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artículo
Publicado 2025
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In recent years, the use of chatbots in higher education has grown significantly, driven by advances in artificial intelligence and its ability to optimize teaching and learning processes. This paper presents a systematic literature review aimed at identifying the main trends, approaches, and findings related to the use of chatbots in higher education. An exhaustive search was conducted across five highly reputable academic databases (Scopus, EBSCOhost, ScienceDirect, Taylor & Francis Online, and ARDI), yielding an initial total of 42,188 documents. After applying strict inclusion and exclusion criteria, 69 scientific papers were selected for detailed analysis. The findings reveal that the most widely used programming language in the development of educational chatbots is R (45.2%), followed by Python and Java (22.5% each). In addition, 66.6% of the analyzed papers were published in Q1 j...
2
artículo
Publicado 2014
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In the present investigation a simulation model was elaborated to propose and to evaluate improvements in a center of distribution of foods of human consumption. They took as indicators to evaluate the acting of the system; the level of service that perform the center, the time of answer, so much in the reception as the despatch and the operative costs. With the simulation model they were executed a series of experiments; as the plant layout of the warehouse, modifications in the reception processes and shipping, obtaining this way a configuration that the yield of the system increases in study in approximately 40%.
3
artículo
Publicado 2014
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In the present investigation a simulation model was elaborated to propose and to evaluate improvements in a center of distribution of foods of human consumption. They took as indicators to evaluate the acting of the system; the level of service that perform the center, the time of answer, so much in the reception as the despatch and the operative costs. With the simulation model they were executed a series of experiments; as the plant layout of the warehouse, modifications in the reception processes and shipping, obtaining this way a configuration that the yield of the system increases in study in approximately 40%.
4
artículo
Publicado 2021
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This work describes the aggregation process and explains the optical behavior of graphene oxide quantum dots (GOQDs) in different solvents using molecular dynamics, DFT, and experimental observations. The optical behavior of electrochemically synthesized GOQDs in different solvents was analyzed by UV–Vis spectroscopy, and dependence between the spectra and the solvents (water, ethanol, acetone, chloroform, toluene, and n-hexane) was found. Molecular dynamics methods were used to determine that the local structure of the solvent molecules and the nature of intermolecular forces between GOQDs dominate their aggregation state and their optical properties in each solvent. These computational studies based on liquid-liquid systems provide a fast and straightforward approach to develop synthesis and purification methods that allow tailored advanced optical properties of GOQDs. © 2021 Elsevi...
5
artículo
Publicado 2021
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In this work, the optical and electronic properties of a TiO2/graphene oxide quantum dots (GOQDs) composite were studied by experimental and computational methods. The experimental procedures were made on TiO2 and GOQDs nanoparticles synthesized by a sol-gel method and one-pot electrochemical carbonization, respectively. The characterization of these materials and the TiO2/GOQDs composite was made using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron microscopy (XPS), FT-IR spectroscopy, and dynamic light scattering (DLS). The experimental measurements of the optical properties of these materials by UV–Vis absorption spectroscopy indicate that the addition of GOQDs promotes the expansion of the radiation absorption of TiO2 towards the visible range. Similarly, photoelectrochemical tests performed to determine the electronic properties ...
6
artículo
Publicado 2022
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We have determined the 50 Lethal dose of the Metanolic extract of Plantago major "Llanten" given by intraperitoneal route. We have found that 50LD was 4000 mg/Kg. Of animal weigtht, using 36 mice divided in six groups with 6 animal s each one. 40 rats divided in four groups of ten animals each one received on the back 2 mI of carragenin 1 % to the air pouch. After 30 minutes, the extract and diclofenac were administered. Six hours afterwards the animal s were killed. The exudate obtained was used to find the leucocyte count in the Coulter Counter. The rest of the material was centrifuged to determine the concentracion of proteins with de Gornall colorimetric method using the Biuret reactive and a model of protein lof 70 g/L. We found the anti-inflammatory properties of the methanolic extract, administered by the intraperitoneal route 400 mg/Kg. and 800mg/Kg and with diclofenac using the ...
7
artículo
Publicado 2019
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Purpose: Hereditary Breast and Ovarian Cancer (HBOC) syndrome is responsible for ~5–10% of all diagnosed breast and ovarian cancers. Breast cancer is the most common malignancy and the leading cause of cancer-related mortality among women in Latin America (LA). The main objective of this study was to develop a comprehensive understanding of the genomic epidemiology of HBOC throughout the establishment of The Latin American consortium for HBOC-LACAM, consisting of specialists from 5 countries in LA and the description of the genomic results from the first phase of the study. Methods: We have recruited 403 individuals that fulfilled the criteria for HBOC from 11 health institutions of Argentina, Colombia, Guatemala, Mexico and Peru. A pilot cohort of 222 individuals was analyzed by NGS gene panels. One hundred forty-three genes were selected on the basis of their putative role in suscept...
8
artículo
Publicado 2014
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This work was supported by the Fermi National Accelerator Laboratory under U.S. Department of Energy Contract No. DE-AC02-07CH11359, which included the MINERvA construction project. Construction support was also granted by the United States National Science Foundation under Grant No. PHY-0619727 and by the University of Rochester. Support for participating scientists was provided by NSF and DOE (USA), by CAPES and CNPq (Brazil), by CoNaCyT (Mexico), by CONICYT (Chile), by CONCYTEC, DGI-PUCP and IDI/IGI-UNI (Peru), by Latin American Center for Physics (CLAF), and by RAS and the Russian Ministry of Education and Science (Russia). We thank the MINOS Collaboration for use of its near detector data. Finally, we thank the staff of Fermilab for support of the beam line and the detector.
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The MINERvA collaboration operated a scaled-down replica of thesolid scintillator tracking and sampling calorimeter regions of the MINERvA detector in a hadron test beam at the Fermilab Test Beam Facility. This paper reports measurements with samples of protons, pions, and electrons from 0.35 to 2.0 GeV/c momentum. The calorimetric response to protons, pions, and electrons is obtained from these data. A measurement of the parameter in Birks' law and an estimate of the tracking efficiency are extracted from the proton sample. Overall the data are well described by a Geant4-based Monte Carlo simulation of the detector and particle interactions with agreements better than 4% for the calorimetric response, though some features of the data are not precisely modeled. These measurements are used to tune the MINERvA detector simulation and evaluate systematic uncertainties in support of the MINE...
