Implicaciones de la fotogrametría y de las técnicas láser en la identificación y caracterización de las trazas antrópicas sobre restos óseos en los yacimientos arqueológicos del pleistoceno

Tesis por compendio de publicaciones[ES] La tafonomía durante las últimas décadas ha demostrado ser una disciplina de gran relevancia para la explicación e interpretación de los yacimientos arqueológicos y paleontológicos. La tafonomía es una disciplina que permite proponer diferentes tipos de soluciones a los diversos problemas interpretativos encontrados en los yacimientos arqueológicos. A través de la experimentación y de su enfoque analógico deductivo permite proponer hipótesis explicativas. Durante los últimos años el análisis de las marcas de corte ha generado una gran expectación. Este tipo de trazas están asociadas a la acción humana y pueden resultar de gran importancia para explicar el comportamiento de las poblaciones prehistóricas. De este modo, las marcas de corte resultan ser una herramienta clave en la explicación del debate caza-carroñeo, y pueden ayudar a explicar qué pasos se siguen en el procesado de una carcasa animal. Es relevante también el análisis de las marcas de corte en relación a la selección de las materias primas con las que fueron realizadas dichas marcas, en cuanto al aprovechamiento de las carcasas. Por lo tanto, es crucial, la definición correcta y la información obtenida de estas y también la realización de una identificación de los materiales utilizados en el proceso de aprovechamiento de los animales. Desde finales del siglo XIX, los investigadores toman conciencia de la relevancia que puede tener el estudio de las alteraciones que aparecen sobre los huesos, catalogándolas en un primer momento de forma descriptiva. A raíz de la irrupción de la tafonomía en la investigación arqueológica, algunos investigadores han tratado de discriminar las distintas clases de marcas que aparecen en los huesos, experimentando con diferentes métodos para observar mejor las marcas de corte. En la actualidad, la metodología más utilizada, se basa en la aplicación de técnicas microscópicas usando para estas investigaciones microscopios electrónicos de barrido (Scanning Electron Microscope - SEM). En estos últimos años, los investigadores, a partir de estas técnicas, han sido capaces de lograr resultados espectaculares gracias a las mediciones tridimensionales que han podido obtener de las marcas de corte en huesos. La documentación 3D de las marcas de corte con estas técnicas microscópicas obtiene muy buenos resultados, pero también plantea diferentes inconvenientes: utiliza equipos económicamente muy costosos, en muchos casos las muestras necesitan de una preparación antes de realizar el proceso, sólo técnicos especialistas en el campo pueden realizar un manejo óptimo del instrumento y por último su principal inconveniente, es que es un equipo fijo de trabajo, por lo que no se puede desplazar hasta el yacimiento arqueológico. Con el fin de resolver todas estas problemáticas y con el objetivo de mejorar la metodología ampliando el volumen de los datos susceptibles de ser analizados, en esta Tesis Doctoral se explica el uso de la fotogrametría y de la visión computacional para llevar a cabo estos estudios. Más concretamente, se describe el proceso de captura de datos, el procesado de los mismos y los análisis estadísticos y morfométricos realizados a los datos resultantes obtenidos a partir de estas técnicas. Para realizar este estudio, se han llevado a cabo varios cientos de siluetas de marcas de cortes experimentales en huesos y en fósiles, realizados con diferentes materias primas (sílex, basalto, cuarcita y metal). Esta muestra constituye una de las mayores bases de datos de este tipo recopiladas hasta el día de hoy. Por último, se sugieren nuevas líneas de investigación a las que este procedimiento podría ser fácilmente aplicable

Evaluation of Different LiDAR Technologies for the Documentation of Forgotten Cultural Heritage under Forest Environments

In the present work, three LiDAR technologies (Faro Focus 3D X130—Terrestrial Laser Scanner, TLS-, Kaarta Stencil 2–16—Mobile mapping system, MMS-, and DJI Zenmuse L1—Airborne LiDAR sensor, ALS-) have been tested and compared in order to assess the performances in surveying built heritage in vegetated areas. Each of the mentioned devices has their limits of usability, and different methods to capture and generate 3D point clouds need to be applied. In addition, it has been necessary to apply a methodology to be able to position all the point clouds in the same reference system. While the TLS scans and the MMS data have been geo-referenced using a set of vertical markers and sphere measured by a GNSS receiver in RTK mode, the ALS model has been geo-referenced by the GNSS receiver integrated in the unmanned aerial system (UAS), which presents different characteristics and accuracies. The resulting point clouds have been analyzed and compared, focusing attention on the number of points acquired by the different systems, the density, and the nearest neighbor distance

New technologies applied to modelling taphonomic alterations

Archaeology is developing considerably through the incorporation and application of several methodologies and techniques from science, technology, engineering and mathematics (STEM) disciplines. These technologies have significantly improved our ability to document, preserve, study and present highly precise and accurate digital models of whole sites and archaeological elements, as well as specific details of them. In this article, we will review the different 3D documentation techniques currently available in archaeology, focusing on bone taphonomy. Our aim is to characterise the range of alterations that fossil bones may experience. Thus, here we present a review of the existing literature and future perspectives on how to approach the 3D study of carnivore and rodent tooth marks, cut and percussion marks, biochemical alterations and other Bone Surface Modifications (BSMs)

Assessment of the geothermal potential in the region of Ávila (Spain): An integrated and interactive thermal approach

Exploring and exploiting a geothermal resource has become one of the most prolific tasks for contributing to the global sustainable development. Despite this fact, several countries, such as Spain, are still far from achieving a generalized use of these renewable systems. The reason for this underuse often derives from the lack of information and characterization of the geothermal energy source. Considering this, the present research aims to provide relevant data about the geothermal potential of the Spanish region of Ávila. The geological context of this province lays the foundations for considering the region as a promising site for different geothermal uses. In order to estimate the geothermal energy potential of the region, the existing geological information has been complemented with thermal surveys carried out in the study area. The experimental measuring has consisted of the register of the underground temperature in piezometers of variable depth and natural springs distributed throughout the province. The processing of these records has allowed knowing the thermal evolution of the subsoil at the different levels evaluated in the research. Results show that there are two main potential areas in the province that could be successfully used for heating purposes (maybe as part of district heating systems) and for future deeper evaluations in the sense of Hot Dry Rock (HDR) techniques. Final conclusions have also been included in an interactive and open-source tool that allows visualizing the thermal findings with the aim of planning future geothermal uses in the region

Micro-photogrammetric characterization of cut marks on bones

In the last few years, the study of cut marks on bone surfaces has become fundamental for the interpretation of archaeological sites and prehistoric butchery practices. Due to the difficulties in the correct identification of cut marks, many criteria for their description and classifications were suggested. This article presents an innovative methodology which supplements the microscopic study of cut marks. Despite the benefits of using scanning electron microscopy (SEM) for the two-dimensional identification of these marks, it has a number of drawbacks such as the high costs and, consequently, the limited sample studied. In this article, a low-cost technique for the analysis of cut mark micromorphology from a tri-dimensional perspective is introduced. It provides a high-resolution approach to cut mark characterisation such as morphology, depth, width, and angle estimation as well as section determination, measured directly on the marks on bones. Macro-photogrammetry records quantitative and qualitative information which can be statistically processed with standard multivariate and geometric morphometric tools

Integration of a wearable mobile mapping solution and advance numerical simulations for the structural analysis of historical constructions: a case of study in San Pedro church (Palencia, Spain)

This work aims at enhancing the current methodologies used for generating as-built CAD models suitable for advanced numerical simulations. To this end, this paper proposes the use of a wearable mobile mapping system that allows one to improve the digitalization stage in terms of flexibility and time required. The noise showed by the resulting point cloud, based on the simultaneous location and mapping (SLAM) solution, demands a post-processing stage that introduces the use of a parameter-free noise reduction filter. This filter improves the quality of the point cloud, allowing for the adjustment of surfaces by means of parametric and non-parametric shapes. These shapes are created by using reverse engineering procedures. The results showed during this investigation highlight a novel application of this sensor: the creation of as-built CAD models for advanced numerical simulations. The results of this investigation are complemented by a valuable contribution with respect to the use of an advanced restoration solution, by means of textile reinforced mortar. To this end, the CAD model is used as the geometrical base for several numerical simulations by means of the finite element method. All this procedure is applied in a construction with structural problems.European Commission | Ref. SOE1 / P5 / P0258Junta de Castilla y León | Ref. SA075P17Junta de Castilla y León | Ref. EDU / 1100/2017European Commission | Ref. H2020-MSCA-IF-2019, n. 679 894785; proyecto AVATA

Geophysical exploration for shallow geothermal applications: A case study in Artà, (Balearic Islands, Spain)

[EN] Within the installation of a shallow geothermal system, the lack of information on the subsoil frequently leads to errors in the design of the geothermal wellfield. This research presents the application of geophysics, combining 2D and 3D electrical resistivity tomography surveys and the geological information of a certain area for defining the structural distribution of the underground. Processed electrical resistivity data allow elucidating possible geological units and the thermal behavior of the in-depth materials. Two different assumptions (with different locations of the wells) are designed by using the specific geothermal software GES-CAL. Results show, that Case 1 (based on the geophysical results, so avoiding complex areas) allows the reduction of the global drilling length, and hence, the general initial investment of the system (around 20% lower). Meanwhile, Case 2 (without considering the geophysics) is less economically advantageous and could also present technical difficulties during the drilling process, as well as the possible alteration to the normal system operation. The study highlights the benefits of geophysics as an effective approach to characterize the underground and to help to understand its thermal behavior, which is, in turn, crucial for a proper geothermal design.S

Characterizing Geological Heterogeneities for Geothermal Purposes through Combined Geophysical Prospecting Methods

Geothermal energy is becoming essential to deal with the catastrophic effect of climate change. Although the totality of the Earth’s crust allows the exploitation of shallow geothermal resources, it is important to identify those areas with higher thermal possibilities. In this sense, geophysical prospecting plays a vital role in the recognition and estimation of potential geothermal resources. This research evaluates the geothermal conditions of a certain area located in the center of Spain. The evaluation is mainly based on geological and geophysical studies and, in particular, the Time Domain Electromagnetic Method and the Electrical Resistivity Tomography. Once we analyzed the geology and the historical thermal evidence near the study area, our geophysical results were used to define the geothermal possibilities from a double perspective. In relation to anomalous heat gradient, the identification of a fault and the contact with impermeable granitic materials at the depth of 180 m denotes a potential location for the extraction of groundwater. Regarding the common ground-source heat-pump uses, the analysis has allowed the determination of the most appropriate area for the location of the geothermal well field. Finally, the importance of accurately defining the position of the drillings was confirmed by using software GES-CAL

Investigating the potential of the slurry technology for sustainable pig farm heating

Sustainable energy development in the farming sector is an essential strategy to respond the combined challenge of achieving a reliable and affordable solution but including mitigation and adaptation to climate change. Intensive breeding farms require maintaining an adequate indoor thermal environment that results in high energy demands, usually covered by fossil fuels and electricity. This paper addresses the application of the combined slurry technology for a particular pig farm that currently uses a diesel boiler to supply the piglet heating energy needs. The study also considers different options based on closed ground source heat pump systems. After the design of the slurry alternative and the geothermal ones, notable advantages are detected compared to the existing diesel system. Results show that the implementation of the slurry technology implies an important reduction of the operational costs, which, in turn, involves short amortization periods for this system in relation to the diesel one. Greenhouse gases emissions are also highly reduced in the slurry alternative based on the low electricity use of the heat pump. The environmental side is reinforced by the reduction of polluting substances such as methane of ammonia derived from the descent of temperature of the slurry

Evaluation of different methodologies for calculating the energy demand and their influence on the design of a low enthalpy geothermal system

The increasing importance of shallow geothermal resources in the decarbonization of heating and cooling systems requires the correct management of all the project stages. One of the fundamental steps in this process is determining the space energy demand, which plays a significant role in the subsequent geothermal design. In the context of Spain, different tools are available for the estimation of the mentioned parameter. For evaluating these procedures, this research applies the principal energy demand calculation tools and uses the outcomes for the later design of the shallow geothermal system. Results show how the Spanish official tools (HULC and CE3X) provide lower energy demand values adjusted to the construction conditions of the building that allow the optimization of the geothermal well field. On the contrary, simpler, and more intuitive applications (regular spreadsheets and GES-CAL) assume higher heating energy demands, which in turn implies an oversizing of the geothermal scheme. Even though all the procedures ensure to cover the energy requirements of the building, the most precise tools manage to reduce the initial investment of the system and its operating costs, in addition to reducing the global CO2 emissions because of the lower power of the associated geothermal heat pump