Prof. Dr. Walid Tawfik
Laser App. in metrology,photochemistry&agriculture, National institute of laser enhanced sciences, Cairo University, Cairo, Al Qāhirah, Egypt
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Academic Career Length
52Years (1975-Present)
(Calculated once Scilit publication data is synced: current year − year of first publication + 1)
Representative Publications
View All Publications5 March 2004 in Journal of Analytical Atomic Spectrometry
Journal Article
MIMarwa A. Ismail
Marwa A. Ismail
HIHisham Imam
Hisham Imam
AEAsmaa Elhassan
Asmaa ElhassanWalid TawfikMHMohamed Abdel Harith
Mohamed Abdel HarithIn the present work a detailed study has been performed on the effect of the matrix on the limit of detection (LOD) and the plasma parameters of the laser induced breakdown spectroscopy (LIBS) technique. The LOD of magnesium, silicon, manganese and copper as minor elements was evaluated in aluminium standard sample alloys compared to the values of the LOD of the same elements in standard steel alloys. The effect of changing the matrix on the laser induced plasma plume parameters, namely the plasma temperature Te and the electron density Ne, has been also studied. Calibrations were achieved for the four elements with linear regression coefficients between 98–99% on average. According to the obtained results Mn and Cu have the lowest LOD in the steel alloy matrix, while Mg has much lower LOD in the aluminium alloy matrix. These results may be interpreted in view of the compatibility of the physical properties of the elements existing in the same matrix. Approximately similar electronic structure and values of melting point, density, atomic weight, etc., may facilitate better conditions for energy transfer within the matrix. From the application view point, it is possible for LIBS in the on-line industrial process control to follow up only a single element (that with the lowest LOD in such matrix) as a marker for the correct alloying in metals and mixing in pharmaceuticals.
1 November 2020 in Computational and Theoretical Chemistry
Journal Article
AMAbdelrhman A. Menazea
Abdelrhman A. Menazea
HEHend A. Ezzat
Hend A. Ezzat
WOWessam Omara
Wessam Omara
OBOsama H. Basyouni
Osama H. Basyouni
SISamah A. Ibrahim
Samah A. Ibrahim
MIMedhat A. Ibrahim
Medhat A. Ibrahim
+2
2 May 2020 in Optical and Quantum Electronics
Journal Article
20 October 2003 in Applied Optics
Journal Article
MSMohamad Sabsabi
Mohamad SabsabiVDVincent Detalle
Vincent Detalle
MHMohamed Abdel Harith
Mohamed Abdel HarithWalid TawfikHIHisham Imam
Hisham Imam
The purpose of this paper is to provide the reader with comparative information about two new commercial echelle spectrometers equipped with intensified CCD (ICCD) detectors for laser-induced breakdown spectroscopy analysis. We carried out a performance comparison between two commercial ICCD/echelle spectrometers [ESA 3000 (LLA Instruments GmbH, Berlin-Adlershof, Germany) and a Mechelle 7500 (Multichannel Instruments, Stockholm, Sweden)] for the determination of the concentrations of Be, Mg, Si, Mn, Fe, and Cu in the same Al alloy samples adopting the same experimental conditions. The results show that both systems, despite their differences in terms of resolution, have similar performance in terms of sensitivity and precision of measurements for these elements in an Al alloy matrix at least for the range of wavelength 280–400 nm studied in this work.
8 March 2021 in Environmental Science and Pollution Research
Journal Article
MSMohamed E Shaheen
Mohamed E ShaheenWalid TawfikAMAsmaa F. Mankoula
Asmaa F. Mankoula
JGJoel E. Gagnon
Joel E. Gagnon
BFBrian J. Fryer
Brian J. Fryer
FEFarouk El-Mekawy
Farouk El-Mekawy
About Me
Professor Walid Tawfik is the Chairman of the Department of Laser Applications in Metrology, Photochemistry and Agriculture (LAMPA), and head of the central lab at the National Institute of Laser (NILES), at Cairo University, Egypt. He received his PhD on 2000 in laser spectroscopy, “Study of photon molecular interaction dynamics using short laser pulses”, where he did his experiments at Technical Uni. Munich, Germany. He is interested in the applications of laser-induced plasma spectroscopy and ultrafast lasers in environmental pollution detection and laser cancer treatment; currently, he has two international projects in these fields. In Oct 2021, 2022,2023 he was officially chosen two times among the distinguished scientists in the world's top 2% - in the field of photonics, according to the survey given by Stanford University USA. In May 2022, he was chosen and awarded the World Scientist Medal “Scholar Badge,” representing the Arab Republic of Egypt through 103 countries by ARID (Arab research id) Organization. He has published two books’ chapters and several Scopus papers. He is a senior member at international professional societies like IEEE, OSA, APS, and SPIE. He has collaborated with different international groups in the applications of laser spectroscopy and ultrafast lasers at Georgia Tech USA, Uni. of Electro-Communications Japan, POSTECH Uni. South Korea, Quaid-i-Azam Uni. Pakistan, KSU Saudi Arabia, Max-Planck Inst. Germany and Lodz Uni. of Tech. Poland.
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