627 research outputs found

    Diseño y evaluación de un programa de informática aplicada a la investigación educativa

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    Este artículo presenta un estudio empírico de carácter evaluativo sobre el programa de la asignatura "Informática Aplicada a la Investigación Educativa". Esta materia surge en los nuevos planes de estudio de la Facultad de Ciencias de la Educación, concretamente como parte de la Licenciatura Pedagogía, y supone una respuesta del plan a la necesidad de formación científica en la actual Sociedad del Conocimiento, un aspecto que tiene escasa tradición en cuanto a propuestas curriculares. Ello justifica que abordemos tanto el contexto curricular y científico en que surge la materia, como la propuesta de programa de formación y su evaluación.This article presents an empiric study of evaluative character about the program proposed in Informática Aplicada a la Investigación Educativa. This matter arises on new sillabi of the ability of Sciences of the Education, specifically like part of the Licentiate of Pedagogy. It supposes an answer from the plan to the necessity of scientific formation in the current Society of the Knowledge, and it lacking tradition as for previous curricular proposals in this sense. This is justified that we approach the evaluative and scientific context, the proposal of formation and, its evaluation

    Improvement of biomethane potential of sewage sludge anaerobic co-digestion by addition of “sherry-wine” distillery wastewater

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    Co-digestion of sewage sludge (SS) with other unusually treated residues has been reported as an efficient method to improve biomethane production. In this work, Sherry-wine distillery wastewater (SWDW) has been proposed as co-substrate in order to increase biomethane production and as a breakthrough solution in the management of both types of waste. In order to achieve this goal, different SS:SW-DW mixtures were employed as substrates in Biomethane Potential (BMP) tests. The biodegradability and biomethane potential of each mixture was determined selecting the optimal co-substrate ratio. Results showed that the addition of SW-DW as a co-substrate improves the anaerobic digestion of SS in a proportionally way in terms of CODs and biomethane production The optimal co-substrates ratio was 50:50 of SS:SW-DW obtaining %VSremoval ¼ 54.5%; YCH4 ¼ 225.1 L CH4/kgsv or 154 L CH4/kgCODt and microbial population of 5.5 times higher than sole SS. In this case, %VSremoval ¼ 48.1%; YCH4 ¼ 183 L CH4/ kgsv or 135 L CH4/kgCODt. The modified Gompertz equation was used for the kinetic modelling of biogas production with successful fitting results (r2 ¼ 0.99). In this sense, at optimal conditions, the maximum productivity reached at an infinite digestion time was (YMAX CH4 ) ¼ 229 ± 5.0 NL/kgSV; the specific constant was K ¼ 25.0 ± 2.3 NL/kgSV$d and the lag phase time constant was (l) ¼ 2.49 ± 0.1

    Thermophilic and mesophilic temperature phase anaerobic codigestion (TPAcD) compared with single-stage co-digestion of sewage sludge and sugar beet pulp lixiviation

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    The performance of temperature phase anaerobic co-digestion (TPAcD) for sewage sludge and sugar beet pulp lixiviation (using the process of exchanging the digesting substrate between spatially separated thermophilic and mesophilic digesters) was tested and compared to both single-stage mesophilic and thermophilic anaerobic co-digestion. Two Hydraulic Retention Times (HRT) were studied in the thermophilic stage of anaerobic digestion in two temperature phases, maintaining the optimum time of the mesophilic stage at 10 days, obtained as such in single-stage anaerobic co-digestion. In this way, we obtained the advantages of both temperature regimes. Volatile solids removal efficiency from the TPAcD system depended on the sludge exchange rate, but fell within the 72.6e64.6% range. This was higher than the value of 46.8% obtained with single-stage thermophilic digestion and that of 40.5% obtained with mesophilic digestion. The specific methane yield was 424e468 ml CH4 per gram of volatile solids removed, similar to that of single-stage mesophilic anaerobic digestion. The increase in microbial activity inside the reactor was directly proportional to the organic loading rate (OLR) (or inversely proportional to the HRT) and inversely proportional to the size of the microbial population in single-stage anaerobic co-digestion systems

    Seeking to enhance the bioenergy of municipal sludge: Effect of alkali pre-treatment and soluble organic matter supplementation

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    The aim of this research is to enhance the mesophilic anaerobic digestion of municipal sludge from Cadiz-San Fernando (Spain) wastewater treatment plant at 20 days hydraulic retention time (HRT). Two different strategies were tested to improve the process: co-digestion with the addition of soluble organic matter (1% v/v); and alkali sludge pre-treatment (NaOH) prior to co-digestion with glycerine (1% v/v). Methane production (MP) was substantially enhanced (from 0.36 ± 0.09 L CH4 l/d to 0.85 ± 0.16 L CH4 l/d), as was specific methane production (SMP) (from 0.20 ± 0.05 L CH4/g VS to 0.49 ± 0.09 L CH4/g VS) when glycerine was added. The addition of glycerine does not seem to affect sludge stability, the quality of the effluent in terms of pH and organic matter content, i.e. volatile fatty acids (VFA), soluble organic matter and total volatile solid, or process stability (VFA/Alkalinity ratio < 0.4). Alkali pre-treatment prior to co-digestion resulted in a high increase in soluble organic loading rates (more than 20%) and acidification yield (more than 50%). At 20 days HRT, however, it led to overload of the system and total destabilization of the mesophilic anaerobic co-digestion of sewage sludge and glycerine

    Mesophilic anaerobic co-digestion of sewage sludge with glycerine: Effect of solids retention time

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    The main objective of this paper is to examine the effect of the increase in organic loading rates (OLRs), by reducing the solids retention time (SRT) from 20 d to 5 d, in single-phase mesophilic anaerobic co-digestion of sewage sludge with glycerine (1% v/v). It was experimentally confirmed that anaerobic co-digestion of these biowastes under steady-state conditions can achieve an 85 ± 5% reduction in volatile fatty acids (VFA) at SRTs of between 20 and 9 d, with a methane production yield of around 0.8 l CH4/l/d. Decreases in the SRT not only allow the sludge stability and biogas production to be maintained, but also lead to an increase in the waste that could be treated and lower operating costs. Therefore, mesophilic anaerobic co-digestion of sewage sludge and glycerin at a SRT lower than 20 d is possible and preferable due to being more economical and environmentally friendl

    Biomethane production improvement by enzymatic pretreatments and enhancers of sewage sludge anaerobic digestion

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    Enzymatic hydrolysis is recognised as an effective pre-treatment for increasing biodegradability of sludge. In this work, isolated commercial enzymes as well as in-situ enzymes producer bacteria were used respectively as enhancers and pre-treatments of sewage sludge. Biodegradability of sample as well as biomethane potential production were studied. Results showed that depuration efficiencies in terms of CODs (73.5-85.5 %) and TVS (28.5-42.7 %) were more than twice the control value. In addition, pre-treated samples as well as enhanced samples with enzymes generated more biomethane than control. The optimal ones, were those with the isolated proteases (P) and with bacteria (Bacillus licheniformis) treatment in-situ (F), producing a total volume of 72.4 ± 2.62 ml CH4 and 114 ml ± 0.46 CH4, respectively, increasing the biogas volume in 3.65 and 5.77 times respectively compared with control

    FACTORES QUE INCIDEN EN EL DESEMPEÑO ACADEMICO DE LOS ALUMNOS DEL CECYTEO EN LAS CIUDADES DE OAXACA

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    Mediante un análisis de factores socioeconómicos de siete ciudades de Oaxaca se pretende analizar la manera en que estos factores inciden en el desempeño académico de los alumnos de nivel medio superior del Colegio de Estudios Científicos y Tecnológicos del Estado de Oaxaca (CECYTEO), ubicados en cada una de estas ciudades, tomando en cuenta la región en que se encuentran ubicados, mismos que comprenden las Ciudades de Juchitán de Zaragoza, Ciudad Ixtepec, Santo Domingo Tehuantepec, Ixtlán de Juárez, San Juan Bautista Cuicatlán, y la Zona Metropolitana de Oaxaca (Tlalixtac de Cabrera y San pablo Etla). Para poder abordar estos factores es importante retomar aspectos como la Marginación, Rezago Social, Desarrollo Humano, Índice Educativo, Tasa de Asistencia Escolar y la Tasa de Alfabetización en un período comprendido del año 2005-2015. Considerando además que la educación en las Ciudades de Oaxaca se da en múltiples variaciones de indicadores y de contexto

    First contributions of Donato García as Mineralogy Professor at the Royal Cabinet of Natural History of Madrid (Spain) in the Nineteenth Century

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    Donato Garcíawas the mineralogy professor at the Royal Cabinet of Natural History and Central University of Madrid from 1816 to 1853. In addition to teaching mineralogy, he gathered geological and mineralogical material for didactic purposes, and for exhibitions in the hall of the Cabinet. He was a key figure in developing the subject matter of mineralogy in Spain during the first half of the nineteenth century. Donato Garcia likewise promoted the careers of very important future teachers at the Military Academy of Engineers, Natural Sciences Museums, and Universities, integrating oral lectures, mineral testing, visual recognition, and the use of crystallographic models. This paper investigates how the crystallographic system proposed by Haüy (in the mid-thirties) was assimilated through unpublished documents of Donato García’s mineralogical lessons from 1824 to 1825, obtained from Spain’s Archivo General de Palacio (Madrid). Hence, this manuscript can be considered the first scientific work reliably attributable to Donato and based on the notes of his pupil José Musso y Valiente, which stands as an early attempt to create a handbook of mineralogy in Spanish. The novel approach to teaching mineralogy is furthermore compared with lessons published by disciple Antonio María Cisneros y Lanuza in 184
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