Urmia University is a public university in the city of Urmia, West Azerbaijan province, Iran. The university has six campuses, seven faculties, more than 14,000 students, and exclusive research centers in Microelectronic, Antenna and Microwave Laboratory, NanoTechnology, MEMS, and Artimia. The university also has two satellite campuses in Khoy and Miyandoab city. Nazlu campus of Urmia University is the biggest university campus in northwest of Iran. Urmia University is considered one of Iran's "Grade A" universities by Iranian Ministry of Science. Wikipedia.
Hassanpour H.,Urmia University
LWT - Food Science and Technology | Year: 2015
Native populations of raspberry fruits (Rubus spp.) were coated with Aloe vera gel and were then assayed for the antioxidant capacity, total anthocyanin, total phenol, antioxidant enzyme activities and postharvest quality after 8 days storage at 4°C, relative to a control group. These berries, coated with Aloe vera gel, showed a higher antioxidant capacity, total anthocyanin and total phenol than those of the controls (non-treated) group. The treated fruits exhibited less incidence of decay during storage at 4°C than the control group. Thus postharvest life (as affected by fungal decay) was longer for berries treated with Aloe vera gel than for the control fruit. However, total soluble solid, titratable acidity and pH were predominantly influenced by storage periods. Aloe vera gel treatments could reduce the natural decay that happens over time. The activities of antioxidant enzymes, including glutathione peroxidase (GSH-POD), glutathione reductase (GR), superoxide dismutase (SOD), ascorbate peroxidase (AsA-POD) and guaiacol peroxidase (G-POD) were enhanced. The nonenzyme components such as reduced glutathione (GSH) and oxidized glutathione (GSSG) were also increased by Aloe vera gel. In conclusion, raspberry fruits treated with Aloe vera gel maintained higher levels of antioxidant capacity, total phenol, total anthocyanin and antioxidant enzymes during storage periods. © 2014 Elsevier Ltd.
Rezapour S.,Urmia University
Environmental Earth Sciences | Year: 2014
Monitoring general variability of soil attributes is a fundamental requirement from the point of view of understanding and predicting how ecosystems yield. In order to monitor impact of different land use types on the combination of morphological, clay mineralogical and physicochemical characterizes, 42 soil samples (0-30 cm) were described and analyzed. Soil samples belonging to Cambisols and Vertisols reference soil groups collected from three neighboring land use types included cropland (under long-term continuous cultivation), grassland, and forestland. The soils were characterized by high pH (mean of 7.1-7.5) and calcium carbonate equivalent (CCE) (mean of 35-97 g kg-1) in the three land use types. The weakening in soil structure, hardening of consistency, and lighting of soil color occurred for the cropland under comparable condition with grassland and forest. Changes in land use types produced a remarkable change in the XRD patterns of clay minerals containing illite and smectite due the dynamic and removal of potassium. Continuous cultivation resulted in an increase in sand content up to 35 % while silt and clay content decreased up to 22 and 18 %, respectively, as compared to the adjoining grassland and forest mainly as a result of the difference of dynamic alterational and erosional process in the different land use. Long-term cultivation caused a negative and degradative aspects on soil heath as is manifested by the increasing in soil pH (a rise of 0.3-0.46 unit), electrical conductivity (EC) (a rise of 1.78-5.5 times), sodium absorption ration (SAR) (a rise of 10-51 %), exchangeable sodium percentage (ESP) (a rise of 3-46 %), and the decrease in soil organic C (a drop of 12-41 %), along with soil fertility attributes. Overall, the general distribution of soil organic C, total N, available P and K, cation exchange capacity (CEC), and exchangeable cations (Ca, Mg, and K) followed the order: forestland > grassland > cropland. The general distribution of EC, SAR, ESP, and exchangeable Na, however, followed the order: cropland > grassland > forestland. Soil quality index (SQI), calculated based on some physicochemical properties, specified that cultivation led to a negative effect in SQI for both Cambisols (a drop of 10-17 %) and Vertisols (a drop of 17 %) as compared to those of under grassland and forestland. © 2013 The Author(s).
Jafarmadar S.,Urmia University
Fuel | Year: 2013
In this investigation, the energy and exergy analyses are carried out in pre and main chambers of a Lister 8.1 indirect injection diesel engine (IDI) diesel engine for two loads (BMEP of 2.96 bar and 5.9 bar as 50% and full load operations) at maximum torque engine speed (730 rpm). The energy analyses are carried out during a closed engine cycle by using a computational fluid dynamics (CFD) code. The results for the pressure in cylinder for two loads are compared with the corresponding experimental data and show good agreement. Also, for the exergy analysis in the chambers, a developed in-house computational code is applied. Various exergy components are identified and calculated separately with crank position at both loads. The results show that at partial and full load operations 56% and 77% of total irreversibility are related to combustion process in main chamber, respectively. This work demonstrates that multidimensional modeling can be used at complex chamber geometry to gain more insight into the effect of flow field on the combustion process accounting for the second-law of thermodynamics. © 2012 Elsevier Ltd. All rights reserved.
Gholizadeh S.,Urmia University
Computers and Structures | Year: 2013
The main contribution of the present paper is to propose an efficient hybrid optimization algorithm for layout optimization of truss structures. To achieve this, computational merits of the cellular automata (CA) and the particle swarm optimization (PSO) are integrated. In the proposed hybrid algorithm a CA-based mechanism is utilized as the velocity updating equation of the particles in the framework of the sequential unconstrained minimization techniques and therefore it is denoted as sequential cellular PSO (SCPSO). The numerical results demonstrate that SCPSO not only converges to better solutions but also provides faster convergence rate in comparison with other algorithms. © 2013 Elsevier Ltd. All rights reserved.
Jafarmadar S.,Urmia University
Energy | Year: 2014
In this investigation, the energy and exergy analyses are carried out for a Lister 8.1 IDI (indirect injection) diesel engine at four different EGR (exhaust gas recirculation) mass fractions (0%, 10%, 20% and 30%) and at 50% load operation. The energy analysis is performed during a closed cycle by using a three-dimensional CFD (Computational Fluid Dynamics) code. For the exergy analysis, an in-house computational code is developed, which uses the results of the energy analysis at different EGR mass fractions. The cylinder pressure results for baseline engine are compared with the corresponding experimental data that shows a good agreement. With crank position at different EGR mass fractions, various exergy components and the cumulative exergy are identified and calculated separately. It is found that at 50% load operation, as EGR mass fraction increases from 0% to 30% (in 10% increments), exergy efficiency decreases from 31.74% to 25.38%. Also, the cumulative irreversibility related to the combustion chamber decreases from 29.8% of the injected fuel exergy to 25.5%. This work demonstrates that multidimensional modeling can be used to simulate the effect of various EGR mass fractions and gain more insight into the impact of flow field on combustion process in IDI engines from the second law perspective. © 2014 Elsevier Ltd.