http://blogs.najah.edu/author/emp_2022 An-Najah Blogs :: en-us Wed, 24 Apr 2024 21:11:36 IDT Wed, 24 Apr 2024 21:11:36 IDT [email protected] [email protected] http://blogs.najah.edu/staff/emp_2022/article/Effect-of-Annealing-and-of-Effect-of-Annealing-and-of-Cooling-Rates-on-n-GaAs-Electrode-Photoelectrochemical-CharacteristicsPublished ArticlesThe effect of annealing of the n-GaAs semiconductor on its characteristics in photoelectrochemical PEC systems has been investigated The photocurrent densities vs potential plots were improved by annealing Cell efficiency and short-circuit current densities were enhanced for the annealed n-GaAs The effect of the rate of cooling of heated n-GaAs wafers was also investigated It was found that the slowly cooled electrodes gave better dark current density vs potential plots for samples annealed below 600C For samples annealed at higher temperatures quenching gave better dark-current density vs potential plots For n-GaAs slowly cooled electrodes from temperatures below 600C showed better photocurrent densityvspotential plots and higher efficiency n-GaAs samples quenched from temperatures above 700C showed better photocurrent density vs potential plots and higher efficiency than their slowly cooled counterparts http:wwwhindawicomGetArticleaspx?doi=1010800882751031000116115 http://blogs.najah.edu/staff/emp_2022/article/Modification-of-n-Si-Characteristics-by-Annealing-and-Cooling-at-Different-RatesPublished ArticlesThe effect of annealing of the n-Si semiconductor on its characteristics in photoelectrochemical systems has been investigated The annealing improved the dark current density vs potential plots The surface was improved by annealing as manifested by SEM results The effect of the cooling rate on preheated n-Si wafers was also investigated It was found that the slowly cooled electrodes gave better dark current density vs potential plots for samples annealed at lower than 550C For samples annealed at higher temperatures quenching gave better dark-current density vs potential plots SEM measurements showed parallel results to these findings Enhanced surface textures were observed for slowly cooled wafers from temperatures below 550C Samples quenched from temperatures above 550C showed better surfaces than slowly cooled counterparts http:wwwhindawicomGetArticleaspx?doi=1010800882751031000116124http://blogs.najah.edu/staff/emp_2022/article/Energy-consideration-in-the-two-capacitor-problemPublished ArticlesA derivation of the specific electrostatic energy loss for two interacting capacitors is given The connecting wires are assumed to be superconducting The method of derivation is based purely on the Poynting vector involved in the process without any reference to the nature of the mechanism that may be involved in achieving a final equilibrium statehttp://blogs.najah.edu/staff/emp_2022/article/A-spectroscopic-study-of-preferential-solvation-of-Febipy2CN2-in-binary-aqueous-2-ethoxy-ethanol-mixturesPublished ArticlesPreferential Solvation of his-22-bipyridyl biscyanoironII was investipated in 2-ethoxy ethanol water binary aqueous mixtures The treatment showed that preferential solvation by 2-ethoxy ethanol occurs The preferential solvation constant at 29815 K was found to be equal to 496006 and the free energy of preferential solvations Ghas a value of 397 KL mol-1http://blogs.najah.edu/staff/emp_2022/article/-ATOMIC-TRANSITION-PROBABILITIES-IN-RuIPublished ArticlesAccurate absolute atomic transition probabilities are reported for 482 lines of Rul These are determined by combining branching fractions measured using the 10 m Fourier transform spectrometer at the National Solar Observatory with radiative lifetimes and measured using time-resolved laser induced fluorescencehttp://blogs.najah.edu/staff/emp_2022/article/Radiative-lifetimes-in-TI-IPublished ArticlesRadiative lifetimes for more than 160 levels in Ti I are reported These accurate lifetimes or -5 percent are measured using time-resolved laser-induced fluorescence on a titanium atomic beam These lifetimes confirm the recent renormalization of the Oxford Ti I oscillator strengths confirm the revision of the solar abundance of titanium and provide a foundation for a much more extensive set of Ti I oscillator strengths http://blogs.najah.edu/staff/emp_2022/article/Radiative-lifetimes-in-Ni-IIPublished ArticlesRadiative lifetimes for 12 levels in Ni ii are measured using time-resolved laser-induced fluorescence The lifetimes are used to establish a more accurate absolute scale for earlier transition probability measurements - Issues involved in extending time-resolved laser-induced fluorescence into the vacuum-uv region are discussedhttp://blogs.najah.edu/staff/emp_2022/article/RuI-is-radiative-lifetimes-and-stellar-abundancesPublished ArticlesRadiative lifetimes for 50 odd-parity levels in Ru I are determined using time-resolved laser-induced fluorescence on a Ru atomic beam The implication of the lifetime measurements for the Ru abundance in red giant stars with an enhanced heavy-element abundance is discussedhttp://blogs.najah.edu/staff/emp_2022/article/-Lifetimes-branching-ratios-and-transition-probabilities-in-Co-IIPublished ArticlesThe radiative lifetime of 14 levels in the z5F z5D and z5G terms of Co II have been measured with use of time-resolved laser fluorescence spectroscopy with a Co-ion beam Our lifetime values are shorter by 15-50 than earlier results from beam-foil time-of-flight measurements The lifetimes were converted to 41 individual transition probabilities with use of branching ratios measured on spectra recorded with the 1-m Fourier-transform spectrometer at the Kitt Peak National Observatory On average our transition probabilities agree with those of Kurucz and Peytremann; for AS =1 transitions their calculated values are lower than our experimental results by a factor of 14http://blogs.najah.edu/staff/emp_2022/article/-TWO-STEP-OPTOGALVANIC-EFFECT-USING-INTERSECTING-LASER-BEAMSPublished ArticlesElectric fields in the cathode fall region of a glow discharge are accurately measured in a small volume defined by the intersection of two laser beams The fields are determined from linear Stark effects in Rydberg levels The Rydberg atoms are produced via a two-step laser excitation and detected with optogalvanic effectshttp://blogs.najah.edu/staff/emp_2022/article/Pulsed-ion-source-for-laser-spectroscopy-Application-to-NbIIPublished ArticlesA novel pulsed ion source suitable for laser spectroscopy on any metallic element is described The source is based on a large-bore low-pressure hollow-cathode discharge The first direct radiative lifetime measurements in Nb II are reported Radiative lifetimes for z5G and z3D levels of Nb II are determined using time-resolved laser-induced fluorescence on a Nb II ion beamhttp://blogs.najah.edu/staff/emp_2022/article/Radiative-lifetimes-in-Rh-I-and-in-Ta-IPublished ArticlesRadiative lifetimes of 22 levels in Rh I and of 35 levels in Ta I are reported The lifetimes are measured with the use of time-resolved laser-induced fluorescence on an atomic beam The Rh I lifetimes resolve the discrepancy between the spectroscopically determined solar abundance of Rh and the abundance of Rh determined from chondritic meteoriteshttp://blogs.najah.edu/staff/emp_2022/article/Radiative-lifetimes-in-Hf-IPublished ArticlesRadiative lifetimes of 25 levels in neutral hafnium are reported Measurements are made on a sputtered atomic beam through the use of time-resolved laser-induced fluorescence The system is shown to be useful for lifetimes from a few n sec to over 2 sechttp://blogs.najah.edu/staff/emp_2022/article/Radiative-lifetimes-in-Re-IPublished ArticlesAbstract Radiative lifetimes of nine levels of neutral rhenium are reported with an accuracy of 5 Improved oscillator strengths derived from the lifetimes bring the spectroscopically determined upper limit for the solar abundance of Re closer to the abundance of Re in chondritic meteoriteshttp://blogs.najah.edu/staff/emp_2022/article/Radiative-lifetimes-in-W-I-using-a-novel-atomic-beam-sourcePublished ArticlesThe first direct radiative lifetime measurements in W I are described Radiative lifetimes of 15 levels from the 5d46sa 6D6pz7D0 5d46sa 6D6pz 5F 0 5d5a 6S6pz7P0 and 5d46sa 6D6pz 5P0 terms are reported with an accuracy of 5 The lifetimes are measured using time-resolved laser-induced fluorescence and a novel atomic-beam source This novel hollow cathode effusive beam source produces an intense beam of ground-state W atoms and metastable W atomshttp://blogs.najah.edu/staff/emp_2022/article/RADIATIVE-LIFETIMES-IN-MoI-USING-A-NOVEL-ATOMIC-BEAM-SOURCEPublished ArticlesRadiative lifetimes of the 4d5 a6S5pz 7Po levels and the 4d5 a6S5p z 5P0 levels in Mol are reported as follows: r z 7P04 = 159 ns r z 7 P03 = 170 ns r z 7 P02 = 171 ns r z5 P03 = 223 ns -r z5 P02 = 221 ns and r z 5 P01 = 217 ns 5 The lifetimes are measured using time resolved laser induced fluorescence and a novel atomic beam source This novel hollow cathode effusive beam source produces an intense beam of ground state Mo atoms and metastable Mo atoms Our measurements on the z 7 P0 levels are in agreement with earlier lifetime measurements Our measurements on the z 5 P0 levels are the first direct radiative lifetime measurements of these levels; the z 5 P0 measurements are of particular interest because the a5S-z 5P0 multiplet is used to determine the solar abundance of Mohttp://blogs.najah.edu/staff/emp_2022/article/Non-self-consistent-energy-calculations-with-a-density-dependent-effective-interactionPublished ArticlesIt is first argued that nuclear energy calculations with a density-dependent force may be carried out in a basis which is not self-consistent The underlying formalism is outlined and the rearrangement energy is shown to be due in this approach to the survival of an unlinked diagram which would be cancelled in the absence of density dependence The formalism is then applied in first order perturbation theory to the calculation of the binding energies of the closed shell nuclei 4He 16O and 40Ca and of the single-particle energies of 5He 17O and 41Ca The force employed throughout is the Skyrme III force but with a model-density dependent term replacing the three-body term The binding energies obtained are generally in good agreement with empirical values As for the single-particle energies we obtain qualitative agreement with available experimental data and contributions due to rearrangement which are in agreement with the estimates given by Elton