Lozada Flores, Octavio
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Preferred name
Lozada Flores, Octavio
Official Name
Lozada Flores, Octavio
Alternative Name
olozada
Lozada-Flores, O.
Main Affiliation
ORCID
Scopus Author ID
57192956110
Researcher ID
DWQ-8121-2022

Research Output
Now showing 1 - 10 of 10
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Data-Driven Innovation for Intelligent Technology : Perspectives and Applications in ICT

2024 , Ponce, Hiram , Brieva, Jorge , Lozada Flores, Octavio , Martinez-Villaseñor, Lourdes , Moya-Albor, Ernesto , Hiram Ponce , Jorge Brieva , Octavio Lozada-Flores , Lourdes Martínez-Villaseñor , Ernesto Moya-Albor

This book focuses on new perspectives and applications of data-driven innovation technologies, applied artificial intelligence, applied machine learning and deep learning, data science, and topics related to transforming data into value. It includes theory and use cases to help readers understand the basics of data-driven innovation and to highlight the applicability of the technologies. It emphasizes how the data lifecycle is applied in current technologies in different business domains and industries, such as advanced materials, healthcare and medicine, resource optimization, control and automation, among others. This book is useful for anyone interested in data-driven innovation for smart technologies, as well as those curious in implementing cutting-edge technologies to solve impactful artificial intelligence, data science, and related information technology and communication problems. ©Springer. ©The authors. ©The editors

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Design of Promising Uranyl(VI) Complexes Thin Films with Potential Applications in Molecular Electronics

2024 , Monzón González, César Raúl , Sánchez Vergara, María Elena , Elías-Espinosa, Milton Carlos , Rodríguez-Valencia, Sergio Arturo , Byron José López‐Mayorga , López-Mayorga, Byron José , Castillo-Arroyave, José León , Toscano, Rubén Alfredo , Lozada Flores, Octavio , Álvarez Toledano, Cecilio

In this work, it is proposed the development of organic semiconductors (OS) based on uranyl(VI) complexes. The above by means of the synthesis and the characterization of the complexes by Infrared spectroscopy, Nuclear magnetic resonance spectroscopy, mass spectrometry, and X-ray diffraction. Films of these complexes were deposited and subsequently, topographic and structural characterization was carried out by Scanning Electron Microscopy, X-ray diffraction, and Atomic Force Microscopy. Additionally, the nanomechanical evaluation was performed to know the stiffness of uranyl films using their modulus of elasticity. Also, the optical characterization took place in the devices and their bandgap value ranges between 2.40 and 2.93 eV being the minor for the film of the uranyl complex with the N on pyridine in position 4 (2 c). Finally, the electrical behavior of the uranyl(VI) films was evaluated, and important differences were obtained: the uranyl complex with the N on pyridine in position 2 (2 a) film is not influenced by changes in lighting and its current density is in the order of 10-3 A/cm2 . The film with uranyl complex with the N on pyridine in position 3 (2 b) and 2 c presents a greater current flow under lighting conditions and two orders of magnitude larger than in film 2 a. In these films 2 b and 2 c, ohmic behavior occurs at low voltages, while at high voltages the charge transport changes to space-charge limited current behavior. © 2024 The Authors. ChemistryOpen published by Wiley-VCH GmbH.

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Influence of the Polymeric Matrix on the Optical and Electrical Properties of Copper Porphine-Based Semiconductor Hybrid Films

2023 , Sánchez Vergara, Maria Elena , Hernández Méndez, Joaquín André , González Verdugo, Daniela , Giammattei Funes, Isabella María , Lozada Flores, Octavio

In this study, we assessed the electrical and optical behavior of semiconductor hybrid films fabricated from octaethyl-21H,23H-porphine copper (CuP), embedded in polymethylmethacrylate (PMMA), and polystyrene (PS). The hybrid films were characterized structurally and morphologically using infrared spectroscopy (IR), atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Subsequently, the PMMA:CuP and PS:CuP hybrid films were evaluated optically by UV–vis spectroscopy, as well as electrically, with the four-point collinear method. Hybrid films present a homogeneous and low roughness morphology. In addition, the PS matrix allows the crystallization of the porphin, while PMMA promotes the amorphous structure in CuP. The polymeric matrix also affects the optical behavior of the films, since the smallest optical gap (2.16 eV) and onset gap (1.89 eV), and the highest transparency are obtained in the film with a PMMA matrix. Finally, the electrical behavior in hybrid films is also affected by the matrix: the largest amount of current carried is approximately 0.01 A for the PS:CuP film, and 0.0015 A for the PMMA:CuP film. Thanks to the above properties, hybrid films are promising candidates for use in optoelectronic devices.

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High-Temperature Precipitation Design-of-Experiments Simulation in Low-Alloy Cr–Mo–Ni Hot Forging Steel

2021 , Gonzalez-Ojeda, Roberto , Lozada Flores, Octavio , Gonzalez-Reyes, Gonzalo , Sanchez-Moreno, Jose Manuel

The role of alloying elements such as Cr, Mo and Mn on low-alloy 8620 steel during hot forging operations is not yet clear, as, during deformation in the 1000~1100◦C temperature range, the austenite grain size remains small, ensuring the capacity of the forged part to be subsequently modified by surface hardening procedures. This work analyzed a deformed bar considering hardness at different geometry zones, along with SEM and TEM microstructures of previous austenite grains and lamellar martensite spacing. Moreover, Thermocalc simulations of M7C3, M23C6 and MnS precipitation were combined with Design of Experiments (DOE) in order to detect the sensitivity and significant variables. The values of the alloying elements’ percentages were drastically modified, as nominal values did not produce precipitation, and segregation at the austenite matrix may have been responsible for short-term, nanometric precipitates producing grain growth inhibition. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

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Preparation of Hybrid Films Based in Aluminum 8-Hydroxyquinoline as Organic Semiconductor for Photoconductor Applications

2023 , Sánchez Vergara, María Elena , Cantera Cantera, Luis Alberto , Ríos, Citlalli , Salcedo, Roberto , Lozada Flores, Octavio , Dutt, Ateet

In the present work, we have investigated an organic semiconductor based on tris(8-hydroxyquinoline) aluminum (AlQ3) doped with tetracyanoquinodimethane (TCNQ), which can be used as an organic photoconductor. DFT calculations were carried out to optimize the structure of semiconductor species and to obtain related constants in order to compare experimental and theoretical results. Subsequently, AlQ3-TCNQ films with polypyrrole (Ppy) matrix were fabricated, and they were morphologically and mechanically characterized by Scanning Electron Microscopy, X-ray diffraction and Atomic Force Microscopy techniques. The maximum stress for the film is 8.66 MPa, and the Knoop hardness is 0.0311. The optical behavior of the film was also analyzed, and the optical properties were found to exhibit two indirect transitions at 2.58 and 3.06 eV. Additionally, photoluminescence measurements were carried out and the film showed an intense visible emission in the visible region. Finally, a photoconductor was fabricated and electrically characterized. Applying a cubic spline approximation to fit cubic polynomials to the J-V curves, the ohmic to SCLC transition voltage VON and the trap-filled-limit voltage VTFL for the device were obtained. Then, the free carrier density and trap density for the device were approximated to n0=4.4586×10191m3 and Nt=3.1333×10311m3, respectively.

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Effect of Mo on high entropy Ti-Nb-Zr-Ta alloy: Phase equilibria, microstructure and mechanical properties

2023 , Aranda, Víctor A. , Figueroa, I. A. , Amigó-Borrás, V. , Gonzalez-Ojeda, Roberto , Lozada Flores, Octavio , Vidilli, André Luiz , Barcelos Otani, Lucas , González, Gonzalo

Thermal and mechanical properties of Ti-Nb-Ta-Zr high entropy alloys are often influenced by element content and manufacturing routes, producing significant differences between mechanical properties and microstructure. This work presents a Ti-Nb-Ta-Zr alloy in which Mo is added by adjusting the composition with phase equilibria simulation, improving the mechanical properties based on a mixture of two chemically different solid solutions (BCC1 and BCC2). The materials were produced by arc-melting suction casting. Characterization of the dendritic and interdendritic zones was carried out by means of X-ray spectroscopy, indicating the segregation of Ta and Nb in BCC1 and Zr and Ti in BCC2 phases. The dislocation density increased preferentially in the interdendritic Zr-Ti rich zones. The mechanical properties results were related to the chemical differences between the BCC1 and BCC2 lattice parameters induced by the Mo addition. With Mo segregating between both BCC cells, the resulting microstructure increased the yield strength, being confirmed with the kernel average maps, which showed that, after compression tests, the interdendritic zone accumulated a high density of dislocations, resulting in the segregation of Ti and Zr, affecting the mechanical response of Mo containing alloy. © 2023 Elsevier B.V.

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Enhancing STEAM in Education 4.0: A Review of Data-Driven Technological Improvements

2024-01-01 , Escobar Castillejos, David , Barrera Ánimas, Ari Yair , Lozada Flores, Octavio , Noguez, Julieta

Universities have fulfilled the role of organizations dedicated to the promotion of intellectual knowledge and the fostering of creative thinking. Educational institutions function as the central place for students to acquire specialized knowledge in their respective disciplines, while also developing competencies and beliefs that contribute to the progress of society. As technology advances, universities are facing a new revolution in the paradigms of education, which is making them adapt their established methodologies. Education 4.0 aims to improve education through cutting-edge technology and automation. Furthermore, the use of data-driven methodologies allows educators to automate the processes of assessment and evaluation, which could enhance the accuracy of comprehending educational outcomes. Universities are currently promoting the integration of analytical reasoning and creative expression using multidisciplinary techniques such as STEAM. This approach ensures that students not only acquire technical expertise, but also develop the essential skills of creativity, adaptability, and humanistic understanding that are necessary in the current job market. The objective of this chapter is to discuss the development and importance of STEAM within Education 4.0, emphasizing the potential of data-driven technologies. ©Springer

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Improving engineering students’ understanding of classical physics through visuo-haptic simulations

2024 , Guillermo Mena Sánchez , Lozada Flores, Octavio , Murrieta Caballero, Dione , Noguez, Julieta , Escobar Castillejos, David

Introduction: The teaching process plays a crucial role in the training of professionals. Traditional classroom-based teaching methods, while foundational, often struggle to effectively motivate students. The integration of interactive learning experiences, such as visuo-haptic simulators, presents an opportunity to enhance both student engagement and comprehension. Methods: In this study, three simulators were developed to explore the impact of visuo-haptic simulations on engineering students’ engagement and their perceptions of learning basic physics concepts. The study used an adapted end-user computing satisfaction questionnaire to assess students’ experiences and perceptions of the simulators’ usability and its utility in learning. Results: Feedback from participants suggests a positive reception towards the use of visuo-haptic simulators, highlighting their usefulness in improving the understanding of complex physics principles. Discussion: Results suggest that incorporating visuo-haptic simulations into educational contexts may offer significant benefits, particularly in STEM courses, where traditional methods may be limited. The positive responses from participants underscore the potential of computer simulations to innovate pedagogical strategies. Future research will focus on assessing the effectiveness of these simulators in enhancing students’ learning and understanding of these concepts in higher-education physics courses.

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Organic Semiconductor Devices Fabricated with Recycled Tetra Pak®-Based Electrodes and para-Quinone Methides

2024 , Sánchez Vergara, María Elena , Santillán Esquivel, Eva Alejandra , Ballinas-Indilí, Ricardo , Lozada Flores, Octavio , Miranda-Ruvalcaba, René , Álvarez-Toledano, Cecilio

This work presents the synthesis of para-quinone methides (p-QMs), which were deposited as films using the high vacuum sublimation technique after being chemically characterized. The p-QMs films were characterized morphologically and structurally using scanning electron microscopy, atomic force microscopy, and X-ray diffraction. In addition, their optical behavior was studied by means of ultraviolet–visible spectroscopy, and the optical gaps obtained were in the range of 2.21–2.71 eV for indirect transitions, indicating the semiconductor behavior of the p-QMs. The above was verified through the manufacture and evaluation of the electrical behavior of rigid semiconductor devices, in which fluorine-doped tin oxide-coated glass slides (FTO) were used as an anode and substrate. Finally, as an original, ecological, and low-cost application, the FTO was replaced by substrates and anodes made from recycled Tetra Pak®, generating flexible semiconductor devices. Although the electrical current transported depends on the type of p-QMs, the substituent in its structure, and the morphology, the kinds of substrate and anode also influence the type of electrical behavior of the device. This current–voltage study demonstrates that p-QM2 with 4-Cl-Ph as a radical, p-QM3 with 4-Et2N-Ph as a radical, and p-QM6 with 5-(1,3-benzodioxol) as a radical can be used in optoelectronics as semiconductor films. ©The authors ©MDPI

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Microstructural, microscratch and nanohardness mechanical characterization of secondary commercial HPDC AlSi9Cu3-type alloy

2020 , Salas Reyes, Antonio Enrique , Altamirano Guerrero, Gerardo , Rodríguez Ortiz, Gabriel , Reyes Gasga, José , García Robledo, Jaime Francisco , Lozada Flores, Octavio , Costa, Patricia Sheilla

A key issue in producing high quality aluminum automotive components using High-Pressure Die Casting (HPDC) process is minimizing the amount of imperfections. In the present research work, by means of optical microscopy (OM), SEM, TEM and AFM characterization techniques, microstructural evolution of secondary commercial HPDC AlSi9Cu3-type alloy was studied. For this purpose, one Al-alloy called C1 containing nominal composition and a second one called C2 going out of specification were employed. In addition to metallographic characterization, Vickers and nanohardness and microscratch mechanical testing techniques were applied to analyze material behavior. Furthermore, complementary thermodynamic calculations were done to estimate alloy phases precipitation as function of temperature. Results indicate that globular and ramified dendrites are developed in C1 and C2 Al-alloys, respectively, due the major solidification time between them. In fact, gas porosity and shrinkage microporosity were detected. α-Fe particle increased in size but not in volume fraction, as Al2Cu and β-Fe intermetallics do. Mostly, it was found that α-Fe particle growth following a coring behavior, formed by nanospherical particles. Thus, main shrinkage microporosity is associated with Al2Cu precipitate, where shrinkage pores in alloy C2 present several nanoparticles located between dendrite arms, identify by SEM and TEM analysis. Finally, hardness of alloys differs in 30 HV values due intermetallics population, whereas nanohardness allowed measuring single value of each phase. Because no major nanohardness differences were observed, microscratch resistance behaves similar in both alloys. Hence, present microstructural/mechanical characterization results can be taken into account for redesign and improving commercial HPDC Al-components.

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