Optimización de los parámetros de operación en un proceso de tratamiento de aguas por electro-oxidación

En este estudio se evaluó la electro-oxidación como tratamiento para aguas residuales provenientes del proceso de producción de resinas fenólicas. Los experimentos se llevaron a cabo en un reactor tipo batch a escala laboratorio con una configuración monopolar con electrodos de grafito y titanio. Se realizaron ensayos preliminares con un volumen de muestra de 200 ml, un área sumergida de 25.13 cm2 para el electrodo de grafito (ánodo) y 40 cm2 para el electrodo de titanio (cátodo) y un tiempo de residencia de 240 minutos, 15 voltios y una agitación de 200 rpm.113 p.This study evaluated the electro-oxidation of phenolic resins production wastewater treatment. The experiments were carried out in a laboratory scale batch reactor with a monopolar configuration was built with graphite (anode) and titanium (cathode) electrodes. Prelimary tests were carried out with a sample volume of 200 ml, a submerged area of 25.13 cm2 for the graphite electrode and 40 cm2 for the titanium electrode and 240 minutes as a residence time, voltage of 15 V and an agitation value of 200 rpm.Contenido parcial: Aguas contaminadas con fenol -- Procesos electroquímicos de oxidación avanzada -- Electro-Oxidación -- Aspectos técnicos de operación de la electro-oxidación -- Especificaciones técnicas de la celda para electro-oxidación -- Diseño de experimentos

Notes on beta-deformations of the pure spinor superstring in AdS(5) x S(5)

We study the properties of the vertex operator for the beta-deformation of the superstring in AdS(5) x S(5) in the pure spinor formalism. We discuss the action of supersymmetry on the infinitesimal beta-deformation, the application of the homological perturbation theory, and the relation between the worldsheet description and the spacetime supergravity description.Comment: LaTeX, 74pp

Special issue: Innovations in farming systems approaches: Introduction

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Who uses Transport Network Companies?: Characterization of Demand and its Relationship with Public Transit in Medellín

Transport Network Companies (TNCs) have become a popular alternative for mobility due to their ability to provide on-demand flexible mobility services. By offering smartphone-based, ride-hailing services capable of satisfying specific travel needs, these modes have transformed urban mobility worldwide. However, to-date, few studies have examined the impacts in the Latin American context. This analysis is a critical first step in developing policies to promote efficient and sustainable transport systems in the Latin-American region. This research examines the factors affecting the adoption of on-demand ride services in Medellín, Colombia. It also explores whether these are substituting or competing with public transit. First, it provides a descriptive analysis in which we relate the usage of platform-based services with neighborhood characteristics, socioeconomic information of individuals and families, and trip-level details. Next, factors contributing to the election of platform-based services modeled using discrete choice models. The results show that wealthy and highly educated families with low vehicle availability are more likely to use TNCs compared to other groups in Medellín. Evidence also points at gender effects, with being female significantly increasing the probability of using a TNC service. Finally, we observe both transit complementary and substitution patterns of use, depending on the context and by whom the service is requested

Pure Spinor Integration from the Collating Formula

We use the technique developed by Becchi and Imbimbo to construct a well-defined BRST-invariant path integral formulation of pure spinor amplitudes. The space of pure spinors can be viewed from the algebraic geometry point of view as a collection of open sets where the constraints can be solved and a free independent set of variables can be defined. On the intersections of those open sets, the functional measure jumps and one has to add boundary terms to construct a well-defined path integral. The result is the definition of the pure spinor integration measure constructed in term of differential forms on each single patch.Comment: 22 page

Reporte de caso: diabetes mellitus tipo 1 inducida por pembrolizumab en un paciente con adenocarcinoma de pulmón

Presentamos el caso de una paciente sin comorbilidades metabólicas con diagnóstico de adenocarcinoma de pulmón en manejo con pembrolizumab, quien, posterior al tercer ciclo de tratamiento, debuta con cetoacidosis diabética, requiere manejo para crisis hiperglucémica e insulina. Se realizó diagnóstico de diabetes mellitus tipo 1 y se reintrodujo el tratamiento de pembrolizumab a 200 mg cada tres semanas además del manejo con insulina. En la actualidad la paciente permanece con una respuesta parcial posterior a 1 año del diagnóstico y sigue en manejo con insulinoterapia. En vista que en la actualidad no se cuenta con protocolos y guías de manejo para esta entidad, se realiza revisión del manejo y de la literatura debido a que solo se encuentran 6 casos reportados, siendo este el primer caso reportado en Colombia

Análisis comparativo de adhesión a la dieta mediterránea entre niñas y adolescentes de gimnasia rítmica

Introduction: Eating habits are one of the underlying aspects in rhythmic gymnastics as a sport with an aesthetic component. Objective: To evaluate adherence to the Mediterranean diet (MD) in girls and adolescents who perform rhythmic gymnastics, and the relationship of this adherence with Body Mass Index (BMI) and waist circumference. Methods: A prospective, descriptive comparative cross-sectional study with the participation of 221 gymnasts aged between 7 and 17 years. Adherence to the Mediterranean diet was analyzed using the KIDMED test. The waist circumference, height and weight of each gymnast were measured and the BMI calculated. Results: 41.63%, 52.94% and 5.43% of the total sample exhibited high, medium and low adherence, respectively, to the Mediterranean diet. The Mann-Whitney U test indicated significant differences in the rate of adherence to the Mediterranean diet between the two age groups, U = 5007.0, p = .016, r = .162. The adolescent gymnasts had greater adherence than the younger gymnasts. The total sample showed a positive correlation of the rate of adherence with weight (Rho = .143, p = .034), BMI (Rho = .152, p = .024) and waist circumference (Rho = .180, p = .007). Conclusions: The eating habits of adolescent gymnasts with regard to the Mediterranean diet are healthier than those of the younger gymnasts. All participants had normal BMI values. The KIDMED values of the total sample were related to weight and BMI. The high percentages of younger gymnasts with mean adherence to the MD evidenced the need to approximate their eating habits with Mediterranean standards.Introducción: Los hábitos alimentarios son uno de los aspectos fundamentales en la gimnasia rítmica como deporte de componente estético. Objetivo: Evaluar la adhesión a la dieta mediterránea (DM) en niñas y adolescentes de gimnasia rítmica y su relación con el Índice de Masa Corporal (IMC) y el perímetro de cintura. Métodos: Estudio prospectivo, transversal, descriptivo y comparativo en donde participaron 221 gimnastas entre 7 y 17 años. Se analizó la adhesión a la dieta mediterránea a través del test KIDMED. Fueron medidos el perímetro de cintura, así como la altura y el peso de cada gimnasta, calculando el IMC. Resultados: 41,63%, 52,94% y 5,43% de la muestra total demostraron la adhesión a la dieta mediterránea alta, mediana y baja respectivamente. El test U de Mann-Whitney apuntó diferencias significativas del índice de adhesión a la dieta mediterránea entre los dos grupos de edad, U = 5007,0, p = ,016, r = ,162. Las gimnastas adolescentes presentaron mayor adhesión que las niñas. La muestra total mostró una correlación positiva del índice de adhesión con el peso (Rho = ,143, p = ,034), IMC (Rho = ,152, p = ,024), y perímetro de cintura (Rho = ,180, p = ,007). Conclusiones: Los hábitos de las gimnastas adolescentes con relación a la dieta mediterránea son más saludables que los de las gimnastas niñas. Todas presentaron valores normales de IMC. Los valores de Kidmed de la muestra total se relacionaron al peso y al IMC. Los elevados porcentajes de gimnastas niñas con adhesión mediana a la DM evidencian la necesidad de aproximar sus hábitos a los estándares mediterráneos. Nivel de evidencia II; Estudio de diagnóstico comparativo