In this study, Laser Shock Peening (LSP) effect on the polymeric composite materials has been investigated experimentally. Polymeric composite materials are widely used because they are easy to fabricate and have many attractive features. Unsaturated polyester resin as a matrix was selected and Aluminum powder with micro particles as a reinforcement material was used with different volume fraction (2.5%, 5% and 7.5%). Hand lay-up process was used for preparation the composites. Fatigue test with constant amplitude with stress ratio (R =-1) was carried out before and after LSP process with two levels of energy (1Joule and 2Joule). The result showed an increase in the endurance strength of 25.448% at 7.5% volume fraction when peened is 1J

The electrospun nanofibers membranes (ENMs) have gained great attention due to their superior performance. However, the low mechanical strength of ENMs, such as the rigidity and low strength, limits their applications in many aspects which need adequate strength, such as water filtration. This work investigates the impact of electrospinning parameters on the properties of ENMs fabricated from polyacrylonitrile (PAN) solved in N, N-Dimethylformamide (DMF). The studied electrospinning parameters were polymer concentration, solution flow rate, collector rotating speed, and the distance between the needle and collector. The fabricated ENMs were characterized using scanning electron microscopy (SEM) to understand the surface morphology and es

PAN/PMMA) with different blend ratios (80/20, 75/25,70/30,65/35, and 60/40) wt% undoped and doped with various lithium (Li) salts (LiCO3, Li2SO4H2O, and LiCl) at 20 wt %. Different techniques were employed to investigate the composition and optical properties of the prepared blend samples undoped and doped with Lithium salts like FT-IR and UV-Visible spectroscopies. The optical properties analysis declared that the energy gap increased from (4.0 eV to 4.20 eV) by increasing of PMMA ratio from 20 to 40 wt %. In contrast, the energy gap reduced and shifted toward the low energy side by adding lithium salts; the minimum energy gap value was 2 eV obtained from 65 % PAN and 35 % PMMA doped with Li2CO3. The optical constants were determ

Zinc sulfide (ZnS) thin films were deposited on glass substrates using pulsed laser deposition technique. The laser used is the Q-switched Nd: YAG laser with 1064nm wavelength and 1Hz pulse repetition rate and varying laser energy 700mJ-1000mJ with 25 pulse. The substrate temperature was kept constant at 100°C. The structural, morphological and optical properties of ZnS thin films were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscope (AFM) and UV-VIS spectrophotometer.

  This work reports the study of heat treatment effect on the structural, morphological, optical and electrical properties of poly [3-hexylthiophene] and its blend with [6,6]-phenyl C61 butyric acid methyl ester ( P3HT:PC61BM). X-ray diffraction (XRD) measurements show that the crystallinity of the films increased with annealing. The evaluation of surface roughness and morphology was investigated using atomic force microscope (AFM), and field emission scanning microscope(FESEM). The optical properties were emphasized a strong optical absorption of P3HT compared with the blend. Hall effect measurement was used to study the electrical properties which revealed there is an increase in the electrical conductivity and Hall mobility of th

The effect of heat treatment using different annealing temperatures on optical properties of bulk heterojunction blend (BHJ) Alq3: C60 thin films which are fabricated by the spin coating technique were investigated in this study. The films have been coated on a glass substrate with speed of 2000 rpm for one min and treated with different annealing temperature (373, 423 and 473) K under vacuum. The optical properties and the chemical bonds structure of blends as-deposited and heat treated have been studied by UV-Vis spectroscopic and Fourier Transform-Infra Red (FTIR) measurements respectively. The results of UV visible show that the optical energy gap decreasing with increasing the annealing temperature for the ratio (100:1) while decrea

Rare earth elements (Cerium, Lanthanum and Neodymium) doped CdS thin films are prepared using the chemical Spray Pyrolysis Method with temperature 200 oC. The X-ray diffraction (XRD) analysis refers that pure CdS and CdS:Ce, CdS:La and CdS:Nd thin films showed the hexagonal crystalline phase. The crystallite size determined by the Debye-Scherrer equation and the range was (35.8– 23.76 nm), and it was confirmed by field emission scanning electron microscopy (FE-SEM). The pure and doped CdS shows a direct band gap (2.57 to 2.72 eV), which was obtained by transmittance. The room-temperature photoluminescence of pure and doped CdS shows large peak at 431 nm, and two small peaks at (530 and 610 nm). The Current – voltage measurement in da

In this work the interaction of plasma jet with water and hydrogen peroxide liquids used for assisted teeth bleaching by plasma jet had been study. A homemade plasma jet system was used. The plasma jet supply by 15 W electrical power generated by high voltage power supply of 9.6 kV peak to peak and frequency of 33 kHz .this power supply generate high electric field on electrodes that would be enough to ionize the argon gas. Some important agents were study such as the effect of the Ar gas flow rates on the length of the plasma jet, the influence of plasma jet on some properties of water and two hydrogen peroxide concentrations 25 % and 30 % like pH, conductivity and liquid temperature for different exposure time. The liquids temperature

Objectives: This study aimed to evaluate and compare the effect of plasma treatment versus conventional treatment on the micro shear bond strength (μSBS), surface roughness, and wettability of three different CAD/CAM materials. Materials and methods: Sixty cylindrical specimens (5 mm diameter ×3 mm height) were prepared from three different CAD/CAM materials: Group A: Zirconia, Group B: Lithium disilicate, and Group C: Resin nano-ceramic. Each group was subdivided into two subgroups according to surface treatment used: Subgroup I: Conventional treatment, zirconia was sandblasted with Al2O3, while lithium disilicate and resin nano-ceramic were etched with hydrofluoric acid. Subgroup II: Plasma treatment, the surface of each material was tr

Dentures that are not cleaning and maintained properly may prone to contamination by different microbial pathogens that result in several oral conditions. This study was design to compare the antimicrobial effect of different denture cleansers oxalic, tartaric, citric acids and alkaline peroxide with microwave irradiation on the growth of Candida albicans and Staphylococcus aureus respectively. Microwave oven used to disinfect specimens of heat-activated acrylic resin and soft linear. Oxalic, citric, tartaric acids, and alkaline peroxide were also used. Microorganisms that tested were Candida albicans and Staphylococcus aureus separately. Treatment with microwave or tartaric acid could achieve sterilization of both hot cured acrylic resins