Equation of Equilibrium Moisture Content of Wood under Vacuum by Regression Analysis

2010 ◽  
Vol 139-141 ◽  
pp. 645-648
Author(s):  
Song Lin Yi ◽  
Yong Dong Zhou ◽  
Zheng Bin He ◽  
Xiao Jiang Feng ◽  
Bi Guang Zhang
Keyword(s):  
Experimental Data ◽  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Pressure Range ◽  
Solid Wood ◽  
Chinese Fir ◽  
Regression Equation ◽  
Drying Method ◽  
Temperature And Pressure ◽  
Highly Correlated

Relationship among equilibrium moisture content (EMC), temperature and pressure was established under vacuum condition, and EMC regression equation was constructed based on experimental data, with Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) as Experimental material, and MC was measured by oven-drying method. The experimental temperature range was from 40 to 90°C at the interval of 10°C, and pressure range was from 0.02 to 0.08 MPa at the interval of 0.02 MPa. EMC Comparison of Chinese fir and paper wafer sensor showed: EMC of paper wafer sensor changed in the same trend of solid wood. A regression equation was presented and the calculated EMC value was highly correlated with experimental data. This regression equation can be used to predict EMC under vacuum, especially for automatic control system of wood drying under vacuum.

scholarly journals Thermodynamic properties and moisture sorption isotherms of two pharmaceutical compounds

2018 ◽  
Author(s):  
Amel Zammouri ◽  
M. Ben Zid ◽  
N. Kechaou ◽  
N. Boudhrioua Mihoubi
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Water Sorption ◽  
Pharmaceutical Preparations ◽  
Sorption Isotherms ◽  
Integral Enthalpy ◽  
Isotherm Models ◽  
Water Sorption Isotherms

This investigation examines and compares the water sorption isotherms and the thermodynamic properties of two pharmaceutical preparations (Hypril and Azix) intended to be manufactured with the same process plant and equipment. The moisture equilibrium isotherms were determined at 50, 60 and 70 °C using a gravimetric technique. Five isotherm models were explored for their fitting to the experimental data. Azix showed sigmoid type II isotherms while Hypril showed type III isotherms according to the BET classification. All investigated models fitted well the water sorption isotherms of Hypril. By contrast, only GAB and Adam and Shove equations gave appropriate fit to the experimental data of Azix. For both formulations, the isosteric heat and the differential entropy decreased sharply with the increase of equilibrium moisture content to minimum values and thereafter remain constant. In the case of Azix, the integral enthalpy decreased with equilibrium moisture content while the integral entropy increased until reaching a constant value. Contrariwise, Hypril showed decreasing of the integral enthalpy and entropy with the equilibrium moisture content. Keywords: sorption isotherm, enthalpy, entropy, spreading pressure, pharmaceutical formulations  

Comparative Analysis of Sorption Isotherms for Wood Pellets and Solid Wood

2019 ◽  
Vol 35 (4) ◽  
pp. 475-479 ◽  
Author(s):  
Jun Sian Lee ◽  
Shahab Sokhansanj ◽  
C. Jim Lim ◽  
Anthony Lau ◽  
Tony Bi
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Sorption Isotherms ◽  
Solid Wood ◽  
Wood Chips ◽  
Published Data ◽  
Wood Pellets ◽  
Wood Pellet ◽  
Equilibrium Relative Humidity

Abstract.The published data on equilibrium moisture content vs. equilibrium relative humidity (EMC-ERH) for wood pellet do not cover the range of temperature and relative humidity to which a pellet is exposed to during its storage and handling. A few published EMC-ERH relations covering a wider range of temperatures and relative humidity are available for solid wood (lumber) and wood chips. The question is whether the data for solid wood is applicable to wood pellets. For this research, we examined the sorption isotherms of wood pellets and solid wood. The analysis shows that EMC for solid wood is higher than the EMC for wood pellet for a relative humidity larger than 30%. The slope of EMC-ERH isotherm for solid wood in the range of 30%-70% is slightly steeper than the slope of isotherm for wood pellet, indicating the pellet’s EMC is less sensitive to ERH when compared to EMC-ERH for solid wood. Keywords: EMC, ERH, Densified biomass, Equilibrium moisture content, Equilibrium relative humidity, Solid wood, Wood pellets.

Sorption Isotherms and Isosteric Heat of Peanut Pods, Kernels and Hulls

2007 ◽  
Vol 13 (3) ◽  
pp. 231-238 ◽  
Author(s):  
P.C. Corrêa ◽  
A.L.D. Goneli ◽  
C. Jaren ◽  
D.M. Ribeiro ◽  
O. Resende
Keyword(s):  
Experimental Data ◽  
Relative Humidity ◽  
Moisture Content ◽  
Mathematical Models ◽  
Equilibrium Moisture Content ◽  
Sorption Isotherms ◽  
Isosteric Heat ◽  
Statistical Parameters ◽  
Peanut Hulls ◽  
Pass Through

This study was carried out to evaluate the sorption isotherms of peanut pods, kernels and hulls for several temperature and humidity conditions and to fit different mathematical models to the experimental data, selecting the one best fitting the phenomenon. The dynamic method was applied to obtain the hygroscopic equilibrium moisture content. The environmental conditions were provided by means of an atmospheric conditioning unit, in which removable perforated trays were placed to allow air to pass through peanut mass, each one containing 50 g of the product. The mathematical models frequently used for the representation of hygroscopicity of agricultural products were fit to the experimental data. Based on those results, it was concluded that peanut pods, kernels and hulls presented differentiated hygroscopicity. The equilibrium moisture content for peanut pods, kernels and hulls increased with an increase in the relative humidity at any particular temperature and decreased with increase in temperature at constant relative humidity. At a constant water activity, peanut hulls samples had higher equilibrium moisture content than the pods and kernels samples. Based on statistical parameters, the modified Henderson and Chung-Pfost models were found to adequately describe the sorption characteristics of peanut pods, kernels and hulls. Isosteric heat of desorption were evaluated by applying the Clausius—Clapeyron equation to experimental isotherms and decreased with increasing moisture content. The peanut hulls had higher isosteric heat of sorption than that peanut pods and kernels.

Equilibrium Moisture Content of Ganoderma Lucidum

2019 ◽  
Vol 889 ◽  
pp. 266-274
Author(s):  
Pham Van Kien ◽  
Nguyen Hay ◽  
Le Anh Duc
Keyword(s):  
Experimental Data ◽  
Regression Analysis ◽  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Ganoderma Lucidum ◽  
Regression Coefficient ◽  
Least Square ◽  
Quadratic Regression ◽  
Least Square Regression ◽  
Linear Least Square

Equilibrium moisture content (EMC) of Ganoderma Lucidum was determined experimentally at three different experimental temperature (30, 40 and 50°C) and relative humidity ranged from 11.1 to 93.58% using a gravimetric technique. The experimental data of equilibrium moisture content obtained was fitted to four mathematical models (Modified Henderson, Modified Chung ˗ Pfost, Modified Oswin and Modified Haley). A non-linear least square regression analysis was used to evaluate the model constants based on the parameters as: standard error of estimate (SEE), the residual sum of squares (RSS), the quadratic regression coefficient (R2). The result showed that the modified Chung ˗ Pfost model best fitted the experimental data.

Experimental Study and Modelling of Moisture Sorption Isotherms of Salted Largehead Hairtail (Trichiurus lepturus) at 25 and 35°C

2014 ◽  
Vol 1033-1034 ◽  
pp. 681-689
Author(s):  
Zhong Yang Ren ◽  
Yan Yan Wu ◽  
Zhen Hua Duan ◽  
Lai Hao Li ◽  
Xian Qing Yang
Keyword(s):  
Experimental Data ◽  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Water Activity ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
The Body ◽  
Trichiurus Lepturus ◽  
Moisture Sorption Isotherms

The moisture sorption characteristics of salted largehead hairtail (Trichiurus lepturus) were investigated within the limits of water activity (0.11-0.98) at 25 and 35°C using a self-made instrument for the measurement of the equilibrium moisture content according to the static gravimetric method. The shape of the sorption isotherms was sigmoidal. The moisture sorption isotherms exhibited significant hysteresis. The hysteresis of salted fish may be due to the salt permeating into the body of the fish as a result of desorption and adsorption processes. Seventeen mathematical models were fit to the experimental data for the equilibrium moisture content at different water activity levels. The Ferro-Fontan equation provided the best fit for the experimental data of the equilibrium moisture content among the 17 models assessed for the sorption isotherms at 25 and 35°C. The net isosteric heats of sorption decreased gradually with increases in moisture content. The isosteric heats of sorption ranged from 44.59 kJ/mol to 45.61 kJ/mol between the moisture contents of 22.22% and 43.25% for salted largehead hairtail.

Estimation of Equilibrium Moisture Content of Pistachio Powder through the ANN and GA Approaches

2014 ◽  
Vol 10 (4) ◽  
pp. 747-755
Author(s):  
Hamid Tavakolipour ◽  
Mohsen Mokhtarian
Keyword(s):  
Experimental Data ◽  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
High Performance ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Similar Data ◽  
Intelligent Tools ◽  
Artificial Neural Network Ann

Abstract In this study, two intelligent tools of genetic algorithm (GA) and artificial neural network (ANN) were employed to use experimental data to predict equilibrium moisture content (EMC) of Persian pistachio powder. Initially the moisture sorption isotherms of pistachio powder were determined by gravimetric method at different temperatures (15, 25, 35 and 40°C) and constant relative humidity’s (0.11, 0.23, 0.36, 0.49, 0.62, 0.75 and 0.88 aw values) and then traditional mathematical models including BET, Iglesias and Chirife, GAB, Caurie and Freundlich were used to check the fitness of experimental data. Later the experimental data were compared with similar data obtained from GA and ANN models. The overall results showed that the Caurie model had high performance to predict EMC and revealed that GA model had greater accuracy to predict EMC of pistachio powder with very high R2 values (equal to 0.9996).

scholarly journals Moisture sorption isotherms of millet seeds

2000 ◽  
Vol 18 (No. 3) ◽  
pp. 86-90 ◽  
Author(s):  
N.D. Menkov ◽  
D.I. Gelyazkov
Keyword(s):  
Experimental Data ◽  
Relative Humidity ◽  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Static Method ◽  
Moisture Contents ◽  
Moisture Sorption Isotherms ◽  
The Relationship

The equilibrium moisture contents were determined for millet seeds of two cultivars using the gravimetric static method at 10, 25 and 40°C over a range of relative humidities from 0.112 to 0.868. The sorption capacity of the seeds decreased with an increase in temperature at constant relative humidity. The hysteresis effect is not distinctly expressed but statistically significant. The differences between equilibrium moisture contents of the cultivars are small. Four models were applied for analyzing the experimental data using the following equations: modified Chung-Pfost, modified Halsey, modified Oswin, and modified Henderson. The modified Chung-Pfost model was found to be the most suitable for describing the relationship between equilibrium moisture content, relative humidity and temperature.

scholarly journals THERMODYNAMIC PROPERTIES OF WATER DESORPTION OF SOYBEAN BRAN

2015 ◽  
Vol 33 (2) ◽  
Author(s):  
Isabel Cristina Machado Corrêa ◽  
Caciano P. Zapata Noreña
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Integral Enthalpy ◽  
Isokinetic Temperature ◽  
Water Desorption ◽  
Spreading Pressure ◽  
Differential Enthalpy ◽  
Enthalpy And Entropy

The differential and integral thermodynamic properties (enthalpy, entropy, Gibbs free energy, temperature isokinetic and spreading pressure) of soybean bran were determined. Experimental data obtained from the literature were adjusted appropriately by GAB equation (R2>0.95), whose parameters were used to estimate the thermodynamic properties of desorption of soybean bran. The differential enthalpy and entropy increased with decreasing equilibrium moisture content and the isokinetic temperature confirmed the linear chemical compensation between the enthalpy and entropy and the process was enthalpy driven. The spreading pressure increased with increasing water activity. The integral enthalpy decreased with increasing equilibrium moisture content, whereas the integral entropy increased, but negative values, reaching up to -0.02 kJ/mol.K.

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