Evaluation of moisture sorption models and modified Mualem model for prediction of desorption isotherm for wood materials

Zhang, Xiaobo; Zillig, Wolfgang; Künzel, Hartwig M.; Zhang, Xu; Mitterer, Christoph

doi:10.1016/j.buildenv.2015.05.021

Cited by 30 publications

(15 citation statements)

References 30 publications

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“…All samples were investigated at different relative humidities of 33%, 55%, and 75%. The equilibrium moisture content (mass (g/g)) of each sample was calculated as [34,35,36] u=(m−mo)/mo, where m is the mass of the specimen at the moisture stage and m o is the mass at the oven-dried stage. The relevant main adsorption and desorption curves are presented in Figure 10.…”

Section: Resultsmentioning

confidence: 99%

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Excellent Fireproof Characteristics and High Thermal Stability of Rice Husk-Filled Polyurethane with Halogen-Free Flame Retardant

et al. 2019

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The thermal stabilities, flame retardancies, and physico-mechanical properties of rice husk-reinforced polyurethane (PU–RH) foams with and without flame retardants (FRs) were evaluated. Their flammability performances were studied by UL94, LOI, and cone calorimetry tests. The obtained results combined with FTIR, TGA, SEM, and XPS characterizations were used to evaluate the fire behaviors of the PU–RH samples. The PU–RH samples with a quite low loading (7 wt%) of aluminum diethylphosphinate (OP) and 32 wt% loading of aluminum hydroxide (ATH) had high thermal stabilities, excellent flame retardancies, UL94 V-0 ratings, and LOIs of 22%–23%. PU–RH did not pass the UL94 HB standard test and completely burned to the holder clamp with a low LOI (19%). The cone calorimetry results indicated that the fireproof characteristics of the PU foam composites were considerably improved by the addition of the FRs. The proposed flame retardancy mechanism and cone calorimetry results are consistent. The comprehensive FTIR spectroscopy, TG, SEM, and XPS analyses revealed that the addition of ATH generated white solid particles, which dispersed and covered the residue surface. The pyrolysis products of OP would self-condense or react with other volatiles generated by the decomposition of PU–RH to form stable, continuous, and thick phosphorus/aluminum-rich residual chars inhibiting the transfer of heat and oxygen. The PU–RH samples with and without the FRs exhibited the normal isothermal sorption hysteresis effect at relative humidities higher than 20%. At lower values, during the desorption, this effect was not observed, probably because of the biodegradation of organic components in the RH. The findings of this study not only contribute to the improvement in combustibility of PU–RH composites and reduce the smoke or toxic fume generation, but also solve the problem of RHs, which are abundant waste resources of agriculture materials leading to the waste disposal management problems.

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Section: Resultsmentioning

confidence: 99%

“…Using this method, the adsorption and desorption isotherm curves were recorded. Further details of the measurement are presented in the literature [34,35,36].…”

Section: Methodsmentioning

confidence: 99%

Excellent Fireproof Characteristics and High Thermal Stability of Rice Husk-Filled Polyurethane with Halogen-Free Flame Retardant

et al. 2019

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“…The model is not defined for a = 0 . Furthermore, it can be noticed that ρ 2 R 1 T = O( 10 8 ) and that p 2 = O( 10 7 ) according to (Zhang et al 2015). Thus, to avoid rounding errors and computational difficulties when solving the parameter estimation problem, the parameter p 2 is replaced by…”

Section: Models For Water Adsorptionmentioning

confidence: 99%

“…Given the magnitude of ρ 2 R 1 T and that p 2 = O( 10 −8 ) according to (Zhang et al 2015), the parameter p 2 is replaced by p 2 ←֓ ρ 2 R 1 T p 2 . So the VG model is finally formulated as:…”

Section: Models For Water Adsorptionmentioning

confidence: 99%

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Parameter estimation and model selection for water sorption in a wood fibre material

et al. 2020

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The sorption curve is an essential feature for the modelling of heat and mass transfer in porous building materials. Several models have been proposed in the literature to represent the amount of moisture content in the material according to the water activity (or capillary pressure) level. These models are based on analytical expressions and few parameters that need to be estimated by inverse analysis. This article investigates the reliability of eight models through the accuracy of the estimated parameters. For this, experimental data for a wood fibre material are generated with special attention to the stop criterion to capture long time kinetic constants. Among five sets of measurements, the best estimate is computed. The reliability of the models is then discussed. After proving the theoretical identifiability of the unknown parameters for each model, the primary identifiability is analysed. It evaluates whether the parameters influence on the model output is sufficient to proceed the parameter estimation with accuracy. For this, a continuous derivative-based approach is adopted. Seven models have a low primary identifiability for at least one parameter. Indeed, when estimating the unknown parameters using the experimental observations, the parameters with low primary identifiability exhibit large uncertainties. Finally, an Approximation Bayesian Computation algorithm is used to simultaneously select the best model and estimate the parameters that best represent the experimental data. The thermodynamic and Feng-Xing models, together with a proposed model in this work, were the best ones selected by this algorithm.

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Evaluation of the diffusion coefficient and sorption isotherm of the different layers of early Netherlandish wooden panel paintings

et al. 2017

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Evaluation of moisture sorption models and modified Mualem model for prediction of desorption isotherm for wood materials

Cited by 30 publications

References 30 publications

Excellent Fireproof Characteristics and High Thermal Stability of Rice Husk-Filled Polyurethane with Halogen-Free Flame Retardant

Excellent Fireproof Characteristics and High Thermal Stability of Rice Husk-Filled Polyurethane with Halogen-Free Flame Retardant

Parameter estimation and model selection for water sorption in a wood fibre material

Evaluation of the diffusion coefficient and sorption isotherm of the different layers of early Netherlandish wooden panel paintings

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