A Probabilistic Model and Capturing Device for Remote Simultaneous Estimation of Spectral Emissivity and Temperature of Hot Emissive Materials

Estimating the temperature of hot emissive samples (e.g. liquid slag) in the context of harsh industrial environments such as steelmaking plants is a crucial yet challenging task, which is typically addressed by means of methods that require physical contact. Current remote methods require information on the emissivity of the sample. However, the spectral emissivity is dependent on the sample composition and temperature itself, and it is hardly measurable unless under controlled laboratory procedures. In this work, we present a portable device and associated probabilistic model that can simultaneously produce quasi real-time estimates for temperature and spectral emissivity of hot samples in the [0.2, 12.0μm ] range at distances of up to 20m . The model is robust against variable atmospheric conditions, and the device is presented together with a quick calibration procedure that allows for in field deployment in rough industrial environments, thus enabling in line measurements. We validate the temperature and emissivity estimates by our device against laboratory equipment under controlled conditions in the [550, 850∘C ] temperature range for two solid samples with well characterized spectral emissivity’s: alumina ( α−Al2O3 ) and hexagonal boron nitride ( h−BN ). The analysis of the results yields Root Mean Squared Errors of 32.3∘C and 5.7∘C respectively, and well correlated spectral emissivity’s.This work was supported in part by the Basque Government (Hazitek AURRERA B: Advanced and Useful REdesign of CSP process for new steel gRAdes) under Grant ZE-2017/00009

On the Duality Between Retinex and Image Dehazing

Image dehazing deals with the removal of undesired loss of visibility in outdoor images due to the presence of fog. Retinex is a color vision model mimicking the ability of the Human Visual System to robustly discount varying illuminations when observing a scene under different spectral lighting conditions. Retinex has been widely explored in the computer vision literature for image enhancement and other related tasks. While these two problems are apparently unrelated, the goal of this work is to show that they can be connected by a simple linear relationship. Specifically, most Retinex-based algorithms have the characteristic feature of always increasing image brightness, which turns them into ideal candidates for effective image dehazing by directly applying Retinex to a hazy image whose intensities have been inverted. In this paper, we give theoretical proof that Retinex on inverted intensities is a solution to the image dehazing problem. Comprehensive qualitative and quantitative results indicate that several classical and modern implementations of Retinex can be transformed into competing image dehazing algorithms performing on pair with more complex fog removal methods, and can overcome some of the main challenges associated with this problem

Composite Polymer Hydrogels with high and Reversible Elongation under Magnetic Stimuli

The field of soft actuators is dominated by elastomers that experience mechanical deformations in response to external stimuli. In this context, magnetic stimuli attract considerable interest because of their easy application, tunability, fast response, remote actuation, and safe penetration in biological environments. Since very recently, research interests in the field are being redirected towards hydrogels, which could virtually replace elastomers, overcoming their limitations and expanding the field of application of soft actuators. The mechanical actuation of hydrogels is a nascent field full of challenges, such as achieving reliable and significant responsiveness. Here we demonstrate that the combination of a physical polymer hydrogel with a dispersed phase consisting of clusters of magnetic particles, results in magnetic hydrogel composites that exhibit high and reversible elongation in response to magnetic stimuli. Our analyses show that this response is strongly dependent on the matrix elasticity, the concentration of magnetic particles, and the particle distribution within the network of polymer nanofibres. Our strategy for the maximization of the response of magnetic hydrogels should be a catalyst for the development of novel applications of composite hydrogels, such as a valve remotely actuated by a magnetic field that we also present here as a proof-of-concept. © 2021 The Author(s).Dr. Mariusz Barczak is acknowledged for help with SEM imaging of iron particles. Ms. Laura Quesada de la Torre is acknowledged for help with design of graphical abstract. This study was supported by project FIS2017-85954-R (Ministerio de Economía, Industria y Competitividad, MINECO, and Agencia Estatal de Investigación, AEI, Spain, cofunded by Fondo Europeo de Desarrollo Regional, FEDER, European Union ). CGV acknowledges financial support by Ministerio de Ciencia, Innovación y Universidades and University of Granada, Spain, for her FPU17/00491 grant. AZ thanks the Russian Science Foundation, project 20-12-00031, for the financial support. LRA thanks the Spanish State Research Agency (Spanish Ministry of Science and Innovation ) through Juan de la Cierva Incorporacion Fellowship ( IJC2018-037951-I ). Funding for open access charge: Universidad de Granada / CBUA

In situ real-time monitoring of the mechanism of self-assembly of short peptide supramolecular polymers

Making use of the combination of multiparametric Fluorescence Lifetime Imaging Microscopy (FLIM) and single-molecule Fluorescence Lifetime Correlation Spectroscopy (FLCS), we have been able to study for the early stages of the fluorenylmethyloxycarbonyl-diphenylalanine (Fmoc-FF) self-assembly process with single-molecule resolution, the kinetics of fiber formation, the packaging of the peptides within the fibers and the capacity of the peptides to reassemble after disruption (self-healing) in the presence of different metallic cations. Other techniques such as FTIR, TEM, DSC and DFT calculations support our findings. The impact that the mechanism of self-assembly has on the physical (rigidity and self-healing) properties of the resulting gels have also been evaluated by rheology. Calcium ions are able to promote the self-assembly of Fmoc-FF faster and more efficiently, forming more rigid hydrogels than do cesium ions. The reasons behind this effect may be explained by the different capacities that these two cations have to coordinate with the peptide, modulate its hydrophobicity and stabilize the water-solute interphase. These findings shed light on the impact that small changes have on the process of self-assembly and can help to understand the influence of the environmental conditions on the in vivo uncontrolled self-assembly of certain proteins

NTIRE 2018 Challenge on Spectral Reconstruction from RGB Images

This paper reviews the first challenge on spectral image reconstruction from RGB images, i.e., the recovery of whole-scene hyperspectral (HS) information from a 3- channel RGB image. The challenge was divided into 2 tracks: the “Clean” track sought HS recovery from noise- less RGB images obtained from a known response func- tion (representing spectrally-calibrated camera) while the “Real World” track challenged participants to recover HS cubes from JPEG-compressed RGB images generated by an unknown response function. To facilitate the challenge, the BGU Hyperspectral Image Database was extended to provide participants with 256 natural HS training images, and 5+10 additional images for validation and testing, re- spectively. The “Clean” and “Real World” tracks had 73 and 63 registered participants respectively, with 12 teams competing in the final testing phase. Proposed methods and their corresponding results are reported in this review