Abdellatif Bouchalkha

• PhD
• Researcher at Technology Innovation Institute

We combine density functional theory simulations and sensing experiments to evaluate the gas detection performance of two transition metals dichalcogenides MoS2 and WS2. Specifically, we examine their sensitivity, detectivity, response and recovery times towards carbon dioxide (CO2), and carbon monoxide (CO). Our DFT simulations reveal remarkable s...

Advanced super-resolution imaging techniques require specific approaches for accurate and consistent estimation of the achievable spatial resolution. Fisher information supplied to Cramer-Rao bound (CRB) has proved to be a powerful and efficient tool for resolution analysis and optical setups optimization. However, the standard CRB is not applicabl...

Visible-light-driven photocatalysis using layered materials has garnered increasing attention regarding the degradation of organic dyes. Herein, transition-metal dichalcogenides MoS 2 and WS 2 prepared by chemical vapor deposition as well as their intermixing are evaluated for photodegradation (PD) of methylene blue under solar simulator irradiatio...

Layered transition metals dichalcogenides such as MoS2 and WS2 have shown a tunable bandgap, making them highly desirable for optoelectronic applications. Here, we report on one-step chemical vapor deposited MoS2, WS2 and MoxW1-xS2 heterostructures incorporated into photo-conductive devices to be examined and compared in view of their use as potent...

Molybdenum disulfide one of the graphene analogs and a typical representative of transition metal dichalcogenides, has recently received great attention due to its outstanding electrical and optical properties, such as the bandgap tuning, high carrier mobility and efficient optical absorption. Nanostructured Molybdenum disulfide for instance with s...

Amorphous alloy samples based on Zr with additional metals were irradiated using He ions at operating energy of 40 KeV under room temperature conditions with fluence from 510 17 to 710 17 cm-2. The phase analysis of the samples is conducted using an X-ray diffractometer (Rigaku). XRD analysis revealed formation of amorphous, crystalline and amorp...

Laser propagation through a medium is often accurately explained by geometrical optics where light is described as rays. When considering wave diffraction, a more generalized description of physical optics is used. Faced with the complexity of interactions of a laser beam with the atmosphere, and the additional challenges of deploying a physical...

The onset of scaling in oil pipelines can halt or drastically reduce oil production, causing huge financial losses and delays. Current methods used to monitor scaling can take weeks, while the scaling process only takes few hours. The proposed sensor is designed for online monitoring of strontium ions concentration in seawater as an early scaling i...

Thirteen international scientists in the field of Lasers, Photonics and Optoelectronics will present during the seminar.

The analysis, calculations and graphical charts presented here in this paper are based directly on a recently published paper by the first two of the above-named authors. In the present paper, it is clearly demonstrated that all of the following nine (or eleven including the centripetal acceleration and total mechanical energy) principal physical p...

One of the most important roles of the wireless sensor networks (WSN) is to avoid wiring costs, be self-sustainable and be able to function for several years. However, due to the slow progress in battery technology, power continues to be a limited resource in wireless sensor communication and electric energy storage remains to be an important issue...

A Wireless Sensor Networks (WSNs) should be autonomous, self-sustainable and able to function for several years. However, due to the slow advancement in battery technology, battery power continues to be a limited resource in wireless sensor communication and thus electric energy storage remains to be an important issue. The aim of this work is to c...

This paper presents the electromagnetic wave propagation in deep underground oil pipelines. The aim of this work is to analyze the attenuation of the electromagnetic waves in the pipelines caused by the oil medium under high temperature conditions. The work involves the modeling of a downhole oil pipeline. The simulations are focused on computing t...

Scale Deposition in pipelines is becoming a major concern to oil companies. The accumulations of mineral salts, if not detected and treated, can cause failure of the sensors and reduction of oil production which eventually affect well integrity. In this paper, we present three different methods for the detection of scale deposition using light sens...

Magnetic Flux Leakage (MFL) techniques are the commonly used methods in the inspection of oil pipelines. This technique presents several limitations in detecting cracks. In this paper we present a novel method using ultrasound waves to obtain 3-d images of pipeline inner surfaces. Using this technique, cracks on the inner surface of a steel pipelin...

The authors measure the hot phonon population of the GaAs LO phonons using a picosecond Raman scattering technique. Their samples were a series of GaAs/Al0.4Ga0.6As superlattices (SLS) with a fixed well width (Lz) and varying barrier width (Lb). An abrupt increase in the phonon generation rate was observed as Lb decreased over a narrow range. This...

Using picosecond Raman scattering, hot-phonon occupation numbers (N) of GaAs and GaAs-like LO phonons have been studied over a wide range of structural parameters in more than 30 GaAs/AlxGa1-xAs superlattices. In addition, simultaneous measurements of these LO phonon modes in bulk GaAs and AlxGa1-xAs alloys are made for comparison. N values of both...

Using picosecond Raman scattering, hot phonon occupation numbers (N's) of GaAs, GaAs-like, and AlAs-like LO phonons have been studied over a wide range of structural parameters in more than 20 GaAs/AlxGa1−xAs superlattices. In addition, simultaneous measurements of these LO phonon modes in bulk GaAs and AlxGa1−xAs alloys are made for comparison. N'...

A new sample holder for the Janis Supervaritemp Dewar has been designed which allows very accurate temperature readings at the sample and avoids sample breakage by reducing thermally induced stress. In addition, the successful operation of this helium dewar using liquid nitrogen has been achieved allowing temperatures above 80 K, stable to within ±...

Scope and method of study. The optical properties of GaAs/Al_{x}Ga _{1-x}As quantum wells (QW's) and ZnSe epilayer were investigated in the picosecond and subpicosecond time scales. The phonon confinement and propagation were investigated systematically using time-resolved Raman scattering techniques on several series of GaAs/Al_ {x}Ga_{1-x}As samp...

Picosecond pulses are used to measure the hot phonon generation rate ((partial)Nq/(partial)t) of Raman active GaAs LO phonons in several GaAs/AlxGa1-xAs superlattices (SL's) and quantum wells (QW's). Drastic increase in (partial)Nq/(partial)t is observed as the barrier width (Lb) decreased below a critical value for SL's with x >= 0.4. This is inte...

Picosecond pulses are used to measure the hot phonon generation rate ((partial)Nq/(partial)t) of Raman active GaAs LO phonons in several GaAs/AlxGa1-xAs superlattices (SL's) and quantum wells (QW's). Drastic increase in (partial)Nq/(partial)t is observed as the barrier width (Lb) decreased below a critical value for SL's with x >= 0.4. This is inte...

A Comment on the Letter by D. S. Kim et al. Phys. Rev. Lett. 68, 1002 (1992).

We report the first observation of a confined-to-propagating transition of LO phonons in GaAs/Al{sub {ital x}}Ga{sub 1-{ital x}}As superlattices (SL's). Picosecond Raman scattering was used to investigate the generation rate of nonequilibrium GaAs LO phonons in two series of GaAs/Al{sub {ital x}}Ga{sub 1-{ital x}}As SL's with constant GaAs layer wi...

Temperature studies of the LA[110] Brillouin shift have been conducted on the mixed ferroelectric-antiferroelectric system, Rb1-x(NH4)xH2PO4 for two ammonium concentrations (x=0.28 and 0.42). The shift undergoes a softening around 100 K, followed by a hardening of the mode below 50 K. This is due to both a linear (piezoelectric) and a quadratic cou...

The optical properties of GaAs/Al[sub x]Ga[sub 1[minus]x]As quantum wells (QW's) and ZnSe epilayer were investigated in the picosecond and subpicosecond time scales. The phonon confinement and propagation were investigated systematically using time-resolved Raman scattering techniques on several series of GaAs/Al[sub x]Ga[sub 1[minus]x]As samples....