Assessing the function of pounding tools in the Early Stone Age: A microscopic approach to the analysis of percussive artefacts from Beds I and II, Olduvai Gorge (Tanzania)

This study explores the function of quartzite pounding tools from Olduvai Gorge (Tanzania) using microscopic and use wear spatial distribution analysis. A selection of pounding tools from several Bed I and II assemblages excavated by Mary Leakey (1971) were studied under low magnification (<100×), and the microscopic traces developed on their surfaces are described. Experimental data and results obtained from analysis of the archaeological material are compared in order to assess activities in which pounding tools could have been involved. Results show that experimental anvils used for meat processing, nut cracking and/or bone breaking have similar wear patterns as those observed on archaeological percussive artefacts. This is the first time that a microscopic analysis is applied to Early Stone Age pounding artefacts from Olduvai Beds I and II, and this paper highlights the importance that percussive activities played during the Early Pleistocene, suggesting a wider range of activities in addition to knapping and butchering

Potencial del cultivo de salicornia en la región Lambayeque para la recuperación de suelos salinizados para la producción de biodiesel

La presente investigación se ha centrado en la región Lambayeque ubicada al norte del Perú, que cuenta con 55 mil hectáreas de suelos salinos y salinizados (Pérez, 2010). Si bien en estos suelos no se pueden sembrar cultivos agrícolas por las propiedades propias del terreno (altos contenidos de sales), estos pueden ser aprovechados para el sembrío de cultivos energéticos destinados para la producción de biocombustibles. Uno de estos cultivos es la salicornia que se cultiva con muy poco agua y hasta puede ser irrigada con agua de mar. Además, crece en zonas de climas secos, calurosos o de bajas temperaturas. Las semillas de salicornia contienen de 25% a 36% de aceite (casi el doble que las de soja) según lo expresa Eganathan (et al., 2008), y puede usarse para producir biocombustibles, con un rendimiento promedio por hectárea de 1.893 litros de biodiesel

Correlation between students’ workload and attendance as related towards final grades: A case of study on Statistics for first-year Engineering students

In this work, a monitoring experience of student workload and attendance is presented. During four academic years, from 2015 until 2019, first-year students of an Engineering degree have been asked, three times a week, to estimate their autonomous workload devoted to the Statistics subject. The monitoring strategy has been anonymous, open and voluntary and has shown a high ratio of participation: 407 students out of 433. To generate the final dataset this information has been combined with attending records to classroom-based lectures and final grades achieved. Results indicate that declared student’s workload hardly reaches the 90 hours of autonomous work established in the ECTS ratio of our university. Nonparametric comparisons show strong statistical evidences of the relationship between final grades in the subject and declared workload and attendance. We find that attendance is crucial in order to achieve a homogeneous workload along the semester and a success in the subject’s grading.De La Calle-Arroyo, C.; Rodríguez-Aragón, L. (2020). Correlation between students’ workload and attendance as related towards final grades: A case of study on Statistics for first-year Engineering students. En 6th International Conference on Higher Education Advances (HEAd'20). Editorial Universitat Politècnica de València. (30-05-2020):707-716. https://doi.org/10.4995/HEAd20.2020.11131OCS70771630-05-202

The invasive species Asparagopsis taxiformis (Bonnemaisoniales, Rhodophyta) on Andalusian coast (Southern Spain): reproductive stages, new records and invaded communities

The invasive species Asparagopsis taxiformis (Bonnemaisoniales, Rhodophyta) on Andalusian coasts (Southern Spain): reproductive stages, new records and invaded communities.The present study provides new records from Andalusian coasts of the exotic invasive seaweed Asparagopsis taxiformis (Delile) Trevisan. These records demonstrate that A. taxiformis has rapidly and widely expanded its distribution range in this region, from Almería to Cádiz (Strait of Gibraltar).The latter locality may represent the western geographical limit of the species in the Mediterranean Sea. Spermatangial heads and cystocarps were observed in the collected gametophytes. Additionally, we report the first record of the tetrasporophytic stage, Falkenbergia hillebrandii (Bornet) Falkenberg from the Andalusian coast, although tetraspores were not encountered in these samples. Consequently, information on the affected communities and arguments for considering A. taxiformis as an invasive species in the Andalusian coast are provided.La especie invasora Asparagopsis taxiformis (Bonnemaisoniales, Rhodophyta) en las costas andaluzas (Sur de España): fases reproductivas, nuevas citas y comunidades invadidas. El presente trabajo aporta nuevas citas para las costas andaluzas de la especie exótica invasora de macroalga Asparagopsis taxiformis (Delile) Trevisan. Estas citas muestran que la especie ha aumentado ampliamente su área de distribución de manera rápida en esta región, desde Almería hasta Cádiz (Estrecho de Gibraltar). Esta última localidad representaría el límite occidental de la especie en el mar Mediterráneo. En las muestras recogidas de gametofitos se pudieron observar ramas espermatangiales y cistocarpos. Se aporta la primera cita del estadio tetrasporofítico, Falkenbergia hillebrandii (Bornet) Falkenberg en las costas andaluzas, aunque no se observaron tetrásporas en estas muestras. Se informa sobre las comunidades afectadas y se dan argumentos para considerar a A.taxiformis invasora en las costas andaluzas

Rotation and moment redistribution capacity of fiber-reinforced concrete beams: parametric analysis and code compliance

Fiber-reinforced concrete (FRC) has been proved to be a competitive solution for structural purposes. Extensive research has highlighted the benefits of adding fibers on the post-cracking strength, reduced crack spacing and crack width, and improved durability, among others. However, these aspects are related to serviceability limit states, and significant work remains to be done in terms of ultimate limit state behavior of FRC members. As recent publications have emphasized, reinforced concrete beams with low reinforcement ratios may result in a reduction of deformation capacity and, hence, to a loss of ductility. To further investigate this topic, this paper presents the results of a numerical parametric study of simply and continuous supported hybrid-reinforced concrete (HRC) beams made with different amounts of fibers and reinforcement ratios. The deformation, rotational, and moment redistribution capacity of those were assessed by means of a finite-element model previously calibrated using experimental results available in the literature. The results showed that there is a significant reduction of rotation capacity and moment redistribution for lightly reinforced (hybrid) members. Finally, the paper contains practical recommendations in terms of minimum reinforcement ratios that guarantee adequate rotation and redistribution capacity of HRC members. As such, the results of this study can provide a contribution toward more reliable structural designs of HRC members.The authors express their gratitude to the Spanish Ministry of Economy, Industry and Competitiveness for the financial support received under the scope of the project CREEF (PID2019-108978RB-C32). Likewise, the first author acknowledges the Spanish Ministry of Science, Innovation and University for providing support through the PhD Industrial Fellowship (DI-17-09390) in collaboration with Smart Engineering Ltd. (UPC's Spin-Off).Peer ReviewedPostprint (published version

Connect Smart Cities and Heritage Through Augmented Reality

This chapter aims to connect the digital resources of knowledge with the historical and cultural heritage in the context of smart cities. Specifically, combining the joint intervention in the Real Sitio of El Pardo and Aranjuez, as well as the Foundation Square of the University of Alcalá, both in Spain. Through traditional historical research and the innovative use of new technologies like augmented reality (AR), a historical, biological and cultural heritage is conserved, consisting of forests, gardens, agricultural spaces, urban centers and palatial residences. Cultural and artistic heritage is a resource of the first magnitude for the sustainable development of smart cities. It evolves with time and society; it is this that determines what goods are to be conserved and protected for posterity, according to the values attributed to them. Hence, the importance of achieving an awareness in society plays an active part in the conservation, enjoyment and dissemination of heritage. In this context, the augmented reality is presented as a powerful tool for contextualizing and disseminating the heritage, as well as to make the resources created more accessible, making an innovative use of the new technologies applied to the transfer of knowledge and the enhancement of a country’s cultural and historical heritage

Augmented reality in architecture: rebuilding archeological heritage

With the development in recent years of augmented reality and the appearance of new mobile terminals and storage bases on-line, we find the possibility of using a powerful tool for transmitting architecture. This paper analyzes the relationship between Augmented Reality and Architecture. Firstly, connects the theoretical framework of both disciplines through the representation concept. Secondly, describes the milestones and possibilities of Augmented Reality in the particular field of archaeological reconstruction. And lastly, once recognized the technology developed, we face the same analysis from a critical point of view, assessing their suitability to the discipline that concerns us is the architecture and within archeology

Experimental characterization of concrete-to-concrete interface shear strength design-oriented constitutive parameters

In concrete composite systems, the shear strength between concrete layers cast at different times determines the mechanical performance of the structure. Different mechanisms are identified as potential shear–transfer actions through the concrete interface, namely cohesion, friction, and dowel action in case of shear reinforcement crossing the interface, and their role on the shear strength is largely determined by the shape and roughness of the interface. Codes provide formulation to predict the shear strength based on cohesion and friction variables depending on roughness parameters. However, the mechanical approach for the interface shear strength is not well-established yet and, as a result, the design-oriented expressions proposed by codes for determining the strength of composite structural members are under continuous review. In the present study, shear strength of concrete composite elements with different surface textures representative of precast and in-situ concrete constructions —left as-cast surface, resin treatment surface, indented surface and surface with bolts— was assessed. To that aim, a comprehensive experimental programme consisting on push-off tests on small-scale and large-scale specimens was conducted. Based on the test results, the coefficients of concrete cohesion and friction for the different textures were determined, assessing the possible scale effect of the mechanical performance. The experimental shear strength obtained for various cases was compared with the code provisions, showing consistent agreement.Monserrat-López was supported by the Ministerio de Universidades (Spain) with the Recovery, Transformation and Resilience Plan (RD 289/2021 and order UNI/551/2021) of NextGenerationEU; Postdoctoral Margarita Salas Fellowship funded by Universitat Politècnica de València. The study was also possible due to the Spanish Government’s Centre for the Development of Industrial Technology (CDTI) through the IDI-20210535 financial support.Peer ReviewedPostprint (published version