Low-Cost Prototype to Automate the 3D Digitization of Pieces: An Application Example and Comparison

This work is aimed at describing the design of a mechanical and programmable 3D capturing system to be used by either 3D scanner or DSLR camera through photogrammetry. Both methods are widely used in diverse areas, from engineering, architecture or archaeology, up to the field of medicine; but they also entail certain disadvantages, such as the high costs of certain equipment, such as scanners with some precision, and the need to resort to specialized operatives, among others. The purpose of this design is to create a robust, precise and cost-effective system that improves the limitations of the present equipment on the market, such as robotic arms or rotary tables. For this reason, a preliminary study has been conducted to analyse the needs of improvement, later, we have focused on the 3D design and prototyping. For its construction, there have been used the FDM additive technology and structural components that are easy to find in the market. With regards to electronic components, basic electronics and Arduino-based 3D printers firmware have been selected. For system testing, the capture equipment consists of a Spider Artec 3D Scanner and a Nikon 5100 SLR Camera. Finally, 3D models have been developed by comparing the 3D meshes obtained by the two methods, obtaining satisfactory results

Stability and Thermal Properties Study of Metal Chalcogenide-Based Nanofluids for Concentrating Solar Power

Nanofluids are colloidal suspensions of nanomaterials in a fluid which exhibit enhanced thermophysical properties compared to conventional fluids. The addition of nanomaterials to a fluid can increase the thermal conductivity, isobaric-specific heat, diffusivity, and the convective heat transfer coefficient of the original fluid. For this reason, nanofluids have been studied over the last decades in many fields such as biomedicine, industrial cooling, nuclear reactors, and also in solar thermal applications. In this paper, we report the preparation and characterization of nanofluids based on one-dimensional MoS2 and WS2 nanosheets to improve the thermal properties of the heat transfer fluid currently used in concentrating solar plants (CSP). A comparative study of both types of nanofluids was performed for explaining the influence of nanostructure morphologies on nanofluid stability and thermal properties. The nanofluids prepared in this work present a high stability over time and thermal conductivity enhancements of up to 46% for MoS2-based nanofluid and up to 35% for WS2-based nanofluid. These results led to an increase in the efficiency of the solar collectors of 21.3% and 16.8% when the nanofluids based on MoS2 nanowires or WS2 nanosheets were used instead of the typical thermal oil

An App about healthy habits as an educational resource during the pandemic

Educational institutions and their agents play a fundamental role in improving people’s health literacy and quality of life. We intend here to describe and justify an educational resource embodied in an application for mobile devices developed through a subsidized project by the Ministry of Health (Government of Andalusia); the purpose of this app is to educate young people in healthy habits. The application was designed to be easily used in both smartphones and tablets with the aim of achieving good physical, psychological and social health. The project comprises several phases and the results we have so far show that, from an early age, health institutions and educational settings must work in partnership, increasing health literacy levels. This cooperative work combined with the use of this innovative approach presents an important potential for change in the lifestyles of younger generations. This type of intervention took on a special role in the pandemic context, allowing for the maintenance of the educational stimulus in a safe context.Project of the three-year period 2017–2019. This study was funded by the Health Council of the Government of Andalusia, in compliance with Resolution of 20 December 2016, of the General Secretariat of Healthcare Research, Development and Innovation, in the call of grants for the funding of Research in Biomedicine, Life Sciences, Development and Innovation in Andalusia for the year 2016, with file number PIN-0445-2016 and a total duration of 36 months. This study was funded by EPIT 2021 (University of Huelva, Spain). Currently it is also supported by the Andalusian ERDF Operational Program 2014–2020 (reference UHU-202062).info:eu-repo/semantics/publishedVersio

Chitosan biofilms: Insights for the selective electromembrane extraction of fluoroquinolones from biological samples

A selective electromembrane extraction procedure for the extraction of Enrofloxacin, Marbofloxacin and Flumequine, usually employed as antibiotic in veterinarian use, is proposed by using a chitosan biofilm, composed by 60% (w/w) chitosan and 40% (w/w) Aliquat®336, as active biopolymeric support. The interaction mechanism occurring between the target drugs and the biopolymer has been deeply studied using the Quantum Theory of Atoms in Molecules. The obtained results show the interaction between the extracted fluoroquinolones and the biomembrane is stabilized by two hydrogen bonds formed between both the carboxyl and keto groups of the drugs with both the amine and hydroxyl groups of glucosamine in the biopolymer. The energetic results agree with the high extraction efficiency obtained for Marbofloxacin, Enrofloxacin and Flumequine in terms of enrichment factors (83, 82 and 58, respectively) in presence of other fluoroquinolones. Under optimum conditions, the proposed electromembrane extraction method exhibits wide linear ranges of 4.2e200 mg L1 , 5.6e200 mg L1 and 5.1e200 mg L1 , respectively; low limits of detection close to 1.3 mg L1 and appropriate repeatability (relative standard deviation values 4e7%).Fondos Europeos FEDER, Ministerio de Ciencia e Innovación y Agencia Estatal de Investigación, de España - PGC2018-096608- B-C22Ministerio de Ciencia, Innovación y Universidades de España - RED2018-102522-TJunta de Andalucía - 2019/FQM-106Premio Mensual Publicación Científica Destacada de la US. Facultad de Químic

Psychological Discomfort in Nursing Degree Students as a Consequence of the COVID-19 Pandemic

Students are a population at risk of developing psychological complications, such as psychological discomfort, stress, and anxiety, among other problems, especially during the current health crisis due to the COVID-19 pandemic. The present study’s objective was to analyze the effects of the COVID-19 pandemic on the psychological discomfort of final-year nursing students. A crosssectional descriptive observational study was carried out. To analyze the psychological discomfort of the participants, the Kessler test (previously validated) was used. The results of this test were divided into two levels (High ≥ 21/Low < 21), showing high sensitivity as a screening method for anxiety and depression. Questionnaires were sent via email to final-year nursing students of Spanish and South American universities, inviting them to participate voluntarily. The sample consisted of 400 students, with an average age of 23.29 years and a sex proportion of 82.75% women and 17.28% men. Almost all participants (n = 396) belonged to Spanish universities, and the greatest participation corresponded to Andalusian universities (64.5%). The average psychological discomfort was high (M = 27.94). Statistically significant relationships were detected between age, sex, and feeling ready for the world of work, observing no relationships with the rest of the studied variables. The sample of 4th-year students of the Degree of Nursing presented a high level of psychological discomfort. This pathology does not seem to be related to having suffered from COVID-19 or being in contact with infected people during the practicum and is more strongly related to personal sociodemographic variables and students’ preparation for the world of workUniversity of Huelv

Biogeographic, atmospheric, and climatic factors influencing tree growth in Mediterranean Aleppo pine forests

There is a lack of knowledge on how tree species respond to climatic constraintslike water shortages and related atmospheric patterns across broad spatial and temporal scales.These assessments are needed to project which populations will better tolerate or respond to globalwarming across the tree species distribution range. Warmer and drier conditions have been forecastedfor the Mediterranean Basin, where Aleppo pine (Pinus halepensisMill.) is the most widely distributedconifer in dry sites. This species shows plastic growth responses to climate, being particularly sensitiveto drought. We evaluated how 32 Aleppo pine forests responded to climate during the second half ofthe 20th century by using dendrochronology. Climatic constraints of radial growth were inferred byfitting the Vaganov-Shashkin (VS-Lite) growth model to ring-width data from our Aleppo pine forestnetwork. Our findings reported that Aleppo pine growth decreased and showed the highest commoncoherence among trees in dry, continental sites located in southeastern and eastern inland Spain andAlgeria. In contrast, growth increased in wetter sites located in northeastern Spain. Overall, across theAleppo pine network tree growth was enhanced by prior wet winters and cool and wet springs,whilst warm summers were associated with less growth. The relationships between site ring-widthchronologies were higher in nearby forests. This explains why Aleppo pine growth was distinctlylinked to indices of atmospheric circulation patterns depending on the geographical location of theforests. The western forests were more influenced by moisture and temperature conditions drivenby the Western Mediterranean Oscillation (WeMO) and the Northern Atlantic Oscillation (NAO),the southern forests by the East Atlantic (EA) and the august NAO, while the Balearic, Tunisian andnortheastern sites by the Arctic Oscillation (AO) and the Scandinavian pattern (SCA). The climaticconstraints for Aleppo pine tree growth and its biogeographical variability were well captured by theVS-Lite model. The model performed better in dry and continental sites, showing strong growthcoherence between trees and climatic limitations of growth. Further research using similar broad-scaleapproaches to climate-growth relationships in drought-prone regions deserves more attention

Improving the efficiency of the concentrating solar power plants using heat transfer nanofluids with gold nanoplates: An analysis from laboratory to industrial scale

We report about the remarkable changes in the thermophysical properties of the heat transfer fluid used in concentrating solar power plants with parabolic-trough collectors (Dowtherm A, a mixture of diphenyl oxide and biphenyl) by addition of Au nanoplates in mass fractions around 10−2 wt%. The resulting nanofluids are stable for weeks, and their enhanced physical properties make them good candidates for the application. Particularly, with 4.8·10−2 wt% of Au nanoplates, specific heat increases by 12.0 ± 1.2 % at 523 K and thermal conductivity increases by 24.9 ± 6.1 % at 373 K, with no measurable changes in density or dynamic viscosity. This set of physical properties allows to make a realistic estimation of the performance of a prototypical concentrating solar power plant using these nanofluids for solar-to-thermal energy conversion. We determine, using computational cost-free numerical models available in literature, that the performance of a concentrating solar power plant could increase up to 35.1 %, compared to the predicted 24.7 % with the conventional heat transfer fluid, with neither rheological penalties nor economically prohibitive structural changes. The findings here reported may contribute to encourage the application of heat transfer nanofluids in order to improve the efficiency of concentrating solar power plants, and to consolidate a working scheme that positively promotes the transition from laboratory scale to industrial scale. © 2023 The Author