36 research outputs found

    Understanding Uncertainties in Thermographic Imaging

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    7 p.The present article proposes a workflow based on free/open-source software solutions for the acquisition of competences in engineering courses related to the use of thermographic images. The approach is aimed to three-dimensional visualization techniques over thermographic images to improve the comprehension and interpretation of the different error sources that affects the measurements, and therefore the conclusions and analysis derived from them. The present work is framed inside the virtual laboratories discipline, as the new learning material can be employed for the acquisition of competences and skills. Additionally, it can be used for the evaluation of competences in asynchronous and e-learning programs. The learning materials could be easily deployed in a learning management system, allowing the students to work with the models by means of open-source solutions easily, both in asynchronous and face-to-face courses. Consequently, the present approach will improve the application of professional techniques, so the future professionals will reach the working market better prepared.S

    Evaluation of a High Throughput Starch Analysis Optimised for Wood

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    Starch is the most important long-term reserve in trees, and the analysis of starch is therefore useful source of physiological information. Currently published protocols for wood starch analysis impose several limitations, such as long procedures and a neutralization step. The high-throughput standard protocols for starch analysis in food and feed represent a valuable alternative. However, they have not been optimised or tested with woody samples. These have particular chemical and structural characteristics, including the presence of interfering secondary metabolites, low reactivity of starch, and low starch content. In this study, a standard method for starch analysis used for food and feed (AOAC standard method 996.11) was optimised to improve precision and accuracy for the analysis of starch in wood. Key modifications were introduced in the digestion conditions and in the glucose assay. The optimised protocol was then evaluated through 430 starch analyses of standards at known starch content, matrix polysaccharides, and wood collected from three organs (roots, twigs, mature wood) of four species (coniferous and flowering plants). The optimised protocol proved to be remarkably precise and accurate (3%), suitable for a high throughput routine analysis (35 samples a day) of specimens with a starch content between 40 mg and 21 µg. Samples may include lignified organs of coniferous and flowering plants and non-lignified organs, such as leaves, fruits and rhizomes

    Evaluation of uncertainties for CIELAB color coordinates

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    7 pags., 1 figs., 1 tab.CIELAB color coordinates are characteristics of visible object¿s spectra widely used in color science, and a reliable evaluation of the uncertainty associated with measured color coordinates is desirable. The calculation of CIELAB color coordinates requires the application of a nonlinear transformation. We consider two ways to calculate the uncertainty of CIELAB color coordinates that originates from the uncertainty of the observed spectrum. The ¿rst approach is based on a linearization of the nonlinear transformation and a propagation of variances and covariances. The second approach is a Monte Carlo procedure that completely accounts for the nonlinearity of the trans- formation. While the approach based on linearization results in analytical formulas, the adequacy of linearization ought to be checked and the proposed Monte Carlo method can serve as a reference method for this purpose. We illustrate such proceed- ing in a large range of scenarios and explore those cases for which the method based on linearization may safely be applied.This work has been carried out within EMRP project IND 52“Multidimensional Reflectometry for Industry.” The EMRP isjointly funded by the EMRP participating countries within EURAMET and the European Union.Peer Reviewe

    Faraday’s Law of Induction by Experiment

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