Defect and Diffusion Forum Vol. 398

Abstract: Polylactic Acid (PLA) has been used widely in packaging application because of its biodegradability. The aim of this study is to produce PLA nanocomposites by solvent casting incorporating montmorillonite nanoclays (MMT) and titanium dioxide (TiO2) nanoparticles. The effect of different loadings of MMT in PLA and different loadings of TiO2 on chemical structure and surface wettability were studied. The nanocomposites were prepared by solvent casting at different loadings of MMT (0, 2, 4, 6 wt %) and different loadings of TiO2 (1 and 3 wt %) respectively. The chemical structure and surface wettability were determined. The absorption peaks in the range of 3550-3200 cm-1 had increased after incorporating of TiO2 and it indicated that there is the presence of stretching vibration of O-H groups. Moreover, increasing the percentage of TiO2 mass in the nanocomposites decreased the contact angle with water which led to increasing the wettability of the nanocomposites.

Abstract: Recently, lead iodide is the most materials employment in the perovskite solar cell application. This paper has studied the character of preparation, structural and optical properties of pbI₂ materials. Structural properties are included investigation of the measurements X-Ray Diffraction (XRD), Scan Electron Microscopy (SEM), Fourier Transform InfraRed spectroscopy (FTIR) and Atomic Force Microscopy (AFM) tests to the PbI₂ thin films samples. Optical properties are included the investigation UV-Vis test of the thin film samples deposited on glass substrates and investigated the Absorption, Transmittance and evaluated energy gap (E_g = 2.3 eV).

Abstract: Dynamic shafts subjecting to salty rain water, especially in places with no rain water drainage networks, is undesirable because this media causes corrosion of the parts of shaft that increases as increasing of shaft immersion in a salty media (NaCl) also, increasing of concentration which in turns reducing number of operation runs. Increasing salt concentration from 3% to 6% NaCl results in decreasing of operation runs from 25600 to 17100 runs. Also, increasing salt concentration leads to raise the effect of alternating stress that makes strain hardening factor drop to 0.45 and ratio of dynamic shear stress to static one raise to 2.44 that affects shaft metal performance to resist fatigue. Samples were also, treated by oxy acetylene surface hardening and were cooled by immersion in oil then immersion in 6% NaCl salty solution, the results showed that number of operation runs before failure had increased up to 71022, the effect of alternating stress had decreased down to 6100 N/m², surface strain hardening factor had increased up to , also ratio of dynamic shear stress to static one had decreased down to 0.839. This is a good indicator of the effectiveness of surface hardening process of shaft parts that subject to salty rain water during maintenance operations.

Abstract: Zinc oxide (ZnO) thin films were coated onto Indium Tin Oxide (ITO) glass substrate using spin coating technique as a function of annealing temperature. The thin film preparation was undertaken by utilising zinc acetate dihydrate, ethanol and diethanolamine as the precursors. The films were coated at room temperature prior to being annealed at temperatures ranging from 300 °C to 450 °C. The resulting crystalline structure and surface morphology of the thin films were then examined using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). UV-visible spectrophotometer was also used to record the optical absorbance in wavelengths ranging from 200 to 800 nm. The findings revealed that the ZnO thin films showed a single phase of wurtzite with n-type semiconductor, with the lowest value of band gap energy of 3.28 eV for ZnO thin films annealed at 350 °C. FESEM results showed that the ZnO nanoparticles were very compact on the surface, whereby the average particle size was equivalent to 108.5, 115.3, 108.2 and 107.8 nm at the temperatures 300 °C, 350 °C, 400 °C, and 450 °C, respectively. Additionally, the highest photoconversion efficiency (0.11%) recorded for the sample was annealed at 350^◦C. Thus, annealing temperature was found to significantly affect the optical and electrical properties of ZnO nanoparticle seed layer, as well as its band gap energy and surface morphology.

Abstract: Concrete is considered a low tensile resistance material and a weak material against cracking. The weak properties of concrete has been enhanced by utilizing fibers to reinforce it. In this research, the effects of the polypropylene fibers on several properties of plain concrete have been studied. It was found that the polypropylene fibers has enhanced the concrete ductility and the concrete crack control. The compressive strength of plain concrete has been increased by adding polypropylene fibers to it and also the flexural and splitting strengths. The best results were at fibers ratio of 1%. When the polypropylene fibers ratio has changed different effects on concrete properties have been obtained.

Abstract: We design hydro geochemical study to show the effect of Shari Lake on Samarra groundwater. tow samples (Jelam 1,Jelam 2 ) that nearby Shari lake and other samples taken from different location from Samarra city ( Efraz ,SDI factory , Golden Mosque, Samarra university ). Then sent samples to specific laboratory for chemical and microbial test .the result shows the locations (Jelame 1, Jelame 2) have highest value in PH, but SDI factory location has highest value in Sulfate. The result show affect ground water in this city by salt and mineral that found in watershed and ground structure specially limestone that flow throw ground that lead to dissolve salt and mineral then arise the value of studied data.