A systematic approach is presented to achieve the stable grasping of objects through a two-finger robotic hand, in which each finger cavity was filled with granular media. The compaction of the latter, controlled by vacuum pressure, was used to adjust the structural and contact stiffness of the finger. The grasping stability was studied under the concurrent effect of an external torque and applied vacuum pressure. Stable grasping was defined as the no slippage condition between the grasped object and the two fingers. Three control schemes were adopted and applied experimentally to ensure the effectiveness of the grasping process. The results showed that stable and unstable grasping regions exist for each combination of applied torque and vacuum pressure. The two-finger robotic hands can be further improved for applications that require high load-carrying capabilities.
In this paper, variable gain nonlinear PD and PI fuzzy logic controllers are designed and the effect of the variable gain characteristic of these controllers is analyzed to show its contribution in enhancing the performance of the closed loop system over a conventional linear PID controller. Simulation results and time domain performance characteristics show how these fuzzy controllers outperform the conventional PID controller when used to control a nonlinear plant and a plant that has time delay.
The control of prostheses and their complexities is one of the greatest challenges limiting wide amputees’ use of upper limb prostheses. The main challenges include the difficulty of extracting signals for controlling the prostheses, limited number of degrees of freedom (DoF), and cost-prohibitive for complex controlling systems. In this study, a real-time hybrid control system, based on electromyography (EMG) and voice commands (VC) is designed to render the prosthesis more dexterous with the ability to accomplish amputee’s daily activities proficiently. The voice and EMG systems were combined in three proposed hybrid strategies, each strategy had different number of movements depending on the combination protocol between voic
... Show MoreA study of irrigation water was conducted Baghdad city to find out extent of its pollution by some heavy metals (Pb, Cd, Ni, Co, CU, Cr, Zn and Fe). Water samples were collected randomly from different sources (river, well and stream). Results showed that the concentration of studied heavy metals were as follows: Lead between 0.43-11.75 mg L-1, Cadmium between 0.01-0.95 mg L-1, Nickel between 0.008-0.46 mg L-1, Cobalt between Nil - 0.185 mg L-1, Copper is between 0.326 - 1.58 mg L-1, Chromium is between Nil-0.068 mg L-1, Zinc 0.398-1.182 mg L-1, as for Iro
Recently, numerous the generalizations of Hurwitz-Lerch zeta functions are investigated and introduced. In this paper, by using the extended generalized Hurwitz-Lerch zeta function, a new Salagean’s differential operator is studied. Based on this new operator, a new geometric class and yielded coefficient bounds, growth and distortion result, radii of convexity, star-likeness, close-to-convexity, as well as extreme points are discussed.
Hydatid disease is a zoonotic infection caused by Echinococcus species. The cystic form of this infection mostly involves liver and lung. Hydatid disease of the parotid gland even in endemic regions is a very rare entity that may be easily overlooked in daily practice. Herein, I present a case report of a 60-year-old Iraqi female patient who presented with a progressively painless mass in her right parotid. It was diagnosed radiologically as a hydatid cyst and was excised successfully. Histopathologic examination of the resected specimen confirmed the hydatid cyst. This case emphasizes the importance of considering hydatidosis in the differential diagnosis of any parotid mass, especially in endemic countries.
 
... Show MoreThe current research studies the aesthetic framework for the dialectical development of the functions of the contemporary theater director in an aesthetic approach to the mechanisms of functional overlap between the dramaturgy and direction functions, and scenography and direction, the detection of the controversial structure of that overlap, and what can be summed up in the following question: (what are the aesthetic approaches of the dialectical development in the function of the contemporary theatre director?). The research is determined by a pivotal aim which is (knowing the aesthetic nature of the dialectical development in
In this paper, an analytical solution describing the deflection of a cracked beam repaired with piezoelectric patch is introduced. The solution is derived using perturbation method. A novel analytical model to calculate the proper dimensions of piezoelectric patches used to repair cracked beams is also introduced. This model shows that the thickness of the piezoelectric patch depends mainly on the thickness of the cracked beam, the electro-mechanical properties of the patch material, the applied load and the crack location. Furthermore, the model shows that the length of the piezoelectric patches depends on the thickness of the patch as well as it depends on the length of the cracked beam and the crack depth. The additio
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