Search results for: Souad Slimani
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 37

Search results for: Souad Slimani

37 Identifying Coloring in Graphs with Twins

Authors: Souad Slimani, Sylvain Gravier, Simon Schmidt

Abstract:

Recently, several vertex identifying notions were introduced (identifying coloring, lid-coloring,...); these notions were inspired by identifying codes. All of them, as well as original identifying code, is based on separating two vertices according to some conditions on their closed neighborhood. Therefore, twins can not be identified. So most of known results focus on twin-free graph. Here, we show how twins can modify optimal value of vertex-identifying parameters for identifying coloring and locally identifying coloring.

Keywords: identifying coloring, locally identifying coloring, twins, separating

Procedia PDF Downloads 116
36 The Management of the Urban Project between Challenge and Need: The Case of the Modernization Project of Constantine

Authors: Mouhoubi Nedjima, Sassi Boudemagh Souad

Abstract:

In this article, and through the modernization project of metropolis of Constantine (PMMC) experience in Algeria, discussed to highlight the importance of management in an urban project at various levels: strategic and operational. The statement we attended to reach is to evaluate the modernization project of metropolis of Constantine in the light of management and prove the relation between a good urban management and the success of an urban project.

Keywords: urban project, strategic management, operational management, the modernization project of constantine

Procedia PDF Downloads 487
35 GE as a Channel Material in P-Type MOSFETs

Authors: S. Slimani, B. Djellouli

Abstract:

Novel materials and innovative device structures has become necessary for the future of CMOS. High mobility materials like Ge is a very promising material due to its high mobility and is being considered to replace Si in the channel to achieve higher drive currents and switching speeds .Various approaches to circumvent the scaling limits to benchmark the performance of nanoscale MOSFETS with different channel materials, the optimized structure is simulated within nextnano in order to highlight the quantum effects on DG MOSFETs when Si is replaced by Ge and SiO2 is replaced by ZrO2 and HfO2as the gate dielectric. The results have shown that Ge MOSFET have the highest mobility and high permittivity oxides serve to maintain high drive current. The simulations show significant improvements compared with DGMOSFET using SiO2 gate dielectric and Si channel.

Keywords: high mobility, high-k, quantum effects, SOI-DGMOSFET

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34 "Project" Approach in Urban: A Response to Uncertainty

Authors: Mouhoubi Nedjima, Sassi Boudemagh Souad

Abstract:

In this paper, we will try to demonstrate the importance of the project approach in the urban to deal with uncertainty, the importance of the involvement of all stakeholders in the urban project process and that the absence of an actor can lead to project failure but also the importance of the urban project management. These points are handled through the following questions: Does the urban adhere to the theory of complexity? Does the project approach bring hope and solution to make urban planning "sustainable"? How converging visions of actors for the same project? Is the management of urban project the solution to support the urban project approach?

Keywords: strategic planning, project, urban project stakeholders, management

Procedia PDF Downloads 476
33 Numerical and Experimental Study of Heat Transfer Enhancement with Metal Foams and Ultrasounds

Authors: L. Slimani, A. Bousri, A. Hamadouche, H. Ben Hamed

Abstract:

The aim of this experimental and numerical study is to analyze the effects of acoustic streaming generated by 40 kHz ultrasonic waves on heat transfer in forced convection, with and without 40 PPI aluminum metal foam. Preliminary dynamic and thermal studies were done with COMSOL Multiphase, to see heat transfer enhancement degree by inserting a 40PPI metal foam (10 × 2 × 3 cm) on a heat sink, after having determined experimentally its permeability and Forchheimer's coefficient. The results obtained numerically are in accordance with those obtained experimentally, with an enhancement factor of 205% for a velocity of 0.4 m/s compared to an empty channel. The influence of 40 kHz ultrasound on heat transfer was also tested with and without metallic foam. Results show a remarkable increase in Nusselt number in an empty channel with an enhancement factor of 37,5%, while no influence of ultrasound on heat transfer in metal foam presence.

Keywords: acoustic streaming, enhancing heat transfer, laminar flow, metal foam, ultrasound

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32 Control Law Design of a Wheeled Robot Mobile

Authors: Ghania Zidani, Said Drid, Larbi Chrifi-Alaoui, Abdeslam Benmakhlouf, Souad Chaouch

Abstract:

In this paper, we focus on the study for path tracking control of unicycle-type Wheeled Mobile Robots (WMR), by applying the Backstepping technic. The latter is a relatively new technic for nonlinear systems. To solve the problem of constraints nonholonomics met in the path tracking of such robots, an adaptive Backstepping based nonlinear controller is developed. The stability of the controller is guaranteed, using the Lyapunov theory. Simulation results show that the proposed controller achieves the objective and ensures good path tracking.

Keywords: Backstepping control, kinematic and dynamic controllers, Lyapunov methods, nonlinear control systems, Wheeled Mobile Robot (WMR).

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31 Long-term Monitoring on Rangelands in Southwest Algeria and Impact of Overgrazing and Droughts on Biodiversity and Soil: Case of the Rogassa Steppe (Wilaya of El Bayadh)

Authors: Slimani Halima

Abstract:

One of the main problems of degradation of arid steppe rangelands in the southern Mediterranean is the loss of plant diversity and changes in soil properties. During the last decades, these rangelands faced two main driving forces: climate through more or less lasting and recurrent droughts and overgrazing by sheep. In the present work, the preexisting system was an arid steppe with alfa grass (Stipa tenacissima L.) as the dominant plant, which was considered to be the "keystone" species toward the whole ecosystem structure and functioning. Vegetation and soil change was monitored for 45 years along a grazing intensity gradient. Changes in species richness and diversity, in the vegetation and in the soil, enabled to better understand climate fluctuations effects in comparison to overgrazing ones. The aim is to assess the impacts of grazing and climatic variability and change on biodiversity,vegetation and soil over a period of 45 years, based on data from seven reference years.

Keywords: biodiversity, desertification, droughts, el bayadh, overgrazing, soil, steppe

Procedia PDF Downloads 59
30 Microstructure and Excess Conductivity of Bulk, Ag-Added FeSe Superconductors

Authors: Michael Koblischka, Yassine Slimani, Thomas Karwoth, Anjela Koblischka-Veneva, Essia Hannachi

Abstract:

On bulk FeSe superconductors containing different additions of Ag, a thorough investigation of the microstructures was performed using optical microscopy, SEM and TEM. The electrical resistivity was measured using four-point measurements in the temperature range 2 K ≤ T ≤ 150 K. The data obtained are analyzed in the framework of the excess conductivity approach using the Aslamazov-Larkin (AL) model. The investigated samples comprised of five distinct fluctuation regimes, namely short-wave (SWF), onedimensional (1D), two-dimensional (2D), three-dimensional (3D), and critical (CR) fluctuation regimes. The coherence length along the c-axis at zero-temperature (ξc(0)), the lower and upper critical magnetic fields (Bc1 and Bc2), the critical current density (Jc) and numerous other superconducting parameters were estimated with respect to the Ag content in the samples. The data reveal a reduction of the resistivity and a strong decrease of ξc(0) when doping the 11-samples with silver. The optimum content of the Ag-addition is found at 4 wt.-% Ag, yielding the highest critical current density.

Keywords: iron-based superconductors, FeSe, Ag-addition, excess conductivity, microstructure

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29 Dimensionality and Superconducting Parameters of YBa2Cu3O7 Foams

Authors: Michael Koblischka, Anjela Koblischka-Veneva, XianLin Zeng, Essia Hannachi, Yassine Slimani

Abstract:

Superconducting foams of YBa2Cu3O7 (abbreviated Y-123) were produced using the infiltration growth (IG) technique from Y2BaCuO5 (Y-211) foams. The samples were investigated by SEM (scanning electron microscopy) and electrical resistivity measurements. SEM observations indicated the specific microstructure of the foam struts with numerous tiny Y-211 particles (50-100 nm diameter) embedded in channel-like structures between the Y-123 grains. The investigation of the excess conductivity of different prepared composites was analyzed using Aslamazov-Larkin (AL) model. The investigated samples comprised of five distinct fluctuation regimes, namely short-wave (SWF), one-dimensional (1D), two-dimensional (2D), three-dimensional (3D), and critical (CR) fluctuations regimes. The coherence length along the c-axis at zero-temperature (ξc(0)), lower and upper critical magnetic fields (Bc1 and Bc2), critical current density (Jc) and numerous other superconducting parameters were estimated from the data. The analysis reveals that the presence of the tiny Y-211 particles alters the excess conductivity and the fluctuation behavior observed in standard YBCO samples.

Keywords: Excess conductivity, Foam, Microstructure, Superconductor YBa2Cu3Oy

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28 Antimicrobial Activity of Some Alimentary and Medicinal Plants

Authors: Akrpoum Souad, Lalaoui Korrichi

Abstract:

Vicia faba L.,Vaccinium macrocarpon, Punica granatum, Lavandula officinalis, Artemisia absinthium, Linum capitatum and Camellia sinensis were frequently used in our alimentation. In this study, we have tested the antimicrobial activity of their ethanolic and methanolic extracts on some pathogen bacteria, then their ability to in vivo inhibit the growth of Strepcoccus pneumonia. The phytochemical screening has given the composition of the most active extracts. According to the obtained results, the ethanolic extract of Lavendula. officinalis and A absinthium has shown an inhibition of all the tested strains of becteria3. The ethanolic extract of L. officinalis has given the highest activity against S. pneumoniae, followed by the methanolic extract of C. sinensis 1, 2 and P. granatum. The phytochemical screening showed that the most active extracts contained mainly naturels compounds.

Keywords: plants, extracts, antimicrobial activity, streptococcus pneumoniae, phytochemical screening

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27 Forecasting Direct Normal Irradiation at Djibouti Using Artificial Neural Network

Authors: Ahmed Kayad Abdourazak, Abderafi Souad, Zejli Driss, Idriss Abdoulkader Ibrahim

Abstract:

In this paper Artificial Neural Network (ANN) is used to predict the solar irradiation in Djibouti for the first Time that is useful to the integration of Concentrating Solar Power (CSP) and sites selections for new or future solar plants as part of solar energy development. An ANN algorithm was developed to establish a forward/reverse correspondence between the latitude, longitude, altitude and monthly solar irradiation. For this purpose the German Aerospace Centre (DLR) data of eight Djibouti sites were used as training and testing in a standard three layers network with the back propagation algorithm of Lavenber-Marquardt. Results have shown a very good agreement for the solar irradiation prediction in Djibouti and proves that the proposed approach can be well used as an efficient tool for prediction of solar irradiation by providing so helpful information concerning sites selection, design and planning of solar plants.

Keywords: artificial neural network, solar irradiation, concentrated solar power, Lavenberg-Marquardt

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26 Comparative Toxicity of Garlic Juice and Dicofol to Population of Citrus Mites

Authors: Y. Atibi, A. Boutaleb Joutei, T. Slimani

Abstract:

Insecticidal properties of Alliaceae are widely known, they are plant with varied biological properties. Garlic and onion are known for their positive effect on health, including the prevention of cardiovascular disease and some digestive cancers. These health benefits molecules are also responsible for pest potential control of Alliaceae. With these properties, we can consider using Alliaceae as acaricides. The purpose of this study was to compare the effect of chemical and biopesticides on citrus mites, especially Tetranychus urticae, Panonychus citri and Eutetranychus orientalis. Chemical treatment (Dicofol) and biopesticides (Garlic juice + Alcohol) applied on this study to control the various stages of mites, have reduced the proliferation of mobile forms and reducing the number of eggs to acceptable levels. Garlic juice + alcohol revealed efficiency from 50 to 57.69 % against the mobile forms of T. urticae, however, it was effective against the mobile forms of P. citri and E. orientalis with an efficiency of 85.71 % and 100 % respectively, its action has also reduced the number of eggs of T. urticae and E. orientalis at low levels. Therefore, this biopesticide is conceivable viewpoint technical and economic as the infestation by mite is low.

Keywords: Garlic juice, acaricide, biopesticide, mites, alcohol, Tetranychus urticae, Panonychus citri, Eutetranychus orientalis.

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25 Impact of the Xanthan Gum on Rheological Properties of Ceramic Slip

Authors: Souad Hassene Daouadji, Larbi Hammadi, Abdelkrim Hazzab

Abstract:

The slips intended for the manufacture of ceramics must have rheological properties well-defined in order to bring together the qualities required for the casting step (good fluidity for feeding the molds easily settles while generating a regular settling of the dough and for the dehydration phase of the dough in the mold a setting time relatively short is required to have a sufficient refinement which allows demolding both easy and fast). Many additives haveadded in slip of ceramic in order to improve their rheological properties. In this study, we investigated the impact of xanthan gumon rheological properties of ceramic Slip. The modified Cross model is used to fit the stationary flow curves of ceramic slip at different concentration of xanthan added. The thixotropic behavior studied of mixture ceramic slip-xanthan gumat constant temperature is analyzed by using a structural kinetic model (SKM) in order to account for time dependent effect.

Keywords: ceramic slip, xanthan gum, modified cross model, thixotropy, viscosity

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24 Sliding Mode MRAS Observer for Optimized Backstepping Control of Induction Motor

Authors: Chaouch Souad, Abdou Latifa, Larbi Chrifi Alaoui

Abstract:

This paper deals with sensorless backstepping control of induction motor using MRAS technique associated to sliding mode approach. A high order genetic algorithm structure is used to approximate a control law designed by the Backstepping technique, and to find the best parameters globally optimized. However, the Backstepping control approach is unsuitable for high performance applications because the need of a speed sensor for increased accuracy and the absence of any error decay mechanism. In this paper a nonlinear observer, obtained by combining sliding mode structure and model reference adaptive system (MRAS), is designed for the rotor flux and rotor speed estimations. To validate the proposed method, the results are presented for showing the improved drive characteristics and performances.

Keywords: Backstepping Control, Induction Motor, Genetic Algorithm, Sliding Mode observer

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23 Preliminary Phytochemical Screening, Analysis of Phenolic Compounds and Antioxidant Activity of Genista cephalantha Spach. (Fabaceae)

Authors: Chebbah Kaoutar, Marchioni Eric, Menad Ahmed, Mekkiou Ratiba, Sarri Djamel, Ameddah Souad, Boumaza Ouahiba, Seghiri Ramdane, Benayache Samir, Benayache Fadila

Abstract:

This study was designed to estabilish a preliminary phytochemical screening, evaluate the phenolic and flavonoid content according to the Folin-Ciocalteu procedure, and aluminum chloride method respectively and to determine qualitatively, using HPLC-UV method, the most important products present in ethyl acetate (EtOAc) and n-butanol (n-BuOH) extracts of the aerial parts of Genista cephalantha Spach. from East Algeria. The antioxidant activity of these extracts was spectrophotometrically tested by measuring their ability to scavenge a stable DPPH free radical and by β-Carotene/linoleic acid bleaching assay. Evaluated extracts showed a good activity in both antioxidant system assays.

Keywords: phenolic compounds, flavonoids, HPLC-DAD-UV, antioxidant activity, genista cephalantha, fabaceae

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22 Perception of Training Actors on the Effectiveness of Training Carried Out within the Company

Authors: Oussedik Lydia, Zaouani-Denoux Souâd

Abstract:

In an economic context characterized by intense competition and the impact of new technologies, companies have a constant need to adapt to the environment and the changes imposed. This situation leads companies to take training actions to develop employees’ required skills. Further, training is considered as a strategic lever for the company's growth. Accordingly, an increasing number of companies are adopting training to ensure continuous employees qualification. Thus, the aim of this research is to understand the process of training engineering occurring in the context of a company's continuous training, which will help to identify the gaps that can hinder or promote the development of employees' knowledge and skills. The research methodology is based on a mixed-method approach. Interviews and questionnaires are implemented to collect qualitative and quantitative data. The study results can help managers to identify gaps at each stage of training design. Finally, the research findings provide important information to help design a training plan to support the development of employees' knowledge and performance.

Keywords: training engineering, training needs, training plan, competences, continuing training, perception

Procedia PDF Downloads 104
21 The Urban Project: Metropolization Tool and Sustainability Vector - Case of Constantine

Authors: Mouhoubi Nedjima, Sassi Boudemagh Souad, Chouabbia Khedidja

Abstract:

Cities grow, large or small; they seek to gain a place in the market competition, which talks to sell a product that is the city itself. The metropolis are large cities enjoying a legal status and assets providing their dominions elements on a territory larger than their range, do not escape this situation. Thus, the search for promising tool metropolises better development and durability meet the challenges as economic, social and environmental is timely. The urban project is a new way to build the city; it is involved in the metropolises of two ways, either to manage the crisis and to meet the internal needs of the metropolis, or by creating a regional attractiveness with their potential. This communication will address the issue of urban project as a tool that has and should find a place in the panoply of existing institutional tools. Based on the example of the modernization project of the metropolis of eastern Algeria "Constantine", we will examine what the urban project can bring to a city, the extent of its impact but also the relationship between the visions actors so metropolization a success.

Keywords: urban project, metropolis, institutional tools, Constantine

Procedia PDF Downloads 378
20 The Urban Project and the Urban Improvement to the Test of the Participation, Case: Project of Modernization of Constantine

Authors: Mouhoubi Nedjima, Sassi Boudemagh Souad

Abstract:

In the framework of the modernization of the city of Constantine, and in order to restore its status as a regional metropolis and introduce it into the network of cities international metropolises, a major urban project was launched: project of modernization and of metropolitanization of the city of Constantine (PMMC). Our research project focuses on the management of the project for the modernization of the city of Constantine (PMMC) focusing on the management of some aspects of the urban project whose participation, with the objective assessment of the managerial approach business. Among the cases revealing taken into account in our research work on the question of participation of actors and their organizations, the operation relating to "the urban improvement in the city of the Brothers FERRAD in the district of Zouaghi". This operation with the objective of improving the living conditions of citizens has faced several challenges and obstacles that have been in major part the factors of its failure. Through this study, we examine the management process and the mode of organization of the actors of the project as well as the level of participation of the citizen to finally propose managerial solutions to conflict situations observed.

Keywords: the urban project, the urban improvement, participation, Constantine

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19 The Use of Multivariate Statistical and GIS for Characterization Groundwater Quality in Laghouat Region, Algeria

Authors: Rouighi Mustapha, Bouzid Laghaa Souad, Rouighi Tahar

Abstract:

Due to rain Shortage and the increase of population in the last years, wells excavation and groundwater use for different purposes had been increased without any planning. This is a great challenge for our country. Moreover, this scarcity of water resources in this region is unfortunately combined with rapid fresh water resources quality deterioration, due to salinity and contamination processes. Therefore, it is necessary to conduct the studies about groundwater quality in Algeria. In this work consists in the identification of the factors which influence the water quality parameters in Laghouat region by using statistical analysis Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA) and geographic information system (GIS) in an attempt to discriminate the sources of the variation of water quality variations. The results of PCA technique indicate that variables responsible for water quality composition are mainly related to soluble salts variables; natural processes and the nature of the rock which modifies significantly the water chemistry. Inferred from the positive correlation between K+ and NO3-, NO3- is believed to be human induced rather than naturally originated. In this study, the multivariate statistical analysis and GIS allows the hydrogeologist to have supplementary tools in the characterization and evaluating of aquifers.

Keywords: cluster, analysis, GIS, groundwater, laghouat, quality

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18 Mixed Convective Heat Transfer of Flow around a Radial Heat Sink

Authors: Benkherbache Souad

Abstract:

This work presents the numerical results of the mixed convective heat transfer of a three-dimensional flow around a radial heat sink composed of horizontal circular base fitted with rectangular fins. The governing equations of mass, momentum, and energy equation are solved by the finite volume method using the commercially available CFD software Fluent 6.3.26. The circular base of the heat sink is subjected to uniform heat generation; the flow enters through the sides of the heat sink around the fins then the heat is transmitted from the base to the fins afterwards the fluid. In this study two fluids are utilized, in the first case, the air for the following Reynolds numbers Re=600,900,1200 and a Grashof number Gr=3.7x10⁶, in the second case a water based nano fluid for which two types of nano particles (Cu and Al₂O₃) are carried out for Re=25 and a Richardson number Ri=2.7(Ri=Gr/Re²). The effect of the number of the fins of the heat sink as well as the type and the volume fraction of nano particles of the nano fluid were investigated. Results have been presented for N=15 and N=20 fins. The effect of the nano particles concentrations and the number of fins on the temperature in the heat sink and the Nusselt number has been studied.

Keywords: heat sink, mixed convection, nano fluid, volumetric heat generation

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17 Removal of Oxytetracycline Using Sonophotocatalysis: Parametric Study

Authors: Bouafia-Chergui Souâd, Chabani Malika, Bensmaili Aicha

Abstract:

Water treatment and especially, medicament pollutants are nowadays important problems. Degradation of oxytetracycline was carried out using combined process of low-frequency ultrasound (US), ultraviolet irradiation and a catalyst. The effectiveness of the coupled processes has been evaluated by studying the effects of various operating parameters including initial OTC concentration, solution pH and catalyst mass. For the photolysis process, the monochromatic ultraviolet light wavelength utilized was 365 nm. The sonolysis experiments were performed with ultrasound at a frequency of 40 kHz. The heterogeneous photocatalysis was studied in the presence of TiO2. The processes were employed individually, and simultaneously to examine the details of the processes and to investigate the contribution of each process. Low UV intensity (12W), low pH and high mass of TiO2 conditions enhanced the sono-photocatalytic degradation of OTC. The results showed that the individual contribution sonochemical and photochemical reactions are very low, however, their coupling increases the degradation rate of 8 times compared to photolysis and 2 times compared to sonolysis. There is a synergistic effect between the two modes of radiation, UV and U.S. leading to 82.04% degradation yield. An application of these combined processes on the treatment of a real pharmaceutical wastewater was examined.

Keywords: sonolysis, photocatalysis, combined process, antibiotic

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16 Sandwich Structure Composites: Effect of Kenaf on Mechanical Properties

Authors: Maizatulnisa Othman, Mohamad Bukhari, Zahurin Halim, Souad A. Muhammad, Khalisani Khalid

Abstract:

Sandwich structure composites produced by epoxy core and aluminium skin were developed as potential building materials. Interface bonding between core and skin was controlled by varying kenaf content. Five different weight percentage of kenaf loading ranging from 10 wt% to 50 wt% were employed in the core manufacturing in order to study the mechanical properties of the sandwich composite. Properties of skin aluminium with epoxy were found to be affected by drying time of the adhesive. Mechanical behavior of manufactured sandwich composites in relation with properties of constituent materials was studied. It was found that 30 wt% of kenaf loading contributed to increase the flexural strength and flexural modulus up to 102 MPa and 32 Gpa, respectively. Analysis were done on the flatwise and edgewise compression test. For flatwise test, it was found that 30 wt% of fiber loading could withstand maximum force until 250 kN, with compressive strength results at 96.94 MPa. However, at edgewise compression test, the sandwich composite with same fiber loading only can withstand 31 kN of the maximum load with 62 MPa of compressive strength results.

Keywords: sandwich structure composite, epoxy, aluminium, kenaf fiber

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15 Evaluation of Milk Production of an Algerian Rabbit Population Raised in Aures Area

Authors: Moumen Souad, Melizi Mohamed

Abstract:

In order to characterize rabbits does of an Aures local population raised in Algeria, a study of their milk yield was realized in the experimental rabbitry of El Hadj Lakhdhar University. Milk production of does was measured every day during the days following 215 parturitions. It was estimated by weighing the female before and after the single daily suckling (10–15 min between the two weighing operations). The various calculated parameters were the quantity of milk produced per day, per week and the total quantity produced in 21 days, as well as the intake of milk by young rabbits. The analysis concerned the effects of the number of successive litters (3 classes: 1 to 3 and more) and of the average number of the number of young rabbits suckled per litter (6 classes: from 1-2 kits to more than 6). During the 21 days of controlled lactation, the average litter size was 6±3. The rabbits of the Aures area produced on average 2544.34±747 g in 21 days that is 121 g of milk/day or 21 g of milk/kit/day. The milk yield increased from 526, 1035, 1240 and 2801 g to 760, 1365, 1715 and 3840 for week 1, 2, 3 and the total period of lactation, respectively. Nevertheless, milk production available per kit and per day decreased linearly with kits number in the litter for each of the 3 weeks considered. On the other hand the milk yield was not affected by the weight at birth of kits.

Keywords: milk production, litter size, rabbit, Aures area, Algeria

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14 Frailty Models for Modeling Heterogeneity: Simulation Study and Application to Quebec Pension Plan

Authors: Souad Romdhane, Lotfi Belkacem

Abstract:

When referring to actuarial analysis of lifetime, only models accounting for observable risk factors have been developed. Within this context, Cox proportional hazards model (CPH model) is commonly used to assess the effects of observable covariates as gender, age, smoking habits, on the hazard rates. These covariates may fail to fully account for the true lifetime interval. This may be due to the existence of another random variable (frailty) that is still being ignored. The aim of this paper is to examine the shared frailty issue in the Cox proportional hazard model by including two different parametric forms of frailty into the hazard function. Four estimated methods are used to fit them. The performance of the parameter estimates is assessed and compared between the classical Cox model and these frailty models through a real-life data set from the Quebec Pension Plan and then using a more general simulation study. This performance is investigated in terms of the bias of point estimates and their empirical standard errors in both fixed and random effect parts. Both the simulation and the real dataset studies showed differences between classical Cox model and shared frailty model.

Keywords: life insurance-pension plan, survival analysis, risk factors, cox proportional hazards model, multivariate failure-time data, shared frailty, simulations study

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13 Environmental Factors Affecting Knowledge Transfer between the Context of the Training Institution and the Context of the Work Environment: The Case of Agricultural Vocational Training

Authors: Oussedik Lydia, Zaouani-Denoux Souâd

Abstract:

Given the evolution of professions, training is becoming a solution to meet the current requirements of the labor market. Notably, the amount of money invested in training activities is considerable and continuously increasing globally. The justification of this investment becomes an obligation for those responsible for training. Therefore, the impact of training can be measured by the degree to which the knowledge, skills, and attitudes acquired through training are transferred to the workplace. Further, knowledge transfer is fundamental because the objective of any training is to be close to a professional environment in order to improve the productivity of participants. Hence, the need to better understand the knowledge transfer process in order to determine the factors that may influence it. The objective of this research is to understand the process of knowledge transfer that can occur between two contexts: professional training and the workplace, which will provide further insight to identify the environmental factors that can hinder or promote it. By examining participants' perceptions of the training and work contexts, this qualitative approach seeks to understand the knowledge transfer process that occurs between the two contexts. It also aims to identify the factors that influence it. The results will help managers identify environmental factors in the training and work context that may impact knowledge transfer. These results can be used to promote the knowledge transfer process and the performance of the trainees.

Keywords: knowledge transfer, professional training, professional training in agriculture, training context, professional context

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12 Effect of Phaseolus vulgaris Inoculation on P. vulgaris and Zea mays Growth and Yield Cultivated in Intercropping

Authors: Nour Elhouda Abed, Bedj Mimi, Wahid Slimani, Mourad Atif, Abdelhakim Ouzzane, Hocine Irekti, Abdelkader Bekki

Abstract:

The most frequent system of cereal production in Algeria is fallow-wheat. This is an extensive system that meets only the half needs some cereals and fodder demand. Resorption of fallow has become a strategic necessity to ensure food security in response to the instability of supply and the persistence of higher food prices on the world market. Despite several attempts to replace the fallow by crop cultures, choosing the best crop remains. Today, the agronomic and economic interests of legumes are demonstrated. However, their crop culture remains marginalized because of the weakness and instability of their performance. In the context of improving legumes and cereals crops as well as fallow resorption, we undertook to test, in the field, the effect of rhizobial inoculation of Phaseolus vulgaris in association with Zea Mays. We firstly studied the genetic diversity of rhizobial strains that nodulate P.vulgaris isolated from fifteen (15) different regions. ARDRA had shown 18 different genetic profiles. Symbiotic characterization highlighted a strain that highly significantly improved the fresh and dry weight of the host plant, in comparison to the negative control (un-inoculated) and the positive control (inoculated with the reference strain CIAT 899). In the field, the selected strain increased significantly the growth and yield of P.vulgaris and Zea Mays comparing to the non-inoculated control. However, the mix inoculation (selected strain+ Ciat 899) had not given the best parameters showing, thus, no synergy between the strains. These results indicate the replacing fallow by a crop legume in intercropping with cereals crops.

Keywords: fallow, intercropping, inoculation, legumes-cereals

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11 Histological Changes in the Culex pipiens Mosquito Larvae Treated by the Entomopathogenic Fungus Beauveria bassiana

Authors: Fatma Sahir- Halouane, Sonia Hamid, Farida Tihar-Benzina, Fatiha Bouhlali, Souad Lourchane

Abstract:

The Culicidae are biting insects, the most harmful to people, they are almost all bloodsuckers, and they are responsible of the spread of many important diseases such as malaria, yellow fever, and elephantiasis. Entomopathogenic microorganisms occupy an important place among the alternative methods of fighting against pests insect. The fungus Beauveria bassiana is an entomopathogenic agent naturally present in the ecosystems. It offers a very interesting potential for controlling populations of mosquitoes. This study aimed to show the histological changes that occured in Culex pipiens larvae infected with Beauveria bassiana. The 4th instar larvae were infected with B. bassiana in 10-7 spore/ml dilution, the histological section was studied showing that the fungi infected all the body parts specially Cuticle, Epiderms, fat bodies and midgut. After then the insect have a white appearance and covered with a thick coat of hyphea. The obtained results show that the application of Beauveria bassiana on cuticle of the fourth stage larvae of Culex pipiens was dependent of an apparent disturbance on the structure of the cuticle or there has been the degeneration of its different parts, infection of the fungus does not stop at the body walls. Therefore, it affects even the Adipose tissue, epidermal cells and intestine.

Keywords: Culex pipiens, Beauveria bassiana, histological changes, cuticle, intestine and adipose tissue

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10 BeamGA Median: A Hybrid Heuristic Search Approach

Authors: Ghada Badr, Manar Hosny, Nuha Bintayyash, Eman Albilali, Souad Larabi Marie-Sainte

Abstract:

The median problem is significantly applied to derive the most reasonable rearrangement phylogenetic tree for many species. More specifically, the problem is concerned with finding a permutation that minimizes the sum of distances between itself and a set of three signed permutations. Genomes with equal number of genes but different order can be represented as permutations. In this paper, an algorithm, namely BeamGA median, is proposed that combines a heuristic search approach (local beam) as an initialization step to generate a number of solutions, and then a Genetic Algorithm (GA) is applied in order to refine the solutions, aiming to achieve a better median with the smallest possible reversal distance from the three original permutations. In this approach, any genome rearrangement distance can be applied. In this paper, we use the reversal distance. To the best of our knowledge, the proposed approach was not applied before for solving the median problem. Our approach considers true biological evolution scenario by applying the concept of common intervals during the GA optimization process. This allows us to imitate a true biological behavior and enhance genetic approach time convergence. We were able to handle permutations with a large number of genes, within an acceptable time performance and with same or better accuracy as compared to existing algorithms.

Keywords: median problem, phylogenetic tree, permutation, genetic algorithm, beam search, genome rearrangement distance

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9 Motivational Profiles of Choice of Medical Studies: Cross-Sectional Study

Authors: Rajae Tahri, Omar Chokairi, Asmae Saadi, Souad Chaouir

Abstract:

Background: The factors motivating students to choose a medical career is a long-standing topic of publication and discussion. To our knowledge, no national study on the motivation for choosing medical studies has been published to date. Population and methods: This is an observational, descriptive, and cross-sectional study of first-year medical students at the Faculty of Medicine and Pharmacy of Rabat. An anonymous questionnaire comprising 16 questions was developed and distributed to students during Embryology tutorials. The students were free to fill it in or not. The number of students who consented to participate in the survey was 266. The variables studied are the socio-demographic variables of the students and the reasons for choosing medical studies. Results: The most strongly and frequently chosen reasons for choice by our students were saving lives (64.9%), helping others (62.1%), love of medicine (57%), and reducing suffering (56.5%). The comparison of the results according to gender showed a significant difference between the degree of self-motivation of girls compared to that of boys (p <0.001). The reason that stood out the most for them was teamwork. The presence of a health professional in the family was associated with strong extrinsic motivation (p = 0.005). Conclusion: Understanding medical student career choices would improve our knowledge of the factors that influence medical student learning and performance. This knowledge will make it possible to adapt the educational strategies to maintain the motivation of the students throughout their course as well as during their exercise.

Keywords: motivation, motivational profiles, medical studies, Morocco

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8 Enhancing Cellulose Acetate Films: Impact of Glycerol and Ionic Liquid Plasticizers

Authors: Rezzouq Asiya, Bouftou Abderrahim, Belfadil Doha, Taoufyk Azzeddine, El Bouchti Mehdi, Zyade Souad, Cherkaoui Omar, Majid Sanaa

Abstract:

Plastic packaging is widely used, but its pollution is a major environmental problem. Solutions require new sustainable technologies, environmental management, and the use of bio-based polymers as sustainable packaging. Cellulose acetate (CA) is a biobased polymer used in a variety of applications such as the manufacture of plastic films, textiles, and filters. However, it has limitations in terms of thermal stability and rigidity, which necessitates the addition of plasticizers to optimize its use in packaging. Plasticizers are molecules that increase the flexibility of polymers, but their influence on the chemical and physical properties of films (CA) has not been studied in detail. Some studies have focused on mechanical and thermal properties. However, an in-depth analysis is needed to understand the interactions between the additives and the polymer matrix. In this study, the aim is to examine the effect of two types of plasticizers, glycerol (a conventional plasticizer) and an ionic liquid, on the transparency, mechanical, thermal and barrier properties of cellulose acetate (CA) films prepared by the solution-casting method . Various analytical techniques were used to characterize these films, including infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), water vapor permeability (WVP), oxygen permeability, scanning electron microscopy (SEM), opacity, transmission analysis and mechanical tests.

Keywords: cellulose acetate, plasticizers, biopolymers, ionic liquid, glycerol.

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