59 research outputs found

    Ice morphology modification and solute recovery improvement by heating and annealing during block freeze-concentration of coffee extracts

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    Several treatments on ice blocks can be applied during block freeze-concentration to increase the solute recovery from the ice. In the present study, the changes in the ice block’s temperature and the application of annealing during the block freeze-concentration of aqueous coffee extracts were studied. The ice block was subjected to heating and annealing prior to the thawing stage. The effect of coolant temperature during ice block heating (T = -10 and -5 °C) and the application of annealing (+, -) on solute recovery and ice structure morphology was evaluated. The use of annealing during block freeze-concentration modified the ice crystal morphology and increased the solute recovery only when it is applied at the highest temperature. In general, the annealing process increased the size and circularity of the ice crystals, consequently improving the solute recovery. Thus, annealing can be used to increase the solute recovery during block freeze-concentration.Postprint (published version

    Freeze desalination by the integration of falling film and block freeze concentration techniques

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    Block and falling film freeze concentration are two technologies that separate water by freezing,with the potential to desalinate seawater. In this study, the integration of two freeze concentration techniques as an alternative to obtain potable water was analysed. Water with 0.5%–8% NaCl was freeze-concentrated by the falling film technique. The ice from each stage was fractionally thawed to recover the solids retained inPostprint (updated version

    Progressive stirred freeze-concentration of ethanol-water solutions

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    © 2017 Progressive freeze-concentration is a technology to separate water from solutions by freezing. In the present investigation, ethanol-water solutions were freeze-concentrated by the progressive stirred technique. The freezing stage was carried out in a stirring vessel. Solute recovery by the fractionated thawing of ice was also studied. The effects of stirring speed (500, 1000, and 2000 rpm), initial concentration of the solution (3%, 5%, and 8% ethanol), and temperature of the thawing stage (0, 10, and 20 °C) on the solute yield and average distribution coefficient were determined using response surface analysis. The ethanol concentration was found to have increased by 1.3 and 2.1 times at the end of the freeze concentration process. It was found that the initial concentration had a significant effect on the distribution coefficient. In addition, the average yield was increased by 28% by fractionated thawing. Subsequently, a non-dimensional analysis of the distribution coefficient was developed to yield a model to predict the distribution coefficient as a function of the Reynolds number, the relationship between the average ice growth rate and the stirring speed, the agitator diameter, and the liquid fraction. This technique proved to be valid with respect to the concentration of ethanol-water solutions, with better yields being obtained at low initial concentrations. This model is the first of its kind to describe the ethanol-water interaction in agitated freeze-concentration systems.Postprint (author's final draft

    Volatile compounds, sensory quality and ice morphology in falling-film and block freeze concentration of coffee extract

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    Coffee extract was freeze-concentrated through block and falling-film techniques. Solute retention and concentration efficiency were determined after one stage of these processes. Ice morphology was characterized through image analysis. Preservation of volatile compounds was determined through GC–MS. The effect of coffee extract on flavour was determined after freeze concentration through sensory evaluation. Solute occlusion was higher for falling-film than for block freeze-concentration, with an average distribution coefficient of 0.45 and 0.29, respectively. The ice crystal size was lower for the falling-film technique; this explains the higher solute occlusion. The dewatering capacity was higher for the falling-film technique, as this process is faster than block freeze-concentration. The most abundant volatile compounds of the coffee extracts were preserved after freeze concentration with both techniques. In the same way, no differences were found in most of the sensory attributes of the freeze-concentrated extract obtained using both techniques. Our results confirm the benefits of the block and falling-film freeze concentration techniques in preserving the quality of coffee extracts.Postprint (author's final draft

    Reescribir los retos del agua con una amplia base social. Grupo Operativo: Partenariado del Agua de la Cuenca del Ebro-Aragón.

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    El Partenariado del Agua del Ebro-Aragón, es un Proyecto que se está ejecutando como Grupo Operativo dentro del Programa de Desarrollo Rural de Aragón 14-20.El estudio y recopilación de los aspectos técnicos, económicos y sociales del regadío generará una geodatabase que permitirá trabajar en tres laboratorios de innovación donde se abordará la búsqueda de casos de éxito y buenas prácticas, así como el análisis de todo ello para analizarlo y obtener una prospectiva de las infraestructuras de riego. El tercer taller se encargará de la comunicación interna y externa del Proyecto, sirviendo de canal de adquisición de información y de herramienta para la difusión de los resultados,El proyecto pretende reescribir los retos del agua desde una visión actualizada para pasar a diseñar una visión de futuro, un esbozo de cómo debería evolucionar la gestión del agua, con una perspectiva técnica, pero socialmente integradora y con la ambición de crear un modelo atractivo, en el que todos los ciudadanos del Ebro-Aragón, quieran instalarse.Palabras clave: agua, regadío, gobernanza, integració

    Lo glocal y el turismo. Nuevos paradigmas de interpretación.

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    El estudio del turismo se realiza desde múltiples escalas y enfoques, este libro aborda muchos temas que es necesario discutir desde diversas perspectivas; es el caso de la reflexión sobre la propia disciplina y sus conceptos, así como los asuntos específicos referidos al impacto territorial, los tipos de turismo, las cuestiones ambientales, el tema de la pobreza, la competitividad, las políticas públicas, el papel de las universidades, las áreas naturales protegidas, la sustentabilidad, la cultura, el desarrollo, la seguridad, todos temas centrales documentados y expuestos con originalidad y dominio del asunto. Lo multiescalar es básico para la comprensión del sistema turístico, sistema formado de procesos globales, regionales y locales. El eje de discusión del libro es lo glocal, esa interacción entre lo nacional y local con lo global

    Consens d’escales i eines per a la valoració multidimensional de les persones a Catalunya

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    Model d'atenció integral; Valoració multidimensional; DiagnòsticModelo de atención integral; Valoración multidimensional; DiagnósticoComprehensive care model; Multidimensional valuation; DiagnosisActualment no existeix a Catalunya un consens sobre quin hauria de ser el mínim comú denominador d’escales i eines d’elecció per a la valoració de les diferents dimensions de les persones grans amb multimorbiditat, fragilitat, cronicitat complexa o avançada. Aquest escenari fa evident la necessitat de disposar d’escales i eines consensuades i compartides que facilitin l’aproximació multidimensional a aquestes persones de forma objectiva i pragmàtica, amb l’objectiu d'ajudar els professionals en aquest procés d’individualització de l’atenció. És per aquest motiu que, impulsat per la Direcció General de Planificació i Recerca en Salut i per l’oficina eSalut, s’ha promogut i desenvolupat aquest consens i es vol assegurar que la proposta pugui ser suportada en l’entorn digital
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