Diseño y construcción de un prototipo de robot con tres grados de libertad para posicionamiento de objetos

Actualmente los cambios tecnológicos son cada vez más rápidos, influyendo en la tecnología que la industria salvadoreña utiliza, es por ello que en ITCA-FEPADE Sede Central se diseñó y construyó un prototipo de brazo robot con tres grados de libertad que permite el posicionamiento de objetos de forma muy precisa. Como es conocido, la industria busca elementos que le permitan hacer sus procesos más eficientes, rápidos, seguros y de calidad, es por ello que muchas empresas han optado por realizar inversiones en el área de la robótica industrial, al ser una tecnología que cada vez se vuelve más común en nuestro país, es necesario que ITCA-FEPADE como institución educativa pueda formar de forma teórica-practica sobre los principios de funcionamiento de los brazos robot. Es por ello que se diseñó y fabricó un brazo robot de tres ejes. Para poder realizarlo se diseñó y construyó elementos que permitieran la integración de tecnologías utilizadas en los brazos robot industriales, utilizando servo motor, drivers, un PLC electro neumático, una estructura que permite realizar movimientos de piezas de forma muy precisa, siendo así el brazo robot un elemento de práctica completo

The digital maturity of the Spanish press. A case study

Buscamos un método fiable para medir el índice de madurez digital (IMD) de la prensa española. Metodología: Utilizamos el método del caso, con un estudio del diario Abc. Nos basamos en datos cuantitativos y cualitativos. En cuanto a las técnicas hemos combinado las entrevistas, con la observación participante y la consulta a expertos. Resultados: El modelo se ha ensayado con éxito y es aplicable al estudio de cualquier medio informativo. El diario Abc registra a 31 julio 2018 un Índice de Madurez Digital, de 72,50 puntos sobre un máximo de 100. Significa que se encuentra en un estado Avanzado de madurez digital. Conclusiones: La Prensa española, representada en este caso por la cabecera nacional de Vocento, se encuentra en un proceso bastante avanzado de transformación y madurez digital, aunque aún queda camino para que la Web marque las rutinas más importantes del trabajo periodístico.This research aims to set a reliable methodology to measure the digital maturity index (IMD) of the Spanish press. Methodology: For the analysis we are using the case method, with a focus on Abc newspaper. We rely on quantitative and qualitative data. In terms of techniques, we have combined interviews, participant observation and expert consultation. Results: The model has been successfully tested and is fully applicable to any other newspaper. ABC holds at July, 31st 2018 a Digital Maturity Index of 72.50 points out of a maximum of 100. It means an advanced state of digital maturity. Conclusions: The Spanish Press, represented in this research by Abc —a brand of Vocento Group— is nowadays in an advanced process of transformation and digital maturity, although there is still a room for improvement for the website to become the backbone for the most important routines of journalism

Sustainability, corporate social responsibility, non-financial reporting and company performance: Relationships and mediating effects in Spanish small and medium sized enterprises

©2022. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Submitted, Accepted, Published, version of a Published Work that appeared in final form in [Sustainable Production and Consumption]. To access the final edited and published work see[https://doi.org/10.1016/j.spc.2022.11.015]© 2022 The Authors. Published by Elsevier Ltd on behalf of Institution of Chemical Engineers. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4.0/). This document is the Accepted version of a Published Work that appeared in final form in Sustainable Production and Consumption. To access the final edited and published work see https://doi.org/10.1016/j.spc.2022.11.015Sustainability, Corporate Social Responsibility (CSR), and non-financial reporting and their relationships with company performance are burning topics. Although all these terms are familiar to companies, specifically large ones, most European companies are small and medium-sized enterprises (SMEs), and studies explicitly addressing SMEs are limited. For this reason, this paper aims to fill the existent gap in the literature concerning SMEs by analyzing the relationship between sustainability, CSR, non-financial information, and performance. The objective of this study is to analyze several aspects: (1) The influence of pressures, incentives, and barriers on sustainability, (2) The influence of sustainability, CSR, and non-financial disclosure on performance, and (3) The mediating effect of CSR and non-financial disclosure. For this purpose, there has been an e-mail survey to managers, financial directors, or administration managers of Spanish SMEs. In addition, a Partial Least Squares Structural Equation Modelling (PLS-SEM) model has been used on a final sample of 126 Spanish SMEs. The study's main outcome is that sustainability positively influences CSR and non-financial reporting in the case of SMEs. Therefore, regardless of the specific characteristics derived from the size of the company and the possible lack of resources, the results for SMEs align with those of large companies obtained by previous studies. This study has important academic/theoretical implications for SME managers and policymakers because implementing policies encouraging CSR practices and sustainability strategies will create a better society and positively impact SMEs' performance. © 2022 The Authors. Published by Elsevier Ltd on behalf of Institution of Chemical Engineers. This is an open acces

Implementación del Balanced Scorecard en las agencias públicas: una experiencia en los servicios municipales deportivos

The public sector is involved in a context of change. Decentralization, performance measurement and a greater emphasis on outputs are some of the main changes. To give public sector managers efficient tools, the adoption of what is considered to be private sector management styles and techniques is now becoming commonplace. The Balanced Scorecard approach has emerged as a new tool that meets many of the above-mentioned challenges faced by public organizations. Nonetheless, few reports of detailed experience in public sector entities are available. This research paper offers an insight into the process of elaborating the Balanced Scorecard for a public sector agency of sport services.El sector público está inmerso en un contexto de cambios, entre ellos la descentralización, la medición de la ejecución y un mayor énfasis en los resultados. Para dar a los gestores del sector público herramientas eficientes, la adopción de estilos y técnicas del sector privado se está convirtiendo en una práctica común. El Balanced Scorecard ha emergido en las administraciones públicas como una nueva herramienta que satisface las necesidades de información y gestión de muchos de los cambios mencionados. No obstante, es poca la literatura disponible sobre su aplicación en las entidades del sector público. Esta investigación ofrece una visión del proceso de elaboración de un Balanced Scorecard para una agencia pública de servicios deportivos.This research was carried out with financial support from the Spanish National R&D Plan through research project number SEJ2007-67441-ECON-FEDER (Ministry of Science and Innovation) and from the Regional Government of Andalusia (Spain), Centre of Andalusian Studies (PRI160/09) and from the Department of Innovation, Science and Enterprise (Research project number P09-SEJ-5395)

The Mayan Tropical Rainforest: An Uncharted Reservoir of Tritrophic Host-Fruit Fly-Parasitoid Interactions

Over a two–year period, we surveyed natural areas of the Mayan rainforest in Quintana Roo, Mexico. We found 11 species of Anastrepha Schiner (Diptera: Tephritidae) infesting 25 species of fruits belonging to ten plant families. We report the first records of 10 host plant species of the genus Anastrepha, which include the first report of a plant family (Putranjivaceae) serving as host of Anastrepha fraterculus (Wiedemann) infesting Drypetes lateriflora (Sw.) Krug and Urb. (Putranjivaceae). Pouteria reticulata (Engl.) Eyma (Sapotaceae) was found, for the first time, to be infested by Anastrepha serpentina (Wiedemann) and by a new undescribed species of Anastrepha. We also report Casimiroa microcarpa Lundell (Rutaceae) as a possible ancestral host for the Mexican fruit fly, Anastrepha ludens (Loew), in Central America. The family Sapotaceae was the best-represented host group with three fruit fly species recovered: A. serpentina, an economically-important species, found in eight host plants, and A. hamata and A. sp. (new species). We recorded six species of koinobiont parasitoids: Doryctobracon areolatus Szepligeti, Utetes (Bracanastrepha) anastrephae Viereck, Opius hirtus Fisher, and Doryctobracon zeteki Musebeck, (all Braconidae), and Aganaspis pelleranoi (Brethés) and Odontosema anastrephae Borgmeier, (both Figitidae). All these parasitoid species represent at least a new report for their host plants. Of the whole parasitoid community, D. areolatus was the most important parasitoid species with 52.7% of presence in 12 host plant species, parasitizing six fruit fly species. The interaction between fruit flies and their parasitoids with host plants depends on fruit availability, which is crucial for the survival of each of these species. Conserving the landscape of the Mayan rainforest is important not only for species conservation, but also for the maintenance of fruit fly host plants in orchard agroecosystems in southeastern Mexico

Implicaciones económicas de la pandemia de covid-19 en un sector turístico regional de México

In Mexico, the Magical Towns Program is a government strategy designed to stimu­late and diversify economic activities that boost local economies in 177 small touristic towns. The aim of this study is to com­pare the impact of covid-19 confinement measures on the local economy linked to tourism in eight out of the nine Magical Towns (MTs) of Michoacan. To achieve aim, an experiment was designed with two sample groups, one of people and the other of companies from MTs’. The economic impact was measured with two indices that were compared for each sample group among the MTs using Fisher’s technique known as Least Significant Differences (LSD). The results sug­gest that the population perceived a high impact (72/100), while companies perceived a regular impact (49/100). The LSD test suggests that economic impact of confinement was homogeneous in 25 contrasts, which did not show significant differences. On the other hand, there were three contrasts, with a MT as a common factor (Tzintzuntzan), in which a greater economic impact than the rest was perceived.En México, el Programa Pueblos Mágicos es una estrategia gubernamental diseñada para estimular y diversificar las actividades económicas que impulsen las economías locales en 177 ciudades turísticas pequeñas. El presente estudio tiene como objetivo comparar la afectación que las medidas de confinamiento por el covid-19 ocasio­naron a la economía local vinculada con el turismo en 8 de los 9 pueblos mágicos (PM) de Michoacán. Para alcanzar dicho objetivo, se diseñó un experimento con dos grupos muestrales, uno de personas y otro de empresas de los PM. La afectación económica se midió con dos índices que se compararon para cada grupo muestral entre los PM mediante la técnica de Fisher conocida como Mínimas Diferencias Sig­nificativas (MDS). Los resultados sugieren que la población percibió un alto impacto (72/100), mientras que las empresas per­cibieron un impacto regular (49/100). La prueba MDS indica que la afectación econó­mica del confinamiento fue homogénea en 25 contrastes, que no mostraron diferencias significativas; en cambio, en tres contrastes sí las hubo, con un PM como factor común (Tzintzuntzan), en el que se percibió una afectación económica mayor que en el resto

Multiplicity of solutions in model‑based multi objective optimization of wastewater treatment plants

Wastewater treatment process design involves the optimization of multiple conflicting objectives. The detection of different equivalent solutions in terms of objective values is crucial for designers in order to efficiently switch to the new optimal operation policies if changes in the process conditions or new constraints occur. In this work, the dynamic multi-objective optimization of a municipal wastewater treatment plant model is carried out. The aim is to simultaneously optimize an economic cost term and an effluent quality index. The selected process variables for the optimization are (1) an aeration factor in the aerated tank previous to the clarifier, and (2) an internal recycle flow rate. Their time profiles are approximated using the control vector parameterization technique. To solve the multi-objective problem and find the Pareto front, the NSGA-II algorithm has been used. The simulation of different realistic scenarios which impose operational constraints (e.g., maintenance operations) reveals that, indeed, multiple solutions exist at least in some areas of the Pareto front. It is observed that different control profiles can produce nearly identical results in terms of Pareto solutions. The a priori knowledge of these equivalent solutions for different scenarios provides the decision makers with alternative choices to be adapted to their organizations policies when events altering decision variables bounds or adding new constraints to the process model occur.The authors are grateful to Ministry of Science, Innovation and Universities (MICINN) and FEDER for their fnancial support (Projects DPI2016-77538-R and RTI2018-099139-B-C21

Influence of continental history on the ecological specialization and macroevolutionary processes in the mammalian assemblage of South America: Differences between small and large mammals

Background: This paper tests Vrba's resource-use hypothesis, which predicts that generalist species have lower specialization and extinction rates than specialists, using the 879 species of South American mammals. We tested several predictions about this hypothesis using the biomic specialization index (BSI) for each species, which is based on its geographical range within different climate-zones. The four predictions tested are: (1) there is a high frequency of species restricted to a single biome, which henceforth are referred to as stenobiomic species, (2) certain clades are more stenobiomic than others, (3) there is a higher proportion of biomic specialists in biomes that underwent through major expansion-contraction alternation due to the glacial-interglacial cycles, (4) certain combinations of inhabited biomes occur more frequently among species than do others. Results: Our results are consistent with these predictions. (1) We found that 42 % of the species inhabit only one biome. (2) There are more generalists among species of Carnivora than in clades of herbivores. However, Artiodactyla, shows a distribution along the specialization gradient different from the one expected. (3) Biomic specialists are predominant in tropical rainforest and desert biomes. Nevertheless, we found some differences between small and large mammals in relation to these results. Stenobiomic species of micromammalian clades are more abundant in most biomes than expected by chance, while in the case of macromammalian clades stenobiomic species are more frequent than expected in tropical rainforest, tropical deciduous woodland and desert biomes only. (4) The most frequent combinations of inhabited biomes among the South American mammals are those with few biomes, i.e., the ones that suffered a higher rate of vicariance due to climatic cycles. Conclusion: Our results agree with the resource-use hypothesis and, therefore, with a major role of the past climatic changes as drivers of mammalian evolution. Nevertheless, deviations from the expectations indicate the importance of differences in reproductive traits and paleobiogeographic history for the macroevolutionary processes involved. In the case of South American mammals, the Pliocene Great American Biotic Interchange strongly influences the ecological characteristics of this assemblage. Furthermore, the Andes have acted as a fertile ground for speciation in environments prone to vicariance. Finally, the micromammals appear as more prone to biomic specialization than larger species. These factors are responsible for some of the differences found between South America and Africa in the studied pattern. For example, the extensive South American mountain ranges favour a higher number of combinations of inhabited biomes in comparison with Africa

Porous Titanium Cylinders Obtained by the Freeze-Casting Technique: Influence of Process Parameters on Porosity and Mechanical Behavior

 The discrepancy between the stiffness of commercially pure titanium and cortical bone  tissue compromises its success as a biomaterial. The use of porous titanium has been widely studied,  however, it is still challenging to obtain materials able to replicate the porous structure of the bones  (content, size, morphology and distribution). In this work, the freeze‐casting technique is used to  manufacture cylinders with elongated porosity, using a home‐made and economical device. The  relationship between the processing parameters (diameter and material of the mold, temperature  gradient), microstructural features and mechanical properties is established and discussed, in terms  of ensuring biomechanical and biofunctional balance. The cylinders have a gradient porosity  suitable for use in dentistry, presenting higher Young’s modulus at the bottom, near the cold spot  and, therefore better mechanical resistance (it would be in contact with a prosthetic crown), while  the opposite side, the hot spot, has bigger, elongated pores and walls.  Ministry of Economy and Competitiveness of Spain  grant  MAT2015‐71284‐P  FEDER‐Junta de Andalucía Research  Project (Modeling and implementation of the freeze casting technique: gradients of porosity with a tribomechanical equilibrium and electro‐stimulated cellular behavior).

Instrumentos rotatorios: su uso, separación y efecto en complicaciones endodónticas postoperatorias

ResumenEl uso de instrumentos de níquel-titanio en el campo de la endodoncia ha permitido que el tratamiento de conductos se lleve a cabo de manera más predecible y eficiente. Sin embargo, a pesar de las mejoras que se han hecho en el diseño de las limas y en las aleaciones del metal, la fractura de los instrumentos rotatorios continúa siendo una complicación no deseada, problemática y frustrante. La separación de los instrumentos rotatorios se debe frecuentemente al uso incorrecto o excesivo de los mismos. Si la fractura ocurre, el paciente debe ser informado del incidente y se debe considerar el remover o no el fragmento del instrumento. El presente reporte describe un caso de seguimiento a cinco años en un molar mandibular con dos instrumentos endodónticos rotatorios separados en los conductos mesiovestibular y mesiolingual, que no afectaron de forma adversa el resultado del tratamiento.AbstractIntroduction of nickel-titanium instruments in the field of endodontics has made conventional root canal therapy more predictable and efficient. However, despite improvements in file designs and metal alloys, fracture of rotary instruments during endodontic treatment still represents a problematic, unwanted and frustrating complication. File separation often results from incorrect use or overuse of an endodontic instrument. If breakage occurs, patients should be informed about the incident and consideration should be given to whether or not to remove the fragment. This report describes a five year follow-up case of a mandibular molar with two separated endodontic rotary instruments lodged into the mesio-buccal and mesio-lingual canals which did not negatively affect the outcome of root canal treatment