http://hdl.handle.net/2117/665 Thu, 23 May 2013 01:43:11 GMT 2013-05-23T01:43:11Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/19103 Title: Analysis of sedimentation and resuspension processes of aquaculture biosolids using an oscillating grid Authors: Masaló Llorà, Ingrid; Guadayol, Oscar; Peters, Francesc; Oca Baradad, Joan Abstract: Sedimentation and resuspension processes of aquaculture biosolids (non-ingested feed and faeces) are analysed using vertically oscillating grids as a source of turbulence in fluid tanks. An oscillating grid system consists of a container in which a grid is stirred vertically generating a well-known turbulent field that is function of amplitude and frequency of oscillation, distance between grid and measurement point, and mesh spacing of the grid. The grid used in this study had a mesh spacing of 1.2 cm, and was calibrated using different amplitudes (1, 1.5 and 2 cm), frequencies (from 1 to 6 Hz) and distances (2.4, 2.7 and 3 cm). After calibration, the turbulence needed to resuspend biosolids and to maintain them in the water column following different times of consolidation, and with biosolids of different origin, was analysed. It was observed that the turbulence needed to resuspend aquaculture biosolids increased with the time of consolidation. When the turbulence was decreased after a resuspension process, the next sedimentation of biosolids showed a hysteretic behaviour: turbulence needed to resuspend a fixed percent of biosolids from the tank bottom is substantially higher than that needed to maintain the same percentage suspended in the water column. Differences in resuspension behaviour of biosolids originated in different tanks were also observed. The method provides useful information that can be compared with turbulence generated by fish swimming activity, in order to determine the culture conditions, which can promote self-cleaning conditions in a particular tank. Description: Menció d'Honor 2010 que atorga l'Aquacultural Engineering Society Mon, 06 May 2013 11:20:17 GMT http://hdl.handle.net/2117/19103 2013-05-06T11:20:17Z Masaló Llorà, Ingrid; Guadayol, Oscar; Peters, Francesc; Oca Baradad, Joan no Turbulence, Fish faeces, Solid waste, Resuspension, Oscillating grid Sedimentation and resuspension processes of aquaculture biosolids (non-ingested feed and faeces) are analysed using vertically oscillating grids as a source of turbulence in fluid tanks. An oscillating grid system consists of a container in which a grid is stirred vertically generating a well-known turbulent field that is function of amplitude and frequency of oscillation, distance between grid and measurement point, and mesh spacing of the grid. The grid used in this study had a mesh spacing of 1.2 cm, and was calibrated using different amplitudes (1, 1.5 and 2 cm), frequencies (from 1 to 6 Hz) and distances (2.4, 2.7 and 3 cm). After calibration, the turbulence needed to resuspend biosolids and to maintain them in the water column following different times of consolidation, and with biosolids of different origin, was analysed. It was observed that the turbulence needed to resuspend aquaculture biosolids increased with the time of consolidation. When the turbulence was decreased after a resuspension process, the next sedimentation of biosolids showed a hysteretic behaviour: turbulence needed to resuspend a fixed percent of biosolids from the tank bottom is substantially higher than that needed to maintain the same percentage suspended in the water column. Differences in resuspension behaviour of biosolids originated in different tanks were also observed. The method provides useful information that can be compared with turbulence generated by fish swimming activity, in order to determine the culture conditions, which can promote self-cleaning conditions in a particular tank. http://hdl.handle.net/2117/18953 Title: Efectos genéticos y ambientales en la composición química de la judía: estudio de algunas moléculas relacionadas con el valor sensorial y nutritivo Authors: Rivera Pinzano, Ana; Plans Pujolràs, Marçal; Sabaté Reboll, José; Ferreira, Juan José; Almirall Malivern, Antonio Rafael; Casañas Artigas, Francesc Tue, 23 Apr 2013 12:11:08 GMT http://hdl.handle.net/2117/18953 2013-04-23T12:11:08Z Rivera Pinzano, Ana; Plans Pujolràs, Marçal; Sabaté Reboll, José; Ferreira, Juan José; Almirall Malivern, Antonio Rafael; Casañas Artigas, Francesc no http://hdl.handle.net/2117/17841 Title: Technological or tradicional tools for documents correction? A Case study in higher education Authors: Kallas, Zein; Ornat Longarón, Cèsar Mon, 18 Feb 2013 14:43:45 GMT http://hdl.handle.net/2117/17841 2013-02-18T14:43:45Z Kallas, Zein; Ornat Longarón, Cèsar no http://hdl.handle.net/2117/17552 Title: Ethnic identity and dietary habits among Hispanic immigrants in Spain Authors: Romo Muñoz, Rodrigo Alejandro; Gil Roig, José María Abstract: Purpose – Focussing on Latin American immigrants in Barcelona, the objective of this paper is twofold: to measure their degree of ethnical identity; and to analyse the relationship between food habits and their ethnical identity. Design/methodology/approach – Face-to-face interviews with a representative sample of Latin American immigrants in the Metropolitan area of Barcelona are undertaken. Ethnic identity is measured using the MEIM scale, which combines aspects from the social identity and personal development theories. Finally, a Multinomial Logit Model is used to identify the relationship between food habits and ethnical identity. Findings – Results indicate that the higher the level of ethnic identity and feeling of belonging of immigrants in Catalonia, the greater the persistence of dietary habits from the country of origin. Contrasting with results from other studies, no correlation is found between the persistence of dietary habits and either the length of time spent in Spain or the level of integration into the Catalan culture (measured through use of the Catalan language). Research limitations/implications – Findings should logically be interpreted within the context of the population and sample studied. Further research should be addressed to analyze other immigrant groups such as Muslims, Asians and Eastern Europeans. Originality/value – This study explores the strength of traditional food habits of immigrants living in a foreign cultural environment and the role of ethnic identity in contributing to this strength. While past literature focussing on this topic is based on atheoretical and partial indicators to measure ethnic identity, this study provides evidence on the usefulness of using a theory-based and multidimensional measure. The behaviour of Latin American immigrants in Spain is used as a case study. Thu, 31 Jan 2013 16:35:54 GMT http://hdl.handle.net/2117/17552 2013-01-31T16:35:54Z Romo Muñoz, Rodrigo Alejandro; Gil Roig, José María no Ethnic groups, Ethnic identity, Food habits, Latin American immigrants, Spain Purpose – Focussing on Latin American immigrants in Barcelona, the objective of this paper is twofold: to measure their degree of ethnical identity; and to analyse the relationship between food habits and their ethnical identity. Design/methodology/approach – Face-to-face interviews with a representative sample of Latin American immigrants in the Metropolitan area of Barcelona are undertaken. Ethnic identity is measured using the MEIM scale, which combines aspects from the social identity and personal development theories. Finally, a Multinomial Logit Model is used to identify the relationship between food habits and ethnical identity. Findings – Results indicate that the higher the level of ethnic identity and feeling of belonging of immigrants in Catalonia, the greater the persistence of dietary habits from the country of origin. Contrasting with results from other studies, no correlation is found between the persistence of dietary habits and either the length of time spent in Spain or the level of integration into the Catalan culture (measured through use of the Catalan language). Research limitations/implications – Findings should logically be interpreted within the context of the population and sample studied. Further research should be addressed to analyze other immigrant groups such as Muslims, Asians and Eastern Europeans. Originality/value – This study explores the strength of traditional food habits of immigrants living in a foreign cultural environment and the role of ethnic identity in contributing to this strength. While past literature focussing on this topic is based on atheoretical and partial indicators to measure ethnic identity, this study provides evidence on the usefulness of using a theory-based and multidimensional measure. The behaviour of Latin American immigrants in Spain is used as a case study. http://hdl.handle.net/2117/17395 Title: Flow pattern in aquaculture circular tanks: Influence of flow rate, water depth, and water inlet & outlet features Authors: Oca Baradad, Joan; Masaló Llorà, Ingrid Thu, 17 Jan 2013 11:45:42 GMT http://hdl.handle.net/2117/17395 2013-01-17T11:45:42Z Oca Baradad, Joan; Masaló Llorà, Ingrid no http://hdl.handle.net/2117/16683 Title: Time series outlier and intervention analysis: Irrigation management influences on soil water content in silty loam soil Authors: Basem, Aljoumani; Sánchez Espigares, Josep Anton; Cañameras Riba, Núria; Josa March, Ramon; Monserrat, Joaquim Abstract: Understanding the field soil water regime is fundamental in scheduling irrigation as well as for monitoring water flow and solute transport. This study was carried out on variable interval irrigation and used time series analysis techniques to predict the soil water content at the interested depth by measuring one single depth in order to precisely determine the next irrigation time and its effect on soil water content at the interested depth. Volumetric water content of silty loam soil in Barcelona was measured in situ with capacitance soil moisture sensors at five depths within the root zone for a horticultural crop during its life cycle in 2010. The time series consisted of hourly measurements of soil water content and was transformed to a stationary situation. Subsequently, the transformed data were used to conduct analyses in the time domain in order to obtain the parameters of a seasonal autoregressive integrated moving average (ARIMA) model. In the case of variable interval irrigation, predicting the soil water content time series cannot be properly explained by the ARIMA model and its underlying normality assumption. By completing the ARIMA model with intervention analysis and outlier detection, the prediction of soil water content in variable interval irrigation can be made. The transfer function models were then used to predict water contents at depths of interest (0.20, 0.35, 0.50 and 0.60 m depths) as well as the average water content WAVG in the top 0.60 m soil profile by measuring water content at 0.10 m depth. As a result, the predictions were logical. Also, the next irrigation time and its effect on soil water content at the depth of interest were correctly estimated. To confirm results of the models, the experiment was repeated in 2011, and the predicted and observed values agree reasonably well. Description: Soil volumetric water content; Autoregressive integrated moving average (ARIMA); Outlier detection; Transfer function model Tue, 09 Oct 2012 11:01:57 GMT http://hdl.handle.net/2117/16683 2012-10-09T11:01:57Z Basem, Aljoumani; Sánchez Espigares, Josep Anton; Cañameras Riba, Núria; Josa March, Ramon; Monserrat, Joaquim no Autoregressive integrated moving average (ARIMA), Outlier detection, Soil volumetric water content, Transfer function model Understanding the field soil water regime is fundamental in scheduling irrigation as well as for monitoring water flow and solute transport. This study was carried out on variable interval irrigation and used time series analysis techniques to predict the soil water content at the interested depth by measuring one single depth in order to precisely determine the next irrigation time and its effect on soil water content at the interested depth. Volumetric water content of silty loam soil in Barcelona was measured in situ with capacitance soil moisture sensors at five depths within the root zone for a horticultural crop during its life cycle in 2010. The time series consisted of hourly measurements of soil water content and was transformed to a stationary situation. Subsequently, the transformed data were used to conduct analyses in the time domain in order to obtain the parameters of a seasonal autoregressive integrated moving average (ARIMA) model. In the case of variable interval irrigation, predicting the soil water content time series cannot be properly explained by the ARIMA model and its underlying normality assumption. By completing the ARIMA model with intervention analysis and outlier detection, the prediction of soil water content in variable interval irrigation can be made. The transfer function models were then used to predict water contents at depths of interest (0.20, 0.35, 0.50 and 0.60 m depths) as well as the average water content WAVG in the top 0.60 m soil profile by measuring water content at 0.10 m depth. As a result, the predictions were logical. Also, the next irrigation time and its effect on soil water content at the depth of interest were correctly estimated. To confirm results of the models, the experiment was repeated in 2011, and the predicted and observed values agree reasonably well. http://hdl.handle.net/2117/16392 Title: Nanofibrillated cellulose (NFC) as a potential reinforcement for high performance cement mortar composites Authors: Ardanuy Raso, Mònica; Claramunt Blanes, Josep; Arévalo Peces, Raquel; Parés Sabatés, Ferran; Aracri, Elisabetta; Vidal Lluciá, Teresa Abstract: In this work, nanofibrillated cellulose (NFC) has been evaluated as a potential reinforcement for cement mortar composites. Two types of vegetable fibres with different composition and properties (cellulose content and microfibrillar angle), sisal, and cotton linters pulps, were initially characterized in order to assess their reinforcement capability. Sisal pulp was found to be most suitable as reinforcement for their brittle cementitious matrix. Nanofibrillated cellulose was produced by the application of a high intensity refining process of the sisal pulp. It was found that 6 hours of refining time was required to obtain the desired nanofibrillation of the fibers. Cement mortar composites reinforced with both the sisal fibers and the nanofibrillated cellulose were prepared, and the mechanical properties were determined under flexural test. The cement mortar composites reinforced with the nanofibrillated cellulose exhibited enhanced flexural properties, but lower values of fracture energy, than the ones reinforced with the conventional sisal fibres. Tue, 28 Aug 2012 08:27:11 GMT http://hdl.handle.net/2117/16392 2012-08-28T08:27:11Z Ardanuy Raso, Mònica; Claramunt Blanes, Josep; Arévalo Peces, Raquel; Parés Sabatés, Ferran; Aracri, Elisabetta; Vidal Lluciá, Teresa no In this work, nanofibrillated cellulose (NFC) has been evaluated as a potential reinforcement for cement mortar composites. Two types of vegetable fibres with different composition and properties (cellulose content and microfibrillar angle), sisal, and cotton linters pulps, were initially characterized in order to assess their reinforcement capability. Sisal pulp was found to be most suitable as reinforcement for their brittle cementitious matrix. Nanofibrillated cellulose was produced by the application of a high intensity refining process of the sisal pulp. It was found that 6 hours of refining time was required to obtain the desired nanofibrillation of the fibers. Cement mortar composites reinforced with both the sisal fibers and the nanofibrillated cellulose were prepared, and the mechanical properties were determined under flexural test. The cement mortar composites reinforced with the nanofibrillated cellulose exhibited enhanced flexural properties, but lower values of fracture energy, than the ones reinforced with the conventional sisal fibres. http://hdl.handle.net/2117/15842 Title: Mesophilic and thermophilic anaerobic biodegradability of water hyacinth pre-treated at 80 °C Authors: Ferrer Martí, Ivet; Campos Pozuelo, Elena; Flotats Ripoll, Xavier; Palatsi Civit, Jordi Abstract: Water hyacinth (Eichornia crassipes) is a fast growing aquatic plant which causes environmental problems in continental water bodies. Harvesting and handling this plant becomes an issue, and focus has been put on the research of treatment alternatives. Amongst others, energy production through biomethanation has been proposed. The aim of this study was to assess the anaerobic biodegradability of water hyacinth under mesophilic and thermophilic conditions. The effect of a thermal sludge pre-treatment at 80 C was also evaluated. To this end, anaerobic biodegradability tests were carried out at 35 C and 55 C, with raw and pre-treated water hyacinth. According to the results, the thermal pre-treatment enhanced the solubilisation of water hyacinth (i.e. increase in the soluble to total chemical oxygen demand (COD)) from 4% to 12% after 30 min. However, no significant effect was observed on the methane yields (150–190 L CH4/kg volatile solids). Initial methane production rates for thermophilic treatments were two fold those of mesophilic ones (6–6.5 L vs. 3–3.5 L CH4/kg COD day). Thus, higher methane production rates might be expected from thermophilic reactors working at short retention times. The study of longer low temperature pre-treatments or pre-treatments at elevated temperatures coupled to thermophilic reactors should be considered in the future. Fri, 11 May 2012 18:43:39 GMT http://hdl.handle.net/2117/15842 2012-05-11T18:43:39Z Ferrer Martí, Ivet; Campos Pozuelo, Elena; Flotats Ripoll, Xavier; Palatsi Civit, Jordi no Water hyacinth (Eichornia crassipes) is a fast growing aquatic plant which causes environmental problems in continental water bodies. Harvesting and handling this plant becomes an issue, and focus has been put on the research of treatment alternatives. Amongst others, energy production through biomethanation has been proposed. The aim of this study was to assess the anaerobic biodegradability of water hyacinth under mesophilic and thermophilic conditions. The effect of a thermal sludge pre-treatment at 80 C was also evaluated. To this end, anaerobic biodegradability tests were carried out at 35 C and 55 C, with raw and pre-treated water hyacinth. According to the results, the thermal pre-treatment enhanced the solubilisation of water hyacinth (i.e. increase in the soluble to total chemical oxygen demand (COD)) from 4% to 12% after 30 min. However, no significant effect was observed on the methane yields (150–190 L CH4/kg volatile solids). Initial methane production rates for thermophilic treatments were two fold those of mesophilic ones (6–6.5 L vs. 3–3.5 L CH4/kg COD day). Thus, higher methane production rates might be expected from thermophilic reactors working at short retention times. The study of longer low temperature pre-treatments or pre-treatments at elevated temperatures coupled to thermophilic reactors should be considered in the future. http://hdl.handle.net/2117/15838 Title: Start-up strategies of thermophilic anaerobic digestion of sewage sludge Authors: Gimenez-Lorang, Antonio; Ferrer Martí, Ivet; Flotats Ripoll, Xavier; Palatsi Civit, Jordi Abstract: The aim of the present work was to evaluate two different strategies to convert a continuous mesophilic anaerobic reactor into thermophilic, treating sewage sludge. The compared strategies were a single direct temperature change, from 358 to 558C, and a multi-step temperature change (358–438–508–558C). The single direct step strategy was shown to be as effective as the more conservative multi-step strategy, recovering the system efficiency after 20 days in terms of methane yield, although there was a higher volatile fatty acids accumulation and higher propionate/acetate ratio values during the temperature transition. From the results of the multi-step strategy it could be stated that the critical process performance during temperature transition occurred between 43 and 508C, which should be taken into account to define more accurate future transition strategies. Sewage sludge thermophilic vs mesophilic biodegradability was assessed by means of anaerobic biodegradability tests, and no significant statistical differences in biodegradability or methane yields were found. Fri, 11 May 2012 18:21:45 GMT http://hdl.handle.net/2117/15838 2012-05-11T18:21:45Z Gimenez-Lorang, Antonio; Ferrer Martí, Ivet; Flotats Ripoll, Xavier; Palatsi Civit, Jordi no anaerobic digestion, mesophilic, sewage sludge, thermophilic The aim of the present work was to evaluate two different strategies to convert a continuous mesophilic anaerobic reactor into thermophilic, treating sewage sludge. The compared strategies were a single direct temperature change, from 358 to 558C, and a multi-step temperature change (358–438–508–558C). The single direct step strategy was shown to be as effective as the more conservative multi-step strategy, recovering the system efficiency after 20 days in terms of methane yield, although there was a higher volatile fatty acids accumulation and higher propionate/acetate ratio values during the temperature transition. From the results of the multi-step strategy it could be stated that the critical process performance during temperature transition occurred between 43 and 508C, which should be taken into account to define more accurate future transition strategies. Sewage sludge thermophilic vs mesophilic biodegradability was assessed by means of anaerobic biodegradability tests, and no significant statistical differences in biodegradability or methane yields were found. http://hdl.handle.net/2117/15263 Title: Performance of an Ultrasonic Ranging Sensor in Apple Tree Canopies Authors: Gil Moya, Emilio; Escolà Agustí, Alexandre; Planas de Martí, Santiago; Rosell Polo, Joan Ramon; Pomar Gomá, Jesús; Camp Feria-Carot, Fernando; Solanelles Batlle, Francesc; Gràcia Aguila, Felip; Llorens Calveras, Jordi Mon, 20 Feb 2012 16:08:30 GMT http://hdl.handle.net/2117/15263 2012-02-20T16:08:30Z Gil Moya, Emilio; Escolà Agustí, Alexandre; Planas de Martí, Santiago; Rosell Polo, Joan Ramon; Pomar Gomá, Jesús; Camp Feria-Carot, Fernando; Solanelles Batlle, Francesc; Gràcia Aguila, Felip; Llorens Calveras, Jordi no http://hdl.handle.net/2117/14087 Title: Diseño de tanques en acuicultura intensiva Authors: Oca Baradad, Joan; Masaló Llorà, Ingrid; Gutiérrez, Carmen Sun, 27 Nov 2011 18:28:58 GMT http://hdl.handle.net/2117/14087 2011-11-27T18:28:58Z Oca Baradad, Joan; Masaló Llorà, Ingrid; Gutiérrez, Carmen no http://hdl.handle.net/2117/13666 Title: Digestión anaerobia de subproductos de la industria cárnica Authors: Palatsi Civit, Jordi; Rodríguez-Abalde, Ángela; Fernández García, Belén; Flotats Ripoll, Xavier Wed, 26 Oct 2011 09:43:50 GMT http://hdl.handle.net/2117/13666 2011-10-26T09:43:50Z Palatsi Civit, Jordi; Rodríguez-Abalde, Ángela; Fernández García, Belén; Flotats Ripoll, Xavier no http://hdl.handle.net/2117/13619 Title: Codigestion of cow and guinea pig manure in low-cost tubular digesters at high altitude Authors: Garfi, Marianna; Ferrer Martí, Laia; Pérez Bort, Irene; Flotats Ripoll, Xavier; Ferrer Martí, Ivet Fri, 21 Oct 2011 12:59:03 GMT http://hdl.handle.net/2117/13619 2011-10-21T12:59:03Z Garfi, Marianna; Ferrer Martí, Laia; Pérez Bort, Irene; Flotats Ripoll, Xavier; Ferrer Martí, Ivet no http://hdl.handle.net/2117/13603 Title: Effects of tillage systems in dryland farming on near-surface water content during the late winter period Authors: Josa March, Ramon; Hereter Quintana, Agnès Abstract: Tillage systems modify, at least temporarily, some of the physical properties of soil, such as soil porosity. Tillage also has an indirect effect on soil water content throughout the growth cycle, particularly in areas with a Mediterranean climate. This paper presents the results of monitoring the water content in the topsoil (0–0.20 m) of three adjacent plots during February to May cycles starting in 1994–1995 and ending in 1998–1999. Each of the plots had a surface area of 2700 m2, an 8% slope and Calcic Cambisol soil. Starting in 1994, three different tillage systems were applied: conventional tillage, which is typical of the area (CT); minimum tillage (MT); and no-tillage (NT). Two vertical 200 mm TDR probes were permanently installed in each plot and measurements were taken every week. The results show that, under an NT system, the soil had significantly higher water content than the other two soil plots. However, this increased quantity of water did not denote increased crop production; on the contrary, these preliminary data point to a decrease in crop production. Thu, 20 Oct 2011 14:30:33 GMT http://hdl.handle.net/2117/13603 2011-10-20T14:30:33Z Josa March, Ramon; Hereter Quintana, Agnès no Tillage systems modify, at least temporarily, some of the physical properties of soil, such as soil porosity. Tillage also has an indirect effect on soil water content throughout the growth cycle, particularly in areas with a Mediterranean climate. This paper presents the results of monitoring the water content in the topsoil (0–0.20 m) of three adjacent plots during February to May cycles starting in 1994–1995 and ending in 1998–1999. Each of the plots had a surface area of 2700 m2, an 8% slope and Calcic Cambisol soil. Starting in 1994, three different tillage systems were applied: conventional tillage, which is typical of the area (CT); minimum tillage (MT); and no-tillage (NT). Two vertical 200 mm TDR probes were permanently installed in each plot and measurements were taken every week. The results show that, under an NT system, the soil had significantly higher water content than the other two soil plots. However, this increased quantity of water did not denote increased crop production; on the contrary, these preliminary data point to a decrease in crop production. http://hdl.handle.net/2117/13584 Title: Induced changes in soil properties on account of introduction of conservation tillage systems: evaluation of the effects on soil fertility Authors: Dalmau, Laura; Hereter Quintana, Agnès; Josa March, Ramon Wed, 19 Oct 2011 09:47:57 GMT http://hdl.handle.net/2117/13584 2011-10-19T09:47:57Z Dalmau, Laura; Hereter Quintana, Agnès; Josa March, Ramon no Soil fertility