Iraqi Journal of Physics

In the current research, an eco-biosynthesis method for synthesizing silver nanoparticles (AgNPs) is reported using thymus vulgaris leaves (T. vulgaris) extracts. The optical and structural properties of the nanoparticles were determined using uv-visible, x-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). In addition, the synthesis factors such as temperature, molar ratio of silver nitride and thymus vulgaris leaves extract was investigated. The XRD pattern presented higher intensity for the five characteristic peaks of silver. FESEM images for same samples indicated that the particle size was distributed between 24-56 nm. The mixtures were used to inhibit two kinds of bacteria which are Gram negative (E. coli (and Gram positive (S-aureus) as tested for antibacterial activity by agar well diffusion method. The results showed the effectiveness of the synthesized AgNPs on inhabitation the growing up of the bacteria and their isolates.

In this work, the copper metal was treated using Nd:YAG laser with energy 1Joul to enhance corrosion resistance and improve surface properties. The copper metal has many applications in industry as well as water, oil and gas pipes. The same conditions, (laser power density, scan speed, distance between paths, medium gas-air) were applied in the laser surface treatment, After laser treatment, the samples microstructures were investigated using optical microscope (OM) to examine micro structural changes due to laser irradiation. Specimen surfaces were investigated using atomic force microscopy (AFM), X-ray diffraction (XRD), macro hardness, and corrosion test before and after laser treatment to examine the surface properties changes as a result of laser irradiation, and X-ray fluorescence (XRF). Results showed that laser irradiation enhances the corrosion resistance of the metal copper. Corrosion rates as low as 0.550 mpy for laser treated samples were obtained in comparison to 0.699 mpy obtained for the untreated samples. The corrosion protection afforded by laser treatment is attributed mainly to the grain refinement of the top surface layer. This layer is found to consist of nano-scale grains. Higher hardness and lower average roughness due to laser surface treatment.

Biochemical and physiological properties depend on the size of ions and the thermodynamic quantities of ion hydration in numerous states. The diffusion coefficient (D) of lanthanide series ions (Ln+3) in solution (1.558-1.618 ×10−9 m2 s−1) as calculated by the Einstein–Smoluchowski relation depended on conductance measurements as electro - analytical measurement. The association constant (KA) of Ln+3 ions (210.3-215.3 dm3 mole-1) was calculated by using the Shedlovsky method, and the hydrodynamic radius was (1.515-1.569 ×10−10 m) as calculated by Stokes–Einstein equation. ΔHo, values were obtained from the literature. The thermodynamic functions (ΔGo, ΔSo) were calculated by suitable equations, ΔGo, for ion hydration, had negative values in the range (13.25 - 13.31 kJ/mole), ΔSo also were of negative values, results have been shown in the limit (11.299 - 12.573 kJ/ K. mole).

The nuclear structure including the matter, proton and neutron densities of the ground state, the nuclear root-mean-square (rms) radii and elastic form factors of one neutron 23O and 24F halo nuclei was studied by the two body model of (core+n) within the harmonic oscillator (HO) and Woods-Saxon (WS) radial wave functions. The calculated results show that the two body model within the HO and WS radial wave functions succeed in reproducing neutron halo in these exotic nuclei. Moreover, the Glauber model at high energy was used to calculate the rms radii and reaction cross section of these nuclei. The calculated results were compared with the experimental data.

In this work, a magnetic switch was prepared using two types of ferrofluid materials, the pure ferrofluid and ferrofluid doped with copper nanoparticles (10 nm). The critical magnetic field (Hc) and the state of magnetic saturation (Hs) were studied using three types of laser sources. The main parameters of the magnetic switch measured using pure ferrofluid and He-Ne Laser source were Hc (0.5 mv, 0.4 G), Hs (8.5 mv, 3 G). For the ferrofluid doped with copper nanoparticles were Hc (1 mv, 4 G), Hs (15 mv, 9.6 G), Using green semiconductor laser for the Pure ferrofluid were Hc (0.5 mv, 0.3 G) Hs (15 mv, 2.9 G). While the ferrofluid doped with copper nanoparticles were Hc (0.5 mv, 1 G), Hs (12 mv, 2.8 G) and by using the violet semiconductor laser the pure ferrofluid parameters were Hc (0.5 mv, 0.5 G), Hs (15 mv, 3.5 G) while the ferrofluid doped with copper nanoparticles are Hc (0.5 mv, 1 G), Hs (15 mv, 3.3 G).