نبراس فاضل علي الشمري

Abstract. By using the spray pyrolysis technique, un-doped and Fluorine highly doped iron oxide Fe2O3 thin films were deposited on a glass substrate at a temperature of 380 oC and at different dopant concentrations (10, 15, and 20) %. The crystal structure and optical characterization of the deposited thin film were performed by x-ray diffraction and UV-Vis spectrophotometer. The XRD results revealed that the presence of a very wide peak in-between (15-35) o angles, this gives evidence that un-doped and F-doped Fe2O3 thin films have very low crystallinity and amorphous structures. The optical absorbance edge was shifted towards short wavelengths (blue shift) and the absorbance was reduced with the increase of Fluorine dopant content. The optical constants such as absorption, extinction coefficients, and the optical conductivity of the deposition films were investigated as a function of dopant content. The optical energy band gap of un-doped and Fe2O3:F thin films was found to be increased when increasing of the Fluorine content and exhibited a direct allowed energy gap (Eg) from (2.55 to 2.7) eV which can related to the Burstein-Moss effect.

Abstract: In this work the luminescent solar concentrators (LSC) plates doped with Al-Anthedin dye was prepared by at the solid state laboratory at room temperature with different thicknesses and concentrations .The Anthedin dye concentrations were (1×10-4 , 2×10-4 and 3×10-4 ) mol/L. The optical characteristics have been studied such as absorption and energy gap also the optical constants such as the absorption coefficient and extinction coefficient were calculated for all panels. Increasing the concentration of the Al-Anthedin dye led to increase the values of absorbance, absorption and extinction coefficient. The results also demonstrate that the value of the energy gap was decreased with increasing the concentrations from (2.2eV) for the lowest concentration to (2.1eV)for the highest one. Keywords: Polyemer, Epoxy resin, Al-Anthedin dye, Optical properties

Abstract: The effect of discharge voltage of a discharge tube were investigated.The discharge voltage (700,800,900,1000,1100,1200) volt were applied under pressure of helium gas was (7Pa) and the inter electrode distance was (130mm). The measurements were achieved without and with parallel magnetic field of (25 mT). The electron temperature calculated from Id – Vd characteristics curves of double Langmuir probe. Results of electron temperature indicated that the behavior of electron temperature decreased with increasing the discharge voltage with and without the magnetic field.But their values at (B=0) was smaller than the corresponding values at (B=25 mT). Keywords: Glow discharge, Langmuir probes, Plasma diagnoistics

In this work a modified Freeman Ion source, used for ion sputtering, is designed and constructed. The choice of this ion source was based on its remarkable success in the semiconductor industry employing ion implantation techniques. A detailed technical description of the design and the fabrication of the ion source are given. Thermionic emission current measurements were performed and the discharge characteristics of the ion source were closely monitored. Also, the effects of some parameters such as; sputtering voltage, pressure, magnetic field strength, arc voltage and filament current on the value of the sputtered electrode current were studied. It was found that these parameters can be independently varied, enabling us to control the ion source operation and the sputtering process. The primary results of the extracted ion beams, using a simple stainless steel extraction plate, show a reduction in the detected total ion beam current under sputtering process.

In this research work a hybrid composite material have been prepared contains one matrix which is unsaturated polyester resin(UNPE) and fabricated fibers, a hybrid composite materials that were prepared are: A hybrid composite material consists of unsaturated polyester resin(UP) as a matrix reinforced with two different fabricated fibers(EF(W.R) +KF(W.R))(H1). A hybrid composite material consists of unsaturated polyester resin(UP) as a matrix reinforced with two different fabricated fibers(EF(W.R) +CF(W.R))(H2). A hybrid composite material consists of unsaturated polyester resin(UP) as a matrix reinforced with three different fabricated fibers(EF(W.R)+CF(W.R)+KF(W.R)). The volume fraction for all hybrid composite material is 30%. All samples related to mechanical tests were prepared by hand layup process in preparation the hybrid molds. A mechanical tests (impact) were done for the three samples. The results were compared among each other. Also, the effect of the exposure time of the ultraviolet(uv)on impact strength were studied for the above samples. The results shows that as the exposure time increases the impact strength decreases for all prepared samples.

In this study the luminescent solar concentrators (LSC) plates doped with fluorescein-sodium dye laser have been prepared in the laboratory at room temperature with(0.5mm) thickness .The concentration of the fluorescein-sodium dye laser were( 10-5,10-4) mol/L. Then they compared with pure epoxy panel. The optical characteristics have been studied like (absorption, transmittance, reflectance and energy gap) also the optical constant were calculated including (absorption. coefficient, refraction index and extinction coefficient ) for all panels. The effect of increasing concentration leads to shift the absorbance, absorption coefficient and extinction coefficient towards higher wavelength, their values also increase with increasing the concentrations. With regard to transmission ,reflectance and refractive index the concentration effect also leads to the same displacement, but their values decrease with increasing the concentration. The results also shown that the value of the energy gap is decreased from (3.6eV) for epoxy resin to (2.3,2.25)eV for the both concentrated panels.

سيتمإ إنعقاد دورة بتاريخ 21-25/ 11 / 2021

تاريخ إنعقاد الندوة : 10-4-2017