Elaboración de guías de laboratorio de sistemas de control y medidas en subestaciones eléctricas

El estudio consiste en una guía metodológica de laboratorio en el área de automatización de subestaciones eléctricas, aplicando estrategias didácticas y de aprendizaje del conocimiento. Establece guías de laboratorio con instrumentos y equipos que simulen un escenario real de automatización, utilizando el controlador de bahía Ingepac EF-CD, a través de sus botoneras y mediante protocolos de comunicación usados en la industria eléctrica

Attitudes towards condom use in older adults residents of Monterrey Nuevo Leon, Mexico

Introducción: El uso del condón es efectivo para prevenir Infecciones de Transmisión Sexual. Se han identificado cifras bajas de uso en adultos mayores. Lo cual puede ser atribuible a diversas actitudes negativas. Objetivo: Conocer las actitudes hacia el uso del condón, la relación que existe entre estas y las características sociodemográficas, y entre el uso del condón en el último encuentro sexual en adultos mayores. Métodos: Estudio correlacional conformado por 110 adultos mayores residentes de Monterrey, Nuevo León. Se empleo un muestreo virtual. Resultados: Se encontraron actitudes negativas de los efectos sobre la experiencia sexual, promiscuidad e inhibición en una cuarta parte de los participantes. Y actitudes positivas en las actitudes globales, el impacto interpersonal y la relación segura en la mayoría de los participantes. Se encontró asociación entre estado civil y efectos sobre la experiencia sexual (p = 0.012). No se encontró asociación entre el uso del condón en el último encuentro sexual y las actitudes. Conclusión: Se encontraron más actitudes positivas que negativas, situación que no es congruente con la baja frecuencia de uso del condón en el último encuentro sexual, reflejando la importancia de futuras investigaciones que permitan explorar otros factores involucrados para el desarrollo de la conducta.Introduction: Condom use is effective in preventing sexually transmitted infections. Low rates of condom use have been identified in older adults. This may be attributable to various negative attitudes. Objective: To determine attitudes towards condom use, the relationship between these attitudes and sociodemographic characteristics, and between condom use in the last sexual intercourse in older adults. Methods: Correlational study of 110 older adults residents of Monterrey, Nuevo León. An online virtual sampling was used. Results: Negative attitudes regarding the effects on sexual experience, promiscuity and inhibition were found in a quarter of the participants. And positive attitudes on global attitudes, interpersonal impact and safe relationship in the majority of participants. Associations were found between marital status and effects on sexual experience (p = .012). No association was found between condom use at last sexual intercourse and attitudes toward condom use. Conclusion: More positive than negative attitudes were found, a situation that is not congruent with the low frequency of condom use in the last sexual encounter, reflecting the importance of future research to explore other factors involved in the development of the behavior

Mis casos clínicos de especialidades odontológicas

Libro que muestra la atención de casos clínicos particulares referente a las diferentes especialidades odontológicasLibro que muestra la atención de casos clínicos particulares referente a las diferentes especialidades odontológicasUniversidad Autónoma de Campeche Universidad Autónoma del Estado de Hidalgo Universidad Autónoma del Estado de Méxic

High-Power-Factor LC Series Resonant Converter Operating Off-Resonance with Inductors Elaborated with a Composed Material of Resin/Iron Powder

The most common problems with magnetic cores in high-stress applications are changes in their permeability and low saturation flux density, forcing designers to use special nanocrystalline cores, which raises the overall cost of the circuit. This paper evaluates the performance of a low-cost magnetic material composed of unsaturated polyester la mination resin COR61-AA-531EX and 200 mesh iron powder with a grain size of 74 µm, which has magnetic properties of the so-called “soft magnetic composites”, which have good magnetic characteristics in high-frequency and high-stress applications. This composite material was used for the elaboration of magnetic cores for the inductors of a resonant converter, which aims to achieve a high power factor, where in this type of application, there are large current and voltage excursions in the magnetic components that vary between high and low frequencies, being a suitable application for testing the inductors with a magnetic core of resin/iron powder. The converter was designed to operate off-resonance at different switching frequencies from 300 kHz to 800 kHz to feed a resistive load with a power output of 19 watts. The operation of the circuit was experimentally validated using a resistive load at the output, validating the theoretical analysis and achieving a power factor above 98%

Asociación entre características sociodemográficas, síntomas depresivos, estrés y ansiedad en tiempos de la COVID-19

Introduction: The COVID-19 pandemic has affected the mental health of the population. Depressive symptoms, stress, and anxiety are negative responses that can occur in risky situations in which uncertainty, the unknown or crisis situations are faced, such as the current health crisis. Objective: To identify the association between sociodemographic factors and depressive symptoms, level of stress and anxiety in times of COVID-19 in inhabitants of the city of Saltillo Coahuila, Mexico.Methods: Cross-sectional predictive correlational study. The population was inhabitants of the city of Saltillo Coahuila, Mexico. The sample consisted of 501 participants, who were collected through an online survey that was made available from October 5 to 24, 2020.Results: Age (OR = .93; 95% CI: .900 - .979) and being without a partner (OR = 2.64; 95% CI: 1.347 - 5.201) increase the probability of suffering severe depressive symptoms. Younger people were .95 more likely to have elevated stress. Being a woman (OR = 2.37; 95% CI: 1,144 - 4,915) and not having a job (OR = 2.62; 95% CI: 1,308 - 5,254) was associated with a higher probability of suffering from severe anxiety.Conclusion: Associations were found in sociodemographic factors such as sex, age and economic income with depressive symptoms, level of stress and anxiety in times of COVID-19. These results project preliminary data on some aspects related to mental health in the Mexican context during the current health crisis.Introducción: La pandemia por la COVID-19 ha afectado la salud mental de la población. Los síntomas depresivos, estrés y ansiedad son respuestas negativas que pueden presentarse ante situaciones de riesgo en las que se hace frente a la incertidumbre, lo desconocido o situaciones de crisis, como la actual crisis sanitaria. Objetivo: Identificar la asociación entre los factores sociodemográficos y síntomas depresivos, nivel de estrés y ansiedad en tiempos de la COVID-19 en habitantes de la ciudad de Saltillo Coahuila, México.Métodos: Estudio correlacional predictivo de corte transversal. La población fueron habitantes de la ciudad de Saltillo Coahuila, México. La muestra fue de 501 participantes, recolectados a través de una encuesta online que se habilitó del 5 al 24 de octubre de 2020.Resultados: La edad (OR = .93; 95% IC: .900 – .979) y estar sin pareja (OR = 2.64; 95% IC: 1.347 – 5.201) aumenta la probabilidad de sufrir síntomas depresivos severos. Personas más jóvenes tuvieron .95 mayor probabilidad de presentar estrés elevado. Ser mujer (OR = 2.37; 95% IC: 1.144 – 4.915) y no contar con empleo (OR = 2.62; 95% IC: 1.308 – 5.254) se asoció con mayor probabilidad de sufrir ansiedad severa.Conclusión: Se encontró asociación en factores sociodemográficos como el sexo, edad e ingreso económico con los síntomas depresivos, nivel de estrés y ansiedad en tiempos de la COVID-19. Estos resultados proyectan datos preliminares de algunos aspectos relacionados con la salud mental en el contexto mexicano durante la actual crisis sanitaria

Análisis de las propiedades psicométricas de la Escala de Comer Emocional (Emotional Eating Scale [EES-C]) en adolescentes mexicanos

Introduction: Emotional eating is a form of disordered eating and is defined as the act of consuming food in response to negative emotions such as sadness, depressive symptoms, stress, anxiety and irritability. The Emotional Eating Scale for Children and Adolescents (EES-C) allows to identify the emotions that originate or appear in the CE. Objective: To evaluate the psychometric properties of the EES-C in adolescents residing in Northeast Mexico. And to analyze the relationships of the CE according to the sex, age and nutritional status of the participants. Material and Methods: Confirmatory factor analysis (CFA), reliability (internal consistency) and convergent validity of the EES-C in Spanish was performed. Participated 631 adolescents enrolled in the 7th to 9th grade of basic education residing in Northeast Mexico participated. Weight and height measurements were made and the nutritional status of the participants was obtained. Results: The goodness of fit indexes of the proposed model were acceptable: (CFI=0.921; GFI=0.907; AGFI=0.876; SRMS=0.055 and RMSEA=0.068). The internal consistency was acceptable (α=0.92). The average age of the participants was 13.74 years (SD=0.90), the weight ranged between 30.9 and 130.4kg (SD=13.20). Conclusions: The confirmatory factor analysis of the proposed model has a high internal consistency, and five-factor factor structure has an adequate fit. It can be used to measure emotional eating in Mexican adolescents. It is recommended to contrast this model in similar populations.Introducción: Comer emocional (CE) es una forma de alimentación desordenada y se define como el acto de consumir alimentos en respuesta a emociones negativas tales como tristeza, sínto-mas depresivos, estrés, ansiedad e irritabilidad. La Escala de Comer Emocional para Niños y Adolescentes (Emotional Eating Scale [EES-C]) permite identificar las emociones que originan o se presentan en el CE. Objetivo: Evaluar las propiedades psicométricas de la EES-C en adolescentes residentes en el Noreste de México; y analizar la relación del CE de acuerdo a sexo, edad y estado nutricional de los participantes. Material y Métodos: Se realizó análisis factorial confirmatorio (AFC), se analizó la fiabilidad (con-sistencia interna) y validez convergente de la EES-C. Participaron 631 adolescentes que cursaban entre el 7º y 9º grado de educación básica residentes en el Noreste de México. Se realizaron me-diciones de peso y estatura y se obtuvo el estado nutricional de los participantes. Resultados: Los índices de bondad de ajuste del modelo propuesto fueron aceptables: (CFI=0,921; GFI=0,907; AGFI=0,876; SRMS=0,055 y RMSEA=0,068), así como la consistencia interna (α=0,92). La edad promedio de los participantes fue 13,74 años (DE=0,90), el peso osciló entre 30,9 y 130,4kg (DE=13,20). Conclusiones: El AFC del modelo propuesto tiene una consistencia interna alta y estructura fac-torial de cinco factores con un ajuste adecuado. Puede ser utilizada para medir el CE en adoles-centes mexicanos. Se recomienda contrastar este modelo en poblaciones similares

Series RLC Resonant Circuit Used as Frequency Multiplier

Currently, the design of resonant power converters has only been developed while operating in the steady state, while the design operating in the transient stage has not been considered nor reported. This paper is interested in testing the performance of the resonant circuits operating in the transient stage and finding applications where benefits can be obtained from this form of operation. One application in which it is possible to obtain benefits from designing resonant circuits in the transient state is in the area of frequency multiplication. Usually, to achieve frequency multiplication, it is necessary to resort to complex methods and special devices that increase the complexity of the design and the total cost of the circuit. This paper evaluates the performance of a series RLC resonant circuit operating in the transient stage and with an underdamped response acting as a frequency multiplier, where the oscillation frequency of the current in the resonant tank is “n” number of times the switching frequency of the square voltage source at the input with a duty cycle of D = 50%. To validate the analysis, a circuit was designed to deliver an output power of 30 watts to a resistive load, where the switching frequency of the square voltage source at the input was 500 kHz. Since a multiplier value “n” equal to fifteen was chosen, the current in the resonant tank reached an oscillation frequency of 7.5 MHz. The design methodology was validated by simulations in SPICE, complying with the established design parameters

Series RLC Resonant Circuit Used as Frequency Multiplier

Currently, the design of resonant power converters has only been developed while operating in the steady state, while the design operating in the transient stage has not been considered nor reported. This paper is interested in testing the performance of the resonant circuits operating in the transient stage and finding applications where benefits can be obtained from this form of operation. One application in which it is possible to obtain benefits from designing resonant circuits in the transient state is in the area of frequency multiplication. Usually, to achieve frequency multiplication, it is necessary to resort to complex methods and special devices that increase the complexity of the design and the total cost of the circuit. This paper evaluates the performance of a series RLC resonant circuit operating in the transient stage and with an underdamped response acting as a frequency multiplier, where the oscillation frequency of the current in the resonant tank is “n” number of times the switching frequency of the square voltage source at the input with a duty cycle of D = 50%. To validate the analysis, a circuit was designed to deliver an output power of 30 watts to a resistive load, where the switching frequency of the square voltage source at the input was 500 kHz. Since a multiplier value “n” equal to fifteen was chosen, the current in the resonant tank reached an oscillation frequency of 7.5 MHz. The design methodology was validated by simulations in SPICE, complying with the established design parameters

Association between sociodemographic characteristics, depressive symptoms, stress and anxiety in times of COVID-19

Introducción: La pandemia por la COVID-19 ha afectado la salud mental de la población. Los síntomas depresivos, estrés y ansiedad son respuestas negativas que pueden presentarse ante situaciones de riesgo en las que se hace frente a la incertidumbre, lo desconocido o situaciones de crisis, como la actual crisis sanitaria. Objetivo: Identificar la asociación entre los factores sociodemográficos y síntomas depresivos, nivel de estrés y ansiedad en tiempos de la COVID-19 en habitantes de la ciudad de Saltillo Coahuila, México. Métodos: Estudio correlacional predictivo de corte transversal. La población fueron habitantes de la ciudad de Saltillo Coahuila, México. La muestra fue de 501 participantes, recolectados a través de una encuesta online que se habilitó del 5 al 24 de octubre de 2020. Resultados: La edad (OR = .93; 95% IC: .900 – .979) y estar sin pareja (OR = 2.64; 95% IC: 1.347 – 5.201) aumenta la probabilidad de sufrir síntomas depresivos severos. Personas más jóvenes tuvieron .95 mayor probabilidad de presentar estrés elevado. Ser mujer (OR = 2.37; 95% IC: 1.144 – 4.915) y no contar con empleo (OR = 2.62; 95% IC: 1.308 – 5.254) se asoció con mayor probabilidad de sufrir ansiedad severa. Conclusión: Se encontró asociación en factores sociodemográficos como el sexo, edad e ingreso económico con los síntomas depresivos, nivel de estrés y ansiedad en tiempos de la COVID-19. Estos resultados proyectan datos preliminares de algunos aspectos relacionados con la salud mental en el contexto mexicano durante la actual crisis sanitaria.Introduction: The COVID-19 pandemic has affected the mental health of the population. Depressive symptoms, stress, and anxiety are negative responses that can occur in risky situations in which uncertainty, the unknown or crisis situations are faced, such as the current health crisis. Objective: To identify the association between sociodemographic factors and depressive symptoms, level of stress and anxiety in times of COVID-19 in inhabitants of the city of Saltillo Coahuila, Mexico. Methods: Cross-sectional predictive correlational study. The population was inhabitants of the city of Saltillo Coahuila, Mexico. The sample consisted of 501 participants, who were collected through an online survey that was made available from October 5 to 24, 2020. Results: Age (OR = .93; 95% CI: .900 - .979) and being without a partner (OR = 2.64; 95% CI: 1.347 - 5.201) increase the probability of suffering severe depressive symptoms. Younger people were .95 more likely to have elevated stress. Being a woman (OR = 2.37; 95% CI: 1,144 - 4,915) and not having a job (OR = 2.62; 95% CI: 1,308 - 5,254) was associated with a higher probability of suffering from severe anxiety. Conclusion: Associations were found in sociodemographic factors such as sex, age and economic income with depressive symptoms, level of stress and anxiety in times of COVID-19. These results project preliminary data on some aspects related to mental health in the Mexican context during the current health crisis

High-Power-Factor LC Series Resonant Converter Operating Off-Resonance with Inductors Elaborated with a Composed Material of Resin/Iron Powder

The most common problems with magnetic cores in high-stress applications are changes in their permeability and low saturation flux density, forcing designers to use special nanocrystalline cores, which raises the overall cost of the circuit. This paper evaluates the performance of a low-cost magnetic material composed of unsaturated polyester la mination resin COR61-AA-531EX and 200 mesh iron powder with a grain size of 74 µm, which has magnetic properties of the so-called “soft magnetic composites”, which have good magnetic characteristics in high-frequency and high-stress applications. This composite material was used for the elaboration of magnetic cores for the inductors of a resonant converter, which aims to achieve a high power factor, where in this type of application, there are large current and voltage excursions in the magnetic components that vary between high and low frequencies, being a suitable application for testing the inductors with a magnetic core of resin/iron powder. The converter was designed to operate off-resonance at different switching frequencies from 300 kHz to 800 kHz to feed a resistive load with a power output of 19 watts. The operation of the circuit was experimentally validated using a resistive load at the output, validating the theoretical analysis and achieving a power factor above 98%