In this research, a variable stiffness actuator is proposed to enhance the damping of the mechanical vibrating system. The frequency response analysis of the vibrating system is dependant in order to analyze and synthesis this semi-active damping, where the suggested process is using active filter to estimate the present frequency of the vibration system, and this will limit the value of the stiffness of the vibrated system. Two active filter s are needed, low-pass-filter (LPF) to choose the higher stiffness of the actuator at small frequencies as well as more damping and high-pass-filter (HPF) to choose the lower stiffness of the actuator at high frequencies as well as more damping, and so
... Show MoreThe aim of this article is to present the exact analytical solution for models as system of (2+1) dimensional PDEs by using a reliable manner based on combined LA-transform with decomposition technique and the results have shown a high-precision, smooth and speed convergence to the exact solution compared with other classic methods. The suggested approach does not need any discretization of the domain or presents assumptions or neglect for a small parameter in the problem and does not need to convert the nonlinear terms into linear ones. The convergence of series solution has been shown with two illustrated examples such (2+1)D- Burger's system and (2+1)D- Boiti-Leon-Pempinelli (BLP) system.
Recently, Knowledge Management Systems (KMS) consider one of the major fields of study in educational institutions, caused by the necessity to identify their knowledge value and success. Hence, based on the updated DeLone and McLean’s Information Systems Success Model (DMISSM), this study set out to assess the success of the Perceived Usefulness of Knowledge Management Systems (PUKMS) in Iraqi universities. To achieve this objective, the quantitative method is selected as the research design. In total, 421 university administration staff members from 13 Iraqi private universities were conducted. This study highlights a number of significant results depending on structural equation modeling which confirms that system, information, and s
... Show MoreIn this article, a continuous terminal sliding mode control algorithm is proposed for servo motor systems. A novel full-order terminal sliding mode surface is proposed based on the bilimit homogeneous property, such that the sliding motion is finite-time stable independent of the system’s initial condition. A new continuous terminal sliding mode control algorithm is proposed to guarantee that the system states reach the sliding surface in finitetime. Not only the robustness is guaranteed by the proposed controller but also the continuity makes the control algorithm more suitable for the servo mechanical systems. Finally, a numerical example is presented to depict the advantages of the proposed control algorithm. An application in the rota
... Show MoreIn this paper, the fill factor of the N749/TiO2 solar cell is studied and calculated using the analysis method at standard conditions; i.e., T=300k and 100 mW/cm2 irradiation.. The current density was derived and calculated using the donor-acceptor model according to the quantum transfer theory in DSSC solar cells. We estimate the influence parameters in DSSC that's an equivalent circuit to the I-V curves for three solvents. The fill factor parameters of the N749/TiO2 device are found to be 0.137,0.146 and 0.127 with Butanol, Ethanol and Acetonitrile for carrier concentration . 1018 1/cm3 respectively. The photovoltaic characteristics ISc , Vco<
... Show MoreCurrent study aimed to investigate the effect of piroxicam on some hematological
and biochemcal parameters. For this reason forty males mature Sprage Dawlley rats
were divided into four equal groups. control group administrated distilled water
(G1), and three groups administrated (20mg/kg,30mg/kg,40mg/kg) body weight of
piroxicam for 45 days. The results showed significant decrease (P<0.05) in
hemoglobin (Hb) and packed ceq volume (PCV) in groups treated with
(30,40)mg/kg of piroxicam, while the treated groups produced significant increease
(P<0.05) in the total white blood cell count (WBC). On the serum biochemical
porameters, Piroxicam caused increase in the level of liver enzyme amunotans ferase
(ALT)