical limestone moors of the Valladolid Province (Spain). Soils tested have evolved from Tertiary grey silts and clays generating clayey to loamy textures. Vegetation on these soils is a Pinus halepensis forest from reforestation and two Mediterranean brush degraded covers. Horton infiltration model has been adjusted using data from the trials. Soil hydrologic groups from runoff Curve Number model have been also determined for every soil tested. Finally, soil infiltration conditions are moderate for everyone, but much better in the pine forest than in the others. Final infiltration rate is medium to-low. Soils belong to C and D Hydrologic Soil Groups according to their texture, saturated hydraulic conductivity and minimum infiltration rate, although pine forest shows a certain group B quality. These results would allow better approach for the Hydrologic Soil Groups proposed by the Curve Number Method for using them in simulation hydrologic models to estimate floods and land-use planning or to estimate design flows of fluvial infrastructures in river basins with similar lands to those studied here. © Universidad de La Rioja.

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