Spatial and Temporal Investigation of Dew Potential based on Long-Term Model Simulations in Iran

Since water shortage has been a serious challenge in Iran, long-term investigations of alternative water resources are vital. In this study, we performed long-term (1979–2018) model simulation at seven locations (costal, desert, mountain, and urban conditions) in Iran to investigate temporal and spatial variation of dew formation. The model was developed to simulate the dew formation (water and ice) based on the heat and mass balance equation with ECMWF-ERA-Interim (European Centre for Medium-Range Weather Forecasts–Re-Analysis) meteorological data as input. According to the model simulation, the maximum mean yearly cumulative dew yield (~65 L/m2) was observed in the mountain region in the north part of Iran with a yearly mean cumulative dew yield was ~36 L/m2. The dew yield showed a clear seasonal variation at all selected locations with maximum yields in winter (mean monthly cumulative 3–8 L/m2 depending on the location). Here we showed that dew formation is frequent in northern Iran. In other areas, where there was suffering from water-stress (southern and central parts of Iran), dew can be a utilized as an alternative source of water. The dew yield during 2001–2014 was lower than the overall mean during the past 40 years a result of climate change in Iran.Since water shortage has been a serious challenge in Iran, long-term investigations of alternative water resources are vital. In this study, we performed long-term (1979-2018) model simulation at seven locations (costal, desert, mountain, and urban conditions) in Iran to investigate temporal and spatial variation of dew formation. The model was developed to simulate the dew formation (water and ice) based on the heat and mass balance equation with ECMWF-ERA-Interim (European Centre for Medium-Range Weather Forecasts-Re-Analysis) meteorological data as input. According to the model simulation, the maximum mean yearly cumulative dew yield (similar to 65 L/m(2)) was observed in the mountain region in the north part of Iran with a yearly mean cumulative dew yield was similar to 36 L/m(2). The dew yield showed a clear seasonal variation at all selected locations with maximum yields in winter (mean monthly cumulative 3-8 L/m(2) depending on the location). Here we showed that dew formation is frequent in northern Iran. In other areas, where there was suffering from water-stress (southern and central parts of Iran), dew can be a utilized as an alternative source of water. The dew yield during 2001-2014 was lower than the overall mean during the past 40 years a result of climate change in Iran.Peer reviewe

Spatial and Temporal Investigation of Dew Potential based on Long-Term Model Simulations in Iran

Since water shortage has been a serious challenge in Iran, long-term investigations of alternative water resources are vital. In this study, we performed long-term (1979–2018) model simulation at seven locations (costal, desert, mountain, and urban conditions) in Iran to investigate temporal and spatial variation of dew formation. The model was developed to simulate the dew formation (water and ice) based on the heat and mass balance equation with ECMWF-ERA-Interim (European Centre for Medium-Range Weather Forecasts–Re-Analysis) meteorological data as input. According to the model simulation, the maximum mean yearly cumulative dew yield (~65 L/m2) was observed in the mountain region in the north part of Iran with a yearly mean cumulative dew yield was ~36 L/m2. The dew yield showed a clear seasonal variation at all selected locations with maximum yields in winter (mean monthly cumulative 3–8 L/m2 depending on the location). Here we showed that dew formation is frequent in northern Iran. In other areas, where there was suffering from water-stress (southern and central parts of Iran), dew can be a utilized as an alternative source of water. The dew yield during 2001–2014 was lower than the overall mean during the past 40 years a result of climate change in Iran

Exergy analysis of energy-intensive production processes: advancing towards a sustainable chemical industry

Exergy analysis is becoming a very powerful strategy to evaluate the real efficiency of a process. Its application in the chemical industry is still at an early stage but many interesting remarks can be obtained from the recent research in the most energy intensive processes of the chemical industry: the production of chemicals, the cement industry, the paper industry and, the iron and steel industry. The present review analyzes the opportunities and challenges in those sectors by considering exergy analyses as the first required step (although not sufficient) to advance towards a more sustainable chemical industry. Social, environmental and economic factors play a role in the critical evaluation of a process and exergy could be considered as the property that joins together those three cores of sustainability

Synthesis and evaluation of the size and the morphology of SIO [indice inférieur 2] nanoparticles in ICP RF plasma reactors

The synthesis of SiO[indice inférieur 2] nanoparticles in radio frequency (RF) plasma reactors is studied.The effect of feed rate, quench gas injection and reactor configuration, on the final size distribution and morphology of the prepared nanoparticles, are investigated.The laser scattering is used as a technique complementary to scanning electron microscopy (SEM) and the nitrogen absorption (BET) techniques, to determine the morphology, size and aggregation level of the resulting nanopowders. It is demonstrated that the quench gas configuration and reactor geometry can now be designed to control the morphology and size of the nanoparticles in these reactors. Depending on the preparation conditions and the reactor configuration chosen, various nanostructured products have been synthesised: i.e. highly aggregated nanostructured, partially sintered nanospheres and spherical nanoparticles with very low levels of aggregation. These nanostructures have their primary particles sized between 10 and 200 nm, while the aggregates sizes can lie in the range of between hundreds of nanometer to several micrometers. Computational fluid dynamics (CFD) modelling, using Fluent 6.2.16, and the fine particle model (FPM) are further employed to better understand the time-temperature history of the generated particles.The results are utilised to describe the effects of the above mentioned parameters on the formation (nucleation and growth) of the nanoparticles and clusters by various mechanisms. By combining the experimental measurements with the numerical results, the critical parameters that should be considered for a large scale production process are identified as: establishing the proper quench gas configuration, the extension of high temperature regions and the reduction of fluid circulations within the reactor

Synthesis and evaluation of the size and the morphology of SIO [indice inférieur 2] nanoparticles in ICP RF plasma reactors

The synthesis of SiO[indice inférieur 2] nanoparticles in radio frequency (RF) plasma reactors is studied.The effect of feed rate, quench gas injection and reactor configuration, on the final size distribution and morphology of the prepared nanoparticles, are investigated.The laser scattering is used as a technique complementary to scanning electron microscopy (SEM) and the nitrogen absorption (BET) techniques, to determine the morphology, size and aggregation level of the resulting nanopowders. It is demonstrated that the quench gas configuration and reactor geometry can now be designed to control the morphology and size of the nanoparticles in these reactors. Depending on the preparation conditions and the reactor configuration chosen, various nanostructured products have been synthesised: i.e. highly aggregated nanostructured, partially sintered nanospheres and spherical nanoparticles with very low levels of aggregation. These nanostructures have their primary particles sized between 10 and 200 nm, while the aggregates sizes can lie in the range of between hundreds of nanometer to several micrometers. Computational fluid dynamics (CFD) modelling, using Fluent 6.2.16, and the fine particle model (FPM) are further employed to better understand the time-temperature history of the generated particles.The results are utilised to describe the effects of the above mentioned parameters on the formation (nucleation and growth) of the nanoparticles and clusters by various mechanisms. By combining the experimental measurements with the numerical results, the critical parameters that should be considered for a large scale production process are identified as: establishing the proper quench gas configuration, the extension of high temperature regions and the reduction of fluid circulations within the reactor