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Drying characteristics of Quercus were determined experimentally as a function of temperature, air velocity, and variety (Quercus Persica and Quercus Libani). In order to estimate and select a suitable drying curve, five different thin layer drying models were fitted to the experimental data. Experiments were performed at the air temperatures of 50, 60 and 70°C. At each temperature level, two air velocities were adjusted: 0.5 and 1m/s. The effect of air temperature was found to be significant in comparison to air velocity for drying of fresh Quercus fruits. Increasing air velocity at constant air temperature resulted in the decrease of drying time. Among all the selected drying models, the Page model was found as the best mathematical model for describing the drying kinetics of Quercus fruits. Based on the results, drying temperature of 70 oC and air velocity of 1 m/s are the optimum values for drying Quercus fruit. Drying time and Page model constants were found to be dependent significantly on the variables studied.

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The objective of this study was to investigate dehydration kinetics of barberry (Berberis vulgaris L.) at different drying temperatures (60 ºC, 70 ºC, 80 ºC), air velocities (0.3 m s-1, 0.5 m s-1, 1 m s-1) with two types of pretreatment. Drying time and colour quality during dehydration were experimentally determined. Barberries were dried from the initial moisture content of 73.44% (w.b.) to the required moisture content of 18% (w.b.). Dehydration kinetics was monitored by measuring barberries weights at regular intervals. Convective drying curves were obtained for the treated and untreated barberries. The effect of two dipping pretreatments on drying kinetics of barberries was also studied. The two pretreatments were thermal shocking by immersing barberries in hot water, followed by cold water cooling, and dipping in olive oil and food grade K2CO3. Colour of the dried product was altered significantly during drying. The results indicated that the use of low temperatures is adequate for preserving this property. The air temperature significantly affected drying time and hunter colour indices of barberries (P< 0.05). With heat shocking and treatment with olive oil and K2CO3, drying time was reduced to about 40% and 60%, respectively. The total colour change (ΔE) and hue angle (H) increased with temperature. Moisture transfer from the test samples was described by applying the Fick’s diffusion model for calculating the effective diffusivity. The effective moisture diffusivity (Deff) of barberry increased as the drying air temperature increased. The Deff values were higher for the treated samples than the untreated ones. These values were also higher for the samples treated with olive oil and K2 CO3 emulsion than those treated with hot water. The effective diffusivity of the untreated and the pre-treated varied between 2.57×10-13 and 9.67×10-12 m2 s-1, respectively. Higher colour change was observed in barberries treated with olive oil and K2CO3 emulsion. Statistical analysis showed that temperature and pretreatment had the most significant effect on drying time at p<0.01.

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Mechanical properties of non-split pistachio nuts are among the lada required for the design of equipment needed for processing of the nut. Unsplit pistachio nut samples were uniaxially loaded to determine the nut’s needed splitting force and energy, as well as Poisson’s ratio and Young’s modulus of elasticity. The tests were carried out at four moisture contents (5, 10, 15 and 20% wb), under four loading rates (10, 20, 30 and 40 mm min-1), and on two varieties (O’hadi and Badami) of the nut. The highest splitting forces for the varieties (281.9 N for Badami and 102.4 N for O’hadi) were obtained at a moisture content of 5% wb and loading rate of 40 mm min-1, while the lowest forces, 97.0 N for Badami and 16.8 for the case of O’hadi, occured at moisture contents of 20% wb along with loading rate of 10 mm min-1. Different trends were observed between O'hadi and Badami varieties for the required energy to split nuts with increasing moisture content and loading rates. By increasing moisture content, Poisson’s ratio for unsplit pistachio nuts increased from 0.374 to 0.388 and from 0.326 to 0.337 for O’hadi and Badami varieties, respectively. Young’s modulus exhibited an indirect relationship with moisture content while a direct relationship with loading rate, in either of the varieties. Increase in moisture content from 5 to 20% wb led to a decrease in Young's modulus, from 322.59 to 223.23 MPa and from 816.25 to 719.28 MPa, for O’hadi and Badami variety nuts, respectively.

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Jujube (Zizyphus jujube Mill), a valuable medicinal plant, is consumed either as fresh fruit or dried product in Iran. Drying jujube guarantees a longer shelf time while preserving its quality to be used in medical and pharmaceutical industries. In this research paper, the influence of several drying conditions on the effective moisture diffusivity, activation energy, energy consumption and required specific energy in the drying of jujube is presented. Temperature levels of 50, 60 and 70 ºC and hot air velocities of 0.5, 1 and 1.5 (m s-1) were used as the treatments. Effective moisture diffusivity of jujube fruit during the drying process was in the range of 1.1532-5.1895×10-10 (m2 s-1) for the first period and 0.4036–2.3064×10-10 (m2 s-1) for the second period. Also, the values of energy of activation in both periods were determined to be between 34.97 and 74.20 (kJ mol-1). The energy consumption and the required specific energy for drying were in the range of 79.1- 92.46 (kW h) and 203.59 – 900.08 (kW h kg-1), respectively. Results show that energy consumption diminished when temperature increased at each air velocity, while it increased with increasing hot air velocity.

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In this paper, the performance evaluation of a two-way hybrid photovoltaic/thermal (PV/T) solar collector was analytically and experimentally carried out. Mathematical expressions for operating parameters in glass to glass and glass to tedlar PV/T solar collectors were developed and experimentally validated by a glass to tedlar PV/T solar collector system. Also the influence of air flow rate on the solar collector performance was investigated. The results showed that the glass to glass PV/T solar collector gave higher outlet air temperature, cell temperature and thermal efficiency than the glass to tedlar PV/T solar collector. However, back surface temperature and electrical efficiency were higher in case of glass to tedlar collector. Increasing the air flow rate led to a lower outlet air temperature and a higher electrical efficiency of the photovoltaic module. Maximum experimental electrical efficiency, thermal efficiency and overall thermal efficiency for the glass to tedlar PV module were found to be 10.35, 57.9 and 84.5%, respectively.

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Black tea sample was dried by a vibro-fluidized bed dryer to find its aerodynamic behavior and thermal performance during drying. The drying experiments were conducted at three different inlet air temperatures of 100, 115 and 130°C and fluidization condition at five vibration intensity levels of 0 (no vibration), 0.063, 0.189, 0.395 and 1.184. The results showed that bed channeling and defluidization problems were decreased in vibration condition. The vibration system decreased the requirement of minimum fluidization velocity of tea particles and this velocity reduced by increasing the vibration intensity. In the experiments, the maximum evaporation rate (13×10-3 kgv m-2 s-1) was at the vibration intensity of 1.184 and inlet air temperature of 130°C. Also the minimum specific energy consumption (4953.785 kJ kgv-1) was observed at 1.184 vibration intensity and 100°C inlet air temperature condition. Based on lower minimum fluidization velocity and specific energy consumption, the vibration intensity of 1.184 and inlet air temperature of 100°C were recommended for drying black tea particles.

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In the present study, shearing properties of sugar cane stems were determined at five moisture content levels (46, 54, 62, 70 and 78% wb), three shearing speed (5, 10 and 15 mm min^-1) and at ten positions on the stem. For measuring the shearing forces, the stems were severed by using a computer aided cutting apparatus. Decrease in moisture content of stem from 78 to 46% wb led to 16.3 and 16.7% decrease in the shearing strength and specific shearing energy, respectively. The maximum and average values of shearing strength of the two moisture contents were found to be 3.482 and 3.1 MPa, and the specific shearing energies were 112 MJ mm^-2 and, 102.6 MJ mm^-2, respectively. Both the shearing strength and the specific shearing energy were found to be higher in the lower region of the stem due to structural heterogeneity. Results showed that with the increase in shearing speed from 5 to 15 mm min^-1, shearing strength and the specific shearing energy increased 3.2 and 4.6%, respectively. The results of ANOVA indicated that effects of the mentioned factors were significant at 1% probability level. The shearing model assessment revealed that the third order polynomial model exhibited the best performance in fitting with experimental data and, by using this model, a significant correlation was found between shearing strength, specific shearing energy, and moisture content (R²= 0.989 and SE= 0.001). Also, a significant correlation was found between shearing strength, specific shearing energy, and shearing speed by using Hoerl model (R²= 0.989 and SE= 0.005).

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In this study, green pepper was dried by a laboratory scale microwave-convective dryer. The effects of microwave power on drying rate, effective moisture diffusivity, and energy consumption of green pepper were studied at four different microwave powers of 180, 360, 540, and 720W. The drying data were fitted to the four thin-layer drying models. The moisture reduction of the green pepper samples, from 2.894 to 0.1 kg water kg^-1 dry matter, lasted 120 and 495 seconds at microwave power of 720 and 180W, respectively. The drying model assessment revealed that the Midilli model exhibited the best performance in fitting the experimental data, providing the highest R² (0.927), and the lowest RMSE (0.2065) and χ² (0.0555). With increase in microwave (drying) power from 180 to 720W, moisture diffusivity increased from 6.249×10^-9 to 3.445×10^-8 m² s^-1. Results also indicated that drying rate increased by increasing the microwave power and decreased continuously with passing of drying time and decreasing moisture content. The least specific energy consumption (7.2 MJ kg^-1 water) was at microwave power of 360 W and the highest (9.26 MJ kg^-1 water) was at 540W.

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A method based on Machine Vision System (MVS) is hereby employed to evaluate grape drying through an assessment of the fruit’s shrinkage and quality during the dehydration. Experimental data as well as captured images are obtained at an air velocity of 1.4 m s^-1 and different drying temperatures (50, 60, 70ºC). The results indicated the effect of temperature on the moisture content, shrinkage and color changes. The moisture content along with color changes (ΔE) were modeled and linear regressions applied to correlate the fruit’s shrinkage as well as color features to the moisture content. The results obtained, displayed that there existed good linear relationships between the fruit’s moisture content, and shrinkage as well as color. The results also revealed that the moisture content vs. quality of the grape could be online evaluated through machine vision during the drying process.

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In the present study, saffron was dried using a heat pump-assisted hybrid photovoltaic-thermal solar dryer. The effect of different drying air temperatures at three levels (40, 50, and 60^oC) and two different modes of the dryer (with and without heat pump system) were investigated on drying behaviour of saffron. After collecting the pertinent data, eleven drying models were used to describe drying characteristics of saffron. Quality characteristics of the dried products (including: colouring, aromatic strength and bitterness) were also evaluated. The results indicated that drying time decreased by 62% with increasing air temperature from 40 to 60^oC. Moreover, applying heat pump with the dryer reduced RH of drying air and, consequently, enhanced drying rate and shortened drying period by 40%. A two-term drying model presented a relatively higher R² and lower, MBE, and RMSE values at both modes of drying and, therefore, was selected to explain drying behaviour of saffron among the other models. The results of saffron quality evaluation showed that colouring characteristics of saffron improved with drying temperature and heat pump system. Meanwhile, aromatic strength of saffron increased with increasing air temperature. But, no significant change in bitterness was observed at different levels of temperature and heat pump system.

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The present study investigated the influence of air temperature and velocity on the drying kinetics and specific energy consumption during fluidized bed drying of soybean at 80, 100, 120 and 140ºC and airflow rates of 1.8, 3.1 and 4.5 m s^-1. Six mathematical models for describing the fluidized bed drying behavior were investigated. The value of the drying rate coefficient (k) increased with increasing air temperature and velocity and thus reduced the drying time. Although the Midilli model showed the best fit, the Page’s model was selected, since it had almost a similar performance but the model is simpler with two parameters instead of four. The drying of soybean seeds took place in the falling rate period and was controlled by moisture diffusion. A third order polynomial relationship was found to correlate the effective moisture diffusivity with moisture content. Effective diffusivity increased with decreasing moisture content and increasing temperature and air velocity. It varied from 4.595×10⁻¹¹ to 3.325×10⁻¹⁰ m² s^-1 over the temperature and velocity ranges. Values of the activation energy for moisture diffusion were determined as 35.33, 32.85 and 30.73 kJ mol^-1 for air velocities of 1.8, 3.1 and 4.5 m/s, respectively. It was found that decrease in energy of activation caused an increase in drying rate. The minimum and the maximum specific energy requirements for drying of soybean seeds were determined as 26.90 and 111.05 kWh kg^-1 for 140ºC with 1.8 m s^-1 and 80ºC with 4.5 m s^-1 air velocity, respectively.

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This study aimed to examine the effectiveness of combined microwave-ultrasonic pasteurization system on Escherichia coli and vitamin C content in sour cherry juice (SCJ). Based on the findings, microwave output power, ultrasound power, and ultrasonic exposure time as well as the microwave-induced temperature were the most effective factors in reducing E. coli and vitamin C content. In addition, the microwave-induced temperature and ultrasonic exposure time, as independent variables, were both effective on E. coli removal. At higher temperatures, the effectiveness of ultrasonic waves as well as cavitation intensity declined. However, their combined effect (ultrasound and temperature) was more significant than their individual effect. It was also found that any increase in ultrasound power, ultrasonic exposure time, and microwave output power led to a significant reduction in vitamin C content, while the ultrasound power was the most effective. On the basis of RSM modeling, the optimum processing condition was: 352.21W microwave output power, 49.94˚C temperature, 475.13W ultrasound power and 6 minutes of exposure time. On the basis of response surface methodology (RSM) modelling, the maximum vitamin C content was 142.5 mg per 100 mL with no remaining E. coli.

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The purpose of this research was to predict and optimize the fish biodiesel characteristics using its permittivity properties. The parameters of biodiesel permittivity properties such as έ, dielectric constant, and ε″, loss factor at microwave frequencies of 434, 915, and 2,450 MHz, were used as input variables. The fish biodiesel characteristics, as Fatty Acid Methyl Ester (FAME) content and flash point at three different levels of reaction time 3, 9, and 27 min and catalyst concentrations 1, 1.5, and 2% w w_oil^-1, were selected as output parameters for the models. Linear Regression (LR), the Multi-Layer Perceptron (MLP), and the Radial Basis Function (RBF) as the methods of Artificial Neural Networks (ANN), and the response surface methodology were compared for prediction and optimization of FAME content and flash point. A comparison of the results showed that the RBF recorded higher coefficient of determination at frequency of 2,450 MHz as 0.999 and 0.988 and lower root mean square error as 0.009 and 0.023 for FAME content and flash point, respectively. The optimum condition was obtained using RSM by FAME content of 89.88% and flash point of 152.7°C with desirability of 0.998.