80 research outputs found
Classification of red grapes according to their state of ripeness using a low-cost multispectral device
[ES] El objetivo del presente trabajo fue evaluar la idoneidad de un sensor multiespectral de bajo costo para la determinación del estado de maduración de uvas tintas. El dispositivo propuesto se basa en un sensor multiespectral, con 18 bandas de detección en el rango entre los 410 y los 940 nm. La recogida de muestras se llevó a cabo en un viñedo comercial situado en Rociana del Condado, Huelva. El dispositivo propuesto se utilizó para adquirir la respuesta espectral de 80 racimos de uva en condiciones de
laboratorio. Tras esto, cada una de las muestras fue analizada mediante métodos estándar de laboratorio para obtener indicadores objetivos de su estado de maduración (sólidos solubles totales y acidez). Los 18 valores de reflectancia ofrecidos por el sensor fueron usados como datos de entrada para entrenar redes neuronales artificiales para la clasificación de las muestras de uva en función de los parámetros objetivo. Los resultados obtenidos fueron prometedores, lo cual allana el camino hacia la implementación de un sistema para la monitorización del estado de maduración de uvas asequible para los vinicultores.[EN] The present work aims to evaluate a low-cost multispectral device for non-destructive grape ripening status assessment. The proposed device is based on a multispectral sensor, with a spectral response of 18 channels in a range from 410 to 940 nm. The experimental validation was carried out in a commercial vineyard in Rociana del Condado, Huelva. The proposed device was used to analyze 80 grape samples under laboratory conditions. After being processed with the proposed device the grape samples were analyzed with standard chemical methods to generate ground truth values of ripening status indicators (solid soluble content, and acidity). The 18-reflectance data corresponding to the spectral channels of the employed sensor, were used as input variables for developing artificial neural network models to classify the berries samples based on the mentioned ripeness indicators. The obtained results were promising, which paves the way for the implementation of a portable grape ripening appraisal system affordable for grape growers
Electrical conductivity of oxidized-graphenic nanoplatelets obtained from bamboo: Effect of the oxygen content
The large-scale production of graphene and reduced-graphene oxide (rGO) requires low-cost and eco-friendly synthesis methods. We employed a new, simple, cost-effective pyrolytic method to synthetize oxidized-graphenic nanoplatelets (OGNP) using bamboo pyroligneous acid (BPA) as a source. Thorough analyses via high-resolution transmission electron microscopy and electron energy-loss spectroscopy provides a complete structural and chemical description at the local scale of these samples. In particular, we found that at the highest carbonization temperature the OGNP-BPA are mainly in a sp2 bonding configuration (sp2 fraction of 87%). To determine the electrical properties of single nanoplatelets, these were contacted by Pt nanowires deposited through focused-ion-beam-induced deposition techniques. Increased conductivity by two orders of magnitude is observed as oxygen content decreases from 17% to 5%, reaching a value of 2.3 103 S m-1 at the lowest oxygen content. Temperature-dependent conductivity reveals a semiconductor transport behavior, described by the Mott three-dimensional variable range hopping mechanism. From the localization length, we estimate a band-gap value of 0.22(2) eV for an oxygen content of 5%. This investigation demonstrates the great potential of the OGNP-BPA for technological applications, given that their structural and electrical behavior is similar to the highly reduced rGO sheets obtained by more sophisticated conventional synthesis methods
Garvicins AG1 and AG2 : two novel class IId bacteriocins of lactococcus garvieae Lg-Granada
Funding: This research was funded by the Spanish Ministry of Science, Innovation, and Universities, grant number RTI2018-098530-B-I00. The APC was funded by the Spanish Ministry of Science, Innovation, and Universities, grant number RTI2018-098530-B-I00.Lactococcus garvieae causes infectious diseases in animals and is considered an emerging zoonotic pathogen involved in human clinical conditions. In silico analysis of plasmid pLG50 of L. garvieae Lg-Granada, an isolate from a patient with endocarditis, revealed the presence of two gene clusters (orf 46–47 and orf 48–49), each one encoding a novel putative bacteriocin, i.e., garvicin AG1 (GarAG1; orf 46) and garvicin AG2 (GarAG2; orf 48), and their corresponding immunity proteins (orf 47 and orf 49). The chemically synthesised bacteriocins GarAG1 and GarAG2 presented inhibitory activity against pathogenic L. garvieae strains, with AG2 also being active against Listeria monocytogenes, Listeria ivanovii and Enterococcus faecalis. Genetic organisation, amino acid sequences and antimicrobial activities of GarAG1 and GarAG2 indicate that they belong to linear non-pediocin-like one-peptide class IId bacteriocins. Gram-positive bacteria that were sensitive to GarAG2 were also able to ferment mannose, suggesting that this bacteriocin could use the mannose phosphotransferase transport system (Man-PTS) involved in mannose uptake as a receptor in sensitive strains. Intriguingly, GarAG1 and GarAG2 were highly active against their own host, L. garvieae Lg-Granada, which could be envisaged as a new strategy to combat pathogens via their own weapons.Publisher PDFPeer reviewe
A multiscale material model for metallic powder compaction during hot isostatic pressing
The prediction of the distortions during Near-Net-Shape Hot Isostatic Pressing (NNS-HIP) is an intrinsic multiscale problem where the local interactions among particles determine the macroscopic distortions taking place
during the sintering and densification of a component. In this work, a multiscale approach is proposed to solve
this problem. In particular, a viscoplastic constitutive model capable of predicting macroscopic contractions
during a HIP process with high accuracy has been developed, implemented and validated. The macroscopic
model incorporates the mechanical behaviour predicted at the meso-scale by means of multiple-particle finite
element models (MP-FEM) of an agglomerate of powder particles. The model is validated through the prediction
of distortions during HIP of a full scale industrial case. It is concluded that adding the microscopic information of
the HIP process to simulate the contractions at the macroscopic level results in a considerable improvement of
the accuracy of the predictions
Clasificación de cultivos y de sus medidas agroambientales mediante segmentación de imágenes QuickBird
En la últimas décadas han ido creciendo considerablemente
los conocimientos y la sensibilización
sobre la protección al medioambiente en
muy diversas áreas, entre las que se encuentra la
Agricultura. El uso intensivo del laboreo ocasiona
graves daños medioambientales como la
erosión del suelo, la contaminación de las aguas
superficiales (escorrentía y colmatación de embalses),
el descenso del contenido de la materia
orgánica y de la biodiversidad de los suelos labrados,
y el aumento de la emisión de CO2 del
suelo a la atmósfera. Actualmente, la Unión Europea
sólo subvenciona a los agricultores que
cumplen lo que se conoce como “Medidas Agroambientales
o de Condicionalidad” cuyo diseño
ha estado dentro de las competencias de las Políticas
Agrarias Autonómicas, Nacionales y Europeas.
Estas medidas consisten en alterar el
perfil y la estructura del suelo lo menos posible,
dejando éste sin labrar y permanentemente protegido
por cubiertas vegetales (rastrojo) en el
caso de cultivos herbáceos (ej. trigo, maíz, girasol),
o por cubiertas vegetales vivas o inertes
(restos de poda) en el caso de cultivos leñosos
(principalmente cítricos y olivar). El seguimiento
del cumplimiento de estas medidas se realiza a través de visitas presenciales a un 1% de
los campos susceptibles de recibir ayudas. Este
método es ineficiente y provoca muchos errores
con la consiguiente presentación de un ingente
número de reclamaciones. Para subsanar esta
problemática, en este artículo presentamos los resultados
obtenidos en la clasificación de los cultivos
y las medidas agroambientales asociadas a
éstos en una imagen multiespectral QuickBird tomada
a principios de Julio de una zona típica de
cultivos en régimen de secano de Andalucía. Se
aplicaron 5 métodos de clasificación (Paralelepípedos,
P; Mínima Distancia, MD; Distancia de
Mahalanobis, MC; Mapeo del Ángulo Espectral,
SAM; y Máxima Probabilidad, ML) para la discriminación
de rastrojo de trigo quemado y sin
quemar, arbolado, carreteras, olivar, cultivos herbáceos
de siembra primaveral y suelo desnudo.
Además, la imagen es segmentada en objetos
para comparar la fiabilidad obtenida aplicando
los métodos anteriores partiendo tanto de píxeles
como de objetos como Unidades Mínimas de
Información (MIU). El análisis de los resultados
permite concluir que las clasificaciones de todos
los usos de suelo basadas en objetos claramente
mejoraron las basadas en píxeles, obteniéndose
precisiones (overall accuracy) mayores al 85%.
La elección de un método de clasificación u otro
influye en gran medida en la precisión de los
mapas obtenidos.
Debido a que la precisión del mapa temático
que necesitamos obtener ha de ser muy elevada
para tomar decisiones sobre Conceder / No conceder
las ayudas, sería interesante estudiar si el
incremento de la resolución espacial que se obtenga
gracias a la fusión de imágenes multiespectral
y pancromática de QuickBird para
obtener una imagen fusionada con resolución espacial
de la pancromática (0.7 m) y espectral de
la multiespectral (4 bandas) mejora la precisión
de cualquiera de los métodos de clasificación estudiadosSoil management in crops is mainly based on
intensive tillage operations, which have a great
relevancy in terms of increase of atmospheric
CO2, desertification, erosion and land degradation.
Due to these negative environmental impacts,
the European Union only subsidizes
cropping systems which require the implementation
of certain no-tillage systems and agro-environmental
measures, such as keeping the
winter cereal residues and non-burning of stubble
to reduce erosion, and to increase the organic
matter, the fertility of soils and the crop production.
Nowadays, the follow-up of these agrarian
policy actions is achieved by ground visits to
sample targeted farms; however, this procedure is
time-consuming and very expensive. To improve
this control procedure, a study of the accuracy
performance of several classification methods
has been examined to verify if remote sensing
can offer the ability to efficiently identify crops
and their agro-environmental measures in a typical
agricultural Mediterranean area of dry conditions.
Five supervised classification methods
based on different decision rule routines, Parallelepiped
(P), Minimum Distance (MD), Mahalanobis
Classifier Distance (MC), Spectral Angle Mapper (SAM), and Maximum Likelihood
(ML), were examined to determine the most suitable
classification algorithm for the identification
of agro-environmental measures such as
winter cereal stubble and burnt stubble areas and
other land uses such as river side trees, vineyard,
olive orchards, spring sown crops, roads and bare
soil. An object segmentation of the satellite information
was also added to compare the accuracy
of the classification results of pixel and
object as Minimum Information Unit (MIU). A
multispectral QuickBird image taken in early
summer was used to test these MIU and classification
methods. The resulting classified images
indicated that object-based analyses clearly outperformed
pixel ones, yielding overall accuracies
higher than 85% in most of the classifications.
The choice of a classification method can markedly
influence the accuracy of classification
maps
Application of the Kalman filter in the processing of very noisy measurements, a case study: motorcycle dyno with aerodynamic analysis capability
[ES] En este trabajo se presenta una aplicación del filtro de Kalman para tratar medidas altamente ruidosas de cara a su empleo en un sistema de control. En concreto, el sistema con el que se ha trabajado es un banco de potencia para motocicletas al que se ha añadido un ventilador de gran potencia capaz de generar una corriente de aire a una velocidad igual a la que está desarrollando la motocicleta sobre el rodillo, permitiendo así la realización de estudios aerodinámicos. Las variables a medir se ven fuertemente
afectadas por ruido generado por el inversor que alimenta el ventilador, por las interferencias provocadas por los pulsos de la bobina de alta tensión de la motocicleta o por las turbulencias de la corriente de aire en el caso del sensor de velocidad del aire. Además, teniendo en cuenta que varias de las señales a medir son pulsos que deben computarse en cada intervalo de control, también van a producirse errores que pueden considerarse ruidos del proceso. El filtro de Kalman, empleado para tratar las medidas y algunas de las variables calculadas en el algoritmo consiguen reducir el ruido de todas las variables a valores aceptables que permiten la realización de las acciones de control y trazado de curvas de potencia y par de la motocicleta
Digital image correlation after focused ion beam micro-slit drilling: A new technique for measuring residual stresses in hardmetal components at local scale
A new method has been developed for measuring residual stresses at the surface of hardmetal components with
higher spatial resolution than standard X-ray diffraction methods. It is based on measuring the surface displacements produced when stresses are partially released by machining a thin slit perpendicularly to the tested
surface. Slit machining is carried out by focused ion beam (FIB). Measurement of the displacement fields around
the FIB slit are performed by applying an advanced digital image correlation algorithm based on Fourier analysis
with sub-pixel resolution. This method compares SEM images of the same area of the hardmetal surface before
and after slitting. The method has been successfully applied to as-ground and femto-laser textured surfaces
showing good correlation with the standard sin2
ψ XRD technique. It is concluded that texturing induced by laser
pulses in the femtoseconds regime is not perfectly adiabatic, since residual stresses are reduced by 15
Digital image correlation after focused ion beam micro-slit drilling: A new technique for measuring residual stresses in hardmetal components at local scale
A new method has been developed for measuring residual stresses at the surface of hardmetal components with higher spatial resolution than standard X-ray diffraction methods. It is based on measuring the surface dis-placements produced when stresses are partially released by machining a thin slit perpendicularly to the tested surface. Slit machining is carried out by focused ion beam (FIB). Measurement of the displacement fields around the FIB slit are performed by applying an advanced digital image correlation algorithm based on Fourier analysis with sub-pixel resolution. This method compares SEM images of the same area of the hardmetal surface before and after slitting. The method has been successfully applied to as-ground and femto-laser textured surfaces showing good correlation with the standard sin2 psi XRD technique. It is concluded that texturing induced by laser pulses in the femtoseconds regime is not perfectly adiabatic, since residual stresses are reduced by 15%
Detection of kinase domain mutations in BCR::ABL1 leukemia by ultra-deep sequencing of genomic DNA
The screening of the BCR::ABL1 kinase domain (KD) mutation has become a routine analysis in case of warning/failure for chronic myeloid leukemia (CML) and B-cell precursor acute lymphoblastic leukemia (ALL) Philadelphia (Ph)-positive patients. In this study, we present a novel DNA-based next-generation sequencing (NGS) methodology for KD ABL1 mutation detection and monitoring with a 1.0E−4 sensitivity. This approach was validated with a well-stablished RNA-based nested NGS method. The correlation of both techniques for the quantification of ABL1 mutations was high (Pearson r = 0.858, p < 0.001), offering DNA-DeepNGS a sensitivity of 92% and specificity of 82%. The clinical impact was studied in a cohort of 129 patients (n = 67 for CML and n = 62 for B-ALL patients). A total of 162 samples (n = 86 CML and n = 76 B-ALL) were studied. Of them, 27 out of 86 harbored mutations (6 in warning and 21 in failure) for CML, and 13 out of 76 (2 diagnostic and 11 relapse samples) did in B-ALL patients. In addition, in four cases were detected mutation despite BCR::ABL1 < 1%. In conclusion, we were able to detect KD ABL1 mutations with a 1.0E−4 sensitivity by NGS using DNA as starting material even in patients with low levels of disease.Tis project was funded in part by CRIS CANCER FOUNDATION
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