This article includes the preparation of luminescence materials from rare earth (Eu ) ion doping Yttrium Oxide (Y₂O₃) 70% and SiO₂ 25% and study the characteristics of phosphors for ultraviolet to visible conversion. The phosphor materials have been synthesized by two steps: Preparing the powder by solid state method using Y₂O₃, SiO₂ and Eu₂O₃ with doping materials concentration (70%, 25% and 5%) respectively and different calcination temperature (1000, 1200 and 1400 ^oC).

   The second step is to prepare the colloid solution by dispersing the produced powder in a polyvinyl alcohol solution (4%) .

Powde

سمير خلف فياض * و محسن طالب د.نوال عزت عبد اللطيف*, مجلة الهندسة والتكنولوجيا, 2010

Gallium arsenide diamondoids structural and vibrational properties are investigated using density functional theory at the PBE/6-31(d) level and basis including polarization functions. Variation of energy gap as these diamondoids increase in size is seen to follow confinement theory for diamondoids having nearly equiaxed dimensions. Density of energy states transforms from nearly single levels to band structure as we reach larger diamondoids. Bonds of surface hydrogen with As atoms are relatively localized and shorter than that bonded to Ga atoms. Ga-As bonds have a distribution range of values due to surface reconstruction and effect of bonding to hydrogen atoms. Experimental bulk Ga-As bond length (2.45 Å) is within this distribu

Thin films whose compositions can be expressed by (GeS₂)_100-xGa_x (x=0, 6,12,18) formula were obtained by thermal evaporation technique  of bulk material at a base pressure of ~10^-5 torr. Optical transmission spectra of the films were taken in the range of 300-1100 nm then the optical band gap, tail width of localized states,  refractive index, extinction coefficient were calculated. The optical constants were found to increase at low concentration of Ga (0 to12%) while they decreases with further addition of Ga. The optical band gap was found to change in opposite manner to that of optical constants. The variation in the optical parameters are explained in terms of average bond energy

Thin film technology is one of the most important technologies
that have contributed to the development of semiconductors and their
applications in several industrial fields. The Iron Oxides (Fe20) and
(Co3O4) thin films and their applications are of importance, in that these
two materials are considered as important industrial materials, and used
in spectrally selective coating, temperature sensors, resistive heaters, and
photo cells.
Thin films of Iron Oxide (Fe20,), Cobalt Oxide (Co304) and
their mixtures in different ratios (75:25, 50:50, 25:75) were prepared by
the method of chemical spray pyrolysis deposition at different thicknesses
(77s t S200) nm on cover-glass substrates: thickness of (1) mm at

Nano TiO₂ thin films on glass substrates were prepared at a constant temperature of (373 K) and base vacuum (10_-3 mbar), by pulsed laser deposition (PLD) using Nd:YAG laser at 1064 nm wavelength. The effects of different laser energies between (700-1000)mJ on the properties of TiO₂ films was investigated. TiO₂ thin films were characterized by X-ray diffraction (XRD) measurements have shown that the polycrystalline TiO₂ prepared at laser energy 1000 mJ. Preparation also includes optical transmittance and absorption measurements as well as measuring the uniformity of the surface of these films. Optimum parameters have been identified for the growth of high-quality TiO₂ films

Low- and medium-carbon structural steel components face random vibration and dynamic loads (like earthquakes) in many applications. Thus a modification to improve their mechanical properties, essentially damping properties, is required. The present study focuses on improving and developing these properties, significantly dampening properties, without losing the other mechanical properties. The specimens used in the present study are structural steel ribbed bar ISO 6935 subjected to heating temperatures of (850, 950, and 1050) ˚C, and cooling schemes of annealing, normalizing, sand, and quenching was selected. The damping properties of the specimens were measured experimentally with the area under the curve for the loadi

CdS and CdTe thin films were thermally deposited onto glass substrate. The CdCl2 layer was deposited onto CdS surface. These followed by annealing for different duration times to modify the surface and interface of the junction. The diffraction patterns showed that the intensity of the peaks increased with the CdCl2/annealed treatment, and the grain sizes are increased after CdCl2/annealed treatment