As the prices of the fuel and power had fluctuated many times in the last decade and new policies appeared and signed by most of the world countries to eliminate global warming and environmental impact on the earth surface and humanity exciting, an urgent need appeared to develop the renewable energy harnessing technologies on the short-term and long-term and one of these promising technologies are the vertical axis wind turbines, and mostly the combined types. The purpose of the present work is to combine a cavity type Savonius with straight bladed Darrieus to eliminate the poor self-starting ability for Darrieus type and low performance for Savonius type and for this purpose, a three-bladed Darrieus type with symmetric

In the present paper a low cost mechanical vibration shaker of rotating unbalanced type with uniaxial shaking table was designed and constructed in an attempt to provide opportunities for experimental testing and application of vibration in experimental modal analysis, stress relief of weldments, effect of vibration on heat transfer and seismic testing of civil engineering structures. Also, it provides unexpressive solution to enhance the knowledge and technical skills of students in mechanical vibration laboratory. The shaker consists of a five main parts shaker frame, shaker table, flexible support, drive motor, and eccentricity mechanism. The experimental results show that the amplitude of the shaker is increased with increasing the f

Laser shock peening (LSP) is deemed as a deep-rooted technology for stimulating compressive residual stresses below the surface of metallic elements. As a result, fatigue lifespan is improved, and the substance properties become further resistant to wear and corrosion. The LSP provides more unfailing surface treatment and a potential decrease in microstructural damage. Laser shock peening is a well-organized method measured up to the mechanical shoot peening. This kind of surface handling can be fulfilled via an intense laser pulse focused on a substantial surface in extremely shorter intervals. In this work, Hydrofluoric Acid (HF) and pure water as a coating layer were utilized as a new technique to improve the properti

ABSTRACT Background:Hydrogen absorption and related degradation in the mechanical properties of Ni-Ti based orthodontic wires has been demonstrated following exposure to fluoride prophylactic agents. This study was designed to investigate the effects of three fluoride containing agents on the load deflection characteristics of heat activated nickel titanium arch wires during unloading phase. Material and method: Eighty specimens of heat activated nickel titanium arch wires were obtained from Ortho Technology Company, half of which had a 0.016 inch round and 0.019x0.025 rectangular. Ten specimens from both wire size were immersed in one of the tested fluoride prophylactic agents (neutral sodium fluoride gel, stannous fluoride gel or phos-flu

IN this work, a titanium dental implant was modified by electro-polymerized of 4-allyl-2-methoxyphenol (Eugenol) using direct current lower than 3.5 volt. The modification of titanium dental implant was achieved to improve its corrosion resistant. Fourier transform infrared spectroscopy (FTIR) was employed to confirm the electro-polymerization of Eugenol to Poly Eugenol (PE) on pure titanium. Deposition of PE on titanium was confirmed by X-ray diffraction and was characterized by thermogravimetric analysis (TGA). The surface morphology of polymeric film were examined through scanning electron microscopy (SEM). Coated titanium by (PE) revealed a good corrosion protection efficiency even at temperature ranged (293-323)K in artificial saliva.

In this work, corrosion parameters were evaluated using potentiodynamic polarization curves. In order to determine corrosion parameters of potential and current density of the interesting metal, carbon steel, environmental conditions of external corrosion of buried carbon steel pipeline in Iraqi soil were prepared in the laboratory using simulated prepared conditions. Solutions of sodium chloride at different concentrations (300, 1100, 1900, 2700, and 3500 ppm) were used. pH of solution were acidic at pH =5, and alkaline at pH = 9. Laboratory conditions were similar to those of Iraqi soil where the pipelines were buried. Temperature was constant at 20 °C. Potentiodynamic polarization curves, of potential vs. log current density, were ob

Blades of gas turbine are usually suffered from high thermal cyclic load which leads to crack initiated and then crack growth and finally failure. The high thermal cyclic load is usually coming from high temperature, high pressure, start-up, shut-down and load change. An experimental and numerical analysis was carried out on the real blade and model of blade to simulate the real condition in gas turbine. The pressure, temperature distribution, stress intensity factor and the thermal stress in model of blade have been investigated numerically using ANSYS V.17 software. The experimental works were carried out using a particular designed and manufactured rig to simulate the real condition that blade suffers from. A new cont

The variation of compression index C_c and swelling index C_s with the degree of saturation S was studied on unsaturated and fully saturated soils for different degrees of saturation (100%, 91%, 85%, 75%, 60%), several mathematical equations were found to describe these relationships, these equations can be used to predict settlement during the consolidation process in unsaturated and fully saturated soils.

In this study, the concentrations of uranium for four species of plants; Spinacia, Brassica Oleracea, BEASSICA Oleracea Var Capitata and Beta Vulgaris were measured in addition to the measurement of uranium concentrations in the selected soil by calculating the number of significant traces of alpha in CR-39. The 2.455 Bq/kg in Spinacia plant were the highest concentration while the lowest concentration of uranium were 1.91 Bq/kg in BEASSICA Oleracea Var Capitata plant. As for the transfer factor, the highest value 0.416 were found in Spinacia plant and the lowest value 0.323 were found in BEASSICA Oleracea Var Capitata plant. The uranium in the models studied in it did not exceed the international limit, according to the International Atomi