Charge-transfer (CT) complexes of adenine (Ade.), guanine (Gua.), xanthine (Xan.), and inosine (Ino.) as electron donors with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), 2,3,5,6-tetrabromo-1,4-benzoquinone (Bromanil)(BA) as π – electron acceptors and iodine (Iod.) as σ – electron acceptor were studied and their electronic spectra recorded .In each case one (CT) band was observed and recorded. These spectroscopic investigations made in ethanol solvent at (20°C) temperature. The values of equilibrium constant (KCT), change in standard free energy (ΔG°), molar extinction coefficient (εCT(, absorption band energy (hνCT) of CT complexes and the association energy of the CT complexes-excited state (W) were calculated and studie

Abstract

    Corrosion-fatigue occurs by the combined actions of cyclic loading and corrosive environment. The effect of shot peening on cumulative corrosion-fatigue life of 1100-H12 Al alloy was investigated. Before fatigue testing, specimens were submerged in 3.5%NaCl solution for 71 days. Constant fatigue tests were performed with and without corrosive environment. Cumulative corrosion-fatigue tests were also carried out in order to determine the fatigue life before and after shot peening. The constant fatigue life was significantly reduced due to corrosive environment and the endurance fatigue limit was reduced by 13% compared with dry fatigue. In case of shot peening the cumul

      This research aims to investigate parameters for magnesium (Mg)  carbon (C), and carbon/magnesium plasma produced by the exploding electrical wire (EEW) technique. In this work, C and Mg nanoparticles were synthesized. The plasma spectra with three different current values (50, 75 and 100A) were recorded using optical emission spectroscopy (OES). The plasma electron temperature (Te), electron density (ne), plasma frequency (fp), Debye length (ℷD), and Debye number (ND) provided by arc discharge plasma were  calculated. Boltzmann plots were  used to calculate the electron temperature (Te); electron density (ne) was calculated by Stark broadening . The results showed that the electron temperature and electron density increa

The effect of ethanol and methanol solvent, and their mixture has been studied on the absorption and fluorescence spectra of laser dye Rhodamine B at concentration of (10-4) Molar at room temperature. The molar absorption coefficient has been determined for mixture which was (3.223) at wave number (18181.8 cm-1), Also the Quantum Efficiency of the two solvents (ethanol and methanol) and their mixture have been calculated ,which was for mixture spectrum (38.94%) and it was larger comparing with other and solvents. The characteristics of spectrum has been determined by calculating (??) of absorption spectrum for the solvents and its mixture at maximum wave number ( ) cm-1 depending on solvent polarity and the transitions between molecular ene

The influence of sintering and annealing temperatures on the structural, surface morphology, and optical properties of Ag2Cu2O4 thin films which deposited on glass substrates by pulsed laser deposition method have been studied. Ag2Cu2O4 powders have polycrystalline structure, and the Ag2Cu2O4 phase was appear as low intensity peak at 35.57o which correspond the reflection from (110) plane. Scan electron microscopy images of Ag2Cu2O4 powder has been showed agglomerate of oxide particles with platelets shape. The structure of thin films has been improved with annealing temperature. Atomic Force micrographs of Ag2Cu2O4 films showed uniform, homogenous films and the shape of grains was almost spherical and larger grain size of 97.85 nm has o

The electronic characteristics, including the density of state and bond length, in addition to the spectroscopic properties such as IR spectrum and Raman scattering, as a function of the frequency of Sn₁₀O₁₆, C₂₄O_6, and hybrid junction (Sn₁₀O₁₆/C₂₄O₆) were studied. The methodology uses DFT for all electron levels with the hybrid function B3-LYP (Becke level, 3-parameters, Lee–Yang-Parr), with 6-311G (p,d)  basis set, and Stuttgart/Dresden (SDD) basis set, using Gaussian 09 theoretical calculations. The geometrical structures were calculated by Gaussian view 05 as a supplementary program. The band gap was calculated and compared to the measured valu

   This paper concerns is the preparation and characterization of a bidentate ligand [4-(5,5dimethyl-3-oxocyclohex-1-enylamino)-N-(5-methylisoxazol-3-yl) benzene sulfonamide].  The ligand was prepared from fusing of sulfamethoxazole and dimedone at (140) ºC for half hour.              The complex was prepared by refluxing the ligand with a bivalent cobalt ion using ethanol as a solvent. The prepared ligand and complex were identified using Spectroscopic methods. The proposed tetrahedral geometry around the metal ions studied were concluded from these measurements. Both molar ratio and continuous variation method were studied to determine metal to ligand ratio (M:L). The M to L ratio wa

The photo-electrochemical etching (PECE) method has been utilized to create pSi samples on n-type silicon wafers (Si). Using the etching time 12 and 22 min while maintaining the other parameters 10 mA/cm² current density and HF acid at 75% concentration.. The capacitance and resistance variation were studied as the temperature increased and decreased for prepared samples at frequencies 10 and 20 kHz. Using scanning electron microscopy (SEM), the bore width, depth, and porosity % were validated. The formation of porous silicon was confirmed by x-ray diffraction (XRD) patterns, the crystal size was decreased, and photoluminescence (PL) spectra revealed that the emission peaks were centered at 2q of 28.5619° and 28.7644° for et

A tetradentate (N2O2) Schiff base (H2Ldfm) was successfully synthesized via condensation of curcumin / diferuloylmethane (dfm) and L-leucine amino acid (HL). There were three different methods that used for synthesizing H2Ldfm; (refluxing, grading, and fusion). Ten different metal complexes were also successfully synthesized by combination of the Schiff base (H2Ldfm) and 1,10-phenanthroline (phen) ligand to form a hexadentate (N4O2) mixed ligands (Ldfm , phen) with ten different metal salts (M) where{ M= Al(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Ag(I), Cd(II), Hg(II), and Pb(II)}. The molar ratio of reactants was (1:1:1) (M: H2Ldfm : phen). The new Schiff base and its new complexes were characterized by different physicochemical tec

    The electronic properties (such as energy gap HOMO levels. LUMO levels, density of state and density of bonds in addition to spectroscopic properties like IR spectra, Raman spectra, force constant and reduced masses as a function of frequency) of coronene C₂₄ and reduced graphene oxide C₂₄O_X , where x=1-5, were studied.. The  methodology employed was  Density Functional Theory (DFT) with Hybrid function B3LYP and 6-311G** basis sets. The energy gap was calculated for C₂₄ to be 3.5 eV and for C₂₄O_x was from 0.89 to 1.6862 eV  for x=1-5 ,respectively.   These energy gaps values are comparable to the measured gap of Graphene (1-2.2 eV). The spectroscopic propertie