The aim of this research is to explore the influence of hysteresis on heat transport in soils under experimental laboratory conditions. The obtained results shown that, thermal properties as are volumetric specific he...The aim of this research is to explore the influence of hysteresis on heat transport in soils under experimental laboratory conditions. The obtained results shown that, thermal properties as are volumetric specific heat capacity (Cv) and thermal conductivity (θ) showed a positive linear correlation with soil volumetric water content (θ). However, thermal diffusivity values (θ) shown divergences between heat transferred and soil moisture. A spatial-temporal hysteresis pattern was observed on the whole of the thermal properties. This fact was related with factors as: degree of saturation, the influence of temperature difference on the heat transport, and the geometry of the water layer around the particle.展开更多
The purpose of this research is to explore the variability on the soil thermal conductivity -?- after a prescribe fire, and to assess the effects of the ashes on the heat transfer once it’s were incorporated into the...The purpose of this research is to explore the variability on the soil thermal conductivity -?- after a prescribe fire, and to assess the effects of the ashes on the heat transfer once it’s were incorporated into the soil matrix. Sampling plot was located in the Montgrí Massif (NE of Spain). A set of 42 soil samples between surface and 5 cm depth was collected before and after the fire. To characterize the soil chemical and physical variables were analyzed. To determine the variability on the soil λ a dry-out curve per scenario (before and after fire) was determined. SoilRho ? method based on ASTM D-5334-08 which was validated by LabFerrer was used. Soil thermal conductivity has shown changes in their values. Indeed, in all moisture scenarios the values of soil λ decreased after soil was burnt. The critical point in the relationshipθ(λ) for the soil after fire which always was stronger than soil before to be burnt. Soil with “white” ashes showed a high thermal conductivity. An X-Ray diffractometry analysis allowed to clarify and to verify these results. To sum up, we could say that thermal conductivity presents changes when the scenario changes, i.e. before and after to be burnt. On the other hand, the volume of ashes incorporated on the soil increased the differences between no burnt and burnt soil, showing even some improvements on the heat transfer when water content started to govern the process.展开更多
文摘The aim of this research is to explore the influence of hysteresis on heat transport in soils under experimental laboratory conditions. The obtained results shown that, thermal properties as are volumetric specific heat capacity (Cv) and thermal conductivity (θ) showed a positive linear correlation with soil volumetric water content (θ). However, thermal diffusivity values (θ) shown divergences between heat transferred and soil moisture. A spatial-temporal hysteresis pattern was observed on the whole of the thermal properties. This fact was related with factors as: degree of saturation, the influence of temperature difference on the heat transport, and the geometry of the water layer around the particle.
文摘The purpose of this research is to explore the variability on the soil thermal conductivity -?- after a prescribe fire, and to assess the effects of the ashes on the heat transfer once it’s were incorporated into the soil matrix. Sampling plot was located in the Montgrí Massif (NE of Spain). A set of 42 soil samples between surface and 5 cm depth was collected before and after the fire. To characterize the soil chemical and physical variables were analyzed. To determine the variability on the soil λ a dry-out curve per scenario (before and after fire) was determined. SoilRho ? method based on ASTM D-5334-08 which was validated by LabFerrer was used. Soil thermal conductivity has shown changes in their values. Indeed, in all moisture scenarios the values of soil λ decreased after soil was burnt. The critical point in the relationshipθ(λ) for the soil after fire which always was stronger than soil before to be burnt. Soil with “white” ashes showed a high thermal conductivity. An X-Ray diffractometry analysis allowed to clarify and to verify these results. To sum up, we could say that thermal conductivity presents changes when the scenario changes, i.e. before and after to be burnt. On the other hand, the volume of ashes incorporated on the soil increased the differences between no burnt and burnt soil, showing even some improvements on the heat transfer when water content started to govern the process.
