Antiresonant hollow-core fibers (AR-HCFs) have opened up exciting possibilities for high-energy a... more Antiresonant hollow-core fibers (AR-HCFs) have opened up exciting possibilities for high-energy and high-power laser delivery, thanks to their exceptionally low nonlinearities and high damage thresholds. While these fiber designs offer great potential for handling kilowatt-class powers, it is crucial to understand their fundamental limitations by investigating their performance at multi-kW power levels. Until now, efforts to deliver a narrow-linewidth single-mode laser at multi-kW power levels through a hollow core fiber have been unsuccessful. Here, we demonstrate the successful delivery of a record 2.2 kW laser power with a spectral linewidth of 84 GHz, centered at 1080 nm, while maintaining over 95% efficiency. This was achieved using a 6.25 m long AR-HCF with low-loss properties. Furthermore, we show power delivery of 1.7 kW with a spectral linewidth as narrow as 38 GHz. Our results could lead to a new generation of fiber-based laser beam delivery systems with applications in pr...
Bio-grafía: escritos sobre la biología y su enseñanza, 2019
La Educación Ambiental es necesariamente interdisciplinaria" nos dice Torres (2002) dentro de los... more La Educación Ambiental es necesariamente interdisciplinaria" nos dice Torres (2002) dentro de los criterios que debe cumplir la educación ambiental para que sea significativa en los contextos escolares y cotidianos de nuestros estudiantes. La necesidad de perspectivas más amplias para analizar realidades sociales y naturales atraviesa todas las ramas del conocimiento y requiere de la totalidad de las disciplinas para su construcción. En el presente texto, se muestra un acercamiento al trabajo interdisciplinar realizado en el Colegio Campestre ICAL, con estudiantes de décimo grado, que tuvo como fin generar una complejización de conocimientos relacionados con el fenómeno de la Minería en Colombia. Ello se llevó a cabo a través de la integración y adecuación de los planes de estudios en las asignaturas biología y ciencias sociales en torno a este problema sociocientífico. La estrategia de salida pedagógica fue crucial para brindar los elementos necesarios para el objetivo. Se destaca la comprensión holística del concepto por parte de los estudiantes, quienes relacionan dinámicas naturales con dinámicas antrópicas dentro del territorio.
Suelos agrarios abandonados en el Área Metropolitana de Madrid y estrategias de recuperación
E.T.S. Arquitectura (UPM) eBooks, Nov 30, 2021
De acuerdo con el CORINE Land Cover, en el área metropolitana de Madrid, hay más de11 mil hectáre... more De acuerdo con el CORINE Land Cover, en el área metropolitana de Madrid, hay más de11 mil hectáreas de terrenos en los que se han abandonado las prácticas agrarias. Prácticamente la mitad se localizan en suelos clasificados como no urbanizables, pero también un significativo 41% se corresponden con suelos urbanizables. Los suelos agrarios en regresión han pasado a estar cubiertos mayoritariamente por prados y pastizales (9.400 ha), por matorrales (2.500 ha) y por superficies forestales (2.300 ha). Se han identificado tres ámbitos diferenciados con tres estrategias: de fomento de espacios agroecológicos de cultura, experimentación y capacitación próximos a las mayores ciudades, por otro de recuperación del potencial productivo para vincularlo a sistemas alimentarios locales y por último, de estrategias de regeneración agroecológica en entornos señalados para proceso de renaturalizació
Performance Based Reservoir Characterization in a Tight Gas Reservoir System — Case Study from Lajas and Punta Rosada Formations in the Neuquén Basin, Argentina
Proceedings of the 5th Unconventional Resources Technology Conference, 2017
El proyecto consiste en un espacio adaptado a programas de formacion para el trabajo en el munici... more El proyecto consiste en un espacio adaptado a programas de formacion para el trabajo en el municipio de Oiba Santander. El diseno y dimensionamiento se basa en un proceso de investigacion bajo la linea metodologica de arquitectura, teoria, diseno y contexto del arquitecto Enrique Yanez. El desarrollo formal y funcional tuvo en cuenta aspectos importantes como el desarrollo urbano y social del municipio, ademas de adaptarse al marco normativa vigente (Esquema de Ordenamiento territorial).
La obesidad y el Sindrome Metabolico (SM) se han convertido en patologias epidemicas en el ambito... more La obesidad y el Sindrome Metabolico (SM) se han convertido en patologias epidemicas en el ambito mundial. Sin embargo, no existen estudios regionales que evaluen estas entidades en el entorno laboral, por lo que el motivo de este trabajo fue determinar su comportamiento en trabajadores de turno fijo y rotatorio en una empresa del estado Lara-Venezuela. Materiales y Metodos: Se realizo un estudio de campo, transversal y analitico en 230 individuos seleccionados al azar, pertenecientes al personal operativo (de turno rotatorio y fijo) que labora dentro de los comedores industriales de la empresa Sercoinfal CA. Se aplico un modelo de regresion logistica para estudiar la relacion entre el diagnostico o no de SM como variable dependiente, y el sexo, edad, turnos rotatorio/fijo y cargos de trabajo como variables independientes. Resultados : La prevalencia de sobrepeso y obesidad en la muestra estudiada fue del 48,3% y 30,4% respectivamente. El grupo de turno fijo mostro una prevalencia d...
We use a laboratory experiment to study the impact of transparency on reducing corruption in cont... more We use a laboratory experiment to study the impact of transparency on reducing corruption in contexts where embezzlement and bribery can co-occur. These contexts are closely related to grand corruption settings, where different types of corruption occur and allow people in power to take advantage of their position. Transparency is expected to have a positive effect on reducing corruption. However, our results show that transparency decreases embezzlement by roughly ten percentage points, while it has no significant effect on bribery. The observed differential impact of transparency could be attributed to strategic lying by the resource manager, who acts as if low public investment rates were a consequence of bad luck (low budget) instead of misappropriation. This suggests that the impact of transparency cannot be generalized to all types of corruption when different types co-exist.
Air pollution has been an environmental and health problem in the world, several methods of multi... more Air pollution has been an environmental and health problem in the world, several methods of multivariable linear regression has been proposed to determine levels of association and dependence between air pollutants and meteorological parameters. These parameters are characterized by redundant and irrelevant information, which is detrimental to a regression model. In this context a dependence analysis using Multiple Linear Regression and Principal Component Regression in air pollutants and meteorological parameters was developed, found a strong correlation between ozone and temperature (0.8) for Tlalnepantla station, as well as a determination coefficient of 82%. The PCR model proved that meteorological parameter such as temperature and relative humidity have a significant impact on the air pollution in Mexico City
Enemigos públicos plantea una relectura del nadaísmo a partir de documentación que hasta ahora no... more Enemigos públicos plantea una relectura del nadaísmo a partir de documentación que hasta ahora no había sido explorada, para señalar su incidencia tanto en los debates literarios y en la legitimación de una nueva poética, como en las repercusiones culturales de su permanente exteriorización. En primer lugar, se analiza la importancia de la correspondencia para aglutinar a un grupo de escritores noveles en un movimiento, su conformación, y cómo el nadaísmo, a pesar de presentarse como una ruptura intelectual, logró condensar una nueva forma de sociabilidad en la juventud de la época. En segundo lugar, se abordan las particularidades del contexto intelectual colombiano en los años sesenta y se demuestra que el nadaísmo tuvo validez como manifestación poética en cuanto participó de una red de comunicación alternativa en América Latina. En tercer lugar, se proporciona un acercamiento a las relaciones editoriales de los jóvenes poetas debido a la necesidad de exponer una producción impre...
Journal of Economic Behavior & Organization, 2021
Abstract Experimental participants in a cheating game draw a random number and then report any nu... more Abstract Experimental participants in a cheating game draw a random number and then report any number they wish, receiving a monetary payoff based only on the report. We study how these reports depend on the level of observability of both the random draw and the report by the experimenter. Our results show that whereas increasing the observability of the random draw decreases cheating, increasing the anonymity of the reports does not affect average reports.
This paper experimentally investigates the impact of suggestive messages and tipping on a third p... more This paper experimentally investigates the impact of suggestive messages and tipping on a third party’s judgment. The experimental design uses a model with three players, wherein two players (A and B) create a joint project, and the third player (C) decides how to divide the project’s earnings between the first two players. In two treatments, player B has an opportunity to influence player C’s decision via a numeric message or an ex-post tip. The main finding of this paper is that giving player B the option to suggest a specific amount to the allocator does not increase his share. In contrast, when player C knows that player B can send him a tip, the share awarded to player B increases.
This paper studies, theoretically and experimentally, whether the entitlement effect created by d... more This paper studies, theoretically and experimentally, whether the entitlement effect created by deservingness affects the willingness to lie. In a laboratory experiment, we compare the lying behavior of high-endowment participants with low-endowment participants. In one treatment, the allocation of the endowment is decided by participants' effort, and in the other, it is determined by a random draw. When participants lie to keep money directly determined by their effort, those who receive the high endowment lie more than those who receive the low endowment. In contrast, when income is determined by a random draw, lying is the same regardless of the endowment. These findings are consistent with our model of relative entitlement concerns where less deserving individuals are discouraged from lying because they believe that other individuals are more deserving than themselves.
We consider the Dirichlet Laplacian in a three-dimensional waveguide that is a small deformation ... more We consider the Dirichlet Laplacian in a three-dimensional waveguide that is a small deformation of a periodically twisted tube. The deformation is given by a bending and an additional twisting of the tube, both parametrized by a coupling constant δ. We expand the resolvent of the perturbed operator near the bottom of its essential spectrum and we show the existence of exactly one resonance, in the asymptotic regime of δ small. We are able to perform the asymptotic expansion of the resonance in δ, which in particular permits us to give a quantitative geometric criterion for the existence of a discrete eigenvalue below the essential spectrum. In the particular case of perturbations of straight tubes, we are able to show the existence of resonances not only near the bottom of the essential spectrum but near each threshold in the spectrum. We also obtain the asymptotic behavior of the resonances in this situation, which is generically different from the first case.
Yes it does ! Indeed an extended version of Levinson's theorem is proposed for a system involving... more Yes it does ! Indeed an extended version of Levinson's theorem is proposed for a system involving complex eigenvalues. The perturbed system corresponds to a realization of the Schrödinger operator with inverse square potential on the half-line, while the Dirichlet Laplacian on the half-line is chosen for the reference system. The resulting relation is an equality between the number of eigenvalues of the perturbed system and the winding number of the scattering system together with additional operators living at 0-energy and at infinite energy.
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Papers by daniel parra