scholarly journals An efficient numerical model for liquid water uptake in porous material and its parameter estimation

2019 ◽  
Vol 75 (2) ◽  
pp. 110-136
Author(s):  
Ainagul Jumabekova ◽  
Julien Berger ◽  
Denys Dutykh ◽  
Hervé Le Meur ◽  
Aurélie Foucquier ◽  
...  
Keyword(s):  
Parameter Estimation ◽  
Numerical Model ◽  
Porous Material ◽  
Water Uptake ◽  
Liquid Water

A simple numerical model to estimate water availability in saline soils

Soil Research ◽  
2018 ◽  
Vol 56 (3) ◽  
pp. 264 ◽  
Author(s):  
Mohammad Hossein Mohammadi ◽  
Mahnaz Khataar
Keyword(s):  
Numerical Model ◽  
Water Content ◽  
Soil Water ◽  
Water Uptake ◽  
Soil Salinity ◽  
Irrigation Water ◽  
Weighting Function ◽  
Water Salinity ◽  
Irrigation Water Salinity ◽  
Evapotranspiration Rate

We developed a numerical model to predict soil salinity from knowledge of evapotranspiration rate, crop salt tolerance, irrigation water salinity, and soil hydraulic properties. Using the model, we introduced a new weighting function to express the limitation imposed by salinity on plant available water estimated by the integral water capacity concept. Lower and critical limits of soil water uptake by plants were also defined. We further analysed the sensitivity of model results to underlying parameters using characteristics given for corn, cowpea, and barley in the literature and two clay and sandy loam soils obtained from databases. Results showed that, between two irrigation events, soil salinity increased nonlinearly with decreasing soil water content especially when evapotranspiration and soil drainage rate were high. The salinity weighting function depended greatly on the plant sensitivity to salinity and irrigation water salinity. This research confirmed that both critical and lower limits (in terms of water content) of soil water uptake by plants increased with evapotranspiration rate and irrigation water salinity. Since the presented approach is based on a physical concept and well-known plant parameters, soil hydraulic characteristics, irrigation water salinity, and meteorological conditions, it may be useful in spatio-temporal modelling of soil water quality and quantity and prediction of crop yield.

scholarly journals On the implications of aerosol liquid water and phase separation for organic aerosol mass

2017 ◽  
Vol 17 (1) ◽  
pp. 343-369 ◽  
Author(s):  
Havala O. T. Pye ◽  
Benjamin N. Murphy ◽  
Lu Xu ◽  
Nga L. Ng ◽  
Annmarie G. Carlton ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Organic Compounds ◽  
Water Uptake ◽  
Liquid Water ◽  
Transport Model ◽  
Organic Aerosol ◽  
Water Soluble ◽  
Organic Nitrates ◽  
Monitoring Networks ◽  
Chemical Transport Model

Abstract. Organic compounds and liquid water are major aerosol constituents in the southeast United States (SE US). Water associated with inorganic constituents (inorganic water) can contribute to the partitioning medium for organic aerosol when relative humidities or organic matter to organic carbon (OM ∕ OC) ratios are high such that separation relative humidities (SRH) are below the ambient relative humidity (RH). As OM ∕ OC ratios in the SE US are often between 1.8 and 2.2, organic aerosol experiences both mixing with inorganic water and separation from it. Regional chemical transport model simulations including inorganic water (but excluding water uptake by organic compounds) in the partitioning medium for secondary organic aerosol (SOA) when RH  >  SRH led to increased SOA concentrations, particularly at night. Water uptake to the organic phase resulted in even greater SOA concentrations as a result of a positive feedback in which water uptake increased SOA, which further increased aerosol water and organic aerosol. Aerosol properties, such as the OM ∕ OC and hygroscopicity parameter (κorg), were captured well by the model compared with measurements during the Southern Oxidant and Aerosol Study (SOAS) 2013. Organic nitrates from monoterpene oxidation were predicted to be the least water-soluble semivolatile species in the model, but most biogenically derived semivolatile species in the Community Multiscale Air Quality (CMAQ) model were highly water soluble and expected to contribute to water-soluble organic carbon (WSOC). Organic aerosol and SOA precursors were abundant at night, but additional improvements in daytime organic aerosol are needed to close the model–measurement gap. When taking into account deviations from ideality, including both inorganic (when RH  >  SRH) and organic water in the organic partitioning medium reduced the mean bias in SOA for routine monitoring networks and improved model performance compared to observations from SOAS. Property updates from this work will be released in CMAQ v5.2.

scholarly journals Effect of a Combination of Moderate-Temperature Heat Treatment and Subsequent Wax Impregnation on Wood Hygroscopicity, Dimensional Stability, and Mechanical Properties

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 920 ◽  
Author(s):  
Lin Yang ◽  
Hong-Hai Liu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Water Uptake ◽  
Significant Influence ◽  
Liquid Water ◽  
Dimensional Stability ◽  
Bending Strength ◽  
Wood Properties ◽  
Moderate Temperature ◽  
Temperature Heat Treatment

Wood is an environmentally friendly material, but some natural properties limit its wide application. To study the effect of a combination of heat treatment (HT) and wax impregnation (WI) on wood hygroscopicity, dimensional stability, and mechanical properties, samples of Pterocarpus macrocarpus Kurz wood were subjected to HT at a moderate temperature of 120 °C and a high temperature of 180 °C, for a 4 h duration. Subsequently, half of the 120 °C HT samples were treated with WI at 90 °C. The results showed that 180 °C HT and WI decreased the capacity of adsorption and liquid water uptake and swelled the wood significantly, while WI had the biggest reduction. The effect of 120 °C HT was significant only on decreasing the capacity of adsorption and the swelling of liquid water uptake. The bending strength (MOR) of wood decreased only after 180 °C HT, and 120 °C/4h HT and WI had no significant influence on MOR. The bending stiffness (MOE) increased significantly after 180 °C HT and WI, while 120 °C/4h HT had no significant influence on MOE. Therefore, the combination of moderate-temperature HT can act synergistically in the improvement of certain aspects of wood properties such as capacity of water adsorption and liquid water uptake. WI effectively improved wood hygroscopicity, dimensional stability, and mechanical properties.

Porous material parameter estimation: A Bayesian approach

2012 ◽  
Author(s):  
Cameron Fackler ◽  
Eric Dieckman ◽  
Ning Xiang
Keyword(s):  
Parameter Estimation ◽  
Porous Material ◽  
Bayesian Approach ◽  
Material Parameter

scholarly journals Satellite and Numerical Model Investigation of Two Heavy Rain Events over the Central Mediterranean

2011 ◽  
Vol 12 (4) ◽  
pp. 634-649 ◽  
Author(s):  
Sante Laviola ◽  
Agata Moscatello ◽  
Mario Marcello Miglietta ◽  
Elsa Cattani ◽  
Vincenzo Levizzani
Keyword(s):  
Water Vapor ◽  
Numerical Model ◽  
Liquid Water ◽  
Heavy Rain ◽  
Sensor Data ◽  
Retrieval Algorithm ◽  
Central Mediterranean ◽  
Model Simulations ◽  
Wide Range ◽  
Rain Events

Abstract Two heavy rain events over the Central Mediterranean basin, which are markedly different by genesis, dimensions, duration, and intensity, are analyzed. Given the relative low frequency of this type of severe storms in the area, a synoptic analysis describing their development is included. A multispectral analysis based on geostationary multifrequency satellite images is applied to identify cloud type, hydrometeor phase, and cloud vertical extension. Precipitation intensity is retrieved from (i) surface rain gauges, (ii) satellite data, and (iii) numerical model simulations. The satellite precipitation retrieval algorithm 183-Water vapor Strong Lines (183-WSL) is used to retrieve rain rates and cloud hydrometeor type, classify stratiform and convective rainfall, and identify liquid water clouds and snow cover from the Advanced Microwave Sounding Unit-B (AMSU-B) sensor data. Rainfall intensity is also simulated with the Weather Research and Forecasting (WRF) numerical model over two nested domains with horizontal resolutions of 16 km (comparable to that of the satellite sensor AMSU-B) and 4 km. The statistical analysis of the comparison between satellite retrievals and model simulations demonstrates the skills of both methods for the identification of the main characteristics of the cloud systems with a suggested overall bias of the model toward very low rain intensities. WRF (in the version used for the experiment) seems to classify as low rain intensity regions those areas where the 183-WSL retrieves no precipitation while sensing a mixture of freshly nucleated cloud droplets and a large amount of water vapor; in these areas, especially adjacent to the rain clouds, large amounts of cloud liquid water are detected. The satellite method performs reasonably well in reproducing the wide range of gauge-detected precipitation intensities. A comparison of the 183-WSL retrievals with gauge measurements demonstrates the skills of the algorithm in discriminating between convective and stratiform precipitation using the scattering and absorption of radiation by the hydrometeors.

A Novel Application of the Thermal Probe: Nonlinear and Phase Change Problems

2015 ◽  
Vol 137 (10) ◽  
Author(s):  
M. H. Adjali
Keyword(s):  
Thermal Conductivity ◽  
Parameter Estimation ◽  
Numerical Model ◽  
Phase Change ◽  
Estimation Technique ◽  
Thermal Probe ◽  
Temperature Dependent ◽  
Agar Gel ◽  
Nonlinear Numerical Model ◽  
Thermal Conductivities

This paper reports on a new application of the thermal probe in nonlinear systems. Whereas the thermal probe has been originally developed to determine the thermal conductivity in linear cases (where the thermophysical properties are considered independent of the temperature), the method used here exploits a direct nonlinear numerical model associated with a parameter estimation technique to determine temperature dependent thermal conductivities. It has been applied to a water-agar gel during phase change and the thermal conductivities within the corresponding temperature interval could be determined.

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