A presença de menores em conteúdos comerciais e o seu efeito negativo no público:

This article analyzes the reaction of the audience of the Spanish youtuber Verdeliss, who has the largest community of Spanish followers in the field of parenting and motherhood, to the presence of her underage children in the contents that she publishes on YouTube. A survey made among 1,336  followers of her YouTube channel found that the majority of them feel uncomfortable because of the presence of minors in videos where commercial brands are also promoted. This group rates the youtuber worse in almost all dimensions related to her persuasive ability, and they also buy fewer products recommended by her. Likewise, in a qualitative analysis of 284 comments to open-ended questions, it was observed that there are several arguments within this group of uncomfortable followers, among which stand out their discomfort with the excessive exposure of minors, a frontal rejection to the commodification of their image, and a call on competent authorities to protect the minors. Taking into account the differences in the evaluation of the youtuber, these results suggest that sharenting could produce negative effects in the promotion of brands.Este artículo analiza la reacción de la audiencia de la youtuber española Verdeliss, con la mayor comunidad de seguidoras en España en ámbito de la crianza y la maternidad, en relación a la presencia de sus hijas e hijos menores en los contenidos que publica en su canal de YouTube. En una encuesta realizada a 1.336 seguidoras, se constató que más de la mitad de las mismas se sienten incómodas por la presencia de menores en videos en los que además se promocionan marcas comerciales. Este grupo valora peor a la youtuber en casi todas las dimensiones relacionadas con su capacidad persuasiva y además compra menos productos recomendados por ella en sus vídeos. Asimismo, en un análisis cualitativo de 284 comentarios en preguntas de respuesta abierta se pudo apreciar que existen varios argumentos dentro de este grupo de seguidoras más críticas con la youtuber, entre los que destacan su malestar por la excesiva exposición de los menores, un rechazo frontal a la mercantilización de la imagen de estos y un llamamiento a las instituciones competentes a que protejan a los menores. A la vista de las diferencias en la valoración de la youtuber, los resultados sugieren que el sharenting puede producir efectos negativos en la promoción de marcas comerciales.Este artigo discute a reação da audiência da youtuber espanhola Verdeliss, com a maior comunidade de seguidoras em Espanha no campo da parentalidade e da maternidade, em relação à presença das suas filhas e filhos menores nos conteúdos publicados no seu canal de YouTube. Em nossa pesquisa realizada a 1.336 seguidoras, verificou-se que a majoria deles se sentem desconfortáveis com a presença de menores em vídeos que também promovem marcas comerciais. Este grupo availa  a youtuber pior em quase todas as dimensões relacionadas com a sua capacidade persuasiva e também compra menos produtos recomendados por ela nos seus vídeos. Igualmente, em uma análise qualitativa de 284 comentários em questões abertas mostrou que existem vários argumentos dentro deste grupo de seguidoras mais críticas com a youtuber, entre os quais se destaca o seu mal-estar sobre a exposição excessiva de menores, uma rejeição frontal da mercantilização da sua imagem e um apelo às instituições competentes para que protegem os menores. Tendo em conta as diferenças na avaliação da youtuber, os resultados sugerem que o sharenting pode produzir efeitos negativos na promoção de marcas comerciais

Elastic tunneling charge transport mechanisms in silicon quantum dots / SiO2 thin films and superlattices

The role of different charge transport mechanisms in Si /SiO2 structures has been studied. A theoretical model based on the Transfer Hamiltonian Formalism has been developed to explain experimental current trends in terms of three different elastic tunneling processes: (1) trap assisted tunneling; (2) transport through an intermediate quantum dot; and (3) direct tunneling between leads. In general, at low fields carrier transport is dominated by the quantum dots whereas, for moderate and high fields, transport through deep traps inherent to the SiO 2 is the most relevant process. Besides, current trends in Si /SiO2 superlattice structure have been properly reproduced

Children’s exposure on Instagram: instamoms, brand presence and legal loophole

El fenómeno influencer ha permitido a personas previamente desconocidas adquirir altos niveles de popularidad mediante la exhibición de imágenes que recrean sus actividades, sus intereses o su vida cotidiana. Las instamadres son influencers que comparten en la red social Instagram contenido relacionado con su vida familiar, mostrando con frecuencia a sus hijas e hijos pequeños. En sus publicaciones se aprecia alta presencia de marcas comerciales, pero la naturaleza de la relación que mantienen con la publicidad no siempre es clara. Mediante una ficha ad hoc, se han analizado 1.000 publicaciones de diez cuentas de instamadres populares para cuantificar la frecuencia con la que muestran en ellas a menores y la presencia de marca. En el 45,6% de los posts analizados aparecen menores y estas publicaciones reciben un 41% más de likes que aquellas en las que no los hay. En más de la mitad de las publicaciones analizadas aparecen marcas comerciales, y se percibe un incremento al respecto entre 2019 (43,3%) y 2020 (63,5%). Solo en una de cada cinco ocasiones en las que hay una marca se explicita que es publicidad, y por tanto, hay alguna remuneración. Nuestro trabajo demuestra que los niños y niñas son elementos frecuentes en las cuentas de sus instamadres, y contribuyen a generar comunidades grandes y atractivas para la industria publicitaria. Es necesario regular tanto la aparición en estas cuentas de menores como el modo en el que se hace presente la publicidad en ellas.The influencer phenomenon has allowed previously unknown people to attract high levels of popularity through the display of images that recreate their activities, their interests, or their daily life. Instamoms are influencers who share content related to their family life on Instagram, frequently showing their young daughters and sons. In their publications, it is appreciated that commercial brands figure prominently, although the nature of the role they play in advertising strategies is not always clear. Through an ad hoc guide, 1 000 publications from ten popular Instagram accounts were analysed to quantify the frequency in which they show minors, and the presence of brands. Minors appear in 45.6% of the posts analysed and these publications receive 41% more likes than those in which there are no children. Trademarks appear in more than half of the publications analysed, with a pronounced increase in this respect between 2019 (43.3%) and 2020 (63.5%). Only one out of five there is a brand, and they explain that it is paid advertising. Minors feature frequently in the accounts of their mothers, and they contribute to generating large and attractive communities for the advertising industry. It is necessary to regulate the way in which advertising appears on these accounts, as well as the presence of their sons and daughters in them

YouTube celebrity endorsement: audience evaluation of source attributes and response to sponsored content. A case study of influencer Verdeliss

This article analyses follower response to the growing number of product endorsements present in YouTube videos published under the username “Verdeliss” by Estefanía Unzu Ripoll, Spain’s most popular YouTube influencer on the topic of maternity and childcare. Results of a self-administered online survey of 949 Verdeliss followers focused on their individual evaluations of source attributes indicate that Unzu Ripoll’s YouTube fans tend to buy products she endorses on the basis of her perceived likeability and expertise, and that the overall influence she exerts on their purchasing decisions is slight. In closing, the authors offer insights into how social media influencers can enhance the effectiveness of their online endorsements and identify tactics brands can employ to ensure that the influencers they collaborate with are optimally suited to promote their products

A transfer Hamiltonian model for devices based on quantum dot arrays

We present a model of electron transport through a random distribution of interacting quantum dots embedded in a dielectric matrix to simulate realistic devices. The method underlying the model depends only on fundamental parameters of the system and it is based on the Transfer Hamiltonian approach. A set of noncoherent rate equations can be written and the interaction between the quantum dots and between the quantum dots and the electrodes is introduced by transition rates and capacitive couplings. A realistic modelization of the capacitive couplings, the transmission coefficients, the electron/hole tunneling currents, and the density of states of each quantum dot have been taken into account. The effects of the local potential are computed within the self-consistent field regime. While the description of the theoretical framework is kept as general as possible, two specific prototypical devices, an arbitrary array of quantum dots embedded in a matrix insulator and a transistor device based on quantum dots, are used to illustrate the kind of unique insight that numerical simulations based on the theory are able to provide

Transport in quantum dot stacks using the transfer Hamiltonian method in self-consistent field regime

The non-coherent rate equation approach to the electrical transport in a serial quantum dot system is presented. The charge density in each quantum dot is obtained using the transfer Hamiltonian formalism for the current expressions. The interactions between the quantum dots and between the quantum dots and the electrodes are introduced by transition rates and capacitive couplings. Within this framework analytical expressions for the current and the charge in each quantum dot are presented. The effects of the local potential are computed within the self-consistent field regime. Despite the simplicity of the model, well-known effects are satisfactorily explained and reproduced. We also show how this approach can be extended into a more general case

Thermal and transport properties of pristine single-layer hexagonal boron nitride : a first principles investigation

Molecular dynamics is used in combination with density functional theory to determine the thermal transport properties of the single-layer hexagonal boron nitride (SL h-BN) from ab initio calculations. Within this approach, the possible anisotropy in the thermal conductivity of SL h-BN was studied. For samples with finite length (of the order of 20 nm), we find a significant dependence of the conductivity on the transport direction. We make a direct comparison of the results obtained for two-dimensional (2D) layers and for nanoribbons with similar size, and show that, as a consequence of edge scattering, the ribbon geometry induces a significant decrease in the conductivity, and produces a strong change in the anisotropy. For the zigzag and armchair transport directions, the dependence of the thermal conductivity on the system length was also obtained, as well as its value in the 2D bulk limit case. A very small anisotropy was found for the limit of long samples, in contrast with the finite length ones. This is explained analyzing the dependence of the average square group velocities on the transport direction and the phonon frequency

Statistical Analysis of the Global Solar Radiation in Cúcuta using the ANOVA Model

Objective: This paper presents a statistical analysis of solar radiation in the city of Cúcuta, aiming to provide a detailed description of its variability between 2005 and 2015. This information represents an assessment tool to study the solar potential of the region for photovoltaic system design, motivated by the need to improve the cost-effectiveness of this technology, and thus increase its penetration in the Colombian electric grid. Methodology: Three weather databases with hourly data were studied, from which the one with the largest amount of data available was selected. By means of the R Studio software, two types of statistical methods were executed: single factor variance analysis (ANOVA) and Bonferroni test. From this, graphs representing the statistical summary of solar radiation values in the last decade were obtained. Results: The ANOVA showed a p-value of 6,28x10-7, indicating that there is a statistically significant difference in the sample mean between the different years of study. Likewise, the years and months with the greatest deviation and the possible causes for the variability of this parameter were identified. Conclusions: Despite showing a stable behavior, the radiation of the city of Cúcuta requires a very specific analysis for its use in applications that need a high sensitivity in the handling of this information, since there are statistically significant variations that can occur for its use. Funding: Universidad Francisco de Paula Santander        Objetivo: Esta investigación presenta un análisis estadístico de la radiación solar en la ciudad de Cúcuta, con el objetivo de brindar una descripción detallada de su variabilidad entre los años 2005 y 2015. Esta información representa una herramienta evaluativa en el estudio del potencial solar de la región para el diseño de sistemas fotovoltaicos, partiendo de la necesidad de mejorar la relación costo/beneficio de esta tecnología, y así incrementar su penetración en la matriz eléctrica colombiana. Metodología: Se realizó un estudio de tres bases de datos climatológicas con información horaria, seleccionando aquella con la mayor cantidad de datos disponibles. Por medio del software R Studio, se ejecutaron dos tipos de métodos estadísticos: análisis de la varianza de un solo factor (ANOVA) y test de Bonferroni. A partir de esto, se obtuvieron gráficas que representan el resumen estadístico de los valores de radiación solar en la última década. Resultados: El análisis ANOVA arrojó un valor p de 6,28x10-7, indicando que existe una diferencia estadísticamente significativa de la media muestral entre los diferentes años de estudio. Asimismo, se identificaron los años y meses con mayor desviación y las posibles causas de la variabilidad de este parámetro. Conclusiones: A pesar de tener un comportamiento estable, la radiación de la ciudad de Cúcuta requiere de un análisis muy específico para su uso en aplicaciones que necesiten una alta sensibilidad en el manejo de esta información, ya que hay variaciones estadísticamente significativas que se pueden presentar para su uso. Financiamiento: Universidad Francisco de Paula Santander.      

A transfer Hamiltonian approach for an arbitrary quantum dot array in the self-consistent field regime

A transport methodology to study electron transport between quantum dot arrays based on the transfer Hamiltonian approach is presented. The interactions between the quantum dots and between the quantum dots and the electrodes are introduced via transition rates and capacitive couplings. The effects of the local potential are computed within the self-consistent field regime. The model has been developed and expressed in a matrix form in order to make it extendable to larger systems. Transport through several quantum dot configurations has been studied in order to validate the model. Despite the simplicity of the model, well-known effects are satisfactorily reproduced and explained. The results qualitatively agree with other results obtained using more complex theoretical approaches

Electronic transport in QD based structures: from basic parameters to opto-electronic device simulations

We present a theoretical model that explains the optoelectronic response of nanodevices based on large quantum dot (QD) arrays. The model is grounded on rate equations in the self-consistent field regime and it accurately describes the most important part of the system: the tunnel junctions. We demonstrate that the ratio between the optical terms and the transport rates determines the final device response. Furthermore, we showed that to obtain a net photocurrent the QD has to be asymmetrically coupled to the leads