# Abou Bakr Belkaid University of Tlemcen

• Tlemcen, Algeria
Recent publications
2-((E)-((4-(((E)-4-Nitrobenzylidene)amino)phenyl)imino)methyl)naphthalen-1-ol, was synthesised followed by metalation with Fe(III), Co(III), Cu(II), Zn(II) and Ni(II) metals. The compounds were characterised by different methods CHN, AAS, IR, NMR, XRD, TGA and UV–Vis. The results reveal that the ligand has bidentate behavior, and it is bound with metals by a coordination bond through both the nitrogen atom of the azomethine group and the oxygen atom, this provided an octahedral geometry. The X-ray diffraction of the compounds indicate that the ligands and complexes of Co(III), Fe(III) and Zn(II) have a crystalline nature, whereas the Ni(II) and Cu(II) have an amorphous structure. The agar diffusion method (hole plate) was used to evaluate the ligand’s and its complexes’ antibacterial and antifungal effects on Salmonella enterica serovar typhi and Candida albicans, respectively. It was observed that the Fe(III) complex had the best activity among the compounds against microbial strains. Cytotoxicity of new metal complexes was also assessed against A549, HepG-2 and PC-3 cancer cells. Results demonstrated that the Cu(II) complex displayed the preeminent activity among the synthesised compounds against all the tested cell lines. Furthermore, molecular docking simulation revealed that the Fe(III) complex is shown to have a high affinity with the active sites of two targets of microbial strains. Also, the Cu(II) complex shown to has a high affinity with the active sites of three targets of A-549, HepG-2 and PC-3 cancer cells, which was confirmed by the formation of the different modes of interaction. Communicated by Ramaswamy H. Sarma
New highly fluorescent 2-imino-2H-pyrano[3,2-c]pyridin-5(6H)-onesderivatives were synthesized using a simple route. The present molecules were prepared by two methods with good yield. The structures were characterized by NMR1H, 13 C, and elemental analysis. Also, the effect of solvent and concentration on the fluorescence properties were demonstrated. However, the high fluorescence intensity in the range of 70,000–75,000 a. u. was obtained with a concentration equal to 10− 6 M of prepared molecules. The intensity was influenced also by the molecule structure and solvent.
Mesoporous CeO2-supported iron nanoparticles were prepared by the hard template method with different iron loading. The catalysts were characterized by XRD, BET, UV–Vis, ICP, SEM–EDX, MET and TPR. The catalysts showed high activity and stability in the photo-Fenton oxidation of aqueous phenol solution using near-ultraviolet irradiation (254 nm) at room temperature and neutral pH. The catalytic performance has been monitored in terms of aromatics and total organic carbon (TOC), and phenol conversion. Also, a comparative study between the CeO2 activity and catalysts was monitored which demonstrates that iron has a synergistic effect in the phenol photo-Fenton oxidation. Moreover, the formation of OH· and O2· radicals accelerates the process by reducing Fe³⁺ to Fe²⁺ and Ce⁴⁺ to Ce³⁺ which leads to a total phenol oxidation at short time process. The total phenol conversion was obtained at 15 min with Fe/CeO2(60) and 20 min with Fe/CeO2(20).
The present paper is dealt with a predator–prey model in which the growth of the prey population is influenced by the Allee effect while the predator species are contended with the prey population following the Crowley–Martin type response function. The proposed model is comprehensively analyzed in terms of stability and manifestation of bifurcation of the system. The system unveils the bi-stability together with the existence of a separatrix. In view of the eminence of spatial ecology, the dynamical complexity emanating from the induction of the Allee effect in prey species of a Crowley–Martin reaction–diffusion predator–prey model is also investigated profoundly. The results of numerical simulations reveal that the present system dynamics is motivated by both the Allee effect and diffusion-controlled pattern formation growth to hot spots, stripe-hot spot mixtures, stripes, labyrinthine, stripe-cold spot mixtures, and cold spots replication. The theoretical consequences of the spatiotemporal model under study are validated through numerical simulations.
The pace and magnitude of land use and land cover (LULC) change are of global concern due to its role in pressing issues such as climate change, food security, soil degradation and biodiversity loss. The present study analyzed the spatiotemporal changes in LULC in the Hafir-Zariffet forest of Tlemcen, Northwest Algeria. We also simulated possible future LULC scenarios for the area. LULC maps of 1989, 1999, 2009 and 2019 were classified using the Random Forest Algorithm in R software and change assessed via intensity analysis. The results revealed that the first decade (1989–1999) showed a faster intensity of change compared to the second (1999–2009) and the third decades (2009–2019). Sparse wooded maquis experienced a major decline (1989–2019) of 15.19% whereas open matorral (+ 14.30), forest (+ 0.15%), and agriculture (+ 1.33%) increased. The simulation at a skill measure of > 0.50 showed that the open matorral could witness the highest loss of 29.13% while forest cover, sparse wooded maquis, settlement and barelands, and agriculture could increase by 9.51%, 13.26%, 0.56% and 5.79%, respectively between 2019 and 2039 based on the change pattern between 2009 and 2019 in the study area. The substantial decline of open matorral and the expansion of agriculture, settlement and barelands could pose a threat to the ecology of the environment as the changes will impact the ecosystem functions of the landscape. The findings of this study provide useful information on understanding spatiotemporal LULC change in the semi-arid Mediterranean region and can assist sustainable land development policies.
Friction pendulum base isolation system (FPS) is currently a widely used practice for the protection of structural and non-structural components of buildings against the destructive effects of earthquakes, due to its significant features such as the steadiness of its physical properties and its durability compared to other base isolation devices such as elastomeric bearings. This paper is focused on an examination of the dynamic response of metallic building fitted with a friction pendulum base isolation damper. The analyses were elaborated with a three-dimensional (3D) numerical modelling. Fast nonlinear time history analysis (FNA) with ten seismic signals is applied in this work employing a structural analysis programme. The results obtained from the investigations of different cases studied with and without the isolated bearing base were summarized in tables and graphics and discussed. In addition, the hysteretic behaviour of the FPS device was examined and discussed under a major seismic event. Furthermore, to explore the performance and subsequently the level of damages that can occur in the steel frame elements in the case of its three alternatives (braced, unbraced and isolated), nonlinear static analyses (pushover procedure) were carried out and the results analysed. The paper showed the significant ability of the FPS damper to dissipate the response of the steel frame under extreme conditions considering various types of earthquake recordings and different levels of dynamic loadings, without resorting to the need to reinforce with additional steel members.
Background: Potatoes are extremely important compared to other vegetable crops. Several species of fungi cause severe damage to different components of the plant (leaves, stems, and tubers), leading to significant losses during cultivation and even after harvest. In the framework of the investigation for alternative methods against the proliferation of these fungi, the present work focuses on the study of the antifungal effect of essential oils of some plants that could be used to solve these problems without the use of harmful chemical substances. Aim and purpose: This study aims to discuss the chemical composition of essential oils of Artemisia herba alba and Ammoides verticillata and evaluate their in vitro and in vivo antifungal activities in order to prevent fungal diseases of potatoes and replace chemical pesticides that cause neurodegenerative diseases. Materials and methods: Essential oils extracted from the aerial parts of the plants Artemesia herba alba and Ammoides verticillata were analyzed by gas chromatography-mass spectrometry (GC/MS) and tested individually and in combination for their antifungal effects against Fusarium solani, Penicillium expansum, and Aspergillus flavus, by the radial growth technique. Results: The essential oil of A. herba alba was mainly composed of hydrocarbon monoterpenes (80.8%), while the oil of A. verticillata was mainly composed of oxygenated monoterpenes (54.4%). The study on the antifungal effect of essential oils in vitro showed that essential oil of A. Verticillata was more effective against P. expansum (64.40%) than A. flovus (41.10%) and F. solani (53.30%), and the oil of A.herba alba was more effective against A. flavus (54.40%) and (42%) F. Solani. While the combination of these two essential oils of A. verticillata and A. herba-alba gave excellent results, i.e., 100% against P. expansum and A. flavus and 94.40% against F. solani and provided an in vivo protection to the potato in the range of 80% to 90% against the three fungi. Conclusion: A. herba alba and A. verticillata individual and combined essential oils are very effective antifungal biocides that can be used as an alternative to chemical pesticides to prevent their harmful effects on health.
Plasmonic structures have attracted a lot of attention due to their potential application in all optical integrated circuits. In this matter, four and eight output-channel DEMUXs have been designed using nanodisk resonators coupled with a T-shaped and a MIM waveguide. Implementing several nanodisk resonators with different radii gives a red shifted responses. By setting the output ports on the two sides of the global cavity, we made better use of space. The air and silver are used as insulator and metal layers, and the Drude model characterizes the permittivity of silver. The COMSOL Multiphysics software that worked with the FEM method has been used for the numerical simulation of the proposed structures. The basic filter uses a high-pass filter, resulting in a single mode filter that overcomes the double-mode nanodisk resonator problem. Results shows that our proposed four and eight DEMUXs have a high average transmission peaks of 65.67%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$65.67\%$$\end{document} and 57.44%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$57.44\%$$\end{document} with 15.375 nm and 15.625 nm average FWHM, and a low cross talk of -\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$-$$\end{document} 24.85 dB and -\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$-$$\end{document} 31.24 dB in average, respectively. The proposed structures have a high potential for use in optical communication circuits due to the large number of outputs with high transmission and low cross talk.
We study the global dynamics of a susceptible‐vaccinated‐infected‐recovered model that incorporates nonlocal diffusion. By identifying the basic reproduction number ℛ0$${\mathrm{\mathcal{R}}}_0$$ of the model, we obtain the following threshold‐type results: (i) If ℛ0<1$${\mathrm{\mathcal{R}}}_0<1$$, then the epidemic becomes extinct in the sense that the infection‐free equilibrium is globally attractive; (ii) if ℛ0>1$${\mathrm{\mathcal{R}}}_0>1$$ and the diffusion coefficients are the same for all classes, then the epidemic persists in the sense that the system is uniformly persistent; and (iii) if ℛ0>1$${\mathrm{\mathcal{R}}}_0>1$$, the diffusion coefficients for susceptible, and the vaccinated classes are zero, then the system admits a unique endemic equilibrium, and the omega‐limit set is included in the singleton of the endemic equilibrium. Our results show that ℛ0$${\mathrm{\mathcal{R}}}_0$$ is an essential value for determining global epidemic dynamics in our model.
The present work uses a number of empirical models from geotechnical earthquake engineering (CPT-based liquefaction models) in combination with some geostatistics tools to assess the soil liquefaction potential over an extended area at the Airport of Algiers (Algeria), by the kriging approach. The SIG software program along with variograms and the kriging method were all applied together for the purpose of modeling the variation of the liquefaction potential (PL) against liquefaction in the region under study. This approach allowed determining the missing data in that region. This geostatistical method helped to draw maps at different soil depths. The results obtained revealed that the models developed were potentially capable of accurately estimating the needed data. This study made it possible to determine a number of parametric quantities that support the empirical correlation between the liquefaction potential index and liquefaction. The results show that the higher the standard deviation, the greater the uncertainty.
The thermohydraulic performance of an enhanced PTC’s tube is evaluated in this paper. A passive method is used by introducing transversal inserts on the bottom part of the receiver. The height of the inserts is investigated using MCRT method coupling FVM for Reynolds number range from 2.36∙10^4 to 11. 3∙10^4.The heat transfer fluid used in this study is the Therminol VP1. The numerical results show that the tube enhanced by inserts augments the reliability of the system, and the introduction of the inserts into the receiver tube decreases the temperature difference over the circumferential area of the absorber tube and minimizes the heat losses, and also increase the lifetime of the receiver.
This paper presents the room temperature performance of Si MOSFET nanowires subjected to NBTI (Negative Bias temperature Instability) and HCI (Hot Carrier Injection) stress. The static and dynamic characterizations were carried out with an enormous amount of stress adequate for a trapping / detrapping corresponding to NBTI and HCI. A simulated aging test bench has been designed to evaluate the lifetime of trapping / detrapping loads under resistive stress with an ambient temperature of 300K.
Road congestion and traffic jams are serious problems for drivers, causing them more delay in reaching their destinations. Motivated by these considerations, this article proposes an intelligent scheduling algorithm based on vehicular ad hoc networks (VANETs) and Cloud computing to schedule traffic lights to smooth road traffic and reduce waiting time on the road, called CCITL (cloud computing based intelligent traffic light protocol). In CCITL, we involve cloud computing by using conventional and vehicular clouds to have a global view of the road network and take advantage of the cloud computing capabilities to calculate the most appropriate traffic signal formulas and combinations with their phase durations in a dynamic way. This allows to ensure the fluidity of the traffic and the arrival at the destination in a short time while minimizing the waiting time on the different segments of the road network. Our proposed protocol has been developed and evaluated over OMNET++ simulator with the simulator of urban mobility (SUMO). The simulation results showed that CCITL greatly contributed to the alleviation of traffic congestion as well as to the reduction of the dwell time of vehicles in the different segments, thus reducing delays and waiting in intersections.
This article aims to investigate the buckling and free vibration behaviors of nanocomposite beams reinforced with functionally graded (FG) agglomerated carbon nanotubes (CNTs) in polymeric beams matrix. In order to estimate the material properties of the FG CNTs reinforced beam, the Eshelby-Mori-Tanaka rule on the basis of equivalent fiber is employed. Moreover, the Lagrange's principle is used to achieve the governing equations under supposition of the refined higher order beam theory without need of any shear correction factor. The differential quadrature finite element method (DQFEM) as a robust and precise numerical procedure is utilized to achieve the natural frequencies and buckling loads with various boundary supports. Then, the assessment of the effects of different factors such as of CNTs agglomeration parameters, different patterns of CNTs distribution, length to thickness quotients, and mixed boundary conditions on the vibrational and buckling responses of agglomerated CNTs reinforced beam are explored. It is concluded that the current numerical solution based DQFEM is efficient and accurate for predicting the mechanical behavior of the nanocomposite structures. Moreover, the stability and vibration responses of the NC beams can be significantly affected by tailoring the agglomeration parameters.
Due to its higher porosity, the interfacial transition zone (ITZ), that is, the zone between the hardened cement paste (HCP) and the aggregate, is the weakest point in concrete. It is less resistant to cracking than both HCP and aggregate, and microcracks begin in this zone when the load is applied and propagates into the mass of concrete. The goal of this research is to investigate how various dosages of cassava flour (CF) addition affect the ITZ and how this is related to the mechanical properties of concrete, including its resistance to sulfuric acid. CF is added as a percentage of Portland pozzolanic cement (PPC) used as a binder, with dosages of 1, 2, 3, 4, and 5%. The morphology of CF and PPC was studied using x-ray diffraction (XRD) and x-ray fluorescent (XRF) techniques. Changes in the thickness of the ITZ were observed using a scanning electron microscope (SEM). The effect of sulfuric acid was observed by immersing samples of concrete in a 2% sulfuric acid solution. The results show that adding CF up to 3% progressively reduced the thickness of ITZ and improved the densification of concrete. As more CF was added, the ITZ began to widen again, but even at 5% CF addition, the thickness of the ITZ remained well below that of the control. The workability of fresh concrete decreased with an increase in CF dosage, but CF addition increased the compressive, tensile, and flexural strengths of hardened concrete. The greatest compression resistance was achieved at a 3% cassava flour addition level, which was 83.8 MPa after 180 days of curing and 8.9 MPa, 4.7 MPa for flexural and splitting strengths, respectively, after 90 days of curing. All the concrete samples containing CF had lower strengths than the control after immersion in sulfuric acid, with the concrete with 3% CF performing better than the others. The research concludes that CF used as an additive to concrete in dosages up to 5% improves the ITZ zone, leading to improved mechanical properties. However, resistance to sulfuric acid attacks is reduced. In all tests, it has been shown that a CF dosage of 3% gives the best results.
Background and objective Small cerebral aneurysms are currently commonly treated non-invasively by flow diverter device. These stents lead to thrombotic occlusion of the aneurysm soon after their placement. The purpose of this work is to model clotting into intracranial aneurysms with and without stents, using a non-Newtonian of blood behavior, and to investigate the importance of stent to generate desired thrombus in intracranial aneurysms. Method The description of blood flow is made by the Boltzmann lattice equations, while thrombosis is modeled by the "fluid age" model. The lattice Boltzmann method is a computational technique for simulating fluid dynamics. The method is based on a mesoscopic approach, where the fluid is represented by a set of particles that move and interact on a grid. The model for blood coagulation is described by lattice Boltzmann Method, and it doesn't take into account the complicated coagulation pathway, this main idea is developed using the model of residence time of blood: all fluid in the domain is assumed to be capable of clotting, given enough time. The fluid age is measured by a passive scalar using a transport equation, and the node coagulates if the fluid age increases enough. Three small aneurysms of different sizes and shapes with three stents of various porosities were used to test the ability of the model to predict thrombosis. The "occlusion rate" parameter is used to assess the effectiveness of the flow diverter device. Results For the large aspect ratio factor, the occlusion is: 91% for flow diverter devise with seven struts. For medium aspect ratio, a rate of 80% is achieved. An occlusion rate of slightly more than 30% is obtained for very small aneurysms with low aspect ratio. The Newtonian model underestimates the volume of thrombosis generated. The difference in the prediction of the thrombosis volume between the Newtonian and no-Newtonian Carreau-Yasuda models is approximately 10%. Conclusion The occlusion rate is proportional to the aspect ratio form factor. For the large and medium aspect ratio factors, the occlusion is satisfactory. Concerning very small aneurysms with low aspect ratio, aneurysm occlusion is low. This rate can be improved to almost complete occlusion if the flow diverter device is doubled. The generality of the model suggests its extensibility toward any other type of thrombosis (stenosis, thrombosis in aortic aneurysms).
Background: Over the last three decades the incidence of thyroid cancer (TC) has increased in many regions of the world, however little is known about TC incidence and trends in Algeria. Material and methods: Using data from the Oran cancer registry (OCR) we assessed TC incidence and trends in Oran for the period 1996-2013 with the historical data method. The incidence curves were unstable and did not show any clear trend. Therefore, we actively collected data on TC for the period 1996-2013 using the multisource approach and the independent case ascertainment method. Results: Analysis of actively collected and validated data showed a significant increase in the incidence of TC. We compared the two databases to identify differences. There were 558 TC cases during the period 1996-2013 in the OCR, while our active data collection enabled us to find 1,391 TC cases during the same period. The completeness rate in the OCR was 40.1%. These differences were due to our approach that consisted in the inclusion of a greater number of health facilities and laboratories (44 versus 23 in the OCR), and the active data collection in the nuclear medicine facility of the University Hospital of Tlemcen that we undertook. Conclusions: The application of the recommendations of the International Agency for Research on Cancer (IARC) to enhance data completeness and quality, and an active collection of TC data in the nuclear medicine facility of the University Hospital of Tlemcen should make the OCR an essential tool for decision-making in public health and for directing health policy towards health priorities.
We report ab initio DFT calculations to investigate the effect of the BN layer on the electronic and optical properties of graphene. The electronic properties of graphene/h-BN bilayers have been calculated with the Generalized Gradient Approximation (GGA) and modified Becke-Johnson (mBJ) exchange potential. This latter potential is used in the aims to improve the energy band gap value of graphene/h-BN bilayers. The dielectric function, the absorption spectrum and electron energy loss spectra (EELS) of graphene/h-BN bilayers have been evaluated for both parallel (//) and perpendicular (⊥) directions. Our results show a slight gap opening at K-point at the level of the Dirac cone in the graphene/h-BN bilayers band structure. In addition, the superposition of the boron nitride layer on the graphene causes opposite effects on EELS depending on the type of polarizations. Our comparison with the earlier studies shows that the BN-doped graphene gives a better gap value than the graphene/h-BN bilayers. However, the electronic and optical properties of graphene are also enhancing by adding a BN layer which can be promising for the application of bilayer graphene in nanotechnology.
Objectives: There has been little focus on the non-cancer causes of death in patients with renal cell carcinoma (RCC). Therefore, we aimed to assess the frequency and risk of different causes of death, stratified by tumor stage, and demographics, after a diagnosis of RCC in the United States. Materials and methods: Data on eligible patients with RCC from January 1, 2000, to December 31, 2018, in the United States were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Standardized mortality ratios for causes of death were calculated using the SEER*Stat software 8.3.9.2 for the overall population and stratified subgroups. Results: A total of 165,969 patients with RCC were included and 60,290 (36.3%) died during follow-up. The majority of deaths were due to kidney cancer (51.3%) but a significant proportion was non-cancer causes (37.6%). The proportion of deaths attributed to RCC decreased with increasing follow-up with non-cancer causes becoming dominant after the fifth year following RCC diagnosis. Overall, cardiovascular diseases and cerebrovascular diseases were the most common non-RCC-related causes of death. AJCC stage I and localized RCC had the most deaths attributed to non-cancerous causes (66.2% and 61.2%, respectively) while AJCC stage IV and distant RCC had the most deaths due to RCC (86.2% and 86.5%, respectively). Conclusion: A large proportion of RCC patients die of non-cancerous causes especially early-stage patients and advanced-stage patients who survive >5 years. Coordination of multidisciplinary care with relevant specialists depending on the stage of the disease is needed to better prevent death overtime from non-cancer causes.
In this study, a novel Benzil Bis-Hydrazone (BBH) sensor with two C = N–N = C moieties was designed and synthesized based on the condensation reaction between benzil-dihydrazone (b) and cinnamaldehyde. The BBH probe in dimethylsulfoxide showed extremely weak fluorescence. However, the same solution exhibited an intensive fluorescence enhancement (152-fold) with the introduction of Zn(II) ions. In contrast, no or negligible fluorescence changes were observed when other ions were added. The fluorogenic behavior of BBH towards the examined cations indicated an excellent selectivity of the BBH sensor for Zn(II) cations without any interference from other cations like Fe(II), Mg(II), Cu(II), Co(II), Mn(II), Cr(III), Hg(II), Sn(II), Al(I), La(III), Ca(II), Ba(II), Na(I), K(I), and especially Cd(II). Moreover, the UV–vis spectrophotometric titrations revealed that a 1:1 stoichiometric complex BBH-Zn(II) was formed during the Zn(II) sensing and the binding constant value for this complex was calculated to be equal to 106.8. Further, in order to show the affinity of the BBH sensor for Zn(II) cations, it was deemed necessary to determine the limit of detection (LOD) which was found to equal to 2.5 10–4 M. Graphical Abstract
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• Economics and Business Department/ MECAS Laboratory
• Département des Sciences Economiques
• Département d'informatique
• Département des Sciences de la Terre et de l’Univers
• Département de Chimie
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