Piezoelectric structures are nowadays used in many different applications. A better understanding of the influence of material properties and geometrical design on the performance of these structures helps to develop piezoelectric structures specifically designed for their application. Different equivalent circuits have been introduced in the literature to investigate the behaviour of piezoelectric transducers. The model parameters are usually determined from measurements covering the characteristic frequencies of the piezoelectric transducer. This article introduces an analytical technique for calculating the mechanical and electrical equivalent system parameters and characteristic frequencies based on material properties and geom

Applications of superconductor compounds were considered as modern and important topics, especially these which are exposures to one of the nuclear radiation kinds. So, we gone to investigate the influence of fast neutrons irradiation on electrical and structural characteristics of HgxSb1-xBa2Ca2Cu3O8+δ superconducting compound at (x = 0.7) in ratio. The superconducting specimens were synthesized using solid state technique. Specimens were exposure to the nuclear radiation using fast neutrons with doses (0, 9.06 x1010, 15.3 x 1010 and 18.17 x 1010) n/cm2 respectively. Electrical and X-ray diffraction properties of superconductor specimens before and after irradiation were investigated under standard conditions. Results of X-ray diffraction

The optical properties for the components CuIn(SexTe1-x)2 thin films with both values of selenium content (x) [0.4 and 0.6] are studied. The films have been prepared by the vacuum thermal evaporation method with thickness of (250±5nm) on glass substrates. From the transmittance and absorbance spectra within the range of wavelength (400-900)nm, we determined the forbidden optical energy gap (Egopt) and the constant (B). From the studyingthe relation between absorption coefficient (α) photon energy, we determined the tails width inside the energy gap.
The results showed that the optical transition is direct; we also found that the optical energy gap increases with annealing temperature and selenium content (x). However, the width of l

In this work, the effects of solvent properties on the characteristics of absorption and fluorescence for two laser dyes was studied. Dyes used in this work include Coumarin 5400 and DCM, while the solvents include ethanol, methanol, acetone, propanol and chloroform. Coumarin 5400 dye shows sharp fluorescence peaks in the green band of visible region while the DCM dye shows relatively wide band within 590-630 nm. Therefore, the selection of any dye for random gain medium applications should be performed after determining the most appropriate solvent as the optimum fluorescence characteristics are obtained.

Basrah crude oil Vacuum residue 773+ K with specific gravity 1.107 and 4.87wt. % sulfur, was treated with hexane commercial fraction provided from Al-Taji Gas Company for preparing deasphaltened oil(DAO)suitable for hydrotreating process. Deasphaltening was carried out with 1h mixing time, 10ml:1g solvent to oil ratio and at room temperature. Hexane deasphaltened oil was hydrotreated on presulfied commercial Co-Mo/γ-Al2O3 catalyst in a trickle bed reactor. The hydrotreating process was carried out at temperature 660 K,LHSV 1.3 h^ –1, H2/oil ratio 300 l/l and constant pressure of 4MPa. The hydrotreated product was distillated under vacuum distillation unit. It is found that the mixture of 75% of vacuum residue with 25% anthracene satisfie

Crystalline In2O3 Thin films have been prepared by flash evaporation. We have studied the crystal structure of as deposited at 303K and annealed at 523K using X-ray diffraction. The Hall Effect measurements confirmed that electrons were predominant charges in the conduction process (i.e n-type).It is found that the absorption coefficient of the prepared films decreases with increasing Ta. The d.c conductivity study showed that the conductivity increase with increasing Ta , whereas the activation energy decreases with increasing Ta. Also we study the barrier tunneling diode for In2O3/Si heterostructure grown by Flash evaporation technique. (capacitance-voltage C-V) spectroscopy measurements were performed at 303 K and at the annealing temper