Sabeur Msolli

Bio: Sabeur Msolli is an academic researcher from Dongguk University. The author has contributed to research in topics: Diamond & Electronic packaging. The author has an hindex of 7, co-authored 28 publications receiving 162 citations. Previous affiliations of Sabeur Msolli include University of Toulouse & Arts et Métiers ParisTech.

A nanocrystalline structured NiO/MnO2@nitrogen-doped graphene oxide hybrid nanocomposite for high performance supercapacitors

Abstract: Nitrogen doped graphene oxide (NGO) has been widely used to investigate active electrode materials for high-performance supercapacitors. NGO has attracted wide attention due to the efficient method of doping with GO, which can increase the electron mobility, leading to desirable electrochemical properties. Therefore, in the present study we focus on the ternary hybrid composite of NiO/MnO2@nitrogen-doped graphene oxide, which was synthesized via a hydrothermal process. The synthesized hybrid nanocomposite was characterized using Raman spectra, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), and field-emission transmission electron microscopy (FE-TEM). The structural and morphological studies of the hybrid nanocomposite shows its nanocrystalline behaviour. The nanocrystalline hybrid composite exhibited a high specific capacitance of 1490 F g−1 at a current density of 0.5 A g−1, energy density of 477 W h kg−1, and power density of 1844 W kg−1, together with good rate capability and cyclic stability. The results show a good specific capacitance retention of ∼98% after 2000 continuous charge–discharge cycles; this indicates that the hybrid nanocomposite can be a promising electroactive material for supercapacitors. The improved performance of the NiO@MnO2/NGO electrode structure means that it offers an effective way to fabricate high performance supercapacitors.

Prediction of the dynamic equivalent stiffness for a rubber bushing using the finite element method and empirical modeling

Abstract: A hybrid method using an approximation that is based on the finite element analysis and empirical modeling is proposed to analyze the dynamic characteristics of a rubber bushing. The hyperelastic–viscoplastic model and an overlay method are used to obtain the hysteresis of the rubber bushing in the finite element analysis. A spring, fractional derivatives, and frictional components are used in the empirical model to obtain the dynamic stiffness in wide ranges of the excitation frequencies and amplitudes. The parameters of the proposed empirical model are determined using the hysteresis curves that were obtained from the finite element analysis. The dynamic stiffness of the rubber bushing in the wide ranges of the frequencies and amplitudes was predicted using the proposed hybrid method and was validated using lower arm bushing experiments. The proposed hybrid method can predict the dynamic stiffness of a rubber bushing without the performance of iterative experiments and the incurrence of a high computational cost, making it applicable to analyses of full-size vehicles with numerous rubber bushings under various vibrational loading conditions.

Synthesis of a Co3O4@gold/MWCNT/polypyrrole hybrid composite for DMMP detection in chemical sensors

Abstract: Chemical sensors based on a nanocrystalline Co3O4/gold@MWCNT/polypyrrole decorated hybrid composite were fabricated, and their sensitivity properties to stimulant dimethylmethylphosphonate (DMMP) were characterized. The hybrid composite was decorated by a hydrothermal process in the presence of cobalt/gold precursors, and the characteristics were determined by Raman, XRD, XPS, SEM-EDX, and FE-TEM analysis. The cyclability and linearity of the detection response for chemical sensors in the presence of DMMP vapor were determined by using a crystal microbalance. The hybrid composite material should possess excellent selectivity, stability, and reasonable sensitivity in the presence of N2 gas at room temperature for DMMP detection. The response of the composite showed retainability when exposed to the DMMP component, due to the high resistance response, fast response time, rapid recovery, and good reproducibility.

An extended model for void growth and coalescence - application to anisotropic ductile fracture

Abstract: A model for the axisymmetric growth and coalescence of small internal voids in elastoplastic solids is proposed and assessed using void cell computations. Two contributions existing in the literature have been integrated into the enhanced model. The first is the model of Gologanu-Leblond-Devaux, extending the Gurson model to void shape effects. The second is the approach of Thomason for the onset of void coalescence. Each of these has been extended heuristically to account for strain hardening. In addition, a micromechanically-based simple constitutive model for the void coalescence stage is proposed to supplement the criterion for the onset of coalescence. The fully enhanced Gurson model depends on the flow properties of the material and the dimensional ratios of the void-cell representative volume element. Phenomenological parameters such as critical porosities are not employed in the enhanced model. It incorporates the effect of void shape, relative void spacing, strain hardening, and porosity. The effect of the relative void spacing on void coalescence, which has not yet been carefully addressed in the literature. has received special attention. Using cell model computations, accurate predictions through final fracture have been obtained for a wide range of porosity, void spacing, initial void shape, strain hardening, and stress triaxiality. These predictions have been used to assess the enhanced model. (C) 2000 Elsevier Science Ltd. All rights reserved.

Recent Advances in Metal Chalcogenides (MX; X = S, Se) Nanostructures for Electrochemical Supercapacitor Applications: A Brief Review.

Abstract: Supercapacitors (SCs) have received a great deal of attention and play an important role for future self-powered devices, mainly owing to their higher power density. Among all types of electrical energy storage devices, electrochemical supercapacitors are considered to be the most promising because of their superior performance characteristics, including short charging time, high power density, safety, easy fabrication procedures, and long operational life. An SC consists of two foremost components, namely electrode materials, and electrolyte. The selection of appropriate electrode materials with rational nanostructured designs has resulted in improved electrochemical properties for high performance and has reduced the cost of SCs. In this review, we mainly spotlight the non-metallic oxide, especially metal chalcogenides (MX; X = S, Se) based nanostructured electrode materials for electrochemical SCs. Different non-metallic oxide materials are highlighted in various categories, such as transition metal sulfides and selenides materials. Finally, the designing strategy and future improvements on metal chalcogenide materials for the application of electrochemical SCs are also discussed.