Thermal modulation spectroscopy for bandgap determination in plasma-assisted molecular beam epitaxy-grown AlN E. A. Contreras, L. Vargas-Hernández, M. A. Zambrano-Serrano, R. Trejo-Hernández, H. Félix-Quintero, J. C. Avila-Gaxiola, Y. L. Casallas-Moreno, C. M. Yee-Rendón, M. López-López Journal of Vacuum Science and Technology A Vacuum Surfaces and Films, 2026 A thermal modulation reflectance (TMR) technique is developed and implemented as a contactless, nondestructive optical characterization method for wide-bandgap semiconductor thin films. The physical principles underlying TMR are presented and applied to AlN films grown on Si(111) substrates by plasma-assisted molecular beam epitaxy. The influence of the Al/N growth ratio on the structural, optical, and morphological properties of the films is systematically investigated. The films exhibit a predominantly planar surface morphology with some hillocklike features. TMR measurements enable the determination of the optical bandgap of AlN. A correlation is observed between the bandgap and the Al/N growth ratio. As the samples approach stoichiometric conditions (Al/N = 1), the bandgap energy increases, reaching a maximum value of 6.07 eV.
Feature comparison from laser speckle imaging as a novel tool for identifying infections in tomato leaves H. Félix-Quintero, J.C. Avila-Gaxiola, J.R. Millan-Almaraz, C.M. Yee-Rendón Smart Agricultural Technology, 2024 • Laser Speckle imaging differentiates healthy and diseased leaves non-invasively. • Leaf degradation over time shown by reduced feature vector distances in one week. • Apple's Vision library validated for effective plant disease diagnosis and health tracking. In the present work we propose the use of laser speckle imaging as non-invasive and marker-free qualitative technique that highlights significant differences between healthy and diseased leaves through image analysis. We observed distinct visual variations, indicating the detectable impact of viral infection on leaf structure. Additionally, leaves tend to homogenize visually over time due to degradation, as evidenced by decreased measured feature vector distances after a week. Statistical analyses, including MANOVA and ANOVA, underscored the significance of parameters like contrast, energy, and variance in distinguishing leaf health states. These findings emphasize the potential of laser speckle imaging for plant health monitoring. Furthermore, our results validate the utility of Apple's Vision library, specifically the VNGenerateImageFeaturePrintRequest() function, as a powerful tool for plant disease diagnosis and health tracking.
Effect of Drying Temperature on Agave tequilana Leaves: A Pretreatment for Releasing Reducing Sugars for Biofuel Production Evangelina Avila‐Gaxiola, Jorge Avila‐Gaxiola, Oscar Velarde‐Escobar, Francisco Ramos‐Brito, Gelacio Atondo‐Rubio, Cristo Yee‐Rendon Journal of Food Process Engineering, 2017 The leaves of Agave tequilana Weber variety Blue represent a viable, inexpensive, and renewable source of lignocellulosic biomass and fructans for the production of second generation biofuels. The objective was to study the effect of drying temperature on the release of reducing sugars for the agave leaves. It was found that with pretreatment‐drying at 100°C for 30.5 ± 1.0 min had a maximum of the release of reducing sugars with a 66% increment compared to 60°C. An aqueous extract obtained from the powder of the leaves after drying did not show the presence of furfural and hydroxymethylfurfural compounds. Phenolic compounds were detected in order of 120.8 ± 1.0 mg L−1 below 1 g L−1 reported to cause inhibition of the alcoholic fermentation. In addition the drying of the leaves also can be used as preservation of agave leaf for biomass storing. The results show that pretreatment‐drying allow increase the release of reducing sugars, avoids thermal degradation and does not produce significant concentrations of fermentation inhibitors.Practical ApplicationsThe research in industrial waste materials has received special attention worldwide because it is potential for production of biofuels. This study propose a simple method of drying that acts as a thermal pretreatment of Agave tequilana Weber variety Blue leaves that increases the release of reducing sugars, avoids thermal degradation, not produce significant concentrations of fermentation inhibitors for ethanol production and can be used as a preservation method for storing biomass of the agave leaves. The results would be useful not only in the energy field but also in the alimentary and pharmaceutical industry. Fructans and phenolic compounds found in the agave are used as functional ingredients in the food industry and also bioactive compounds that by themselves promotes future research for the Agave tequilana.
RECENT SCHOLAR PUBLICATIONS
Thermal modulation spectroscopy for bandgap determination in plasma-assisted molecular beam epitaxy-grown AlN EA Contreras, L Vargas-Hernández, MA Zambrano-Serrano, ... Journal of Vacuum Science & Technology A 44 (3) , 2026 2026.0
Magnetic map of Cr adatom, Cr dimer and Cr–O on Co (0001) hcp: first principles calculations JC Ávila-Gaxiola, MEE Ávila-Gaxiola, JG Ibarra-Armenta, S Meza-Aguilar The European Physical Journal B 98 (6), 129 , 2025 2025.0
Feature comparison from laser speckle imaging as a novel tool for identifying infections in tomato leaves H Félix-Quintero, JC Avila-Gaxiola, JR Millan-Almaraz, CM Yee-Rendón Smart Agricultural Technology 9, 100603 , 2024 2024.0 Citations: 6
A magnetic map of O/Fe/Mn/Fe (001) multilayer with DFT+ U scheme JC Avila-Gaxiola, JG Ibarra-Armenta, RE Félix-Medina, S Meza-Aguilar, ... Surface Science 718, 122006 , 2022 2022.0 Citations: 6
Ethanol production from Agave tequilana leaves powder by Saccharomyces cerevisiae yeast applying enzymatic saccharification without detoxification JC Avila-Gaxiola, E Avila-Gaxiola Industrial Crops and Products 177, 114515 , 2022 2022.0 Citations: 11
Treatments to improve obtention of reducing sugars from agave leaves powder J Avila-Gaxiola, OJ Velarde-Escobar, JR Millan-Almaraz, F Ramos-Brito, ... Industrial Crops and Products 112, 577-583 , 2018 2018.0 Citations: 18
Effect of Drying Temperature on Agave tequilana Leaves: A Pretreatment for Releasing Reducing Sugars for Biofuel Production E Avila‐Gaxiola, J Avila‐Gaxiola, O Velarde‐Escobar, F Ramos‐Brito, ... Journal of Food Process Engineering 40 (3), e12455 , 2017 2017.0 Citations: 24
Ferromagnetism and 2D-surface ordered alloy formation in MnxFe1-x monolayer on MgO (001) surface JC Ávila-Gaxiola, JU Gallardo Zazueta, FC Delgado Nieblas, ... Available at SSRN 6238081 , 0
Smart Agricultural Technology H Félix-Quintero, JC Avila-Gaxiola, JR Millan-Almaraz, CM Yee-Rendón
MOST CITED SCHOLAR PUBLICATIONS
Effect of Drying Temperature on Agave tequilana Leaves: A Pretreatment for Releasing Reducing Sugars for Biofuel Production E Avila‐Gaxiola, J Avila‐Gaxiola, O Velarde‐Escobar, F Ramos‐Brito, ... Journal of Food Process Engineering 40 (3), e12455 , 2017 2017.0 Citations: 24
Treatments to improve obtention of reducing sugars from agave leaves powder J Avila-Gaxiola, OJ Velarde-Escobar, JR Millan-Almaraz, F Ramos-Brito, ... Industrial Crops and Products 112, 577-583 , 2018 2018.0 Citations: 18
Ethanol production from Agave tequilana leaves powder by Saccharomyces cerevisiae yeast applying enzymatic saccharification without detoxification JC Avila-Gaxiola, E Avila-Gaxiola Industrial Crops and Products 177, 114515 , 2022 2022.0 Citations: 11
Feature comparison from laser speckle imaging as a novel tool for identifying infections in tomato leaves H Félix-Quintero, JC Avila-Gaxiola, JR Millan-Almaraz, CM Yee-Rendón Smart Agricultural Technology 9, 100603 , 2024 2024.0 Citations: 6
A magnetic map of O/Fe/Mn/Fe (001) multilayer with DFT+ U scheme JC Avila-Gaxiola, JG Ibarra-Armenta, RE Félix-Medina, S Meza-Aguilar, ... Surface Science 718, 122006 , 2022 2022.0 Citations: 6
Thermal modulation spectroscopy for bandgap determination in plasma-assisted molecular beam epitaxy-grown AlN EA Contreras, L Vargas-Hernández, MA Zambrano-Serrano, ... Journal of Vacuum Science & Technology A 44 (3) , 2026 2026.0
Magnetic map of Cr adatom, Cr dimer and Cr–O on Co (0001) hcp: first principles calculations JC Ávila-Gaxiola, MEE Ávila-Gaxiola, JG Ibarra-Armenta, S Meza-Aguilar The European Physical Journal B 98 (6), 129 , 2025 2025.0
Ferromagnetism and 2D-surface ordered alloy formation in MnxFe1-x monolayer on MgO (001) surface JC Ávila-Gaxiola, JU Gallardo Zazueta, FC Delgado Nieblas, ... Available at SSRN 6238081 , 0
Smart Agricultural Technology H Félix-Quintero, JC Avila-Gaxiola, JR Millan-Almaraz, CM Yee-Rendón
