Directional control valve is the main part in hydraulic system which has complex construction, such as moving spool to control the direction of actuator for required speed. Utilizing MR fluid properties, direct interface can be realized between magnetic field and fluid power without the need for moving parts like spool in directional control valves. This paper dedicates the experimental test of four ways, three position MR directional control valve. The experimental methods were done by connecting the MR directional control valve with hydraulic actuators. The experiment was conducted to show the principle work of the valve functionally and performance test for valve was done. The valve works proportionally to control the direction and speed of hydraulic actuators. As a result, the experimental result demonstrates the operation of MR directional control valve using two configurations. The experimental about ON-OFF and proportional operations is discussed. The MR directional control valve can replace many types of the spool directional control valve for controlling hydraulic actuator.
Background: Joint hypermobility was first mentioned by Hippocrates as an isolated feature, when he described the Celts' Incapacity to Pull a Bowstring or Throw a Dart, Due to The Slackness of Their Limbs
Objective: to determine the prevalence of mitral valve prolapse(MVP)in patients with benign hypermobility syndrome (BJHS).
Type of the study: Cross –sectional study.
Methods: Ninety patients with BJHS were included in this study. Full cardiological assessment was done for all of them, which include clinical examination, electrocardiography and echocardiography. Cardiac assessment was done for another sixty age and sex matched (
... Show MoreBased on Lyapunov exponent criterion, the aircraft lateral-directional stability during critical flight cases is presented. A periodic motion or limit cycle oscillation isdisplayed. A candidate mechanism for the wing rock limit cycle is the inertia coupling between an unstable lateral-directional (Dutch roll) mode with stable longitudinal (short period) mode. The coupling mechanism is provided by the nonlinear interaction of motion related terms in the complete set equations of motion. To analyze the state variables of the system, the complete set of nonlinear equations of motion at different high angles of attack are solved. A novel analysis including the variation of roll angle as a function of angle of attack is proposed. Furthermore
... Show MoreSteel-concrete-steel (SCS) structural element solutions are rising due to their advantages over conventional reinforced concrete in terms of cost and strength. The impact of SCS sections with various core materials on the structural performance of composites has not yet been fully explored experimentally, and in this work, both slag and polypropylene fibers were incorporated in producing eco-friendly steel-concrete-steel composite sections. This study examined the ductility, ultimate strength, failure modes, and energy absorption capacities of steel-concrete-steel filled with eco-friendly concrete, enhanced by polypropylene fiber (PPF) to understand its impact on modern structural projects. Eco-friendly concrete was produced by the partial
... Show MoreThis research deals with study of the effect of additives on rheological properties (yield point, plastic viscosity ,and apparent viscosity) of emulsions. Twenty seven emulsion samples were prepared; all emulsions in this investigation are invert emulsions when water droplets are dispersed in diesel oil. The resulting emulsions are called water-in-oil (W/O) emulsions. The rheological properties of these emulsions were investigated using a couett coaxial cylinder rotational viscometer (Fann-VG model 35 A), by measuring shear stress versus shear rate. It was found that the effect of additives on rheological properties of emulsions as follow: the increase in the concentration of asphaltic material tends to increase the rheological propertie
... Show MoreThe cutting transport problem in the drilling operation is very complex because many parameters impact the process, which is nonlinearity interconnected. It is an important factor affecting time, cost and quality of the deviated and horizontal well. The main objective is to evaluate the influence of main drilling Parameters, rheological properties and cuttings that characterise lifting capacity through calculating the minimum flow rate required and cutting bed height and investigate these factors and how they influenced stuck pipe problems in deviated wells for Garraf oil field. The results obtained from simulations using Well Plan™ Software were showed that increasing viscosity depends on other conditions for an increase or dec
... Show MoreBackground: IL-4 is an antibodies inflammatory cytokine which has an important role in protecting against the inflammatory reactions in most of diseases. Here, we try to highlights the role of this cytokine in chronic Rheumatic heart disease and its correlation with the extent of histopathological abnormalities.
Patients and Methods: Rheumatic mitral valve surgical fragments were taken from a total of 48 Iraqi patients with chronic rheumatic heart disease under mitral valve replacement surgery in Ibn Al- Bitar Hospital for Cardiac Surgery-Iraq-Baghdad. Paraffin embedded mitral valve tissue sections were prepared. IL-4-expressing cells were detected by using immunohistochemical staining technique and
Lowering the emission, fuel economy and torque management are the essential
requirements in the recent development in the automobile industry. The main engine control
input that satisfies the above requirements is the throttling angle which adjusts the air mass
flow rate to the engine port. Due to the uncertainty and the presence of the nonlinear
components in its dynamical model, the sliding mode control theory is utilized in this work
for the throttle valve angle control system to design a robust controller for this system in the
presence of a nonlinear spring and Coulomb friction. A continuous sliding mode control law
which consists of a saturation function, instead of a signum function, and the integral of
ano
Half of the oil production of the worldwide is a result of the water flooding project. But the main concern of this process is mobility control of the injected fluid, because the unfavorable mobility ratio leads to fingering effect. Adding polymer to the injection water increase the water viscosity, therefore, the displacement will be more stable and have a greater sweep efficiency.
Using of polymer flooding has received more attention these days. Polymer has great potential in the Middle East region, especially in reservoir with high temperature and salinity.
The main objective of this work is to show the effect of shear rate, salinity, temperature, polymer concentration on polymer v
... Show MoreRecently, emulgel has emerged as one of the most interesting topical preparations in the field of pharmaceutics. In this research clotrimazole was formulated as topically applied emulgel ; different formulas were prepared. The prepared emulgels were evaluated for their physical appearance , rheological behaviour , and in vitro drug release . The influence of the type of gelling agent (carbopol 934 and methyl cellulose), the concentration of both the emulsifying agent (2% and 4% w/w of mixture of span 20 and tween 20) and the oil phase (5% and 7.5% w/w of liquid paraffin) and the type of oil phase (liquid paraffin and cetyl alcohol), on the drug release from the prepared emulgels was invest
... Show More