A numerical method is developed for calculation of the wake geometry and aerodynamic forces on two-dimensional airfoil under going an arbitrary unsteady motion in an inviscid incompressible flow (panel method). The method is applied to sudden change in airfoil incidence angle and airfoil oscillations at high reduced frequency. The effect of non-linear wake on the unsteady aerodynamic properties and oscillatory amplitude on wake rollup and aerodynamic forces has been studied. The results of the present method shows good accuracy as compared with flat plate and for unsteady motion with heaving and pitching oscillation the present method also shows good trend with the experimental results taken from published data. The method shows good results for a wide range of unsteady motion of a two-dimensional airfoil.
he genus Hirudo is an invertebrate animal that got major concerns to human. However, genetics of Hirudo has been unwell considered in Iraq. In order to gain a deeper understanding in the outline of the genetic of Hirudo that were used in alternative medicine clinics, nineteen specimens of Hirudo were obtained. Fourteen of them (H.verbana, n=10; H. orientalis, n=4) were obtained from some different clinics and scientific centres in Baghdad, Iraq between January and March 2022, these specimens were considered as non-local leeches. The other (native isolates) leeches (H. orientalis, n=5) were collected in 2014 from two localities in Erbil, northern Iraq. ITS-2, COI and 12S-rRNA of Hirudo spp were amplified using conventional polymerase chain r
... Show MoreThis study was design to investigate the dimensional stability of heat-activated acrylic resin with different methods of flask cooling (15 minutes rapid cooling, one hour bench cooling, four hours delayed deflasking, and 24 hours delayed deflasking) at different time intervals (immediately, two days, seven days, 30 days) after deflasking. Heat-activated acrylic resin was used to prepare acrylic samples. Then, measurement of the distances where achieved between the centers of selected marks in the acrylic samples. They were measured at different time intervals for different methods of flask cooling. The results showed that the group samples of the four hours and 24 hours of delayed deflasking was insignificantly different from the control an
... Show MoreBackground: Limited data are available on the dimensional stability and surface roughness of ThermoSens, which is a material used in denture processing. This study aimed to measure the vertical teeth changes and surface roughness of ThermoSens dentures prepared using three different investment materials. Materials and methods: For the dimensional changes test, 30 complete maxillary dentures were prepared using different investment methods: group I, dental stone; group II, silicone putty; and group III, a mixture of dental stone and plaster (ratio, 1:1; n = 10 for each group). Four screws were attached to the dentures: two were attached to the buccal surface of the canine and first molar, and the other two were attached in the flange areas o
... Show MoreAn experimental study was carried out to improve the surface roughness quality of the stainless steel 420 using magnetic abrasive finishing method (MAF). Four independent operation parameters were studied (working gap, coil current, feed rate, and table stroke), and their effects on the MAF process were introduced. A rotating coil electromagnet was designed and implemented to use with plane surfaces. The magnetic abrasive powder used was formed from 33%Fe and 67% Quartz of (250µm mesh size). The lubricant type SAE 20W was used as a binder for the powder contents. Taguchi method was used for designing the experiments and the optimal values of the selected parameters were found. An empirical equation representing the r
... Show MoreY Adnan, H Atiyah, IH Neamah…, International Development Planning Review, 2024
The tight gas is one of the main types of the unconventional gas. Typically the tight gas reservoirs consist of highly heterogeneous low permeability reservoir. The economic evaluation for the production from tight gas production is very challenging task because of prevailing uncertainties associated with key reservoir properties, such as porosity, permeability as well as drainage boundary. However one of the important parameters requiring in this economic evaluation is the equivalent drainage area of the well, which relates the actual volume of fluids (e.g gas) produced or withdrawn from the reservoir at a certain moment that changes with time. It is difficult to predict this equival
The ground state charge, neutron, proton and matter densities, the associated nuclear radii and the binding energy per nucleon of 8B, 17Ne, 23Al and 27P halo nuclei have been investigated using the Skyrme–Hartree–Fock (SHF) model with the new SKxs25 parameters. According to the calculated results, it is found that the SHF model with these Skyrme parameters provides a good description on the nuclear structure of above proton-rich halo nuclei. The elastic charge form factors of 8B and 17Ne halo nuclei and those of their stable isotopes 10B and 20Ne are calculated using plane-wave Born approximation with the charge density distributions obtained by SHF model to investigate the effect of the extended charge distributions of proton-rich nucl
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