Relating the Phase Behaviour of Ionic Liquid – Block copolymer Hybrids to Mechanical Properties and Conductivity

Idriss Blakey,Thomas Bennett,Kevin S. Jack,Kristopher J. Thurecht 한국고분자학회 2016 한국고분자학회 학술대회 연구논문 초록집 Vol.41 No.2

Filtering and Intrusion Detection Approach for Secured Reconfigurable Mobile Systems

Idriss, Rim,Loukil, Adlen,Khalgui, Mohamed,Li, Zhiwu,Al-Ahmari, Abdulrahman The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.5

This paper deals with reconfigurable secured mobile systems where the reconfigurability has the potential of providing a required adaptability to change the system requirements. The reconfiguration scenario is presented as a run-time automatic operation which allows security mechanisms and the addition-removal-update of software tasks. In particular, there is a definite requirement for filtering and intrusion detection mechanisms that will use fewer resources and also that will improve the security on the secured mobile devices. Filtering methods are used to control incoming traffic and messages, whereas, detection methods are used to detect malware events. Nevertheless, when different reconfiguration scenarios are applied at run-time, new security threats will be emerged against those systems which need to support multiple security objectives: Confidentiality, integrity and availability. We propose in this paper a new approach that efficiently detects threats after reconfigurable scenarios and which is based on filtering and intrusion detection methods. The paper's contribution is applied to Android where the evaluation results demonstrate the effectiveness of the proposed middleware in order to detect the malicious events on reconfigurable secured mobile systems and the feasibility of running and executing such a system with the proposed solutions.

Filtering and Intrusion Detection Approach for Secured Reconfigurable Mobile Systems

Rim Idriss,Adlen Loukil,Mohamed Khalgui,Zhiwu Li,Abdulrahman Al-Ahmari 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.5

This paper deals with reconfigurable secured mobile systems where the reconfigurability has the potential of providing a required adaptability to change the system requirements. The reconfiguration scenario is presented as a run-time automatic operation which allows security mechanisms and the addition-removal-update of software tasks. In particular, there is a definite requirement for filtering and intrusion detection mechanisms that will use fewer resources and also that will improve the security on the secured mobile devices. Filtering methods are used to control incoming traffic and messages, whereas, detection methods are used to detect malware events. Nevertheless, when different reconfiguration scenarios are applied at run-time, new security threats will be emerged against those systems which need to support multiple security objectives: Confidentiality, integrity and availability. We propose in this paper a new approach that efficiently detects threats after reconfigurable scenarios and which is based on filtering and intrusion detection methods. The paper’s contribution is applied to Android where the evaluation results demonstrate the effectiveness of the proposed middleware in order to detect the malicious events on reconfigurable secured mobile systems and the feasibility of running and executing such a system with the proposed solutions.

Determining the stress level of monotonic plastically pre-hardened metal sheets using the spherical instrumented indentation technique

Mohamad Idriss,Olivier Bartier,Gérard Mauvoisin,Xavier Hernot 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

In this paper, a methodology, for calculating the stress level of monotonic plastically pre-hardened materials, using the instrumented indentation technique (IIT) coupled to the inverse analysis technique (IAT) is presented. In this methodology, the Voce work-hardening law is always considered as the work hardening law of the studied material. This methodology has shown a very good efficiency in determining the stress levels and the plastic strains undergone by two pre-hardened pseudo-materials. That was encouraging for applying this methodology on real metal sheets. Three metal sheets were studied (DC01 and DP600 steels and aluminum alloy 2017). In the case of the as-received sheets, the identified laws show precise results for plastic strains between 3 % and 6 % which correspond approximately to the representative strain in the case of spherical indentation. Tensile samples were then pre-hardened by imposing a monotonic plastic strain. Three levels of plastic pre-strains were imposed. Concerning low pre-hardening levels, very satisfying results were obtained where this methodology showed a great efficiency in determining the stress level and the plastic pre-strain undergone by the prehardened sheet. For high pre-hardening levels, a small under-estimation of the stress level and the plastic pre-strain was obtained. In this latter case, work is being carried out to improve the results by enriching the experimental data provided for the inverse analysis computations.

Behaviour of unsaturated tuff- calcareous sand mixture on drying-wetting and triaxial paths

Goual, Idriss,Goual, Mohamed Sayeh,Taibi, Said,Abou-Bekr, Nabil Techno-Press 2011 Geomechanics & engineering Vol.3 No.4

The aim of the paper is to study the hydro-mechanical behaviour of a tuff and calcareous sand mixture. A first experimental phase was carried out in order to find the optimal mixture. This showed that the material composed of 80% tuff and 20% calcareous sand provides the maximum mechanical strength. The second experimental phase concerns the study of the drying- wetting behaviour of the optimal mixture. Triaxial shear tests in saturated and unsaturated states at constant water content were carried out on samples initially compacted at the MPO. Experimental results let to deduce the parameters necessary for the prediction of the hydro-mechanical behaviour of pavement formulated from tuff and calcareous sand mixtures, related to moisture. This optimal mixture satisfies the regulation rules and hence constitutes a good local eco-material, abundantly available, for the conception of pavements.

Curvature ductility of confined HSC beams

Bouzid Haytham,Idriss Rouaz,Sahnoune Ahmed,Benferhat Rabia,Tahar Hassaine Daouadji 국제구조공학회 2024 Structural Engineering and Mechanics, An Int'l Jou Vol.89 No.6

Tahar Hassaine Daouadji2,4 The present paper investigates the curvature ductility of confined reinforced concrete (RC) beams with normal (NSC) and high strength concrete (HSC). For the purpose of predicting the curvature ductility factor, an analytical model was developed based on the equilibrium of internal forces of confined concrete and reinforcement. In this context, the curvatures were calculated at first yielding of tension reinforcement and at ultimate when the confined concrete strain reaches the ultimate value. To best simulate the situation of confined RC beams in flexure, a modified version of an ancient confined concrete model was adopted for this study. In order to show the accuracy of the proposed model, an experimental database was collected from the literature. The statistical comparison between experimental and predicted results showed that the proposed model has a good performance. Then, the data generated from the validated theoretical model were used to train the artificial neural network (ANN) prediction model. The R² values for theoretical and experimental results are equal to 0.98 and 0.95, respectively which proves the high performance of the ANN model. Finally, a parametric study was implemented to analyze the effect of different parameters on the curvature ductility factor using theoretical and ANN models. The results are similar to those extracted from experiments, where the concrete strength, the compression reinforcement ratio, the yield strength, and the volumetric ratio of transverse reinforcement have a positive effect. In contrast, the ratio and the yield strength of tension reinforcement have a negative effect.

One-shot synthesis of a nickel oxide/carbon composite electrocatalyst for a sensor capable of electrochemically detecting the antibiotic chloramphenicol in real samples

Zoubir Jallal,Radaa Chaimae,Bakas Idriss,Tamimi Malika,Qourzal Samir,Assabbane Ali 한국탄소학회 2023 Carbon Letters Vol.33 No.3

In this study platform, electrocatalytic detection of the antibiotic chloramphenicol (CAP) in phosphate buffer (pH 7) was easily achieved using a carbon paste electrode modified with NiO nanoparticles (note NiO-CPE). The peak reduction potential of chloramphenicol on the modified electrode is at (− 0.60 V/NiO-CPE vs. Ag/AgCl), its electrochemical behavior is completely irreversible, and controlled by adsorption phenomena. An excellent electrocatalytic activity has been demonstrated by the modified elaborated electrode towards the NO2 attracting group on the side chain of chloramphenicol. The structure and chemical composition of the NiO-CPE sensor were analyzed by SEM, and the X-ray diffraction results indicated that nickel oxide microcrystals were formed on the carbon sheets. The electrochemical characteristics of the NiO-CPE sensor were examined by cyclic voltammetry and electrochemical impedance spectroscopy in comparison with the unmodified carbon. Since the DPV technique allows plotting the linearity curve between the electrocatalytic current intensity of the Chloramphenicol peak and their concentration, the proposed sensor showed a remarkable detection limit of 1.08 × 10–8 mol/L M (S/N = 3) and a wide determination range from 100 to 0.1 µM for Chloramphenicol. The developed sensor was successfully applied in the detection of Chloramphenicol in real samples.

The effectiveness of position of coupled beam with respect to the floor level

Yasser Abdal Shafey, Gamal,Lamiaa K., Idriss Techno-Press 2022 Coupled systems mechanics Vol.11 No.6

In spite of extensive testing of the individual shear wall and the coupling beam (CB), numerical and experimental researches on the seismic behavior of CSW are insufficient. As far as we know, no previous research has investigated the affectations of position of CB regarding to the slab level (SL). So, the investigation aims to enhance an overarching framework to examine the consequence of connection positions between CB and SL. And, three cases have been created. One is composed of the floor slab (FS) at the top of the CB (FSTCB); the second is created with the FS within the panel depth (FSWCB), and the third is employed with the FS at the bottom of the CB (FSLCB). And, FEA is used to demonstrate the consequences of various CB positions with regard to the SL. Furthermore, the main measurements of structure response that have been investigated are deformation, shear, and moment in a coupled beam. Additionally, wall elements are used to simulate CB. In addition, ABAQUS software was used to figure out the strain distribution, shear stress for four stories to further understand the implications of slab position cases on the coupled beam rigidity. Overall, the findings show that the position of the rigid linkage among the CB and the FS can affect the behavior of the structures under seismic loads. For all structural heights (4, 8, 12 stories), the straining actions in FSWCB and FSLCB were less than those in FSTCB. And, the increases in displacement time history response for FSWCB are around 16.1-81.8%, 31.4-34.7%, and 17.5% of FSTCB.

Evolution of Pb-Free and Partially Pb-Substituted Perovskite Absorbers for Efficient Perovskite Solar Cells

Mohd Aizat A. Wadi,Towhid H. Chowdhury,Idriss M. Bedja,Jae-Joon Lee,Nowshad Amin,Md. Aktharuzzaman,Ashraful Islam 대한금속·재료학회 2019 ELECTRONIC MATERIALS LETTERS Vol.15 No.5

Announced as one of the top 10 research breakthroughs in 2016, perovskite solar cells (PSC) have advanced rapidly as anestablished photovoltaic technology. The power conversion efficiency (PCE) of PSCs has increased quickly from 3.8% to23.7% within a period of just 7 years. This very high PCE has been achieved by using perovskite compounds with lead (Pb)as the divalent metal ion. However, for further scale-up and commercialization, the toxicity of Pb has been identified as oneof the key drawbacks for this technology. Numerous avenues for development of lead-free low-toxicity perovskite absorbershave been pursued. The unclear effect of using low-toxicity materials on optimal performance with suitable characteristics hasmotivated the writing of this review. Results from low-toxicity perovskite solar cells utilizing partial or complete substitutionof the Pb2+cation as the absorber layer are discussed in detail. Moreover, we discuss the limitations of low-toxicity absorbermaterials. This review summarizes the key points of film quality control, degradation effect, Pb replacement suitability, andphotovoltaic performance of reported low toxicity alternate perovskite absorbers for PSCs.

Statistical analysis and modelization of tool life and vibration in dry face milling of AISI 52100 STEEL in annealed and hardened conditions

Benghersallah, Mohieddine,Medjber, Ali,Zahaf, Mohamed Zakaria,Tibakh, Idriss,Amirat, Abdelaziz Techno-Press 2020 Advances in materials research Vol.9 No.3

The objective of the present work is to investigate the effect of cutting parameters (Vc, fz and ap) on tool life and the level of vibrations velocity in the machined part during face milling operation of hardened AISI 52100 steel. Dry-face milling has been achieved in the annealed (28 HRc) and quenched (55 HRc) conditions using multi-layer coating micro-grain carbide inserts. Statistical analysis based on the Response surface methodology (RSM) and ANOVA analysis have been conducted through a plan of experiments methodology using a reduced Taguchi table (L9) in order to obtain engineering models for tool life and vibration velocity in the workpiece for both heat treatment conditions. The results show that the cutting speed has a dominant influence on tool life for both soft and hard part. Cutting speed and feed per tooth is the most significant parameters for vibration levels. Comparing the experimental values with those predicted by the developed engineering models of tool life and levels of vibrations velocity, a good correlation has been obtained (between 97% and 99%) in annealed and hard conditions.