Numerical simulations are carried out to investigate the possibility of observing
extrasolar planet nearby star via optical telescopes. Several techniques are
considered in this study in order to quantitatively assess their quality in suppressing
the wings of the point spread function of optical telescope of a reference star. The
optical telescope with circular Gaussian shape aperture reveals extrasolar planet
even with contrast ratio 10-7 while the square Gaussian shape aperture reveals the
planet with 10-5.

The current research is a spectroscopic study of Coumarin 334 dissolved in methanol. The range of concentrations of the prepared stock solution was (3.39x10^-9 to 2.03x10^-8) M. Some optical characteristics of this dye were investigated such as absorbance and transmission spectra, absorption coefficient, refractive and extinction coefficients, oscillation and dispersion energies, and energy band gap. The absorbance spectra were recorded at 452 nm using Broad Band Cavity Enhanced Absorption Spectroscopy (BBCEAS) which depends on increasing the path length of the traveling light from the source to the detector. The minimum absorbance amount was 0.07 with a low concentration of 3.39x10^-9 M. As a result, the ot

In this work the structural, optical and sensitive properties of Cerium - Copper oxide thin film prepared on silicon and glass substrate by the spray pyrolysis technique at a temperature of (200, 250, 300 °C). The results of (XRD) showed that all the prepared films were of a polycrystalline installation and monoclinic crystal structure with a preferable directions was (111) of CuO. Optical characteristics observed that the absorption coefficient has values for all the prepared CuO: Ce% (104 cm-1) in the visible spectrum, indicating that all the thin films prepared have a direct energy gap. Been fabrication of gas sensors of (CuO: Ce %) within optimum preparation conditions and study sensitivity properties were examined her exposed to ni

In this work copper nanopowder was created at different liquid
medias like DDDW, ethylene glycol and Polyvinylpyrrolidone
(PVP). Copper nanopowder prepared using explosion wire process
and investigated the effects of the exploding energy, wire diameter,
the type of liquid on the particle size, and the particles size
distribution. The nanoparticles are characterized by x-ray diffraction,
UV-visible absorption spectroscopy and transmission electron
microscopy (TEM). The x-ray diffraction results reveal that the
nanoparticles continue to routine lattice periodicity at reduced
particle size. The UV-Visible absorption spectrum of liquid solution
for copper nanoparticles shows sharp and single surface Plasmon
r

Films of pure Poly (methyl methacrylate) PMMA and Iron chromate doped PMMA have been prepared using casting method. Transmission and absorptance spectra have been recorded in the wavelength range (300-900) nm, in order to calculate, single oscillator energy, dispersion energy proposed by Wemple - DiDomenico model, average oscillator strength, average oscillator wavelength. The refractive index data at infinite wavelength which was found to obey single oscillator model which was found to increase from 2.27-2.56 as the doping percentage increase. The decreasing in the optical energy gap which was found according to Tauc model were (3.74-3.63) eV , is in good agreement with that obtained by wimple-DiDomenico model. The inverse behavior comp

  The influence of annealing on quaternary compound Ag0.9Cu0.1InSe2 (ACIS) thin film is considered a striking semiconductor for second-generation solar cells. The film deposited by thermal evaporation with a thickness of about 700 nm at R.T and vacuum annealing at temperatures (373,473) K for 1 hour. It was deposited in a vacuum of 4.5*10-5 Torr on a glass substrate. From XRD and AFM analysis, it is evident that Ag0.9Cu0.1InSe2 films are polycrystalline in nature, having ideal stoichiometric composition. Structural analysis indicated that annealing the films following the deposition resulted in the increasing polycrystalline phase with the preferred orientation along (112) direction. , increasing crystallite size and average grain size

Fe3O4:Ce thin films were deposited on glass and Si substrates by Pulse Laser Deposition Technique (PLD). Polycrystalline nature of the cubic structure with the preferred orientation of (311) are proved by X-ray diffraction. The nano size of the prepared films are revealed by SEM measurement. Undoped Iron oxide and doped with different concentration of Ce films have direct allowed transition band gap with 2.15±0.1 eV which is confirmed by PL Photoluminescence measurements. The PL spectra consist of the emission band located at two sets of peaks, set (A) at 579±2 nm , and set (B) at 650 nm, respectively when it is excited at an excitation wavelength of 280 nm at room temperature. I-V characteristics have been studied in the dark and under v

the researchers pointed that the poet relied on several means in the form of poetic images, including analogy, and the metaphor with its various elements, The chromatic component has also been used in the formation of its poetic image,and resorted to the correspondence of the senses and the symbol of two types:Self-code, public code : And we find a variety of symbolic stems from different sources, from these symbols, what is religious, including what is historical and what is legendary, and such symbols, which resorted to the rare places of his poems confined to the myths contained in the Bible, His use of the general symbols was ineffective in the poetic picture, relying on the metaphor and metaphor.

The aim of the research is to shed light on the stages of developing the Iraqi virtual science Library(IVSL) project, and to define its distinctive role in providing all kinds of electronic resources to researchers from professors and graduate students, to identify its contents , the entry interfaces and applications of use, and provide them through electronic portals to publishing houses, research institutions and international universities, The research sample included the teaching staff and researchers participating in educational qualification courses at the Continuing Education Center at the University of Baghdad, The research population and its sample consisted of the category of (IVSL) users, and its sample (387) users. Analysis meth

The perturbed equation of motion can be solved by using many numerical methods. Most of these solutions were inaccurate; the fourth order Adams-Bashforth method is a good numerical integration method, which was used in this research to study the variation of orbital elements under atmospheric drag influence.  A satellite in a Low Earth Orbit (LEO), with altitude form perigee = 200 km, was selected during 1300 revolutions (84.23 days) and A_Sat / M_Sat value of 5.1 m²/ 900 kg. The equations of converting state vectors into orbital elements were applied. Also, various orbital elements were evaluated and analyzed. The results showed that, for the semi-major axis, eccentricity and inclination have a secula