Optimization of Seebeck nanoantenna-based infrared harvesters

In this letter, the authors develop an optimized Seebeck nanoantenna design suitablefor IR harvesting applications. The design is optimized via the so-called particle-swarm-optimization algorithm (PSO), an evolutionary algorithm able to drive the morphology of anano-object towards an optimum. Along with the so-called nanoloading technique, efforts aresubsequently addressed to understand the physical mechanisms behind the wave energy to voltageconversion, from both numerical and theoretical perspectives. In particular, the thermal andintrinsic impedance are considered to be the key issues beneath the device’s response.ITESO, A.C

Computational Analysis of a Spiral Thermoelectric Nanoantenna for Solar Energy Harvesting Applications

Thermo-electrical nanoantennas have been proposed as an alternative option for conversion solar energy harvesting applications. In this work, the response of a spiral broadband antenna has been obtained from numerical and theoretical simulations perspectives. The results show that this device exhibits a responsivity of 20mV/W under 117W/cm2, for a single-frequency radiation. We discuss strategies for enhanced efficiency

Seebeck Nanoantennas for Infrared Detection and Energy Harvesting Applications

In this letter we introduce a new type of infrared sensor, based on thermocouple nanoantennas, which enables the energy detection and gathering in the mid-infrared region. The proposed detector combines the Seebeck effect, as a transduction mechanism, with the functionalities of the optical antennas for optical sensing. By using finite-element numerical simulations we evaluate the performance and optical-to-electrical conversion efficiency of the proposed device, unveiling its potential for optical sensing and energy harvesting applications.Comment: 4 pages, 3 figures, Invited paper at EUCAP 201

El liderazgo transformacional y la identidad institucional de una Escuela de Educación Básica, Salitre, Ecuador, 2020

El presente estudio de carácter científico denominado “El liderazgo transformacional y la identidad institucional de una Escuela de Educación Básica, Salitre, Ecuador, 2020”, elaborado con la finalidad de optar el grado de maestro en administración educativa en la Universidad César Vallejo, tuvo como objetivo determinar la relación entre el liderazgo transformacional y la identidad institucional, estudio que asumió el enfoque cuantitativo, tipo no experimental y diseño descriptivo correlacional, el mismo que aplicara dos cuestionarios a 41 docente llegando a verificar la existencia de correlación positiva media, entre la dimensión competencias directivas y la identidad institucional, con Rho de Spearman, de 0,420, y Sig., de 0,006, del mismo modo una correlación positiva media entre la calidad de los procesos del liderazgo transformacional y la identidad institucional, con Rho de Spearman, de 0,490, y Sig. 0,001 (bilateral), asimismo, que las competencias laborales y la identidad institucional, tienen un valor Rho de Spearman, de 0,495, que indica correlación positiva media, con un Sig. 0,001 (bilateral), y finalmente que el liderazgo transformacional se encuentra significativamente relacionada con la identidad institucional, conforme el valor del Rho de Spearman, encontrado de 0,511, que indica una correlación positiva considerable y un Sig. 0,01 (bilateral

Particle swarm optimization of nanoantennabased infrared detectors

The multi-resonant response of three-steps tapered dipole nano-antennas, coupled to a resistive and fast micro-bolometer, is investigated for the efficient sensing in the infrared band. The proposed devices are designed to operate at 10.6 µm, regime where the complex refractive index of metals becomes important, in contrast to the visible counterpart, and where a full parametric analysis is performed. By using a particle swarm algorithm (PSO) the geometry was adjusted to match the impedance between the nanoantenna and the microbolometer, reducing the return losses by a factor of 650 percent. This technique is compared to standards matching techniques based on transmission lines, showing better accuracy. Tapered dipoles, therefore, open the route towards an efficient energy transfer between load elements and resonant nanoantennas

Geotourism and local development based on geological and mining sites utilization, zaruma-portovelo, Ecuador

This study offers a detailed assessment of the geosites and mining sites present in the Zaruma-Portovelo mining district (Ecuador) through their qualitative and quantitative assessment. It shows up the potentiality of this area taking advantage of its geological-mining heritage. The methodological process includes: (i) compilation and inventory of all the sites within the study area with particular geological or mining interest; (ii) preparation of reports and thematic cartography, (iii) assessment and classification of the elements of geological-mining interest; (iv) SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis and TOWS (Threats, Opportunities, Weaknesses, Strengths) matrix preparation seeking strategies to guarantee the viability of geotourism. A total of 16 sites of geological interest and 11 of mining interest were identified. The 77% of these sites was proved to be of high and very high interest in scientific terms. Likewise, their susceptibility to degradation assessed from their vulnerability and fragility was found to be high or very high in the 30% of the cases. As for the protection priority, all the studied sites obtained a medium-high result. Finally, the study based on the SWOT-TOWS revealed the possibility of applying action strategies in order to facilitate the compatibility of geotourism with the current productive activities, despite the difficult situation in the study area created by mining activities

Semiconductor Surface State Engineering for THz Nanodevices

This chapter is dedicated to study the semiconductor surface states, which combined with nanolithography techniques could result on remarkable properties of advanced nanodevices suitable for terahertz (THz) signal detection or harvesting. The author presents the use of low-dimensional semiconductor heterostructures for the development of the so-called self-switching diodes (SSDs), studying by simulation tool key parameters in detail such as the shape and size of the two-dimensional electron gas system. The impact of the geometry on the working principle of the nanodevice and the effects on current-voltage behavior will be described in order to acquire design guidelines that may improve the performance of the self-switching diodes when applied to low-power square-law rectifiers as well as elements in rectennas by appropriately setting the size of the components

Near-field mapping of dipole nano-antenna-coupled bolometers

The near-field characteristics of single, double, and arrays of connected dipole nano-antennas coupled to bolometers were studied by infrared scattering scanning near-field optical microscopy (s-SNOM) and analyzed by numerical simulations. Results were consistent with classical antenna theory showing the expected pi phase difference across the terminals of the dipoles. However, according to the observed differences between the measurements and simulations, the symmetry of the amplitude signal appeared to be sensitive with respect to the position of the bolometric element relative to the dipoles. The effect of the position of the bolometer on the associated near-field distribution suggests an influence on the coupling and efficiency of energy transfer into these detectors, which could be important for determining tolerances in the fabrication of such devices. These results show how near-field measurements in general can provide critical information to guide the design of nano-antennas, nano-antenna-phased arrays, and integrated photonic devices

Propuestas para el mejoramiento de la gestión financiera. Caso de estudio Inmobiliarias de Guayaquil.

El objetivo de esta investigación es proponer estrategias para optimizar la gestión financiera de las empresas inmobiliarias en la ciudad de Guayaquil que permitan ampliar la rentabilidad y sostener el incremento de las negociaciones de los inmuebles. Se busca que el planteamiento de la hipótesis, referente a si son convenientes las estrategias y estas sean aceptadas en base a precios hedónicos sea comprobada en el transcurso del desarrollo del estudio. La investigación realizada presenta un soporte bibliográfico, la experticia de negociaciones inmobiliaria y el análisis de los datos descritos en encuestas y estadí­sticas referentes al campo inmobiliario, obteniendo resultados, que se relacionan a las decisiones tomadas. El estudio determinó que las inversiones efectuadas optimizan los resultados con un Valor Actual Neto positivo de 478.462 dólares y una Tasa Interna de Retorno del 37%, dando viabilidad a la propuesta y a los procesos estratégicos realizados, concluyendo que los propietarios de las empresas inmobiliarias, deben emplear los diversos recursos y estrategias de manera adecuada al viabilizar sus estados financieros con éxito, seguridad y perseverancia

Diagnóstico de las fuentes no tradicionales de financiamiento empleadas por las PYMES del Cantón Quevedo. Ecuador

From a survey applied to 360 microentrepreneurs from the Quevedo Canton, Ecuador, non-traditional sources of financing were identified, such as alternatives to bank financing and that are most used by small and medium-sized enterprises (Pymes), as well as towards which activities they are channel these resources, what are their financing needs, in order to determine the incidence of internal factors such as: Poor organizational structure, limited access to financing sources, difficulty in absorbing personnel training costs that have low productivity and external factors such as the environment where they operate, government procedures, little availability of financing sources, in the organizational development of Pymes. The research carried out showed that the most used non-traditional source of financing is credit to suppliers.A partir de una encuesta aplicada a 360 microempresarios del Cantón Quevedo, Ecuador se identificaron las fuentes no tradicionales de financiamiento, como, alternativas al financiamiento bancario y que mas se utilizan por  las pequeñas y medianas empresas (Pymes), así­ como hacia cuales  actividades se canalizan estos recursos, cuáles son sus necesidades de financiamiento, para poder determinar la incidencia de factores internos como: deficiente estructura organizativa, acceso limitado a fuentes de financiamiento, dificultad para absorber costos de capacitación del personal que repercute en una baja productividad y externos como: el entorno donde se desenvuelven, trámites gubernamentales, poca disponibilidad de fuentes de financiamiento, en el desarrollo organizacional de las pymes. La investigación realizada demostró que la fuente no   tradicional de financiamiento más utilizada es el crédito a proveedores