Characterization of electrical crosstalk in 4T-APS arrays using TCAD simulations

TCAD simulations have been conducted on a CMOS image sensor in order to characterize the electrical component of the crosstalk between pixels through the study of the electric field distribution. The image sensor consists on a linear array of five pinned photodiodes (PPD) with their transmission gates, floating diffusion and reset transistors. The effect of the variations of the thickness of the epitaxial layer has been addressed as well. In fact, the depth of the boundary of the epitaxial layer affects quantum efficiency (QE) so a correlation with crosstalk has been identified.Ministerio de Economía y Competitividad TEC2015-66878-C3-1RJunta de Andalucía TIC 2012-2338Office of Naval Research (USA) N00014141035

An Experimentally-Validated Verilog-A SPAD Model Extracted from TCAD Simulation

Single-photon avalanche diodes (SPAD) are photodetectors with exceptional characteristics. This paper proposes a new approach to model them in Verilog-A HDL with the help of a powerful tool: TCAD simulation. Besides, to the best of our knowledge, this is first model to incorporate a trap-assisted tunneling mechanism, a cross-section temperature dependence of the traps, and the self-heating effect. Comparison with experimental data establishes the validity of the model.Junta de Andalucía TIC 2012-2338Ministerio de Economía y Competitividad TEC2015-66878-C3-1-ROffice of Naval Research (USA) N00014141035

Perceived Similarity With Gay Men Mediates the Effect of Antifemininity on Heterosexual Men’s Antigay Prejudice

This research examined the hypothesis that heterosexual men’s motivation to differentiate themselves from gay men mediates the relationship between the antifemininity norm of masculinity and antigay prejudice. We assessed masculinity through three concepts: status, thoughness, and antifemininity. Participants then reported their perceived similarity with gay men and their antigay prejudice. The results showed that antifemininity was the best predictor of both perceived similarity and antigay prejudice: The more people endorsed the antifemininity norm, the more they perceived themselves as dissimilar from gay men and showed antigay prejudice. More important, perceived similarity mediated the effect of antifemininity on antigay prejudice. These findings provide direct evidence for the link between masculinity and the motivation to differentiate oneself from gay men, and they suggest that antigay prejudice accomplishes the identity function of maintaining unambiguous gender boundaries

Tribological Properties of Ti6Al4V Titanium Textured Surfaces Created by Laser: Effect of Dimple Density

The loss of energy due to friction is one of the major problems industries are facing nowadays. Friction and wear between sliding components reduce the mechanical efficiency of machines and have a negative impact on the environment. In recent years, surface texturing has shown tremendous ability to reduce friction and wear. Micro-features generated on surfaces act as a secondary reservoir for lubricants and wear debris receptacles to further reduce abrasion. In addition, surface texturing boosts hydrodynamic pressure, which increases the elasto-hydrodynamic lubrication regime of the Stribeck curve, reducing friction and wear. Amongst all different techniques to texture surfaces, laser texturing is the most popular due to its advantages such as high accuracy, good consistency and celerity as compared to other techniques. This study investigated the effect of laser texturing on the tribological properties of Ti6Al4V in contact with a ceramic ball. The effect of varying the dimple density on friction and wear was studied using a ball-on-flat reciprocating tribometer under lubricated conditions. Results show that friction and wear were reduced for all the textured samples as compared to an untextured sample, with important friction and wear reductions for the samples with the highest dimple densities. For samples with intermediate dimple densities, the friction coefficient stayed low until the dimples wore out from the surface and then increased to a value similar to the friction coefficient of the untextured surface. The dimple wear-out time observed in these specimens was greatly influenced by the dimple density

Texturing design of WC-Co through laser parameter selection to improve lubricant retention ability of cutting tools

Laser Surface Texturing (LST) is widely used to modify hard material surfaces improving their physic-chemical and mechanical properties. This technology is particularly relevant for tungsten carbides, a material that requires high complexity methods when other micro-machining processes are used. LST allows innovative cutting tool designs that improve the machining behavior and enlarge the cutting tool lifetime. This research analyses the influence of LST parameters on the track dimensions, roughness, microstructure, hardness, and lubricant retention ability of the modified surfaces. Twelve combinations of energy density of pulse and scanning speed created different geometrical patterns on WC-Co surfaces. LST parameters were related to specific shape and dimensions of the linear grooves. Energy density was proven as the most influential parameter for dimensional characteristics and roughness values. Specific channel morphologies increased the lubricant expansion area up to 50%, leading the lubricant to a linear track direction. Low scanning speed and high energy density also increased the surface hardness up to 20%. The surface composition was also modified. The thermal effect of the laser treatments and the non-protective atmosphere increased the oxygen on the surface and modified the WC-Co microstructure. However, the thermal affected zone is considerably low compared to other texturing processes. © 2022 The AuthorsThis work was supported by the Spanish Government ( MINECO/AEI/FEDER , Grant Project DPI2017–84935-R )

Nanosecond Pulsed Laser Irradiation of Titanium Alloy Substrate: E ects of Periodic Patterned Topography on the Optical Properties of Colorizing Surfaces

Most of the current works based on surface treatments of metals by laser marking technology are focused on the modification of the color tonality of flat surfaces, or the development of specific topography features, but the combination of both processes is not usually evaluated, mainly due to the complexity of controlling the optical properties on rough surfaces. This research presents an analysis of the influence of the micro-geometrical characteristics of periodic patterned laser tracks on the chromaticity and reflectance of Ti6Al4V substrates. The samples were irradiated with an infrared nanosecond pulsed laser in air atmosphere, taking as the control parameter the scan speed of the beam. A roughness evaluation, microscopic inspection, and absorption and chromaticity examination were conducted. Although micro-crack growth was detected in an isolated case (10 mm/s), the possibility of adjusting the result color was demonstrated by controlling the heat-a ected zone thickness of the textures. The results of rough/colored combined textures allow new perspectives in industrial design to open, particularly in aesthetic applications with special properties

Evaluation of the Joining Response of Biodegradable Polylactic Acid (PLA) from Fused Deposition Modeling by Infrared Laser Irradiation

The development of high-complexity geometry parts is one of the main goals of additive manufacturing technology. However, the failure of printed structures and the joining of different parts to create complex assemblies represents a real challenge in the research of efficient and sustainability techniques for the permanent assembly of polymers. Laser welding processes have been used as a single-step method to join metals for years. Nowadays, the growing trend in the use of thermoplastics for additive manufacturing has led to the need to adapt this technique to materials with a very specific nature and which are more sensitive to thermal effects. In addition, the possibility of transmitting the laser beam through transparent polymer layers allows to us focus the energy supply on internal sections of the assembled components. In this research, an infrared laser marking system was used to join two different samples of polylactic acid manufactured by fused deposited modeling technology. In order to increase the effectiveness of the bonding process, a transparent and a dark sample have been used as assembly material, focusing the laser beam on the interface area of the two parts. By means of tensile tests, dimensional measurement and the use of optical microscopy techniques, a basis was established that links the supplied energy by laser to the joining performance

Identificación de estilos de aprendizaje de los alumnos: Análisis de resultados

El conocimiento de los estilos de aprendizaje que presentan los alumnos matriculados en nuestras clases, entendemos que es de vital importancia para poder desarrollar metodologías de aula, y elaborar actividades acordes con la/s tipología/s dominante/s, y adaptarlas a los demás grupos significativos. Esta práctica permitiría desarrollar al máximo (dentro de las posibilidades actuales) las capacidades, y en consecuencia el aprendizaje de los alumnos. En este trabajo se han estudiado los estilos de aprendizaje de una muestra representativa de alumnos, durante los cursos académicos 1999-00 y 2004-05, para a continuación establecer posibles correlaciones entre los diferentes estilos y el comportamiento de los alumnos en cada una de las asignaturas del primer curso de la titulación de Arquitectura Técnica de la Universidad de Sevilla.In order to develop methodological approaches for our classes we consider of the outmost importance having a wide knowledge of the different learning strategies shown by students enrolled in our courses, as well as creating a range of activities according to the prevalent tipologies with the aim of adapting them to the other significant groups. Such practice would allow to develop (within our current means) students´ capacities and, as a consecuence, learning. Learning strategies have been studied for this work taken from a student´s sampling done during the 1999-00 academic year and the 2004-05 one, so that possible correlations can be established among the different methodological approaches and students´ behaviour for each course corresponding to the first academic year leading to the degree in Technical Architecture from the University of Seville

Mejora del rendimiento en Ingeniería a través de blended-learning

This investigation was carried out at the School of Advanced Architectural Engineering at the University of Seville with students registered in Materials Science in Architectural Engineering. We aimed to analyse if significant statistical differences exist in academic results when students receive teaching via face-toface or blended learning methods to be able to adequately design new undergraduate teaching methodologies. The 212 students who make up the sample are those who receive both methods of teaching The design was preexperimental using only one group with pre-test and post-test as well as using descriptive and correlational methods as resources. The results indicate that statistically significant results exist in favour of blended learning. Esta investigación se ha realizado en la Escuela Técnica Superior de Ingeniería de Edificación de la Universidad de Sevilla, con alumnos matriculados en la asignatura Materiales de Construcción-I Se analiza si existen diferencias estadísticamente significativas en los resultados académicos cuando los alumnos reciben docencia en la modalidad blended-learning y presencial, para poder diseñar de manera adecuada las metodologías docentes de los nuevos estudios de grado. Los 212 alumnos que conforman la muestra, son los que reciben las dos modalidades de formación. El diseño ha sido pre-experimental de un solo grupo con pretest y postest, además de recurrir al método descriptivo y correlacional. Los resultados indican que existen diferencias estadísticamente significativas a favor del blended-learning

Aportes del ciclo de Kolb al pensamiento numérico del área de matemáticas de estudiantes de grado cuarto

1 recurso en línea (176 páginas) : ilustraciones color, tablas, gráficas.La investigación “Aportes del ciclo de Kolb al pensamiento numérico del área de matemáticas en estudiantes de grado cuarto de la I.E San Luis de Gaceno”. Tuvo como objetivo analizar los aportes del ciclo de Kolb en el desarrollo del pensamiento numérico en estudiantes de grado cuarto de la I.E San Luis de Gaceno; adicionalmente, se contrastaron los antecedentes investigativos de los últimos 15 años en Latinoamérica y específicamente en Colombia relacionados con los presupuestos teóricos de David Kolb (1984), Meintosh (1992), Jhon Dewey (1890) y Kut Lewin (1890). La investigación es de enfoque mixto (Sampieri, 2000) con enfasis en lo cualitativo (Taylor y Bogdan, 1984), en la Investigación Acción Educativa (Natalia Vallejos, 2015) y en la línea de investigación “Educación en Matemáticas”. La unidad de estudio fueron estudiantes con edades que oscilan entre los 10 y 12 años; los instrumentos de investigación se centraron en una revisión documental, pruebas de tipo SABER y de preguntas abiertas, test, talleres pedagógicos, observación directa y triangulación de datos. La investigación fortaleció conocimientos del pensamiento numérico, también se evidencia aportes en la creatividad y el compañerismo, es decir el ciclo de Kolb permite la construcción de aprendizajes significativos, promueve ambientes de aprendizaje en el aula donde ningún estudiante se sentirá excluido del conocimiento, podrán compartir y aplicar lo aprendido.Bibliografía y webgrafía: páginas 139-143.MaestríaMagíster en Educació