This paper presents a vibration suppression control design of cantilever beam using two piezoelectric patches. One patch was used as an actuator element, while the other was used as a sensor. The controller design was designed via the balance realization reduction method to elect the reduced order model that is most controllable and observable. the sliding mode observer was designed to estimate six states from the reduced order model but three states are only used in the control law. Estimating a number of states larger than that used is in order to increase the estimation accuracy. Moreover, the state estimation error is proved bounded. An optimal LQR controller is designed then using the estimated states with the sliding mode observer, to suppress the vibration of a smart cantilever beam via the piezoelectric elements. The control spillover problem was avoided, by deriving an avoidance condition, to ensure the asymptotic stability for the proposed vibration control design. The numerical simulations were achieved to test the vibration attenuation ability of the proposed optimal control. For 15 mm initial tip displacement, the piezoelectric actuator found able to reduce the tip displacement to about 0.1 mm after 4s, while it was 1.5 mm in the open loop case. The current experimental results showed a good performance of the proposed LQR control law and the sliding mode observer, as well a good agreement with theoretical results.
Several studies have indicated that more than 600 cities in the world (intermas of rapid growth and development) will generate about 60% of international economic growth between 2010 and 2025 . by 2025 , 66% of the worlds population will live in urban areas the management of cities will face challenges that accompany this increase in the population which requires preparing to face these challenges and problems and the need to provide the aim of the research to know the readiness of Baghdad city to implement the strategies of urban management throught on asmple representing the ( Advisiry group for the comprechnsive development plan for the city of Baghdad 2030 and its supporters ) in the municipality of Baghdad and the number of
... Show MoreThe Disi water samples were collected from different Disi aquifer wells in Jordan using a clean polyethylene container of 10-liter size. A hyper-pure germanium (HPGe) detector with high- resolution gamma-ray spectroscopy and a low background counting system was used for the identification of unknown gamma-rays emitting from radionuclides in the environmental samples. The ranges of specific activity concentrations of 226Ra and 228Ra in the Disi aquifer water were found to be from 0.302 ± 0.085 to 0.723 ± 0.207 and from 0.047 ± 0.010 to 0.525 ± 0.138 Bq L−1, with average values of 0.516 ± 0.090 and 0.287 ± 0.091 Bq L−1, respectively. The average combined radium (226Ra + 228Ra) activity and radium activity ratio (228Ra/226Ra) in Disi
... Show MoreThe present research had dealt with preparing bars with the length of about (13 cm) and adiametar of (1.5 cm) of composite materials with metal matrix represented by (Al-Cu-Mg) alloy cast enforced by (ZrO2) particles with chosen weight percentages (1.5, 2.5 ,3.5, 5.5 %). The base cast and the composite materials were prepared by casting method by uses vortex Technique inorder to fix up (ZrO2) particles in homogeneous way on the base cast. In addition to that, two main groups of composite materials were prepared depending on the particles size of (ZrO2) , respectively. &n
... Show MoreHigh temperature superconductors with a nominal composition HgBa2Ca2Cu3O8+δ
for different values of pressure (0.2,0.3, 0.5, 0.6, 0.9, 1.0 & 1.1)GPa were prepared by
a solid state reaction method. It has been found that the samples were semiconductor
P=0.2GPa.while the behavior of the other samples are superconductor in the rang
(80-300) K. Also the transition temperature Tc=143K is the maximum at P is equal to
0.5GPa. X-ray diffraction showed a tetragonal structure with the decreasing of the
lattice constant c with the increasing of the pressure. Also we found an increasing of
the density with the pressure.
This study aimed to determine the possibility of culturing genus Artemia in under laboratory conditions for locally culturing and producing. Different salinity concentrations were used, ranging from 5-40g/l . the results showed that the concentration 30g/l is the best for hatching. This concentration recorded hatching efficiency of 68800 nauplii/g cysts and hatching percentage of 45.86%, while the concentration 5g/l recorded less hatching efficiency and hatching percentage of 20266 nauplii/g and 13.5% respectively . Investigating the effect of salinity on individuals survival and growth using saline concentrations ranging from 30to 100g/l, revealed that the best percentage was 75.00% in the first week with 70g/l, whilst the best rates of
... Show MoreMulti-nationalities companies are the main companies in the progressed
countries that improve the current technology and, thus, become the main source of it.
These companies, in the first place, aim to increase the profits of its
investments to satisfy stock holders in the original countries to which these companies
belong.
It is a mean to interfere in the economic of countries especially the growing
ones and exploit their important natural resources. Since this research focus on the
dangers of these companies, mechanism of its work and its dangers on the most
important natural resources of our country which is oil; therefore, the research
confirm that this important natural treasure must be under an Iraqi cont
The tracking of satellites motion and their path around the earth is important things in the mechanical of satellites motion. Significant parameters for the determination of time entrance and existence of the satellite could be obtained from the shadow of the earth. In the present work the tracking and time determination for entry and exit from earth shadow have been studied. In the present work we built a software for tracking the motion of satellites in orbit around the earth and determine the change of both distance and speed as a function of time. The perturbations effect on the satellite has been neglected from the earth atmosphere drag and the earth gravity and other effects. The equation for calculating the shadow is solved using num
... Show MoreIn this paper, a new approach was suggested to the method of Gauss Seidel through the controlling of equations installation before the beginning of the method in the traditional way. New structure of equations occur after the diagnosis of the variable that causes the fluctuation and the slow extract of the results, then eradicating this variable. This procedure leads to a higher accuracy and less number of steps than the old method. By using the this proposed method, there will be a possibility of solving many of divergent values equations which cannot be solved by the old style.
A sensitive, accurate, and affordable colorimetric method was developed for assaying prednisolone (PRZ) in various medicinal forms. The procedure involves the oxidation of PRZ by ferric ions, followed by complexation of the resulting ferrous ions with ferricyanide to produce a greenish-blue product. Common complexation conditions were thoroughly investigated. The mole ratio of FeCl₃·6H₂O to K₃Fe(CN)₆ was 8:1. The proposed mechanism of complexation was suggested and considered. Various parameters were optimized, including the reduction of the colorimetric reaction temperature to 50°C and the duration of heating and analysis to 20-30 minutes. The calibration curve was linear over the range of 1-60 µg/mL. The limit of detection (LOD
... Show MoreThe study was conducted to detect the effect of addition of 0.03, 0.06 and0.10% potassium sorbate and 0.10, 0.15, 0.20 and 0.30% sodium propionate upon the sensory properties of laboratory made biscuit. The statistical analysis of the results revealed no significant differences (P<0.05) between the propionate treatment (A,B,C,D) and between the sorbate treatment (E,F,G) and the control (H) in most sensory properties of biscuit prior to storage. Upon six month storage of biscuit made with addition of different levels of sodium propionate 20-40C (room temperature) no significant differences (P<0.05) were shown on softness, flakiness and color in comparison with the control . No significant differences (P<0.05) were also
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