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Showing 2 results for Pirmohamadi
Volume 16, Issue 88 (6-2019)
Abstract
In thisresearch, for the first time, the replacement of valerian extract with chemical preservatives in orange
juice has been investigated. Whey Permeate Powder is also used as a source of minerals and vitamins in orange
juice. In this experimental study, an antioxidant effect of valerian extract was determined and its
compounds were determined. Then, the effect of juice extract on three levels of 1.25, 0.63 and 0.13 ml
and 1.5, 1 and 0.5 percent of whey permeate powder on the chemical properties of orange juice during the
storage period in three intervals. The period of 1, 14 and 30 days was studied. The tests performed on
prepared samples including: formalin index, acidity, vitamin C, pH and antioxidant properties, and the
results obtained by Expert design-7 software are analyzed and shown in the diagram. The results indicated that the pH increased at high levels of whey permeate powder and extract during the period of 1, 14 and 30 days. Also, the decreasing in acidity with increasing whey permeate powder percent is probably due to the low acidity of whey permeate powder to the extract and the sample of orange juice's control (is a witness). By adding single levels of whey permeate powder and extract, the vitamin C increased and then decreased with increase of during maintenance. Also, the effect of valerian extract was greater than whey permeate powder in vitamin reduction over a period of time.
Seyyed Reza Naghibi, Ali Akbar Pirmohamadi, ,
Volume 18, Issue 1 (3-2018)
Abstract
This paper considers the issue of precise control of robotic manipulators in the presence of dynamic uncertainties along with hard nonlinear perturbation such as friction using Modified Transpose Effective Jacobian and model based friction compensator. In order to model friction in robot joints, The LuGre friction model has been used and its unknown parameters have been identified by a bio-inspired optimization algorithm called Cuttlefish. By comparing Cuttlefish with other meta-heuristic algorithms such as Glowworm swarm optimization, its superiorities have been proved. After accurate identification of model parameters and determine frictions function, using Modified Transpose Effective Jacobian and model-based friction compensator, a two link planar manipulator has been controlled experimentally. Furthermore in order to compare the controller performance with other methods, the mentioned manipulator has been controlled using computed torque controller and transpose Jacobian besides Adaptive Neural Network Radial Based Function friction compensators. Experimental results offer the Modified Transpose effective Jacobian control method has privileges for better tracking control with more accuracy and better friction compensating as well as better robustness against dynamic uncertainties with lower computational efforts.