Showing 6 results for Minaee
H. Mortezapour, B. Ghobadian, M. H. Khoshtaghaza, S. Minaee,
Volume 14, Issue 4 (7-2012)
Abstract
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.
H. Darvishi, M. H. Khoshtaghaza, S. Minaee,
Volume 16, Issue 5 (9-2014)
Abstract
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.
B. Hosseinzadeh Samani, M. H. Khoshtaghaza, S. Minaee, S. Abbasi,
Volume 17, Issue 4 (7-2015)
Abstract
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.
Volume 18, Issue 2 (7-2014)
Abstract
The need for flexibility in manufacturing, increased competition, and quick response to meet customer demands in the right time are the necessary subject of discussion in a manufacturing area. There are a number of reasons that affect on a flexible manufacturing system. Scheduling is one significant reason, and affects on a policy that has a direct connection with the dispatching rules. The selection of a rule can be based on several criteria, in which each criterion influences the interactions between them. Thus, a model for the analytical network process (ANP) is needed to find an appropriate dispatching rule. Also, due to the problem nature and uncertainty in the process of pairwise comparison and interactions between the criteria, as well as the selection of dispatching rules, there is no single exact method to be used for solving the presented model. Therefore, considering the existing characteristics in multi-criteria decision making (MCDM) under uncertainty, the ANP model with the interval-valued intuitionistic fuzzy set is used. Then selection of the dispatching rules considering the view of industry experts is done. Finally, the appropriate ranking for this selection is proposed.
F. Ganjeizadeh Rohani, V. Mahdavi, M. M. AMinaee,
Volume 19, Issue 1 (1-2017)
Abstract
Pesticides are one of the major pollutants in the environment. The residue of pesticides has been reported to be at a critical level in agricultural crops, especially in greenhouse crops. Tomato is considered as an important vegetable in Iranian food basket and is produced in fields and greenhouses. So, the current study aimed to assess diazinon and oxydemeton-methyl levels in tomatoes sampled from five Kerman greenhouses. The extraction of these pesticides was carried out by mixture of dichloromethane and acetone. The extracts were cleaned up according to solid-phase extraction method. The pesticide residue was then determined by capillary gas chromatography and through nitrogen-phosphorus detection. The obtained results showed that the recovery level was estimated at 86.7 and 84.3% with RSD≤ 16.0%, the limit of detection was estimated at 0.026 and 0.035 mg kg-1, limits of quantification stood at 0.091 and 0.115 mg kg-1, and linearity r2= 0.997 and r2= 0.989 for diazinon and oxydemeton-methyl, respectively, in tomato samples. The mean of diazinon residue was calculated at 0.276 mg kg-1, which was 5.52 times the national Maximum Residue Limit (MRL= 0.05 mg kg-1), and the mean of oxydemeton-methyl was 1.624 mg kg-1, being 1.624 times the MRL (1 mg/kg).
S. R. Karimi Akandi, S. Minaee, T. Tavakoli Hashjin, G. Najafi, S. Sh. Ghodsi,
Volume 19, Issue 4 (7-2017)
Abstract
Compressive and shear properties of Aloe Vera leaves were investigated for gel extraction. This information is useful in the design of processing equipment and improving gel production lines in order to decrease losses and enhance product quality. Effects of loading speed (10, 50, and 100 mm min-1), temperature (20, 40, and 60˚C), and diameter of the cylindrical loading head (70, 140, and 210 mm) on the leaf compression properties, as well as the effect of loading speed on the shear properties were examined. The results showed that increasing the temperature would decrease the modulus of elasticity. Loading head diameters had a significant effect on the required force for crushing the leaves and extracting the gel. Based on the results, the best loading combination for extracting Aloe Vera gel from the leaf is 20˚C temperature, loading head diameter of 14 cm, and loading speed of 100 mm min-1. Shear forces of upper and lower leaf surfaces increased with loading speed. However, speed of loading had no effect on the shear forces at the edges and center of the leaf. The shear force was similar at different speeds for edge and center regions as well as for upper and lower surfaces of the leaf. Two gel extraction machines were developed based on the shear and compression properties of Aloe Vera leaves.