6,418 research outputs found

    Preliminary analysis for the calculation of the fractal dimension of different types of shorelines on the Andalusian coast

    Get PDF
    En este trabajo se analiza la correlación entre la dimensión fractal de diferentes tipos de costas en Andalucía en función de la escala de digitalización y tipo de costa. Para ello se han digitalizado, a diferentes escalas que van 1:1.000 a 1:20.000, tramos significativos de la costa andaluza utilizando ortofotografías de alta resolución. Para testar la metodología desarrollada, los tramos elegidos son de una amplia variedad morfológica, como playas abiertas, costas acantiladas, sectores con amplias infraestructuras y marismas mareales. Los resultados del análisis, plasmados en el cálculo de la dimensión fractal para cada tipo de costa, vierten información sobre la importancia de la escala en las mediciones costeras y cómo varía su impacto en función de las características de la costa.The correlation between the fractal dimension of different types of costs in Andalusia in terms of digitizing scale and type of expense is analyzed in this work. Significant sections of the Andalusian coast were digitized at different scales ranging from 1:1,000 to 1:20,000, by means of the use of high resolution orthophotos. In order to test the developed methodology, the chosen sections show a wide morphological variety, as open beaches, coastal cliffs, sectors with large infrastructures and tidal marshes. The results of the analysis, reflected in the calculation of the fractal dimension for each type of expense, provide information about the importance of scale in coastal measurements and how their impact varies depending on the characteristics of the coast

    Resonant tunneling through a small quantum dot coupled to superconducting leads

    Full text link
    We address the problem of non-linear transport through discrete electronic levels in a small quantum dot coupled to superconducting electrodes. In our approach the low temperature I-V characteristics can be calculated including all multiple quasi-particle and Andreev processes. The limit of very weak coupling to the leads and large charging energies is briefly analyzed comparing the calculated lineshapes of the I-V curves with recent experimental results. When the coupling to the leads increases and Coulomb blockade effects can be neglected, the combination of multiple Andreev processes and resonant transmission gives rise to a rich subgap structure which largely differs from the one found in the more studied S-N-S systems. We show how multiple processes can be included within a simple sequential tunneling picture qualitatively explaining the subgap structure. We suggest an experimental set-up where the predicted effects could be observed.Comment: 11 pages, 4 postscript figures, to be published in Phys. Rev. B (rapid communications

    A comparative Digital Soil Mapping (DSM) study using a non-supervised clustering analysis and an expert knowledge based model - A case study from Ahuachapán, El Salvador

    Get PDF
    DSM is the inference of spatial and temporal soil property variations using mathematical models based on quantitative relationships between environmental information and soil measurements. The quality of DSM information depends on the method and environmental covariates used for its estimations. We compared two DSM methods to predict soil properties such as Organic Matter “MO” (%), Sand (%), Clay (%), pH (H2O), Phosphorus (mg/kg), Effective Cationic Exchange Capacity “CICE” (cmol/L), Potassium (cmol/L) and Water Holding Capacity (mm/m) for the department of Ahuachapán in El Salvador to support the activities of the Agriculture Landscape Restoration Initiative (ALRI) in the countr

    A comparative Digital Soil Mapping (DSM) study using a non-supervised clustering analysis and an expert knowledge based model - A case study from Ahuachapán, El Salvador

    Get PDF
    DSM is the inference of spatial and temporal soil property variations using mathematical models based on quantitative relationships between environmental information and soil measurements. The quality of DSM information depends on the method and environmental covariates used for its estimations. We compared two DSM methods to predict soil properties such as Organic Matter “MO” (%), Sand (%), Clay (%), pH (H2O), Phosphorus (mg/kg), Effective Cationic Exchange Capacity “CICE” (cmol/L), Potassium (cmol/L) and Water Holding Capacity (mm/m) for the department of Ahuachapán in El Salvador to support the activities of the Agriculture Landscape Restoration Initiative (ALRI) in the countr

    On the generalised Chaplygin gas: worse than a big rip or quieter than a sudden singularity?

    Full text link
    Although it has been believed that the models with generalised Chaplygin gas do not contain singularities, in a previous work we have studied how a big freeze could take place in some kinds of phantom generalised Chaplygin gas. In the present work, we study some types of generalised Chaplygin gas in order to show how different sorts of singularities could appears in such models, in the future or in the past. We point out that: (i) singularities may not be originated from the phantom nature of the fluid, and (ii) if initially the tension of the brane in a brane-world Chaplygin model is large enough then an infrared cut off appears in the past.Comment: 19 pages, 6 figures. Discussion expanded and references added. Version to appear in the International Journal of Modern Physics

    Wide range group delay tuning in lossy fiber ring resonators

    Get PDF
    22nd International Conference on Optical Fiber Sensors, OFS 2012, Beijing, China, 15-19 Oct. 2012We demonstrate theoretically and experimentally that a wide-range tuning of group delay values can be achieved in a\ud lossy fiber ring resonator. The tuning mechanism relies simply on varying the loss/coupling ratio in the resonator. This\ud simple structure may be used advantageously in different regimes for many sensing configurations, both for achieving\ud extremely high sensitivity enhancements (by working close to critical coupling, where the group index becomes\ud extremely large) or suppression of undesired refractive index effects (e.g. Kerr effect), by working in the under-coupled\ud regime

    Mapping the sustainable development goals into the EDINSOST sustainability map of bachelor engineering degrees

    Get PDF
    © 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This Research to Practice Work in Progress paper presents the work conducted on the use of the Sustainability Map of Bachelor Engineering Degrees (a tool developed by the EDINSOST project) to analyze how Sustainable Development Goals (SDGs) are developed in each Degree. Over recent years, there has been a growth in the importance of working sustainability based on the SDGs. To identify which learning objective of each SDG corresponds to each learning outcome of the EDINSOST Sustainability Map, a correspondence matrix has been defined. The matrix contains the learning outcomes of the EDINSOST Sustainability Map in its rows, and the 17 SDGs in the columns. The cells of the matrix contain the learning objectives of the SDGs that correspond to each learning outcome of the EDINSOST Sustainability Map. This work in progress presents the first results of the process of mapping the SDGs into the EDINSOST Sustainability Map of Engineering Bachelor Degrees. Early results show that some of the 169 learning objectives are not applicable to Engineering Degrees. Likewise, we have seen that learning objectives have been defined more for policy makers than for engineers, and therefore adaptation is not an easy task. However, the work done has helped us to verify that the EDINSOST Sustainability Map can help in the introduction of the SDGs into the curriculum.Peer ReviewedPostprint (author's final draft

    A learning tool to develop sustainable projects

    Get PDF
    This paper presents a tool developed to help engineers to design and develop sustainable projects. The tool has been designed to introduce and evaluate the sustainability of engineering projects in general, but here we show its application to assess the final project of an engineering degree. This tool is a guide for students to introduce and estimate the sustainability of their projects, but it also helps teachers to assess them. The tool is based on the Socratic Methodology and consists of a matrix where each cell contains several questions that students must consider during the project development and which they must answer in their project report. A positive or negative mark is assigned to every cell, and the sum of all marks states the project sustainability. However, the result is not as simplistic as a final number, but a descriptive sustainability analysis where questions are answered and every mark justified. A pilot test with some students has obtained good results, but the first Final Degree Project using this methodology will be read in July 2016.Peer ReviewedPostprint (author's final draft

    How plants inspire façades. From plants to architecture: Biomimetic principles for the development of adaptive architectural envelopes

    Get PDF
    Façades have an important role in the control of energy waste in buildings, nevertheless most of them are designed to provide static design solutions, wasting large amounts of energy to maintain the internal comfort. However, biological adaptation solutions are complex, multi-functional and highly responsive. This paper proposes a biomimetic research of the relationship that can be developed between Biology and Architecture in order to propose innovative façade design solutions. We focus on plants, because of plants, like buildings, lack of movement and remain subject to a specific location. Nevertheless, plants have adapted to the environment developing special means of interaction with changing external issues. This paper provides a methodology to create a data collection of plant adaptations and a design mapping to guide the transfer from biological principles to architectural resources, as well as two design concept cases, opening new perspectives for new possible technical solutions and showing the potential of plant adaptations to environmental conditions at a specific climate. Further step is the transformation of some design concepts into technical solutions through experiments with new technologies that include multi-material 3D printing or advances in material science
    corecore