Phase-locking of a Nonlinear Optical Cavity via Rocking: Transmuting Vortices into Phase Patterns

We report experimental observation of the conversion of a phase-invariant nonlinear system into a phase-locked one via the mechanism of rocking [G. J. de Valcarcel and K. Staliunas, Phys. Rev. E 67, 026604 (2003)]. This conversion results in that vortices of the phase-invariant system are being replaced by phase patterns such as domain walls. The experiment is carried out on a photorefractive oscillator in two-wave mixing configuration.A model for the experimental device is given that reproduces the observed behavior.Comment: 9 pages and 4 figure

Adaptive activities for inclusive learning using multitouch tabletops: An approach

Proceedings of the International Workshop on Personalization Approaches in Learning Environments. Girona, Spain, July 15, 2011.Also published online by CEUR Workshop Proceedings (CEUR-WS.org, ISSN 1613-0073)People with cognitive disabilities have some difficulties with memory, literacy skills, attention and problem solving. Computers and specifically, adaptation mechanisms can be used to improve their learning. The adaptation allows fitting the learning process to each user. This paper presents a proposal to adapt learning activities while people are interacting using multitouch tabletops. The adaptation mechanism takes into account structural aspects, content adaptation and the interaction provided.This work has been funded by the Spanish Government (ASIES Project - Ministerio de Ciencia e Innovación de España, TIN2010-17344). The D2-Player has been funded by Fundación Sindrome de Down Madrid

Sidon-Ramsey and BhB_{h}-Ramsey numbers

For a given positive integer $k$, the Sidon-Ramsey number \SR(k) is defined as the minimum value of $n$ such that, in every partition of the set $[1, n]$ into $k$ parts, there exists a part that contains two distinct pairs of numbers with the same sum. In other words, there is a part that is not a Sidon set. In this paper, we investigate the asymptotic behavior of this parameter and two generalizations of it. The first generalization involves replacing pairs of numbers with $h$-tuples, such that in every partition of $[1, n]$ into $k$ parts, there exists a part that contains two distinct $h$-tuples with the same sum. Alternatively, there is a part that is not a $B_h$ set. The second generalization considers the scenario where the interval $[1, n]$ is substituted with a non-necessarily symmetric $d$-dimensional box of the form $\prod_{i=1}^d[1,n_i]$. For the general case of $h\geq 3$ and non-symmetric boxes, before applying our method to obtain the Ramsey-type result, we needed to establish an upper bound for the corresponding density parameter.Comment: 11 page

Doped-iron oxide nanocrystals synthesized by one-step aqueous route for multi-imaging purposes

New doped inorganic nanocrystals (NC) consisting on iron oxide and other metal integrated into the structure have been synthesized in one-step by adapting the oxidant precipitation synthesis route for magnetite. Different metals have been chosen to confer extra and unique properties to the resulting magnetic hetero-nanostructure: Co and Gd for enhancing transversal and longitudinal relaxivities for magnetic resonance imaging and Bi and Au for achieving X-ray absorption for computed tomography imaging. Apart of that, gold optical properties are interesting for photothermal therapy and iron oxides for magnetic hyperthermia. All metals have been incorporated into the magnetite structure in different ways during the synthesis: by forming a solid solution, by modifying the surface of the NCs, or by co-crystallization with the magnetite. The nanostructure formed in each case depends on the ionic radius of the secondary metal ion and the solubility of its hydroxide that control the co-precipitation in the initial steps of the reaction. Magnetic properties and imaging capabilities of the hetero-nanostructures have been analyzed as a function of the element distribution. Due to the synergistic combination of the different element properties, these magnetic hetero-nanostructures have great potential for biomedical applications

Adaptación y validación de un cuestionario para medir burnout académico en estudiantes de medicina de la universidad Ricardo Palma: Adaptation and validation of a questionnaire to measure academic burnout in medical university students

Introduction: Evaluate the validity and reliability of an instrument adapted to Peru to measure pre-presenceof Burnout Syndrome in university students of the career of Human Medicine at the UniversityRicardo Palma, taking as a starting point the Burnout Inventory of Maslach - Student Survey (MBISS). Methods: Cross-sectional analytical study, with level of application research. Validity was evaluated byanalysis of factorial structure with the principal components method, Kaiser-Meyer Olkin tests and Varimax rotation were applied; the reliability by the Cronbach alpha value. Results: 223 students from the Faculty of Human Medicine of the Ricardo Palma University were included, from November to December 2016. The prevalence of academic Burnout found was 28.25% (63); The Kaiser-Meyer Olkin fitness test had a result of 0.813 and Barlett's sphericity test of 1007.5 (p <0.000). The cumulative variance explained by 3 factors was calculated to be 55.4%. The instrument obtained a Cronbach's Alpha coefficient = 0.794, with correlations between the items, Emotional Exhaustion (α =, 855), Cynicism (α = 0.623) and Academic Efficiency (α = 0.744). Conclusion: The adapted and validated instrument gathers the psychometric properties to be considered a useful and reliable instrument initially in human medicine students of the Ricardo Palma University, presenting an adequate factorial structure and internal consistency to determine the level of Burnout Syndrome Academic.   DOI 10.25176/RFMH.v19.n1.1794Introducción: Evaluar lLa validez y fiabilidad de un instrumento adaptado al Perú para medir la pre-senciadel Síndrome de Burnout en estudiantes universitarios de la carrera de Medicina Humana en la UniversidadRicardo Palma, tomando como punto de partida el Inventa-rio de Burnout de Maslach - Student Survey (MBISS). Métodos: Estudio transversal analítico, con nivel de investigación aplicativo. Se evaluó la validez poranálisis de estructura factorial con el método de componentes principales, se apli-caron las pruebas de Kaiser- Meyer Olkin y la rotación Varimax; la confiabilidad por el valor alfa de Cronbach. Resultados: Fueron incluidos 223 estudiantes de la Facultad de Medicina Humana de la Universidad Ricardo Palma, en el periodo noviembre a diciembre del año 2016. La prevalencia de Burnout académico encontrada fue 28,25% (63); La prueba de adecuación de Kaiser-Meyer Olkin tuvo un resultado de 0.813 y la prueba de esfericidad de Barlett de 1007.5 (p<0.000). Se calculó la varianza acumulada explicada por 3 factores fue de 55.4%. El instrumento obtuvo un coeficiente Alfa de Cronbach= 0,794, con correlaciones entre los ítems, Agotamiento Emocional (α= ,855), Cinismo (α=0,623) y Eficacia Académica (α= 0,744). Conclusión: El instrumento adaptado y validado reúne las propiedades psicométricas para ser con-siderado un instrumento útil y fiable inicialmente en estudiantes de medicina humana de la Universidad Ricardo Palma, presentando una adecuada estructura factorial y consistencia interna para la determinación del nivel de Síndrome de Burnout Académico.   DOI 10.25176/RFMH.v19.n1.179

Development of a Telemetry and Yield-Mapping System of Olive Harvester

Sensors, communication systems and geo-reference units are required to achieve an optimized management of agricultural inputs with respect to the economic and environmental aspects of olive groves. In this study, three commercial olive harvesters were tracked during two harvesting seasons in Spain and Chile using remote and autonomous equipment that was developed to determine their time efficiency and effective based on canopy shaking for fruit detachment. These harvesters work in intensive/high-density (HD) and super-high-density (SHD) olive orchards. A GNSS (Global Navigation Satellite System) and GSM (Global System for Mobile Communications) device was installed to track these harvesters. The GNSS receiver did not affect the driver’s work schedule. Time elements methodology was adapted to the remote data acquisition system. The effective field capacity and field efficiency were investigated. In addition, the field shape, row length, angle between headland alley and row, and row alley width were measured to determinate the optimum orchard design parameters value. The SHD olive harvester showed significant lower effective field capacity values when alley width was less than 4 m. In addition, a yield monitor was developed and installed on a traditional olive harvester to obtain a yield map from the harvested area. The hedge straddle harvester stood out for its highly effective field capacity; nevertheless, a higher field efficiency was provided by a non-integral lateral canopy shaker. All of the measured orchard parameters have influenced machinery yields, whether effective field capacity or field efficiency. A saving of 40% in effective field capacity was achieved with a reduction from 4 m or higher to 3.5 m in alley width for SHD olive harvester. A yield map was plotted using data that were acquired by a yield monitor, reflecting the yield gradient in spite of the larger differences between tree yield

C and L band fiber lasers enhanced by ultrafast laser inscribed artificial backscatter reflectors

This letter presents an experimental comparison between two linear-cavity erbium-doped fiber lasers (EDFL) assisted by two different artificial backscatter fiber-based reflectors. Both reflectors were inscribed by femtosecond laser direct writing, one of them within a single-mode fiber (SMF) and the other one within a multi-mode fiber (MMF). Although the erbium-doped fiber amplifier (EDFA) used in both structures was the same and both reflectors were manufactured under the same parameters, the reflection spectrum of each was clearly different due to their different physical properties. The first linear-cavity EDFL, consisting of an SMF-based reflector with 9µm core and 125µm cladding, resulted in a single laser emission line located in the C-band and centered at 1564.4 nm, exhibiting an optical signal-to-noise ratio (OSNR) of 52dB when pumped at 100mW. On the other hand, a single laser emission line with a similar OSNR but in L-band (centered at 1574.5nm) was obtained when using an MMF-based reflector with 50µm core and 125µm cladding.Ministerio de Educación, Cultura y Deporte (PhD grant FPU2018/02797); European Commission (Next generation EU/PTR); FEDER (A way to make Europe); MCIN/AEI/10.13039/501100011033 (PDC2021-121172-C21, PID2019-107270RB)

Wavelength-switchable L-band fiber laser assisted by random reflectors

A wavelength-switchable L-band erbium-doped fiber laser (EDFL) assisted by an artificially controlled backscattering (ACB) fiber reflector is here presented. This random reflector was inscribed by femtosecond (fs) laser direct writing on the axial axis of a multimode fiber with 50 um core and 125 um cladding with a length of 17 mm. This microstructure was placed inside a surgical syringe to be positioned in the center of a high-precision rotation mount to accurately control its angle of rotation. Only by rotating this mount, three different output spectra were obtained: a single wavelength lasing centered at 1574.75 nm, a dual wavelength lasing centered at 1574.75 nm and 1575.75 nm, and a single wavelength lasing centered at 1575.5 nm. All of them showed an optical signal-to-noise ratio (OSNR) of around 60 dB when pumped at 300 mW.This work was financed by the program “José Castillejo para estancias de movilidad en el extranjero de jóvenes doctores”, funded by the Ministerio de Universidades of Spain (reference CAS21/00351); the Spanish AEI projects PID2019-107270RB, funded by MCIN/AEI/10.13039/501100011033 and FEDER “A way to make Europe”, and projects PDC2021-121172 and TED2021-130378B funded by MCIN/ AEI/10.13039/501100011033 and European Union “Next generation EU”/PTR. Finally, the work was also founded by the Ministerio de Educación, Cultura y Deporte of Spain (PhD grant FPU2018/02797)

Influencia de las nuevas tecnologías en los resultados de la asignatura “Fundamentos de Química” en la Ingeniería Técnica Industrial

En la titulación de Ingeniería Técnica Industrial de la Universidad de Jaén se ha ido implantando los créditos ECTS en todas las asignaturas, empezando en 2005 con las del primer curso, para concluir en 2007 con toda la Titulación. Aquí se presenta la parte de la experiencia correspondiente a la asignatura de Fundamentos de Química.El programa es básicamente el mismo aunque hay una reducción del tiempo del profesor dedicado a las clases presenciales. Esta circunstancia llevó al profesorado que imparte Fundamentos de Química en la Ingeniería Técnica Industrial, a comenzar a usar las nuevas tecnologías enfocadas a la puesta en práctica nuevos instrumentos docentes, tratando de mejorar la calidad del proceso de enseñanza y aprendizaje.En esta comunicación se exponen los objetivos de partida para la elaboración de guías didácticas como instrumento base para el desarrollo del proceso docente, la metodología y los resultados en la evaluación de los alumnos