Piezoelectric structures are nowadays used in many different applications. A better understanding of the influence of material properties and geometrical design on the performance of these structures helps to develop piezoelectric structures specifically designed for their application. Different equivalent circuits have been introduced in the literature to investigate the behaviour of piezoelectric transducers. The model parameters are usually determined from measurements covering the characteristic frequencies of the piezoelectric transducer. This article introduces an analytical technique for calculating the mechanical and electrical equivalent system parameters and characteristic frequencies based on material properties and geom

In this paper, we introduced a mathematical model for Iraqi Airways Company about evaluating its objectives and strategies. First, we studied Iraqi Airways schedules with different departure cities for each airline path. Then, we applied some fuzzy integrals for determining the best airline path.

A field Experiment was carried out in Baghdad for the purpose of compare five horticulture machines during used two types of fuel deffirance in octane number, normal and super fuel which produced in Iraqi and measuring the vibrations transmitted of the three axes are longitudinal X , lateral Y and vertical Z from handlebar in (Mowers) to the operator which walks behind the mower, and the determine of the productivity practical of cutting, productivity passing and fuel consumption. Experiment Factorial used with two factors, The first factor was Five Mowers vary in width , types, weight and company manufacturer, The Second factor was the types of fuel used internal combination engine horticulture mowers were Normal fuel with Octane Number 82

The synthesis of gold nanoparticles AuNPs was achievedby the reduction of sodium tetrachloroaurate (III) (NaAuCl4) with ceftriaxone sodium (CR) in aqueous solutionswithout the use of other reducing agent. The effect of reactants concentration, temperature and pH on the sizes and morphology of AuNPs were also studied. The synthesized AuNPs were characterized by UV- visible spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), and atomic force microscope (AFM) analysis. Conjugation of antibiotic with the nanoparticles was characterized by FTIR spectrophotometry.

The telescope works to magnify images of distant objects in general, but it needs special optical elements to complete the task to the fullest. The telescope needs optimal balance values of the optical parameters used to produce the best image, such as the effective focal length and the diameter of the pupil aperture, which are combined in a single concept called the focal number. The ground-based binary telescope relies on special lenses and an exceptional prism to achieve a hybrid design that produces clear images of relatively distant terrestrial objects. The pupil diameter of the telescope is relatively large to ensure that the largest possible amount of light is received, and as a result, a good image is obtained.

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The goal of this paper is to study dynamic behavior of a sporadic model (prey-predator). All fixed points of the model are found. We set the conditions that required to investigate the local stability of all fixed points. The model is extended to an optimal control model. The Pontryagin's maximum principle is used to achieve the optimal solutions. Finally, numerical simulations have been applied to confirm the theoretical results.

    The main focus of research is on the nature of applications in the fields of science and technology, particularly nanotechnology. In this paper, a simple, non-toxic, inexpensive, and environmentally friendly green method was used to synthesize TiO₂ nanoparticles using the extraction of portulacaria afra plant leaves and TiCl₄ as a precursor. The synthesized titanium dioxide nanoparticles were characterized by scanning electron microscopy, atomic force microscopy, X-ray diffraction patterns, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller analysis. The SEM image of TiO₂ nanoparticles showed a few spherical, non-agglomerated particles. The average diameter of the nanoparticles, ac

The synthesis of gold nanoparticles AuNPs was achievedby the reduction of sodium tetrachloroaurate (III) (NaAuCl4) with ceftriaxone sodium (CR) in aqueous solutionswithout the use of other reducing agent. The effect of reactants concentration, temperature and pH on the sizes and morphology of AuNPs were also studied. The synthesized AuNPs were characterized by UV- visible spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), and atomic force microscope (AFM) analysis. Conjugation of antibiotic with the nanoparticles was characterized by FTIR spectrophotometry.

   In this study a new composite material have been prepared and characterized through polymerization of ethylene glycol located between the Bentonite layers with phthalic anhydride. The results showed that the polymer binds with the structure of clay through hydrogen bonding also the polymerization process led to shatter of the three-dimension crystal structure of the clay and isolating layers in the form of nano-scale two-dimensional sheets, the polymer growth around the clay isolated layers work to increase the size particles at microscopic scale.                              &