Traditional thermal methods of drying food have often led to loss of flavours, nutrients, vitamins, etc., which encourages non-thermal pretreatments such as osmotic dehydration (OD) and/or high electric field (HEF...Traditional thermal methods of drying food have often led to loss of flavours, nutrients, vitamins, etc., which encourages non-thermal pretreatments such as osmotic dehydration (OD) and/or high electric field (HEF) application to improve the overall product quality. The aim of this study was to evaluate the effect of osmotic dehydration (50% sucrose) with high electric field strengths of 0.5 and 1.0 kV/cm as pretreatments on the drying kinetics and mass transfer of green apples during convective drying at 65 ~C and microwave drying at 1 W/g. The added value of the OD and HEF on the drying kinetics, and the effective mass transfer coefficients of the subsequent drying methods were investigated through this research. The efficacy of these pre-treatments was assessed and compared using cell disintegration index, product texture and thus bring forth new correlations between these pre-treatments and the cell disintegration index using dielectric spectroscopy and its effect on the product texture.展开更多
We investigate experimentally the depositions of two contiguous debris flows flowing into a main river reach.The aim of the present experimental research is to analyze the geometry and the mutual interactions of debri...We investigate experimentally the depositions of two contiguous debris flows flowing into a main river reach.The aim of the present experimental research is to analyze the geometry and the mutual interactions of debris flow deposits conveyed by these tributaries in the main channel.A set of 19 experiments has been conducted considering three values of the confluence angle,two slopes of the tributary,and three different triggering conditions(debris flows occurring simultaneously in the tributaries,or occurring first either in the upstream or in the downstream tributary).The flow rate along the main channel was always kept constant.During each experiment the two tributaries had the same slope and confluence angle.The analysis of the data collected during the experimental tests indicates that the volume of the debris fan is mainly controlled by the slope angle,as expected,while the shape of the debris deposit is strongly influenced by the confluence angle.Moreover,in the case of multiple debris flows,the deposit shape is sensitive to the triggering conditions.Critical index for damming formation available in literature has been considered and applied to the present case,and,on the basis of the collected data,considerations about possible extension of such indexes to the case of multiple confluences are finally proposed.展开更多
文摘Traditional thermal methods of drying food have often led to loss of flavours, nutrients, vitamins, etc., which encourages non-thermal pretreatments such as osmotic dehydration (OD) and/or high electric field (HEF) application to improve the overall product quality. The aim of this study was to evaluate the effect of osmotic dehydration (50% sucrose) with high electric field strengths of 0.5 and 1.0 kV/cm as pretreatments on the drying kinetics and mass transfer of green apples during convective drying at 65 ~C and microwave drying at 1 W/g. The added value of the OD and HEF on the drying kinetics, and the effective mass transfer coefficients of the subsequent drying methods were investigated through this research. The efficacy of these pre-treatments was assessed and compared using cell disintegration index, product texture and thus bring forth new correlations between these pre-treatments and the cell disintegration index using dielectric spectroscopy and its effect on the product texture.
基金supported by the project GAPDEMM – GIS-based integrated platform for Debris Flow Monitoring, Modeling and Hazard Mitigation – founded by Fondazione Cassa di Risparmio di Padova e Rovigo in framework of Progetti di Eccellenza 2011-2012
文摘We investigate experimentally the depositions of two contiguous debris flows flowing into a main river reach.The aim of the present experimental research is to analyze the geometry and the mutual interactions of debris flow deposits conveyed by these tributaries in the main channel.A set of 19 experiments has been conducted considering three values of the confluence angle,two slopes of the tributary,and three different triggering conditions(debris flows occurring simultaneously in the tributaries,or occurring first either in the upstream or in the downstream tributary).The flow rate along the main channel was always kept constant.During each experiment the two tributaries had the same slope and confluence angle.The analysis of the data collected during the experimental tests indicates that the volume of the debris fan is mainly controlled by the slope angle,as expected,while the shape of the debris deposit is strongly influenced by the confluence angle.Moreover,in the case of multiple debris flows,the deposit shape is sensitive to the triggering conditions.Critical index for damming formation available in literature has been considered and applied to the present case,and,on the basis of the collected data,considerations about possible extension of such indexes to the case of multiple confluences are finally proposed.