Mortaza Aghbashlo - Academia.edu (original) (raw)

Papers by Mortaza Aghbashlo

Research paper thumbnail of Influence of drying conditions on the effective moisture diffusivity, energy of activation and energy consumption during the thin-layer drying of berberis fruit (Berberidaceae)

Energy Conversion and Management, 2008

Berberis is known as a medicinal and ornamental plant in the world. Berberis fruit is used in med... more Berberis is known as a medicinal and ornamental plant in the world. Berberis fruit is used in medicine to cure liver, neck and stomach cancer, blood purification and mouth scent. Dried berberis fruit using new technology was preserved for relatively long time. Thin-layer drying simulation was used to obtain experiment data, using laboratory scale hot-air dryer of the static tray. Fick’s second law was used as a major equation to calculate the moisture diffusivity with some simplification. The calculated value of moisture diffusivity varied from a minimum of 3.320 × 10−10 to a maximum of 9 × 10−9 m2/s and the value of energy activation from a minimum of 110.837 to a maximum of 130.61 kJ/mol of from 50 °C to 70 °C with drying air velocities of 0.5–2 m/s. The high value of the energy of activation for berberis fruit probably related to the tissue of berberis fruit and high moisture content (about 74.28%w.b), and intensive changes in Deff values for a different air temperature at consta...

Research paper thumbnail of Prediction of carrot cubes drying kinetics during fluidized bed drying by artificial neural network

Journal of Food Science and Technology-mysore

This article presents static and recurrent artificial neural networks (ANNs) to predict the dryin... more This article presents static and recurrent artificial neural networks (ANNs) to predict the drying kinetics of carrot cubes during fluidized bed drying. Experiments were performed on square−cubed carrot with dimensions of 4, 7 and 10 mm, air temperatures of 50, 60 and 70°C and bed depths of 3, 6 and 9 cm. Initially, static ANN was used to correlate the outputs (moisture ratio and drying rate) to the four exogenous inputs (drying time, drying air temperature, carrot cubes size, and bed depth). In the recurrent ANNs, in addition to the four exogenous inputs, two state input and output (moisture ratio or drying rate) were applied. A number of hidden neurons and training epoch were investigated in this study. The dying kinetics was predicted with R2 values of greater than 0.94 and 0.96 using static and recurrent ANNs, receptively.

Research paper thumbnail of DRYING AND REHYDRATION CHARACTERISTICS OF SOUR CHERRY (PRUNUS CERASUS L.): DRYING AND REHYDRATION CHARACTERISTICS OF SOUR CHERRY

Journal of Food Processing and Preservation, 2009

ABSTRACTThe effect of air temperature and velocity on the drying kinetics of sour cherry was inve... more ABSTRACTThe effect of air temperature and velocity on the drying kinetics of sour cherry was investigated using a laboratory scale static-type dryer at air temperatures of 60, 70 and 80C and air velocities of 0.3, 0.6 and 0.9 m/s. The Weibull distribution model was fitted to experimental data using nonlinear regression analysis techniques in the MATLAB computer program. The high regression coefficients (R2 > 0.998) and low reduced chi-square and root mean square error indicated that the Weibull model is suitable for predicting moisture ratio. Correlations of the Weibull model constants with the variables T and V were determined. The effective diffusivity of sour cherry varied between 3.46 × 10-9 and 13.08 × 10-9 m2/s. The activation energy of sour cherry was in the range of 64.39–66.05 kJ/mol. Rehydration tests indicated that the rehydration capacity of dried samples at air temperature of 70C and air velocity of 0.3 m/s is better than other experiments.The effect of air temperature and velocity on the drying kinetics of sour cherry was investigated using a laboratory scale static-type dryer at air temperatures of 60, 70 and 80C and air velocities of 0.3, 0.6 and 0.9 m/s. The Weibull distribution model was fitted to experimental data using nonlinear regression analysis techniques in the MATLAB computer program. The high regression coefficients (R2 > 0.998) and low reduced chi-square and root mean square error indicated that the Weibull model is suitable for predicting moisture ratio. Correlations of the Weibull model constants with the variables T and V were determined. The effective diffusivity of sour cherry varied between 3.46 × 10-9 and 13.08 × 10-9 m2/s. The activation energy of sour cherry was in the range of 64.39–66.05 kJ/mol. Rehydration tests indicated that the rehydration capacity of dried samples at air temperature of 70C and air velocity of 0.3 m/s is better than other experiments.PRACTICAL APPLICATIONSAll commercial flow dryers are designed based on thin-layer drying principles. One of the most important aspects of drying technology is the modeling of the drying process. The prediction of drying kinetics of agricultural products under various conditions is very useful in design and optimization of dryers. In this paper, the Weibull distribution model is used for modeling thin-layer drying of sour cherry. Weibull's model constants include the effect of drying variable on drying kinetics and could be a useful tool for the modeling of drying kinetics. The rehydration characteristics of a dried product are used as a quality index and they indicate the physical and chemical changes during drying as influenced by processing conditions, sample pretreatment and composition. Optimizing the drying conditions in order to obtain the dried product with good rehydration characteristics is vital, since rehydration governs the subsequent operations.All commercial flow dryers are designed based on thin-layer drying principles. One of the most important aspects of drying technology is the modeling of the drying process. The prediction of drying kinetics of agricultural products under various conditions is very useful in design and optimization of dryers. In this paper, the Weibull distribution model is used for modeling thin-layer drying of sour cherry. Weibull's model constants include the effect of drying variable on drying kinetics and could be a useful tool for the modeling of drying kinetics. The rehydration characteristics of a dried product are used as a quality index and they indicate the physical and chemical changes during drying as influenced by processing conditions, sample pretreatment and composition. Optimizing the drying conditions in order to obtain the dried product with good rehydration characteristics is vital, since rehydration governs the subsequent operations.

Research paper thumbnail of Modeling of Thin-Layer Drying of Apple Slices in a Semi-Industrial Continuous Band Dryer

International Journal of Food Engineering, 2010

The drying kinetics of apple slices was investigated in a semi-industrial continuous band dryer. ... more The drying kinetics of apple slices was investigated in a semi-industrial continuous band dryer. Apple slices with a thickness of 5 mm were dried at temperatures of 50, 60 and 70 • C, air velocities of 0.5, 1.0 and 1.5 m/s and chain linear velocity of 1.85E-04, 2.22E-04 and 2.78E-04 m/s. The Weibull model was fitted to the experimental data of moisture ratio against sample position using MATLAB computer program. The low reduced chi-square and RMSE and the high regression coefficients indicated the suitability of the Weibull model for predicting moisture ratio of apple slices during drying in length of continuous band dryer. Correlations of the scale and shape parameter of the Weibull model with the variables of T, U a and U c were determined. The transport of water during drying was described by Fick's second low and effective diffusivity varied from 9.24E-08 to 3.5E-07 m 2 /s. The energy of activation was described by the Arrhenius equation and varied from 35.37 to 45.51 kJ/mol.

Research paper thumbnail of Thermodynamic analysis of fluidized bed drying of carrot cubes

Fuel and Energy Abstracts, 2010

In this study, the energy and exergy analyses of fluidized bed drying of carrot cubes were invest... more In this study, the energy and exergy analyses of fluidized bed drying of carrot cubes were investigated. Drying experiments were conducted at inlet air temperatures of 50, 60, and 70 °C, BD (bed depths) of 30, 60, and 90 mm and square-cubed carrot dimensions of 4, 7, and 10 mm. The effects of drying variables on energy utilization, energy utilization ratio, exergy loss and exergy efficiency were studied. The energy utilization and energy utilization ratio varied between 0.105–1.949 kJ/s and 0.074–0.486, respectively. The exergy loss and exergy efficiency were found to be in the range of 0.206–1.612 kJ/s and 0.103–0.707, respectively. The results showed that small particles, deep beds and high inlet air temperatures increased energy utilization, energy utilization ratio, and exergy loss due to high value of heat and mass transfer. Also, the exergy efficiency had maximum value when higher drying air temperature, larger CS (cube size) and shorter BD were used for drying experiment.

Research paper thumbnail of EVALUATION OF THIN-LAYER DRYING MODELS FOR DESCRIBING DRYING KINETICS OF BARBERRIES ( BARBERRIES VULGARIS )

Journal of Food Process Engineering, 2009

ABSTRACTBarberry is known as a medicinal and ornamental plant throughout the world. Edible fruit ... more ABSTRACTBarberry is known as a medicinal and ornamental plant throughout the world. Edible fruit from the barberry is used in medicine to treat liver, neck and stomach cancer, for purification of the blood and for breath freshness. In order to assess and select a suitable form of the drying curve, six different semitheoretical and/or empirical models were fitted to the experimental data. Experiments were performed at air temperatures of 50, 60 and 70C. At each temperature, three air velocity values were selected: 0.5, 1 and 2 m/s. Consequently, of all the drying models, the Page model was selected as the best mathematical model according to R2, χ2 and root mean square error parameters. Constants related to the Page model are reported and regressed against air condition using multiple regression analysis.Barberry is known as a medicinal and ornamental plant throughout the world. Edible fruit from the barberry is used in medicine to treat liver, neck and stomach cancer, for purification of the blood and for breath freshness. In order to assess and select a suitable form of the drying curve, six different semitheoretical and/or empirical models were fitted to the experimental data. Experiments were performed at air temperatures of 50, 60 and 70C. At each temperature, three air velocity values were selected: 0.5, 1 and 2 m/s. Consequently, of all the drying models, the Page model was selected as the best mathematical model according to R2, χ2 and root mean square error parameters. Constants related to the Page model are reported and regressed against air condition using multiple regression analysis.PRACTICAL APPLICATIONAll commercial flow dryers are designed on thin-layer drying principles. Thin-layer drying means to dry as one layer of sample particles or slices. In this paper we present a mathematical model for thin-layer drying of barberry fruits (moisture ratio against time). Definition of moisture ratio as a function of time and drying condition has many advantages such as (1) easy control of dryer system, (2) lower energy consumption, (3) less thermal damage to the products and (4) lower investment. It is believed that the present study should be useful to people seeking (1) to optimize the design of drying systems and their components, and (2) to identify appropriate applications and optimal configurations for drying systems.All commercial flow dryers are designed on thin-layer drying principles. Thin-layer drying means to dry as one layer of sample particles or slices. In this paper we present a mathematical model for thin-layer drying of barberry fruits (moisture ratio against time). Definition of moisture ratio as a function of time and drying condition has many advantages such as (1) easy control of dryer system, (2) lower energy consumption, (3) less thermal damage to the products and (4) lower investment. It is believed that the present study should be useful to people seeking (1) to optimize the design of drying systems and their components, and (2) to identify appropriate applications and optimal configurations for drying systems.

Research paper thumbnail of Prediction of Energy and Exergy of Carrot Cubes in a Fluidized Bed Dryer by Artificial Neural Networks

Drying Technology, 2011

In this study both static and recurrent artificial neural networks (ANNs) were used to predict th... more In this study both static and recurrent artificial neural networks (ANNs) were used to predict the energy and exergy of carrot cubes during fluidized bed drying. Drying experiments were conducted at air temperatures of 50, 60, and 70°C; bed depths of 3, 6, and 9 cm; and square-cubed carrot dimensions of 4, 7, and 10 mm. Five hundred eighteen patterns, obtained from experiments, were used to develop the ANN models. Initially, a static ANN was applied to correlate the outputs (energy and exergy of carrot cubes) to the four exogenous inputs (drying time, drying air temperature, carrot cube size, and bed depth). In the recurrent ANNs, in addition to the four exogenous inputs, two state inputs and outputs (energy and exergy of carrot cubes) were used. To find optimum ANN models, various numbers of hidden neurons were investigated. The energy and exergy of carrot cubes were predicted with R 2 values of greater than 0.95 and 0.97 using static and recurrent ANNs, respectively. Accordingly, the optimal recurrent model could be utilized for determining the appropriate drying conditions of carrot cubes to reach the optimal energy efficiency in fluidized bed drying.

Research paper thumbnail of Optimization of an Artificial Neural Network Topology for Predicting Drying Kinetics of Carrot Cubes Using Combined Response Surface and Genetic Algorithm

Drying Technology, 2011

In this study, the advantages of integrated response surface methodology (RSM) and genetic algori... more In this study, the advantages of integrated response surface methodology (RSM) and genetic algorithm (GA) for optimizing artificial neural network (ANN) topology of convective drying kinetic of carrot cubes were investigated. A multilayer feed-forward ANN trained by back-propagation algorithms was developed to correlate output (moisture ratio) to the four exogenous input variables (drying time, drying air temperature, air velocity, and cube size). A predictive response surface model for ANN topologies was created using RSM. The response surface model was interfaced with an effective GA to find the optimum topology of ANN. The factors considered for building a relationship of ANN topology were the number of neurons, momentum coefficient, step size, number of training epochs, and number of training runs. A second-order polynomial model was developed from training results for mean square error (MSE) of 50 developed ANNs to generate 3D response surfaces and contour plots. The optimum ANN had minimum MSE when the number of neurons, step size, momentum coefficient, number of epochs, and number of training runs were 23, 0.37, 0.68, 2,482, and 2, respectively. The results confirmed that the optimal ANN topology was more precise for predicting convective drying kinetics of carrot cubes.

Research paper thumbnail of Modeling of thin-layer drying of potato slices in length of continuous band dryer

Energy Conversion and Management, 2009

The main goal of this paper is to investigate the thin-layer drying behavior of potato slices in ... more The main goal of this paper is to investigate the thin-layer drying behavior of potato slices in a semi-industrial continuous band dryer. Potato slices with thickness of 5 mm were used for drying experiments. The experiments were done at air temperatures of 50, 60 and 70 °C, air velocities of 0.5, 1 and 1.5 m/s and chain linear velocities of 1.85 × 10−4, 2.22 × 10−4 and 2.78 × 10−4 m/s. Three drying models were fitted to the experimental data of moisture ratio in order to assess a suitable form of the drying curve for potato drying. The Page model was selected as the best according to R2, χ2 and RMSE. The effective diffusivity varied from 3.17 × 10−7 to 15.45 × 10−7 m2/s and the energy of activation was found in the range of 39.49–42.34 kJ/mol.

Research paper thumbnail of Performance analysis of drying of carrot slices in a semi-industrial continuous band dryer

Journal of Food Engineering, 2009

This paper presents the energy and exergy analysis of drying process in a semi-industrial continu... more This paper presents the energy and exergy analysis of drying process in a semi-industrial continuous band dryer. Experiments were performed on thin layer drying of carrot slices with thickness of 5 mm, at air temperatures of 50, 60 and 70 °C, drying air mass flow rates of 0.61, 1.22 and 1.83 kg/s and feeding rates of 2.98 × 10−4, 3.48 × 10−4 and 4.16 × 10−4 kg/s. The effects of drying variables were evaluated on weight loss of dried products, energy utilization, energy utilization ratio, exergy loss and exergy efficiency. An amount of 250 g of fresh material was used on each band for drying experiments and the weight loss of dried samples were found to be in the range of 51.6–84.4% of initial weight. The energy utilization and energy utilization ratio varied between 3.78–25.57 kJ/s and 0.1554–0.3752, respectively. The exergy loss and exergy efficiency were found to be in the range of 0.6677–14.1577 kJ/s and 0.5527–0.9329, respectively.

Research paper thumbnail of Energy and Exergy Analyses of Thin-Layer Drying of Potato Slices in a Semi-Industrial Continuous Band Dryer

Research paper thumbnail of Influence of drying conditions on the effective moisture diffusivity, energy of activation and energy consumption during the thin-layer drying of berberis fruit (Berberidaceae)

Energy Conversion and Management, 2008

Berberis is known as a medicinal and ornamental plant in the world. Berberis fruit is used in med... more Berberis is known as a medicinal and ornamental plant in the world. Berberis fruit is used in medicine to cure liver, neck and stomach cancer, blood purification and mouth scent. Dried berberis fruit using new technology was preserved for relatively long time. Thin-layer drying simulation was used to obtain experiment data, using laboratory scale hot-air dryer of the static tray. Fick’s second law was used as a major equation to calculate the moisture diffusivity with some simplification. The calculated value of moisture diffusivity varied from a minimum of 3.320 × 10−10 to a maximum of 9 × 10−9 m2/s and the value of energy activation from a minimum of 110.837 to a maximum of 130.61 kJ/mol of from 50 °C to 70 °C with drying air velocities of 0.5–2 m/s. The high value of the energy of activation for berberis fruit probably related to the tissue of berberis fruit and high moisture content (about 74.28%w.b), and intensive changes in Deff values for a different air temperature at constant air velocity. The input energy values and specific energy requirement for thin-drying of berberis fruit were found to be in the range of 0.643348–35.20032 (kWh) and 20.9355–1110.0700 (kWh/kg) from 50 °C to 70 °C with drying air velocities of 0.5–2 m/s, respectively.

Research paper thumbnail of Influence of drying conditions on the effective moisture diffusivity, energy of activation and energy consumption during the thin-layer drying of berberis fruit (Berberidaceae)

Energy Conversion and Management, 2008

Berberis is known as a medicinal and ornamental plant in the world. Berberis fruit is used in med... more Berberis is known as a medicinal and ornamental plant in the world. Berberis fruit is used in medicine to cure liver, neck and stomach cancer, blood purification and mouth scent. Dried berberis fruit using new technology was preserved for relatively long time. Thin-layer drying simulation was used to obtain experiment data, using laboratory scale hot-air dryer of the static tray. Fick’s second law was used as a major equation to calculate the moisture diffusivity with some simplification. The calculated value of moisture diffusivity varied from a minimum of 3.320 × 10−10 to a maximum of 9 × 10−9 m2/s and the value of energy activation from a minimum of 110.837 to a maximum of 130.61 kJ/mol of from 50 °C to 70 °C with drying air velocities of 0.5–2 m/s. The high value of the energy of activation for berberis fruit probably related to the tissue of berberis fruit and high moisture content (about 74.28%w.b), and intensive changes in Deff values for a different air temperature at consta...

Research paper thumbnail of Prediction of carrot cubes drying kinetics during fluidized bed drying by artificial neural network

Journal of Food Science and Technology-mysore

This article presents static and recurrent artificial neural networks (ANNs) to predict the dryin... more This article presents static and recurrent artificial neural networks (ANNs) to predict the drying kinetics of carrot cubes during fluidized bed drying. Experiments were performed on square−cubed carrot with dimensions of 4, 7 and 10 mm, air temperatures of 50, 60 and 70°C and bed depths of 3, 6 and 9 cm. Initially, static ANN was used to correlate the outputs (moisture ratio and drying rate) to the four exogenous inputs (drying time, drying air temperature, carrot cubes size, and bed depth). In the recurrent ANNs, in addition to the four exogenous inputs, two state input and output (moisture ratio or drying rate) were applied. A number of hidden neurons and training epoch were investigated in this study. The dying kinetics was predicted with R2 values of greater than 0.94 and 0.96 using static and recurrent ANNs, receptively.

Research paper thumbnail of DRYING AND REHYDRATION CHARACTERISTICS OF SOUR CHERRY (PRUNUS CERASUS L.): DRYING AND REHYDRATION CHARACTERISTICS OF SOUR CHERRY

Journal of Food Processing and Preservation, 2009

ABSTRACTThe effect of air temperature and velocity on the drying kinetics of sour cherry was inve... more ABSTRACTThe effect of air temperature and velocity on the drying kinetics of sour cherry was investigated using a laboratory scale static-type dryer at air temperatures of 60, 70 and 80C and air velocities of 0.3, 0.6 and 0.9 m/s. The Weibull distribution model was fitted to experimental data using nonlinear regression analysis techniques in the MATLAB computer program. The high regression coefficients (R2 > 0.998) and low reduced chi-square and root mean square error indicated that the Weibull model is suitable for predicting moisture ratio. Correlations of the Weibull model constants with the variables T and V were determined. The effective diffusivity of sour cherry varied between 3.46 × 10-9 and 13.08 × 10-9 m2/s. The activation energy of sour cherry was in the range of 64.39–66.05 kJ/mol. Rehydration tests indicated that the rehydration capacity of dried samples at air temperature of 70C and air velocity of 0.3 m/s is better than other experiments.The effect of air temperature and velocity on the drying kinetics of sour cherry was investigated using a laboratory scale static-type dryer at air temperatures of 60, 70 and 80C and air velocities of 0.3, 0.6 and 0.9 m/s. The Weibull distribution model was fitted to experimental data using nonlinear regression analysis techniques in the MATLAB computer program. The high regression coefficients (R2 > 0.998) and low reduced chi-square and root mean square error indicated that the Weibull model is suitable for predicting moisture ratio. Correlations of the Weibull model constants with the variables T and V were determined. The effective diffusivity of sour cherry varied between 3.46 × 10-9 and 13.08 × 10-9 m2/s. The activation energy of sour cherry was in the range of 64.39–66.05 kJ/mol. Rehydration tests indicated that the rehydration capacity of dried samples at air temperature of 70C and air velocity of 0.3 m/s is better than other experiments.PRACTICAL APPLICATIONSAll commercial flow dryers are designed based on thin-layer drying principles. One of the most important aspects of drying technology is the modeling of the drying process. The prediction of drying kinetics of agricultural products under various conditions is very useful in design and optimization of dryers. In this paper, the Weibull distribution model is used for modeling thin-layer drying of sour cherry. Weibull's model constants include the effect of drying variable on drying kinetics and could be a useful tool for the modeling of drying kinetics. The rehydration characteristics of a dried product are used as a quality index and they indicate the physical and chemical changes during drying as influenced by processing conditions, sample pretreatment and composition. Optimizing the drying conditions in order to obtain the dried product with good rehydration characteristics is vital, since rehydration governs the subsequent operations.All commercial flow dryers are designed based on thin-layer drying principles. One of the most important aspects of drying technology is the modeling of the drying process. The prediction of drying kinetics of agricultural products under various conditions is very useful in design and optimization of dryers. In this paper, the Weibull distribution model is used for modeling thin-layer drying of sour cherry. Weibull's model constants include the effect of drying variable on drying kinetics and could be a useful tool for the modeling of drying kinetics. The rehydration characteristics of a dried product are used as a quality index and they indicate the physical and chemical changes during drying as influenced by processing conditions, sample pretreatment and composition. Optimizing the drying conditions in order to obtain the dried product with good rehydration characteristics is vital, since rehydration governs the subsequent operations.

Research paper thumbnail of Modeling of Thin-Layer Drying of Apple Slices in a Semi-Industrial Continuous Band Dryer

International Journal of Food Engineering, 2010

The drying kinetics of apple slices was investigated in a semi-industrial continuous band dryer. ... more The drying kinetics of apple slices was investigated in a semi-industrial continuous band dryer. Apple slices with a thickness of 5 mm were dried at temperatures of 50, 60 and 70 • C, air velocities of 0.5, 1.0 and 1.5 m/s and chain linear velocity of 1.85E-04, 2.22E-04 and 2.78E-04 m/s. The Weibull model was fitted to the experimental data of moisture ratio against sample position using MATLAB computer program. The low reduced chi-square and RMSE and the high regression coefficients indicated the suitability of the Weibull model for predicting moisture ratio of apple slices during drying in length of continuous band dryer. Correlations of the scale and shape parameter of the Weibull model with the variables of T, U a and U c were determined. The transport of water during drying was described by Fick's second low and effective diffusivity varied from 9.24E-08 to 3.5E-07 m 2 /s. The energy of activation was described by the Arrhenius equation and varied from 35.37 to 45.51 kJ/mol.

Research paper thumbnail of Thermodynamic analysis of fluidized bed drying of carrot cubes

Fuel and Energy Abstracts, 2010

In this study, the energy and exergy analyses of fluidized bed drying of carrot cubes were invest... more In this study, the energy and exergy analyses of fluidized bed drying of carrot cubes were investigated. Drying experiments were conducted at inlet air temperatures of 50, 60, and 70 °C, BD (bed depths) of 30, 60, and 90 mm and square-cubed carrot dimensions of 4, 7, and 10 mm. The effects of drying variables on energy utilization, energy utilization ratio, exergy loss and exergy efficiency were studied. The energy utilization and energy utilization ratio varied between 0.105–1.949 kJ/s and 0.074–0.486, respectively. The exergy loss and exergy efficiency were found to be in the range of 0.206–1.612 kJ/s and 0.103–0.707, respectively. The results showed that small particles, deep beds and high inlet air temperatures increased energy utilization, energy utilization ratio, and exergy loss due to high value of heat and mass transfer. Also, the exergy efficiency had maximum value when higher drying air temperature, larger CS (cube size) and shorter BD were used for drying experiment.

Research paper thumbnail of EVALUATION OF THIN-LAYER DRYING MODELS FOR DESCRIBING DRYING KINETICS OF BARBERRIES ( BARBERRIES VULGARIS )

Journal of Food Process Engineering, 2009

ABSTRACTBarberry is known as a medicinal and ornamental plant throughout the world. Edible fruit ... more ABSTRACTBarberry is known as a medicinal and ornamental plant throughout the world. Edible fruit from the barberry is used in medicine to treat liver, neck and stomach cancer, for purification of the blood and for breath freshness. In order to assess and select a suitable form of the drying curve, six different semitheoretical and/or empirical models were fitted to the experimental data. Experiments were performed at air temperatures of 50, 60 and 70C. At each temperature, three air velocity values were selected: 0.5, 1 and 2 m/s. Consequently, of all the drying models, the Page model was selected as the best mathematical model according to R2, χ2 and root mean square error parameters. Constants related to the Page model are reported and regressed against air condition using multiple regression analysis.Barberry is known as a medicinal and ornamental plant throughout the world. Edible fruit from the barberry is used in medicine to treat liver, neck and stomach cancer, for purification of the blood and for breath freshness. In order to assess and select a suitable form of the drying curve, six different semitheoretical and/or empirical models were fitted to the experimental data. Experiments were performed at air temperatures of 50, 60 and 70C. At each temperature, three air velocity values were selected: 0.5, 1 and 2 m/s. Consequently, of all the drying models, the Page model was selected as the best mathematical model according to R2, χ2 and root mean square error parameters. Constants related to the Page model are reported and regressed against air condition using multiple regression analysis.PRACTICAL APPLICATIONAll commercial flow dryers are designed on thin-layer drying principles. Thin-layer drying means to dry as one layer of sample particles or slices. In this paper we present a mathematical model for thin-layer drying of barberry fruits (moisture ratio against time). Definition of moisture ratio as a function of time and drying condition has many advantages such as (1) easy control of dryer system, (2) lower energy consumption, (3) less thermal damage to the products and (4) lower investment. It is believed that the present study should be useful to people seeking (1) to optimize the design of drying systems and their components, and (2) to identify appropriate applications and optimal configurations for drying systems.All commercial flow dryers are designed on thin-layer drying principles. Thin-layer drying means to dry as one layer of sample particles or slices. In this paper we present a mathematical model for thin-layer drying of barberry fruits (moisture ratio against time). Definition of moisture ratio as a function of time and drying condition has many advantages such as (1) easy control of dryer system, (2) lower energy consumption, (3) less thermal damage to the products and (4) lower investment. It is believed that the present study should be useful to people seeking (1) to optimize the design of drying systems and their components, and (2) to identify appropriate applications and optimal configurations for drying systems.

Research paper thumbnail of Prediction of Energy and Exergy of Carrot Cubes in a Fluidized Bed Dryer by Artificial Neural Networks

Drying Technology, 2011

In this study both static and recurrent artificial neural networks (ANNs) were used to predict th... more In this study both static and recurrent artificial neural networks (ANNs) were used to predict the energy and exergy of carrot cubes during fluidized bed drying. Drying experiments were conducted at air temperatures of 50, 60, and 70°C; bed depths of 3, 6, and 9 cm; and square-cubed carrot dimensions of 4, 7, and 10 mm. Five hundred eighteen patterns, obtained from experiments, were used to develop the ANN models. Initially, a static ANN was applied to correlate the outputs (energy and exergy of carrot cubes) to the four exogenous inputs (drying time, drying air temperature, carrot cube size, and bed depth). In the recurrent ANNs, in addition to the four exogenous inputs, two state inputs and outputs (energy and exergy of carrot cubes) were used. To find optimum ANN models, various numbers of hidden neurons were investigated. The energy and exergy of carrot cubes were predicted with R 2 values of greater than 0.95 and 0.97 using static and recurrent ANNs, respectively. Accordingly, the optimal recurrent model could be utilized for determining the appropriate drying conditions of carrot cubes to reach the optimal energy efficiency in fluidized bed drying.

Research paper thumbnail of Optimization of an Artificial Neural Network Topology for Predicting Drying Kinetics of Carrot Cubes Using Combined Response Surface and Genetic Algorithm

Drying Technology, 2011

In this study, the advantages of integrated response surface methodology (RSM) and genetic algori... more In this study, the advantages of integrated response surface methodology (RSM) and genetic algorithm (GA) for optimizing artificial neural network (ANN) topology of convective drying kinetic of carrot cubes were investigated. A multilayer feed-forward ANN trained by back-propagation algorithms was developed to correlate output (moisture ratio) to the four exogenous input variables (drying time, drying air temperature, air velocity, and cube size). A predictive response surface model for ANN topologies was created using RSM. The response surface model was interfaced with an effective GA to find the optimum topology of ANN. The factors considered for building a relationship of ANN topology were the number of neurons, momentum coefficient, step size, number of training epochs, and number of training runs. A second-order polynomial model was developed from training results for mean square error (MSE) of 50 developed ANNs to generate 3D response surfaces and contour plots. The optimum ANN had minimum MSE when the number of neurons, step size, momentum coefficient, number of epochs, and number of training runs were 23, 0.37, 0.68, 2,482, and 2, respectively. The results confirmed that the optimal ANN topology was more precise for predicting convective drying kinetics of carrot cubes.

Research paper thumbnail of Modeling of thin-layer drying of potato slices in length of continuous band dryer

Energy Conversion and Management, 2009

The main goal of this paper is to investigate the thin-layer drying behavior of potato slices in ... more The main goal of this paper is to investigate the thin-layer drying behavior of potato slices in a semi-industrial continuous band dryer. Potato slices with thickness of 5 mm were used for drying experiments. The experiments were done at air temperatures of 50, 60 and 70 °C, air velocities of 0.5, 1 and 1.5 m/s and chain linear velocities of 1.85 × 10−4, 2.22 × 10−4 and 2.78 × 10−4 m/s. Three drying models were fitted to the experimental data of moisture ratio in order to assess a suitable form of the drying curve for potato drying. The Page model was selected as the best according to R2, χ2 and RMSE. The effective diffusivity varied from 3.17 × 10−7 to 15.45 × 10−7 m2/s and the energy of activation was found in the range of 39.49–42.34 kJ/mol.

Research paper thumbnail of Performance analysis of drying of carrot slices in a semi-industrial continuous band dryer

Journal of Food Engineering, 2009

This paper presents the energy and exergy analysis of drying process in a semi-industrial continu... more This paper presents the energy and exergy analysis of drying process in a semi-industrial continuous band dryer. Experiments were performed on thin layer drying of carrot slices with thickness of 5 mm, at air temperatures of 50, 60 and 70 °C, drying air mass flow rates of 0.61, 1.22 and 1.83 kg/s and feeding rates of 2.98 × 10−4, 3.48 × 10−4 and 4.16 × 10−4 kg/s. The effects of drying variables were evaluated on weight loss of dried products, energy utilization, energy utilization ratio, exergy loss and exergy efficiency. An amount of 250 g of fresh material was used on each band for drying experiments and the weight loss of dried samples were found to be in the range of 51.6–84.4% of initial weight. The energy utilization and energy utilization ratio varied between 3.78–25.57 kJ/s and 0.1554–0.3752, respectively. The exergy loss and exergy efficiency were found to be in the range of 0.6677–14.1577 kJ/s and 0.5527–0.9329, respectively.

Research paper thumbnail of Energy and Exergy Analyses of Thin-Layer Drying of Potato Slices in a Semi-Industrial Continuous Band Dryer

Research paper thumbnail of Influence of drying conditions on the effective moisture diffusivity, energy of activation and energy consumption during the thin-layer drying of berberis fruit (Berberidaceae)

Energy Conversion and Management, 2008

Berberis is known as a medicinal and ornamental plant in the world. Berberis fruit is used in med... more Berberis is known as a medicinal and ornamental plant in the world. Berberis fruit is used in medicine to cure liver, neck and stomach cancer, blood purification and mouth scent. Dried berberis fruit using new technology was preserved for relatively long time. Thin-layer drying simulation was used to obtain experiment data, using laboratory scale hot-air dryer of the static tray. Fick’s second law was used as a major equation to calculate the moisture diffusivity with some simplification. The calculated value of moisture diffusivity varied from a minimum of 3.320 × 10−10 to a maximum of 9 × 10−9 m2/s and the value of energy activation from a minimum of 110.837 to a maximum of 130.61 kJ/mol of from 50 °C to 70 °C with drying air velocities of 0.5–2 m/s. The high value of the energy of activation for berberis fruit probably related to the tissue of berberis fruit and high moisture content (about 74.28%w.b), and intensive changes in Deff values for a different air temperature at constant air velocity. The input energy values and specific energy requirement for thin-drying of berberis fruit were found to be in the range of 0.643348–35.20032 (kWh) and 20.9355–1110.0700 (kWh/kg) from 50 °C to 70 °C with drying air velocities of 0.5–2 m/s, respectively.