Towards a new generation of transport services adapted to multimedia application

Une connexion d'ordre et de fiabilité partiels (POC, partial order connection) est une connexion de transport autorisée à perdre certains objets mais également à les délivrer dans un ordre éventuellement différent de celui d'émission. L'approche POC établit un lien conceptuel entre les protocoles sans connexion au mieux et les protocoles fiables avec connexion. Le concept de POC est motivé par le fait que dans les réseaux hétérogènes sans connexion tels qu'Internet, les paquets transmis sont susceptibles de se perdre et d'arriver en désordre, entraînant alors une réduction des performances des protocoles usuels. De plus, on montre qu'un protocole associé au transport d'un flux multimédia permet une réduction très sensible de l'utilisation des ressources de communication et de mémorisation ainsi qu'une diminution du temps de transit moyen. Dans cet article, une extension temporelle de POC, nommée TPOC (POC temporisé), est introduite. Elle constitue un cadre conceptuel permettant la prise en compte des exigences de qualité de service des applications multimédias réparties. Une architecture offrant un service TPOC est également introduite et évaluée dans le cadre du transport de vidéo MPEG. Il est ainsi démontré que les connexions POC comblent, non seulement le fossé conceptuel entre les protocoles sans connexion et avec connexion, mais aussi qu'ils surpassent les performances des ces derniers lorsque des données multimédias (telles que la vidéo MPEG) sont transportées

DISEÑO CURRICULAR ARTICULADO DESDE LA ENSEÑANZA DE LA SEGREGACIÓN SOCIO- ESPACIAL, EN LAS INSTITUCIONES EDUCATIVAS DE CARÁCTER PÚBLICO DE LA COMUNA SEIS, DE LA CIUDAD DE IBAGUE, DEPARTAMENTO DEL TOLIMA

La investigación está enmarcada bajo la línea detrabajo Segregación socio espacial en el contextode la ciudad de Ibagué, respectivamente en la comunanúmero seis, Dentro de la investigación se determinaronlos mecanismos por los cuales se originala diferenciación social en nuestro país de manerageneral, para posteriormente recaer a un planolocal referenciado como Ibagué.Marcando una pauta inicial frente a generar unanálisis académico de forma precisa. Mediantela caracterización de la población, y la inclusiónde elementos cartográficos que evidencia la segregaciónen el sector de forma metodológica medianteinstrumentos y técnicas directos de inmersión. Loanteriormente estipulado, ha sido analizado bajoel área de conocimiento geográfico, articulandoun diseño curricular que permita la enseñanza dela segregación espacial en la media secundariaacadémica en las instituciones educativas públicasque convergen en la comuna.Palabras Clave: desigualdad social, segregaciónsocio-espacial, Territorialización, uso del suelo,currículo

Influence of operating temperature on the activation efficiency of Li-ion cells with xLi2MnO3-(1-x)LiMn0.5Ni0.5O2 electrodes

In this study, the effect of operating temperature at 55 °C on xLi2MnO3-(1-x)LiMn0.5Ni0.5O2 electrodes during the charge/discharge process at different current densities was investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used for structural and morphological analysis of the fabricated cathode materials, while charge-discharge curves and differential capacity were used to study the electrochemical behavior. Results confirm the formation of the structures with two phases associated with the components of the layered material. It was found that at 55 °C, a capacity higher than 357 mAh g-1 could be achieved at a voltage of 2.5-4.8 V vs. Li/Li+, which was larger than the capacity achieved at room temperature. At 55 °C, a change in valence could be observed during charging and discharging due to the change in the position of the peaks associated with Mn and Ni, highlighting cathodic material with x = 0.5 as the material that retains the layered structure at this temperature. This work confirms the good performance of electrodes made with this material at elevated temperatures and gives a better understanding of its electrochemical behavior

QdS requise par une application de simulation interactive distribuée dans un environnement réseau grande distance

Ces dernières années, les évolutions technologiques conjointes de l'informatique et des télécommunications ont conduit au développement de nouvelles applications distribuées, multimédias, nécessitant le traitement informatique et le transfert différé ou en temps réel de tous les types de données. Parmi ces applications, les applications de simulation interactive distribuée (DIS : Distributed Interactive Simulation) présentent des caractéristiques très contraignantes (trafic évolutif, contraintes de temps réel et de fiabilité notamment) qui rendent difficile tant la caractérisation de leur trafic que la spécification de la QoS (QoS : Quality of service) dont elles ont besoin. Cet article présente tout d’abord les caractéristiques majeures des applications DIS ; dans un second temps sont exposés les résultats d’une analyse de la QoS requise par ce type d’application dans un environnement réseau grande distance. Enfin, les conclusions de l’article présentent les principes de conception d’une architecture de bout en bout garantissant la QoS proposée dans un environnement Internet nouvelle génération

Electric current generation by increasing sucrose in papaya waste in microbial fuel cells

The accelerated increase in energy consumption by human activity has generated an increase in the search for new energies that do not pollute the environment, due to this, microbial fuel cells are shown as a promising technology. The objective of this research was to observe the influence on the generation of bioelectricity of sucrose, with different percentages (0%, 5%, 10% and 20%), in papaya waste using microbial fuel cells (MFCs). It was possible to generate voltage and current peaks of 0.955 V and 5.079 mA for the cell with 20% sucrose, which operated at an optimal pH of 4.98 on day fifteen. In the same way, the internal resistance values of all the cells were influenced by the increase in sucrose, showing that the cell without sucrose was 0.1952 ± 0.00214 KΩ and with 20% it was 0.044306 ± 0.0014 KΩ. The maximum power density was 583.09 mW/cm2 at a current density of 407.13 A/cm2 and with a peak voltage of 910.94 mV, while phenolic compounds are the ones with the greatest presence in the FTIR (Fourier transform infrared spectroscopy) absorbance spectrum. We were able to molecularly identify the species Achromobacter xylosoxidans (99.32%), Acinetobacter bereziniae (99.93%) and Stenotrophomonas maltophilia (100%) present in the anode electrode of the MFCs. This research gives a novel use for sucrose to increase the energy values in a microbial fuel cell, improving the existing ones and generating a novel way of generating electricity that is friendly to the environment.Campus Trujill

Effect of x on the Electrochemical Performance of Two-Layered Cathode Materials xLi2MnO3–(1−x)LiNi0.5Mn0.5O2

In our study, the cathodic material xLi2MnO3–(1−x)LiNi0.5Mn0.5O2 was synthesized by means of the co-precipitation technique. The effect of x (proportion of components Li2MnO3 and LiNi0.5Mn0.5O2) on the structural, morphological, and electrochemical performance of the material was evaluated. Materials were structurally characterized using X-ray diffraction (XRD), and the morphological analysis was performed using the scanning electron microscopy (SEM) technique, while charge–discharge curves and differential capacity and impedance spectroscopy (EIS) were used to study the electrochemical behavior. The results confirm the formation of the structures with two phases corresponding to the rhombohedral space group R3m and the monoclinic space group C2/m, which was associated to the components of the layered material. Very dense agglomerations of particles between 10 and 20 µm were also observed. In addition, the increase in the proportion of the LiNi0.5Mn0.5O2 component affected the initial irreversible capacity and the Li2MnO3 layer’s activation and cycling performance, suggesting an optimal chemical ratio of the material’s component layers to ensure high energy density and long-term durability

Green Energy Generated in Single-Chamber Microbial Fuel Cells Using Tomato Waste

"This research used tomato waste as a substrate (fuel) in Single Chamber-Microbial Fuel Cells (scMFC) on a small scale. The electrochemical properties were monitored, the functional groups of the substrate were analyzed by Fourier Transform Infrared Spectrophotometry (FTIR) and a microbiological analysis was performed on the electrodes in order to identify the microorganisms responsible for the electrochemical process. The results show voltage peaks and an electrical current of 3.647 ± 0.157 mA and 0.957 ± 0.246 V. A pH of 5.32 ± 0.26 was measured in the substrate with an electrical current conductivity of 148,701 ± 5849 mS/cm and an internal resistance (Rint) of 77. 517 ± 8.541 Ω. The maximum power density (PD) displayed was 264.72 ± 3.54 mW/cm2 at a current density (CD) of 4.388 A/cm2 . On the other hand, the FTIR spectrum showed a more intense decrease in its peaks, with the compound belonging to the phenolic groups being the most affected at 3361 cm−1 . The micrographs show the formation of a porous biofilm where molecular identification allowed the identification of two bacteria (Proteus vulgaris and Proteus vulgaris) and a yeast (Yarrowia lipolytica) with 100% identity. The data found show the potential of this waste as a source of fuel for the generation of an electric current in a sustainable and environmentally friendly way, generating in the near future a mechanism for the reuse of waste in a beneficial way for farmers, communities and agro-industrial companies.

Formación continuada docente: desafíos y oportunidades para una educación de calidad

This paper aims to present a literature review in relation to the continuing education of teachers with their pedagogical practice, with special emphasis on the Dialogical Pedagogical Education, understood as a type of documentary research on how different authors have dealt with a specific topic (Gomes, 2019. p.1). ) The information used for this literature review was obtained through a bibliographic search in databases and academic search engines such as: SCIELO, REDALYC, HIGHBEAM, DIALNET and GOOGLE ACADEMIC, which initially yielded a total of 195 products related to the topic. After applying the selection criteria, 52 references were included. After an analysis of the information, it can be concluded that there are some successful continuous teacher training practices, such as Dialogical Pedagogical Training. This practice, centered on dialogue, allows teachers to reflect on their pedagogical practice and encourages collaboration between teachers and their students, in addition to promoting a constructivist approach to learning, where students actively participate in the teaching-learning process. Despite the efforts made to date to improve teacher training in Colombia, there are still many important challenges, such as the consolidation of a teacher training subsystem that guarantees resources to finance graduate studies. Also required is the implementation of rigorous continuing education programs for teachers, so that they can keep abreast of new educational trends and didactic tools appropriate to the Colombian reality, in order to ensure quality education for all Colombians.El presente trabajo pretende presentar una revisión bibliográfica en relación de la formación continuada de maestros con su práctica pedagógica, haciendo un especial énfasis en la Formación Pedagógica Dialógica, entendido este artículo como un tipo de investigación documental acerca de la forma en que diferentes autores han tratado un tema específico (Gomes, 2019. pág.1) La información usada para esta revisión de literatura se obtuvo mediante una búsqueda bibliográfica en bases de datos y buscadores académicos tales como: SCIELO, REDALYC, HIGHBEAM, DIALNET y GOOGLE ACADÉMICO, lo que arrojó un total de 195 productos relacionados con el tema. Luego de aplicar los criterios de selección se incluyeron 52 referencias. Luego de un análisis de la información, se puede concluir que existen algunas prácticas exitosas de formación continua para maestros, como la Formación Pedagógica Dialógica. Esta práctica, centrada en el diálogo, permite que el profesor reflexione sobre su práctica pedagógica e incentiva la colaboración entre maestros y sus alumnos, además de promover un enfoque constructivista del aprendizaje, donde los estudiantes participan en el proceso de enseñanza-aprendizaje. A pesar de los esfuerzos realizados hasta la actualidad para mejorar la formación de docentes en Colombia, todavía hay muchos desafíos importantes, como la consolidación de un subsistema de formación docente que garantice recursos para el financiamiento de estudios de posgrado. También se requiere la implementación de programas de formación continua rigurosos para los maestros, para que puedan estar al tanto de las nuevas tendencias educativas y de las herramientas didácticas adecuadas a la realidad colombiana, con el fin de garantizar una educación de calidad para todos los colombianos

Recruitment characteristics and non-adherence associated factors of fibromyalgia patients in a randomized clinical trial : a retrospective survival analysis

Introduction: Fibromyalgia is a complex pain condition that affects mostly women. Given the disease's lack of understanding, patients report poor adherence to medication and mistrust of medical services. This study aims to describe the recruitment characteristics and non-adherence associated factors of fibromyalgia patients to an RCT. Methods: We performed a retrospective longitudinal analysis with data from our ongoing RCT. We investigated characteristics of subjects recruited, consented, and randomized. Adherence was studied using survival analysis techniques, and its associated factors were identified using Cox proportional hazards regression model. Results: 524 subjects were contacted, 269 were eligible, 61 consented and 40 subjects were randomized. Thirtyeight percent were non-adherent to the protocol with a median of visits of five. The recruitment survey reported that 90% would likely participate in RCTs, 52% had previous participation, and 19% were aware of RCTs by their physicians. Some barriers were investigator-related (staff's friendliness and receiving the results of their trial participation) and center-related (privacy-confidentiality issues and the institution's reputation), without difference between adherent and non-adherent participants. We report significant factors for non-adherence as VAS anxiety score of 5 or more (5.3 HR, p = 0.01), Body Mass Index (BMI) (0.91 HR, p = 0.041) and Quality of Life (QoL) – Personal development subdomain (0.89 HR, p = 0.046). Conclusion: Recruitment and adherence of fibromyalgia patients is a challenge; however, they seem eager to participate in RCTs. We recommend creating a comfortable, friendly and trusting environment to increase the recruitment rate. Higher anxiety, lower BMI and lower quality of life were associated with a higher attrition rate

Influencia de la ferrita de cobalto en la propiedades magnetoeléctricas de las películas delgadas de ferrita de bismuto depositadas por spin coating

Las películas de (1-x) BiFeO3- (x) CoFe2O4 variando la concentración (x = 0, 0.1, 0.2 y 0.3), fueron depositadas por spin coating sobre sustratos de Pt (Pt/TiO2/SiO2/Si) a partir de soluciones precursoras con una concentración de 0.05 molar, la cual fue obtenida por sol-gel. En la caracterización de las películas delgadas se estudió la estructura y las propiedades magnetoeléctricas mediante difracción de rayos X, corriente de fuga, constante dieléctrica, curva de histéresis ferroeléctrica y ferromagnética. En el difractograma de rayos X se muestran picos característicos con la formación de BiFeO3 y el crecimiento de los picos pertenecientes al CoFe2O4 con el aumento de x. Todas las muestras revelan poca corriente de fuga, siendo la menor de 10-10 A / cm2 para (0.8) BiFeO3- (0.2) CoFe2O4.  La constante dieléctrica se incrementó en el rango de 102Hz a 105Hz luego disminuyó debido a la relajación dieléctrica, para todas las muestras la pérdida dieléctrica es menor al 4%. Todas las películas muestran polarización y magnetización remanentes mayores a 60 μC/cm2 y 30 emu/gr  respectivamente.  Palabras clave: magnetoeléctricas, películas, ferromagnética  y ferroeléctrica