The development of an optical design tool for atmospheric dispersion correction

In ground based astronomical observations, atmospheric dispersion shifts the image of the object at different wavelengths due to the wavelength-dependent index of refraction of the atmosphere. Thus, using an Atmospheric Dispersion Corrector (ADC) is mandatory in order to avoid any wavelength dependent losses. Typical ADC configurations, for high resolution astronomical instruments, are two counter-rotating prisms, a set of, at least, four prisms paired together. With the arrival of large telescopes with higher angular magnification, and spectrographs with higher resolution, the requirements on the dispersion correction are becoming more critical due to the impact on the produced science (e.g. radial velocity precision). We developed an ADC optical design tool in order to select the best set of glasses in terms of residuals, transmission, resulting image quality, Fresnel losses, taking into account the required spectral range and typical atmospheric conditions where the ADC will be working. A demonstration of the capabilities of the tool is presented with the analysis of the impact of different melt data, the effect of different glass Sellmeier coefficients between catalog and measured ones, that can create a difference in the residuals above few tens of milli-arcseconds (mas). The tool allows the investigation of critical steps on the ADC design phase and speeds up the glass selection process critical for the harder requirements of the future instruments/telescopes

EL PROCESO DE CERTIFICACIÓN DE EMPAQUE DE PEPINO PERSA PARA LA EXPORTACIÓN HACIA EUROPA

La exportación de hortalizas hacia Europa, representa para México un sector muy importante, puesto que genera empleos, divisas y una oportunidad de crecimiento económico, sin embargo, los lineamientos para este procedimiento son múltiples, diversos y complicados de cumplir por diferentes razones, existen aspectos como la inocuidad, calidad agroalimentaria, por mencionar algunas, que se deben cumplir para el mercado Europeo, es importante mencionar que cada país puede imponer sus propias medidas que requiera, por ello es importante conocer el proceso de certificación de empaque para el traslado de pepino persa hacia Europa

Silver Nanoparticles Offer Effective Control of Pathogenic Bacteria in a Wide Range of Food Products

According to the Food and Agriculture Organization (FAO), food wastage still causes massive economic loss. A major role in this loss is played by the activities of microbial organisms. Treatments such as heat and irradiation can reduce microorganisms in fruits and vegetables and hence reduce postharvest loss. However, some of these treatments can injure the fruit. Effective chemical treatments against bacterial infestations can result in resistance. A more recent method is the use of silver nanoparticles. These can act in a number of ways including at cellular level by inhibiting the cell wall synthesis, by binding to the surface of the cell membrane and by interposing between the DNA base pairs, and by inhibiting biofilm formation, affecting the thiol group of enzymes, affecting bacterial peptides and hence interfering with cell signaling and attaching to the 30S ribosome subunit. A ground-breaking way to survey the effects of the silver nanoparticles on bacterial populations is by flow cytometry. It allows measurement of many characteristics of single cells, including their functional characteristics such as viability and cell cycle. Bacterial viability assays are used with great efficiency to evaluate antibacterial activity by evaluating the physical rupture of the membrane of the bacteria

Passivity-based control of islanded microgrids with unknown power loads

In this paper, the control problem of microgrids (MGs)operating in islanded mode is approached from a passivity-based control perspective. A control scheme is proposed that, relying only on local measurements for the power converters included in the network representation, achieves both voltage regulation and power balance in the network through the generation of grid-forming and grid-following nodes. From the mathematical perspective, the importance of the contribution lies in the feature that, exploiting a port-controlled Hamiltonian representation of the MG, the closed-loop system’s stability properties are formally proved using arguments from the theory of non-linear dynamical systems. Fundamental for this achievement is the decomposition of the system into subsystems that require a control law and another whose variables can evolve in a free way. From the practical viewpoint, the advantage of the proposed controller lies in the feature that the power demanded by the loads is satisfied without neither computing its specific value nor solving the non-linear algebraic equations given by the power flow, avoiding the computational burden associated with this task. The usefulness of the scheme is illustrated via a numerical simulation that includes practical considerations.Universidad Tecnológica de Bolíva

RIESGOS LABORALES EN SALUD MENTAL EN EL PERSONAL DE LA UNIVERSIDAD LAICA ELOY ALFARO DE MANABÍ, POR LA PANDEMIA DE COVID-19

This research focuses on Universidad Laica Eloy Alfaro de Manabí (ULEAM) personnel, who work under different labour regimes. This study aims to identify the effects on officials' mental health during teleworking due to the COVID-19 pandemic. A mixed-method research was employed. Besides, a descriptive study was applied, which used data from psychological consultations carried out during confinement through Tele assistance and results of a survey applied to characterize the university community and identify aspects affecting the officials' mental health. The analysis of the results was gathered from the guidelines of the governing bodies of work, health, and higher education in the country and theoretical positions issued through various authors and national and international organizations. The main findings showed an affectation on the population's mental health, and the most prevalent were those that reflected symptoms of somatoform and cognitive disorders. The data permitted to obtain references to prevent occupational risks that deepen the effects on mental health, given the progressive face-to-face return to work that Ecuador has begun in the field of higher education.  El artículo se sustenta en una investigación realizada con el personal de la Universidad Laica Eloy Alfaro de Manabí (ULEAM), que trabaja bajo diferentes regímenes laborales, con el objetivo de identificar las afectaciones a la salud mental de los funcionarios durante el teletrabajo, por la pandemia del COVID-19. El enfoque investigativo fue mixto, se aplicó un estudio descriptivo que empleó datos de las consultas psicológicas realizadas durante el confinamiento, por medio de la teleasistencia; así como resultados de una encuesta aplicada para caracterizar la comunidad universitaria e identificar aspectos que inciden en la afectación a su salud mental. El análisis de los resultados se coligió desde las directrices de los entes rectores del trabajo, salud y educación superior del país; así como desde posturas teóricas emitidas a través de varios autores y organizaciones nacionales e internacionales. Los principales hallazgos evidenciaron una afectación a la salud mental de la población estudiada, y fueron los más prevalentes aquellos cuadros que reflejaron síntomas de trastorno somatomorfos y cognitivos. Los datos permitieron obtener referencias para prevenir riesgos laborales que profundicen las afectaciones a la salud mental, ante el retorno laboral presencial progresivo iniciado en Ecuador, en el ámbito de la educación superior

Procesos simples que disminuyen el contenido de sodio y nitritos en jamones

Introduction: Ham is a product highly consumed by society; however it contains some elements that make it a non-recommended food. Thus, it has been attempted to eliminate or reduce those components.Material and Methods: Content of sodium, nitrites, peroxides and total coliforms were compared after processes of Washing (W) and Simple Cooking (SC) in turkey and pork ham in a cross-sectional analytical experimental study. Furthermore, sensory acceptance of thesamples through an acceptance test of five points was evaluated. One-way ANOVA with post hoc Bonferroni were used to assess the mean difference between groups. The value of p≤0.05 was considered statistically significant.Results: Both processes reduced the amount of sodium in both types of ham in statistically significant way (p≤0.001). The major percentage of reduction was presented with SC: 73.4% for turkey ham and 63.5% for pork ham. Likewise, the higher percentage of nitrite reduction was 50.6% in pork ham with SC technique (p≤0.05). Peroxide index decreased with both techniques in both hams without statistical significance. Total coliforms count was kept constant in all samples. Higher sensory acceptance of W concerning SC in all sensory characteristics was observed.Conclusions: W and SC techniques reduce sodium, nitrite and peroxide index without affecting the sanitation of hams. Furthermore, W is accepted in all sensory categories. We recommend using W technique before consumption of the product.Introducción: El jamón, producto altamente consumido por la sociedad, contiene algunos elementos que lo convierten en un alimento no recomendable, por lo que se ha buscado eliminar o reducir esos componentes.Material y Métodos: Se compararon los contenidos de sodio, nitritos, índice de peróxidos y coliformes totales resultantes de los procesos de Lavado (L) y Cocción Simple (CS) aplicados al jamón de pavo y de cerdo en un estudio transversal analítico experimental. Además, se evaluó la aceptación sensorial de las muestras a través de una prueba de aceptación de cinco puntos. Se aplicó la prueba ANOVA de 1 vía con post hoc de Bonferroni para valorar la diferencia de medias entre grupos. El valor de p≤0,05 se consideró estadísticamente significativo.Resultados: Ambos procesos redujeron la cantidad de sodio en ambos tipos de jamón de manera estadísticamente significativa (p≤0,001). El mayor porcentaje de reducción se presentó con CS: 73,4% para el jamón de pavo y 63,5% para el jamón de cerdo. Asimismo, el mayor porcentaje de reducción de nitritos fue de 50,6% con la técnica de CS en el jamón de cerdo (p≤0,05). El índice de peróxidos disminuyó con ambas técnicas en ambos jamones sin significancia estadística. El conteo de coliformes totales se mantuvo constante en todas las muestras. Se observó una mayor aceptación sensorial de L sobre CS en todas las características sensoriales.Conclusiones: Las técnicas de L y CS reducen sodio, nitritos e índice de peróxidos sin afectar la sanidad de los jamones. Asimismo, L es aceptada sensorialmente en todas sus categorías. Se recomienda utilizar la técnica de L antes del consumo del producto

Nivel de calidad de vida laboral de las obstetras hospitales de MINSA nivel III. Trujillo - 2016

Con el objetivo de determinar el nivel de calidad de vida laboral de las obstetras Hospitales de MINSA nivel III. Trujillo-2016; se realizó una investigación de tipo descriptivo simple, en una muestra de 38 obstetras de los hospitales del MINSA nivel III: Belén y Regional, a quienes se les aplicó una encuesta sobre la calidad de vida, compuesta por tres parámetros: ambiente laboral, honorarios y trato. El nivel de calidad de vida laboral de las obstetras según ambiente laboral, honorarios y trato; es inadecuado en un 28.9% (11 Obstetras) y adecuado un 71.1% (27 Obstetras). Sobre la calidad de la vida laboral de las Obstetras según ambiente laboral en el 10.5% (4 Obstetras) es inadecuado y en el 89.5% (34 Obstetras) es adecuado, mientras que en la calidad de la vida laboral según Honorarios en un 60.5% (23 Obstetras) es inadecuado y en el 39.5% (15 Obstetras) es adecuado. Por último, según el trato en el 7.9% (3 Obstetras) es inadecuado y en un 92.1% (35 Obstetras) es adecuado.With the objective of determining the level of quality of work life of obstetricians Hospitals of MINSA level III. Trujillo-2016; a simple descriptive research was carried out in a sample of 38 obstetricians from MINSA hospitals level III: Belén and Regional, to whom a quality of life survey was applied, composed of three parameters: work environment, fees and Treatment. The level of quality of work life of obstetricians according to work environment, fees and treatment; it is inadequate in 28.9% (11 Obstetricians) and adequate 71.1% (27 Obstetricians). On the quality of working life of the Obstetricians according to work environment in 10.5% (4 Obstetricians) is inadequate and in 89.5% (34 Obstetricians) it is adequate, while in the quality of working life according to Honoraries in 60.5% (23 Obstetricians) is inadequate and in 39.5% (15 Obstetricians) it is adequate. Finally, according to the treatment in 7.9% (3 Obstetricians) it is inadequate and in 92.1% (35 Obstetricians) it is adequate.Tesi

Dynamic Characterization of Typical Electrical Circuits via Structural Properties

The characterization of a class of electrical circuits is carried out in terms of both stability properties and steady-state behavior. The main contribution is the interpretation of the electrical topology (how the elements that conform the circuits are interconnected) in terms of mathematical properties derived from the structure of their models. In this sense, at what extent the topology by itself defines the dynamic behavior of the systems is explained. The study is based on the graph theory allowing capturing, departing from the well-known Kirchhoff laws, the topology of the circuits into several matrices with specific structure. The algebraic analysis of these matrices permits identifying conditions that determine whether the system is stable in the sense of Lyapunov and the kind of steady-state behavior that it exhibits. The approach is mainly focused on typical topologies widely used in practice, namely, radial, ring, and mesh networks

Factibilidad tecnica de fabricar un tablero a partir de fibras de carton reciclado aplicando un retardante de fuego

81 p.El presente estudio tuvo como finalidad la fabricación de tableros de fibras de alma alveolada, para lo cual se utilizó un molde que permitiera la conformación de un tablero tipo panal de abejas, empleando fibras provenientes de cartón reciclado, y así determinar su posible uso en tabiquería, para lo cual se aplicaría un retardante de fuego de marca nacional para permitir su uso al interior deviviendas. Para lograr este objetivo se realizaron innumerables ensayos con el fin de fabricar un tablero de características aceptables, pero después de meses de ensayos en los que se emplearon distintos moldes y condiciones de trabajo, no fue posible el desarrollar un tablero, que reuniese las características necesarias para ser evaluadas, razón por la cual, bajo estas nuevas condiciones, no se justificaba la aplicación del retardante de fuego, dado que no se logró con éxito el objetivo principal de esta memoria, este es determinar su factibilidad y establecer procesos para la conformación de un tablero de características físicas y mecánicas aceptables. De igual manera, esta memoria podría ser un aporte en la realización de futuros estudios, ya que se presentan todos los procedimientos realizados y se analizan las posibles deficiencias generadas en el proceso de fabricación, así como también, se entregan algunas recomendaciones, que ayudarían en próximas investigaciones relacionadas, o incluso en la finalización de esta