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"Torres, Juan"
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A 3D Printed Toolbox for Opto-Mechanical Components
In this article we present the development of a set of opto-mechanical components (a kinematic mount, a translation stage and an integrating sphere) that can be easily built using a 3D printer based on Fused Filament Fabrication (FFF) and parts that can be found in any hardware store. Here we provide a brief description of the 3D models used and some details on the fabrication process. Moreover, with the help of three simple experimental setups, we evaluate the performance of the opto-mechanical components developed by doing a quantitative comparison with its commercial counterparts. Our results indicate that the components fabricated are highly customizable, low-cost, require a short time to be fabricated and surprisingly, offer a performance that compares favorably with respect to low-end commercial alternatives.
Journal Article
Disability for basic and instrumental activities of daily living in older individuals
To know the prevalence, associated factors and temporal trends of disabilities for basic and instrumental activities of daily living in older people in Spain from 2009 to 2017.
Disability in older people is associated with health problems, increased health costs and low quality of life. There are no updated data in Spain with a representative sample about disability.
Cross-sectional study with 25,465 non-institutionalized older people who participated in the European Health Survey in 2009 and 2014 and the National Health Survey in 2011/12 and 2017 in Spain. The prevalence rates of disability were evaluated using the Katz Scale and Lawton and Brody Scale. Logistic regression was used to determine if there was an association between basic and instrumental activities of daily living and sociodemographic characteristics.
More individuals had disability for instrumental activities of daily living (31.9%) than disability for basic activities of daily living (11.1%). The most predominant disability for instrumental activities of daily living was performing severe housework (34%). The prevalence of disabilities decreased from 2009 to 2017. In general, disability was associated with female gender, advanced age, lower education, restricted daily activity, being bedridden and higher pain levels.
There is a considerable prevalence of disabilities for basic and instrumental activities of daily living in older people in Spain. Although the disability prevalence has decreased slowly from 2009 to 2017, it continues to remain a health problem. Gender may influence the disabilities for basic and instrumental activities of daily living. Health policymakers should establish prevention strategies and effective interventions (e.g., physical exercise) for prevention and reduction of the disabilities for basic and instrumental activities of daily living, particularly in older females.
Journal Article
Thermodiffusive desalination
Desalination could solve the grand challenge of water scarcity, but materials-based and conventional thermal desalination methods generally suffer from scaling, fouling and materials degradation. Here, we propose and assess thermodiffusive desalination (TDD), a method that operates entirely in the liquid phase and notably excludes evaporation, freezing, membranes, or ion-adsorbing materials. Thermodiffusion is the migration of species under a temperature gradient and can be driven by thermal energy ubiquitous in the environment. Experimentally, a 450 ppm concentration drop was achieved by thermodiffusive separation when passing a NaCl/H
2
O solution through a single channel. This was further increased through re-circulation as a proof of concept for TDD. We also demonstrate via molecular dynamics and experiments that TDD in multi-component seawater is more amenable than in binary NaCl/H
2
O solutions. Numerically, we show that a scalable cascaded channel structure can further amplify thermodiffusive separation, achieving a concentration drop of 25000 ppm with a recovery rate of 10%. The minimum electric power consumption in this setup can be as low as 3 Wh
e
m
−3
, which is only 1% of the theoretical minimum energy for desalination. TDD has potential in areas with abundant thermal energy but limited electrical power resources and can contribute to alleviating global freshwater scarcity.
Current desalination technologies are energy intensive and suffer from membrane degradation and fouling. Here, authors propose and explore the potential of thermodiffusion as a means of membrane-free, single-phase thermal desalination. A pathway towards a feasible thermodiffusive desalination is provided.
Journal Article
Energy storage in structural composites by introducing CNT fiber/polymer electrolyte interleaves
This work presents a method to produce structural composites capable of energy storage. They are produced by integrating thin sandwich structures of CNT fiber veils and an ionic liquid-based polymer electrolyte between carbon fiber plies, followed by infusion and curing of an epoxy resin. The resulting structure behaves simultaneously as an electric double-layer capacitor and a structural composite, with flexural modulus of 60 GPa and flexural strength of 153 MPa, combined with 88 mF/g of specific capacitance and the highest power (30 W/kg) and energy (37.5 mWh/kg) densities reported so far for structural supercapacitors.
In-situ
electrochemical measurements during 4-point bending show that electrochemical performance is retained up to fracture, with minor changes in equivalent series resistance for interleaves under compressive stress.
En route
to improving interlaminar properties we produce grid-shaped interleaves that enable mechanical interconnection of plies by the stiff epoxy. Synchrotron 3D X-ray tomography analysis of the resulting hierarchical structure confirms the formation of interlaminar epoxy joints. The manuscript discusses encapsulation role of epoxy, demonstrated by charge-discharge measurements of composites immersed in water, a deleterious agent for ionic liquids. Finally, we show different architectures free of current collector and electrical insulators, in which both CNT fiber and CF act as active electrodes.
Journal Article
Are Trends of Gulf Stream Transport Uniform Along the Florida Shelf?
The Gulf Stream and Yucatán Current are key components of the Atlantic Ocean's circulation system. Although the Florida Current at 27°N has been continuously monitored for over 40 years, spatial variability in transport along the broader Florida Shelf remains less explored. Three decades (1993–2023) of satellite altimetry allow assessment of surface transport trends across four primary transects from the Yucatán Channel to 30°N, and along 32 supplementary sections tracking the Gulf Stream path. Bayesian regression reveals negative trends upstream, while quasi‐stable behavior downstream (off North Florida). Wavelet analysis identifies dominant seasonal to decadal variability, with the strongest coherence within the straits. Model (HYbrid Coordinate Ocean Model) output confirms spatially heterogeneous trends and downstream stabilization of volume transport. These findings suggest that trends of the Gulf Stream are spatially non‐uniform, involving apparent transport reductions balanced by downstream compensation. Thus, it is necessary to resolve along‐stream variability when assessing long‐term changes in western boundary current systems.
Journal Article
Substitution of histidine 95 by tyrosine in the prion protein causes spontaneous neurodegeneration in transgenic mice
Prion diseases are neurodegenerative disorders caused by a change in conformation of the prion protein from the cellular form (PrP C ) to a misfolded isoform (PrP Sc ). PrP C is a copper binding protein via histidine residues in the octapeptide repeats (OR) and the non-OR region located at the N-terminus. Although the functional implication of copper binding to PrP C is still under investigation, copper may play a role in prion disease. In this study, we describe transgenic mice expressing mouse prion protein replacing histidine 95 by tyrosine (PrP H95Y) to disrupt the non-OR copper-binding site. Transgenic mice overexpressing PrP H95Y showed clinical signs and died at about 100 days with spongiform degeneration and PK-resistant PrP. Inoculation of brain homogenate from mice overexpressing PrP H95Y to Tga20 mice expressing wild-type PrP also causes lethal, spongiform encephalopathy. We conclude that this substitution could promote PrP C -PrP Sc conversion and induce spontaneous prion disease in vivo .
Journal Article
Scalable nano-architecture for stable near-blackbody solar absorption at high temperatures
Light trapping enhancement by nanostructures is ubiquitous in engineering applications, for example, in improving highly-efficient concentrating solar thermal (CST) technologies. However, most nano-engineered coatings and metasurfaces are not scalable to large surfaces ( > 100 m
2
) and are unstable at elevated temperatures ( > 850
°
C), hindering their wide-spread adoption in CST. Here, we propose a scalable layer nano-architecture that can significantly enhance the solar absorption of an arbitrary material. Our electromagnetics modelling predicts that the absorptance of cutting-edge light-absorbers can be further enhanced by more than 70%, i.e. relative improvement towards blackbody absorption from a baseline value without the nano-architecture. Experimentally, the nano-architecture yields a solar absorber that is 35% optically closer to a blackbody, even after long-term (1000 h) high-temperature (900
°
C) ageing in air. A stable solar absorptance of more than 97.88 ± 0.14% is achieved, to the best of our knowledge, the highest so far reported for these extreme ageing conditions. The scalability of the layer nano-architecture is further demonstrated with a drone-assisted deposition, paving the way towards a simple yet significant solar absorptance boosting and maintenance method for existing and newly developed CST absorbing materials.
Nanostructures are generally unstable above 850
°
C in air, limiting their use in high-temperature solar thermal applications. Here, a scalable ceramic nano-architecture layer can significantly enhance and stabilise the absorption of an arbitrary solar absorber.
Journal Article
Quantum transport of high-dimensional spatial information with a nonlinear detector
Information exchange between two distant parties, where information is shared without physically transporting it, is a crucial resource in future quantum networks. Doing so with high-dimensional states offers the promise of higher information capacity and improved resilience to noise, but progress to date has been limited. Here we demonstrate how a nonlinear parametric process allows for arbitrary high-dimensional state projections in the spatial degree of freedom, where a strong coherent field enhances the probability of the process. This allows us to experimentally realise quantum transport of high-dimensional spatial information facilitated by a quantum channel with a single entangled pair and a nonlinear spatial mode detector. Using sum frequency generation we upconvert one of the photons from an entangled pair resulting in high-dimensional spatial information transported to the other. We realise a
d
= 15 quantum channel for arbitrary photonic spatial modes which we demonstrate by faithfully transferring information encoded into orbital angular momentum, Hermite-Gaussian and arbitrary spatial mode superpositions, without requiring knowledge of the state to be sent. Our demonstration merges the nascent fields of nonlinear control of structured light with quantum processes, offering a new approach to harnessing high-dimensional quantum states, and may be extended to other degrees of freedom too.
High-dimensional quantum states allow for several advantages in quantum communication, but protocols such as teleportation require additional entangled photons as the dimension increases. Here, the authors show how to transport a high-dimensional quantum state from a bright coherent laser field to a single photon, using two entangled photons as the quantum channel.
Journal Article
Light-nuclei production and search for the QCD critical point
We discuss the potential of light-nuclei measurements in heavy-ion collisions at intermediate energies for the search of the hypothetical QCD critical end-point. A previous proposal based on neutron density fluctuations has brought appealing experimental evidences of a maximum in the ratio of the number of tritons times protons, divided over deuterons square,
O
tpd
. However these results are difficult to reconcile with the state-of-the-art statistical thermal model predictions. Based on the idea that the QCD critical point can lead to a substantial attraction among nucleons, we propose new light-nuclei multiplicity ratios involving
4
He in which the maximum would be more noticeable. We argue that the experimental extraction is feasible by presenting these ratios formed from actual measurements of total and differential yields at low and high collision energies from FOPI and ALICE experiments, respectively. We also illustrate the possible behavior of these ratios at intermediate energies applying a semiclassical method based on flucton paths using the preliminary NA49 and STAR data for
O
tpd
as input.
Journal Article