{"title":"ROBLE, CANTO Y ALMA","authors":"H. Domínguez","doi":"10.56029/nx1967","DOIUrl":"https://doi.org/10.56029/nx1967","url":null,"abstract":"","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44413656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
En la mañana del 7 de octubre de 1571, las costas de Lepanto acogieron uno de los combates más singulares y conocidos de la Edad Moderna. Ese día, dos enormes escuadras se encontraron en el antiguo golfo de Lepanto, una frente a la otra, con un claro objetivo: destruir al enemigo. Durante mucho tiempo (y todavía hoy), se habló de ello como el choque entre dos civilizaciones. Una icónica batalla que será representada en las artes de manera propagandística con numerosas representaciones acerca del enfrentamiento naval, que nos dejan vislumbrar algunas de las claves dinásticas, espirituales y simbólicas de un momento crucial para la Monarquía Hispánica.
{"title":"ARTE Y SOCIEDAD: LA REPRESENTACIÓN DE LA BATALLA DE LEPANTO EN LA DINASTÍA DE LOS AUSTRIA","authors":"Ángel Marrero Pimienta","doi":"10.56029/nx1923","DOIUrl":"https://doi.org/10.56029/nx1923","url":null,"abstract":"En la mañana del 7 de octubre de 1571, las costas de Lepanto acogieron uno de los combates más singulares y conocidos de la Edad Moderna. Ese día, dos enormes escuadras se encontraron en el antiguo golfo de Lepanto, una frente a la otra, con un claro objetivo: destruir al enemigo. Durante mucho tiempo (y todavía hoy), se habló de ello como el choque entre dos civilizaciones. Una icónica batalla que será representada en las artes de manera propagandística con numerosas representaciones acerca del enfrentamiento naval, que nos dejan vislumbrar algunas de las claves dinásticas, espirituales y simbólicas de un momento crucial para la Monarquía Hispánica.","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45463376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Modelos matematicos del secado en capa delgada para la levadura cervecera (Saccharomyces cerevisiae) fueron estudiados y verificados con datos experimentales. Doce (12) diferentes modelos matematicos de secado fueron comparados de acuerdo a tres parametros estadisticos, i.e., coeficiente de correlacion, error de la raiz cuadrada de la media y chi (χ²)-cuadrado. La cinetica de secado en capa delgada de la levadura cervecera fue experimentalmente estudiada en un secador de tunel de laboratorio y la modelacion matematica, usando los modelos de secado en capa delgada presente en la literatura, fue realizada. Los experimentos se realizaron a una temperatura de secado de 40, 50 y 60 oC y a una velocidad de aire de 1.2 m/s. Las curvas de secado obtenidas de los datos experimentales fueron ajustadas a los modelos de secado en capa delgada. Los resultados muestran que el modelo de Page es el modelo mas apropiado para predecir el comportamiento de secado en capa delgada de la levadura cervecera.
{"title":"Determination of suitable thin-layer drying models for brewer’s yeast (Saccharomyces cerevisiae)","authors":"Rolando Mendieta, Masoud Haerinejad, Apolinar Picado","doi":"10.5377/NEXO.V28I2.3421","DOIUrl":"https://doi.org/10.5377/NEXO.V28I2.3421","url":null,"abstract":"Modelos matematicos del secado en capa delgada para la levadura cervecera (Saccharomyces cerevisiae) fueron estudiados y verificados con datos experimentales. Doce (12) diferentes modelos matematicos de secado fueron comparados de acuerdo a tres parametros estadisticos, i.e., coeficiente de correlacion, error de la raiz cuadrada de la media y chi (χ²)-cuadrado. La cinetica de secado en capa delgada de la levadura cervecera fue experimentalmente estudiada en un secador de tunel de laboratorio y la modelacion matematica, usando los modelos de secado en capa delgada presente en la literatura, fue realizada. Los experimentos se realizaron a una temperatura de secado de 40, 50 y 60 oC y a una velocidad de aire de 1.2 m/s. Las curvas de secado obtenidas de los datos experimentales fueron ajustadas a los modelos de secado en capa delgada. Los resultados muestran que el modelo de Page es el modelo mas apropiado para predecir el comportamiento de secado en capa delgada de la levadura cervecera.","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2017-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47764125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-02DOI: 10.5377/NEXO.V28I01.1779
L. Aguilera, J. A. N. Zapata, Benjamín Otto Ortega Morales
A selection of 30 previously isolated bacteria of different types were taken, mainly Bacillus, which had been previously identified by microbiological and molecular methods to be epilithic biofilms from Chapultepec's Castle in Mexico City, DF. Different methodologies were practiced to determine which of them were forming biofilms and their quantification, the ureasa test and the production of crystals of calcium carbonate in Petry plate with Luria Bertani enriched with calcium carbonate to 0.2 %. The crystals obtained were submitted to diffraction of X-rays and Electronic Microscopy of Sweep. The results show that all microorganisms tested were involved in the process of biofilm formation, and only 12 isolates, including the IS16 (Bacillus subtilis); IIS15a (Bacillus cereus) and IIIS10 (Bacillus subtilis) strains, were the best biofilm formers with high UFC / mL, good in terms of bioprecipitation of carbonates. Particularly, the strains IIIS4 (Bacillus megaterium), IS5 (Bacillus subtilis), IIIS9b (Bacillus subtilis), 21 (Pantoea agglomerans) and IIIS5 (Bacillus simplex). May be some of the microorganisms could be capable of producing urease, to induce precipitation of calcite that contributes to the restoration. As of now, little is known about the participation of Pantoea agglomerans in processes of biorrestauration by means of bioprecipitation of crystals of calcium carbonate and due to the fact that a good response was obtained from the test of ureasa and the crystals obtained were mainly Calcita (99 %), this work shows the feasibility of using this native microorganisms for their activation to achieve the restoration of the worn monuments.
{"title":"La bioprecipitación de carbonato de calcio por la biota nativa como un método de restauración.","authors":"L. Aguilera, J. A. N. Zapata, Benjamín Otto Ortega Morales","doi":"10.5377/NEXO.V28I01.1779","DOIUrl":"https://doi.org/10.5377/NEXO.V28I01.1779","url":null,"abstract":"A selection of 30 previously isolated bacteria of different types were taken, mainly Bacillus, which had been previously identified by microbiological and molecular methods to be epilithic biofilms from Chapultepec's Castle in Mexico City, DF. Different methodologies were practiced to determine which of them were forming biofilms and their quantification, the ureasa test and the production of crystals of calcium carbonate in Petry plate with Luria Bertani enriched with calcium carbonate to 0.2 %. The crystals obtained were submitted to diffraction of X-rays and Electronic Microscopy of Sweep. The results show that all microorganisms tested were involved in the process of biofilm formation, and only 12 isolates, including the IS16 (Bacillus subtilis); IIS15a (Bacillus cereus) and IIIS10 (Bacillus subtilis) strains, were the best biofilm formers with high UFC / mL, good in terms of bioprecipitation of carbonates. Particularly, the strains IIIS4 (Bacillus megaterium), IS5 (Bacillus subtilis), IIIS9b (Bacillus subtilis), 21 (Pantoea agglomerans) and IIIS5 (Bacillus simplex). May be some of the microorganisms could be capable of producing urease, to induce precipitation of calcite that contributes to the restoration. As of now, little is known about the participation of Pantoea agglomerans in processes of biorrestauration by means of bioprecipitation of crystals of calcium carbonate and due to the fact that a good response was obtained from the test of ureasa and the crystals obtained were mainly Calcita (99 %), this work shows the feasibility of using this native microorganisms for their activation to achieve the restoration of the worn monuments.","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2015-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70885958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-06-30DOI: 10.5377/NEXO.V27I01.1439
Benigno Leyva-de la Cruz
One of the medullary problems that has affected the productivity of the companies in general, is the deterioration of the pieces of their technological equipment for waste. In such a sense, the study of the behavior of the superficial hardness of these components during its useful life is of vital importance, to be able to recommend an efficient structure, as for the material and treatment to select. In this work was carried out a study on the variation of the superficial hardness that experiences the radial rollers of transporters yacobi during their period of exploitation. The influence was determined that have about the hardness the combined effect of the temperature, the force, the number of revolutions, and the cooling regime in the steel AISI 1045, laminate and temperate. The determination the superficial hardness of 12 rollers was made before and after the setting in exploitation with an instrument to measure hardness portable model 316 with range of mensuration of 20 - 65 HRC and appreciation 1,5 points, assuring the condition of normality for a level of trust of 95%. The results obtained indicate that the hardness of the rollers is before 47,5 HRC and 41,67 HRC and after the exploitation respectively. Also, the analysis of made variance refers that significant difference exists before among the values of the superficial hardness and after the setting in exploitation, what indicated the necessity to carry out a meticulous analysis of the causes that are causing this variation to improve the quality of the process. Key words: Hardness; rollers; productivity; temperature; normality
{"title":"VARIACIÓN DE LA DUREZA SUPERFICIAL DE LOS RODILLOS RADIALES DE TRANSPORTADORES YACOBI.","authors":"Benigno Leyva-de la Cruz","doi":"10.5377/NEXO.V27I01.1439","DOIUrl":"https://doi.org/10.5377/NEXO.V27I01.1439","url":null,"abstract":"One of the medullary problems that has affected the productivity of the companies in general, is the deterioration of the pieces of their technological equipment for waste. In such a sense, the study of the behavior of the superficial hardness of these components during its useful life is of vital importance, to be able to recommend an efficient structure, as for the material and treatment to select. In this work was carried out a study on the variation of the superficial hardness that experiences the radial rollers of transporters yacobi during their period of exploitation. The influence was determined that have about the hardness the combined effect of the temperature, the force, the number of revolutions, and the cooling regime in the steel AISI 1045, laminate and temperate. The determination the superficial hardness of 12 rollers was made before and after the setting in exploitation with an instrument to measure hardness portable model 316 with range of mensuration of 20 - 65 HRC and appreciation 1,5 points, assuring the condition of normality for a level of trust of 95%. The results obtained indicate that the hardness of the rollers is before 47,5 HRC and 41,67 HRC and after the exploitation respectively. Also, the analysis of made variance refers that significant difference exists before among the values of the superficial hardness and after the setting in exploitation, what indicated the necessity to carry out a meticulous analysis of the causes that are causing this variation to improve the quality of the process. Key words: Hardness; rollers; productivity; temperature; normality","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2014-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70885738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-06-30DOI: 10.5377/NEXO.V27I01.1440
D. A. Rodríguez
Integrated audits have quickly emerged in the different audit’s units because of the benefits it provides to organizations. Institutions that regulate the profession of auditing and senior management of different organizations began recommending integrated approach in order to evaluate with holistic approach all business processes’ risks and controls. The estate of the art of integrated audits was known through a structured survey, which was based on the theory established by the Information Systems Audit and Control Association (ISACA). Some activities were categorized under an integral approach, not integrated as expected, however, the research provides information in order to clarify both terms; Based on this clarification, many audit’s professionals can make adjustments to their internal processes and maintain the integrated approach. A new integrated audit concept was proposed in order to act as a reference to achieve the integrated approach. Keywords: Integrated Audit; Risks; Controls; Methodologies; State of the Art
{"title":"AUDITORÍAS INTEGRADAS: SITUACIÓN ACTUAL EN NICARAGUA","authors":"D. A. Rodríguez","doi":"10.5377/NEXO.V27I01.1440","DOIUrl":"https://doi.org/10.5377/NEXO.V27I01.1440","url":null,"abstract":"Integrated audits have quickly emerged in the different audit’s units because of the benefits it provides to organizations. Institutions that regulate the profession of auditing and senior management of different organizations began recommending integrated approach in order to evaluate with holistic approach all business processes’ risks and controls. The estate of the art of integrated audits was known through a structured survey, which was based on the theory established by the Information Systems Audit and Control Association (ISACA). Some activities were categorized under an integral approach, not integrated as expected, however, the research provides information in order to clarify both terms; Based on this clarification, many audit’s professionals can make adjustments to their internal processes and maintain the integrated approach. A new integrated audit concept was proposed in order to act as a reference to achieve the integrated approach. Keywords: Integrated Audit; Risks; Controls; Methodologies; State of the Art","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2014-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70885793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-06-30DOI: 10.5377/NEXO.V27I01.1441
M. A. Aguirre, Marta García
{"title":"LA FAMILIA DE FUNCIONES DISTRIBUCIONALES (Fórmula)","authors":"M. A. Aguirre, Marta García","doi":"10.5377/NEXO.V27I01.1441","DOIUrl":"https://doi.org/10.5377/NEXO.V27I01.1441","url":null,"abstract":"","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2014-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70885940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Castro, R. Cerdá, N. Betanco, F. Canelo, X. López, A. García, M. Benavente
En este trabajo, se estudio el equilibrio y la cinetica de adsorcion de Cd(II), Ni(II) en quitosano y Cr(VI) en quitosano modificado con cobre. Para ello, soluciones de iones metalicos a diferentes concentraciones, fueron puestas en contacto con el adsorbente y se agitaron por un periodo de 3 – 4 h. Al final del proceso, las muestras fueron analizadas en un espectrometro de absorcion atomica. Los datos experimentales del equilibrio de adsorcion de los iones metalicos fueron evaluados aplicando las isotermas de Langmuir y Freundlich; mientras los datos cineticos fueron evaluados utilizando los modelos cineticos de pseudo-primer orden y pseudo-segundo orden. Los resultados del proceso demostraron que los iones fueron eficazmente adsorbidos por el quitosano (Cd y Ni) y por el Cu-quitosano (Cr). Ademas, se comprobo que los datos experimentales del equilibrio de adsorcion de Cr(VI) y Ni(II) se ajustan al modelo de Langmuir; mientras que los datos experimentales del Cd(II) fueron mejor ajustados por el modelo de Freundlich. Mediante el uso de la isoterma de Langmuir se determino la capacidad maxima de adsorcion de cromo (29.7 mg/g Cu-quitosano), cadmio (102.0 mg/g quitosano) y niquel (83.31 mg/g quitosano). Los resultados de la cinetica de adsorcion de los iones metalicos mostraron que los datos experimentales fueron mejor ajustados por el modelo de pseudo-segundo orden; es decir, el paso limitante en la velocidad es la reaccion de adsorcion y no la transferencia de masa. DOI: http://dx.doi.org/10.5377/nexo.v26i2.1285 Nexo Revista Cientifica Vol. 26, No. 02, pp. 56-68/Diciembre 2013
{"title":"Estudio del equilibrio y cinética de adsorción de Cd(II), Ni(II) y Cr(VI) usando Quitosano y Quitosano modificado con cobre","authors":"S. Castro, R. Cerdá, N. Betanco, F. Canelo, X. López, A. García, M. Benavente","doi":"10.5377/NEXO.V26I2.1285","DOIUrl":"https://doi.org/10.5377/NEXO.V26I2.1285","url":null,"abstract":"En este trabajo, se estudio el equilibrio y la cinetica de adsorcion de Cd(II), Ni(II) en quitosano y Cr(VI) en quitosano modificado con cobre. Para ello, soluciones de iones metalicos a diferentes concentraciones, fueron puestas en contacto con el adsorbente y se agitaron por un periodo de 3 – 4 h. Al final del proceso, las muestras fueron analizadas en un espectrometro de absorcion atomica. Los datos experimentales del equilibrio de adsorcion de los iones metalicos fueron evaluados aplicando las isotermas de Langmuir y Freundlich; mientras los datos cineticos fueron evaluados utilizando los modelos cineticos de pseudo-primer orden y pseudo-segundo orden. Los resultados del proceso demostraron que los iones fueron eficazmente adsorbidos por el quitosano (Cd y Ni) y por el Cu-quitosano (Cr). Ademas, se comprobo que los datos experimentales del equilibrio de adsorcion de Cr(VI) y Ni(II) se ajustan al modelo de Langmuir; mientras que los datos experimentales del Cd(II) fueron mejor ajustados por el modelo de Freundlich. Mediante el uso de la isoterma de Langmuir se determino la capacidad maxima de adsorcion de cromo (29.7 mg/g Cu-quitosano), cadmio (102.0 mg/g quitosano) y niquel (83.31 mg/g quitosano). Los resultados de la cinetica de adsorcion de los iones metalicos mostraron que los datos experimentales fueron mejor ajustados por el modelo de pseudo-segundo orden; es decir, el paso limitante en la velocidad es la reaccion de adsorcion y no la transferencia de masa. DOI: http://dx.doi.org/10.5377/nexo.v26i2.1285 Nexo Revista Cientifica Vol. 26, No. 02, pp. 56-68/Diciembre 2013","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2014-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70885269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
La TIR (tasa interna de retorno) es el metodo de evaluacion de rentabilidad de proyectos de inversion mejor conocido. Esta tasa interna de retorno representa, en la interpretacion tradicional de las tasas de interes, a la tasa de interes ganada por una inversion alternativa sobre el saldo no recuperado de una inversion. Sin embargo, cuando se presenta una inconsistencia, basada en la aparicion de raices multiples, se acude a la Tasa Interna de Retorno Modificada (TIRM) para aportar una definicion a la toma de decisiones. El trabajo sostiene que este metodo de la TIRM puede ser utilizado siempre en la toma de decisiones economicas financieras, porque conceptualmente utiliza valores en sus variables de decision, mucho mas cercanos a los que operan en el mercado y en el conocimiento de quien toma la decision, involucrando en su resultado el que se puede obtener con los metodos tradicionales, en el caso que estos se aplican con solvencia. Aun, este metodo se comprobara es efectivo en el caso de proyectos de inversion con diferentes horizontes de planificacion. DOI: http://dx.doi.org/10.5377/nexo.v26i2.1287 Nexo Revista Cientifica Vol. 26, No. 02, pp. 83-87/Diciembre 2013 Palabras clave: TIR; tasa interna de retorno; TIR modificada; proyectos de inversion.
{"title":"Propuesta para el uso exclusivo de la tasa interna de retorno modificada en la toma de decisión de proyectos industriales de inversión","authors":"J. Medina, R. L. Romero, G. Pérez","doi":"10.5377/NEXO.V26I2.1287","DOIUrl":"https://doi.org/10.5377/NEXO.V26I2.1287","url":null,"abstract":"La TIR (tasa interna de retorno) es el metodo de evaluacion de rentabilidad de proyectos de inversion mejor conocido. Esta tasa interna de retorno representa, en la interpretacion tradicional de las tasas de interes, a la tasa de interes ganada por una inversion alternativa sobre el saldo no recuperado de una inversion. Sin embargo, cuando se presenta una inconsistencia, basada en la aparicion de raices multiples, se acude a la Tasa Interna de Retorno Modificada (TIRM) para aportar una definicion a la toma de decisiones. El trabajo sostiene que este metodo de la TIRM puede ser utilizado siempre en la toma de decisiones economicas financieras, porque conceptualmente utiliza valores en sus variables de decision, mucho mas cercanos a los que operan en el mercado y en el conocimiento de quien toma la decision, involucrando en su resultado el que se puede obtener con los metodos tradicionales, en el caso que estos se aplican con solvencia. Aun, este metodo se comprobara es efectivo en el caso de proyectos de inversion con diferentes horizontes de planificacion. DOI: http://dx.doi.org/10.5377/nexo.v26i2.1287 Nexo Revista Cientifica Vol. 26, No. 02, pp. 83-87/Diciembre 2013 Palabras clave: TIR; tasa interna de retorno; TIR modificada; proyectos de inversion.","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2013-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70885358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Learning Objects are key elements within e-Learning environment because describe the created educational material for students, besides, it permits the reusing and sharing in di_erent Learning Management Systems. Usually, when teachers need to create and structure educational experiences, they attend to repositories for retrieving resources fitted to their interest, for reducing the e_ort and the computational time. In this paper, a proposal is presented for merging Learning Objects from heterogeneous repositories; the model is based on semantic relationships between Learning Objects retrieved from a meta-search engine, as an alternative for locating fitted educational resources for teacher’s interest. The model exposed in the proposal has been implemented as initial prototype, which retrieves Learning Objects from open repositories. An initial study results confirm the usefulness of the model.
{"title":"A New Merging Algorithm Based on Semantic Relationships of Learning Objects","authors":"Elio Rivas-Sanchez, J. S. Guerrero, V. Menéndez","doi":"10.5377/NEXO.V26I2.1286","DOIUrl":"https://doi.org/10.5377/NEXO.V26I2.1286","url":null,"abstract":"Learning Objects are key elements within e-Learning environment because describe the created educational material for students, besides, it permits the reusing and sharing in di_erent Learning Management Systems. Usually, when teachers need to create and structure educational experiences, they attend to repositories for retrieving resources fitted to their interest, for reducing the e_ort and the computational time. In this paper, a proposal is presented for merging Learning Objects from heterogeneous repositories; the model is based on semantic relationships between Learning Objects retrieved from a meta-search engine, as an alternative for locating fitted educational resources for teacher’s interest. The model exposed in the proposal has been implemented as initial prototype, which retrieves Learning Objects from open repositories. An initial study results confirm the usefulness of the model.","PeriodicalId":40344,"journal":{"name":"Nexo Revista Cientifica","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2013-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70885476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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