In this study, the electro-hydraulic servo system for speed control of fixed displacement hydraulic motor using proportional valve and (PID) controller is investigated theoretically ,experimentally and simulation . The theoretical part includes the derivation of the nonlinear mathematical model equation of (valve – motor ) combination system and the derivation of the transfer function for the complete hydraulic system , the stability test of the system during the operation through the transfer function using MATLAB package
V7.1 have been done. An experimental part includes design and built hydraulic test rig and simple PID controller .The best PID gains have been calculated experimentally and simulation, speed control performance tests for the system at different thermal conditions for hydraulic oil have been done , Simulation analysis for (EHSS) using Automation Studio package V5.2 have been done . Comparison was made between experimental work and simulation work .The experimental results show good performance for (EHSS) using simple (PID) controller at hydraulic oil temperature around (60 – 70 ) and good speed response and performance for hydraulic motor with constant rotation speed (700) rpm with different load disturbance applied on the hydraulic motor .
This study was conducted at the poultry farm of the Department of Animal Production/College of Agriculture/University of Baghdad/Abu Ghraib, on 252 birds (180 females and 72 males). This study aims to observe the effect of melatonin implantation and exposure to different light colors and their interaction on characteristics of fertility and hatching of local Iraqi chickens. The birds were divided into three sections (white, red and green) each section contains two lines, one of which has been planted melatonin under the skin of the neck of birds and the other has not been planted hormones. The results showed that melatonin implantation and exposure to different light colors did not significantly affect the hatching rate of fertilized eggs a
... Show MoreThis study was designed for isolation and molecular identification of Nontuberculous Mycobacterium (NTM) from fish during the period between October and December 2017 from Karbla province, Iraq. This study included 200 fresh fish samples from four different species including Spondyliosoma cantharus, Liza abu, Carassius carassius and Cyprinuscarpio. Three samples of each fish were taken including gills, muscles and all internal organs. The samples were processed by decontamination, concentration of 4% sodium hydroxide, and 0.1 ml of sediment was streaking on Löwenstein Johnson (LJ) media; then the bacterial cultures were incubated at 28-30 °C for 3days up to 4 weeks and suspected colonies were stained with acid fast stain to confir
... Show MoreVocational stresses and their relation with the level of ambition among the lecturers of the university In general , vocational stresses affect the attention and the process of focusing making individual busy with solving of his daily problems instead of his job. The vocational stresses , anxiety and tension are factors effecting the physical and psychological ability of the individual. This study aims to measure the vocational stresses among the lecturers of the university , to measure the level of ambition among them, to identify the statistical differences significant among them according to sex variable, to identify the differences significant in level of ambition among them according to sex variable and to identify the correlation r
... Show MoreA study of the singlet and triplet states of two electron systems in the first excited state was performed using a simple quantum mechanical model, which assigns the 1s,and 2s orbital with two different variational parameters. Our results agree with a high level calculation used by Snow and Bills.
Construction projects have a special nature and affect them many factors making them exposed to multiple risks as a result of the length of the implementation period and the multiplicity of stages, starting from the decision stage through implementation until the final delivery, which leads to increased uncertainty and the likelihood of risk.
The process of analysis and risk management is one of the effective and productive methods that are used in managing the construction projects for the purpose of increasing the chances of ending the project successfully in terms of cost, time and quality and at the lowest possible problems.
The research aims first to the effective planning for analysis and risk managemen
... Show MoreThe political system in Indonesia, since gaining independence from the Dutch colonialism on the seventeenth of August 1945, has gone through long stages. The Indonesian constitution stipulated that the country is based on a democracy. In 1956 the first free elections were held in Indonesia, and President Sukarno announced the adoption of the directed democratic system Then, during the era of President Suharto, the state entered a phase called democracy based on the Five Pancasila principles, which is a false democracy because it served the interests of Suharto, who in his long reign had political and economic corruption leading up to 1998, when the Indonesian people revolted, and the government of Soeharto was overthrown
... Show MoreThis work is concerned with a two stages four beds adsorption chiller utilizing activated carbon-methanol adsorption pair that operates on six separated processes. The four beds that act as thermal compressors are powered by a low grade thermal energy in the form of hot water at a temperature range of 65 to 83 °C. As well as, the water pumps and control cycle consume insignificant electrical power. This adsorption chiller consists of three water cycles. The first water cycle is the driven hot water cycle. The second cycle is the cold water cycle to cool the carbon, which adsorbs the methanol. Finally, the chilled water cycle that is used to overcome the building load. The theoretical results showed that average cycle cooling power
... Show MoreFinite element modeling of transient temperature distribution is used to understand physical phenomena occurring during the dwell (penetration) phase and moving of welding tool in friction stir welding (FSW) of 5mm plate made of 7020-T53 aluminum alloy at 1400rpm and 40mm/min.
Thermocouples are used in locations near to the pin and under shoulder surface to study the welding tool penetration in the workpiece in advance and retreate sides along welding line in three positions (penetrate (start welding) , mid, pullout (end welding)).
Numerical results of ANSYS 12.0 package are compared to experimental data including axial load measurements at different tool rotational speeds (710rpm.900rpm.1120rpm and 1400rpm) Based on the experiment
In this study, the effect of the combination of micro steel fibers and additives (calcium hydroxide and sodium carbonate) on the size of cracks formation and healing them were investigated. This study aims to apply the use of self-healing phenomenon to repair cracks and to enhance the service life of the concrete structures. Micro steel fibers straight type were used in this research with 0.2% and 0.4% by volume of concrete. A weight of 20 and 30 kg/m3 of Ca(OH)2 and 2 and 3 kg/m3 of Na2CO3 were used as a partial cement replacement. The results confirm that the concrete cracks were significantly self-healed up to 30 days re-curing. Cracks width up to 0.2 mm were comp
... Show MoreAlO-doped ZnO nanocrystalline thin films from with nano crystallite size in the range (19-15 nm) were fabricated by pulsed laser deposition technique. The reduction of crystallite size by increasing of doping ratio shift the bandgap to IR region the optical band gap decreases in a consistent manner, from 3.21to 2.1 eV by increasing AlO doping ratio from 0 to 7wt% but then returns to grow up to 3.21 eV by a further increase the doping ratio. The bandgap increment obtained for 9% AlO dopant concentration can be clarified in terms of the Burstein–Moss effect whereas the aluminum donor atom increased the carrier's concentration which in turn shifts the Fermi level and widened the bandgap (blue-shift). The engineering of the bandgap by low
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