In this work, MWCNT in the epoxy can be prepared at room temperature and thickness (1mm) at different concentration of CNTs powder. Optical properties of multi-walled carbon nanotubes (CNTs) reinforced epoxy have been measured in the range of (300-800)nm. The electronic transition in pure epoxy and CNT/epoxy indicated direct allowed transition. Also, it is found that the energy gap of epoxy is 4.1eV and this value decreased within range of (4.1-3.5)eV when the concentration of CNT powder increased from (0.001-0.1)% respectively.
The optical constants which include (the refractive index (n), the extinction coefficient (k), real (ε1) and imaginarily (ε2) part of dielectric constant calculated in the of (300-800)nm at different concentration of CNT powder. It decreased with increasing of CNT and the values take at λ=550nm.
A nanocrystalline CdS thin film with 100 nm thickness has been prepared by thermal evaporation technique on glass substrate with substrate temperature of about 423 K. The films annealed under vacuum at different annealing temperature 473, 523 and 573 K. The X-ray diffraction studies show that CdS thin films have a hexagonal polycrystalline structure with preferred orientation at (002) direction. Our investigation showed the grain size of thin films increased from 9.1 to 18.9 nm with increasing the annealing temperature. The optical measurements showed that CdS thin films have direct energy band gap, which decreases with increasing the annealing temperature within the range 3.2- 2.85 eV. The absorbance edge is blue shifted. The absorption
... Show MoreBackground: This study aimed to evaluate the effect addition of polyester fibers on the some mechanical properties of heat cured acrylic resin (implant strength, flexural strength and hardness) Materials and methods: Ninety specimens were used in the study. Thirty specimens were used for impact strength measurements (80mm X 10mm X 4mm) length, width and thickness respectively. The specimens divided into three test groups (n=10), first group formed from heat cure acrylic resin without fiber reinforcement. Second group was formed from heat cure acrylic resin was reinforced with 2 mm length polyester fiber and third group was formed from heat cure acrylic resin reinforced with 4mm length polyester fiber, impact strength measured by impact test
... Show MoreThe paper include studies the effect of solvent of dye doped in polymeric laser sample which manufactured in primo press way, which is used as an active (R6G) tunable dye lasers. The remarks show that, when the viscosity of the solvent (from Pure Water to Ethanol), for the same concentration and thickness of the performance polymeric sample is increased, the absorption spectrum is shifts towards the long wave length (red shift), & towards short wave length (blue shift) for fluorescence spectrum, also increased the quantum fluorescence yield. The best result we obtained for the quantum fluorescence yield is (0.882) with thickness (0.25mm) in Ethanol solvent in concentration (2*10-3mole/liter), while when we used the Pure Water as a solvent,
... Show MoreThe paper include study the effect thickness of the polymeric sample which is manufactured by thermo press way. The sample was used as an active tunable R6G laser media. The remarks show that, when the thickness of the samples is increased, with the same concentration, the spectrum will shift towards the short wavelength, & the quantum fluorescence yield will increased. The best result we obtained for the quantum fluorescence yield is (0.68) at the sample, with thickness (0.304mm) in Ethanol solvent, while when we used the Pure Water as a solvent, we found that the best quantum fluorescence yield is (0.63) at (0.18mm) thickness of the sample.
Cadmium sulfide and Aluminum doped CdS thin films were prepared by thermal evaporation technique in vacuum on a heated glass substrates at 373K. A comparison between the optical properties of the pure and doped films was made through measuring and analyzing the transmittance curves, and the effect of the annealing temperature on these properties were estimated. All the films were found to exhibit high transmittance in the visible/ near infrared region from 500nm to 1100nm.The optical band gap energy was found to be in the range 2.68-2.60 eV and 2.65-2.44 eV for CdS and CdS:Al respectively , with changing the annealing temperature from room temperature to 423K.Optical constants such as refractive index, extinction coefficient, and complex di
... Show MoreThin films of Mn2O3 doped with Cu have been fabricated using the simplest and cheapest chemical spray pyrolysis technique onto a glass substrate heated up to 250 oC. Transmittance and absorptance spectra were studied in the wavelength range (300 -1100) nm. The average transmittance at low energy was about 60% and decrease with Cu doping, Optical constants like refractive index, extinction coefficient and dielectric constants (εr), (εi) are calculated and correlated with doping process.
Ti6Al4V thin film was prepared on glass substrate by RF
sputtering method. The effect of RF power on the optical properties
of the thin films has been investigated using UV-visible
Spectrophotometer. It's found that the absorbance and the extinction
coefficient (k) for deposited thin films increase with increasing
applied power, while another parameters such as dielectric constant
and refractive index decrease with increasing RF power.
Iron-Epoxy composite samples were prepared by added
different weight percentages (0, 5, 10, 15, and 20 wt %) from Iron
particles in the range of (30-40μm) as a particle size. The contents
were mixed carefully, and placed a circular dies with a diameter of
2.5 cm. Different mechanical tests (Shore D Hardness, Tensile
strength, and Impact strength ) were carried out for all samples. The
samples were immersed in water for ten weeks, and after two weeks
the samples were take-out and drying to conducting all mechanical
tests were repeated for all samples. The hardness values increased
when the Iron particle concentration increased while the Impact
strength is not affected by the increasing of Iron particles
c