Publications Scientifiques et Pédagogiques

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Relationship between surface roughness and chip morphology when turning hardened steel
(PRODUCTION ENGINEERING ARCHIVES, 2020) ABIDI Youcef
Hard machining is a process which has become highly recommended in manufacturing industry to replace grinding and perform production. The important technological parameters that determine this process are tool wear, machined surface roughness, cutting force and morphology of the removed chip. In this work, an attempt has been made to analyse the morphology and form of chip removed during turning of hardened steel AISI 1045 (40HRC) with mixed ceramic tool type CC650. Using a Taguchi plan L9, whose factors are cutting speed and feed rate with three levels for each. Macroscopic and microscopic results of chip morphology were correlated with these two cutting parameters additional to surface roughness. Sufficient experimental results were obtained using the mixed ceramic tool when turning of hardened steel AISI 1045 (40HRC) at high cutting speeds. Roughness of machined surface confirmed that it is influenced by feed rate. Chips show a sawtooth shape for all combinations of the experimental plan used. The chip form changed with cutting parameters variation and given an important indicator of suraface quality for industriel. Having the indicators on the surface quality from simple control of chip without stopping machining give an important advantage in order to maximize production and reduce costs.
Ge(Sn) growth on Si(001) by magnetron sputtering
(Materials Today Communications, 2020) BENOUDIA Mohamed Cherif (Co-Auteur)
The semi-conductor Ge1−xSnx exhibits interesting properties for optoelectronic applications. In particular, Ge1−xSnx alloys with x ≥ 0.1 exhibit a direct band-gap, and integrated in complementary-metal-oxide-semiconductor (CMOS) technology, should allow the development of Si photonics. CMOS-compatible magnetron sputtering deposition was shown to produce monocrystalline Ge1−xSnx films with good electrical properties at low cost. However, these layers were grown at low temperature (< 430 K) and contained less than 6% of Sn. In this work, Ge1−xSnx thin films were elaborated at higher temperature (> 600 K) on Si(001) by magnetron sputtering in order to produce low-cost and CMOS-compatible relaxed pseudo coherent layers with x ≥ 0.1 exhibiting a better crystallinity. Ge1−xSnx crystallization and Ge1−xSnx crystal growth were investigated. Crystallization of an amorphous Ge1−xSnx layer deposited on Si(001) or Ge(001) grown on Si(001) leads to the growth of polycrystalline films. Furthermore, the competition between Ge/Sn phase separation and Ge1−xSnx growth prevents the formation of large-grain Sn-rich Ge1−xSnx layers without the formation of β-Sn islands on the layer surface, due to significant atomic redistribution kinetics at the crystallization temperature (T = 733 K for x = 0.17). However, the growth at T = 633 K of a highly-relaxed pseudo-coherent Ge0.9Sn0.1 film with low impurity concentrations (< 2 × 1019 at cm−3) and an electrical resistivity four orders of magnitude smaller than undoped Ge is demonstrated. Consequently, magnetron sputtering appears as an interesting technique for the integration of optoelectronic and photonic devices based on Ge1−xSnx layers in the CMOS technology
Impact of gravity on directional solidification of refined Al-20wt.%Cu alloy investigated by in situ X-radiography
(Journal of Alloys and Compounds, 2020) BENOUDIA Mohamed Cherif (Co-Auteur)
Gravity effects such as natural convection in the liquid phase and buoyancy forces acting on the solid phase have a strong influence on the grain structure and microstructure formation dynamics during the solidifi cation of metal alloys. It is thus very useful to undertake experimental studies that will provide benchmark data for a deeper understanding of the role of such gravity effects. In this paper, we study the formation of the equiaxed grain structure during refined Al-20wt.%Cu solidification in a temperature gradient for three different configurations: horizontal, vertical upward and vertical downward solidification. The key grain characteristics, namely grain size, grain elongation and grain growth orientation, were determined for all experiments. A comparative analysis was performed to identify the dominant effects of gravity using the experiment in horizontal configuration as reference case. The impact of buoyancy on the grain structure formation was highlighted for the experiment in vertical upward configuration, inducing a final grain structure with a wider grain size distribution. For the experiment in vertical downward configuration, the final grain structure is composed of thinner and longer grains. The origin of these differences was linked to the impact of grain flotation and solute flows on the equiaxed microstructure development. © 2020 Elsevier B.V. All rights
GENERATION AND PHYSICAL CHARACTERIZATION OF HOUSEHOLD WASTE IN ANNABA CITY
(Environmental Engineering and Management Journal, 2020) CHENITI Hamza
This study is a physical characterization of household waste in the town of Annaba (Algeria North East). Based on an adequate sampling protocol that takes into account the constraints of Algerian cities; Annaba city was taken as a case study for the rapprochement of the situation in Algeria. A quantity of 90 to 120 kg was sorted for each type of habitat in the city during four seasons of the year 2010 to 2011 according to 11 components of household wastes. Variations in the percentages of some components depending on the seasons and the type of habitat were recorded, especially the organic matter, the plastic, the glasses, and metals. Also; the weighing of the samples showed the variation of the production ratio per capita according to the season and the type of habitat. However, the largest production ratio was recorded for the height standing and the small one for low standing.
Convergence of a Two-parameter Family of Conjugate Gradient Methods with a Fixed Formula of Stepsize
(Boletim da Sociedade Paranaense de Matemática., 2020) Bouaziz Khelifa; Laskri Yamina (Co-Auteur)
We prove the global convergence of a two-parameter family of conjugate gradient methods that use a new and different formula of stepsize from Wu [14]. Numerical results are presented to confirm the effectiveness of the proposed stepsizes by comparing with the stepsizes suggested by Sun and his colleagues [2,12].
Impact of growth velocity on grain structure formation during directional solidification of a refined Al-20 wt.%Cu alloy
(Journal of Crystal Growth, 2020) BENOUDIA Mohamed Cherif (Co-Auteur)
The paper presents detailed analyses of solidification experiments performed on a refined Al-20 wt.%Cu alloy using the SFINX (Solidification Furnace with IN situ X-radiography) laboratory facility. Directional solidifica tions of a sheet-like sample were carried out in a horizontal configuration, with the main surface of the sample parallel to the ground. The sample was solidified for a wide range of cooling rates to obtain various grain structures, from columnar to elongated and equiaxed. The formation of the grain structure was observed in-situ and in real-time by X-radiography, which allows the dynamic of solidification phenomena to be thoroughly analyzed. Based on the radiographs, quantitative measurements were performed to accurately describe the so lidified grain structure, namely the nucleation position, nucleation rate, grain size, grain elongation factor and growth orientation. The experiments showed that increasing the growth velocity leads to a decrease of both the grain size and grain elongation factor, resulting in a more homogeneous and isotropic grain distribution. The grain characteristic parameters were also sensitive to variations of the temperature gradient in the Field-of-View. The results were discussed by analyzing the impact of the solidification parameters on the constitutionally undercooled liquid zone ahead of the solidification front
In situ measurements of the structure and strain of a π-conjugated semiconducting polymer under mechanical load
(Journal of Applied Physics, 2020) BENOUDIA Mohamed Cherif (Co-Auteur)
In this work, in situ studies of organic thin films under stretching are developed. A high efficiency PffBT4T-2OD π-conjugated polymer (PCE11) was coated directly on a stretchable substrate in order to examine the impact of tensile strain on the structural properties. For that purpose, in situ grazing incidence x-ray diffraction coupled with optical microscopic observations have been carried out to measure the structural parameters of PCE11 and to probe the mechanical behavior of polymer chains under uniaxial tensile load. It is observed that in the range between 0% and 15%–20% of stretching, the polymer chains become more oriented. Meanwhile, an increase in negative values of deformation, i.e., compression of the polymer chains along the film normal was measured. Beyond this range of stretching, the polymer order declined and the stress was relaxed. This relaxation is explained by the increased number of cracks spreading over the entire film as observed using optical microscopy.
EXHAUSTIVE STUDY OF THE PV MODULE IMPLEMENTED IN THE REGION OF ANNABA ALGERIA
(LATVIAN JOURNAL OF PHYSICS AND TECHNICAL SCIENCES, 2020) DEKHANE Azzeddine
Algeria, like any other country, has drawn up its roadmap for the use and promotion of renewable energy sources. Motivated by its commitment to the international community in the fight against global warming and its possession of one of the largest solar fields in the world, a series of laws and institutions have consolidated this ambitious schedule. As known, both the climate and the geological area of Algeria take place among the foremost favoured countries in the field of solar energy. The present paper aims at proposing a simple model of photovoltaic module. The authors used Matlab/Simulink software to predict the current-voltage and power voltage characteristics according to the influence of several factors, such as solar irradiance, cell temperature and series resistance, on the efficiency of photovoltaic module. The proposed experimental investigation can easily predict the curves (current-voltage and power-voltage) of a PV module, where both of simulation and practical results are identical. A single-crystal line photovoltaic module was introduced close to Badji-Mokhtar Annaba University, Annaba (Algeria) to show the impact of climatic conditions in this coastal region and partial shading on characteristics
On Bullen-Type Inequalities for Fractional Integrals with Exponential Kernels
(Sahand Communications in Mathematical Analysis (SCMA), 2020) LAKHDARI Abdelghan (Co-Auteur)
In this paper, we investigate the Bullen inequality in the context of fractional integrals with exponential kernels. Build ing upon the foundational works in the field, we first introduce a new integral identity. From this identity, we derive several novel Bullen-type inequalities for differentiable convex functions. To vali date our theoretical findings, we provide a numerical example along with graphical representations, demonstrating the accuracy and applicability of our results. The results obtained are not only new for the fractional integrals considered in our study, but as α pproaches 1, we also derive additional novel results for the classical integral
Gait biometrics: investigating the use of the lower inner regions for people identification from landmark frames
(the institution of engineering and technology, 2020) DOGHMANE Nouredine
The recent technological advances in surveillance, forensic and biometric systems to deter or even reduce the increasing number of crimes and prevent them is still questionable. The use of gait biometrics has attracted unprecedented interest due to its capability to work with low-resolution footage recorded from a distance. In contrast to mainstream research on gait biometrics which uses holistic silhouette features, the authors investigate the use of the bottom dynamic section within the human body to derive the most discriminative features for gait recognition. A new escriptor based on 7 Hu's moments is proposed describing the inner lower limb regions between the limbs being extracted only from landmark frames within one gait cycle. In order to assess the discriminatory potency of gait features from the lower regions for people identification, a number of experiments are conducted on the CASIA-B gait database to investigate the recognition rates using the KNN classifier and deep learning. The comparative analysis is performed against well-established research studies which were tested on the CASIA-B data set. The obtained results confirm the consistency of features extracted from the lower regions for gait recognition even under the impact of various factors.
Brine Evaporation Speed Enhancement by Solar Energy for Optimization of Salt Production of Lake Merouane El Oued Southeastern of Algeria
(Journal of the Polish Mineral Engineering Society, 2020-02) ISSAM Rouaiguia (Co-Auteur)
In this present paper we will study an assembly of two systems for collecting solar energy at the unit of SME (Salins Merouane El Meghaier) located in southeastern Algeria, by the development of a black grid floating in the brine and a reflection mirror of the solar radiation directed towards the evaporating surface in the test pan P4 and also a witness pan P0 which helps us to illustrate the influence of these two systems, results will be obtained suggest an increase in the evaporation-crystallization rate of P4 compared to that of P0 which is due to the improvement of the annual production of SME unit.
Data-Driven and Model-Based Methods for Fault Detection and Diagnosis
(Elsevier Science Publishing, 2020-02-17) MANSOURI Majdi; HARKAT Mohamed Faouzi (Co-Auteur)
Data-Driven and Model-Based Methods for Fault Detection and Diagnosis covers techniques that improve the quality of fault detection and enhance monitoring through chemical and environmental processes. The book provides both the theoretical framework and technical solutions. It starts with a review of relevant literature, proceeds with a detailed description of developed methodologies, and then discusses the results of developed methodologies, and ends with major conclusions reached from the analysis of simulation and experimental studies. The book is an indispensable resource for researchers in academia and industry and practitioners working in chemical and environmental engineering to do their work safely.. • Outlines latent variable based hypothesis testing fault detection techniques to enhance monitoring processes represented by linear or nonlinear input-space models (such as PCA) or input-output models (such as PLS) • Explains multiscale latent variable based hypothesis testing fault detection techniques using multiscale representation to help deal with uncertainty in the data and minimize its effect on fault detection • Includes interval PCA (IPCA) and interval PLS (IPLS) fault detection methods to enhance the quality of fault detection • Provides model-based detection techniques for the improvement of monitoring processes using state estimation-based fault detection approaches • Demonstrates the effectiveness of the proposed strategies by conducting simulation and experimental studies on synthetic data
Reliable Fault Detection and Diagnosis of Large-Scale Nonlinear Uncertain Systems Using Interval Reduced Kernel PLS
(IEEE Access, 2020-04) HARKAT Mohamed Faouzi (Co-Auteur)
Kernel partial least squares (KPLS) models are widely used as nonlinear data-driven methods for faults detection (FD) in industrial processes. However, KPLS models lead to irrelevant performance over long operation periods due to process parameters changes, errors and uncertainties associated with measurements. Therefore, in this paper, two different interval reduced KPLS (IRKPLS) models are developed for monitoring large scale nonlinear uncertain systems. The proposed IRKPLS models present an interval versions of the classical KPLS model. The two proposed IRKPLS models are based on the Euclidean distance between interval-valued observations as a dissimilarity metric to keep only the more relevant and informative samples. The rst proposed IRKPLS technique uses the centers and ranges of intervals to estimate the interval model, while the second one is based on the upper and lower bounds of intervals for model identi cation. These obtained models are used to evaluate the monitored interval residuals. The aforementioned interval residuals are fed to the generalized likelihood ratio test (GLRT) chart to detect the faults. In addition to considering the uncertainties in the input-output systems, the new IRKPLS-based GLRT techniques aim to decrease the execution time when ensuring the fault detection performance. The developed IRKPLS-based GLRT approaches are evaluated across various faults of the well-known Tennessee Eastman (TE) process. The performance of the proposed IRKPLS-based GLRT methods is evaluated in terms of missed detection rate, false alarms rate, and execution time. The obtained results demonstrate the ef ciency of the proposed approaches, compared with the classical interval KPLS.
Direct Observations of the Structural Properties of Semiconducting Polymer: Fullerene Blends under Tensile Stretching
(Materials, 2020-07-10) ALIOUAT Mouaad Yassine; BENOUDIA Mohamed Cherif (Co-Auteur)
We describe the impact of tensile strains on the structural properties of thin films composed of P BT4T-2OD -conjugated polymer and PC71BM fullerenes coated on a stretchable substrate, based on a novel approach using in situ studies of flexible organic thin films. In situ grazing incidence X-ray di raction (GIXD) measurements were carried out to probe the ordering of polymers and to measure the strain of the polymer chains under uniaxial tensile tests. A maximum 10% tensile stretching was applied (i.e., beyond the relaxation threshold). Interestingly we found di erent behaviors upon stretching the polymer: fullerene blends with the modified polymer; fullerene blends with the 1,8-Diiodooctane (DIO) additive. Overall, the strain in the system was almost twice as low in the presence of additive. The inclusion of additive was found to help in stabilizing the system and, in particular, the – packing of the donor polymer chains.
Interval-Valued Features Based Machine Learning Technique for Fault Detection and Diagnosis of Uncertain HVAC Systems
(IEEE Access, 2020-08) HARKAT Mohamed Faouzi (Co-Auteur)
The operation of heating, ventilation, and air conditioning (HVAC) systems is usually disturbed by many uncertainties such as measurement errors, noise, as well as temperature. Thus, this paper proposes a new multiscale interval principal component analysis (MSIPCA)-based machine learning (ML) technique for fault detection and diagnosis (FDD) of uncertain HVAC systems. The main goal of the developed MSIPCA-ML approach is to enhance the diagnosis performance, improve the indoor environment quality, and minimize the energy consumption in uncertain building systems. The model uncertainty is addressed by considering the interval-valued data representation. The performance of the proposed FDD is investigated using sets of synthetic and emulated data extracted under different operating conditions. The presented results con rm the high-ef ciency of the developed technique in monitoring uncertain HVAC systems due to the high diagnosis capabilities of the interval feature-based support vector machines and k-nearest neighbors and their ability to distinguish between the different operating modes of the HVAC system.
Number of Pixel Change Rate and Unified Average Changing Intensity for Sensitivity Analysis of Encrypted inSAR Interferogram
(International information and engineering technology associatin, 2020-09-21) Mayache Hicham
The transmission of images from satellites to earth is on the brink of many threats which can affect the confidentiality of the data as well as its quality. Several encryption algorithms are used to secure the transmitted images. The objective in this work is to analyze the sensitivity of a particular type of satellite image, which is an interferogram from interferometric imaging systems inSAR system. This image is encrypted by cryptosystem based on the Advanced Encryption Standard with key length of 256 bits (AES-256) standard and the asymmetric Rivest, Shamir & Adelman (RSA) encryption algorithm using Counter mode encryption (CTR) mode and Output FeedBack (OFB) mode. The analysis made in this paper is carried out on two types of sensitivity. The first analysis is the sensitivity to change of a pixel in the original interferogram and the second is the sensitivity to the key. Two parameters are used to assess sensitivity: The Number of Pixel Change Rate (NPCR) and the Unified Average Changing Intensity (UACI). The obtained results show that the two modes AES-256-OFB and AES-256-CTR are favorable but cannot be implemented on board a satellite without providing a mechanism capable of compensating for the low resistance to error propagation. Metrics on the clear and encrypted interferogram are exploited such as the Structural Similarity Index (SSIM), Gradient-based Structural Similarity (GSSIM), The use of these metrics, allowed us to see that a change of one pixel in the interferogram and the change of the encryption key will affect the quality of the interferogram, as well as a statistical histogram analysis.
Ge(Sn) growth on Si(001) by magnetron sputtering
(Materials Today Communications, 2020-11-26) BENOUDIA Mohamed Cherif (Co-Auteur)
The semi-conductor Ge1–xSnx exhibits interesting properties for optoelectronic applications. In particular, Ge1–xSnx alloys with x ≥ 0.1 exhibit a direct band-gap, and integrated in complementary-metal-oxide semiconductor (CMOS) technology, should allow the development of Si photonics. CMOS-compatible magne tron sputtering deposition was shown to produce monocrystalline Ge1–xSnx films with good electrical properties at low cost. However, these layers were grown at low temperature (< 430 K) and contained less than 6 % of Sn. In this work, Ge1–xSnx thin films were elaborated at higher temperature (> 600 K) on Si(001) by magnetron sputtering in order to produce low-cost and CMOS-compatible relaxed pseudo-coherent layers with x ≥ 0.1 exhibiting a better crystallinity. Ge1–xSnx crystallization and Ge1–xSnx crystal growth were investigated. Crys tallization of an amorphous Ge1–xSnx layer deposited on Si(001) or Ge(001) grown on Si(001) leads to the growth of polycrystalline films. Furthermore, the competition between Ge/Sn phase separation and Ge1–xSnx growth prevents the formation of large-grain Sn-rich Ge1–xSnx layers without the formation of β-Sn islands on the layer surface, due to significant atomic redistribution kinetics at the crystallization temperature (T = 733 K for x = 0.17). However, the growth at T = 633 K of a highly-relaxed pseudo-coherent Ge0.9Sn0.1 film with low impurity concentrations (< 2 × 1019 at cm–3 ) and an electrical resistivity four orders of magnitude smaller than undoped Ge is demonstrated. Consequently, magnetron sputtering appears as an interesting technique for the integration of optoelectronic and photonic devices based on Ge1–xSnx layers in the CMOS technology.
Evaluation and Analysis of Interferograms from an InSAR Radar En crypted by an AES-Based Cryptosystem with The Five Encryption Modes
(International Journal on Electrical Engineering and Informatics, 2020-12) Mayache Hichem
This paper falls within the framework of the security of satellite images, in particular interferograms from an Interferometric Synthetic Aperture Radar (inSAR) system. The innovation of this work consists in the application of a cryptosystem based on two algorithms Advanced Encryption Standard (AES) and the Rivest, Shamir and Adleman (RSA) encryption algorithm for securing interferograms of inSAR systems. AES employs five encryption modes Electronic Code Book (ECB), Cipher Bloc Chaining (CBC), Cipher FeedBack (CFB), Output FeedBack (OFB), and counter-mode encryption (CTR). The use of the AES algorithm alone can only ensure the confidentiality function. In the proposed cryptosystem confidentiality is ensured by the AES algorithm, authenticity is guaranteed by the RSA algorithm, and integrity is ensured by two parameters; the correlation function between the adjacent pixels and the SSIM parameters (structural similarity index SSIM). For evaluation and analysis of security performance for interferogram encryption, several test metrics are employed. These metrics are: Analysis of histograms of the encrypted interferograms, correlation between the adjacent pixels, between the original interferogram and the encrypted interferogram, SSIM between the original interferogram and the decrypted one. Moreover, we exploit the analysis of resistance to error propagation for the five modes. The obtained results show a superiority of the OFB and CTR modes for the encryption of in SAR interferograms compared to ECB, CFB, and CBC modes. It is noteworthy, that the main criteria that can be used to choose between OFB and CTR for encryption of satellite images are ropagation of errors and the complexity material for their locations on the edges of the satel lites propagation of errors and the complexity material for their locations on the edges of the satellites. OFB mode is employed in satellites to minimize the number of on-board circuits, which is decisive for satellites. CTR mode is recommended by the CCSDS (Consultative Committee for Space Data Systems) for telemetry (TM) and remote control (TC) encryption.
A Novel Fault Diagnosis of Uncertain Systems Based on Interval Gaussian Process Regression: Application to Wind Energy Conversion Systems
(IEEE Access, 2020-12) HARKAT Mohamed Faouzi (Co-Auteur)
Fault detection and diagnosis (FDD) of wind energy conversion (WEC) systems play an important role in reducing the maintenance and operational costs and increase system reliability. Thus, this paper proposes a novel Interval Gaussian Process Regression (IGPR)-based Random Forest (RF) technique (IGPR-RF) for diagnosing uncertain WEC systems. In the proposed IGPR-RF technique, the effective interval-valued nonlinear statistical features are extracted and selected using the IGPR model and then fed to the RF algorithm for fault classi cation purposes. The proposed technique is characterized by a better handling of WEC system uncertainties such as wind variability, noise, measurement errors, which leads to an improved fault classi cation accuracy. The obtained results show that the proposed IGPR-RF technique is characterized by a high diagnosis accuracy (an average accuracy of 99.99%) compared to the conventional classi ers.
Analysis of the compromise between cutting tool life, productivity and roughness during turning of C45 hardened steel
(PRODUCTION ENGINEERING ARCHIVES, 2021) ABIDI Youcef
Tool wear and surface roughness as performance indexes are considered to be the most important in terms of hardened materials’ machinability. The best combination of cutting parameters which en hances the compromise between tool life, productivity and machined surface quality contribute to benefice on production cost, which makes manufacturing industry interested in it. The aim of this research is to investigate the life of ceramic cutting tool and machining productivity together with surface roughness during turning of hardened steel C45, with focus on the selection of the optimal cutting parameter combination. The experiments are carried out based on uni-factorial planning meth odology of cutting speeds and feed rates. The results show that the mixed ceramic tool is suitable for turning hardened steel C45 (40 HRC) and the conclusion is that it performed well in terms of tool life, productivity and surface quality at a combination of cutting speed (200 m/min), feed (0.08 mm/rev) and depth of cut (0.3 mm). Additionally, a tool life model has been proposed which is presented very high coefficient of determination.

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