276 research outputs found
Carbon Paste Electrodes Made from Different Carbonaceous Materials: Application in the Study of Antioxidants
This work describes the sensing properties of carbon paste electrodes (CPEs) prepared from three different types of carbonaceous materials: graphite, carbon microspheres and carbon nanotubes. The electrochemical responses towards antioxidants including vanillic acid, catechol, gallic acid, l-ascorbic acid and l-glutathione have been analyzed and compared. It has been demonstrated that the electrodes based on carbon microspheres show the best performances in terms of kinetics and stability, whereas G-CPEs presented the smallest detection limit for all the antioxidants analyzed. An array of electrodes has been constructed using the three types of electrodes. As demonstrated by means of Principal Component Analysis, the system is able to discriminate among antioxidants as a function of their chemical structure and reactivity
Enose lab made with vacuum sampling: quantitative applications
A lab-made electronic nose (Enose) with vacuum sampling and a sensor array, comprising
nine metal oxide semiconductor Figaro gas sensors, was tested for the quantitative analysis of
vapor–liquid equilibrium, described by Henry’s law, of aqueous solutions of organic compounds:
three alcohols (i.e., methanol, ethanol, and propanol) or three chemical compounds with different
functional groups (i.e., acetaldehyde, ethanol, and ethyl acetate). These solutions followed a fractional
factorial design to guarantee orthogonal concentrations. Acceptable predictive ridge regression
models were obtained for training, with RSEs lower than 7.9, R2 values greater than 0.95, slopes
varying between 0.84 and 1.00, and intercept values close to the theoretical value of zero. Similar
results were obtained for the test data set: RSEs lower than 8.0, R2 values greater than 0.96, slopes
varying between 0.72 and 1.10, and some intercepts equal to the theoretical value of zero. In addition,
the total mass of the organic compounds of each aqueous solution could be predicted, pointing
out that the sensors measured mainly the global contents of the vapor phases. The satisfactory
quantitative results allowed to conclude that the Enose could be a useful tool for the analysis of
volatiles from aqueous solutions containing organic compounds for which Henry’s law is applicable.The authors are grateful to the Foundation for Science and Technology (FCT,
Portugal) and FED-ER under Programme PT2020 for financial support by national funds FCT/MCTES
to CIMO (UID/AGR/00690/2019) and SusTEC (LA/P/0007/2020)info:eu-repo/semantics/publishedVersio
Breast Cancer Detection by Means of Artificial Neural Networks
Breast cancer is a fatal disease causing high mortality in women. Constant efforts are being made for creating more efficient techniques for early and accurate diagnosis. Classical methods require oncologists to examine the breast lesions for detection and classification of various stages of cancer. Such manual attempts are time consuming and inefficient in many cases. Hence, there is a need for efficient methods that diagnoses the cancerous cells without human involvement with high accuracies. In this research, image processing techniques were used to develop imaging biomarkers through mammography analysis and based on artificial intelligence technology aiming to detect breast cancer in early stages to support diagnosis and prioritization of high-risk patients. For automatic classification of breast cancer on mammograms, a generalized regression artificial neural network was trained and tested to separate malignant and benign tumors reaching an accuracy of 95.83%. With the biomarker and trained neural net, a computer-aided diagnosis system is being designed. The results obtained show that generalized regression artificial neural network is a promising and robust system for breast cancer detection. The Laboratorio de Innovacion y Desarrollo Tecnologico en Inteligencia Artificial is seeking collaboration with research groups interested in validating the technology being developed
Comunicación educación un campo de resistencias
El presente libro obedece a la imperiosa necesidad de desplegar
la potencia de la Facultad de Ciencias de la Comunicación en la
Corporación Universitaria Minuto de Dios -UNIMINUTO, de
otras comunidades académicas y de los espacios de movimiento
social interesados en deconstruir los discursos de comunicación y
educación desde la perspectiva del pensamiento crítico. En este caso
entendemos potencia como la fuerza individual y colectiva capaz
de rebasar la racionalidad dominante en la sociedad contemporánea,
colonizada por la economía como única mirada del mundo; esto es,
potencia como ímpetu insospechado por el poder.
Por otra parte, el libro tiene como eje articulador el concepto
de resistencia, definido este como el acto de recrear la realidad a
partir de las posibilidades que ofrece la comunicación, para generar
producción de sentido y dinamizar el cambio social. Propone realizar
el ejercicio de concebir el mundo desde una perspectiva diferente
a la hegemónica y de crear multiplicidades que trabajen unidas,
reconociendo sus diferencias pero vinculándose en un “lugar común”
del cual, cada una de ellas, regrese a su lugar cotidiano transformada
por la acción colectiva del campo de Comunicación - Educación
Comunicación educación un campo de resistencias
El presente libro obedece a la imperiosa necesidad de desplegar
la potencia de la Facultad de Ciencias de la Comunicación en la
Corporación Universitaria Minuto de Dios -UNIMINUTO, de
otras comunidades académicas y de los espacios de movimiento
social interesados en deconstruir los discursos de comunicación y
educación desde la perspectiva del pensamiento crítico. En este caso
entendemos potencia como la fuerza individual y colectiva capaz
de rebasar la racionalidad dominante en la sociedad contemporánea,
colonizada por la economía como única mirada del mundo; esto es,
potencia como ímpetu insospechado por el poder.
Por otra parte, el libro tiene como eje articulador el concepto
de resistencia, definido este como el acto de recrear la realidad a
partir de las posibilidades que ofrece la comunicación, para generar
producción de sentido y dinamizar el cambio social. Propone realizar
el ejercicio de concebir el mundo desde una perspectiva diferente
a la hegemónica y de crear multiplicidades que trabajen unidas,
reconociendo sus diferencias pero vinculándose en un “lugar común”
del cual, cada una de ellas, regrese a su lugar cotidiano transformada
por la acción colectiva del campo de Comunicación - Educación
Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions
We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe
Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV
Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe
Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV
Peer reviewe
Educación ambiental y sociedad. Saberes locales para el desarrollo y la sustentabilidad
EL LIBRO PERMITE REFLEXIONAR SOBRE LA IMPORTANCIA DE FOMENTAL LA EDUCACIÓN AMBIENTAL PARA RESOLVER LA PROBLEMÁTICA AMBIENTALEL LIBRO PRESENTA DIFERENTES TRABAJOS QUE ESTUDIAN EL TEMA D ELA SUSTENTABILIDAD, ENFATIZANDO LA IMPORTANCIA DE LA EDUCACIÓN AMBIENTAL Y LA TRANSDISCIPLINANINGUN
Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC
Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe
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