Studies on Landfill Leachate Transportation and Its Impact on Soil Characteristics

Leachate from an untreated landfill or landfill with damaged liners will cause the pollution of soil and ground water. Here an attempt was made to generate knowledge on concentrations of all relevant pollutants in soil due to municipal solid waste landfill leachate and its migration through soil and also to study the effect of leachate on the engineering properties of soil. To identify the pollutants in soil due to the leachate generated from municipal solid waste landfill site, a case study on an unlined municipal solid waste landfill at Kalamassery has been done. Soil samples as well as water samples were collected from the site and analysed to identify the pollutants and its effect on soil characteristics. The major chemicals in the soil were identified as Ammonia, Chloride, Nitrate, Iron, Nickel, Chromium, Cadmium etc.. Engineering properties of field soil samples show that the chemicals from the leachate of landfill may have effect on the engineering properties of soil. Laboratory experiments were formulated to model the field around an unlined MSW landfill using two different soils subjected to a synthetic leachate. The Maximum change in chemical concentration and engineering property was observed on soil samples at a radial distance of 0.2 m and at a depth of 0.3 m. The pollutant (chemicals) transport pattern through the soil was also studied using synthetic leachate. To establish the effect of pollutants (chemicals) on engineering properties of soil, experiments were conducted on two types soils treated with the synthetic chemicals at four different concentrations. Analyses were conducted after maturing periods of 7, 50, 100 and 150 days. Test soils treated with maximum chemical concentration and matured for 150 days were showing major change in the properties. To visualize the flow of pollutants through soil in a broader sense, the transportation of pollutants through soil was modeled using software ‘Visual MODFLOW’. The actual field data collected for the case study was used to calibrate the modelling and thus simulated the flow pattern of the pollutants through soil around Kalamassery municipal solid waste landfill for an extent of 4 km2. Flow was analysed for a time span of 30 years in which the landfill was closed after 20 years. The concentration of leachate beneath the landfill was observed to be reduced considerably within one year after closure of landfill and within 8 years, it gets lowered to a negligible level. As an environmensstal management measure to control the pollution through leachate, permeable reactive barriers are used as an emerging technology. Here the suitability of locally available materials like coir pith, rice husk and sugar cane bagasse were investigated as reactive media in permeable reactive barrier. The test results illustrates that, among these, coir pith was showing better performance with maximum percentage reduction in concentration of the filtrate. All these three agricultural wastes can be effectively utilized as a reactive material. This research establishes the influence of leachate of municipal solid waste landfill on the engineering properties of soil. The factors such as type of the soil, composition of leachate, infiltration rate, aquifers, ground water table etc., will have a major role on the area of influence zone of the pollutants in a landfill. Software models of the landfill area can be used to predict the extent and the time span of pollution of a landfill, by inputting the accurate field parameters and leachate characteristics. The present study throws light on the role of agro waste materials on the reduction of the pollution in leachate and thus prevents the groundwater and soil from contamination

Knowledge Building in Landscape Architecture

The objective of this study was to develop an internet-based seminar framework applicable for landscape architecture education. This process was accompanied by various aims. The basic expectation was to keep the main characteristics of landscape architecture education also in the online format. On top of that, four further objectives were anticipated: (1) training of competences for virtual team work, (2) fostering intercultural competence, (3) creation of equal opportunities for education through internet-based open access and (4) synergy effects and learning processes across institutional boundaries. This work started with the hypothesis that these four expected advantages would compensate for additional organisational efforts caused by the online delivery of the seminars and thus lead to a sustainable integration of this new learning mode into landscape architecture curricula. This rationale was followed by a presentation of four areas of knowledge to which the seminar development was directly related (1) landscape architecture as a subject and its pedagogy, (2) general learning theories, (3) developments in the ICT sector and (4) wider societal driving forces such as global citizenship and the increase of open educational resources. The research design took the shape of a pedagogical action research cycle. This approach was constructive: The author herself is teaching international landscape architecture students so that the model could directly be applied in practice. Seven online seminars were implemented in the period from 2008 to 2013 and this experience represents the core of this study. The seminars were conducted with varying themes while its pedagogy, organisation and the technological tools remained widely identical. The research design is further based on three levels of observation: (1) the seminar design on the basis of theory and methods from the learning sciences, in particular educational constructivism, (2) the seminar evaluation and (3) the evaluation of the seminars’ long term impact. The seminar model itself basically consists of four elements: (1) the taxonomy of learning objectives, (2) ICT tools and their application and pedagogy, (3) process models and (4) the case study framework. The seminar framework was followed by the presentation of the evaluation findings. The major findings of this study can be summed up as follows: Implementing online seminars across educational and national boundaries was possible both in term of organisation and technology. In particular, a high level of cultural diversity among the seminar participants has definitively been achieved. However, there were also obvious obstacles. These were primarily competing study commitments and incompatible schedules among the students attending from different academic programmes, partly even in different time zones. Both factors had negative impact on the individual and working group performances. With respect to the technical framework it can be concluded that the majority of the participants were able to use the tools either directly without any problem or after overcoming some smaller problems. Also the seminar wiki was intensively used for completing the seminar assignments. However, too less truly collaborative text production was observed which could be improved by changing the requirements for the collaborative task. Two different process models have been applied for guiding the collaboration of the small groups and both were in general successful. However, it needs to be said that even if the students were able to follow the collaborative task and to co-construct and compare case studies, most of them were not able to synthesize the knowledge they had compiled. This means that the area of consideration often remained on the level of the case and further reflections, generalisations and critique were largely missing. This shows that the seminar model needs to find better ways for triggering knowledge building and critical reflection. It was also suggested to have a more differentiated group building strategy in future seminars. A comparison of pre- and post seminar concept maps showed that an increase of factual and conceptual knowledge on the individual level was widely recognizable. Also the evaluation of the case studies (the major seminar output) revealed that the students have undergone developments of both the factual and the conceptual knowledge domain. Also their self-assessment with respect to individual learning development showed that the highest consensus was achieved in the field of subject-specific knowledge. The participants were much more doubtful with regard to the progress of generic competences such as analysis, communication and organisation. However, 50% of the participants confirmed that they perceived individual development on all competence areas the survey had asked for. Have the additional four targets been met? Concerning the competences for working in a virtual team it can be concluded that the vast majority was able to use the internet-based tools and to work with them in a target-oriented way. However, there were obvious differences regarding the intensity and activity of participation, both because of external and personal factors. A very positive aspect is the achievement of a high cultural diversity supporting the participants’ intercultural competence. Learning from group members was obviously a success factor for the working groups. Regarding the possibilities for better accessibility of educational opportunities it became clear that a significant number of participants were not able to go abroad during their studies because of financial or personal reasons. They confirmed that the online seminar was to some extent a compensation for not having been abroad for studying. Inter-institutional learning and synergy was achieved in so far that many teachers from different countries contributed with individual lectures. However, those teachers hardly ever followed more than one session. Therefore, the learning effect remained largely within the seminar learning group. Looking back at the research design it can be said that the pedagogical action research cycle was an appropriate and valuable approach allowing for strong interaction between theory and practice. However, some more external evaluation from peers in particular regarding the participants’ products would have been valuable.

Aprendizaje colaborativo de la escritura mediante organización de contenidos y tareas.

Resumen tomado de la publicación. Incluye tablas, gráficos e imágenes capturadas de la pantalla del ordenador. Artículo seleccionado de SIIE (Simposio Internacional de Informática Educativa) 2004, extendido y revisado para su publicación en IE Comunicaciones

An??lisis y monitorizaci??n de la interacci??n en entornos colaborativos mediante el uso de SNA

Resumen tomado del autor

El trabajo en equipo en el Proceso Administrativo y de Compras en OPL Carga de Bucaramanga

El proceso administrativo y de compras de OPL Carga tiene algunas falencias entre ellas: fallas en la Comunicación entre el personal operativo, no se realizan llamadas internas usando con frecuencia el email, produciendo la saturación de solicitudes las cuales terminan sin ser resueltas en cuanto a roles se refiere, no hay enfoque de procesos en vista que no se tiene claras las tareas de cada cargo, adicionalmente no hay claridad en los subprocesos, perjudicando el proceso con el aumento de costos, pérdida de tiempo, las responsabilidades de los funcionario no todas las veces se ejecutan en el tiempo asignado, el liderazgo compartido presenta ambigüedades. Objetivos: Definir el trabajo en equipo en el proceso administrativo y de compras en OPL carga de Bucaramanga. La investigación que a realizar es de tipo descriptivo, busca descubrir las falencias o características que permiten diseñar y desarrollar un modelo de solución para los problemas del equipo de OPL Carga S.A.S. Materiales y métodos: La investigación efectuada es de tipo descriptivo, el objetivo es definir el modelo del trabajo en equipo y describir las falencias en el proceso administrativo y de compras en OPL carga de Bucaramanga, que permitan obtener un diagnóstico integral que conlleve a la implementación de estrategias de solución. Resultados: Se identificaron las falencias en los siguientes aspectos: Variable comunicación, rendimiento, destrezas complementarias, propósito significativo y meta específicas de los funcionarios en OPL carga sección administrativa. Conclusiones: El modelo de trabajo en equipo que OPL aplica es jerárquico, en el que se ofrece estabilidad, seguridad, se toman decisiones en forma piramidal, mediante la planeación de tareas, la colaboración, igualdad y respeto por los miembros, trabajando en pro de la solución de problemas. Se construyó un plano conceptual que permitió exponer la interpretación que la estudiante tiene de las teorías, investigaciones y antecedentes válidos para la comprensión del problema investigado. Área comunicacional: Coordinar acciones tendientes para que los funcionarios respondan a tiempo los emails atenientes a su trabajo. Área condiciones de trabajo: Clarificar y diseñar las reglas de comportamiento al interior de los equipos de trabajo que redunden en el mejoramiento del mismo y la búsqueda de soluciones oportunas. Área metas específicas: Procurar mediante auditorías el cumplimiento de las metas y objetivos propuestos por cada equipo de trabajo.

El rol del profesor en el aprendizaje colaborativo mediado por ordenador.

Resumen basado en el de la publicación

Aprendizaje colaborativo en enseñanza a distancia : entorno genérico para configurar, realizar y analizar actividades en grupo.

Profundizar en el estudio y desarrollo de modelos de soporte para el aprendizaje colaborativo a distancia, que permite proponer una arquitectura fundamentada en los principios del paradigma CSCL (Computer Supported Collaborative Learning). La arquitectura propuesta aborda un tipo de problema concreto que requiere el uso de técnicas derivadas del trabajo colaborativo, la inteligencia artificial, interfaces de usuario así como ideas tomadas de la Pedagogía y la Psicología. Se diseña una solución completa, abierta y genérica. La arquitectura aprovecha las nuevas tecnologías para lograr un sistema efectivo de apoyo a la educación a distancia. Se organiza en cuatro niveles: el de Configuración, el de Experiencia, el de Organización y el de Análisis. A partir de ella se implementa un sistema llamado Degree. En Degree, cada uno de los niveles de la arquitectura da lugar a un subsistema independiente pero relacionado con los otros. La aplicación saca partido del uso de espacios de trabajo estructurados. El subsistema Configurador de Experiencias permite definir los elementos de un espacio de trabajo y una experiencia y adaptarlos a cada tipo de usuario. El subsistema Manejador de Experiencias recoge las contribuciones de los usuarios para construir una solución conjunta de un problema. Las intervenciones de los alumnos se estructuran basándose en un grafo conversacional genérico. Además, se registran todas las acciones de los usuarios para representar explícitamente el proceso completo que lleva a la solución. Estos datos también se almacenan en una memoria común que constituye el subsistema llamado Memoria Organizativa de Experiencias. El subsistema Analizador estudia las intervenciones de los usuarios. Este análisis permite inferir conclusiones sobre la forma en que trabajan los grupos y sus actitudes frente a la colaboración, teniendo en cuenta además el conocimiento subjetivo del observador. El proceso de desarrollo en paralelo de la arquitectura y el sistema sigue un ciclo de refinamiento en cinco fases con sucesivas etapas de prototipado y evaluación formativa. Cada fase de este proceso se realiza con usuarios reales y se consideran las opiniones de los usuarios para mejorar las funcionalidades de la arquitectura así como la interfaz del sistema. Esta aproximación permite, además, comprobar la utilidad práctica y la validez de las propuestas que sustentan este trabajo.

Aula : un sistema ubicuo de enseñanza-aprendizaje colaborativo.

Resumen tomado de la publicación

¿Evaluando o bordando retales? : un modelo de evaluación receptivo centrado en el evaluando para escenarios CSCL.

Monográfico con el título: la investigación y la innovación universitaria, un campo emergente y en coordinación

Lo que el ojo no ve : un estudio de caso basado en procesos de indagación co(wiki)laborativos.

Resumen basado en el de la publicación

La formaci??n pr??ctica interdisciplinar de Magisterio en un entorno tecnol??gico y colaborativo

Resumen tomado de la publicaci??n

Una Propuesta de Marco Instruccional Basado en la Taxonomía de Bloom.

Resumen basado en el de la publicación

Aprendizaje activo en Ingeniería de Telecomunicaciones : un caso de estudio.

Resumen basado en el de la publicación

Ativação do sistema renina-angiotensina-aldosterona em cães assintomáticos com doença mixomatosa valvular mitral

As doenças cardíacas são um achado frequente na prática clínica. Saber se pacientes assintomáticos com doença mixomatosa da válvula mitral necessitam ou não de medicação numa fase inicial da doença não é tarefa fácil. A ativação neuro-hormonal, apesar de ter um efeito benéfico compensatório a curto prazo, torna-se deletéria a longo prazo, sendo que para isso é necessária intervenção farmacológica para inibir a sua atividade O SRAA (sistema renina angiotensina aldosterona) tem importantes mecanismos patofisiológicos implicados no desenvolvimento da insuficiência cardíaca congestiva e tem como produto final a aldosterona, que contribui para a remodelagem cardíaca. Neste trabalho verifiquei a inexistência de uma diferença significativa de valores de aldosterona sérica de cães assintomáticos com Doença Mixomatosa Valvular Mitral (estadio B2 da classificação ACVIM) e os valores do intervalo de referência desta hormona. Concluí também não haver relação entre a idade, ureia, creatinina, rácio Proteina-Creainina, Pressões arteriais sistólica, média e diastólica, frequência de pulso, parâmetros de remodelagem cardíaca e padrão do fluxo transmitral com os valores da aldosterona medidos. É através da evidência destes achados que sugiro a não instituição de um IECA neste tipo de pacientes. O uso precoce de IECA pode não só não trazer vantagens terapêuticas nesta fase da doença como também vai promover o aparecimento precoce de fenómenos de “escape da aldosterona”.

Dynamics of convectively driven banded jets in the laboratory

The banded organization of clouds and zonal winds in the atmospheres of the outer planets has long fascinated observers. Several recent studies in the theory and idealized modeling of geostrophic turbulence have suggested possible explanations for the emergence of such organized patterns, typically involving highly anisotropic exchanges of kinetic energy and vorticity within the dissipationless inertial ranges of turbulent flows dominated (at least at large scales) by ensembles of propagating Rossby waves. The results from an attempt to reproduce such conditions in the laboratory are presented here. Achievement of a distinct inertial range turns out to require an experiment on the largest feasible scale. Deep, rotating convection on small horizontal scales was induced by gently and continuously spraying dense, salty water onto the free surface of the 13-m-diameter cylindrical tank on the Coriolis platform in Grenoble, France. A “planetary vorticity gradient” or “β effect” was obtained by use of a conically sloping bottom and the whole tank rotated at angular speeds up to 0.15 rad s−1. Over a period of several hours, a highly barotropic, zonally banded large-scale flow pattern was seen to emerge with up to 5–6 narrow, alternating, zonally aligned jets across the tank, indicating the development of an anisotropic field of geostrophic turbulence. Using particle image velocimetry (PIV) techniques, zonal jets are shown to have arisen from nonlinear interactions between barotropic eddies on a scale comparable to either a Rhines or “frictional” wavelength, which scales roughly as (β/Urms)−1/2. This resulted in an anisotropic kinetic energy spectrum with a significantly steeper slope with wavenumber k for the zonal flow than for the nonzonal eddies, which largely follows the classical Kolmogorov k−5/3 inertial range. Potential vorticity fields show evidence of Rossby wave breaking and the presence of a “hyperstaircase” with radius, indicating instantaneous flows that are supercritical with respect to the Rayleigh–Kuo instability criterion and in a state of “barotropic adjustment.” The implications of these results are discussed in light of zonal jets observed in planetary atmospheres and, most recently, in the terrestrial oceans.