Los desafíos de la evaluación por competencias en el ámbito educativo

Resumen Este artículo tiene por objetivo principal ser un aporte a las discusiones y reflexiones sobre el rol formativo de la evaluación por competencias en el ámbito educativo. Se plantea su relación con los perfiles curriculares que se orientan a los nuevos contextos laborales. Se sostiene la necesidad de establecer lineamientos, diseños, implementaciones y desarrollos instrumentales para determinar los impactos de los aprendizajes por competencias como una forma de evidenciar la apropiación de saberes integrales complejos. Se asume el desafío que tiene la práctica evaluativa por competencias al incorporar a los principales actores del proceso de enseñanza y aprendizaje, a objeto de realizar una evaluación más participativa y democrática. Para ello se realiza una breve descripción y análisis teórico-conceptual sobre las competencias en el mundo educativo. Se profundiza sobre la evaluación por competencias como una nueva práctica evaluativa destacando los criterios integrales y formativos de estas prácticas. Se analiza cómo la evaluación por competencias puede orientar e influir en el mejoramiento de los aprendizajes y prácticas pedagógicas. Para concluir se plantean unas consideraciones finales de la evaluación por competencias a modo de balance y desafíos para el ámbito educativo, sobre todo aquellos relacionados por la preocupación en el proceso previo al resultado final de un producto de aprendizaje

Adelante / Endavant

Séptimo desafío por la erradicación de la violencia contra las mujeres del Institut Universitari d’Estudis Feministes i de Gènere "Purificación Escribano" de la Universitat Jaume

Hydrocessing of an asphaltenic coal residue

A residue from deasphalting of coal liquids obtained by direct coal liquefaction of a subbituminous Spanish coal was processed by thermal and catalytic hydrotreatment under the conditions of hydrovisbreaking and hydrocracking respectively. The hydrotreatment reduced the viscosity of the starting material and the catalyst produced the inhibition of the coke formation.Peer reviewe

Visbreaking of an asphaltenic coal residue

A residue from deasphalting of liquids obtained by direct liquefaction of a Spanish subbituminous coal was processed by thermal treatment. This residue is rich in asphaltenes which do not undergo cracking easily and are coke precursors in thermal cracking. The kinetics of the cracking and coke formation reactions were studied and the viscosity, coke content, boiling point distribution, elemental analysis and aromaticity of the reaction products were determined. The experimental data fit the first-order kinetic model proposed. The main effects produced by the thermal treatment were a large decrease in the viscosity from 4608 mm2 s−1 for the feedstock to 939 mm2 s−1 for the product. The conversion of the heavy fraction (b.p. > 350°C and soluble in toluene) increased with the temperature and residence time, the conversion to coke being higher than the conversion to light products (b.p. < 350°C and soluble in toluene).Peer reviewe

Application of petroleum processing technology to the upgrading of coal syncrude

The feasibility of producing distillate fuels (gasoline, diesel and aviation fuels) from coal syncrude was determined. A syncrude from direct liquefaction of subbituminous coal was first deasphalted by ultrasonic disaggregation in n-hexane, to reduce the heteroatom content. The oil was then catalytically hydrogenated in a continuous hydroprocessing unit at 450°C and 10 MPa hydrogen pressure. The hydroprocessed oil was fractionated by vacuum distillation and the cuts obtained were characterized. The high aromaticity of the hydroprocessed oil necessitated a second hydrotreatment under conditions suitable for hydrogenation of aromatic structures. Deasphalting removed 39% of the N, 43% of the S and 47% of the O. The first hydrotreatment removed 99% of the S, 87% of the N and 37% of the O, and increased the HC ratio. The second hydrotreatment provided an important reduction in aromaticity, necessary to achieve certain fuel quality specifications.The authors wish to thank the Commission of the European Communities (Contract No. EN3V-0055-E) and DGCYT (CE89-0007) for financial support.Peer reviewe

Upgrading of an asphaltenic coal residue: Thermal hydroprocessing

A residue from deasphalting a syncrude obtained by direct coal liquefaction of a subbituminous Spanish coal was processed by thermal hydrotreatment. Kinetic study of the cracking reaction and coke formation reaction has been performed. The viscosity, coke content, boiling point distribution, elemental analysis, and aromaticity of the reaction products have been determined. The experimental data fits with the first-order kinetic model proposed. The main effects observed with the thermal hydrotreatment have been a large decrease of the viscosity that varies from 4608 cSt in the feedstock to 147 cSt in the products. The conversion of the heavy fraction (bp > 350 °C and soluble in toluene) and asphaltenes increased with the temperature and residence time, and the formation of coke was inhibited even at the hardest reaction conditions used. At 425 °C a kinetic control conducts the reaction, the cracking reaction with lower activation energy was more favorable and the coke formation (condensation) remained almost completely inhibited.This study was sponsored by the UE contract No. EN3V-0055E and by the Spanish DGICYT project CE89-0007.Peer reviewe

DNA methylation changes after cryopreservation: MSAP analysis by multivariant statistical methods

Cryopreservation allows long-term conservation, and the genetic stability of the preserved material is one of its most important features compared to other conservation techniques. However, this stability has been questioned and in some cases epi-genetic instability after cryopreservation has been detected. Epigenetic information includes heritable signals that modulate gene expression but are not encoded in the primary nucleotide sequence. DNA methylation is the most extensively studied epigenetic modification and it has been connected to many crucial biological processes. The central issue of this work was to detect epigenetic changes in the cytosine methylation pattern throughout the whole cryopreservation process in an encapsulation-dehydration protocol in Mentha xpiperita apices. Although many techniques have been described for analysing DNA methylation, MSAP (methylation sensitive amplified polymorphism) is widely used. The global DNA methylation status has been stud ied after each step of the cryopreservation protocol. The effect of the addition during the procedure of vitamin E or ascorbic acid was also evaluated. AII the methylation variations detected were statistically analysed via multinomial logistic regression in order to test their significance. This study intends to introduce a new statistical approach to address methylation data in this contexto The results obtained showed and statistically proved that significant differences in the methylation pattern existed among the steps of the protocol

La herencia de una guerra. Diálogos para la memoria

El objetivo principal del proyecto es la recuperación de la memoria histórica de la guerra civil española. Otros objetivos son comprender la evolución económica, social, política y cultural de España durante los años treinta; desarrollar una sensibilidad comprometida, responsable y activa, con la democracia actual en España y los derechos humanos como un logro irrenunciable; e identificar, analizar y explicar los hechos, personajes, problemas, etapas y procesos más significativos de la reciente Historia de España y las nacionalidades y regiones que lo integran. La metodología consiste en la realización de entrevistas a los alumnos de los Tramos I y II sobre sus vivencias acerca de la Guerra Civil. El Seminario de Historia Oral coordina las entrevistas en forma de cuestionarios trabajados en el aula y los profesores del Claustro facilitan el contacto entre los alumnos. Las entrevistas se graban en vídeo y cassete, se realizan fotografías expuestas en dos exposiciones y todo el material gráfico se utiliza en el Seminario de Nuevas Tecnologías y su Aplicación en el Aula. De igual manera, colaboran el responsable de la Biblioteca Popular Hortaleza para la búsqueda de material bibliográfico y hemerográfico y el Servicio de Documentación de La 2 de RTVE para la recuperación de imágenes de los años treinta y cuarenta, especialmente, de los archivos NO-DO. En cuanto a las actividades realizadas destacan el vaciado de fondos de la Biblioteca Popular de Hortaleza relativos a la Guerra Civil y la exposición de todo el trabajo realizado en el Centro Cultural Carril del Conde del distrito de Hortaleza.Madrid (Comunidad Autónoma). Consejería de Educación. Dirección General de Ordenación AcadémicaMadridMadrid (Comunidad Autónoma). Subdirección General de Formación del Profesorado. CRIF Las Acacias; General Ricardos 179 - 28025 Madrid; Tel. + 34915250893ES

Two-stage liquefaction of a Spanish subbituminous coal

A Spanish subbituminous coal has been processed in two-stage liquefaction in a non-integrated process. The first-stage coal liquefaction has been carried out in a continuous pilot plant in Germany at Clausthal Technical University at 400°C of temperature, 20 MPa hydrogen pressure and anthracene oil as solvent. The second-stage coal liquefaction has been performed in continuous operation in a hydroprocessing unit at the Instituto de Carboquimica at 450°C and 10 MPa hydrogen pressure, with two commercial catalysts: Harshaw HT-400E (Co-Mo/Al2O3) and HT-500E (Ni-Mo/Al2O3). The total conversion for the first-stage coal liquefaction was 75.41 wt% (coal d.a.f.), being 3.79 wt% gases, 2.58 wt% primary condensate and 69.04 w% heavy liquids. The heteroatoms removal for the second-stage liquefaction was 97–99 wt% of S, 85–87 wt% of N and 93–100 wt% of O. The hydroprocessed liquids have about 70% of compounds with boiling point below 350°C, and meet the sulphur and nitrogen specifications for refinery feedstocks. Liquids from two-stage coal liquefaction have been distilled, and the naphtha, kerosene and diesel fractions obtained have been characterized.The authors wish to thank the European Community (contract No. EN3V- 0055-E) and CICYT (CE89-0007) for financial support.Peer reviewe