Search results for: Bouaziz Amira

Authors: Amira Ben Rabeh, Faouzi Benzarti, Hamid Amiri, Mouna Bouaziz

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Alzheimer is a disease that affects the brain. It causes degeneration of nerve cells (neurons) and in particular cells involved in memory and intellectual functions. Early diagnosis of Alzheimer Diseases (AD) raises ethical questions, since there is, at present, no cure to offer to patients and medicines from therapeutic trials appear to slow the progression of the disease as moderate, accompanying side effects sometimes severe. In this context, analysis of medical images became, for clinical applications, an essential tool because it provides effective assistance both at diagnosis therapeutic follow-up. Computer Assisted Diagnostic systems (CAD) is one of the possible solutions to efficiently manage these images. In our work; we proposed an application to detect Alzheimer’s diseases. For detecting the disease in early stage we used the three sections: frontal to extract the Hippocampus (H), Sagittal to analysis the Corpus Callosum (CC) and axial to work with the variation features of the Cortex(C). Our method of classification is based on Support Vector Machine (SVM). The proposed system yields a 90.66% accuracy in the early diagnosis of the AD.

Keywords: Alzheimer Diseases (AD), Computer Assisted Diagnostic(CAD), hippocampus, Corpus Callosum (CC), cortex, Support Vector Machine (SVM)

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Authors: Bouaziz Amira, Zaatout Nawel

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Background: Antimicrobial resistance is an urgent global health challenge in human and veterinary medicine, where migratory birds play a major role in the dissemination of multi-drug-resistant bacteria. The aim of this study was to screen for the presence of carbapenemase-producing Gram-negative bacteria (GNB) in the little egret (Egrettagarzetta) migratory bird stools in Algeria. Materials/Methods: In January 2014, 12 feacal samples were collected in Garaet El-Tarf, Oum El-Bouaghi city, Algeria. Samples were subjected to selective isolation of carbapenem-resistant GNB. Representative colonies were identified using the VITEK system. The obtained isolates were subjected to antibiotic susceptibility testing using the disc-diffusion method as well as carbapenemase production was verified by the modified Carba NP test. Results: In total, ten E. coli were obtained and were resistant to amoxicillin/clavulanic acid (100%), ertapenem (70%), cefoxitin (60%) cefotaxime (20%), cefepime (20%), ciprofloxacin (20%) and aztreonam (10%). The phenotypic detection results revealed that six out of the obtained strains were positive for the modified Carba NP test. Conclusion: The present study suggests that the little egret (Egretta garzetta) could be considered a reservoir of carbapenem-resistant Gram-negative bacteria.

Keywords: antimicrobial resistance, E. coli, Egretta garzetta, carbapenem resistance, dissemination

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Authors: Amel Bouaziz, Seddik Khennouf, Mussa Abu Zarga, Shtayway Abdalla, Saliha Djidel, Assia Bentahar, Saliha Dahamna, Smain Amira

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The present study aimed to evaluate the hypotensive and the in vitro antioxidant activities of Crataegus azarolus L. (Rosaceae), a plant widely used as natural remedy for hypertension in folk medicine. The antioxidant potential of methanolic extract (ME)and its three fractions of Chloroform (CHE), ethyl acetate (EAE)and water (AqE) have been investigated using several assays, including the DPPH scavenging, ABTS scavenging, hydroxyl radical scavenging. Inhibition of lipid peroxidation was performed by the β-carotene bleaching assay, ferric thiocyanate method and thiobarburic acid method. Total phenolic and total flavonoid contents of the extracts were estimated using Folin-Chiocalteu reagent and AlCl3, respectively. EAE extract showed the highest polyphenolic and flavonoids contents (396,04±1.20 mg GAE/g of dry extract and 32,73 ± 0.03mg QE/g of dry extract) respectively. Similarly, this extract possessed the highest scavenging activity for DPPH radical (IC 50 = 0,006±0,0001mg /ml), ABTS radical (IC50=0.0035±0,0007 mg/ml) and hydroxyl radical(IC 50=0,283± 0.01 mg/ml). In addition, the EAE exhibited the highest antioxidant activity in the inhibition of linoleic acid/ß-carotene coupled oxidation (89,21%), lipid peroxidation in the ferric thiocyanate(FTC) method (90.13%), and thio-barbituric acid (TBA) method (74.23%). Intravenous administration of Me and EAE decreased mean arterial blood pressure, systolic and diastolic blood pressure in anesthetized rats dose-dependently, at the dose range of 0.4 to 12 mg/kg. The mean arterial blood pressure dropped by 27.58 and 39.37% for ME and EAE, respectively. In conclusion, The present study supported the significant potential to use C. azarolus by-products as a source of natural antioxidants and provides scientific justification for its traditional uses as cardio-protective and anti-hypertensive remedy.

Keywords: Crataegus azarolus, polyphenols, flavonoids, hypertension, antioxidant activity, free radicals, peroxidation

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Authors: Sahar Maâlej Dammak, Anis Jedidi, Rafik Bouaziz

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With the great mass of pages managed through the world, and especially with the advent of the Web, their manual annotation is impossible. We focus, in this paper, on the semiautomatic annotation of the web pages. We propose an approach and a framework for semantic annotation of web pages entitled “Querying Web”. Our solution is an enhancement of the first result of annotation done by the “Semantic Radar” Plug-in on the web resources, by annotations using an enriched domain ontology. The concepts of the result of Semantic Radar may be connected to several terms of the ontology, but connections may be uncertain. We represent annotations as possibility distributions. We use the hierarchy defined in the ontology to compute degrees of possibilities. We want to achieve an automation of the fuzzy semantic annotation of web resources.

Keywords: fuzzy semantic annotation, semantic web, domain ontologies, querying web

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Authors: Hafsi Khebab, Zirari Mounir, Mohamed Nadjib Bouaziz

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High Global Warming Potential refrigerants (HydroFluroCarbons) are one of the worst greenhouse gases used in a wide variety of applications, including refrigeration and air-conditioning. Nanotechnology is a promising field in sustainable energy to reduce energy and ecological resource consumption for HVACR (heat, ventilation, air conditioning, and refrigeration) systems. Most researchers reported an improvement in heat transfer coefficient, Coefficient of performance. In this report, a brief summary has been done on the performance enhancement of the Vapor Compression Refrigeration system using HFC134a with nano refrigerants.

Keywords: nanorefrigerant, HFCs, greenhouse gases, GWP, HVACR systems, energy saving

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Authors: Mohamed Zaher Bouaziz

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Our study examines the Ohlson Model, which links a company's market value to its equity and net earnings, in the context of the evolution of the Canadian accounting model, characterized by more extensive use of fair value and a broader measure of performance after IFRS adoption. Our hypothesis is that if equity is reported at its fair value, this valuation is closely linked to market capitalization, so the weight of earnings weakens or even disappears in the Ohlson Model. Drawing on Canada's adoption of the International Financial Reporting Standards (IFRS), our results support our hypothesis that equity appears to include most of the relevant information for investors, while earnings have become less important. However, the predictive power of earnings does not disappear.

Keywords: fair value accounting, Ohlson model, IFRS adoption, value-relevance of equity and earnings

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Authors: Ghazi Bouaziz, Abderrahim Derouiche, Damien Brulin, Hélène Pigot, Eric Campo

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Automatic ADL classification is a crucial part of ambient assisted living technologies. It allows to monitor the daily life of the elderly and to detect any changes in their behavior that could be related to health problem. But detection of ADLs is a challenge, especially because each person has his/her own rhythm for performing them. Therefore, we used a correlation matrix to extract custom rules that enable to detect ADLs, including eating activity. Data collected from 3 different individuals between 35 and 105 days allows the extraction of personalized eating patterns. The comparison of the results of the process of eating activity extracted from the correlation matrices with the declarative data collected during the survey shows an accuracy of 90%.

Keywords: elderly monitoring, ADL identification, matrix correlation, meal-taking activity

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Authors: Amira Abdulrazzaq

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This paper is studying the opinion of faculty members and students about the future of education (e-learning) at the University of Bahrain. Through quantitative analysis a distribution of two surveys, one targeting students of IT College, and College of Arts and the other targeting Faculty members of both Colleges. Through the above survey, the paper measures the following factors: awareness and acceptance, satisfaction, usability, and usefulness. Results indicate positive reactions of all above factors.

Keywords: e-learning, education, moodle, WebCT

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Authors: El Andari Chifaa, Bouaziz Rached

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The central focus of this paper was to check whether the Okun’s law in Tunisia is valid or not. For this purpose, we have used quarterly time series data during the period 1990Q1-2014Q1. Firstly, we applied the error correction model instead of the difference version of Okun's Law, the Engle-Granger and Johansen test are employed to find out long run association between unemployment, production, and how error correction mechanism (ECM) is used for short run dynamic. Secondly, we used the gap version of Okun’s law where the estimation is done from three band pass filters which are mathematical tools used in macro-economic and especially in business cycles theory. The finding of the study indicates that the inverse relationship between unemployment and output is verified in the short and long term, and the Okun's law holds for the Tunisian economy, but with an Okun’s coefficient lower than required. Therefore, our empirical results have important implications for structural and cyclical policymakers in Tunisia to promote economic growth in a context of lower unemployment growth.

Keywords: Okun’s law, validity, unit root, cointegration, error correction model, bandpass filters

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Authors: Alouaoui Redha, Ferhat Samira, Bouaziz Mohamed Najib

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In this work, we examine the thermal radiation effect on heat and mass transfer in steady laminar boundary layer flow of an incompressible viscous micropolar fluid over a vertical plate, with the presence of a magnetic field. Rosseland approximation is applied to describe the radiative heat flux in the energy equation. The resulting similarity equations are solved numerically. Many results are obtained and representative set is displayed graphically to illustrate the influence of the various parameters on different profiles. The conclusion is drawn that the flow field, temperature, concentration and microrotation as well as the skin friction coefficient and the both local Nusselt and local Sherwood numbers are significantly influenced by Magnetic parameter, material parameter and thermal radiation parameter.

Keywords: MHD, micropolar fluid, thermal radiation, heat and mass transfer, boundary layer

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Authors: Amira Bousselmi

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This article presents a PIFA antenna designed for geolocation applications (GNSS) operating on 1.278 GHz, 2.8 GHz, 5.7 GHz and 10 GHz. To improve the performance of the antenna, an artificial magnetic conductor structure (AMC) was used. Adding the antenna with AMC resulted in a measured gain of 4.78 dBi. The results of simulations and measurements are presented. CST Microwave Studio is used to design and compare antenna performance. An antenna design methodology, design and characterization of the AMC surface are described as well as the simulated and measured performances of the AMC antenna are then discussed. Finally, in Section V, there is a conclusion.

Keywords: antenna multiband, global navigation system, AMC, Galeleo

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Authors: Amira Masood, Zainah Alshouri, Noor Bantan, Samira Kutbi

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Artificial intelligence is continuously becoming more advanced and more widespread and is present in many of our day-to-day lives as a means of assistance in numerous different fields. A growing number of people, companies, and corporations are utilizing Canva and its AI tools as a method of quick and easy media production. Hence, in order to test the integrity of the rapid growth of AI, this paper will explore the usefulness of Canva's advanced design features as well as their accuracy by determining user satisfaction through a survey-based research approach and by investigating whether or not AI is successful enough that it eliminates the need for human alterations.

Keywords: artificial intelligence, canva, features, users, satisfaction

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Authors: Abshari Nabilah Fiqi, Sekar Ayu Dian Kusumaningtyas, Amira Eka Pratiwi

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Since a very long time ago, Indonesia are well known for their hospitality. Hospitality has been one of the civility concepts that represented Indonesia’s culture. However, as an Indonesian, we found that nowadays we are starting to lose this particular culture. The influence of modern culture is undeniably strong. As a capital city, Jakarta is one of the most modern cities in Indonesia. We conduct this experimental study to find out whether the people in Jakarta are still willing to maintain their identity as a friendly Indonesian or not by testing their willingness to reply greetings from strangers.

Keywords: city, civility, culture, greetings, hospitality, modern

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Authors: Bouaziz H., Soudania N., Essafia M., Ben Amara I., Hakim A., Jamoussi K., Zeghal Km, Zeghal N.

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In this investigation, we have evaluated the effects of arsenic trioxide on hepatic function in pregnant and lactating Swiss albino mice and their suckling pups. Experiments were carried out on female mice given 175 ppm As2O3 in their drinking water from the 14th day of pregnancy until day 14 after delivery. Our results showed a significant decrease in plasma levels of total protein and albumin, cholesterol and triglyceride in As2O3 treated mice and their pups. The hyperbilirubinemia and the increased plasma total alkaline phosphatase activity suggested the presence of cholestasis. Transaminase activities as well as lactate deshydrogenase activity in plasma, known as biomarkers of hepatocellular injury, were elevated indicating hepatic cells’damage after treatment with As2O3. Exposure to arsenic led to an increase of liver thiobarbituric acid reactive substances level along with a concomitant decrease in the activities of superoxide dismutase, catalase and glutathione peroxidase and in glutathione.

Keywords: antioxidant status, arsenic trioxide, hepatotoxicity, mice, oxidative stress

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Authors: Abshari Nabilah Fiqi, Amira Eka Pratiwi, Sekar Ayu Dian Kusumaningtyas

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Indonesia is one of the developing countries in the world. However, people in Indonesia, especially in big and modern cities like Jakarta (the capital city of Indonesia), have shown some consumptive behavior. As an indicator, there are about 173 malls and department stores in Jakarta, and of course these malls and department store is always crowded by visitors. This study is trying to describe the dynamics of consumptive behavior that shown by people in Jakarta. We are trying to find out why Indonesian love to go to the malls and department stores despite the low income.

Keywords: consumptive behavior, hedonism, mall, shopping

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Authors: A. Ghadbane, M. N. Bouaziz, S. Hanini, B. Baggoura, M. Abbaci

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The spacer grids are used to fix the rods bundle in a nuclear reactor core also act as turbulence-enhancing devices to improve the heat transfer from the hot surfaces of the rods to the surrounding coolant stream. Therefore, the investigation of thermal-hydraulic characteristics inside the rod bundles is important for optima design and safety operation of a nuclear reactor power plant. This contribution presents a feasibility study to use the ribbed spacer grids as mixing devices. The present study evaluates the effects of different ribbed spacer grids configurations on flow pattern and heat transfer in the downstream of the mixing devices in a 2 x 2 rod bundle array. This is done by obtaining velocity and pressure fields, turbulent intensity and the heat transfer coefficient using a three-dimensional CFD analysis. Numerical calculations are performed by employing K-ε turbulent model. The computational results obtained are promising and the comparison with standard spacer grids shows a clear difference which required the experimental approach to validate.

Keywords: PWR fuel assembly, spacer grid, mixing vane, swirl flow, turbulent heat transfer, CFD

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Authors: Amira Zouaoui, Hamed Belloumi, Ferid Kourda

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This paper presents the analysis and design of a DC–AC resonant converter applied to induction heating. The proposed topology based on the series-parallel half-bridge resonant inverter is described. It can operate with Zero-Voltage Switching (ZVS). At the resonant frequency, the secondary current is amplified over the heating coil with small switching angle, which keeps the reactive power low and permits heating with small current through the resonant inductor and the transformer. The operation and control principle of the proposed high frequency inverter is described and verified through simulated and experimental results.

Keywords: induction heating, inverter, high frequency, resonant

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Authors: H. Bouaziz, M. Sefi, J. de Lapuente, M. Borras, N. Zeghal

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Although arsenic trioxide has been the subject of toxicological research, in vitro cytotoxicity and genotoxicity studies using relevant cell models and uniform methodology are not well elucidated. Hence, the aim of the present study was to evaluate the cytotoxicity and genotoxicity induced by arsenic trioxide in human keratinocytes (HaCaT) using the MTT [3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and alkaline single cell gel electrophoresis (Comet) assays, respectively. Human keratinocytes were treated with different doses of arsenic trioxide for 4 h prior to cytogenetic assessment. Data obtained from the MTT assay indicated that arsenic trioxide significantly reduced the viability of HaCaT cells in a dose-dependent manner, showing a IC50 value of 34.18 ± 0.6 µM. Data generated from the comet assay also indicated a significant dose-dependent increase in DNA damage in HaCaT cells associated with arsenic trioxide exposure. We observed a significant increase in comet tail length and tail moment, showing an evidence of arsenic trioxide -induced genotoxic damage in HaCaT cells. This study confirms that the comet assay is a sensitive and effective method to detect DNA damage caused by arsenic.

Keywords: arsenic trioxide, cytotoxixity, genotoxicity, HaCaT

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Authors: Amira Kaddour

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To curb the problem of liquidity in times of financial crises, two cases arise; the Bailout or Bailin, two opposite choices that elicit the analysis of their effect on moral hazard. This paper attempts to empirically analyze the effect of these two types of events on the behavior of investors. For this end, we use the Emerging Market Bonds Index (EMBI-JP Morgan), and its excess of return, to detect the change in the risk premia through a Markov switching model. The results showed the transition to two types of regime and an effect on moral hazard; Bailout is an incentive of moral hazard, Bailin effectiveness remains subject of credibility.

Keywords: Bailout, Bailin, Moral hazard, financial crisis, Markov switching

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Authors: Amira Zrelli, Tahar Ezzedine

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Routing protocol may enhance the lifetime of sensor network, it has a highly importance, especially in wireless sensor network (WSN). Therefore, routing protocol has a big effect in these networks, thus the choice of routing protocol must be studied before setting up our network. In this work, we implement the routing protocol collect tree protocol (CTP) which is one of the hierarchic protocols used in structural health monitoring (SHM). Therefore, to evaluate the performance of this protocol, we choice to work with Contiki system and Cooja simulator. By throughput and RSSI evaluation of each node, we will deduce about the utility of CTP in structural monitoring system.

Keywords: CTP, WSN, SHM, routing protocol

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Authors: Manar Y. Abd El-Aziz, Alyaa E. Morgham, Amira A. El-Fallal, Heba Tolla E. Abo El Naga

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Sport wears almost preferred with knitted fabrics, specially interlock construction. But, there is a need for higher comfortability and functional properties for fabrics to be more fitted to this application. This study compared cotton and polyester microfibers and blended them to improve the functional activity of interlock in sport wear by mercerized and non-mercerized. also, fabric dyeing and dyeability are affected by mercerization. Many functional properties, such as UV protection as well as antimicrobial activity. The changes in different mechanical as well as physical properties were investigated. The washing fastness properties of the dyed fabrics are also given. The changes in moisture regain, loss in weight, and burst and burst elongation for all mercerized fabrics have been studied.

Keywords: interlock, mercirization, dyeability, function properties, moisture management

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Authors: Amira Zrelli, Tahar Ezzeddine

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Measurement and monitoring of temperature, humidity and strain variation are very requested in great fields and areas such as structural health monitoring (SHM) systems. Currently, the use of fiber Bragg grating sensors (FBGS) is very recommended in SHM systems due to the specifications of these sensors. In this paper, we present the theory of Bragg sensor, therefore we try to measure the efficient variation of strain, temperature and humidity (SV, ST, SH) using Bragg sensor. Thus, we can deduce the fundamental relation between these parameters and the wavelength of Bragg sensor.

Keywords: Fiber Bragg Grating Sensors (FBGS), strain, temperature, humidity, structural health monitoring (SHM)

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Authors: Khadidja Rahmani, Nahla Bouaziz

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Algeria is known for its rich heritage. It owns an immense historical heritage with a universal reputation. Unfortunately, this wealth is withered because of abundance. This research focuses on the Ksourian model, which constitutes a large portion of this wealth. In fact, the Ksourian model is not just a witness to a great part of history or a vernacular culture, but also it includes a panoply of assets in terms of energetic efficiency. In this context, the purpose of our work is to evaluate the performance of the old techniques which are derived from the Ksourian model , and that using the simulation tools. The proposed method is decomposed in two steps; the first consists of isolate and reintroduce each device into a basic model, then run a simulation series on acquired models. And this in order to test the contribution of each of these dialectal processes. In another scale of development, the second step consists of aggregating all these processes in an aboriginal model, then we restart the simulation, to see what it will give this mosaic on the environmental and energetic plan .The model chosen for this study is one of the ksar units of Knadsa city of Bechar (Algeria). This study does not only show the ingenuity of our ancestors in their know-how, and their adapting power to the aridity of the climate, but also proves that their conceptions subscribe in the current concerns of energy efficiency, and respond to the requirements of sustainable development.

Keywords: dialectal processes, energy efficiency, evaluation, Ksourian model, simulation tools

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Authors: H. Bouaziz-Ketata, G. Ben Salah, Z. Aidi, C. Kallel, H. Kammoun, F. Fakhfakh, N. Zeghal

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The present study was performed to evaluate the potential protective effect of Hyparrhenia hirta methanolic extract in NaNO3-induced genotoxic and hematotoxic effects. Male Wistar rats were randomly divided into three groups: a control group and two treated groups during 50 days with NaNO3 administered at a dose of 400 mg kg-1 bw either alone in drinking water or co-administered with Hyparrhenia hirta at a dose of 200 mg kg-1 bw. NaNO3 treatment showed a significant increase in the frequencies of total chromosomal aberrations, aberrant metaphases and micronucleus in bone-marrow cells. In parallel, the NaNO3-treated group showed a significant decrease in red blood cell count, hemoglobin and hematocrit and a significant increase in total white blood cell, in neutrophil and eosinophil counts. Platelet count, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration remained unchanged in treated groups compared to those of controls. Hyparrhenia hirta methanolic extract appeared to be effective against genotoxic and hematotoxic changes induced by nitrate, as evidenced by the improvement of the markers cited above.

Keywords: Hyparrhenia hirta, sodium nitrate, erythrocytes, genotoxicity

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Authors: Amr Mansour Mohsen, Hesham Ahmed Hassan, Amira M. Idrees

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Document Analysis is an important research field that aims to gather the information by analyzing the data in documents. As one of the important targets for many fields is to understand what people actually want, sentimental analysis field has been one of the vital fields that are tightly related to the document analysis. This research focuses on analyzing text documents to classify each document according to its opinion. The aim of this research is to detect the emotions from text documents based on enriching the lexicon with adapting their content based on semantic patterns extraction. The proposed approach has been presented, and different experiments are applied by different perspectives to reveal the positive impact of the proposed approach on the classification results.

Keywords: document analysis, sentimental analysis, emotion detection, WEKA tool, NRC lexicon

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Authors: Rym Taktak, Achwek Elghazel, Jamel Bouaziz

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In the present work, we explored the potential of tribological behavior of tricalcium phosphate-Fluorapatite (β Tcp-Fap) bioceramic which has attracted considerable attention for orthopedics and dental applications. The approximate representatives Fap-βTcp were respectively [{13.26 wt%, 86.74 wt%} {19.9 wt%, 80.1 wt%},{ 26.52 wt%, 73.48 wt%}, {33.16 wt%, 66.84 wt%} and {40 wt%, 60 wt%}. The effects of Fluorapatite additives on friction and wear behavior were studied and discussed. The wear test was conducted using pion-disk tribometer at room temperature under dry condition using a constant sliding speed of 0,063 m/s, and three loads 3, 5 and 8 N. The wear rate and friction coefficient of β Tcp with different additive amounts were compared. An Alumina ball specimens were used as the pin and flat surface β Tcp-Fap specimens as the antagonist counterface. The results show a huge difference between the wear rate of β TCP samples and the other β TCP-Fap composites for all normal forces applied. This result shows the beneficial effect of fluorapatite on the tribological behavior of the β TCP. Moreover, we note that β Tcp-26% Fap specimens exhibit, under dry condition, the lower friction coefficient and the smaller wear rate than other biocomposites. Thereby, the friction and wear behavior is influenced by the addition of fluorapatite, the applied normal force, and the sliding velocity. To extend the understanding of the wear process, the surface topography of β Tcp-26% Fap specimens and the wear track obtained during the wear tests were studied using a surface profilometer, optical microscopy, and scanning electron microscopy.

Keywords: alumina, bioceramic, friction and wear test, tricalcium phosphate

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Authors: Karima Tayaa, Amina Bouaziz

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The rapid expansion in the scientific fields and the growth of communication technology increased the use of English as international language in the world. Hence, over the past few decades, many researchers have been emphasizing on how the teaching and learning of English as a foreign or as an additional language can best help students to perform successfully. English for specific purpose is today quite literally regarded as the most global language discipline which existed practically in every country in the world. ESP (English for Specific Purposes) involves teaching and learning the specific skills and language needed by particular learners for a particular purpose. The P in ESP is always a professional purpose which is a set of skills that learners currently need in their work or will need in their professional careers. It has had an early origin since 1960’s and has grown to become one of the most prominent of English language teaching today. Moreover, ESP learners are usually adults who have some quittances with English and learn the language so as to communicate and perform particular profession. Related activities are based on specific purposes and needs. They are integrated into subject matter area important to the learners. Unlike general English which focuses on teaching general language courses and all four language skills are equally stressed, ESP and practically needs analysis determine which language skills are the most needed by the learners and syllabus designed accordingly. This paper looked into the origin, characteristics, development of ESP, the difference between ESP and general English. Finally, the paper critically reviews the role of needs analysis in the ESP.

Keywords: English language teaching, English for general purposes, English for specific purposes, needs analysis

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Authors: Amira Khelil, Habib Affes

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The XXIst century is characterized by promoting teamwork as one of the main drivers of firms` performance. Collective competence is becoming crucial in developing and maintaining a firm’s competitive advantage, as well as its contributions to organizational innovation. In other words, the improvement of collective competence for a firm is no longer a choice, but rather an obligation. Learning capabilities of a firm in the context of knowledge management are assumed to be the main drivers of collective competence. Although there are some efforts to consider these concepts together; they are mostly discussed separately in the management theory. Thus, this paper aims to offer a holistic approach for development collective competence on the basis of Knowledge Management and Organizational Learning Capabilities. A theoretical model that defines a relationship between knowledge management, organizational learning and collective competence is presented at the end of this paper.

Keywords: collective competence, exploitation learning, exploration learning, knowledge management, organizational learning capabilities

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Authors: Hosam El-Sayed, Amira Abou El-Kheir, Salwa Mowafi, Marwa Abou Taleb

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Two proteinic biopolymers; namely keratin and sericin, were extracted from their respective natural resources by simple appropriate methods. The said proteins were dissolved in the appropriate solvents followed by regeneration in a form of film polyvinyl alcohol. Proteinium thiocyanate (PTC) composite was prepared by reaction of a regenerated film with potassium thiocyanate in acid medium. In another experiment, the said acidified proteins were reacted with potassium thiocyante before dissolution and regeneration in a form of PTC composite. The possibility of using PTC composite for determination of the concentration of iron III ions in domestic as well as industrial water was examined. The concentration of iron III cations in water was determined spectrophotometrically by measuring the intensity of blood red colour of iron III thiocyanate obtained by interaction of PTC with iron III cation in the tested water sample.

Keywords: iron III cations, protein, sensor, thiocyanate, water

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Authors: Amira Amamou, Mnaouar Chouchane

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This paper investigates the bifurcation and nonlinear behavior of two degrees of freedom model of a symmetrical balanced rigid rotor supported by two identical journal bearings. The fluid film hydrodynamic reactions are modeled by applying both the short and the long bearing approximation and using half Sommerfeld solution. A numerical integration of equations of the journal centre motion is presented to predict the presence and the size of stable or unstable limit cycles in the neighborhood of the stability critical speed. For their stability margins, a continuation method based on the predictor-corrector mechanism is used. The numerical results of responses show that stability and bifurcation behaviors of periodic motions depend strongly on bearing parameters and its dynamic characteristics.

Keywords: hydrodynamic journal bearing, nonlinear stability, continuation method, bifurcations

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