Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Tawfik, Walid" wg kryterium: Autor


Wyświetlanie 1-2 z 2
Tytuł:
Controlling the plasma electron number density of copper metal using NIR picosecond laser-induced plasma spectroscopy
Autorzy:
Fikry, Mohamed
Tawfik, Walid
Omar, Magdy
Powiązania:
https://bibliotekanauki.pl/articles/2033963.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
picosecond
LIPS
laser induced plasma spectroscopy
copper
electron density
Stark broadening
Opis:
In this paper, we investigate a new method to control the plasma electron number density of copper metal using a near-infrared (NIR) picosecond Nd:YAG laser-induced plasma spectroscopy (LIPS) technique. The applied laser parameters are as follows; laser pulse energy and intensity varied from 29.2 to 59.4 mJ ± 3% and from 6.01×1010 to 12.35×1010 W/cm2 ± 5%, respectively, for a single pulse at 170 ps pulse duration, and beam diameter about 0.5 ± 0.1 mm. By considering the Stark broadening of a specific spectral line, electron density can be calculated using a neutral copper line at 521.8 nm, assuming the local thermodynamic equilibrium (LTE) condition. The observed electron density values were 1.09×1016, 2.24×1016, 3.60×1016, and 4.75×1016 cm–3 for the laser pulse energies 29.2, 41, 52.4, and 59.4 mJ, respectively. The plasma electron density values are increased with the increase in laser pulse energy. Such findings were interpreted due to an increase in the mass ablation rates with laser pulse energy. The obtained results explore the ability to control the plasma electron density by controlling the picosecond pulse energy. These results can contribute to the development of plasma technologies and their applications in many fields.
Źródło:
Optica Applicata; 2021, 51, 3; 365-374
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and performance evaluation of vehicular visible light communication system under different weather conditions and system parameters
Autorzy:
El-Mokadem, Eslam S.
Tawfik, Nagwan I.
Aly, Moustafa H.
El-Deeb, Walid S.
Powiązania:
https://bibliotekanauki.pl/articles/2204173.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
visible light communication
beam divergence
bit error rate
vehicular communication
laser diode
Opis:
Vehicular visible light communication is an emerging technology that allows wireless communication between vehicles or between vehicles and infrastructure. In this paper, a vehicular visible light communication system is designed using a non-return to zero on-off keying modulation scheme under the effect of different weather conditions such as clear, haze, and fog. The first model is a light emitting diode-based system and the second is a laser diode-based system. For both models, the influence of system parameters such as beam divergence, transceiver aperture diameters, and receiver responsivity is studied. The impact of the use of the trans-impedance amplifier is also investigated for both models. It was concluded that in the presence of the amplifier, output power of the light emitting diode and laser diode model are increased by 98.46 μW and 0.4719 W, respectively. The performance of the two proposed models is evaluated through bit error rate, quality factor, eye diagram, and output power to have some insightful results about the quality of service for the two proposed models. Under a specific weather condition, the performance of the system would be critical and other techniques should be applied. The maximum achievable link distance for the laser-based and light-emitting diode-based systems is 190 m at a data rate of 25 Gbps and 80 m at a data rate of 60 kbps, respectively, under the same system parameters and weather conditions. The obtained results provide a full idea about the availability of constructing our proposed model in a practical environment, showing a higher performance of the laser diode-based model than that of the light emitting diode-based model.
Źródło:
Opto-Electronics Review; 2023, 31, 2; art. no. e145580
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies