Search published articles
Showing 2 results for Asgharnia
M. Asgharnia , S. Yeganeh , S.a. Jafarpour, R. Safari,
Volume 7, Issue 2 (Spring 2018)
Abstract
Aims: Wastes related to the fisheries industry include 50% of the weight of fish. Using these raw materials to produce protein hydrolysate results in the production of peptides with functional properties. The aim of this study was to produce protein hydrolysate by chemical method from silver carp (Hypophthalmichthys molitrix) viscera and its application as a culture media for Pseudomonas aeruginosa.
Materials and Methods: The present experimental research on silver carp was conducted at the Caspian Sea Ecology Research Institute. After freeze-thawing of viscera at 4°C, acidic and alkaline hydrolysis was done at 2 pH of 3.3 and 12, and 2 temperatures of 70°C and 85°C. Peptones produced from these treatments (3 replicates for each treatment) were used as a nitrogen source of Pseudomonas aeruginosa culture media at 48 hours and compared with commercial Nutrient Broth culture media. The data were analyzed by SPSS 17, using two-way analysis of variance, Independent T-test, and Duncan test.
Findings: The lowest and the highest Degree of Hydrolysis were related to alkaline hydrolysis at 70°C and 85°C, respectively (p<0.05). Bacteria growth trend in culture media containing peptone at 85°C did not show any significant difference during 48 hours except 24 hours (p>0.05), but these treatments showed significant difference with the control at all of times (p<0.05). Treatments of culture media had no significant differences at 70°C during 48 hours (p>0.05).
Conclusion: The alkaline hydrolysis in higher temperature is better than acidic hydrolysis and growth of Pseudomonas aeruginosa in the produced peptone can be done as well as that of commercial culture media.
Volume 17, Issue 3 (5-2017)
Abstract
In this paper, an optimal Fractional-order Proportional-Integral-Derivative (FOPID) controller is proposed to control an offshore 5MW wind turbine’s pitch angle in above rated speed. The proposed pitch controller regulates the generator angular speed and consequently the generator power to its nominal value without any knowledge of the model. In order to find the parameters of the controller, a hybrid cost function is proposed, which consists of sum of absolute error signal and absolute rate of control signal in three different wind speeds. The wind speeds are chosen in the beginning, middle and at the end of the interval, thus, the optimized controller is able to show an acceptable performance in whole range of wind speeds, without any demand to nonlinear and complex controllers. To this end, the proposed cost function is minimized using three optimization algorithms: Differential Evolution (DE), Firefly algorithm and Particle Swarm Optimization (PSO). In order to evaluate the robustness of proposed FOPID, numerous wind profiles with different speeds and fluctuations are applied and the results are compared with the optimal integer order PID controller. The comparison demonstrates that the proposed FOPID has more effective performance and robustness than optimal integer order PID.
