In this work, the effects of size, and temperature on the linear and nonlinear optical properties in InGaN/GaN inverse parabolic and triangular quantum wells (IPQW and ITQW) for different concentrations at the well center were theoretically investigated. The indium concentrations at the barriers were fixed to be always x_max = 0.2. The energy levels and their associated wave functions are computed within the effective mass approximation. The expressions of optical properties are obtained analytically by using the compact density-matrix approach. The linear, nonlinear, and total absorption coefficients depending on the In concentrations at the well center are investigated as a function of the incident photon energy for different

            In this study, pure SnO₂ Nanoparticles doped with Cu were synthesized by a chemical precipitation method. Using SnCl₂.2H₂O, CuCl₂.2H₂O as raw materials, the materials were annealed at 550°C for 3 hours in order to improve crystallization. The XRD results showed that the samples crystallized in the tetragonal rutile type SnO₂ stage. As the average SnO₂ crystal size is pure 9nm and varies with the change of Cu doping (0.5%, 1%, 1.5%, 2%, 2.5%, 3%),( 8.35, 8.36, 8.67, 9 ,7, 8.86)nm respectively an increase in crystal size to 2.5% decreases at this rate and that the crystal of SnO₂ does not change with the introduction of Cu, and S

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

 Thin  films   of  pure   tin mono-sulfide  SnS with thicknesses of   (0.85) μm  were prepared by chemical spray  pyrolysis  technique  and  annealed for  two  hours with 673K.The effect of annealing on structural and optical properties for films prepared was  studied.  X-Ray   diffraction  analysis  showed   the  polycrystalline  with   orthorhombic structure.  It was  found  that   annealing process increased the intensity of diffraction peaks. Optical   properties  of  all  samples  were studied by  recording  the  absorption  and  transmission &nbsp

Molar conductance (Λ) of ionizable side chains amino acids, lysine (Lys) and arginine (Arg) with dehydroascorbic acid (DHA) in water and in NaCl solutions was measured at temperatures range 298 K to 313 K. The limited molar conductance (Λo) and the constant of the ions association (KA) are calculated using the Shedlovsky techniques. The dynamic radius of the concerned ion (R) is calculated by used Stokes–Einstein relation. The heat of association, the Gibbs free energy, the change of entropy and activation energy (ΔHo/ kJ mol-1, ΔGo/ kJ mol-1, ΔSo/J K-1 mol-1, and ΔES/ kJ mol-1) respectively), also calculated. The data show increases the molar conductance with increas

     In this study the as-deposited and heat treated at 423K of conductive blende graphene oxide (GO) / poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) thin films was prepared with different PEDOT:PSS concentration (0, 0.25, 0.5, 0.75 and 1.0)wt% on pre-cleaned glass substrate by spin coating technique. The energy dispersive X-ray Analysis (EDX) show the existence of higher amount of carbon and oxygen related to hydroxyl and carbonyl  groups. X-ray diffraction (XRD) analysis of the as-deposited and annealed GO/PEDOT:PSS thin films blend indicated that the film prepared  show broad peak around 8.24 corresponding to the (001) level refers to GO, this peak shifted to the lower 2θ with increasing PEDOT:PSS concentr

Zinc sulfide(ZnS) thin films of different thickness were deposited on corning glass with the substrate kept at room temperature and high vacuum using thermal evaporation technique.the film properties investigated include their absorbance/transmittance/reflectance spectra,band gap,refractive index,extinction coefficient,complex dielectric constant and thickness.The films were found to exhibt high transmittance(59-98%) ,low absorbance and low reflectance in the visible/near infrared region up to 900 nm..However, the absorbance of the films were found to be high in the ultra violet region with peak around 360 nm.The thickness(using optical interference fringes method) of various films thichness(100,200,300,and 400) nm.The band gap meas