Publications

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2019
AbdelAziem, A., K. M. El-Katib, M. A. Hafez, and Y. Badr, "Effect of annealing on La0.8Sr0.2MnO3 thin films prepared by pulsed laser deposition", Spectrochimic a Acta- Part A:Molecular and biomolecular spectroscopy, 2019.
Abdelsalam, E. M., Y. A. Attia, H. E. Hassan, and Y. Badr, "Effect of laser irradiation and Ni nanoparticles on biogasproductionfrom Anaerobic Digestion of Slurry", Waste and Biomass Valorization, 2019.
2017
Abdelsalam, E., M. Samer, Y. A. Attia, M. A. Abdel-Hadi, H. E. Hassan, and Y. Badr, "Effects of Co and Ni nanoparticles on biogas and methane production from anaerobic digestion of slurry", Energy Conversion and Management, vol. 141, pp. 108-119, 2017. AbstractWebsite
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2015
Morimoto, Y., D. He, W. Hijikata, T. Shinshi, T. Nakai, and N. Nakamura, "Effect of high-frequency orbital and vertical oscillations of the laser focus position on the quality of the cut surface in a thick plate by laser beam machining", Precision Engineering, vol. 40, pp. 112 - 123, 2015. AbstractWebsite

Abstract In laser beam machining with oxygen gas, striations are formed on the cut surface due to the cyclic oxidization reaction, which is affected by the cutting conditions and the thermal properties of the workpiece. The formation of striations causes an increase in surface roughness. In order to reduce the surface roughness, we propose controlling the formation of striations by utilizing multi-DOF oscillation of the focus position of the laser. In this paper, we construct a laser machining system in which positioning control of the focus position is achieved by driving the focal lens. The effect of orbital oscillation of the laser focus position parallel to the top surface of the workpiece and vertical oscillation perpendicular to this surface on the formation of striations was evaluated by performing laser cutting tests on thick mild steel plates. The experimental results show that control of the formation of striations can be realized by choosing the appropriate oscillation conditions. The surface roughness with oscillation was less than half that without oscillation.

Salah, A., A. Mansour, M. B. Mohamed, I. M. Azzouz, S. Elnaby, and Y. Badr, "Effects of nanoparticles size and concentration and laser power on nonlinear optical properties of Au and Au-CdSe nanocrystals", Applied Surface Science, vol. 353, pp. 112-117, 2015. AbstractWebsite
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2011
Graça, M. P. F., H. Fawzy, Y. Badr, M. M. Elokr, C. Nico, R. Soares, L. C. Costa, and M. A. Valente, "Electrical, dielectric and structural properties of borovanadate glass systems doped with samarium oxide", Physica Status Solidi (C) Current Topics in Solid State Physics, vol. 8, no. 11-12, pp. 3107-3110, 2011. AbstractWebsite
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2009
Battisha, I. K., M. A. Salem, A. M. S. Nahrawy, Y. Badr, B. Elouady, and M. Kamal, "Erbium activated monolith silica-phosphate glasses planar waveguide and up-conversion mechanism", International Journal of Nano and Biomaterials, vol. 2, no. 1-5, pp. 191-203, 2009. AbstractWebsite
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2007
Badr, Y., and M. A. Mahmoud, "Effect of PbS shell on the optical and electrical properties of PbSe core nanoparticles doped in PVA", Physica B: Condensed Matter, vol. 388, no. 1-2, pp. 134-138, 2007. AbstractWebsite
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Badr, Y., and M. A. Mahmoud, "Excimer laser photofragmentation of metallic nanoparticles", Physics Letters, Section A: General, Atomic and Solid State Physics, vol. 370, no. 2, pp. 158-161, 2007. AbstractWebsite
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2006
Badr, Y., and M. A. Mahmoud, "Effect of PVA surrounding medium on ZnSe nanoparticles: Size, optical, and electrical properties", Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, vol. 65, no. 3-4, pp. 584-590, 2006. AbstractWebsite
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Badr, Y., and M. A. Mahmoud, "Effect of silver nanowires on the surface-enhanced Raman spectra (SERS) of the RNA bases", Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, vol. 63, no. 3, pp. 639-645, 2006. AbstractWebsite
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Shaltout, I., and Y. Badr, "Effects of Sm3+/Yb3+co-doping and temperature on the Raman, IR spectra and structure of [TeO2-GeO2-K2O-Sm2O3/Yb2O3] glasses", Physica B: Condensed Matter, vol. 381, no. 1-2, pp. 187-193, 2006. AbstractWebsite
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Badr, Y., and M. A. Mahmoud, "Enhancement of the optical properties of poly vinyl alcohol by doping with Silver nanoparticles", Journal of Applied Polymer Science, vol. 99, no. 6, pp. 3608-3614, 2006. AbstractWebsite
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2005
Badr, Y., A. Salah, and I. K. Battisha, "Effect of Europium ion concentrations on the photoluminescence emission of nano-crystalline BaTiO3prepared by sol-gel technique", Journal of Sol-Gel Science and Technology, vol. 34, no. 3, pp. 219-226, 2005. AbstractWebsite
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2004
Badr, Y., A. S. Elwanees, and M. A. Mahmoud, "The effect of delay time on the CO and CH3 radicals resulting from the photolysis of acetone by 193 nm excimer laser", Journal of Photochemistry and Photobiology A: Chemistry, vol. 165, no. 1-3, pp. 187-191, 2004. AbstractWebsite
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Badr, Y., M. A. Elkhodary, and I. Annan, "Evaluation of some properties of dental ceramic as affected by different types of lasers and gamma radiations", Proceedings of SPIE - The International Society for Optical Engineering, vol. 5313, pp. 72-90, 2004. Abstract
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2002
Abdel Sattar, A. M., I. M. Azzouz, M. Salah Shafik, and Y. A. Badr, "Effect of synthecizers on the optical properties of Er3+ions in erbium glass lasers", 3rd Workshop on Photonics and its Application at Egyptian Engineering Faculties and Institutes, pp. 76-106, 2002. Abstract
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1995
Gaffar, M. A., Y. A. Badr, and A. M. Mebed, "Effect of doping on the structural changes associated with the high temperature phase transition of LiNH4SO4 crystals", physica status solidi (a), vol. 148, no. 1, pp. 143-152, 1995. AbstractWebsite
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1989
Badr, Y. A., and S. B. El-Guiziri, "Effect of γ-radiation on the phase transition temperature of Li0.5(NH4)0.5SO4", Journal of Physics and Chemistry of Solids, vol. 50, no. 12, pp. 1261 - 1264, 1989. AbstractWebsite

Polycrystalline lithium-ammonium sulphate samples were subjected to X-ray diffraction analysis for determining the lattice parameters of the prepared mixed crystals. The compositions of the samples were determined using X-ray microanalysis. The Li0.5(NH4)0.5SO4 samples were irradiated with different doses of γ-radiation in order to investigate the effect of this ionizing radiation on the phase transition temperatures Tc1 and Tc2. The temperature dependence of the d.c. resistivity ρd.c. and dielectric constant ϵ of irradiated samples showed (i) a shift of Tc1 to higher temperatures; (ii) a shift of Tc2 to lower temperatures; and (iii) the appearance of a new anomaly near 128°C at moderately high γ-doses. The mechanisms giving rise to this behaviour are discussed.

Badr, Y. A., and S. B. El-Guiziri, "Effect of γ-radiation on the phase transition temperature of Li0.5(NH4)0.5SO4", Journal of Physics and Chemistry of Solids, vol. 50, no. 12, pp. 1261 - 1264, 1989. AbstractWebsite

Polycrystalline lithium-ammonium sulphate samples were subjected to X-ray diffraction analysis for determining the lattice parameters of the prepared mixed crystals. The compositions of the samples were determined using X-ray microanalysis. The Li0.5(NH4)0.5SO4 samples were irradiated with different doses of γ-radiation in order to investigate the effect of this ionizing radiation on the phase transition temperatures Tc1 and Tc2. The temperature dependence of the d.c. resistivity ρd.c. and dielectric constant ϵ of irradiated samples showed (i) a shift of Tc1 to higher temperatures; (ii) a shift of Tc2 to lower temperatures; and (iii) the appearance of a new anomaly near 128°C at moderately high γ-doses. The mechanisms giving rise to this behaviour are discussed.

Badr, Y. A., and S. B. El-Guiziri, "Effect of γ-radiation on the phase transition temperature of Li0.5(NH4)0.5SO4", Journal of Physics and Chemistry of Solids, vol. 50, no. 12, pp. 1261-1264, 1989. AbstractWebsite
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1980
Badr, Y. A., F. El‐Kabbany, G. Said, and O. W. Saleh, "Effect of the internal motion of NH 4+ on the properties of some halides", physica status solidi (a), vol. 60, no. 1, pp. 297-301, 1980. AbstractWebsite
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