Exploring available landslide inventories for susceptibility analysis in Gipuzkoa province (Spain)

Similar to many mountainous regions of the world, landslides are a recurrent geological hazard in the Gipuzkoa province (northern Spain) that commonly cause damage to communication infrastructure, such as roads and railways. This geomorphological process also threatens buildings and human beings, albeit to a lesser degree. Over time, different institutions and academic research groups have individually collected crucial information on historic and ancient landslides in this region, resulting in various landslide inventories. However, these inventories have not been collectively assessed, and their suitability for landslide susceptibility modelling projects has often been assumed without comprehensive evaluation. In this study, we propose a simplified method to explore, describe, and compare the various landslide inventories in a specific study area to assess their suitability for landslide susceptibility modelling. Additionally, we present the results of an illustrative experiment that demonstrates the direct effect of using different inventories in landslide susceptibility modelling through a data-driven approach. We found that out of the five digitally available inventories in the study area, only three provide sufficient guarantees to be used as input data for susceptibility modelling. Furthermore, we observed that each individual inventory exhibited inherent biases, which directly influenced the resulting susceptibility map. We believe that our proposed methods can be easily replicated in other study areas where multiple landslide inventory sources exist, and that our work will induce other researchers to conduct preliminary assessments of their inventories as a critical step prior to any landslide susceptibility modelling project.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Txomin Bornaetxea is financially supported by the postdoctoral fellowship program of the Basque Govern- ment (Grant Numbers POS_2020_2_0010) and hosted by the University of the Basque Country (UPV/EHU, Group IT1678) in the framework of a scientific collaboration with the Geological Survey of Canada as well as his association with the Geomorphology Group of the Research Institute for the Geo-Hydrological Pro- tection in Perugia, Italian National Research Council (CNR-IRPI)

On the feasibility of collaborative green data center ecosystems

The increasing awareness of the impact of the IT sector on the environment, together with economic factors, have fueled many research efforts to reduce the energy expenditure of data centers. Recent work proposes to achieve additional energy savings by exploiting, in concert with customers, service workloads and to reduce data centers’ carbon footprints by adopting demand-response mechanisms between data centers and their energy providers. In this paper, we debate about the incentives that customers and data centers can have to adopt such measures and propose a new service type and pricing scheme that is economically attractive and technically realizable. Simulation results based on real measurements confirm that our scheme can achieve additional energy savings while preserving service performance and the interests of data centers and customers.Peer ReviewedPostprint (author's final draft

Cambios del nivel del mar durante el Holoceno en el Cantábrico a partir del estudio de la Turbera de Trengandín

[Resumen] El estudio de dos depósitos proporcionan nuevos datos acerca de los cambios del nivel del mar durante el Holoceno. De acuerdo con ellos, durante el Sub-Boreal el nivel del mar no estuvo por encima de -2 m con respecto al nivel actual. El análisis sugiere que el nivel del mar ascendió gradualmente desde los -50 m al inicio del Holoceno, y no hay evidencias que sustenten la existencia de un nivel del mar más alto que el actual, al menos hasta el Sub-Atlántico.[Abstract] The study of two deposits provides new data about sea level changes in the bay of Biscay during the Holocene. According to these data, the sea level was not above -2 m respect to present level during Sub-Boreal periodo The analysis suggests that sea level rose gradually from - 50 m at the beginning of the Holocene, and there is not evidence that support a level higher than present at least until Sub-Atlanti

Adaptive Importance Sampling for Performance Evaluation and Parameter Optimization of Communication Systems

We present new adaptive importance sampling techniques based on stochastic Newton recursions. Their applicability to the performance evaluation of communication systems is studied. Besides bit-error rate (BER) estimation, the techniques are used for system parameter optimization. Two system models that are analytically tractable are employed to demonstrate the validity of the techniques. As an application to situations that are analytically intractable and numerically intensive, the influence of crosstalk in a wavelength-division multiplexing (WDM) crossconnect is assessed. In order to consider a realistic system model, optimal setting of thresholds in the detector is carried out while estimating error rate performances. Resulting BER estimates indicate that the tolerable crosstalk levels are significantly higher than predicted in the literature. This finding has a strong impact on the design of WDM networks. Power penalties induced by the addition of channels can also be accurately predicted in short run-time

CFD Analysis of the cooling of a power transformer with different oil types

El objetivo de este trabajo es realizar estudio de la refrigeración de un transformador de potencia inmerso en aceite, mediante técnicas CFD (Dinámica de fluidos computacional). En concreto diseñaremos la parte del devanado, que es donde el fluido del sistema entra en contacto con las bobinas del transformador. Para ello se realizará un modelo a escala de esta parte del sistema de refrigeración. El primer apartado consiste en obtener el mejor modelo posible para la simulación. Elaboraremos dos mallados, cuya diferencia está en el tamaño de los elementos que lo forman. Al final vemos que el modelo con más elementos y por lo tanto el más preciso es el mejor para este cometido. La principal duda era si la mayor calidad de simulación y por tanto uso de recursos, justificaba la diferencia de resultados. En este estudio se valorarán diferentes aceites empleados en la refrigeración de transformadores, tanto de origen mineral como biodegradables. Para ello, se utilizarán, 4 aceites: un aceite de origen mineral, otro hecho a partir de soja, el tercero proveniente de la colza y por último uno sintético. Los aceites biodegradables y de origen vegetal se están abriendo un hueco en el mercado y se están empezando a implementar en los sistemas de refrigeración de transformadores de potencia. Mediante este estudio veremos qué diferencias tienen con los que se han usado históricamente, que son los de origen mineral. El propósito de este trabajo es un estudio teórico del impacto de modificar la geometría de los canales de refrigeración del transformador para el uso de esteres naturales. En este ensayo no hemos tenido en cuenta las cualidades de cada tipo de aceite referidas a seguridad, mantenimiento, su facilidad de obtención etc. Cualidades que sí se tienen en cuanta a la hora de elegir el fluido para un sistema de refrigeración. Veremos las grandes diferencias que existen entre las dos tipologías de aceite. Entre todos ellos, el que ha sido capaz de enfriar mejor el devanado de nuestro transformador es el aceite mineral. Dentro de los aceites biodegradables el que mejores resultados obtiene es el aceite vegetal 1 o aceite de soja. Aunque en muchos aspectos obtenga resultados parecidos al aceite vegetal 3 (sintético), en general es el que obtiene los valores más fiables. El que peor consigue enfriar el devanado y obtiene los peores resultados, lejos de los otros dos, es el aceite vegetal 2, proveniente de la colza. La última parte del ensayo consiste en ver si un aumento de tamaño en de nuestra pieza en determinados puntos influye en la refrigeración y si gracias a ello podemos igualar las prestaciones entre los aceites minerales y los biodegradables. Los datos obtenidos nos muestran que, como es lógico, al aumentar el tamaño de los conductos, mejoran los resultados. Esto es muy importante ya que hemos podido comprobar que, si se quieren cambiar los aceites de origen mineral por la nueva generación de aceites vegetales, al aumentar las dimensiones del sistema se pueden igualar e incluso superar las prestaciones, contando además con las cualidades que tienen los aceites biodegradables frente a los minerales.The aim of this work is to study the cooling of a power transformer immersed in oil, using CFD (Computational Fluid Dynamics) techniques. Specifically, we will design the winding part, which is where the system fluid meets the transformer coils. To do this, a scale model of this part of the cooling system will be made. The first section consists of obtaining the best possible model for the simulation. Two grids will be created, the difference between them is the size of the elements that make up the model. In the end we see that the model with more elements and therefore the more accurate one is the best for this task. The main doubt was whether the higher quality of the simulation, and therefore the use of resources, justified the difference in results. In this study, different oils used in the cooling of transformers, both of mineral and biodegradable origin, will be evaluated. Four oils will be used for this purpose: one oil of mineral origin, another made from soya, the third from rapeseed and finally a synthetic oil. Biodegradable oils of vegetable origin are opening a niche in the market and are beginning to be implemented in the cooling systems of power transformers. Through this study we will see how they differ from those that have been used historically, which are those of mineral origin. The purpose of this work is a theoretical study of the impact of modifying the geometry of the transformer cooling channels for the use of natural esters. In this test, we have not considered the qualities of each type of oil regarding safety, maintenance, ease of obtaining, etc. These qualities are considered when choosing the fluid for a cooling system. We will see the major differences between the two types of oil. Among all of them, the one that has been able to cool the winding of our transformer the best is mineral oil. Among the biodegradable oils, the one with the best results is vegetable oil 1 or soya oil. Although in many aspects it obtains similar results to vegetable oil 3 (synthetic), in general it is the one that obtains the most reliable values. Vegetable oil 2, which comes from rapeseed, is the one with the worst winding cooling and the worst results, far behind the other two. The last part of the test is to see if an increase in the size of our part at certain points influences the cooling and if this allows us to equalize the performance between mineral oils and biodegradable oils. The data obtained show that, logically, as the size of the ducts increases, the results improve. This is very important because we have been able to verify that, if we want to change the oils of mineral origin for the new generation of vegetable oils, by increasing the dimensions of the system, the performance can be equalized and even surpassed, also considering the qualities that biodegradable oils have over mineral oils.Grado en Ingeniería en Tecnologías Industriale

TOURIST CHARACTERISTICS AND ECONOMIC VALUATION OF NATURE TOURISM IN SEBLAT NATURE PARK, NORTH BENGKULU DISTRICT

Forests are renewable natural resources that play an important role in controlling the earth's ecosystems, especially in supporting human life and other living organisms. Seblat Nature Park is a conservation area that can be used for recreation and culture. The Seblat Elephant Training Center (PLG) is a form of utilization of the area as the main tourist attraction of the TWA Seblat. The benefits of the resources contained in the TWA Seblat nature tourism do not yet have a market price so that tourists and the public still value it low. Therefore it is necessary to evaluate the benefits of nature tourism in the TWA Seblat to reflect the value of the tourism object. This study aims to determine the characteristics of tourists and the economic value of nature tourism based on travel costs in the Seblat Nature Park. This research was conducted from August to October 2022 at the Seblat Nature Park, North Bengkulu Regency. The number of respondents taken was 45 people, with data collection techniques in the form of interviews. To calculate the economic valuation of natural tourism, the Travel cost method (TCM) is used. Data were analyzed using descriptive qualitative and quantitative descriptive methods. The characteristics of tourists at TWA Seblat are dominated by visitors aged 17-25 years, history of high school/vocational school education, private sector employees and students, and single status. PLG Seblat is the main tourist destination with a visit motivation for refreshing. Sources of information on the whereabouts of TWA Seblat verbally, arriving with a group of friends using transportation in the form of motorbikes. Visitors at TWA Seblat generally come from within North Bengkulu Regency with a distance of 11-50 km. Visits Distance and access are the main factors that influence visits to TWA Seblat. The economic value of nature tourism in TWA Seblat is Rp. 122,787,408 / year.             Keyword:  Tourist characteristic, economic valuation, travel cos

Anthropocene Geomorphic Change. Climate or Human Activities?

An analysis of the evolution of sedimentation rates and disasters caused by surface geologic processes during the last century, at a global scale, is presented. Results show that erosion/sedimentation processes and frequency of such disasters increased substantially, especially after midtwentieth century, coinciding with the period of intense change known as the ?Great Acceleration.? Increases for this type of disasters are significantly greater than for other disasters related to natural processes, and about 1 order of magnitude in little more than half a century. This implies an important ?global geomorphic change.? Comparisons and correlations between changes observed in those processes and potential natural (rainfall) and human (degree of land surface transformation) drivers showed a strong relationship with the latter, and not so clear with the former. This suggests that the intensification of surface geologic processes is most likely due to a greater extent to a land transformation/geomorphic processes coupling than a climate/geomorphic processes one.Funding was provided by projects: CAMGEO CGL2006–11341, Spain; PICT2011–1685, Argentina; MTM2014–56235‐C2–2 and CGL2017–82703‐R, Spain