This work is focused on studying the effect of liquid layer level (height above a target material) on zinc oxide nanoparticles (ZnO and ZnO2) production using liquid-phase pulsed laser ablation (LP-PLA) technique. A plate of Zn metal inside different heights of an aqueous environment of cetyl trimethyl ammonium bromide (CTAB) with molarity (10-3 M) was irradiated with femtosecond pulses. The effect of liquid layer height on the optical properties and structure of ZnO was studied and characterized through UV-visible absorption test at three peaks at 213 nm, 216 nm and 218 nm for three liquid heights 4, 6 and 8 mm respectively. The obtained results of UV–visible spectra test show a blue shift accompanied with decreasing the liquid level above the target due to the increase in ablation rate and particles production. This blue shift indicates getting a smaller size of nanoparticles and the quantum confinement property of nanoparticles. Also the FTIR transmittance spectra of ZnO2 nanoparticles prepared in these states show a characteristic ZnO absorption at 435 cm−1 – 445 cm-1.
In this work, lead oxide (PbO) thin films were deposited using D.C. sputtering method on a surface of glass substrates and then thermally annealed at a temperature of 473K with annealing times of (1,2 and 3) hours. The structural, morphological, and optical properties of films were determined using X-ray diffraction (XRD), atomic force microscopy (AFM), FT-IR, and UV-Visible spectroscopy. The structure studies confirmed that PbO films are polycrystalline structures in an orthorhombic phase with average grain size (24.51, 29.64, 46.49, 16) nm with increasing annealing time. From AFM, the roughness of the film surface (3.26, 1.76, 1.61, 1.79) nm as the film annealing time increases. The optical band gap values of the PbO thin fi
... Show MoreBackground: Decalcification of surface enamel adjacent to fixed orthodontic appliances, in the form of white spot lesions, is a wide spread and familiar well-known side effect of orthodontic treatment. The present study was carried out to evaluate the effect of enamel protective agent (Clinpro white varnish) on shear and tensile bond strength of Dentaurum orthodontic stainless steel brackets by using 3M Unitek and Ormco as orthodontic adhesive agents. Materials and methods: Sixty-four extracted human upper first premolar teeth were selected and randomly divided into two groups with 32 teeth each, representing the shear and tensile bond strength testing groups. Then according to the type of bonding adhesive and the addition of Clinpro before
... Show MoreThe effect of 532nm Diode Pumped Solid State (DPSS) laser at power density of 5.234 W/cm2 on the growth of Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus was evaluated. These bacteria were isolated from samples taken from burn and infected wound areas of 55 patients admitted to the burn-wound unit in Al-Kindy teaching hospital in Baghdad during the period from October 2012 to March 2013. Each isolate was identified using microscopic, cultural and biochemical methods. A standard bacterial suspension was prepared for each isolate. Serial dilutions were then prepared and a dilution of 10-5 was selected. Irradiation experiments included four groups: (L-P-) bacterial suspension in saline solution, (L-P+) bacteria
... Show MoreThis work presents the characteristics of plasma produced by fundamental wavelength (1064 nm) Q- switched Nd:YAG laser on Ag:Ni alloy in distilled water were investigated at different laser energies by optical emission spectroscopy technique. The size of produced nanoparticles from Ag:Ni target in distilled water were studied, by x-ray diffraction, UV-visible absorbance and atomic force microscopy, at different laser energies. Spectroscopic measurements show that electron temperature and electron density increase with increasing laser energy. It was found from AFM measurements that the produced nanoparticle size decrease from 97.13 nm to 71.20 nm, while XRD shows that the crestalline size decrease from 15.5 nm to 9 nm with increasing pul
... Show MoreA variety of oxides were examined as additives to a V2O5/Al2O3 catalyst in order to enhance the catalytic performance for the vapor phase oxidation of toluene to benzoic acid. It was found that the modification with MoO3 greatly promoted the little reaction leading to improve catalyst performance in terms of toluene conversion and benzoic acid selectivity. The effect of catalyst surface area, catalyst promoters, reaction temperature, O2/toluene, steam/toluene, space velocity, and catalyst composition to catalyst performance were examined in order to increase the benzoic acid selectivity and yield.
To the Banks capital several uses, including the protection of deposits and this was approved by the Basel Committee, And Finance long-term investments which intended to investment in fixed assets that are essential to the continuation of banking activity, Fixed assets not financed from the funds of the deposit, but the owner equity do this jop. the current research tries to prove the effect of banks capital on fixed assets for a sample of iraqi private banks (bank of baghdad and Iraqi middle east Investment bank), for the period from 2011 until 2014. The research concluded that the capital of bank of baghdad affect on his total fixed assets by (84%), and the capital of Iraqi middle east Investment bank affect on his total fixed assets b
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