2019
Authors
Martins, RC; Magalhães, S; Jorge, P; Barroso, T; Santos, F;
Publication
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Abstract
Metabolomics is paramount for precision agriculture. Knowing the metabolic state of the vine and its implication for grape quality is of outermost importance for viticulture and wine industry. The MetBots system is a metabolomics precision agriculture platform, for automated monitoring of vineyards, providing geo-referenced metabolic images that are correlated and interpreted by an artificial intelligence self-learning system for aiding precise viticultural practices. Results can further be used to analyze the plant metabolic response by genome-scale models. In this research, we introduce the system main components: (i) robotic platform; (ii) autonomous navigation; (iii) sampling arm manipulation; (iv) spectroscopy systems; and (v) non-invasive, real-time metabolic hyper-spectral imaging monitoring of vineyards. The full potential of the Metbots system is revealed when metabolic data and images are analyzed by big data AI and systems biology vine plant models, establishing a new age of molecular biology precision agriculture. © Springer Nature Switzerland AG 2019.
2019
Authors
Fujiwara, E; Hayashi, JG; Delfino, TD; Jorge, PAS; de Barros Cordeiro, CMD;
Publication
IEEE SENSORS JOURNAL
Abstract
An optical fiber anemometer based on a flexible multi-FBG curvature sensor is reported. The probe is comprised of a structured polymer shell with embedded single-mode fibers with written fiber Bragg gratings. When the sensor is bent, the different spectral shift of the Bragg wavelengths allows the determination of the mechanical stimulus. Moreover, the probe was also used as a cantilever sensor for assessing the airflow speed in a wind tunnel. The sensor presented sensitivities of 0.8 nm/m(-1) and 1.05 pm/(m/s) for curvature and square speed measurements, respectively, and the sensing characteristics can be improved by simply changing the material and the geometry of the bulk polymer shell, providing a versatile and feasible probe for the mechanical and flow measurements.
2019
Authors
Monteiro Silva, F; Jorge, PAS; Martins, RC;
Publication
CHEMOSENSORS
Abstract
The feasibility of a compact, modular sensing system able to quantify the presence of nitrogen, phosphorus and potassium (NPK) in nutrient-containing fertilizer water was investigated. Direct UV-Vis spectroscopy combined with optical fibers were employed to design modular compact sensing systems able to record absorption spectra of nutrient solutions resulting from local producer samples. N, P, and K spectral interference was studied by mixtures of commercial fertilizer solutions to simulate real conditions in hydroponic productions. This study demonstrates that the use of bands for the quantification of nitrogen with linear or logarithmic regression models does not produce analytical grade calibrations. Furthermore, multivariate regression models, i.e., Partial Least Squares (PLS), which consider specimens interference, perform poorly for low absorbance nutrients. The high interference present in the spectra has proven to be solved by an innovative self-learning artificial intelligence algorithm that is able to find interference modes among a spectral database to produce consistent predictions. By correctly modeling the existing interferences, analytical grade quantification of N, P, and K has proven feasible. The results of this work open the possibility of real-time NPK monitoring in Micro-Irrigation Systems.
2019
Authors
Mendes, JP; Coelho, L; Kovacs, B; de Almeida, JMMM; Pereira, CM; Jorge, PAS; Borges, MT;
Publication
SENSORS
Abstract
A sensing configuration for the real-time monitoring, detection, and quantification of dissolved carbon dioxide (dCO(2)) was developed for aquaculture and other applications in freshwater and saline water. A chemical sensing membrane, based on a colorimetric indicator, is combined with multimode optical fiber and a dual wavelength light-emitting diode (LED) to measure the dCO(2)-induced absorbance changes in a self-referenced ratiometric scheme. The detection and processing were achieved with an embeded solution having a mini spectrometer and microcontroller. For optrode calibration, chemical standard solutions using sodium carbonate in acid media were used. Preliminary results in a laboratory environment showed sensitivity for small added amounts of CO2 (0.25 mg.L-1). Accuracy and response time were not affected by the type of solution, while precision was affected by salinity. Calibration in freshwater showed a limit of detection (LOD) and a limit of quantification (LOQ) of 1.23 and 1.87 mg.L-1, respectively. Results in saline water (2.5%) showed a LOD and LOQ of 1.05 and 1.16 mg.L-1, respectively. Generally, performance was improved when moving from fresh to saline water. Studies on the dynamics of dissolved CO2 in a recirculating shallow raceway system (SRS+RAS) prototype showed higher precision than the tested commercial sensor. The new sensor is a compact and robust device, and unlike other sensors used in aquaculture, stirring is not required for correct and fast detection. Tests performed showed that this new sensor has a fast accurate detection as well as a strong potential for assessing dCO(2) dynamics in aquaculture applications.
2019
Authors
Vasconcelos, H; Almeida, JMMMd; Saraiva, C; Jorge, PAS; Coelho, L;
Publication
Proceedings
Abstract
2019
Authors
Guimaraes, D; Ferreira, MFS; Ribeiro, R; Dias, C; Lima, A; Martins, RC; Jorge, PAS;
Publication
FOURTH INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS
Abstract
A high-resolution advanced laser induced breakdown spectroscopy prototype was used to quantify lithium (Li) in lithiniferous rocks. Samples were collected from Barroso's mine (Portugal), claimed as Western Europe's largest spodumene Li discovery. 51 samples from a reverse circulation drill were collected, one for each meter interval, dried, milled, pressed into pellets and further analyzed by laser induced breakdown spectroscopy. Quantification was attempted using either linear models based on the intensity of selected Li spectral lines or advanced chemometrics methods. The latter was very successful, with correlation coefficients of 0.97 against certified laboratory results.
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